JP2005095741A - Water treatment method and water treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water treatment method and a water treatment apparatus which can obtain recyclable reclaimed water by removing and separating ion components contained in water to be treated. <P>SOLUTION: The water treatment method adjusts the pH of the water to be treated to alkaline or acidic by adding an alkaline agent or an acid thereto by using a pH controller 1. The water to be treated, after the pH adjustment is passed through a reverse osmosis membrane device 3 to remove the ion components contained in the water to be treated, and the treated water passed through the reverse osmosis membrane is fed to an ion exchange resin column 5 to remove the ion components remaining in the treated water. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a water treatment method and a water treatment apparatus for obtaining treated water that can be recycled by subjecting treated water such as waste liquid discharged from various facilities to predetermined treatment.

  In recent years, social demands for environmental protection have increased, and various proposals have been made regarding technologies for preventing the release of harmful substances to the environment (see, for example, Patent Document 1). This proposal is intended to remove cyanide and other harmful substances from gases that may be released to the outside.

Although the above-mentioned treatment is for a gas body, it is strongly desired that waste liquid is generated from various treatment facilities such as a waste treatment facility, and that harmful substances can be removed from these to produce water in a recyclable state.
JP 2001-41437 A

  However, these waste liquids contain a large amount of salt substances, and a large amount of chemicals is required to chemically treat the waste liquid. For this reason, reuse is difficult and the load of the water treatment plant increases. Moreover, since the salt concentration of the reclaimed water after a water treatment is high, there exists a problem in the utilization. That is, if reclaimed water with a high salt concentration is used, the equipment will be corroded, or harmful effects will occur due to the corrosion products. Furthermore, there are many cases where ammonia, calculation, sulfuric acid, cyanide and the like are mixed in the waste water, and it is strongly demanded that these can be reliably removed.

  The objective of this invention is providing the water treatment method and water treatment apparatus which can obtain the reclaimed water which can be recycled by isolate | separating and removing the ionic component contained in to-be-processed water.

  In the water treatment method according to the present invention, an alkaline agent or an acid is injected into the water to be treated to adjust to an alkaline or acidic pH, and the treated liquid after this pH adjustment is passed through a reverse osmosis membrane into the treated water. The ionic component contained is separated, the treated water that has passed through the reverse osmosis membrane is allowed to flow into the ion exchange resin, and the ionic component remaining in the treated water is separated.

  In the water treatment method of the present invention, an alkaline agent or an acid is injected into the water to be treated to adjust the pH to either alkaline or acidic, and the water to be treated after the pH adjustment is subjected to the first reverse treatment. The ionic component contained in the water to be treated is separated through the osmosis membrane, and either the alkaline agent or the acid is injected into the treated water that has passed through the first reverse osmosis membrane to be either alkaline or acidic. The pH is adjusted, and after adjustment of the pH, it is allowed to flow as treated water for the second reverse osmosis membrane, the ionic components contained in the treated water are separated, and the treated water that has passed through the second reverse osmosis membrane is ion-exchanged. The ion component remaining in the treated water may be separated by flowing in the resin.

  Furthermore, in the water treatment method of the present invention, an oxidizing agent may be injected into the water to be treated, and cyan being treated may be decomposed into cyanic acid to improve the cyan separation performance by the reverse osmosis membrane.

  The water treatment apparatus according to the present invention includes a pH adjusting apparatus that adjusts to an arbitrary pH by injecting an alkaline agent or an acid into the water to be treated, and the water to be treated that has been adjusted by the pH adjusting apparatus into a reverse osmosis membrane. A reverse osmosis membrane device for separating ionic components contained in the water to be treated, and an ion exchange resin tower for separating the ionic components remaining in the treated water by flowing the treated water passing through the reverse osmosis membrane into the ion exchange resin It is characterized by comprising.

