JP2020036599A - Seafood culture water purifier, seafood culture device and purification method of seafood culture water - Google Patents

Abstract

To provide a seafood culture water purifier capable of easily acquiring clean water from water to be purified containing solid organic matters and ammonium ion, a seafood culture device capable of easily culturing seafoods and comprising the seafood culture water purifier, and a purification method of seafood culture water capable of easily culturing seafoods.SOLUTION: There is provided a seafood culture water purifier 1 for purifying water to be purified 3, in the water to be purified 3 in a purification tank 4, micro bubbles of a gas including ozone are generated, for removing solid organic matters and ammonium ion in the water to be purified 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fish and shellfish culture water purification device, a fish and shellfish culture device, and a method of purifying fish and shellfish culture water, and more particularly, to easily obtain clean water from purified water containing solid organic matter and ammonium ions. Fish and shellfish cultivation water purification device, fish and shellfish cultivation water purification device with fish and shellfish cultivation water purification device, and fish and shellfish cultivation water that can easily cultivate fish and shellfish It relates to a purification method.

  Fish, shellfish, aquatic plants, and the like (hereinafter, sometimes referred to as “fish and shellfish”) may be cultured in a breeding aquarium. In the water in the breeding aquarium, dirt gradually accumulates due to leftovers of food given to the fish and shellfish, excretion of the fish and shellfish, and dead bodies of the fish and shellfish. If the degree of water contamination in the breeding aquarium is large, the health of the fish and shellfish is impaired. Therefore, it is necessary to purify the accumulated water in the breeding aquarium into clean water suitable for breeding fish and shellfish by using various purifying devices.

  In the breeding aquarium, in particular, accumulation of solid organic matter suspended without dissolving in water and accumulation of ammonium ions dissolved in water become problems. Solid organic matter reduces the dissolved oxygen in water by spoiling in water, causes suffocation of fish by attaching to fish gills, and interferes with light transmission in water and impairs plant photosynthesis. Sometimes. In addition, ammonium ions dissolved in water may harm the health of fish and shellfish in water. Techniques for obtaining clean water by decomposing solid organic substances or ammonium ions in water are already known.

  For example, in Patent Literature 1, "In order to generate large bubbles by opening and expanding the bubbles at a stretch from under pressure while producing a large amount of bubbles while minimizing and supplying a large amount of bubbles necessary for adsorption of the suspension, The bubbles easily adsorb the suspension and the foam adsorbing the suspension stays for a while, so the contact time of the foam with the suspension becomes longer, and the foams are easily aggregated and concentrated. It is easy to grow into a stable foam, and the foam is discharged out of the tank in a state where the stable foam is formed, so that the ability to remove the suspended matter can be significantly increased. " Column 0024). However, Patent Document 1 does not disclose or suggest that ammonium ions dissolved in water are removed.

  Patent Document 2 discloses that “contacting microbubbles with microorganisms inhabiting natural waters increases the rate of microbial growth, activates them, and nitrates or nitrates ammoniacal nitrogen. A method of purifying natural waters is disclosed (see claim 2 of Patent Document 2). However, Patent Document 2 does not describe nor suggest that solid organic matter suspended in water is removed.

  Conventionally, in order to remove solid organic matter suspended in water and decompose ammonium ions dissolved in water, an apparatus capable of removing solid organic matter as disclosed in Patent Document 1 and Patent Document 2 It must be used in combination with a device capable of decomposing ammonium ions as disclosed. However, there is a problem that operation and control of the device become complicated by using a plurality of devices.

Patent No. 5130428 JP-A-2006-272307

  The problem to be solved by the present invention is to have a fish and shellfish culture water purification device, which can easily obtain clean water from water to be purified containing solid organic matter and ammonium ions, and a fish and shellfish culture water purification device, An object of the present invention is to provide a fish and shellfish cultivation apparatus capable of easily cultivating fish and shellfish, and a method of purifying fish and shellfish cultivation water capable of easily cultivating fish and shellfish.

