Providing clean and safe sanitation can really transform people’s lives, reducing diarrhoea in children by a third and increasing school attendance, particularly for girls – amongst other benefits. And at a wider scale it helps with development: for every $1 invested in sanitation, nations can see a return of more than $9 in increased productivity, lower healthcare costs, less illness and fewer untimely deaths.
Understanding this, the Bill and Melinda Gates Foundation has challenged inventors to engineer a toilet to process human waste into a resource without the need for running water, electricity or a septic system – at a cost of less than 5 cents a day. Innovative schemes are being worked on around the world.
A self-contained, solar-powered toilet and wastewater treatment system that breaks down water and human waste has been designed by the California Institute of Technology (USA). Excess power generated will be stored to provide a backup energy source for night-time operation or use under low-sunlight conditions.
In the Netherlands, Delft University of Technology is using microwave technology to transform human waste into electricity. The waste is turned into a gas, which can then be fed to a solid oxide fuel cell to generate electricity.
The National University of Singapore is experimenting with biological charcoal (biochar) to dry and combust faeces. The heat generated will be used to extract water from urine by boiling it under pressure. The system can be further improved using activated carbon and ion-exchange resins to recover highly purified water.
The University of Kwazulu-Natal, South Africa, is developing a system that can safely dispose of pollutants and recover materials such as water and CO2 from urine in community bathroom blocks.
In India, Eram Scientific Solutions hopes to make public toilets more accessible to the urban poor using the eco-friendly and hygienic eToilet, which can be maintained and operated remotely, improving local services in terms of both quality and consistency.
RTI International (USA) is developing a self-contained toilet system that disinfects liquid waste and turns solid waste into fuel or electricity through a revolutionary new biomass energy conversion unit.
The University of Colorado Boulder (USA) is using sunlight, directed and focused with a solar dish and concentrator, to disinfect liquid-solid waste and produce biological charcoal (biochar) that can be used as a replacement for wood charcoal or chemical fertilizers.