Roshan Raj Shrestha, Tommy Ka Kit Ngai, Bipin Dongol, Binod Dahal, Upendra Paudya

Abstract

Arsenic Poisoning in the groundwater of Terai in Nepal is now becoming a new challenge for the nation’s water supply sector. About 30,000 shallow tube wells have been tested for arsenic out of which 7 % of them are found to contain arsenic levels exceeding the Nepali guideline (50 ppb). Household level arsenic removal filters are one of the options that can be immediately adopted by arsenic affected communities. In this context, a joint effort of researchers form MIT (USA), and ENPHO (Kathmandu), developed a promising household scale arsenic removal technology. This technology is a modified version of the household scale Biosand Filter for microbiological quality improvement in drinking water. The ABF uses the process of aeration, adsorption and filtration for removal of arsenic. Efficiency tests show that this filter removes more than 95 % of arsenic and 99 % of iron. This system does not deteriorate microbiological quality of water, which is normally a major disadvantage of most of the other household level arsenic removal filters so far practiced. World Bank has recently presented the DM2003 award to MIT/ENPHO/RWSSSP for the promotion of this simple technology on a wider scale in Nepal. This paper highlights technological details, performance and social acceptance of this system.

   

Keywords: arsenic, drinking water treatment, appropriate technology, developing country

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