Photocatalytic Environmental Purification Technology - March 2004

Photocatalytic Environmental Purification Technology - March 2004

Photocatalytic technology using titanium dioxide, developed by the Kyushu Center of the National Institute of Advanced Industrial Science and Technology (AIST), has been applied to the purification of liquids and gases, and has attracted particular attention in water treatment and air purification. The technology uses titanium dioxide-coated fine hollow glass spheres and ceramic materials to efficiently decompose toxic substances such as volatile organic compounds (VOCs) and nitrogen oxides (NOx).

For example, a plant in Kumamoto, Japan, has installed an industrial wastewater purification system that uses photocatalytic technology to treat approximately 5,000 cubic meters of wastewater per day. Mitsubishi Heavy Industries has also developed an air pollution control system using this technology, which has successfully reduced VOCs in factory exhaust gas by more than 90%.

This technology uses ultraviolet light to promote a chemical reaction on the surface of titanium dioxide, which breaks down VOCs and NOx into harmless carbon dioxide and water. Because it consumes little energy and uses no chemicals, this technology has been used to combat air pollution in urban areas such as Tokyo and Osaka. Photocatalytic technology is spreading as a low-cost, environmentally friendly technology, and is expected to spread further in the future.