Silver lining
contamination for longer than three
months. In the form of water purification
tablets or liquid, it is a cost-efficient
and user-friendly way to provide clean
water.
To be considered safe, a source
of drinking water must be free from
pathogens and high levels of harmful
substances.
KTU’s water purification products can
be used while travelling or, for example,
during army operations in regions where
there is a limited supply of clean water
and for other industrial and individual
purposes.
The water purification products based
on the KTU formula do not add any
odours or taste to the water. The biggest
challenge in the process of developing
water disinfection technology is to
keep the balance between technology
that destroys microbes while not being
harmful to the user.
The KTU prototype for industry is ready
for use, and the product for individual
users is currently in refinement process.
The KTU drinking water disinfection
technology is patented and currently,
the invention is being expanded into
international markets. Commercialisation
of t he pr oduct i s f aci l i t at ed by
KTU National Innovation and
Entrepreneurship Centre — the one-stop
shop for knowledge-intensive business to
meet research.
A team of researchers at Kaunas
University of Technology (KTU, Lithuania)
is developing water disinfection
technology based on several different
water treatment methods. This affords
a strong purification effect by using less
than the usual concentration of active
ingredients. This technology not only
efficiently destroys the microbes existing
in the water, but the treated water
is protected from secondary microbial
contamination — microbes do not breed
in open water containers for more than
several months.
Silver is one of the active ingredients in
the water purification process and has
been used for drinking-water disinfection
since ancient times.
Long-term stability is the characteristic
trait of some of the disinfectants used in
the method, allowing the product to be
stored for several years without losing its
disinfecting characteristics.
The technology ensures that treated
drinking water that is stored in the open
is protected from secondary microbial
More and more doctors are discovering the powerful
infection-fighting qualities of silver, one of the
ingredients in the KTU water purification process.
With the water crises in South Africa
and California, the lure of desalination
is tempting — but the process requires
enormous amounts of energy.
Richard Boudreault is Canadian
company Awn Nanotech’s founder. The
company takes its name from the small
needles that some plants use to catch
water from the atmosphere. He is a
physicist and serial entrepreneur who
has already launched a dozen other
small tech-centric start-ups.
Boudreault says he wondered
if it might be possible to use
nanotechnology to produce water
without any electricity and realised it
might be possible to tap the energy
within the drop itself. Surface tension
pulls particles towards each other until
it forms a sphere. That tension can be
used as a force of energy.
Working alongside college students,
his team developed a water harvesting
textile from a fine mesh of carbon
nanotubes. On one side of the mesh,
the material is hydrophilic, meaning
it attracts water. The other side is
hydrophobic, or water repelling.
So, as water particles settle on
the mesh, they are pushed through
from one side to the other, forming
droplets. “Because of the surface
tension, [water] finds its way
through,” Boudreault says. This clean,
mineralised water then drips down into
34
Harvesting water with nanotechnology
Boudreault says he wondered if it might be possible to use
nanotechnology to produce water without any electricity.
storage tanks, where it is ready to be
consumed.
The process works without any
power, but they realised they could
greatly increase the water output by
Water Sewage & Effluent March/April 2018
adding a small fan about the size that
is required to cool a computer. The fan
runs on a small solar panel.
“It’s extremely simple technology, so
it’s extremely durable,” Boudreault says.