Process for treating waste water containing cutting oil

摘要

A process for treating waste water containing cutting oil is disclosed, which includes the steps of adding a cationic organic compound to waste water containing used cutting oil to coagulate water-insoluble matter in the water and to thereby form coagulated particles, adding an anionic organic polymer to cause those particles to grow into flocculated flocs, and separating the flocculated flocs. The process of the invention can treat waste water containing used cutting oil in an industrially beneficial way without producing a large amount of sludge.