Department Process Engineering

VUNA Project – Nutrient Recovery from Urine

Welcome to the website about the research project VUNA (2010-2015). In 2016, the Eawag spin-off Vuna Ltd was created:

The VUNA Project aimed at recovering nutrients from urine, by developing a dry sanitation system, which is affordable, produces a valuable fertiliser, promotes entrepreneurship and reduces pollution of water resources.

Research within the VUNA Project

The VUNA Project researched on the following topics. Download the VUNA Final Report for a detailed overview on our results. Also visit our publications list below, to access numerous publications free of charge.

Nutrient Recovery from Urine

Our body excretes the majority of nutrients in the urine (and not in the faeces). By collecting urine separately, we can recover valuable nutrients, e.g. nitrogen, phosphorus, potassium. At the same time, we prevent pollution of surface waters with high nutrient loads. 

Overview Presentation: VUNA Processes

VUNA Nutrient Recovery Pilots

Eawag's main building: 
Forum Chriesbach


eThekwini Municipality:
Customer Care Centre

Field Test Site: 

VUNA Nutrient Recovery Technologies

Risks of Using Urine

Urine and Fertiliser Quality

The foremost goals of urine treatment are the recovery of nutrients for beneficial use. However, the urine treatment processes must also ensure that the end-products are safe to use, provide adequate human and environmental health protection, and are of adequate quality to ensure optimal market value. Pathogens and pharmaceuticals could potentially impact the quality of end products. 

Research activities:

  • Removing pharmaceuticals: The majority of pharmaceutical residues are excreted in the urine (and not the faeces). Hence, the separate collection of urine isolates pharmaceuticals and prevents them from entering the environment. Experiments showed that long-term storage is not sufficient to remove pharmaceuticals. Nevertheless, processes occurring during nitrification, are suitable to remove certain pharmaceuticals. Virtually all pharmaceuticals can be removed in an activated carbon filter.
  • Inactivating pathogens: Whereas some pathogens can be excreted in the urine, others are introduced from cross-contamination with faeces during urine collection. We evaluated the viability of representative pathogens during urine treatment. We observed partial disinfection through urine storage and nitrification. Distillation is assumed to eliminate all pathogens due to high temperatures. Research partners: Environmental Chemistry Laboratory at EPFL.

Fertiliser from Urine

Testing VUNA fertilisers on crops

In VUNA affiliated projects, our fertilisers are being tested in South Africa and Switzerland. At the UKZN Agricultural Engineering Department in Pietermaritzburg, crop scientists fertilised maize in a pot trial with struvite, dehydrated and pasteurised latrine faecal sludge pellets and commercial superphosphate. 

At ETH in Zurich, the Plant Nutrition Group produced isotope-marked struvite and nitrification/distillation product. The tests in ETHZ's greenhouse showed that plants assimilate nutrients from VUNA fertilisers at least as readily as from commercial fertilisers.

In 2015, the Federal Office of Agriculture (FOAG) issued a temporary license for our: 

Urine Collection Network

eThekwini Water and Sanitation introduced urine-diverting toilets as a system to supply sanitation to unserved regions, where water is scarce and water-borne sewer systems are too costly. Therefore a cost-efficient and optimised urine collection approach is necessary to harvest the valuable nutrients in urine.

Research activities:

  • Optimising urine collection: We aim to make urine collection more cost efficient. Therefore, we implemented a pilot urine collection scheme to gain experiences and suggest improvements. Based on the evaluated costs, we are currently developing a business plan.
  • Performance Modelling: The entire system of urine collection, transport and decentralised treatment consists of a large number of interconnected elements (e.g. toilets, storage tanks, treatment reactors) which influence the overall system performance (e.g. pollution control, urban hygiene, fertilizer production). Using a combination of system analysis and mathematical modelling we identified critical elements, evaluated the value of particular measurement schemes and estimated the overall system performance.

Social and Economic Aspects of Urine-Diverting Toilets

The success of any sanitation programme depends on people's willingness to accept it. Urine-diverting toilets are still not well accepted by many. In order to increase acceptance, health and hygiene education is needed.

