JP2018113925A - Water treatment apparatus, water treatment method, and device for producing aquatic life rearing water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water treatment apparatus and water treatment method suppressing fouling of a film, capable of performing stable operation, and treating organic polymer-containing water.SOLUTION: A water treatment apparatus 1 for treating organic polymer-containing water that contains organic polymer, the water treatment apparatus 1 includes: a raw water tank 12 for storing organic polymer-containing water; an ozone treatment device 22 as organic treatment means for circulating the water of the raw water tank 12 and treating organic substances; and a filtration device 16 for filtering the water of the raw water tank 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water treatment apparatus and a water treatment method for treating high molecular organic substance-containing water containing a high molecular organic substance such as protein. The present invention also relates to an apparatus for producing breeding water for aquatic organisms using the water treatment method.

  When the membrane filtration is continuously operated, fouling in which the amount of filtered water decreases occurs. As a method for suppressing this fouling or a method for washing the membrane, generally, a method in which a sodium hypochlorite aqueous solution is caused to flow backward from the secondary side to the primary side of the membrane is used. Further, as a method for enhancing the cleaning of the membrane, a method of cleaning the membrane by reversing chlorine-containing water from the secondary side of the membrane and holding the water for a predetermined time (see Patent Document 1), microbubbles, There is a method using nanobubbles (refer to Patent Document 2).

  In particular, when water containing a high molecular organic substance including a high molecular organic substance such as a protein such as aquaculture or aquarium is to be subjected to membrane filtration treatment, the high molecular organic substance such as a protein may promote fouling. In addition, once fouling has occurred, it is necessary to perform chemical cleaning using acid, alkali, etc., which increases costs such as maintenance costs for cleaning and the installation of a preliminary system in anticipation of equipment shutdown. It becomes.

JP-A-10-015365 JP 2010-253457 A

  An object of the present invention is to provide a water treatment apparatus and a water treatment method for treating high molecular organic substance-containing water that can suppress fouling of a membrane and can be stably operated. Moreover, the objective of this invention is providing the manufacturing apparatus of the breeding water of aquatic organisms using the water treatment method.

  The present invention is a water treatment apparatus for treating high molecular organic substance-containing water including high molecular organic substances, and performs organic substance treatment by circulating the raw water tank storing the high molecular organic substance containing water and the water in the raw water tank. It is a water treatment apparatus provided with an organic matter treatment means and a membrane filtration means for subjecting the water in the raw water tank to a membrane filtration treatment.

  In the water treatment apparatus, the organic matter concentration measuring means is provided between the raw water tank and the membrane filtration means, and the circulation is circulated from the raw water tank to the organic matter treatment means according to the organic matter concentration measured by the organic matter concentration measuring means. It is preferable to control the flow rate.

  In the water treatment device, the high molecular organic substance-containing water is a breeding water for aquatic organisms, and it is preferable to reuse the membrane filtration treated water obtained by membrane filtration treatment by the membrane filtration means as breeding water.

  In the water treatment apparatus, the organic matter treatment means is preferably a means using ozone microbubbles.

  The present invention is also 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 is stored in a raw water tank, and the organic substance treatment is performed by circulating water in the raw water tank. This is a water treatment method in which the water in the raw water tank is subjected to membrane filtration treatment.

  In the water treatment method, it is preferable that an organic substance concentration is measured between the raw water tank and the membrane filtration process, and a circulation flow rate circulating from the raw water tank to the organic substance treatment is controlled according to the measured organic substance concentration.

  In the water treatment method, the high molecular organic substance-containing water is breeding water for aquatic organisms, and it is preferable to reuse the membrane filtration treated water obtained by the membrane filtration treatment as breeding water.

  In the water treatment method, the organic matter treatment is preferably performed using ozone microbubbles.

