JP2015029933A - Potable water manufacturing apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a potable water manufacturing apparatus and a method capable of manufacturing, when chlorine is included within freshwater (pure water), potable water based on a simple method.SOLUTION: The provided apparatus includes: a sodium chloride supply unit 51 for supplying sodium chloride (NaCl) into a branch line Land another branch line Lbranching from a freshwater line Lfor supplying freshwater (pure water) 50; an electrolysis unit 52 for electrolyzing the freshwater 50 into which sodium chloride has been supplied for obtaining chlorine-containing water including chlorine generated as a result of this electrolysis 52; and a merging line Lfor merging the chlorine-containing water with the freshwater 50 of the freshwater line L.

Description

  The present invention relates to a drinking water production apparatus and method.

  Conventionally, a device for producing drinking water and salt, which includes a reverse osmosis membrane device and an electrodialysis unit, has been proposed as a desalination treatment (see, for example, Patent Document 1). In such a production apparatus, raw water containing salt such as seawater is supplied to the reverse osmosis membrane device to produce desalted water by desalting, while the concentrated salt water concentrated by the reverse osmosis membrane device is supplied to the electrodialysis unit. Then, further concentrate to make concentrated brine. And the salt is manufactured by carrying out the evaporative crystallization of the obtained concentrated brine with an evaporator.

When supplying fresh water obtained by a reverse osmosis membrane device as drinking water, if there is a request for containing hypochlorous acid, calcium hypochlorite (Ca (ClO) ₂ : bleached powder) or Ca (OH) ₂ Mineral content and hypochlorous acid are contained by adding CaCO ₃ or the like.

  In addition, the production of hypochloric acid requires efficient contact between chlorine gas and seawater, resulting in a complicated apparatus configuration (see, for example, Patent Document 2).

  In addition, the salt content in seawater is desalted by electrodialysis, while producing acid, alkali and chlorine, and supplying the desalted solution to the reverse osmosis membrane device, the procurement and storage of chemicals can be simplified. There is a proposal of desalination for reducing the power of the apparatus (for example, see Patent Document 3).

Japanese Patent No. 2887105 JP-A-6-262172 JP 2012-61402 A (Patent No. 5238778)

  By the way, when separately purchasing a conventional medicine, there is a problem in that the running cost of drinking water production increases in the production of drinking water. Moreover, in patent document 2 and 3 mentioned above, there exist the following problems.

  In the proposal of Patent Document 2, since hypochlorous acid is injected into seawater before pretreatment, the organic substance contained in seawater reacts with hypochlorous acid, and harmful trihalomethanes are easily generated. There is. In addition, since hypochloric acid is introduced in the pretreatment, there is a problem that membrane deterioration of the reverse osmosis membrane device during the desalination treatment is promoted.

  According to the proposal of Patent Document 3, in order to realize a reduction in power of the reverse osmosis membrane device, the larger the desalination rate in electrodialysis, the more effective the effect. However, much power consumption is required in the electrodialysis device. And a large amount of hydrochloric acid and sodium hydroxide are generated. There is a problem that the excess hydrochloric acid and sodium hydroxide are mixed with each other and neutralized to form salt water and discarded.

  This invention is made | formed in view of such a situation, and provides the drinking water manufacturing apparatus and method which can manufacture drinking water by a simple method, when chlorine is contained in fresh water (pure water). For the purpose.

  According to a first aspect of the present invention for solving the above problems, a branch line branched from a fresh water line for supplying fresh water, a sodium chloride supply unit for supplying sodium chloride to the branch line, and fresh water supplied with the sodium chloride are electrically A drinking water production comprising: an electrolysis part that decomposes into chlorine-containing water containing chlorine generated in the electrolysis; and a merge line that joins the chlorine-containing water to fresh water in a fresh water line In the device.

  According to the present invention, free chlorine-containing water having a predetermined concentration can be obtained by electrolysis using sodium chloride, and drinking water can be produced stably.

  According to a second invention, in the first invention, a valuable material supply unit for supplying a valuable material is provided on the downstream side of the electrolysis unit, and the valuable material is supplied to the chlorine-containing water, and then merged with the fresh water. It exists in the drinking water manufacturing apparatus characterized by doing.

  According to the present invention, a valuable material-containing drinking water containing, for example, a calcium salt, a magnesium salt, or the like can be produced by supplying the valuable material to the chlorine-containing water.

  According to a third aspect of the present invention, there is provided the drinking water producing apparatus according to the first aspect, further comprising a chlorine meter for measuring a residual chlorine concentration in the fresh water combined with the chlorine-containing water.

  According to the present invention, after the chlorine-containing water is merged with the fresh water, it is possible to obtain an optimum residual chlorine concentration as drinking water.

  According to a fourth invention, in the first invention, the fresh water is fresh water from which salt in the raw water has been removed by the desalination unit, and the salt-enriched water in which the salt in the raw water has been concentrated by the desalination unit is electrodialyzed. An electrodialysis unit for obtaining concentrated brine and diluted brine, a reaction crystallization unit for recovering residual ions in the diluted brine as valuable materials, and a salt-removed water, and an evaporated crystal for evaporating and crystallization of the concentrated brine A solid-liquid separation unit for solid-liquid separation of the concentrated sodium chloride slurry from the evaporative crystallization unit, and a sodium chloride supply line for supplying the solid-liquid separated sodium chloride to the sodium chloride supply unit And a valuable resource supply line for supplying the recovered valuable resource to the valuable resource supply unit.

