Membrane filtration is one of the most reliable methods for water treatment. However, wider application is limited due to biofouling caused by accumulation of microorganisms on the membrane surface. This report details a heatable carbon nanotube composite membrane with self-cleaning properties for sustainable recovery from biofouling. Microfiltration polycarbonate/carbon-nanotubes hybrid membranes were fabricated using drawable nanotubes that maintained the porosity and provided electrical conductivity to the membrane. Less than 25 V potential and 2-3 W power increase membrane temperature to 100°C in ~10 s. This temperature is above what most microbial life, bacteria and viruses can handle. When this membrane was employed, filtered Escherichia coli collected on its surface were successfully annihilated within 1 min. Ohmic heating of this membrane could be an effective solution to combat biofouling and complications associated with membrane-based filtration. This is a novel and highly desirable approach to combat biofouling, due to its simplicity and economic advantage.
Keywords: Carbon nanotubes; Escherichia coli; biofouling; drawable and spinnable CNT; membranes; ohmic heating; water and wastewater treatment.