Arsenic Contamination in SouthArsenic Contamination in South--east Asia Region :east Asia Region :TECHNOLOGIES FOR ARSENIC MITIGATIONTECHNOLOGIES FOR ARSENIC MITIGATION

M. M. Feroze Feroze AhmedAhmed Ph.D., FIE, MASCEProfessor of Civil/Environmental Engineering

Bangladesh Univ. of Eng. & Tech., Dhaka, Bangladesh

Outline of PresentationOutline of Presentation

OO Arsenic Contamination: Global and SouthArsenic Contamination: Global and South--east Asia Scenarioeast Asia Scenario

OO Arsenic Mitigation Water Supply TechnologiesArsenic Mitigation Water Supply Technologies

OO Arsenic Detection and Measurement TechnologiesArsenic Detection and Measurement Technologies

OO Costs of Water Supply for Arsenic MitigationCosts of Water Supply for Arsenic Mitigation

Worldwide Arsenic Contamination of Groundwater

WAIRAKI. NEW

ZEALAND

RONPHIBUN DISTRICT. THAILAND

RED RIVER DELTA VIETNAM

TAIWAN

KYUSHU. JAPAN

KAMCHATKAINNER 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

LEGEND

OO Treatment of Arsenic Contaminated Water;Treatment of Arsenic Contaminated Water;

OO Alternative water Supply OptionsAlternative water Supply Options

OO Treatment of surface waterTreatment of surface waterOO Deep Deep tubewelltubewell;;OO Dug/Ring well;Dug/Ring well;OO Rainwater harvesting;Rainwater harvesting;

00 Piped Water Supply adopting any of the above Piped Water Supply adopting any of the above Technological OptionTechnological Option

ARSENIC MITIGATION WS TECHNOLOGIESARSENIC MITIGATION WS TECHNOLOGIES

Major Treatment ProcessesMajor Treatment ProcessesOO Oxidation and SedimentationOxidation and SedimentationOO Coagulation and FiltrationCoagulation and Filtration

OO AluminiumAluminium AlumAlumO O Iron saltsIron saltsOO Naturally Occurring Iron Naturally Occurring Iron

OO SorptiveSorptive FiltrationFiltrationOO ActivatedActivated AluminaAluminaOO Granulated Ferric Hydroxide/OxideGranulated Ferric Hydroxide/OxideO O Metallic Iron/ Iron OreMetallic Iron/ Iron OreOO Synthetic Composite Active MaterialsSynthetic Composite Active MaterialsO O Ion ExchangeIon Exchange

OO Membrane FiltrationMembrane FiltrationOO NanoNano FiltrationFiltrationOO Reverse OsmosisReverse Osmosis

TREATMENT OF ARSENIC CONTAMINATED WATERTREATMENT OF ARSENIC CONTAMINATED WATER

Processes Mainly Based on OxidationProcesses Mainly Based on Oxidation

Passive Sedimentation ( Bashi Pani)In-situ OxidationSolar Oxidation (SORAS)

AdvantageAdvantage• No Chemical added

LimitationsLimitations• Not reliable• Reduction is variable• Reduction is dependent on

alkalinity, presence of adsorbing substances like iron, aluminum etc.

TREATMENT OF ARSENIC CONTAMINATED WATERTREATMENT OF ARSENIC CONTAMINATED WATER

Inlet to TW

Tray (75 mm slope)

Section X-X

1400 mm

1100 mm

600 mm

35 mmGI pipe

150 mm Wash out

75 mm

Coagulation, CoCoagulation, Co--precipitation And Adsorption Processes precipitation And Adsorption Processes -- Household UnitsHousehold Units

Flexible Plastic Pipe

ClothScreen

SandFilter

PVC Slotted Screen

Top Bucket

BottomBucket

Bucket Treatment Unit

Stevens Institute Technology

Chemicals

Mixing stick

Main bucketInterior bucket

Slits

Outlet with cloth filter

Plastic pipe to deliver treated water

Filter sand

Transfer of chemical mixed water

TREATMENT OF ARSENIC CONTAMINATED 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

DB

Coagulation, CoCoagulation, Co--precipitation And Adsorption Processes precipitation And Adsorption Processes -- Community UnitsCommunity Units

