Additive release and prediction of biofilm-colonized microplastics in three typical freshwater ecosystems

Widely used plastics are discarded and broken into microplastics (MPs), threatening the health of plants and animals, and affecting the natural world. The global spread of plastic additives, as unavoidable components in plastic preparation, raises concerns about their leaching in different environments. This paper aims to infer the leaching of hazardous plastic additives (e.g.FP-127 fluorescent additives) by investigating the effect of biofilm communities on the release of additives from plastics after 35 days of incubation in three typical freshwater ecosystems (Hubing Pool, Baogong Park, and Feihe River) in Hefei, China. In this research, we prepared different plastics, crushed them and then put them into natural freshwater we sampled in the laboratory. The results showed that the biofilms attached to the various MPs contained different biomass that were related to water environmental conditions and the properties of MPs. Compared to the natural release in deionized water, the concentration of leaching MPs additives can be 5, 10, and 20 times higher in Hubing Pool, Baogong Park, and Feihe River, respectively. The analysis results also clearly showed that the relative abundance of core communities was proportional to FP-127 additive leaching from the MPs into the surrounding environment. Moreover, we also modeled two equations to predict the release of additives. These findings would be valuable for predicting the potential of MPs to release toxic additives under different freshwater ecosystems.