Point-source tracking of microplastics in sewerage systems. Finding the culprit

Area of Science:

• Environmental Science
• Analytical Chemistry
• Water Treatment

Background:

• Microplastic (MP) research often prioritizes removal techniques over source identification in wastewater treatment plants (WWTPs).
• Understanding MP sources is crucial for effective environmental management and pollution control.

Purpose of the Study:

• To investigate the presence, chemical composition, size, and mass of microplastics in wastewater from various sources.
• To identify the primary sources and types of microplastics entering WWTPs.
• To evaluate methods for microplastic fiber identification.

Main Methods:

• Utilized focal plane array micro Fourier Transform Infrared spectroscopy (FPA-μFTIR) for MP quantification.
• Analyzed wastewater samples from industrial laundry facilities, domestic sewage, and WWTP influent.
• Employed post-processing software to compare aspect ratio and elongation ratio methods for fiber identification.

Main Results:

• Industrial laundry wastewater exhibited the highest MP concentration (6900 counts L⁻¹ or 716 μg L⁻¹).
• Domestic sewage and WWTP influent showed comparable MP levels (approx. 1500-1600 counts L⁻¹).
• Polyester fibers were a predominant MP type, linked to textile washing.

Conclusions:

• Laundry activities, particularly textile washing, are a significant source of microplastics in wastewater.
• Domestic activities contribute substantially to the microplastic load in wastewater systems.
• Accurate identification methods are essential for characterizing microplastic pollution from various sources.