A toilet in an office or apartment building usually has a simple purpose: waste goes in, water carries it away and the sewage system takes over. In parts of Europe, that routine is being redesigned. Special toilets can separate urine before it is diluted with flushing water, allowing the liquid to be collected inside the building and treated as a source of plant nutrients. The approach is now operating in commercial and residential properties, including the European Space Agency's headquarters in Paris and a major private bank in Geneva. Across several installations, around 3 million litres of urine are being recycled each year. The resulting product can be used as fertiliser, while recovered water can return to the building's flushing system.
Get breaking news anytime, anywhere. Download the TOI app now!
The Swiss technology separating urine from ordinary wastewater
The system depends on catching urine before it becomes part of a much larger stream of wastewater. Specially designed toilets and urinals direct the liquid through separate pipes without adding large amounts of flush water. That makes a difference because ordinary sewage contains a mixture of water, urine, faeces and other household waste. Separating the urine while it is still concentrated means the nutrients can be recovered without first treating an enormous volume of diluted wastewater.
VunaNexus, a Swiss company developing this approach, has installed its technology in several large buildings. The treatment equipment can sit in the basement, turning what normally disappears into the sewer into a separate material that can be processed and reused.