Research activities:

  • Social acceptance: We accompanied the introduction of the VUNA technologies with studies, which investigated the socio-cultural perceptions and factors influencing users’ acceptance. 
  • Campaigning for health & hyigene: Based on our findings from the acceptance studies, we developed appropriate educational activities and awareness material, e.g. for households and schools.
  • Incentives for urine production: By giving urine a financial value, we tested how to increase toilet use, improve hygiene, reduce loss of valuable nutrients and augment household income for the poorest.
  • Business model: To better understand the value chain from urine to fertiliser, we analysed the various components of the nutrient recovery system with a business perspective.

About us

An acronym, name and motto at the same time, VUNA stands for Valorisation of Urine Nutrients in Africa, and is the name of our project. In isiZulu, the language of the project area in the municipality of eThekwini, South Africa, the word 'vuna' means harvest. A healthy harvest follows a balanced nutrient application to the crops. And, in the case of the VUNA project, we harvest the necessary nutrients from urine.

Project Team

Steering Committee

Principal Investigators 

Project Coordination

Urine Treatment Processes

Risks of Using Urine


Urine Collection Networks

Social and Economic Opportunities

Bill & Melinda Gates Foundation 

Former Team Members

  • Complete Recovery: Michael Wächter, Mathias Mosberger, Maximilian Grau, Sara Rhoton
  • Nitrification: Alexandra Florin, Corine Uhlmann, Gabriel Kämpf
  • Distillation: Michael Wächter, Samuel Huber, Mischa Schwaninger, Thomas Gmeinwieser 
  • Electrolysis: Christina Fritzsche, Annette Remmele, Anja Sutter
  • Struvite: Maximilian Grau, Sara Rhoton, Merlien Reddy, Sibongile Maqubela, Mlungisi Mthembu, Samukelisiwe ‘Thandi’ Cele, Musawenkosi ‘Moussa’ Ndlovu 
  • Process Control: Ana Santos, Lorenzo Garbani Marcantini, Angelika Hess, Elisabeth Grimon
  • Pharmaceuticals: Birge D. Oezel Duygan, Annette Remmele
  • Pathogens: Manfred Schoger, Ariane Schertenleib, Sara Oppenheimer, Simon Schindelholz
  • Urine Collection: Peter Spohn, Lucky Sibiya
  • Performance Modelling: Theresa Rossboth, Thomas Hug, Andreas Scheidegger
  • Social Acceptance: Elisa Roma, Marietjie Coertzen
  • Incentives: Leeanne MacGregor
  • Business model: Luzius Etter
  • BMGF: Alyse Schrecongost 
  • Documentation: Corine Uhlmann, Nina Gubser, Susan Mercer


For an overview on the VUNA Project, download the VUNA Final Report 2015. For more in-depth information, have a look at the news articles, videos, and publications below.


VUNA on YouTube


VUNA at the Faecal Sludge Management Conference 2012

Media coverage

Pour la revue de presse en langue française, veuillez visiter le site en français.

Für das deutschsprachige Medienecho besuchen sie bitte unsere Seite auf deutsch.

English Media Coverage

2014 Annual Report ETH Domain: Fertilize Plants Instead of Contaminating Water

The Mercury: Good soil and hard work Harvesting nutrients that are flushed away Urine could hold secret to crop fertilisation

AlphaGalileo: Urine as a Commercial Fertilizer? Gates funds urine project in South Africa Breakthrough - How pee could help poor farmers (Radio)

zimbio: Number 1 New Fertilizer: Urine May Become Commercial Fertilizer

Washlink: Urine as a Commercial Fertilizer?

