Epsilon Archive for Student Projects

Abstract

Pharmaceutical residues in municipal wastewater represent a persistent environmental challenge, as conventional treatment processes for these types of compounds are insufficient. This study investigates the feasibility and performance of a GOD-HRP cascade reaction, with silica encapsulated vermiculite matrix as support for degradation of pharmaceutical residues in conventionally treated wastewater. Enzyme activity assays confirmed successful immobilization of the enzymes on vermiculite and retained catalytic function following silica encapsulation. The immobilized enzymes composite was incorporated into a laboratory-scale column system and evaluated over three continuous sample periods, for a total time of 9 hours. High-performance liquid chromatography (HPLC) analysis of eluates demonstrated that 9 out of 16 targeted pharmaceuticals, including venlafaxine, metoprolol, clarithromycin, bisoprolol, and citalopram, were removed with efficiencies exceeding 95% throughout the whole experiment. Nuclear magnetic resonance (NMR) analysis further confirmed the transformation of organic compounds during enzymatic treatment and revealed excessive H2O2 production in later sampling periods, likely causing partial inactivation of HRP and reduced removal of irbesartan, fexofenadine, and oxazepam. Compounds, such as carbamazepine and lamotrigine, showed minimal removal, which highlights the need for further optimization through multi-enzyme systems or mediator-assisted strategies. Obtained results demonstrate the potential of enzyme immobilization on mineral supports for advanced wastewater treatment. Further long-term testing under realistic operational conditions, scale-up studies are needed to fully evaluate the potential of application of this method as a purification technology. This work contributes to ongoing pilot initiatives at Kungsängsverket and provides insights for the development of sustainable solutions to pharmaceutical pollution in urban water systems.