  Further, the present invention is an apparatus for producing water for breeding aquatic organisms, comprising an aquarium for breeding the aquatic organisms, a raw aquarium for storing breeding water from the aquarium, and an organic substance by circulating water in the raw aquarium An organic matter treatment means for performing treatment, a membrane filtration means for subjecting the water in the raw water tank to a membrane filtration process, and a return means for returning at least a part of the treated water subjected to the membrane filtration treatment by the membrane filtration means to the water tank. It is a device for producing water for breeding underwater organisms.

  In the present invention, in a water treatment apparatus and a water treatment method for treating high molecular organic substance-containing water, fouling of the membrane is suppressed and stable operation is possible. Moreover, the manufacturing apparatus of the breeding water of aquatic organisms using the water treatment method can be provided.

It is a schematic structure figure showing an example of the water treatment equipment concerning the embodiment of the present invention. It is a figure which shows the LC-OCD measurement result of the breeding water which breeded the Japanese flounder. It is a schematic block diagram which shows the water treatment apparatus used by the comparative example. It is a graph which shows the result of an Example and a comparative example.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  An example of a water treatment apparatus according to an embodiment of the present invention is schematically shown in FIG.

  The water treatment apparatus 1 includes a raw water tank 12 that stores high-molecular organic substance-containing water, an ozone treatment apparatus 22 that includes an ozone generator 24 as an organic substance treatment unit that circulates water in the raw water tank 12 and performs organic substance treatment, A membrane filtration device 16 is provided as membrane filtration means for membrane filtration of the water in the water tank 12. The water treatment device 1 may include a water tank 10 for breeding aquatic organisms, a membrane filtration water tank 18 for storing membrane filtered water, and an activated carbon treatment device 20 as an ozone decomposition unit. The water treatment device 1 may include an organic matter concentration measuring device 14 as an organic matter concentration measuring unit between the raw water tank 12 and the membrane filtration device 16.

  In the water treatment apparatus 1 of FIG. 1, the overflow outlet of the water tank 10 and the raw water inlet of the raw water tank 12 are connected by a raw water pipe 40. The circulation outlet of the raw water tank 12 and the inlet of the ozone treatment apparatus 22 are connected by a raw water circulation pipe 52 through a pump 36, and the outlet of the ozone treatment apparatus 22 and the circulation inlet of the raw water tank 12 are fed through raw water through a flow meter 38. They are connected by a circulation pipe 54. The raw water outlet of the raw water tank 12 and the inlet of the membrane filtration device 16 are connected by a raw water supply pipe 42 via a pump 30. The outlet of the membrane filtration apparatus 16 and the inlet of the membrane filtration water tank 18 are connected by a membrane filtration water pipe 44, and the outlet of the membrane filtration water tank 18 and the inlet of the activated carbon treatment apparatus 20 are connected via a pump 32 to the membrane filtration water supply pipe 46. Connected by. The outlet of the activated carbon treatment device 20 and the inlet of the water tank 10 are connected by a return pipe 48. An organic substance concentration measuring device 14 is installed between the raw water tank 12 and the membrane filtration device 16, that is, in the raw water supply pipe 42. The lower part of the membrane filtration water tank 18 and the secondary side inlet of the membrane filtration device 16 are connected by a backwash water pipe 50 through a pump 34. The primary outlet of the membrane filtration device 16 and the backwash drainage inlet of the raw water tank 12 are connected by a backwash drainage pipe 58. An ozone generator 24 is connected to the lower part of the ozone treatment device 22 by an ozone supply pipe 56. A control device 26 is connected to the organic substance concentration measuring device 14 by an electrical connection means or the like, the control device 26 and the flow meter 38 are connected by an electrical connection means or the like, and the control device 26 and the pump 36 are connected to an inverter 28. It is connected by an electrical connection means or the like.

  The operation of the water treatment method and the water treatment apparatus 1 according to this embodiment will be described.

  In the aquarium 10, aquatic organisms such as fish are bred in breeding water. The breeding water usually contains high-molecular organic substances such as proteins, suspended substances and the like with the breeding of aquatic organisms. Breeding water in the aquarium 10, that is, polymer organic matter-containing water including polymer organic matter and the like is sent to the raw water tank 12 through the raw water pipe 40. Part of the polymer organic matter-containing water in the raw water tank 12 is supplied to the ozone treatment device 22 through the raw water circulation pipe 52 by the pump 36.

