| Abstract
| - A simple arsenic removal system was used in Bangladeshby six households for 4 months to treat well watercontaining 190−750 μg/L As as well as 0.4−20 mg/L Feand 0.2−1.9 mg/L P. The system removes As from a 16-Lbatch of water in a bucket by filtration through a sand bedfollowing the addition of about 1.5 g of ferric sulfate and0.5 g of calcium hypochlorite. Arsenic concentrations in allbut 1 of 72 samples of treated water were below theBangladesh drinking water standard of 50 μg/L for As.Approximately half of the samples also met the World HealthOrganization (WHO) guideline of 10 μg/L. At the twowells that did not meet the WHO guideline, observationswere confirmed by additional experiments in one case ([P]= 1.9 mg/L) but not in the other, suggesting that thelatter household was probably not following the instructions.Observed residual As levels are consistent with predictionsfrom a surface complexation model only if the sitedensity is increased to 2 mol/mol of Fe. With the exceptionof Mn, the average concentrations of other inorganicconstituents of health concern (Cr, Ni, Cu, Se, Mo, Cd,Sb, Ba, Hg, Pb, and U) in treated water were below theirrespective WHO guideline for drinking water.
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