The practical application of the capacitive deionization(CDI)enhanced ultrafiltration(CUF)technology is hampered due to low performance of electrodes.The current study demonstrated a novel super-aligned carbon nanotube(SACNT)/activated carbon(AC)composite electrode,which was prepared through coating AC on a cross-stacked SACNT film.The desalination capability and water purification performance of the prepared electrode were systematically investigated at different applied voltages(0.8-1.2 V)with a CDI system and a CUF system,respectively.In the CDI tests,as compared with the control AC electrode,the SACNT/AC electrode achieved an approximately 100％increase in both maximum salt adsorption capacity and average salt adsorption rate under all the applied voltage conditions,demonstrating a superior desalination capability.Meanwhile,a conspicuous increase by an average of～26％in charge efficiency was also achieved at all the voltages.In the CUF tests,as compared with the control run at 0 V,the treatment runs at 0.8,1.0,and 1.2 V achieved a 2.40-fold,2.08-fold,and 2.43-fold reduction in membrane fouling(calculated according to the final transmembrane pressure(TMP)data at the end of every purification stage),respectively.The average TMP increasing rates at 0.8,1.0,and 1.2 V were also roughly two times smaller than that at 0 V,indicating a dramatical reduction of membrane fouling.The SACNT/AC electrode also maintained its superior desalination capability in the CUF process,resulting in an overall improved water purification efficiency.