title: Formation of PCDD/Fs and PCBs in the process of production of 1,4-dichlorobenzene.
abstract: The occurrence and distribution of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in a typical process of production of 1,4-dichlorobenzene (p-DCB) were investigated systematically in this study. P5CDFs and H6CDFs were the main congeners of PCDD/Fs, while only low levels of other PCDD/Fs were detected in the samples. The concentrations of PCBs were up to 4614 ng/g in the semi-manufactured products, and 1797 ng/g in the product p-DCB. It was also found that high chlorinated PCB congeners increased with the further chlorination. The levels of PCDD/Fs decreased obviously in the purification process, while PCBs could not be removed effectively. Polychlorophenols and other important dioxin precursors (1,4-dichloro-2-phenoxybenzene and 2-phenyl-2',5,5'-trichlorophenol) were also analyzed. Polychlorophenols which ortho- and para-positions of the hydroxyl were substituted by chlorine were the main congeners. In addition, a possible pathway of the formation of PCDD/Fs and PCBs in the production of p-DCB was presented. The results of this article suggest that re-estimation on the risk of using p-DCB products, especially the products for daily use such as mothballs, is expected.
authors.affiliation: Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Liu
authors.forename: Minghui
authors.initials: M
authors.lastname: Zheng
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Xing
authors.forename: Xingru
authors.initials: X
authors.lastname: Zhao
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Ma
authors.forename: Yong
authors.initials: Y
authors.lastname: Qian
mesh_terms: D001572:Benzofurans / Q000737:chemistry*; D002617:Chemical Industry; D002722:Chlorobenzenes / Q000737:chemistry*; D004147:Dioxins / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D008420:Manufactured Materials / Q000032:analysis; D011078:Polychlorinated Biphenyls / Q000737:chemistry*
chemical_list: D001572:Benzofurans; D002722:Chlorobenzenes; D004147:Dioxins; C018511:4-dichlorobenzene; D011078:Polychlorinated Biphenyls