Means for solving the above-mentioned problems include:
(1) A fish and shellfish culture water purification apparatus for purifying water to be purified, wherein microbubbles of gas containing ozone are generated in the water to be purified in the purification tank to remove solid organic substances and ammonium ions in the water to be purified. Fish and shellfish culture water purification equipment,
(2) The fish and shellfish culture water purification apparatus according to (1), wherein the gas is a gas obtained by converting oxygen in the atmosphere into ozone.
(3) The apparatus for purifying fish and shellfish culture water according to (1) or (2), wherein the gas is injected into a microbubble generator that generates microbubbles.
(4) A foam separation device, comprising an ozone gas generator, wherein the foam separation device comprises: the septic tank; a water pipe arranged so as to be able to supply the purified water to the septic tank; A water pressure pump provided in a part of the water pipe for pressure-feeding the water to be purified, a gas pressure pipe provided to be able to press-in the gas into the water to be purified, and a gas pressure pipe inserted into the water to be purified from the gas pressure pipe. The micro-bubble generator for generating micro-bubbles of the gas, wherein the ozone gas generator is connected to the gas injection pipe. Fish and shellfish culture water purification device according to any one of the above,
(5) A breeding aquarium containing the water to be purified, and any one of (1) to (4) above, wherein the water to be purified in the breeding water tank is provided so as to be supplied to the septic tank. Fish and shellfish culture water purifying device,
(6) A downstream treatment tank to which purified water purified by the fish and shellfish culture water purification device is sent is provided downstream of the fish and shellfish culture water purification device. )
(7) A method for purifying fish and shellfish culture water that generates microbubbles of gas containing ozone in the water to be purified in the breeding aquarium to remove solid organic matter and ammonium ions in the water to be purified;
(8) a step of supplying the purified water in the breeding aquarium to a purification tank, a step of generating microbubbles of a gas containing ozone in the purified water in the purification tank, and floating the microbubbles in the purification tank. Step, a step of performing foam separation by discharging the microbubbles floating near the water surface to the outside of the septic tank, and a step of feeding the water after performing the foam separation to a breeding aquarium or a post-treatment tank, The method for purifying fish and shellfish culture water according to the above (7), comprising:
(9) The method for purifying fish and shellfish culture water according to (7) or (8), wherein the gas is gas obtained by converting oxygen in the atmosphere into ozone.

  According to the fish and shellfish culture water purification apparatus of the present invention, both solid organic matter and ammonium ions present in the purified water can be reduced, and clean water can be easily obtained.

FIG. 1 is a schematic diagram showing an example of a fish and shellfish culture water purification device. FIG. 2 is a schematic diagram showing another example of the fish and shellfish culture water purification device. FIG. 3 is a schematic diagram illustrating an example of a fish and shellfish culturing apparatus. FIG. 4 is a graph showing a relationship between an elapsed time after generation of microbubbles and ammonia nitrogen removed together with foam separation in the example.

  The fish and shellfish culture water purifying apparatus according to the present invention has a septic tank, and water to be purified in the septic tank generates microbubbles of a gas containing ozone (hereinafter sometimes simply referred to as “ozone gas”). .

  The septic tank may be any water tank that can contain the water to be purified. Further, the septic tank only needs to be large enough to remove solid organic substances and ammonium ions by generating microbubbles. The shape of the septic tank is not particularly limited, and may be a column, a prism, a truncated cone, a truncated pyramid, or the like.

  The water to be purified in the septic tank has solid organic matter and ammonium ions. The solid organic substance may be any organic substance that is suspended without dissolving in water, and the type of the solid organic substance is not particularly limited. The solid organic matter is usually an organic matter released in fish and shellfish cultivation activities, and specific examples of the solid organic matter include fish dung, leftover food, and debris of aquatic plants. The size of the solid organic matter is not particularly limited, and may be any size as long as it can float near the water surface by the buoyancy of the microbubbles described below.

  The water to be purified may be fresh water or seawater. The water to be purified is preferably a salt water containing about 0.5% by mass or more and 5% by mass or less of sodium chloride. When the water to be purified contains sodium chloride within the above numerical range, fine microbubbles are easily generated in the water to be purified.

  Microbubbles are minute bubbles generated in the water to be purified, and usually only need to have a bubble diameter of 100 μm or less. As for the size of the microbubbles, the average of the bubble diameter is more preferably 1 μm or more and 50 μm or less. When the size of the microbubbles is within the above numerical range, the generation of radicals due to the disappearance of the microbubbles, which will be described later, and the formation of stable foam due to the joining of the microbubbles occur in a well-balanced manner. The size of the microbubbles is measured, for example, by a light blocking method using a submerged particle counter. The average of the bubble diameters is determined by, for example, arithmetically averaging the bubble diameters of 100 or more microbubbles.

