Patent ID: 9403705
Filing Date: 2016-08-02
CPC Classification: B01D,C02F

Claim Text:
1. A water treatment method comprising: a flocculating step of adding an anionic polymer flocculant to water to be treated containing suspended solids to form flocculated flocs; a granulating step of stirring the water to be treated to granulate the flocculated flocs; and a solid-liquid separating step of performing solid-liquid separation of generated granulated substances to obtain treated water, wherein before the anionic polymer flocculant is added, a cationic polymer flocculant having a cationic group rate of 10 to 50 mole % is added to the water to be treated, wherein an inorganic coagulant is added to the water to be treated together with the cationic polymer flocculant or before the addition of the cationic polymer flocculant, and wherein the granulating step and the solid-liquid separating step are performed in a granulation type flocculating and settling tank maintaining a sludge blanket therein.