JP2008073006A - Method for cleaning rearing water of aquatic life and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for cleaning rearing water of an aquatic life, dispensing with the use of chemicals and a complicate operation management, effective for suppressing the increase of the turbidity and color of the water, eliminating proteins, total nitrogen, ammoniacal nitrogen and nitrite-nitrogen from rearing water and automatically keeping the water to neutral state by preventing the lowering of the pH of the water to be treated. <P>SOLUTION: The rearing water cleaning method comprises a filtering step to use sand as the filtering material in the cleaning of rearing water 2, a pH adjusting step to use oyster shell and a foam separation step. The foam separation step performs foam separation treatment of the rearing water 2 by supplying a gas to the rearing water 2 in a separation tank 7, the gas is supplied to the separation tank 7 in the form of fine bubbles, the fine bubbles are formed by generating bubbles by a means for exclusively generating bubbles and then dividing the bubbles generated by a bubble-shearing means and/or formed by the bubble-shearing means itself, and the fine bubbles are used in the step to perform the foam separation treatment of the rearing water. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a purification method and apparatus for breeding water used for breeding aquatic organisms such as fish and invertebrates in various industries such as fishery, fishery processing, food processing, live fish transportation, aquarium, and aquaculture. is there. Water purification covers a wide range, such as human waste treatment, but the present invention is not intended for wastewater treatment of discarded water, such as human waste treatment, and in particular, a water purification method that continues to be used as breeding water for aquatic organisms and It relates to the device.

  Conventionally, various purification devices have been used for purifying water for breeding aquatic organisms. Among them, a purification device comprising a filter, an oxidizer charging device, and a foam separation device is often used for purifying water for aquatic organisms. For example, a purification device as shown in FIG. It has been proposed as a purification method (see Patent Document 1). Further, in recent years, not only a purification method using a direct oxidant, but also water purification of aquatic organisms may be performed by activating water molecules of water to be treated using a high voltage pulse. For example, FIG. Has been proposed as a method for purifying water for breeding aquatic organisms (see Patent Document 2).

  As shown in FIG. 10, the structure of the purification device comprising a filter, an oxidizer charging device, and a foam separation device includes a water storage tank 101 storing water product breeding water, and water to be treated in the water storage tank 101. The pump 102 to be transferred, the filtration tank 103 for filtering the treated water stored in the water storage tank 101, and the ozone-containing gas generated by the ozonizer 108 are brought into contact with the treated water filtered through the air diffuser 109. Ozone dissolution tank 104, coral sand tank 105 and catalyst reaction tank 106 for decomposing oxidant remaining in the water to be treated by contact with ozone, ozone decomposer 110 for decomposing ozone-containing gas, and water to be treated for decomposing oxidant A purification apparatus comprising a foam separation tank 107 for separating foam, and purifying the water to be treated by the filtration means, the ozone contact means, and the foam separation means A.

  The effect is that after the water to be treated is introduced from the water storage tank 101 to the filtration tank 103 by the pump 102 and filtered, the ozone-containing gas generated by the ozonizer 108 is treated in the ozone dissolution tank 104 through the air diffuser 109. Purify and sterilize in contact with water, adjust the pH of the water to be treated in the coral sand tank 105, decompose the remaining oxidant in the catalytic reaction tank 106, and finally generate foam in the foam separation tank 107 By doing so, the contaminated component was purified from the treated water of the aquatic product breeding water.

  In addition, as shown in FIG. 11, an aquatic organism rearing water purification apparatus using high voltage pulses includes rearing water 205, an insulating water tank 204 containing gravel 208 at the bottom, a high voltage pulse generator 201, and a current limiter. The electrode 203 includes a resistor 202 and an insulating covering 206.

  The effect is that the high-voltage pulse output from the high-voltage pulse generator 201 passes through the current limiting resistor 202 and is weakened within a range that does not adversely affect the fish body. Induced and applied to 204, activated water molecules while forming an electric field in the breeding water 205, promoted decomposition of organic substances in water and emission into the air, and suppressed generation of ammonia.

Japanese Patent Laid-Open No. 7-214081 JP 2000-287580 A

  However, the purification device of Patent Document 1 has a problem in that it is difficult to adjust the amount of ozone generated to be brought into contact with the water to be treated, and complicated operation management is required for adjustment. In addition, a catalyst necessary for decomposing the remaining oxidant has to be synthesized, and there is a problem that labor and cost are increased.

  Further, in the purification device of Patent Document 2, although radicals generated by high voltage pulses are excellent in oxidizing power, their lifetime is short, and the generated radicals can only oxidize only a part in contact with the water to be treated, or There was a problem that it was difficult to maintain the activity of water, such as disappearing before being efficiently mixed with the water to be treated. Furthermore, as described in Patent Document 2, the simplest purification method includes the replacement of breeding water. However, this also has a problem that dirty spent breeding water must be separately purified. It was.

