School of Environmental Science and Engineering, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
Environ Sci Technol. 2015 Mar 3;49(5):2716-23. doi: 10.1021/es5053599. Epub 2015 Feb 11.
Polybrominated diphenyl ethers (PBDEs) contained in waste printed wiring board (PWB) matrix and surface dust can be emitted into the air during thermal process, which is widely used to detach the electronic components from the base boards of waste PWB. In this study, PBDEs concentrations in air and dust samples were detected in a PWB-heating workshop, and then heating experiments of PBDEs-containing materials in a quartz tube furnace were performed to investigate the PBDEs emission mechanism. The results showed that the mean concentrations of Σ8PBDEs in PM10 and TSP were 479 and 1670 ng/m(3), respectively. Compared with surface dust collected from waste PWB (15600 ng/g), PBDEs concentrations in dust from the workshop floor (31,100 ng/g), heating machine inside (84,700 ng/g), and the cyclone extractor (317,000 ng/g), were condensed after thermal process. Heating experiments showed that the emission rates of PBDEs from PBDEs-containing dust were obviously higher than those from PWB fragments in the first 1-h time. The cumulative amounts of PBDEs emitted from dust increased rapidly at first, and then leveled off to become asymptotic to the maximum amounts. At the temperature of 300 °C, the PBDEs emission from dust mainly occurred within the first 5 min, and the average emission rates for BDE-28, -47, and -99 among the first 5 min were 1230, 4480, and 1950 ng/(g·min), respectively. During the initial 1-h period, the trends of PBDEs emission from PWB fragments had a linear increase, and the emission rates of penta-BDE (BDE-47, -99, -100) at different temperatures were at a range of 9.75-11.5 ng/(g·min). All the results showed that PBDEs emission from PWB waste happened during thermal process, and management strategies were provided to reduce the occupational exposure level of PBDEs for workers.
多溴联苯醚 (PBDEs) 存在于废弃印刷线路板 (PWB) 基质和表面灰尘中，在热过程中会释放到空气中，而热过程广泛用于从废弃 PWB 的基板上分离电子元件。在这项研究中，检测了 PWB 加热车间空气中和灰尘样本中的 PBDEs 浓度，然后在石英管式炉中进行了含 PBDEs 材料的加热实验，以研究 PBDEs 的排放机制。结果表明，PM10 和 TSP 中∑8PBDEs 的平均浓度分别为 479 和 1670ng/m3。与从废弃 PWB 收集的表面灰尘（15600ng/g）相比，车间地板灰尘（31100ng/g）、加热机内部灰尘（84700ng/g）和旋风除尘器灰尘（317000ng/g）中的 PBDEs 浓度在热过程后被浓缩。加热实验表明，在最初的 1 小时内，含 PBDEs 灰尘中的 PBDEs 排放量明显高于 PWB 碎片中的排放量。灰尘中 PBDEs 的累积排放量最初迅速增加，然后趋于稳定并达到最大量。在 300°C 时，灰尘中 PBDEs 的排放主要发生在最初的 5 分钟内，前 5 分钟内 BDE-28、-47 和-99 的平均排放速率分别为 1230、4480 和 1950ng/（g·min）。在最初的 1 小时内，PWB 碎片中 PBDEs 的排放趋势呈线性增加，不同温度下五溴联苯醚（BDE-47、-99、-100）的排放速率在 9.75-11.5ng/（g·min）之间。所有结果表明，PWB 废物中的 PBDEs 在热过程中排放，为减少工人接触 PBDEs 的职业暴露水平提供了管理策略。
