JP2006166741A - Denitrification method, denitrification device, and denitrification filter medium for aquatic animal breeding water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a denitrification method, denitrification apparatus, and denitrification of water for aquatic animal breeding for the purpose of remarkably delaying or omitting the time of water exchange or washing of aquatic animal breeding tanks generally performed. Proposal of filter media for use.
[MEANS FOR SOLVING PROBLEMS] The method for denitrifying aquatic animal breeding water according to the present invention comprises bringing aquatic animal breeding water into contact with a filter medium in which a microorganism carrier and a hydrogen donor comprising a product derived from animal or vegetable oils and fats that are solid at room temperature are mixed. It is characterized by being processed.
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Description

  The present invention provides a denitrification method, a denitrification apparatus, and a denitrification method for aquatic animal breeding water for the purpose of remarkably delaying or omitting the time of water exchange and washing of aquatic animal breeding tanks that are generally performed. It relates to a filter medium for nitrogen.

  Various aquatic animals such as freshwater fish, saltwater fish, and sea beasts are bred at facilities such as aquariums and general households. Phenomenon that adheres will be seen. Such a phenomenon not only hinders the appreciation of aquatic animals, but it is nothing but a worsening of the living environment for aquatic animals. In addition, once attached algae and the like, there is no other way but to take physical removal means such as wiping off, and it becomes extremely hard work especially in a huge water tank. Therefore, in order to prevent such a phenomenon, it is an important problem to clean the breeding water.

For this reason, a method is generally employed in which the breeding water in the water tank is circulated and the circulating water is treated by sand filtration or the like to remove suspended substances in the water. A method of adsorbing and removing organic substances dissolved in water by activated carbon filtration or the like is also generally employed.
However, although the above-mentioned filter medium is effective for the purpose of removing solid fouling, the nitrogen content that increases from food, manure, etc. is dissolved in water in an ionic state. That is, since the inside of the water tank is kept in an aerobic state, organic nitrogen and ammonium ions are dissolved in water by changing to nitrous acid and nitrate ions by the action of aerobic bacteria. For this reason, the above filter medium cannot remove such nitrous acid and nitrate ions.

In general, wastewater (wastewater) treatment or the like employs a method (biological treatment) of denitrification by denitrifying bacteria in an anaerobic state as a method for removing nitrogen. For example, a denitrification reaction using methanol as a hydrogen donor is represented by the following formula.
^{_{6NO 3 - + 5CH 3 OH →}} 3N 2 + 5CO 2 + 7H 2 O + 6OH -
6NO ₂ ⁻ + CH ₃ OH → 3N ₂ + CO ₂ + 5H ₂ O + 6OH ⁻
This method maintains wastewater (wastewater) under anaerobic conditions with low dissolved oxygen (DO) and uses nitrate or nitrite respiration of denitrifying bacteria to reduce nitrate and nitrite ions to nitrogen gas. Is.
However, in the aquarium used for breeding aquatic animals, an aerobic state is essential and there is a problem that it cannot be brought into an anaerobic state. In addition, methanol or the like is used as a hydrogen donor in wastewater (wastewater) treatment, but it cannot be applied to the breeding of aquatic animals because it threatens the life of aquatic animals. Thus, the creation of anaerobic conditions and the use of hydrogen donors that are safe for aquatic animals are problematic.

As a method for utilizing the above biological treatment and supporting denitrifying bacteria under anaerobic conditions, there is a method using a microorganism carrier. That is, in this method, only the inside of the pores of the microorganism carrier becomes anaerobic, and denitrifying bacteria are immobilized (supported) therein. This denitrifying bacteria decomposes nitric acid and nitrite ion in water into nitrogen gas and water by using a nearby hydrogen donor as a nutrient source (consumption source) to prevent accumulation of nitrogen in water which adversely affects aquatic animals. At this time, since the hydrogen donor is consumed together with the nitrogen decomposition, it is necessary to add it at regular intervals.
However, in the case of using a liquid liquid such as methanol as a hydrogen donor that is consumed together with nitrogen removal, an amount equal to or more than the nitrogen content expected to be produced must be added in advance, which affects the aquatic animals (Toxicity etc.) was large and could not be applied at all. In addition, it was difficult to manage by adding a very small amount of hydrogen donor each time.

