A Sequencing Electroreduction-electrooxidation System Driven by Atomic Hydrogen for Enhancing 2,4-Dichloronitrobenzene Removal from Wastewater

Environ Res. 2024 Apr 23:118986. doi: 10.1016/j.envres.2024.118986. Online ahead of print.ABSTRACTThe sequencing electroreduction-electrooxidation process has emerged as a promising approach for the degradation of the chloronitrobenzenes (CNBs) due to its elimination of electro-withdrawing groups in the reduction process, facilitating further removal in the subsequent oxidation process. Herein, we developed a cathode consisting of atom Pd on a Ti plate, which enabled the electro-generation of atomic hydrogen (H*) and the efficient electrocatalytic activation of H2O2 to hydroxyl radical (•OH). Cyclic voltammetry (CV) curves and electron spin resonance (ESR) spectra verified the existence of H* and •OH. The electroreduction-electrooxidation system achieved 94.7% of 20 mg L-1 2,4-DCNB removal with a relatively low H2O2 addition (5 mM). Moreover, the inhibition rate of Photobacterium phosphoreum in the effluent decreased from 95% to 52% after the sequencing electroreduction-electrooxidation processes. It was further revealed that the H* dominated the electroreduction process and triggered the electrooxidation process. Our work sheds light on the effective removal of electron-withdrawing groups substituted aromatic contaminants from water and wastewater.PMID:38663671 | DOI:10.1016/j.envres.2024.118986
Source: Environmental Research - Category: Environmental Health Authors: Source Type: research