  According to the present invention, when a predetermined amount of chlorine is contained in the desalinated fresh water, sodium chloride obtained from the salt-concentrated water can be supplied without using chlorine gas from the outside separately as in the prior art. The chlorine raw material can be covered in the desalination facility.

  According to a fifth invention, in the fourth invention, the sodium chloride separated in the solid-liquid separation is used to obtain an aqueous solution of sodium hydroxide and hydrochloric acid, and an aqueous solution of sodium hydroxide is added to the reaction crystallization part. It exists in the drinking water manufacturing apparatus provided with the sodium hydroxide aqueous solution supply line to supply.

  According to the present invention, an aqueous sodium hydroxide solution can be supplied on-site as a chemical agent under alkaline conditions in the reaction crystallization part, and a magnesium salt can be recovered by crystallization reaction under alkaline conditions.

  A sixth invention is the drinking water producing apparatus according to the fourth invention, further comprising a hydrochloric acid supply line for supplying the hydrochloric acid to the reaction crystallization part.

According to the present invention, hydrochloric acid can be supplied on site as a chemical agent under acidic conditions in the reaction crystallization part, and the calcium salt can be recovered by crystallization reaction under acidic conditions.
A seventh invention is the drinking water producing apparatus according to the fourth invention, wherein the electrodialysis section comprises a membrane having ion selectivity.

  According to the present invention, monovalent ions and divalent ions can be selected by using a selective membrane capable of selecting arbitrary ions in the electrodialysis section.

  The eighth invention is generated by electrolysis of a sodium chloride supply step of supplying sodium chloride to fresh water branched from a fresh water line supplying fresh water, and electrolyzing the fresh water supplied with the sodium chloride. There exists an electrolysis process which makes chlorine containing water containing chlorine, and the said chlorine containing water joins the fresh water of a fresh water line, and it exists in the drinking water manufacturing method characterized by the above-mentioned.

  According to the present invention, free chlorine-containing water having a predetermined concentration can be obtained by electrolysis using sodium chloride, and drinking water can be produced stably. In addition, since only fresh water and sodium chloride are supplied to the electrolysis section, scale adhesion to the electrode surface of the electrolysis section can be prevented, and the maintenance frequency can be greatly reduced.

  A ninth aspect of the invention is the eighth aspect of the invention, further comprising a valuable material supply step for supplying a valuable material on a downstream side of the electrolysis unit, and after supplying the valuable material to the chlorine-containing water, the ninth water is joined with the fresh water. It is in the drinking water manufacturing method characterized by doing.

  According to the present invention, a valuable material-containing drinking water containing, for example, a calcium salt, a magnesium salt, or the like can be produced by supplying the valuable material to the chlorine-containing water.

  According to a tenth aspect of the present invention, in the eighth aspect of the invention, there is provided a drinking water production method characterized by measuring a residual chlorine concentration in fresh water combined with the chlorine-containing water.

  According to the present invention, after the chlorine-containing water is merged with the fresh water, it is possible to obtain an optimum residual chlorine concentration as drinking water.

  An eleventh aspect of the invention is that in the eighth aspect, the fresh water is fresh water from which salt in the raw water has been removed by the desalination unit, and the salt-enriched water in which the salt in the raw water has been concentrated by the desalination unit is electrodialyzed. An electrodialysis step for obtaining concentrated brine and diluted brine, a reaction crystallization step for recovering residual ions in the diluted brine as valuable materials, and using the salt solution as a salt-removed water, and an evaporated crystal for evaporating and crystallization of the concentrated brine A solid-liquid separation step for solid-liquid separation of the concentrated sodium chloride slurry from the evaporative crystallization portion, and a sodium chloride supply step for supplying the solid-liquid separated sodium chloride to the sodium chloride supply portion And a valuable sodium supply step of supplying the recovered valuables to the valuable supply part.

  According to the present invention, when a predetermined amount of chlorine is contained in the desalinated fresh water, sodium chloride obtained from the salt-concentrated water can be supplied without using chlorine gas from the outside separately as in the prior art. The chlorine raw material can be covered in the desalination facility.

  A twelfth aspect of the invention is the eleventh aspect of the invention, in which the solid-liquid separated sodium chloride is used to obtain an aqueous sodium hydroxide solution and hydrochloric acid, and the aqueous sodium hydroxide solution is used as the reaction crystallization step. A method for producing drinking water, comprising a step of supplying a sodium hydroxide aqueous solution to be supplied.

  According to the present invention, an aqueous sodium hydroxide solution can be supplied on-site as a chemical agent under alkaline conditions in the reaction crystallization part, and a magnesium salt can be recovered by crystallization reaction under alkaline conditions.

  A thirteenth invention is the drinking water production method according to the eleventh invention, further comprising a hydrochloric acid supply step for supplying the hydrochloric acid to the reaction crystallization step.

  According to the present invention, hydrochloric acid can be supplied on-site as a chemical agent under acidic conditions in the reaction crystallization part, and by removing the carbonic acid component under acidic conditions, precipitation of calcium carbonate is suppressed, and hydroxylation is achieved. Magnesium can be recovered with high purity.

