Comparison of Microplastic Detection Methods in Wastewater Treatment Plants

A plastic can be turn to millions fragments of microplastic particles by anthropogenic activities and environmental events (such as wind, UV light, the water wave action). Due to their surface hydrophobicity, adsorb persistent organic pollutants, the potential to transport contaminants and persistent properties, microplastics have the potential to become widely dispersed in the water environment via hydrodynamic processes and water currents. Plastic materials are durable and rather than decomposing, they break down into small plastic particles over time. These small particles that are less than 5 mm usually defined as microplastic. As a consequence of large plastic production rates, plastic waste accumulation in natural environment rapidly increased all over the World. However, the effects of plastic wastes in different ecosystems are still largely unknown. Water and wastewater treatment plants are important facilities to estimate plastic waste release or retention amount to the environment. The field of microplastic pollution is in its infancy, and there are not yet widely accepted standards for sample collection, laboratory analyses, quality assurance/quality control (QA/QC) or reporting of microplastics in environmental samples. Up to date, few studies have quantified microplastics in wastewater. Moreover, the lack of a standardized and applicable method to identify microplastics in complex samples, such as wastewater, has limited the accurate assessment of microplastics and may lead to an incorrect estimation. In this study, microplastic sampling techniques, extraction methods and identification methods of microplastics in wastewater were compared. It was concluded that studies were mostly done with grap type sampling, wet peroxite oxidation and identification methods with microscope and Fourier Transform Infrared Spectrophotometer (FT-IR). In the FT-IR analysis to determine the polymer structure of microplastics, the most common type of polymer was found to be polypropylene (PP) and polyethylene (PE).