Electrochemical Nitrate Reduction to Ammonia and Organic Pollutant Removal from Wastewater in a Bipolar Membrane Electrolyser

Water scarcity and contamination are the major challenges threatening the human health and sustainable development of our society. One of the utmost concerns comes from the imbalance of the global nitrogen cycle due to anthropogenic nitrate water contamination. High concentrations of nitrate in water bodies can cause eutrophication issues, leading to negative effects on biodiversity, fisheries, and recreational activities. Similarly, the contamination of freshwater systems by chemical compounds such as micropollutants (MPs) and per- and polyfluoroalkyl substances (PFAS) from industrial and human activities is also receiving significant public attention. These organic pollutants are believed to raise considerable toxicological concerns, even though most are present at low concentrations in the environment. Eliminating pollutants from water using electricity is becoming an attractive approach for water treatment. Meanwhile, electrochemical nitrate reduction to ammonia (NH₃) (NO₃RR) using renewable energy has gained intensive interest as a method to close the nitrogen cycle. This research project, undertaken at Institut Européen des Membranes (IEM), aims to integrate nitrate reduction to ammonia with the removal of micropollutants/PFAS from both drinking water and wastewater in a bipolar membrane electrolyser. This advanced, highly synergistic system is poised to tackle two of the most pressing global challenges—energy-efficient ammonia production and the water scarcity crisis—simultaneously. By converging the processes of nitrate reduction and micropollutant/PFAS elimination into a single operation, our proposed method not only signifies a leap towards mitigating climate change effects but also promises a substantial enhancement in water quality, addressing the urgent need for safe and accessible water.