Publications – Referenced (with Links to RefWorks)

Nutrient Recovery Processes

Florin, A. (2013) Full nitrification of urine by adding a base, 38 p, Institutional Repository
Fritzsche, C. (2012) The formation of chlorinated organics during electrolytic urine treatment, 74 p, Institutional Repository
Fumasoli, A.; Etter, B.; Sterkele, B.; Morgenroth, E.; Udert, K. M. (2016) Operating a pilot-scale nitrification/distillation plant for complete nutrient recovery from urine, Water Science and Technology, 73(1), 215-222, doi:10.2166/wst.2015.485, Institutional Repository
Fumasoli, A.; Morgenroth, E.; Udert, K. M. (2015) Modeling the low pH limit of Nitrosomonas eutropha in high-strength nitrogen wastewaters, Water Research, 83, 161-170, doi:10.1016/j.watres.2015.06.013, Institutional Repository
Huber, S. J. (2011) Temperature dependent removal of sodium chloride (NaCl) from synthetic nitrified urine, 46 p, Institutional Repository
Mašić, A.; Santos, A. T. L.; Etter, B.; Udert, K. M.; Villez, K. (2015) Estimation of nitrite in source-separated nitrified urine with UV spectrophotometry, Water Research, 85, 244-254, doi:10.1016/j.watres.2015.08.031, Institutional Repository
Remmele, A. (2013) The influence of anode material and current density on the emissions of disinfection by-products (DBPs) during electrolytic treatment of stored urine, 33 p, Institutional Repository
Udert, K. M.; Wächter, M. (2012) Complete nutrient recovery from source-separated urine by nitrification and distillation, Water Research, 46(2), 453-464, doi:10.1016/j.watres.2011.11.020, Institutional Repository
Udert, K. M.; Buckley, C. A.; Wächter, M.; McArdell, C. S.; Kohn, T.; Strande, L.; Zöllig, H.; Fumasoli, A.; Oberson, A.; Etter, B. (2015) Technologies for the treatment of source-separated urine in the eThekwini Municipality, Water SA, 41(2), 212-221, doi:10.4314/wsa.v41i2.06, Institutional Repository
Uhlmann, C. (2014) Dynamics of complete and partial nitrification of source-separated urine, 32 p, Institutional Repository
Zöllig, H.; Remmele, A.; Morgenroth, E.; Udert, K. M. (2017) Removal rates and energy demand of the electrochemical oxidation of ammonia and organic substances in real stored urine, Environmental Science: Water Research and Technology, 3(3), 480-491, doi:10.1039/c7ew00014f, Institutional Repository
Zöllig, H.; Fritzsche, C.; Morgenroth, E.; Udert, K. M. (2015) Direct electrochemical oxidation of ammonia on graphite as a treatment option for stored source-separated urine, Water Research, 69, 284-294, doi:10.1016/j.watres.2014.11.031, Institutional Repository
Zöllig, H.; Morgenroth, E.; Udert, K. M. (2015) Inhibition of direct electrolytic ammonia oxidation due to a change in local pH, Electrochimica Acta, 165, 348-355, doi:10.1016/j.electacta.2015.02.162, Institutional Repository
Zöllig, H. (2015) Electrolysis for the treatment of stored source-separated urine, 147 p, doi:10.3929/ethz-a-010549050, Institutional Repository
Zöllig, H.; Remmele, A.; Fritzsche, C.; Morgenroth, E.; Udert, K. M. (2015) Formation of chlorination byproducts and their emission pathways in chlorine mediated electro-oxidation of urine on active and nonactive type anodes, Environmental Science and Technology, 49(18), 11062-11069, doi:10.1021/acs.est.5b01675, Institutional Repository

Risks of Using Urine

Bischel, H. N.; Özel Duygan, B. D.; Strande, L.; McArdell, C. S.; Udert, K. M.; Kohn, T. (2015) Pathogens and pharmaceuticals in source-separated urine in eThekwini, South Africa, Water Research, 85, 57-65, doi:10.1016/j.watres.2015.08.022, Institutional Repository
Bischel, H. N.; Schertenleib, A.; Fumasoli, A.; Udert, K. M.; Kohn, T. (2015) Inactivation kinetics and mechanisms of viral and bacterial pathogen surrogates during urine nitrification, Environmental Science: Water Research and Technology, 1(1), 65-76, doi:10.1039/c4ew00065j, Institutional Repository
Decrey, L.; Kazama, S.; Udert, K. M.; Kohn, T. (2015) Ammonia as an in situ sanitizer: inactivation kinetics and mechanisms of the ssRNA virus MS2 by NH3, Environmental Science and Technology, 49(2), 1060-1067, doi:10.1021/es5044529, Institutional Repository
Decrey, L.; Udert, K. M.; Tilley, E.; Pecson, B. M.; Kohn, T. (2011) Fate of the pathogen indicators phage ΦX174 and Ascaris suum eggs during the production of struvite fertilizer from source-separated urine, Water Research, 45(16), 4960-4972, doi:10.1016/j.watres.2011.06.042, Institutional Repository


