JPH0889969A - Method for purifying service water and device therefor - Google Patents

Abstract

PURPOSE: To purify a service water line more easily than conventional one by exerting the oxidizing and decomposing action of active oxygen on a part of the service water discharged from the line and then returning the water to the line. CONSTITUTION: A part of service water is discharged from a water tank 1 by a pump P. The oxidizing and decomposing action of active oxygen is exerted in an electrolyzer 2 to purify the water, and the purified water is returned to the tank 1 through a catalytic tank 3. The water in the tank is gradually purified in this way. Otherwise, the water is electrolyzed in the presence of sodium chloride or sodium bromide to form hypochlorous acid and active oxygen. Further, the hypochlorous acid or hypobromous acid formed by elecrtolysis is catalytically decomposed to decrease the concn. of the hypochlorous acid or hypobromous acid below a specified concn., and the active oxygen is formed at the same time. Consequently, the service water line is purified more easily than conventional one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention purifies water such as a cooling tower, an aquarium for aquaculture and storage of seafood, an aquarium for exhibiting seafood at restaurants and the like, aquarium for appreciation of aquariums, etc. Method and apparatus.

[0002]

2. Description of the Related Art Conventionally, in the system of cooling water for cooling equipment, scale accumulates and microorganisms propagate with time. Accumulation of scale and accumulation of mucilage (slime) and pollutants (sludge) by microorganisms lead to early deterioration of equipment and decrease in efficiency, and microbial reproduction may adversely affect the indoor environment.

However, renewal of pipes constituting the system of equipment and removal / cleaning of scale / sludge and the like require a large cost and cannot be performed so frequently. Also,
Injecting a chlorine-based drug is generally performed to suppress the growth of microorganisms and algae, but there are drawbacks in terms of management and cost.

Further, for the removal of dirt dissolved in water for use in, for example, fish tanks, the water is circulated by a pump and the dirt is removed by a filtering device or the like. Further, when purifying the system of this water, the water tank was emptied to clean the inside, and was disinfected and sterilized with a chemical or the like. In the case of a large water tank, an operator puts on an aqualung to enter and regularly clean the glass surface in the system.

However, since the filtration device is clogged, the filter material and the adsorbent are often replaced. In addition, purification of the water system is very time-consuming, and it is difficult to purify excretions from seafood, proteins derived from food waste, etc., and their decomposition products (urea, uric acid, especially ammonia). It was

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention
An object of the present invention is to provide a method and a device that can purify water more easily than before. Further, the present invention is intended to provide a method capable of purifying a water system more easily than ever before.

[0007]

In order to solve the above problems, the present invention takes the following technical means.

The method for purifying water according to the present invention is characterized in that a part of the water taken out from the water system is subjected to an oxidative decomposition action of active oxygen so as to be returned to the original system. is there.

[0009] Further, a part of the water taken out from the water system is electrolyzed so as to generate active oxygen, and the water subjected to the oxidative decomposition action of the active oxygen is returned to the original system again. Can also be implemented as.

Also, a part of the water taken out from the water system is mixed with water in which active oxygen has been generated by electrolysis, so that the water subjected to the oxidative decomposition action of active oxygen is returned to the original system again. It can also be implemented as a matter of course.

Further, it can be carried out by electrolyzing in the presence of sodium chloride to generate hypochlorous acid and active oxygen.

It is also possible to carry out electrolysis in the presence of sodium bromide to produce hypobromite and active oxygen.

Further, by decomposing hypochlorous acid or hypobromite generated by electrolysis with a catalyst, hypochlorous acid or hypobromite is reduced to a predetermined concentration or less, while active oxygen is generated. It can also be carried out as if it had been done.

The purifying apparatus of the present invention comprises an electrolyzer for electrolyzing so as to generate active oxygen in a part of the water taken out from the water system, and the active oxygen generated by the electrolyzer is used. It is characterized in that the water used for the oxidative decomposition action of is returned to the original system again.

Further, the purifying device of the present invention comprises an electrolyzer for supplying water in which active oxygen is generated by electrolysis, and water containing active oxygen supplied by the electrolyzer is used as water for use. It is characterized in that it is mixed with a part of the water taken out from the system, and the water which has been subjected to the oxidative decomposition action of active oxygen is returned to the original system again.

[0016]

The present invention has the following actions.

[0017] By oxidizing and decomposing active oxygen on a portion of the water used to remove the water, the water is purified, and the purified water is returned to the original system. Can be gradually purified.