  The rising speed of the microbubbles is lower than that of normal bubbles, and the microbubbles disappear by dissolving the gas inside the water. Free radicals are generated as the microbubbles disappear. As will be described later, in the present invention, free radicals generated when the microbubbles disappear are reacted with the solid organic matter to generate a large amount of hydroxyl groups on the surface of the solid organic matter. Some of the microbubbles form stable foam without disappearing in water. The stable foam is formed by joining a plurality of microbubbles. The stable foam slowly rises in the water and can reach near the surface of the water.

  The amount of microbubbles generated in the water to be purified is not particularly limited. When the amount of microbubbles is small, solid organic matter and dissolved ammonia may not be sufficiently removed by the microbubbles. As long as the effects of the present invention are achieved, the amount of microbubbles generated in the water to be purified can be appropriately adjusted.

  The method of generating microbubbles in the purified water is not particularly limited.For example, a turbulent flow method of generating microbubbles by shearing bubbles in a turbulent flow, dissolving a large amount of gas under high pressure in the purified water. And then pressurize and depressurize to generate microbubbles by depressurizing, and create a high-speed vortex in the water to be purified, blow gas into the vortex, cut and crush the bubbles in the vortex, and generate gas Microbubbles can be generated by a liquid shearing method or the like.

  The gas contained in the microbubbles may contain a gas other than ozone as long as the effects of the present invention are exhibited. For example, the gas contained in the microbubbles may contain nitrogen, oxygen, argon, carbon dioxide, and the like as needed.

  Next, an example of a reaction mechanism in which solid organic matter and ammonium ions are removed by microbubbles in the water to be purified will be described.

  In the purified water, the gas in the microbubbles gradually dissolves into the purified water. This causes the microbubbles to shrink and eventually disappear. When the microbubbles disappear in water, free radicals such as hydroxyl radicals are generated from the surface of the microbubbles. Further, the ozone contained in the gas released into water when the microbubbles disappear, reacts with water to generate hydroxyl radicals. Therefore, the microbubbles of the gas containing ozone according to the present invention can generate a large amount of hydroxyl radicals by disappearing in water. Incidentally, the hydroxyl radical may be referred to as a hydroxy radical, and may be represented by a formula of .OH.

When hydroxyl radicals react with solid organic matter in the purified water, the solid organic matter is not completely decomposed, and a number of hydrophilic hydroxyl groups are formed on the surface of the solid organic matter. In the water to be purified, ammonium ions (NH ⁴⁺ ), which are cations, are adsorbed to hydroxyl groups formed on the surface of the solid organic matter. When ammonium ions are adsorbed on all the hydroxyl groups formed on the surface of the solid organic substance, the surface of the solid organic substance becomes hydrophobic. The solid organic substance having a hydrophobic surface is easily adsorbed on the surface of a stable foam formed by joining microbubbles, and floats in water together with the stable foam. By removing the stable foam that has floated to the vicinity of the water surface from the water, solid organic substances adhering to the surface of the microbubbles and ammonium ions adsorbed on the surface of the solid organic substance can be simultaneously removed from the purified water. Note that solid organic matter and ammonium ions may remain in purified water obtained after removing the stable foam, but the solid organic matter content and ammonium ion concentration in the water to be purified before removing the stable foam may be reduced. In comparison, the content of solid organic matter and the ammonium ion concentration in the purified water after the removal of the stable foam are both greatly reduced.

The gas in the microbubbles is preferably a gas obtained by converting oxygen in the atmosphere into ozone. The atmosphere contains about 20% oxygen O ₂ by volume. By performing discharge treatment, ultraviolet irradiation, or the like on the atmosphere, a gas in which part or all of oxygen O _{2 in} the atmosphere has been changed to ozone O ₃ can be obtained. As the gas in the microbubbles, a gas in which all of the oxygen contained in the atmosphere has been changed to ozone may be used, or a gas in which some of the oxygen in the atmosphere has been changed to ozone may be used. . In order to prevent the concentration of ozone contained in the gas from becoming too high, it is preferable to use a gas in which part of oxygen in the atmosphere is changed to ozone.

