Imagine a toilet that doesn’t need water and turns human waste into burnable fuel.
That’s the goal of a research team led by RTI International and Duke University.
The two institutions along with a consortium that includes NASA and the U.S. Navy have won a $1.3 million grant from the Bill & Melinda Gates Foundation to create the toilet. The Gates foundation launched a “Reinvent the Toilet Challenge” as part of its efforts to improve global health, especially in developing countries.
Stipulations to receive funding were stringent:
- The toilet has to be a stand-alone unit that does not require piped-in water, a sewer connection or outside electricity
- The cost to operate could be no more than 5 cents per person per day
- The units also must be easy to install, use and maintain
The grant announcement of the grant came the day after Gates hosted an event about the competition.
“We couldn’t be happier with the response that we’ve gotten,” Gates said.
The United Nations estimates disease caused by unsafe sanitation results in about half the hospitalizations in the developing world.
About 1.5 million children die each year from diarrheal disease. Scientists believe most of these deaths could be prevented with proper sanitation, along with safe drinking water and improved hygiene.
RTI says its system will disinfect liquid waste, dry and burn solid waste and use the resulting energy from the combustion to produce electricity.
Dr. Brian Stoner of RTI is the principal investigator for the project. Dr. Jeff Glass of Duke is a co-investigator and the lead on the liquid disinfection module.
“More than 2 billion people worldwide do not have access to safe and effective sanitation,” said Stoner, who is a senior fellow in materials and electronic technologies at RTI. “This unique design offers solutions to several problems that have plagued developing nations by providing a toilet that effectively disposes of waste without requiring outside resources. It will also have the capacity to capture and recycle water, energy and other valuable resources that are in human waste.”
The RTI and Duke researchers plan to utilize NASA experience in development of waste treatment systems for spacecraft.
RTI says it already has a means of burning the dried pellets produced by the toilet: A “Thermoelectric Enhanced Cookstove Add-on” device. The electricity produced by the heat will be stored in a battery.
Advanced Diamond Technologies and Duke will work to develop a disinfection system for liquid waste.
“The proposed system will take advantage of current best practices in waste management while leveraging recent innovations in electrochemical disinfection technology employing robust, low cost, conducting diamond, thin film electrodes,” said Duke’s Glass.
The foundation expects to field test its first prototypes within the next three years.
Most of the prototypes on display this week in the open courtyard of the foundation’s Seattle headquarters turn solid waste into energy. This is both a practical and pragmatic solution to the solid waste puzzle, said Carl Hensman, program officer for the foundation’s water, sanitation and hygiene team.
Many recycle waste into other usable substances such as animal feed, water for irrigation, or even just energy and water to run their own systems.
The Gates toilet focus started just about a year ago, and including grants announced Tuesday, $370 million in foundation dollars have been committed to reinventing the toilet. Hensman said the foundation decided to hold a toilet fair this week to show how far the scientists have gotten in that time, and to give them an opportunity to learn from each other and potentially collaborate.
Among those scheduled to attend the toilet fair were government ministers from African nations, utility workers and potential financial partners like UNICEF and Oxfam.
Reinventing the toilet has the potential to improve lives as well as the environment.
Flush toilets waste tons of potable drinking water each year, fail to recapture reusable resources like the potential energy in solid waste and are simply impractical in so many places.
Gates predicted the result of this project would reach beyond the developing world.
“If we do it right, there’s every possibility that some of these designs would also be solutions for rich and middle-income countries,” Gates said.
(The Associated Press contributed to this report.)