  Further, the water treatment apparatus of the present invention includes a first pH adjustment apparatus that adjusts pH to either alkaline or acidic by injecting an alkaline agent or acid into the water to be treated, and the first pH adjustment. A first reverse osmosis membrane device that separates ionic components contained in the water to be treated by passing the water to be treated whose pH is adjusted by the device through the reverse osmosis membrane, and the treated water that has passed through the first reverse osmosis membrane device. A second pH adjuster that injects either the alkaline agent or the acid to adjust the pH to either alkaline or acidic, and treated water that has been adjusted to pH by the second pH adjuster The second reverse osmosis membrane device that separates the ionic components contained in the water to be treated and the treated water that has passed through the second reverse osmosis membrane device are allowed to flow into the ion exchange resin. Disperse ionic components remaining in water It may be constituted by an ion exchange resin column to.

  In the water treatment apparatus of the present invention, an electric regeneration type ion exchange resin apparatus may be used instead of the ion exchange resin tower.

  Further, the water treatment apparatus of the present invention is provided with an oxidant injection apparatus that injects an oxidant into the water to be treated, decomposes cyan in the process into cyanic acid, and improves the cyan separation performance by the reverse osmosis membrane. May be.

  Further, the water treatment apparatus of the present invention is provided on the downstream side of the anion regeneration waste liquid discharge side of the ion exchange tower, in which an oxidizing agent is injected into the anion regeneration waste liquid, and cyan in the regeneration waste liquid is decomposed into cyanic acid. Alternatively, it may be configured to have an oxidant injection device that completely decomposes.

  Further, in the water treatment apparatus of the present invention, provided on the downstream side of the concentrated waste liquid discharge side of the electric regeneration type ion exchange resin apparatus, an oxidizing agent is injected into the concentrated waste liquid, and cyan in the concentrated waste liquid is decomposed into cyanic acid, or A configuration having an oxidant injection device for complete decomposition may be used.

  Moreover, in the water treatment apparatus of the present invention, an ozone waste liquid treatment apparatus may be provided instead of the oxidant injection apparatus, and ozone may be injected into the waste liquid.

  In this case, you may provide the evaporative concentrator which concentrates the waste liquid from an oxidant injection apparatus, and obtains distilled water in the downstream of an oxidant injection apparatus.

  Moreover, you may provide the granulation apparatus which dries or deposits a concentrated waste liquid and collect | recovers the ionic component in a concentrated waste liquid as solid on the concentration waste liquid discharge side of an evaporative concentrator.

  Furthermore, in the water treatment apparatus of the present invention, an activated carbon adsorption tower for removing organic components in the water to be treated may be provided upstream of the reverse osmosis membrane.

  According to the present invention, after adjusting the pH of the water to be treated to an alkaline or acidic state, the water to be treated is passed through a reverse osmosis membrane to separate ionic components in the water to be treated, and then further ion exchange Since residual ion components are separated by the resin, recyclable recycled water from which harmful components such as cyan are removed can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a basic system configuration diagram showing the first embodiment. In FIG. 1, waste liquid discharged from various processing facilities (not shown) is transferred to a pH adjusting device 1 and adjusted to an arbitrary pH by injection of a neutralizing agent such as an alkali agent or an acid. For example, when ammonia is contained in the waste liquid, the pH is adjusted from neutral to acidic. If the waste liquid contains cyan, the pH is adjusted from neutral to alkaline. As is well known, this utilizes the chemical characteristic that ammonia is stably held in an acidic liquid and cyan is stably held in an alkaline liquid.

  The treated water (waste liquid) adjusted in pH by the pH adjusting device 1 is transferred to a reverse osmosis membrane (hereinafter referred to as RO membrane) device 3 by a transfer pump 2. In the RO membrane device 3, ion components contained in the water to be treated are separated by the RO membrane and discharged as treated water. The separated ionic component is discharged out of the system as a concentrated waste liquid. The discharged concentrated waste liquid is returned to the upstream facility when there is an ion component processing facility in the upstream facility (not shown).

