1. Arsenic Removal From Well Water in Underdeveloped Countries Trygve Hoff Dr. Harold Walker, Advisor

2. Introduction Arsenic contamination is a growing problem throughout the world Arsenic contamination is a growing problem throughout the world Argentina, Chile, China, India, Mexico, United States, Vietnam, Thailand and BangladeshArgentina, Chile, China, India, Mexico, United States, Vietnam, Thailand and Bangladesh Worst cases in Bangladesh and West Bengal regionsWorst cases in Bangladesh and West Bengal regions

3. Bangladesh Epidemic Problem originated in the 1970s Problem originated in the 1970s –UNICEF program to provide “safe” water –Arsenic wasn’t a known pollutant at the time –Saved thousands of lives from microbial pathogens, but … 35-77 Million citizens at risk of arsenic poisoning (Out of a pop. of 125 Million) 35-77 Million citizens at risk of arsenic poisoning (Out of a pop. of 125 Million)

4. Bangladesh Epidemic Tube well options: Tube well options: –Shallow Well –Deep Well Deep Concerns Deep Concerns –Renewability –Contamination from drilling? Deep Aquifer Shallow Aquifer Construction Cost: $100 Renewable: Yes As Contamination: Yes Construction Cost: $1000 Renewable: ?? As Contamination: No Southern Bangladesh Clay Layer [As] 3m clay 100m aquifer of gray sand 40m aquitard marine clay Deep Sandy Aquifer

5. Bangladesh Epidemic Arsenic Source: Geological Arsenic Source: Geological –Rock, Clay, Peat and Sand potential sources –Increased [As] due to desorption from iron oxides Change in pH, oxidation/reductions, and competing anions Change in pH, oxidation/reductions, and competing anions Excessive irrigation pumping in dry season with carbon-caused mobilization Excessive irrigation pumping in dry season with carbon-caused mobilization

6. Bangladesh Epidemic The World Health Organization has set a guideline value of 0.01mg/l or 10 ppb The World Health Organization has set a guideline value of 0.01mg/l or 10 ppb –Bangladesh wells range from 0 to 1660 ppb

7. Health Risks Arsenic poisoning appears after 10 years of consumption as arsenicosis Arsenic poisoning appears after 10 years of consumption as arsenicosis –Can lead to: Keratosis Keratosis Gangrene Gangrene Skin Cancer Skin Cancer Kidney Cancer Kidney Cancer Bladder Cancer Bladder Cancer Lung Cancer Lung Cancer

8. Health Risks 10 year old children are developing the arsenicosis 10 year old children are developing the arsenicosis Cancers appear after 20 years Cancers appear after 20 years –Huge epidemic expected in the near future

9. Health Risks Treatments are limited Treatments are limited –Consumption of only arsenic free water –Zinc, Selenium, and Vitamin A for repair of the skin –Chelation therapy Not proven to help patients Not proven to help patients

10. Research Goal To find a temporary process that satisfies these objectives: To find a temporary process that satisfies these objectives: 1.Effectively removes [As] to a potable level – Less than 10 ppb 2.Is economically feasible in undeveloped situations – Bangladesh Average Per Capita Income is $450 3.Requires minimal technological understanding

11. Experimental Details Three methods were used to treat the samples: Three methods were used to treat the samples: 1.The STAR method – FeCl 3 mixed into sample, poured through sand filter 2.The 3-Kalshi method – Sample poured through sand, iron filings, and sand 3.Granular Ferric Hydroxide Column

12. STAR Setup Ferric Chloride Packet Water Sand Filter

13. 3-Kalshi Setup Contaminated Water Coarse Sand Iron Shavings Fine Sand Wood Charcoal—Not Used Collected Water

14. GFH Column(s) Contaminated Water Treated Water

15. Results The GFH column performed sub par The GFH column performed sub par –Possibly due to: Channeling of the media Channeling of the media Inadequate contact time Inadequate contact time Media grains too large—Insufficient surface area and sorption sites Media grains too large—Insufficient surface area and sorption sites

16. Results The GFH removed just over 80% [As] The GFH removed just over 80% [As]

17. Results STAR and 3-Kalshi methods both successfully removed the arsenic STAR and 3-Kalshi methods both successfully removed the arsenic

18. Economic Analysis Average income is $450 Average income is $450 –Bangladesh is ranked 176 th of 271 countries Average Family size of 6 people Average Family size of 6 people Consumption assumed to be 50 liters/day/person Consumption assumed to be 50 liters/day/person –Arsenic poisoning only through consumption –Only treat drinking and cooking water

19. Economic Analysis STAR: Packets available for $4/family/year STAR: Packets available for $4/family/year 3-Kalshi: Iron available for$4.50/family/year 3-Kalshi: Iron available for$4.50/family/year –Iron fines available at $30/ton –3 kg shavings for ~240 liters GFH: Initial cost of $7.00 for two columns, materials $2.00/family/year afterward GFH: Initial cost of $7.00 for two columns, materials $2.00/family/year afterward

20. Ease of Use STAR: Simple STAR: Simple –Drop packet in, pour through sand filter –Collect clean water 3-Kalshi: Simple 3-Kalshi: Simple –Pour water into top bucket –Collect clean water GFH: Very difficult GFH: Very difficult –Requires technical training for a family member –Pump necessary for correct flow rate and pressure –Need a field test kit to determine when breakthrough has been reached

21. Conclusion The STAR method is most efficient and cheapest, and is easiest to use The STAR method is most efficient and cheapest, and is easiest to use 3-Kalshi method is plausible, though doesn’t remove as much [As] 3-Kalshi method is plausible, though doesn’t remove as much [As] GFH is a good method, but best used in neighborhoods that have a treatment plant and technicians GFH is a good method, but best used in neighborhoods that have a treatment plant and technicians Education of the population is KEY Education of the population is KEY