JP2002330665A - Method for cleaning water in water tank and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a maintenance-free energy-saving method for exterminating algae in a fish breeding tank, etc., and provide an apparatus for the method. SOLUTION: A top-opened electrolyzing apparatus is placed in a filter tank installed outside of a water tank. The electrolyzing apparatus is provided with a pair of electrodes separated from each other by a diaphragm and water is introduced from the water tank to the cathode part or the anode part of the electrolyzing apparatus. The water supplied from the water tank is passed through the cathode part or the anode part and through the bottom slit under the diaphragm of the electrolyzing apparatus, introduced into the counter electrode part and returned to the water tank from the upper part of the counter electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus which enable maintenance-free and energy-saving algicidal treatment of fish tanks and the like.

[0002]

2. Description of the Related Art An aquarium for aquarium fish and an aquarium for aquaculture of fish and shellfish are usually maintained in a state of being exposed to light. Moss and algae begin to adhere to gravel and the like, and if left unattended, the inside of the aquarium is covered and soiled, resulting in adverse effects such as deterioration of aesthetics. For this reason, aquarium owners have conventionally implemented various purification methods. Algae removal methods are broadly classified into physical methods, biological methods, and chemical methods.

[0003] The physical method is a reliable method as a removing method, but removing moss and algae adhering to aquatic plants and gravel is very complicated and requires considerable time and labor. For this reason, physical methods were unacceptable to ordinary users. In addition, since moss and algae removed by the physical method do not die, there is a problem that those not caught by the filtration filter land again in the water tank and propagate again.

[0004] Biological methods using algae vegetation are not troublesome, but a large amount of algae vegetation is required to remove all moss and algae that grow in the aquarium. The beauty of the creatures that you want to breed and appreciate will be impaired.
In addition, these alga-eating organisms feed on only certain algae, so their use is limited.

As chemical methods, there are a chemical addition method and a chemical treatment method such as ultraviolet irradiation or ozone treatment. In the former, a drug that inhibits photosynthesis is generally used, but since the tank user adds it at any time, the drug manufacturer must consider the damage to general organisms in the tank due to overfilling and take effect. Must be small. On the other hand, in the latter case, it is necessary to newly install the device itself outside the water tank, and a large installation area is required including the auxiliary equipment, and the price is high. As described above, as for the method of removing moss, algae, and the like that grow in the aquarium, at present, there is no solution that can satisfy all the effects, labor, and price.

[0006]

It is well known that hydrogen peroxide is effective in killing alga. It is also known that it is an environmentally friendly drug because it is converted into water and oxygen after decomposition. However, since hydrogen peroxide is an unstable substance and is difficult to store for a long period of time, it is hardly used as a drug for general aquarium users. On the other hand, it is well known that hydrogen peroxide can be generated by an electrolytic method using a carbon-based electrode and oxygen. Therefore,
It is conceivable that hydrogen peroxide generated from this electrolysis device is taken out and used as algae removing means in a water tank. However, such an apparatus has to be a very large apparatus in addition to the very complicated structure of the electrolysis cell itself, and also includes ancillary equipment necessary for performing electrolysis.

[0007] However, recently, aquariums for appreciating fish for general users are called set aquariums or system aquariums, which have enhanced palatability as interiors of rooms, are very compact in appearance, and are very compact in appearance. The location is designed to be used very little. Therefore, attaching the above-described large-scale hydrogen peroxide generating electrolyzer to such an ornamental fish breeding aquarium causes extremely inconvenience in terms of cost and appearance for general aquarium users, and is practical. is not.

[0008]

Means for Solving the Problems As a result of elaborate efforts to overcome the above problems, an electrolytic device for generating hydrogen peroxide is incorporated in the main body of the water tank, and the algicidal effect is reduced from the device. We succeeded in generating a sufficient amount of hydrogen peroxide that can be expressed.

That is, according to the present invention, an open top electrolysis apparatus is provided inside a filtration tank provided outside a water tank container, the electrolysis apparatus has a pair of electrodes with a diaphragm interposed therebetween, and a cathode of the electrolysis apparatus is provided. Aquarium water is introduced into the cathode or anode part, and after passing through the cathode or anode part, it is introduced into the counter electrode part through the slit under the septum at the bottom of the electrolyzer, and the water tank is introduced from the upper part of the counter electrode part. The present invention relates to an aquarium water purification device configured to return to FIG. In the present invention, the anode of the electrolysis apparatus is a noble metal-based electrode, the cathode is a carbonaceous electrode, the distance between the anode and the diaphragm is 1 to 10 mm, and the distance between the cathode and the diaphragm is 0 to 10 mm.
The present invention relates to the aquarium water purification apparatus described above, wherein

