WO2020012786A1

WO2020012786A1 - Water treatment device and water treatment method

Info

Publication number: WO2020012786A1
Application number: PCT/JP2019/020573
Authority: WO
Inventors: 明広高田; 圭一郎福水
Original assignee: オルガノ株式会社
Priority date: 2018-07-09
Filing date: 2019-05-24
Publication date: 2020-01-16

Abstract

Provided are a water treatment device and a water treatment method for treating polymeric-organic-matter-containing water, the device and method being capable of suppressing fouling of a membrane and being capable of operating in a stable manner. A water treatment device 1 for treating polymeric-organic-matter-containing water that contains polymeric organic matter, wherein the water treatment device 1 comprises: a water tank 10 for retaining the polymeric-organic-matter-containing water; a raw water tank 12 for retaining the polymeric-organic-matter-containing water from the water tank 10; an ozone treatment device 22, which is a peroxide-adding means for adding peroxide while circulating water in the raw water tank 12; a membrane filtration device 14 for performing a membrane filtration treatment on the water in the raw water tank 12; a concentrated-water-returning means for returning at least some of concentrated water obtained in the membrane filtration treatment to the raw water tank 12; an activated carbon treatment device 18, which is a peroxide-decomposing means for performing a decomposition treatment on peroxide in membrane-filtered water obtained in the membrane filtration treatment; and a treated-water-returning means for returning at least some of treated water that was subjected to the decomposition treatment by the activated carbon treatment device 18 to the water tank 10.

Description

Water treatment device and water treatment method

The present invention provides a water treatment apparatus and a water treatment method for treating polymer organic substance-containing water containing polymer organic substances such as proteins, or removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen. The present invention relates to a water treatment device and a water treatment method.

連続 When the membrane filtration is continuously operated, a phenomenon (fouling) occurs in which the surface of the membrane is contaminated and pores of the membrane are blocked. As a method of suppressing this fouling or a method of cleaning the film, a method of backflowing an aqueous solution of sodium hypochlorite from the secondary side to the primary side of the film is generally used. As a method for further improving the cleaning property of the membrane, a method of cleaning the membrane by flowing back water containing chlorine from the secondary side of the membrane and holding the water for a predetermined time (see Patent Document 1), And a method using microbubbles of nanobubbles (see Patent Document 2).

However, there is a case where the above method does not sufficiently suppress the fouling. In particular, when attempting to perform membrane filtration of water containing high-molecular organic matter such as protein, such as cultivation water for aquaculture and aquariums, the high-molecular-weight organic matter such as protein may promote fouling. is there.

にも Fouling may also occur due to the proliferation of bacteria that inhabit the seawater and organic matter in the seawater, even when attempting to remove suspended substances in the seawater using an ultrafiltration membrane or a microfiltration membrane.

窒素 Especially, when trying to treat seawater containing nitrogen compounds such as ammonia, such as in aquaculture or aquariums, nitrogen may become a nutrient source for bacteria and promote fouling.

Also, when trying to remove suspended matter in seawater containing nitrogen compounds such as ammonia such as in aquaculture or aquariums using ultrafiltration membranes or microfiltration membranes, if the concentration of ammonia in seawater increases, the water itself will Since it is toxic to fish and the like, it is desirable to remove ammonia nitrogen. As a countermeasure, biological treatment is generally used, but the entire system becomes large-scale and a large installation space is required.

When fouling occurs, the pressure inside the membrane module rises rapidly, and there is a possibility that stable membrane processing cannot be performed. Furthermore, once a membrane has been fouled, it is necessary to perform chemical cleaning using an acid or alkali, and the cost and equipment area, such as maintenance costs for cleaning and installation of a spare line in anticipation of equipment shutdown, etc. Causes swelling.

方法 In the method of Patent Document 1, an aqueous solution of sodium hypochlorite is used to suppress fouling of the film. However, the cost of chemicals required for cleaning the film and the trouble of replenishing chemicals are required. In addition, since a backflow step and an immersion step are required, it is necessary to stop the membrane filtration step.

As a method for removing suspended substances and ammonia nitrogen in halide ion-containing water containing halide ions and ammonia nitrogen while suppressing fouling of the film, peroxidation is performed by treating the halide ion-containing water with ozone. There is a method of filtering a peroxide-containing water that has generated a substance and generated a peroxide using an ultrafiltration membrane or a microfiltration membrane (see Patent Document 3).

では In the method of Patent Document 3, if the amount of generated peroxide is small, fouling of the film occurs, and stable film processing may not be performed. Further, there is no description that the film is recovered by adjusting the amount of peroxide injected to the film in which fouling has once occurred.

In the method of Patent Document 3, there is no means for confirming that ammonia nitrogen has been sufficiently removed. For example, when the quality of raw water changes, the removal of ammonia nitrogen becomes insufficient and a stable ammonia Nitrogen treatment cannot be performed.

JP-A-10-015365 JP 2010-253457 A Japanese Patent No. 6251095

目的 An object of the present invention is to provide a water treatment apparatus and a water treatment method for treating high-molecular-organic-content-containing water, which can suppress fouling of the membrane and can operate stably.

の An object of the present invention is to provide a water treatment apparatus and a water treatment method capable of performing stable membrane treatment of halide ion-containing water containing halide ions and ammonium nitrogen.

Another object of the present invention is to provide a water treatment apparatus and a water treatment method capable of performing stable treatment of ammonia nitrogen with respect to halide ion-containing water containing halide ions and ammonia nitrogen.

The present invention relates to a water treatment apparatus for treating high-molecular organic substance-containing water containing high-molecular organic substances, and a water tank for storing the high-molecular organic substance-containing water, and a raw water tank for storing the high-molecular organic substance-containing water from the water tank. A peroxide adding means for adding a peroxide while circulating the water in the raw water tank, a membrane filtration means for performing a membrane filtration treatment on the water in the raw water tank, and a membrane filtration treatment by the membrane filtration means. A concentrated water returning means for returning at least a part of the concentrated water to the raw water tank; a peroxide decomposing means for decomposing a peroxide of the membrane filtration water obtained by the membrane filtration treatment by the membrane filtration means; A treated water returning means for returning at least a part of the treated water decomposed by the oxide decomposing means to the water tank.

The present invention relates to a water treatment apparatus for treating high-molecular organic substance-containing water containing high-molecular organic substances, and a water tank for storing the high-molecular organic substance-containing water, and a raw water tank for storing the high-molecular organic substance-containing water from the water tank. And membrane filtration means for performing membrane filtration of water in the raw water tank, peroxide addition means for adding peroxide to concentrated water obtained by membrane filtration treatment by the membrane filtration means, and the peroxide addition means A peroxide-containing water returning means for returning at least a part of the peroxide-containing water obtained by the above to the raw water tank, and decomposing the peroxide of the membrane filtration water obtained by the membrane filtration treatment by the membrane filtration means. A water treatment apparatus comprising: a peroxide decomposing means; and a treated water returning means for returning at least a part of the treated water decomposed by the peroxide decomposing means to the water tank.

において In the water treatment apparatus, it is preferable that the peroxide adding unit is a unit using ozone.

The present invention relates to a water treatment apparatus for removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen, and a peroxide generating means for generating peroxide in the halide ion-containing water. A membrane filtration means for filtering the peroxide-containing water having generated the peroxide using an ultrafiltration membrane or a microfiltration membrane, and a peroxide for decomposing the peroxide at a stage subsequent to the membrane filtration means. An oxide decomposition means, and a return means for returning at least a part of the treated water decomposed by the peroxide decomposition means and adding the treated water to the halogen compound ion-containing water, wherein the ultrafiltration membrane or the precision A water treatment apparatus for adjusting an amount of generation of the peroxide based on a behavior of a transmembrane pressure difference of a filtration membrane.

It is preferable that the water treatment apparatus further includes a control unit that monitors the transmembrane pressure difference and controls the generation amount of the peroxide.

The present invention relates to a water treatment apparatus for removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen, and a peroxide generating means for generating peroxide in the halide ion-containing water. A membrane filtration means for filtering the peroxide-containing water having generated the peroxide using an ultrafiltration membrane or a microfiltration membrane, and a peroxide for decomposing the peroxide at a stage subsequent to the membrane filtration means. An oxide decomposing means, a return means for returning at least a part of the treated water decomposed by the peroxide decomposing means and adding the treated water to the halogen compound ion-containing water; An oxide concentration measuring means, and controlling the amount of the peroxide generated by the peroxide generating means based on the measurement value of the residual oxide concentration measuring means, Performing a breakpoint processing of the serial ammonia nitrogen, a water treatment device.

において In the water treatment apparatus, it is preferable that the residual oxide concentration measuring means can measure the total halogen amount and the free halogen amount, respectively.

In the water treatment apparatus, the peroxide generation means may adjust the difference between the total halogen amount and the free halogen amount measured by the residual oxide concentration measuring means to be within 20% of the total halogen amount. It is preferable to control the amount of oxide generated.

において In the water treatment apparatus, it is preferable that the peroxide generating means is an ozone generating means.

The present invention is a water treatment method for treating high-molecular organic substance-containing water containing high-molecular organic substances, wherein the high-molecular organic substance-containing water sent from the water tank to the raw water tank is circulated to the raw water tank to remove peroxide. A peroxide addition step to be added, a membrane filtration step of performing membrane filtration of water in the raw water tank, and a concentrated water returning at least a part of the concentrated water obtained by the membrane filtration processing in the membrane filtration step to the raw water tank. A return step, a peroxide decomposition step of decomposing the peroxide of the membrane filtration water obtained by the membrane filtration treatment in the membrane filtration step, and at least a part of the treated water decomposed by the peroxide decomposition step. A process of returning treated water to the water tank.

The present invention is a water treatment method for treating high-molecular-weight organic-containing water containing high-molecular-weight organic matter, and a membrane-filtration step of membrane-filtering high-molecular-weight organic-containing water sent from a water tank to a raw water tank; and A peroxide addition step of adding peroxide to the concentrated water obtained by the membrane filtration treatment by the filtration step, and at least a part of the peroxide-containing water obtained by the peroxide addition step is returned to the raw water tank. A peroxide-containing water returning step, a peroxide decomposition step of decomposing the peroxide of the membrane filtration water obtained by the membrane filtration treatment in the membrane filtration step, and treated water decomposed by the peroxide decomposition step A process of returning at least a part of the water to the water tank.

において In the water treatment method, it is preferable that the peroxide adding step is a step using ozone.

Further, the present invention is a water treatment method for removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen, wherein the peroxide is generated in the halide ion-containing water. A generating step, a membrane filtration step of filtering the peroxide-containing water that has generated the peroxide using an ultrafiltration membrane or a microfiltration membrane, and a decomposition treatment of the peroxide at a later stage of the membrane filtration step. A peroxide decomposition step, and a return step of returning at least a part of the treated water decomposed in the peroxide decomposition step and adding it to the halogen compound ion-containing water, the ultrafiltration membrane or A water treatment method, wherein the amount of generated peroxide is adjusted based on the behavior of the transmembrane pressure difference of the microfiltration membrane.

