The Next Generation “Green” Toilet that Turns Human Waste into Clean Water and Electricity


Nanotechnology Innovation in Waterless Toilets

Author: Dr. Steven Mufamadi

According to the World Health Organization (WHO) there is about 2.4 billion people worldwide that are living with inadequate sanitation and unsafe hygiene practices, majority of them are in developing countries. Those leaving in poor sanitation conditions are at risk with life-threatening sanitation-related diseases such as e-coli diarrhoea, salmonella food poisoning, cholera, polio, hepatitis A and so forth. Many high-tech solutions to solve sanitation or toilet challenges have been developed, however they are hampered by being expensive or difficult to use.

In a recent discovery, the scientists at the Cranfield University have developed a waterless and inexpensive toilet employing an eco-friendly nano membrane, with capabilities to turn human waste into energy and clean water. The project was funded in part by the Bill & Melinda Gates Foundation’s reinvent the toilet challenge program in 2012.

Waterless Nano Membrane Toilet 1
Waterless Nano Membrane Toilet (Figure 1)

The magic inside the toilet begins after closing the toilet lid and the human waste is removed by a rotating chamber (Figure 1). Thereafter human waste is filtered through a nano membrane toilet as follows; vaporized water molecules one side, while the solid waste, pathogens and odourous compounds are diverted into a different chamber. The vaporized water molecules transport through nano-coated hydrophilic beads chamber, thereafter the water vapour condense and drain into collected bowl located under this chamber. This pathogen free clean water is safely used for household cleaning and/or farm irrigation.

In the second “gasifier” chamber, solid waste is converted into ash and energy via incineration. The ash is nutrient-rich and can be used as fertilizers during farming, and the energy that is generated by heat can be used to power low voltage objects such as smartphones and so forth.

Waterless Nano Membrane Toilet (Figure 2)
Waterless Nano Membrane Toilet (Figure 2)

Other benefits of these next generation “green” waterless toilets are odourless, portable and inexpensive. Furthermore, it can be used in the areas that lack sewage, water and electricity.

This waterless toilet is to be trialled and tested in Ghana this year. Should it be available in South Africa, the toilet will be suitable for those leaving in areas where sanitation conditions are regressing. Examples of these include townships and rural villages, this would be of great use to them.