  A fourteenth invention is the drinking water production method according to the eleventh invention, wherein the electrodialysis step comprises a membrane having ion selectivity.

  According to the present invention, monovalent ions and divalent ions can be selected by using a selective membrane capable of selecting arbitrary ions in the electrodialysis section.

  According to the present invention, chlorine-containing water containing chlorine can be easily produced by supplying sodium chloride to fresh water and electrolyzing, and by mixing this chlorine-containing water with fresh water, drinking water containing chlorine of a desired concentration Can be manufactured.

FIG. 1 is a schematic view of a drinking water production apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic view of another potable water production apparatus according to the first embodiment of the present invention. FIG. 3 is a schematic view of a drinking water production apparatus according to the second embodiment of the present invention. FIG. 4 is a schematic view of a drinking water production apparatus according to the third embodiment of the present invention. FIG. 5 is a schematic view of a drinking water production apparatus according to the fourth embodiment of the present invention. FIG. 6 is a schematic view of a drinking water production apparatus according to the fourth embodiment of the present invention. FIG. 7 is a schematic view of a drinking water production apparatus according to the fourth embodiment of the present invention. FIG. 8 is a membrane layout diagram showing the ion permeability of the ion exchange membrane of the electrodialysis unit according to the fourth embodiment of the present invention. FIG. 9 is a membrane layout diagram showing the ion permeability of the ion exchange membrane of the electrodialysis unit according to the fourth embodiment of the present invention. FIG. 10 is a membrane layout diagram showing the ion permeability of the ion exchange membrane of the electrodialysis unit according to the fourth embodiment of the present invention. FIG. 11 is a membrane layout diagram showing the ion permeability of the ion exchange membrane of the electrodialysis unit according to the fourth embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited to each following embodiment, It can implement by changing suitably. Moreover, the structure of the drinking water manufacturing apparatus which concerns on each embodiment can be implemented combining suitably.

(First embodiment)
FIG. 1 is a schematic view of a drinking water production apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic view of another potable water production apparatus according to the first embodiment of the present invention.
As shown in FIG. 1, the drinking water producing apparatus 10A supplies a branch line L ₂₁ branched from a fresh water line L ₁₁ that supplies fresh water (pure water) 50 and sodium chloride (NaCl) to the branch line L _21. Sodium chloride supply unit 51, electrolysis unit 52 that electrolyzes fresh water supplied with sodium chloride to produce chlorine-containing water containing chlorine generated by the electrolysis, and chlorine-containing water is supplied to fresh water line L ₁₁ . A merging line L ₂₂ that merges with the fresh water 50.

  The electrolysis unit 52 supplies sodium chloride (NaCl) to the branched water obtained by branching a part of the permeated water, and the sodium chloride mixed solution is electrolyzed to reduce the free chlorine (hypochlorous acid) concentration to about 1000 ppm. It contains chlorine-containing water.

The valuable material supply unit 53 supplies a predetermined amount of valuable materials such as minerals (calcium salt (Ca salt), magnesium salt (Mg salt)) as the valuable material 54 to the chlorine-containing water.
This supply amount is adjusted and added so that it may become the desired density | concentration contained in the target drinking water.

  When this mineral content is added, it is on the downstream side of electrolysis.

  The fresh water applied to drinking water is not particularly limited, such as fresh water obtained by desalinating seawater, or pure water obtained by treating industrial water with water.

A chlorimeter 56 for measuring chlorine is provided on the downstream side of the merging line L ₂₂ , and the residual chlorine in the drinking water 55 is monitored to be a predetermined value.

  Conventionally, chlorine gas is used when the predetermined chlorine-containing water is used as the drinking water, but in the present invention, sodium chloride is used, so that the free chlorine-containing drinking water can be produced stably.

Drinking water production apparatus 10B of FIG. 2, to obtain a fresh W ₁₁ using the desalination apparatus 12.
Desalination apparatus 12, distilling the feed seawater W, together with obtaining a fresh W ₁₁ salinity in the feed seawater W is removed to obtain a salinity concentrate W ₁₂ salinity in the feed seawater W enriched. In addition, the desalination apparatus 12 discharges the fresh water W ₁₁ as drinking water through the line L ₁₂ and discharges the salt-enriched water W ₁₂ as drainage W ₂₀ through the line L ₁₃ . Although it does not specifically limit as the desalination apparatus 12, The membrane separation method using a reverse osmosis membrane apparatus etc. can be applied besides the evaporation method.

Here, as a reverse osmosis membrane device, for example, a plurality of reverse osmosis membrane elements (reverse osmosis membrane modules) are provided in a container, and fresh water W ₁₁ obtained by processing with each reverse osmosis membrane element and salinity are obtained. connect the retentate line for leading out (discharge) the concentrated water W ₁₂ from each container and (concentrated water discharge path) permeate tube (freshwater discharge path) is arranged.

  As a reverse osmosis membrane of a reverse osmosis membrane device, a general reverse osmosis (RO) membrane (hereinafter also referred to as “RO membrane”), an NF (Nanofiltration) membrane (hereinafter also referred to as “NF membrane”), etc. Can be used.

