Four years after the Bill and Melinda Gates Foundation awarded $710,000 for the development of a revolutionary waterless toilet, the technology has received a second financial boost.
Researchers will use the money to continue developing the lab prototype of the Nano Membrane Toilet, as developers at Cranfield University call it, and begin field trials in Africa.
Estimates suggest more than 2.4 billion people around the world still live in unsanitary conditions. Without access to clean running water, these at-risk communities face life-threatening sanitation-related diseases.
The waterless and easy-to-use Nano Membrane is meant to offset this scarcity.
Alison Parker, a lecturer in International Water and Sanitation at Cranfield Water Science Institute, says her team’s new design is meant to serve poor urban areas, as those will be easiest to accommodate.
“The toilet will be used in dense urban areas where a number of factors make providing good sanitation very challenging, Parker told Business Insider in March, after receiving the $710,000, “but where it would be possible to facilitate visits from a maintenance technician.”
How the toilet works
After a person has done their business and closed the lid, the rotating toilet bowl turns 270 degrees to deposit the waste in a vat underneath. A scraper tool then wipes off any residual waste from the bowl.
The solid waste stays on the bottom while the liquid rises to the top. Extremely thin fibres, known as nanofibers, are arranged in bundles inside the chamber. They help move the water vapour that exists as part of the liquid waste into a vertical tube in the rear of the toilet.
Next, water passes through specially designed bundles that help condense the vapour into actual water, which flows down through the tube and settles in a tank at the front of the toilet.
As for the solid waste that’s left behind, a battery-powered mechanism lifts the remaining matter out of the toilet and into a separate holding chamber. There it’s coated in a scent-suppressing wax and left to dry out.
Every week, a local technician visits the community to remove the solid waste and water, and replace the toilet’s batteries if needed.
Residents can then use the water for tending to their plants, cleaning their homes, cooking, and bathing. The solid waste ends up at a thermo-processing plant to be turned into energy for the community.