Efficient degradation of halogenated disinfection by products in a three-dimensional electrode reactor with MnO2/NiMn-LDH/C as particle electrodes: Performance prediction and mechanism exploration

Abstract

In this work, an in situ novel MnO2/NiMn-LDH/C composite material was designed and used as a particle electrode in a three-dimensional electrochemical continuous flow system, which degraded dichloroacetamide (DCAcAm) because a suitable nickel-manganese metal ratio leads to the construction of MnO2 and NiMn-LDH, and the addition of carbon contributes to the formation of a hierarchical structure. The effects of different conditions were explored by single factor experiments and response surface design experiments. A high removal rate of 89 % was obtained under optimal conditions (current density of 12 mA/cm2, flow rate of 0.5 mL/min, electrolyte concentration of 0.175 mol/L, and a pollutant concentration of 10.5 g/L). According to density functional theory (DFT) calculations, electron paramagnetic resonance (EPR) measurements and free radical quenching experiments, the corresponding electrocatalytic mechanism and reaction pathways were clarified. The application of response surfaces was utilized to predict degradation performance. The results of the recycling experiments show the good stability of this electrode. Finally, the actual chlorin wastewater degradation experiment results showed that the COD and TOC of this wastewater decreased by 76.03 % and 72.41 %, respectively, after 90 min of electrocatalytic degradation. This study offers a novel theoretical framework and technical support for the control of HAcAms.