To provide a water treating method and a water treatment apparatus which allow to sufficiently exhibit calcium removing capacity even in a case of high or low salt concentration in raw water, and reduce a used amount of a calcium removing agent as much as possible.
This invention relates to the water treating method, in which the raw water containing calcium ions is separated into treated water and condensed water by a permeable membrane device. The condensed water is returned to a raw water tank through a crystallization reactor and a settling tank. In the crystallization reactor, calcium sulfate seed crystal is added to the condensed water to crystalize calcium ions and sulfate ions in the condensed water as calcium sulfate crystal. In the settling tank, the calcium sulfate crystal in the condensed water sent from the crystallization reactor is precipitated, and the supernatant is returned to the raw water tank. Part of the calcium sulfate crystal precipitated in the settling tank is recovered to the crystallization reactor as the calcium sulfate seed crystal. Residual calcium sulfate crystal precipitated in the settling tank is discharged to the outside of the system.
TANIDA KATSUYOSHI
TAJI AKIHIRO
SHIOZAKI MIKIO
| JP2006305541A | 2006-11-09 | |||
| JPH11188389A | 1999-07-13 | |||
| JP2001252662A | 2001-09-18 | |||
| JPH04271893A | 1992-09-28 | |||
| JPH10137757A | 1998-05-26 | |||
| JP2006305541A | 2006-11-09 | |||
| JPH11188389A | 1999-07-13 | |||
| JP2001252662A | 2001-09-18 | |||
| JPH04271893A | 1992-09-28 |
| WO2009004988A1 | 2009-01-08 | |||
| WO2009004988A1 | 2009-01-08 |