[0010] The present invention also provides the above-mentioned purification apparatus,
Water tank water is introduced at a flow rate of 1 to 2000 ml / min into the cathode or anode of the electrolysis apparatus, and the ratio of the volume ratio of air to tank water introduced per unit time into the cathode (air / water tank). The present invention relates to a method for purifying aquarium water, characterized by introducing air in an amount within a range of 0.1 to 500, and applying a direct current of 1.5 to 15 V between both electrodes. In addition, the present invention provides that when the amount of hydrogen peroxide per hour produced in the electrolyzer is X mg and the amount of water in the water tank is Y liter,
The present invention relates to the above-described method for purifying aquarium water, wherein the electrolysis conditions are set so as to satisfy a relationship of ≦ 24X / Y ≦ 50.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The aquarium water purification device of the present invention is provided with an open top electrolysis device inside a filtration tank installed outside the aquarium container. The upper part of the electrolysis apparatus is open, and water tank water pumped by a circulation pump is usually introduced into the electrolysis cell. The electrolyzer has electrodes that form a pair with a diaphragm interposed therebetween, and water is introduced into a cathode or an anode of the electrolyzer. The introduced aquarium water passes through the cathode portion or the anode portion, passes through a slit under the septum at the bottom of the electrolysis device, is introduced into the counter electrode portion, and is returned from the upper portion of the counter electrode portion to the aquarium container. The method of introducing the aquarium water into the electrolysis cell is not particularly limited, but as shown in FIG.
Is branched and led to an electrolytic cell. Water supply to the electrolysis cell usually utilizes a water tank water circulation pump. The supply amount to the electrolytic cell is, of course, set to be less than the drainage amount from the discharge elbow, but is preferably set to be lower than the water amount supplied to the filter medium in order to provide a sufficient filtering function. . Usually, the water volume of the water tank water circulation pump is set to 5 liters or more per minute. Furthermore, the lower limit of the amount of water supplied to the electrolytic cell is set at 1 per minute in order to increase the frequency of aquarium water circulation.
It is preferably at least milliliter, more preferably at least 5 milliliter. Further, the upper limit is preferably 2000 ml or less, more preferably 1000 ml or less, in order to increase the concentration of hydrogen peroxide in the electrolytic cell.
By setting the water supply amount in the above range, the algicidal effect can be more effectively exhibited.

Next, an example of the structure of the electrolytic cell will be described. FIG.
5 are cross-sectional views when the electrolytic cell is viewed from a direction perpendicular to the electrode surface. Aquarium water is introduced into the electrolysis cell through the inlet 6 and discharged from the electrolysis cell through the outlet 7 into the aquarium body. 1, 2, 3, and 4 are electrodes, 1 and 2 and 3 and 4, or 2 and 4 are paired electrodes, an anode and a cathode. Reference numeral 5 denotes a flow path partition plate with a diaphragm. As long as there is a space to be built in the water tank, the structure of the electrolytic cell can be used by stacking two or more units as shown in FIG. Note that the present invention is not limited to the illustrated format. FIG. 6 shows the electrolytic cell shown in FIG. 2 in detail. In this figure, a DC power supply and an air pump used for performing electrolysis are connected to an electrolysis cell.

As the DC power supply, a device that can convert a household AC power supply into DC, a dry battery, and the like are preferably used. It is preferable to apply a DC voltage of 1.5 to 15 V between both electrodes. More preferably, it is 3 to 10V. The reason why the high voltage is not applied at this time is that the pH in the cathode part rapidly rises due to the high voltage, and inorganic ions such as calcium contained in the aquarium water react and precipitate on the carbonaceous electrode or the diaphragm. This is to prevent In order to extend the life of the electrode, the polarity may be reversed periodically for a short time (for example, every 10 minutes for 5 seconds) in order to extend the electrode life. Further, a solar cell can be preferably used. For the type of solar cell,
When the apparatus was connected to the electrolytic cell and operated, the DC voltage was 1.5
There is no particular limitation as long as it can maintain V to 15 V,
The light source can be obtained from aquarium lighting.