  The treated water from which the ion component has been separated by the RO membrane device 3 is sent to the ion exchange resin tower 5 by the transfer pump 4. As is well known, the ion exchange resin tower 5 is one in which an ion exchange resin is filled in a container, and a liquid is allowed to flow in the container so that the ion components in the liquid are adsorbed and separated by the ion exchange resin. When the amount of adsorption reaches the limit, the operation is temporarily stopped, and regenerative chemicals (alkaline agent and acid) are injected, washed, and regenerated. And after discharging | emitting a regeneration waste liquid, adsorption | suction of an ionic component is performed again.

  In this case, when the ion exchange resin towers 5 are connected in parallel in a plurality of stages and one of the ion exchange resin towers 5 is stopped for the above-described cleaning and regeneration, the other ion exchange resin tower 5 is put into an operation state. It is better to operate as follows. That is, if the ion exchange resin tower 5 is operated in a single unit, the waste liquid treatment cannot be performed at the time of regeneration of the ion exchange resin, and continuous operation cannot be performed. However, the ion exchange resin tower 5 is installed in a plurality of stages in parallel and operated alternately. Continuous processing of waste liquid becomes possible.

  The treatment with the ion exchange resin has high ion separation performance and can also produce pure water. Therefore, the treated water treated by the ion exchange resin tower 5 is regenerated as pure water and becomes reusable water.

  In this way, the pH of the water to be treated is adjusted by the pH adjusting device 1, the water to be treated after pH adjustment is flowed to the RO membrane device 3, the ionic components in the water to be treated are separated by the RO membrane, and the ion exchange resin Since the residual ion component is adsorbed and separated in the column 5, treated water substantially equivalent to pure water is obtained, and various reuses are possible.

  FIG. 2 is a basic system configuration diagram showing the second embodiment. In this embodiment, an electric regeneration type ion exchange resin device 6 is used instead of the ion exchange resin tower 5 shown in FIG. As shown in FIG. 3, this electric regeneration type ion exchange resin apparatus 6 is composed of a cation exchange membrane 61 and an anion exchange membrane 62, each having a central desalting chamber 63 and concentration chambers 64, 64 on both sides thereof. It is divided into rooms. A DC voltage having a corresponding polarity is applied to the cation exchange membrane 61 and the anion exchange membrane 62, and a mixed bed ion exchange resin 65 is filled in the central desalting chamber.

  In this electric regeneration type ion exchange resin device 6, the water to be treated flows into the central desalting chamber 63, where it remains in the liquid by the action of the ion exchange resin 65 and the ion exchange membranes 61 and 62. The ion component is adsorbed and separated and treated while being regenerated. That is, the ionic component in the liquid is first adsorbed by the ion exchange resin 65. The ion component adsorbed on the ion exchange resin 65 moves into the concentration chambers 64 and 64 on both sides by the ion exchange membranes 61 and 62 to which a voltage of a predetermined polarity is applied, and the ion exchange resin 65 is regenerated. That is, since the ion exchange resin 65 adsorbs the ion component in the liquid while being regenerated, the adsorption capacity is not limited. Accordingly, even if only one unit is used, continuous adsorption separation of ion components can be performed without stopping the operation for regeneration.

  In the configuration of FIG. 2, waste liquid discharged from various processing facilities is transferred to the pH adjusting device 1 and adjusted to alkaline or acidic pH by injection of a neutralizing agent such as an alkaline agent or an acid. The water to be treated whose pH is adjusted by the pH adjusting device 1 is transferred to the RO membrane device 3 by the transfer pump 2. In the RO membrane device 3, ion components contained in the water to be treated are separated by the RO membrane and discharged as treated water.

  The treated water from which the ion component has been separated by the RO membrane device 3 is sent to the desalting chamber 63 of the electric regeneration type ion exchange resin device 6 by a transfer pump. As described above, the electric regeneration type ion exchange resin device 6 adsorbs and separates ion components in the liquid while regenerating the ion exchange resin 65. The waste liquid from which the ionic component has been separated is discharged out of the system from the concentration chambers 64, 64 on both sides, or is returned to the upstream facility when there is an ionic component processing facility in the upstream facility (not shown).