Therefore, Patent Document 1 includes higher fatty acids such as capric acid, lauric acid, myristic acid, bartimic acid, stearic acid, and behenic acid, and higher alcohols such as myristyl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol, urethane sponge, and the like. There has also been a proposal to solve the above-mentioned problems by impregnating the material into a filter medium and using it as a filter medium.
Japanese Patent Laid-Open No. 2002-263665

However, the higher fatty acids and higher alcohols used in the method of Patent Document 1 are not necessarily not affected by aquatic animals, even if not as much as the methanol, and the nutrient source (consumption source) of denitrifying bacteria ) Is not preferred, and it is safer and preferred for denitrifying bacteria, that is, a suitable hydrogen donor has been desired. Furthermore, in this patent document 1, a urethane sponge is used for the purpose of impregnating higher fatty acids and higher alcohols. However, this urethane sponge or PVA (polyvinyl alcohol) system has a considerable influence on aquatic animals. Are known, and it has been unsuitable to use them for supporting denitrifying bacteria, which are anaerobic bacteria.
Therefore, the present invention has no adverse effects on aquatic animals, and a denitrification method, a denitrification apparatus, and a denitrification filter medium using a hydrogen donor suitable as a nutrient source (consumption source) for denitrifying bacteria The purpose is to propose.

  The present invention was obtained as a result of diligent research in view of the above, and the first invention is to provide aquatic animal breeding water, a microorganism-supporting body and a hydrogen donor comprising a product derived from animal and vegetable fats and oils that are solid at room temperature The present invention relates to a method for denitrifying water for aquatic animal breeding, characterized in that it is treated by contacting with a mixed filter medium.

  Further, the second invention of the present invention is characterized in that the inside of the container is filled with a filter medium in which a microorganism carrier and a hydrogen donor composed of a product derived from animal and vegetable fats and oils that are solid at room temperature are mixed. The present invention relates to a denitrification device for aquatic animal breeding water.

  Furthermore, the third invention of the present invention relates to a filter material for denitrification of water for aquatic animal breeding, characterized in that a product derived from animal or vegetable oils and fats that is solid at room temperature is used as a hydrogen donor.

In the denitrification method of the first invention of the present invention, the denitrifying bacterium carried on the microorganism carrier uses a hydrogen donor comprising a product derived from animals and plants that is solid at room temperature as a suitable nutrient source (consumption source). Nitrogen and nitrite ions can be decomposed into nitrogen gas and water to reliably prevent accumulation of nitrogen in water, which adversely affects aquatic animals. The environment can be maintained for a long time. In addition, since the hydrogen donor is solid at room temperature, it is easy to handle when mixed with a microorganism carrier to obtain a filter material, and continuous (continuous) addition such as conventional methanol is possible. I don't need it.
Therefore, in the first invention of the present invention, the nitrogen content in the aquarium is not finally increased by the above-described denitrification, and a breeding environment suitable for aquatic animals can be maintained over a long period of time. Water exchange or the like is basically unnecessary, or the exchange time can be extremely prolonged.

  In particular, it is desirable to use a cellulose carrier having pores inside as the microorganism carrier. In this case, the cellulose carrier is a naturally derived product, has no adverse effect on aquatic animals, and is suitable for carrying denitrifying bacteria. is there.

  Moreover, the denitrification apparatus of 2nd invention of this invention does not limit the shape of the container which accommodates a filter medium, It can set suitably according to the magnitude | size of a water tank or the amount of process (circulation) water. . For example, a household tank with only one tank may be sized and shaped to be attached to the side or upper part of the tank, and a multi-tank tank has a separate device that collects and processes the circulating water from each tank. In a facility such as an aquarium that has several large aquariums, a facility having a capacity capable of treating a large amount of circulating water may be used. Thus, it can be used as various products (equipment) corresponding to each from a household water tank having only one tank to a facility having several huge water tanks such as an aquarium.

  In the above-described denitrification method and denitrification apparatus, the mode of bringing the aquatic animal breeding water into contact with the filter medium is not limited, but regardless of which mode is selected, the breeding water in the tank is circulated for treatment. It is preferable to expand the effect.

  The filter material for denitrification of the third invention of the present invention is a hydrogen donor comprising a product derived from animals and plants that is solid at room temperature, and is initially used by mixing with the above-mentioned microorganism carrier, and thereafter hydrogen according to consumption. Only the donor needs to be replenished, the above-described denitrification method can be carried out, and a breeding environment suitable for aquatic animals can be maintained over a long period of time.

