Behavior of arsenical wastes co-disposed with domestic solid wastes

Abstract

There is some concern in the UK as to the possible effects of leaching of arsenic-bearing wastes because of the toxicity of arsenic. The leaching characteristics of selected arsenic-bearing wastes were established and the processes that restrict arsenic mobility when co-deposited with solid domestic waste in landfills were investigated. Arsenic mobility in the landfill can be controlled by the initial leaching of the wastes and by a combination of adsorption, reactions mediated by oxidation-reduction and pH conditions, and biological activity. Calculations show that least attenuation and greatest mobility of arsenic can occur under mildly reducing conditions in the pH range of 5-9. Greatest attenuation and least mobility occurs under strongly reducing conditions and at neutral pH. Volatilization of arsenic was significant at neutral pH values, and further work is in process to assess the environmental significance of this process. 2 figures, 7 tables.