Therefore, when fresh water W ₁₁ obtained by desalinating the supplied sea water W with a reverse osmosis membrane device is used, it is desalted, and therefore electrolysis unit 52 suppresses scale generation by electrolysis without pretreatment. it can. In addition, when fresh water that has been desalinated by a reverse osmosis membrane device is used, organic substances are hardly contained, and there is almost no by-product such as trihalomethanes.

  According to the present invention, free chlorine-containing water having a predetermined concentration can be obtained by electrolysis using sodium chloride, and drinking water can be produced stably. In addition, since only fresh water and sodium chloride are supplied to the electrolysis section, scale adhesion to the electrode surface of the electrolysis section can be prevented, and the maintenance frequency can be greatly reduced.

Table 1 shows measurements of sodium (Na) content, chlorine (Cl) content, hypochlorous acid (HClO) content, and total dissolved solids (TDS) at each line point in the drinking water production line of FIG. An example is shown. Point 1 and 5, a fresh water W ₁₁ freshwater line L _11, point 2 is the fresh water W ₁₁ which branches into branch line L _21, point 3 is the supply line of sodium chloride, Point 4 containing chlorine have been chlorine-containing water confluence before merging line L _22, point 6 is mixed water of chlorine-containing water and fresh water W ₁₁ freshwater line L ₁₁ after the confluence of chlorine is contained.

  As shown in Point 4, the free chlorine concentration is 1000 ppm, and as shown in Point 6, the mixed water is 0.49 ppm. In addition, when making desired chlorine concentration, it sets suitably by adjustment of the branching ratio of the fresh water W11 to the electrolysis part 52, adjustment of the supply amount of sodium chloride, and adjustment of the current conditions in the electrolysis part 52.

According to the present embodiment, from fresh water W ₁₁ that has been desalinated in the reverse osmosis membrane device, using safe sodium chloride (NaCl salt), while suppressing scale deposition on the electrode surface in the electrolysis unit 52, Drinking water containing free chlorine can be produced stably.

Here, sodium chloride (NaCl) Sodium chloride supplied to the supply portion 52 may be used crystallization treated sodium chloride salinity concentrate W ₁₂ during the desalination process (solid). Thereby, drinking water can be manufactured, without purchasing a chemical | medical agent from the outside.

Also, valuable resources (Ca salt, Mg salt, etc.) recovered from the salt concentrated water W ₁₂ can be used as the valuable resources for the mineral supplied from the valuable material supply unit 53. Thereby, drinking water can be manufactured, without purchasing the chemical | medical agent for addition of a valuable material from the outside.

(Second Embodiment)
Next, a drinking water production apparatus according to the second embodiment of the present invention will be described. Below, it demonstrates centering around difference with the drinking water manufacturing apparatus which concerns on the said 1st Embodiment. In addition, about the same component as the drinking water manufacturing apparatus which concerns on the said 1st Embodiment, the same code | symbol is attached | subjected and duplication of description is avoided.

FIG. 3 is a schematic view of a drinking water production apparatus according to the second embodiment of the present invention.
As shown in FIG. 3, the drinking water production apparatus 10C according to the present embodiment is supplied with seawater by a reverse osmosis membrane apparatus 12A having a reverse osmosis membrane 12a as a desalination unit in the drinking water production apparatus 10B shown in FIG. Electrodialysis unit 13 to obtain concentrated brine W ₁₃ and diluted brine W ₁₄ by electrodialyzing salt-enriched water W ₁₂ enriched with W salt, and recovering residual ions in diluted brine W ₁₄ as valuable material 54 , A reaction crystallization part 23 used as salt-removed water, an evaporation crystallization part 21 for evaporating and crystallization of the concentrated brine W ₁₃ , and a solid solution for separating the concentrated sodium chloride slurry S ₁ from the evaporative crystallization part 21 into solid and liquid. a liquid separation section 22, a sodium chloride (NaCl) 34, which is solid-liquid separation, the sodium chloride supply line L ₅₀ is supplied to the sodium chloride supply unit 51, recovered valuable materials in reactive crystallization analyzing unit 23 (Ca salt, Mg Salt) 54, valuables A valuable material supply line L ₅₁ for supplying to the supply unit 53 is provided.

The electrodialysis unit 13 includes an electrodialysis membrane (ED: Elecrodialysis membrane) 13a. Electrodialysis unit 13, salinity salinity concentrate W ₁₂ electrodialysis to salinity concentrate W ₁₂ salinity concentrate enriched brine W of ₁₃ and salt concentration water W in ₁₂ was removed by electrodialysis membrane 13a Diluted brine W ₁₄ is obtained.
As an electrodialysis method, for example, a cation exchange membrane that transmits only cations and an anion exchange membrane that transmits only anions are alternately arranged, and voltage is applied from both ends of the cation exchange membrane and the anion exchange membrane. It is configured so that a direct current can be applied by applying it. In the electrodialysis unit 13, concentrated obtained by treating the salt concentration water W ₁₂ brine W ₁₃ and diluted brine W _14, respectively, they are discharged by the discharge line L _14, L _15.

Here, the supply line L ₁₃ supplies the salinity concentrate W ₁₂ from the reverse osmosis unit 12 is partly branched into the electrodialysis unit 13 side, salinity concentrate W ₁₂ that is not branched, the feed line L ₁₃ And discharged to the outside as drainage 17.

