Occurrence and characteristics of microplastics in surface water and sediment of Zayandeh-rud river, Iran

Background: Zayandeh-rud river is the most important in central regions of Iran and present study aimed to provide new insights into microplastics (MPs) pollution surface water sediments this river. Methods: Water sediment samples were collected July 2021 from 19 sampling sites along Organics matters removed by wet peroxide oxidation (WPO), MPs extracted floatation ZnCl2 -saturated salt filtration on a polytetrafluoroethylene (PTFE) membrane filter. Trapped filter counted qualified stereomicroscope. Results: found 13 The minimum maximum levels 0 51±16.5 particles/m3 , respectively. also detected all except first two (the level was 58±25.9 particles/kg as dry sediment). Fragments common shape both samples. 72.3% 1-5 mm size, while percentage for 49.2%. five main polymer types polyethylene terephthalate (PET), (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC). Conclusion: These longtime persistence plastics environment significant threat environmental human health need serious attention restrict release