  The present invention has been made in view of the above-described problems of the prior art, and does not require the use of chemicals such as oxidizing agents or complicated operation management, and suppresses the increase in turbidity and chromaticity of breeding water. Breeding of aquatic organisms that can remove protein, total nitrogen, ammonia nitrogen and nitrite nitrogen from the breeding water, and can automatically maintain neutrality so that the pH of the treated water does not decrease A water purification method and apparatus are provided.

  In addition, when used for the purification of breeding water in an aquarium or other exhibition tank, keep the pH of the breeding water neutral so that the turbidity and chromaticity of the breeding water are not increased. An object of the present invention is to provide a method and an apparatus for purifying water for aquatic organisms, which can remove proteins accumulated in water, total nitrogen, ammonia nitrogen and nitrite nitrogen, and maintain the transparency of an exhibition tank. In addition, when used for rearing water purification of rearing water tanks for land farming and live fish transportation, it is necessary to maintain neutrality so that the pH of the rearing water does not decrease and to accumulate proteins, total nitrogen, ammonia nitrogen, It is an object of the present invention to provide an aquatic organism rearing water purification method and apparatus that can smoothly breed aquatic organisms by removing nitrite nitrogen.

  In the method for purifying breeding water used for breeding aquatic organisms, the present invention includes a filtration step, a pH adjustment step, and a foam separation step in the breeding water purification step, and includes the following configuration as a preferred embodiment.

  The filter medium used for the filtration step is sand.

  The said pH adjustment process is kept neutral so that the pH of this breeding water may not fall by making oyster shell contact the breeding water of aquatic organisms.

  The pH adjustment step maintains the pH of the breeding water at 7 ≦ pH <8.6.

  The foam separation step is to supply a gas to the breeding water in the separation tank and subject the breeding water to a foam separation process. The gas supplied into the separation tank is a fine bubble, and the fine bubble is , After generating bubbles by means for generating only bubbles, fine bubbles generated by shearing the bubbles by means for shearing the bubbles and / or fine bubbles generated from the means for shearing the bubbles themselves, The fine bubbles are used for foam separation treatment of breeding water.

  In the breeding water purification apparatus used for breeding aquatic organisms, the purification apparatus includes a filter, a pH adjustment tank, and a foam separation treatment apparatus.

  The purification device is composed of a filter using sand as a filter medium, a pH adjusting tank filled with oyster shells as a pH adjusting material, and a foam separation processing device, and the foam separation processing device performs foam separation processing. It has a separation tank, a means for generating only bubbles in the separation tank, and a means for shearing the bubbles and / or generating fine bubbles.

  The aquatic organism rearing water purification method and apparatus according to the present invention has the above-described configuration, so that the following excellent effects can be obtained.

  (1) The purification process includes a filtration process, a pH adjustment process, and a foam separation process in the breeding water purification process, so that foaming components derived from residual feed and body surface mucus of aquatic organisms can be efficiently removed from the breeding water. Compared to the case where only the filtration step and the pH adjustment step are included, the turbidity of the breeding water is halved, the chromaticity is 1/3 to 1/2, the protein is 2/3, and the total nitrogen is 1/10 to 1 / 3. In addition, since the breeding water is efficiently purified, the amount of breeding water exchanged can be reduced in the closed purification system.

  (2) When sand is used as a filter medium in the filtration step, it can be easily obtained at a low cost.

  (3) By using oyster shell as a pH adjusting material for the pH adjusting tank, no agent is required when adjusting pH, and oyster shell dissolves as the action of substances that lower the pH of breeding water is suppressed. The pH of the breeding water does not fluctuate due to excessive input, and the pH of the breeding water can be kept neutral. It is also excellent from the viewpoint of reducing the environmental burden of recycling waste and from the effective use of paid waste.

  (4) After the fine bubbles used in the foam separation processing apparatus generate bubbles by means for generating only bubbles, the fine bubbles generated by shearing the bubbles by means for shearing the bubbles and / or the bubbles Since the bubbles are generated from the shearing means itself, the diameter of the bubbles supplied into the foam separation processing apparatus can be made fine, and a large amount of fine bubbles can be generated in the foam separation processing apparatus. Therefore, foaming components such as proteins and surfactants can be efficiently removed from the breeding water.

  (5) A large amount of air bubbles are generated in the production of fine bubbles to be supplied to a filter using sand as a filter medium, a pH adjusting tank filled with oyster shells as a pH adjusting material, and a foam separation processing apparatus as a rearing water purification device for aquatic organisms. By using a foam separation processing device that has two steps, a part that generates bubbles and a part that refines bubbles, the processing equipment can be set compactly, operation management is easy, and a certain treated water quality is obtained. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 9, but it goes without saying that the present invention is not limited to the embodiments. FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a block diagram showing an embodiment in the foam separation process.