It should be noted that even if a part of the water taken out from the water system is electrolyzed so as to generate active oxygen, and the water subjected to the oxidative decomposition action of the active oxygen is returned to the original system again. Well, some water taken out from the water system is mixed with water that has generated active oxygen by electrolysis so that the water that has undergone the oxidative decomposition action of active oxygen is returned to the original system again. May be.

When electrolysis is carried out in the presence of sodium chloride to generate hypochlorous acid and active oxygen, the following reaction occurs at the anode electrode.

[0020] _{^{2Cl - → Cl 2 + 2e -}} ... Cl 2 + H 2 O → HClO + HCl ... HClO → HCl + (O) ... (O) is active oxygen. The HCl generated in and is neutralized with NaOH generated at the cathode electrode and returns to NaCl.

When electrolysis is performed in the presence of sodium bromide to produce hypobromite and active oxygen, the following reaction is performed.

[0022] _{^{2Br - → Br 2 + 2e -}} ... Br 2 + H 2 O → HBrO + HBr ... HBrO → HBr + (O) ... hypochlorite, since hypobromite to produce active oxygen and degrade over time, water When the water containing hypochlorous acid and hypobromite returns to the system, the active oxygen generated by decomposition of hypochlorous acid and hypobromite causes not only the water itself but also the water system. The equipment / device to be formed can be purified more easily than before.

When the pH becomes higher, hypochlorous acid and hypobromite change to ClO ⁻ and BrO ⁻ as follows.

[0024] ^{HClO⇔H + + ClO - HBrO⇔H + +} BrO - ClO -, BrO - when changes, hypochlorite, oxidizing power as compared with the state of the hypobromous acid is reduced to a few tenths of a I will end up. Therefore, hypochlorous acid is added in the presence of an acid such as hydrochloric acid.
It is preferable that H is adjusted to a weakly acidic region of 7 or less and used, and hypobromite is preferably adjusted to a substantially neutral region of pH of 6 to 8.5 or less and used. Therefore, sodium bromide is suitable when a metal is used in the system of water and is applied to applications where there is a problem of rust.

Furthermore, by decomposing hypochlorous acid or hypobromous acid generated by electrolysis with a catalyst, the hypochlorous acid or hypobromic acid is reduced to a predetermined concentration or less, while active oxygen is generated. By using such a method, the water can be further purified by the active oxygen generated by the decomposition of hypochlorous acid or hypobromite, and the residual chlorine concentration can be reduced.

Therefore, in particular, when the present invention is applied to a water system containing organisms such as fish and shellfish, the residual chlorine concentration is lowered to a predetermined concentration or less,
It is possible to reduce adverse effects on living things as much as possible.

Furthermore, when hypochlorous acid or hypobromic acid and active oxygen are produced at a high concentration by electrolysis, microorganisms and the like existing in the water are suitably sterilized and purified by the action of the high concentration of active oxygen. In addition, it is possible to reduce the residual chlorine concentration by the catalyst to generate active oxygen, and it is possible to parallelize the advantage that the adverse effect on the organisms in the system can be reduced as much as possible.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the accompanying drawings. (Example 1) As shown in FIGS. 1 and 2, in this example, the water in the aquarium 1 for culturing and breeding aquatic seafood is purified. In the aquarium, excrement of fish and seafood and food,
The food waste decomposes into ammonia nitrogen and nitrite, which are purified by exerting an oxidative decomposition action of active oxygen. The purification was performed without putting seafood in the aquarium.

A part of the water for use is taken out from the water tank 1 by the pump P, and the electrolyzer 2 exerts an oxidative decomposition action of active oxygen to purify the water, and the water is returned to the original water tank 1 via the catalyst tank 3. I'm trying to bring it back. In this way, the water in the aquarium is gradually purified. In this example, electrolysis was performed so as to generate active oxygen in a part of the water extracted from the water system, and the water subjected to the oxidative decomposition action of active oxygen was returned to the original system again. However, some of the water taken out from the water system is mixed with water that has generated active oxygen by electrolysis, and the water that has undergone the oxidative decomposition of active oxygen is returned to the original system. May be. .

As shown in FIG. 2, the electrolyzer 2 comprises an electrolysis passage 4 and a known rectifier (not shown) for supplying a current to the electrolysis passage 4. The electrolytic passages 4 are formed by disposing the cathode electrode plates 6 on both sides of the anode electrode plate 5 and between them.
Are connected in series (not shown). The distance between the anode electrode plate 5 and the cathode electrode plate 6 can be preferably set within a range of about 1 to 10 mm, but in this embodiment, it is set to 4 mm, and the electrolytic passages 4 connected in series are provided. Has a total length of 500 mm. Packing 7 is provided between both electrodes to prevent short circuit.
The packing 7 has a frame shape in which the inside is hollowed out, leaving the outer assembled portion. The hollowed-out internal portion forms the electrolytic passage 4. A stainless steel plate 10 is provided outside the both cathode electrode plates 6 via a packing 8 and a vinyl chloride plate 9.

