7. A household scale toilet which
produces clean water and ash
Dewatering
membranes
Screw to remove solids
Waterless flush
Clean water
reservoir
Gasifier
Holding chamber
It’s crazy that we flush 10L of drinking water down the toilet every time we flush it!
But we get clean water piped to our homes, and sewage piped away. Imagine if your daily water collection looked more like this – queuing at a water point to collect supplies and having to carry it home. And these guys are lucky – many of them have bikes! Water is too precious to be flushed away with our waste!
1.7 billion people use the simplest form of waterless toilet – a pit latrine. But is is hard to keep them hygienic….. while in use……
….. And certainly during emptying!
So BMGF issued their Reinvent the Toilet Challenge
And this is Cranfield’s response: A household scale toilet which produces clean water and ash. Let me take you through the key points:
The rotating bowl and scraper are key to make it “flush” without water.
The membranes – basically sieves with very small holes - allow us to extract pure water from the human waste. The water can be used in the home for washing.
The gasifier burns the remaining solids.
We have designed it for the 2.4 billion people who currently lack access to sanitation. But it may well be a technology that is transferred back to high income countries to help solve water scarcity.