Utilization of Lapsi seed stone (choerospondias axillaris) as source of activated charcoal for removal of arsenic

People inhabited in Terai region of Nepal use ground water as the main source of drinking water that are contaminated with arsenic at concentration level higher than guide line value set by WHO. The arsenic in the ground water is originated from the dissolution of naturally occurring arsenic containing minerals. Nepal, being a poor country, cannot afford to adopt costly and sophisticated technology to remove arsenic. Adsorptive removal of arsenic utilizing the activated charcoal prepared from the locally available Lapsi (chorespondias axillaris, Roxb) seed stone is presented. Tons of Lapsi seed stones are generated as waste which can be carbonized to activated charcoal. The adsorption capacity for arsenic is quite low for raw charcoal but activation followed by iron impregnation greatly enhances it. The low cost activated charcoal prepared from locally available Lapsi seed stones can be used in community level at point- of- use treatment for arsenic contaminated ground water of Terai region of Nepal.