  Ozone microbubbles generated by the ozone generator 24 are supplied to the ozone treatment device 22 from below through an ozone supply pipe 56. In the ozone treatment device 22, circulation treatment (here mainly, decomposition treatment of the organic matter) of the organic matter in the polymer organic matter-containing water is performed by the ozone microbubble (here, the organic matter treatment step). Further, in the ozone treatment device 22, the concentrated suspended matter and the like are separated into solid and liquid by pressure floating using ozone microbubbles. The ozone-treated water that has undergone the organic treatment is circulated to the raw water tank 12 through the raw water circulation pipe 54. Exhaust ozone may be discharged through an ozone discharge pipe or the like and processed by an ozone removing device.

  On the other hand, the raw water in the raw water tank 12 is supplied to the membrane filtration device 16 through the raw water supply pipe 42 by the pump 30. In the membrane filtration device 16, the suspended substances remaining in the raw water are filtered and removed using a membrane (membrane filtration step).

  The membrane filtered water subjected to membrane filtration is stored in the membrane filtered water tank 18 as needed through the membrane filtered water pipe 44 and then supplied to the activated carbon treatment apparatus 20 as needed through the membrane filtered water supply pipe 46 by the pump 32. The In the activated carbon treatment apparatus 20, residual ozone in the membrane filtrate is decomposed by activated carbon (ozone decomposition step).

  The treated water obtained by decomposing the residual ozone may be returned to the water tank 10 through the return pipe 48 and reused as breeding water (returning process). The pump 32 and the return pipe 48 function as return 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 and reusing it, it is possible to reduce the cost of makeup water and drainage.

  When the membrane filtration device 16 needs to be washed, the membrane filtration water is backflowed from the membrane filtration water tank 18 through the backwash water pipe 50 by the pump 34 from the secondary side to the primary side of the membrane filtration device 16. May be washed (back washing step). The backwash drainage may be discharged out of the system, or may be supplied to the raw water tank 12 through the backwash drainage pipe 58.

  In the water treatment apparatus 1 according to the present embodiment, the organic organic substance-containing water is stored in the raw water tank 12, the water in the raw water tank 12 is circulated to perform organic substance treatment, and the water in the raw water tank 12 is subjected to membrane filtration treatment. In addition, fouling of the membrane caused by high molecular organic substances or living organisms is suppressed, and the membrane filtration device 16 can be stably operated. By performing the organic matter treatment by circulating the water in the raw water tank, the organic matter can be efficiently decomposed by the multistage treatment.

  During the backwashing step, the organic material may be circulated or stopped. When the backwash wastewater supplied to the raw water tank 12 contains a large amount of organic polymer and the like, it is preferable to carry out the organic matter circulation treatment even during the backwash process.

  The high molecular weight organic material is an organic material having a weight average molecular weight in the range of 100,000 to 2,000,000. The weight average molecular weight is a wet oxidation method (column: 2007) using a LC-OCD (Liquid Chromatography-Organic Carbon Detection) apparatus (manufactured by DOC-LABOR, mobile 12007) as a method for grasping the components of organic substances contained in waste water. HW50S). LC-OCD is a method of dividing an organic substance into molecular weights and measuring the organic substance concentration of each component. As an example of LC-OCD measurement, FIG. 2 shows the analysis results of breeding water in which flounder was raised. The LC-OCD spectrum shown in FIG. 2 indicates that the shorter the retention time (RT: Retention Time) [min], the larger the molecular weight of the organic substance, but the retention time (RT) is detected around 26 to 34 minutes. The peaks that are observed are high molecular organic substances such as proteins having a weight average molecular weight in the range of 100,000 to 2,000,000.

