Reductive dechlorination of 2,4-dichlorophenol using nanoscale Fe^0: influencing factors and possible mechanism  

作　　者：CHENG Rong WANG JianLong ZHANG WeiXian 

机构地区：[1]Laboratory of Environmental Technology,INET,Tsinghua University,Beijing 100084,China [2]Department of Civil and Environmental Engineering,Lehigh University,Bethlehem,PA 18015-3176,USA

出　　处：《Science China Chemistry》2007年第4期574-579,共6页中国科学（化学英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant Nos. 50325824, 50678089) the Excellent Young Teacher Program of MOE

摘　　要：Nanoscale Fe0 was synthesized through a reductive method in this paper. The experiments were per-formed to investigate the reduction of 2,4-dichlorophenol (2,4-DCP) by nanoscale Fe0 under different conditions. The pathways for the reduction of 2,4-DCP by nanoscale Fe0 were discussed. Batch studies demonstrated that the mechanism includes adsorption, dechlorination and cleavage of the benzene ring. Dechlorination, which occurs after 2,4-DCP molecule is adsorbed on the interface of Fe particle, is an interfacial reaction. One or two chlorine atom can be removed from 2,4-DCP to form 2-chlorophenol, 4-chlorophenol or phenol. As the concentration of 2,4-DCP increased, the relative dechlorination ratio decreased. However, the reduced quantities of 2,4-DCP increased. Temperature can influence dechlo-rination rate and pathway. Dechlorination is prior to cleavage of the benzene ring at a higher tempera-ture, but at a lower temperature, adsorption may be the main pathway, and cleavage of the benzene ring may be prior to dechlorination.Nanoscale Fe0 was synthesized through a reductive method in this paper. The experiments were performed to investigate the reduction of 2,4-dichlorophenol (2,4-DCP) by nanoscale Fe0 under different conditions. The pathways for the reduction of 2,4-DCP by nanoscale Fe0 were discussed. Batch studies demonstrated that the mechanism includes adsorption, dechlorination and cleavage of the benzene ring. Dechlorination, which occurs after 2,4-DCP molecule is adsorbed on the interface of Fe particle, is an interfacial reaction. One or two chlorine atom can be removed from 2,4-DCP to form 2-chlorophenol, 4-chlorophenol or phenol. As the concentration of 2,4-DCP increased, the relative dechlorination ratio decreased. However, the reduced quantities of 2,4-DCP increased. Temperature can influence dechlorination rate and pathway. Dechlorination is prior to cleavage of the benzene ring at a higher temperature, but at a lower temperature, adsorption may be the main pathway, and cleavage of the benzene ring may be prior to dechlorination.

关 键 词：NANOSCALE Fe^0 2 4-DCP adsorption DECHLORINATION CLEAVAGE of the benzene ring 

分 类 号：O621[理学—有机化学]