Recovery of Plant Nutrients from Dilute Solutions of Human Urine and Preliminary Investigations on Pot Trials

Kocaturk N. P., Baykal A. B.

CLEAN-SOIL AIR WATER, vol.40, no.5, pp.538-544, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 40 Issue: 5
  • Publication Date: 2012
  • Doi Number: 10.1002/clen.201100193
  • Journal Name: CLEAN-SOIL AIR WATER
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.538-544
  • Istanbul Technical University Affiliated: Yes


Within the context of Ecological Sanitation (ECOSAN), human urine has been the subject of research and practice as a potential fertilizer in the recent years. Although quite a lot had been done with original undiluted urine with promising outcomes, not much appears in the literature which concentrates on dilute solutions of urine. This is important because unless waterless toilets are employed, urine will be diluted with flush water in actual use. In this work, dilute solutions of urine are investigated with emphasis on the recovery of plant nutrients. A natural zeolite namely clinoptilolite was loaded with nitrogen, phosphorus, and potassium as an indirect route of processing urine. The results have revealed that hydrolysis is completed in shorter times in dilute samples. Clinoptilolite could successfully remove plant nutrients from all dilute solutions. Nitrogen could be recovered up to 86% with higher efficiencies at higher concentrations in general. Recovery of orthophosphates increases with increasing concentration to reach 96%, however, potassium could not be recovered. The preliminary experiments with grass have revealed that nutrient loaded clinoptilolite was as effective as chemical fertilizers while direct application of original and diluted solutions of urine had shown inferior yields.