High desalination permeability, wetting and fouling resistance on superhydrophobic carbon nanotube hollow fiber membrane under self-powered electrochemical assistance

• Preparation of superhydrophobic carbon nanotube hollow fiber membrane.
• High flux, salt rejection, and wetting resistance during membrane distillation.
• Improved fouling resistance under electrochemical assistance.

Global shortage of fresh water is becoming an increasingly serious problem. Membrane distillation is an attractive technology, but suffers from low permeability, insufficient wetting and fouling resistance. In this work, membrane distillation coupling with electrochemistry was developed to achieve high desalination performance on superhydrophobic CNT hollow fiber membrane. The prepared membrane possessed higher permeability, better wetting resistance with permeate flux of 1.3–1.6 folds, water entry pressure of 1.4–1.7 folds as high as conventional PVDF and PP hollow fiber membranes. When it worked as cathode at a low voltage of 0.5 V, its fouling resistance was further improved and no flux loss occurred in 36 h operation for feed containing natural organic matter, while 15% flux loss was observed under open circuit. Interestingly, the energy consumed by electrochemical assistance can be self-powered by thermoelectric power generating module from the temperature gradient between feed and permeate.

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