  In this way, the pH of the water to be treated is adjusted by the pH adjusting device 1, the water to be treated after pH adjustment is flowed to the RO membrane device 3, the ionic components in the water to be treated are separated by the RO membrane, and further the electric regeneration type Since the residual ion component is adsorbed and separated by the ion exchange resin apparatus 6, treated water substantially equivalent to pure water is obtained, and various reuses are possible.

  In addition, the use of the electric regeneration type ion exchange resin apparatus 6 eliminates the need to stop the operation for regenerating the ion exchange resin, and enables one unit to perform continuous treatment for 24 hours. That is, since it is not necessary to stop the operation for regenerating the ion exchange resin, it is not necessary to provide a spare machine for the operation stop and perform the alternate operation, and the equipment can be made compact. Further, since no chemicals are used for ion exchange resin regeneration, generation of secondary waste is eliminated.

  FIG. 4 shows an embodiment in which the pH adjusting device and the RO membrane device are provided in two stages. The treatment liquid discharged from the RO membrane device 3 provided in the previous stage (referred to as the first RO membrane device) is sent to the newly provided second pH adjusting device 7 where the alkali solution and the acid are used. It is adjusted to an arbitrary pH and sent to the second RO membrane device 8 by the transfer pump 4. Although not shown in the figure, the pH adjusting device (referred to as the first pH adjusting device) 1 is provided in the previous stage of the first RO membrane device 3 as shown in FIGS. Further, although not shown, the ion exchange resin tower 5 shown in FIG. 1 or the electric regeneration type ion exchange resin device 6 shown in FIG. 2 is connected to the subsequent stage of the second RO membrane device 8. .

  As described above, the reason why the pH adjusting device and the RO membrane device are provided in two stages is to separate each of the substances to be separated when the water to be treated coexists with different properties. For example, when ammonia and cyanide coexist in the water to be treated (waste liquid), the pH adjusting device (first pH adjusting device) 1 shown in FIG. The pH of the solution is adjusted to acidic and ammonia is retained in the water to be treated. The water to be treated (waste liquid) whose pH is adjusted to acidic is transferred to the first RO membrane device 3, and the ionic component (ammonia) is separated and discharged by the RO membrane.

  The treated water discharged from the first RO membrane device 3 is injected with an alkaline agent as a neutralizing agent by the second pH adjusting device 7 shown in FIG. 4 to adjust the pH to alkaline. This keeps cyan stable in water. After the pH is adjusted to be alkaline by the second pH adjusting device 7 as described above, it is transferred to the second RO membrane device 8 as water to be treated, and the ionic component (cyan) is separated and discharged by the RO membrane. .

  The treated water from which the ion component has been separated by the second RO membrane device 8 is sent to the ion exchange resin tower 5 or the electric regeneration type ion exchange resin device 6, and the ion component remaining in the treated water is adsorbed and separated. .

  As described above, ammonia is separated by the first RO membrane device 3 and cyan is separately separated by the second RO membrane device 8, and the separation performance can be improved. Furthermore, since the remaining ionic components are adsorbed and separated by the ion exchange resin tower 5 or the electric regeneration type ion exchange resin device 6, it is possible to effectively separate the water to be treated in which components having different properties coexist. And treated water equivalent to pure water can be obtained and reused in various directions.

  FIG. 5 shows an embodiment in which an oxidant injection device is provided and cyan is decomposed in advance. In this embodiment, an oxidant injection device 9 is provided upstream of the first pH adjustment device 1. For this reason, the waste liquid is first transferred to the oxidant injection device 9, and cyan in the waste liquid is decomposed into cyanic acid or completely decomposed by the injection of the oxidant. Thereafter, the pH is adjusted through the pH adjusting device 1 as in the previous embodiments, and then the ion component is separated by the RO membrane device 3.

