Emission factors of particulate matter, CO and CO₂ in the pyrolytic processing of typical electronic wastes

A self-designed experimental device was employed to simulate the pyrolytic dismantling process of selected electronic wastes (E-wastes), including printed wiring boards (PWBs) and plastic casings. The generated particulate matter (PM) of different particle sizes, carbon monoxide (CO) and carbon dioxide (CO₂) were determined, and the corresponding emission factors (EFs) were estimated. Finer particles with particle sizes of 0.4-2.1 μm accounted for 78.9% and 89.3% of PM emitted by the pyrolytic processing of PWBs and plastic casings, respectively, and the corresponding EFs were 9.68 ± 4.81 and 18.49 ± 7.2 g/kg, respectively. The EFs of CO and CO₂ from PWBs and plastic casings were 55.9 ± 26.9 and 1182 ± 439 g/kg, and 133.6 ± 34.6 and 2827 ± 276 g/kg, respectively. Compared with other emission sources, such as coal, biomass, and traffic exhaust, the EFs of E-wastes were relatively higher, especially for PM. There were significant positive correlations (p < 0.05) of the initial contents of carbon and nitrogen in PWBs with the related EFs of PM, CO, and CO₂, while the correlations for plastic casings were insignificant. The EFs of CO of PWBs were significantly positively correlated with the corresponding EFs of PM and the parent polycyclic aromatic hydrocarbons (PAHs); however, the same result was not observed for plastic casings.