Critical review on microplastics in landfill leachate

Area of Science:

• Environmental Science
• Environmental Chemistry
• Waste Management

Background:

• Microplastic (MP) pollution is a significant global environmental issue.
• Landfills are major repositories of plastic waste and a potential source of MPs.
• Landfill leachate (LL) acts as a critical pathway for MP release into the environment.

Purpose of the Study:

• To systematically review existing studies on microplastics in landfill leachate.
• To identify dominant polymer types, shapes, colors, and sizes of MPs in LL.
• To highlight challenges in comparing studies and suggest future research directions.

Main Methods:

• Systematic literature review of studies on MPs in landfill leachate.
• Analysis of publication trends by country, with China, India, and the United States leading.
• Characterization of MP polymer type using micro-Fourier transform infrared spectroscopy (FTIR) and Raman techniques.

Main Results:

• Polyethylene (PE) was the most abundant polymer type in LL, followed by polypropylene.
• Fibers were the most prevalent MP shape, with black and blue being common colors.
• MP sizes in leachate ranged from 0.03 to 5 mm, though comparisons were hindered by methodological differences.

Conclusions:

• Microplastic pollution via landfill leachate is a significant environmental pathway.
• Polyethylene, particularly in fiber form, dominates MP contamination in LL.
• Further investigation into high-density PE landfill liners is crucial to prevent environmental degradation.