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

摘要

The use of source separated human urine as fertilizer is one of the major suggestions of the newnsanitation concept ECOSAN. Urine is rich in nitrogen, phosphorus and potassium which act asnplant nutrients, however its salinity is high for agricultural and landscape purposes. Moreover,ncharacteristics change significantly throughout storage where salinity increases to higher valuesnas the predominant form of nitrogen shifts from urea to ammonium. Transferring nitrogen innhuman urine onto the natural zeolite clinoptilolite and using the subsequently recoverednammonium from the exhausted clinoptilolite for agricultural/landscape purposes is suggested asnan indirect route of using urine in this work. Results reporting the outcome of the proposednprocess together with characterization of fresh and stored urine, and preliminary work on thenapplication of the product on the landscape plant Ficus elastica are presented. Up to 97% of thenammonium in stored urine could be transferred onto clinoptilolite through ion exchange and aboutn88% could be recovered subsequently from exhausted clinoptilolite, giving an overall recovery ofn86%. Another important merit of the suggested process was the successful elimination of salinity.nPreliminary experiments with Ficus elastica had shown that the product, i.e. clinoptilolitenexhausted with ammonium, was compatible with the synthetic fertilizer tested.