TITLE Development of Ultraviolet Ray/Ozone Combination Dioxin Decomposition and Treatment Technique
(Joint Program to Promote Technological Development with the Private Sectors)


Dioxin etc. (dioxin) emitted from incinerators are now grave problems. High levels of residual dioxin are detected from surrounding soil. Our objective was development of a technique to decompose incinerator residual dioxin etc. without a secondary contamination.


Put dioxin-contaminated soil etc. into a wash tank and allow dioxin to dissolve in water. Send the water to a decomposition equipment and, after dioxin decomposition, send the water back to the wash tank. This allows reducing dioxin amount finally below the soil environmental standards and the water quality environmental standards in a closed system.
The decomposition equipment generates hydroxy radicals and decomposes dioxin by blowing ozone into the equipment through an ozone tower and irradiating ultraviolet rays through an ultraviolet ray tower. Our ultraviolet ray tower is characteristically structured to realize remarkably higher dioxin decomposing capacity with less ozone infusion amount than similar treatment methods reported generally.

Outlines of research and development

1)  Outlines of drainage treatment equipment

The drainage treatment equipment has been manufactured as units to allow trucking to treatment spots. The wash tank unit has a stock solution tank that can wash dioxin-contaminated soil and store dioxin-containing drainage. The ultraviolet ray/ozone combination underwater dioxin removal unit has an ozone generator and an ultraviolet ray tower.
This equipment has been installed at a recycle facility in Sapporo that has dust incinerators and allows experiments using incineration fly ash, inorganic soil, and drainage from wet type exhaust gas absorbers.

2) The achievements of 2003

a)      In the experiment for decomposing dioxins, we researched treatment factor and we made a trial  caluculation of the reduce greenhouse gass emissions.

b)     We made experiments for decomposing dioxins of the compound pollutions and obtained basic data.

c)      We designed and fabricated a small machinery of advanced oxidation process and use in the laboratory experiment.

4)  Schedule

The development for 2004 will be performed on the basis of the findings obtained in the present experiments.