において In the water treatment method, it is preferable that the transmembrane pressure difference is monitored to control the generation amount of the peroxide.

Further, the present invention is a water treatment method for removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen, wherein the peroxide is generated in the halide ion-containing water. A generating step, a membrane filtration step of filtering the peroxide-containing water that has generated the peroxide using an ultrafiltration membrane or a microfiltration membrane, and a decomposition treatment of the peroxide at a later stage of the membrane filtration step. A peroxide decomposing step, a returning step of returning at least a part of the treated water decomposed in the peroxide decomposing step and adding the treated water to the halogen compound ion-containing water, and a step preceding the peroxide decomposing step. A residual oxide concentration measuring step, and based on the measured value of the residual oxide concentration measuring step, controlling the amount of the peroxide generated in the peroxide generating step, Performing a breakpoint processing of the ammonia nitrogen by oxides, water treatment process.

In the water treatment method, it is preferable to measure the total halogen amount and the free halogen amount in the residual oxide concentration measuring step.

In the water treatment method, the peroxide in the peroxide generation step may be such that a difference between the total halogen amount and the free halogen amount measured in the residual oxide concentration measuring step is within 20% of the total halogen amount. It is preferable to control the amount of oxide generated.

において In the water treatment method, the peroxide generation step is preferably an ozone generation step.

According to the present invention, it is possible to provide a water treatment apparatus and a water treatment method for treating high-molecular-organic-content-containing water, which can suppress fouling of the membrane and can operate stably.

According to the present invention, stable membrane treatment can be performed on halide ion-containing water containing halide ions and ammonium nitrogen.

According to the present invention, stable treatment of ammonia nitrogen can be performed on halide ion-containing water containing halide ions and ammonia nitrogen.

It is a schematic structure figure showing an example of a water treatment device concerning an embodiment of the present invention. It is a schematic structure figure showing other examples of a water treatment device concerning an embodiment of the present invention. It is a schematic structure figure showing other examples of a water treatment device concerning an embodiment of the present invention. It is a schematic structure figure showing other examples of a water treatment device concerning an embodiment of the present invention. It is a schematic structure figure showing other examples of a water treatment device concerning an embodiment of the present invention. It is a schematic structure figure showing other examples of a water treatment device concerning an embodiment of the present invention. It is a figure which shows the LC-OCD measurement result of the breeding water which raised the flounder. 4 is a graph showing the transmembrane pressure with respect to the elapsed days in Example 1 and Comparative Example 1. 9 is a graph showing the transmembrane pressure with respect to the elapsed days in Example 2 and Comparative Example 2. 11 is a graph showing the transmembrane pressure when the amount of injected ozone in Example 3 is changed. It is a graph which shows the break point of ammonia.

(4) An embodiment of the present invention will be described below. The present embodiment is an example for implementing the present invention, and the present invention is not limited to the present embodiment.

概略 An outline of an example of a water treatment apparatus according to an embodiment of the present invention is shown in FIG. 1 and its configuration will be described.

The water treatment apparatus 1 adds a peroxide while circulating the water in the raw water tank 12, a water tank 10 for storing the high molecular organic substance-containing water, a raw water tank 12 for storing the high molecular organic substance-containing water from the water tank 10. An ozone treatment device 22 having an ozone generator 24 is provided as a peroxide addition device, and a membrane filtration device 14 is provided as a membrane filtration device for performing membrane filtration of water in the raw water tank 12. An activated carbon treatment device 18 is provided as a peroxide decomposition means for decomposing the peroxide of the membrane filtration water to be obtained. The water treatment device 1 may include a membrane filtration tank 16 and a treatment tank 20.

1, the outlet of the water tank 10 and the raw water inlet of the raw water tank 12 are connected by a pipe 40 via a pump 26 and a strainer 38, and the outlet of the raw water tank 12 and the inlet of the membrane filtration device 14 are connected. The outlet of the membrane filtration device 14 and the inlet of the membrane filtration water tank 16 are connected by a pipe 44, and the outlet of the membrane filtration water tank 16 and the outlet of the activated carbon treatment device 18 are connected by a pipe 42 via a pump 28. Of the activated carbon treatment device 18 and the inlet of the treated water tank 20 are connected by a pipe 48, and the treated water outlet of the treated water tank 20 and the water tank 10 are connected to the pump 32. It is connected by a treated water return pipe 50 via the same. The backwash water outlet of the treatment water tank 20 and the backwash water inlet on the secondary side of the membrane filtration device 14 are connected by a pipe 58 via the pump 34. A concentrated water outlet on the primary side of the membrane filtration device 14 and a concentrated water inlet of the raw water tank 12 are connected by a concentrated water return pipe 56. A pipe 66 is connected to a concentrated water outlet of the membrane filtration device 14.

The circulating water outlet of the raw water tank 12 and the circulating water inlet of the ozone treatment device 22 are connected by a circulation pipe 52, and the circulating water outlet of the ozone treatment device 22 and the circulating water inlet of the raw water tank 12 are connected by a circulation pipe 54. I have. The ozone generator 24 is connected to the lower part of the ozone treatment device 22 by a pipe 60.

動作 The operation of the water treatment method and the water treatment device 1 according to the present embodiment will be described.

水中 Underwater creatures such as fish are raised in the aquarium 10 in the breeding water. The breeding water usually contains high-molecular-weight organic substances such as proteins, suspended substances, and the like accompanying breeding of aquatic organisms. The breeding water in the water tank 10, that is, water containing high molecular organic matter including high molecular organic matter and the like is sent to the raw water tank 12 through the pipe 40 by the pump 26. If necessary, a strainer 38 may be provided in the middle of the pipe 40 to remove relatively large solids in the high-molecular-weight-organic-material-containing water.

一部 A part of the high-molecular-organic-content-containing water in the raw water tank 12 is sent to the ozone treatment device 22 through the circulation pipe 52. Ozone generated by the ozone generator 24 is supplied to the ozone treatment device 22 through a pipe 60. In the ozone treatment device 22, a circulation process (here, mainly a decomposition process of the organic substance) of the organic substance in the high-molecular organic substance-containing water is performed by the ozone. Further, in the ozone treatment apparatus 22, the concentrated suspended substance and the like are separated into solid and liquid by pressurized levitation using ozone. The ozone-treated water subjected to the organic matter treatment is circulated to the raw water tank 12 through the circulation pipe 54. That is, peroxide is added while circulating the high-molecular-organic-content-containing water sent from the water tank 10 to the raw water tank 12 to the raw water tank 12 (peroxide adding step). The exhausted ozone may be exhausted through the pipe 62 and processed by an ozone removing device. Scum and the like generated in the ozone treatment device 22 may be discharged through the pipe 64.

On the other hand, the raw water in the raw water tank 12 is sent to the membrane filtration device 14 through the pipe 42 by the pump 28. In the membrane filtration device 14, the remaining suspended substances and the like in the raw water are removed by filtration using a membrane (membrane filtration step). At least a part of the concentrated water obtained in the membrane filtration step is returned to the raw water tank 12 through the concentrated water return pipe 56 (a concentrated water return step). The concentrated water return pipe 56 and the like function as concentrated water returning means for returning at least a part of the concentrated water to the raw water tank 12. By returning the concentrated water to the raw water tank 12, the concentration of the suspended solids increases, and the efficiency of pressurized floating in the ozone treatment device 22 can be increased.

膜 The membrane filtered water that has been subjected to membrane filtration is stored in the membrane filtration tank 16 as necessary through the pipe 44, and then supplied to the activated carbon treatment device 18 through the pipe 46 by the pump 30. In the activated carbon treatment device 18, peroxide such as residual ozone in the membrane filtration water is decomposed by activated carbon (peroxide decomposition step).

The treated water in which peroxides such as residual ozone are decomposed is stored in a treated water tank 20 as necessary through a pipe 48, and then at least a part of the treated water is passed through a treated water return pipe 50 by a pump 32 through a water tank 10. And may be reused, for example, as breeding water (processed water return step). The pump 32 and the treated water return pipe 50 function as treated water returning means for returning at least a part of the treated water to the water tank 10. By returning the treated water to the water tank 10 for reuse, it is possible to reduce the cost for makeup water and drainage.

When the membrane filtration device 14 needs to be washed, a part of the treated water is back-flushed from the treated water tank 20 through the pipe 58 by the pump 34 from the secondary side of the membrane filtration device 14 to the primary side as backwash water. Alternatively, the membrane may be washed (backwash step). The backwash drainage is discharged through a pipe 66. The membrane filtration water in the membrane filtration tank 16 may be used as the backwash water.

In the water treatment apparatus 1 according to the present embodiment, the high-molecular-weight-organic-material-containing water is stored in the raw water tank 12, the water in the raw water tank 12 is circulated to perform organic matter treatment, and the water in the raw water tank 12 is subjected to membrane filtration. Further, it is possible to suppress the fouling of the membrane due to a high molecular organic substance, a living organism, or the like, and to perform a stable operation of the membrane filtration device 14. By circulating the water in the raw water tank and performing the organic matter treatment, the organic matter can be efficiently decomposed by the multi-stage treatment. During the backwashing step, the organic material may be circulated or stopped.

High molecular organic substances are organic substances having a weight average molecular weight in the range of 100,000 to 2,000,000. The weight-average molecular weight can be determined by a wet oxidation method using LC-OCD (Liquid Chromatography-Organic Carbon Carbon Detection) device (manufactured by DOC-LABOR, mobile 12007) as a method for grasping the components of organic substances contained in the wastewater. HW50S). LC-OCD is a method of dividing an organic substance for each molecular weight and measuring the organic substance concentration of each component. As an example of the measurement of LC-OCD, FIG. 7 shows the results of analysis of the breeding water for flounder. The LC-OCD spectrum shown in FIG. 7 indicates that the shorter the retention time (RT: Retention time) [min] on the horizontal axis, the larger the molecular weight of the organic substance is, but the retention time (RT) is detected around 26 to 34 min. The peak indicated is a high molecular weight organic substance such as a protein having a weight average molecular weight in the range of 100,000 to 2,000,000.

Ozone microbubbles are, for example, fine ozone-containing bubbles containing ozone having a diameter of about 10 μm to 100 μm. An ozone treatment device using ozone microbubbles causes the suspended substance to be hydrophobically adsorbed and floated on the surface of ozone microbubbles, which are microbubbles containing ozone, with respect to water containing high molecular organic substances including high molecular organic substances and suspended substances. In addition to the separation and removal, the effect of oxidizing organic substances by the ozone microbubbles is obtained. In addition, by using ozone as microbubbles, the ozone microbubbles can be held in the tank of the ozone treatment device 22 for a long time, so that the reaction time with organic substances increases, and the processing effect of organic substances increases dramatically. Conceivable.

