Canadian-made toilet aims to lay waste to sanitation diseases
Published Saturday, December 1, 2012 7:30AM EST
The humble toilet is not something most Canadians spend a lot of time thinking about. It’s a necessity, sure, but hardly a luxury.
It’s difficult to imagine, then, that for a third of the world’s population, using a toilet is a privilege they will never know.
More than 2.5 billion people -- yes, billion -- still defecate in the open, using fields or rivers or simply a plastic bag. Those living in villages use foul-smelling buckets or unsanitary latrines. Most enjoy no privacy while doing their business, sitting on or over a vessel that’s a prime vector for disease.
According to the World Health Organization, diarrheal diseases linked to poor sanitation are responsible for the deaths of at least 1.5 million children every year. That’s more deaths than AIDS, malaria and measles combined.
But many are working to change that -- including a team of University of Toronto engineers who are intent on building a better toilet that could be used anywhere.
The U of T team has just received the next phase of funding in a $2.2-million grant from the Bill and Melinda Gates Foundation to develop a waterless, hygienic toilet.
The design will require complete shift in thinking. The toilet we know today hasn't changed much in its design since it was invented around 200 years ago and popularized by the unfortunately-named Thomas Crapper. A toilet for the developing nations of Asia and sub-Saharan Africa, though, cannot depend on running water and sewer systems.
So last year, the Bill & Melinda Gates Foundation launched the "Reinventing the Toilet Challenge," giving grants to eight institutions around the world to develop toilets that could be operated for pennies a day, and wouldn’t require periodic emptying like a composting toilet often does.
As well, the contest aims to create a toilet that not only removes pathogens from the waste but somehow creates energy, clean water, or nutrients. And of course, the ideal design would also be something that everyone would want to use—in wealthy as well as developing nations.
U of T engineering professor Mark Kortschot, who is part of the development team, says the challenge is not an easy one.
"The challenge is to develop a toilet that can work off-grid, with no connection to sewer, water or electricity," Kortschot told CTV News Channel this week.
Of the eight teams in the original competition, the U of T team came in third, behind a team from the California Institute of Technology, which has invented a solar-powered toilet that generates hydrogen and electricity, as well as a team Loughborough University in U.K., which created a toilet that produces biological charcoal, minerals and clean water.
The Toronto team’s solution is a squat toilet that drops the waste onto an inclined belt that separates the liquid and solid streams. The liquid stream drops into a sand filter while ultraviolet light cleans the urine.
"It would produce a disinfected liquid that could be used on a vegetable garden for instance," Kortschot explained.
The solid waste dropped onto the belt gets flattened into a disc that is then allowed to dry out. The waste stays on the belt to dry, moving along when each user turns a hand crank.
"Each person who uses the toilet winds the belt a little further along, where it would dry over 24 hours,” says Kortschot.
From there, the waste is sent to a specialized combustion chamber, similar to a charcoal barbeque, to slowly incinerate the solid waste without the need for flames.
The research team -- which also includes members from Western University in London, Ont., and the University of Queensland -- will now use an extra $40,000 in funding and the next 15 months to simplify the toilet, reduce its complexity and minimize odour.
"We now want to develop it to the point that it could be field tested and streamlined for mass production," Kortschot said.
Working with local partners in Bangladesh, the team hopes to have an operational prototype by December of 2013 -- one that uses readily available materials and equipment that can be maintained locally.
Bill Gates has said that inventing new toilets is one of the most important things that can be done to reduce child deaths and disease around the world. What's more, better toilets could also help wealthier countries conserve precious fresh water for other important purposes, such as drinking water.
“Innovative solutions change people’s lives for the better,” Gates said in August, during the first phase of the contest. “If we apply creative thinking to everyday challenges, such as dealing with human waste, we can fix some of the world’s toughest problems.”