  Microbubbles in the water to be purified are preferably generated by a microbubble generator. The microbubble generator may be any device having a function of taking in a gas containing ozone from the outside, releasing the gas into water, and generating microbubbles of the gas in water. When the microbubble generator takes in the gas containing ozone, microbubbles of the gas containing ozone are generated in the purified water.

  Preferably, the gas is pressed into a microbubble generator that generates microbubbles. By injecting gas, more microbubbles can be generated in the water to be purified. The pressure at which gas is injected into the microbubble generator is not particularly limited. In order to inject the gas, for example, a pump or the like may be used to pressurize the inside of a pipe connected to the microbubble generator.

  A conventionally known device can be used as the microbubble generator. As an example of a microbubble generator, a microbubble generating nozzle capable of generating microbubbles from a discharge outlet by a turbulent flow method is given. FIG. 1 shows an example in which a commercially available microbubble generating nozzle is used as the microbubble generator.

  In FIG. 1, purified water 3 is sent to a purification tank 4 through a water pipe 2. By providing the water pressure pump 16 in a part of the water pipe 2, the water to be purified can be sent from the upstream side of the water pipe 2 to the purification tank 4. The to-be-purified water 3 stored in the septic tank 4 is taken into the inside of the submersible pump 5 from the water intake 6 of the submersible pump 5 provided at the bottom of the septic tank 4. The water 3 to be purified taken into the submersible pump 5 is returned to the purification tank 4 through the discharge port 7 of the submersible pump 5. A microbubble generating nozzle 8 is connected to the discharge port 7. The air suction pipe 9 in the microbubble generation nozzle 8 is connected to an ozone gas generator 11 via a tube 10. The ozone gas generated by the ozone gas generator 11 passes through the tube 10 and is taken into the microbubble generation nozzle 8 from the air suction pipe 9. In FIG. 1, a tube 10 that connects the ozone gas generator 11 and the microbubble generation nozzle 8 functions as a gas injection pipe for injecting ozone gas into the purified water in the submersible pump 5. In the microbubble generating nozzle 8, the water to be purified and the ozone gas are mixed to form a turbulent flow, so that microbubbles of the ozone gas are generated in the water to be purified. Thereafter, water to be purified containing microbubbles of ozone gas is discharged from the outlet of the microbubble generating nozzle 8 to the purification tank 4. In order to press the ozone gas generated in the ozone gas generator 11 into the water to be purified, the ozone gas generator 11 may have a gas press-in function, or separately from the ozone gas generator 11, for example, press-fitting various pumps or the like. The member may be provided on a part of the tube 10. In the example in FIG. 1, the septic tank 4, the water pipe 2, the water pressure pump 16, the tube 10, and the microbubble generating nozzle 8 form a foam separation device.

  As another example of the microbubble generator, there is a microbubble generator capable of generating microbubbles by a pressurization and decompression method. FIG. 2 shows an example in which a microbubble generator using a pressurization and decompression method is used as a microbubble generator.

  In FIG. 2, the water 23 to be purified is sent to a purification tank 24 through a water pipe 22. By providing the water pressure pump 17 in a part of the water pipe 22, the water to be purified can be sent from the upstream side of the water pipe 22 to the purification tank 24. The water 23 to be purified contained in the purification tank 24 is pumped out of the water purification tank 24 via a pipe 20 from an intake 26 provided in the water. The pipe 20 has a water intake 26 at one end provided in the septic tank 24, has a discharge port 27 at the other end provided in the septic tank 24, and has the water intake 26 and the discharge port 27. , The pump 30 and the gas dissolving tank 19 are connected in this order from the upstream side. In the pipe 20, a branch is provided between the water intake 26 and the pump 30, and a gas press-fitting pipe 28 extends from the branch. An ozone generator 29 is provided at the end of the gas injection pipe 28 opposite to the branch. The ozone gas generated in the ozone gas generator 29 is blown into the purified water 23 pumped from the water intake 26 at a branch portion where the gas injection pipe 28 branches. Thereafter, the purified water into which the ozone gas has been blown is sent to the gas dissolving tank 19 maintained at a high pressure by the pump 30. In the gas dissolving tank 19, the ozone gas exceeds the saturation amount under a constant pressure condition and dissolves in the water to be purified. Thereafter, the purified water 23 is sent to the discharge port 27. At the discharge port 27 under atmospheric pressure conditions, the ozone gas which has been supersaturated in the purified water in the pipe 20 is discharged into the water as microbubbles. As a result, water to be purified containing microbubbles is discharged from the discharge port 27 into the purification tank 24. In order to press the ozone gas generated in the ozone gas generator 29 into the water to be purified, the ozone gas generator 29 may have a gas press-in function. The member may be provided on a part of the gas injection pipe 28. In the example in FIG. 2, the water inlet 26, the pipe 20, the pump 30, the gas dissolving tank 19, and the discharge port 27 form a microbubble generator using a pressurizing and depressurizing method. Further, in the example in FIG. 2, a foam separation device is formed by the septic tank 24, the water supply pipe 22, the water pressure pump 17, the gas pressure pipe 28, and the microbubble generator.