If the concentration of residual ozone in the membrane filtration water is high and it is feared that it will be returned to the water tank 10 and affect the breeding of living organisms, etc. Preferably, means are provided. By providing the peroxide decomposing means at the subsequent stage of the membrane filtration device 14, the effect of peroxides such as residual ozone on the breeding of living organisms can be reduced. For this reason, when the raw water is breeding water for aquaculture, aquariums, or the like, even if the treated water is returned to the aquarium 10, the effect on living organisms can be reduced.

In the example of FIG. 1, all of the treated water is returned to the aquarium 10 and added to the breeding water. However, at least a part of the treated water may be returned to the aquarium 10 and added to the breeding water. May be returned to the aquarium 10 and added to the breeding water, or all of the treated water may be returned to the aquarium 10 and added to the breeding water. From the viewpoint of reducing the amount of water used, it is preferable that a part of the treated water be returned to the water tank 10, and it is more preferable that all of the treated water be returned to the water tank 10. By using a closed circulation system in which all of the treated water is returned to the water tank 10, there is an advantage that the amount of water used can be reduced. In addition, the circulation may be performed constantly or periodically. Normally, in order to maintain the water quality in the water tank 10 as much as possible, it is sufficient to circulate constantly.

(2) Another example of the water treatment apparatus according to the embodiment of the present invention is schematically shown in FIG.

The water treatment apparatus 3 includes a water tank 10 for storing high-molecular-weight organic-material-containing water, a raw water tank 12 for storing high-molecular-weight organic-material-containing water from the water tank 10, and membrane filtration means for performing membrane filtration of water in the raw water tank 12. A membrane filtration device 14; an ozone treatment device 22 including an ozone generator 24 as a peroxide addition unit for adding peroxide to the concentrated water obtained by the membrane filtration treatment by the membrane filtration device 14; An activated carbon treatment device 18 is provided as a peroxide decomposing means for decomposing the peroxide of the membrane filtration water obtained by the membrane filtration process. The water treatment apparatus 1 may include a membrane filtration water tank 16, a treatment water tank 20, and a concentrated water tank 68.

2, the outlet of the water tank 10 and the raw water inlet of the raw water tank 12 are connected by a pipe 74, and the raw water outlet of the raw water tank 12 and the inlet of the membrane filtration device 14 are connected via a pump 70 and a strainer 38. And the outlet of the membrane filtration device 14 and the inlet of the membrane filtration water tank 16 are connected by the pipe 44, and the outlet of the membrane filtration water tank 16 and the inlet of the activated carbon treatment device 18 are connected. The outlet of the activated carbon treatment device 18 and the inlet of the treated water tank 20 are connected by a pipe 48 via a pipe 46 via a pump 30, and the treated water outlet of the treated water tank 20 and the water tank 10 are connected via a pump 32 to treated water It is connected by a return pipe 50. The backwash water outlet of the treatment water tank 20 and the backwash water inlet on the secondary side of the membrane filtration device 14 are connected by a pipe 58 via the pump 34.

A concentrated water outlet of the membrane filtration device 14 and a concentrated water inlet of the concentrated water tank 68 are connected by a pipe 80, and a backwash drainage outlet of the membrane filtration device 14 and a backwashed drainage inlet of the concentrated water tank 68 are connected by a pipe 78, The outlet of the concentrated water tank 68 and the inlet of the ozone treatment device 22 are connected by a pipe 82 via a pump 72, and the outlet of the ozone treatment device 22 and the inlet of the raw water tank 12 are connected by a peroxide-containing water return pipe 84. ing. The ozone generator 24 is connected to the lower part of the ozone treatment device 22 by a pipe 60.

動作 The operation of the water treatment method and the water treatment device 3 according to the present embodiment will be described.

水中 Underwater creatures such as fish are raised in the aquarium 10 in the breeding water. The breeding water usually contains high-molecular-weight organic substances such as proteins, suspended substances, and the like accompanying breeding of aquatic organisms. The breeding water in the water tank 10, that is, water containing high-molecular-weight organic matter including high-molecular-weight organic matter is sent to the raw water tank 12 through a pipe 74. The high-molecular organic substance-containing water is mixed with a peroxide-containing water to which a peroxide described later is added in the raw water tank 12, and then sent as mixed water to the membrane filtration device 14 through the pipe 76 by the pump 70. If necessary, a strainer 38 may be provided in the middle of the pipe 76 to remove relatively large solids in the high-molecular-weight-organic-material-containing water.

において In the membrane filtration device 14, the suspended substances and the like remaining in the raw water are removed by filtration using a membrane (membrane filtration step).

When the membrane filtration device 14 needs to be washed, a part of the treated water is back-flushed from the treated water tank 20 through the pipe 58 by the pump 34 from the secondary side of the membrane filtration device 14 to the primary side as backwash water. Alternatively, the membrane may be washed (backwash step). The backwash wastewater is supplied to a concentrated water tank 68 through a pipe 78 and mixed with the concentrated water from the membrane filtration device 14. The membrane filtration water in the membrane filtration tank 16 may be used as the backwash water.

The concentrated water of the membrane filtration device 14 is stored in a concentrated water tank 68 as necessary through a pipe 80, and then supplied to the ozone treatment device 22 through a pipe 82 by a pump 72.

一方で On the other hand, the ozone generated by the ozone generator 24 is supplied to the ozone treatment device 22 through a pipe 60. In the ozone treatment device 22, the treatment of the organic matter in the concentrated water (here, mainly the decomposition treatment of the organic matter) is performed by ozone. Further, in the ozone treatment apparatus 22, the concentrated suspended substance and the like are separated into solid and liquid by pressurized levitation using ozone. The ozone-treated water subjected to the organic matter treatment is returned to the raw water tank 12 through the peroxide-containing water return pipe 84. That is, peroxide is added to the concentrated water obtained by the membrane filtration process in the membrane filtration step (peroxide addition step), and at least a part of the peroxide-containing water obtained by the peroxide addition step is converted into the raw water tank 12. (Peroxide-containing water return step). The peroxide-containing water return pipe 84 and the like function as a peroxide-containing water return means for returning at least a part of the peroxide-containing water to the raw water tank 12. By returning the peroxide-containing water to the raw water tank 12, the peroxide-containing water comes into contact with the membrane of the membrane filtration device 14, and fouling can be suppressed. The exhausted ozone may be exhausted through the pipe 62 and processed by an ozone removing device. Scum and the like generated in the ozone treatment device 22 may be discharged through the pipe 64.

In the water treatment apparatus 3 according to the present embodiment, the high-molecular-weight-organic-containing water is stored in the raw water tank 12, the water in the raw water tank 12 is subjected to membrane filtration, and the concentrated water obtained by the membrane filtration is subjected to organic matter treatment. By returning the water to the water tank 12, fouling of the membrane due to high molecular organic matter, living organisms, or the like is suppressed, and the stable operation of the membrane filtration device 14 becomes possible. Further, the suspended substance is concentrated by the membrane of the membrane filtration device 14, and the efficiency of pressurized flotation in the ozone treatment device 22 can be increased.

The

water treatment apparatuses

1 and 3 and the water treatment method according to the present embodiment are applied to treatment of breeding water used for breeding underwater organisms such as aquariums and aquaculture, and the breeding water may be seawater. Or fresh water. The present invention is suitably applied to the treatment of water containing high-molecular organic matter, including high-molecular organic matter such as proteins, generated in the process of breeding underwater organisms such as aquariums and aquaculture. When breeding an organism, the organic matter concentration in the breeding water varies depending on factors such as feeding (for example, ± 0.5 to 10 mg / L). In particular, it is suitable for the treatment of seawater containing high molecular organic matter such as proteins generated in the process of breeding underwater organisms such as aquariums and aquaculture, and for the cultivation of underwater organisms such as fish and the underwater organism such as fish in aquariums. It is more suitable for closed circulation treatment used for breeding water treatment. That is, the

water treatment apparatuses

1 and 3 according to the present embodiment can be suitably used as a production apparatus or a treatment apparatus for breeding water for aquatic organisms.

濃度 The concentration of the high molecular organic substance in the water containing the high molecular organic substance is, for example, in the range of 0.1 to 5 mg / L. The concentration of the suspended substance in the water containing the high molecular organic substance is, for example, in the range of 10 to 100 mg / L.

Examples of the peroxide addition means in the

water treatment apparatuses

1 and 3 include an ultraviolet oxidation treatment apparatus and the like in addition to an ozone treatment apparatus having an ozone generator. From the viewpoint of processing performance and the like, an ozone treatment device including an ozone generator is preferable. The peroxide adding means is preferably an ozone treatment device using ozone, and more preferably an ozone treatment device using ozone microbubbles.

(3) Another example of the water treatment apparatus according to the embodiment of the present invention is schematically shown in FIG. 3 and its configuration will be described.

The water treatment device 4 includes an ozone treatment device 22 having an ozone generator 24 as a peroxide generation means, a membrane filtration device 14 having an ultrafiltration membrane or a microfiltration membrane as a membrane filtration means, and a peroxide. An activated carbon treatment device 18 is provided as peroxide decomposition means for performing decomposition treatment. The water treatment apparatus 4 may include a water tank 10, a raw water tank (also referred to as a peroxide-containing water tank) 12, a membrane filtration water tank 16, a treated water tank 20, and a concentrated water tank 68.

In the water treatment apparatus 4 of FIG. 3, the outlet of the water tank 10 and the inlet of the raw water tank (peroxide-containing water tank) 12 are connected by a pipe 85, and the outlet of the raw water tank (peroxide-containing water tank) 12 is connected to the membrane filtration device. 14 is connected by a pipe 86 via a pump 140 and a strainer 38, a permeate outlet of the membrane filtration device 14 and an inlet of the membrane filtration tank 16 are connected by a pipe 88, and an outlet of the membrane filtration tank 16 is The inlet of the treatment device 18 is connected by a pipe 90 via a pump 142, the outlet of the activated carbon treatment device 18 and the inlet of the treatment water tank 20 are connected by a pipe 92, and the outlet of the treatment water tank 20 and the water tank 10 are connected by a pump 144. Are connected by a return pipe 94.

The concentrated water outlet of the membrane filtration device 14 and the concentrated water inlet of the concentrated water tank 68 are connected by a pipe 96, and the outlet of the concentrated water tank 68 and the inlet of the ozone treatment device 22 are connected by a pipe 98 via a pump 146. The outlet of the treatment device 22 and the inlet of the raw water tank (peroxide-containing water tank) 12 are connected by a pipe 100. An ozone generator 24 is connected to the lower part of the ozone treatment device 22 by a pipe 110 via a valve 178. A flow meter 172 for measuring the flow rate of ozone is provided downstream of the valve 178 in the pipe 110. A pipe 106 for discharging exhausted ozone is connected to an exhausted ozone outlet at the upper part of the ozone treatment device 22, and a pipe 108 branched from an upstream side of a valve 178 in the pipe 110 is connected to the pipe 106 via a valve 176. . A pipe 104 for discharging generated scum or the like is connected to an upper side surface of the ozone treatment device 22. The lower part of the treated water tank 20 and the secondary side of the membrane filtration device 14 are connected by a pipe 102 via a pump 148. As a pressure measuring means, a pressure gauge 160 is installed downstream of the strainer 38 in the pipe 86, a pressure gauge 162 is installed in the pipe 88, and a pressure gauge 164 is installed in the pipe 96.

