Work packages

In Novaquatis, we studied whether, in what form and in what circumstances the NoMix technology is a viable option. As a wide range of questions are involved, the projects were organized into work packages reflecting the stages of a possible nutrient cycle.

Introduction

The NoMix technology promotes water pollution control and conserves resources. Public attitudes to this innovation are favourable. Various methods have been developed for treating urine and removing micropollutants. Urine transport remains problematic. The results of the Novaquatis project suggest that it would be worth finding solutions to this problem – or avoiding it altogether by treating urine directly on site. For urine source separation could make a significant contribution to resolving the world’s increasingly serious water pollution control issues. [...]

 

 

Nova 1: Is the NoMix toilet acceptable?

An innovation for private bathrooms can only be widely implemented if it is accepted by the public. For this reason, all Swiss NoMix pilot projects were accompanied by sociological studies. 1750 people were surveyed – and their attitudes towards urine source separation are highly favourable. Despite a number of deficiencies, the NoMix toilet is well accepted, especially in public buildings. Further development efforts are now required on the part of the sanitary industry. Currently available models can, however, also be used – with careful supporting measures – in order to contribute to further improvements in urine source separation. [...]

Nova 2: Does the sanitary technology work?

The principle of NoMix is simple: urine is collected separately from other wastewater. But, in practice, this is still not as simple as it sounds – especially when it comes to sanitary technology. For example, pipes may be blocked by urine scale, and designing and producing a modern NoMix appliance is a costly enterprise. Novaquatis approached these problems in various ways: through research on precipitation, feedback from pilot projects and round-table discussions to explore the interests of the parties concerned. [...]

Nova 3: Storage and transport.

The key problem for the NoMix system is how urine is to be transported from the toilet to a central treatment plant. Nova 3 proposes transitional solutions that would allow the NoMix technology to be integrated into the existing wastewater management system and further developed: after temporary storage, urine is transported via the sewer system. Implementation of the NoMix technology in practice is supported by a newly developed computer model. One important finding is that only 60–75% of urine excreted is collected by today’s NoMix toilets. [...]

Nova 4: Urine treatment and fertilizer production.

Urine contains high levels of nutrients – and these should not be allowed to enter waterbodies. One attractive option, therefore, could be to recover nutrients for use as fertilizers in agriculture. Novaquatis studied a broad range of processes – biological, chemical and physical – both for the production of fertilizers and for the removal of nutrients. It was shown that the various processes are suitable for different purposes and, in most cases, are not energy-intensive. This means that treatment can be adapted to meet specific requirements. [...]

Nova 5: Are micropollutants in urine problematic?

On average, for all medicines and hormones ingested, 60–70% of the active ingredient is excreted in the urine – with major differences between individual compounds. But in a urine-based fertilizer, micropollutants are undesirable. As has been shown by chemical and ecotoxicological analytical tests, these substances can be removed from urine by certain treatment processes. Separate treatment of urine would be beneficial for water pollution control since it would reduce the ecotoxicological hazard potential posed by pharmaceuticals in wastewater by an estimated 50%. [...]

Nova 6: Urine-based fertilizers?

The nitrogen, phosphorus and potassium required for Swiss agriculture is now largely provided by artificial fertilizers. Urine-based fertilizers could be used as a substitute for 15–37% of the total. In surveys, farmers and consumers are in favour of the idea – provided that health risks are excluded. Experiments from Nova 4 showed that urine-based products are as effective as artificial fertilizers. But before they can be introduced on a large scale, a careful assessment of costs and benefits – and elaborate approval procedures – will be required. [...]

Nova 7: Evaluation.

Nova 7 evaluates the impacts of the NoMix technology on urban wastewater management, focusing on two aspects – water pollution control and nutrient recycling. Essentially, a positive view is taken of the new concept – both globally and with regard to Europe. The NoMix technology increases the energy efficiency of the entire system, compared with conventional processes. In addition, it has the potential ultimately to become economically competitive. [...]

Nova 8: NoMix technology for fast-industrialising countries?

The introduction of flush toilets in fast-industrialising countries often has a devastating impact on the environment, owing to the lack of appropriate wastewater treatment measures. In the Chinese city of Kunming, situated in the basin of the heavily polluted Lake Dianchi, the potential for treatment at sewage plants is virtually exhausted. If water quality is to be improved, measures such as urine source separation will be required. Stakeholders’ attitudes towards the NoMix technology are highly positive – which could pave the way for the large-scale implementation of this system. [...]

Pilot projects: Does NoMix work in real life?

Pilot projects involving NoMix toilets are challenging, since these lavatories do not (yet) function as smoothly as conventional models. However, to permit further development, they need to be tested in practice. In Switzerland, four pilot projects were carried out in apartments and public buildings. It was concluded that while it is certainly possible to introduce NoMix toilets, close monitoring of the process is required. In addition, projects in private households are more problematic than in public settings. The experience gained is of great importance both for the development of the technology and for practical purposes. [...]

Practical guide: Would a NoMix toilet be a suitable option for me?

NoMix is not yet a mature technology. Certain elements of the system, such as urine treatment, have not progressed beyond the laboratory stage. While the sanitary technology is already available, NoMix toilets do not meet the standard of conventional models in various respects, and they require careful maintenance. A NoMix toilet should therefore only be installed after due consideration of all aspects, and the project objectives should be clearly defined from the outset. The experience gained from Novaquatis can help to ensure that NoMix installations are properly planned. [...]