OREANDA-NEWS. Panasonic Corporation announced that it has developed a highly effective water purification system using a newly developed photocatalyst. This system is capable of effective detoxification of polluted water by harmful heavy metals, such as arsenic, chromium, and persistent organic matter at a reaction rate of up to 100 times that of conventional methods. This developed photocatalyst has a unique structure and is easy to collect from the polluted water after the detoxification and is recyclable. Through this development, a water purification system which is small size and isolated from municipal water networks can be realized, making is suitable for developing countries, where safe and low cost drinking water is needed.

Increasing demands and shortage of clean drinking water resources due to the rapid development of industrialization, population growth and long-term droughts have become a global issue. In polluted areas, drinking water may contain metal pollutants at levels more than double international standards. The slurry photocatalytic water treatment technology[3] has the potential to resolve these problems that especially occur in contaminated groundwater since this technology efficiently reduces the toxicity of harmful pollutants by a maximum of 99.99%: trivalent arsenic and hexavalent chromium are converted into less harmful chemicals. As no consumption of chemical materials is carried out during the photocatalytic water treatment, the technology has a lower impact on the environmental in comparison to conventional chemical water treatments.

The developed technology has the following features:
- The separation rate of the particulate synthetic photocatalyst from water is optimized by means of the designing of surface physicochemical properties of the photocatalyst.
- The photocatalyst possesses a large surface-area to volume-ratio which contributes the efficient detoxification of the harmful pollutants. Throughput of water treatment is thoroughly enhanced by this photocatalyst incorporated in the slurry photocatalytic water treatment technology, by 50 times in the case of arsenic pollutants and by 100 times in the case of persistent organic materials.
- Solar UV light is utilized as a light source for the slurry photocatalytic water treatment technology, making a low cost and environmentally friendly treatment system.

This development is based on the following new technologies:
1. Synthesis technology of the photocatalyst by utilizing the inherent electrostatic interaction between two particles
2. Slurry technology to control the transition between the particulate photocatalyst aggregation and the suspension.
Panasonic holds 10 Japanese patents and 6 overseas patents, including pending application, for this development.
A part of this technology has been demonstrated in the joint research subjects with the Department of Chemical Engineering, Indian Institute of Science in Bangalore, India.