The introduction of air into the electrolytic cell takes place only on the cathode surface. Although the method is not particularly limited, for example, when the carbonaceous electrode is graphite felt,
A diffuser is provided at the bottom to allow air to pass through the inside or surface of the felt. For example, the method shown in FIGS. 7 and 8 can be used. a and b are described by changing the viewpoint by 90 degrees. An air diffuser 10 is provided near the cathode 9. In FIG. 7, air bubbles are emitted from the tip of the straight pipe, and in FIG. 8, the air bubbles are emitted from a portion of the L-shaped diffuser provided below the cathode. In the case of a gas diffusion electrode, it goes without saying that a method of passing air through the surface opposite to the surface through which the aquarium water is passed is used. FIG. 9 shows an example of an electrolysis device suitably used in the purification device of the present invention. a, b, and c are cross-sectional views when viewed from above, front, and side, respectively.

When hydrogen peroxide is produced industrially by electrolysis, usually pure oxygen or PSA oxygen is used.
Since this device requires a relatively small amount of hydrogen peroxide,
Air can be used instead of high purity oxygen. Air is introduced into the cathode section. The introduction of air is useful not only as a raw material for producing hydrogen peroxide, but also for stripping ammonia excreted from fish and the like into a water tank and releasing it to the outside of the system. If ammonia is accumulated in the aquarium as it is, it has a neurotoxic effect on fish in the aquarium, and the fish die. Normally, these ammonias are detoxified by nitrifying bacteria that have propagated in the water tank, but when the electrolytic device is used, the growth of nitrifying bacteria may be suppressed, so that ammonia remains in the water tank. It will be easy situation. If the air flow rate is too small, sufficient hydrogen peroxide will not be generated, and ammonia in the water tank cannot be sufficiently removed. On the other hand, if it is too large, the carbon dioxide gas in the air reacts with the calcium ions and magnesium ions in the aquarium water, and water-insoluble inorganic salts such as calcium carbonate and magnesium carbonate precipitate on the cathode, which may shorten the electrode life. There is. For this reason, the ratio of the volume ratio of air introduced into the cathode unit per unit time and water in the tank (air / water in the tank) is 0.1 to 0.1%.
Preferably, an amount of air in the range of 500 is introduced,
In particular, it is preferable to introduce an amount of air in the range of 0.2 to 100.

The cathode is not particularly limited as long as it can be applied to on-site production of hydrogen peroxide, and examples thereof include graphite, carbon fiber material, porous amorphous carbon molded product, and gas diffusion electrode. . Examples of graphite include those obtained by extruding and firing coke and those obtained by CIP molding and firing. Examples of the carbon fiber material include a carbon fiber knitted material. Examples of the carbon fiber knitted material include commercially available graphite felt and cloth, but other carbon fiber materials may be used.
Glassy carbon (glassy carbon) can be exemplified as a porous amorphous carbon molded body. further,
A porous amorphous carbon material is a non-crystalline, substantially non-oriented, ie, non-anisotropic, porous carbon material. Examples of such a carbon material include a porous amorphous carbon fiber material and a porous amorphous carbon molded product. The above-mentioned carbonaceous electrode may be subjected to fluorine treatment or silica treatment to impart water repellency.

A noble metal electrode or a carbonaceous material is used for the anode. As a noble metal-based electrode, a substance having a small overvoltage and a very small consumption compared to other metals and oxides is preferable, and thus gold, platinum, iridium, ruthenium, nickel, titanium, which can be used for a long time with almost no change. And their oxides, and their alloys and the like. For example, an electrode material coated with platinum or a platinum-based (including platinum-iridium) based on a titanium material can be used. Further, a metal web having a large surface area per unit area can be used. Examples of the material of the metal web include nickel, stainless steel, iron, copper, platinum, and alloys thereof. The shape of the anode is not particularly limited, but a plate, a net, or a bar is preferably used. As the carbonaceous material, the same materials as those usable for the cathode can be used.

The anode and the cathode may be installed on either the upstream side or the downstream side as long as they are installed so as to face each other with the diaphragm interposed therebetween. However, when the number of electrodes is 1: 2 as shown in FIG. 4 or FIG. 5 and one of the electrodes is sandwiched between the counter electrodes, the same processing is performed because the center electrode is used on both sides. Is required.

The diaphragm allows a current to flow between the anode and the cathode and secures a flow path of water in the electrolytic device. The diaphragm is not particularly limited as long as a current flows between the anode and the cathode, but an electronically insulating and porous film can be preferably used, and a porous fluororesin, a hydrocarbon-based resin, an ion exchange membrane, or the like can be used. used.

Specifically, as the porous fluororesin,
Polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE) is used as a hydrocarbon-based resin.
A), those using polyacetylene, cellulose, polychlorinated ethylene and the like can be used. These substrates may be copolymerized in an appropriate ratio. Further, those obtained by chemically modifying the base material by adding an additive thereto are also preferably used.