The water in the water tank is made to flow by a pump P from a hole H penetrating below one of the stainless steel plates 10, passes through a hole H penetrating each of the vinyl chloride plate 9 and the cathode electrode plate 6, and passes through the anode electrode plate 5. The anode electrode plate 6 and the anode electrode plate 5 through the electrolytic passage 4 (inner part of the packing 7) and through the hole H penetrating above the anode electrode plate 5, To the other side. It passes through the electrolytic passage 4 (inside the packing 7) between the cathode electrode plate 6 and the anode electrode plate 5 on the opposite surface side, and the cathode electrode plate 6, the vinyl chloride plate 9 and the stainless steel plate 10 are formed in the same manner as described above. It flows out through a hole (not shown) passing through each lower part. The electrolyzer 2 having the same structure is used in the following embodiments.

Since hypochlorous acid generated during electrolysis decomposes with time to generate active oxygen, when the water containing hypochlorous acid returns to the system of water, hypochlorous acid is generated. With the active oxygen generated by decomposition, not only the water itself but also the equipment / device forming the water system can be purified more easily than before.

The anode electrode plate 5 defining the electrolytic passage 4 is defined.
The electrode polarities of the cathode electrode plate 6 and the cathode electrode plate 6 were changed by a known electrical method, and the electrodes were changed at regular intervals (set at intervals of about 10 minutes). By doing so, the charged substance in the flowing water of the electrolysis passage 4 is prevented from depositing and growing on the corresponding opposite charging electrode, the generation of active oxygen is prevented from decreasing, and the water having a constant purifying power is continuously provided. Can be supplied. Also, when the polarities of both electrode plates are fixed, only the electrode plate selected on the anode side will melt away, which causes a one-sided phenomenon, but by changing the electrode polarity, the side that became the anode will melt away. To go. Therefore, the rate of wear of both electrodes over time can be made substantially equal.

The water after passing through the electrolyzer 2 is returned to the original water tank 1 through the nickel peroxide catalyst tank 3. The water after passing through the electrolyzer 2 contains hypochlorous acid and sodium hypochlorite produced in the electrolyzer 2, and the original aquarium 1 was used to avoid adverse effects on seafood. This is because it is preferable to reduce the residual chlorine concentration before returning.

The water is brought into contact with the nickel peroxide catalyst.
As a result, it decomposes hypochlorous acid, etc.
I'm trying to use it. As a nickel peroxide catalyst
For example, nickel trioxide hydrate (Ni₂O₃． H
₂O) alone or as a nickel trioxide trihydrate (Ni₃
O_Four． H₂O) and / or nickel dioxide hydrate (Ni
O ₂． H₂O) that uses the mixture of
Wear. As a catalyst, activated carbon fiber is mixed with nickel peroxide
A cylinder was mixed and molded into a cylindrical shape.

With the above structure, the water in the water tank was purified. In this example, in order to more clearly understand the purification effect, 3,000 cc of human urine diluted 10 times with water and left for 3 days was used as a sample of water to be purified. The concentration of ammonia nitrogen in the sample before purification is 980p
The pm and COD were 250 ppm and the pH was 8.4.
In addition, 10% of 25% saline solution was added to the sample at the beginning of purification.
c was added. The flow rate of the circulating water is 10 liters / minute, and the electrolysis condition in the electrolysis device 2 is a constant current of 1
It was 0 Amp and 3V.

Electric conductivity (× 1,000 μs / cm) of the water in the water tank 1 after a certain period of time (before the start of purification, after 20 minutes, after 40 minutes, after 1 hour, after 2 hours and after 3 hours) , Hydrogen ion concentration (pH), ammonia nitrogen concentration (pp
m), concentration of nitrite nitrogen (ppm), COD value, residual chlorine concentration before catalytic treatment (ppm), residual chlorine concentration after catalytic treatment (ppm) are shown in Table 1.

The water in the aquarium 1 for aquaculture does not actually pollute up to this point, but even the extremely polluted water such as the sample of this example could be sufficiently purified. In particular, the effect of reducing the concentrations of ammoniacal nitrogen, nitrogen nitrite, etc. is great. Ammoniacal nitrogen and nitrous nitrite are harmful and toxic to seafood, and at the same time promote the growth of algae, fungi and bacteria in water, and cause slime generation in the circulation route of water.