  Next, a fish and shellfish cultivation apparatus according to the present invention will be described.

  As shown in FIG. 3, the fish and shellfish cultivation apparatus 31 according to the present invention includes a breeding aquarium 32 and the fish and shellfish cultivation water purification apparatus 33. In the breeding aquarium 32, organisms such as fish, shellfish, and aquatic plants are bred. In the breeding water in the breeding aquarium, dirt accumulates due to remaining food and dead organisms. The breeding water with accumulated dirt contains a large amount of solid organic matter suspended in the water and dissolved ammonium ions. The breeding water in which such dirt accumulates has an adverse effect on the growth of fish and the like in the breeding water, and is thus to be purified water that needs to be purified. As shown in FIG. 3A, the water to be purified in the breeding aquarium 32 can be supplied to the purification tank in the fish and shellfish culture water purification device 33. Specifically, as in the examples shown in FIGS. 1 and 2, when the fish and shellfish cultivation water purification device has a water supply pipe, the upstream end of the water supply pipe may be connected to the breeding aquarium 32. Thereby, the water to be purified in the breeding aquarium 32 is supplied to the septic tank through the water pipe. The amount of the water to be purified supplied to the septic tank may be adjusted according to the processing capacity of the septic tank.

  In the fish and shellfish culture water purification device 33, purified water is purified to obtain purified water. Specifically, purified water is obtained by generating microbubbles of gas containing ozone in the water to be purified in the purification tank of the fish and shellfish culture water purification device 33, and removing stable foams floating near the water surface. Can be As shown in FIG. 3 (4), solid organic matter and ammonium ions are discharged from the water to be purified together with the stable foam of the microbubbles removed from the septic tank. Therefore, the purified water purified by the fish and shellfish culture water purification device 33 has a lower amount of solid organic substances suspended in water and a lower concentration of ammonium ions dissolved in water than the purified water before purification. As shown by (2) in FIG. 3, in order to generate microbubbles of a gas containing ozone, ozone gas may be injected into the water to be purified by the ozone gas generator.

  The purified water obtained in the fish and shellfish culturing device 33 may be returned directly to the breeding aquarium 32, or may be sent to the post-treatment tank 35 and then returned to the breeding aquarium 32. The post-treatment tank 35 has a function of further purifying purified water so that the water quality becomes more suitable for the growth of fish and shellfish in the breeding aquarium 32. In the example in FIG. 3, as shown by (3), purified water obtained by the fish and shellfish cultured water purification device 33 is sent to the post-stage purification tank 35.

  An example of the post-stage septic tank is a biological treatment tank. In the biological treatment tank, suspended microorganisms are present, and explosion of water in the tank decomposes solid organic matter remaining in the purified water by an oxidation reaction of the microorganism. As another example of the latter-stage septic tank, there is a filtration tank for physically filtering fine substances floating in purified water using a membrane, a mesh, or the like. It should be noted that only one post-stage septic tank may be provided, or a plurality of post-stage septic tanks may be provided.

  When the fish and shellfish cultivation apparatus according to the present invention is used, the purified water from which solid organic substances and ammonium ions have been removed can be obtained by operating only the fish and shellfish cultivation water purification apparatus. In the fish and shellfish cultivation apparatus according to the present invention, it is not necessary to use two apparatuses, a solid organic matter separation apparatus and an ammonium ion separation apparatus. Therefore, purified water suitable for the growth of fish and shellfish in a breeding aquarium can be obtained relatively easily by the fish and shellfish cultivation apparatus according to the present invention.

