Characterization of residues from dismantled imported wastes

Residues from the imported wastes dismantling process create a great burden on the ambient environment. To develop appropriate strategies for the disposal of such residues, their characteristics were studied through background value analysis and toxicity leaching tests. Our results showed that the heavy metals concentrations in residues were high, particularly those of Cu (7180 mg kg−1), Zn (2783 mg kg−1), and Pb (1954 mg kg−1). Toxicity leaching tests revealed a high metal releasing risk of such residues if they are disposed of in a landfill. However, the residues of imported wastes were also found to have some intrinsic metal recycling value.

► Contents of Cu, Zn, and Pb are 414, 38, and 64 times higher than the background values.
► Leaching levels of Cu, Pb, and Cd exceed each corresponding criterion.
► Landfill are unsuitable for residues disposal.
► Recycling is a good choice for residues disposal.