Bill Gates invests $1 million in toilet that recycles human waste

A self-contained sewage recycling system being designed by Duke and Missouri engineers. (Duke University)

A new-fangled toilet, such as the one being rolled out in Toronto -- air conditioned and spacious with stainless steel fittings and a lit interior -- is hardly practical for the developing world.

And yet safer sanitation is a priority for many countries, what with 1.8 million people dying each year of water-borne diseases such as diarrhea.

The benefits of toilets for the 2.5 billion people worldwide who don't have them extend well beyond health issues. In many countries, girls can't go to school because of a lack of toilets. Pit latrines and in-the-open defecation are often norms that convince parents to keep their daughters at home. An affordable toilet, one that fits with local needs, could transform communities in a number of ways.

So the Bill and Melinda Gates Foundation in 2011 kicked off a novel competition, offering cash prizes for anyone who could come up with a next-generation toilet for the third world and last August, Gates announced the winners of his "Reinvent the Toilet Challenge."

The California Institute of Technology in the United States won a $100,000 first prize for designing a solar-powered toilet that generates hydrogen and electricity. Loughborough University in the United Kingdom won the $60,000 second place prize for a toilet that produces biological charcoal, minerals, and clean water. University of Toronto in Canada won the third place prize of $40,000 for a toilet that sanitizes feces and urine and recovers resources and clean water. (While U of T professors plan to role out a pilot project in Bangladesh, they aren't ready to showcase its toilet yet, a professor told The Star.)

Now, there's more news on the challenge, this time out of Duke University and the University of Missouri, where researchers have been given $1.18 million to continue developing a toilet that conceivably - wait for it - can recycle sewage into drinking water.

The idea, according to a report by WUNC public radio in North Carolina, features a waste recycling system that fits into a standard shipping container: "people empty their latrines into a sewage receptacle (currently, latrines are often emptied into rivers), the waste gets funnelled through a series of tubes and is pressurized at extreme temperatures, and the byproduct is clean, possibly drinkable water."

Marc Deshusses, a professor of civil and environmental engineering at Duke’s Pratt School of Engineering, is leery of saying the system turns human waste into drinking water. At least not yet. “We have to be aware that there are going to be cultural barriers,” he told WUNC.

“We’re not yet saying that this will be drinking water. But even if you can recycle water for flushing, that would be very big progress.”

Rick Westhead is a foreign affairs writer at The Star. He was based in India as the Star’s South Asia bureau chief from 2008 until 2011 and reports on international aid and development. Follow him on Twitter @rwesthead