Treatment of arsenic in Bangladesh well water using a household co-precipitation and filtration system

Laboratory and field tests were conducted to evaluate the effectiveness of a household filtration process and investigate the effects of phosphate and silicate on the removal of arsenic from Bangladesh groundwater by ferric h ydroxides. Fe/As ratios of greater than 40 (mg/mg) were required to reduce arsenic to less than 50 mug/L in Bangladesh well a ater due to the presence of elevated phosphate and silicate concentrations. The household filtratio n process included co-precipitation of arsenic by adding a packet (approxim ately 2 g) of ferric and hypochlorite salts to 20 L of well water and subse quent filtration of the water through a bucket sand filter. A field demonst ration study was performed to test the treatment system in seven households in Bangladesh in March and April 2000. Experimental results obtained from the participating families proved that the household treatment process remo ved arsenic from approximately 300 mug/L in the well water to less than 50 mug/L. The participating families liked this simple and affordable process and used it to prepare clean water for drinking and cooking. A larger scale held test is currently underway. (C) 2001 Elsevier Science Ltd. All rights reserved.