| 摘要 |
PROBLEM TO BE SOLVED: To enable treated water having high clarity to be obtained by reducing the addition amount of an inorganic coagulant.SOLUTION: A wastewater treatment method includes: adding, to wastewater, an organic coagulant including a water-soluble polymer which contains 5-40 mol% of a cationic monomer of formula (1): CH=CR-CO-X-Q-NRRR.Z, 0-10 mol% of an anionic monomer of formula (2): RCH=CR-A-B, and 60-95 mol% of another monomer, and in which, when measurement is carried out at 25°C, a value obtained by dividing a 0.5% solution viscosity by a 0.5% salt viscosity is 5-50, and the 0.5% salt viscosity is 5-30 mPa s; and further adding a polymer flocculant. |