  The aquatic organisms in the present invention are living organisms that mainly live underwater such as fish and invertebrates, and the aquatic animal breeding tank 1 is the main inhabitants underwater such as fish and invertebrates. It is a water tank used when raising living organisms.

  The aquatic organism breeding water 2 in the present invention includes a foaming component having a foaming action such as a pollutant, various nitrogen, proteins, and a surfactant.

  The oyster shell 6 in the present invention is obtained by removing an edible portion from an oyster that is an aquatic organism, and is filled in the pH adjustment tank 5 by 50% or more with respect to the weight of the aquatic organism bred in the breeding aquarium 1. And a pH adjuster to be brought into contact with the breeding water 2 after being filtered by the filter 4.

  The neutrality in the present invention is 6.4 ≦ pH <9.0. When the breeding water is purified by a circulation type that does not use the pH adjustment function for the purification of breeding water of aquatic organisms and suppresses the addition of new breeding water, the pH of the breeding water becomes less than 6.4 due to the accumulation of nitrate nitrogen. descend. Therefore, by bringing the breeding water 2 and the oyster shell 6 into contact, the breeding water 2 is maintained at 6.4 ≦ pH <9.0, which is a pH at which aquatic organisms are liable to live, and is an oxidizing bacterium that inhabits the filtration process. It is preferable to maintain the pH of the breeding water 2 at 6.4 ≦ pH <9.0 so that the activity is maintained.

  The gas in the present invention is a gas necessary for respiration such as oxygen. When air is used, air is particularly preferable because it is not necessary to prepare a separate gas.

  The bubble 15 in the present invention is a gas mass having a diameter in the breeding water 2 exceeding 1 mm, and the fine bubble 16 is a gas mass having a diameter of 1 mm or less. The foam 17 is a foamed component contained in the breeding water 2 that comes into contact with the bubbles 15 and the fine bubbles 16 and foams.

  In this invention, it is preferable to include a filtration process, a pH adjustment process, and a foam separation process in the purification process of the breeding water used for breeding of aquatic organisms. Filtration process to filter out solids such as excrement and residual food of the breeding body accumulated in the breeding water 2 and oxidize ammonia nitrogen derived from the excrement and residual feed of the breeding body to nitrate nitrogen In addition, a pH adjustment step is required to keep the pH neutral so that the pH of the breeding water 2 is not lowered by nitrate nitrogen accumulated in the breeding water 2, and the excrement of the breeding body In order to separate and remove foaming components such as protein derived from residual bait and body surface mucus from the breeding water 2, a foam separation step is necessary.

  In the present invention, it is preferable that the filter medium in the filtration step in the purification of breeding water for aquatic organisms is sand. The filter medium used in the filtration process plays two roles as a solid habitat and a habitat for oxidizing bacteria that oxidize ammoniacal nitrogen to nitrate nitrogen. If it is only a function, it becomes a filter material for resin and ceramic, but sand that is inexpensive and easily available is more preferable.

  In the present invention, the pH adjusting material for keeping the pH of the breeding water 2 neutral so as not to lower the pH of the breeding water 2 in the pH adjustment step in the purification of the breeding water of aquatic organisms is the oyster shell 6. It is preferable. The pH adjuster has the same function even with calcium carbonate such as coral and ore, but oyster shells often become waste. It is particularly preferable that the pH adjusting material is oyster shell from the viewpoint of effective utilization of waste from the treatment.

  In the present invention, it is preferable to maintain the pH of the breeding water 2 at 7 ≦ pH <8.6 by bringing the breeding water 2 and the oyster shell 6 into contact with each other in the pH adjustment step in the purification of the breeding water of the aquatic organisms. More preferably, 7.3 ≦ pH <8.4. The activity of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria adhering to the filter media is significantly reduced, and ammonia nitrogen and nitrite nitrogen are accumulated in the breeding water, preventing the influence on the breeding of aquatic organisms. For this purpose, 7 ≦ pH is preferable. Moreover, pH <8.6 is preferable in order to prevent hydrogen ions from being extremely reduced in the breeding water and preventing a part of the ammonia nitrogen in the breeding water from being present as ammonia.

  In the present invention, the foam separation step in the purification of the aquatic organism's breeding water is to supply gas to the breeding water 2 in the separation tank 8 and to perform the foam separation process on the breeding water 2, and to supply it to the separation tank 8. The gas is a fine bubble 16, and after the fine bubble 16 generates the bubble 15 by means for generating only the bubble 15, the fine bubble 16 generated by shearing the bubble 15 by means for shearing the bubble 15 and / or Or it is the fine bubble 16 which generate | occur | produces from the means itself which shears the bubble 15, and it is preferable that the fine bubble 16 foam-treats the breeding water 2. FIG. It is not necessary to prepare a separate gas by using air in the foam separation process, and further, in the generation of the fine bubbles 16 to be supplied into the foam separation processing device 7, a part that generates a large amount of bubbles and the miniaturization of the bubbles 15 are performed. By introducing the two steps of the portion to be performed, it becomes possible to supply a large amount of air and fine bubbles 16 to the foam separation processing device 7, and excrement, residual food and body surface mucus from the breeding water 2 It is preferable because foaming components such as proteins derived from can be efficiently separated.

