Antimony mobility from E-waste plastic in simulated municipal solid waste landfills

Area of Science:

• Environmental Science
• Geochemistry
• Waste Management

Background:

• Electronic waste (e-waste) contains antimony (Sb), a potential environmental contaminant.
• Disposal of e-waste in municipal solid waste (MSW) landfills raises concerns about Sb leaching.
• Plastic from cathode ray tube (CRT) televisions exhibits high Sb concentrations.

Purpose of the Study:

• To assess the fate and leachability of antimony (Sb) from e-waste plastic in simulated landfill conditions.
• To compare Sb leaching using different standard methods and actual MSW leachate.
• To investigate factors influencing Sb mobility in anaerobic landfill environments.

Main Methods:

• Utilized simulated anaerobic landfill lysimeters for long-term leaching studies.
• Employed three batch leaching tests: Toxicity Characteristic Leaching Procedure (TCLP), EPA Method 1313, and MSW leachate extraction.
• Focused on plastic from CRT television sets due to high Sb content.

Main Results:

• Sb leachability was similar between EPA 1313 and TCLP tests (~0.1% by weight at pH 4.93).
• MSW leachate extracted significantly less Sb (~0.02% by weight).
• Simulated landfill experiments showed Sb leaching of ~0.01% by weight at a liquid-to-solid ratio of 3.
• Solution pH was not the primary factor controlling Sb leachability.

Conclusions:

• Landfill leachate conditions, particularly reducing environments, decrease Sb concentrations compared to standard leaching tests.
• Sb behavior in landfills differs from arsenic, likely due to anaerobic decomposition.
• E-waste management strategies must consider the specific leaching behavior of Sb under landfill conditions.