  Next, a method for purifying fish and shellfish culture water according to the present invention will be described.

  The method for purifying fish and shellfish culture water according to the present invention includes a step of generating microbubbles of a gas containing ozone in the water to be purified in the breeding aquarium. More specifically, microbubbles of a gas containing ozone may be generated in the water to be purified using a known method such as a pressurized and depressurized method and a gas-liquid shearing method. The microbubbles may be generated in a breeding aquarium or may be generated in a water tank other than the breeding aquarium. For example, microbubbles of gas containing ozone may be generated in the water to be purified in the clarification tank after the water to be purified in the breeding aquarium is transferred to another purification tank different from the breeding aquarium.

  The method for purifying fish and shellfish culture water according to the present invention preferably includes a step of floating microbubbles in a septic tank. More specifically, microbubbles are generated in the purified water in the septic tank, and stable foams formed by joining the microbubbles are caused to float up to near the surface of the purified water contained in the septic tank. I just want to be able. Further, the microbubbles generated in the water to be purified only need to be floated for a time sufficient to remove solid organic substances and ammonium ions in the water to be purified.

Solid organic matter is adsorbed on the surface of the stable foam of the microbubbles floating near the water surface, and ammonium ion is adsorbed on the solid organic matter. Therefore, the stable foam floating near the water surface is discharged to the outside from the septic tank, and foam separation is performed to separate the foam and water, whereby the solid organic matter and ammonium ions are discharged to the outside together with the foam. Therefore, after the foam separation, the contents of solid organic substances and ammonium ions that adversely affect the growth of fish and shellfish are small, and clean purified water can be obtained. By sending the purified water to the breeding tank, water having a quality suitable for growing fish and shellfish is supplied to the breeding tank. Further, the purified water obtained after performing the foam separation may be treated in a post-treatment tank in order to further purify the water.

  Next, the operation of the fish and shellfish culture water purification apparatus according to the present invention will be described.

  The purification tank of the fish and shellfish culture water purification apparatus according to the present invention contains purified water containing solid organic matter and ammonium ions. When microbubbles of a gas containing ozone are generated in the purified water, the microbubbles themselves disappear in the water, and the ozone itself reacts with the water, thereby generating a large amount of hydroxyl radicals. These hydroxyl radicals react with the solid organic substance to form a large amount of hydroxyl groups on the surface of the solid organic substance. The surface of the solid organic substance becomes hydrophobic due to the adsorption of ammonium ions in water to the hydroxyl group. The solid organic substance having a hydrophobic surface adheres to the surface of the microbubble and floats up to near the water surface together with the stable foam of the microbubble. By taking out the foam floating near the water surface from the septic tank, the solid organic matter attached to the surface of the foam and the ammonium ion attached to the hydroxyl group on the surface of the solid organic matter can be taken out of the water at the same time. Therefore, the purified water obtained after performing the foam separation treatment has a lower content of solid organic substances and ammonium ions that adversely affect the growth of fish and shellfish than the purified water. As described above, by performing the foam separation processing using the fish and shellfish culture water purification apparatus according to the present invention, it is possible to easily obtain clean water suitable for the culture of fish and shellfish without harming the health of living organisms. be able to.

  Next, examples will be described.

(Example 1)
Normal salt and ammonia water were added to 700 L of purified water containing solid organic matter in the breeding aquarium used for sturgeon cultivation so that the salt concentration of the purified water was 1% by mass and the concentration of ammonia nitrogen was 2 ppm. And Japanese Pharmacopoeia standards). Next, the purified water was supplied at a flow rate of 30 L / hour to a septic tank which was a small-sized experimental water tank of about 10 L. Using an ozone gas generator and a microbubble generator, microbubbles of ozone gas were generated in the water to be purified in the purification tank so that ozone gas was injected under a condition of 4 L / min. After floating the microbubbles in the purified water, the water containing the stable bubbles of the microbubbles that floated to the vicinity of the water surface was collected, and the concentration of ammonia nitrogen in the water containing the stable bubbles was measured over time. The measurement results were as shown by the straight line indicated by "ozone gas" in FIG.

(Comparative Example 1)
An experiment was performed in the same manner as in Example 1, except that air was injected into the microbubble generator instead of the ozone gas, and microbubbles due to the air were generated in the water to be purified. The measurement result of the ammonia nitrogen concentration in the water containing the stable foam was as shown by the straight line indicated by "air" in FIG.

