Micro-electrolysis based nitrate reduction from aqueous solution by CNTs-Al-Cu composite under alkaline environment

CNTs-Al was prepared by ball milling combined with sintering process and then used for CNTs-Al-Cu synthesis with chemical deposition method. The obtained CNTs-Al-Cu composite was systematically characterized and its NO 3 − -N reduction performance under alkaline condition was also evaluated. As indicated by the reduction batch experiment, 80.2% of NO 3 − -N removal efficiency was obtained in 90 min at pH of 9. The product of the reduction process was dominated by NO 2 − -N, which was further reduced to harmless N 2 . The reusability of CNTs-Al-Cu composite was evaluated, and the experiment results showed that 68.1% of NO 3 − -N removal efficiency was maintained after 3 cycles of regeneration. Finally, based on the characterization results and kinetic analysis, it was concluded that micro-electrolysis was mainly responsible for the removal of NO 3 − -N by CNTs-Al-Cu.