Low Cost Arsenic Mitigation

E. SHAM; E. M. FARFÁN TORRES

Puerto Iguazú, Misiones

Workshop; Solar Safe Water; 2005

Plataforma Solar Almeria y Laboratorio de Actividad Química CNEA

High As concentration  in groundwater is of increasing consern due to the risks to human health and ecology and it is imperative that solutionsa are found soon. Household arsenic removal units are developed in many programsfor thier implementation in rural isolated areas. For larger scale the common purification method is precipitation by adding coagulant agents into the contaminated water. However in isolated rural areas the managing of the chemical substances used for precipitation are difficult to use for not training personal. The implementation of an arsenis removal method for this kind of population must be use very simple technology and materials available in the region. We have work in the developping of an arsenic mitigation system based in the adsorption and filtration of arsenic using sand containing an iron source, stones and charcoal. Operation of the system is extremely simple as no reagents are involved. In this conditions the major removal process is adsorption of arsenic by the iron oxide produced at the surface of the iron filling. In our work arsenic contaminated water from Tres Horcones, a rural school in the Chaco of Salta, was used. The arsenic content before treatment was 0.17 mg/L. The mitigation system was constructed with two different particle size fractions of sand collected at the Teuquito River located near Tres Horcones. The fine sand was disposed over a layer of medium size stones (gravel) and medium particle size sand containing an iron network was disposed at the top of the filtration media. Arsenic was efectively removed to values of 0.02 to 0.008 mg/L