The evaporative crystallization unit 21 evaporates and concentrates the concentrated brine W ₁₃ supplied from the electrodialysis unit 13 to obtain a salt (sodium chloride (NaCl)) 34 and also obtains evaporated water W ₁₅ . Further, the evaporated water W ₁₅ from the evaporative crystallization unit 21 merges with the fresh water W ₁₁ via the supply line L ₃₅ and the supply line L ₁₂ to become drinking water 55. The evaporative crystallization unit 21 supplies the evaporating water W ₁₅ to the cooling crystallization unit 24 via the line W ₁₉ .

Here, the evaporative crystallization unit 21 can be exemplified by, for example, a multi-effect evaporator, a thin film evaporator or a drum dryer, and the discharge for discharging the precipitate sodium chloride slurry S ₁ obtained by the evaporation process. A line L ₁₇ is connected to the solid-liquid separator 22.

The solid-liquid separation unit 22 performs solid-liquid separation on the concentrated sodium chloride slurry S ₁ from the evaporative crystallization unit 21, and obtains sodium chloride (solid) 34 as a valuable material.
Further, the sodium chloride removal slurry S ₂ from which sodium chloride has been separated is discharged through the discharge line L ₁₈ .
Further, the separated sodium chloride is supplied via a sodium chloride supply line L ₅₀ sodium chloride supply unit 51.

The reaction crystallization unit 23 crystallizes multivalent ions as valuable materials 54 by a reaction crystallization method.
For example, when crystallizing calcium salt (Ca salt), it is recovered as a valuable material (calcium sulfate, calcium carbonate, etc.) 54 under alkaline conditions and acidic conditions.

Here, the crystallization reaction under alkaline conditions uses calcium hydroxide (Ca (OH) ₂ ) or the like as a drug. In the crystallization reaction under acidic conditions, for example, sulfuric acid (H ₂ SO ₄ ), hydrochloric acid (HCl) or the like is used as a chemical agent.
Here, using sulfuric acid and hydrochloric acid to supply before recovery of magnesium hydroxide, the pH of the diluted brine W ₁₄ is lowered and the carbonic acid component in the water is volatilized / reduced by the following reaction formulas (1) and (2). By removing it, precipitation of calcium carbonate is suppressed. Thereby, magnesium oxide can be recovered with high purity.
Ca (HCO ₃ ) ₂ + 2HCl → CaCl ₂ + 2H ₂ O + 2CO ₂ ↑ (1)
Ca (HCO ₃ ) ₂ + H ₂ SO ₄ → CaSO ₄ + 2H ₂ O + 2CO ₂ ↑ (2)

  In the reaction crystallization unit 23, first, the Ca salt is recovered as the valuable material 54 by the reaction crystallization, and then the Mg salt is recovered as the valuable material 54 under alkaline conditions.

  The desalinated water from which the valuable material 54 has been collected is treated as the waste water 17. Alternatively, a part of the water may be returned to the inlet side of the reverse osmosis membrane device 12 as recycled water and reused. At this time, boron in the circulating water may be collected and removed by an ion exchange method or an adsorption method. Further, except that boron is collected by adsorption and / or ion exchange, it may be removed, for example, by electrodialysis.

According to the present embodiment, sodium chloride 34 is recovered from the salt-concentrated water W ₁₂ from the reverse osmosis membrane device 12A, and this is supplied to the sodium chloride supply unit 51 to produce chlorine-containing water on-site. be able to. Further, by collecting the polyvalent ions remaining in the diluted brine W _{14 as a} valuable material (Ca salt, Mg salt) 54 in the reaction crystallization part 23, the valuable material 54 can be supplied on-site and the mineral content is included. Chlorine-containing water can be produced.

Next, the whole operation | movement of the drinking water manufacturing apparatus 10C which concerns on this Embodiment is demonstrated.
Supplying sea water W supplied to the reverse osmosis unit 12 is on the salt concentration water W ₁₂ salinity enriched freshwater W ₁₁ and in the feed seawater W which salt has been removed in the feed seawater W by desalination process . Fresh water W ₁₁ is discharged through supply line L ₁₂ , partially branched, supplied with sodium chloride at sodium chloride supply unit 51, and electrolyzed at electrolysis unit 52, thereby containing chlorine containing free chlorine Obtain water. Further, a mineral component which is a valuable material 54 is also added to obtain drinking water 55 containing a desired mineral component. At this time, residual chlorine is measured by a chlorine meter 56.
Salinity concentrate W ₁₂ from the reverse osmosis unit 12, together with a portion through a supply line L ₁₃ is supplied to the electrodialysis unit 13, a portion is discharged as waste W _20.

Electrodialysis unit 13 salinity concentrate is supplied to the W ₁₂ is salinity salinity concentrate W of ₁₂ is further salinity concentrated concentrated brine W ₁₃ and salt concentration water W in ₁₂ removed by electrodialysis membrane 13a a diluted brine W _14. Here, the concentrated brine W ₁₃ is rich in monovalent salts (Na (sodium) salt, K (potassium) salt, etc.) contained in the salt-enriched water W ₁₂ . The diluted brine W ₁₄ is rich in polyvalent salts (Mg (magnesium) salt, Ca (calcium) salt, etc.) contained in the salt-enriched water W ₁₂ .
Sodium chloride 34 separated by the evaporative crystallization unit 21 and the solid-liquid separation unit 22 is supplied on-site to the sodium chloride supply unit 51 via the sodium chloride supply line L ₅₀ , and chlorine-containing water is supplied by the electrolysis unit 52. To manufacture.

