Technologies to Remove Arsenic from Drinking Water
One in five deaths in Bangladesh is caused by drinking water
contaminated with arsenic, according to a study recently published in the
medical journal The Lancet by an international team of
researchers. (To read more about the study, read “Deadly
Effect of Arsenic in Drinking Water Measured”.)
Scientists at the Lawrence Berkeley National Laboratory
(Berkeley Lab), in collaboration with University of California (UC) Berkeley, have developed low-cost, sustainable technical
solutions to the arsenic problem, accompanied by a business model that is
informed by culturally relevant data, lessons from failed technologies and
implementations, and public-health success stories from other parts of South Asia.
“It’s not just about technology to remove arsenic from water – several technology solutions have been developed and nearly every one has failed in implementation,” says Susan Addy, a guest researcher at Berkeley Lab and postdoctoral scholar at UC Berkeley’s Department of Civil and Environmental Engineering. “We have to design for implementation and sustainability, which means delivering a business model that can survive over time, along with a technology that the business would manage.”
The Berkeley Lab team is led by Ashok Gadgil, Acting Director of Berkeley Lab’s Environmental Energy Technologies Division and recipient of a 2009 Heinz Award for his efforts to improve energy efficiency and enhance the quality of life in developing countries. His team includes Addy, along with students from UC Berkeley’s School of Public Health, Haas School of Business, the engineering and economics departments, and the economics department and Global Change Programme at Jadavpur University (Kolkata, India). They’ve spent significant time on the ground in Bangladesh and West Bengal (India) meeting with NGOs, community advocates, government officials, religious leaders and affected families. The purpose was to gather information on why other attempts at addressing the arsenic problem failed, including an examination of the issues competing for Bangladeshis’ time and resources, and gaps in available prevention information and health education.
Arsenic in drinking water, even at dangerously high concentrations, is tasteless, odorless and colorless, and the effects of arsenic poisoning on the human body often do not present themselves until long after exposure begins. During their discussions with locals on why other decontamination methods failed, the team learned that when maintenance or replacement was required for household-scale water-treatment filters and devices, it often was put off in favor of other pressing concerns, or the technology was abandoned altogether.
Gadgil encountered a similar situation more than a decade earlier while working on a water disinfection system, UV Waterworks, to battle Bengal cholera in India. What worked there – and has been replicated successfully in several other countries using UV Waterworks – was a locally owned community-scale facility, similar to a local micro-utility for safe drinking water. The team developed a similar business model specifically tailored to address the arsenic problem in Bangladesh.
“A local financial institution provides capital to a village council which contracts with a private company to build a treatment facility,” explains Gadgil. Under this scenario, the company would operate and maintain the facility under contract to the local village council, which would set the price of water for the community. Community members would not have to learn how to operate and maintain equipment, and revenues from sales would provide the funding to sustain the facility over the long term, and provide for ongoing prevention education.
Berkeley Lab scientists first became aware of the arsenic problem in Bangladesh in the late 1990s, and soon thereafter began working on an effective approach to removing the contaminant from drinking water and save lives. To date, they have developed two low-cost methods that can be applied to their community-scale business model – ECAR (electrochemical arsenic remediation) and ARUBA (arsenic removal using bottom ash).
The ARUBA method uses bottom ash, a widely available waste material from coal-fired power plants coated with an iron-containing chemical to absorb and chemically bind to arsenic in water. The result is a solid particle that can be filtered out, leaving the water safe for drinking. ARUBA has proven effective in laboratories and in the field, and the minimal manufacturing required can be done using simple room temperature and pressure processes.
ECAR is a simpler technology that has proven equally effective in the laboratory, and requires minimal materials – a tub or small tank, two metal plates, and a small amount of electric power (a car battery or photovoltaic source are sufficient). An electric charge slowly dissolves an iron electrode immersed in a container of the contaminated water, forming rust particles in the water. Arsenic binds to the rust, creating a solid that settles to the bottom or can be filtered out. Laboratory testing has demonstrated that when applied to water with arsenic concentration as high as 3,000 parts per billion (ppb), ECAR reduces arsenic concentration to below 10 ppb (the World Health Organization-recommended maximum). It is possible to reduce concentrations to 2 ppb or less.
According to the Lancet study, some 70 million Bangladeshis are drinking arsenic-contaminated well water. Berkeley Lab researchers estimate the cost of just the technical arsenic remediation of 10 liters per day of water (needed per person) to be about $1 annually using the ECAR method. Using the ARUBA method, the cost per person would be between $7 and $15 annually. However, ECAR needs a small amount of electricity, ARUBA does not.
The costs associated with continuing to drink arsenic-contaminated water are tremendous to the extent they are calculable (lost income and impaired health might be two measures to examine). Both ARUBA and ECAR provide cost-effective water remediation in small facilities designed to supply drinking water for about 500 to 1,000 people. Waste generated from both the ARUBA and ECAR processes is considered safe for disposal according to U.S. Environmental Protection Agency (EPA) standards.
This fall, with funding from UC Berkeley’s Blum Center for Developing Economies, UC Berkeley’s Sustainable Products and Solutions Program, and the EPA’s P3 Program, the ECAR team will set up a pilot program in West Bengal, India in collaboration with Jadavpur University to undertake a technical trial of the ECAR technology in a field setting. Meanwhile, ARUBA is ready for deployment, and in search of licensees.
“It’s not just about technology to remove arsenic from water – several technology solutions have been developed and nearly every one has failed in implementation,” says Susan Addy, a guest researcher at Berkeley Lab and postdoctoral scholar at UC Berkeley’s Department of Civil and Environmental Engineering. “We have to design for implementation and sustainability, which means delivering a business model that can survive over time, along with a technology that the business would manage.”
The Berkeley Lab team is led by Ashok Gadgil, Acting Director of Berkeley Lab’s Environmental Energy Technologies Division and recipient of a 2009 Heinz Award for his efforts to improve energy efficiency and enhance the quality of life in developing countries. His team includes Addy, along with students from UC Berkeley’s School of Public Health, Haas School of Business, the engineering and economics departments, and the economics department and Global Change Programme at Jadavpur University (Kolkata, India). They’ve spent significant time on the ground in Bangladesh and West Bengal (India) meeting with NGOs, community advocates, government officials, religious leaders and affected families. The purpose was to gather information on why other attempts at addressing the arsenic problem failed, including an examination of the issues competing for Bangladeshis’ time and resources, and gaps in available prevention information and health education.
Arsenic in drinking water, even at dangerously high concentrations, is tasteless, odorless and colorless, and the effects of arsenic poisoning on the human body often do not present themselves until long after exposure begins. During their discussions with locals on why other decontamination methods failed, the team learned that when maintenance or replacement was required for household-scale water-treatment filters and devices, it often was put off in favor of other pressing concerns, or the technology was abandoned altogether.
Gadgil encountered a similar situation more than a decade earlier while working on a water disinfection system, UV Waterworks, to battle Bengal cholera in India. What worked there – and has been replicated successfully in several other countries using UV Waterworks – was a locally owned community-scale facility, similar to a local micro-utility for safe drinking water. The team developed a similar business model specifically tailored to address the arsenic problem in Bangladesh.
“A local financial institution provides capital to a village council which contracts with a private company to build a treatment facility,” explains Gadgil. Under this scenario, the company would operate and maintain the facility under contract to the local village council, which would set the price of water for the community. Community members would not have to learn how to operate and maintain equipment, and revenues from sales would provide the funding to sustain the facility over the long term, and provide for ongoing prevention education.
Berkeley Lab scientists first became aware of the arsenic problem in Bangladesh in the late 1990s, and soon thereafter began working on an effective approach to removing the contaminant from drinking water and save lives. To date, they have developed two low-cost methods that can be applied to their community-scale business model – ECAR (electrochemical arsenic remediation) and ARUBA (arsenic removal using bottom ash).
The ARUBA method uses bottom ash, a widely available waste material from coal-fired power plants coated with an iron-containing chemical to absorb and chemically bind to arsenic in water. The result is a solid particle that can be filtered out, leaving the water safe for drinking. ARUBA has proven effective in laboratories and in the field, and the minimal manufacturing required can be done using simple room temperature and pressure processes.
ECAR is a simpler technology that has proven equally effective in the laboratory, and requires minimal materials – a tub or small tank, two metal plates, and a small amount of electric power (a car battery or photovoltaic source are sufficient). An electric charge slowly dissolves an iron electrode immersed in a container of the contaminated water, forming rust particles in the water. Arsenic binds to the rust, creating a solid that settles to the bottom or can be filtered out. Laboratory testing has demonstrated that when applied to water with arsenic concentration as high as 3,000 parts per billion (ppb), ECAR reduces arsenic concentration to below 10 ppb (the World Health Organization-recommended maximum). It is possible to reduce concentrations to 2 ppb or less.
According to the Lancet study, some 70 million Bangladeshis are drinking arsenic-contaminated well water. Berkeley Lab researchers estimate the cost of just the technical arsenic remediation of 10 liters per day of water (needed per person) to be about $1 annually using the ECAR method. Using the ARUBA method, the cost per person would be between $7 and $15 annually. However, ECAR needs a small amount of electricity, ARUBA does not.
The costs associated with continuing to drink arsenic-contaminated water are tremendous to the extent they are calculable (lost income and impaired health might be two measures to examine). Both ARUBA and ECAR provide cost-effective water remediation in small facilities designed to supply drinking water for about 500 to 1,000 people. Waste generated from both the ARUBA and ECAR processes is considered safe for disposal according to U.S. Environmental Protection Agency (EPA) standards.
This fall, with funding from UC Berkeley’s Blum Center for Developing Economies, UC Berkeley’s Sustainable Products and Solutions Program, and the EPA’s P3 Program, the ECAR team will set up a pilot program in West Bengal, India in collaboration with Jadavpur University to undertake a technical trial of the ECAR technology in a field setting. Meanwhile, ARUBA is ready for deployment, and in search of licensees.
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