Abstract: In this presentation, a series of asymmetric polyethersulfone (PES) membranes are introduced for the wastewater treatment applications. Firstly, the effects of different additives during membrane preparation on the morphologies and physical properties of fabricated membranes are discussed. It is found that the asymmetric membranes with three-dimensional pore networks in PES matrix without the presence of macrovoids can be achieved under optimal loading of water or polyvinylpyrrolidone (PVP) additives using non-solvent induced phase separation (NIPS) process. The resulted PES membranes exhibit a remarkable water permeation flux and a BSA rejection, which are suitable for ultrafiltration. Secondly, the synthesized PES membranes can be utilized as ion-selective membranes to concentrate the nitrate ions in water. Our results demonstrated that the high selectivity of nitrate ions over fluoride ions and sulfate ions can be obtained at low applied potential less than 3 V. The collected nitrate ions in water are further converted to ammonia through electrochemical reduction process, offering a promising avenue to address the environmental impacts associated with nitrate-containing wastewater and reduce the energy intensity as well as the carbon footprint linked to the traditional Haber-Bosch method for producing ammonia.