Efficient nitrate-to-ammonia conversion for circular nitrogen economy

Abstract

The development of an economically feasible system for the electrochemical treatment of nitrate-rich wastewater is hampered by the complexity of the matrices. The use of membrane-free systems can be beneficial to avoid contamination by organic impurities and dissolved salts, but their implementation is challenging considering that ammonia is susceptible to anodic oxidation. This article previews a new approach that maximizes ammonia recovery by integrating a nitrate electrochemical reduction cell with a UV-assisted stripping unit that converts over 70% of nitrate into ammonia chloride.