  As an organic substance processing means, an ultraviolet oxidation processing apparatus etc. other than an ozone processing apparatus provided with an ozone generator are mentioned. From the viewpoint of processing performance and the like, an ozone processing apparatus including an ozone generator is preferable. As the organic substance treatment means, an ozone treatment apparatus using ozone microbubbles is preferable.

  The ozone microbubble is, for example, a fine ozone-containing bubble containing ozone having a diameter of about 10 μm to 100 μm. Ozone treatment equipment using ozone microbubbles floats by adsorbing suspended substances on the surface of ozone microbubbles, which are fine bubbles containing ozone, to water containing polymer organic substances including polymer organic substances and suspended substances. While separating and removing, the organic substance oxidation effect by an ozone microbubble is acquired. Moreover, since ozone microbubbles can be held in the tank of the ozone treatment device 22 for a long time by using ozone as microbubbles, the reaction time with organic matter increases, and the treatment effect of organic matter is drastically improved. Conceivable.

  The membrane filtration device 16 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).

  If the concentration of residual ozone in the membrane filtered water is high and there is a concern that it will be returned to the aquarium 10 and affect the breeding of living organisms, etc., an ozone decomposing means such as an activated carbon treatment device 20 will be installed downstream of the membrane filtration device 16. It is preferable to provide it. By providing the ozonolysis means at the subsequent stage of the membrane filtration device 16, it is possible to reduce the influence of residual ozone on the breeding of organisms. For this reason, even when the raw water is aquaculture, breeding water such as an aquarium, etc., even if the treated water is returned to the aquarium 10, the influence on living organisms can be reduced.

  Examples of the ozonolysis means include an activated carbon treatment apparatus such as an activated carbon packed tower packed with activated carbon, a packed tower packed with a Pd-supported carrier, a peroxide decomposition catalyst such as titanium oxide, platinum, etc. From the viewpoint, an activated carbon treatment apparatus such as an activated carbon packed tower is preferable. Further, the water flow direction to the packed tower packed 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.

  In the example of FIG. 1, all of the treated water is returned to the aquarium 10 and added to the breeding water, but at least a part of the treated water may be returned to the aquarium 10 and added to the breeding water. A part of the water may be returned to the water tank 10 and added to the breeding water, or all of the treated water may be returned to the water tank 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 is returned to the water tank 10, and it is more preferable that all the treated water is returned to the water tank 10. By setting it as the closed circulation system by which all the treated water is returned to the water tank 10, there exists an advantage that the amount of water to be used can be reduced. Further, the circulation may be performed constantly or periodically. Usually, in order to keep the water quality in the water tank 10 as much as possible, it may be circulated at all times.

  In the water treatment method and the water treatment apparatus according to this embodiment, the organic matter concentration measuring device 14 is provided as an organic matter concentration measuring means between the raw water tank 12 and the membrane filtration device 16, and the organic matter of the raw water measured by the organic matter concentration measuring device 14 is used. It is preferable to control the circulation flow rate circulating from the raw water tank 12 to the ozone treatment device 22 according to the concentration. When the organic matter concentration of the raw water measured by the organic matter concentration measuring device 14 is high, the circulation flow rate circulating from the raw water tank 12 to the ozone treatment device 22 is increased, and when the organic matter concentration is low, the ozone treatment device is fed from the raw water tank 12 to the ozone treatment device 22. What is necessary is just to make low the circulating flow volume which circulates to 22. Further, the circulation flow rate may be controlled so that the organic matter concentration of the raw water measured by the organic matter concentration measuring device 14 is not more than a predetermined reference value (for example, 1 mg / L or less). If the organic matter concentration of the raw water measured by the organic matter concentration measuring device 14 temporarily increases, such as exceeding a predetermined reference value, the supply of raw water from the raw water tank 12 to the membrane filtration device 16 is stopped, Circulation treatment from the water tank 12 to the ozone treatment device 22 may be performed for a predetermined time.

