arsenic removal from well water in underdeveloped countries

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

3. Bangladesh Epidemic 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)

4. Bangladesh Epidemic Tube well options: Shallow Well Deep Well Deep Concerns Renewability Contamination from drilling?

5. Bangladesh Epidemic 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 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 Bangladesh wells range from 0 to 1660 ppb

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

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

9. Health Risks 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

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

11. Experimental Details Three methods were used to treat the samples: The STAR method FeCl3 mixed into sample, poured through sand filter The 3-Kalshi method Sample poured through sand, iron filings, and sand Granular Ferric Hydroxide Column

12. STAR Setup

13. 3-Kalshi Setup

14. GFH Column(s)

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

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

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

18. Economic Analysis Average income is $450 Bangladesh is ranked 176th of 271 countries Average Family size of 6 people 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 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

20. Ease of Use STAR: Simple Drop packet in, pour through sand filter Collect clean water 3-Kalshi: Simple Pour water into top bucket Collect clean water 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 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 Education of the population is KEY