Low Cost Arsenic Mitigation

EDGARDO L. SHAM; E. M. FARFÁN TORRES

Puerto Iguazú

Workshop; Solar Safe Water, Tecnologias Emergentes para estudiar problemas de tratamiento de agua en Países en Desarrollo; 2005

Unión Europea ? CNEA ? Ministerio de Educación y Ciencia de España ?Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas ? Fundación Balseiro ? Plataforma Solar Almeria ? Universidad Nacional de San Martín

High As concentration in groundwater is increasing concern due to the risks to human health and ecology and it is imperative that solutions are found soon. Household arsenic removal units are developed in many programs for their 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 prepared personal. The implementation of an arsenic removal method for this kind of population must be use very simple technology and materials available in the region. We have work in the developing of a 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 these 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 nearTres 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 effectively removed to values of 0.02 to 0.008 mg/L.