動作 The operation of the water treatment method and the water treatment device 4 according to the present embodiment will be described.

水 Halogen ion-containing water containing a suspended substance and containing halide ions and ammonium nitrogen stored in the water tank 10 is stored in a raw water tank (peroxide-containing water tank) 12 as necessary. The halide ion-containing water is mixed in a raw water tank (peroxide-containing water tank) 12 with a peroxide-containing water that has generated a peroxide, which will be described later. It is supplied to the device 14. If necessary, a strainer 38 may be provided in the middle of the pipe 86 to remove relatively large solids in the halide ion-containing water.

In the membrane filtration device 14, suspended substances in the mixed water, that is, suspended substances contained in the halide ion-containing water as raw water are removed by filtration using an ultrafiltration membrane or a microfiltration membrane (membrane). Filtration step).

膜 The membrane filtered water (permeated water) that has been subjected to membrane filtration is stored in the membrane filtered water tank 16 as necessary through a pipe 88, and then supplied to the activated carbon treatment device 18 through a pipe 90 by a pump 142. In the activated carbon treatment device 18, the halogen oxo acid, which is a peroxide in the membrane filtered water, is decomposed by activated carbon to form halide ions (peroxide decomposition step).

The peroxide is decomposed, and the treated water containing halide ions is stored in the treated water tank 20 as necessary through the pipe 92, and then returned to the water tank 10 through the return pipe 94 by the pump 144, and contains the halide ions. It is added to water (return step). The pump 144 and the return pipe 94 function as return means for returning at least a part of the treated water decomposed by the peroxide decomposing means and adding the treated water to the halogen compound ion-containing water.

The concentrated water in the membrane filtration device 14 is stored in the concentrated water tank 68 as necessary through a pipe 96, and then supplied to the ozone treatment device 22 through a pipe 98 by a pump 146.

一方で On the other hand, the ozone generated by the ozone generator 24 is supplied to the ozone treatment device 22 through a pipe 110. In the ozone treatment device 22, as shown in the following formula 1, a halogen oxo acid such as hypohalous acid (HXO), which is a peroxide, is generated by the reaction between the halide ion contained in the concentrated water and ozone ( Peroxide generation step). Halogen oxo acids such as hypohalous acid have oxidizing power and are effective in oxidizing and sterilizing organic substances. The discharged ozone is discharged through a pipe 106, and scum generated in the ozone treatment device 22 is discharged through a pipe 104. The portion of the ozone generated by the ozone generator 24 that is not supplied to the ozone treatment device 22 is discharged through the

pipes

110, 108, and 106. That is, the amount of ozone supplied to the ozone treatment device 22 is adjusted by the degree of opening and closing of the

valves

176 and 178.

[Equation 1]
X ⁻ + O ₃ → O ₂ + OX ⁻
OX ⁻ + H ₂ O → HXO + OH ⁻
(Where X ⁻ is a halide ion such as chloride ion (Cl ⁻ ), bromide ion (Br ⁻ ) and iodide ion (I ⁻ ), and X is a halogen such as Cl, Br and I. is there.)

When X ⁻ is a chloride ion, a halogen oxo acid such as hypochlorous acid (HClO), which is a peroxide, is formed by a reaction between chloride ion contained in the concentrated water and ozone as shown in the following formula 2. appear.

[Equation 2]
Cl ⁻ + O ₃ → O ₂ + OCl ⁻
OCl ⁻ + H ₂ O → HClO + OH ⁻

When X ^- is a bromide ion, a halogen oxo acid such as hypobromous acid (HBrO), which is a peroxide, is formed by a reaction between the bromide ion contained in the concentrated water and ozone as shown in the following formula 3. appear.

[Equation 3]
Br ⁻ + O ₃ → O ₂ + OBr ⁻
OBr ⁻ + H ₂ O → HBrO + OH ⁻

The peroxide-containing water that has generated peroxide is supplied to a raw water tank (peroxide-containing water tank) 12 through a pipe 100 and mixed with the halide ion-containing water from the water tank 10.

When the membrane filtration device 14 needs to be washed, a part of the treated water is back-flushed from the treated water tank 20 to the primary side from the secondary side of the membrane filtration device 14 through the pipe 102 by the pump 148 as the backwash water. Alternatively, the membrane may be washed (backwash step). The backwash wastewater is supplied to the concentrated water tank 68 through the pipe 96 and mixed with the concentrated water from the membrane filtration device 14. The membrane filtration water in the membrane filtration tank 16 may be used as the backwash water.

In the water treatment apparatus 4 according to the present embodiment, a peroxide containing halogen oxoacid having an oxidizing and sterilizing power such as hypobromous acid or bromic acid generated from a peroxide generation apparatus such as the ozone treatment apparatus 22 including the ozone generation apparatus 24 is used. By supplying the mixed water of the oxide-containing water and the halide ion-containing water to the membrane of the membrane filtration device 14, fouling of the membrane due to organic substances, organisms, and the like can be suppressed. A chemical such as sodium hypochlorite for suppressing fouling of the film may not be used. Then, based on the behavior of the transmembrane pressure of the membrane filtration device 14 measured by the pressure gauge 160, the pressure gauge 162, and the pressure gauge 164, the amount of peroxide generated in the ozone treatment device 22 is adjusted (adjustment). Process). Thereby, stable membrane treatment can be performed on the halide ion-containing water containing halide ions and ammonium nitrogen. That is, the transmembrane pressure difference can be controlled by the amount of generated peroxide while continuing the membrane filtration operation.

The transmembrane pressure of the membrane filtration device 14 is based on, for example, the inlet pressure measured by the pressure gauge 160, the outlet pressure (permeate water pressure) measured by the pressure gauge 162, and the concentrated water pressure measured by the pressure gauge 164. It is obtained by the following equation.
Transmembrane pressure = outlet pressure-[(inlet pressure + concentrated water pressure) / 2]

For example, when the transmembrane pressure increases and reaches a predetermined reference pressure or reaches a predetermined increase, the amount of ozone injected from the ozone generator 24 in the ozone treatment device 22 may be increased (for example, About 10%). When the transmembrane pressure falls below the reference pressure, the ozone injection amount may be reduced or the ozone injection amount may be maintained as it is. In this case, the ozone generator 24 may function as an adjusting means for adjusting the amount of peroxide generated based on the behavior of the transmembrane pressure of the membrane filtration device 14, or the flow at the outlet of the ozone generator 24 may be used. The valve 176 and the valve 178 whose opening degree is adjusted according to the value of the meter 172 may function.

For example, a control device (not shown) is connected to the pressure gauge 160, the pressure gauge 162, the pressure gauge 164, and the ozone generator 24, or the flow meter 172, the valve 176, and the valve 178 are electrically connected to each other. Then, the transmembrane pressure may be monitored, and the amount of peroxide generated in the ozone treatment device 22 may be controlled based on the behavior of the transmembrane pressure.

In the water treatment apparatus 4 according to the present embodiment, the generated halogen oxoacid such as hypohalous acid causes a denitrification reaction of the ammonia nitrogen contained in the halide ion-containing water, as shown in the following equation (4). Because of the denitrification step), both turbidity by the membrane and nitrogen removal of the halide ion-containing water can be achieved.

[Equation 4]
HXO + NH ₃ → NH ₂ X + H ₂ O
_{_{3HXO + 2NH 3 → 2N 2 +}} 3HX + 3H 2 O
(Where X is a halogen such as Cl, Br, I, etc.)

Especially, when X is Br, the generated hypobromous acid easily causes the denitrification of ammonia nitrogen contained in the halide ion-containing water as shown in the following formula 5.

[Equation 5]
HBrO + NH ₃ → NH ₂ Br + H ₂ O
3HBrO + 2NH ₃ → 2N ₂ + 3HBr + 3H ₂ O

Since the concentration of halogen oxoacids such as hypobromite in the membrane filtration water is high and it is feared that it will affect the ecology and the like, a peroxide decomposing means such as an activated carbon treatment unit 18 is provided downstream of the membrane filtration unit 14. Provide. By providing a peroxide decomposing means at the subsequent stage of the membrane filtration device 14, it is possible to reduce the influence on the ecology and the like by the halogen oxo acid such as hypobromous acid. For this reason, when the raw water is breeding water for aquaculture, aquariums, or the like, even if the treated water is returned to the aquarium 10, the effect on living organisms can be reduced.

In the example of FIG. 3, all of the treated water is returned to the water tank 10 and added to the halide ion-containing water, but at least a portion of the treated water is returned to the water tank 10 and added to the halide ion-containing water. Just do it. From the viewpoint of reducing the amount of water used, it is preferable that all of the treated water be returned to the water tank 10. By using a closed circulation system in which all of the treated water is returned to the water tank 10, there is an advantage that the amount of water used can be reduced.

概略 An outline of another example of the water treatment apparatus according to the embodiment of the present invention is shown in FIG. 4 and its configuration will be described.

The water treatment device 5 includes an ozone treatment device 22 having an ozone generator 24 as a peroxide generation means, a membrane filtration device 14 having an ultrafiltration membrane or a microfiltration membrane as a membrane filtration means, and a peroxide. An activated carbon treatment device 18 is provided as peroxide decomposition means for performing decomposition treatment. The water treatment apparatus 5 may include the water tank 10, a raw water tank (peroxide-containing water tank) 160, a membrane filtration water tank 16, and a treated water tank 20.

In the water treatment device 5 of FIG. 4, the outlet of the water tank 10 and the inlet of the ozone treatment device 22 are connected by the pipe 112 via the pump 150 and the strainer 38, and the exit of the ozone treatment device 22 is connected to the raw water tank (containing peroxide). The inlet of a water tank (160) is connected by a pipe (114), the outlet of a raw water tank (peroxide-containing water tank) 160 and the inlet of the membrane filter (14) are connected by a pipe (116) via a pump (152), and the The permeated water outlet and the inlet of the membrane filtration water tank 16 are connected by a pipe 118, and the outlet of the membrane filtration water tank 16 and the inlet of the activated carbon treatment device 18 are connected by a pipe 120 via a pump 154, and the outlet of the activated carbon treatment device 18 And the inlet of the treated water tank 20 are connected by a pipe 122, and the outlet of the treated water tank 20 and the water tank 10 are connected by a return pipe 124 via a pump 156. It is. The ozone generator 24 is connected to the lower part of the ozone treatment device 22 via a pipe 132 via a valve 182. A flow meter 174 for measuring the flow rate of ozone is installed downstream of the valve 182 in the pipe 132. A pipe 136 for discharging the discharged ozone is connected to a discharge ozone outlet at an upper portion of the ozone treatment device 22, and a pipe 138 branched from an upstream side of the valve 182 in the pipe 132 is connected to the pipe 136 via the valve 180. . A pipe 134 for discharging generated scum and the like is connected to an upper side surface of the ozone treatment device 22. The lower part of the treatment water tank 20 and the secondary side of the membrane filtration device 14 are connected by a pipe 126 via a pump 158. As a pressure measuring means, a pressure gauge 166 is installed downstream of the pump 152 in the pipe 116, a pressure gauge 168 is installed in the pipe 118, and a pressure gauge 170 is installed in the pipe 130.

