Emissions from the incineration of electronics industry waste

Abstract

One strategy for dealing with electronics waste is to incinerate the combustible fraction of the waste, either to reduce its volume prior to landfilling or to concentrate valuable metals in the residual ash so they can be reclaimed in a subsequent operation. Since no emissions data are available, experiments were performed in a pilot-scale rotary kiln incinerator over a range of temperatures to investigate the potential toxic emissions from the incineration of electronics waste. The electronics waste burned was a mixture of personal computer motherboards, keyboards, and cases. The flue gas was analyzed for metals, halogens, volatile and semi-volatile organic products of incomplete combustion (PICs), including polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs). Ash residues were analyzed by toxicity characteristic leaching procedure. Measured metal emissions were significant, and consisted primarily of copper, lead, and antimony. No mercury emissions were defected. The presence of brominated flame retardants in the waste resulted in the emission of bromine in its diatomic and ionic forms, along with several brominated organic species. Emissions of PCDDs/Fs were well below regulatory limits, possibly due to the presence of bromine in the waste stream. These preliminary tests suggest that incineration may be a viable option for electronics waste disposal, provided an appropriate particulate control device is used to control metal emissions.