Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, PR China.
Department of Chemistry, COMSATS University Islamabad, 44000, Pakistan.
Environ Pollut. 2023 Oct 1;334:122162. doi: 10.1016/j.envpol.2023.122162. Epub 2023 Jul 8.
The pollution of polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (Cl/Br-PAHs) caused by electronic waste dismantling activities have attracted considerable attention. The present study investigated the emissions and formation of PAHs and Cl/Br-PAHs based on the combustion of printed circuit boards simulating electronic waste dismantling process. The emission factor of ΣPAHs was 648 ± 56 ng/g, which was much lower than that of ΣCl/Br-PAHs (8.80 × 10 ± 9.14 × 10 ng/g). From 25 to 600 °C, the emission rate of ΣPAHs reached a sub-peak of 7.39 ± 1.85 ng/(g•min) at 350 °C, then increased gradually with the fastest rate of 19.9 ± 21.8 ng/(g•min) at 600 °C, whereas that of ΣCl/Br-PAHs was the fastest at 350 °C with a rate of 597 ± 106 ng/(g•min), then decreased gradually. The present study suggested that the formation pathways of PAHs and Cl/Br-PAHs are by de novo synthesis. Low molecular weight PAHs were readily partitioned into gas and particle phases, whereas high molecular weight fused PAHs were only detected in oil phase. However, the proportion of Cl/Br-PAHs in particle and oil phases were different from that of gas phase, whereas similar to that of the total emission. In addition, PAH and Cl/Br-PAH emission factors were used to estimate the emission intensity of pyrometallurgy project in Guiyu Circular Economy Industrial Park, and it was shown that approximately 1.30 kg PAHs and 176 kg Cl/Br-PAHs would be emitted annually. This study revealed that Cl/Br-PAHs would be formed by de novo synthesis, and for the first time provided the emission factors of Cl/Br-PAHs during the heat treatment process of printed circuit board, as well as estimated the contribution of pyrometallurgy, a new electronic waste recovery technology, to environmental Cl/Br-PAH pollution, which provides potential scientific information for governmental decision-making on the control of Cl/Br-PAHs.
电子废物拆解活动造成的多环芳烃（PAHs）和卤代多环芳烃（Cl/Br-PAHs）污染引起了相当大的关注。本研究基于电子废物拆解过程中模拟印刷电路板燃烧，调查了 PAHs 和 Cl/Br-PAHs 的排放和形成。ΣPAHs 的排放因子为 648±56ng/g，远低于 ΣCl/Br-PAHs（8.80×10±9.14×10ng/g）。在 25 至 600°C 之间，ΣPAHs 的排放率在 350°C 时达到 7.39±1.85ng/（g·min）的次高峰，然后逐渐增加，在 600°C 时以最快的速度 19.9±21.8ng/（g·min）增加，而 ΣCl/Br-PAHs 在 350°C 时最快，速度为 597±106ng/（g·min），然后逐渐降低。本研究表明，PAHs 和 Cl/Br-PAHs 的形成途径是从头合成。低分子量 PAHs 容易分配到气-粒相中，而高分子量稠环 PAHs 仅在油相中检测到。然而，Cl/Br-PAHs 在颗粒相和油相中的比例与气相中的比例不同，但与总排放量相似。此外，利用 PAH 和 Cl/Br-PAH 排放因子估算贵屿循环经济产业园火法冶金项目的排放强度，结果表明每年将排放约 1.30kg PAHs 和 176kg Cl/Br-PAHs。本研究表明 Cl/Br-PAHs 是通过从头合成形成的，并且首次提供了在印刷电路板热处理过程中 Cl/Br-PAHs 的排放因子，并估算了火法冶金（一种新的电子废物回收技术）对环境 Cl/Br-PAH 污染的贡献，为政府在 Cl/Br-PAHs 控制方面的决策提供了潜在的科学信息。
