“It is complicated,” says Rory Hadden, a postdoctoral student at the University of Western Ontario and part of the team designing “the Toronto toilet,” third prize winner in the Bill & Melinda Gates Foundation’s Reinvent the Toilet Challenge. “At first, I was overwhelmed by how complicated it is.”
Rory was staffing the University of Toronto’s toilet prototype at this week’s Reinvent the Toilet Fair in the foundation’s Seattle headquarters. His was one of eight university-based teams given a year and US$400,000 to come up with a toilet to suit the needs of the estimated 2.5 billion people worldwide without access to safe and affordable sanitation. The foundation announced four award winners on Tuesday.
Super toilet
The challenge set by the Gates Foundation is tough. The toilets have to be hygienic. They can’t rely on water to flush waste, nor store or process waste in a septic system. Their operational cost must be no more than five cents per user, per day. They must be suited to a single family home. And, to make things even more interesting, they should generate energy and recover water, salt, and other nutrients, instead of discharging pollutants.
All of this makes for some interesting-looking places to do what needs to be done. As with toilets that flush using lots of water, however, the prototypes put most of their working parts below the user interface, so users won’t see the action up close. Check out our photo gallery, with images from the Gates Foundation, to see the systems.
The California Institute of Technology’s toilet won first prize in the Reinvent the Toilet Challenge. It uses solar power and generates hydrogen and electricity. Photo: Bill & Melinda Gates Foundation.
The team from Loughborough University in the United Kingdom took second place in the Reinvent the Toilet Challenge with a toilet system that produces biological charcoal, minerals, and clean water. Photo: Bill & Melinda Gates Foundation.
The team from Delft University of Technology in the Netherlands designed a toilet that converts human waste to fuel gas using microwave technology to transform the waste into electricity. Photo: Bill & Melinda Gates Foundation.
This South African university’s toilet system separates solid waste from liquid waste and extrudes the solids into thin strands for faster drying and stabilization. Photo: Bill & Melinda Gates Foundation.
This system turns human waste into biological charcoal, or biochar. Plans are to set it up in a Nairobi-area slum, where it will process two tons of human waste daily. Photo: Bill & Melinda Gates Foundation.
Not a barbecue
The Toronto toilet, for example, looks like a zigzag conveyer belt hooked up to a barbecue smoker. Rory’s bit is the smoldering chamber, which sits at the end of the conveyer belt and helps sanitize solid waste using a low-temperature, flameless form of combustion.
“Our primary goal is disinfection of both the liquid and the solid stream,” says Rory’s colleague, Zachary Fishman, a research associate on the project from the University of Toronto. “But we’re also really excited about its potential for helping a lot of people in a lot of different places.”
