Fate of Microplastics in Water Resource Recovery Facilities (WRRFs) and National Environmental Loading Estimates

(limit 150 words)Microplastics (<5 mm) entering into WRRFs become a point of source for pollution, but we have fragmentary knowledge about the fate of microplastic inside WRRFs. In this study, we assessed the microplastic pollution in four WRRFs. Our results suggest that activated sludge contained much of the plastic load and only 0.02-0.3% of the microplastic would eventually end up in effluent and thus discharge into waterbodies. But such miniscule percentage would result into release of 256 trillion microplastic particle in waterbodies across the United States. Microplastic particles act as a carrier of invasive species. Striking similarity was observed between activated sludge bacterial community and microplastic associated biofilm by 16s rRNA gene sequencing indicating the colonization of native bacteria from WRRFs on the microplastic surface. Overall, this paper contributes substantially to our current understanding of WRRFs as a point of source of microplastic and the environmental fate of microplastics in effluent water.