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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Nano Membrane Toilet at Reinvent the Toilet Fair, Delhi

Our team really enjoyed our time at the Reinvent the Toilet Fair in Delhi.   We were really inspired by what the other teams had achieved and really happy to receive the feedback all of the Fair attendees.   Here are som...

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Posted 27th March 2014

Video Launch

Our new video which explains the Nano Membrane toilet is launched in time for the Reinvent the Toilet Fair in Delhi....

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Posted 19th March 2014

House of potential target users

Whilst in Kumasi, Ghana, our research team visited the house of an elderly gentleman to gain insight in the potential target users.This photo was a key image in the project because although this man has a very high standard of living with m...

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Posted 17th March 2014

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