動作 The operation of the water treatment method and the water treatment device 5 according to the present embodiment will be described.

水 The halide ion-containing water containing the suspended substance and containing the halide ions and the ammonium nitrogen stored in the water tank 10 is supplied to the ozone treatment device 22 through the pipe 112 by the pump 150. If necessary, a strainer 38 may be provided in the middle of the pipe 112 to remove relatively large solids in the halide ion-containing water.

一方で On the other hand, the ozone generated by the ozone generator 24 is supplied to the ozone treatment device 22 through a pipe 132. In the ozone treatment device 22, as shown in the above formula 1, by the reaction between the halide ions contained in the halide ion-containing water and ozone, halogen oxo acids such as hypohalous acid (HXO), which is a peroxide, are converted. Occurs (peroxide generation step). Halogen oxo acids such as hypohalous acid have oxidizing power and are effective in oxidizing and sterilizing organic substances. The discharged ozone is discharged through a pipe 136, and scum generated in the ozone treatment device 22 is discharged through a pipe 134. The portion of the ozone generated by the ozone generator 24 that is not supplied to the ozone treatment device 22 is discharged through the

pipes

132, 138, and 136. That is, the amount of ozone supplied to the ozone treatment device 22 is adjusted by the degree of opening and closing of the

valves

180 and 182.

In the case where X ⁻ is a chloride ion, as shown in the above formula 2, the reaction between chloride ion contained in the halide ion-containing water and ozone causes halogen such as hypochlorous acid (HClO) which is a peroxide. Oxo acids are generated.

When X ^- is a bromide ion, a reaction between bromide ion contained in the halide ion-containing water and ozone causes halogen such as hypobromite (HBrO), which is a peroxide, as shown in the above formula 3. Oxo acids are generated.

The peroxide-containing water that has generated peroxide is stored in a raw water tank (peroxide-containing water tank) 160 as required through a pipe 114, and then supplied to the membrane filtration device 14 through a pipe 116 by a pump 152. You. In the membrane filtration device 14, suspended substances in the peroxide-containing water, that is, suspended substances contained in the halide ion-containing water as raw water are removed by filtration using an ultrafiltration membrane or a microfiltration membrane. (Membrane filtration step).

透過 The permeated water (membrane filtered water) that has been subjected to membrane filtration is stored in the membrane filtration water tank 16 as necessary through a pipe 118, and then supplied to the activated carbon treatment device 18 through a pipe 120 by a pump 154. In the activated carbon treatment device 18, the halogen oxo acid, which is a peroxide in the membrane filtered water, is decomposed by activated carbon to form halide ions (peroxide decomposition step). The concentrated water of the membrane filtration device 14 is discharged through a pipe 130.

The peroxide is decomposed, and the treated water containing halide ions is stored in the treated water tank 20 as needed through the pipe 122, and then returned to the water tank 10 through the return pipe 124 by the pump 156, and contains the halide ions. It is added to water (return step). The pump 156 and the return pipe 124 function as return means for returning at least a part of the treated water decomposed by the peroxide decomposition means and adding the treated water to the halogen compound ion-containing water.

When the membrane filtration device 14 needs to be washed, a part of the treated water is returned as backwash water from the treated water tank 20 to the primary side of the membrane filtration device 14 from the secondary side through the pipe 126 by the pump 158. Alternatively, the membrane may be washed (backwash step). The backwash drainage is discharged through a pipe 128. The membrane filtration water in the membrane filtration tank 16 may be used as the backwash water.

In the water treatment apparatus 5 according to the present embodiment, the halogen containing a halogen oxo acid having an oxidizing and sterilizing power such as hypobromous acid or bromic acid generated from a peroxide generator such as the ozone treatment apparatus 22 including the ozone generator 24. By supplying the fluoride ion-containing water to the membrane of the membrane filtration device 14, fouling of the membrane due to organic substances, organisms, and the like can be suppressed. A chemical such as sodium hypochlorite for suppressing fouling of the film may not be used. Then, based on the behavior of the transmembrane pressure of the membrane filtration device 14 measured by the pressure gauge 166, the pressure gauge 168, and the pressure gauge 170, the amount of peroxide generated in the ozone treatment device 22 is adjusted (adjustment). Process). Thereby, stable membrane treatment can be performed on the halide ion-containing water containing halide ions and ammonium nitrogen.

The transmembrane pressure of the membrane filtration device 14 is based on, for example, the inlet pressure measured by the pressure gauge 166, the outlet pressure (permeate water pressure) measured by the pressure gauge 168, and the concentrated water pressure measured by the pressure gauge 170. It is determined by the above equation.

For example, when the transmembrane pressure increases and reaches a predetermined reference pressure or reaches a predetermined increase, the amount of ozone injected from the ozone generator 24 in the ozone treatment device 22 may be increased (for example, About 10%). When the transmembrane pressure falls below the reference pressure, the ozone injection amount may be reduced or the ozone injection amount may be maintained as it is. In this case, the ozone generator 24 may function as an adjusting means for adjusting the amount of peroxide generated based on the behavior of the transmembrane pressure of the membrane filtration device 14, or the flow at the outlet of the ozone generator 24 may be used. The valve 180 and the valve 182 whose opening degree is adjusted according to the value of the meter 174 may function.

For example, a control device (not shown) is connected to the pressure gauge 166, the pressure gauge 168, the pressure gauge 170, and the ozone generator 24, or the flow meter 174, the valve 180, and the valve 182 are electrically connected to each other. Then, the transmembrane pressure may be monitored, and the amount of peroxide generated in the ozone treatment device 22 may be controlled based on the behavior of the transmembrane pressure.

In the water treatment apparatus 5 according to the present embodiment, the generated halogen oxo acid such as hypohalous acid causes a denitrification reaction of the ammonia nitrogen contained in the halide ion-containing water, as shown in the above formula (4). Because of the denitrification step), both turbidity by the membrane and nitrogen removal of the halide ion-containing water can be achieved.

Especially, when X is Br, the generated hypobromous acid easily causes the denitrification of ammonia nitrogen contained in the halide ion-containing water as shown in the above formula 5.

In the example of FIG. 4, all of the treated water is returned to the water tank 10 and added to the halide ion-containing water, but at least a portion of the treated water is returned to the water tank 10 and added to the halide ion-containing water. Just do it. From the viewpoint of reducing the amount of water used, it is preferable that all of the treated water be returned to the water tank 10. By using a closed circulation system in which all of the treated water is returned to the water tank 10, there is an advantage that the amount of water used can be reduced.

概略 FIG. 5 schematically shows another example of the water treatment apparatus according to the embodiment of the present invention, and the configuration will be described.

The water treatment device 6 includes an ozone treatment device 22 having an ozone generator 24 as a peroxide generation means, a membrane filtration device 14 having an ultrafiltration membrane or a microfiltration membrane as a membrane filtration means, and a peroxide. An activated carbon treatment device 18 is provided as peroxide decomposition means for performing decomposition treatment. The water treatment device 6 may include a water tank 10, a raw water tank (peroxide-containing water tank) 12, a membrane filtration water tank 16, a treated water tank 20, and a concentrated water tank 68.

In the water treatment device 6 of FIG. 5, the outlet of the water tank 10 and the inlet of the raw water tank (peroxide-containing water tank) 12 are connected by a pipe 85, and the outlet of the raw water tank (peroxide-containing water tank) 12 is connected to the membrane filtration device. 14 is connected by a pipe 86 via a pump 140 and a strainer 38, a permeate outlet of the membrane filtration device 14 and an inlet of the membrane filtration tank 16 are connected by a pipe 88, and an outlet of the membrane filtration tank 16 is The inlet of the treatment device 18 is connected by a pipe 90 via a pump 142, the outlet of the activated carbon treatment device 18 and the inlet of the treatment water tank 20 are connected by a pipe 92, and the outlet of the treatment water tank 20 and the water tank 10 are connected by a pump 144. Are connected by a return pipe 94.

The concentrated water outlet of the membrane filtration device 14 and the concentrated water inlet of the concentrated water tank 68 are connected by a pipe 96, and the outlet of the concentrated water tank 68 and the inlet of the ozone treatment device 22 are connected by a pipe 98 via a pump 146. An outlet of the treatment device 22 and an inlet of the raw water tank (peroxide-containing water tank) 12 are connected by a pipe 100. An ozone generator 24 is connected to the lower part of the ozone treatment device 22 by a pipe 110 via a valve 178. A flow meter 172 for measuring the flow rate of ozone is provided downstream of the valve 178 in the pipe 110. A pipe 106 for discharging exhausted ozone is connected to an exhausted ozone outlet at the upper part of the ozone treatment device 22, and a pipe 108 branched from an upstream side of a valve 178 in the pipe 110 is connected to the pipe 106 via a valve 176. . A pipe 104 for discharging generated scum or the like is connected to an upper side surface of the ozone treatment device 22. The lower part of the treated water tank 20 and the secondary side of the membrane filtration device 14 are connected by a pipe 102 via a pump 148. A residual chlorine measuring device 184 is provided in the pipe 100 as a residual oxide concentration measuring means.

動作 The operation of the water treatment method and the water treatment device 6 according to the present embodiment will be described.

水 Halogen ion-containing water containing a suspended substance and containing halide ions and ammonium nitrogen stored in the water tank 10 is stored in a raw water tank (peroxide-containing water tank) 12 as necessary. The halide ion-containing water is mixed in a raw water tank (peroxide-containing water tank) 12 with a peroxide-containing water that has generated a peroxide, which will be described later, and a breakpoint treatment of ammonia nitrogen by the peroxide is performed. After that, the mixed water is supplied to the membrane filtration device 14 through the pipe 86 by the pump 140. If necessary, a strainer 38 may be provided in the middle of the pipe 86 to remove relatively large solids in the halide ion-containing water.

一方で On the other hand, the ozone generated by the ozone generator 24 is supplied to the ozone treatment device 22 through a pipe 110. In the ozone treatment device 22, as shown in the above formula 1, a reaction between the halide ions contained in the concentrated water and ozone generates halogen oxo acids such as hypohalous acid (HXO) which is a peroxide ( Peroxide generation step). Halogen oxo acids such as hypohalous acid have oxidizing power and are effective in oxidizing and sterilizing organic substances. The discharged ozone is discharged through a pipe 106, and scum generated in the ozone treatment device 22 is discharged through a pipe 104. The portion of the ozone generated by the ozone generator 24 that is not supplied to the ozone treatment device 22 is discharged through the

pipes

valves

176 and 178.

