A sustainable community-based arsenic mitigation pilot project in Bangladesh.

A sustainable community-based arsenic mitigation pilot project has been successfully operating for 22 months in the Chapainawabganj arsenic hot spot (Bangladesh) where safe treated drinking and cooking water derived from tubewells is being supplied below the Bangladesh maximum permissible limit (0.05 ppm total arsenic). There has been close community involvement in all stages and the arsenic removal mechanism used adapted from the simple process of adsorption by natural ferric oxyhydroxide. Supplemented ferric oxyhydroxide produces daily de-contaminated water batches until replaced at the end of the cycle. A regional renewal/recycling centre supplies new, and safely stores used, ferric oxyhydroxide. Recycling is beginning where adsorbed arsenic can be separated prior to ferric oxyhydroxide reuse. The mechanism is flexible regarding water volumes, cycle lengths, pre and post-treatment arsenic concentrations, tubewell chemistries and is cost-effective. Pilot project parameters were set at 60 l per day ( < 0.05 ppm total arsenic) and 16 day cycles per tank for each of the four selected families with pretreatment concentrations up to 1.1 ppm. A maximum of ~ 24 g of arsenic is produced from the approximately 900 g (dry) of ferric oxyhydroxide used per tank per year. Anecdotal evidence possibly suggests positive health effects within a few months and villagers report an improved water taste. The project should contribute to coping with such arsenicosis crises and expansion is planned.