WATER TREATMENT METHOD AND APPARATUS THEREFOR

摘要

In a water treatment method and an apparatus therefor, after an anionic polymer flocculant is added to water to be treated, granulation is performed by stirring, and solid-liquid separation is then performed to obtain treated water, and flocs which are not disintegrated by a shearing force during stirring and have a preferable settling property can be formed, so that the quality of treated water is also improved. Particularly, a water treatment method includes a flocculating step of adding an anionic polymer flocculant to water to be treated to form flocculated flocs, a subsequent granulating step of stirring the water to be treated to granulate the flocculated flocs, and a solid-liquid separation step of performing solid-liquid separation of generated granulated substances, wherein a cationic polymer flocculant having a cationic group rate of 10 to 50 mole % is added to the water to be treated before the anionic polymer flocculant is added.

主权项

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.