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Introduction. Arsenic contamination is a growing problem throughout the world. Argentina, Chile, China, India, Mexico, United States, Vietnam, Thailand and BangladeshWorst cases in Bangladesh and West Bengal regions. Bangladesh Epidemic. Problem originated in the 1970sUNICEF program to provide
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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