| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for flocculating an original liquid, by which suspended matter in the original liquid is formed into flocs having an excellent flocculating property and the dehydration property and peeling property of the flocculated flocs are improved. SOLUTION: A cationic macromolecular flocculant is added to the original liquid containing the suspended matter to produce flocculated flocs and then water glass, which is prepared by adding phosphoric acid to a sodium silicate aqueous solution having 0.72-0.96% SiO<SB>2</SB>concentration and adjusting the pH of the phosphoric acid-added solution to 6-7, is added to the floc-produced original liquid. In other words, the flocculated flocs are formed by the cationic macromolecular flocculant to be used as the flocculant of water purifying sludge and reacted with the added water glass having anionic effectiveness so that they are formed into larger/firmer flocs to be settled/concentrated easily. The safety of the macromolecular flocculant is excellent because the amount of the macromolecular flocculant to be added is equal to or lower than the reference residual amount of an acrylamide monomer in the water. COPYRIGHT: (C)2005,JPO&NCIPI
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