Lisa Deutsch: It is important that many things are considered together and implemented in a coordinated way. In the discussion paper, we show that certain factors for this transformation are already partly in place, including technical innovations, a large number of motivated players and a common vision. What is still lacking, however, is an unambiguous legal framework as well as pilot and lighthouse projects, for example. In some countries, for instance, fertiliser legislation needs to be adapted to allow the use of recycled fertilisers from human faeces. Pilot and lighthouse projects are needed so that people can get an idea of what “sanitation transformation” means. At the same time, the know-how for implementing such systems must also find its way into the training of a wide range of stakeholders, such as in sanitary technology or in the planning or engineering sector. It therefore takes an interplay of different entities and coordinated measures by many different players to make a sanitation and nutrient transformation possible.
Are technologies for resource recovery “from the bowl” already being used in practice?
Kai Udert: Yes. The focus here is on processes for nutrient recovery from urine. Various companies already offer technologies for this. Two processes have been developed at Eawag and one of them is being marketed by the Eawag spin-off Vuna. Another example is the process by the company Sanitation360, which was developed at the Swedish Agricultural University SLU.
Composting of human faeces for the production of fertiliser is also being investigated by various companies and in some cases is already being applied. However, these fertilisers are not approved in Switzerland or Germany due to hygiene concerns.
In order to create trust in the products and to ensure the quality requirements, quality standards are enormously important. In Germany, a standard (DIN SPEC 91421) was developed at the end of 2020 to provide guidelines for the quality assurance of recycled products from dry toilets. It is also important that companies, individuals and research institutes working on this topic network together and address open questions. One local example is the “Circular Sanitation Network Switzerland,” or Valoo for short, which was founded in November 2021.
What needs to be taken into account in dialogue with policy-makers?
Lisa Deutsch: Less is more. As researchers, we are used to explaining everything down to the smallest detail. But in doing so, we expect too much of other stakeholders, for example from politicians, and the actual core message is weakened. It is also important to connect to the other person’s context and experience. That means, for example, that as researchers we cannot use our PowerPoint slides from the last conference for a meeting with politicians, but we have to create new ones. In addition, we have to adjust to the fast pace of day-to-day political business. For example, if a politician leaves briefly during your presentation for an important phone call, this has nothing to do with a lack of respect.