Bonvin, C.; Etter, B.; Udert, K. M.; Frossard, E.; Nanzer, S.; Tamburini, F.; Oberson, A. (2015) Plant uptake of phosphorus and nitrogen recycled from synthetic source-separated urine, Ambio, 44(Suppl. 2), S217-S227, doi:10.1007/s13280-014-0616-6, Institutional Repository

Urine Collection Networks

Hug, T.; Maurer, M. (2012) Stochastic modeling to identify requirements for centralized monitoring of distributed wastewater treatment, Water Science and Technology, 65(6), 1067-1075, doi:10.2166/wst.2012.945, Institutional Repository
Hug, T.; Maurer, M. (2011) Stochastic modeling to identify requirements for centralized monitoring of distributed wastewater treatment, (8 pp.), Institutional Repository
Rossboth, T. (2013) Model-based systems analysis of the collection management of source-separated urine in Ethekwini Municipality/South Africa, 51 p, Institutional Repository

Social and Economic Aspects

Tilley, E.; Logar, I.; Günther, I. (2017) The effect of giving respondents time to think in a choice experiment: a conditional cash transfer programme in South Africa, Environment and Development Economics, 22(2), 202-227, doi:10.1017/S1355770X16000280, Institutional Repository
Tilley, E.; Günther, I. (2016) The impact of conditional cash transfer on toilet use in eThekwini, South Africa, Sustainability, 8(10), 1-16, doi:10.3390/su8101070, Institutional Repository
Tilley, E. (2016) Cost-effectiveness and community impacts of two urine-collection programs in rural South Africa, Environmental Science: Water Research and Technology, 2, 320-335, doi:10.1039/C5EW00237K, Institutional Repository
Tilley, E.; Günther, I. (2014) Data collection made easier?: Choosing between mobile phones and paper, Sandec News, 15, 18-19, Institutional Repository

Publications – Not (yet) referenced

VUNA in General

Urine Treatment Processes

  • Fumasoli, A. (2016) Nitrification of urine as pretreatment for nutrient recovery. PhD thesis, ETH Zurich.
  • Fumasoli, A., Weissbrodt, D., Wells, G.F., Bürgmann, H., Mohn, J., Morgenroth E., Udert K.M. (2015) Low pH selects for nitrosococcus in high and nitrosospira in low salt environments. In preparation.
  • Grau, M.G.P., Rhoton, S., Brouckaert, C.J., Buckley, C.A. (2015) Development of a fully automated struvite reactor to recover phosphorus from source-separated urine collected at urine diversion toilets in eThekwini. Water SA, 41(3), 383-389.
  • Grimon, E. (2015) Sensor characterization & monitoring for soft-sensing of urine nitrification systems. Master’s thesis, ETH Zurich.
  • Hess, A. (2015) Feasibility of UV-Vis spectrophotometry for nitrite estimation in urine nitrification systems. Master’s thesis, ETH Zurich.
  • Santos, A.T.L. (2014) Evaluation of UV spectrophotometry for estimation of nitrite and nitrate in nitrified urine. Master's thesis. Universidade Nova de Lisboa. 
  • Wächter, M., Huber, S., Kluge, J., Mazzotti, M., Udert, K.M. (2015) Selective crystallization of sodium chloride (NaCl) from partially nitrified urine. In preparation.
  • Wächter, M., Schwaninger, M., Gmeinwieser, T., Udert K.M. (2015) Safety assessment for production and storage of nitrified and concentrated fertilizer from human urine. In preparation.

