Reinvent The Toilet Challenge
In 2011 the Bill & Melinda Gates Foundation initiated and funded the competition ‘Reinvent-the-Toilet-Challenge’ (RTTC) in which eight universities with promising entries had to proof their concepts. The target is to develop a mass-produced sanitation system operating grid-free (not connected to electricity grid, piped water, or sewer) with total costs not exceeding 5 US cents per person and day. High user comfort and total resource recovery are also key requirements.
Almost 2.6 billion people worldwide use unsafe toilets or defecate in the open. Poor sanitation causes severe diarrhoea, which kills 1.8 million people each year. With the urbanisation of poverty in the coming decades, this problem is especially daunting in dense urban settlements especially affecting the urban poor.
The core principle of the on-site water recovery technology is a gravity-driven ultrafiltration unit integrated in the back wall of the toilet. GDM filtration is applied in the RTTC project to the recovery of wash and flush water. The special feature of the gravity-driven ultrafiltration is its passive biological activity maintaining the membranes permeable, thus making chemical cleaning or maintenance unnecessary as long as moderate aeration is provided.
For more information about this project:
http://www.eawag.ch/forschung/sww/gruppen/rttc/index_EN
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