Examples of ion exchange membranes include Nafion 117, Nafion 350, Nafion 902, and Nafion 9 having a sulfonic acid group or a carboxylic acid group.
61 (all manufactured by DuPont). The ion exchange membrane has a function to prevent each ion generated at the anode and the cathode from being consumed at the counter electrode, and to promptly perform electrolysis even when the conductivity of the electrode solution is low as in the present invention. I have.

In addition to the above, specific chemical fibers can be used. As the chemical fiber, one that does not deteriorate by reacting with hydrogen peroxide is used, and non-woven fabric or the like whose surface is formed of a paraffin-based polymer is preferably used. The size of the hole of the non-woven cloth to be used does not need to be constant, but if it is too small, it becomes difficult for the current to flow, so that a basis weight of 10 to 50 g / m ² is selected, preferably 30 g / m ^2. ４０40 g / m ² is selected. Further, it is also preferable to use an inorganic material such as glass wool or asbestos as the stalk.

The distance between the anode and the diaphragm is 1 to 10 mm, and the distance between the cathode and the diaphragm is 0 to 1
It is preferable to install them so as to be 0 mm in parallel with each other.
At this time, if the distance between the anode and the diaphragm is too large, the current value decreases, and the amount of generated hydrogen peroxide decreases.
The following is preferable, and when it is too narrow, the treated water does not flow smoothly. In particular, when using a method in which treated water (aquarium water) is passed from the cathode to the anode, the decomposition of the generated hydrogen peroxide is accelerated on the anode surface.
The distance between the anode and the diaphragm is preferably 3 mm or more. On the other hand, if the distance between the carbonaceous electrode of the cathode portion and the diaphragm is too large, the current value decreases, and the amount of generated hydrogen peroxide decreases. When the carbonaceous electrode is made of a porous material, the treated water can penetrate the inside of the electrode without providing a gap between the carbonaceous electrode and the membrane, so that the cathode and the membrane may be in contact with each other. However, depending on the pore size of the carbonaceous electrode, a certain amount of pressure is required when the treatment liquid passes through the inside of the electrode. Therefore, it is also preferable to provide a certain gap (for example, about 1 mm) between the electrode and the diaphragm.

When the inside of the water tank is killed with hydrogen peroxide, the addition of a high concentration of hydrogen peroxide adversely affects the organisms in the water tank, so it is necessary to keep the concentration below a certain level. We have determined a concentration of hydrogen peroxide that can maintain the algicidal effect and does not adversely affect the aquatic organisms. When a certain amount of hydrogen peroxide is continuously generated from the electrolyzer and diluted with the aquarium water, the amount of hydrogen peroxide accumulated in the aquarium water does not increase at a constant rate. This is because hydrogen peroxide is decomposed in the aquarium by an algicidal, sterilizing, and purifying action. The accumulated amount repeatedly increases and decreases with time, and is maintained at a certain concentration or less according to the amount of hydrogen peroxide generated from the electrolytic device. The minimum concentration of hydrogen peroxide required to maintain the algicidal effect varies depending on the amount and type of living organisms, aquatic plants, gravel, food, etc., and the water quality, and the amount is produced by the electrolytic device. Xm of hydrogen peroxide per hour
g and the amount of water in the water tank being Y liters, it has been found that it is preferable to set the electrolysis conditions so as to satisfy the relationship of 1 ≦ (24 × X) / Y ≦ 50. The value indicated by 24X / Y is 1.0
If it is less than 50, a sufficient algicidal effect cannot be obtained, and if it exceeds 50, harmful effects such as death of living organisms or death of aquatic plants will be obtained. This value is preferably selected from 3 or more and 30 or less.

In order to efficiently kill the pollutants floating in the aquarium water, it is effective to set the concentration of hydrogen peroxide in the aquarium water in the electrolyzer high, and the concentration is set at the outlet of the electrolyzer. It is 0.5 mg / L or more, more preferably 1.0 mg / L or more. Usually, this concentration can be controlled by the flow rate of water passed through the electrolysis device, the applied voltage, the amount of water retained in the electrolysis device, and the like, but is not limited to this method.

