A novel membrane photo-electro oxidizer for advanced treatment of coal processing wastewater: Fouling control and permeate quality

This study proposed and evaluated, for the first time, a novel membrane-photo-electrochemical oxidation (MPEO) process combining electrochemical oxidation, UV irradiation, and ceramic microfiltration for the advanced treatment of coal processing wastewater. The MPEO process could achieve 600 h of sustainable and continuous operation with excellent color (similar to 90%) and turbidity (>90%) removal. Without electrochemical oxidation and UV irradiation, severe membrane fouling was observed during direct microfiltration due to the accumulation of high content of polysaccharides, proteins and humic-like substances contained in the feedwater on the membrane. On the other hand, in the MPEO system, these macro-organic molecules were effectively degraded into small molecules by the highly reactive hydroxyl free radical (center dot OH) produced from electrochemical oxidation and UV irradiation. FT-ICR-MS analysis confirmed these results and showed a significant increase in the number of small organic molecules after MPEO treatment. The MPEO system in this study could potentially be an efficient and sustainable treatment process for treating chemical industrial wastewater containing refractory organics.