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

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.