CAS Number: 98-50-0 Arsenic

1. CAS Number: 98-50-0 Arsenic

2. GROUND WATER AND ARSENIC • 1-4-04 STARRING:

3. Something to think about • At least 11 million people in the U.S. currently drink water contaminated with arsenic at levels above 10 ppb, according to the U.S. Environmental Protection Agency (EPA). From: Drinking Water Standard for Arsenic. U.S. Environmental Protection Agency, Office of Water, January 2001. • Arsenic has been found in at least 1,014 of the 1,598 current or former sites on the National Priorities List (NPL), the most serious hazardous waste sites in the nation identified by the U.S. Environmental Protection Agency. Rule #1: Use phrases, not sentences. 6/6 Rule: No more than 6 bullets on slide, no more than six words per bullet.

4. (är´senik) • semimetallic chemical element • stable form: silver-gray, brittle crystalline solid, tarnishes rapidly in air. • high temperatures burns white cloud of arsenic trioxide • A yellow crystalline form and a black amorphous form are also known Rule #2: Use style checker; be consistent There’s an extra space before the A.

5. HISTORY • Used since 3000 B.C. • Arsenic mined by the early Chinese, Greek and Egyptian • Albertus Magnus obtained the element in 1250 A.D. by heating soap and orpiment (arsenic trisulphide, As2S3) • Element has an alchemical symbol

6. Name is from the Greek word arsenikos and the latin word arsenicum, which means "yellow orpiment" Rule #3: Don’t overwhelm the audience

7. Where it does it come from? Rule #4: Use Spelling/Grammar Checker • naturally occurring element • considered a heavy metal • pure form not commonly found in the environment • However, arsenic is found in natural and man-made compounds.

8. Where it does it come from? • About 90% of all arsenic produced is used as a preservative in wood (e.g., pressure-treated lumber). • which contains chromated copper arsenate (CCA). • Used in insecticides, • weed killers, • fungicides, • glass production, • semiconductors, • to make metal alloys • some medications (mostly veterinary). Rule #5: Commas are unnecessary with bullets. No punctuation in a presentation

9. Where does it come from • Various industries release arsenic into the air and groundwater • mines • Smelters • cotton gins • glass manufacturing operations • coal burning facilities • municipal incinerators • leach from landfills Rule #2: Be consistent, revisited

10. Arsenic for medical reasons? • Once a treatment for Syphilis • Experimental for leukemia • Taken in medication

11. brownfield • A brownfield, by definition, is a poten-tially polluted and abandoned commer-cial and industrial site.

12. Brownfield Assessment of the Benton Auto Wreckers Site,Corvallis, Oregon SHAME ON YOU!!! 4-acre Benton Auto Wreckers site, located several miles southwest of the City of Corvallis on State Highway 20 in Benton County, Oregon

13. What is arsenic? Rule #6: Let PowerPoint work for you. These are not proper bullets. Arsenic is a natural element in the earth’s crust. In the environment, arsenic combines with oxygen, chlorine, and sulfur to form inorganic arsenic compounds. In animals and plants, arsenic combines with carbon and hydrogen to form organic arsenic compounds. IARC has reviewed the available data and considers arsenic to be a Group 1 carcinogen.

14. Basic Information • Chemical Formula = C6H8AsNo3 • CAS No = 98-50-0 • Solubility = very soluble in hot water; slightly soluble in cold water, alcohol, and acetic acid; insoluble in acetone, benzene, ether, and chloroform. • Reactivity= condition contributing to instability varies depending on the specific organic arsenic compound.

15. Health Effects • Arsenic compounds are irritants, systemic toxins, and carcinogens in humans. • Acute poisoning initial responses include; burning of the lips, constriction of the throat, and dysphasia. • Initial response is followed by excruciating pain in the abdominal region, severe nausea, vomiting, and diarrhea.

16. Health Effects • Toxic effects on the liver, blood-forming organs, both central and peripheral nervous systems, and the cardiovascular system may also occur. • Convulsions, coma, and death may follow within 24 hours of severe poisonings.

17. Health Effects • Inhalation may damage the mucous membranes of the respiratory system. • Severe irritation of the nasal mucosa, larynx, and bronchi have been observed following exposure. • Exposed skin may become irritated; cases of visual disturbances, hyper pigmentation of the skin, and perforation of the nasal septum have been noted.

18. Health Effects • Chronic exposure causes damage to the nervous and cardiovascular systems, also to the liver. • Anemia and leukocytopenia have been reported to occur following chronic exposures to arsenic compounds. • Cancers of the skin, lungs, larynx, lymphoid system, and viscera have been identified as potential responses to arsenic poisoning.

19. Measurement of Arsenic in Water • Accurate measurement of arsenic in drinking-water at levels relevant to health requires laboratory analysis, using sophisticated and expensive techniques, facilities as well as trained staff not easily available or affordable in many parts of the world. • Field test kits can detect high levels of arsenic bur are typically unreliable at lower concentration of concern for human health.

20. Arsenic Remediation There are currently 9 general processes I. Oxidation II. Coagulation/Co-precipitation III. Sedimentation IV. Filtration V. Adsorption VI. Ion Exchange VII. Membrane/ Reverse Osmosis VIII. Biological IX. Other   Rule 7: Use features to enhance the presentation, not run the show

21. 1. Oxidation • Of the two predominant forms of arsenic in water, arsenate and arsenite, most treatment processes are effective at removing arsenate, but not arsenite, since arsenite is typically non-charged below pH 9.2. Therefore, treatment for the removal of arsenic often includes an oxidation step to convert arsenite to arsenate. •         Oxidation can be simply the addition of oxygen to a compound, or more generally, any reaction involving the loss of electrons from an atom. Aeration, the supplying of air, oxidizes arsenic, converting arsenite to arsenate, and the iron that co-occurs. This is precipitated as FeAsO4. Arsenic can also be oxidized by a number of other chemicals including chlorine, hypochlorite, ozone, permanganate, hydrogen peroxide and Fenton’s reagent (H2O2/Fe2+). Photochemical oxidization proceeds from the reaction of radiant energy and a chemical system. • Oxidation alone does not remove arsenic from solution but must be combined with an arsenic removal process.

