Microplastics in wastewater outlets of Bandar Abbas city (Iran): A potential point source of microplastics into the Persian Gulf

Wastewater discharge is considered to be a significant point source of microplastic (MPs) release into the marine environment. This study is the first attempt to quantify MPs released from the wastewater outfall from Bandar Abbas City into the Persian Gulf. Two wastewater discharge stations at Gursuzan and Suru were sampled. MPs were isolated by an oxidative procedure and subsequent density separation using ZnCl2 solution. The average MP concentration in wastewater and sludge were 70.66 (+/- 14.12, SD) MP.35 L-1 and 6070 (+/- 807.25) MPs.kg(-1), respectively at Confidence Level (CL) (95.0%). The most commonly recovered polymers were polyethylene (PE) and polypropylene (PP) in all size classes. Our findings provides a baseline of MP concentration in wastewater streams and slurry that is discharged from the Bandar Abbas wastewater treatment facility into the Persian Gulf. This highlights the need to undertake more studies at water treatment plants in the region for a realistic assessment of MP discharge into the Persian Gulf. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study quantifies the release of microplastics from the wastewater outfall in Bandar Abbas City into the Persian Gulf, with polyethylene and polypropylene being the most commonly recovered polymers in wastewater and sludge. Further research is needed at water treatment plants in the region to better assess microplastic discharge into the Persian Gulf.