  With this configuration, the waste liquid (treated water) is preliminarily injected with an oxidizing agent, so that cyan in the treated water is decomposed, so that the separation performance of ion components by the RO membrane device 3 is improved. Cyanide contained in the water to be treated can be separated efficiently.

  FIG. 6 shows an embodiment relating to the treatment of the regenerated waste liquid discharged from the ion exchange resin tower 5 shown in FIG. In this embodiment, the oxidant injection device 10 is provided in the conduit of the anion regeneration waste liquid discharged from the ion exchange resin tower 5.

As described above, the ion exchange resin in the ion exchange resin tower 5 adsorbs and separates ion components from the liquid to be treated. However, once the adsorption amount reaches the limit, the operation is stopped, and a regenerative chemical is injected and washed. Let it play. At that time, the recycled waste liquid is discharged. The anion regeneration waste liquid discharged from the ion exchange resin tower 5 is transferred to the oxidant injection device 10 where an oxidant such as Cl ₂ or hydrogen peroxide water is injected and mixed. By this oxidant injection, cyanide in the anion regeneration waste liquid is decomposed into cyanic acid or completely decomposed. After the cyan is decomposed in this way, it is discharged as a waste liquid not containing cyan to the outside of the system or in a form that can be easily separated and recovered by a subsequent processing apparatus (not shown). In this case, since the anion regeneration waste liquid does not contain a substance that interferes with the oxidative decomposition of cyanide, the decomposition efficiency of cyan is improved.

  FIG. 7 shows an embodiment relating to the treatment of the concentrated waste liquid discharged from the electric regeneration type ion exchange resin device 6 shown in FIG. In this embodiment, the oxidizing agent injection device 11 is provided in the conduit of the concentrated waste liquid discharged from the electric regeneration type ion exchange resin device 6.

  In the electric regeneration type ion exchange resin device 6, as described in FIG. 3, the water to be treated flows into the central desalting chamber 63, where the ion exchange resin 65 and the ion exchange membranes 61 and 62 function, The ion component remaining in the inside is adsorbed / separated and treated while being regenerated. The ion component adsorbed on the ion exchange resin 65 moves into the concentration chambers 64 and 64 on both sides by the ion exchange membranes 61 and 62 to which a voltage of a predetermined polarity is applied, and the ion exchange resin 65 is regenerated. This recycled waste liquid is circulated, concentrated and discharged.

The concentrated waste liquid discharged from the electric regeneration type ion exchange resin device 6 in this way is transferred to the oxidant injection device 11 where an oxidant such as Cl ₂ or hydrogen peroxide solution is injected and mixed. By this oxidant injection, cyanide in the concentrated waste liquid is decomposed into cyanic acid or completely decomposed. After the cyan is decomposed in this way, it is discharged as a waste liquid not containing cyan to the outside of the system or in a form that can be easily separated and recovered by a subsequent processing apparatus (not shown).

  FIG. 8 shows an embodiment in which an ozone waste liquid treatment device 12 is provided in place of the oxidizer injection devices 10 and 11 shown in FIGS. FIG. 8 shows the case where the ozone waste liquid treatment device 12 is provided in the conduit of the concentrated waste liquid discharged from the electric regeneration type ion exchange resin device 6, but it is discharged from the ion exchange resin tower 5 shown in FIG. The ozone waste liquid treatment device 12 may be provided in the pipe of the anion regeneration waste liquid.

  With this configuration, ozone is injected into the concentrated waste liquid discharged from the electric regeneration type ion exchange resin device 6 and the anion regeneration waste liquid discharged from the ion exchange resin tower 5. By injecting ozone in this way, cyanide in the waste liquid is decomposed into cyanic acid or completely decomposed. After the cyan is decomposed in this way, it is discharged as waste liquid not containing cyan to the outside of the system or in a form that can be easily separated and recovered by a subsequent processing apparatus (not shown). In addition, ozone becomes oxygen after oxidative decomposition, leaving no residue such as salt. Therefore, the amount of waste liquid generated can be reduced.

  FIG. 9 shows an embodiment relating to the concentration treatment of the treated water after the oxidant is injected into the regenerated waste liquid. In this embodiment, the evaporative concentrator 13 is provided in the pipe of the processing liquid discharged from the oxidant injection device 10 shown in FIG. Needless to say, the evaporative concentrator 13 may be provided in the pipe of the treatment liquid discharged from the oxidant injection device 11 shown in FIG.

  In this case, the oxidant injection device 10 (or 11) discharges treated water in which cyan is decomposed by the oxidant injection. This treated water is transferred to the evaporation concentrator 13 and separated into clean distilled water and concentrated waste liquid by heating. Since distilled water does not contain harmful components, it can be reused or released to the environment.

  On the other hand, the concentrated waste liquid may be discharged out of the system as waste, or may be transferred to the granulator 14 as shown. In this case, the concentrated waste liquid discharged from the evaporation concentrator 13 is concentrated again by the granulator 14. As a result, the deposited salt is discharged out of the system as solid waste. This reduces the volume of waste and reduces emissions.

  FIG. 10 shows an embodiment in which an activated carbon adsorption tower 15 is provided in the previous stage of the pH adjusting device 1 shown in FIGS. 1 and 2. With this configuration, the water to be treated (waste liquid) is first transferred to the activated carbon adsorption tower 15, and the organic components contained in the waste liquid are separated and removed by the activated carbon. Thereafter, the water to be treated is transferred to the pH adjusting device 1 and the same treatment as in each of the above embodiments is performed.

  Here, the organic component in the waste liquid may contain harmful substances and may cause problems in the subsequent RO membrane device 3 and the like. The trouble can be solved.

It is a block diagram which shows one Embodiment of the water treatment apparatus by this invention. It is a block diagram which shows embodiment using the electric regeneration type ion exchange resin apparatus instead of the ion exchange resin tower in one embodiment same as the above. It is operation | movement principle explanatory drawing of the electric regeneration type ion exchange resin apparatus used for this invention. It is a fragmentary figure which shows embodiment which provided the pH adjustment apparatus and RO membrane apparatus of this invention in 2 steps | paragraphs. It is a fragmentary figure which shows embodiment which provided the oxidizing agent injection | pouring apparatus in the front | former stage of the pH adjustment apparatus of this invention. It is a fragmentary figure which shows embodiment which processes the waste liquid of regeneration of an ion exchange resin tower | column of this invention by oxidizing agent injection | pouring. It is a fragmentary figure which shows embodiment which processes the waste liquid for regeneration of an electric regeneration type | mold ion exchange resin apparatus of this invention by oxidizing agent injection | pouring. It is a fragmentary figure which shows embodiment which processes the reproduction | regeneration waste liquid of this invention by ozone injection | pouring. The regeneration of the present invention is a partial view showing an embodiment in which a treatment liquid discharged from an oxidant injection device for gastric juice is concentrated. It is a fragmentary figure which shows embodiment which provided activated carbon adsorption etc. in the front | former stage of the pH adjustment apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st pH adjustment apparatus 3 1st reverse osmosis membrane (RO membrane) apparatus 5 Ion exchange resin tower 6 Electric regeneration type ion exchange resin apparatus 7 2nd pH adjustment apparatus 8 2nd reverse osmosis membrane (RO membrane) Device 9, 10, 11 Oxidant injection device 12 Ozone waste liquid treatment device 13 Evaporation concentrator 14 Granulator

Claims (13)