The diluted brine W ₁₄ from the electrodialysis unit 13 is sent to the reaction crystallization unit 23, and multivalent ions are crystallized by the reaction crystallization method.
By this reaction crystallization, polyvalent ions such as calcium salt (Ca salt) and magnesium salt are recovered as valuable material 54. The recovered valuable materials (Ca salt, Mg salt) 54, via the valuable substance supply line L _51, is supplied on-site valuables supply unit 53.

Therefore, according to the drinking water production apparatus 10C and the method of the present embodiment, when chlorine is contained in the fresh water W ₁₁ , the sodium chloride 34 is produced using the salt-concentrated water W ₁₂ after being desalinated, The chlorine-containing water is produced by electrolysis in the electrolysis section 52 after being supplied to the branched fresh water W ₁₁ , and valuable materials 54 such as Ca salts and Mg salts which are valuable materials from the salt concentration water W ₁₂ are used. The chlorine-containing water can be supplied on-site, and drinking water having a desired composition can be produced stably and inexpensively.

(Third embodiment)
Next, a drinking water production apparatus according to the third embodiment of the present invention will be described. Below, it demonstrates centering around difference with the drinking water manufacturing apparatus which concerns on the said 1st Embodiment. In addition, about the same component as the drinking water manufacturing apparatus which concerns on the said 1st Embodiment, the same code | symbol is attached | subjected and duplication of description is avoided.

FIG. 4 is a schematic view of a drinking water production apparatus according to the third embodiment of the present invention.
As shown in FIG. 4, the drinking water production apparatus 10D according to the present embodiment further removes turbidity contained in the supplied seawater W in the drinking water production apparatus 10C of the second embodiment, and performs pretreatment water. A pretreatment device 11 for W ₁₀ , a dissolution part 29 for dissolving solid-liquid separated sodium chloride, an electrochemical treatment part 30 for obtaining hydrochloric acid 32 and sodium hydroxide aqueous solution 33 using the dissolved sodium chloride aqueous solution, A hydrochloric acid supply line L ₂₅ for supplying the obtained hydrochloric acid 32 to the reaction crystallization part 23 and a sodium hydroxide aqueous solution supply line L ₂₂ for supplying the obtained sodium hydroxide aqueous solution 33 to the reaction crystallization part 23 Prepare.
Further, from the supply line L ₁₅ for supplying concentrated brine W ₁₃ to evaporation crystallization analyzing unit 21 from the electrodialysis unit 13, with discharge line L ₃₁ for discharging the concentrated brine W ₁₃ is provided, the reactive crystallization from electrodialysis unit 13 from the supply line _{L 14} for supplying dilution brine _{W 14} in section 23, discharge line L ₃₂ is provided for discharging the diluted brine W _14.

The dissolution unit 29 uses a part of the separated sodium chloride to dissolve with fresh water W ₁₁ to obtain a sodium chloride aqueous solution. For this dissolution, fresh water W ₁₁ obtained by the desalination treatment and evaporated water W ₁₅ are supplied from one or both of the supply lines L ₃₃ . Dissolved sodium chloride aqueous solution is supplied to the electrochemical processing unit 30 via a supply line L _23.

  The electrochemical treatment unit 30 obtains a hydrochloric acid 32 and a sodium hydroxide (NaOH) aqueous solution 33 by electrochemical treatment such as electrolysis or electrodialysis using the supplied sodium chloride aqueous solution.

  When the valuable material 54 is produced in the reaction crystallization part 23, sodium chloride is used as a crystallization reaction agent by using hydrochloric acid 32 and sodium hydroxide aqueous solution 33 obtained by electrolysis treatment. No need to purchase.

Although not shown in the figure, a hydrochloric acid supply line for supplying hydrochloric acid 32 and a sodium hydroxide aqueous solution supply line for supplying sodium hydroxide aqueous solution 33 are connected to supply line L ₁₂ for discharging fresh water W ₁₁ , You may make it adjust the pH of drinking water.

  Further, in order to supply the hydrochloric acid 32 and the sodium hydroxide aqueous solution 33 for cleaning the reverse osmosis membrane device 12 when the desalination apparatus is shut down, a hydrochloric acid supply line for supplying the hydrochloric acid 32 and the sodium hydroxide aqueous solution 33 are provided. A sodium hydroxide aqueous solution supply line to be supplied may be connected to a predetermined cleaning line.

The adjustment and discharge line L ₃₁ for discharging the concentrated brine W _13, since provision of the discharge line L ₃₂ for discharging the diluted brine W _32, sodium chloride salts and valuable materials (Ca salt, Mg salt) the production of 54 can do.
Thereby, it becomes possible to adjust the production amounts of the sodium chloride 34 and the valuables 54 without changing the power consumption in the reverse osmosis membrane device 12 and the electrodialysis unit 13, and the steam consumption in the crystallization. And drug costs can be optimized.
Further, the ratio of the concentrated brine W ₁₃ and the diluted brine W ₁₄ is not particularly limited, but is preferably about 1.5 to 2.0: 8.5 to 8.0.

