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Updated: May 23, 2026

Electrochemically and Bioelectrochemically Induced Ammonium Recovery
Published on: January 22, 2015
Closing the nitrogen loop: sustainable ammonia production from industrial nitrate waste using a stacked electrolyzer
Paulraj Gnanasekar1, Gowthambabu Vellingiri1,2, Murtadha J AlTammar3
1Photonics Laboratory, Computer, Electrical and Mathematical Sciences and Engineering, CEMSE Division, King Abdullah University of Science and Technology (KAUST), Thuwal - 23955, Saudi Arabia. tienkhee.ng@kaust.edu.sa.
Abstract:
Nitrate in wastewater poses a significant threat to the aquatic ecosystem and disrupts the nitrogen cycle. In this study, we developed a stacked electrolyzer capable of converting nitrate in industrial effluents, even at low concentrations, into green ammonia (NH3) through the nitrate reduction reaction. Our catalyst synergistically transforms the nitrates into vital intermediates (NOx), which are then further reduced to NH3. The stacked electrolyzer achieved a faradaic efficiency of 37% and an NH3 yield of ∼7.8 mg h-1 when treating low-concentration industrial wastewater (1000 ppm). Additionally, it demonstrated a wastewater processing capacity of 5 L day-1 with a single-pass ammonia recovery of 27.7%. Overall, our approach of producing green ammonia from nitrate-laden effluents represents a promising solution for closing the nitrogen cycle.
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