The Nano Membrane Toilet

Treating human waste onsite without external energy or water.

Cranfield University is developing the Nano Membrane Toilet, designed for single-household use (equivalent to 10 people). The toilet is designed to accept urine and faeces as a mixture. The toilet flush uses a unique rotating mechanism to transport the mixture into the toilet without demanding 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. A novel nano-coated bead enables water vapour recovery through encouraging the formation of water droplets at the nanobead surface. Once the droplets form a critical size, the water drains into a collection vessel for reuse at the household level in washing or irrigation applications.

Following release of unbound water, the residual solids (around 20-25% solids) are transported by mechanical screw which drops them into into a coating chamber lined with a replaceable bag. Once inside the coating chamber, the solid matrix is periodically coated with a biodegradable nano-polymer. The nanopolymer coating serves to block odour and acts as a barrier to pathogen transport. The toilet will be powered using a modular hand crank or bicycle power generator supplied for household use that can also power other low voltage items (e.g. mobile phones).

The replaceable bag comprising the coated solids is periodically collected for transport to a locally sited small scale gasifier sized to accommodate around 40 toilets. Both toilet maintenance and solids collection will be undertaken with a trained operative responsible for the franchised area.


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How are universities already addressing local, national and international issues?

This is the question posed by the Association of Commonwealth Universities as part of their "The world beyond 2015 - is higher education ready?" campaign.   When they saw the Nano Membrane Toilet they thought it was an ideal answe...

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Posted 30th July 2014

The Nano Membrane Toilet is a finalist for a Green Gown Award

We're really pleased that the Nano Membrane Toilet has been shortlisted for a prestigious Green Gown Award.   These Awards recognize the exceptional sustainability initiatives being undertaken by universities and colleges across t...

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Posted 28th July 2014

Fantastic week at the Natural History Museum

We had a fantastic week at the Natural History Museum as part of Universities Week.   Many of our visitors were shocked to learn how many people didn't have access to a toilet and were pleased we were doing something about it.&nbs...

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Posted 16th June 2014

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