Clean water for drinking purposes is quite rare in many parts of the world as their sources are polluted and purification methods are not available. Panasonic is developing a new technology to address this problem. This technology uses the sunlight for purification of the water extracted from ground. Recently, a system was presented by the company that uses photocatalysts and sunlight to purify water at a high reaction speed. This readily improves access to clean water, in areas where needed.
The recent breakthrough that led to the discovery of this technology is the system’s ability to bind titanium dioxide (TiO2), a photocatalyst capable to react under ultraviolet light. TiO2 comes in super fine particles and is hard to collect once it has dispersed in the water. Previously, other larger materials were used to bind the TiO2 to them, but it was a loss of active site surface area. The way this technology by Panasonic differs from those found before, is the discovery of zeolite particles’ (a commercial adsorbent and catalyst) ability to bind the TiO2 particles. This solves the problem by enabling photocatalysts to maintain their active site. As the two particles are bound together by electrostatic force, there is no need for the binder chemicals.
As the new photocatalytic particles are stirred, the zeolite releases the TiO2, which then disperses throughout the water. The resultant reaction speed is much faster as compared to other methods and the processing of large amounts of water is supported. The TiO2 binds to the zeolite again if the water is still left, which makes it easy to separate and recover the photocatalysts from the water for later use.
Recently, this technology was showcased at Tokyo’s Eco Products Fair. A number of institutions in India are assisting Panasonic with this project. Extracted water that has been diluted with a number of pollutants, such as residues from agrochemicals and metals from leather tanneries, is used by almost 70% of the Indians – the company claims.
The idea behind this project is to develop a small-scale version of this purification system, which may then be deployed at different places where purification of water is needed, a company representative revealed during the Eco Fair.
http://www.youtube.com/watch?v=gj81GEX16_I