| 摘要 |
A coagulation treatment method for water to be treated that is capable of reducing the degree of inflow of micro flocs reaching a sand filtration layer while realizing a higher density and miniaturization of micro flocs and flocs in a state where the use of an inorganic coagulant is limited by dramatic improvement in residual percentage in a contact-media accumulation tank, based on obtaining a residual percentage (filtration rate) not less than 80% of flocs with particle diameters not less than 7.0 μm in a contact-media accumulation tank from a stage that the water to be treated starts to pass through by interposing the contact-media accumulation tank in a micro flocculation step and a sand filtration step, and filling flocs with particle diameters not less than 7.0 μm in advance at an inlet of the contact-media accumulation tank and/or the vicinity of the inlet. |
