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Title:
The mucilage of opuntia ficus indica: a natural, sustainable, and viable water treatment technology for use in rural Mexico for reducing turbidity and arsenic contamination in drinking water
Physical Description:
Book
Language:
English
Creator:
Young, Kevin Andrew
Publisher:
University of South Florida
Place of Publication:
Tampa, Fla
Publication Date:

Subjects

Subjects / Keywords:
Flocculant
Cactus
Nopal
Prickly pear
Mucilage
Green engineering
Sustainability
Dissertations, Academic -- Chemical Engineering -- Masters -- USF
Genre:
bibliography   ( marcgt )
theses   ( marcgt )
non-fiction   ( marcgt )

Notes

Abstract:
ABSTRACT: The use of natural environmentally benign agents in the treatment of drinking water is rapidly gaining interest due to their inherently renewable character and low toxicity. We show that the common Mexican cactus produces a gum-like substance, cactus mucilage, which shows excellent flocculating abilities and is an economically viable alternative for low-income communities. Cactus mucilage is a neutral mixture of approximately 55 high-molecular weight sugar residues composed basically of arabinose, galactose, rhamnose, xylose, and galacturonic acid. We show how this natural product was characterized for its use as a flocculating agent. Our results show the mucilage efficiency for reducing arsenic and particulates from drinking water as determined by light scattering, Atomic Absorption and Hydride Generation-Atomic Fluorescence Spectroscopy. Flocculation studies proved the mucilage to be a much faster flocculating agent when compared to Al2(SO4)3 with the efficiency increasing with mucilage concentration. Jar tests revealed that lower concentrations of mucilage provided the optimal effectiveness for supernatant clarity, an important factor in determining the potability of water. Initial filter results with the mucilage embedded in a silica matrix prove the feasibility of applying this technology as a method for heavy metal removal. This project provides fundamental, quantitative insights into the necessary and minimum requirements for natural flocculating agents that are innovative, environmentally benign, and cost-effective.
Thesis:
Thesis (M.A.)--University of South Florida, 2006.
Bibliography:
Includes bibliographical references.
System Details:
System requirements: World Wide Web browser and PDF reader.
System Details:
Mode of access: World Wide Web.
Statement of Responsibility:
by Kevin Andrew Young.
General Note:
Title from PDF of title page.
General Note:
Document formatted into pages; contains 167 pages.

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aleph - 001790249
oclc - 144571408
usfldc doi - E14-SFE0001492
usfldc handle - e14.1492
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ABSTRACT: The use of natural environmentally benign agents in the treatment of drinking water is rapidly gaining interest due to their inherently renewable character and low toxicity. We show that the common Mexican cactus produces a gum-like substance, cactus mucilage, which shows excellent flocculating abilities and is an economically viable alternative for low-income communities. Cactus mucilage is a neutral mixture of approximately 55 high-molecular weight sugar residues composed basically of arabinose, galactose, rhamnose, xylose, and galacturonic acid. We show how this natural product was characterized for its use as a flocculating agent. Our results show the mucilage efficiency for reducing arsenic and particulates from drinking water as determined by light scattering, Atomic Absorption and Hydride Generation-Atomic Fluorescence Spectroscopy. Flocculation studies proved the mucilage to be a much faster flocculating agent when compared to Al2(SO4)3 with the efficiency increasing with mucilage concentration. Jar tests revealed that lower concentrations of mucilage provided the optimal effectiveness for supernatant clarity, an important factor in determining the potability of water. Initial filter results with the mucilage embedded in a silica matrix prove the feasibility of applying this technology as a method for heavy metal removal. This project provides fundamental, quantitative insights into the necessary and minimum requirements for natural flocculating agents that are innovative, environmentally benign, and cost-effective.
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The Mucilage of Opuntia Ficus Indica: A Natural, Sustainable, and Viable Water Treatment Technology for Use in Rural Mexi co for Reducing Turbidity and Arsenic Contamination in Drinking Water by Kevin Andrew Young A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering Department of Chemical Engineering College of Engineering University of South Florida Major Professor: Norma Alcantar, Ph.D. Babu Joseph, Ph.D. Thomas Pichler, Ph.D. Peter Stroot, Ph.D. Ryan Toomey, Ph.D. Maya Trotz, Ph.D. Date of Approval: April 6, 2006 Keywords: flocculant, cactus, nopal, pric kly pear, mucilage, green engineering, sustainability Copyright 2006, Kevin Andrew Young

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Dedication The dedications of a thousand theses would not suffice as a thank you to my loving parents, Mr. Je ffery B. Young and Mrs. Nan cy S. Young, for their sacrifice, hard work, under standing and support for my goals. The successes I have experienced would not have been possible without them selflessly adopting my personal goals as their own. Fo r that, I am eternally grateful. This work is also dedicated to the memories of those lives lost from arsenic poisoning due to cont aminated drinking water.

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Acknowledgements I am forever indebted to my major pr ofessor, Dr. Norma Alcantar, for her undying patience, dedication, care, concern, and assistance. I also am intensely grateful for each and every instance wh ere she prioritized her graduate students before her own professional and personal obligations. This thesis also would not have been possible without t he following contributions. Dr. Alessandro Anzalone for his hel p in the beginning stages of the project. USF STARS (Students, Teachers, and Resources in the Sciences) for fellowship funding and invaluable elementary science classroom experience; National Science Fo undation (NSF) Grant No. 0139348. NSF for providing funding for this project; NSF Grant No. 0442977. Dr. Thomas Pichler, Dr. Maya Trotz, and their students for their support in the use of laboratory equipment. My heroes: Ms. Sabrina Gates, Mrs. Sharyn Gibson, and Mr. Dan McFarland, for being infinitely more than high school teachers. Kristina Dearborn for being a fl awless role model and keeping me grounded in an atmosphere where reality can be fleeting. My mahal for love, encouragement, and reaffirming that Chemical Engineering is a fulfilling passion but c ould never satisfy as a lifestyle.

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i Table of Contents List of Tables iv List of Figures v Abstract vii Chapter One: Introduction 1 1.1. Thesis Structure 1 1.2. Introduction 2 1.3. Turbidity and Arsenic Poisoning 2 1.4. Introduction to this Study 5 1.5. Significance of this Study 6 1.6. Research Goals 7 1.6.1. Goal One: Turbidity Removal 7 1.6.2. Goal Two: Arsenic Removal 7 1.6.3. Goal Three: C hemical Characterization 7 1.6.3. Goal Four: Cultural Sensitivity 8 1.6.4. Goal Five: Insights into Interdisciplinary Collaboration 8 1.7. Delimitations and Limitations of this Study 8 Chapter Two: Flocculation, Arsenic Removal, and the Socio-Cultural Aspects of Water Quality 9 2.1. Water Treatment: Turbidity 9 2.2. Water Treatment: Arsenic Removal 13 2.3. Investigated Modes of Arsenic Remediation 19 2.3.1. Bangladesh and West Bengal, India 19 2.3.2. Mexico 32 Chapter Three: Water Contamination in Four Mexican Communities 38 3.1. Zimapn 40 3.2. Region Lagunera 41 3.3. Hierve el Agua 41 3.4. Temamatla 42 3.5. Socio-Cultural Impact Assessment in Temamatla 43 3.6. Implications for This Project 45

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ii Chapter Four: The Mexican Cactus as a Natural Technology for Water Treatment 47 4.1. Current Options: Natural Technologies 47 4.2. Proposed Source of Natural Fl occulant: Opuntia ficus-indica 49 4.2.1. Current Uses 50 4.3. The Mucilage of Opuntia ficus-indica 52 4.3.1. Chemical Composition 52 4.3.2. Extraction Techniques 54 4.3.3. Current Applications 57 Chapter Five: Physical and Chemical Analytical Methods 58 5.1. Mucilage Characterization: Raman Spectroscopy 58 5.2. Turbidity 58 5.2.1. Cylinder Tests 58 5.2.2. Jar Tests 59 5.2.3. Light Scattering 59 5.3. Arsenic Removal 59 5.3.1. Hydride Generation Atom ic Fluorescence Spectroscopy 59 5.3.2. Atomic Absorption (AA) Spectroscopy 60 Chapter Six: Experiment al Procedures 62 6.1. Turbidity Experiments 62 6.1.1 Materials 62 6.1.2. Cylinder Test Procedure 63 6.1.3. Jar Test Procedure 64 6.2. Arsenic Removal Experiments 66 6.2.1. Materials 66 6.2.2. Single Dose Method Procedure 67 6.2.3. Optimization Procedure 68 Chapter Seven: Results and Discussion 70 7.1. Comparison of Extrac ts: Chemical Composition 70 7.2. A Comparison of Extracts: Flocculation 73 7.2.1. Settling Rate 73 7.2.2. Residual Turbidity 77 7.3. Gelling Extract: Arsenic Removal Efficiency 79 7.3.1. Single Dose Method 79 7.3.2. Optimization 84 7.4. Cultural Sensitivity 85 7.5. Interdisciplinary Collaboration 87 Chapter Eight: Conclusions and Future Work 91 8.1. Summary of Findings 91 8.2. Future Work 93 8.2.1. Mucilage Extraction 93

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iii 8.2.2. Flocculation 94 8.2.3. Arsenic Removal 94 8.2.4. Filter Design 95 8.2.5. Temamatla Implementation 95 8.3. Final Remarks 95 References 96 Appendices 107 Appendix A: Cylinder and Jar Tests Sample Dosage Schemes 108 Appendix B: Material Safety Data Sheets 109 B.1. Aluminum Sulfate 109 B.2. Arsenic(III) Oxide 117 B.3. Arsenic (V) Oxide 126 B.4. Arsenic St andard Solution 135 B.5. Kaolin 143 B.6. Nickel Nitrate 150 B.7. Nitric Acid 158 B.8. Sodium Hdyroxide 159

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List of Tables Table 1: Granular Media Filter Advantages and Disadvantages. 11 Table 2: A Comparison of Filter Types for the Reduction of Turbidity in Drinking Water. 13 Table 3: Contamination in Four Mexican Communities. 40 Table 4: Differences in Detected Mucilage Properties: Molecular Weight An d Sugar Content. 53 Table 5: Reagents Used in Flocculation Experiments. 62 Table 6: Equipment and Instruments Used in Flocculation Experiments. 63 Table 7: Reagents Used in Arsenic Removal Experiments. 66 Table 8: Equipment and Instruments Used in Arsenic Removal Experiments. 66 Table 9: Flocculant Doses for 100 ml Graduated Cylinder Tests from Prepared 1 g L-1 Stock So lutions of Flocculants. 108 Table10: Flocculant Doses for Ea ch 0.5 L Jar Test Compartment from Prepared 1 g L-1 Stock So lutions of Flocculants. 108 iv

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List of Figures Figure 1: Precipitation/Copr ecipitation Process. 15 Figure 2: Membrane Pore Sizes Compared to Sizes of Various Water Contaminants. 16 Figure 3: Adsorption Column with Sorbent. 17 Figure 4: Model of a PRB. 18 Figure 5: Schematic of the Stev ens Institute Technology Bucket Treatment Units. 25 Figure 6: Schematic of the DPHE -Danida Arsenic Mitigation Pilot Project Fill And Draw Units. 26 Figure 7: Schematic of Arsenic Removal Units Attached to a Tubewell in West Bengal, India. 27 Figure 8: Mexican Communities Surv eyed for Contaminated Water. 39 Figure 9: Typical Household Wate r Storage and Usage Area for Low-Income Families in Temamatla. 43 Figure 10: Schematic of a Typical Microbiological Arsenic Treatment Unit. 49 Figure 11: An Example of Opuntia Growing as a Tree in Mexico. 50 Figure 12: McGarvie and Parolis Proposed Mucilage Structure, Taken from Senz, 2004. 54 Figure 13: Modified Goycoolea and C rdenas Extraction Method. 56 Figure 14: The Matching Spectra of CE and NE. 71 Figure 15: The Spectral Differences Between GE and NE. 72 Figure 16: Poly(ethyl cyanoacrylate) and Poly(ethyl acrylamide). 72 v

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Figure 17: Flocculation Rates Comparison. 74 Figure 18: GE Compared To Al 2 (SO 4 ) 3 74 Figure 19: The Effect of Dose on the Settling Rates of GE, CE, and NE. 75 Figure 20: A Comparison Showing the Differences in the Linear Portion of Settling. 76 Figure 21: Residual Turbidity of the Mucilages GE And CE. 77 Figure 22: Residual Turbidity of Al 2 (SO 4 ) 3 GE, and CE in a Low Dose Region. 78 Figure 23: Results of the Sing le Dose Arsenic Tests. 79 Figure 24: Single Dose Experiments to Elicit the Effect of pH on As Removal. 81 Figure 25: Average Gain in Arsenic Concentration Resulting from pH Experiment. 82 Figure 26: Results of the Tri-Level Arsenic Distribution Experiment. 83 Figure 27: Solid Particles Observed In High Concentration As and GE Systems. 84 Figure 28: Results of the Optimiza tion Experiments Illustrating the Importance of Settling Time. 85 vi

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vii The Mucilage of Opuntia Ficus Indica : A Natural, Sustainable, and Viable Water Treatment Technology for Use in Rural Mexico for Reducing Turbidity and Arsenic Contam ination in Drinking Water Kevin Andrew Young ABSTRACT The use of natural environmentally benign agents in the treatment of drinking water is rapidly gaining inte rest due to their inherently renewable character and low toxicity. We show that the common Mexican cactus produces a gum-like substance, cactus mucilage, which shows excell ent flocculating abilities and is an economically viable al ternative for low-income communities. Cactus mucilage is a neutral mixture of approximately 55 high-molecular weight sugar residues composed basically of ar abinose, galactose, rhamnose, xylose, and galacturonic acid. We show how this natural product was characterized for its use as a flocculating agent. Our results show the mucilage efficiency for reducing arsenic and particulates from dr inking water as determined by light scattering, Atomic Absorption and Hydr ide Generation-Atomic Fluorescence Spectroscopy. Flocculation studies prov ed the mucilage to be a much faster flocculating agent when compared to Al 2 (SO 4 ) 3 with the efficiency increasing with mucilage concentration. Jar tests reveal ed that lower concentrations of mucilage provided the optimal effectiveness for super natant clarity, an im portant factor in

PAGE 11

viii determining the potability of water. In itial filter results with the mucilage embedded in a silica matrix prov e the feasibility of applying this technology as a method for heavy metal removal. This pr oject provides fundamental, quantitative insights into the necessary and minimum requirements for natural flocculating agents that are innovative, environmentally benign, and cost-effective.

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1 Chapter One Introduction 1.1. Thesis Structure This document will serve as an introduction to a possible water treatment method for turbidity reduction and arsenic remediation using Opuntia ficus-indica (OFI) mucilage as a natural material. Chapter One serves as an overall introduction to the project. Chapter Two outlines current accepted turbidity reduction and arsenic removal techno logies and analyzes remediation technologies implemented in Bangladesh, West Be ngal, India and Mexico. Chapter Three introduces the four Mexican communities surveyed for water contamination and describes the results of socio-cultural impact assessment in Temamatla, Mexico that helped to shape the goals of this project. Chapter Four is an introduction to natural methods of water treatment and to the natural treatment method analyzed in this study, OFI mucilage. Analytical and experimental methods are detailed in Ch apters Five and Six while results are discussed in Chapter Seven. Chapter Eight serves as conclusions and recommendations for future work.

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2 1.2. Introduction Water is a resource essential for life, and water quality commands much attention from the world community Access to clean water varies with geography, economics, politics, and culture; however, the worldwide community agrees that all of Earths citizens deserve access to the planet s most essential resource. Many people are still affect ed by contaminated, unhygienic drinking water, especially in developing countri es. There are about 1.1 billion people in the world without access to clean wate r. It has been sugges ted that household water treatment will be t he critical path toward improved health due to the relatively slow process of designing, in stalling, and deliver ing piped water to communities [1]. The source of contaminants in dr inking water can run the gamut from chemical to biological to geological in such forms as man-made pollution, stagnation or bacterial contamination, or natural sources of harmful minerals. There are a myriad of guidelines out lining requirements for drinking water contaminant concentrations but only two will be addressed in this thesis: turbidity (particle removal) and arsenic. 1.3. Turbidity and Arsenic Poisoning Drinking water turbidity, or cloudine ss, affects a communitys opinion on the safety of certain water sources. T he visual aspect of cloudy water is enough to discourage any consumer from drinking water from a faucet, well, spring, or any other source. Turbidities less than 5 NTU (nephelometer turbidity units) are

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3 considered to be safe by most cons umers, but the World Health Organization (WHO) unofficially considers 0.1 NTU to be the maximum turbidity allowed for disinfection [2]. The turbidity in any water source is due to solids suspended in the water column. These solids result from a va riety of sources including resuspended sediments, inadequate filtrati on, inorganic particles, or biological sources. All sources of turbidity will decrease the e ffectiveness of the disinfection process because particles promote the growth of microorganisms and protect them from the disinfecting agents. Microbial cont amination in drinking water can cause many hygiene-related illnesses such as di arrhea and infectious diseases [3]. Turbidity reduction can vastly improve t he effectiveness of disinfection methods [2]. Although WHO unofficially consi ders 0.1 NTU as a maximum turbidity allowance, they currently have no guide lines on drinking water turbidity [2]. The prevalence of arsenic in drinking water is variable, depending on water source and location. Arsenic can be found in rainwater, surface waters, and groundwaters [4]. The latter poses th e greatest health ri sk to humans due to direct ingestion of arsenic-contaminated well waters [4]. The WHO recognized the risks of ingesting arseni c-contaminated gr ound water in 1958 and, therefore, in 1993 they reduced the recommended guidelines from 0.05 mg L-1 (50 g L-1) to 0.01 mg L-1 (10 g L-1). The WHO based this guid eline on current detection limits due to equipment diagnostic abilities [5]. Natural arsenic sources include miner als, rocks, soils, sediments, and the atmosphere where arsenic is transported due to industrial effluents, fossil-fuel

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4 combustion products, and natural volcanic emissions. Arsenic is not considered a natural constituent of water, so when it is found it is due to several mobilization mechanisms such as physical, chemical, or biological interactions. Mineral-water interactions are often enough to mobilize arsenic through a solid-solution interaction like precipitation-dissolution, adsorption-desorption, or coprecipitation interactions [4]. Adsorption-desorption is the primary ar senic mobilizing interaction in many environments. The As adsorption-desorpt ion potential is a function of many different variables including pH, r edox potential, As concentration, the concentration of competing and complexi ng ions, aquifer mi neralogy, reaction kinetics, and biological activity [6]. The mechanism relies upon a surface adsorption phenomenon, implyi ng the presence of suspended solids in the groundwater source. Adsorption-desorpti on contributing aquifer solids include iron oxides, aluminum oxides, oxyhydroxides, manganese oxides, silica oxides, aluminosilicate clay minerals, carbonate minerals, aquifer solids covered with an adsorbed layer of humic acids, and soil and sediment particles [6]. This dependence upon the presence of solids in groundwater for the occurrence of adsorption-desorption arsenic mobiliza tion supports a need for the simultaneous reduction of turbidity and mobilized arsenic. Health effects resulting from exposure to inorganic arsenic depend on the exposure amount and exposure duration. Months of exposure to arsenic concentrations of 0.04 mg kg-1 day-1 (considered high) can result in health effects that are usually reversible including di arrhea and cramping, anemia, leukopenia,

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5 and peripheral neuropathy; chronic exposure to high doses for 0.5 to 3 years can result in skin effects like hyperpigment ation. Hyperpigmentation can also be found in those exposed to long durations of low doses (5-15 years). Many other detrimental effects to health are linked to chronic arsenic ingestion including vascular diseases, cardiovascular diseases such as hypertension, diabetes mellitus, immune system disease, respir atory diseases, developmental and reproductive effects, neurological effect s, and hepatotoxic effects [7]. The occurrence of some skin, bladder, and lung cancers have also been linked to arsenicosis [8], or the expo sure to arsenic over a long period of time [9]. 1.4. Introduction to this Study The overall project is a complex interdisciplinary, international research project merging engineering principles, scienti fic explorations, and socio-cultural investigations. As such, a network of re searchers from different disciplines and countries was assembled to efficiently elucidate a solution for this complex problem of drinking water quality facing Mexican comm unities. Relationships were formed between investigators in t he U.S. and collaborator s in Mexico, as well as across the engineering, geology, physical chemistry, and anthropology disciplines. Chemical engineers, geologists and hydrologists, and anthropologists from the University of South Florida in Tampa have combined with counterparts at Mexicos three most important and internationally recognized research institutions to create a su ccessful team of collaborators.

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6 The study represented by this thesis is a contribution to the overall goals of the project. It inclu des culturally sensitive engineering and scientific investigations into the fl occulation and arsenic removal properties of the mucilage of the cactus OFI. It also includes in sights gathered with respect to the success of interdisciplinary collaborations. 1.5. Significance of this Study The WHO recognizes a need for investig ations into new low-cost physical and physical-chemical techniques to remove turbidity from household water [10]. This study seeks to uncover an inno vative new technology that can be implemented for turbidity reduction and arsenic removal in areas of contamination where citizens are ec onomically unable to invest in the established, accepted, and costly methods of drinking water treatment. In doing so, individuals exposed to arsenic c ontamination through in gested groundwater will benefit from an inexpensive, easy to implement, and natur al technology that will be a socially, cultura lly, environmentally, and scientif ically appropriate way to improve their quality of life and health. In the process, a scientific explanation of a naturally observed phenomenon will be provided: the ability of the cactus OFI to reduce turbidity when added to cloudy wate rs. Also, investigations into the ability of OFI extracts to remove hea vy metals from water will uncover new scientific pathways for research into natural arsenic removal methods. WHO recognizes the social applicability of drinking water treatment methods as an essential component in t heir effectiveness [3]. By adhering to

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7 recommended guidelines for social applicabi lity of water remediation projects, this research will also provide a case st udy in the use of socio-cultural impact assessment for the shaping of project methods and goals. 1.6. Research Goals 1.6.1. Goal One: Turbidity Removal This project seeks to determine the scient ific basis for the use of OFI as a natural flocculant in reduci ng drinking water turbidity. Specifically, the mucilage of the OFI will be inve stigated as the primary source of the flocculation process. 1.6.2. Goal Two: Arsenic Removal It is suspected that the mucilage of the OFI will not only be active in reducing turbidity, but also in removing arsenic from contaminated waters. This project will determine the effectiveness of the mucilage in the reduction of arsenic concentration, which will be a contribution to the final project goal of assessing mucilage effectiveness in the removal of heavy metals including arsenic, selenium, cadmium, as well as other harmful metals. 1.6.3. Goal Three: Chem ical Characterization The third goal of this project is to determine the composition of the mucilage in order to determine the source of its flocculation ability. Also, to determine the mechanism by which the mu cilage removes suspended solids and arsenic.

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8 1.6.3. Goal Four: Cultural Sensitivity The third goal of this project is the overreaching umbrella of cultural sensitivity. The turbidity reduction and arsenic removal technology developed must be implementable, acc eptable, and useful in t he houses or towns of lowincome communities. 1.6.4. Goal Five: Insights into Interdisciplinary Collaboration The final goal of this project is to ex tract useful information in the form of protocols and suggestions for success applicable to interdisciplinary collaborations in related studies. 1.7. Delimitations and Limitations of this Study It has been suggested that technologies developed for implementation in low-income, indigenous communities should be simple and easy to produce, inexpensive, employ native or easily accessible material s, and have a rural focus [11]. These guidelines are the design boundar ies for this project. This study also seeks to determine the efficiency of the mucilage of OFI in water treatment in order to determine the least work-intensiv e, most culturally sensitive way to implement Opuntia as a natural method for water treatment in Mexican communities. The mucilage can be separated into diffe rent concentrations of sugars. Depending on the chemical co mposition, it is easy to extract three substances that can be tested to treat water. As a result, only these three extracted chemicals were utilized in the wate r treatment analyses described herein.

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9 Chapter Two Flocculation, Arsenic Removal, and the Socio-Cultural Aspects of Water Quality 2.1. Water Treatment: Turbidity The World Health Organi zation (WHO) considers treating biological contamination of turbid water in the home a challenge due to the effect of turbidity in decreasing access to microbes by inactivation mechanisms such as UV radiation from lamps or sunlig ht [10]. The WHO maintains that, There is a need to investigate, characterize and implement physical and physical-chemical te chnologies for practical and low cost pre-treatment of treatment of household water prior to chlorination, solar disinfection with UV plus heat and UV disinfection with lamps [1]. The WHO currently recognizes four differ ent categories of turbidity-reduction mechanisms (listed below) as potent ial areas for investigation [1]. Settling or plain sedimentation Filtering with fibers, cloth, or membranes Filtering with granular media Slow sand and Biosand filters

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10 Plain Sedimentation Settling, or plain sedim entation, is simply allowing cloudy water sit for a period of time and letting gravity settle the particulates present. Decanting or lad ling out the supernat ant leaves the sediment behind. This can be done with any size of water vessel and has been practiced since ancient times [1]. This process has t he advantage of being a low-cost way to reduce suspended solids and some micr obes, and is generally recommended as pre-treatment before disinfection. Unfort unately, sedimentat ion will not remove clays and smaller solid parti cles, nor will it remove smaller microbes [1]. Also, the settling length for some solids can be as long as two days [1]. Membrane Filter Filtration is another technology that has been in use since ancient times. The WHO recognizes th ree types of filtering: membranous, granular media, and slow s and and Biosand filters. Me mbrane filters include filters made of compressed or cast fi bers like cellulose papers or synthetic polymer filters, spun threads or woven fabrics. Genera lly, filters are placed over a water source and are used widely for point-of-use water supply systems. Funnels are also used to pass water th rough the filters on which solids are collected; a variation of this is the use of porous cartridges. These membrane filters do not always remove all suspended solids or all microbial contamination [1]. Granular Media The use of sand filters, or ot her porous granular media filters are the most widely used physical water treatment technology on the community

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11 level. Different technologies have been pr oduced that include the use of different granular media such as sand, anthracite crushed sandstone, other soft rock, and charcoal. These filters are designed to be used at the household level and include bucket filters, drum filters, barrel filters, r oughing filters (one or more basins), and above or below gr ade cistern filters. Tabl e 1 compares the different granular media filters [1]. Table 1: Granular Media Filter Advantages and Disadvantages. Filter Design Advantages Disadvantages Bucket filter Use on a small scale at household level Simple Can use local, low cost media and buckets Simple to operate manually May require fabrication by user Initial education and training in fabrication and use needed Requires user maintenance Barrel or drum filter Use on a small scale at household or community level Relatively simple Can use local and low cost media and barrels or drums Requires some technical knowledge for fabrication and use Initial education and training needed Roughing filter Use on a small scale at community level Relatively simple Can use local, low cost construction material and media Less amenable to individual household use because of scaling Requires some technical knowledge for construction and use

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12 Bucket filters consist of two buckets one as a filter and the other as a cistern. The filter bucket has holes drilled in the bottom and a layer several centimeters thick of gravel, on top of wh ich is placed an even thicker bed of sand (0.1 to 1mm grain size). Water is pour ed through the filter bucket and collected in the cistern bucket. The collected water has a low turbidity, but the sand must be replaced often to avoid the buildup of biological contaminant s. Bucket filters are commercially available [1]. Drum or barrel filters are generally configured in a down-flow or up-flow design. A 55-gallon drum is se t up much like the filtering bucket in bucket filters. Water is poured through the drum and a pipe at the bottom collects the clean water. For the up-flow design, water is forced up through the bo ttom of the filter bucket and discharged near the top. Diffe rent granular media can be used, even combinations of sand and charcoal [1]. Roughing filters consist of a re ctangular-shaped basin of different compartments of granular media with decreasing particle size in the direction of water flow. Water moves through the filter until non-turbid product is collected at the end. This set-up requires frequent bac kwashing, requiring a certain amount of skill or proper operation [1]. Everything from sponges to charcoal has been employed in the reduction of turbidity for the apparent cleansing of drinking water. Biomass has also been used as a filter medium. Filters have also been made of cotton, wool, linen, pulverized glass, burnt rice hulls, and fresh coconut fibers [1]. Table 2 serves as a comparison of the different types of filter media [1].