  The organic substance concentration measuring device 14 is not particularly limited as long as it can measure the organic substance concentration. Examples of the organic substance concentration measuring device 14 include a spectrophotometer that measures the absorbance of raw water. For example, an organic contamination monitor (UVAM-222K manufactured by Meidensha Co., Ltd.) can be used as the organic concentration measuring device 14.

Although the example of the control method of a circulation flow rate is shown below, it is not limited to this.
(1) Measurement of organic matter concentration in blank water (= A0)
(2) Measurement of organic substance concentration in water containing polymer organic substance (= A1)
(3) Operation A ′ = A1−A0
Output of inverter 28 (%) = B0 + A ′ × B1
B0 = Basic output, B1 = Coefficient (4) The calculation result of (3) above is output to the inverter 28 by the control device 26, and the circulating flow rate of the pump 36 is changed.

  In accordance with the organic matter concentration measured by the organic matter concentration measuring device 14, by controlling the circulation flow rate that circulates from the raw water tank 12 to the ozone treatment device 22, the suspended matter in the polymer organic matter-containing water containing the organic matter such as protein is obtained. It is possible to perform a stable treatment, and it is possible to reduce the running cost of the membrane filtration of the membrane filtration device 16 and the initial cost due to the excessively large water treatment device 1. This is particularly effective when the concentration of macromolecular organic matter in the breeding water varies due to factors such as feeding.

  The water treatment apparatus 1 and the water treatment method according to the present embodiment are applied to treatment of breeding water used when raising aquatic organisms such as aquariums and aquaculture, and the breeding water is fresh water even if it is seawater. May be. It is suitably applied to the treatment of water containing high molecular organic substances including high molecular organic substances such as proteins that are produced in the process of breeding aquatic organisms such as aquariums and aquaculture. When raising an organism, there is a characteristic that the concentration of organic matter in the breeding water varies (for example, ± 0.5 to 10 mg / L) due to factors such as feeding. In particular, it is suitable for the treatment of seawater containing macromolecular organic matter such as proteins, which is produced in the process of breeding aquatic organisms such as aquariums and aquaculture, and aquaculture of aquatic organisms such as fish and aquatic organisms such as fish in aquariums It is more suitable for closed system circulation treatment used for breeding water treatment. That is, the water treatment apparatus 1 according to the present embodiment can be suitably used as a production apparatus or a treatment apparatus for breeding water for aquatic organisms.

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

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

<Example 1>
In the examples, the water treatment device 1 shown in FIG. 1 was used, and in the comparative example, the water treatment device shown in FIG. 3, which is an experimental system in which an ozone treatment device, a membrane filtration device, and an activated carbon treatment device were connected in series, was used. . Table 1 shows experimental conditions for the examples, and Table 2 shows experimental conditions for the comparative examples.

  In the water treatment apparatus shown in FIG. 3 used in the comparative example, after the high molecular organic substance-containing water was stored in the raw water tank 102 from the water tank 100, it was supplied to the ozone treatment apparatus 104 through the strainer 114 by a pump. Ozone microbubbles generated by the ozone generator 116 were supplied to the ozone treatment device 104. The ozone-treated water treated with ozone was stored in the ozone-treated water tank 106 and then supplied to the membrane filtration device 108 by a pump to perform membrane filtration. After the membrane filtered water was stored in the membrane filtered water tank 110, it was supplied to the activated carbon treatment device 112 by a pump to perform activated carbon treatment. The treated water was returned to the water tank 100.

In the Example, according to the organic substance density | concentration measured with the organic substance concentration measuring apparatus 14, the circulation flow volume circulated from the raw | natural water tank 12 to the ozone treatment apparatus 22 was controlled. The control method of the circulation flow rate is shown below.
(1) Organic matter concentration measurement of blank seawater (artificial seawater) (= A0)
(2) Measurement of organic substance concentration in high molecular organic substance-containing water (bred water) (= A1)
(3) Operation A ′ = A1−A0
Output of inverter 28 (%) = B0 + A ′ × B1
B0 = Basic output, B1 = Coefficient (4) The calculation result of (3) above is output to the inverter 28 by the control device 26, and the circulating flow rate of the pump 36 is changed.