  In the present invention, the rearing water purification device used for rearing underwater organisms is preferably composed of a filter 4, a pH adjustment tank 5, and a foam separation treatment device 7. By combining these purification devices, it is possible to filter solids and to oxidize ammonia nitrogen in the breeding water 2 to nitrate nitrogen, to keep the pH of the breeding water neutral, Can be used as a series of devices to separate foaming components such as protein derived from bodily excrement, residual food and body surface mucus, and reared without the need for complicated operation management according to each usage condition This is preferable because water can be purified.

  In the present invention, the rearing water purification device used for rearing aquatic organisms is composed of a filter 4 using sand as a filter medium, a pH adjusting tank 5 filled with oyster shells 6, and a foam separation treatment device 7, The foam separation processing device 7 includes a separation tank 8 that performs the foam separation process, a unit that generates only the bubbles 15 in the separation tank 8, and a unit that shears the bubbles 15 and / or generates fine bubbles 16. It is preferable. By using sand as the filter medium of the filter 4 and the oyster shell 6 as the pH adjuster of the pH adjusting tank 5, it is possible to reduce the environmental load of recycling waste, and the fine bubbles 16 to be supplied into the foam separation treatment device 7 can be reduced. By using the foam separation processing device 7 having two steps of generating a large amount of bubbles and a portion for refining the bubbles 15, a large amount of air and the fine bubbles 16 are converted into the foam separation processing device 7. The foaming components such as protein can be efficiently removed from the breeding water 2 in a space-saving manner.

  In the present invention, the oyster shell 6 filled in the pH adjustment tank 5 is disposed at the bottom of the pH adjustment tank 5, and the breeding water 2 flowing into the pH adjustment tank 5 is an upward flow upward from the bottom of the pH adjustment tank 5. Preferably there is. By raising the flow of the breeding water 2 in the pH adjusting tank 5, the breeding water 2 sufficiently contacts the oyster shell 6, and the contact efficiency between the breeding water 2 and the oyster shell 6 is improved. Moreover, the shape of the oyster shell 6 filled in the pH adjustment tank 5 may be crushed into a fine shape even in an unprocessed natural state. However, in any case, when the oyster shell 6 is filled in the pH adjustment tank 5, the height of the pH adjustment tank 5 is increased so that the oyster shell 6 does not overflow from the pH adjustment tank 5 by the upflow breeding water 2. It is preferable to form the pH adjusting tank 5 so that it does not overflow or overflow.

  In the present invention, the air supplied to the foam separation processing device 7 is preferably fine bubbles 16. If this is the same amount of air, the finer the bubble diameter, the larger the number of bubbles, the easier it is to diffuse into the water to be treated and the dispersion in the foam separation treatment device 7. The contact between the foam component and the fine bubbles 16 is increased, and the foam component in the breeding water can be efficiently separated and discharged, which is preferable.

  In the present invention, the fine bubbles 16 include the fine bubbles 16 and / or the bubbles 15 generated by generating the bubbles 15 by means for generating only the bubbles 15 and then shearing the bubbles 15 by means for shearing the bubbles 15. The fine bubbles 16 generated from the shearing means itself are preferable. This means that a means for generating only the bubbles 15 is provided below the means for shearing the bubbles 15 and generating the fine bubbles 16, and the bubbles 15 generated from the means for generating only the bubbles 15 shear the bubbles 15 and By floating to the position of the means for generating the fine bubbles 16 and shearing the bubbles 15 by the water flow generated by the means for generating the fine bubbles 16, the amount of air supplied to the foam separation processing device 7 is increased. In addition, the bubble diameter can be made fine, and a large amount of fine bubbles 16 can be generated in the foam separation processing device 7, which is preferable.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2. 1 is a breeding tank where fish and invertebrates are raised, 3 is a pump for transferring breeding water 2 flowing out from the bottom of the breeding tank 1 to each device, 4 is a filter using sand as a filter medium, and 5 is pH adjustment. A pH adjusting tank 7 using the oyster shell 6 as a material, 7 is a foam separation processing apparatus. The foam separation processing device 7 has two processes of a separation tank 8 and a part that generates a large amount of bubbles and a part that refines the bubbles 15 when generating the fine bubbles 16 to be supplied into the separation tank 8. The pH adjusting tank 5 is filled with oyster shells 6 at the bottom of the tank, and has a structure in which the oyster shells 6 and the breeding water 2 are efficiently brought into contact with each other by flowing the breeding water 2 from the bottom to the top of the tank. The oyster shell 6 is filled 50% to 100% with respect to the weight of the aquatic organisms bred in the breeding aquarium 1. In the present invention,% is a weight standard. Moreover, the separation tank 8 of the foam separation processing apparatus 7 is provided with an inflow port through which the breeding water 2 flows into the side surface, an outlet through which the foam separation water is discharged at the top, and an outflow port through which the treated breeding water 2 flows out at the bottom. It has been. The separation tank 8 is provided with three stages of shade-shaped shielding plates 9 having a sloped portion penetrating through the center and reducing in diameter toward the upper part from the inner middle part to the upper part with a certain interval. Further, a self-contained fine bubble generator 10 is provided at a position slightly below the intermediate portion inside, and a diffuser plate 11 is provided at a position below the self-supplied fine bubble generator 10 and not reaching the bottom of the separation tank 8. It has been. The self-contained microbubble generator 10 communicates with an intake port 12 that communicates with external air, and the diffuser plate 11 communicates with an intake port 13 that communicates with a blower 14.

