A sequencing electroreduction-electrooxidation system driven by atomic hydrogen for enhancing 2,4-dichloronitrobenzene removal from wastewater

Jia Yuan; Xi Chen; Xueye Wang; Yun Guo; Lehui Ren; Chengxin Niu; Yang Li

doi:10.1016/j.envres.2024.118986

A sequencing electroreduction-electrooxidation system driven by atomic hydrogen for enhancing 2,4-dichloronitrobenzene removal from wastewater

Environ Res. 2024 Apr 23;252(Pt 3):118986. doi: 10.1016/j.envres.2024.118986. Online ahead of print.

Authors

Jia Yuan¹, Xi Chen¹, Xueye Wang¹, Yun Guo¹, Lehui Ren¹, Chengxin Niu¹, Yang Li²

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Tongji Advanced Membrane Technology Center, Shanghai, 200092, China.
² State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Tongji Advanced Membrane Technology Center, Shanghai, 200092, China. Electronic address: 22310353@tongji.edu.cn.

PMID: 38663671
DOI: 10.1016/j.envres.2024.118986

Abstract

The 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.

Keywords: 2,4-Dichloronitrobenzene; Atomic hydrogen; Dehalogenation; Electroreduction-electrooxidation; Hydrogen peroxide; Water treatment.