Barriers to development are often inter-related, perhaps none more so than the linkages between sanitation and access to water. These two seemingly simple provisions influence every facet of life, from healthcare and disease control to education and access to livelihoods. Over 2.5 billion people do not have access to clean toilet facilities or WASH stations and in response to this, researchers at Cranfield University (Bedfordshire, UK) are developing an innovative waterless, nano-tech toilet, the widespread use of which can improve the lives of millions in vulnerable communities around the globe.
The unique design and use of nanotechnology enables the toilet to do more than simply dispose of human waste in a contained, sanitized manner. The toilet is also designed to extract water from the waste, which can be repurposed, and it generates energy from the rest.
Waste to Water
The specifics are a bit technical. For liquid waste, there is a nanotech membrane that filters and condenses the ‘loosely bound water’ (urine) that passes through it. The nano membranes transport the water as a vapour, which allows pathogens and odourous compounds to be separated from the water and be contained within the system. The water vapour then goes through a channel via a gas, into a tube of nano-coated condensing beads. When the vapour passes through, droplets form on the other side of the membrane. Once large enough, the water droplets drain into a basin to be collected. This now-pathogen-free water is safe to use for farming or household cleaning.
While earlier models of the toilet had solid waste collected and transferred to an offside incinerator, the current model has this step included in its design. Solid waste will undergo the same process as above to extract water and the remaining waste (about 20 – 25%) will be carried into a second gasification chamber where it is incinerated and turned into ash and heat. While the R&D for this part of the toilet is still in process, researchers are confident that the system should be able to produce enough energy to power the whole unit, with residual energy remaining to power small gadgets like cellphones. The remaining ash can be re-purposed as fertilizer. The system is powered via a modular hand crank or bicycle-powered generator.
The system took over 3 years to refine and trial use will begin in Ghana in 2016. For distribution, the system will be franchised. Toilets will be rented to households and will be maintained by trained personnel responsible for the franchised area. The innovation been featured by numerous media outlets and was the winner of the “Reinvent the Toilet Challenge” hosted by the Bill and Melinda Gates Foundation.