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13 Table 2: A Comparison of Filter Types fo r the Reduction of Turbidity in Drinking Water. Type of Filtration Media Ease of Use Effectiveness (comments) Cost Granular media, rapid rate depth filters Sand, gravel, diatomaceous earth, coal, other minerals Easy to moderate Moderate* (depends on microbe size and pretreatment) Low to moderate Slow sand filters Sand Easy to moderate (community use) High** in principle but often low in practice Low to moderate Vegetable and animal derived depth filters Coal, sponge, charcoal, cotton, etc. Moderate to difficult Moderate* Low to moderate Fabric, paper, membrane, canvas, etc. filters Cloth, other woven fabric, synthetic polymers, wick siphons Easy to moderate Varies from high to low (with pore size and composition) Varies: low for natural; high for synthetics Moderate typically means 90-99% reductions of larger pathogens (Helminth ova and larger protozoans) and solids-associated pathogens, but lo w (<90%) reductions of viruses and free bacteria, assuming no pre-treatment. With pretreatment (typically coagulation), pathogen reductions are typically >99% (high). **High pathogen reduction means >99%. 2.2. Water Treatment: Arsenic Removal The US Environmental Protection Agency (USEPA) recognizes eight different categories for arsenic treatment technologies applicable to groundwater in their report, Arsenic Treatment Technol ogies for Soil, Waste, and Water [12]. They are as follows:

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14 Precipitation/C oprecipitation Membrane Filtration Adsorption Treatment Ion Exchange Treatment Permeable Reactive Barriers Electrokinetic Treatment Phytoremediation Biological Treatment Precipitation/C oprecipitation This is the most frequently used method for arsenic remediation in groundwater for bot h drinking water and wastewater. This method has reduced levels below the cu rrent USEPA guideline of 0.01 mg L-1. Also, it has the potential to reduce other contaminants that hinder the quality of drinking water, including turbidity, iron, phosphate, manganese, fluoride, color, and odor [13]. Precipitation/coprecipitat ion technologies include the use of a chemical treatment leading to the precipitation or coprecipitatio n of a solid and the subsequent separation of the solid from the water source. Chemicals used to precipitate a solid include ferric chemicals such as salts and sulfates; sulfate chemicals like ammonium, copper, and manganese sulfate; aluminum hydroxide, lime, and a form of pH adjustm ent [12]. An example of a precipitation/coprecipit ation process is illustrated in Figure 1 [12].

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Figure 1: Precipitation/coprecipitation Process. Membrane Filtration This is a process us ed less frequently than precipitation/coprecip itation processes although thei r solids removal efficiencies are comparable. They are also associat ed with having higher operating costs. Membrane filtration is a technology used mostly to treat groundwaters and is characterized by processes including any one of the following: microfiltration, ultrafiltration, nanofiltration, or reverse osmosis. Figure 2 illustrates the pore sizes of different membrane technologies [ 13]. The applicability of this process depends upon the quality of th e feed stream. Suspended solids or any dissolved solid with high molecular weight can po tentially foul the membrane [12]. Depending upon feedwater qua lity, different pretreat ment options must be employed. Also, to increase arsenic remo val efficiencies, prior treatment must be performed to convert As(III) to As(V) since the As(V) tends to have a larger ionic radius [12]. 15

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Figure 2: Membrane Pore Sizes Com pared to Sizes of Various Water Contaminants. Adsorption Adsorption methods are also used less frequently than precipitation/coprecip itation although they also have similar removal efficiencies. This technology includes any proce ss where adsorption is the primary mechanism employed for removal. Adso rption processes can use a combination of precipitation/coprecip itation, ion exchange, and filtration technologies. Generally, they involve a column with a bed of sorbent media through which feedwater is passed. A va riety of sorbents can be used including activated alumina, activated carbon, copper-zin c granules; ferric-hydroxide or ferrichydroxide newspaper pulp; iron oxide coat ed sand or iron filings in sand, KMnO4 coated glauconite, surfactant -modified zeolite, and other s [12, 13]. Adsorption methods generally include regenerating the sorbent through a backwashing 16

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method [12]. Pretreatment is also r equired for adsorption methods due to the same factors affecting fouling in membr ane methods [14, 15]. Figure 3 illustrates a typical adsorption process [12]. Figure 3: Adsorption Column with Sorbent. Ion Exchange Treatments employing ion exch ange for arsenic removal are very similar to the adsorption technique wi th respect to process configuration. The difference is in the replacement of a sorbent with an ion exchange resin [12]. An ion exchange media is used consisting of either a strong or weak acid or base in order to regenerate the resi n after it is fouled with removed arsenic [16]. This technology can provide effective arseni c removal in the range of <0.05 mg L-1 to <0.01 mg L-1, but is used less frequently than prec ipitation/coprecip itation due to the same process sensitivities effect ing membrane filtration and adsorption processes: tedious, skillful regeneration and high cost [12]. 17

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Permeable Reactive Barrier A permeable reactive barrier (PRB) treatment system is placed underground in the dire ction of groundwater flow, creating an in situ arsenic treatment method. This is not a popular treatment technology but has been used as a way to treat contam inated plumes of groundwater. It consists of an underground wall, inside of wh ich is a media that is reactive with arsenic. Water passes through the wall and arsenic is immobilized. PRBs are not effective in aquifers wit h high hydraulic conductiviti es or aquifers deeper than 70 feet. Also, PRB plugging with loos e rock and sediments can hinder PRB effectiveness. Figure 4 illustra tes a generic PRB set-up [12]. Figure 4: Model of a PRB. Electrokinetic The USEPA classifies electrokinetic arsenic treatment methods as an emerging technology. This is a method applicable to not only groundwater but also to soils. Essentially, electrodes are placed in soil or water and a current is passed through the media to be treated. Metals in the form of 18

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19 ions are attracted by the electric field to the electrodes where they are removed [12]. Arsenic species present would have to be in ionic forms for this process to be applicable. This technology is also only suitable to acid-soluble polar compounds [12]. Phytoremediation, or the use of plants (specifically plant roots), to remove contaminants and biological treatments will be addressed in Chapter 4 of this thesis, Section 4.1. 2.3. Investigated Modes of Arsenic Remediation Arsenic contamination can be reduced wi th several different remediation methods falling under the categories described in section 2.2. In this section, an introduction to the multitude of remediat ion techniques tested in Bangladesh and West Bengal, India is followed by a review of removal strategies implemented in the contaminated regions of Mexico. Each remediation technique is described and evaluated with respect to cultural sensit ivity, acceptability, and sustainability. 2.3.1. Bangladesh and West Bengal, India Bangladesh and West B engal, India solved probl ems associated with access to drinking water by installing shallo w tubewells in flood plain aquifers. In solving one health problem, another wa s created arsenic poisoning due to ingestion from contaminated tubewell wate r. Water in the shallow aquifers is routinely contaminated wit h mobilized arsenic above re commended limits, putting millions at risk for arsenic poisoning. Many different scaled-down technologies have been introduced to the r egion and evaluated for their effectiveness. These

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20 methods fall under well-known arsenic re moval categories outlined in section 2.2., paragraph one and include [17]: Oxidation Co-precipitation/adsorption Sorptive filtration Ion exchange Membranes Oxidation Due to arsenic speciation in gro undwater, many technologies take advantage of the easier-to-remove pentav alent form of As(V) by oxidizing the trivalent form As(III), converting it to pent avalent arsenic. This can be done using oxygen, ozone, free chlorine, hypochlor ite, permanganate, hydrogen peroxide, and Fentons reagent; but the most fr equently used are atmospheric oxygen, hypochlorite, and permanganate. However, the use of atmospheric oxygen can take weeks to convert all trivalent s pecies to pentavalent arsenic [18]. The chemical reactions for these three ox idation methods are as follows [17]: H3AsO3 + O2 H2AsO4 + H+ (1) H3AsO3 + HClO HAsO4 2+ 3H+ + Cl(2) 3H3AsO3 + 2KMnO4 3HAsO4 2+2MnO2+ +2K+ + 4H+ + H2O (3) Processes taking advantage of oxidat ion are passive sedimentation, in situ oxidation, and solar oxidation [17]. Passive sedimentation has been discussed in sect ion 1.1.1 as a method for turbidity reduction, but it can also apply in the reduction of arsenic by

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21 oxidation. Drinking water is exposed to atmospheric oxygen during the gathering and storing process and, as a result, this process has been studied to determine if arsenic concentration is reduced. Fifty percent remova l was obtained using passive sedimentation of dr inking water with 380-480 mg L-1 of CaCO3 for alkalinity and 8-12 mg L-1 of iron, but most studies only showed a 25% reduction which is not enough in most of Bangladesh and India [19]. In situ oxidation was performed under t he DPHE (Department of Public Health Engineering) Danida Arsenic Miti gation Pilot Project where a tubewell was aerated by the injection of aerated wa ter into the well. As a result, the atmospheric oxygen converts As(III) to the less mobile pentavalent form and ferrous iron present in the aquifer is converted to ferric iron. This combination of conversion results in a coprecipitati on/adsorption process, reducing mobilized arsenic in the well water by the following equat ions (surface sites are denoted with an italicized S ) [17]: Fe(OH)3 + H3AsO4 FeAsO4H2O + H2O (4) S FeOH0 + AsO4 3+ 3H+ S FeH2AsO4 + H2O (5) S FeOH0 + AsO4 3+ 2H+ S FeHAsO4 + H2O[20] (6) This technology reduces arsenic content by about 50% [21]. Solar oxidation takes advantage of both solar ultraviolet (UV) radiation and atmospheric oxygen [22]. It was found that UV radiation can catalyze the oxidation process with atmospheric oxygen, resulting in a 66% removal rate, on average [17].

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22 Co-precipitation and Adsorption Co-precipitation processes were discussed in section 1.1.2. paragraph two as a method fo r reducing turbidity in drinking water, but coprecipitation coupled with adsorption can also remo ve mobilized arsenic. Seven different coprecipit ation/adsorption technologie s have been implemented and evaluated in Bangladesh a nd India, these include: bucket treatment units (BTU) Stevens Institute Technology (SIT) Bangladesh Council of Scientific and Industrial Research Filter Unit (BCSIR) fill and draw units arsenic removal units attached to tubewells naturally occurring iron Different coagulants/flocculants can be em ployed in this process, some of which are aluminum alum (Al2(SO4)3H2O, also known as aluminum sulfate), ferric chloride (FeCl3), and ferric sulfate (Fe2(SO4)3H2O). The coprecipitation/adsorptio n process is typical of other flocculation methods. A dose of the flocculant is added to water, agitated for a few minutes while aggregated flocs form, slowly stirred for a few minutes to allow for the flocs to gain in size and begin to settle, and then let sit to allow all of the flocs to settle. Arsenic is adsorbed onto these flocs, and, thus, remov ed by sedimentation. Again, for this technology to be efficient, trivalent arsenic must first be oxidiz ed to its charged pentavalent form [17] but this can easil y be performed using atmospheric oxygen or the combination of oxygen and UV radiation [22]. Proposed chemical

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23 reactions for the formation of and coprecipitation/adsorption of the aluminumarsenic complex using alum are as follows Chemical reactions involving ferric salts are the same as equations 4 thr ough 6 and also require pretreatment to oxidize As(III) to As(V) [17]. Alum dissolution: Al2(SO4)3H2O 2Al3+ + 3SO4 2+ 18H2O (7) Aluminum precipitation (acidic): 2Al3+ + 6H2O 2Al(OH)3 + 6H+ (8) Co-precipitation: H2AsO4 + Al(OH)3 Al-As + Other Products (9) The DPHE-Danida Project developed the BTU technology introduced in Bangladesh. It requires the use of two buckets (20 L); one to perform flocculation/coagulation and sedi mentation and the other cons ists of a sand filter to remove resulting contaminants. Next, 200 mg L-1 and 2 mg L-1 doses of a chemical flocculant, alum, are added to the flocculation bucket and stirred rapidly for one to two minutes. Then, the contents are allowed to settle. A valve in a hose connected just above the bottom of the bucket is then opened, allowing the supernatant to flow into the second bucke t (sand filter) [17]. Thousands of these units were distributed in Bangladesh and a rapid pr eliminary study by BAMWSP (Bangladesh Arsenic Mitigation Water Suppl y Project, BDFID (British Department for International Development) and WaterA id in 2001, reported mixed results. They were found to be inefficient in reducing arsenic content below the Bangladesh limit of 50 g L-1 under rural use. The inefficiencies were blamed on

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24 poor mixing conditions and varying pH of water supplies [19]. The BTU technology falls under most of the require ments for socio-cult ural acceptability discussed in the introduction to this chapter but fails to use indigenous materials for remediation. Specifically, the floccul ant is not a material known to community members. The SIT configuration is analogous to the BTU setup. It also consists of two buckets, one for mixing and floccula tion, and the other as a secondary sand filter. The difference in t he SIT technology is the flocculant used, the location of sedimentation, and the confi guration of the sand filter bucket. The SIT uses iron sulphate and calcium hypochlor ide as flocculants. Thes e chemicals are mixed in the first bucket. Then, the bucket contents are poured into the second bucket that consists of a smaller bucket with perforations inserted on top of a sand filter. Sedimentation takes place in this se cond bucket, and water is drawn from underneath the sand filter by a hose [17]. Figure 5 shows the general configuration of the SIT.

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Figure 5: Schematic of the Stevens Inst itute Technology Bucke t Treatment Units. Rapid assessment of the SIT showed arseni c reduction to levels below the 50 g L-1 requirements in 80 95% of cases. However, the sand filter was found to clog frequently due to sedimentation in the second bucket [ 19]. This method fails under the requirements for cultural sensit ivity for the same reasons as the BTU method. It uses foreign chemical flo cculants and requires skillful operation. The BCSIR filter unit is similar to both the BTU and SIT methods with the differences again in the flocculant chemicals and the sand filter treatment [17, 23]. The flocculant is a mixture of ir on oxide, alum, acti vated charcoal and calcium carbonate. The flocs formed se ttle and the entire bucket of water is passed through a sand filter that contai ns iron-bearing minerals of various grain sizes. Drawbacks of this technology are the requirement of the flocculant dose on level of contamination [23] and the lack of dependence on indigenous materials (the use of chemicals as a flo cculant). The BCSIR claims that arsenic contaminated drinking water can be re duced to levels below the 50 g L-1 25

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standard for waters containing up to 2.7 mg L-1 As [23]. However, the BCSIR did not take part in the rapi d assessment program [17]. The fill and draw unit initiated by DPHE-Danida Arsenic Mitigation Pilot Project is essentially a larger version of the aforementioned methods, aimed at community-based use instead of individual household use. Flocculation takes place in a large (600 L) tank with a mixer of flat-blade impellers and is operated by hand. Chemical oxidants and floccu lants are added, mixe d, and allowed to settle. The resulting supernatant is wi thdrawn from a few inches above the sludge line near the bottom of the tank and passed through a sand filter, finally collected at the end for dr inking purposes. These units performed better because the mixing and flocculation are be tter controlled, resulting in higher removal efficiencies. These units are still serving communities and some educational institutions in the form illustrated in Figure 6 [17]. Figure 6: Schematic of the DPHE-Danida Arsenic Mitigation Pilot Project Fill and Draw Units. 26

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Arsenic removal units attached to tubewells have been implemented in West Bengal, India and are designed and built to be attached directly to a tubewell outlet. This employs the use of sodium hypochlorite and alum for coagulation, followed by sedimentation and subsequent filt ration through an upflow filter unit. This technology is des igned to be used for an entire village and has been shown to remove 90% of arsenic from the contaminat ed source with an initial concentration of 0.3 mg L-1 [17]. A schematic of th is design is presented in Figure 7. Figure 7: Schematic of Arsenic Removal Units Attached to a Tubewell in West Bengal, India. It was found that most drinking water sources with low amounts of iron precipitates (<1 mg L-1) also had low arsenic values (<50 g L-1), and those with iron precipitates between 1 and 5 mg L-1 only satisfied the 50 g L-1 limit 50% of the time, and those with >5 mg L-1 only satisfied the limit 25% of the time. It has also been found that only aeration and subsequent sedi mentation of drinking water with high iron content suitably removes arsenic. From this data and data showing that Iron Removal Plants (IRP) wh ich use the same methods of aeration 27

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28 and sedimentation with subsequent filtration, also removed arsenic without any added chemicals, medium scale IRPs were installed in district towns. These IRPs suitably remove arsenic with the only disadvantage of the technologys high use being treated water for backwashing the filters [17]. Sorptive Filtration Sorptive filtration requires t he use of a sorptive media, and all proposed media have one universal dr awback: saturation, meaning the media is spent and can no longer remove ar senic without regeneration [17]. The different media types empl oyed fall under two broad categories: foreign (usually chemical-based), and indigenous (usually natural-based). Some sorptive media investigated for arsenic removal are as follows [17]: Foreign: activated alumina activated carbon iron coated sand iron and manganese coated sand kaolinite clay hydrated ferric oxide activated bauxite titanium oxide silicon oxide Indigenous: oxidized iron-rich soil

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29 clay minerals iron ore iron scrap iron filings processed cellulose Both the foreign material-based filters and indigenous f ilters are generally effective at removing arsenic but must be frequently regenerated and most suffer the effects of fouling [17]. The use of indigenous materials is well advised in devising a sustainable arsenic removal technology, but these technologies suffer the same two drawbacks as the foreign materials: labor-intensive regeneration and problems with fouling. Ion Exchange This process is similar to sorp tive filtration except that the sorptive media is replaced with a synt hetic ion exchange resin designed for optimized removal. This technology also requires regeneration when the resin is spent. An example of the chemical process is outlined below (where italicized R denotes resin). Arsenic Removal 2 R -Cl + HAsO4 2R 2HAsO4 + 2Cl(10) Regeneration R 2HAsO4 + 2N+ +2Cl2 R -Cl + HAsO4 2+ 2Na+[17] (11) The ion exchange process efficiency, lik e most others, depends on an oxidation pretreatment step [17]. The use of a foreign ion exchange resin in community

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30 households does not fit the requirement that materials be familiar to community members. Also, regenerat ion with other chemicals is labor-intensive and adds another step with a foreign material. Al though this technology is promising for arsenic removal, it is not an ideal te chnology from the su stainability standpoint. Membranes The membrane technologies pr oposed and tested for use in Bangladesh and India are similar to and fall under the same category as the membrane technologies discussed previously in section 2.2. The MRT-1000 and Reid System Ltd. technologies relie d upon reverse osmosis on the household level to remove arsenic and found that both effectively removed arsenic, but the technologies are too costly for wide implementation [17]. J.I. Oh et al ., 2000, at the University of Tokyo, developed one interesting technology [24]. It employed the use of a bicycle pump to feed contaminated drinking water at low pressure to a filtration system. This technology was developed for use in regions without access to electricity. Nanofiltration and reverse osmosis were both tested, and th e reverse osmosis system removed the most arsenic at a pressure of 4 MPa. However, the nanofiltra tion unit was highly efficient at removing arsenate (As(V)), s howing a 99% removal, but less efficient at removing arsenite (As(III)), with 55% removal. Oxidativ e pretreatment to convert arsenite to arsenate will help the total arsenic removal efficiency [24]. The reverse osmosis system adequately re moves arsenic to below the 50 g L-1 standard, but the technology, like the other reverse osmosis method, is costly

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31 and is not comprised of indigenous materi als, leading to the conclusion that it, too, is unsuitable for sustai nability cultural sensitivity. In summary, none of the techniques for arsenic removal tested in Bangladesh or India fit the requirements fo r sustainability with respect to cultural sensitivity laid forth by Shaban et al. 2005, that provide the boundaries for our project. The requirements that technologies developed for implementation in low-income, rural communities should be simple, easy to produce, inexpensive, employ indigenous or easily accessible materials, and have a rural focus [11], are not considered in existing technol ogies. The coprecipitation/adsorption technologies such as the BTUs and Sits are easy to produce, inexpensive, and have a rural focus, but they do not employ indigenous or easily accessible materials due to their dependence on chemical flocculants. Sorptive filtration units also tend to employ chemicals for the regeneration of sorptive medias, as does ion exchange technologie s and both produce waste materials. Also, neither sorptive filtration nor ion exchange has a rural focus, both relying on laborintensive regeneration processes. The nanofiltration and reverse osmosis membrane technologies are promising with regards to arsenic removal but fail when held up to the standards of sustainability due to their high capital and operation costs. The technology with the most room for improvement with respect to sustainability is the coprec ipitation/adsorptio n processes like the BTUs and SITs. If their dependence upon chemical flocculants can be alleviated, they will fit well within the guidelines for sust ainable arsenic removal tech nologies in low-income,

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32 indigenous communities. This project seeks to develop a similar filtration unit that employs flocculation, precipitation, and filtration but uses only indigenous, easily accessible materials. 2.3.2. Mexico Due to the minimal success of in-hom e filters and other remedies in Bangladesh and West Bengal, India, t here is a growing demand for natural flocculants that will perform at effici encies comparable to existing chemical flocculants and simultaneously remove suspended solids, as well as heavy metals [25]. To ensure a sustainable im pact, the natural technology must also be socially appropriate, producing a minimi zed effect on the lives of affected individuals while simultaneously increasing their quality of life. It is this need that motivated the initiation of a project to investigate the scientific basis, feasibility, and product development of a natural filter for use in Mexican communities experiencing problems with c ontaminated water supplies. Mexicos geographic, social, and econom ical characteristics make it the ideal location for this water treatment pr oject. Severe heavy metal contamination in water supplies has created a desperat e need for a treatment solution and the current economic conditions provide a co mparable situation with other areas suffering contamination: Bangladesh, China, and India. Also, the Mexican people are extremely familiar with our chosen flocculant source, the nopal cactus (commonly called prickly pear), due to its amazing abundance in the arid

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33 climates of the country. The need for a functional, inexpensive, and accessible flocculant source is also dire due to a lack of funding for the construction and implementation of beneficial water trea tment facilities in affected Mexican communities. Many of the aforementioned arsenic removal technologies have been investigated for use in affe cted communities in Mexico. Those investigated fall into four separate categor ies: adsorption on iron-bas ed adsorbents, adsorption on other adsorbents, precipitation/coprecipitation, and emerging technologies. All of the technologies described in th is section have been studied for use in other countries and have foun d varying success. As a result of knowledge gained from previous impl ementation, most of t he Mexican trials were scientifically successful. However, their social applicability varies and are described below. Iron-based Adsorption Hematite and natural minerals present in Mexican aquifers have been tested for their effici ency in adsorbing mobilized arsenic. Simeonova, 2000, selected natural Hematite for an in situ pilot study of removal from an underground water source in Me xico [26]. Water obtained from the treated water source was cons istently below the Mexic an drinking water standard of 50 g L-1 [26]. Carrillo and Drever, 1998, found similar results in their study of the possibility of using natural aquifer minerals for in situ removal. They found that removal was, at maximum, 80% w hen the natural miner als contained from 10-12% Fe. It was determined that the parti al removal was based on selectivity

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34 for arsenate over the difficult-to-remove arsenite. Quartz, feldspar, calcite, chlorite, illite, and magnetite/hematite were all present in their adsorbent sample [27]. The social acceptability of these iron-based adsorption methods is high based on the use of natural, indigenous materi als. However, there is a lack of a rural focus to these methodologies. There is a limited ability for residents in rural communities to inject adsorbents into aquifers for in situ treatment. Also, due to the possible presence of a governmental distrust amongst community members, the prospect of injecting anything in to an aquifer may cause suspicion. Adsorption The adsorption techniques studi ed include the us e of natural, indigenous non-ferric minerals a nd natural zeolites. A naturally occurring, clayrich limestone material called Soyatal Formation was analyzed for its ability to adsorb arsenic and was found to be an outstanding per former. Contaminated water samples of 600 g L-1 were cleaned to below 30 g L-1 As. It was found that a weight ratio of 1: 10 rock-to-water is the proper dosage to reduce arsenic levels from 500 g L-1 to below 30 g L-1 [28]. It would follow that lower doses would be required for contaminated water with lower levels of arsenic. The Soyatol Formation owes its abilities to its composition; it contains kaolinite and illite, which are both known arsenic adsorbers [28]. Natural zeolites of the clinoptilolit e variety formed in Mexico were also investigated for their adsorption efficiency and were found to reduce

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35 contaminated water with 200 g L-1 As to 10 g L-1, the WHO recommended limit. The presence of anions and cations di d not effect the arsenic removal [29]. Both of these natural minerals are ex cellent arsenic absorbers and also fit the requirements for social acceptability If implemented in such a way that individual households could have control of their water treatment, this method would also have a rural focus. The limiting factor with these methods is sustainability. While both minerals are form ed in Mexico, mining of the minerals could affect the cost of such a treatment. Precipitation/C oprecipitation Combination treatments consisting of alum and a polymeric anion flocculant (PAF), as well as ferric sulfate flocculation have been determined to be efficient modes of remediation. The combination flocculant removed 99% of arsenic at an NaOH-adjusted pH of 7.1 and the PAF played no part in As removal [30]. The ferric sulfate removal process investigated consisted of a tank outfitt ed with a manual agitat or. Ferric sulfate salts were added by individual households (10 families) and the tanks were agitated and left to settle for three hours. The clean water was then decanted. Removal was total in seven of the ten systems and >93% in the other three [31]. Both flocculation methods are scientifically solid, but socially unacceptable. The use of unindigenous chem icals to treat contaminated water is a source of instability with respect to sustainability due to distrust in unfamiliar materials. Also, the use of chemicals adv ersely affects the cost of the treatment process.

