Electrochemical oxidation of reverse osmosis concentrate using a pilot-scale reactive electrochemical membrane filtration system: Performance and mechanisms.

Scale-up treatment of real wastewater holds the key to promoting the practical application of electrochemical filtration technology. This work used a pilot-scale Ti/Pd reactive electrochemical membrane (REM) system (12 REM modules with a total REM area of 0.144 m) to treat high-salinity reverse osmosis concentrate (ROC) from a chemical industry park. The pilot-scale Ti/Pd REM system demonstrated effective electrochemical degradation of ROC wastewater, achieving removal efficiencies of 82.3 ± 1.9% for COD and 46.7 ± 5.6% for TN at a membrane flux of 90 L/(m·h) and a cell voltage of 5 V, with an energy consumption of 0.045 kWh/g-COD. Singlet oxygen (O) and reactive chlorine species were identified as the two primary reactive oxygen species generated in the Ti/Pd REM system. Fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) analysis indicated that the pilot-scale Ti/Pd REM treatment effectively oxidized humic acid-like substance and unsaturated aromatic compounds. Overall, the Ti/Pd REM technology shows a promising application potential for the treatment of high-salinity ROC from the chemical industry.