A decade ago, Diana Yousef was working as an advisor for NASA, trying to figure out how to recycle wastewater in space. Her team was studying a breathable material that could absorb clean water out of waste, but the idea didn't get off the ground.
"It sort of hung around in my brain for a number of years while I was doing other things," Yousef told Business Insider.
Five years later, she found a way to apply the concept on Earth.
In 2015, Yousef founded a company called change:WATER Labs, which produces a toilet called the iThrone. The device uses a breathable membrane to remove water from waste, essentially dehydrating it.
The iThrone is picking up steam: Next month, the company is launching a pilot program that will deliver at least five toilets to a hospital and school in Uganda. The toilets will in total serve up to 1,000 people who would otherwise defecate in latrines. By 2021, the company hopes to start selling the toilets to the public — mostly to construction contractors and non-governmental organizations that deliver humanitarian aid.
A 'shrink-wrap for crap'
Around 2 billion people don't have access to basic sanitation facilities, which means they often defecate outside. That can contaminate food and water supplies, which consequently raises people's risk of diseases like cholera and dysentery. Each year, around 827,000 people die because of unclean water, poor sanitation, and lack of hygiene.
The iThrone is designed so there's no need to flush, meaning it can operate without plumbing or power. Households could conserve up to 130,000 gallons of water per year by using the iThrone instead of a regular flush toilet, the company estimates.
Plus, unlike other free-standing toilets, it doesn't have to be emptied out every day or two.
Instead, a rubber membrane inside the toilet bowl immediately absorbs water from feces, then releases it into the air as water vapor. Since poop is mostly water, the dehydrated feces shrink down considerably. The company estimates that the membrane, which it calls a "shrink-wrap for crap," can reduce the volume of feces by 95%.
That means the toilet only needs to be emptied once a month, which significantly cuts the cost of collecting waste.
But, of course, there's still one problem: the smell.
To eliminate foul odor, microbes installed inside the toilet feed on the organic carbon in urine. That feeding process produces energy that powers an external fan. The company refers to this as a "pee-powered" bio-battery.
Women and girls who lack access to a private toilet face a higher risk of sexual assault
Yousef's concept is somewhat similar to the Omni Processor: a machine that essentially boils human waste to remove water vapor, then distills that vapor to produce clean drinking water. The Omni's waste-treating process is backed by the Bill and Melinda Gates Foundation (Gates plugged it on "The Tonight Show" in 2015 by drinking "poop water").
But unlike the Omni Processor, the iThrone doesn't turn water vapor into drinkable water. Yousef said that step requires too much energy.
However, the Omni Processor isn't a toilet — it processes waste from communal toilets. Yousef's goal, on the other hand, is to give people, especially women and girls, greater access to private toilets.
Women and girls who lack such facilities in or near their home face a higher risk of sexual assault, Yousef said. And girls who don't have private toilets at school often skip classes when they have their period. When they do attend, some attempt to avoid going to the bathroom.
"Girls make all sorts of compromises to get through a day of school," Yousef said. "They don't drink. They don't eat. They go to school tired." Eventually, she said, some drop out.
Yousef said many potential investors she talks to are surprised to hear about these issues — or even that people lack toilets at all.
"Oftentimes, they've never seen a place in the world where people don't have toilets," she said. "They immediately ask me: 'Is this a toilet I can use at Burning Man?'"