(Fourth embodiment)
Next, a drinking water production apparatus according to the fourth embodiment of the present invention will be described. Below, it demonstrates centering on difference with the drinking water manufacturing apparatus based on the said 1st thru | or 3rd embodiment. In addition, about the same component as the drinking water manufacturing apparatus which concerns on the said 1st Embodiment, the same code | symbol is attached | subjected and duplication of description is avoided.

5 to 7 are schematic views of a drinking water production apparatus according to the fourth embodiment.
As shown in FIG. 5 thru | or 7, the drinking water manufacturing apparatus 10E, F, and G which concern on this Embodiment make reaction crystallization part the 1st reaction crystallization part 23A and the 2nd reaction crystallization part 23B. In addition, in the first reaction crystallization unit 23A, the obtained hydrochloric acid 32 is supplied from the hydrochloric acid supply line L ₂₅ to crystallize the Ca salt. In the second reaction crystallization analyzing unit 23B, and it supplies the resulting aqueous solution of sodium hydroxide 33 sodium hydroxide solution supply line L _26, and to perform the crystallization of Mg salt.

  First, the state of ion permeation due to the difference in ion permeability properties of the electrodialysis membrane will be schematically described with reference to FIGS.

FIG. 8 shows a monovalent ion selective cation exchange membrane (CS) and a monovalent ion selective anion exchange membrane (AS) arranged alternately.
In this case, monovalent Na ions and K ions permeate to become concentrated brine 1 containing Na ions, K ions, and Cl ions. Diluted brine 1 contains divalent Ca ions, Mg ions, and SO _4. Ions stay.

FIG. 9 shows an alternate arrangement of a cation exchange membrane (C) and a monovalent ion selective anion exchange membrane (AS).
In this case, monovalent Na ions and K ions, divalent Ca ions and Mg ions permeate to become concentrated brine 1 containing Ca ions, Mg ions Na ions, K ions and Cl ions. Remains divalent SO ₄ ions.

FIG. 10 shows a monovalent ion selective cation exchange membrane (CS), an anion exchange membrane (A), and a cation exchange membrane (C) between monovalent ion selective anion exchange membranes (AS). Is arranged.
In this case, in the diluted brine 1, monovalent Na ions and K ions are transmitted, and divalent Ca ions, Mg ions, and SO ₄ ions remain. The concentrated brine 1 is supplied with monovalent Na ions and K ions, and includes Na ions, K ions, Cl ions, and sulfate ions. From the diluted brine 2, monovalent Na ions and K ions are discharged. Monovalent Na ions, K ions, divalent Ca ions, Mg ions, and Cl ions flow into the concentrated brine 2.

FIG. 11 shows a monovalent ion selective cation exchange membrane (CS), a monovalent ion selective anion exchange membrane (AS), and a cation between monovalent ion selective anion exchange membranes (AS). An exchange membrane (C) is arranged.
In this case, in the diluted brine 1, monovalent Na ions and K ions are transmitted, and divalent Ca ions, Mg ions, and SO ₄ ions remain. The concentrated brine 1 is supplied with monovalent Na ions and K ions, and contains Na ions, K ions, and Cl ions. In the diluted brine 2, monovalent Na ions and K ions are discharged, and sulfate ions remain. The concentrated brine 2 is supplied with monovalent Na ions, K ions, divalent Ca ions, and Mg ions, and includes Ca ions, Mg ions, Na ions, K ions, and Cl ions.

  Table 2 shows the difference in ion permeation due to these ion permeabilities.

When the ion-permeable electrodialysis unit 13 shown in FIG. 8 is used, the configuration shown in FIG. 5 is preferable.
In FIG. 5, the first reaction crystallization part 23 </ b> A and the second reaction crystallization part 23 </ b> B are arranged in the supply line L ₁₄ for the diluted brine W ₁₄ .
In FIG. 8, the diluted brine W ₁₄ is crystallized in the first reaction crystallization part 23A to obtain a Ca salt first. Next, crystallization is performed in the second reaction crystallization part 23B to obtain an Mg salt.

When the ion-permeable electrodialysis unit 13 shown in FIG. 9 is used, the configuration shown in FIG. 6 is preferable.
In FIG. 6, the first reaction crystallization part 23A and the second reaction crystallization part 23B are arranged in the supply line L ₁₅ of the concentrated brine W ₁₃ .
In FIG. 9, the diluted brine W ₁₄ is crystallized in the first reaction crystallization part 23A to obtain a Ca salt first. Next, crystallization is performed in the second reaction crystallization part 23B to obtain an Mg salt.
In this case, it is preferable that sulfate ions are removed from the concentrated brine W ₁₃ .

When the ion-permeable electrodialysis unit 13 shown in FIGS. 10 and 11 is used, the configuration shown in FIG. 7 is preferable.
7, the supply line L ₁₅ of concentrated brine W ₁₃ as two, and the supply line L _15A of concentrated brine W _13A, and a supply line L _15B of concentrated brine W _13B, the supply line L _15A of concentrated brine W _13A Is connected to the evaporative crystallization part 21 and evaporates and crystallizes.
On the other hand, the supply line L _15B for the concentrated brine W _13B is connected to the first reaction crystallization part 23A and then connected to the second reaction crystallization part 23B.
In the configuration shown in FIG. 7, the concentrated brine W ₁₃ is crystallized by the first reaction crystallization unit 23A to first obtain a Ca salt. Next, crystallization is performed in the second reaction crystallization part 23B to obtain an Mg salt.

