| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an advanced method for treating biologically-treated water, with which an inorganic flocculant is added to biologically-treated water, the flocculant-added water is subjected to flocculation treatment, the flocculation-treated water is subjected to solid-liquid separation to obtain separated water, and the separated water is subjected to membrane separation and when the separated water is obtained, the separated water which is the water to be supplied to a membrane and has such high quality that the clogging of the membrane is prevented satisfactorily is obtained by making small the amount of the inorganic flocculant to be added. <P>SOLUTION: The advanced method for treating biologically-treated water comprises the steps of: adding a water-soluble polymer having a phenolic hydroxyl group to the biologically-treated water and agitating them; adding the inorganic flocculant to the polymer-added agitated water and agitating them; subjecting the flocculant-added agitated water to flocculation treatment; subjecting the flocculation-treated water to solid-liquid separation to obtain the separated water; and subjecting the separated water to membrane separation. Since the water-soluble polymer having the phenolic hydroxyl group is added to biologically-treated water before the inorganic flocculant is added, the amount of the inorganic flocculant required to obtain the high-quality water to be supplied to the membrane can be drastically reduced and the quality of the flocculation-treated water can be remarkably improved. <P>COPYRIGHT: (C)2007,JPO&INPIT |
