Dechlorination of Carbon Tetrachloride by Sulfide-Modified Nanoscale Zerovalent Iron

Sulfide-modified nanoscale zerovalent iron (S-nZVI) could potentially be efficient in the degradation of haloalkane contaminants due to its high reactivity. In this study, we investigated the efficiency of carbon tetrachloride (CCl4, CT) degradation by S-nZVI under various conditions, including initial pH of solution, CT concentration, S-nZVI dosage, and ambient temperature. Results showed that reductive degradation of CT by S-nZVI followed pseudo-first-order kinetics. The rate of CT degradation showed negative correlation to CT concentration, while higher initial pH of solution (in the range of 3–9), higher S-nZVI dosage, and higher ambient temperature would stimulate CT degradation. Comparison among S-nZVI, nZVI, and FeS suggested that S-nZVI had the highest efficiency for CT degradation. This can be result from the unique surface structure and physicochemical property of S-nZVI.