Title:
HIGH-PERFORMANCE PRETREATMENT SYSTEM FOR DESULFURIZED WASTEWATER FOR REVERSE OSMOSIS MEMBRANE
Document Type and Number:
WIPO Patent Application WO/2022/210467
Kind Code:
A1
Abstract:
According to the present invention, a method for treating high-hardness water containing calcium and magnesium includes: adding an alkali metal hydroxide and sodium carbonate to the high-hardness water to achieve a pH of 9.5 to 11.5; removing a resulting precipitate; adding an inorganic acid and an iron-based flocculant to the liquid from which the precipitate has been removed, to achieve a pH of 2.5 to 4.5; removing a resulting floc; subjecting the liquid from which the floc has been removed to separation treatment by means of a reverse osmosis membrane to separate the same into permeated water and concentrated water; and subjecting the concentrated water to evaporation to dryness to obtain a dry solid material.
Inventors:
MATSUKAWA KYOHEI (JP)
ITO YOSHIAKI (JP)
TAKEUCHI KAZUHISA (JP)
KOBAYASHI KAZUKI (JP)
ITO YOSHIAKI (JP)
TAKEUCHI KAZUHISA (JP)
KOBAYASHI KAZUKI (JP)
Application Number:
PCT/JP2022/014808
Publication Date:
October 06, 2022
Filing Date:
March 28, 2022
Export Citation:
Assignee:
MITSUBISHI HEAVY IND LTD (JP)
MITSUBISHI POWER LTD (JP)
MITSUBISHI POWER LTD (JP)
International Classes:
C02F1/44; B01D61/02; B01D61/04; C02F1/04; C02F1/52; C02F1/58; C02F5/00; C02F9/02; C02F9/04; C02F9/10
Foreign References:
| JP2015128754A | 2015-07-16 | |||
| JPH10137540A | 1998-05-26 | |||
| JP2003170174A | 2003-06-17 | |||
| JPH1085742A | 1998-04-07 | |||
| JPS5193789A | 1976-08-17 | |||
| JPH10137540A | 1998-05-26 | |||
| JP2006305541A | 2006-11-09 | |||
| JP2012213676A | 2012-11-08 |
Attorney, Agent or Firm:
KIKUMA, Tadayuki (JP)
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