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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Reinvent the Toilet Phase 1. Design Team progress photos.

Created with flickr slideshow.As we have now reached the end of Phase one the Design Team wanted to show some snaps of the project as it's developed over the course of the year.This album shows primary research in Ghana, early idea gen...

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Posted 17th September 2014

Partnerships

We’d like to take an opportunity to acknowledge and thank the partners we’ve worked with so far on the Nano Membrane Toilet.   They’ve all done exceptional work.   Model Products worked built the technical 'works-like' rig t...

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Posted 15th September 2014

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

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