  Next, the operation of the embodiment of the present invention will be described. First, breeding water 2 of aquatic organisms (hereinafter referred to as breeding water) containing foaming components derived from residual feed and body surface mucus of aquatic organisms is pressed into the top of the filter 4 from the bottom of the breeding aquarium 1 by a pump 3. The After the press-fed breeding water 2 is filtered by the filter 4, it flows into the lower part of the pH adjustment tank 5 filled with the oyster shell 6 at the bottom. The inflowing breeding water 2 flows out from the upper part of the pH adjustment tank 5 while coming into contact with the oyster shell 6 in an upward flow, and is returned to the breeding tank 1 again. The breeding water 2 is also transferred to the foam separation processing device 7 arranged in parallel with the pump 3 that is press-fitted into the filter 4. The breeding water 2 that has flowed in from the side surface of the separation tank 8 of the foam separation processing device 7 stays in the separation tank 8 for a certain period of time. At the same time, air in the atmosphere is introduced through the air inlet 13 by the blower 14, whereby the bubbles 15 are supplied from the diffuser plate 11 to the separation tank 8. Further, the microbubbles 16 are supplied into the separation tank 8 by the self-contained microbubble generator 10 that sucks air in the atmosphere through the air inlet 12. At this time, the bubbles 15 and the fine bubbles 16 collide violently in the vertical direction in the foam separation processing device 7 and are sheared by the water flow including the fine bubbles 16 to become the fine bubbles 16 and dissolved in the breeding water 2. It becomes foam 17 in contact with the foaming component. The foam 17 floats along the shielding plate 9 and is generated on the water surface while the foam 17 rising in the separation tank 8 is suppressed from descending again to the bottom of the separation tank 8. The foam 17 produced | generated on the water surface is discharged | emitted from the discharge port of the separation tank 8 as foam separation water, and foam separation processing is performed. On the other hand, the breeding water 2 from which the foam 17 has been removed from the breeding water 2 flows out again from the bottom of the separation tank 8 as the breeding water 2 and flows into the breeding tank 1.

Next, processing conditions relating to the breeding water purification apparatus will be described. A series of processing facilities of the breeding aquarium 1, the filter 4, the pH adjustment tank 5, and the foam separation treatment device 7 are connected in a closed type, and the type of aquatic organisms bred in the breeding aquarium 1 and the water in the breeding aquarium 1 Although it varies depending on the breeding density of the organism (kg / m ³ ), the breeding water 2 in the breeding aquarium 1 is circulated at a flow rate that makes one round in about one hour. In addition, the breeding water 2 in the foam separation treatment device 7 is also circulated in parallel in the same manner as the filter 4 and the pH adjustment tank 5. The flow rate of the breeding water 2 in the foam separation treatment device 7 varies depending on the type of aquatic organisms bred in the breeding aquarium 1 and the breeding density (kg / m ³ ) of the aquatic organisms in the breeding aquarium 1, but the filter 4 Or smaller than the flow rate circulating through the pH adjusting tank 5. Because the smaller the amount of breeding water 2 circulating in the foam separation treatment device 7, the smaller the foam separation treatment device 7, the smaller the installation area occupied by the treatment equipment, and more efficient breeding water This is because the purification can be performed.

  In this embodiment, closed type equipment is used, but in purifying water for breeding aquatic organisms, the same effect can be obtained even when carried out while pouring.

  Next, the test of the breeding water purification in the aquatic organism of the present invention was conducted. The measurement method of the test is shown below.

(1) Measurement of pH The pH in breeding water of aquatic organisms was measured with a portable pH meter WM-22EP manufactured by Toa DKK in accordance with JIS K0102.

