| 摘要 |
PROBLEM TO BE SOLVED: To provide an iron and steel waste water treatment method that very easily separates and removes suspended solids in waste water, in which coarse SS and fine SS coexist, of a system of reusing suspended solids-removed treated water as cooling water, and at the same time, suppresses scale deposition due to calcium dissolved in the treated water.SOLUTION: In a treatment method of iron and steel waste water containing suspended solids of a system of using suspended solids-removed treated water as cooling water, a state where coarse SS and fine SS coexist and at least one organic flocculant exists in water in turbulent flow at a flow rate of 0.5 m/s or more is produced, whereby the coarse SS and fine SS are flocculated and precipitated by the same treatment to remove such suspended solids at the same time, and the pH of treated water after the removal of the suspended solids is made 8.3 or less to suppress scale deposition due to calcium in a system of cyclically using the treated water as cooling water. |
