Arsenic Contamination in South
Arsenic Contamination in South
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-
east Asia Region :
east Asia Region :
TECHNOLOGIES FOR ARSENIC MITIGATION
TECHNOLOGIES FOR ARSENIC MITIGATION
M.
M.
Feroze
Feroze
Ahmed
Ahmed
Ph.D., FIE, MASCE
Professor of Civil/Environmental Engineering
Bangladesh Univ. of Eng. & Tech., Dhaka, Bangladesh
Outline of Presentation
Outline of Presentation
O
O
Arsenic Contamination: Global and South
Arsenic Contamination: Global and South
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-
east Asia Scenario
east Asia Scenario
O
O
Arsenic Mitigation Water Supply Technologies
Arsenic Mitigation Water Supply Technologies
O
O
Arsenic Detection and Measurement Technologies
Arsenic Detection and Measurement Technologies
O
Worldwide Arsenic Contamination of Groundwater
WAIRAKI. NEW ZEALAND RONPHIBUN DISTRICT. THAILANDRED RIVER DELTA VIETNAM TAIWAN KYUSHU. JAPAN KAMCHATKA INNER MONGOLIA. CHINA SHANXI PROVINCE. CHINA XINJIANG PROVINCE. CHINA BENGAL DESTA. WEST BENGAL. BANGLADESH GREAT HUNGARIANPLAIN. HUNGARY. ROMANIA LAVRION PENINSULA. GREECE SOUTH-WEST ENGLAND MASSIF CENTRAL. FRANCE ASHANTI REGION. GHANA ZIMBABWE SOUTHAFRICA CHACO-PAMPEAN PLAIN. ARGENTINA NORTH-WEST ARGENTINA ANTOFAGASTA CHILE DOMINICA HALIFAZ. NOVA SCOTIA EL SALVADOR ZIMAPAN VALLEY LAGUNERA DISTRICT. MEXICO WESTERN U.S.A. ALEUTIAN ISLANDS FAIRBANKS. ALASKA BRITISH COLUMBIA YELLOWSTONE PARK NORTH-CENTRAL MEXICO Arsenic-affected aquifers
Arsenic related to mining operations Geothermal waters
O
O
Treatment of Arsenic Contaminated Water;
Treatment of Arsenic Contaminated Water;
O
O
Alternative water Supply Options
Alternative water Supply Options
O
O
Treatment of surface water
Treatment of surface water
O
O
Deep
Deep
tubewell
tubewell
;
;
O
O
Dug/Ring well;
Dug/Ring well;
O
O
Rainwater harvesting;
Rainwater harvesting;
0
0
Piped Water Supply adopting any of the above
Piped Water Supply adopting any of the above
Technological Option
Technological Option
ARSENIC MITIGATION WS TECHNOLOGIES
Major Treatment Processes
Major Treatment Processes
O
O
Oxidation and Sedimentation
Oxidation and Sedimentation
O
O
Coagulation and Filtration
Coagulation and Filtration
O
O
Aluminium
Aluminium
Alum
Alum
O
O
Iron salts
Iron salts
O
O
Naturally Occurring Iron
Naturally Occurring Iron
O
O
Sorptive
Sorptive
Filtration
Filtration
O
O
Activated
Activated
Alumina
Alumina
O
O
Granulated Ferric Hydroxide/Oxide
Granulated Ferric Hydroxide/Oxide
O
O
Metallic Iron/ Iron Ore
Metallic Iron/ Iron Ore
O
O
Synthetic Composite Active Materials
Synthetic Composite Active Materials
O
O
Ion Exchange
Ion Exchange
O
O
Membrane Filtration
Membrane Filtration
O
O
Nano
Nano
Filtration
Filtration
O
O
Reverse Osmosis
Reverse Osmosis
TREATMENT OF ARSENIC CONTAMINATED WATER
Processes Mainly Based on Oxidation
Processes Mainly Based on Oxidation
Passive Sedimentation ( Bashi Pani)
In-situ Oxidation
Solar Oxidation (SORAS)
Advantage
Advantage
•
No Chemical added
Limitations
Limitations
• Not reliable
• Reduction is variable
• Reduction is dependent on
alkalinity, presence of
adsorbing substances like iron,
aluminum etc.