[0026]

EXAMPLES Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(Example 1) An upper surface filtration tank (NEW Quick Flow 600, manufactured by Nissau Co., Ltd.), a heater, and a light were attached to a 60 L water tank. The electrolytic device shown in FIG. 2 was attached to a position shown in FIG. 1 in the upper filtration tank. For the anode, cathode, and diaphragm of the electrolyzer,
Titanium platinum plates (Exerode RN-1000, 50 mm x 100 mm, manufactured by Nippon Carlit Co., Ltd.)
Graphite felt (GF, manufactured by Nippon Carbon Co., Ltd.)
-20-2F, 60 mm x 100 mm), Nafion 1
17 (manufactured by DuPont, 550 mm × 90 mm), the distance between the anode and the diaphragm was 5 mm, the distance between the cathode and the diaphragm was 1 mm, and the height of the slit for treating solution transfer under the diaphragm was 5 m.
m. An air diffuser is attached to the bottom of the cathode, and an air pump (CHIKARA, manufactured by Nissau Co., Ltd.)
α1500) to blow air. The introduction rate of the treatment liquid was set to be about 600 ml / min. DC 5 volts was continuously applied between both electrodes. An ornamental fish was placed in the aquarium, and the aquarium water was continuously purified at 26 ° C. by the above-mentioned electrolyzer. Even after one month, moss, algae, etc. were hardly adhered to the aquarium glass surface. No abnormalities such as death of the ornamental fish in the aquarium and illness were observed.

(Comparative Example) An experiment was conducted under exactly the same conditions as in the above example except that the electrolytic device was not installed. After about one week, moss and algae began to adhere to the surface of the aquarium glass. After a month, it spread on the entire surface of the aquarium glass so that the inside of the aquarium could hardly be observed.

[0029]

As described above, moss and algae in an aquarium for fish breeding and the like can be killed by using the aquarium water purification apparatus of the present invention, so that maintenance-free aquarium water can be purified. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic view of an aquarium container.

FIG. 2 is an example of a cross-sectional view when the electrolytic cell is viewed from a direction perpendicular to an electrode surface.

FIG. 3 is an example of a sectional view when the electrolytic cell is viewed from a direction perpendicular to an electrode surface.

FIG. 4 is an example of a cross-sectional view when the electrolytic cell is viewed from a direction perpendicular to an electrode surface.

FIG. 5 is an example of a cross-sectional view when the electrolytic cell is viewed from a direction perpendicular to an electrode surface.

FIG. 6 is a schematic diagram of the electrolytic cell shown in FIG.

FIG. 7 is an example of a schematic diagram when air is introduced from a diffuser tube to a cathode portion.

FIG. 8 is an example of a schematic diagram when air is introduced into a cathode portion from an air diffuser.

FIG. 9 is an example of an electrolysis device according to the present invention.

[Explanation of symbols]

 1, 2, 3, 4 electrodes 5 Channel partition plate with diaphragm 6 Inlet 7 Outlet 8 Water absorption pipe or water absorption pipe 9 Cathode 10 Air diffusion pipe

Continued on the front page (72) Inventor Yoshiyuki Shimo 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Pref. Nishiishi Mitsui Co., Ltd. (72) Inventor Keisuke Nakayama 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa F-term in Mitsubishi Central Research Laboratory (reference) 2B104 CA03 ED01 EF09 4D061 DA06 DB01 DB02 EA01 EB01 EB05 EB13 EB19 EB28 EB29 EB30 EB39 ED06 GC20 4K021 AB15 BA02 BB02 BB03 BC01 CA01 CA04 CA08 DB02 DB12

Claims (4)

[Claims] 1. An electrolysis apparatus having an open top provided inside a filtration tank installed outside a water tank vessel, the electrolysis apparatus having a pair of electrodes with a diaphragm interposed therebetween, and a cathode or an anode of the electrolysis apparatus. Aquarium water is introduced into the part, the aquarium water passes through the cathode part or the anode part, passes through the slit below the septum at the bottom of the electrolysis device, is introduced into the counter electrode part, and returns to the aquarium container from the upper part of the counter electrode part. Aquarium water purification device. 2. The electrolysis apparatus according to claim 1, wherein the anode is a noble metal electrode, the cathode is a carbonaceous electrode, the distance between the anode and the diaphragm is 1 to 10 mm, and the distance between the cathode and the diaphragm is 0 to 10 mm. The aquarium water purification device according to claim 1, wherein the device is installed. 3. The aquarium water purifying apparatus according to claim 1, wherein the cathode or anode of the electrolyzer is disposed at a rate of 1 to 3 minutes per minute.
Water is introduced at a flow rate of 2000 ml, and the amount of air is such that the ratio of the volume ratio of air introduced into the cathode per unit time to the tank water (air / water tank) is in the range of 0.1 to 500. , And applying a direct current of 1.5 to 15 V between both electrodes. 4. Assuming that the amount of hydrogen peroxide per hour produced by the electrolyzer is X mg and the amount of water in the tank is Y liter, the electrolysis conditions are set so as to satisfy the relationship of 1 ≦ 24X / Y ≦ 50. The method for purifying aquarium water according to claim 3, wherein: