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
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
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.
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.
Technologies to Remove Arsenic from Drinking Water
July 20, 2010