New insights on the role of NaCl electrolyte for degradation of organic pollutants in the system of electrocatalysis coupled with advanced oxidation processes

作者：Tian, Lei; Zhu, Meng; Zhang, Long-Shuai; Zhou, Li-Juan; Fan, Jie-Ping^*; Wu, Dai-She; Zou, Jian-Ping^*

来源：Journal of Environmental Chemical Engineering, 2022, 10(3): 107414.

DOI：10.1016/j.jece.2022.107414

• Electrocatalysis
• Advanced oxidation processes
• Degradation
• Organic pollutants
• Sodium chloride
• Chlorine-substituted byproducts

The role of sodium chloride (NaCl) in pollutant degradation in electrocatalysis coupled with advanced oxidation processes (EAOPs) system remains debatable and the formation of toxic chlorine-substituted byproducts during this process has raised growing concern. Herein, the role of NaCl electrolyte for the degradation of p-nitrophenol (4-NP) in the EAOPs (Co3O4/PMS/NaCl) system was identified. Different from the effect of mass transfer, the presence of NaCl electrolyte improved the 4-NP degradation efficiency and the degradation products were affected by the concentrations of peroxymonosulfate (0.01-8 mM) and Cl- (10-100 mM). Besides, different active species (SO4 center dot-, HOCl, or Cl-center dot/ClO center dot) with different amounts can be produced in the EAOPs systems with three typical PMS concentrations (0.01, 0.032 and 4 mM). Moreover, the formation of chlorine-substituted byproducts can be effectively avoided via adjusting the concentrations of PMS and NaCl to inhibit the formation of Cl-center dot/ClO center dot. Finally, this EAOPs system was used to degrade the kimchi processing wastewater and 34% of COD and 99% of TN were removed, revealing it has a good practical application. This study illuminates a new role of NaCl as the electrolyte for the degradation of organic pollutants in the EAOPs system for the first time.

• 单位
  南昌航空大学; 南昌大学