  The trend of the transmembrane pressure difference between the example and the comparative example is shown in FIG.

  As shown in FIG. 4, compared to the comparative example, in the example, an increase in the transmembrane pressure difference of the membrane filtration device could be suppressed. From these results, it was suggested that the fouling of the membrane can be suppressed by the water treatment device and the water treatment method of the example, and the stable operation of the membrane filtration device and the chemical cleaning frequency of the membrane can be suppressed. Moreover, by setting the circulation flow rate to the ozone treatment device high, it is possible to suppress the increase in the transmembrane pressure difference of the membrane filtration device, but costs such as the electricity cost of the pump are required.

  Thus, in the Example, in the water treatment apparatus and the water treatment method for treating high molecular organic substance-containing water, fouling of the membrane was suppressed and stable operation became possible.

  DESCRIPTION OF SYMBOLS 1 Water treatment apparatus, 10,100 Water tank, 12,102 Raw water tank, 14 Organic substance concentration measuring apparatus, 16,108 Membrane filtration apparatus, 18,110 Membrane filtration water tank, 20,112 Activated carbon treatment apparatus, 22,104 Ozone treatment apparatus, 24,116 Ozone generator, 26 control device, 28 inverter, 30, 32, 34, 36 pump, 38 flow meter, 40 raw water piping, 42 raw water supply piping, 44 membrane filtered water piping, 46 membrane filtered water supply piping, 48 Return piping, 50 Backwash water piping, 52, 54 Raw water circulation piping, 56 Ozone supply piping, 58 Backwash drainage piping, 106 Ozone-treated water tank, 114 strainer.

Claims (9)

A water treatment apparatus for treating water containing polymer organic matter including polymer organic matter,
A raw water tank for storing the polymer organic matter-containing water;
An organic matter treatment means for treating the organic matter by circulating the water in the raw water tank;
Membrane filtration means for membrane filtration treatment of the water in the raw water tank,
A water treatment apparatus comprising: The water treatment device according to claim 1,
An organic matter concentration measuring means is provided between the raw water tank and the membrane filtration means,
A water treatment apparatus characterized by controlling a circulation flow rate circulating from the raw water tank to the organic matter treatment means according to the organic matter concentration measured by the organic matter concentration measurement means. The water treatment device according to claim 1 or 2,
The water containing a high molecular organic substance is a breeding water for aquatic organisms, and a membrane filtration treated water obtained by membrane filtration treatment by the membrane filtration means is reused as breeding water. The water treatment device according to any one of claims 1 to 3,
The water treatment apparatus, wherein the organic substance treatment means is means using ozone microbubbles. A water treatment method for treating polymer-containing water containing polymer organic matter,
A water treatment method characterized by storing the polymer organic matter-containing water in a raw water tank, circulating the water in the raw water tank to perform organic treatment, and subjecting the water in the raw water tank to membrane filtration. The water treatment method according to claim 5,
A water treatment method characterized in that an organic substance concentration is measured between the raw water tank and a membrane filtration treatment, and a circulation flow rate circulating from the raw water tank to the organic substance treatment is controlled according to the measured organic substance concentration. The water treatment method according to claim 5 or 6,
The water-containing method is characterized in that the high molecular organic substance-containing water is a breeding water for aquatic organisms, and the membrane filtration treated water obtained by the membrane filtration treatment is reused as breeding water. The water treatment apparatus according to any one of claims 5 to 7,
In the organic matter treatment, the treatment is performed using ozone microbubbles. An apparatus for producing water for breeding underwater organisms,
A tank for breeding the aquatic organisms;
A raw water tank for storing breeding water from the water tank;
An organic matter treatment means for treating the organic matter by circulating the water in the raw water tank;
Membrane filtration means for membrane filtration treatment of the water in the raw water tank,
A return means for returning at least a part of the treated water subjected to membrane filtration by the membrane filtration means to the water tank;
An apparatus for producing water for breeding aquatic organisms, comprising: