Assessment of Noise and Heavy Metals (Cr, Cu, Cd, Pb) in the Ambience of the Production Line for Recycling Waste Printed Circuit Boards

摘要

The crush - pneumatic separation - corona electrostatic separation production line provides a feasible method for industrialization of waste printed circuit boards (PCBs) recycling. To determine the potential environmental contamination in the automatic line workshop, noise and heavy metals (Cr, Cu, Cd, Pb) in the ambience of the production line have been evaluated in this paper. The mean noise level in the workshop has been reduced from 96.4 to 79.3 dB since the engineering noise control measures were employed. Noise whose frequency ranged from 500 to 1000 Hz is controlled effectively. The mass concentrations of TSP and PM_10 in the workshop are 282.6 and 202.0μg/m~3, respectively. Pb (1.40μg/m~3) and Cu (1.22 μg/m~3) are the most enriched metals in TSP samples followed by Cr (0.17 μg/m~3) and Cd (0.028 μg/m~3). The concentrations of Cu, Pb, Cr, and Cd in PM_10 are 0.88, 0.56, 0.12, and 0.88 μg/m~3, respectively. Among the four metals, Cr and Pb are released into the ambience of die automatic line more easily in the crush and separation process. Health risk assessment shows that noncancerous effects might be possible for Pb (HI = IAS), and noncancerous effects are unlikely for Cr, Cu, and Cd. The carcinogenic risks for Cr and Cd are 3.29 × 10~(-8) and 1.61 × 10~(-9) respectively. It indicates that carcinogenic risks on workers are relatively light in the workshop. These findings suggest that this technology is advanced from the perspective of environmental protection in the waste PCBs recycling industry.