Low-cost irrigation water for arsenic removal in north Chile

摘要

URBAN LIFE AND agriculture in the North of Chile one of the most arid places in the world are affected by high concentrations of arsenic in water supplies (Alonso et al, 1992). Historically protective measures against this problem have evolved toward a widespread potable water treatment only in large communities leaving distant villages exposed to high concentration of arsenic in potable water. On the agricultural side crops cultivated with high concentration of this contaminant in the region, constitutes a direct route of arsenic exposure for which no countermeasures still exists. Arsenic adsorption onto precipitated ferric hydroxide and floc separation, is the process under current use to remove arsenic from potable water in the North of Chile. The limited profits of local agriculture is a severe restriction to use this process to remove arsenic from irrigation water whose total cost is 1,5 US$/m~3. Recently, new projects and ideas have emerged in the region as a result of an increasing degree of public awareness. In this work a low-cost water treatment system for arsenic removal based on its adsorption over corroding iron is discussed as a solution for a safe development of agricultural activities.