Africa Water, Sanitation & Hygiene January - February 2016 vol.11 no.1 | Page 32

Sanitation

The Nano Membrane Toilet
Treating human waste onsite without external energy or water.

C

ranfield University is developing the Nano Membrane
Toilet which will be able to treat human waste on-site
without external energy or water. The toilet is designed
for single-household use (equivalent to 10 people) and
will accept urine and faeces as a mixture. The toilet is
still under development; this is the vision of how it will
work: 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.

Alternative toilet options
When standard pit latrines are not feasible in emergency
response due to ground conditions, preference or land
dispute, sanitation becomes complicated. Latrines with
containers that are transported to a faecal sludge treatment
and disposal facility are one option. However, safe disposal
in an acute emergency is an unexplored area of emergency
equipment development.
Activities Undertaken
Report on Dollo Ado
UDDT latrines
In Dollo Ado, Ethiopia,
where there is rocky ground
and an excavator is needed
to dig ‘normal’ pit latrines,
Urine Diversion Dry Toilet
(UDDT) latrines are being
used. A report on this has
been written to disseminate
lessons learnt, plus CDC
have funding via R2HC to
examine the performance
of the UDDT vaults by
examining the temperature, and die off of Ascaris eggs in
the vaults – which is ongoing.

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.

Field visit to tiger worms latrines
Field visits to Dire Dawa in Ethiopia and Monrovia in
Liberia to see the progress of the tiger worm latrines has
communicated some positive conclusions ranging from
positive acceptance by the community, and the worms are
effective in digesting the faecal waste at an optimum level
– little fresh faeces seen inside the pits.

Following release of unbound water, the residual solids
(around 20-25% solids) are transported by mechanical
screw into a gasifier 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.
The toilet will be rented by the households and
maintenance will be undertaken with a trained operative
responsible for the franchised area.
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Africa Water, Sanitation & Hygiene • January - February 2016

Liberia tiger worm toilets – seeding of worms