1,4-ジオキサン汚染地下水の生物浄化に関する研究
1,4-ジオキサンによる地下水汚染の特徴と生物浄化の可能性
1,4-ジオキサンは,発がん性の疑いがある一方,高い水溶性を示すとともに揮発性や吸着性,生分解性等が低いことから,いったん水中へ放出されると広域に拡散してしまい,除去が困難な物質である。実際に国内の河川や地下水等において1,4-ジオキサンが検出される事例が報告されており,我が国では,各種基準において規制の対象となっている。1,4-ジオキサンの浄化手法としては,促進酸化法が挙げられるが,この手法は投入エネルギーや処理コストが高くなるといった問題がある。本研究では,1,4-ジオキサン分解菌を用いる生物浄化に着目し,その可能性を検証した。その結果,実汚染地下水において環境基準値未満まで1,4-ジオキサン濃度を低減できることが明らかとなった。
キーワード: | 1,4-ジオキサン,地下水汚染,1,4-ジオキサン分解菌,生物浄化 |
*1 技術センター 建築技術研究所 環境研究室
*2 大阪大学
*3 北里大学
A Study of Biotreatment for Groundwater Contaminated with 1,4-Dioxane
The Situation of Groundwater Contaminated with 1,4-Dioxane and Possibilities of Treatment Using 1,4-Dioxane Degrading Bacteria
1,4-Dioxane, suspected to be a human carcinogen, is highly soluble in water, but a volatilization rate of 1,4-Dioxane to atmosphere and an adsorption rate to solids are very low. In addition, it is seemed to be hardly bio-degraded. Therefore, it is difficult to eliminate 1,4-dioxane which has been released to aquatic environments. It has been reported that 1,4-dioxane is detected in groundwater or river in Japan. So 1,4-dioxane is regulated under several standards. The effective treatment for 1,4-dioxane is advanced oxidation processes, but the cost of treatment and input energy are very high. In this paper, the authors investigated the possibility for treatment using a 1,4-dioxane degrading bacteria, because the energy input and cost of biotreatment using 1,4-dioxane degrading bacteria might be low. As a result, this treatment can reduce concentration of 1,4-dioxane to below environmental quality standards for groundwater.
Keywords: | 1,4-dioxane, groundwater contamination , 1,4-dioxane degrading bacteria, biotreatment |
*1 Environmental Engineering Research Section, Building Engineering Research Institute, Technology Center
*2 Osaka University
*3 Kitasato University