The VUNA project is a multi-disciplinary collaborative project funded by the Bill & Melinda Gates Foundation to undertake research into the collection and processing of urine from urine diversion dry toilets (UDDTs). The aim of the project is to recover the nutrients present in urine to produce fertilizer. EAWAG, the Swiss Federal Institute of Aquatic Science and Technology, is the lead organisation on this project, with the University of KwaZulu-Natal (Pollution Research Group, PRG) and eThekwini Water and Sanitation (EWS) as project partners. 

The VUNA project is guided by three concepts:

• Separation at the source: Waste streams with different compositions, for example urine and faeces should be treated separately according to their properties.

• Decentralization: The waste streams should be treated as closely to the source as possible, thereby minimizing the water and energy required for transportation.

• Resource recovery: Treatment should focus on recovering the resources contained in the waste streams. Urine is a concentrated nutrient solution, which can be converted into a fertilizer, while faeces contain energy-rich organic substances.

The project involves several major components carried out by the different partners. The first major component of the project involves developing and optimizing reactors for urine treatment and nutrient recovery. Two reactor setups are being tested: a struvite reactor and a combination of nitrification and evaporation reactor. The reactors will be installed in the communities that have been selected as study sites for urine collection and treatment. These reactors process urine that is collected from communities using UDDTs and recover phosphorous and other nutrients that are important as fertilizers. 

The second major component, Network Management, involves establishing the logistics for the collection and transport of urine from the households to the treatment, and developing a software program to monitor field data on the number, size and performance of reactors required to recover the most nutrients at the lowest costs. 

The third component examines the socio-economic aspects of scaling up this type of work into a sustainable sanitation management process. When implementing a new sanitation system the needs of the community (public health, financial considerations, environmental protection, nutrient recovery) and the preferences of the users have to be well balanced. 

The final component examines the socio-economic factors that influence the willingness of households to use the UDDTs and collect and bring their urine to collection sites within their communities. One study under this component is investigating the economic feasibility of household urine collection. Two other studies focus on the social, cultural, and political factors influencing user acceptance of UDDT, urine collection and nutrient recycling.