(2) Measurement of ammoniacal nitrogen Ammoniaous nitrogen in aquatic animal breeding water is produced using chlorine / ammonia and produced monochloramine by reaction with salicylate using a portable multi-item water quality analyzer DR / 2400 manufactured by HACH. The color was developed in the presence of a catalyst and measured as ammoniacal nitrogen (mg / L) by absorptiometry at a wavelength of 655 (nm).

(3) Measurement of nitrite nitrogen Nitrite nitrogen in the water of aquatic organisms is based on JIS K010243, using a portable multi-item water quality analyzer DR / 2400 manufactured by HACH USA, and using sodium nitrite as a standard substance Nitrite nitrogen (mg / L) was measured.

(4) Measurement of turbidity Turbidity in breeding water of aquatic organisms was measured with a surface scattering turbidimeter TB400G-4-1-1 / B / S manufactured by Yokogawa Electric. The surface scattering turbidimeter is composed of a detector and a converter composed of a measuring tank and a detector, and turbidity measurement is performed at a flow rate of 4 to 6 (L / min) from the lower side of the measuring tank. The measured water is overflowed in the upper part of the measurement tank, light is irradiated from the tungsten lamp to the overflowed measurement water surface, the scattered light is collected, and the turbidity (mg) is measured while measuring the intensity ratio with the irradiated light with a converter. / L).

(5) Measurement of chromaticity The chromaticity of breeding water of aquatic organisms is based on JIS K01010, using a portable multi-item water quality analyzer DR / 2400 manufactured by HACH, USA, and chromaticity with platinum and cobalt as standard substances. Measured as (degrees).

(6) Measurement of protein The protein in the breeding water of aquatic organisms is based on the Lowry-Folin method, and BSA (bovine serum albumin) is used as a standard substance with a spectrophotometric method at a wavelength of 750 (nm). / L).

(7) Measurement of total nitrogen Total nitrogen in aquatic animal breeding water is obtained by oxidizing all nitrogen compounds to nitrate ions by persulfuric acid decomposition using a portable multi-item water quality analyzer DR / 2400 manufactured by HACH, USA. Under the condition, nitrate ion and chromotropic acid were reacted, and the total nitrogen (mg / L) was measured by absorptiometry at a wavelength of 410 (nm).

[Example 1]
First, in the purification of aquatic organism breeding water in the present invention, using a filter and a foam separation treatment apparatus as a treatment facility, the pH variation of the breeding water due to the presence or absence of a combination of pH adjusting tanks, ammonia nitrogen, and nitrite nitrogen were measured. .

  As a test apparatus based on an embodiment of the present invention, a filter, a pH adjusting tank, and a foam separation treatment apparatus are manufactured, and using breeding water using fish as an aquatic organism, the pH of the breeding water, ammonia nitrogen, nitrous acid Nitrogen was measured under the following conditions. The test results are shown in FIGS.

  FIG. 3 is a graph showing the transition of the pH of the breeding water with and without the pH adjustment tank. FIG. 4 is a graph showing the transition of ammoniacal nitrogen in the breeding water with and without the pH adjustment tank. FIG. 5 is a graph showing the transition of nitrite nitrogen in breeding water with and without a pH adjustment tank.

(Testing conditions for rearing water purification)
-Breeding density of fish in the breeding tank: 5 (kg / m ³ )
・ Daily water change amount to breeding tank: 1% (%) of water amount
・ Type of feeding: fillet such as horse mackerel, krill, clams ・ Fish weight: 3.7 (kg)
・ Feeding amount: 1-2 (%) of fish weight
・ Circulating flow rate to the filter and pH adjustment tank: 0.8 (m ³ / h)
・ Circulating flow rate to the foam separation treatment device: 0.4 (m ³ / h)
-Filter media: φ0.6 (mm) silica sand-Filter effective capacity: 120 (L)
・ Oyster shell filling amount in pH adjustment tank: 3.6 (kg)
・ Effective capacity of pH adjustment tank: 14 (L)
-Specification of foam separation processing device: Combined use of diffuser plate and self-contained fine bubble generator-Effective capacity of foam separation processing device: 14 (L)

(Test conditions)
(A) Put 15 kinds of 15 fish into the breeding tank so that the breeding density of the fish in the breeding tank is 5 (kg / m ³ ), and let the breeding water pass through each test device by a predetermined amount. , Purified the breeding water.

  (B) The pH of the breeding water, ammonia nitrogen, and nitrite nitrogen were measured 1 (times / day), and the fluctuation of the breeding water quality was observed.

[Comparative Example 1]
In the test facility of Example 1, the pH of the breeding water, ammonia nitrogen, and nitrite nitrogen were measured in the same manner under the condition where the pH adjusting tank was not combined. The test results are shown in FIGS.

