Arsenic Removal From Drinking Water in Bangladesh

Arsenic Removal From Drinking
Water in Bangladesh
Innovation Moving Into the Real World
Matt Simmons
Arsenic Solutions, Inc.
& Cooperative Research Centre for
Waste Management and Pollution Control-
Sydney, Australia

Background
■ Arsenic Causes Many Health Problems
■ Bangladesh Has est. 40m Affected People

Background
■ Arsenic Present in Groundwater as
Arsenic(III) and (V)
■ Effective Removal Typically Requires a
Pre-oxidation Step to As(V)
■ Chemical Oxidants Such as Chlorine or
Permanganate Normally Used Are
Expensive and Cause Other Problems

Innovation Step
■ CRC Invented and Patented a Process to
Accelerate Arsenic Oxidation With Natural
Dissolved Oxygen , Using UV Light
■ Synergistic Use of Natural Iron as Both the
Photo-absorber and Co-precipitant for Removal
■ We Found Sunlight or Existing UV Technology
Could Be Used
■ It Appeared that Mine Waste Would Be The
Major Use

Innovation
■ $2 million Arsenic R&D
Project Undertaken
■ Mine Wastes Were the
Initial Focus-Fe(II) &
As(III) are “Friends”
■ Discovered Fe(II) Can
Aid Arsenic Removal
■ Application to
Bangladesh &
Elsewhere Came Later

Existing Acid Mine Waters in Montana,
USA
Mine site
Arsenic(III) Iron(II)/arsenic(III)
ppb mole ratio
Bullion Mine 410 506
Crystal Mine 930 36
Londonderry 1090 12
Susie Mine* 12000 22
Susie Mine 11420 39
Washington #1 540 13
Washington #2 150 219

• Large Scale
“FeOx” Reactor
•Demonstrated in
Montana with EPA &
DOE

Solar Oxidation Trials in Montana, USA
With DOE & EPA

Oxidation of Arsenic at USA Mine Site
As(V), mg/L
20
15
10
5
100% As(V)
0
Time of day
0 2 4 6
Hours of Sunlight

Known Problem Areas For Arsenic in
Groundwater

Montana Leads to Bangladesh:
Simple-Low Tech Solution

Bi-Lateral Aid Provides Clean Water “On-Tap”

Swiss Adaptation
of FeOx
(“SODIS” SODIS”Wegelin
and Sommer-1998)

Use of Citrate Speeds the
Reaction

Adoption of Innovation &
Commercialization
■ Effective in Typical USA Groundwater
■ Field Testing Done
■ “Non-Chlorine” Technology Attractive
■ Industrial Applications Found
■ Infrastructure/Partners Found
■ Regulations and Verification Addressed
With Partners & Stakeholders
■ Low Levels Waiting on Official MCL

Technology Transfer in USA
■ Fast Oxidation Can Use Existing Equipment
■ Cheaper and Safer than KMnO4,
Chlorine or Ozone
■ Compatible with Existing Treatment Methods:
Lime Softening, Coagulation, Alumina
Adsorption, Membrane Filtration
■ Other Contaminants Such as Manganese
also Oxidised

Treatment of Residuals Needs
to be Considered
■ Need to View the Whole “Problem”
■ CRC Group Performed Extensive Work On
Stability of Arsenic-Containing Residuals
■ Stabilized Arsenic Wastes Which Passed
USEPA-TCLP Test, Failed When Subjected
To Immersion in Aerated Water

Water Immersion Test
Measuring Cylinder
De-mineralized water
Filter cloth
Sample
Air bubbles

Calcium Arsenate
in cement
400
300
As, mg/ L
200
100
0
aerated water
No CO2
0 20 40 60
Days

Calcium Arsenite
in Cement
8000
As, mg/L
6000
4000
2000
0
air
No CO2
0 20 40 60
Days

As Bearing Ferrihydrite in Cement
As, mg/L
5
4
3
2
1
air
No CO2
0
0 50 100
Days

Concluding Remarks
■ Iron UV-Oxidation Process an Economic
Alternative to Chemical Oxidants
■ Process Compatible with Existing Water
Treatment Methods to Remove Arsenic
■ Looking Beyond Original R&D Goals Key to
Success
■ High Science Gives High Tech and Low Tech
Applications
■ Development of Different Partners for Each
Application

Summary
■ Technology Suited to New or Retrofit process
As it Fits in Existing Industrial Infrastructure
■ Patents In-place:Upside for Developers
■ $1 million Montana Test Done, Other Field
Work Done
■ Bangladesh & Developing Countries Projects
Not “Commercial”but Aid Commercialization
■ Now Know This Can be Used to Help Solve
USA Problem
http://www.arsenic.org