Degradation pathways of PCBs upon UV irradiation in hexane
Degradation pathways of PCBs upon UV irradiation in hexane
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DOI：
10.1016/s0045-6535(99)00062-4
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发表时间：
1999-10-01
期刊：
影响因子：
8.8
通讯作者：
Xu, XB
中科院分区：
文献类型：
--
作者：
Miao, XS;Chu, SG;Xu, XB
采用汞灯研究了8种PCB同系物（5、31、52、77、87、126、138、169）在己烷中的光降解。上述五氯苯酚同系物的降解反应均为准一级反应。多氯联苯分解的主要产物是氯化程度较低的联苯，没有发现多氯联苯-溶剂加合物。PCB环上不同位置氯原子的反应活性一般为邻位> Meta >对位，当两个苯环上氯原子数不相等时，光脱氯主要发生在取代度较高的环上，在光降解过程中，形成一些共面PCB同系物，使溶液的TEQ缓慢降低甚至升高。(C)1999爱思唯尔科技有限公司。保留所有权利。
The photodegradations of eight individual PCB congeners (5, 31, 52, 77, 87, 126, 138, 169 ) in hexane have been investigated employing a mercury lamp. All degradation reactions of the above mentioned PCS congeners are of the pseudo first order. The principal products of PCB decomposition are the less chlorinated biphenyls, and no PCB-solvent adducts are found. Symmetrical and coplanar PCB congeners show lower photoreactivities. The reactivities of the chlorine atoms at various positions of PCB rings are generally in the order: ortho > meta > para. Photodechlorinations occur mainly on the more substituted rings, when the numbers of chlorine atoms on the two phenyl rings are unequal, During photodegradation, some coplanar PCB congeners are formed, which make the TEQ of solutions to decrease slowly or even to increase. (C) 1999 Elsevier Science Ltd. All rights reserved.