Denitrification enhancement by electro-sorption/reduction using a layered metal oxide electrode loaded with Pd-Cu nanoparticles

Abstract

The green and efficient removal of nitrate (NO3−) in groundwater is a major challenge for safe water supply. In this study, palladium (Pd) and copper (Cu) nanoparticles were loaded on nickel-aluminium (NiAl)-layered metal oxide (LMO) to improve the catalytic activity of electro-sorption/reduction of NO3− by electrodes. The Pd-Cu bimetallic nanoparticles can effectively improve the transmission of electrons in electrodes. In addition, denitrification with the NiAl-LMO electrode loaded with Pd-Cu was superior to that with LMO loaded with Pd. Furthermore, electro-sorption/reduction was a more effective denitrification mode, which improved the efficiency and produced fewer by-products. The electro-sorption process not only enhanced denitrification, but also improved the selectivity of reduced to nitrogen. Thus, our study provides a green capacitive deionization (CDI) electrode material and efficient electric adsorption mode to enhance the denitrification. Keywords: Capacitive deionization electrode, Layered metal oxide, Catalysis, Electro-sorption mode, Denitrification enhancement