Adsorption and reclamation of wastewater nitrogen and the value of human urine as a nitrogen fertiliser

Abstract: Ammonium adsorption and ammonium ion exchange technique are possible alternatives for ammonium reclamation at conventional wastewater treatment plants. There are a few ion exchange applications that have been suggested for nitrogen reclamation, which can be further developed. It was indicated that a small amount of ammonium was adsorbed to sand due to a low adsorption capacity. It seemed, however, as the adsorption capacity was not completely utilised during the warm seasons when employing wastewater infiltration systems. An increased adsorption would, therefore, not automatically have a significant impact on the nitrogen retention; this due to the weak binding between the ammonium ions and sand grains. When comparing human urine with commercial fertilisers and green manure crops as nitrogen fertilisers, it was indicated that utilising human urine regenerated the lowest net exergy consumption. The distance of the urine transports had a great impact on the exergy consumption.