  By using a pH adjustment tank filled with oyster shells in the purification equipment for breeding water, the pH of the breeding water remained at 7.8 or higher in the closed circulation purification over 40 days. On the other hand, in a test facility that combines a filter and a foam separation treatment device, the pH of the breeding water gradually decreases according to the number of test days without pH adjustment using oyster shells, and is reared in a closed circulation purification over 40 days. The pH of the water dropped to 6.2 (see Figure 3).

  By using a pH adjustment tank filled with oyster shells in the breeding water purification equipment, the ammonia nitrogen in the breeding water remained below 0.1 (mg / L) in a closed circulation purification over 40 days. . On the other hand, in a test facility that combines a filter and a foam separation treatment device, if there is no pH adjustment with oyster shells, the ammoniacal nitrogen of the breeding water starts to increase from 10 days, and the test period is the maximum after 16 days It increased to 1.68 (mg / L). After that, it changed from 0.6 to 1.1 (mg / L), and showed a tendency for ammonia nitrogen to occupy in the breeding water (see FIG. 4).

  By using a pH adjustment tank filled with oyster shells in the breeding water purification equipment, the nitrite nitrogen in the breeding water remained below 0.02 (mg / L) in a closed circulation purification over 40 days. did. On the other hand, in a test facility that combines a filter and a foam separation treatment device, if there is no pH adjustment with oyster shells, the nitrite nitrogen of the breeding water begins to increase from the 17th day, and the maximum test period is reached after 38 days. It was 4.4 (mg / L), which increased exponentially (see FIG. 5).

  From this, in the purification of breeding water for aquatic organisms, by using a filter, a pH adjustment tank, and a foam separation treatment device, it is possible to suppress a decrease in the pH of the breeding water and an increase in ammonia nitrogen and nitrite nitrogen. .

[Example 2]
Next, in the breeding water for aquatic organisms in the present invention, various water quality fluctuations of the breeding water depending on the presence or absence of the combination of the foam separation treatment apparatus were measured using a filter and a pH adjusting tank as the treatment equipment.

  As a test apparatus based on an embodiment of the present invention, a filter, a pH adjusting tank, and a foam separation treatment apparatus are manufactured, and using the breeding water using fish as an aquatic organism, the turbidity, chromaticity, protein, Total nitrogen was measured under the following conditions. The test results are shown in FIGS.

  FIG. 6 is a graph showing the transition of the turbidity of breeding water with and without the foam separation treatment device. FIG. 7 is a graph showing the transition of the chromaticity of the breeding water with and without the foam separation processing device. FIG. 8 is a graph showing the transition of the breeding water protein with and without the foam separation treatment apparatus. FIG. 9 is a graph showing the transition of the total nitrogen of the breeding water with and without the foam separation treatment device.

  The test conditions for breeding water purification are the same as in Example 1.

(Test conditions)
(A) Put 15 kinds of 15 fish into the breeding tank so that the breeding density of the fish in the breeding tank is 5 (kg / m ³ ), and let the breeding water pass through each test device by a predetermined amount. , Purified the breeding water.

  (B) The turbidity, chromaticity, protein and total nitrogen of the breeding water were measured 1 (times / day), and the water quality transition of the breeding water was observed.

[Comparative Example 2]
In the test facility of Example 2, the turbidity, chromaticity, protein, and total nitrogen of the breeding water were similarly measured under the condition that the foam separation treatment apparatus was not combined. The test results are shown in FIGS.

  By using a foam separation treatment apparatus for the purification system of breeding water, the turbidity of breeding water changed from 0.06 to 0.14 (mg / L) in a closed circulation purification over 45 days. On the other hand, the turbidity of the breeding water changed from 0.11 to 0.34 (mg / L) in the test equipment combined with a filter and a pH adjustment tank without a foam separation treatment device (see FIG. 6).

  By using the foam separation treatment device for the purification equipment for breeding water, the chromaticity of the breeding water changed from 2 to 8 (degrees) in the closed circulation purification for 45 days. On the other hand, in the test equipment combined with a filter and a pH adjustment tank without a foam separation treatment device, the chromaticity of the breeding water changed from 4 to 25 (degrees) (see FIG. 7).

  By using the foam separation treatment apparatus for the purification system of breeding water, the protein of breeding water changed at 8 to 24 (mg / L) in the closed circulation purification over 45 days. On the other hand, in the test equipment combined with a filter and a pH adjustment tank without a foam separation treatment device, the protein of the breeding water changed from 8 to 36 (mg / L) (see FIG. 8).

  By using the foam separation treatment device for the purification system of the breeding water, the total nitrogen of the breeding water changed from 10 to 180 (mg / L) in the closed-type circulation purification over 45 days. On the other hand, in the test equipment combined with a filter and a pH adjustment tank without a foam separation treatment device, the total nitrogen of the breeding water changed from 130 to 500 (mg / L) (see FIG. 9).