When X ⁻ is a chloride ion, a halogen oxo acid such as hypochlorous acid (HClO), which is a peroxide, is formed by the reaction between the chloride ion contained in the concentrated water and ozone as shown in the above formula 2. appear.

When X ^- is a bromide ion, a halogen oxo acid such as hypobromite (HBrO), which is a peroxide, is formed by a reaction between the bromide ion contained in the concentrated water and ozone as shown in the above formula 3. appear.

The peroxide-containing water that has generated the peroxide is supplied to a raw water tank (peroxide-containing water tank) 12 through a pipe 100, mixed with the halide ion-containing water from the water tank 10, and, as described above, is mixed with the peroxide. A breakpoint treatment of ammonia nitrogen by the substance is performed.

In the water treatment apparatus 6 according to the present embodiment, as shown in the above formula 4, the generated halogen oxo acid such as hypohalous acid causes a denitrification reaction of the ammonia nitrogen contained in the halide ion-containing water ( Because of the denitrification step), both turbidity by the membrane and nitrogen removal of the halide ion-containing water can be achieved.

In the water treatment apparatus 6 according to the present embodiment, the peroxide containing halogen oxoacid having oxidizing and sterilizing power, such as hypobromous acid or bromic acid, generated from a peroxide generator such as the ozone treatment apparatus 22 including the ozone generator 24 is used. By supplying the mixed water of the oxide-containing water and the halide ion-containing water to the membrane of the membrane filtration device 14, fouling of the membrane due to organic substances, organisms, and the like can be suppressed. A chemical such as sodium hypochlorite for suppressing fouling of the film may not be used.

As described above, in the conventional water treatment apparatus and the water treatment method such as the method of Patent Document 3, there is no means for confirming that ammonia nitrogen has been sufficiently removed. For example, when the raw water quality fluctuates, The removal of ammonia nitrogen may be insufficient.

In the water treatment apparatus 6 according to the present embodiment, ammonia nitrogen is sufficiently treated by measuring the residual oxide concentration by the residual chlorine measuring apparatus 184 at a stage prior to the activated carbon treatment apparatus 18 (peroxide decomposition step). You can be sure that. Therefore, it is possible to stably treat the ammonium ion-containing water containing the halide ions and the ammonia nitrogen, and to sufficiently remove the ammonia nitrogen even if the water quality changes.

When the ammonium ion is contained in the halide ion-containing water, the amount of halogen oxo acid generated in the peroxide generating means such as an ozone treatment device is lower than the amount required by the break point method described below. Since residual halogen in peroxide-containing water exists in the form of bound halogen, the residual halogen concentration is calculated by measurement of total chlorine, and even if it is detected as residual halogen, the removal of ammonia nitrogen is insufficient. It is thought to be.

In the water treatment apparatus 6 according to the present embodiment, the residual oxide concentration is measured by a residual chlorine measuring device 184 which is a residual oxide concentration measuring means installed before the activated carbon treatment device 18 which is a peroxide decomposing means. The amount of peroxide generated in the ozone treatment device 22 is controlled based on the measurement value of the residual oxide concentration measuring means (control step). By controlling the amount of peroxide generated and performing a breakpoint treatment of ammonia nitrogen, it is possible to sufficiently remove ammonia nitrogen from halide ion-containing water containing halide ions and ammonium nitrogen. A stable film processing can be performed.

Break point treatment is a method of decomposing and removing ammonia nitrogen by adding an oxidizing agent (peroxide) larger than the theoretical value with respect to the concentration of ammonia nitrogen in the water to be treated. The graph of FIG. 11 shows the free chlorine and the total chlorine with respect to the added hypochlorous acid concentration (mg / L) when hypochlorous acid was added as a halogen-based oxidizing agent to ammonia-containing water containing ammonia, respectively. It is a graph which shows the measured residual chlorine concentration (mg / L). As hypochlorous acid is added to the ammonia-containing water, bound chlorine is initially formed and residual chlorine (total chlorine) increases with the amount of hypochlorous acid added, but when it reaches the maximum point, When residual chlorine is used to decompose chloramine (bound chlorine) and decreases and reaches a minimum point, residual chlorine (free chlorine) increases again in proportion to the amount of hypochlorous acid added. This minimum point is called a breakpoint, at which point all of the ammonia has been consumed. Therefore, the amount of peroxide required to decompose ammonia-nitrogen beyond the break point is generated, whereby ammonia-nitrogen can be sufficiently removed. By controlling the amount of peroxide generated by the ozone treatment device 22 based on the residual oxide concentration measured by the residual oxide concentration measuring means, even if the water quality of the halide ion-containing water fluctuates, the ammonia nitrogen Can be sufficiently removed.

The residual oxide concentration measuring means is not particularly limited as long as it can measure the residual oxide amount, and is not particularly limited. At least one of the total halogen amount (free halogen amount + bonded halogen amount) and the free halogen amount Is preferable, and it is more preferable that the total amount of halogen and the amount of free halogen can be measured respectively. The residual oxide concentration measuring means is, for example, a residual chlorine measuring means and may be any one capable of measuring the residual chlorine amount, and is not particularly limited, but the total chlorine amount (free chlorine amount + bound chlorine amount). It is preferable to be able to measure at least one of the free chlorine amount and the free chlorine amount, and it is more preferable that the total chlorine amount and the free chlorine amount can be measured. As the residual oxide concentration measuring means, a measuring device capable of measuring both the total halogen amount and the free halogen amount, for example, both the total chlorine amount and the free chlorine amount, or the total halogen amount, for example, the total chlorine amount may be used. And a measuring device that can measure the amount of free halogen, for example, the amount of free chlorine. The total amount of halogen and the amount of free halogen are measured by the residual oxide concentration measuring means, respectively, and the amount of peroxide generation is set so that the difference between the measured total amount of halogen and the amount of free halogen is within 20% of the total amount of halogen. It is preferable to control the amount of peroxide generated by the means. Further, by the residual oxide concentration measuring means, the total halogen amount and the free halogen amount are respectively measured, and the amount of the free halogen exceeds a predetermined value in a state where the amount of the bound halogen calculated based on the measured value is not detected. Thus, it is preferable to control the amount of peroxide generated by the peroxide generating means. For example, the total chlorine amount and the free chlorine amount are respectively measured by the residual chlorine measuring means, and based on the measured values, in a state where the combined chlorine amount calculated as (total chlorine amount−free chlorine amount) is not detected, It is preferable to control the amount of peroxide generated by the peroxide generating means so that the amount of free chlorine is equal to or more than a predetermined value. Here, the “state where no bound halogen amount (bound chlorine amount) is detected” means that the difference between the total halogen amount and the free halogen amount is within 20% of the total halogen amount. It means that the difference in chlorine concentration is within ± 20%.

The installation position of the residual chlorine measurement device 184 may be any position as long as it is in front of the peroxide decomposing means, and may be the pipe 100, or may be installed in the raw water tank (peroxide-containing water tank) 12 or the membrane filtration water tank 16. Alternatively, they may be installed in the

pipes

86, 88, 90.

As a method of judging that the break point has been exceeded based on the measurement by the residual chlorine measuring means, for example, total chlorine is continuously measured (monitored) together with the addition of ozone, and the break point is determined by observing the minimum point. It may be judged that it has exceeded, or the free chlorine may be continuously measured with the addition of ozone, and it may be judged that the break point has been exceeded by observing the rise of the free chlorine, or with the addition of ozone. Both total chlorine and free chlorine are continuously measured, and it may be judged that the break point has been exceeded by observing the minimum point of total chlorine and observing the rise of free chlorine, or when there is a certain amount of ozone added. When both total chlorine and free chlorine are measured at the same time, there is almost no difference between the total chlorine amount and the free chlorine amount (for example, the difference between the measured values is 20% If it is the inner), it may be determined to exceed the break point.

For example, when the difference between the total chlorine amount and the free chlorine amount exceeds 20%, the amount of ozone injected from the ozone generator 24 in the ozone treatment device 22 may be increased (for example, about 10%). When the difference between the total chlorine amount and the free chlorine amount is within 20%, the ozone injection amount may be reduced or the ozone injection amount may be maintained as it is. In this case, the ozone generator 24 may function as control means for controlling the amount of peroxide generated based on the measurement value of the residual chlorine measuring device 184, or the flow meter 172 at the outlet of the ozone generator 24 The valve 176 and the valve 178 whose opening degree is adjusted according to the value may function.

For example, a control device (not shown) and a residual chlorine measuring device 184 and an ozone generating device 24, or a flow meter 172, a valve 176, and a valve 178 are connected to each other by an electrical connection or the like. The measurement value of 184 may be monitored to control the amount of peroxide generated in the ozone treatment device 22.

In the example of FIG. 5, all of the treated water is returned to the water tank 10 and added to the halide ion-containing water, but at least a portion of the treated water is returned to the water tank 10 and added to the halide ion-containing water. Just do it. From the viewpoint of reducing the amount of water used, it is preferable that all of the treated water be returned to the water tank 10. By using a closed circulation system in which all of the treated water is returned to the water tank 10, there is an advantage that the amount of water used can be reduced.

概略 FIG. 6 schematically shows another example of the water treatment apparatus according to the embodiment of the present invention, and its configuration will be described.

The water treatment device 7 includes an ozone treatment device 22 having an ozone generator 24 as a peroxide generation means, a membrane filtration device 14 having an ultrafiltration membrane or a microfiltration membrane as a membrane filtration means, and a peroxide. An activated carbon treatment device 18 is provided as peroxide decomposition means for performing decomposition treatment. The water treatment device 7 may include the water tank 10, a raw water tank (peroxide-containing water tank) 160, a membrane filtration water tank 16, and a treated water tank 20.

In the water treatment device 7 of FIG. 6, the outlet of the water tank 10 and the inlet of the ozone treatment device 22 are connected by the pipe 112 via the pump 150 and the strainer 38, and the exit of the ozone treatment device 22 is connected to the raw water tank (containing peroxide). The inlet of the water tank 160 is connected by a pipe 114, the outlet of the peroxide-containing water tank 160 and the inlet of the membrane filtration device 14 are connected by a pipe 116 via a pump 152, and the permeated water outlet of the membrane filtration device 14 The inlet of the membrane filtration water tank 16 is connected by a pipe 118, the outlet of the membrane filtration water tank 16 is connected to the inlet of the activated carbon treatment device 18 by a pipe 120 via a pump 154, and the outlet of the activated carbon treatment device 18 is connected to the treatment water tank 20. Is connected by a pipe 122, and the outlet of the treated water tank 20 and the water tank 10 are connected by a return pipe 124 via a pump 156. . The ozone generator 24 is connected to the lower part of the ozone treatment device 22 by a pipe 132 via a valve 182. A flow meter 174 for measuring the flow rate of ozone is installed downstream of the valve 182 in the pipe 132. A pipe 136 for discharging the discharged ozone is connected to a discharge ozone outlet at an upper portion of the ozone treatment device 22, and a pipe 138 branched from an upstream side of the valve 182 in the pipe 132 is connected to the pipe 136 via the valve 180. . A pipe 134 for discharging generated scum and the like is connected to an upper side surface of the ozone treatment device 22. The lower part of the treatment water tank 20 and the secondary side of the membrane filtration device 14 are connected by a pipe 126 via a pump 158. As a residual oxide concentration measuring means, a residual chlorine measuring device 186 is installed in the pipe 114.