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36 Emerging Technologies Electro-remediation was discussed in section 2.2 of this thesis. A form of electro-remediat ion, electrocoagulatio n, was performed in the Comarca Lagunera region of Mexico fo r treating contaminated well water. Electrocoagulation is a technique unlik e those discussed above. It does not require chemicals, nor does it require labor-intensive and cost sensitive regeneration, as do most f ilters and ion exchange technol ogies. Results of the pilot study show removal of more than 99% of arsenic due to the mutualistic effect of the presence of magnetite par ticles and amorphous iron oxyhydroxides [32]. Electrodialysis was also investigated by Clifford and Li n who found it most effective at removing arsenic in waters with low levels of arsenite (73% removal). Elevated arsenite concentration reduced removal to only 28% [33]. Phytoremediation was also investigated in Mexico, specifically in the mine sites and hot springs of Chihuahua. An investigation into arsenic-bearing plants of the region identif ied a native plant, Eleocharis sp. with great potential for arsenic removal [34]. Emerging technologies are exciting due to their ability to be both scientifically and socially acceptable. Electro-remediation does not have a rural focus; however, due to the fact that ma ny rural families in under-developed countries do not have access to electricit y. Phytoremediation, however, is an ideal technology from the social acceptability and su stainability standpoints. Plants are easily reproduced an d are an indigenous, natural resource trusted by communities. The technique outlined in th is thesis can potentially be considered

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37 as a combination of the scient ific acceptability of precip itation/coprecipitation with the social and sustainability s ensibilities of phytoremediation.

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38 Chapter Three Water Contamination in Four Mexican Communities Just as arsenic contaminated drinking water is quickly be coming a globally recognized problem in areas such as Bangladesh and India where millions of residents are potentially exposed to ars enic contamination [17], the same problem is also being uncovered in lowincome, indigenous communities in rural Mexico. Razo, et al. 2004, studied the Villa de la Paz-Matehuala region to determine the effect of mining in t he area on sands, sediments, and surface waters, and found arsenic levels in Carbone ra and Cerrito Blanco well systems to be greater than 6,000 g L-1, or more than 120 times the Mexican water quality guidelines at that time (<50 g L-1) [35]. Sediment sample s from the wells were not studied, but sediments from nearby channels were found to be as much as 20 times the Mexican guidelines [35]. Anot her Mexican region si milar to the Villa de la Paz-Matehuala area is the mining dist rict of Zimapn. Previously reported figures for groundwater arsenic contaminat ion in Zimapn show levels greater than 300 g L-1 [36]. Mejia et al. [37] studied ur ine samples from children in Villa de la Paz and found arsenic levels greater than 100 g g-1 in 28% of children tested, proving a need for a technological solution. The first action taken under the project was a survey of drinking water supplies of Mexican towns chosen becaus e of known or suspected drinking

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water contamination, due to t heir proximity to either geologic or industrial sources of arsenic contamination. University of South Florida (USF) geologists examined water samples from four different co mmunities, Region Lagunera, Zimapn, Hierve el Agua, and Temamatl a, illustrated in Figure 8, for arsenic concentration using hydride generation-atomic fluoresc ence spectrometry. They also noted suspended solid presence in the samples. The results are summarized in Table 3 along with suspected sources of arsenic contamination. The test community for this project was chosen based on the presence of arsenic contamination above WHO recommended guidelines and t he presence of suspended solids. Figure 8: Mexican Communities Surveyed for Contaminated Water. 39

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40 Table 3: Contamination in Four Mexican Communities. Location As ( g L-1) Suspended Solids Contamination Source Hierve el Agua >518 None Geologic Zimapn > 221 None Industrial Region Lagunera >563 None Industrial Temamatla > 29 Present Geologic Drinking water standard < 50 3.1. Zimapn USF engineers and geologis ts found an average arsenic concentration in drinking water samples taken from Zi mapn, Mexico to be greater than 221 g L1, more than four times the Mexica n standard and more than 22 times the recommended WHO guidelines. Zimapn is mainly a mining district where Ag, Zn, and Pb ores are processed. Also, smelters operated in the district until the 1940 s. Wastes from these industries have collected in areas along the Toliman River. It is these industrial sources, as well as arseni c-bearing minerals, contaminating the drinking water of Zimapn[38, 39]. Arsenic was initially found in shallow wells of the Zimapn basin in 1992 as pa rt of a study detecting cholera. Residents of this region obtain drinking water from these shallow wells due to the lack of groundwater supplies in the semi-arid landscape [39]. While arsenic contamination in this r egion is well above arsenic standard guidelines, the residents of Zimapn were not experiencing contamination due to suspended solids, so this study did not adopt Zimapn as a test community.

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41 3.2. Region Lagunera Arsenic contamination in Region Lagunera is attri buted mainly to mining sources, and the population drinking co ntaminated water show As-related skin disorders [40]. Pineda-Zavaleta et al studied children from three primary schools in the region and found that 92% had urinary ar senic levels above 50 g L-1, indicating widespread exposure [41]. US F researchers found data to corroborate previous studies: arsenic levels greater than 550 g L-1. However, once again, this region did not have contaminati on due to suspended solids so it was not adopted as a test community. 3.3. Hierve el Agua Hierve el Agua is a region well known for its mineral-rich waters. There are canals and terraces built in Oaxaca Mexico of unknow n purpose but the waters riches lead prognosticators to two separate hypotheses: either the region was used agricultural purposes or for salt production [42]. If either of these hypotheses is true, the creat ors of the irrigation features could not have known the mineral-laden waters bore high levels of arsenic. We found As levels greater than 500 g L-1 in Hierve el Agua, mainly due to geologic sources. The name Hierve el Agua translates to Boiling Water and is an appropriate moniker for the region, which owes its popularity to the prevalence of hot springs. Unfortunately, the belief that natural spring water from hot springs is healthier than piped water leads many to drink copious amounts of the arsenic-laden health water. Mot hers even lead small ch ildren to sip from

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42 the springs. Due to the staunch belief t hat these waters ar e beneficial and the absence of a problem with suspended solids Hierve el Agua was not considered as a test community. 3.4. Temamatla Temamatla was the community chosen for study due to its dual contamination of arsenic and suspended solids from volcanic sources and a suspected collapsed well, respectively. Temamatla lies 25 miles southeast of Mexico City, providing fairly easy travel to the study site by collaborators in Mexico City and their Tam pa counterparts. Most co mmunity members obtain their drinking water from a centralized we ll due to limited water resources. City workers deliver water to households on a regular basis where it is stored in 55 gallon water barrels and used for all of the households water needs (Figure 9).

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Figure 9: Typical Household Water Storage and Usage Area for Low-income Families in Temamatla. 3.5. Socio-Cultural Impact Assessment in Temamatla 43 USF Anthropologist, Dr. Davis-Salaza r, directed the second step crucial to our success: socio-cultural impac t assessment. This is a necessary component of this project because part of the motivation for this project is the use of a locally available material, namely the nopal cactus with which most rural Mexican communities are intimately fam iliar. We will create an inexpensive, straightforward process with this material that local communities will be able to use, and will want to use. However, in developing countries non-locally designed

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44 water systems have had minor success in terms of performance and sustainability due to limited community par ticipation, and, more specifically, a failure to integrate local knowledge, customs, and belie fs in system design and implementation, particularly in rural areas of Latin Americ a. In other parts of the world, most notably Bangladesh, arsenic mitigation projects, specifically, have identified important so cial and cultural factors that affect the degree of success of such projects. These factors include the value placed on water quality by the local community, the communitys level of knowledge concerning the health consequences of arsenic-contaminated water, the degree of compatibility between the organizational requi rements of the water tec hnology and the social and political structures of the local community, and gender and age-based differences in household water use and expo sure to arsenic-contaminated water. Anthropology, defined by its holistic approach to the st udy of the human experience, is in a unique position to integrate loca l knowledge and experience with empirical data to develop socially informed and culturally sensitive water supply and treatment programs. In Temamatla, the site of our pilot study, our water tests indicate arsenic levels above normal. Residents, however, remain very concerned about their water quality and, therefore, are very receptive to our efforts. Interestingly, a comment made by the mayor of the town indicates that any remediation efforts in Temamatla should be readily apparent th at is, visible to the local residents because they will want proof that action has been taken to solve the problem. This indicates that the water treatment process we design for Temamatla must

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45 be somewhat physically conspicuous. USF anthropologists determined that Temamatla citizens preferred a domestic f ilter for use by individual households out of convenience due to existing drinki ng water infrastructure and a certain amount of distrust of community officials. It was also determined that a filter based on a Mexican cactus that grows abundantly in the community and across the country would be more readily accept ed than a chemical-based filter design. We were able to interview the locals and speak with the mayor of the city. We obtained very positive responses to our project because there is a collective awareness about water quality. Additio nally, the people responded exceptionally well to the project socially because we explained that we w ould be utilizing the nopal plant to remediate their problem. They know the plant; they use it regularly in their diet and know its availability in the region. As a final phase of the planning grant, we will design a filter-kit for the main well. This is something that is feasible since the line is centralized and it is already maintained by two state workers from 5am to 10pm daily. Economically, this is a better solution than implementing the filte r-kits domestically since we will have to train only the two workers and because the water flow is relatively small (20 L s-1). We expect that each community for this project will design specific solutions according to their needs. 3.6. Implications for This Project The results of the soci o-cultural assessment provided more design boundaries for this project. In summary, a culturally accepted water treatment

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46 method would be one in an in-home filter form with te chnology based on native Mexican cactus. Also, a centralized treatment system placed at the drinking water source would be an acceptable, economic application with respect to the culture of Temamatla. Most importantly, to maintain community trust and interest in the project, visibility is key.

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47 Chapter Four The Mexican Cactus as a Natural Technology for Water Treatment 4.1. Current Options: Natural Technologies USEPA-recognized natural technolog ies for water treatment are all considered emerging tec hnologies by the a gency. They acknowledge two very different biological treatment options : phytoremediation and microbiological removal processes. Phytor emediation exploits some pl ants natural ability to remove heavy metals through root uptake, and microbi al processes use microbes that can aid in the precipitati on/coprecipitation of arsenic either by producing conditions supporting precipitation or by converting arsenic to species that are easier to remove [12]. Phytoremediation is a viable technology for sm all-scale water sources serving communities of less than 10,000 people. Elless et al. 2005, demonstrated this technology in New Mexico, employing Pteris vittata ferns with root systems submerged in contaminated wate r. `Throughputs as high as 1944 L day-1 were treated and resulti ng arsenic levels were lower than the detection limit of 2 g L-1. However, the initial c ontamination nev er exceeded 14 g L-1 [43]. This technology would have to be evaluat ed further in order to treat sources with higher levels of arsenic contamination.

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48 Other plants investigated for use in phytoremediation are poplar, cottonwood, sunflower, Indian mustard, and corn [12]. This is a technology highly dependent upon agricul tural factors such as temperature, sunlight, seasons, etc. These variables can be controlled by treating the water in a greenhouse environment with a cont rolled environment [12]. Microbiological removal processes ex ploit sulfate-reducing and arsenicreducing bacteria to create im proved conditions for precip itation/coprecipitation. A simple schematic of a typical biologica l treatment process is shown in Figure 10 [12]. Katsoyiannis et al. 2004, used bacteria native to iron-rich groundwaters in an upflow packed-media filter to remo ve iron and arsenic from drinking water [44]. The two most prevalent bacteria were Gallionella ferruginea and Leptothrix ochracea The two most important factors in their biologica l treatment were redox potential and dissolved oxygen concentration. A redox potential of 320 mV was optimal for the removal of As, specific ally in the trivalent form. Residual As values were always below 5 g L-1 at this redox potential. This is due to oxidation of As(III) to its pentavalent form at this redox potential [44].

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Figure 10: Schematic of a Typical Microbiological Arsenic Treatment Unit. The successes of phytoremediation and microbiological treatment for arsenic removal are promising, giving weig ht to both of these emerging fields. There are currently no natural flocculants used for the removal of arsenic to the best of our knowledge. 4.2. Proposed Source of Natural Flocculant: Opuntia ficus-indica The genus Opuntia is the largest under the Cactaceae family. Varieties of Opuntia can be found from Wester n Canada south to the tip of South America. The Opuntia species chosen as a flocculant source for this project, Opuntia ficus indica also known as nopal or prickly pear, is commonly found and cultivated in Mexico where it grows in tree-like proportions (Figure 11). The nopal cactus was 49

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chosen as a flocculant source based on its ubiquity in Mexico and due to the Mexican peoples familiarity with the nontoxic cactus. There is also previous empirical knowledge of the nopal being used since ancient times in Latin America to reduce turbidity and hardness in natural spring waters [45]. Figure 11: An Example of Opuntia Growing as a Tree in Mexico. 4.2.1. Current Uses Opuntia ficus-indica is widely used for its nutritional value. It is used as a fruit crop and a vegetable crop for human c onsumption [46, 47], and as a forage crop for livestock in drought conditi ons [46]. The fruit of the Opuntia is commonly referred to as tunas, their Spanish name [48 ]. Typically, the fruit is dried for use during the winter, but sometimes a sauce is made from boiled, unripe fruits. They are also used for their skins, (f ood coloring), their syrup (tuna honey), fermented and nonfermented be verages, and in the dri ed form as tuna cheese [49]. The seeds of the tuna have also been ground and used as a meal by some American Indians. The fruits have been shown to be a source of sugars (15% 50

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51 sugars and 85% water) and even a source of small amounts of Vitamin C. They typically have a pH around 6.5 and are rich in calcium and phosphorous [46]. The advantage of using Opuntia as a fruit crop is the ab ility to grow cactus in otherwise unfertile, rocky soil. Crop concentrations of 20,000 kg of fruit hectare-1 have been produced, which equates to about 2,800 kg of sugar [48]. The use of Opuntia as a vegetable crop is less popular. Typically, only the young joints of the cactus (nopalitos) are used as a vegetable in Hispanic households [50]. They are typically cook ed as a green vegetable or marinated as part of a salad [46]. The cactus skin and thorns can be easily removed, leaving the edible insides of the cactus pad [51]. Opuntia pads have been shown to be made up of 87% water, 1% protein, 0.1% fat, 1.3% ash, 1.1% crude fiber, and 5.4% carbohydrates [50]. In drought conditions, when grasses and other forage crops are no longer edible, the Opuntia cactus remains green and is used as an emergency feed crop for ranging livestock in both the s outhwestern United States and Mexico [51]. The spines are burned off, soaked in water, or washed with soda to eliminate their harmful effects on the liv estock. Sheep have lived for up to 8 months eating entirely Opuntia [46]. Opuntia is not used exclusively as a food source. They are popular as ornamental and hedge plants and the stem of the cact us is used in producing decorative elements [46].

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52 4.3. The Mucilage of Opuntia ficus-indica The mucilage of O puntia ficus-indica is a thick, gummy substance and is what provides the cactis natural ability to store large amounts of water. When in water, the mucilage swells, producing uniq ue surface-active properties seen in many natural gums, giving the mucilage a suspected ability to precipitate particles and ions from aqueous solutions. The mucilage is extracted from the pads of the cactus. Diced nopal cladodes have been used for centuries in Latin America as a primitive technology for th e rapid flocculation of turbid natural spring waters, but a scientific baseline has never been provided for this observed phenomenon [45]. 4.3.1. Chemical Composition The mucilage of Opuntia ficus-indica is composed of 55 sugar residues including arabinose, rhamnose, galacto se, and xylose, and some, specifically Burbanks cv Spineless, show fractions of glucans and glycoproteins [52]. The mucilage of Opuntia ficus-indica has been a source of some confusion amongst investigators [45]. The molecular weight of the mucilage has been reported as different values, probably also due to differences in extraction techniques and the possibility of contaminant s [45]. In 1981, Tracht enberg and Mayer reported a molecular weight of 4.3 106 g mol-1 [53], but a study by Crdenas et al. in 1997, reported a value of 3 106 g mol-1 [54], and in 2000, Medina-Torres et al. reported 2.3 106 g mol-1 [53-55].

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53 In 2001, Madjoub et al isolated two separate mucilage fractions, calling one the high weight sample (HWS) wit h a molecular weight of 13 106 g mol-1 and the other the low weight sample (LWS) with a molecular weight of 3.9 103 g mol-1 [56]. The HWS was determined to make up about 10% of the total mucilage content and was devoid of proteins. It c ontained about 20% charged sugar [56], leading to the possibility of it s potential to interact with divalent cations [45]. The sugars detected in the HWS were the same as reported previously in the literature and in this thesis. Madjoubs LWS was determined to be co mposed mostly (~80%) of protein with a nitrogen composition of 2.2% [56] helping to confirm the presence of glycoproteins in mucilage. Table 4 summa rizes research results on the chemical constituents of Opuntia mucilage. Table 4: Differences in Detected Muc ilage Properties: Molecular Weight and Sugar Content. Author MW (g mol-1) Galactose Rhamnose Arabinose Xylose Uronic acid Galactose/ Arabinose Crdenas et al (1997) [54] 3 106 + + + + Trachtenberg & Mayer (1282) [57] 1.56 106 McGarvie and Parolis (1981) [58] + + + + + McGarvie and Parolis (1981) [59] + + + 1.5/3 Trachtenberg & Mayer (1981) [53] 4.3 106 + + + + + 4.9/3 McGarvie and Parolis (1979) [60] + + + + + 1.3/3 Paulsen and Lund (1979) [61] + + + + + 2.3/3 Saag et al. (1975) [62] + + + + + 3.5/3

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McGarvie and Parolis studied the chemic al structure of the mucilage and proposed the structure represen ted in Figure 12, with R indicating the presence of different arabinose and xylo se forms, D-Gal indicating D-galacturonic acid, Gal indicating galactose, and Rha indicating Rhamnose [45, 58, 59]. Figure 12: McGarvie and Parolis's Propos ed Mucilage Structure, Taken from Senz, 2004. 4.3.2. Extraction Techniques The mucilage was extracted prior to t he inception of the portion of the project described by this thesis. What fo llows is an overview of the techniques used to extract the mucilage used in the flocculation and arsenic removal project. The cactus pads used for the gelling extr act (GE) and the nongelling extract (NE) were cut from plants obtained from Li ving Stones Nursery, Tucson, Arizona and pads used for the combined extract (CE) were obtained from Blue Diamond Nursery, Las Vegas, Nevada. They were then potted and allowe d to acclimate in direct sunlight before the mucilage was extracted. 54

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55 In total, three types of mucilage we re extracted. A modified method detailed by Goycoolea and Crdenas was us ed to obtain GE and NE [63], and CE, consisting of GE & NE, was obtaine d using the method outlined by MedinaTorres et al. [55]. All mucilage types extr acted were stored dry and at room temperature. Gelling and Nongelling Extracts The Goycoolea and Crdenas method was used as a guideline in extracting the GE and NE used in the flocculation and arsenic experiments. However, changes were made in order to maximize mucilage extraction. The actual procedure implemented is outlined in Figure 13 with boxes highli ghting the modified steps.

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Figure 13: Modified Goycoolea and Crdenas Extraction Method. Combined Extract The Medina-Torres et al. 2000, method [55] is a modified version of a method used by McGarvie and Parolis in 1979 [55, 60]. Two nopal pads were macerated in a blender and the resulting solids and liquid supernatant were separated in a centrifuge at 4000 rpm. The resulting supernatant was collected and mucilage was precipitated with a 1:2 ratio of pulp to acetone. The acetone was decanted and the precipitate was washed with a 1:1 volume ratio of precipitate to isopropanol. The resulti ng precipitate was ai r dried on a watch glass. 56

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57 4.3.3. Current Applications Opuntia mucilage has been extract ed and evaluated for uses including dietary fiber [64], medicinal [65-69], digestive [70, 71], lime mortar additive [72], and emulsifying agents [73]. The Opuntia is used as a food source by many Latin Americans and the mucilage component of Opuntia contributes to the dietary fiber component of the cactus [64]. T he mucilage has also been investigated for its use in controlling blood glucose levels in diabetics and cholesterol in guinea pigs fed a high-cholesterol diet. It si gnificantly reduced both blood glucose and cholesterol levels [66-68, 74]. It has also been studied for its wound-healing abilities and was found to significantly effect healing in rats when administered topically [75]. Other non-medical uses of Opuntia mucilage have been investigated. In Mexico, nopal juice is sometimes added to lime mortar to reduce cracking and water penetration. However, in investigating nopal muci lages role in the strength of the mortar, Crdenas et al ., found that, while it may decrease water penetration and cracking, it also reduces the mechanical strength of the lime mortar [72]. The mucilage has also been suggested for use in food industries due to its efficiency in stabiliz ing oil-water emulsions [73].

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58 Chapter Five Physical and Chemical Analytical Methods 5.1. Mucilage Characteriz ation: Raman Spectroscopy Raman Spectroscopy (RS) is adept at determining functionalization of chemical structures, es pecially those of organic compounds, from their vibrational spectra. Samp les analyzed with RS can exist in either the solid, liquid, or gas states [76]. The sample s of GE, NE, and CE analyzed were in the solid phase (powder form), a condition that RS is particularly suited for since conventional Infrared Spectroscopy (IR) provides water band interference [76]. The mucilage samples were loaded in a capillary tube, inserted in the Raman Spectrometer, and their vibrational spec tra were analyzed. The system was purged with nitrogen to reduce interfer ence from ambient contaminants. 5.2. Turbidity 5.2.1. Cylinder Tests The abilities of the three mucilages (G E, NE, and CE) and aluminum sulfate to settle suspended solids were tested with standard cylinder tests [77-86]. The tests were performed with 50 g L-1 concentrations of kaolin in 100 mL graduated cylinders (control). They were treated with varying doses of mucilage extract and aluminum sulfate, and the fall of solid/liquid interface height with respect to time

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59 was recorded. High concentrations of kaolin were chosen since they mimic mud conditions and make the interface visible. 5.2.2. Jar Tests The residual turbidity of the result ing supernatant after the suspended solids have been settled is another benc hmark with which to measure the flocculation effectiveness of the three mu cilages (GE, NE, and CE). Residual turbidity tests were carried out according to standard jar test procedures [77, 84, 87-96]. They were performed with 0.5 g L-1 kaolin suspensions in a standard jar test apparatus (ECE MLM4, ECE Engin eering, Canada) consisting of four identical 500 mL compartments. 5.2.3. Light Scattering A turbidimeter (Micro 100, HF Scientif ic, North Andover, Massachusetts) was used to measure the turbidity of jar test supernatant in Ne phelometer Turbidity Units (NTU), the accepted unit of turbidit y [97]. A sodium lamp was utilized. Indexed cuvettes were filled with supernat ant and inserted in the optical well. The highest measurement was recorded as the turbidity of the supernatant. 5.3. Arsenic Removal 5.3.1. Hydride Generation Atomic Fluorescence Spectroscopy Arsenic concentrations for the singl e-dose methods were determined by hydride generation-atomic fluorescence spectrometry (HGAFS) in the Center for Water and Environmental Analysis at the University of South Florida. A

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60 PSAnalytical 10.055 Millennium Excalibur in strument was used to determine the total arsenic content of treated samples. Then, 10 mL of each 20 mL sample was added to 15 mL of concentrated hydroc hloric acid, used in HG-AFS in order to produce excess H+, and 1 mL of saturated potassium iodide to convert arsenic species to arsenite for analysis. Then, 24 mL of deionized water were added to make the final volume 50 mL [98]. Te traborohydride is then added in order to form arsenic hydride (AsH3), which is then atomiz ed in a hydrogen flame. Fluorescence spectrometry is then utilized to establish the arsenic concentration in the sample. Arsenic calibration curves are determined through the use of standards prepared with arsenic reference solutions. HG-AFS is a particularly useful technique due to the minimal pr esence of interference from matrix interactions [99]. 5.3.2. Atomic Absorption (AA) Spectroscopy Atomic absorption spectrometry was used to analyze total arsenic content in water samples. The graphite furnace (GF) technique was chosen for use in a Varian Zeeman 240Z Atomic Absorption Sp ectrometer (AAS). The GF technique is the most widely used and, as a resul t, the most well understood. In a graphite tube atomizer, there is the combination of an atmo sphere of inert gas and reducing conditions produced by inca ndescent graphite that makes this technique perfect for analyzing pure analytes Also, GF technique provides a longer residence time (two to three time s greater than flam e atomic absorption spectroscopy), leading to less interferences [100].

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61 Acidified arsenic samples (0.4% HNO3) were diluted by 5 with 5% Nitric Acid in order to fit within the analyza ble limits of the AAS (10 60 g L-1 As). Then, 1000 mg L-1 As standard was diluted to 10, 20, and 30 g L-1 standards and used to form the calibration curve, us ing the New Rational method for fitting. Finally, 20 l samples consisting of 15 l of diluted As samples and 5 l of a Nickel Nitrate modifier were injected into the graphite furnac e of the AAS. The contents were atomized and analyzed with the concent rations taken from absorption peak height.

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62 Chapter Six Experimental Procedures 6.1. Turbidity Experiments 6.1.1 Materials The reagents, equipment, and instruments used in the flocculation experiments performed are list ed in Table 5 and Table 6. Table 5: Reagents Used in Flocculation Experiments. Name Short Name Manufacturer Serial/Catalog No. Aluminum Silicate (hydrated) Kaolin Fisher Scientific S71954 Sodium Hydroxide NaOH Acros Organics 206060010 Aluminum Sulfate Al2(SO4)3H2O Fisher Scientific S70495 Gelling Extract GE Nongelling Extract NE Combined Extract CE Extracted according to procedures outlined in section 5.1, this thesis.

