Improvement of the conventional flat plate electrode: Application of filtered Pd@Ti electrode in the removal of toxic chlorinated PPCPs

Abstract

In order to change the mass transfer efficiency of conventional flat plate electrodes in the catalytic process, a new filtered Pd@Ti electrode has been prepared. The results indicated that the filtered Pd@Ti electrode had the best removal efficiency of 99.59% on diclofenac (DCF) at the flux of 40.85 L/m2∙h-1. Compared to unfiltered Pd@Ti electrodes, the removal efficiency was 1.18 times higher, the current efficiency was 2.15 times higher and the cost of electricity was 69.05% lower. The electrocatalytic hydrodechlorination process of DCF by filtered Pd@Ti electrode mainly relies on indirect reductive dechlorination by H* adsorbed on the electrode surface. The removal efficiency of the filtered Pd@Ti electrode remained above 80% after six cycles. The removal mechanism and reaction pathway of filtered Pd@Ti electrode for dechlorination of different chlorinated PPCPs were proposed. Furthermore, the ecotoxicity of chlorinated PPCPs and their products were evaluated by using the toxicity estimation software tool (T.E.S.T.) model. This study confirmed the promising application of filtered Pd@Ti electrodes for the removal and detoxification of chlorinated PPCPs in wastewater.