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

• Argentina, Chile, China, India, Mexico, United
  States, Vietnam, Thailand and Bangladesh
• Worst cases in Bangladesh and West Bengal regions

3
Bangladesh Epidemic

• Problem originated in the 1970s
• UNICEF program to provide safe water
• Arsenic wasnt 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 largeInsufficient 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 for4.50/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 doesnt
  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