Arsenic Removal for Potable Water Using a Low-tech Fe

Coagulation/Filtration System

Eric Rivera, Civil Engineering NMSU

Luis Villareal, Civil Engineering NMSU

Adrian Hanson, Ph.D., PE, NMSU Professor Environmental Engineering

AMP URCA Conference4/17/08Corbet Center

Acknowledgements

• New Mexico Alliance for Minority Participation (AMP)

• Desert Sands Mutual Domestic Water System• Edward Livingston; Livingston and associates

inc.

Arsenic• A toxic element found in natural deposits in

the earth.• Dissolved into ground water as it moves

through the aquifer matrix.• Other sources:

– Fertilizers– Animal feeding operations– Industrial practices; copper smelting, mining, coal

burning

Health risks• Cancer; bladder, lungs, skin, kidney, nasal

passages, liver, and prostate. (USEPA)

• Skin pigmentation changes, and hyperkeratosis(thickening of the skin) (WHO)

• Arsenic in drinking-water will cause 200,000 -- 270,000 deaths from cancer in Bangladesh alone. (NRC, 1998; Smith, et al, 2000).

National Contamination Levels

Arsenic concentrations found in at least 25% of ground-water samples.

EPA Regulations

• Maximum Contaminate Level (MCL)– 10 parts per billion (.010 parts per million) as of

January 23, 2006 – Any water system serving 15 locations or 25

residents year-round

Desert Sands• Two operating wells, and one new well

awaiting approval• 17-27 parts per billion Arsenic• Serves about 650 connections (1,500 people).• EPA has granted an extension to meet new

standards• Recently had arsenic removal using an iron

oxide filter system: costly to maintain.–$30,000 or more per year

Proposed Solution

• Low-tech FeCL3 Coagulation/filtration system–Complete removal of Arsenic–Low costs–Low maintenance–Simple operation

The Treatment Method

• Coagulation-Creates particles that As adsorbs to and settles with.

• Filtration-removes remaining As/particles.

Treatment Train

Inlet

Static mixer

Settling Chamber Filter

Outlet

Flocculation Chamber

Jar Testing

Results

Results

Arsenic Removal in Emergency Response Water Treatment

Portable Rapid Deployment System

Chemical Delivery• Solid FeCl3 and solid Chlorine• Longer shelf-life for emergency situations

Results• Reaction can occur rapidly enough to be effective• Oxidation is a problem

Problems• Oxidation

Future Applications• Emergency Treatment Unit (ETU)• Solid Chemical Delivery

Thank YouThank You

QUESTIONS?