  By using electrodialysis using a membrane having ion permeability shown in FIG. 11, target ions are separated into diluted brine and concentrated brine, and therefore, it is particularly preferable to use it as a recovery of valuable material 54.

10A to 10G Drinking water production device 11 Pretreatment device 12 Reverse osmosis membrane device 12a Reverse osmosis membrane 13 Electrodialysis unit 13a Electrodialysis membrane 21 Evaporation crystallization unit 22 Solid-liquid separation unit 23 Reaction crystallization unit 30 Electrochemical processing unit 31 Hydrochloric acid Production Department 32 Hydrochloric Acid 55 Drinking Water W Supply Seawater W ₁₀ Pretreatment Water W ₁₁ Fresh Water W ₁₂ Salt Concentrated Water W ₁₃ Concentrated Brine W ₁₄ Diluted Brine W ₂₀ Drainage L ₁₀ Sea Water Line L ₁₁ Fresh Water Line L ₂₁ Branch Line L ₂₅ Hydrochloric Acid Supply Line L ₂₆ Sodium hydroxide aqueous solution supply line

Claims (14)

A branch line branched from a fresh water line for supplying fresh water;
A sodium chloride supply unit for supplying sodium chloride to the branch line;
Electrolyzing fresh water supplied with the sodium chloride, and electrolyzing part to make chlorine-containing water containing chlorine generated by the electrolysis,
A drinking water production apparatus comprising: a merging line for merging the chlorine-containing water with fresh water in a fresh water line. In claim 1,
A drinking water production apparatus comprising a valuable material supply unit that supplies a valuable material on a downstream side of the electrolysis unit, and supplies the valuable material to the chlorine-containing water, and then merges with the fresh water. In claim 1,
An apparatus for producing drinking water, comprising a chlorine meter for measuring a residual chlorine concentration in fresh water combined with the chlorine-containing water. In claim 1,
The fresh water is fresh water from which salt in raw water has been removed by a desalination unit,
An electrodialysis unit that electrodialyzes the salt-enriched water in which the salt in the raw water is concentrated by the desalination unit to obtain concentrated brine and diluted brine,
Recovering residual ions in the diluted brine as valuable materials, and a reaction crystallization part to be used as salt-removed water;
An evaporation crystallization part for evaporating and crystallization of the concentrated brine;
A solid-liquid separation unit for solid-liquid separation of the concentrated sodium chloride slurry from the evaporative crystallization unit;
A sodium chloride supply line for supplying the solid-liquid separated sodium chloride to the sodium chloride supply unit;
A drinking water production apparatus comprising: a valuable resource supply line that supplies the recovered valuable resource to the valuable resource supply unit. In claim 4,
Using the sodium chloride separated into the solid and liquid, an electrochemical treatment unit for obtaining a sodium hydroxide aqueous solution and hydrochloric acid,
A drinking water production apparatus comprising a sodium hydroxide aqueous solution supply line for supplying the sodium hydroxide aqueous solution to the reaction crystallization part. In claim 4,
A drinking water production apparatus comprising a hydrochloric acid supply line for supplying the hydrochloric acid to the reaction crystallization unit. In claim 4,
The said electrodialysis part is equipped with the membrane which has ion selectivity, The drinking water manufacturing apparatus characterized by the above-mentioned. A sodium chloride supply step for supplying sodium chloride to fresh water branched from a fresh water line for supplying fresh water;
An electrolysis step of electrolyzing the fresh water supplied with the sodium chloride to obtain chlorine-containing water containing chlorine generated by the electrolysis;
A method for producing drinking water, wherein the chlorine-containing water is joined to fresh water in a fresh water line to produce drinking water. In claim 8,
A drinking water production method comprising: a valuable material supply step for supplying a valuable material on a downstream side of the electrolysis unit, wherein the valuable material is supplied to the chlorine-containing water and then merged with the fresh water. In claim 8,
The drinking water manufacturing method characterized by measuring the residual chlorine concentration in the fresh water which merged the said chlorine containing water. In claim 8,
The fresh water is fresh water from which salt in raw water has been removed by a desalination unit,
Electrodialysis step of obtaining a concentrated brine and a diluted brine by electrodialyzing the salt-enriched water in which the salt in the raw water is concentrated by the desalination unit,
A reaction crystallization step of recovering residual ions in the diluted brine as valuables and using salt-removed water;
An evaporation crystallization step of evaporating and crystallization of the concentrated brine;
A solid-liquid separation step for solid-liquid separation of the concentrated sodium chloride slurry from the evaporative crystallization part;
A sodium chloride supply step of supplying the sodium chloride separated into solid and liquid to the sodium chloride supply unit;
A drinking water manufacturing method comprising: a valuable sodium supply step for supplying the recovered valuables to the valuable resource supply unit. In claim 11,
An electrochemical treatment step of obtaining an aqueous sodium hydroxide solution and hydrochloric acid using the solid-liquid separated sodium chloride;
A drinking water production method comprising: a sodium hydroxide aqueous solution supply step for supplying the sodium hydroxide aqueous solution to the reaction crystallization step. In claim 11,
And a hydrochloric acid supply step for supplying the hydrochloric acid to the reaction crystallization step. In claim 11,
In the electrodialysis step, a drinking water production method using a membrane having ion selectivity.

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