TREATMENT OF ARSENIC CONTAMINATED WATERTREATMENT OF ARSENIC CONTAMINATED WATER

y = 0.8718x + 0.4547R2 = 0.6911

20

30

40

50

60

70

80

90

100

20 30 40 50 60 70 80 90 100

Iron Removal , %

Ars

enic

Rem

ova

l ,%

Correlation Between Arsenic and Iron Removal

Pump

Back washing Water supply

Overheadwater 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 WATERTREATMENT OF ARSENIC CONTAMINATED WATER

Iron CoatedCrushed BrickParticles

Perforated PlateCovered Cloth

Flexible WaterDelivery Pipe

Treated Waterin a Bucket

Support

Lid

Shapla Filter

ActivatedAlumina

Oxidation

Sedimentation Unit

SandFiltrationUnit

BUET Activated Alumina

Sorptive Filtration- Household Type

Arsenic Contaminated Tubewell Water

Arsenic safe Water

Adsorbing Media

SAFI Filter

Raw Water

Filter Media 1Sand, IronFillings & Brick Chips

Filter Media 2Sand, Charcoal &Brick Chips

Filtered Water

Sono 3-Kalshi

TREATMENT OF ARSENIC CONTAMINATED WATERTREATMENT OF ARSENIC CONTAMINATED WATER

Tubewell

Outlet(Treated Water)

Inlet( Water from Tubewell)

Aqua-BindArsenic

Aqua-BindFilter Media

Lift PumpBucket ContainingTreated Water

Deliver Hose Pipe

Raising Hose Pipe

Apyron ARU

Alcan Enhanced Activated Alumina

Sorptive Filtration- Community Type

ContaminatedWater Inflow

Treated Water Outflow

Gravel Filter Bed Adsorption Tower

SIDKO(Bangladesh)Pal Tockner (India) ARU

Chlorine Source

Sieve

Stabilizer

Stone Chips

StandResin Column (Ion Exchanger)

Column Head Tap

Tetrahedron Ion Exchange Unit

TREATMENT OF ARSENIC CONTAMINATED WATERTREATMENT OF ARSENIC CONTAMINATED WATER

Raw Water

ClearWater

Water fromPond

FilterSand

CoarseAggregate

Under DrainageSystem

Handpump for waterSupply to Filter

Slow Sand Filter (Pond Sand Filter ( PSF))Slow Sand Filter (Pond Sand Filter ( PSF))

ALTERNATIVE WATER SUPPLY OPTIONSALTERNATIVE WATER SUPPLY OPTIONS-- Surface Water TreatmentSurface Water Treatment

MultiMulti--Stage Roughing and Slow Sand FiltersStage Roughing and Slow Sand Filters

Raw Water

Clear Water

FilterSand

CoarseAggregate

Under DrainageSystem

To OverheadReservoir

X

XXX

Hydraulic Grade LineX

ALTERNATIVE WATER SUPPLY OPTIONSALTERNATIVE WATER SUPPLY OPTIONS-- Surface Water TreatmentSurface Water Treatment

ALTERNATIVE WATER SUPPLY OPTIONSALTERNATIVE WATER SUPPLY OPTIONS-- Surface Water TreatmentSurface Water Treatment

Source of Surface Water

Storage/ Sedimentation

Mixing Flocculation

Coagulants

Secondary Sedimentation

Filtration Disinfection

Chlorine

StorageTank

To Distribution

Small-scale Conventional Surface Water Treatment Plant

Silty clay

Arsenic ContaminatedShallow Aquifer (Sandy silt )

Arsenic-safeDeep Aquifer(Fine to medium sand)

Water Table

Clay Seal

Clayey Layer

Strainer

Sand Trap

Relatively Impermeable

Hand Pump

Manually Operated Deep Tubewell

RequirementsO Availability of deep

aquifers separated from shallow contaminated aquifers by relatively impermeable layers.

O The annular space of bore holes of the deep tubewellsis required to be sealed at the level of impermeable strata to avoid percolation of arsenic contaminated water.

