| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technology achieving stable and effective treatment, using a simple method, of wastewater containing highly concentrated oil in which extracted n-hexane concentration (oil part) is oil part/BOD=1/5 to 1/1, which has not been directly biologically treated heretofore.SOLUTION: A biological treatment method for wastewater containing highly concentrated oil is provided in which, upon treating oil-containing wastewater containing extracted n-hexane concentration (oil part) at a ratio of oil part/BOD=1/5 to 1/1 relative to BOD concentration (BOD of wastewater is 1 to 5 times of extracted n-Hex concentration), the oil-containing wastewater is introduced into a first treating tank, is subjected to biological treatment with living group mainly comprising non aggregative bacteria, and then the treated water containing the on aggregative bacteria is further subjected to biological treatment in an activated sludge tank or a second treating tank as a catalytic oxidation tank having a fixed bed or a fluidized carrier. In addition, the biological treatment in the first treating tank is performed at pH of 4.0 or more and 5.9 or less.</p> |
