Toxic metals in WEEE: Characterization and substance flow analysis in waste treatment processes

• Published in: The Science of the total environment Vol. 463-464; pp. 1124 - 1132
• Main Authors: Oguchi, Masahiro, Sakanakura, Hirofumi, Terazono, Atsushi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.2013
• Subjects: case studies; chemistry; electronic equipment; Environment; heavy metals; Household Articles; Incineration; Japan; landfills; material flow analysis; Metals; Metals - chemistry; Metals - toxicity; methods; Municipal solid waste; Recycling; Refuse Disposal; Refuse Disposal - methods; Resource recovery; Substance flow; Toxic metal; toxic substances; toxicity; Waste electrical and electronic equipment (WEEE); waste treatment; Japan; Waste electrical and electronic equipment (WEEE); Resource recovery; Toxic metal; Incineration; Substance flow; Municipal solid waste
• DOI: 10.1016/j.scitotenv.2012.07.078
• ISSN: 0048-9697; 1879-1026

Waste electrical and electronic equipment (WEEE) has received extensive attention as a secondary source of metals. Because WEEE also contains toxic substances such as heavy metals, appropriate management of these substances is important in the recycling and treatment of WEEE. As a basis for discussion toward better management of WEEE, this study characterizes various types of WEEE in terms of toxic metal contents. The fate of various metals contained in WEEE, including toxic metals, was also investigated in actual waste treatment processes. Cathode-ray tube televisions showed the highest concentration and the largest total amount of toxic metals such as Ba, Pb, and Sb, so appropriate recycling and disposal of these televisions would greatly contribute to better management of toxic metals in WEEE. A future challenge is the management of toxic metals in mid-sized items such as audio/visual and ICT equipment because even though the concentrations were not high in these items, the total amount of toxic metals contained in them is not negligible. In the case of Japan, such mid-sized WEEE items as well as small electronic items are subject to municipal solid waste treatment. A case study showed that a landfill was the main destination of toxic metals contained in those items in the current treatment systems. The case study also showed that changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. Because the flow changes might lead to an increase in the amount of toxic metals released to the environment, the flows of toxic metals and the materials targeted for resource recovery should be considered simultaneously. ► Appropriate management of toxic metals contained in WEEE is important during recycling and treatment of WEEE. ► CRT TVs contain large amount of toxic metals with high concentration and thus appropriate management is highly important. ► Mid-sized equipment is a future target for managing toxic metals in WEEE because the total amount is not negligible. ► Changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. ► The flows of toxic metals and valuable materials should be managed simultaneously in recycling and treatment of WEEE.