We are developing the Nano Membrane Toilet which will be able to treat human waste on-site without external energy or water.

Key facts

    • The Nano Membrane Toilet is being developed to enable those without plumbing to have access to safe and hygienic facilities.
    • We have come up with an innovative solution which uses nanotechnology to convert human waste to water and ash.
    • The nano membrane toilet was named by the Financial Times as one of the '50 ideas to change the world'. 2.3 billion people worldwide lack access to safe sanitation and 1.8 billion drink water contaminated by human faeces.
    • The prototype of the toilet has been showcased in a permanent display at the Bill & Melinda Gates Foundation Discovery Centre in Seattle. The interactive display is open to the public, engaging the minds of manufacturing partners and the next generation of researchers in this area.
    • The self-contained waterless system is suitable for 10 users per day and the expected life of the toilet is 10 years.
    • The system produces clean water that can be used around the home and to water plants. No chemicals are used.
  • Funded by The Bill & Melinda Gates Foundation ‘Reinvent the Toilet Challenge'

Impact of our research

The Nano Membrane Toilet will be able to treat human waste on-site without external energy or water. It is designed for single-household use (equivalent to 10 people) and will accept urine and faeces as a mixture. The flush uses a unique rotating mechanism without using any water whilst simultaneously blocking odour and the user’s view of the waste.

Solids separation (faeces) is principally accomplished through sedimentation. Loosely bound water (mostly from urine) is separated using low glass transition temperature hollow-fibre membranes. The unique nanostructured membrane wall facilitates water transport in the vapour state rather than as a liquid state which yields high rejection of pathogens and some odorous volatile compounds. The water will be collected for reuse at the household level in washing or irrigation applications.

Following release of unbound water, the residual solids are transported by mechanical screw into a combustor which will convert them into ash and energy. The energy will power the membrane processes, and there may be extra energy for charging mobile phones or other low voltage items.

Why the research was commissioned

The research was commissioned by the Bill & Melinda Gates Foundation to find innovative approaches – based on fundamental engineering processes – for the sustainable management of human waste.

Why Cranfield?

We have long-standing expertise in water and sanitation research, including being a founding member of Water and Sanitation for Urban Poor (WSUP). For the Nano Membrane Toilet project, we have brought together researchers from a variety of disciplines to meet the challenge of reinventing the toilet.