new Japanese technology that uses sunlight and photocatalysts to turn polluted
water into safe drinking water is being tested in India. The new system called
‘Photocatalytic Water Purification Technology’ has the ability to bind titanium
dioxide (TiO2), a photocatalyst that reacts under ultraviolet light.
of the difficulties associated with TiO2 is that it is difficult to collect
once dispersed in water, since it comes in super fine particles. Previous
methods of binding it to larger matter have already been used, but they
suffered a loss of active site surface area.
company Panasonic, which developed the new technology, has found a way to bind
the TiO2 to another particle, zeolite (a commercial adsorbent and catalyst),
which solves that problem by enabling photocatalysts to maintain their active
site. The method requires no binder chemicals because the two particles are bound
together by electrostatic force.
the photocatalytic particles are stirred, TiO2 is released from the zeolite and
dispersed throughout the water. As a result, reaction speed is much faster than
other methods of fixing TiO2 on the surface of substrates, and a larger volume
of water can be processed in a short amount of time, ‘Gizmag’ reported.
the water is left still, it will cause TiO2 to bind to zeolite again, making it
easy to separate and recover the photocatalysts from the water so they can be
used again later.
said it is working to lower costs and maintenance requirements with the water
purification systems and aims to make this technology available right across
India and other emerging nations.
is working with a number of institutions in India to test the product and its
company said around 70 per cent of the population of India relies on ground
water, which is exposed to different types of pollution, from agrochemical
residues to metals from leather tanneries.
will certainly help the people of developing countries who rely on the ground
waters and difficult to purify due to insufficient infrastructure.
Gizmag and Panasonic