Excessive hypochlorous acid generated by electrolysis and used for purification of water can corrode metals,
Since it is harmful to the seafood to be raised, it was possible to reduce the residual free chlorine by installing the above-mentioned catalyst tank 3 in the circulation route. (Example 2) As shown in FIGS. 2 and 3, in this example, the aquarium 1 for fish and shellfish was cleaned. A part of the water in the water tank is taken out by the pump P, the electrolyte aqueous solution 11 is added from the electrolyte aqueous solution tank, and a strong oxidative decomposition action of active oxygen is exerted on the water in the electrolyzer 2 to kill algae. It is sterilized and purified, and is returned to the original water tank 1 via the filter F. In this example, purification was carried out without putting seafood in the aquarium.

The water tank 1 has a rectangular shape (630 × 85 × 40).
(H) mm) made of vinyl chloride having a capacity of 200 liters was used.

The distance between the anode electrode plate 5 and the cathode electrode plate 6 in the electrolytic passage 4 of the electrolyzer 2 was set to 4 mm, and the electrolysis condition was 15 V at a constant current of 3 Amp.
The flow rate of the water tank in the water tank 1 was 7 liters / minute. The electrolyte solution 11 is used every 15 minutes for 10 minutes for 10 minutes.
It is supplied at a flow rate of cc / min, and during this period, the electrolyzer 2 is operated and electrolysis is performed. Then, when the electric conductivity of the water in the water tank 1 reaches a certain value, the pump P that supplies the aqueous electrolyte solution 11 is stopped. The electric conductivity when the pump P that supplies the aqueous electrolyte solution 11 was stopped was 800 μS / cm, but from 300 μS / cm to 5,0 depending on the application and water quality.
It can be suitably set between 00 μS / cm. The electrolyzer 2 is operated even after the supply pump P for the aqueous electrolyte solution 11 is stopped.
The operation was stopped for 0 minutes and repeated for 5 minutes. The stop / run interval can be set arbitrarily according to the application and water quality. Further, as in Example 1, the electrolyte aqueous solution may be initially added in advance in a fixed amount corresponding to the amount of water used.

The electrolyte aqueous solution tank is provided to supply the electrolyte aqueous solution 11 to the circulating water, and the salt solution 2.
Stores a 5% aqueous solution.

In this example, in order to more clearly grasp the purification effect, a mixture of the following was used in order to promote the reproduction of algae more than it actually is. 150 liters of tap water and 25 liters of reservoir water (algae are fully propagated,
It was a deep yellow-green color with a mass of green algae floating on the surface of the water. Fluoroscopy (white disc) 12-13 cm) and human urine 1
Liters (mixed to promote the growth of algae by creating a situation of water pollution equivalent to the excrement of farmed fish including ammonia).

Of this, 120 liters is the water tank 1 of the embodiment.
(Water depth 230 mm) and the remaining 56 liters were stored in a water tank for comparison.

Then, for purification on the next day, a mixture of the following was used. Water tank 1 water 5 for comparison of the previous day
There are 6 liters (algae were very proliferating due to direct sunlight at midday in midsummer), 119 liters of tap water, and 1 liter of human urine.

From this, 120 is added to the water tank 1 for purification.
1 liter, 56 liters were stored in a water tank for comparison. The water in the aquarium for comparison was further used for purification on the next day.

The aquarium 1 for the examples and comparisons was installed in a place exposed to direct sunlight in August.
Purification was performed 7 times in total during the daytime from 8:00 am to 5:00 pm. The water temperature of the water tank 1 was about 27 to 35 ° C.

After completing the purification for one day, the following items were measured. A total of 4.5 liters of a 2.5% sodium chloride aqueous solution was supplied by the fourth day.

The electric conductivity (μs / cm) was measured by using a Coductivity Meter AB-6 manufactured by Organo. The transparency (cm) was measured by reading the water depth at which a black cross on a white disc can be discerned. Chemical oxygen demand COD Mn (mg / liter) 10
It was measured by the oxygen consumption by acidic potassium permanganate at 0 ° C. Ammoniacal nitrogen concentration (mg / liter) was measured by the Nessler method (absorptiometric method). Wavelength 425 nm. HACH water quality analyzer DR / 200
Type 0 was used. Table 2 shows the measurement results.

From Table 2, it can be seen that the quality of the water in the water tank 1 is improving day by day. (Example 3) In the same manner as in Example 2, purification was performed by using a 2.5% aqueous solution of sodium bromide as the electrolyte aqueous solution 11. The aqueous solution of sodium bromide was supplied every 18 minutes at a flow rate of 10 cc / min for 2 minutes only, and a total of 2.8 liters was supplied on the first day. In this example also, purification was carried out without putting seafood in the aquarium. Table 3 shows various measurement results.

