Ammonia production from pulsed electrolysis of amino acids

Abstract The recovery of nitrogen products from waste streams will aid both fertilizer production and wastewater treatment efforts. The production of ammonia from glycine was used as a model reaction to evaluate the effectiveness of a novel reverse pulse electrolysis process to recover ammonia from bio-waste sludge. The reverse pulse electrolysis used a short pulse to a positive potential followed by a short pulse to a negative potential to produce ammonia from amino acids, and possible other organic nutrients. This study was conducted to establish a basic understanding of reverse pulse electrolysis compared to traditional direct current (DC) (i.e., single potential) electrolysis. DC electrolysis and base catalyzed chemical hydrolysis were shown to produce less ammonia than the reverse pulsing electrolysis technique. The efficiency of different electrode materials and reverse pulse potentials were also investigated. The ammonia production efficiency improved by optimizing the positive and negative potentials for reverse pulse electrolysis. Finally, the mechanism of ammonia production was explored by electrolyzing other organic amines and amino acids, in addition to glycine. It was found that increasing the number of amine groups on the organic compound, rather than increasing the number of carboxylate groups, improved ammonia production efficiency. Graphical abstract