Quantitative and qualitative study of micro and nanoplastics in the effluent of the municipal wastewater treatment plant in the south of Tehran

Document Type : Research Paper


1 Ph. D. Student, Environmental Pollution, Islamic Azad University, West Tehran Branch, Tehran, Iran

2 Associate Professor, Environmental Pollution, Islamic Azad University, West Tehran Branch, Tehran, Iran

3 Associate Professor, Department of Microbiology, Faculty of Biology, Campus of Sciences, University of Tehran, Tehran, Iran

4 Professor, Faculty of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran


Municipal wastewater investigation is one of the most important ways of studying micro and nanoplastics since effluents are an important factor in bringing these pollutants to the environment. In this study, from November-December 2019 to December 2020, 4-liter effluents (48 samples in total) of the wastewater treatment plant in the south of Tehran were sampled every month. After preparing these samples and examining them by SEM microscopy, the particles were detectable in three forms (i.e. fiber, fragment, and film); on average, 47.48% of the fiber, 47.47% of the fragment and 13.04% of the film. The average number of samples was estimated more than 3000 microplastics per 1 liter of effluent sample. The lowest and highest numbers of microplastics were found in spring (5905) and summer samples (4873), respectively, 34.72% of which was related to nanoplastics. Also, the average results of 20 Raman tests from 48 samples showed that the highest amount of microplastics is primarily related to polypropylene and then related to polyethylene.


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