Tokyo, Japan — Teijin Limited announced today that an advanced oxidation process has proven its effectiveness in decomposing 1,4-dioxane, a highly persistent organic solvent. With the Japanese government now considering the introduction of 1,4-dioxane discharge regulations, Teijin’s system could have promising applications in the Japanese market and beyond.
The process combines ozone and hydrogen peroxide to produce the hydroxyl radical, the most powerful oxidant available for water treatment. A joint development project now being conducted by Teijin and PUB, Singapore’s national water agency, has demonstrated that the process significantly reduces persistent pollutants such as pharmaceutical residue and endocrine-disrupting compounds.
The water-soluble organic solvent 1,4-dioxane dissolves numerous organic materials, making it suitable for a wide range of industrial applications. However, the World Health Organization’s International Agency for Research on Cancer has classified the solvent in category 2B (possibly carcinogenic), and in 2009 Japan’s Ministry of the Environment set the standard for 1,4-dioxane in wastewater at 0.05mg/l or less.
Both biologically and chemically stable, 1,4-dioxane requires the use of special degrading bacteria for biological treatment. Adsorption is difficult in treatments that use activated carbon, and the substance is hard to break down even with oxidation treatments that use ozone. In view of the extreme difficulty of treating 1,4-dioxane, the Japanese government is carefully considering the introduction of discharge regulations in the near future.