From Table 3, it can be seen that the quality of the water in the water tank 1 is improving day by day. (Embodiment 4) As shown in FIGS. 2 and 4, in this embodiment, the aquarium 1 in which carp is bred was purified as a water system.

The carp breeding aquarium 1 was made of acrylic with a width of 1,000 mm, a depth of 650 mm, a height of 480 mm and a water depth of 310 mm, and the amount of water used was 200 liters. Sixteen carp of about 90 to 100 g were bred.
The water temperature of the water in the water tank was about 24 to 26 ° C.

A part of the water taken out from the carp breeding aquarium 1 was first filtered with a filter F to remove coarse debris such as leftover food.
Electrolyzer 2 for water of 5 liters / minute by pump P
(The distance between both electrodes is set to 4 mm), catalyst tank 3, chiller
12 and the flow meter 13 to return to the water tank 1 from the sprinkler pipe 14 (supplementing dissolved oxygen by aeration of water). As the catalyst, one obtained by kneading nickel peroxide into activated carbon fiber and molding it was used. Aquarium 1 taken out
The water of the
11 (2.5% saline solution) is supplied by a metering pump P at a flow rate of 5 cc / min.

The electric conductivity of the water in the water tank 1 is 500 μs /
Since the electrolysis reaction is carried out without supplying the electrolytic aqueous solution 11 when the value reaches cm or more, the supply is stopped. The electrolysis reaction may be performed continuously or intermittently by a timer. In this example, a 20-minute cycle was conducted in which electrolysis was performed for 5 minutes and rested for 15 minutes. That is, electrolysis was performed for 5 minutes in 1 hour x 3 times for a total of 15 minutes. Depending on the type of fish or shrimp to be raised and the degree of contamination of the aquarium 1, the electric conductivity when stopping the supply of the aqueous electrolyte solution 11 can be suitably selected from 500 to 3,000 μs / cm, but in this embodiment, 800-1,200μs /
cm.

The extracted water in the water tank 1 is subjected to the oxidative decomposition action of the active oxygen produced in the electrolyzer 2 (electrolysis at a constant current of 3 Amp and 4 V), such as filth, ammonia and nitrite ions in the water. Is oxidatively decomposed and purified.
In addition, pathogenic microorganisms existing in the water are sterilized and disinfected with active oxygen and hypochlorous acid. The remaining hypochlorous acid is decomposed by the catalyst to release active oxygen, which further oxidatively decomposes and sterilizes.

On the other hand, as a comparative experiment, part of the water in the water tank 1 was taken out and circulated in the same route while the electrolyzer 2 was stopped. The example and the comparative experiment were carried out in parallel, and 16 carp of each were bred for 30 days in August.

Table 4 shows the results of measurement such as weight gain of carp in Examples and Comparative Experiments, and Table 5 shows pH, COD (mg / liter), NH ₄ -N concentration (mg / liter), (NO ₂
Concentration of -N) (mg / l), shows the results of measurement of water quality, such as concentration (mg / liter) of (NO ₃ -N).

In the example, the free residual chlorine concentration of the water after passing through the electrolyzer 2 was measured to be 0.5 to 0.8.
The concentration of free residual chlorine was 0.05 to 0.10 mg / liter, which was obtained by decomposing hypochlorous acid with a catalyst and then opening the cock under the flow meter 13 to collect water. Further, the free residual chlorine concentration of the water after aeration with the sprinkling pipe 14 was 0 to 0.02 mg / liter.

The water in the aquarium 1 of the example was transparent and clean until the end of the 30-day experiment. In addition, the carp was healthy without algae adhering to the inner surface of the acrylic tank 1. The filter F was not clogged, and the amount of water used in the circulating water tank 1 did not decrease.

On the other hand, in a comparative experiment, the water in the water tank 1 became visibly polluted every day, and yellow-green algae began to adhere to the inner surface of the transparent acrylic water tank 1 in places. . Moreover, since the amount of circulating water gradually decreased, the filter F and the catalyst tank 3 were washed twice during the experiment. The residual food dropped on the bottom of the aquarium 1 was removed as much as possible. The carp began to stay still at the bottom of the aquarium 1 as the number of days passed and the water quality gradually deteriorated. And the weakened three carp died of some illness.

As shown in Table 4, the weight gain and feed efficiency of the example were better than those of the comparative experiment. The feed efficiency of the comparative experiment was calculated by adding the weights of three dead carp.