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63 Table 6: Equipment and Instruments Used in Flocculation Experiments. Name Manufacturer Serial/ Catalog No. Model No. Range Description Minimix Laboratory Mixer/Jar Test Apparatus ECE Engineering M443 ECE MLM4 Four 500 mL sample jars, 12V DC AccuSeries II Analytical Balances Fisher Scientific 13-265-220 Accu-124 Max: 120 grams Readability: 0.1 mg, taring, repeatability: 0.1 mg, linearity: .2 mg, Accumet 1003 pH Meter Fisher Scientific 1003 -6 to 20 pH Resolution: 0.1, 0.01 pH Probe Accumet 13-620-111 0 to 14 pH Accuracy: <.05 pH at 25 C Micro 100 Turbidimeter HF Scientific 40228/20001 Micro 100 0 to 1000 NTU Accuracy: 2% reading + 0.01 NTU, 30 mL sample size 6.1.2. Cylinder Test Procedure The procedure was uniform throughout each cylinder test performed according to the following step-by-step explanation. Initially, a 50 g L-1 kaolin suspension was pr oduced by diluting 5 g of powdered kaolin in 100 mL of Milli-Q water in a 100 mL glass volumetric flask fitted with a glass stopper. The volume tric flask was then stoppered and fully inverted 10 times in order to ensure t he presence of a well-mixed suspension. The suspension was then allowed to sit for 24 hours before use. After a 24 h period, the cylinder test s were performed. The suspension was mixed well by inverting the flask 10 ti mes. Then, the pH of the suspension was adjusted to 7 by adding the requi red amount of NaOH. The neutral

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64 suspension was then mixed again by inve rsion and added to a 100 mL graduated cylinder fitted with a glass stopper. Using the appropriate micropipette and micropipette tip, the desired dose of flocculant (either Al2(SO4)3, GE, NE, or CE) was added. An example of the dosage sc heme is outlined in Appendix A. The cylinder was then capped and inverted 10 times to ensure the suspension and flocculant were well mixed. The cyli nder was placed on a level surface and flocs immediately began to form and settle. T he height of the visible solid/liquid interface was then recorded with time until the flocs were fully settled 1 6.1.3. Jar Test Procedure The procedure followed for all jar tests performed was as is detailed in this section. There were four steps to performing the residual turbidity tests: suspension preparation, cuvette indexing, the jar tests, and the final light scattering measurements. Suspension Preparation Initially, a 0.5 g L-1 kaolin suspension was produced by diluting 0.5 g of powder ed kaolin in 1 L of Milli-Q water in a 1 L glass volumetric flask with a glass stopper. This dilution was repeated once in order to prepare another liter of sus pension. Each flask was in verted 10 times to ensure that the suspensions were we ll mixed. Then, the suspens ions were allowed to sit for 24 hours before use. 1 The solid/liquid interface was measured against the tic marks on the graduated cylinder. Time was recorded exactly as the interface passed a tic mark (1 cm3). The distance between the tic marks was then measured and the measured hei ght was calculated based on this interval.

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65 Cuvette Indexing Since light scattering was employed to determine the residual turbidity, it was im perative that turbidimeter cu vettes be indexed. To do this, the turbidimeter cuvette compartment was capped; the turbidimeter was turned on, and allowed to warm up for about 5 minutes. Four clean, capped turbidimeter cuvettes were chosen and the outsides were wiped to remove fingerprints and dust. The empty cuvette was inserted into the turbidimeter compartment. The cuvette was rotated fractions of a turn, stopping to allow the reading to stabilize until the lowest NTU reading was determined. Finally, this position was marked on the cuvette cap and this procedure was repeated for the other four cuvettes. Jar Tests Initially, the paddle header was remo ved from the apparatus jars. Then, a two-step procedure wa s used to fill the jars. First, one flask containing the previously prepared kaolin suspension was inverted 10 times to resuspend the kaolin. The stopper was removed and the flask was inverted over the jars, quickly filling each compartment equally 2 This was done ag ain for the second flask. Any volume difference was corrected by quickly transferring suspension from over-filled compartments to under-fille d compartments. The mixing paddle header was replaced on the jars and mixing was started at 100 rpm. The desired flocculant dose (GE, CE, or Al2(SO4)3) was then added to the jars. An example of dosage schemes is presented in Appendix A. Stirring continued for 2 minutes at 100 rpm. The speed was reduced to 20 rpm for 5 minutes. Stirring was then 2 It is imperative that the filling of the jars be performed as quickly as possible to ensure the suspension in each jar test apparatus compartment is equally mixed.

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66 stopped and the flocs formed were allowed to settle for 30 minutes. Samples of the supernatant were colle cted from each compartmen t by opening the valve set ~3 cm above the bottom of the jars an d filling a turbidimeter cuvette. The cuvettes were then inserted into the turb idimeter and aligned wit h the previously marked indexed alignment. The highest measurement was then recorded as the supernatant turbidity 6.2. Arsenic Removal Experiments 6.2.1. Materials The reagents, equipment, and instru ments used in the arsenic experiments are listed in Table 7 and Table 8. Table 7: Reagents Used in Arsenic Removal Experiments. Name Short Name Manufacturer Serial/Catalog No. Arsenic (III) Solid Arsenic (III) Oxide Acros Organics R45 28 34 50/53 Arsenic (V) Solid Arsenic (V) Oxide Acros Organics R45 23/25 50/53 Arsenic Standard As2O3H2O Hach Company 14571-42 Sodium Hydroxide NaOH Acros Organics 106060010 Aluminum Sulfate Al2(SO4)3 Fisher Scientific S70495 Nickel Nitrate Ni(NO3)6H2O Fisher Scientific N62-500 Gelling Extract GE Nongelling Extract NE Combined Extract CE Mucilage was extracted according to procedures outlined in section 5.1, this thesis. Table 8: Equipment and Instruments Used in Arsenic Removal Experiments. Name Manufacturer Serial/ Catalog No. Model No. Range Description Screw-top Glass Vials Fisher Scientific 0333921J FS60957C-4 5 mL Screw thread with PC lined cap, made from Type I, Class B borosilicate glass

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67 Table 8: Contd. Polystyrene Round Bottom Tubes Becton Dickinson 352027 8 mL Graduated with screw cap Syringe Becton Dickinson 309603 4120416 5 mL Luer-LokTM tip, latex free, single use, disposable, 1/5mL graduation Syringe Filter Fisher Scientific 09-719-A R4DN26317 25 mm 0.22 m pore size Mixed Cellulose Ester (MCE), sterile, 50/package Centrifuge Tubes Fisher Scientific 05-539-7 11197003 50 mL Sterile, polypropylene, plug seal cap AccuSeries II Analytical Balances Fisher Scientific 13-265-220 Accu-124 Max: 120 grams Readability: 0.1 mg, taring, repeatability: 0.1 mg, linearity: .2 mg, Accumet 1003 pH Meter Fisher Scientific 1003 -6 to 20 pH Resolution: 0.1, 0.01 pH Probe Accumet 13-620-111 0 to 14 pH Accuracy: <.05 pH at 25 C Atomic Absorption Spectrometer Varian, Inc. Zeeman 240Z 10 100 g L-1 Detection limit: 10 g L-1 6.2.2. Single Dose Method Procedure The arsenic tests were carried out using GE due to its convincing effectiveness as a flocculent of suspended so lids. Initial tests were performed by preparing a standard arsenic so lution from solid As(III) and As(V) stock in a 50 mL centrifuge vial, removing 20 mL bef ore sample, dosing wit h 0.10, 1.0, and 10 mg L-1 GE, inverting 10 times, and removing a 20 mL afte r sample from the top of the vial (the air-water interface) afte r 1 h. The samples were examined using hydride generation-atomic fluorescence spectrometry for total As content. In light of the data obtained, new exper iments were designed with a taller water column (300 mL of As standard prepared from a 1000 mg L-1 stock diluted

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68 to ~80 g L-1 in a 1000 mL graduated cylinder) in order to determine more precisely the As concentrati ons at the air-water interf ace. Three columns were dosed with 5 mg L-1 GE and inverted 10 times. Then, 5 mL samples were taken from the top of the column after one hour and filtered wit h 0.22 micron mixed cellulose ester syringe filt ers, acidified with 0.4 % HNO3, and tested for total As content using atomic absorpt ion spectroscopy. This series of experiments was performed at three different mucilage pH s held constant: 7, 8, and 9. Experiments were also performed in order to elicit the arsenic distribution in the water column. A 500 mL beaker containing a port at the bottom was outfitted with a 2mm nylon tube at the 250 mL level so samples could be taken from the bottom and the middle of the syst em. The system was dosed with 5 mg L-1 GE and stirred for 10 s. The system wa s then placed on a level surface. Samples were taken at 0.5 h intervals and examined with AAS. Finally, an experiment was perform ed with concentrated arsenic (10.34 mg L-1) and a high dosage concentra tion of GE (187.5 mg L-1) in a 50 mL centrifuge tube. A 20 mL sample of the arsenic solution was reserved as a before sample and 40 mL was added to the cent rifuge tube. A 15 mL dose of 0.5 g L-1 GE was added to the centrifuge tube, in verted 10 times, and a 20 mL after sample was taken from t he top. These samples we re examined with HG-AFS. 6.2.3. Optimization Procedure New arsenic tests were performed using a make-up method designed to replace spent mucilage removed from the t op of the column. A mucilage pH of 8

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69 was chosen due to its apparent superior performance in creating the arsenic concentration differential. The same 300 mL water column set-up was used with identical As stock solution and GE dosage. The column was initially dosed with 2.5 mg L-1 GE and inverted 10 times. A 5 mL sample was taken at the air-water interface after 0.5 h and treated the same as the previous test. The 5 mL sample was then replaced with 5 mL of GE at a concentration of 2.5 mg L-1 at the top of the column. This procedure was performed at 0.5 h interv als for four hours. The samples were examined using at omic absorption spectroscopy. Based on the performance of GE in removing As, a simple filter was designed consisting of 400 mL of sand in a beaker containing a port level at the bottom. The filter was init ially rinsed with 50 mL of dist illed water, allowing all of the water to drain. Then, it was dosed with 50 mL of GE at 1 mg L-1, allowing the solution to completely run through the filt er and discarding the filtrate. A 50 mL volume of a 5 mg L-1 solution prepared from As(V) solid was then poured into the filter and collected from the bottom port. The samples were then analyzed with Hydride Generation-Atomic Fluorescence Spectrometry.

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70 Chapter Seven Results and Discussion Experimental results ar e presented and discussed in this chapter. A presentation and discussion of the chemic al composition of the mucilage is followed by the results of the turbidity and arsenic st udy. An evaluation of the cultural sensitivity of t he project is then followed by an evaluation of the interdisciplinary work involved in this study. 7.1. Comparison of Extracts: Chemical Composition Raman IR analysis of GE, NE, and CE ex tracts highlighted their differences and similarities. Curiously, the spectrum for the CE matched exactl y with the NE, as can be seen in Figure 22.

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Figure 14: The Matching Spectra of CE and NE. The real differences were found to be between GE and NE (Figure 15). The NE spectrum shows a broad peak in t he isolated OH region (3600-3200 cm-1) and peaks in the region suggesting liberation m ode of residual water molecules (~800 cm-1). These are both split in the GE spectrum, suggesting two types of O-H stretching, isolated OH species and resi dual water molecules attached to the complex structure of the muc ilage with is a combination of polyethers. However, the real differences occur in areas rela ting to nitrogen bonding (Figure 15). Both show nitrile peaks between 2200 cm-1 and 2400 cm-1, but NE shows a much stronger peak. GE shows a peak in a region generally attributed to C-NH2 bonds (~1100 cm-1). We believe it is this to whic h the mucilage owes its water treating properties. 71

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Figure 15: The Spectral Differences Between GE and NE. The structures of GE and NE/CE have si milar properties of polymers that show the same functionality. Poly(eth yl cyanoacrylate), in Figure 16, shows similar structural composition to NE/CE, is known as a bonding agent, and has been investigated as a colloidal carrier of drugs. Figure 16 also shows poly(ethyl acrylamide), a polymer with similar struct ure to GE. It also exhibits similar properties as GE, such as its ability to form a gel, its use as a thickening agent, and its ability to flocculate colloidal systems [101]. Figure 16: Poly(ethyl cyanoacryla te) and Poly(ethyl acrylamide). 72

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73 7.2. A Comparison of Extracts: Flocculation 7.2.1. Settling Rate The gelling extract was found to be the best performer with respect to suspended solids removal as determined by standard cylinder tests. It out performed NE, CE, and Al2(SO4)3, a widely used chemical flocculant and benchmark for this study, whose usage co uld cause contami nation and an extra separation step in drin king water treatment. The fall in liquid-solid interface was recorded with time, and rates were measured from the linear decay portion of settling. The pH was a constant value of 7 during these experiments. The GE performed at rates 3.3 times faster than that of Al2(SO4)3 at flocculant doses of 3 mg L-1 (2.20 cm min-1 for GE versus 0.67 cm min-1 for Al2(SO4)3 in Figure 1). The control (no flocculant dose) se ttled at a rate of 0.56 cm min-1. As can be seen in Figure 18, at a GE dose of 0.01 gm L-1, the mucilage performed at a rate equivalent to Al2(SO4)3 dosed at 300 times that concentration (3 mg L-1), proving that the GE is a more effectiv e flocculent than the popular Al2(SO4)3 with respect to settling rate and requiring the use of le ss material to obtain the same results.

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Figure 17: Flocculation Rates Comparison. Figure 18: GE Compared to Al2(SO4)3. 74

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The flocculation effectiveness of all three types of mucilage with respect to settling rate increases when dosage concent ration is increased. The effect of dose concentration is illustrated in Figure 19. Figure 19: The Effect of Dose on t he Settling Rates of GE, CE, and NE. The effectiveness of the flocculants in th is study is directly related to the size of the flocs formed. Larger flocs fa ll faster under the infl uence of gravity, leading to a faster settling rate. Larger flocs require more restructuring of the settled solids in the graduated cylinders, leading to a shorter linear settling portion. As the large flocs pile up they begin to rearrange, leading to an earlier removal from the linear settling scheme. Examining the data in Figure 20, it is obvious that GE performs as a faster flo cculant due to its ability to form larger 75

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flocs than NE, CE, and Al2(SO4)3, as is evidenced by its relatively early departure from the linear scheme (5 min in co mparison to the controls 21 min). Figure 20: A Comparison Showing the Di fferences in the Linear Portion of Settling. The cylinder test results suggest that the ability of GE to form a gel, much like polyacrylamide, provides it with excellent floc-forming properties. The ability of GE to perform at the sa me efficiencies of Al2(SO4)3, at doses 300 times smaller is a testament to its attractiveness as a flocculant alternative when settling rate is a critical variable. Adding this to the fa ct that it is deriv ed from a renewable resource and is a green tec hnology supports GE, CE, or NE as viable flocculant alternatives. 76

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7.2.2. Residual Turbidity Residual turbidity is a critical aspect to the evaluation of the efficiency of a flocculant. Results of jar te sts performed with GE, CE, and Al2(SO4)3 show that while higher mucilage doses improve settling rate, they degenerate residual turbidity (Figure 21). These results s uggest that GE, CE, and NE are extremely efficient at quickly floccula ting systems, but do not completely rid the system of suspended solids. However, as is illustr ated in Figure 22, at extremely low doses (approximately 1 g L-1 and below), the mucilage prov ides residual turbidities comparable to Al2(SO4)3. Figure 21: Residual Turbidity of the Mucilages GE and CE. 77

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Figure 22: Residual Turbidity of Al2(SO4)3, GE, and CE in a Low Dose Region. These tests were performed with solu tions of very high turbidity not indicative of the turbidities found in Temamatla. Also, the suspended solids in the well water were observed to be of larger particle size than the kaolin used in this study. As a result, GE, NE, or CE would all be applicabl e in Temamatla. However, in areas with high turbidities, residual turbidity can be reduced by inexpensive secondary filtration, possibly built into the filter desi gn that is the final goal of the overall project. 78

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7.3. Gelling Extract: Arsenic Removal Efficiency 7.3.1. Single Dose Method The data from the initial single dose experiments (Figure 31) showed a variety of effects. The GE mucilage wa s definitely transporting the As in the 30 mL water column. Different concentrations showed increases of mucilage at the bottom of the column (0.1 and 37.5 mg L-1) while the others exhibited decreasing arsenic concentrations. It was conclud ed that GE was either entrapping the As and transporting it to the air-wat er interface or to the bo ttom of the column, as it did with suspended solids. Figure 23: Results of the Si ngle Dose Arsenic Tests. 79

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80 Single dose experiments with CE show ed little or no removal, so this extract was abandoned for the rest of the arsenic study. The focus shifted to eliciting the mechanism and performance of GE in removing As. Experiments designed to determine the arsenic concentration at the top of the water column, when dosed at different GE pH, revealed the action of the mucilage-As complex in the water column and exposed the optimal pH for GE As removal efficiency. The resu lts are illustrated in Figure 33 and Figure 34. At pH of 7 and 9, the GE caused a minimal aver age increase of As at the top of the water column. However, at a pH of 8, the top As concentrati on was increased by 11 g L-1. This does not agree wit h the action the GE distributed in flocculating suspended solids.

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Figure 24: Single Dose Experiments to E licit the Effect of pH on As Removal 81

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Figure 25: Average Gain in Arsenic Concentration Resulting from pH Experiment. To adequately determine the action of the GE, a tri-level experiment was designed, the results of whic h are presented in Figure 35. It is important to note that in this experiment, the samples were filtered in order to remove the entire mucilage-As complex. As a result of this procedural difference, a decrease in arsenic concentration represents t he samples containing mucilage-As complexes. The data suggests that GE does, in fact, transport the As to the top of the water column. At 1.5 h, the top concentration is at 57 g L-1, reflecting a 33% removal. After 1.5 h, the data reflects a restructuring of the As concentration profile, probabl y due to an event occurring during the sampling at 1.5 h. The system experi enced perturbation. Howe ver, at 3 h, the top concentration is 63.5 g L-1, or 26% removal. 82

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Figure 26: Results of the Tri-leve l Arsenic Distribution Experiment. The results of a concentrat ed test performed with 10.4 mg L-1 As and 65 mg L-1 GE dose seem to contradict the hy pothesis that the mucilage transports As to the top of the water column. A removal of 41% As was found at the top with this experiment, using HG-AFS, keeping in mind that an increase in As at the top of the column would have transla ted to As removal since these samples were not filtered. It s eems that at high concentrati ons, the mucilage-As system reaches a critical concentration, changing conformation and actually sinks to the bottom of the water column. This is corroborated by visual inspection in a reproduction of this test performed in a graduated cylinder. Shin y, solid particles can be seen entrapped in the mesh of the GE and sinking to the bottom (Figure 27). These solid particles could be As or simply small air bubbles trapped in the 83

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sinking mucilage, each demonstrating t he action of the mucilage at high concentrations. Figure 27: Solid Particles Observed in High Concentration As and GE Systems. The results of preliminary filter tests are presented in Figure 36. This demonstrates the ability of GE to be used in a filter form with a silica matrix. This quick, crude experiment exhibited an As re moval of 3%. The results from the single-dose tests suggest that as much as 41% removal could be obtained if the filter design and mucila ge dosage are optimized. 7.3.2. Optimization The optimization data in Figure 37 conf irms what was found in the tri-level experiment of Figure 35. The data show s a lag time of 1.5 h before a decrease in As concentration. As removal of 35% was reached afte r 3 h, compared with 33% in the tri-level experiment. This lag time is a result of the GE-As complex diffusing to the air-water interface. This lag time will depend on water column height. As was seen in the tri-level experiment, perturbing the water column 84

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disturbs the As concentration profile. For the optimization experiments performed where they were shaken each ti me after they were dosed there was no lag or removal exhibited due to the inabili ty of the GE to di stribute in the water column. Figure 28: Results of the Optimization Ex periments Illustrating the Importance of Settling Time. 7.4. Cultural Sensitivity The delimitations of this st udy were laid out in section 1.5 of this thesis. They consisted of guidelines aimed at keep ing the project in the realm of cultural sensitivity. To summarize, in order to be culturally sensitive with respect to lowincome, indigenous communities, the projec t must provide a technology that is simple, easily produced, and inexpensive, employ indigenous or easily 85

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86 accessible materials, and have a rural focus. The results of keeping within these guidelines are listed below. Simplicity The extraction techniques for GE mucilage are extensive and difficult. However, now that the Opunt ia mucilage has been identified as a flocculant, simple extraction techniques can be explored if extraction is to be done by communities. If the mucilage is ex tracted by a third party and provided to the community members, the actual tr eatment techniques consisting of simple dosing and decanting techniques are simple and universally known.Reproducibility This technology is extremely reproducible. The GE is derived from a renewable resource, t he Opuntia ficus-i ndica that grows abundantly in arid and semi-arid regions. The project has at no point departed from the Opuntia cactus as a flocculant source, for the very reason that it is a renewable resource. Cost Expensive treatment techniques have never been introduced into this study. The most cost-intensive step of the procedure exists in extraction. However, it remains to be determined if macerated Opuntia cladodes can be used for As removal and to what extent. If that were the case, no expensive extraction step would be required. Materials All materials employed in this proposed technology are familiar to community members in our target community and any other community in an arid or semi-arid region. Rural Focus The focus of this study has always been the community members of the rural town of Temamatla, Mexico. Using GE for water treatment

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87 is an easy method not requiri ng any hard labor or materials unavailable to rural individuals. 7.5. Interdisciplinary Collaboration This extensive project has successf ully overcome challenges found in both multidisciplinary and in ternational collaborations. We found the five major challenges to the project were not only due to the complexities of the international aspect of the problem, as might be expected, but also arose due to some unexpected difficultie s in dealing between the di sciplines of engineering, anthropology, and geology. They are as follows: Building, maintaining, and improving rapport between all parties involved Creating project legitimacy in the eyes of all disciplines involved. Making and sustaining valuable relationships amongst departmental, cultural, and intellectual differences Cultural sensitivity including disciplinespecific vernacular, viewpoints, research methods, and principles Sustaining future involvement after each aspect of the project is complete Re-imagining borders between the disciplines can break down these hurdles in the way of success. In this section, suggestions and observations, more adequately described as lessons le arned are offered for the improvement of current and future interdiscipl inary, international projects.

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88 It may seem obvious that a positive rapport must be achieved for success when interacting with communities in diffe rent countries, but it can be taken for granted that a rapport must be established and maintained amongst the research group members. This relationship can be established through group meetings and maintained through const ant communication. Email list serves can facilitate communication of ideas, concerns, and info rmation. Make sure to include every team member in important co mmunications and meetings. When dealing with community members in any setting, one must instill a feeling of urgency or legitimacy in order to gain support from the community. This same attitude should be applied to in terdisciplinary relationships. In our project we are chemical engineers work ing with anthropologists who are helping to focus our research toward meeting a communitys technological need. The engineering discipline is traditionally st eeped in quantitative data and eschews or simply does not understand t he benefits of qualitative dat a that anthropological expertise can provide. It becomes the data owners responsibility to relay the legitimacy of their data with respect to t he goals of the project. In asking an anthropologist to describe their interactions with engineers one can expect a multitude of responses both positive a nd negative. These difficulties in communicating legitimacy between disciplines can easily be overcome. Start with choosing indivi duals from other disciplin es that have experience working with your discipl ine. Often, those with experience have developed personal ways to overcome these difficu lties. In our case, we chose an anthropologist specialized in applied anthropol ogy in the area of water quality.

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89 She is adept at collecting useful qualitative dat a and especially a dept at relaying that data in a manner that communi cates its legitimacy and subsequent applicability to engineering principles. Also, make an effort to understand the diverse disci plines involved in the project. Start by reading publ ications from the other disciplines. If possible, find articles pertaining to the research subject. This can give a good idea of what can be expected out of the research team me mbers. Strides in the direction of legitimacy and rapport can be made by produc ing a small amount of high-impact reading material on the research subject from your field of interest to the team members from other disciplines. From the engineering per spective, difficulties can arise when attempting to explain the importance of numerical data to those who are not on the same mathematical or scientific level. Patience is key in overcoming this hurdle. In presenting data, eliminate supporting data that does not directly support the research findings. Also, detailing ex perimental procedures when dealing with nonscientists can be tedious and tiresome for your audience. In this case, simplification is key in facilitating the legitimacy of your data and suggestions for further work. Cultural differences abound in both international and interdisciplinary relationships. Cultural sensitivity can provide a way to re-imagine and bridge these boundaries. Languages are not only di fferent from one nation to the next but also between disciplines. Vernacul ar from one engineerin g subject to the next differs, as well as from engineering to science and social sciences. Reading

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90 publications from other disci plines can also help familiarity. Be prepared to answer questions about the meaning of terms used and do not be shy answering questions. Sustaining involvement of all research team mem bers can be a problem in every endeavor. However, in interdiscip linary work, this problem is exacerbated by all the aforementioned inher ent difficulties. Taking steps to improve rapport, legitimacy, team relations, and cultural se nsitivity can be valuable in sustaining involvement.

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91 Chapter Eight Conclusions and Future Work 8.1. Summary of Findings The three mucilage fractions (GE, CE, and NE) of Opuntia ficusindica are efficient flocculants with respect to settling rate when compared to the flocculating abilities of the widely used chemical flocculant Al2(SO4)3. The GE fraction of the mucilage prov ides the fastest settling rate of suspended solids. In comparison to Al2(SO4)3, GE flocculates at a rate 3.3 times faster when both are dosed at 3 mg L-1 in a 5 g L-1 kaolin slurry. GE provides a comparable settling rate to Al2(SO4)3 when dosed at a concentration 300 ti mes less than the required amount of Al2(SO4)3. The efficiency of the three extracts is directly related to their flocforming abilities. GE is a better flocculant because it produces the largest flocs. Settling rates increase with increasing mucilage dose concentrations.

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92 Residual turbidity increases with increasing mucilage dose concentrations. Mucilage doses less than 1 g L-1 provide comparable residual turbidities with Al2(SO4)3. The GE fraction of Opuntia ficus-indica mucilage is a promising arsenic removal agent. When added to arseniccontaminated water, GE forms a complex with the As and floats to t he air-water interface. Arsenic removals of 33% and 35% were found for systems containing between 80 and 90 g L-1 As and dosed with 5 mg L-1 GE. 41% removal was found from a syst em containing high levels of arsenic (~10 mg L-1) and dosed with high conc entrations of GE (~65 mg L-1). In this system, the GE-As comp lex appeared to sink to the bottom of the water column, sug gesting that high levels of As and high levels of GE perform more closely with the action of GE and suspended solids. Preliminary results suggest the muc ilage of Opuntia ficus-indica can be utilized in filter form as a pr omising technology for arsenic removal. The abilities of Opuntia ficus-indica to flocculate and remove arsenic are due to the chemical composit ion of the three fractions.