  Table 1 below shows the experimental conditions used in Example 1 and Comparative Example 1.

  As shown in FIG. 4, the concentration of ammonia nitrogen in the water containing the stable foam formed by the microbubbles of the ozone gas in the first embodiment is different from that of the water containing the stable foam formed by the microbubbles in the atmosphere in the second embodiment. Was higher than the concentration of ammonia nitrogen. Thereby, it was confirmed that more ammonium ions were foam-separated from the water to be purified in Example 1 than in Example 2.

  Specifically, the removal rate of ammonia nitrogen from the purified water in Example 1 was about 0.5 mg / hour. On the other hand, the removal rate of ammonia nitrogen from the water to be purified in Comparative Example 1 was about 0.3 mg / hour. Thereby, it was confirmed that in Example 1, the ability to remove ammonium ions existing in water was improved about 1.7 times as compared with Comparative Example 1. From the above, it was confirmed that by performing a foam separation operation using microbubbles of ozone gas, ammonium ions present in the water to be purified can be more efficiently removed.

  Further, it was visually confirmed that the same amount of suspended substance was suspended in the water containing stable foam recovered in Example 1 and the water containing stable foam recovered in Comparative Example 1. Was done. Thus, it was confirmed that the solid organic matter present in the water to be purified was removed by performing the foam separation operation using the microbubbles of ozone gas.

1, 21, 33 Fish and shellfish culture water purification device 2, 22 Water pipe 3, 23 Water to be purified 4, 24 Purification tank 5 Submersible pump 6, 26 Water intake 7, 27 Discharge port 8 Micro bubble generation nozzle 9 Air intake pipe 10 Tube 11, 29, 34 Ozone gas generator 16, 17 Water pressure pump 19 Gas dissolving tank 20 Pipe 28 Gas injection pipe 30 Pump 31 Fish and shellfish cultivation apparatus 32 Breeding water tank 35 Post-processing tank

Claims (9)

  An apparatus for purifying fish and shellfish culture water for purifying water to be purified, wherein microbubbles of gas containing ozone are generated in the water to be purified in the purification tank to remove solid organic substances and ammonium ions in the water to be purified. Fish and shellfish culture water purification equipment.   The fish and shellfish culture water purification apparatus according to claim 1, wherein the gas is gas in which oxygen in the atmosphere is changed to ozone.   The fish and shellfish culture water purification apparatus according to claim 1, wherein the gas is press-fitted into a microbubble generator that generates microbubbles. A foam separation device and an ozone gas generator,
The foam separation device, the septic tank, a water pipe arranged so as to be able to supply the purified water to the septic tank, and a water pressure pump provided to a part of the water pipe for pumping the purified water. Having a gas injection pipe provided so as to be capable of injecting the gas into the water to be purified, and the microbubble generator for generating microbubbles of a gas injected from the gas injection pipe into the water to be purified,
The fish and shellfish cultivation water purification apparatus according to any one of claims 1 to 3, wherein the ozone gas generator is connected to the gas injection pipe.   The fish and shellfish cultivation according to any one of claims 1 to 4, wherein a breeding aquarium containing the purified water and a purified water in the breeding aquarium are provided so as to be supplied to the septic tank. A fish and shellfish cultivation device, comprising: a water purification device.   6. A downstream treatment tank to which purified water purified by the fish and shellfish culture water purification device is sent is provided downstream of the fish and shellfish culture water purification device. Fish and shellfish cultivation equipment.   A method for purifying fish and shellfish culture water in which microbubbles of gas containing ozone are generated in purified water in a breeding aquarium to remove solid organic substances and ammonium ions in the purified water.   A step of supplying the purified water in the breeding aquarium to a purification tank, a step of generating microbubbles of a gas containing ozone in the purified water in the purification tank, and a step of floating the microbubbles in the purification tank. A step of performing foam separation by discharging the microbubbles floating near the water surface to the outside of the septic tank, and a step of sending water after the foam separation to a rearing tank or a post-treatment tank. The method for purifying fish and shellfish culture water according to claim 7, characterized in that:   9. The method according to claim 7, wherein the gas is gas obtained by converting oxygen in the atmosphere into ozone.

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