Unveiling the secondary pollution in the catalytic elimination of chlorinated organics: The formation of dioxins  

作　　者：Jiajia Liu Xiaoxia Dai Zhongbiao Wu Xiaole Weng 

机构地区：[1]Key Laboratory of Environment Remediation and Ecological Health,Ministry of Education,College of Environmental and Resource Sciences,Zhejiang University,and Zhejiang Provincial Engineering Research Center of Industrial Boiler&Furnace Flue Gas Pollution Control,Hangzhou 310058,China

出　　处：《Chinese Chemical Letters》2020年第6期1410-1414,共5页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.21777140,21922607);the Outstanding Youth Project of Zhejiang Natural Science Foundation(No.LR19E080004)。

摘　　要：Since the discovery of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in the process of municipal solid waste incineration(MSWI),a large number of researches have been conducted to reveal their formation mechanisms and emission characteristics.As one of national priority control pollutants,chlorinated organics are inclined to transfer into PCDD/Fs in the heterogeneously catalyzed process,which has been considered to be one of great challenges in environmental catalysis.However,so far direct evidences to support such a conversion process are insufficient,and the reaction mechanisms are lack of exploration.This study investigated the catalytic elimination of chlorobenzene(CBz)over a range of industrially applied active species including Pt,Ru,V,Ce and Mn oxides,and explored their reaction byproducts,chlorine adsorption/desorption behaviors and PCDD/F formations.We found that all of these species could generate the PCDD/Fs,amongst which,Mn species were the most active for PCDD/F formation.Approximately 140 ng I-TEQg-1 PCDD/Fs were detected on the Mn-CNT surface after ageing at250℃for 30 h.Even using the dichloromethane(DCM)as a precursor,significant PCDD/Fs were still detected.The Ru and V species were shown to generate much less polychlorinated byproducts and PCDD/Fs,owning to their sufficiently high abilities in Cl desorption,which were through the semi-Deacon and Br(?)nsted H reactions,respectively.

关 键 词：VOCs oxidation Chlorinated organics Secondary pollution DIOXIN Electrophilic chlorination Environmental catalysis 

分 类 号：X701[环境科学与工程—环境工程] TQ203.2[化学工程—有机化工]