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93 The compositions of NE and CE are very similar and show similar functionality to poly(et hyl cyanoacrylate). It is suggested that the possible nitril e functionality contributes to the flocculation abilities. The composition of GE is differ ent from that of NE and CE, and show similar functionality and properties of poly(ethyl acrylamide). It is sugges ted that the aliphatic amine functionality contributes to its abilities in flocculation and arsenic removal. The cultural sensitivity of low income, indigenous communities was preserved during this study. Suggestions for further interdisci plinary endeavors were extracted from the experiences of this study in the following forms: Build rapport Create and preserve project legitimacy Sustain relationships Respect interdiscipline cultural differences Sustain future involvement 8.2. Future Work 8.2.1. Mucilage Extraction Efforts must be implement ed in the direction of simplifying the mucilage extraction procedures. In or der for the overall project to succeed in its goals of

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94 cultural sensitivity and low socio-cultur al impact, the extraction procedure should be simple enough to be performed in a low-income household. 8.2.2. Flocculation Optimal dosage schemes must be det ermined for the combined goals of fast settling rate and low residual turbid ity. Also, different slurry components should be used to determine the versatility of the mucilage. One of the slurry components should be sediment from the Temamatla well water. 8.2.3. Arsenic Removal An intense arsenic removal investigat ion should be undertaken to elicit the effects of the following variables on the ab ility of mucilage to remove arsenic from contaminated water: Arsenic concentration Mucilage dose System pH Mucilage fraction (GE, NE, CE, or simply macerated and filtered cladodes) Temperature Conductivity Arsenic speciation

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95 8.2.4. Filter Design An engineering study is required to determine the appropriate filter design for combined arsenic and suspended solids removal using Opuntia mucilage. Some of the design parameters requi ring investigation are as follows: Filter type Filter matrix Required throughput Required mucilage concentration Appropriate regeneration scheme 8.2.5. Temamatla Implementation The resulting implementable technology will be introduced to the people of Temamatla and a socio-cultural impac t assessment will be performed to determine the applicability of the technolog y, as well as the feasibility of the technology having a sustained impact. Also the performance of the technology must be evaluated in a real-world setting. 8.3. Final Remarks Opuntia ficus-indica muc ilage is a promising actor in the field of emerging technologies for arsenic removal. The imp lications of this project are exciting. The possibility of introducing an indigenous material as an improver of quality of life and health to concerned residents is attr active from a cultural sensitivity and sustainability standpoint.

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96 References 1. Sobsey, M.D., Managing water in the home: accelerated health gains from improved water supply. 2006, (WHO) World Health Organization: Chapel Hill, CA. 2. WHO (World Health Organization), Acceptibility Aspects in Guidelines for Drinking-water Quality. 2004. 3. Bartram, J., Foreward in Managing water in the ho me: accelerated health gains from improved water supply 2006, (WHO) World Health Organization: Geneva, Switzerland. 4. Smedley, P.L. and D.G. Kinniburgh, Source and Behavior of Arsenic in Groundwater. WHO Arsenic Overview, 2003: p. 1-61. 5. Yamamura, S., J. Bartram, M. Csanady, H.G. Gorchev, and A. Redekopp, Drinking Water Guidelines and Standards. 2003: p. 1-18. 6. Stollenwerk, K.G., Geochemical Processes Controlling Transport of Arsenic in Groundwater: A Review of Adsorption in Arsenic in Groundwater: Geochemistry and Occurrence A.H. Welch and K.G. Stollenwerk, Editors. 2003, Kluwer Academic Publishers: Norwell, MA. p. 67-100. 7. NRC (National Research Council), Arsenic in Drinking Water: 2001 Update. 2001, Washington, DC: Na tional Academy Press. 8. WHO (World Health Organization). Water-related diseases 2001 [cited 2006 April 9]; Available from: http://www.who.int/water_sanitation_health/diseases/arsenicosis/en/print.h tml. 9. NRC (National Research Council), Arsenic in Drinking Water 1999, Washington, DC: National Academy Press.

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97 10. WHO (World Health Organization). Treating turbid water Household water treatment and safe storage 2006 [cited 2006 January 29, 2006]; Available from: http://www.who.int/ household_water/research/turbidity/en/. 11. Shaban, W.A.R., C. F. Harrington, M. Ay ub, and P.J. Harris, A biomaterial based approach for arsenic removal from water. J. Environ. Monit., 2005. 7(4): p. 279-282. 12. EPA (Environmental Protection Agency), Arsenic Treatment Technologies for Soil, Waste, and Water. 2002, Environmental Protection Agency. p. 1-1 16-4. 13. Johnston, R., H. Heignen, and P. Wurzel, Chapter 6: Safe Water Technology in WHO Arsenic Overview 2001. 14. EPA (Environmental Protection Agency), Regulations on t he Disposal of Arsenic Residuals from Drinking Water Treatment Plants 2000, Office of Research and Development. 15. Tidwell, L.G., J. McCloskey, M. Gale, and P. Miranda. Technologies and Potential Technologies for Removi ng Arsenic from Process and Mine Wastewater in REWAS '99 1999. San Sebastian, Spain. 16. EPA (Environmental Protection Agency), Technologies and Costs for Removal of Arsenic from Drinking Water 2000, Environmental Protection Agency. 17. Ahmed, M.F. An Overview of Arsenic Removal Technologies in Bangladesh and India in BUET-UNU International Workshop on Technologies for Arsenic Removal from Drinking Water 2001. Dhaka, Bangladesh. 18. Pierce, M.L. and C.B. Moore, Adsorption of Arsenite and Arsenate on amorphous iron hydroxide. Water Resources, 1982. 16: p. 1247-1253. 19. Rapid Assesment of Household Level Arsenic Removal Technologies Bangladesh Executive Summary 2001, BAMWSP, DFID, WaterAid. p. 124. 20. Mok, W.M. and C.M. Wai, Mobilization of Arsenic in Contaminated River Water in Arsenic in the Environment J.O. Niragu, Editor. 1994, John Wiley & Sons, Inc.: New York.

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98 21. Sarkar, A.R. and O.T. Rahman. In-situ Removal of Arsenic-Experiences of DPHE-Danida Pilot Project in BUET-UNU International Workshop on Technologies for Arsenic Remo val From Drinking Water 2001. Dhaka, Bangladesh. 22. Young, E., Cleaning up arsenic and old waste (using sunlight and air to remove arsenic). New Scientist, 1996. 152: p. 22. 23. Sharmin, N. Arsenic Removal Processes on Trial in Bangladesh in BUETUNU International Workshop on Technologies for Arsenic Removal from Drinking Water. 2001. Dhaka, Bangladesh. 24. Oh, J.I., K. Yamamoto, H. Kitawa ki, S. Nakao, T. Sugawara, M.M. Rahman, and M.H. Rahman, Application of low-pressure nanofiltration coupled with a bicycle pump for the tr eatment of arsenic-contaminated groundwater. Desalination, 2000. 132: p. 307-314. 25. Hoque, B.A., M.M. Hoque, T. Ahmed, S. Islam, A.K. Azad, N. Ali, M. Hossain, and M.S. Hossain, Demand-based water options for arsenic mitigation: an experience from rural Bangladesh. Public Health, 2004. 118: p. 70-77. 26. Simeonova, V.P., Pilot study for arsenic removal. Water Supply, 2000. 18(1/2): p. 636-640. 27. Carrillo, A. and J.I. Derever, Adsorption of arsenic by natural aquifer material in the San Antonio-El Tr iunfo mining area, Baha California, Mexico. Environ. Geol., 1998. 35(4). 28. Ongley, L.K., M.A. Armienta, K. Heggeman, and A.S. Lathrop, Arsenic removal from contaminated water by the Soyatal Formation, Zimapn Mining District, Mexico a potential lo w-cost low-tech remediation system. Geochemistry: Exploration, Environment, Analysis, 2001. 1(1): p. 23-31. 29. Elizalde-Gonzlez, M.P., A.J. Mattuschb, and R. Wennrich, Application of natural zeolites for preconcentration of arsenic species in water samples. J. Environ. Monit., 2001. 3: p. 22-26. 30. Pinon-Miramontes, M., R.G. Bautis ta-Margulis, and A. Perez-Hernandez, Removal of arsenic and fluoride from drinking water with cake alum and a polymeric anionic flocculant. Fluoride, 2003. 36(2): p. 122-128.

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99 31. Gutierrez-Avila, h., S. Becerra-Win kler, H. Brust-Carmona, J. JuarezMendoza, and J. Juarez Patino, Removal of arsenic from water for humna consumption in homes in rural communities in the Comarca Lagunera, Mexico. Salud Pblica de Mxico, 1998. 31(3). 32. Parga, J.R., D.L. Cocke, J.L. Valenzuela, and J.A. Gomes, Arsenic removal via electrocoagulation from heavy metal contaminated groundwater in La Coma rca Lagunera, Mxico. Journal of Hazardous Materials, 2005. B124: p. 247-254. 33. Clifford, D. and C.C. Lin, Arsenic(3) and arsenic (5) removal from drinking water in San Ysidro, New Mexico. 1991, EPA (Environmental Protection Agency): Cincinnatti, OH. p. 119. 34. Flores-Tavizn, E., M.T. Alarcn-He rrera, E. Gonzlez, and E.J. Olgun, Arsenic Tolerating Plants from Mine Si tes and Hot Springs in the SemiArid Region of Chihuahua, Mexico. Acta Biotechnol., 2003. 23(2-3): p. 113-119. 35. Razo, I., L. Carrizales, J. Castro F. Diaz-Barriga, and M. Monroy, Arsenic and Heavy Metal Pollution of Soil, Water, and Sediments in Semi-Arid Climate Mining Area in Mexico. Water, Air, & Soil Polution, 2004. 152(1-4): p. 129-152. 36. Armienta, M.A., G. Villaseor, R. Rodrguez, L.K. Ongley, and H. Mango, The role of arsenic-bearing rocks in groundwater pollution at Zimapn Valley, Mxico. Environ. Geol., 2001. 40: p. 571-581. 37. Meja, J., L. Carrizales, V.M. R odrguez, M.E. Jimnez-Capdeville, and F. Daz-Barriga, Un mtodo para la evaluaci n para la salud en zonas mineras. Salud Pblica de Mxico, 1999. 42: p. 132-140. 38. Mndez, M. and M.A. Armienta, Arsenic phase distribution in Zimapn mine tailings, Mexico. Geofsica Internacional, 2003. 42(1): p. 131-140. 39. Armienta, M.A., R. Rodrguez, A. Aguayo, N. Ceniceros, G. Villaseor, and O. Cruz, Arsenic Contamination of Grou ndwater at Zimapn, Mexico. Hydrogeology Journal, 1997. 5(2): p. 39-46.

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100 40. Del Razo, L.M., G.G. Garcia-Vargas, J. Garcia-Salcedo, M.F. Sanmiguel, M. Rivera, M.C. Hernandez and M.E. Cebrian, Arsenic levels in cooked food and assessment of adult dietary in take of arsenic in the Region Lagunera, Mexico. Food and Chemical Toxico logy, 2002. 40: p. 14231431. 41. Pineda-Zavaleta, A.P., G. Garca-Var gas, V.H. Borja-Aburto, L.C. AcostaSaavedra, E.V. Aguilar, A. Gme z-Munoz, M.E. Cebrin, and E.S. Caldern-Aranda, Nitric oxide and superoxide anion production in monocytes from children exposed to arsenic and lead in region Lagunera, Mexico. Toxicology and Applied Pha rmacology, 2004. 198: p. 283-290. 42. Hewitt, W.P., Hierve el Agua, Mexico: Its Water and Its Corn-Growing Potential. Latin American Antiquit y, 1994. 5(2): p. 177-181. 43. Elless, M.P., C.Y. Poyn ton, C.A. Willms, M.P. Doyle, A.C. Lopez, D.A. Sokkary, B.W. Ferguson, and M.J. Blaylock, Pilot-scale deomonstration of phytofiltration for treatment of ars enic in New Mexico drinking water. Water Research, 2005. 39: p. 3863-3872. 44. Katsoyiannis, I.A. and A.I. Zouboulis, Application of biological processes for the removal of arsenic from groundwaters. Water Research, 2004. 38(1): p. 17-26. 45. Senz, C., E. Seplveda, and B. Matsuhiro, Opuntia spp mucilage's: a functional component with industrial perspectives. Journal of Arid Env., 2004. 57(3): p. 275-290. 46. Mohammed-Yaseen, Y., S.A. Barringer, and W.E. Splittstoesser, A note on the uses of Opuntia spp. in Central/North America. Journal of Arid Env., 1996. 32: p. 347-353. 47. Felker, P. and P. Inglese, Short-Term and Long-Tem Research Needs for Opuntia ficus-indica (L.) Mill. Utilization in Arid Areas. J. PACD, 2003: p. 131-152. 48. Bailey, L.H., Hortus-Third 1976, New York: MacMillan Publishing Co. 1290. 49. Villareal, F., P. Ropjas-Mendoz, V. Arellano, and J. Moreno, Chemical studies on six cactus (nopal) species. Science, 1963. 22: p. 75-82.

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101 50. Rodriguez-Felix, A. and M. Cantwell, Developmental changes to composition and quality of prickly pear cactus cladodes (nopalitos). Plants, Food, and Human Nutrition, 1988. 38: p. 83-93. 51. Russell, C.E. and P. Felker, The prickly pear (Opuntia spp., Cactaceae): A source of human and animal food in semi-arid regions. Economic Botany, 1987. 41: p. 433-445. 52. Amin, E.S., O.M. Awad, and M.M. El-Sayed, The mucilage of Opuntia ficus indica. Carbohydrate Research 1970. 15: p. 159-161. 53. Trachtenberg, S. and A.M. Mayer, Composition and properties of Opunita ficus indica mucilage. Phytochemistry, 1981. 20: p. 2885-2668. 54. Crdenas, A., I. Higuera-Ciapara, and F. Goycoolea, Rheology and aggregation of cactus (Opuntia ficus indica) mucilage in solution. J. PACD, 1997. 2: p. 152-159. 55. Medina-Torres, L., E. Birto-De La Fuente, B. Torrestiana-Sanchez, and R. Katthain, Rheological properties of the mucilage gum (Opuntia ficus indica). Food Hydrocolloids, 2000. 14(5): p. 417-424. 56. Madjoub, H., S. Roudesli, L. Piction, D. Le Cerf, G. Muller, and M. Grissel, Prickly pear nopals pectins from O puntia ficus indica physico-chemical study in dilute and semi-dilute solutions. Carbohydrate Polymers, 2001. 46: p. 69-79. 57. Trachtenberg, S. and A. Mayer, Biophysical properties of Opuntia ficus indica mucilage. Phytochemistry, 1982. 21: p. 2835. 58. McGarvie, D. and P.H. Parolis, Methylation analysis of the mucilage of Opuntia ficus indica. Carbohydrate Research, 1981. 88: p. 305-314. 59. McGarvie, D. and P.H. Parolis, The acid-labile, peripheral chains of the mucilage of Opuntia ficus indica. carbohydrate Research, 1981. 94: p. 5765. 60. McGarvie, D. and P.H. Parolis, The mucilage of Opuntia ficus indica. Carbohydrate Research, 1979. 69: p. 171-179.

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102 61. Paulsen, B.S. and P.S. Lund, Water-soluble polysacc harides of Opuntia ficus indica cv "Burbank's Spineless". Phytochemistry, 1979. 18: p. 569571. 62. Saag, K.M.L., G. Sanderson, P. Moyna, and G. Ramos, Cactaceae mucilage composition. Journal of the Science of Food and Agriculture, 1975. 26: p. 993-1000. 63. Goycoolea, F.M. and A. Crdenas, Pectins from Opuntia spp: A Short Review. J. PACD, 2003: p. 17-29. 64. Senz, C.H., Cladodes: a Source of Dietary Fiber. J. PACD, 1997. 65. Galati, E.M., M.R. Modello, M.T. M onforte, M. Ggalluzzo, N. Miceli, and M.M. Tripodo, Effect of Opuntia ficus-indica (L.) Mill. Cladodes in the Wound-Healing Process. J. PACD, 2003. 66. Fernandez, M.L., A. Trejo, and D. McNamara, Pectin isolated from prickly pear (Opuntia sp.) modifies low density lipoprotein metabolism in cholesterol-fed guineq pigs. J. Nutrition, 1990. 120: p. 1293-1290. 67. Fernandez, M.L., E.C.K. Lin, A. Trejo, and D. McNamara, Prickly Pear (Opuntia sp.) pectin reverses low dens ity lipoprotein receptor suppression induced by a hypercholestero lemic diet in guinea pigs. J. Nutrition, 1992. 122: p. 2330-2340. 68. Fernandez, M.L., E.C.K. Lin, and A. Trejo, Prickly pear (Opuntia sp.) pectin alters hepatic cholesterol met abolism without affecting cholesterol absorption in guinea pigs fed a hypercholesterolemic diet. J. Nutrition, 1994. 124: p. 817-824. 69. Cardenas, M.L., S. Serna, and J. Velasco de la Garza, Effect of raw and cooked nopal (Opuntia ficus-indica ) ingestion on growth and total cholesterol lipoproteins and blood glucose in rats. Archivos Latinoamericanos de Nutricion, 1998. 48(4): p. 316-323. 70. El Kossori, R.L., C. Sachez, E.S. El Boustani, N. Maucourt, Y. Sauvaire, L.K. Mejean, and C. Villaume, Comparison of the effects of prickly pear (Opuntia ficus-indica sp.) fruit, arabic gum, carrageenan, alginic acid, locust bean gum and citrus pectin on viscosity and in vitro digestibility of casein. J. Sci. Food. Agri c., 2000. 80: p. 359-364.

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103 71. Galati, E.M., N. Pergolizzi, M.T. Monforte, and M.N. Tripodo, Study on the increment of the production of gastri c mucus in rats treated with Opuntia ficus indica (L.) Mill. Cladodes. Journal of Ethnopharma col., 2002. 83: p. 229-233. 72. Crdenas, A., W.M. Argue lles, and F.M. Goycoolea, On the Possible Role of Opuntia ficus-indica Mucilage in Lime Mortar Performance in the Protection of Historical Buildings. J. PACD, 1998. 73. Garti, N., Hydrocolloids as emulsifying agents for oil-water emulsions. Journal of Dispersion Sci. Tech nol., 1999. 20((1&2)): p. 327-355. 74. Frati-Munari, A.C., E. Jimenez, and C.R. Ariza, Hypoglycemic effects of Opuntia ficus indica in non-insulin d ependent diabetes mellitus patients. Phytotherapy Research 1990. 4: p. 195-197. 75. Park, E.H. and M.J. Chun, Wound healing activity of Opuntia ficus-indica. Fitoterapia, 2001. 72: p. 165-167. 76. Nyquist, R.A. and R.O. Kagel, Organic Materials in Infrared and Raman Spectroscopy E.G. Brame and J.G. Grassell i, Editors. 1977, Marcel Dekker, Inc.: New York. p. 442 565. 77. Tripathy, T., S.R. Pandey, N.C. Karmakar, R.P. Bhagat, and R.P. Singh, Novel flocculating agent based on sodium alginate and acrylamide. European Polymer Journal, 1999. 35(11): p. 2057-2072. 78. Karmakar, G.P. and R.P. Singh, Flocculation studies using amylosegrafted polyacrylamide. Colloids and Surfaces A: Physiochemical and Engineering Aspects, 1998. 133(1-2): p. 119-124. 79. Tripathy, T. and R.P. Singh, High performance flocculating agent basesd on partially hydrolysed sodium alginate-g-polyacrylamide. European Polymer Journal, 2000. 36(7): p. 1471-1476. 80. Nayak, B.R. and R.P. Singh, Comparative studies on the flocculation characteristics of polyacrylamide gr afted guar gum and hydroxypropyl guar gum. Polymer International, 2001. 50(8): p. 875-884.

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104 81. Besra, L., D.K. Sengupt a, S.K. Roy, and P. Ay, Studies on flocculation and dewatering of kaolin suspensions by anionic polyacrylamide flocculant in the presence of some surfactants. Internationa Journal of Mineral Processing, 2002. 66(1-4): p. 1-28. 82. Besra, L., D.K. Sengupt a, S.K. Roy, and P. Ay, Influence of surfactants on flocculation and dewatering of k aolin suspensions by cationic polyacrylamide (PAM-C) flocculant. Separation and Purification Technology, 2003. 30(3): p. 251-264. 83. Besra, L., D.K. Sengupt a, S.K. Roy, and P. Ay, Influence of polymer adsorption and conformation on flocculation and dewatering of kaolin suspensions. Separation and Purification Te chnology, 2004. 37(3): p. 231246. 84. Singh, R.P., B.R. Na yak, D.R. Biswal, T. Tripathy, and K. Banik, Biobased polymeric flocculants for industrial effluent treatment. Materials Research Innovations, 2003. 7(5): p. 331-340. 85. Zhao, Y.Q., Settling behaviour of polymer flocculated water-treatment sludge II: effects of floc structure and floc packing. Separation and Purification Technology, 2004. 35(3): p. 175-183. 86. Qian, J.W., X.J. Xiang, W.K. Yang, M. Wang, and B.Q. Zheng, Flocculation performance of different polyacrylamide and the relation between optimal dose and cr itical concentration. European Polymer Journal, 2004. 40(8): p. 1699-1704. 87. Rath, S.K. and R.P. Singh, Flocculation characteristics of grafted and ungrafted starch, amylose, and amylopectin. Journal of Applied Polymer Science, 1997. 66(9): p. 1721-1729. 88. Karmakar, N.C., S.K. Rath, B.S. Sastry, and R.P. Singh, Investigation on flocculation characteristics of pol ysaccharide-based graft copolymers in coal fines suspension. Journal of Applied Polymer Science, 1998. 70(13): p. 2619-2625. 89. Rath, S.K. and R.P. Singh, Grafted amylopectin: applications in flocculation. Colloids and Surfaces A: Ph ysiochemical and Engineering Aspects, 1998. 139(2): p. 129-135.

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105 90. Pan, J.R., C. Hyang, S. Chen, and Y.C. Chung, Evaluation of a modified chitosan biopolymer for coagulat ion of colloidal particles. Colloids and Surfaces A: Physiochemical and Engi neering Aspects, 1999. 147(3): p. 359-364. 91. Tripathy, T., R.P. Bhagat, and R.P. Singh, The flocculation performance of grafted sodium alginate and other polymer ic flocculants in relation to iron ore slime suspension. European Polymer Journal, 2001. 37(1): p. 125130. 92. Tripathy, T., N.C. Ka rmakar, and R.P. Singh, Development of novel polymeric flocculant based on grafted sodium alginate for the treatment of cole mine wastewater. Journal of Applied Poly mer Science, 2001. 82(2): p. 375-382. 93. Wang, D. and H. Tang, Modified Inorganic Polymer Flocculant-PFSi: Its Preparation, Characterizati on and Coagulation Behavior. Water Research, 2001. 35(14): p. 3418-3428. 94. Kan, C., C. Huang, and J.R. Pan, Time requirement for rapid-mixing in coagulation. Colloids and Surfaces A: Ph ysiochemical and Engineering Aspects, 2002. 203(1-3): p. 1-9. 95. Nonaka, T., H. Li, K. Makinos e, T. Ogata, and S. Kurihara, Synthesis and functions of water-soluble and t hermosensitive copolymers having phosphonium groups from acryloyloxyethyl trialkyl ph osphonium chloride, N-isopropylacrylamide, and with out/with butylmethacrylate. Journal of Applied Polymer Science, 2003. 90(4): p. 1139-1147. 96. Lee, J.F., P.M. Liau, D.H. Seng, and P.T. Wen, Behavior of organic polymers in drinking water purification. Chemosphere, 1998. 37(6): p. 1045-1061. 97. Scientific, H., Micro 100 Manual 2004: Fort Myers. p. 15. 98. McCarthy, K.T., T. Pi chler, and R.E. Price, Geochemistry of Champagne Hot Springs shallow hydr othermal vent field and associated sediments, Dominica, Lesser Antilles. Chemical Geology, 2005. 224: p. 55-68. 99. Price, R.E., Abundance and Mineralogical Associations of Naturally Occurring Arsenic in the Upper Fl oridan Aquifer, Suwanee Limestone in Department of Geology 2003, University of South Florida: Tampa. p. 74.

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106 100. Welz, B. and M. Sperling, Atomic Absorption Spectrometry 3 ed. 1999, New York: Wiley-VCH. 941. 101. Munk, P. and T.M. Aminabhavi, Introduction to Macromolecular Science 2 ed. 2002, New York: Wiley-Interscience. 609.