  From this, it is possible to suppress the increase in the turbidity, chromaticity, protein, and total nitrogen of the breeding water by using the filter, the pH adjusting tank, and the foam separation treatment device in the purification of the breeding water of the aquatic organisms.

  From the above, in the purification of breeding water for aquatic organisms, if a filter, a pH adjustment tank, and a foam separation treatment device are used, the pH of the breeding water will be 7 or less, and ammonia nitrogen will be 0.1 mg / L. ), Nitrite nitrogen can be suppressed from exceeding 0.02 (mg / L). In addition, since it can efficiently remove foaming components such as excrement and residual food from breeding water in the breeding water and protein derived from body surface mucus of aquatic organisms, compared to the case where the breeding water purification equipment includes only a filter and a pH adjustment tank The turbidity of the breeding water can be reduced to 1/2, the chromaticity to 1/3 to 1/2, the protein to 2/3, and the total nitrogen to 1/10 to 1/3. Since closed breeding water purification can be performed in this way, it is possible to reduce the amount of water exchanged for breeding water of aquatic organisms. In addition, the present invention can safely purify aquatic organisms without adding chemicals or ozone during the breeding of aquatic organisms or adding an oxidizing agent generated by electrolysis.

It is the block diagram which showed embodiment in this invention. It is the block diagram which showed embodiment of the foam separation process in this invention. It is the graph which showed transition of pH of breeding water in Example 1 and comparative example 1 of the present invention. It is the graph which showed transition of the ammonia nitrogen of the breeding water in Example 1 and Comparative Example 1 of this invention. It is the graph which showed transition of the nitrite nitrogen of the breeding water in Example 1 and Comparative Example 1 of this invention. It is the graph which showed transition of the turbidity of breeding water in Example 2 and comparative example 2 of the present invention. It is the graph which showed transition of the chromaticity of breeding water in Example 2 and comparative example 2 of the present invention. It is the graph which showed transition of the protein of breeding water in Example 2 and comparative example 2 of the present invention. It is the graph which showed transition of the total nitrogen of breeding water in Example 2 and comparative example 2 of the present invention. It is the outline | summary of the example of an apparatus which purifies the breeding water of the aquatic organism using the conventional oxidizing agent. It is the outline | summary of the example of an apparatus which purifies the breeding water of the underwater organism using the conventional high voltage pulse.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Breeding tank 2 Breeding water 3 Pump 4 Filter 5 pH adjustment tank 6 Oyster shell 7 Foam separation processing device 8 Separation tank 9 Shielding plate 10 Self-contained fine bubble generator 11 Air diffuser plate 12 Air inlet 13 Air inlet 14 Blower 15 Air bubble 16 Fine bubbles 17 Foam 101 Water storage tank 102 Pump 103 Filtration tank 104 Ozone dissolution tank 105 Coral sand tank 106 Catalytic reaction tank 107 Foam separation tank 108 Ozonizer 109 Aeration pipe 110 Ozone decomposition tank 201 High voltage pulse generator 202 Current limiting resistor 203 Electrode 204 Water tank 205 Breeding water 206 Insulating rug 208 Gravel

Claims (7)

  In the method for purifying breeding water used for breeding aquatic organisms, the method for purifying breeding water for aquatic organisms includes a filtration step, a pH adjustment step and a foam separation step in the purification step of the breeding water.   The method for purifying water for breeding aquatic organisms according to claim 1, wherein the filter medium used in the filtration step is sand.   3. The aquatic organism according to claim 1, wherein the pH adjusting step maintains neutrality so that the pH of the breeding water does not decrease by bringing oyster shells into contact with the breeding water of the aquatic organism. Rearing water purification method.   4. The method for purifying aquatic organism rearing water according to any one of claims 1 to 3, wherein the pH adjusting step maintains 7 ≦ pH <8.6.   The foam separation treatment step is to supply a gas to the breeding water in the separation tank and subject the breeding water to a foam separation process. The gas supplied into the separation tank is a fine bubble, and the fine bubble Is a fine bubble generated by generating bubbles by means for generating only bubbles and then shearing the bubbles by means for shearing the bubbles and / or fine bubbles generated by the means for shearing the bubbles themselves. The method for purifying water for breeding aquatic organisms according to any one of claims 1 to 4, wherein the fine bubbles foam-treat the breeding water.   An apparatus for purifying water for aquatic organisms, wherein the apparatus for purifying water used for breeding aquatic organisms comprises a filter, a pH adjustment tank, and a foam separation treatment apparatus.   The purification device is composed of a filter using sand as a filter medium, a pH adjustment tank filled with oyster shells, and a foam separation treatment device, and the foam separation treatment device performs a foam separation treatment, The apparatus for purifying water for breeding aquatic organisms according to claim 6, comprising means for generating only bubbles in the separation tank and means for shearing bubbles and / or generating fine bubbles.

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