-- DEEP TIBEWELLDEEP TIBEWELLALTERNATIVE WATER SUPPLY OPTIONSALTERNATIVE WATER SUPPLY OPTIONS

(a) Conventional Dug Well (b) Well with Sanitary Protection

-- Dug/Ring WellsDug/Ring Wells

ALTERNATIVE WATER SUPPLY OPTIONSALTERNATIVE WATER SUPPLY OPTIONS

-- Rainwater HarvestingRainwater Harvesting

Basic RequirementsAdequate Rainfall

-Intensity of Rainfall-Reliability of Rainfall

Distribution of RainfallSuitable Catchment areaStorage TankOperation and Maintenance

ALTERNATIVE WATER SUPPLY OPTIONSALTERNATIVE WATER SUPPLY OPTIONS

Monthly Distribution of Rainfall of an Average Year

500

400

300

200

100

00J F M A M J J A S O N DJ F M A M J J A S O N DR

ainf

all I

nten

sity

, mm

/Mon

th

Month

Catchment Area

The minimum catchment area, A ( m2) required for collection of rainwater for N number of person to be supplied with q litre per capita per day is :

A = 0.365 q N / ( C I )

Rainwater Storage Tank

The minimum volume of storage tank V ( m3) required

V = 0.365 f q N

Where f is the fraction of available rainwater required to be stored

-- Rainwater HarvestingRainwater Harvesting

ALTERNATIVE WATER SUPPLY OPTIONSALTERNATIVE WATER SUPPLY OPTIONS

COST OF WATER SUPPLY BY ARSENIC REMOVAL TECHNOLOGYCOST OF WATER SUPPLY BY ARSENIC REMOVAL TECHNOLOGY

Technology/ProcessTechnology/Process TypeType Cost, $/mCost, $/m33

Oxidation-Sedimentation Urban WS 0.05-Filtration Community 0.10

Coagulation-Sedimentation Household 1.70-Filtration Community 1.21

Sorptive FiltrationO Iron Fillings Household 0.24O Iron Coated brick Chips Household 0.73O Granulated Ferric Hydroxide Community 1.37O Synthetic Active Materials Household 1.84O Activated Alumina Household 2.30

Community 3.24O Ion Exchange Community 3.79

O Reverse Osmosis Community 2 - 4

COST OF WATER SUPPLY BY ALTERNATIVE OPTIONSCOST OF WATER SUPPLY BY ALTERNATIVE OPTIONS

* With full development potentials

Technology

Rainwater Harvesting

Manually operated Deep Tubewell

Pond Sand Filter

Dug/Ring Well

Conventional Treatment

Ground Water Based Piped Water Supply

Capital Recovery

Cost, $/M3

1.830

0.146

0.143

0.249

0.122

0.358

O and M Cost, $/M3

0.304

0.005

0.018

0.007

0.231

0.049

Total Unit Cost,$/M3

2.134

0.1510.028*

0.1610.066*0.2560.072*0.353

0.4070.091*

ARSENIC DETECTION AND MEASUREMENT TECHNOLOGYARSENIC DETECTION AND MEASUREMENT TECHNOLOGY

Laboratory Analysis MethodsLaboratory Analysis Methods

Techniques MDL ,µ/L System Cost Comments(1000 US$)

AAS-HG 0.05-2 20- 100 Single Element

AAS-GF 1 - 5 30 - 100 Single Element

ICP-AES 35 - 50 60 - 200 Multi-element

ICP-MS 0.02 - 1 150 - 400 Multi-element

ASV 0.1 - 2 25 - 50 Free Dissolved As

SDDC 1 - 10 2 - 10 Single Element

ARSENIC DETECTION AND MEASUREMENT TECHNOLOGYARSENIC DETECTION AND MEASUREMENT TECHNOLOGY

Field Measurement Methods (Some Common Field Test Kits)Field Measurement Methods (Some Common Field Test Kits)

Kit Type Kit Type Country of Range of Cost/Kit CosCountry of Range of Cost/Kit Cost/Test t/Test OriginOrigin µg/L US $ US $µg/L US $ US $

E-Mark Kit Germany 5-500

HACH Kit USA 10-500

Quick TM USA 10-1000

AIID&PH Kit India Yes/No

NIPSOM Kit Bangladesh 10 - 700

GPL Kit Bangladesh 10-2500

Asenator Austria/UK <10-500 1,250/185 1 - 240

-10

0 / F

ield

Tes

t Kit

0.4

-1

/ Sa

mpl

e Te

st

THANK YOUTHANK YOUFor Your Kind AttentionFor Your Kind Attention