The hydrogen donor used in the present invention is a product derived from animal and vegetable oils and fats that are solid at room temperature (5-35 ° C.), and the particle size thereof is not particularly limited. For example, it may be about several mm or more, Fine particles of 1 mm or less may be used.
Specific examples of the hydrogen donor include, for example, para rubber seed oil, bran wax, urushi wax, palm fat, nickel fat, owl, coconut oil, dog fat, weasel fat, beef fat, bear fat, pork fat, horse fat, Amaro, carnauba wax, palm wax, beeswax, cotton wax and the like can be used.
These hydrogenated products can also be used. In addition, hydrogenated jojoba oil, hydrogenated palm oil, hydrogenated castor oil and the like that can be solidified by hydrogenation at room temperature can also be used.
In addition, each aquatic animal has a water temperature suitable for breeding depending on the type. For example, a tropical aquatic animal preferably has a water temperature adjustment mechanism that constantly adjusts the water temperature to 30 ° C. or higher. What is solid with respect to the water temperature may be appropriately selected and used.

Also, the microorganism carrier is not particularly limited with respect to its specific configuration, and for example, cellulose, polyester, polypropylene, polyurethane, activated carbon, alumina, silica, glass, etc. can be used, and the particle size is about several mm. Or more than that, fine particles of 1 mm or less may be sufficient. Among them, porous (foamed) cellulose is the most preferable because it is a natural polymer excellent in biodegradability and excellent in biocompatibility. That is, when a cellulosic microorganism carrier and the hydrogen donor are combined to form a filter medium, there is no influence on aquatic animals. Furthermore, cellulose has favorable characteristics such as high air permeability and water absorption, and no generation of toxic gas even when incinerated.
In addition, since cellulose serves as a bait for microorganisms, it may decrease when used for a long period of time. To prevent this, an epoxy derivative having one or more functional epoxy groups, specifically, glycerol disulfate is used. Cellulose surface reinforcement may be achieved by reacting cellulose with an epoxy derivative selected from glycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, and sorbitan polyglycidyl ether (Japanese Patent No. 2851523). reference).

  The hydrogen donor and the microorganism carrier are mixed to obtain a filter medium, but the mixing method is not particularly limited, and for example, the hydrogen donor and the microorganism carrier may be simply mixed and used.

Moreover, in the denitrification method and the denitrification apparatus of the present invention, the method for bringing the filter medium having the above-described configuration into contact with the breeding water in the aquarium is not particularly limited, but typical embodiments are shown below.
For example, a container having water permeability may be used, and the filter medium may be housed therein and immersed in the water tank. In this case, it is sufficient to use a particle size that does not cause the filter medium to fall off from the container, and it is desirable that the breeding water in the aquarium is stirred.
Alternatively, a container having an open top and water permeability at the bottom is used, and a filter medium is accommodated therein (filter medium is laid on the bottom), and water for breeding is supplied from above using a pump or the like for filtration. Processing may be performed by contacting the material, and the processed water may be dropped from the bottom of the container to the water tank and returned.
Alternatively, the container is formed into a flow path such as a cylindrical shape, and a lead-out port and an introduction port are provided, a filter medium is accommodated therein, and the breeding water in the water tank is introduced from the introduction port by a pump or the like and filtered. Processing may be performed in contact with the material, and the processed water may be led out from the outlet and returned to the water tank.
In the first aspect, the breeding water in the aquarium is stirred, and in the second and third aspects, the breeding water is circulated and passed through the filter medium in the container, thereby Denitrification treatment can be performed efficiently.

Further, there are no other conditions relating to the present invention, and for example, the container used in the second invention may have any capacity depending on the amount of treated water, and may have any shape. However, if the target tank for aquatic animal breeding is a household tank, a small tank is suitable, and if it is a huge tank such as an aquarium, a large tank is naturally used.
Although it does not specifically limit, a suitable embodiment regarding the capacity | capacitance of a water tank and a container is shown as an example below.
A filtration tower having a capacity of about 550 ml is installed in the upper part of the water tank as a container in a 60 L water tank, and 500 ml of the cellulosic microorganism carrier and 50 ml of the hydrogen donor are sufficiently mixed and filled in the filtration tower. In this case, it is possible to denitrify the water in the water tank by a downward flow that drops from the top of the filtration tower.

<Example 1>
An upper filter (Big Boy 60cm made by Jex Corporation) is set as a container in a 60cm water tank (Jex Rapiles RV60 type), and 500 ml of a cellulosic microorganism carrier 10 mm square (3M company) and hydrogen donor are used instead of the filter. As a filter medium, 50 ml of granular cotton wax of about 2 to 3 mm was mixed thoroughly and spread flatly. Then, a circulation pump (circulation capacity 0.3 m ³ / Hr) was installed, and the breeding water in the aquarium was passed through the upper filter.
60 L of artificial seawater and 10 saltwater fish cobalt were put into this tank, adjusted to a water temperature of 24 ° C., and fed with 0.2 g of food every day, without changing water and occasionally supplementing only the evaporation.

