Enhanced electrocatalytic oxidation of high-salinity quaternary ammonium compound wastewater using CNTs-(RuxIryO2)/Ti Anode

J Environ Sci (China). 2025 Nov:157:879-889. doi: 10.1016/j.jes.2025.02.031. Epub 2025 Feb 25.

Abstract

The organic pollutants, such as quaternary ammonium compounds, in high salinity flowback water from shale gas extraction may pose a severe risk to public health. Conventional biological technologies have limited effectiveness in the treatment of high-salt wastewaters, whereas electrocatalytic oxidation has shown potential for treating organic pollutants in high-salt flowback water. This study developed a carbon nanotubes (CNTs) doped Ru/Ir oxide coated Ti electrode CNTs-(RuxIryO2)/Ti, which exhibited enhanced electrocatalytic performance for the treatment of quaternary ammonium compound in high-salt wastewater compared to the control metal oxide coated Ti anode (RuxIryO2)/Ti, with pseudofirst-order reaction rate constant improved from 7.36 × 10-3 to 1.12 × 10-2 min-1. Moreover, the CNTs-(RuxIryO2)/Ti anode electrocatalytic oxidation system exhibited excellent cycling stability. Mechanism studies indicated that the CNTs-(RuxIryO2)/Ti electrode enhanced singlet oxygen (1O2) generation, which played a major role in pollutant degradation. Furthermore, the formation of high concentrations of HClO and H2O2 further facilitated the generation of 1O2. This study may provide an efficient and green technology for the treatment of organic pollutants in high-salt shale gas flowback water.

Keywords: CNTs doping; Dimensionally stable anode; Electrocatalytic oxidation; High salt wastewater; Quaternary ammonium compound.

MeSH terms

  • Catalysis
  • Electrodes
  • Nanotubes, Carbon* / chemistry
  • Oxidation-Reduction
  • Quaternary Ammonium Compounds* / chemistry
  • Salinity
  • Titanium / chemistry
  • Waste Disposal, Fluid* / methods
  • Wastewater* / chemistry
  • Water Pollutants, Chemical* / analysis
  • Water Pollutants, Chemical* / chemistry

Substances

  • Wastewater
  • Water Pollutants, Chemical
  • Nanotubes, Carbon
  • Quaternary Ammonium Compounds
  • Titanium