High-efficiency Ti/TiO₂-NTA/PbO₂-Nd anode electrochemical oxidation of coking reverse osmosis concentrated (ROC)

In this study, a Ti/TiO₂-NTA/PbO₂-Nd anode was fabricated for the treatment of coking reverse osmosis concentrate (ROC). The TiO₂-NTA interlayer reduced β-PbO₂ grain size and increased the PbO₂ surface area. Compared to the conventional Ti/PbO₂ electrode, the Ti/TiO₂-NTA/PbO₂-Nd anode demonstrated enhanced electrochemical performance, including higher oxygen evolution potential (OEP), improved hydroxyl radical (•OH) generation, reduced charge transfer resistance, and longer service life. Under optimal conditions (20 mA/cm², pH 6), COD and TOC removal efficiencies reached 88.0 % and 70.8 %, respectively, with high degradation efficiency, current efficiency, and low energy consumption (0.23 kWh/g COD). The degradation followed pseudo-first-order kinetics. Reactive oxygen species contributions to ROC degradation were identified through quenching experiments. Recyclability tests (6 and 80 cycles) and accelerated service life tests confirmed the anode's excellent performance and stability. 3D EEM and GC-MS analysis further demonstrated the effective removal of refractory organics from ROC. These results highlight its potential for long-term wastewater treatment applications.