  An ionic component contained in the water to be treated by injecting an alkaline agent or acid into the water to be treated to adjust the pH to either alkaline or acidic, and passing the liquid to be treated after the pH adjustment through a reverse osmosis membrane. The water treatment method is characterized by separating the ionic components remaining in the treated water by flowing the treated water that has passed through the reverse osmosis membrane into the ion exchange resin.   An alkaline agent or acid is injected into the water to be treated to adjust the pH to either alkaline or acidic, and the water to be treated after pH adjustment is passed through the first reverse osmosis membrane and contained in the water to be treated. The ionic components are separated, and either the alkaline agent or the acid is injected into the treated water that has passed through the first reverse osmosis membrane to adjust the pH to either alkaline or acidic, and after this pH adjustment, The ionic component contained in the water to be treated is separated and the treated water that has passed through the second reverse osmosis membrane is caused to flow into the ion exchange resin and remains in the treated water. A water treatment method characterized by separating ionic components.   The water according to claim 1 or 2, wherein an oxidant is injected into the water to be treated to decompose cyan being treated into cyanic acid, thereby improving the cyan separation performance by the reverse osmosis membrane. Processing method. A pH adjuster for injecting an alkaline agent or acid into the water to be treated to adjust the pH to either alkaline or acidic;
A reverse osmosis membrane device that separates ionic components contained in the water to be treated by passing the water to be treated pH-adjusted by the pH adjusting device through the reverse osmosis membrane;
An ion exchange resin tower for flowing treated water that has passed through the reverse osmosis membrane into the ion exchange resin and separating ion components remaining in the treated water;
A water treatment apparatus comprising: A first pH adjusting device for injecting an alkaline agent or acid into the water to be treated to adjust the pH to either alkaline or acidic;
A first reverse osmosis membrane device that separates ionic components contained in the water to be treated by passing the water to be treated, which has been adjusted by the first pH adjusting device, through the reverse osmosis membrane;
A second pH adjuster that adjusts the pH to either alkaline or acidic by injecting either the alkaline agent or the acid into the treated water that has passed through the first reverse osmosis membrane device;
A second reverse osmosis membrane device for flowing the treated water pH-adjusted by the second pH adjusting device to the reverse osmosis membrane as treated water and separating the ionic components contained in the treated water;
An ion exchange resin tower for flowing treated water that has passed through the second reverse osmosis membrane device into the ion exchange resin and separating ion components remaining in the treated water;
A water treatment apparatus comprising:   6. The water treatment apparatus according to claim 4, wherein an electric regeneration type ion exchange resin apparatus is used in place of the ion exchange resin tower.   5. An oxidant injection device is provided for injecting an oxidant into water to be treated, decomposing cyan being treated into cyanic acid, and improving cyan separation performance by a reverse osmosis membrane. The water treatment apparatus according to claim 6.   An oxidizer injection device that is installed downstream of the anion regeneration waste liquid discharge side of the ion exchange tower and injects an oxidant into the anion regeneration waste liquid and decomposes cyanide in the regeneration waste liquid into cyanic acid or completely decomposes it. The water treatment apparatus according to claim 4 or 5, characterized by having.   Provided on the downstream side of the concentrated waste liquid discharge side of the electric regeneration type ion exchange resin device, and has an oxidizer injection device that injects oxidant into the concentrated waste liquid and decomposes cyanide in the concentrated waste liquid into cyanic acid or completely decomposes it. The water treatment apparatus according to claim 6.   The water treatment apparatus according to claim 8 or 9, wherein an ozone waste liquid treatment apparatus is provided in place of the oxidant injection apparatus, and ozone is injected into the waste liquid.   10. The water treatment apparatus according to claim 8, further comprising an evaporation concentrator provided on a downstream side of the oxidant injection device and concentrating a waste liquid from the oxidant injection device to obtain distilled water. 11.   The water treatment according to claim 11, further comprising a granulation device provided on the concentrated waste liquid discharge side of the evaporative concentrator, and drying or precipitating the concentrated waste liquid to recover an ionic component in the concentrated waste liquid as a solid. apparatus.   The water treatment apparatus according to claim 4 or 5, further comprising an activated carbon adsorption tower provided on the upstream side of the reverse osmosis membrane to remove organic components in the water to be treated.

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