Utilizing scrap printed circuit boards to fabricate efficient Fenton-like catalysts for the removal of pharmaceutical diclofenac and ibuprofen from water

Abstract

Pharmaceutical concentrations in waterways have now gradually increased to alarming levels, posing a threat to the environment and human health. The heterogeneous Fenton-based advanced oxidation process is a promising treatment process for cleaning water from organic pollutants. Utilizing waste-to-resource technologies, electronic waste can be transformed into practical weapons for environmental remediation. In this work, scrap printed circuit boards (PCBs) were used to prepare green, simple, and scalable heterogeneous H2O2 activators namely, non-carbonized catalyst (NC-PCB) under air combustion and carbonized catalyst (C-PCB) under nitrogen pyrolysis. Diclofenac (DCF) and ibuprofen (IBP) were used as model pharmaceutical pollutants to investigate the efficacy of the synthesized catalysts in Fenton-like oxidation. The morphology, composition, and photocatalytic activities of both catalysts were characterized by various analytical techniques. The effect of experimental factors such as catalyst/H2O2 dosages, solution pH, and initial concentrations on the removal rate was studied and optimized. Under optimum conditions, the degradation efficiencies for DCF and IBP using the NC-PCB catalyst were 86% and 66%, respectively, and 61% and 65.7% using C-CPB within 30 min. The TOC removal for DCF and IBP after 60 min was 61% and 50% using NC-CPB and 45% and 43% using C-CPB, respectively. Copper oxides in the catalysts plays the primary role in the degradation process. For five cycles, the catalysts have good reusability and low metal leaching. The degradation kinetics were followed, by a pseudo-first-order model. The present study is expected to provide a new approach for promoting Fenton-like wastewater treatment systems to practical application.