arsenic removal for potable water using a low-tech fe coagulation/filtration system eric rivera,...
TRANSCRIPT
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?