As shown in Table 5, the COD value of the water in the water tank 1 of the example was kept lower than that in the comparative experiment. It can be seen that oxidative decomposition of excrement and leftover food is sufficiently performed. Further, ammonia (NH ₄ —N) and nitrite ion (NO ₂ —N), which are highly toxic to fish, remained at 0.6 mg / liter or less in the examples. The allowable amount of NO ₃ in the fish farm water is 25 to 35 mg.
Although it is generally said that a maximum of 1 / liter, (NO ₃ —N) in the examples is 7.1 mg / liter, which is a sufficiently satisfactory range. On the other hand, in a comparative experiment (NH
₄ -N), (the concentration of NO ₂ -N) is very high, which is 3 fish carp is considered to cause poor overall growth died.

Further, by decomposing the hypochlorous acid generated by electrolysis with a catalyst, the hypochlorous acid is reduced to a predetermined concentration or less, while active oxygen is generated, so that the hypochlorous acid is generated. The water can be further purified by the active oxygen generated by the decomposition of the acid, and the residual chlorine concentration can be lowered. Therefore, for a system of water containing living organisms such as fish and shellfish, it is possible to reduce adverse effects on living organisms by reducing the residual chlorine concentration to a predetermined concentration or less.

Further, by producing a high concentration of hypochlorous acid and active oxygen by electrolysis, microorganisms and the like existing in the water are suitably sterilized and purified by the action of the high concentration of active oxygen, and by a catalyst. By reducing the residual chlorine concentration and generating active oxygen, it is possible to parallelize the advantage that adverse effects on living organisms in the system can be reduced as much as possible.

The present embodiment has the following advantages. 1. Since dissolved oxygen increases and ammonia nitrogen and nitrite nitrogen decrease, the water quality of the water is improved, so that the growth of seafood such as fish, shellfish, shrimp, and crab becomes significantly faster. 2. The breeding density per unit of fish tank is 2
It is possible to perform high-density aquaculture that raises up to 3 times. 3. By sterilizing pathogenic bacteria such as bacteria, viruses, and water molds, diseases of seafood can be prevented and the mortality rate can be reduced. 4. Since deterioration and spoilage of the fed feed can be suppressed, feeding of the feed is improved and feed efficiency is improved. 5. Propagation of excess algae is suppressed, and pollutants in the water are purified, and slime generation can be suppressed. 6. Since the water in the aquarium 1 is circulated for purification, it is sufficiently effective even if the concentration of active oxygen or the like is lowered to some extent. 7. When the residual chlorine concentration is high in the purification and sterilization of the water in the aquarium 1 for aquaculture, it has a bad influence on seafood, but a catalyst is used to decompose residual hypochlorous acid and the like into harmless NaCl and nascent oxygen. As a result, the residual chlorine concentration can be reduced to a low concentration and the active oxygen generated by the decomposition can be effectively used. 8. Heretofore, it has been difficult and expensive to select a drug to be sterilized and sterilized without affecting the aquaculture organisms, and it has been difficult to use it. Further, it is difficult to remove stains due to the adhesion and propagation of algae such as blue-green algae on the water tank 1 and the accompanying circulating water channel, especially on the glass window for observation or viewing. Further, conventionally, it is difficult to sufficiently maintain the dissolved oxygen in the water tank 1 having a high breeding density, and in order to increase the dissolved oxygen, air is blown by a blower, a compressor or the like, or a water wheel is rotated to perform aeration. But,
According to the embodiment, the water rich in dissolved oxygen can be circulated and supplied.

Therefore, the aquarium for transportation, the aquarium for business 1, the aquarium for aquariums, the aquarium for appreciation, the aquaculture aquarium 1,
It is extremely suitable for purifying, disinfecting and sterilizing water such as cages. (Embodiment 5) As shown in FIGS. 2, 5 and 6, in this embodiment, the system of cooling water of the cooling equipment is purified.

A total of 120 liters / minute of water sent from the cooling tower 15 (trade name: HISCOOLING TOWER HT10SQ6 manufactured by Mitsubishi Corp.) via the plastic screen 16 and the 80-liter water tank 1 was pumped to 9 liters per minute. Is sent to the 1st and 2nd chillers 12 (Mitsubishi Corp., trade name package air conditioner PW-5PB1), a part (10% of 12 liters / minute) of water is taken out and the electrolyte aqueous solution 11 is mixed. , Electrolysis device 2 (the distance between both electrodes is 2
mm, and a constant current of 3 Amp, 4 to 5 V) is sent.

