Reinvent your toilet

Teams gathered to present next-generation sanitation methods

BY NICOLETTE EMMINO

Last year, universities from around the world were presented with a challenge — a toilet challenge, that is. The Bill and Melinda Gates Foundation awarded grants to inventors to design an economical and safe waste deposit system.

According to the World Health Organization, 1.1 billion people practice open defecation and every year 1.5 million people, mostly under the age of five, die from water tainted with feces.

“If we apply creative thinking to everyday challenges, such as dealing with human waste, we can fix some of the world’s toughest problems,” Bill Gates said in a statement.

So he set out to get the ball rolling on a new way of depositing our waste by igniting a $40 million program to repair human difficulties such as water, hygiene, and sanitation.

The Reinvent the Toilet Challenge asked participants to meet was required to meet certain guidelines. The toilet should be able to safely dispose of human waste without piped waters, sewers, or electrical connections. It should transform human waste into some useful resource, such as energy or water. Also, it was preferred that it be able to do so at an affordable price (under five cents), and at the same time, not produce any pollutants or use an outside water source.

On August 14 and 15, teams from 29 countries gathered in Seattle, WA, to present their prototypes and concepts. In order to execute demonstrations of this nature and of this size, The Gates Foundation actually brought 50 gallons of fake feces made from soybean rice. Bill Gates awarded prizes to the top three universities that most closely met the requirements of the challenge, as well as a special recognition award for an outstanding design.

And the winners are…

1. California Institute of Technology (CALTECH), USA

(Image via The Gates Foundation)

Caltech was awarded a first prize of $100,000 for its solar-powered toilet that generates hydrogen and electricity. The demonstration consisted of two toilets and one waterless urinal. The waste collected in the toilet can be delivered to a septic holding tank where it is treated and disinfected in the electromechanical reactor. The reactor breaks down the water and waste into fertilizer and hydrogen. The hydrogen can be stored in fuel cells as energy. The waste that is cleansed can be reused to in the toilet or for irrigation purposes. Although it did not meet 100% of the requirements, the team suggests that they could have a fully functional model ready in about three years.

2. Loughborough University, United Kingdom

(Image via The Gates Foundation)

Loughborough University was awarded a prize of $60,000 for its toilet that produces biological charcoal, minerals, and clean water. Their prototype comprises four parts: a hydrothermal carbonization reactor, sludge pump, flash tank, and a solid/liquid separation vessel. In the reactor, bacteria can be destroyed and solid waste can be separated. The team has also looked into using metal microfilters to dewater solid waste after carbonization.

3. University of Toronto, Canada

(Image via The Gates Foundation)

University of Toronto was awarded a prize of $40,000 for its toilet that sanitizes feces and urine and recovers resources and clean water. Their system is made up of a chemical plant featuring filtration, UV, drying, and smoldering unit operations. In this model, solids and liquids are separated and the solid waste is then dried and smoldered and passed through a sand filter. The filtered liquid is disinfected in a thin-film UV reactor.

A special recognition award was granted to Eawag (Swiss Federal Institute of Aquatic Science and Technology) for their toilet interface design.

(Image via The Gates Foundation)

In the future, there will be a second round of the Reinvent the Toilet Challenge. Grants were awarded to four more universities to further develop their designs.

So wait patiently — on the edge of your toilet seat — for new toilet bowls that could change the way you empty your bowels. ■

Check out the video to see highlights from the Reinvent the Toilet Challenge.