Risks of Using Urine

  • Bischel, H.N., Schindelholz, S., Schoger, M., Decrey, L., Bosshard, F., Udert, K.M., Kohn, T. (2015) Bacteria inactivation during drying of struvite fertilizers produced from stored urine. In preparation.
  • Decrey, L., Kohn, T. (2017) Virus inactivation in stored human urine, sludge and animal manure under typical conditions of storage or mesophilic anaerobic digestion. Environmental Science: Water Research & Technology, DOI: 10.1039/c6ew00311g
  • Decrey, L., Kazama, S., Kohn, T. (2016) Ammonia as an In Situ Sanitizer: Influence of Virus Genome Type on Inactivation. Applied Environmental Microbiology, 82, 4909–4920.
  • Decrey, L. (2015) Virus inactivation in human excreta and animal manure. PhD thesis, EPF Lausanne.
  • Oezel Duygan, B.D., Udert, K.M., Remmele, A., McArdell, C.S. (2015) Fate of pharmaceuticals in source-separated urine during storage, biological treatment and powdered activated carbon adsorption. In preparation.
  • Oezel, B.D. (2013) Fate of pharmaceuticals during urine treatment in laboratory batch experiments: can urine be used as fertilizer in South Africa? Master’s thesis, ETH Zurich.
  • Schertenleib, A. (2014) Inactivation of pathogens in urine nitrification reactors. Master’s thesis, EPF Lausanne.
  • Schoger, M. (2011) Bacterial inactivation in struvite recovered from urine in South Africa. Master’s thesis, EPF Lausanne.


  • Bonvin, C. (2013) Recycling of phosphorus & nitrogen from human urine: evaluation of urine based fertilizers in a pot experiment. Master’s thesis, ETH Zurich.

Urine Collection Networks

  • Joseph, H.R. (2015) Develop and describe a suitable logistic collection system for urine harvesting in eThekwini. Master’s thesis, University of KwaZulu-Natal. In preparation.
  • Rossboth,T., Udert, K.M., Maurer, M. (2015) Using stochastic modelling to support urine collection scheme planning in South Africa. In preparation.

Social and Economic Aspects

  • Etter, B., Etter, L., Joseph, H.R., Grau, M.G.P., Chetty, S., Gounden, T., Gebauer, H., Udert, K.M. (2015) Financial opportunities for complete nutrient recovery from source-separated urine in eThekwini, South Africa. In preparation.
  • Mkhize, N., Taylor, M., Udert, K.M., Gounden, T., Buckley C.A. (2017) Urine diversion dry toilets in eThekwini Municipality, South Africa: Acceptance, use and maintenance: through users eyes. Water, Sanitation and Hygiene for Development, in press.
  • Mkhize, N., Taylor, M., Ramsay, L.F., Buckley C.A., Gounden, T. (2015) Urine-diverting toilets acceptance, use and maintenance: through users eyes. In preparation.
  • Okem, A.E., Xulu, S., Tilley, E., Buckley, C., Roma E. (2013) Assessing perceptions and willingness to use urine in agriculture: a case study from rural areas of eThekwini municipality, South Africa. Journal of Water Sanitation and Hygiene for Development 3(4), 582-591.
  • Ramsay, L.F., Coertzen, M., Buckley, C.A., Gounden, T. (2015) The power of perception: views and practices related to urine diversion toilets in the eThekwini Municipality, South Africa. In preparation.
  • Roma, E., Philp, K., Buckley, C., Xulu, S., Scott, D. (2013) User percep- tions of urine diversion dehydration toilets: Experiences from a cross- sectional study in eThekwini Municipality. Water SA 39(2), 305-312.
  • Tilley, E., Günther, I. (2016) The Impact of Conditional Cash Transfer on Toilet Use in eThekwini, South Africa. Sustainability 2016, 8(10), 1070.
  • Tilley, E. (2015) Acceptance, impact & feasibility of incentives for increasing toilet use: a case study in eThekwini, South Africa. PhD Thesis, ETHZ.