動作 The operation of the water treatment method and the water treatment device 7 according to the present embodiment will be described.

一方で On the other hand, the ozone generated by the ozone generator 24 is supplied to the ozone treatment device 22 through a pipe 132. In the ozone treatment device 22, as shown in the above formula 1, by the reaction between the halide ions contained in the halide ion-containing water and ozone, halogen oxo acids such as hypohalous acid (HXO), which is a peroxide, are converted. Occurs (peroxide generation step). A breakpoint treatment of ammonia nitrogen is performed by the generated peroxide. Halogen oxo acids such as hypohalous acid have oxidizing power and are effective in oxidizing and sterilizing organic substances. The discharged ozone is discharged through a pipe 136, and scum generated in the ozone treatment device 22 is discharged through a pipe 134. The portion of the ozone generated by the ozone generator 24 that is not supplied to the ozone treatment device 22 is discharged through the

pipes

valves

180 and 182.

(4) The peroxide-containing water that has generated peroxide is stored in a peroxide-containing water tank 160 as needed through a pipe 114, and then supplied to the membrane filtration device 14 through a pipe 116 by a pump 152. In the membrane filtration device 14, suspended substances in the peroxide-containing water, that is, suspended substances contained in the halide ion-containing water as raw water are removed by filtration using an ultrafiltration membrane or a microfiltration membrane. (Membrane filtration step).

In the water treatment apparatus 7 according to the present embodiment, the generated halogen oxoacid such as hypohalous acid causes a denitrification reaction of the ammonia nitrogen contained in the halide ion-containing water, as shown in the above formula (4). Because of the denitrification step), both turbidity by the membrane and nitrogen removal of the halide ion-containing water can be achieved.

In the water treatment apparatus 7 according to the present embodiment, the halogen containing a halogen oxoacid having an oxidizing and sterilizing power such as hypobromous acid or bromic acid generated from a peroxide generator such as the ozone treatment apparatus 22 including the ozone generator 24. By supplying the fluoride ion-containing water to the membrane of the membrane filtration device 14, fouling of the membrane due to organic substances, organisms, and the like can be suppressed. A chemical such as sodium hypochlorite for suppressing fouling of the film may not be used.

In the water treatment device 7 according to the present embodiment, ammonia nitrogen is sufficiently treated by measuring the residual oxide concentration by the residual chlorine measuring device 186 before the activated carbon treatment device 18 (peroxide decomposition step). You can be sure that. Therefore, it is possible to stably treat the ammonium ion-containing water containing the halide ions and the ammonia nitrogen, and to sufficiently remove the ammonia nitrogen even if the water quality changes.

In the water treatment device 7 according to the present embodiment, the residual oxide concentration is measured by the residual chlorine measuring device 186 that is the residual oxide concentration measuring device installed in front of the activated carbon treatment device 18 that is a peroxide decomposition device. The amount of peroxide generated in the ozone treatment device 22 is controlled based on the measurement value of the residual oxide concentration measuring means (control step). By performing the ammonia nitrogen breakpoint treatment by controlling the amount of generated peroxide, ammonia nitrogen can be sufficiently removed from halide ion-containing water containing halide ions and ammonia nitrogen. , Stable treatment water quality can be ensured.

The installation position of the residual chlorine measuring device 186 may be any position before the peroxide decomposition means, and may be the piping 114, or may be installed in the raw water tank (peroxide-containing water tank) 160 or the membrane filtration water tank 16. Alternatively, it may be installed in the

piping

116, 118, 120.

For example, if the difference between the total chlorine amount and the free chlorine amount exceeds 20%, the amount of ozone injected from the ozone generator 24 in the ozone treatment device 22 may be increased (for example, about 10%). When the difference between the total chlorine amount and the free chlorine amount is within 20%, the ozone injection amount may be reduced or the ozone injection amount may be maintained as it is. In this case, the ozone generator 24 may function as control means for controlling the amount of peroxide generated based on the measurement value of the residual chlorine measurement device 186, or the flow meter 174 at the outlet of the ozone generator 24 may serve as a control means. The valve 180 and the valve 182 whose opening degree is adjusted according to the value may function.

Further, for example, a control device (not shown) and the residual chlorine measuring device 186 and the ozone generating device 24, or the flow meter 174, the valve 180, and the valve 182 are connected to each other by an electrical connection or the like. The measurement value of the measurement device 186 may be monitored to control the amount of peroxide generated in the ozone treatment device 22.

In the example of FIG. 6, all of the treated water is returned to the water tank 10 and added to the halide ion-containing water, but at least a portion of the treated water is returned to the water tank 10 and added to the halide ion-containing water. Just do it. From the viewpoint of reducing the amount of water used, it is preferable that all of the treated water be returned to the water tank 10. By using a closed circulation system in which all of the treated water is returned to the water tank 10, there is an advantage that the amount of water used can be reduced.

As the peroxide generating means in the

water treatment devices

4, 5, 6, and 7, in addition to an ozone treatment device having an ozone generation device, a UV oxidation device having a UV irradiation device and the like can be given. From the viewpoint of processing performance and the like, an ozone treatment device including an ozone generator is preferable.

The membrane filtration device 14 is not particularly limited as long as it has a filtration membrane such as an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane).

As the peroxide decomposing means, in addition to an activated carbon treatment apparatus such as an activated carbon packed tower filled with activated carbon, a packed tower filled with a peroxide decomposition catalyst such as a Pd-supported carrier, titanium oxide, and platinum, and the like, are included. In view of the above, an activated carbon treatment device such as an activated carbon packed tower is preferable. The direction of water flow to the packed tower filled with the peroxide decomposition catalyst may be either a downward flow or an upward flow, but a downward flow is preferable in order to increase the decomposition rate of the peroxide.

The

water treatment apparatuses

4, 5, 6, 7 and the water treatment method according to the present embodiment are applied to the removal of suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen, and are used for removing halide ion-containing water. May be seawater or freshwater. In particular, it is suitable for treating seawater containing ammonia nitrogen, and is more suitable for closed-system circulation treatment used for cultivation of aquatic organisms such as fish and breeding water for aquatic organisms such as fish in an aquarium. In other words, the

water treatment devices

4, 5, 6, and 7 according to the present embodiment can be suitably used as a device for producing or treating underwater breeding water. Seawater usually contains bromide ions, and ammonia-based nitrogen is usually emitted from aquatic organisms such as fish. When nitrifying and denitrifying ammonia nitrogen, it is necessary to first convert ammonia nitrogen to nitric acid by aerobic biological treatment and then reduce nitric acid to nitrogen gas by anaerobic biological treatment to remove nitrogen from water. Was normal. When such biological treatment is used, a large installation space is required because a nitrification tank under aerobic conditions and a denitrification tank under anaerobic conditions are required. In contrast, in the

water treatment apparatuses

4, 5, 6, and 7 according to the present embodiment, nitrification and denitrification can be performed by one apparatus (the ozone treatment apparatus 22), so that space can be saved.

In the ozone treatment device 22, the concentration ratio of the halide ion is 5 to 50 times and the injection ratio of ozone is 2 to 20 times the concentration (ppm) of the ammonia nitrogen in the halide ion-containing water. Preferably, the injection amount of at least one of the halide salt and ozone is adjusted, and the halogen ion concentration is adjusted so that the halide ion concentration is 5 to 25 times and the ozone injection rate is 2 to 10 times. More preferably, the injection amount of at least one of the chloride salt and ozone is adjusted. This is to optimize the injection rate of ozone used in the treatment in order to make the ratio of the amount of halogen oxo acid such as hypobromite to 1.5 mol or more with respect to the concentration of ammonia nitrogen in the halide ion-containing water. It becomes something. Formula 6 for calculating the ozone injection rate is shown below.

[Equation 6]
Ozone injection rate [mg-O ₃ / L] =
Ozone concentration at outlet of ozone generator [mg-O ₃ / NL] × (ozone flow rate [NL / h] / raw water flow rate [L / h])

と If the injection rate of ozone becomes excessive, the amount of exhausted ozone increases, and the size of the device for removing exhausted ozone may become large. Further, when the concentration of ammonia nitrogen in the halide ion-containing water increases, the treatment can be performed by increasing the ozone injection rate and adding a halide salt such as a bromide salt to the halide ion-containing water. When the concentration of ammonia nitrogen in the halide ion-containing water decreases, the ozone injection rate may be reduced.

Examples of the halide salt include chloride salts such as sodium chloride, and bromide salts such as sodium bromide.

アンモニア The concentration of ammonia nitrogen in the breeding water of seawater is usually 1 ppm or less, the concentration of bromide ion is usually about 50 to 60 ppm, and the concentration of chloride ion is usually about 18,000 to 22,000 ppm. The

water treatment apparatuses

4, 5, 6, 7 and the water treatment method according to the present embodiment treat the halide ion-containing water having an ammonia nitrogen concentration of about 10 ppm or less and a bromide ion concentration of about 50 ppm to 60 ppm. Can be suitably applied.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

<Example 1, Comparative Example 1>
In Example 1, the transmembrane pressure difference was measured for fish breeding water using the water treatment apparatus 1 shown in FIG. In Comparative Example 1, the transmembrane pressure difference was measured using an ozone treatment device and a water treatment device excluding the ozone generation device. Table 1 shows the experimental conditions of Example 1 and Table 2 shows the experimental conditions of Comparative Example 1. FIG. 8 shows the results.

<Example 2, Comparative Example 2>
In Example 2, the transmembrane pressure difference was measured for fish breeding water using the water treatment device 3 shown in FIG. In Comparative Example 2, the transmembrane pressure was measured using an ozone treatment device and a water treatment device excluding the ozone generation device. Table 3 shows the experimental conditions of Example 2 and Table 4 shows the experimental conditions of Comparative Example 2. FIG. 9 shows the results.

In Examples 1 and 2, in a water treatment apparatus and a water treatment method for treating high-molecular organic matter-containing water such as fish breeding water, membrane fouling was suppressed, and stable operation became possible.

