This study evaluated the leaching or release behavior of Bisphenol S (BPS), a common plastic additive, from Polyethersulfone (PES) and Polyphenylsulfone (PPSU) microplastics (MPs) that derive from commercial products such as baby bottles and battery covers. Ultraviolet (UV) irradiation, temperature and humic acid (HA) were shown to affect the BPS release kinetics, which followed the first-order kinetics. The released BPS underwent immediate photolysis under UV254 irradiation. Our results also revealed that photo oxidation of MPs led to the breakage of diphenyl ether sulfone group due to the attack of reactive oxygen species (ROS), which contributed to the leaching mechanisms of BPS. Finally, a release kinetics model was established and predicted a BPS release rate of up to 6862.1 μg per gram of MPs within 8000 h. We further examined the aging of MPs during UV-photogenerated radical attack and analyzed the aging pathway that mainly involved abstraction of an H-atom, ●OH addition on benzene ring, dechlorination, decarboxylation, deamination and cleavage of C-O by ●OH attack, and abstraction of a H-atom by 1O2 attack. This work thus provided new insights into the ROS formation mechanisms and their impacts on the aging and chemical release of MPs in aquatic environments and supported a comprehensive understanding of their environmental fate.

Photo irradiation of BPA-free baby bottles could still leach out toxic chemicals (e.g., Microplastics and Bisphenol S): Radical-mediated environmental weathering of plastics

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.