Improving the degradation of atrazine in the three-dimensional (3D) electrochemical process using CuFe2O4 as both particle electrode and catalyst for persulfate activation

In this study, CuFe2O4 (CFO) magnetic nanoparticles are used as both particle electrode and catalyst for persulfate (PS), applying in the three-dimensional (3D) electrochemical process for atrazine (ATZ) degradation. We studied the effects of operating parameters (i.e., CFO dosage, PS concentration, initial pH, and current density) on ATZ degradation. The optimum ATZ degradation efficiency (>99%) and TOC removal (22.1%) were achieved after 35 min treatment with CFO dosage of 3.0 g/L, PS concentration of 4.0 mM, current density of 4 mA/cm2, and initial pH of 6.3. Several comparative studies of control experiments were carried out, confirming the superior performance of EC/CFO/PS system for ATZ degradation. CFO magnetic nanoparticle electrodes (MNPEs) exhibited a favorable stability during the five runs under optimal conditions. Quenching experiments and electron paramagnetic resonance (EPR) study proved that ATZ was destroyed by free radicals. Meanwhile, the monitored sulfate radical and hydroxyl radical concentration in EC/CFO/PS system revealed that sulfate radical was the dominant reactive radical in ATZ degradation process. Based on the detected intermediates by LC-MS, the pathways of ATZ degradation in the EC/CFO/PS system were proposed. Finally, the study proposed the reaction mechanism of EC/CFO/PS three-dimensional electrochemical process. In brief, EC/CFO/PS 3D electrochemical process was found to be a reliable technology for the remediation of surface water and groundwater contaminated by atrazine.