<Example 3>
Using the water treatment device 4 shown in FIG. 3, the ozone injection amount was changed for fish breeding water (ammonia nitrogen concentration: 0.1 to 0.5 ppm, bromide ion concentration: 60 to 65 ppm) (ammonia nitrogen (NH ₃ —N): ozone (O ₃ ) = 1: 1.5 (molar ratio) → 1: 0.6 → 1: 1.5), between membranes of a membrane filtration device (membrane: ultrafiltration membrane) The differential pressure was measured. The experimental results are shown in FIG. FIG. 10 shows the transmembrane pressure when the amount of injected ozone is changed. The ammonium nitrogen concentration and bromide ion concentration in the breeding water were measured using a portable absorptiometer (DR1900, manufactured by HACH) and an ion chromatography device (761, CompactIC, manufactured by Metrohm).

As can be seen from FIG. 10, when the ozone injection amount is changed from ammonia nitrogen (NH ₃ —N): ozone (O ₃ ) = 1: 1.5 (molar ratio) to 1: 0.6, the transmembrane pressure difference is increased. Increased to 1: 1.5, and the transmembrane pressure decreased.

Thus, by adjusting the amount of peroxide generation based on the behavior of the transmembrane pressure difference of the ultrafiltration membrane or the microfiltration membrane, it is possible to stabilize halide ion-containing water containing halide ions and ammonium nitrogen. It has been found that the film processing can be performed.

<Examples 4 to 6, Comparative Examples 3 and 4>
Using the water treatment apparatus 6 shown in FIG. 5, the ozone injection amount was changed for fish breeding water (ammonia nitrogen concentration: 0.1 to 0.5 ppm, bromide ion concentration: 60 to 65 ppm) (Example 4). Ammonia nitrogen (NH ₃ —N): ozone (O ₃ ) = 1: 1.5 (molar ratio), Example 5; 1: 3, Example 6; 1: 4.5, Comparative Example 3; : 0.6, Comparative Example 4; 1: 1), the free chlorine concentration, the total chlorine concentration, and the ammonia nitrogen concentration were measured. The free chlorine concentration and the total chlorine concentration were measured by a DPD (diethyl-p-phenylenediamine) method using a multi-item water quality analyzer DR / 4000 manufactured by HACH. The ammonia nitrogen concentration was measured using a portable absorptiometer (DR1900, manufactured by HACH). Table 5 shows the experimental results.

わかる As can be seen from Table 5, ammonia nitrogen was sufficiently treated by injecting ozone so that the difference between the total chlorine amount and the free chlorine amount was within 20% of the total chlorine amount.

Thus, it was found that by the methods of Examples 4 to 6, stable treatment of ammonia nitrogen can be performed on halide ion-containing water containing halide ions and ammonia nitrogen.

1,3,4,5,6,7 water treatment equipment, 10 water tank, 12,160 raw water tank (peroxide-containing water tank), 14 membrane filtration equipment, 16 membrane filtration water tank, 18 activated carbon treatment equipment, 20 treatment water tank, 22 ° ozonator, 24 ° ozone generator, 26, 28, 30, 32, 34, 70, 72, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 ° pump, 38 ° strainer, 40, 42, 44, 46, 48, 58, 60, 62, 64, 66, 74, 76, 78, 80, 82, 84, 85, 86, 88, 90, 92, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 126, 128, 130, 132, 134, 136, 138 pipe, 50 treated water Transmission pipe, 52, 54 circulation pipe, 56 concentrated water return pipe, 68 concentrated water tank, 84 peroxide containing water return pipe, 94, 124 return pipe, 160, 162, 164, 166, 168, 170 pressure gauge, 172 174 flow meter, 176, 178, 180, 182 valve, 184, 186 residual chlorine measuring device.

Claims

A water treatment apparatus for treating high-molecular-organic-material-containing water containing high-molecular-weight organic matter,
A water tank for storing high-molecular organic matter-containing water,
A raw water tank for storing the high-molecular organic matter-containing water from the water tank,
Peroxide adding means for adding peroxide while circulating the water in the raw water tank,
Membrane filtration means for performing membrane filtration of the water in the raw water tank,
A concentrated water return means for returning at least a part of the concentrated water obtained by the membrane filtration treatment by the membrane filtration means to the raw water tank,
Peroxide decomposition means for decomposing the peroxide of the membrane filtration water obtained by the membrane filtration treatment by the membrane filtration means,
Treated water returning means for returning at least a part of the treated water decomposed by the peroxide decomposing means to the water tank,
A water treatment apparatus comprising:
A water treatment apparatus for treating high-molecular-organic-material-containing water containing high-molecular-weight organic matter,
A water tank for storing high-molecular organic matter-containing water,
A raw water tank for storing the high-molecular organic matter-containing water from the water tank,
Membrane filtration means for performing membrane filtration of the water in the raw water tank,
Peroxide addition means for adding peroxide to the concentrated water obtained by the membrane filtration treatment by the membrane filtration means,
A peroxide-containing water return means for returning at least a part of the peroxide-containing water obtained by the peroxide addition means to the raw water tank,
Peroxide decomposition means for decomposing the peroxide of the membrane filtration water obtained by the membrane filtration treatment by the membrane filtration means,
Treated water returning means for returning at least a part of the treated water decomposed by the peroxide decomposing means to the water tank,
A water treatment apparatus comprising:
The water treatment device according to claim 1 or 2,
The water treatment apparatus, wherein the peroxide adding means is a means using ozone.
A water treatment apparatus for removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen,
Peroxide generating means for generating a peroxide in the halide ion-containing water,
Membrane filtration means for filtering the peroxide-containing water having generated the peroxide using an ultrafiltration membrane or a microfiltration membrane,
The latter stage of the membrane filtration means, peroxide decomposition means for decomposing peroxide,
Return means for returning at least a part of the treated water decomposed by the peroxide decomposing means and adding to the halogen compound ion-containing water,
With
A water treatment apparatus, wherein the amount of generated peroxide is adjusted based on the behavior of the transmembrane pressure of the ultrafiltration membrane or the microfiltration membrane.
The water treatment device according to claim 4,
The water treatment apparatus further comprising a control unit that monitors the transmembrane pressure difference and controls the amount of the generated peroxide.
A water treatment apparatus for removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen,
Peroxide generating means for generating a peroxide in the halide ion-containing water,
Membrane filtration means for filtering the peroxide-containing water having generated the peroxide using an ultrafiltration membrane or a microfiltration membrane,
The latter stage of the membrane filtration means, peroxide decomposition means for decomposing peroxide,
Return means for returning at least a part of the treated water decomposed by the peroxide decomposing means and adding to the halogen compound ion-containing water,
Before the peroxide decomposition means, residual oxide concentration measurement means,
With
Controlling the amount of the peroxide generated by the peroxide generating means based on the measurement value of the residual oxide concentration measuring means to perform a breakpoint treatment of the ammonia nitrogen by the peroxide. Characteristic water treatment equipment.
The water treatment device according to claim 6,
The water treatment apparatus according to claim 1, wherein the residual oxide concentration measuring means can measure the total halogen amount and the free halogen amount, respectively.
The water treatment device according to claim 7,
The amount of the peroxide generated by the peroxide generating means is adjusted so that the difference between the total halogen amount and the free halogen amount measured by the residual oxide concentration measuring means is within 20% of the total halogen amount. A water treatment device characterized by controlling.
The water treatment apparatus according to any one of claims 4 to 8, wherein
A water treatment apparatus, wherein the peroxide generating means is an ozone generating means.
A water treatment method for treating a polymer organic material-containing water containing a polymer organic material,
A peroxide addition step of adding a peroxide while circulating the polymer organic substance-containing water sent from the water tank to the raw water tank to the raw water tank,
A membrane filtration step of membrane filtration of the water in the raw water tank,
A concentrated water return step of returning at least a portion of the concentrated water obtained in the membrane filtration process by the membrane filtration step to the raw water tank,
A peroxide decomposition step of decomposing the peroxide of the membrane filtration water obtained by the membrane filtration treatment by the membrane filtration step,
A treated water return step of returning at least a part of the treated water decomposed by the peroxide decomposition step to the water tank,
A water treatment method comprising:
A water treatment method for treating a polymer organic material-containing water containing a polymer organic material,
A membrane filtration step of subjecting the high-molecular organic substance-containing water sent from the water tank to the raw water tank to a membrane filtration treatment,
A peroxide addition step of adding a peroxide to the concentrated water obtained by the membrane filtration treatment in the membrane filtration step,
A peroxide-containing water return step of returning at least a portion of the peroxide-containing water obtained by the peroxide addition step to the raw water tank,
A peroxide decomposition step of decomposing the peroxide of the membrane filtration water obtained by the membrane filtration treatment by the membrane filtration step,
A treated water return step of returning at least a part of the treated water decomposed by the peroxide decomposition step to the water tank,
A water treatment method comprising:
The water treatment method according to claim 10 or 11,
A water treatment method, wherein the peroxide adding step is a step using ozone.
A water treatment method for removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen,
A peroxide generating step of generating a peroxide in the halide ion-containing water,
A membrane filtration step of filtering the peroxide-containing water that has generated the peroxide using an ultrafiltration membrane or a microfiltration membrane,
A peroxide decomposing step of decomposing a peroxide at a later stage of the membrane filtration step,
A return step of returning at least a part of the treated water decomposed in the peroxide decomposition step and adding the treated water to the halogen compound ion-containing water,
Including
A water treatment method, wherein the amount of the generated peroxide is adjusted based on the behavior of the transmembrane pressure difference of the ultrafiltration membrane or the microfiltration membrane.
The water treatment method according to claim 13,
A water treatment method comprising monitoring the transmembrane pressure difference and controlling the amount of the peroxide generated.
A water treatment method for removing suspended substances in halide ion-containing water containing halide ions and ammonium nitrogen,
A peroxide generating step of generating a peroxide in the halide ion-containing water,
A membrane filtration step of filtering the peroxide-containing water that has generated the peroxide using an ultrafiltration membrane or a microfiltration membrane,
A peroxide decomposing step of decomposing a peroxide at a later stage of the membrane filtration step,
A return step of returning at least a part of the treated water decomposed in the peroxide decomposition step and adding the treated water to the halogen compound ion-containing water,
A residual oxide concentration measurement step in a preceding stage of the peroxide decomposition step,
Including
Based on the measured value of the residual oxide concentration measurement step, controlling the amount of the peroxide generated in the peroxide generation step, performing a breakpoint treatment of the ammonia nitrogen by the peroxide. Characterized water treatment method.
The water treatment method according to claim 15, wherein
A water treatment method, wherein the total amount of halogen and the amount of free halogen are measured in the residual oxide concentration measuring step.
The water treatment method according to claim 16,
The amount of the peroxide generated in the peroxide generation step is determined so that the difference between the total halogen amount and the free halogen amount measured in the residual oxide concentration measurement step is within 20% of the total halogen amount. A water treatment method characterized by controlling.
The water treatment method according to any one of claims 13 to 17, wherein
A water treatment method, wherein the peroxide generation step is an ozone generation step.