Enhanced permeability, contaminants removal and antifouling ability of CNTs-based hollow fiber membranes under electrochemical assistance

The membrane fouling control is still essential for membrane filtration system, e.g., membrane bioreactors (MBRs). Herein, a novel treatment system that combined electro-oxidation effect with membrane filtration process using CNTs-based hollow fiber membranes (CNTs-HFMs) themselves as electrode materials and basic separation system was developed to treat organic wastewater. Under electrochemical assistance, the CNTs-HFMs performed greatly increased membrane flux and obviously improved selectivity ability even the pollutants with unfavorable removal by size exclusion. This membrane filtration process benefited from the functions of electrochemically enhanced adsorption, electrostatic repulsion, and/or electrochemical degradation. Experimental results indicated that the removal efficiency of protein, glucose and phenol at+1.0 V were about 2.7, 2 and 12 times higher than that of membrane separation alone. Meanwhile, the CNTs-HFMs with electro-assistance had a higher water flux that the same membrane in the absence of electro-assistance. Furthermore, the polluted CNTs-HFMs were efficiently and easily regenerated by an electro-assisted hydraulic cleaning process. This work illustrates that carbon-based hollow fiber membranes coupling with the electro-oxidation effect are promising for wastewater treatment and provides many new insights for the carbon-based hollow fiber membranes in practical applications.