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

Hao-Tian Liu; Han-Qing Zhao; Yi-Rui Yang; Shuang Wu; Jia-Ping Huang; Rui-Han Yu; Hongcheng Bai; Aqiang Ding; Daijun Zhang; Peili Lu

doi:10.1016/j.jes.2025.02.031

Enhanced electrocatalytic oxidation of high-salinity quaternary ammonium compound wastewater using CNTs-(Ru_xIr_yO₂)/Ti Anode

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

Authors

Hao-Tian Liu¹, Han-Qing Zhao², Yi-Rui Yang¹, Shuang Wu¹, Jia-Ping Huang¹, Rui-Han Yu¹, Hongcheng Bai³, Aqiang Ding⁴, Daijun Zhang⁴, Peili Lu⁵

Affiliations

¹ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Chongqing University, Chongqing 400045, China; Department of Environmental Science, College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
² State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Chongqing University, Chongqing 400045, China; Department of Environmental Science, College of Environment and Ecology, Chongqing University, Chongqing 400045, China. Electronic address: hqzhao@cqu.edu.cn.
³ School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China.
⁴ State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Chongqing University, Chongqing 400045, China; Department of Environmental Science, College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
⁵ State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Chongqing University, Chongqing 400045, China; Department of Environmental Science, College of Environment and Ecology, Chongqing University, Chongqing 400045, China. Electronic address: lupl@cqu.edu.cn.

PMID: 40602931
DOI: 10.1016/j.jes.2025.02.031

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-(Ru_xIr_yO₂)/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 (Ru_xIr_yO₂)/Ti, with pseudofirst-order reaction rate constant improved from 7.36 × 10^-3 to 1.12 × 10^-2 min^-1. Moreover, the CNTs-(Ru_xIr_yO₂)/Ti anode electrocatalytic oxidation system exhibited excellent cycling stability. Mechanism studies indicated that the CNTs-(Ru_xIr_yO₂)/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