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; University of Chinese Academy of Sciences, Beijing, 100049, China.
Foreign Economic Cooperation Office, Ministry of Environmental Protection of China, Beijing, 100035, China.
Chemosphere. 2019 Jul;226:492-501. doi: 10.1016/j.chemosphere.2019.03.166. Epub 2019 Mar 29.
Metallurgical processes are currently the predominant anthropogenic sources of multiple unintentional persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs), chlorinated and brominated PAHs (Cl-PAHs and Br-PAHs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polybrominated diphenyl ether (PBDEs). Understanding the formation of multiple POPs is important for source control. These POPs could be formed through fly ash-mediated heterogeneous reactions. In this study, we comprehensively investigated the thermochemical (150-450 °C) formation of these POPs on fly ash samples collected from a secondary aluminum smelter, secondary lead smelter, and iron ore sintering plant. The maximum concentrations of PCNs and PCBs were 154.5 and 181.3 times those in the original fly ash, respectively. Formation variations of PAHs, Cl-PAHs and Br-PAHs, and PBDEs were different from that of PCBs and PCNs. The PAHs concentration, which was the highest among the POPs in the original fly ash, decreased sharply by 95% at 150 °C. The ∑Cl-PAHs and ∑Br-PAHs increased marginally at 250 °C before decreasing slightly at 350 °C. The PBDE concentrations decreased under 250 °C and increased at 350 °C. PCNs, PCBs, and PCDD/Fs showed good correlations, all of which had a negative relationship with the PAHs. There were no significant correlations between PAHs and Cl/Br-PAHs. Low brominated congeners could be formed by destruction of higher brominated congeners because of thermal instability of the PBDEs.
冶金工艺目前是多种人为无意持久性有机污染物（POPs）的主要来源，包括多环芳烃（PAHs）、氯代和溴代多环芳烃（Cl-PAHs 和 Br-PAHs）、多氯联苯（PCBs）、多氯萘（PCNs）和多溴联苯醚（PBDEs）。了解多种 POPs 的形成对于源头控制很重要。这些 POPs 可以通过飞灰介导的非均相反应形成。在这项研究中，我们全面研究了从二次铝冶炼厂、二次铅冶炼厂和铁矿烧结厂收集的飞灰样品中这些 POPs 在 150-450°C 下的热化学形成过程。PCNs 和 PCBs 的最大浓度分别是原始飞灰的 154.5 和 181.3 倍。PAHs、Cl-PAHs 和 Br-PAHs 以及 PBDEs 的形成变化与 PCBs 和 PCNs 不同。在原始飞灰中，PAHs 的浓度是所有 POPs 中最高的，在 150°C 时急剧下降了 95%。∑Cl-PAHs 和∑Br-PAHs 在 250°C 时略有增加，然后在 350°C 时略有下降。在 250°C 以下，PBDE 浓度降低，在 350°C 时增加。PCNs、PCBs 和 PCDD/Fs 相关性较好，均与 PAHs 呈负相关。PAHs 与 Cl/Br-PAHs 之间没有显著相关性。由于 PBDEs 的热不稳定性，低溴代同系物可能通过破坏较高溴代同系物形成。
