Ammonia capture from wastewater with a high ammonia nitrogen concentration by water splitting and hollow fiber extraction

Water contamination caused by ammonia effluents has become a critical environmental issue. In this study, a coupled system of water splitting and hollow fiber extraction was proposed for highly efficient ammonia capture from wastewater that has a high ammonia nitrogen concentration. Our results showed that the ammonia capture ratio reached >99%, while the ammonia nitrogen concentration in the wastewater decreased to <10 mg/L, the concentration of the by-product ((NH4)(2)SO4) increased to as high as 139.1 g/L, and the energy consumption was as low as 111.26 kJ/(mol NH4+-N). Furthermore, the captured ammonia in the form of the (NH4)(2)SO4 with a high concentration can be potentially utilised in the field of carbon-free energy storage and electrical power generation, and can also be directly used as nitrogen fertilizer. These findings suggest that the coupled system of water splitting and hollow fiber extraction is a cost-effective, sustainable, and environmentally-friendly method for ammonia capture. (C) 2020 Elsevier Ltd. All rights reserved.