State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China; Institute of Environment and Health, Jianghan University, Wuhan, 430056, China.
Ecotoxicol Environ Saf. 2019 Oct 30;182:109373. doi: 10.1016/j.ecoenv.2019.109373. Epub 2019 Jun 28.
Co-processing solid waste in cement kilns has become increasingly widespread in recent years. Persistent organic pollutants (POPs) can be unintentionally produced and emitted from cement kilns, especially kilns in which solid waste is co-processed. Unintentionally produced POP formation and emission by cement kilns co-processing solid waste therefore need to be studied in detail to allow the potential risks posed by cement kiln co-processing techniques to be assessed. Many field studies and laboratory simulation experiments have been performed to investigate the formation and release of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). However, the formations, characteristics and emission factors of various emerging unintentionally produced POPs have not been comprehensively reviewed. Here, emissions of well-known unintentionally produced POPs (PCDD/Fs and polychlorinated biphenyls) and emerging unintentionally produced dioxin-like POPs (polybrominated dibenzo-p-dioxins and dibenzofurans, polychlorinated naphthalenes, and chlorinated and brominated polycyclic aromatic hydrocarbons) in cement kilns co-processing solid waste are reviewed, focusing on formations and influencing factors of those unintentional POPs. Data from field studies indicated that the main stages in which POPs are unintentionally produced in cement kilns co-processing solid waste are the cyclone preheater outlet, suspension preheater boiler, humidifier tower, and back-end bag filter. The raw material composition, chlorine and bromine contents, and temperature are the most important factors affecting POP formation. The homolog distributions and congener profiles of POPs formed unintentionally in cement kilns were compared, and it was found that larger amounts of less-chlorinated homologs than more-chlorinated homologs are emitted. Emission factors for various unintentionally produced POPs for cement kilns co-processing solid waste were summarized, and could be useful for compiling global emission inventories for pollutants covered by the Stockholm Convention. This comprehensive review improves our understanding of unintentional production and emissions of POPs by cement kilns co-processing solid waste.
近年来，水泥窑协同处置固体废物已变得越来越普遍。固体废物在水泥窑中的协同处置过程中，可能会意外地产生和排放持久性有机污染物（POPs），特别是在协同处置固体废物的窑中。因此，需要详细研究水泥窑协同处置固体废物时无意产生 POP 的形成和排放，以评估水泥窑协同处置技术带来的潜在风险。已经进行了许多现场研究和实验室模拟实验，以研究多氯二苯并对二恶英和二苯并呋喃（PCDD/Fs）的形成和释放。然而，各种新兴无意产生的 POP 的形成、特征和排放因子尚未得到全面审查。在这里，审查了水泥窑协同处置固体废物中已知的无意产生的 POP（PCDD/Fs 和多氯联苯）和新兴的无意产生的类二恶英 POP（多溴二苯并对二恶英和二苯并呋喃、多氯萘和氯化及溴化多环芳烃）的排放情况，重点介绍了这些无意产生的 POP 的形成和影响因素。现场研究数据表明，在水泥窑协同处置固体废物中无意产生 POP 的主要阶段是旋风预热器出口、悬浮预热器锅炉、加湿器塔和后端袋式过滤器。原材料组成、氯和溴含量以及温度是影响 POP 形成的最重要因素。对水泥窑协同处置固体废物中无意形成的 POP 的同系物分布和同类物分布进行了比较，发现排放的同系物中低氯同系物的量大于高氯同系物的量。总结了水泥窑协同处置固体废物时各种无意产生的 POP 的排放因子，这对于编制《斯德哥尔摩公约》涵盖的污染物的全球排放清单可能很有用。这项全面审查提高了我们对水泥窑协同处置固体废物时无意产生和排放 POP 的理解。
