Characterizing the emission of chlorinated/brominated dibenzo-p-dioxins and furans from low-temperature thermal processing of waste printed circuit board

摘要

This study focuses primarily on the inventory of PCDD/Fs and PBDD/Fs associated with the low-temperature thermal processing of scrap printed circuit boards (PCBs). Twelve 2,3,7,8-substituted PBDD/Fs congeners were found in various sample outputs, with a total content of 60,000 ng TEQ/kg at 250 ℃ under air atmosphere. A rapid increase of PBDD/Fs was produced with 160,000 ng TEQ/kg, at 275 ℃-about twice that under the N_2 atmosphere. At 275 ℃, the total contents of PCDD/Fs were only 170 and 770 ng TEQ/kg under an N_2 and air atmospheres respectively. The results reveal that a large contribution of PBDD/Fs emission may be expected from the dismantling or any other thermal processing of PCB scrap. PCDD/Fs, however, are formed and released into the environment in a variety of ways. Additional research is required to look for the causal factors that affect emissions.