State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; College of Resource and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China.
Environ Pollut. 2023 Sep 15;333:122064. doi: 10.1016/j.envpol.2023.122064. Epub 2023 Jun 15.
As a group of pollutants listed in the Stockholm Convention, polychlorinated biphenyls (PCB) should be eliminated and their releases should be controlled. For this purpose, a complete PCB emission inventory is urgently required. Current unintentional releases of PCB were dominantly focused on waste incineration and non-ferrous metal production industries. The formation of PCB in chlorinated chemical manufacturing processes is poorly understood. In this study, occurrences and inventory of dioxin-like PCB (dl-PCB) in three typical chemical manufacturing processes, including chlorobenzene and chloroethylene production processes, were investigated. The bottom residues, which were high boiling point by-products after rectification tower, contained higher concentration of PCB than other stage samples in monochlorobenzene production and trichloroethylene production processes. The PCB concentrations were as high as 1.58 ng/mL and 152.87 ng/mL, respectively, which should be further concerned. The toxic equivalent quantities (TEQ) of dl-PCB in monochlorobenzene, trichloroethylene, and tetrachloroethylene products were 0.25 μg TEQ/t, 1.14 μg TEQ/t, and 5.23 μg TEQ/t, respectively. The mass concentration and TEQ of dl-PCB determined in this research can be used for the further development of dl-PCB emission inventory from these chemical manufacturing industries. In addition, temporal and spatial trends of PCB releases from typical chemical manufacturing processes from 1952 to 2018 in China were clarified. The releases increased rapidly in the latest two decades and presented an expansion tendency from the southeast coastal areas to northern and central areas. The continuing upward trend for the output and the high dl-PCB TEQ of chloroethylene indicated significant releases of PCB from chemical manufacturing processes and should receive more attention.
作为斯德哥尔摩公约中列出的一组污染物，多氯联苯（PCB）应被消除并控制其排放。为此，迫切需要建立一个完整的 PCB 排放清单。目前，PCB 的无意排放主要集中在废物焚烧和有色金属生产行业。氯化化学制造过程中 PCB 的形成仍知之甚少。在这项研究中，研究了三种典型化学制造过程（包括氯苯和氯乙烯生产过程）中二恶英类 PCB（dl-PCB）的发生和清单。在单氯苯和三氯乙烯生产过程中，精馏塔后作为高沸点副产物的釜底残液中 PCB 的浓度高于其他阶段的样品。PCB 浓度分别高达 1.58ng/mL 和 152.87ng/mL，这应该引起进一步的关注。单氯苯、三氯乙烯和四氯乙烯产品中 dl-PCB 的毒性当量（TEQ）分别为 0.25μg TEQ/t、1.14μg TEQ/t 和 5.23μg TEQ/t。本研究中测定的 dl-PCB 的质量浓度和 TEQ 可用于进一步开发这些化学制造工业中 dl-PCB 排放清单。此外，还阐明了中国 1952 年至 2018 年典型化学制造过程中 PCB 排放的时间和空间趋势。在过去的二十年中，排放量迅速增加，并呈现出从东南沿海地区向北部和中部地区扩展的趋势。氯乙烯产量的持续上升和高 dl-PCB TEQ 表明，化学制造过程中 PCB 的排放量显著增加，应引起更多关注。