TREATMENT OF ARSENIC CONTAMINATED WATER
TREATMENT OF ARSENIC CONTAMINATED WATER
Inlet to TW Tray (75 mm slope)
Section X-X
1400 mm 1100 mm 600 mm 35 mm GI pipe 150 mm Wash out 75 mmCoagulation, Co
Coagulation, Co
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-
precipitation And Adsorption Processes
precipitation And Adsorption Processes
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Household Units
Household Units
Flexible Plastic Pipe Cloth Screen Sand Filter PVC Slotted Screen Top Bucket Bottom Bucket
Bucket Treatment
Unit
Stevens Institute
Technology
Chemicals Mixing stick Main bucket Interior bucket Slits Outlet with cloth filter Plastic pipe to deliver treated water Filte r sand Transfer of chemical mixed waterTREATMENT OF ARSENIC CONTAMINATED WATER
Tubewell Attached
Unit
Fill and Draw Units
Cover Impeller Tank Sludge withdrawal pipe Handle Filtration unit Gear system Treated water
A - Mixing; B - Flocculation; C - Sedimentation; D - Filtration (Up-flow)
A B
C
D
B
Coagulation, Co
Coagulation, Co
-
-
precipitation And Adsorption Processes
precipitation And Adsorption Processes
--
Community Units
Community Units
TREATMENT OF ARSENIC CONTAMINATED WATER
y = 0.8718x + 0.4547 R2 = 0.6911 20 30 40 50 60 70 80 90 100 20 30 40 50 60 70 80 90 100 Iron Removal , % Arsenic Removal ,%
Correlation Between
Arsenic and Iron Removal
Pump
Back washing
Water supply
Overhead
water tank
Chlorination
Pump
Aeration
Inlet pipe
Filter bed
As-Fe Removal plant at
For Urban Water Supply
Aeration, Adsorption and Filtration Process
- Small Town Water Supply
TREATMENT OF ARSENIC CONTAMINATED WATER
Iron Coated Crushed Brick Particles Perforated Plate Covered Cloth Flexible Water Delivery Pipe Treated Water in a Bucket Support Lid
Shapla Filter
Activated Alumina Oxidation Sedimentation Unit Sand Filtratio n UnitBUET Activated Alumina
Sorptive Filtration-
Household Type
Arsenic
Contaminated
Tubewell Water
Arsenic safe
Water
Adsorbing
Media
SAFI Filter
Raw Water Filter Media 1 Sand, IronFillings & Brick Chips Filter Media 2 Sand, Charcoal & Brick Chips Filtered WaterSono 3-Kalshi
TREATMENT OF ARSENIC CONTAMINATED WATER
Tubewell
Outlet (Treated Water) Inlet
( Water from Tubewell)
Aqua-Bind Arsenic Aqua-Bind Filter Media Lift Pump Bucket Containing Treated Water Deliver Hose Pipe Raising Hose
Pipe
Apyron ARU
Alcan Enhanced Activated Alumina
Sorptive Filtration-
Community Type
Contaminated
Water Inflow Treated Water Outflow
Gravel Filter Bed Adsorption Tower
SIDKO(Bangladesh)
Pal Tockner (India) ARU
Chlorine Source
Sieve
Stabilizer
Stone Chips
Stand
Resin Column
(Ion Exchanger)
Column
Head
Tap
Tetrahedron Ion Exchange Unit
TREATMENT OF ARSENIC CONTAMINATED WATER
Raw Water
Clear
Water
Water from
Pond
Filter
Sand
Coarse
Aggregate
Under Drainage
System
Handpump for water
Supply to Filter
Slow Sand Filter (Pond Sand Filter ( PSF))
Slow Sand Filter (Pond Sand Filter ( PSF))
ALTERNATIVE WATER SUPPLY OPTIONS
ALTERNATIVE WATER SUPPLY OPTIONS
Multi
Multi
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-
Stage Roughing and Slow Sand Filters
Stage Roughing and Slow Sand Filters
Raw Water Clear Water
