Influence of polyethylene microplastics on the photocatalytic degradation of dibutyl phthalate and bisphenol A in an aqueous medium

Microplastics have become a major problem in recent years, as they can be seen as a vector for the transport of hydrophobic organic pollutants. The bioavailability of organic pollutants in the marine environment can be altered by microplastics through phototransformation, potentially affecting aquatic toxicity. In the present work, hydrogen peroxide (H2O2), Fe(III) ions and Fe(III)-EDDS (EDDS: Ethylenediamine-N,N'-succinic acid) complexes were used for the photocatalytic degradation of dibutyl phthalate (DBP) and bisphenol A (BPA) adsorbed on polyethylene microplastics (PE-MP) under UVB irradiation in aqueous media. Irradiation experiments were carried out in a photochemical reactor, with HPLC used for analyses. Initial adsorption studies showed intense adsorption of DBP on PE-MP, while BPA exhibited minimal adsorption likely due to differences in water solubility. Direct photolysis of DBP and BPA was minimal, with the presence of PE-MP impacting the degradation rate of DBP but not BPA due to varying adsorption capacities. Photocatalytic degradation using three different catalysts resulted in efficient removal of both pollutants within 120 min. The presence of PE-MP influenced the reaction rate of all photocatalysed reactions, with an inhibitory effect observed mainly due to the shading effect of microplastics. A notable difference was observed in the final removal of DBP compared to BPA, with DBP showing significantly lower removal rates. The results of the present study show that photocatalytic degradation of DBP and BPA is an effective pollutant removal process influenced by the presence of microplastics. Also see: https://micro2024.sciencesconf.org/559444/document