Preparation of Granular Activated Carbon Particle Electrode Loaded with Co3O4 and its Effect on Amoxicillin Wastewater Treatment

Abstract

In this work, granular activated carbon (GAC) loaded with Co3O4 catalyst (Co3O4/GAC) was used as a particle electrode for three-dimensional (3D) electrochemical treatment of amoxicillin (AMX) wastewater. The morphology, crystal structure, surface chemical bonds, specific surface area, and pore structure of the particle electrodes were characterized. Considering AMX and TOC removal rates and electrical energy consumption (EEC), the optimal manufacturing conditions of the Co3O4/GAC were determined as the calcination temperature of 700 °C, the calcination time of 5 h, and the impregnation time of 3 h, respectively. The measurement of electrochemical impedance spectroscopy showed that the interfacial electron transfer property of Co3O4/GAC was much improved compared with GAC. AMX removal rate (96.0%, 40 min), TOC removal rate (84.4%, 2 h), and EEC (87.2 kWh kg−1 TOC) of the 3D-Co3O4/GAC system were all significantly improved compared to the 3D-GAC system (77.9%, 40.3%, 232.9 kWh kg−1 TOC) and the 2D system (66.4%, 3.9%, 2080.3 kWh kg−1 TOC) under the same operating conditions. It was confirmed that Co3O4/GAC catalytically generates ·OH and H · radicals and increases the conductivity inside the reactor. The degradation of AMX was confirmed using ultraviolet-visible spectroscopy and the degradation mechanism of AMX in the 3D-Co3O4/GAC system was proposed.