Researchers at the Eawag aquatic research institute in Switzerland have proposed sustainable urban water management concepts that could facilitate the recovery of nutrients from urine. The systems are currently being tested in the NEST experiment building near Zurich, which was inaugurated on Monday.
While conventional urban water systems – which consist of a drinking water network, sewers and centralised wastewater treatment plants – have proved effective in industrialised countries, they do not provide a sustainable solution for the future, according to the Swiss aquatic research institute Eawag. Ageing infrastructure, increasing urbanisation and a growing global population all require new approaches to water supply and sewage disposal.
This is particularly evident in Asia and Africa, as Eawag researchers argued in the journal “Science”. Their suggestions include treating and re-using used water. The researchers also suggest the need for more efficient technologies in wastewater treatment and for simplifying the treatment of sewage. For instance, wastewater streams should be separated at source to allow for the recovery of nutrients from urine and energy from faeces.
The Swiss researchers already have experience in this field, thanks to the Blue Division Toilet and Vuna projects. The latter project showed how nutrients such as nitrogen, phosphorus and potassium could be recovered from urine. In the NEST modular experimental building in Dübendorf in the canton of Zurich, the researchers are now conducting similar experiments with diversion toilets as part of the Water Hub project.
The researchers emphasise the advantages of decentralised systems, which can be installed without large-scale investments in infrastructure. They also outline the institutional and organisational reforms needed to implement such systems.