Environmental Health Engineering and Management Journal

en Occurrence and removal of microplastics in a municipal wastewater treatment plant with conventional activated sludge process: A case study in Isfahan, Iran عمومى General مقاله اصیل Original Article <div style="text-align: justify;">Background: Microplastics (MPs) are nowadays found in the air and in various terrestrial and aquatic environments and have become emerging pollutants. These particles can absorb other chemicals and microbial contaminants and release them into the environment and food chain. Despite the high efficiency of wastewater treatment plants (WWTPs) in removing MPs, WWTPs are still one of the major sources of MPs discharge to the environment. This study was conducted to evaluate the efficiency of MPs removal in a municipal WWTP with conventional activated sludge in Iran. Methods: MPs particles were counted using a stereomicroscope after the initial preparation steps (sieving, chemical digestion with the catalytic wet peroxidation-oxidation and density separation with NaCl) and then analyzed for particle composition using a Raman micro-spectrometer. Results: MPs concentration in the influent, grit chamber, primary sedimentation tank, and effluent were 843.2 ± 147.5, 315.5 ± 54.7, 80.2 ± 19.1, and 11.13 ± 3.14 items/L, respectively. The overall MPs removal efficiency of the WWTP was 98.7%, with the grit chamber, primary sedimentation tank, and secondary sedimentation tank removed 62.6%, 27.9%, and 8.2% of the total MPs, respectively. The most abundant polymers were polypropylene (PP) and polyethylene (PE). Conclusion: Despite the effective removal of MPs in WWTP, on average 4.47 × 1011 ± 1.03 × 1011 MPs are discharged into the receiving waters through the effluent of this WWTP annually. This means that WWTPs can be one of the major sources of MPs in the environment and efforts should be made to increase the efficiency of WWTPs and equip them with advanced technologies.</div> Microplastics, Plastics, Wastewater, Environmental pollutants, Iran 59 66 http://ehemj.com/browse.php?a_code=A-10-1-277&slc_lang=en&sid=1 Hamze Sharifi hamzesharifi@hlth.mui.ac.ir 100319475328460011709 100319475328460011709 No Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran Hossein Movahedian Attar movahedian@hlth.mui. ac.ir 100319475328460011710 100319475328460011710 Yes Corresponding author: Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran Bijan Bina bbina123@yahoo.com 100319475328460011711 100319475328460011711 No Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran