Characteristics, and seasonal change of microplastics in organized industrial zone wastewater treatment plant

Industrial wastewater is known to be an important source of microplastics (MPs) reaching treatment plants. In this study, the characteristics, seasonal variation, and removal efficiencies of MPs in samples obtained from the wastewater treatment plant (WWTP) of an organized industrial zone (OIZ) for 1 year were evaluated. The average abundance of MPs was found to be 161.3 ± 74.9 MP/L at the WWTP influent and 16.9 ± 6.2 MP/L at the effluent. MP abundance in the sludge cake was found to be 43.2 ± 17.1 MP/g dry weight (dw). In the samples, the dominant shape was fiber, the dominant color was transparent, and the dominant size range was 500–1000 µm. The main MP types in the influent wastewater samples were polyethylene (PE) (29.6 %), Polyester (PES), (25.9 %), polyethylene terephthalate (PET) (22.2 %), and polypropylene (PP) (14.8 %). In contrast, in the effluent wastewater samples, they were PE (41.9 %), PET (19.4 %), and PP (12.9 %). The distribution in the sludge cake was PE (67.9 %), PET (16.1 %), and PES (10.7 %). Future studies should focus on developing new technologies and techniques to increase the removal efficiency of MPs from wastewater and sludge. •MPs ranged between 500 and 1000 µm, predominantly exhibiting a fiber morphology.•PE emerged as the dominant plastic type in wastewater and sludge samples.•Significant seasonal variation in MP concentrations was observed in influent and sludge.•WWTP releases significant amounts of MPs into aquatic ecosystems.