Development of a Methodology for Analyzing Microplastics in Sewage Treatment Plants

Area of Science:

• Environmental Science
• Analytical Chemistry
• Polymer Science

Background:

• Microplastic (MP) pollution is a growing global concern, particularly in wastewater.
• Current analysis methods lack standardization, hindering comparative studies.
• Wastewater treatment plants are key sites for MP monitoring.

Purpose of the Study:

• To develop, optimize, and validate a comprehensive methodological framework for MP extraction and identification in wastewater.
• To establish reliable protocols for analyzing microplastics in complex environmental matrices.
• To address the need for standardized methods in microplastic research.

Main Methods:

• Reference microplastics (PET, HDPE, LDPE, PVC, PP, PS) were synthesized.
• Fenton reagent digestion protocols were evaluated using carbonyl index.
• Density separation was optimized using zinc chloride (ZnCl2) solutions.
• Fourier-transform infrared (FTIR) spectroscopy was used for identification.
• The methodology was validated with real wastewater and sludge samples.

Main Results:

• Optimal Fenton digestion conditions (40-60°C, 2h) preserved MP integrity.
• Zinc chloride demonstrated superior efficiency for MP separation.
• FTIR analysis confirmed no significant spectral changes post-digestion.
• The validated method effectively removed organic matter and recovered spiked MPs.
• Native MPs were reliably identified in environmental samples.

Conclusions:

• The developed methodology is robust and reliable for microplastic extraction and characterization in wastewater.
• This framework supports future monitoring programs and the development of standardized MP analysis protocols.
• The study provides crucial methodological advancements for assessing microplastic pollution in aquatic environments.