The electrolyzer 2 exerts an oxidative decomposition action on bacteria and algae in water to sterilize and decompose salts. Then, it is sent to a catalyst tank 3 in the form of an activated carbon fiber filter to decompose hypochlorous acid and reduce the residual chlorine concentration. Then, return to the original water system piping.

In this example, in order to more clearly understand the purification effect, in order to promote the reproduction of algae more than it actually is,
A total of 250 liters of cooling water was constructed as follows. Pond water (contains a lot of algae, transparency 12 cm)
24 liters, 1 liter of human urine, and tap water to make the rest 250 liters in total. Human urine is added as nutrients for adjusting the ammonia and COD of the water (shown in Table 6) to promote the growth of algae.

First, as a comparative experiment, the cooling tower 15, the first and second chillers 12 were operated without operating the electrolyzer 2.
Was driven for 7 days in August. Water temperature (℃), electrical conductivity (μs / cm), transparency (cm), measured at 3 pm
COD (mg / liter), ammonia nitrogen concentration (m
Various data (g / liter) are shown in Table 7.

The cooling tower 15 is installed on the veranda on the second floor where a summer day is a full day, and the growth of algae is fast. On the 7th day, the yellowish green color becomes very dark and a slime-like mass of algae forms. Now adheres to the plastic screen 16. Yellow-green algae began to adhere to the bottom of the aquarium 1. The water is cloudy and its transparency is 18 cm to 16 c
began to fall to m. Algae gradually propagated, and on the 7th day, the plastic screen 16 in the water tank 1 of the cooling tower 15
Then, green algae started to adhere as a lump.

Here, the comparative experiment is completed, and the electrolyzer 2
The algae killing and purification was started on the 7th day from the contaminated state. The bypass was opened to operate the electrolyzer 2 to purify 12 liters / min, which is 10% of the total amount of cooling water to be circulated, which is 120 liters / min, and return it to the original water system again. Water temperature (° C), electrical conductivity (μs / cm), transparency (cm), COD (mg / liter), ammoniacal nitrogen concentration (mg / liter), measured at 3 pm
Table 8 shows various data of residual chlorine concentration (mg / liter).
Shown in

Sodium bromide 2 was used as the electrolyte aqueous solution 11.
A 5% aqueous solution was supplied at 10 cc / min. As shown in Table 8, on the 3rd day, the electric conductivity was 1,200 μS / cm (of 800 to 2,000 μS / cm, which is the control standard of the water for cooling the cooling tower 15 when using the anticorrosive agent). (Within the range), the addition of the 2.5% aqueous sodium bromide solution was terminated.

Although a 2.5% sodium bromide aqueous solution was used in this example, the same effect can be obtained by using a 2.5% sodium chloride aqueous solution. The oxidizing and sterilizing power of hypochlorous acid works more effectively at pH 4 than in the neutral range.
It is the acidic side of ~ 7. On the other hand, hypobromous acid has a pH of 4-8.
Effective in a wide range of 5. In both cases, the optimum bactericidal power is around pH 5, and if this is 100%, H at pH 8
ClO is reduced to 30%, but HBrO is 90%
It maintains the sterilizing power of and is fully effective. Further, it is said that the pH of the cooling water is preferably 7.0 to 8.0.
Therefore, sodium bromide is suitable when a metal is used in the system of water and is applied to applications where there is a problem of rust.

Since the cooling tower 15 sucks air with a large fan and showers the cooling water, the cooling water is contaminated by dust, insects, insects, etc. in the atmosphere. The mixed organic matter is decomposed into COD components, further ammonia, etc., and algae, bacteria, etc. propagate. These adhere to the piping path, the chiller 12 and the heat exchanger and cause a trouble.

On the first day after the start of purification by the electrolyzer 2, the cooling water which was a pale green due to algae breeding was 2
Almost colorless on the 3rd day, colorless and transparent on the 3rd day, and completely colorless and transparent on the 5th day and thereafter, the mass of green slime mainly composed of algae adhered to the screen 16 completely disappeared.

Conventionally, a chlorine-based agent has been used for sterilizing Legionella spp. In water for cooling the cooling tower, and a residual chlorine concentration of 2 to 5 mg / liter is required to maintain the sterilizing effect. On the other hand, metals such as iron and copper are used in the system in which the cooling water is circulated, and it is necessary to use an anticorrosive agent in combination to prevent corrosion thereof. However, according to the example, there is an advantage that it is not necessary to use an anticorrosive agent together because the residual chlorine concentration is low.

When a chlorine-based chemical is added as an algicidal agent, it is generally said that the concentration of free residual chlorine should be controlled to 1 ppm or less in order to prevent metal corrosion. As described above, according to the examples, it is understood that the concentration lower than this standard has a sufficient algicidal effect.

