Thermal degradation and pollutant emission from waste printed circuit boards mounted with electronic components.
Thermal degradation and pollutant emission from waste printed circuit boards mounted with electronic components.
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DOI：
10.1016/j.jhazmat.2019.121038
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发表时间：
2020-01
影响因子：
13.6
通讯作者：
Jie Guo;Xiaomei Luo;Shufei Tan;O. Ogunseitan;Zhenming Xu
中科院分区：
文献类型：
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作者：
Jie Guo;Xiaomei Luo;Shufei Tan;O. Ogunseitan;Zhenming Xu
电子废物的拆解和回收过程产生了装有电子元件的废弃印刷电路板。在wpcb - ce的热处理过程中，可释放空气污染物，包括颗粒物（PM）和挥发性有机化合物（VOCs）。在本研究中，采用热重分析（TGA）和石英管炉对wpcb - ec中的有机物质进行了热解。我们发现电路板树脂和焊料涂层的降解是一个阶段的过程，而电容器外壳和导线护套的降解则是两个阶段。板树脂TGA加工过程中发生了溴系阻燃剂的脱溴反应，主要产物为HBr和苯酚。电容器皮热解过程中发生脱氯化氢反应，检测出HCl、苯和甲苯。苯只在第一个降解阶段（272-372℃）生成，而甲苯在两个降解阶段都生成。在wpcb - ec加热过程中释放出直径为0.45 ~ 0.5和4 ~ 5 μm的双峰质量尺寸分布的PM。颗粒物浓度在0.3 ~ 0.35 μm和1.6 ~ 2 μm范围内最高。这项研究提供了关于wpcb - ec热处理过程中污染物排放的新数据，以及关于防止有毒接触损害回收者健康的策略的信息。
Waste printed circuit boards mounted with electronic components (WPCB-ECs) are generated from electronic waste dismantling and recycling process. Air-borne pollutants, including particulate matter (PM) and volatile organic compounds (VOCs), can be released during thermal treatment of WPCB-CEs. In this study, organic substances from WPCB-ECs were pyrolyzed by both thermo-gravimetric analysis (TGA) and in a quartz tube furnace. We discovered that board resin and solder coating were degraded in a one-stage process, whereas capacitor scarfskin and wire jacket had two degradation stages. Debromination of brominated flame retardants occurred, and HBr and phenol were the main products during TGA processing of board resin. Dehydrochlorination occurred, and HCl, benzene and toluene were detected during the pyrolysis of capacitor scarfskin. Benzene formation was found only in the first degradation stage (272–372 °C), while toluene was formed both in the two degradation stages. PM with bimodal mass size distributions at diameters of 0.45–0.5 and 4–5 μm were emitted during heating WPCB-ECs. The PM number concentrations were highest in the size ranges of 0.3–0.35 μm and 1.6–2 μm. The research produced new data on pollutant emissions during thermal treatment of WPCB-ECs, and information on strategies to prevent toxic exposures that compromise the health of recyclers.