Arsenic Removal Using Bottom Ash (ARUBA)

Technology

Coal ash before and after coating with rust.

Developed at Lawrence Berkeley National Laboratory, ARUBA (Arsenic Removal Using Bottom Ash) is used to remove arsenic from contaminated drinking water in an efficient, affordable, and safe manner. Using simple chemistry, bottom ash from coal-fired power plants is coated with ferric hydroxide to create ARUBA, to which arsenic binds. Water treatment involves adding ARUBA to water, mixing, and filtering. In field experiments in Bangladesh, ARUBA treatment has been shown reduce arsenic concentrations from over 1000 ppb to 3 ppb (Bangladeshi drinking water standard is 50 ppb, World Health Organization standard is 10ppb). After use, spent ARUBA can be safely disposed of in landfills (EPA approved).

Expenses are minimal: the raw materials needed to produce enough ARUBA for one person for a YEAR cost about 8 U.S. cents! We estimate that total treated water costs would be $7 - $15 per person per year (assuming 10 liters of drinking water per person per day).

ARUBA Arsenic Removal Plant Prototype installed at the Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh (July 2008).
Photo credit: Mahbuba Iasmin.

Applications

ARUBA could be used in the home (in conjunction with a household-size sand filter) or at the community level. We are currently designing a community-based water treatment plant which uses ARUBA to remove arsenic from drinking water.

ARUBA is available for licensing from the Lawrence Berkeley National Laboratory Technology Transfer Division. Contact for more information on licensing ARUBA.