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107 Appendices

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108 Appendix A: Cylinder and Jar Tests Sample Dosage Schemes Table 9: Flocculant Doses for 100 ml Graduated Cylinder Tests from Prepared 1 g L-1 Stock Solutions of Flocculants. Desired Final Flocculant Concentration Appropriate Dose Volume [mg L-1] Into the 0.01 0.001 0.1 0.01 1 0.1 2 0.2 3 0.3 4 0.4 5 0.5 10 1.0 Table 10: Flocculant Doses for Each 0.5 L Jar Test Compartm ent from Prepared 1 g L-1 Stock Solutions of Flocculants. Desired Final Flocculant Concentration Appropriate Dose Volume [mg L-1] [ml] 0.01 0.005 0.1 0.05 0.25 0.125 0.5 0.25 1 0.5 2 1 3 1.5 4 2 5 2.5 10 5

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Appendix B: Material Safety Data Sheets B.1. Aluminum Sulfate ALUMINUM SULFATE 1. Product Identification Synonyms: Sulfuric acid, aluminum salt (3 :2), octadeca hydrate; Cake alum; Patent alum CAS No.: 10043-01-3 (Anhydrous) 7784-318 (Octadecahydrate) Molecular Weight: 666.44 Chemical Formula: Al2(SO4)3.18H2O Product Codes: J.T. Baker: 0564 Mallinckrodt: 3208 2. Composition/Information on Ingredients Ingredient CAS No Percent Hazardous ----------------------------------------------------------------Aluminum Sulfate 10043-01-3 98 -100% Yes 3. Hazards Identification Emergency Overview ------------------------WARNING! HARMFUL IF SWALLOWED OR INHALED. CAUSES IRRITATION TO SKIN, EYES AND RESPIRATORY TRACT. SAF-T-DATA(tm) Ratings (Provided here for your convenience) ---------------------------------------------------------------------------------------------------------Health Rating: 2 Moderate Flammability Rating: 0 None Reactivity Rating: 1 Slight Contact Rating: 2 Moderate Lab Protective Equip: GOGGLES; LAB COAT; VENT HOOD; PROPER GLOVES Storage Color Code: Gr een (General Storage) ---------------------------------------------------------------------------------------------------------109

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Appendix B (Continued) Potential Health Effects --------------------------------This material hydrolyzes in water to form sulfuric acid, which is responsible for the irritating effects given below. Inhalation: Causes irritation to the respiratory tract. Symptoms may include coughing, shortness of breath. Ingestion: Causes irritation to the gastrointestinal tract. Symptoms may include nausea, vomiting and diarrhea. There have been tw o cases of fatal human poisonings from ingestion of 30 grams of alum. Skin Contact: Causes irritation to skin. Symptoms include redness, itching, and pain. Eye Contact: Causes irritation, redness, and pain. Chronic Exposure: No information found. Aggravation of Preexisting Conditions: No information found. 4. First Aid Measures Inhalation: Remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Ge t medical attention. Ingestion: If swallowed, DO NOT INDUCE VOMITING. Give large quantities of water. Never give anything by mouth to an unconsci ous person. Get medical attention immediately. Skin Contact: Wipe off excess material from skin then immediately flush skin with plenty of water for at least 15 minutes. Remove contaminated clothing and shoes. Get medical attention. Wash clothing befor e reuse. Thoroughly clean shoes before reuse. Eye Contact: Immediately flush eyes with plenty of water for at least 15 minutes, lifting upper and lower eyelids occasionally. Get medical attention. 5. Fire Fighting Measures Fire: Not considered to be a fire hazard. 110

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Appendix B (Continued) Explosion: Not considered to be an explosion hazard. Fire Extinguishing Media: Keep in mind that addition of water can c ause the formation of sulfuric acid. Special Information: In the event of a fire, wear full pr otective clothing and NIOSH-approved selfcontained breathing a pparatus with full facepiece operated in the pressure demand or other positive pressure mode. 6. Accidental Release Measures Ventilate area of leak or spill. Ke ep unnecessary and unprotected people away from area of spill. Wear appr opriate personal protective equipment as specified in Section 8. Spills: Pick up and place in a suitable container fo r reclamation or disposal, using a method that does not generate dust. Cover spill with sodium bicarbonate or soda ash and mix. US R egulations (CERCLA) require reporting spills and releases to soil, water and air in excess of reportable quantities. The toll free number for the US Coast Guard Na tional Response Center is (800) 4248802. 7. Handling and Storage Keep in a tightly closed container, stored in a cool, dry, ventilated area. Protect against physical damage. Isolate from incompatible substances. Aluminum sulfate absorbs moisture and becomes a safety hazard when spilled because it absorbs moisture and becomes slippery Containers of this material may be hazardous when empty since they retain product residues (dust, solids); observe all warnings and precautions listed for the product. 8. Exposure Controls/Personal Protection Airborne Exposure Limits: -OSHA Permissible Exposure Limit (PEL): 2 mg/m3 (TWA) soluble salts as Al -ACGIH Threshold Limit Value (TLV): 2 mg/m3 (TWA) soluble salts as Al Ventilation System: A system of local and/or general exhaust is recommended to keep employee exposures below the Airborne Exposure Limits. Local exhaust ventilation is generally preferred because it can control the emissions of the contaminant at its source, preventing dispersion of it into t he general work area. Please refer to the ACGIH document, Industrial Ventilation, A Manual of Recommended Practices most recent edition, for details. 111

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Appendix B (Continued) Personal Respirators (NIOSH Approved): If the exposure limit is ex ceeded and engineering controls are not feasible, a half facepiece particulate respirator (NIOSH type N95 or better filters) may be worn for up to ten times the exposure limit or the maximum use concentration specified by the appropriate regulatory agency or respirator supplier, whichever is lowest.. A full-face piece particulate respirator (NIOSH type N100 filters) may be worn up to 50 times the exposure limit, or the maximum use concentration specified by the appropriate regulatory agen cy, or respirator supplier, whichever is lowest. If oil particles (e.g. lubricants, cutting fluids, glycerine, etc.) are present, use a NIOSH type R or P filter. For emer gencies or instances where the exposure levels are not known, use a full-facepiece positiv e-pressure, air-supplied respirator. WARNING: Air-purifying respirators do not protect workers in oxygen-deficient atmospheres. Skin Protection: Wear impervious protective clothing, in cluding boots, gloves, lab coat, apron or coveralls, as appropriate, to prevent skin contact. Eye Protection: Use chemical safety goggles and/or full face shield where dusting or splashing of solutions is possible. Maintain eye wash fountain and quick-drench facilities in work area. 9. Physical and Chemical Properties Appearance: Colorless crystals. Odor: Odorless. Solubility: 87 g/100 cc water @ 0C (32F). Specific Gravity: 1.69 @ 17C/4C pH: No information found. % Volatiles by volume @ 21C (70F): 0 Boiling Point: No information found. Melting Point: 87C (189F) Decomposes. 112

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Appendix B (Continued) Vapor Density (Air=1): No information found. Vapor Pressure (mm Hg): No information found. Evaporation Rate (BuAc=1): No information found. 10. Stability and Reactivity Stability: Stable under ordinary conditi ons of use and storage. Hazardous Decomposition Products: Hydrolyzes to form dilute sulfuric acid. Toxic and corrosive oxid es of sulfur may be formed when heated to decomposition. Hazardous Polymerization: Will not occur. Incompatibilities: Corrosive to metals in the presence of water. Conditions to Avoid: Moisture and incompatibles. 11. Toxicological Information Anhydrous Material: Oral mouse LD50: 6207 mg/kg; Irritation eyes rabbit: 10 mg/24H severe; investigated as a mutagen and reproductive effector. 18-Hydrate: Oral mouse LD50: > 9 gm /kg; investigated as a mutagen. --------\Cancer List s\-------------------------------------------------------NTP Carcinogen--Ingredient Known An ticipated IARC Category -----------------------------------------------------------Aluminum Sulfate (10043-013) No No None 12. Ecological Information Environmental Fate: No information found. Environmental Toxicity: No information found. 113

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Appendix B (Continued) 13. Disposal Considerations Whatever cannot be saved for recovery or recycling should be managed in an appropriate and approved waste disposal facility. Processing, use or contamination of this product may change the waste management options. State and local disposal regulations may diffe r from federal disposal regulations. Dispose of container and unused contents in accordanc e with federal, state and local requirements. 14. Transport Information Not regulated. 15. Regulatory Information --------\Chemical Inventory Status Part 1\------------------------------Ingredient TS CA EC Japan Australia -------------------------------------------------------------Aluminum Sulfate (10043-01-3) Yes Yes Yes Yes --------\Chemical Inventor y Status Part 2\--------------------------------Canada-Ingredient Korea DSL NDSL Phil. ---------------------------------------------------------Aluminum Sulfate (10043-01-3) Yes Yes No No --------\Federal, State & International Regulations Part 1\----------------SARA 302------SARA 313-----Ingredient RQ TPQ List Chemical Catg. ----------------------------------------------------------Aluminum Sulfate (10043-013) No No No No --------\Federal, State & International Regulations Part 2\----------------RCRA-TSCAIngredient CERCLA 261.33 8(d) ---------------------------------------------------Aluminum Sulfate (10043-01-3) 5000 No No Chemical Weapons Convention: No TSCA 12(b): No CDTA: No SARA 311/312: Acute: Yes Chronic: No Fire: No Pressure: No Reactivity: No (Mixture / Solid) Australian Hazchem Code: None allocated. Poison Schedule: None allocated. 114

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Appendix B (Continued) WHMIS: This MSDS has been prepared according to the hazard criteria of the Controlled Products Regulations (CPR) and the MSDS contains all of the information required by the CPR. 16. Other Information NFPA Ratings: Health: 2 Flammability: 0 Reactivity: 0 Label Hazard Warning: WARNING! HARMFUL IF SWALLOWED OR INHALED. CAUSES IRRITATION TO SKIN, EYES AND R ESPIRATORY TRACT. Label Precautions: Avoid breathing dust. Keep container closed. Use only with adequate ventilation. Wash thoroughly after handling. Avoid contact with eyes, skin and clothing. Label First Aid: If swallowed, DO NOT INDUCE VOMITING. Give large quantities of water. Never give anything by mouth to an unconscious pe rson. If inhaled, remove to fresh air. If not breathing, give artifici al respiration. If breathing is difficult, give oxygen. In case of contact, wipe off excess material from skin then immediately flush eyes or skin with plenty of water for at l east 15 minutes. Remove contaminated clothing and shoes. Wash clothing befor e reuse. In all cases, get medical attention. Product Use: Laboratory Reagent. Revision Information: No Information Found. Disclaimer: ******************************************************************************************** **** Mallinckrodt Baker, Inc. provides the information contained herein in good faith but makes no representation as to its comprehensiveness or accuracy. This document is intended onl y as a guide to the appropriate precautionary handling of the material by a properly trained person using this product. Individuals receiving the information must exercise their independent judgment in determining its appropriateness for a particular purpose. MALLINCKRODT BAKER, I NC. MAKES NO REPRESENTATIONS OR WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE WITH RESP ECT TO THE INFORMATION SET FORTH HEREIN OR THE PRODUCT TO WHICH THE INFORMATION REFERS. ACCORDINGLY, MALLINCKRODT BAKER, INC. WILL NOT BE 115

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116 Appendix B (Continued) RESPONSIBLE FOR DAMAGES RESULTIN G FROM USE OF OR RELIANCE UPON THIS INFORMATION. ******************************************************************************************** **** Prepared by: Environmental Health & Safety Phone Number: (314) 654-1600 (U.S.A.)

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117 Appendix B (Continued) B.2. Arsenic(III) Oxide Material Safety Data Sheet Arsenic (III) Oxide, 99.999% ACC# 99309 Section 1 Chemical Product and Company Identification MSDS Name: Arsenic (III) Oxide, 99.999% Catalog Numbers: AC192490000, AC192490050 Synonyms: Arsenic oxide; Arsenic sesquioxi de; Arsenous oxide; Arsenous acid anhydride; Arsenous acid. Company Identification: Acros Organics N.V. One Reagent Lane Fair Lawn, NJ 07410 For information in North America, call: 800-ACROS-01 For emergencies in the US, call CHEMTREC: 800-424-9300 Section 2 Composition, Information on Ingredients CAS# Chemical Name Percent EINECS/ELINCS 1327-53-3 Arsenic trioxi de 99.999 215-481-4 Section 3 Hazards Identification EMERGENCY OVERVIEW Appearance: white solid. Danger! May be fatal if swallowed. Cancer hazard. Poison! Contains inorganic arsenic. Harmful if inhaled. Causes eye and skin irritation. May cause severe respiratory and digestive tract irritation with possible burns. May cause central nervous system effects. May cause blood abnormalities. May cause lung damage. May cause cardiac disturbances May cause liver and kidney damage. This substance has caused adverse reproductive and fetal effects in animals. Target Organs: Kidneys, central nervous system liver, lungs, cardiovascular system, red blood cells, skin.

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118 Appendix B (Continued) Potential Health Effects Eye: Contact produces irritation, t earing, and burning pain. May cause conjunctivitis. Skin: Causes irritation with burning pai n, itching, and redness. May cause dermatitis. Exposure to arsenic com pounds may produce hyper pigmentation of the skin and hyperkeratoses of plantar and palmar surfaces as well as both primary irritation and sensitization types. Ingestion: May be fatal if swallowed. Causes severe digestive tract burns with abdominal pain, vomiting, and possible de ath. May cause hemorrhaging of the digestive tract. Ingestion of arsenical co mpounds may cause burning of the lips, throat constriction, swallowing difficulties, severe abdo minal pain, severe nausea, projectile vomiting, and profuse diarr hea. Ingestion of arsenic compounds can produce convulsions, coma, and possi bly death within 24 hours. Inhalation: May cause severe irritation of the respiratory tract with sore throat, coughing, shortness of breath and delayed lung edema. Inhalati on of arsenic compounds may lead to irritation of the respirat ory tract and to possible nasal perforation. Long-term exposure to arsenic compounds may produce impairment of peripheral circulation. Chronic: May cause liver and kidney damage. Chronic inhalation may cause nasal septum ulceration and perforation. May cause anemia and other blood cell abnormalities. Chronic skin effects include: cracking, thickening, pigmentation, and drying of the skin. Ars enic trioxide can cause cancer in humans. Other long term effects include: anemia, liver and kidney damage. Chronic exposure to arsenical dust may cause shortness of breath, nausea, chest pains, and garlic odor. Section 4 First Aid Measures Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid. Skin: Get medical aid. Flush skin with plent y of water for at least 15 minutes while removing contaminated clothing and s hoes. Wash clothing before reuse. Ingestion: Call a poison control center. If swallowed, do not induce vomiting unless directed to do so by medical perso nnel. Never give anything by mouth to an unconscious person. Get medical aid.

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119 Appendix B (Continued) Inhalation: Remove from exposure and move to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficul t, give oxygen. Get medical aid. Do NOT use m outh-to-mouth resuscitation. Notes to Physician: Treat symptomatically and supportively. Section 5 Fire Fighting Measures General Information: As in any fire, wear a se lf-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly to xic gases may be generated by thermal decomposition or combustion. Use exti nguishing media appropriate to the surrounding fire. Substance is noncombustible. Extinguishing Media: Substance is noncombustible; use agent most appropriate to extinguish surrounding fire. Do NOT get water inside containers. Flash Point: Not applicable. Autoignition Temperature: Not applicable. Explosion Limits, Lower: Not available. Upper: Not available. NFPA Rating: (estimated) Health: 3; Flam mability: 0; Instability: 0 Section 6 Accidental Release Measures General Information: Use proper personal protective equipment as indicated in Section 8. Spills/Leaks: Vacuum or sweep up material and place into a suitable disposal container. Avoid runoff into storm sewers and ditches which lead to waterways. Clean up spills immediately, observing pr ecautions in the Protective Equipment section. Avoid generating dusty conditions. Provide ventilation. Do not get water inside containers. Section 7 Handling and Storage Handling: Wash thoroughly after handling. Re move contaminated clothing and wash before reuse. Minimize dust generation and accumulation. Avoid contact with eyes, skin, and clothing. Avoid ingesti on and inhalation. Do not allow contact with water. Use only with adequate ventilati on or respiratory protection. Storage: Store in a tightly closed container. St ore in a cool, dry, well-ventilated area away from incompatible substances Do not store in metal containers.

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120 Appendix B (Continued) Section 8 Exposure Controls, Personal Protection Engineering Controls: Use adequate general or local exhaust ventilation to keep airborne concentrations below the permissible exposure limits. See 29CFR 1910.1018 for regulatory requirem ents pertaining to all occupational exposures to inorganic arsenic. Exposure Limits Chemical Name ACGIH NIOSH OSHA Final PELs Arsenic trioxide 0.01 mg/m3 TWA (listed under Arsenic). 5 mg/m3 IDLH (listed under Arsenic).5 mg/m3 IDLH (as As) (listed under Arsenic, inorganic compounds). 0.5 mg/m3 TWA (listed under Arsenic).5 g/m3 Action Level (as As); 10 g/m3 PEL (as As. Cancer hazard see 29 CFR 1 910.1018. Arsine excepted) (listed under Arsenic, inorganic compounds). OSHA Vacated PELs: Arsenic trioxide: No OSHA Vacated PELs are listed for this chemical. Personal Protective Equipment Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protec tion regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate gloves to prevent skin exposure. Clothing: Wear appropriate protective clot hing to prevent skin exposure. Respirators: Follow the OSHA respirator re gulations found in 29 CFR 1910.134 or European Standard EN 149. Use a NIOSH/MSHA or European Standard EN 149 approved respirator if expos ure limits are exceeded or if irritation or other symptoms are experienced.

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121 Appendix B (Continued) Section 9 Physical and Chemical Properties Physical State: Solid Appearance: white Odor: odorless pH: Not available. Vapor Pressure: 66 mm Hg @ 312C Vapor Density: Not available. Evaporation Rate: Negligible. Viscosity: Not available. Boiling Point: 465 deg C Freezing/Melting Point: 312 deg C Decomposition Temperature: Not available. Solubility: 3.7% in water. Specific Gravity/Density: 3.738 Molecular Formula:As2O3 Molecular Weight: 197.84 Section 10 Stability and Reactivity Chemical Stability: Stable under normal temper atures and pressures. Conditions to Avoid: Dust generation, moisture metals, excess heat. Incompatibilities with Other Materials: Incompatible with ch lorine trifluoride, fluorine, hydrogen fluoride, oxygen difl uoride, and sodium chlorate. Can generate arsine, which is an extremely poisonous gas, when arsenic compounds contact acid, alkalies, or water in the presenc e of an active metal (zinc, aluminum, magnesium, manganese, s odium, iron, etc). Hazardous Decomposition Products: Irritating and toxic fumes and gases, oxides of arsenic, arsine. Hazardous Polymerization: Has not been reported.

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122 Appendix B (Continued) Section 11 Toxicological Information RTECS#: CAS# 1327-53-3: CG3325000 LD50/LC50: CAS# 1327-53-3: Oral, mouse: LD50 = 20 mg/kg; Oral, rabbi t: LD50 = 20190 ug/kg; Oral, rat: LD50 = 10 mg/kg; Carcinogenicity: CAS# 1327-53-3: ACGIH: A1 Confirmed Human Carcinogen (lis ted as 'Arsenic').A1 Confirmed Human Carcinogen (listed as 'Ars enic, inorganic compounds'). California: carcinogen, initial date 2/27/87 (listed as Arsenic, inorganic compounds). NTP: Known carcinogen (listed as Ar senic, inorganic compounds). IARC: Group 1 carcinogen (listed as Arsenic). Epidemiology: In a large number of studies, exposure to inorganic arsenic compounds in drugs, food, and water as we ll as in an occupational setting have been causally associated with the development al of cancer, primarily of the skin and lungs. Teratogenicity: Teratogenic effects, including exencephaly, skeletal defects, and genitourinay system defects, of arsenic compounds administered intravenously or intraperitoneally t high doses have been demonstrated in hamsters, rats and mice. Reproductive Effects: May cause reproductive effects. Mutagenicity: No information available. Neurotoxicity: No information available. Other Studies: Section 12 Ecological Information Ecotoxicity: Water flea Daphnia: LC50 = 0.038 mg/L; 24 Hr.; UnspecifiedBacteria: Phytobacterium phosphoreum: EC50 = 31.43-73.73 mg/L; 5,15,30 minutes; Microtox test No data available. Environmental: Terrestrial: Half-life in soil 6.5 years. Aquatic: Tends to bioaccumulate. Will biodegrade to arsine and will bioconcentrate. Physical: No information available. Other: No information available.

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123 Appendix B (Continued) Section 13 Disposal Considerations Chemical waste generators must dete rmine whether a discarded chemical is classified as a hazardous waste. US EPA guidelines for the classification determination are listed in 40 CFR Part s 261.3. Additionally, waste generators must consult state and local hazardous waste regulations to ensure complete and accurate classification. RCRA P-Series: CAS# 1327-53-3: waste number P012. RCRA U-Series: None listed. Section 14 Transport Information US DOT Canada TDG Shipping Name: DOT regulated small quantity provisions apply (see 49CFR173.4) No information available. Hazard Class: UN Number: Packing Group: Section 15 Regulatory Information US FEDERAL TSCA CAS# 1327-53-3 is list ed on the TSCA inventory. Health & Safety Reporting List None of the chemicals are on the Health & Safety Reporting List. Chemical Test Rules None of the chemicals in this product are under a Chemical Test Rule. Section 12b None of the chemicals ar e listed under TSCA Section 12b. TSCA Significant New Use Rule None of the chemicals in th is material have a SNUR under TSCA. CERCLA Hazardous Substances and corresponding RQs CAS# 1327-53-3: 1 lb final RQ; 0.454 kg final RQ

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124 Appendix B (Continued) SARA Section 302 Extremely Hazardous Substances CAS# 1327-53-3: 100 lb TPQ (lower threshold); 10000 lb TPQ (upper thre shold) SARA Codes CAS # 1327-53-3: immediate, delayed. Section 313 This material contains Arsenic trioxide (listed as Arsenic), 99.999%, (CAS# 1327-53-3) which is subject to the r eporting requirements of Section 313 of SARA Title III and 40 CFR Part 373. Clean Air Act: CAS# 1327-53-3 (listed as Arseni c, inorganic compounds) is listed as a hazardous air pollutant (HAP). This material does not contain any Class 1 Ozone depletors. This material does not c ontain any Class 2 Ozone depletors. Clean Water Act: CAS# 1327-53-3 is listed as a Haza rdous Substance under the CWA. CAS# 1327-53-3 is listed as a Priority Pollutant under the Clean Water Act. CAS# 132753-3 is listed as a Toxic Pollutant under the Clean Water Act. OSHA: None of the chemicals in this product are considered highly hazardous by OSHA. STATE CAS# 1327-53-3 can be found on the following state right to know lists: California, New Jersey, Pennsylvania, Minn esota, (listed as Arsenic), Minnesota, (listed as Arsenic, inorganic compounds), Massachusetts. California Prop 65 The following statement(s) is(are) made in order to comply with the California Safe Drinking Water Act: WARNING: This product contains Arsenic tr ioxide, listed as `Arsenic, inorganic compounds', a chemical known to the st ate of California to cause cancer. WARNING: This product contains Arsenic trioxide, listed as `Arsenic (inorganic oxides)', a chemical known to the state of California to cause developmental reproductive toxicity. California No Significant Risk Level : CAS# 1327-53-3: 0.06 g/day NSRL (inhalation); 10 g/day NSRL (except inhalation) (listed under Arsenic) European/International Regulations European Labeling in Accordance with EC Directives Hazard Symbols: T+ N

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125 Appendix B (Continued) Risk Phrases: R 28 Very toxic if swallowed. R 34 Causes burns. R 45 May cause cancer. R 50/53 Very toxic to aquat ic organisms, may cause long-term adverse effects in the aquatic environment. Safety Phrases: S 45 In case of accident or if you feel unwell, seek medical advice immediately (show the label where possible). S 53 Avoid exposure obtain special instructions before use. S 60 This material and its contai ner must be disposed of as hazardou s waste. S 61 Avoid release to the envir onment. Refer to special instructions /safety data sheets. WGK (Water Danger/Protection) CAS# 1327-53-3: 3 Canada DSL/NDSL CAS# 1327-53-3 is listed on Canada's DSL List. Canada WHMIS not available. This product has been classified in acco rdance with the hazard criteria of the Controlled Products Regulations and the MSDS contains all of the information required by those regulations. Canadian Ingredient Disclosure List CAS# 1327-53-3 is listed on t he Canadian Ingredient Disclosure List. Section 16 Additional Information MSDS Creation Date: 6/21/1999 Revision #5 Date: 10/03/2005 The information above is believed to be accurate and represents the best information currently available to us. However, we make no warranty of merchantability or any other warranty, express or implied, with respect to such information, and we assume no liability re sulting from its use. Users should make their own investigations to determine the suitability of the in formation for their particular purposes. In no event shall Fis her be liable for any claims, losses, or damages of any third party or for lost profits or any s pecial, indirect, incidental, consequential or exemplary damages, hows oever arising, even if Fisher has been advised of the possibility of such damages.

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126 Appendix B (Continued) B.3. Arsenic (V) Oxide Material Safety Data Sheet Arsenic(V) oxide ACC# 02088 Section 1 Chemical Product and Company Identification MSDS Name: Arsenic(V) oxide Catalog Numbers: AC192500000, AC192 500250, AC366310000, AC366310050, AC366310250 Synonyms: Arsenic pentoxide; Diarsenic pent aoxide; Arsenic acid anhydride; Arsenic anhydride. Company Identification: Acros Organics N.V. One Reagent Lane Fair Lawn, NJ 07410 For information in North America, call: 800-ACROS-01 For emergencies in the US, call CHEMTREC: 800-424-9300 Section 2 Composition, Information on Ingredients CAS# Chemical Name Percent EINECS/ELINCS 1303-28-2 Arsenic(V) oxi de >99.9 215-116-9 Section 3 Hazards Identification EMERGENCY OVERVIEW Appearance: white solid. Danger! May be fatal if swallowed. Cancer hazard. Contains inorganic arsenic. Harmful if inhaled. Causes eye, skin, and respiratory tract irritation. May cause nervous system effects. May cause fetal effects. Target Organs: Liver, lungs, nervous system, skin. Potential Health Effects Eye: May cause eye irritation. May result in corneal injury. Skin: May cause skin irritation. May cause skin sensitization, an allergic reaction, which becomes evident upon re-ex posure to this material.

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127 Appendix B (Continued) Ingestion: May cause liver damage. Can cause nervous system damage. Ingestion of arsenical compounds may c ause burning of the lips, throat constriction, swallowing difficulties, severe abdominal pain, severe nausea, projectile vomiting, and profuse diarrhea. All soluble arsenic (As) compounds are considered to be poisonous to humans. In organic arsenic is more toxic than organic arsenic. Organic arsenic is excreted more rapidly than inorganic arsenic. Arsenic 5+ is excreted more rapidly than arsenic 3+. Arsenic inhibits enzymes required for cellular respiration an d also competes with phosphorus for incorporation into ATP, depl eting cellular energy stores and leading to cell death. Inhalation: Causes respiratory tract irritation. May cause effects similar to those described for ingestion. Inhalation of ars enic compounds may lead to irritation of the respiratory tract and to possible nasal perforation. Chronic: Chronic ingestion is charac terized by weakness, anorexia, gastrointestinal disturbances, impairment of cognitive function, peripheral neuropathy, and skin disorders. Chronic ingestion may cause fetal effects. Inorganic arsenic compounds may caus e skin and lung cancers in humans. Based on a case report of one family wit h chronic exposure, the spectrum of toxic effects from arsenic pentoxide may include skin rashes, nosebleeds, easy bruising, hair loss, headaches, malaise, and grand mal seizures. Because of mixed exposures, these eeffects cannot be attributed solely to arsenic pentoxide. Section 4 First Aid Measures Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. Skin: Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Get medi cal aid if irritation develops or persists. Ingestion: Call a poison control center. If swallowed, do not induce vomiting unless directed to do so by medical perso nnel. Never give anything by mouth to an unconscious person. Get medical aid. Inhalation: Get medical aid immediately. Remove from exposure and move to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Notes to Physician: Treat symptomatically and supportively.

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128 Appendix B (Continued)) Section 5 Fire Fighting Measures General Information: As in any fire, wear a se lf-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Extinguishing Media: Use water spray to cool fire-exposed containers. Flash Point: Not available. Autoignition Temperature: Not available. Explosion Limits, Lower: Not available. Upper: Not available. NFPA Rating: (estimated) Health: 3; Flam mability: 0; Instability: 0 Section 6 Accidental Release Measures General Information: Use proper personal protective equipment as indicated in Section 8. Spills/Leaks: Vacuum or sweep up material and place into a suitable disposal container. Avoid generating dusty conditions. Provide ventilation. Section 7 Handling and Storage Handling: Wash thoroughly after handling. Re move contaminated clothing and wash before reuse. Do not get in eyes, on skin, or on clothing. Do not ingest or inhale. Use only with adequate ventilation or respirator y protection. Storage: Poison room locked. Section 8 Exposure Controls, Personal Protection Engineering Controls: Use adequate general or local exhaust ventilation to keep airborne concentrations below the permissible exposure limits. See 29CFR 1910.1018 for regulatory requirem ents pertaining to all occupational exposures to inorganic arsenic.

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129 Appendix B (Continued) Exposure Limits Chemical Name ACGIH NIOSH OSHA Final PELs Arsenic(V) oxide 0.01 mg/m3 TWA (as As) (listed under Arsenic, inorganic compounds). 5 mg/m3 IDLH (as As) (listed under Arsenic, inorganic compounds). 5 g/m3 Action Level (as As); 10 g/m3 PEL (as As. Cancer hazard see 29 CFR 1 910.1018. Arsine excepted) (listed under Arsenic, inorganic compounds). OSHA Vacated PELs: Arsenic(V) oxide: No OSHA Vacated PELs are listed for this chemical. Personal Protective Equipment Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protec tion regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clot hing to prevent skin exposure. Respirators: Follow the OSHA respirator re gulations found in 29 CFR 1910.134 or European Standard EN 149. Use a NIOSH/MSHA or European Standard EN 149 approved respirator if expos ure limits are exceeded or if irritation or other symptoms are experienced. Section 9 Physical and Chemical Properties Physical State: Solid Appearance: white Odor: odorless pH: acidic in soln Vapor Pressure: Not available. Vapor Density: Not available. Evaporation Rate: Not available. Viscosity: Not available. Boiling Point: Not available. Freezing/Melting Point: 315 deg C (dec) Decomposition Temperature: 315 deg C Solubility: Soluble.

