Water treatment process and water treatment system
First Claim
1. A water treatment process, comprising:
- a first scale inhibitor supplying step of supplying a calcium scale inhibitor which is a scale inhibitor for inhibiting the deposition of a scale containing calcium and a silica scale inhibitor which is a scale inhibitor for inhibiting the deposition of silica to water containing Ca2+ ions, SO42−
ions, carbonate ions and silica;
a first demineralizing step of separating the water into first concentrated water in which the Ca2+ ions, the SO42−
ions, the carbonate ions and the silica are concentrated and treated water after the first scale inhibitor supplying step; and
a first crystallizing step of supplying seed crystals of gypsum to the first concentrated water so that gypsum is crystallized from the first concentrated water, wherein the water treatment process further comprises, after the first crystallizing step;
a second scale inhibitor supplying step of supplying the calcium scale inhibitor to the water;
a first pH adjusting step of adjusting the water to a pH of 10 or more at which the silica is soluble in the water;
a second demineralizing step of separating the water into second concentrated water in which the Ca2+ ions, the SO42−
ions, the carbonate ions and the silica are concentrated and treated water after the second scale inhibitor supplying step and the first pH adjusting step; and
a second crystallizing step of supplying seed crystals of gypsum to the second concentrated water so that gypsum is crystallized from the second concentrated water.
2 Assignments
0 Petitions
Accused Products
Abstract
Provided are a water treatment system and a water treatment process, which are capable of reproducing water containing salts with high water recovery. In the water treatment system (400) and the water treatment process of the present invention, after a calcium scale inhibitor and a silica scale inhibitor are supplied to water to be treated containing Ca ions, SO4 ions, carbonate ions, and silica, and the water to be treated is separated in a second demineralizing section (210) into second concentrated water in which the Ca ions, the SO4 ions, the carbonate ions, and the silica are concentrated and treated water. In a second crystallizing section (220), seed crystals of gypsum are supplied to the second concentrated water, whereby gypsum is crystallized and removed from the second concentrated water.
44 Citations
34 Claims
-
1. A water treatment process, comprising:
-
a first scale inhibitor supplying step of supplying a calcium scale inhibitor which is a scale inhibitor for inhibiting the deposition of a scale containing calcium and a silica scale inhibitor which is a scale inhibitor for inhibiting the deposition of silica to water containing Ca2+ ions, SO42−
ions, carbonate ions and silica;a first demineralizing step of separating the water into first concentrated water in which the Ca2+ ions, the SO42−
ions, the carbonate ions and the silica are concentrated and treated water after the first scale inhibitor supplying step; anda first crystallizing step of supplying seed crystals of gypsum to the first concentrated water so that gypsum is crystallized from the first concentrated water, wherein the water treatment process further comprises, after the first crystallizing step; a second scale inhibitor supplying step of supplying the calcium scale inhibitor to the water; a first pH adjusting step of adjusting the water to a pH of 10 or more at which the silica is soluble in the water; a second demineralizing step of separating the water into second concentrated water in which the Ca2+ ions, the SO42−
ions, the carbonate ions and the silica are concentrated and treated water after the second scale inhibitor supplying step and the first pH adjusting step; anda second crystallizing step of supplying seed crystals of gypsum to the second concentrated water so that gypsum is crystallized from the second concentrated water. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A water treatment system, comprising:
-
a first scale inhibitor supplying section that supplies a calcium scale inhibitor which is a scale inhibitor for inhibiting the deposition of a scale containing calcium and a silica scale inhibitor which is a scale inhibitor for inhibiting the deposition of silica to water containing Ca2−
ions, SO42−
ions, carbonate ions and silica;a first demineralizing section that is positioned on a downstream side of the first scale inhibitor supplying section and separates the water into first concentrated water in which the Ca2+ ions, the SO42−
ions, the carbonate ions and the silica are concentrated and treated water; anda first crystallizing section including a first crystallizing tank that is positioned on a downstream side of the first demineralizing section and crystallizes gypsum from the first concentrated water and a first seed crystal supplying section that supplies seed crystals of gypsum to the first crystallizing tank, wherein the water treatment system comprises, on a downstream side of the first crystallizing section with respect to the water; a second scale inhibitor supplying section that supplies the calcium scale inhibitor to the water; a first pH adjusting section that supplies a pH adjuster to the water to adjust the pH of the water to 10 or more such that the silica is soluble in the water; a second demineralizing section that is positioned on a downstream side of the second scale inhibitor supplying section and the first pH adjusting section and separates the water into first concentrated water in which the Ca2+ ions, the SO42−
ions, the carbonate ions and the silica are concentrated and treated water; anda second crystallizing section including a second crystallizing tank that is positioned on a downstream side of the second demineralizing section and crystallizes gypsum from the second concentrated water and a second seed crystal supplying section that supplies seed crystals of gypsum to the second crystallizing tank. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
-
Specification