土木与环境工程学报

Dechlorination Kinetics of PCBs Contaminated Transformer Oils by Stabilized Nanoscale Fe

Abstract

Mikaili MA, Ebadi T and Bahmanib F

Yet a careful study of dechlorination kinetics on polychlorinated biphenyls (PCBs) congeners in transformer oil has not been investigated. 29 PCBs congeners were identified in transformer oil. Two sets of experiments were developed to study the effect of starch stabilized iron nano particles (NPs) concentration and temperature on the dechlorination of total PCBs. The experiments initiated with special initial concentration and lasted for an hour. The first order rate constant (k) were slightly influenced by the initial concentration of NPs. The k value changed from 0.0202 ± 0.004 to 0.0456 ± 0.0023 min^-1 with an initial concentration range between 0.1 gL^-1 and 0.5 gL^-1 of NPs. The apparent activation energy for dechlorination was 17.712 kJmol^-1 in a temperature ranging from 35°C to 75°C. The reduction rate and extent of dechlorination were remarkably under the effect of higher temperature. Dehalogenation order of PCBs indicate that in high chlorinated biphenyls the chlorine situated at the following discipline Para(P)P(para)P_(higher) ortho(CP)_(lower) (meta)M have slightly more reactivity compared with PP_ (lower)CP_(higher) M > P_ CP_M > -_CP_M.