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130 Appendix B (Continued) Specific Gravity/Density: Not available. Molecular Formula:As2O5 Molecular Weight: 229.84 Section 10 Stability and Reactivity Chemical Stability: Stable under normal temper atures and pressures. Conditions to Avoid: Excess heat, moist air. Incompatibilities with Other Materials: Acids, aluminum, halogens, zinc, rubidium carbide. Hazardous Decomposition Products: Oxides of arsenic. Hazardous Polymerization: Has not been reported. Section 11 Toxicological Information RTECS#: CAS# 1303-28-2: CG2275000 LD50/LC50: CAS# 1303-28-2: Oral, mouse: LD50 = 55 mg/kg; Oral, rat: LD50 = 8 mg/kg; Carcinogenicity: CAS# 1303-28-2: ACGIH: A1 Confirmed Human Carcinogen (listed as 'Arsenic, inorganic compounds'). California: carcinogen, initial date 2/27/87 (listed as Arsenic, inorganic compounds). NTP: Known carcinogen (listed as Ar senic, inorganic compounds). IARC: Group 1 carcinogen (listed as Arsenic compounds, n.o.s.). Epidemiology: No data available. Teratogenicity: No data available. Reproductive Effects: No data available. Mutagenicity: No data available. Neurotoxicity: No data available.

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131 Appendix B (Continued) Other Studies: Section 12 Ecological Information Ecotoxicity: No data available. No information available. Environmental: No information available. Physical: No information available. Other: Used in wood preservatives, weed control, and as fungicide. Section 13 Disposal Considerations Chemical waste generators must dete rmine whether a discarded chemical is classified as a hazardous waste. US EPA guidelines for the classification determination are listed in 40 CFR Part s 261.3. Additionally, waste generators must consult state and local hazardous waste regulations to ensure complete and accurate classification. RCRA P-Series: CAS# 1303-28-2: waste number P011. RCRA U-Series: None listed. Section 14 Transport Information US DOT Canada TDG Shipping Name: DOT regulated small quantity provisions apply (see 49CFR173.4) ARSENIC PENTOXIDE Hazard Class: 6.1 UN Number: UN1559 Packing Group: II Section 15 Regulatory Information US FEDERAL TSCA CAS# 1303-28-2 is list ed on the TSCA inventory. Health & Safety Reporting List None of the chemicals are on the Health & Safety Reporting List.

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132 Appendix B (Continued) Chemical Test Rules None of the chemicals in this product are under a Chemical Test Rule. Section 12b None of the chemicals ar e listed under TSCA Section 12b. TSCA Significant New Use Rule None of the chemicals in th is material have a SNUR under TSCA. CERCLA Hazardous Substances and corresponding RQs CAS# 1303-28-2: 1 lb final RQ; 0.454 kg final RQ SARA Section 302 Extremely Hazardous Substances CAS# 1303-28-2: 100 lb TPQ (lower threshold); 10000 lb TPQ (upper thre shold) Section 313 This material contains Arsenic( V) oxide (listed as Arsenic, inorganic compounds), >99.9%, (CAS# 1303-28-2) which is s ubject to the reporting requirements of Section 313 of SARA Title III and 40 CFR Part 373. Clean Air Act: CAS# 1303-28-2 (listed as Arseni c, inorganic compounds) is listed as a hazardous air pollutant (HAP). This material does not contain any Class 1 Ozone depletors. This material does not contain any Class 2 Ozone depletors. Clean Water Act: CAS# 1303-28-2 is listed as a Ha zardous Substance under the CWA. None of the chemicals in this pr oduct are listed as Priority Pollutants under the CWA. CAS# 1303 -28-2 is listed as a Toxic Po llutant under the Clean Water Act. OSHA: None of the chemicals in this product are considered highly hazardous by OSHA. STATE CAS# 1303-28-2 can be found on the following state right to know lists: California, New Jersey, Pennsylvania, Mi nnesota, (listed as Arsenic, inorganic compounds), Massachusetts. California Prop 65 The following statement(s) is(are) made in order to comply with the California Safe Drinking Water Act: WARNING: This product contains Arsenic(V) oxide, listed as `Arsenic, inorganic compounds', a chemical known to the st ate of California to cause cancer. WARNING: This product contains Arsenic( V) oxide, listed as `Arsenic (inorganic oxides)', a chemical known to the stat e of California to cause developmental reproductive toxicity.

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133 Appendix B (Continued) California No Significant Risk Level: N one of the chemicals in this product are listed. European/International Regulations European Labeling in Accordance with EC Directives Hazard Symbols: T N Risk Phrases: R 23/25 Toxic by in halation and if swallowed. R 45 May cause cancer. R 50/53 Very toxic to aquat ic organisms, may cause long-term adverse effects in the aquatic environment. Safety Phrases: S 45 In case of accident or if you feel unwell, seek medical advice immediately (show the label where possible). S 53 Avoid exposure obtain special instructions before use. S 60 This material and its contai ner must be disposed of as hazardou s waste. S 61 Avoid release to the envir onment. Refer to special instructions /safety data sheets. WGK (Water Danger/Protection) CAS# 1303-28-2: 3 Canada DSL/NDSL CAS# 1303-28-2 is listed on Canada's DSL List. Canada WHMIS This product has a WHMI S classification of D2A, D1A. This product has been classified in acco rdance with the hazard criteria of the Controlled Products Regulations and the MSDS contains all of the information required by those regulations. Canadian Ingredient Disclosure List CAS# 1303-28-2 is listed on t he Canadian Ingredient Disclosure List.

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134 Appendix B (Continued) Section 16 Additional Information MSDS Creation Date: 9/02/1997 Revision #4 Date: 6/01/2005 The information above is believed to be accurate and represents the best information currently available to us. However, we make no warranty of merchantability or any other warranty, express or implied, with respect to such information, and we assume no liability re sulting from its use. Users should make their own investigations to determine the suitability of the in formation for their particular purposes. In no event shall Fis her be liable for any claims, losses, or damages of any third party or for lost profits or any s pecial, indirect, incidental, consequential or exemplary damages, hows oever arising, even if Fisher has been advised of the possibility of such damages.

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135 Appendix B (Continued) B.4. Arsenic Standard Solution MATERIAL SAFETY DATA SHEET ________________________ ______________ 1. CHEMICAL PRODUCT AND COMPANY IDENTIFICATION Product Name: Arsenic Reference Standard Solution 1000 10 mg/l as As+3 Catalog Number: 1457142 Hach Company Emergen cy Telephone Numbers: P.O.Box 389 (Medical and Transportation) Loveland, CO USA 80539 (303) 623-5716 24 Hour Service (970) 669-3050 (515)232-2533 8am 4pm CST MSDS Number: M00697 Chemical Name: Not applicable CAS No.: Not applicable Chemical Formula: Not applicable Chemical Family: Not applicable Hazard: Carcinogen. Harmful if swallowed Date of MSDS Preparation: Day: 23 Month: 09 Year: 2004 ________________________ ______________ 2. COMPOSITION / INFORM ATION ON INGREDIENTS Sodium Hydroxide CAS No.: 1310-73-2 TSCA CAS Number: 1310-73-2 Percent Range: < 0.1 Percent Range Units: weight / volume LD50: Oral rat LDLo = 500 mg/kg. LC50: None reported TLV: 2 mg/m PEL: 2 mg/m Hazard: Causes severe burns. Toxic. Demineralized Water CAS No.: 7732-18-5 TSCA CAS Number: 7732-18-5 Percent Range: > 99.0 Percent Range Units: volume / volume LD50: None reported LC50: None reported TLV: Not established PEL: Not established

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136 Appendix B (Continued) Hazard: No effects anticipated. Arsenic Trioxide CAS No.: 1327-53-3 TSCA CAS Number: 1327-53-3 Percent Range: < 0.5 Percent Range Units: weight / volume LD50: Oral rat LD50 = 15.1 mg/kg; Oral human LDLo = 29 mg/kg LC50: None reported TLV: 0.2 mg/m3 as As PEL: 0.01 mg/m3 as As Hazard: Poison. Carcinogen. May cause irritation. ________________________ ______________ 3. HAZARDS IDENTIFICATION Emergency Overview: Appearance: Clear, colorless liquid Odor: None HARMFUL IF SWALLOWED CANCER HAZARD CONTAINS MATERI AL WHICH CAN CAUSE CANCER HMIS: Health: 4 Flammability: 0 Reactivity: 0 Protective Equipment: X See protective equipment, Section 8. NFPA: Health: 2 Flammability: 0 Reactivity: 0 Symbol: Not applicable Potential Health Effects: Eye Contact: May cause irritiation Skin Contact: No effects are anticipated Skin Absorption: Will be absorbed through the skin. Effects similar to those of ingestion Target Organs: Blood Liver Ki dneys Central nervous system Ingestion: Can cause: nausea vomiting gas trointestinal irritation convulsions death Target Organs: Blood Liver Ki dneys Central nervous system Inhalation: No data reported. Target Organs: None reported Medical Conditions Aggravat ed: Pre-existing: Liver conditions Kidney conditions blood disorders

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137 Appendix B (Continued) Chronic Effects: Chronic overexposur e may cause central nervous system effects gastrointestinal disturbances kidney damage liver damage muscle aches death Cancer / Reproductive Toxicity Information: An ingredient of this product is an OSHA listed carcinogen. Inorganic Arsenic An ingredient of this mixture is: IARC Group 1: Recognized Carcinogen Inorganic Arsenic An ingredient of this mixture is: NTP Listed Gr oup 1: Recognized Carcinogen Inorganic Arsenic Additional Cancer / Reproduc tive Toxicity Information: Contains: an experimental mutagen. an experimental teratogen. Toxicologically Synergistic Products: None reported ________________________ ______________ 4. FIRST AID Eye Contact: Immediately flush eyes with water for 15 minutes Call physician. Skin Contact (First Aid): Wash skin with plent y of water. Call physi cian if irritation develops. Ingestion (First Aid): Induce vomiting using syrup of ipecac or by sticking finger down throat. Never give anything by mouth to an unconscious person. Call physician immediately. Inhalation: None required. ________________________ ______________ 5. FIRE FIGHTING MEASURES Flammable Properties: Material will not burn. Flash Point: Not applicable Method: Not applicable Flammability Limits: Lower Explosion Limits: Not applicable Upper Explosion Limits: Not applicable Autoignition Temperature: Not applicable Hazardous Combustion Products: Not applicable Fire / Explosion Hazards: None reported Static Discharge: None reported. Mechanical Impact: None reported Extinguishing Media: Use media appropr iate to surrounding fire conditions Fire Fighting Instruction: As in any fi re, wear self-contained breathing apparatus pressure-demand and full protective gear.

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138 Appendix B (Continued) ________________________ ______________ 6. ACCIDENTAL RELEASE MEASURES Spill Response Notice: Only persons properly qualified to res pond to an emergency involving hazardous substances may respond to a spill according to federal regulations (O SHA 29 CFR 1910.120(a)(v)) and per your company's emergency response plan and guidelines/procedures. See Section 13, Special Instructions for disposal assistance. Containment Technique: Releases of this material may contaminate the environment. Absorb spill ed liquid with nonreactive sorbent material. Stop spilled material from being released to the environment. Dike the spill to contain material for later disposal. Clean-up Technique: Avoid contact with spilled material. Absorb spilled liquid with non-reactive sorbent material. Sweep up material. Dispose of material in an E.P.A. approved hazardous waste facility. Decontaminat e the area of the spill with a soap solution. Evacuation Procedure: Evacuate general area (50 foot radius or as directed by your facility's emergency response plan) when: any quantity is spilled. If conditi ons warrant, increase the size of the evacuation. Special Instructions (for accidental rel ease): Mixture contains a component which is regulated as a water pollutant. Mixture contains a component which is regulated as a hazardous air pollutant. 304 EHS RQ (40 CFR 355): Arsenic Trioxide RQ 1 lbs D.O.T. Emergency Response Guide Number: None ________________________ ______________ 7. HANDLING / STORAGE Handling: Avoid contact with eyes skin Do not breathe mist or vapors. Wash thoroughly after handling. Maintain general industrial hygiene practices when using this product. Storage: Keep container tightly closed when not in use. Flammability Class: Not applicable ________________________ ______________ 8. EXPOSURE CONTROLS / PROTECTIVE EQUIPMENT Engineering Controls: Have an eyewas h station nearby. Maintain general industrial hygiene practices when using this product. Personal Protective Equipment:

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139 Appendix B (Continued) Eye Protection: safety gla sses with top and side shields Skin Protection: lab coat disposable latex gloves Inhalation Protection: adequate ventilation Precautionary Measures: Avoid contac t with: eyes skin Do not breathe: mist/vapor Wash thoroughly after handling. TLV: Not established PEL: Not established ________________________ ______________ 9. PHYSICAL / CHEMICAL PROPERTIES Appearance: Clear, colorless liquid Physical State: Liquid Molecular Weight: Not applicable Odor: None pH: 5-7 Vapor Pressure: Not determined Vapor Density (air = 1): Not determined Boiling Point: 100C Melting Point: Not determined Specific Gravity (water = 1): 0.997 Evaporation Rate (water = 1): 1.053 Volatile Organic Compounds Content: Not applicable Partition Coefficient (n-oct anol / water): Not applicable Solubility: Water: Soluble Acid: Soluble Other: Not determined Metal Corrosivity: Steel: Not determined Aluminum: Not determined ________________________ ______________ 10. STABILITY / REACTIVITY Chemical Stability: Stable when stored under proper conditions. Conditions to Avoid: Heating to decomposition. Extr eme temperatures Evaporation Reactivity / Incompatibility: None reported Hazardous Decomposition: Heating to decomposition releases: arsine Hazardous Polymerization: Will not occur. ________________________ ______________ 11. TOXICOLOGICAL INFORMATION Product Toxicological Data: LD50: None reported LC50: None reported

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140 Appendix B (Continued) Dermal Toxicity Data: None reported Skin and Eye Irritation Data: None reported Mutation Data: Arsenic Trioxide: Hum an lung Unscheduled DNA synthesis 1mol/l; Human lymphocyte sister chromatid exchange 2g/cm3 Reproductive Effects Data: Oral M ouse TDLo = 3636 mg/kg : Reproductive Fertility abortion Ingredient Toxicological Data: Arsenic Trio xide: Oral rat LD50 = 15.1 mg/kg; Oral human LDLo = 29 mg/kg ________________________ ______________ 12. ECOLOGICAL INFORMATION Product Ecological Information: -No ecological data available for this product. Ingredient Ecological Information: -No ecological data available for the ingredients of this product. ________________________ ______________ 13. DISPOSAL CONSIDERATIONS EPA Waste ID Number: D004 Special Instructions (Disposal): Dispose of material in an E.P.A. approved hazardous waste facility. Empty Containers: Rinse three times with an appropriate solvent. Dispose of empty container as normal trash. NOTICE (Disposal): These disposal gui delines are based on federal regulations and may be superseded by more stringent state or local requirements. Please cons ult your local environmental regulators for more information. ________________________ _____________ 14. TRANSPORT INFORMATION D.O.T.: D.O.T. Proper Shipping Name: Not Currently Regulated -DOT Hazard Class: NA DOT Subsidiary Risk: NA DOT ID Number: NA DOT Packing Group: NA I.C.A.O.: I.C.A.O. Proper Shipping Name: Not Currently Regulated -ICAO Hazard Class: NA ICAO Subsidiary Risk: NA ICAO ID Number: NA ICAO Packing Group: NA I.M.O.:

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141 Appendix B (Continued) I.M.O. Proper Shipping Name : Not Currently Regulated I.M.O. Hazard Class: NA I.M.O. Subsidiary Risk: NA I.M.O. ID Number: NA I.M.O. Packing Group: NA Additional Information: This product may be shipped as part of a chemical kit composed of various compatible dangerous goods for analytical or testing purposes. This kit would have the following classification: Proper Shipping Name: Chemical Kit Hazard Class: 9 UN Number 3316 ________________________ ______________ 15. REGULATORY INFORMATION U.S. Federal Regulations: O.S.H.A.: This product contains Inorgani c arsenic and is regulated under 29CFR Subpart Z 1910.1018. E.P.A.: S.A.R.A. Title III Section 311/312 Ca tegorization (40 CFR 370): Immediate (Acute) Health Hazard Delayed (Chronic) Health Hazard S.A.R.A. Title III Section 313 (40 CFR 372) : This product contains a chemical(s) subject to the reporting requirements of Section 313 of Title III of SARA. Arsenic Trioxide 302 (EHS) TPQ (40 CFR 355): Arsenic Trioxide 100 lbs. 304 CERCLA RQ (40 CFR 302.4) : Arsenic Trioxide 1 lb. 304 EHS RQ (40 CFR 355): Arsenic Trioxide RQ 1 lbs Clean Water Act (40 CFR 116.4): Arsenic trioxide RQ 1 lb. RCRA: Contains RCRA regulated subst ances. See Section 13, EPA Waste ID Number. C.P.S.C.: Not applicable State Regulations: California Prop. 65: WARNING This pr oduct contains a chemical known to the State of California to cause cancer. Identification of Prop. 65 Ingredient(s): Arsenic (inorganic compounds) Trade Secret Registry: Not applicable National Inventories: U.S. Inventory Status: All in gredients in this product are listed on the TSCA 8(b) Inventory (40 CFR 710). TSCA CAS Number: Not applicable

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142 Appendix B (Continued) ________________________ ______________ 16. OTHER INFORMATION Intended Use: Standard solution References: 29 CFR 1900 1910 (Code of Federal Regulations Labor). Air Contaminants, Federal Register, Vol. 54, No. 12. Thursday, January 19, 1989. pp. 2332-2983. TLV's Threshold Limit Values and Biological Exposure Indices for 1992-1993. American Conference of Govern mental Industrial Hygienists, 1992. Technical Judgment. IARC Monographs on the Evaluation of the Carcinogeni c Risks to Humans. World Health Organization (Volumes 1-42) Supplement 7. France: 1987. In-house information. Fire Protection Guide on Hazardous Materials, 10th Ed. Quin cy, MA: National Fire Protection Fire Protection Guide on Haza rdous Materials, 10th Ed. Quincy, MA: National Fire Protection Association, 1991. List of Dangerous Substances Classi fied in Annex I of the EEC Directive (67/548) Classific ation, Packaging and Labeling of Dangerous Subst ances, Amended July 1992. Revision Summary: Updates in Section(s) 14, _______________________________________ Legend: NA Not Applicable w/w weight/weight ND Not Determined w/v weight/volume NV Not Available v/v volume/volume USER RESPONSIBILITY: Each user should read and understand this information and incorporate it in individual site safety programs in accordance with applicable hazard commu nication standards and regulations. THE INFORMATION CONTAINED HEREIN IS BASED ON DATA CONSIDERED TO BE ACCURATE. HOWEVER, NO WARRANTY IS EXPRESSED OR IMPLIED REGARDING THE ACCURACY OF THESE DATA OR THE RESULTS TO BE OBTAINED FROM THE USE THEREOF. HACH COMPANY

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143 Appendix B (Continued) B.5. Kaolin Material Safety Data Sheet Kaolin, acid washed powder, USP ACC# 12325 Section 1 Chemical Product and Company Identification MSDS Name: Kaolin, acid washed powder, USP Catalog Numbers: K2-500, K2-500LOT001 Synonyms: Aluminum silicate (hydrated); Bolu s Alba; China clay; Porcelain clay; White Bole. Company Identification: Fisher Scientific 1 Reagent Lane Fair Lawn, NJ 07410 For information, call: 201-796-7100 Emergency Number: 201-796-7100 For CHEMTREC assistance, call: 800-424-9300 For International CHEMTREC assistance, call: 703-527-3887 Section 2 Composition, Information on Ingredients CAS# Chemical Name Percent EINECS/ELINCS 1332-58-7 Kaolin 100 unlisted Section 3 Hazards Identification EMERGENCY OVERVIEW Appearance: white to yellow solid. Caution! May cause eye, skin, and respiratory tr act irritation. This is expected to be a low hazard for usual industrial handling. Target Organs: None. Potential Health Effects Eye: Dust may cause mechanical irritation. Skin: Dust may cause mechanical irritation. Ingestion: Ingestion of large amounts may caus e gastrointestinal irritation. Low hazard for usual in dustrial handling. Inhalation: May cause respiratory tract irritati on. Low hazard for usual industrial

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144 Appendix B (Continued) handling. When inhaled as a dust or fume, may cause benign pneumoconiosis. Chronic: Chronic inhalation can cause pneumoconiosis. Section 4 First Aid Measures Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. If irritation develops, get medi cal aid. Skin: Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Get medi cal aid if irritation develops or persists. Wash clothing before reuse. Ingestion: Never give anything by mouth to an unconscious person. Do NOT induce vomiting. If conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or water. Wash mouth out with water. Get medical aid if irritation or symptoms occur. Inhalation: Remove from exposure and move to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficul t, give oxygen. Get medical aid if cough or other symptoms appear. Notes to Physician: Treat symptomatically and supportively. Section 5 Fire Fighting Measures General Information: As in any fire, wear a se lf-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Substance is noncombustible. Extinguishing Media: Use extinguishing media most appropriate for the surrounding fire. Flash Point: Not applicable. Autoignition Temperature: Not applicable. Explosion Limits, Lower: Not available. Upper: Not available. NFPA Rating: (estimated) Health: 1; Flam mability: 0; Instability: 0 Section 6 Accidental Release Measures General Information: Use proper personal protective equipment as indicated in Section 8. Spills/Leaks: Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, observing precautions in the Protective Equipment section. Avoid generating dusty conditions. Provide ventilation.

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145 Appendix B (Continued) Section 7 Handling and Storage Handling: Wash thoroughly after handling. Wa sh hands before eating. Use with adequate ventilation. Minimize dust generat ion and accumulation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid breathing dust. Storage: Store in a tightly closed container. St ore in a cool, dry, well-ventilated area away from incompatible substances. No special precautions indicated. Section 8 Exposure Controls, Personal Protection Engineering Controls: Use adequate general or local exhaust ventilation to keep airborne concentrations below the permissible exposure limits. Exposure Limits Chemical Name ACGIH NIOSH OSHA Final PELs Kaolin 2 mg/m3 TWA (respirable fraction, particulate matter containing no asbestos and < 1% crystalline silica) 10 mg/m3 TWA (total dust); 5 mg/m3 TWA (respirable dust)3000 mg/m3 IDLH (listed under Silica, amorphous). 15 mg/m3 TWA (total dust); 5 mg/m3 TWA (respirable fraction) OSHA Vacated PELs: Kaolin: 10 mg/m3 TWA (t otal dust); 5 mg/m3 TWA (respirable fraction) Personal Protective Equipment Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protec tion regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective glov es to prevent skin exposure. Clothing: Wear appropriate protective clothi ng to minimize contact with skin. Respirators: Follow the OSHA respirator regul ations found in 29 CFR 1910.134 or European Standard EN 149. Use a NIOSH/MSHA or European Standard EN 149 approved respirator if expos ure limits are exceeded or if irritation or other symptoms are experienced.

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146 Appendix B (Continued) Section 9 Physical and Chemical Properties Physical State: Solid Appearance: white to yellow Odor: none reported pH: Not available. Vapor Pressure: Negligible. Vapor Density: Not available. Evaporation Rate: Not applicable. Viscosity: Not available. Boiling Point: Not available. Freezing/Melting Point: 3200 deg F Decomposition Temperature: Not available. Solubility: Insoluble in water. Specific Gravity/Density: 1.8 to 2.6 Molecular Formula:H2Al2Si2O8-H2O Molecular Weight: 258.2 Section 10 Stability and Reactivity Chemical Stability: Stable under normal temper atures and pressures. Conditions to Avoid: Dust generation, excess heat. Incompatibilities with Other Materials: Strong acids, strong bases. Hazardous Decomposition Products: Silicon dioxide, aluminum oxide. Hazardous Polymerization: Has not been reported. Section 11 Toxicological Information RTECS#: CAS# 1332-58-7: GF1670500 LD50/LC50: Not available. Carcinogenicity: CAS# 1332-58-7: Not listed by ACGIH, IARC, NTP, or CA Prop 65. Epidemiology: No information available. Teratogenicity: No information available. Reproductive Effects: No information available.

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147 Appendix B (Continued) Mutagenicity: No information available. Neurotoxicity: No information available. Other Studies: Section 12 Ecological Information No information available. Section 13 Disposal Considerations Chemical waste generators must dete rmine whether a discarded chemical is classified as a hazardous waste. US EPA guidelines for the classification determination are listed in 40 CFR Part s 261.3. Additionally, waste generators must consult state and local hazardous waste regulations to ensure complete and accurate classification. RCRA P-Series: None listed. RCRA U-Series: None listed. Section 14 Transport Information US DOT Canada TDG Shipping Name: Not regulated as a hazardous material No information available. Hazard Class: UN Number: Packing Group: Section 15 Regulatory Information US FEDERAL TSCA CAS# 1332-58-7 is list ed on the TSCA inventory. Health & Safety Reporting List None of the chemicals are on the Health & Safety Reporting List. Chemical Test Rules None of the chemicals in this product are under a Chemical Test Rule. Section 12b None of the chemicals ar e listed under TSCA Section 12b.

