Piet

Every human being produces around a litre of urine per day. Urine contains substantial amounts of nitrogen and phosphates, and these turn cleaning the sewage system into a costly affair. With his no-mix toilet called Piet (a term that combines the words pee and seat), Theo Brandwijk wants to separate urine from faeces. This will make it cheaper to clean the sewage water. What’s more, the nitrogen and phosphates can be recycled to produce fertiliser. “Piet does not come with a toilet seat. Everyone is invited to pee sitting down, which is much more hygienic.” A movement sensor ensures that the special lid opens whenever anyone takes a seat. The urine is diverted down a separate drain and ends up in a tank that is emptied periodically. The faeces disappears through the larger (regular) drain, and the toilet lid automatically closes when the user stands up.