Nutrients in urine: waste them or use them?
How can nutrients in toilet waste be collected and used again from temporary or mobile premises? A new system is being tested in field conditions at a military practice area.
WHAT IS IT ABOUT?
Nutrients that are essential for life are constantly wasted as they leak into the ground and water systems. It is necessary to make better use of existing nutrients, for instance, as fertilisers. This way, renewable phosphorus can be seized for use as a fertiliser. There are problems with nitrogen fertilisers, too: their manufacture by binding nitrogen from the atmosphere consumes a lot of energy.
One solution for a more efficient recovery and recycling of nutrients is sorting nutritious waste fractions produced by people at source. This means separating and utilising the most useful fractions, such as urine, already at source. This practice will become normal in all waste management and sanitation in the future.
The Mobile nutrient recovery under field conditions (MORTTI) project is looking for new solutions for the capture and utilisation of nutrients in urine and faeces. The aim is to develop a functional toilet waste treatment unit, which can be used, for example, at large outdoor events.
The project’s roots are in the Finnish Environment Institute’s proposal for Sitra’s Nutrient Cycle Challenge Contest, held in spring 2016.
What are we doing?
During the project, methods of toilet waste handling will be assessed and a system will be developed and tested for capturing nutrients in urine to make fertiliser and/or soil improver. In addition, a treatment system will be developed, which enables solid toilet waste to be made harmless and/or processed into soil improver.
The system will be piloted in co-operation with the operations of the Finnish Defence Forces, as military practice activities take place throughout the year. During winter 2018-2019, a practice area will be chosen where the piloting can take place and the processing unit can be tested in field conditions. A pilot scheme in the chosen military practice area will be started during the autumn of 2018 and will last about a year.
The equipment will be designed so that it can be easily moved to a variety of destinations. During the project, ways of reusing nutrients recovered from urine will also be examined.
Who are involved?
The Finnish Environment Institute (SYKE), Tampere University of Applied Sciences (TAMK), Global Dry Toilet Association of Finland Huussi ry and the Construction Establishment of the Finnish Defence Administration are responsible for the implementation of the project. Sitra has launched the project and also acts as a sponsor.
Where have we got to so far?
During the autumn of 2017, an evaluation was carried out to identify potential military practice areas suitable for the pilot scheme. Various methods for capturing nitrogen and other nutrients from urine are being compared, and the experiences of using different methods and equipment will be compiled in the spring of 2018.