Oxidative degradation of bisphenol A and 17α-ethinyl estradiol by Fenton-like activity of silver nanoparticles in aqueous solution.

Silver nanoparticles (AgNPs) have been reported to have antibacterial activities and cytotoxicity, resulting from the dissolved silver cation (Ag+) and its soluble complexes. However, to our knowledge, little has been reported about their potential use in degrading organic contaminants such as endocrine-disrupting compounds in aqueous solution. In this first report on the subject, we examined the effectiveness of the oxidative degradation of bisphenol A (BPA) and 17α-ethinyl estradiol (EE2) in water by reactive oxygen species formed during the decomposition of H2O2, assisted by polyvinylpyrrolidone (PVP)-stabilized AgNPs. The dissolution of AgNPs accompanied generation of OH at low pH. The fully dispersed PVP-AgNPs in the presence of H2O2 exhibited fast degradation kinetics for EE2 at a typical aquatic condition of pH (6-7). The oxidation kinetics of BPA and EE2 by PVP-AgNPs can be interpreted using three different modeling approaches: an initial pseudo-first-order, a retarded first-order rate, and Behnajady-Modirshahla-Ghanbery kinetic equation. The findings showed that AgNPs may have potential to facilitate the in situ oxidation for emerging contaminants in the aqueous environment.