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148 Appendix B (Continued) TSCA Significant New Use Rule None of the chemicals in th is material have a SNUR under TSCA. CERCLA Hazardous Substances and corresponding RQs None of the chemicals in this material have an RQ. SARA Section 302 Extremely Hazardous Substances None of the chemicals in this product have a TPQ. Section 313 No chemicals are reportable under Section 313. Clean Air Act: This material does not c ontain any hazardous air pollutants. This material does not contain any Class 1 Ozone depletors. This material does not contain any Class 2 Ozone depletors. Clean Water Act: None of the chemicals in this pr oduct are listed as Hazardous Substances under the CWA. None of the chemicals in this pr oduct are listed as Priority Pollutants under the CWA. None of the chemicals in this produc t are listed as Toxic Pollutants under the CWA. OSHA: None of the chemicals in this product are considered highly hazardous by OSHA. STATE CAS# 1332-58-7 can be found on the following state right to know lists: California, (listed as Silica, amorphous ), New Jersey, (listed as Silica, amorphous), Pennsylvania, Minnesota, Massachusetts. California Prop 65 California No Significant Risk Level: None of the chemicals in this product are listed. European/International Regulations European Labeling in Accordance with EC Directives Hazard Symbols: Not available. Risk Phrases:

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149 Appendix B (Continued) Safety Phrases: S 24/25 Avoid contact with skin and eyes. S 37 Wear suitable gloves. S 45 In case of accident or if you feel unwell, seek medical advice immediately (show the label where possible). S 28A After contact with skin, wa sh immediately with plenty of water WGK (Water Danger/Protection) CAS# 1332-58-7: 0 Canada DSL/NDSL CAS# 1332-58-7 is listed on Canada's DSL List. Canada WHMIS This product has a WHMIS classification of Not controlled.. This product has been classified in acco rdance with the hazard criteria of the Controlled Products Regulations and the MSDS contains all of the information required by those regulations. Canadian Ingredient Disclosure List CAS# 1332-58-7 (listed as Sili ca, amorphous) is listed on the Canadian Ingredient Disclosure List. Section 16 Additional Information MSDS Creation Date: 2/16/1999 Revision #4 Date: 10/03/2005 The information above is believed to be accurate and represents the best information currently available to us. However, we make no warranty of merchantability or any other warranty, express or implied, with respect to such information, and we assume no liability re sulting from its use. Users should make their own investigations to determine the suitability of the in formation for their particular purposes. In no event shall Fis her be liable for any claims, losses, or damages of any third party or for lost profits or any s pecial, indirect, incidental, consequential or exemplary damages

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Appendix B (Continued) B.6. Nickel Nitrate NICKEL NITRATE 1. Product Identification Synonyms: Nickel (II) nitrate, hexahydrate (1:2:6); nickelous nitrate; nitric acid, nickel (2+) salt, hexahydrate; Ni ckelous nitrate, 6Hydrate CAS No.: 13138-45-9 Anhydrous; (13478-00-7 Hexahydrate) Molecular Weight: 290.83 Chemical Formula: Ni(NO3)2 6H2O Product Codes: J.T. Baker: 2784 Mallinckrodt: 6384 2. Composition/Information on Ingredients Ingredient CAS No Percent Hazardous ----------------------------------------------------------------Nickel Nitrate 13138-45-9 90 100% Yes 3. Hazards Identification Emergency Overview ------------------------DANGER! STRONG OXIDIZER. CONTAC T WITH OTHER MATERIAL MAY CAUSE FIRE. HARMFUL IF SWALLOWED OR INHALED. CAUSES IRRITATION TO SKIN, EYES AND RESPIRATORY TRACT. MAY CAUSE ALLERGIC SKIN OR RESPIRATOR Y REACTION. CANCER HAZARD. CAN CAUSE CANCER. Risk of cancer depe nds on duration and level of exposure. Very toxic to aquatic orga nisms; may cause long term adverse effects in the aquatic environment. SAF-T-DATA(tm) Ratings (Provided here for your convenience) ---------------------------------------------------------------------------------------------------------Health Rating: 3 Severe (Cancer Causing) Flammability Rating: 0 None Reactivity Rating: 3 Severe (Oxidizer) Contact Rating: 3 Severe (Life) Lab Protective Equip: GOGGLES & SHIELD; LAB COAT & APRON; VENT 150

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Appendix B (Continued) HOOD; PROPER GLOVES Storage Color Code: Ye llow (Reactive) ---------------------------------------------------------------------------------------------------------Potential Health Effects --------------------------------Inhalation: Causes irritation to the respiratory tr act. Symptoms may include coughing, sore throat, and shortness of breath. Lung damage may result from a single high exposure or lower repeated exposures. Lung allergy occasionally occurs, with asthma type symptoms. Ingestion: Toxic. Symptoms may include abdominal pain, diarrhea, nausea, and vomiting. Absorption is poor, but should it occu r, symptoms may include giddiness, capillary damage, myocardial weakness, central nervous system depression, and kidney and liver damage. Skin Contact: Causes irritation. May cause skin allerg y with itching, redness or rash. Some individuals may become sensitized to t he substance and suffer "nickel itch", a form of dermatitis. Eye Contact: Causes irritation, redness, and pain. Chronic Exposure: Prolonged or repeated exposure to excess ive concentrations may affect lungs, liver and kidneys. Chronic exposure to nickel and nickel compounds is associated with cancer. Aggravation of Preexisting Conditions: Persons with pre-existing skin disorder s, impaired respir atory or pulmonary function, or with a history of asthma, allergies, or sensitization to nickel compounds may be at an increased risk upon exposure to this substance. 4. First Aid Measures Inhalation: Remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Ge t medical attention. Ingestion: Induce vomiting immediately as direct ed by medical personnel. Never give anything by mouth to an unconscious person. Get medical attention. 151

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Appendix B (Continued) Skin Contact: Wipe off excess material from skin then immediately flush skin with plenty of water for at least 15 minutes. Remove contaminated clothing and shoes. Get medical attention. Wash clothing bef ore reuse. Thoroughly clean shoes. Eye Contact: Immediately flush eyes with plenty of wate r for at least 15 mi nutes, lifting lower and upper eyelids occasionally. Get medical attention immediately. 5. Fire Fighting Measures Fire: Not combustible, but substance is a str ong oxidizer and its heat of reaction with reducing agents or combustibles may cause ignition. Increases the flammability of any combustible material. Explosion: Contact with oxidizable substances ma y cause extremely violent combustion. Strong oxidants may explode when shocked, or if exposed to heat, flame, or friction. Also may act as initiation s ource for dust or vapor explosions. Fire Extinguishing Media: Water or water spray in early stages of fire. Foam or dry chemical may also be used. Special Information: Wear full protective clothing and breathing equipment for high-intensity fire or potential explosion conditions. 6. Accidental Release Measures Remove all sources of ignition. Ventilate area of leak or spill. Wear appropriate personal protective equipment as specified in Section 8. Spills: Clean up spills in a manner that does not disperse dust in to the air. Use non-sparking tools and equipment. Reduce airborne dust and prev ent scattering by moistening with water. Pick up spill for recovery or dis posal and place in a closed container. 7. Handling and Storage Keep in a tightly closed container, stored in a cool, dry, ventilated area. Protect against physical damage and moisture. Isol ate from any source of heat or ignition. Avoid storage on wood floor s. Separate from incompatibles, combustibles, organic or other readily oxidizable materials. Areas in which exposure to nickel metal or solubl e nickel compounds may occur should be identified by signs or appropriate m eans, and access to the area should be limited to authorized persons. Containers of this material may be hazardous when empty since they retain product residues (dust, solids); observe all warnings and precautions listed for the product. 152

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Appendix B (Continued) 8. Exposure Controls/Personal Protection Airborne Exposure Limits: -OSHA Permissible Exposure Limit (PEL): soluble Nickel compounds as Ni: 1 mg/m3 (TWA) -ACGIH Threshold Limit Value (TLV): soluble Nickel compounds as Ni: 0.1 mg/m 3 (TWA), A4 Not classifiable as a human carcinogen Ventilation System: A system of local and/or general exhaust is recommended to keep employee exposures below the Airborne Exposure Limits. Local exhaust ventilation is generally preferred because it can control the emissions of the contaminant at its source, preventing dispersion of it into t he general work area. Please refer to the ACGIH document, Industrial Ventilation, A Manual of Recommended Practices most recent edition, for details. Personal Respirators (NIOSH Approved): If the exposure limit is ex ceeded and engineering controls are not feasible, a full facepiece particulate respirator (NIOSH ty pe N100 filters) may be worn for up to 50 times the exposure limit or the maximu m use concentration specified by the appropriate regulatory agency or respirator supplier, whichever is lowest. If oil particles (e.g. lubricants, cutting fluids. glycerine, etc.) are present, use a NIOSH type R or P filter. For emer gencies or instances where the exposure levels are not known, use a full-facepiece positiv e-pressure, air-supplied respirator. WARNING: Air-purifying respirators do not protect workers in oxygen-deficient atmospheres. Skin Protection: Rubber or neoprene gloves and additional protection including impervious boots, apron, or coveralls, as needed in areas of unusual exposure. Eye Protection: Use chemical safety goggles and/or full fa ce shield where dusting or splashing of solutions is possible. Maintain eye wash fountain and quick-drench facilities in work area. Other Control Measures: Eating, drinking, and smoking should not be permitted in areas where solids or liquids containing soluble nickel compounds are handled, processed, or stored. NIOSH recommends pre-placement and periodic medical exams, with maintaining of records for all employees exposed to nickel in the workplace. 9. Physical and Chemical Properties Appearance: Green, transparent crystals. Odor: Odorless. 153

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Appendix B (Continued) Solubility: 238.5g/100cc water @ 0C Specific Gravity: 2.05 pH: 3.5 5.5 (5% solution @ 25C (77F). % Volatiles by volume @ 21C (70F): 0 Boiling Point: 137C (279F) Melting Point: 56.7C (135F) Vapor Density (Air=1): No information found. Vapor Pressure (mm Hg): 0 @ 20C (68F) Evaporation Rate (BuAc=1): No information found. 10. Stability and Reactivity Stability: Stable under ordinary conditions of use and storage. Substance has both oxidant and reducing characteristics, and is unstable when heated or shocked. Hazardous Decomposition Products: Emits toxic fumes of nickel and nitrogen oxides when heated to decomposition. Hazardous Polymerization: Will not occur. Incompatibilities: Aluminum, boron phosphide, cyanides, esters combustible material, phospham, phosphorus, sodium hypophosphite, stannou s chloride, thiocyanates, strong reducing agents, and organic materials. Conditions to Avoid: Heat, shock, friction, incompatibles. 154

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Appendix B (Continued) 11. Toxicological Information Nickelous Nitrate Hexahydrate; Oral rat LD50: 1620 mg/kg. Investigated as a tumorigen. --------\Cancer List s\-------------------------------------------------------NTP Carcinogen--Ingredient Known An ticipated IARC Category -----------------------------------------------------------Nickel Nitrate (13138-45-9) Yes No 1 12. Ecological Information Environmental Fate: When released into water, th is material is not expect ed to evaporate significantly. This material is not expected to significantly bioaccumulate. Environmental Toxicity: Dangerous to the environment. Very toxic to aquatic organisms; may cause long term adverse effects in the aquatic environment. 13. Disposal Considerations Whatever cannot be saved for recovery or recycling should be handled as hazardous waste and sent to a RCRA approv ed waste facility. Processing, use or contamination of this product may change the waste management options. State and local disposal regulations may diffe r from federal disposal regulations. Dispose of container and unused contents in accordanc e with federal, state and local requirements. 14. Transport Informatio=p Domestic (Land, D.O.T.) ---------------------Proper Shipping Name: NICKEL NITRATE Hazard Class: 5.1 UN/NA: UN2725 Packing Group: III Information reported for product/size: 4X25LB International (Water, I.M.O.) ---------------------------Proper Shipping Name: NICKEL NITRATE Hazard Class: 5.1 UN/NA: UN2725 Packing Group: III Information reported for product/size: 4X25LB 155

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Appendix B (Continued) 15. Regulatory Information --------\Chemical Inventory Status Part 1\------------------------------Ingredient TS CA EC Japan Australia -------------------------------------------------------------Nickel Nitrate (13138-45-9) Yes Yes Yes Yes --------\Chemical Inventory Status Part 2\--------------------------------Canada-Ingredient Korea DSL NDSL Phil. ---------------------------------------------------------Nickel Nitrate (13138-45-9) Yes Yes No Yes --------\Federal, State & International Regulations Part 1\----------------SARA 302------SARA 313-----Ingredient RQ TPQ List Chemical Catg. ----------------------------------------------------------Nickel Nitrate (13138-45-9) No No No Nickel cmpd/ --------\Federal, State & International Regulations Part 2\----------------RCRA-TSCAIngredient CERCLA 261.33 8(d) ---------------------------------------------------Nickel Nitrate (13138-45-9) No No No Chemical Weapons Convention: No TSCA 12(b): No CDTA: No SARA 311/312: Acute: Yes Chronic: Yes Fi re: No Pressure: No Reactivity: Yes (Pure / Solid) WARNING: THIS PRODUCT CONTAINS A CHEMICA L(S) KNOWN TO THE STATE OF CALIFORNIA TO CAUSE CANCER. Australian Hazchem Code: 1Y Poison Schedule: None allocated. WHMIS: This MSDS has been prepared according to the hazard criteria of the Controlled Products Regulations (CPR) and the MSDS contains all of the information required by the CPR. 156

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157 Appendix B (Continued) 16. Other Information NFPA Ratings: Health: 1 Flammability: 0 Reactivity: 0 Other: Oxidizer Label Hazard Warning: DANGER! STRONG OXIDIZER. CONT ACT WITH OTHER MATERIAL MAY CAUSE FIRE. HARMFUL IF SWALLOWED OR INHALED. CAUSES IRRITATION TO SKIN, EYES AND RESPIRATORY TRACT. MAY CAUSE ALLERGIC SKIN OR RESPIRATORY REACTION. CANCER HAZARD. CAN CAUSE CANCER. Risk of cancer depends on duration and level of exposure. Very toxic to aquatic organisms; may c ause long term adverse effects in the aquatic environment. Label Precautions: Do not store near combustible materials. Do not get in eyes, on skin, or on clothing. Remove and wash contaminated clothing promptly. Wash thoroughly after handling. Do not breathe dust. Keep container closed. Use only with adequate ventilation. Avoid release to the environment. Label First Aid: If swallowed, induce vomiting immediat ely as directed by medical personnel. Never give anything by mouth to an uncon scious person. If inhaled, remove to fresh air. If not breat hing, give artificial respiration. If breathing is difficult, give oxygen. In case of contact, wipe off ex cess material from skin then immediately flush eyes or skin with plenty of water for at least 15 minutes. Remove contaminated clothing and shoes. Wash clot hing before reuse. In all cases, get medical attention. Product Use: Laboratory Reagent. Revision Information: MSDS Section(s) changed since last revision of document include: 3, 11, 12, 16.

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Appendix B (Continued) B.7. Nitric Acid General Synonyms: azotic acid, aqua fortis Molecular formula: HNO3 CAS No: 7697-37-2 EC No: 231-714-2 Physical data Appearance: colourless liquid with a choking odour Melting point: -42 C Boiling point: 121 C (69% boils at ca. 86C) Specific gravity: 1.41 Vapour pressure: 62 mm Hg at 20 C (68%) Flash point: Explosion limits: Autoignition temperature: Stability Stable. Strong oxidizer. Substances to be avoided include strong bases, strong reducing agents, alkalis, most common metals, organic materials, alcohols, carbides. Corrodes steel. Light-sensitive. Toxicology May be fatal if swallowed or inhaled. Extremely corrosive. Contact with skin or eyes may cause severe burns and pe rmanent damage. TLV 2 ppm. OES longterm 5 mg/m3 Toxicity data (The meaning of any abbreviations which appear in this section is given here. ) IHL-RAT LC50 244 ppm (NO2)/30m ORL-HMN LDLO 430 mg kg-1 Risk phrases (The meaning of any risk phrases which appear in this section is given here.) R8 R23 R24 R25 R34 R41. Transport information (The meaning of any UN hazard codes which appear in this section is given here.) UN No 2031. Packing group II. Hazard class 8.0. Transport category 2. Personal protection Safety glasses or face mask, gloves. Fume cupboard. Safety phrases (The meaning of any safety phrases which appear in this section is given here.) S23 S26 S36 S37 S39 S45. 158

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Appendix B (Continued) B.8. Sodium Hdyroxide SODIUM HYDROXIDE MSDS Number: S4034 --E ffective Date: 03/05/97 1. Product Identification Synonyms: Caustic soda; lye; sodium hydr oxide solid; sodium hydrate CAS No.: 1310-73-2 Molecular Weight: 40.00 Chemical Formula: NaOH Product Codes: J.T. Baker: 3718, 3721, 3722, 3723, 3728, 3729, 3734, 3736, 5045, 5565 Mallinckrodt: 7001, 7680, 7708, 7712, 7772, 7798 2. Composition/Information on Ingredients Ingredient CAS No Percent Hazardous -----------------------------------------------------------Sodium Hydroxide 1310-73-2 99 100% Yes 3. Hazards Identification 159 Emergency Overview ------------------------POISON! DANGER! CORROSIVE. MAY BE FATAL IF SWALLOWED. HARMFUL IF INHALED. CAU SES BURNS TO ANY AREA OF CONTACT. REACTS WITH WATER, ACIDS AND OTHER MATERIALS. J.T. Baker SAF-T-DATA(tm) Ratings (Provided here fo r your convenience) ---------------------------------------------------------------------------------------------------------Health Rating: 3 Severe (Poison) Flammability Rating: 0 None Reactivity Rating: 2 Moderate Contact Rating: 4 Extreme (Corrosive) Lab Protective Equip: GOGGLES; LAB COAT; VENT HOOD; PROPER GLOVES Storage Color Code: White St ripe (Store Separately) ---------------------------------------------------------------------------------------------------------

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Appendix B (Continued) Potential Health Effects --------------------------------Inhalation: Severe irritant. Effects from inhalation of dust or mist vary from mild irritation to serious damage of the upper respir atory tract, depending on severity of exposure. Symptoms may include sneezing, sore throat or runny nose. Severe pneumonitis may occur. Ingestion: Corrosive! Swallowing may cause severe bur ns of mouth, throat, and stomach. Severe scarring of tissue and death may re sult. Symptoms may include bleeding, vomiting, diarrhea, fall in blood pressure. Damage may appears days after exposure. Skin Contact: Corrosive! Contact with skin can cause i rritation or severe burns and scarring with greater exposures. Eye Contact: Corrosive! Causes irritation of eyes, and with greater exposures it can cause burns that may result in permanent im pairment of vision, even blindness. Chronic Exposure: Prolonged contact with dilute solutions or dust has a destructive effect upon tissue. Aggravation of Preexisting Conditions: Persons with pre-existing skin disorders or eye problems or impaired respiratory function may be more susceptible to the effects of t he substance. 4. First Aid Measures Inhalation: Remove to fresh air. If not breathing, give artificial re spiration. If breathing is difficult, give oxygen Call a physician. Ingestion: DO NOT INDUCE VOMITING! Gi ve large quantities of water or milk if available. Never give anything by mouth to an unc onscious person. Get medical attention immediately. 160

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Appendix B (Continued) Skin Contact: Immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Call a physi cian, immediately. Wash clothing before reuse. Eye Contact: Immediately flush eyes with plenty of water for at least 15 minutes, lifting lower and upper eyelids occasionally. Get medical attention immediately. Note to Physician: Perform endoscopy in all cases of sus pected sodium hydrox ide ingestion. In cases of severe esophageal corrosion, the use of therapeutic doses of steroids should be considered. General supportive m easures with continual monitoring of gas exchange, acid-base balance, electrolytes, and fluid intake are also required. 5. Fire Fighting Measures Fire: Not considered to be a fire hazard. Hot or molten material can react violently with water. Can react with certain metals, su ch as aluminum, to generate flammable hydrogen gas. Explosion: Not considered to be an explosion hazard. Fire Extinguishing Media: Use any means suitable for extinguish ing surrounding fire. Adding water to caustic solution generates large amounts of heat. Special Information: In the event of a fire, wear full pr otective clothing and NIOSH-approved selfcontained breathing a pparatus with full facepiece operated in the pressure demand or other positive pressure mode. 161

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Appendix B (Continued) 6. Accidental Release Measures Ventilate area of leak or spill. Ke ep unnecessary and unprotected people away from area of spill. Wear appr opriate personal protective equipment as specified in Section 8. Spills: Pick up and place in a suitable container fo r reclamation or disposal, using a method that does not generate dust. Do not flush caustic residues to the sewer. Residues from spills can be diluted with water, neutralized with dilute acid such as acetic, hydrochloric or sulfuric. Absorb neutralized caustic residue on clay, vermiculite or other inert substance and package in a suitable container for disposal. US Regulat ions (CERCLA) require reporting spills and releases to soil, water and air in exce ss of reportable quantities. The toll free number for the US Coast G uard National Response Cent er is (800) 424-8802. 7. Handling and Storage Keep in a tightly closed container. Protec t from physical damage. Store in a cool, dry, ventilated area away from sources of heat, moisture and incompatibilities. Always add the caustic to water while sti rring; never the reverse. Containers of this material may be hazardous when empt y since they retain product residues (dust, solids); observe all warnings and pr ecautions listed for the product. Do not store with aluminum or magnes ium. Do not mix with acid s or organic materials. 8. Exposure Controls/Personal Protection Airborne Exposure Limits: OSHA Permissible Exposure Limit (PEL): 2 mg/m3 Ceiling ACGIH Threshold Limit Value (TLV): 2 mg/m3 Ceiling Ventilation System: A system of local and/or general exhaust is recommended to keep employee exposures below the Airborne Exposure Limits. Local exhaust ventilation is generally preferred because it can control the emissions of the contaminant at its source, preventing dispersion of it into t he general work area. Please refer to the ACGIH document, Industrial Ventilation, A Manual of Recommended Practices most recent edition, for details. 162

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Appendix B (Continued) Personal Respirators (NIOSH Approved): If the exposure limit is ex ceeded, a half-face dust/mist respirator may be worn for up to ten times the exposure limit or the maximum use concentration specified by the appropriate regulatory agency or respirat or supplier, whichever is lowest. A full-face piece dust/mist respirator may be worn up to 50 times the exposure limit, or the maximum use concentration spec ified by the appropriate regulatory agency, or respirator supplie r, whichever is lowest. For emergencies or instances where the exposure levels are not known, use a full-facepiece positive-pressure, air-supplied respirator. WARNING: Airpurifying respirators do not protect workers in oxygen-deficient atmospheres. Skin Protection: Wear impervious protective clothing, in cluding boots, gloves, lab coat, apron or coveralls, as appropriate, to prevent skin contact. Eye Protection: Use chemical safety goggles and/or a full face shield where splashing is possible. Maintain eye wash fountain and qu ick-drench facilities in work area. 9. Physical and Chemical Properties Appearance: White, deliquescent pellets. Odor: Odorless. Solubility: 111 g/100 g of water. Specific Gravity: 2.13 pH: 13 14 (0.5% soln.) % Volatiles by volume @ 21C (70F): 0 Boiling Point: 1390C (2534F) 163

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Appendix B (Continued) Melting Point: 318C (604F) Vapor Density (Air=1): > 1.0 Vapor Pressure (mm Hg): Negligible. Evaporation Rate (BuAc=1): No information found. 10. Stability and Reactivity Stability: Stable under ordinary conditions of us e and storage. Very hygroscopic. Can slowly pick up moisture from air and reac t with carbon dioxide from air to form sodium carbonate. Hazardous Decomposition Products: Sodium oxide. Decompositi on by reaction with certain metals releases flammable and explosive hydrogen gas. Hazardous Polymerization: Will not occur. Incompatibilities: Contact with water, acids, flamma ble liquids, and organic halogen compounds, especially trichloroethylene, may caus e fire or explosion. Contact with nitromethane and other similar nitro com pounds causes formation of shocksensitive salts. Contact with metals such as aluminum, tin, and zinc causes formation of flammable hydrogen gas. Conditions to Avoid: Moisture, dusting and incompatibles. 164

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Appendix B (Continued) 11. Toxicological Information Irritation data: skin, rabbi t: 500 mg/24H severe; eye rabbit: 50 ug/24H severe; investigated as a mutagen. --------\Cancer List s\-------------------------------------------------------NTP Carcinogen--Ingredient Known An ticipated IARC Category -----------------------------------------------------------Sodium Hydroxide (1310-732) No No None 12. Ecological Information Environmental Fate: No information found. Environmental Toxicity: No information found. 13. Disposal Considerations Whatever cannot be saved for recovery or recycling should be handled as hazardous waste and sent to a RCRA approv ed waste facility. Processing, use or contamination of this product may change the waste management options. State and local disposal regulations may diffe r from federal disposal regulations. Dispose of container and unused contents in accordanc e with federal, state and local requirements. 14. Transport Information Domestic (Land, D.O.T.) ---------------------Proper Shipping Name: SODI UM HYDROXIDE, SOLID Hazard Class: 8 UN/NA: UN1823 Packing Group: II Information reported fo r product/size: 300LB International (Water, I.M.O.) ---------------------------Proper Shipping Name: SODI UM HYDROXIDE, SOLID Hazard Class: 8 UN/NA: UN1823 Packing Group: II Information reported fo r product/size: 300LB 165

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Appendix B (Continued) 15. Regulatory Information --------\Chemical Inventory Status Part 1\------------------------------Ingredient TS CA EC Japan Australia -------------------------------------------------------------Sodium Hydroxide (1310-73-2) Yes Yes Yes Yes --------\Chemical Inventory Status Part 2\--------------------------------Canada-Ingredient Korea DSL NDSL Phil. ---------------------------------------------------------Sodium Hydroxide (1310-73-2) Yes Yes No Yes --------\Federal, State & International Regulations Part 1\----------------SARA 302------SARA 313-----Ingredient RQ TPQ List Chemical Catg. ----------------------------------------------------------Sodium Hydroxide (1310-732) No No Yes No --------\Federal, State & International Regulations Part 2\----------------RCRA-TSCAIngredient CERCLA 261.33 8(d) ---------------------------------------------------Sodium Hydroxide (1310-73-2) 1000 No No Chemical Weapons Convention: No TSCA 12(b): No CDTA: No SARA 311/312: Acute: Yes Chronic: No Fire: No Pressure: No Reactivity: Yes (Pure / Solid) Australian Hazchem Code: 2R Poison Schedule: S6 WHMIS: This MSDS has been prepared according to t he hazard criteria of the Controlled Products Regulations (CPR) and the MSDS contains all of the information required by the CPR. 166

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167 Appendix B (Continued) 16. Other Information NFPA Ratings: Health: 3 Flammability: 0 Reactivity: 1 Label Hazard Warning: POISON! DANGER! CORROSIVE. M AY BE FATAL IF SWALLOWED. HARMFUL IF INHALED. CAUSES BU RNS TO ANY AREA OF CONTACT. REACTS WITH WATER, ACIDS AND OTHER MATERIALS. Label Precautions: Do not get in eyes, on skin, or on clot hing. Do not breathe dust. Keep container closed. Use only with adequate ventilation. Wash thoroughly after handling. Label First Aid: If swallowed, DO NOT INDUCE VOMITING. Give large quantities of water. Never give anything by mouth to an unconscious person. In case of contact, immediately flush eyes or skin with plenty of water for at least 15 minutes while removing contaminated clothing and s hoes. Wash clothing before reuse. If inhaled, remove to fresh air. If not breathing give artificial respiration. If breathing is difficult, give oxygen. In all case s get medical attention immediately. Product Use: Laboratory Reagent. Revision Information: Pure. New 16 section MSDS format, all sections have been revised.