University Researchers Develop Safe, Low-Cost Technology to Decompose Dioxin

A research group led by Dr. Yoshiharu Mitoma, Associate Professor, at the Prefectural University of Hiroshima has developed a safe and low-cost technology to decompose dioxins. Using metallic calcium, which has high reducing capacity, and a catalyst in an alcohol solution, this technology breaks down dioxins by removing chlorine from dioxin molecules. With the aim of developing home-grown environmental remediation technology in Japan, the research team has been working since 2004 under the Industrial Technology Research Grant Program by the New Energy and Industrial Technology Development Organization (NEDO). This research, subsidized by NEDO, is scheduled to be completed in June 2007.

In Japan, the Law Concerning Special Measures against Dioxins came into effect in 2000, with the aim of preventing environmental contamination by dioxins. Under the law, waste incinerators and other designated facilities are required to control their dioxin emissions. With conventional technologies, however, dioxins in incineration ash are not sufficiently exposed to degrading agents because of an oxide layer formed on the surface of the ash. To break down the oxide layer, dioxins normally need to be treated at high temperature or high pressure.

The newly developed technology has succeeded in decomposing 99 percent of dioxins in incineration ash covered with oxide coating, under mild conditions (at room temperature and slight pressure). This is achieved by the reducing capacity of metallic calcium, which is capable of breaking down the oxide layer. Without the use of heat, dioxins can be degraded in a relatively simple system, thus leading to a reduction in equipment and running costs

This technology has recently been put into practical use as a system that treats wastewater samples used for dioxin analysis at chemical analysis companies. The research team is also studying the application of the technology to detoxify dioxins in high-pressure cleaning water at incinerator demolition sites, as one of the Consortium R&D Projects for Regional Revitalization promoted by the Ministry of Economy, Trade and Industry. With a few improvements, this technology can also be applied to the decomposition of agricultural chemicals and asbestos.


- New Equipment Cleans Dioxin-Contaminated Soil (Related JFS article)
http://www.japanfs.org/db/1198-e
- Kyoto University Successfully Engineers Dioxin-Degrading Bacteria (Related JFS article)
http://www.japanfs.org/db/1371-e
- White Rot Fungus Used to Remediate Dioxin-Polluted Soil (Related JFS article)
http://www.japanfs.org/db/1571-e

Posted: 2007/06/29 11:49:18 PM
Japanese version