Making the Most of **it
Toilet turns human waste to biofuel for sanitation-strapped cities
Sit on It
In José Saramago’s novel Blindness, when an epidemic of sightlessness sweeps the city, among the foulest signs of civic breakdown is its inability to handle its own excrement. Human waste piles where it lands, left to the elements and not modern plumbing. To newly minted industrial designer Virginia Gardiner, we might as well be blind to our own waste. Her plumbing-free toilet project, the Gardiner CH4, makes us personally responsible for our intimate product—and makes it useful. The toilet turns human waste into biofuel, which could prove indispensable to the 40 percent of people around the world who have no toilets at all.
“The toilet is an area that all kinds of people, from policy makers to industrial designers, have difficulty thinking about changing,” Gardiner told me. “Not enough designers have looked into ways of fixing the global sanitation crisis with product solutions, and are thinking about issues like user-friendliness and appearance, while taking into consideration that sanitation is all about infrastructure.”
Gardiner took all these factors to heart while developing the toilet to satisfy her master’s thesis last year at London’s Royal College of Art. The exterior is molded in 90 percent horse dung (royal dung from the Queen’s Household Cavalry, no less). A carbon-rich biodegradable material lines the toilet’s interior. After the user does his or her business, a mechanical “flush” drops the package into a lining-wrapped sealed container. Like rolling luggage, the person trucks the container to a community biodigester unit, which composts the waste to produce methane gas.
“Human waste by itself has too low a carbon-to-nitrogen ratio to produce a lot of methane,” explains Gardiner. “The packaging material enhances methane production.” From experiments done with chemical engineers at Imperial College London (and in her own home), Gardiner estimates that a full-scale biodigester could convert 14 kg of human waste to 110 liters of methane to be used for cooking meals.
Gardiner is now taking donations to develop her working prototype into a full-scale system through the Design London program and to begin field testing in Ibadan, Nigeria. Contribute and receive a lovely deer-head candleholder molded from royal dung! The power of poo is the palm of our hands.