Bill Gates Funds Quest to Build Better Toilet to Combat Disease

Photograph by Britton Staniar/Bloomberg

California Institute of Technology's solar-powered winning entry includes a septic holding tank that separates solids and liquids before they move on to a electrochemical reactor that disinfects waste and generates hydrogen to be used as fuel.

When Bill Gates was at the helm of Microsoft, the fate of software products rested on his approval. The technology giant’s co-founder and former chief executive is now judging something completely different: toilets.

With 1.5 million children a year dying of diarrhea related to poor sanitation in the developing world, Gates and his wife Melinda asked their foundation to focus on helping to create a next-generation commode that’s suitable for countries with limited access to water and sewage lines.

“The topic we are discussing today can rightly claim to be the most neglected thing in all the things that are done to help the poor,” said Gates at a ceremony to announce the top four projects at his foundation’s Reinvent the Toilet Fair in Seattle. “The toilet that was invented 200 years ago, the flush toilet, really hasn’t had that many milestone advances.

“If Crapper was born today, he’d find the toilet quite familiar,” Gates said, referring to Thomas Crapper, the plumbing company founder who helped popularize the modern toilet.

Last year, the Bill & Melinda Gates Foundation gave grants to eight institutions to develop low-cost loos that can be operated for 5 cents per user per day, don’t require a connection to a sewer or water to flush, and are hygienic and sustainable for the world’s poorest populations. The projects are also supposed to look at how the waste can be used to generate energy and recover salt, water and other nutrients.

Potties developed by those organizations, plus 27 other related projects built with the foundation’s grants, were on display today. The exhibits even included fecal substitutes made from miso paste, which is meant to mimic the viscosity of human waste. The foundation purchased 50 gallons of the faux feces for use at the expo.

The winning entry went to the California Institute of Technology’s solar-powered white ceramic toilet and stainless metal urinal combo. While it looked normal from above, underneath was a septic holding tank that separates solids and liquids before they move on to a electrochemical reactor that disinfects waste and generates hydrogen to be used as fuel.

Second place went to Loughborough University, based in the U.K., whose system is essentially a pressure cooker for human waste. A long metal tube called a hydrothermal carbonization reactor turns feces into a brown dust called biological charcoal that looks and smells kind of like coffee grounds and can be used as soil or fertilizer. The system also generates clean water from urine and feces, as well as energy by combusting the biological charcoal.

The University of Toronto’s third place john dries and smolders poop to sanitize it, while using a sand filter and ultra-violet light to disinfect pee.

The foundation’s next step will be to decide which models are viable and then getting prototypes to test in the field over the next 15 months, said Carl Hensman, program officer with the foundation’s Water, Sanitation & Hygiene program.

Around 2015, the foundation plans for small pilot studies in places such as sub-Saharan Africa and Bangladesh.


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