Nitrogen recovery from source-separated human urine using clinoptilolite and preliminary results of its use as fertilizer

Abstract

The use of source separated human urine as fertilizer is one of the major suggestions of the new sanitation concept ECOSAN. Urine is rich in nitrogen, phosphorus and potassium which act as plant nutrients, however its salinity is high for agricultural and landscape purposes. Moreover, characteristics change significantly throughout storage where salinity increases to higher values as the predominant form of nitrogen shifts from urea to ammonium. Transferring nitrogen in human urine onto the natural zeolite clinoptilolite and using the subsequently recovered ammonium from the exhausted clinoptilolite for agricultural/landscape purposes is suggested as an indirect route of using urine in this work. Results reporting the outcome of the proposed process together with characterization of fresh and stored urine, and preliminary work on the application of the product on the landscape plant Ficus elastica are presented. Up to 97% of the ammonium in stored urine could be transferred onto clinoptilolite through ion exchange and about 88% could be recovered subsequently from exhausted clinoptilolite, giving an overall recovery of 86%. Another important merit of the suggested process was the successful elimination of salinity. Preliminary experiments with Ficus elastica had shown that the product, i.e. clinoptilolite exhausted with ammonium, was compatible with the synthetic fertilizer tested.

Producción de plántulas de chile jalapeño fertilizadas con orina

“…Sin embargo la aplicación de orina diluida a una CE de 1 dS m -1 causo los mismos efectos en todos los parámetros de crecimiento que la solución Steiner. La orina ha sido recientemente evaluada como un fertilizante alternativo Pradhan et al, 2007;Mnkeni et al, 2008); sin embargo, su aplicación directa ha causado efectos negativos en plantas y suelo atribuidos a la alta salinidad de este residuo (Beler-Baykal y Bayram, 2007;Beler-Baykal et al, 2011), lo cual indica que es requerido diluir la orina previamente a su aplicación como fuente nutritiva orgánica en sistemas productivos agrícolas.…”

“…However, the application of diluted urine at EC of 1 dS m -1 caused the same effects in all growth parameters than Steiner solution. Urine has recently been evaluated as an alternative fertilizer Pradhan et al, 2007;Mnkeni et al, 2008); however, direct application has caused negative effects on plants and soil, attributed to the high salinity of this residue (Beler-Baykal and Bayram, 2007;Beler-Baykal et al, 2011), indicating that is required to dilute urine prior to their use as organic nutrient source in agricultural production systems.…”

“…Regarding high salt content in urine, there is evidence that direct application of undiluted urine increases soil salinity content (Beler-Baykal et al, 2011), which affects the development of plants from seedling to mature stages of production and reproduction, particularly in crops sensitive to salinity (Mnkeni et al, 2008). Two recommended treatments to reduce negative effects of high salinity in urine are pH adjustment by addition of acids and the dilution of the urine to reduce its salinity (Capulín et al, 2005;Garcia et al, 2008;Preciado-Rangel et al, 2011).…”

Recovery of nutrients from biogas digestate with biochar and clinoptilolite

“…Several studies have described the use of clinoptilolite for ammonium, potassium and orthophosphate recovery with high efficiencies from source-separated human urine (Ganrot et al, 2007(Ganrot et al, , 2008Beler-Baykal et al, 2011;Allar & Beler Baykal, 2015) and the liquid fraction of digestate (Kocatürk et al).…”

“…Both inorganic and organic materials have been used successfully for nutrient sorption. Clinoptilolite (a natural zeolite) has been used to remove nutrients from source-separated urine (Ganrot et al, 2007;Beler-Baykal et al, 2011;Allar & Beler Baykal, 2015) and several studies have described the adsorption of ammonium and other nutrients to biochar, a carbonaceous product from the pyrolysis of biomass (Eldridge & ChengRong, 2010;Hale et al, 2013;Sarkhot et al, 2013;Gai et al, 2014;Jassal et al, 2015;Wang et al, 2015c).…”