<Example 2>
An upper filter (Big Boy 45cm made by Jex) is set as a container in a 45cm water tank (Jex Rapiles RV45 type), and a cellulosic microorganism carrier 10mm square (made by Taiho Kogyo Co., Ltd.) coated with surface epoxy instead of the filter 300 ml and 10 ml of granular hydrogenated castor oil of about 5 to 10 mm as a hydrogen donor were mixed thoroughly and spread flatly as a filter medium. Then, a circulation pump (circulation capacity 0.2 m ³ / Hr) was installed, and the breeding water in the water tank was passed through the upper filter.
45 L of fresh water and 10 goldfishes as freshwater fish were added to this aquarium, adjusted to a water temperature of 22 ° C., and fed with 0.1 g of food every day, without replacing water, and occasionally supplementing only the evaporation.

<Example 3>
A plastic cylinder with a diameter of 30 cmφ and a length of 50 cm was set as an external container on a store fixture (bred water tank) 1 m ³ and connected to the fixture with a circulation pump (circulation capacity 1 m ³ / Hr). In this cylinder, 30L of cellulose-based microorganism carrier (3M company) 30L and 1L of granular beef tallow of about 2 to 3mm are thoroughly mixed and filled as a filter material. Water was then circulated by circulating the treated water through the pump.
100 goldfishes (small red) were placed as freshwater fishes in this fixture and reared without feeding the water temperature (about 5 to 15 ° C.) from time to time.

<Example 4>
A 50cm diameter and 50L capacity poly bucket is mixed thoroughly with 1L of cellulose carrier 10mm square (manufactured by 3M) and 100ml of granular beeswax of about 1 to 2mm and packed in a net-like bag (container) as a filter medium. I put it in. And the pump (discharge capability 0.2m < ³ > / Hr) was installed, and the breeding water in a poly bucket was stirred.
30 L of water and 3 green turtles were placed in this bucket and reared with occasional feeding.

<Comparative Example 1>
Set the upper filter (Big Boy 45cm made by Jex Corporation) in a 45cm water tank (Jex Rapiles RV45 model), and flatten 300ml of cellulosic microorganism carrier 10mm square (made by Taiho Kogyo Co., Ltd.) coated with surface epoxy instead of the filter. Laid down. Then, a circulation pump (circulation capacity 0.2 m ³ / Hr) was installed, and the breeding water in the water tank was passed through the upper filter.
45L of fresh water fish and 10 goldfishes were put in this tank, adjusted to a water temperature of 22 ° C, and fed with 0.1g of food every day, without replacing water, and occasionally supplementing only the evaporation.

<Comparative example 2>
An upper filter (Jex Bigboy 45cm) was set in a 45cm water tank (Jex Lapyres RV45 type), and 300ml of granular hydrogenated castor oil of about 5 to 10mm was spread as a hydrogen donor instead of the filter. . Then, a circulation pump (circulation capacity 0.2 m ³ / Hr) was installed, and the breeding water in the water tank was passed through the upper filter.
45L of fresh water fish and 10 goldfishes were put in this tank, adjusted to a water temperature of 22 ° C, and fed with 0.1g of food every day, without replacing water, and occasionally supplementing only the evaporation.

〔result〕
In Examples 1 to 4, any increase in nitrogen content in the breeding water was not observed even in continuous breeding for 6 to 12 months, and the breeding water was also transparent.
As Comparative Example 1, only the cellulosic microorganism carrier was used, and as Comparative Example 2, only the hydrogen donor was used. In both cases, the increase in nitrogen content in the breeding water was 2 mg / L as nitrogen per day, and the nitrogen content accumulated every day. I went. Also, the breeding water gradually became turbid from the initial transparent state, and about one month later, algae was observed on the glass wall of the aquarium, making it difficult to see the inside through the glass wall.

  The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and can be implemented in any manner as long as the configuration described in the claims is not changed.

  The present invention can be applied to various aquatic animal breeding tanks, from a single domestic tank to a facility having a number of huge tanks such as an aquarium.

Claims (3)

  The aquatic animal breeding water is treated by bringing it into contact with a filter medium in which a microorganism carrier and a hydrogen donor comprising a product derived from solid animal and vegetable oils and fats at room temperature are mixed. Nitrogen method.   A denitrification apparatus for aquatic animal breeding water, wherein the container is filled with a filter medium obtained by mixing a microorganism carrier and a hydrogen donor comprising a product derived from animal and vegetable oils and fats that are solid at room temperature.   A filter material for denitrification of water for aquatic animal breeding, characterized in that a product derived from animal and vegetable oils and fats that are solid at room temperature is used as a hydrogen donor.