22. 2. Coagulation/Co-Precipitation Coagulation involves the removal of colloidal (0.001 - 100 microns) and settleable (> 100 microns) particles. Coagulation encompasses all reactions, mechanisms and results in the overall process of particle growth (floc formation) and particle aggregation within a water being treated. Co—precipitation: incorporation of soluble arsenic species into the metal hydroxide floc.

23. Coagulation converts soluble arsenic into insoluble reaction products, allowing separation by sedimentation and/or filtration. *Precipitation: the formation of insoluble compounds Al(AsO4) or Fe(AsO4) *   Co—precipitation: incorporation of soluble arsenic species into the metal hydroxide floc *  Adsorption: the electrostatic binding of soluble arsenic to the external surfaces of the insoluble metal hydroxides

24. There are 4 types of co-precipitation: 1.Inclusion: mechanical entrapment of a portion of the solution surrounding the growing particle. 2.Adsorption: the attachment of an impurity onto the surface of a particle or precipitate. 3.Occlusion: A contaminant is trapped in the interior of a particle of precipitate. 4.Solid-solution formation: another type of occlusion where a particle of precipitate becomes contaminated with a different type of particle that precipitates under similar conditions and is formed from ions whose sizes are nearly equal to those of the original precipitate.

25. 3. Sedimentation Sedimentation is the gravity separation of solids from liquid by settling. It is generally used in conjunction with coagulation/precipitation

26. 4. Filtration Conventional filtration is the separation of solid particles from water by passing the solution through a medium. Particles are removed during filtration as a result of any one or combination of mechanisms: mechanical straining, sedimentation, flocculation,adsorption and/or biological metabolism (AWWA, 1999).

27. 5. Adsorption Adsorption is the accumulation of materials at an interface, the liquid/solid boundary layer. * oxides (e.g. hydrated ferric oxide, titanium oxide, silicon oxide); * iron oxide-coated or MnO2-coated sand; * bauxite, hematite, feldspar; * clay minerals (e.g. kaolinite, bentonite, Bijoypur clay); * synthetic anion exchange resins; * chitin and chitosan; * bone char; * cellulose materials (sawdust, newspaper pulp).

28. 6. Ion Exchange Ion exchange is the reversible interchange of ions between the solid and the liquid phase where there is no permanent change in the structure of the solid. Developed for large-scale applications, ion exchange is probably not appropriate for small hand‑pumped wells, but could potentially be used on a village scale in Bangladesh • Charged functional groups are attached to the matrix through covalent bonding and fall into four groups (Clifford, 1999) • Strongly acidic • Weakly acidic • Strongly basic • Weakly basic

29. 7. Membrane/Reverse Osmosis Membrane separation uses semi-permeable membranes that are selectively permeable to water and certain solutes to separate impurities from water Membranes are able to remove many different kinds of dissolved solids, including arsenic, from water. However, they are usually expensive and therefore are typically considered in applications such as desalination, brackish water conversion and for removal of specific ions, such as arsenic, that are difficult to remove by other means

30. 8. Biological Biological treatment transforms, stabilizes and/or removes arsenic by means of microorganisms. Microorganisms, primarily certain specific bacteria, accomplish this by oxidation/reduction, mineralization,detoxification or methylation. Critical factors include energy and carbon source; aerobic, anoxic or anaerobic conditions; temperature; pH

31. 9. Other Dug Wells Deeper Tube Wells Ponds Solar Distillation Solar distillation uses the sun's energy to evaporate water, which then recondenses. The process of evaporation and recondensation separates all chemicals, including arsenic, from the water. In Bangladesh,where solar energy is plentiful, this approach may be especially suited for application in crisis areas, and, if cost- effective approaches can be developed, in rural are as generally.

32. Point Of Use- POU- Home FilterSystems • Oxidation • Precipitation • Filtration and Removal Rule #8: Pictures/Graphics are great. Show them, don’t tell them Arsenicfilters.com display

33. West Central Environmental Consultants, Inc Can Provide A Complete Cleanup Plant for Arsenic Treated Wood facilities. Contaminants:Chromated Copper Arsenate (CCA) Cost:Full Scale plant capable of treating 100 tons/day of CCA contaminated waste wood will cost around $1,000,000 Rule #9: KEEP IT SIMPLE (KIS) No more than 2 colors in a show; No more than 2 fonts or font sizes on a slide. Other Applications:Remediation of Metal contaminated soil, sludge and other debris Secondary Waste:None Operating Cost:It will cost between $120 to $150 /ton for remediation of of CCA contaminated wood in a 100 ton/day plant Tech Know New Remediation Technologies www.techknow.org

34. State Average Arsenic Concentrations for Systems Finding Arsenic Based on best estimate of average arsenic levels for systems that found arsenic. USGS

35. Rules to Remember • 6x6 Rule • Proofread and use Style Checker • Don’t overwhelm the audience • Use Spelling/Grammar Checker • No punctuation in a presentation • Let PowerPoint work for you • Use features to enhance the show, not be the show • Show them, don’t tell them • KIS Rule