WASTE WATER TREATMENT METHOD

摘要

PROBLEM TO BE SOLVED: To improve the water recovery ratio when cleaning a filter medium, in a waste water treatment method for collecting and removing suspended matter in waste water by using the filter medium.SOLUTION: The waste water treatment method of the embodiment comprises: successively forming a first layer composed of a nonmagnetic particle and a second layer composed of a magnetic particle in a filtration device; collecting the suspended matter in the second layer by introducing the waste water containing the suspended matter into the filtration device and causing the introduced waste to flow through the second layer; mixing the magnetic particle constituting the second layer and the suspended matter by repeating ON operation and OFF operation of magnetic field application means arranged above the second layer, thereby forming slurry composed of the magnetic particle and the suspended matter; discharging the slurry to the outside of the filtration device from a discharge port arranged between the first layer and the magnetic field application means of the filtration device; and separating the discharged slurry into the magnetic particle and the suspended matter and recovering the magnetic particle.