Further, in the water system of the cooling tower, scales are accumulated or microorganisms are propagated over time. Therefore, accumulation of scales, sticky substances (slime) by microorganisms, and pollutants (sludge) Accumulation of deposits leads to a reduction in cooling capacity and early deterioration of equipment, and the reproduction of microorganisms sometimes adversely affects the indoor environment.However, according to this example, impurities in water are decomposed and fungi are removed. There is an advantage that the sterilization can be performed and the scale can be prevented from being clogged in the pipe.

Further, in the case of suppressing the growth of microorganisms by injecting a chemical solution as in the conventional case, blow down is constantly performed to add new water (which requires a considerable amount of water) to remove dirt from the water. Although it was necessary to suppress the progress and the concentration of the chemical solution, according to the embodiment, the sterilization / purification is performed if the water has a certain electric conductivity, so that almost all blow down is performed. It has the advantage of not being necessary. Therefore, the replenishment of new water is very small.

[0081]

[Table 1]

[0082]

[Table 2]

[0083]

[Table 3]

[0084]

[Table 4]

[0085]

[Table 5]

[0086]

[Table 6]

[0087]

[Table 7]

[0088]

[Table 8]

The water purification method and the water purification apparatus of the present invention can be suitably applied to the following. 1. Purification of water for decoration fountains and circulating waterways such as parks, amusement parks, green spaces, exhibition halls, shopping centers, underground shopping malls, public and commercial areas. 2. Purification of circulating muddy bath water for blowing air into warm water in bathtubs that are circulated in sports facilities and baths. 3. Purification of the water in the tank of the humidifier (bread type humidifier, ventilation evaporation humidifier, etc.) to humidify the atmosphere where drying is not desired in hospitals, spinning and textile factories, museums, department stores, etc. This water is likely to be concentrated and dirty, and microorganisms and pathogens are likely to grow.

[0090]

The present invention having the above-mentioned structure has the following effects.

Since the water itself and the water system can be suitably purified by the oxidative decomposition action of the active oxygen contained in the water that has been returned to the original system, it is possible to purify the water or the water system more easily than before. And a device can be provided.

[Brief description of drawings]

FIG. 1 is a system flow chart for explaining purification of an aquarium in Embodiment 1 of the present invention.

FIG. 2 is a schematic perspective view for explaining the electrolyzer of FIG.

FIG. 3 is a system flow diagram for explaining purification of an aquarium in Embodiments 2 and 3 of the present invention.

FIG. 4 is a system flow diagram for explaining purification of a carp breeding aquarium in Example 4 of the present invention.

FIG. 5 is a system flow diagram for explaining purification of cooling water in a fifth embodiment of the present invention.

FIG. 6 illustrates the system flow diagram of FIG. 5 in more detail.

[Explanation of symbols]

 2 Electrolyzer

Claims (8)

[Claims] 1. A part of the water taken out of the water system,
A method for purifying water, which is characterized in that oxidative decomposition of active oxygen is exerted to restore the original system. 2. A method in which a part of the water taken out from the water system is electrolyzed so as to generate active oxygen, and the water subjected to the oxidative decomposition action of the active oxygen is returned to the original system again. Item 1. A method for purifying water according to item 1. 3. A part of the water taken out of the water system,
2. The method for purifying water according to claim 1, wherein water generated by generating active oxygen by electrolysis is mixed, and the water subjected to the oxidative decomposition action of active oxygen is returned to the original system again. 4. The method for purifying water according to claim 2, wherein hypochlorous acid and active oxygen are generated by electrolyzing in the presence of sodium chloride. 5. The method for purifying water according to claim 2, wherein hypobromic acid and active oxygen are produced by electrolyzing in the presence of sodium bromide. 6. A hypochlorous acid or hypobromite generated by electrolysis is decomposed by a catalyst to reduce hypochlorous acid or hypobromite to a predetermined concentration or less, while generating active oxygen. The method for purifying water according to claim 4 or 5, wherein the purification method is performed. 7. An electrolyzer for electrolyzing so as to generate active oxygen in a part of the water taken out from the system for water, and the oxidative decomposition action of the active oxygen generated by the electrolyzer is provided. The water purification device characterized in that the applied water is returned to the original system again. 8. An electrolyzer for supplying water in which active oxygen has been generated by electrolysis, wherein water containing active oxygen supplied by the electrolyzer is taken out from a system of water. An apparatus for purifying water, characterized in that the water mixed with the water and the water subjected to the oxidative decomposition of active oxygen is returned to the original system.