Abiotic Transformation of Carbon Tetrachloride in the Presence of Sulfide andMineral Surfaces

摘要

Abiotic transformations, such as reductive dehalogenation and nucleophilicsubstitution, can influence the fate of halogenated aliphatic compounds in aqueous environments. Sulfide, commonly found in hypoxic environments such as landfill leachate, hazardous waste plumes, and salt marshes, can act as an electron donor (Schreier, 1990; Kriegman-King and Reinhard, 1991) or as a nucleophile (Schwarzenbach, et al., 1985; Haag and Mill, 1988, Barbash and Reinhard, 1989a) to promote transformation of halogenated organics. In subsurface environments, transformation rates of halogenated organic compounds may be influenced by mineral surfaces, in addition to the aqueous chemistry (Estes and Vilker, 1989, Schreier, 1990; Kriegman-King and Reinhard, 1991; Curtis, 1991). The purpose of the work is to show the effect of mineral surfaces in the presence of sulfide on the carbon tetrachloride (CTET) transformation rate. Laboratory studies were conducted to identify and quantify the environmental parameters that govern the transformation rate of CTET. The parameters studied were temperature, pH, mineral surface area, and sulfide concentration.