Mechanisms of interfacial catalysis and mass transfer in a flow-through electro-peroxone process

Abstract

To investigate the catalytic mechanism and mass transfer efficiency in the removal of amitriptyline using an electro-peroxide process, a CuFe2O4-modified carbon cloth cathode was prepared and utilized in a reaction unit. The results demonstrated a remarkable efficacy of the system, achieving 91.0% amitriptyline removal, 68.3% mineralization, 41.2% mineralization current efficiency, and 0.24 kWh/m3 energy consumption within just five minutes of treatment. The study revealed that the exposed Fe atoms of the ferrite nanoparticles, with a size of 22.7 nm and 89.7% crystallinity, functioned as mediators to bind the adsorbed O atoms. The 3dxy, 3dxz, and 3d2z orbitals of Fe atoms interacted with the 2pz orbital of O atoms of H2O2 and O3 to form σ and π bonds, facilitating the adsorption-activation of H2O2 and O3 into hydroxyl radicals. These hydroxyl radicals (∼ 1.15 × 1013 mol/L) were distributed at the cathode-solution interface and rapidly consumed along the direction of liquid flow. The flow-through cathode design improved the mass transfer of aqueous O3 and in-situ generated H2O2, leading to an increased yield of hydroxyl radicals, as well as the contact time and space between hydroxyl radicals and amitriptyline. Ultimately, this resulted in a higher degradation efficiency of the system.