Abstract
The dechlorination of chlorinated hydrocarbons by Si 0 in the presence of heavy metals was studied to understand the feasibility of coupled reduction of chlorinated hydrocarbons and heavy metal ions. Chloroform was the dominant product during the dechlorination processes. Analysis of metal ion concentrations in liquid phases by AAS showed that metal ions was sorbed onto the surface of silicon. Nearly complete degradation of PCE by Si 0 was observed within 700 hr. Unlike the effect of Cu 2+ , Ni 2+ enhanced the rate and efficiency of tetrachloroethylene (PCE) dechlorination. Rapid dechlorination of PCE was achieved within 190 hr when Ni 2+ was amended into the Si 0 -H 2 O system, depicting that Ni 2+ is an effective ion on enhancing the dechlorination rate of PCE. Trichloroethylene (TCE) was the major product of PCE dechlorination. However, the production of TCE was compound-dependent. The produced TCE in Si 0 -H 2 O system accumulated with time with the maximum concentration of 4.2 μM, which corresponded to 63% of PCE dechlorination. This is an abstract of a paper presented at the 229th ACS National Meeting (San Diego, CA 3/13-17/2005).