Better toilet design could save millions of lives


Most Americans do not pay much attention to the porcelain throne. Do your business, shoot the water and get out of the jar. But for billions of people around the world, toilets are a major source of anxiety, illness and economic hardship.

"In developing regions, [sanitation] infrastructure does not exist, toilets are not emptied safely and human waste comes into contact with people, "said Jeffrey Glass, professor of engineering at the university Duke, PopSci by email. Americans, on the whole, use a functionally invisible sewer system and an off-site sewage treatment plant run by a municipal sewerage service to safely handle their shit. Elsewhere, the detrius flows a little more freely. "Thus, pathogens get into the drinking water and into everyday household chores like cleaning."

These flowing industrial entrails have serious consequences for human health. Fecal pathogens include the bacteria responsible for cholera; rotavirus, responsible for intestinal flu; Shigella, the micro-invader responsible for dysentery; and even parasitic worms eager to colonize a new human host. Every year, at least 500,000 children under five die from these diseases. And adults are not safe either: US Centers for Disease Control and Prevention estimate that 9% of the total global disease burden comes from poor sanitation and drinking water contaminated.

Bill Gates, founder of Microsoft and most prominent philanthropist in the world, announced that an international network of technologists, remediation experts and development workers founded by the Bill & Melinda Gates Foundation had finally resolved the international crisis of the crapper. The private organization, which is proud of its public health initiatives, decided to disrupt the bathroom in 2011. Foundation staff contacted engineering firms working in far-flung fields. to encourage them – with subsidies and the potential for a lucrative altruism – to grow. an autonomous germ killing machine.

At a Reinvented Toilet Expo exhibition supported by a foundation in Beijing this week, Mr. Gates took the stage with a useful visual tool: a jar full of poo. "For the first time, this exhibition presents radically new and ready-to-use decentralized technologies and sanitation products," he said. "It's no longer a question of whether we can reinvent the toilet and sanitation systems. It's a question of how quickly this new category of off-network solutions will evolve. According to a press release, the foundation is investing in 20 toilet technologies that it now considers ready to be used on a large scale.

Sedron Technologies, a small engineering firm based in Sedro-Woolley, Washington, about an hour and a quarter from the foundation's headquarters in downtown Seattle, responded to the call. The company has spent two decades in aerospace engineering with companies like Boeing and Lockheed on sanitation. "It was quite a change," says Sara VanTassel, president of Sedron. Only six years later, the firm's bet is paying off: its Omni processor is the centerpiece of the Gates celebration in Beijing.

The machine, which is about the size of four side-by-side shipping containers, combines three existing technologies into a closed-loop system. It begins with the burning of solid fuels, in which solid waste is separated from liquid waste, mechanically dried and ignited. The resulting heat boils water, generating steam for the whole system to work. The third and last process, water treatment, is parallel to combustion and steam creation. Liquid waste recovered earlier in the drying process is filtered and condensed, producing potable water.

The self-sufficient system does not use external energy, but produces a lot. Excess electricity can be injected into the community. "It's really the combination of a lot of standard processes that we know very well. We did it much more effectively, "says VanTassel. She estimates that the first machines will be able to filter water for a community of about 200,000 to 500,000 people.

Since the dawn of human civilization, we have struggled to contain our collective wastes. For millennia, the majority of people squat around holes or pots; sometimes, the solid "night soil" was used in agriculture. Most often, it was channeled into rivers and oceans, where it could easily cause disease. The miraculous water flush toilet appeared in Tudor, England, only a few hundred years ago. Since the 1780s, it has retained its shape, structure and use of a sewer system. Coupled with well-maintained septic tanks or, more generally, with sewage lines, secular problems of poo have disappeared for the residents of the rich countries, who are now buying toilet accessories, such as heated seats and toilets. Bidets in cuvettes at different speeds and water temperatures.

To invent an entirely new system, it was necessary to be creative and the proposals presented to the Gates Foundation were diverse. Pathogens can be destroyed in three ways: chemicals, biological elements such as bacteria that absorb excreta and heat. The engineers followed the three paths. Add to the stipulation that each system must be completely self-contained and that the toilet seats suddenly look more like a porcelain Rubik's cube. "For example, a technology can be very effective for disinfection but is only cost-effective for large batches. It should therefore be used in the neighborhood and beyond rather than in one home, "says Glass. "Another can be very profitable, but requires electricity and can not be used where there is no power grid."

In the past seven years, the foundation has invested $ 200 million in the reinvention of toilets, and Mr. Gates announced that he would devote an additional $ 200 million to Beijing. But there are challenges ahead. the New York Times indicates, for example, that many of the models exposed to the exhibition cost $ 10,000. This price must fall – at around $ 500 – for this piping to be commercially viable. In addition, it remains to be seen whether the communities in which these devices were built actually want to install an Omni processor or the next Firelight toilets from Sedron.

"I think there will always be a huge curve with marketing," she says. Trying something new presents an inherent risk. Sedron is therefore dependent on the first users eager to innovate. "Sanitation is really a government responsibility in some respects and is very centralized," she says. This is why the Gates Foundation "has not just funded technology development, it is also trying to transform the sanitation thinking process into decentralized solutions."

This story has been updated to reflect the number of people that early versions of Omni Processor will be able to serve.