Arsenic and metal contamination of water resources from mining wastes in Korea

Water resources near a gold-mine waste site were studied for the distributi on and contents of contaminants, and their behavior in the surface and grou ndwater systems. Arsenic, cadmium, and manganese were identified with level s exceeding the drinking water guidelines of WHO (World Health Organization ), and their distribution depended upon the differences in source materials and in spatial pH variations. Originating from arsenopyrite, concentration s of dissolved arsenic were controlled by sorption with amorphous iron (Fe( OH)(3)) and carbonate minerals. Cadmium and manganese were derived from the mineral phase including sphalerite (ZnS), otavite (CdCO3), and rhodochrosi te (MnCO3); their concentrations in water resources were limited by the sol ubility of mineral phases. All of these processes are significantly pH-depe ndent, implying that a small decline in pH could result in a drastic increa se in contaminant concentrations and become a pollution threat to the water resources of the Gubong area.