JPH0647589Y2 - Aquarium purification equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a purification device for aquariums.

[Conventional technology and its technical problem]

In recent years, with the change in consumer preference, the tendency to eat fresh, fresh seafood has become stronger, and seafood is produced at the production site, the collection site, and the consumption site, for example, for aquaculture, stockpiling, and shipping adjustment. It is stored in water tanks for storage, consumption and stockpiling, tanks, ponds (hereinafter referred to as tanks). In this case, it is indispensable to circulate and purify seawater and freshwater, and conventionally, a circulation system provided with a physical treatment device or a biological treatment device using a biofilm is used.

However, users often tend to put in an appropriate amount or more of seafood due to economical reasons. As a result, organic nitrogen oxides (ammonia, carbon dioxide, nitrous acid, hydrogen sulfide) due to decomposition of excrement and food residue accumulate in water. In addition, harmful biodegradable substances, for example, proteins such as male sperm and squid smears pass through the eyes of the filter and are not easily removed. As a result, even if a biological treatment device with a calculated decay function is used, exfoliation of the biofilm and bacterial metabolism are caused, and tanks cause water pollution in a short period of time, reducing the survival rate of seafood. It was easy to cause trouble.

Moreover, the conventional purification device has a problem in that it is large in performance, requires a large space around the tanks, and has a complicated structure and requires complicated maintenance such as backwashing in operation. It was

The present invention was devised to solve the above problems, and its purpose is to have a simple and compact structure that does not require a special installation space outside the tanks and does not require special aeration. An object of the present invention is to provide a purifying device for water tanks capable of reliably and efficiently removing organic nitrogen oxides and harmful poor biodegradable substances without the need for a stirring drive mechanism.

[Means for Solving the Problems]

In order to achieve the above object, the present invention is directed to a final treatment mechanism which is arranged in a tank and accommodates a filter medium inside and has a clear water blowout hole toward the outside, and a pretreatment mechanism arranged above this final treatment mechanism. And a biological treatment mechanism which is disposed in the vicinity of the pretreatment mechanism and which purifies the treated water from the pretreatment mechanism with a biofilm and introduces it into the final treatment mechanism, and the pretreatment mechanism for water in tanks including a submersible pump. And a raw water extraction system that leads to the inside of the tank-shaped body so that the pretreatment mechanism forms an annular chamber between the tank-shaped body installed on the final treatment mechanism and the inner surface of the tank-shaped body. A first barrel down from the top,
A closed space is formed at the inner top of the annular chamber by being inserted into the first cylindrical body so as to form an annular flow path communicating with the lower part of the annular chamber and stopping at the upper end of the first cylindrical body so that it does not reach the inner top of the tank. And a foamy filth removal mechanism including a container that communicates with a closed space by a conduit, and the raw water extraction system has a tip portion that communicates with the annular chamber and is located at a site upstream of the tip portion. Is a structure in which an ozone mixing mechanism having a throttle and a conduit leading to the downstream side in the vicinity thereof is interposed, and ozone is dispersed and mixed with the raw water passing through the raw water extraction system and introduced into the annular chamber. Is.

〔Example〕

 An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 to 5 show an embodiment of a purifying apparatus for water tanks according to the present invention.

The device of the present invention basically comprises a pretreatment device A, at least one biological treatment device B ₁ and B ₂ and a final treatment mechanism C, and is wholly installed in a water tank D. The water tank D has a required volume, seafood is stored together with water, and the water level WL is at a level above the final treatment mechanism C. A constant flow of water is formed by a tidal current pump (not shown).

The final processing mechanism C has a closed tank-shaped or box-shaped main body 30 having a large diameter and a relatively low height.
Is erected on top of the final processing mechanism C. As shown in FIGS. 2 and 3, the pre-stage processing apparatus A includes a tank-shaped main body 1 whose upper and lower sides are closed in a watertight manner, and is installed on the main body 30 by the base 1a. Inside the tank-shaped main body 1, a first cylindrical body 2 having a base end fixed to a ceiling plate 1b is hung down, and an annular chamber 3 is provided between the first cylindrical body 2 and the inner wall of the tank-shaped main body. Has been formed.

A tip portion 60 of the raw water withdrawal system 6 is connected to the annular chamber 3 at a desired height level position, preferably tangentially, and in the vicinity thereof, the gas mixture discharged from the tip portion 60 of the raw water withdrawal system 6 is mixed. A flow guide 17 for swirling up the raw water is provided. The flow guide 17 is connected to the tank-shaped body 1 on the outer diameter side and has a passage gap between the inner diameter side and the first cylindrical body 2.
It has 17a. A filler 170 having a coarse structure is arranged below the flow guide 17a as necessary so as to have an appropriate retention of the raw water and a filter bed function.

A second tubular body 4 is inserted into the first tubular body 2 concentrically with the first tubular body 2, and a relatively narrow annular flow path 5 is formed between the second tubular body 4 and the first tubular body 2.
Is formed. The second cylindrical body 4 is watertightly supported by the bottom plate 1c, the upper end thereof is opened at a required distance from the ceiling plate 1b, and the lower end thereof is a treated water extraction system 10 extending from the tank-shaped body 1 to form a biological system. It is led to the processing devices B ₁ and B ₂ .

In the raw water extraction system 6, the upstream side of the tip portion 60 rises to a higher level than the upper end of the second tubular body 4, and the ozone mixing mechanism 11 is connected to this high level portion, and an opening / closing port 80 is provided upstream of this. A cartridge type filter 8 having
An on-off valve 12 is provided to prevent backflow when the operation is stopped. The upstream side thereof is guided by the hose 61 into the underwater d of the water tank D, and is connected to the discharge side of the submersible pump 7 arranged at the bottom of the intake basin 62.

An ejector is preferably used for the ozone body mixing mechanism 11. FIG. 7 shows an example thereof, which is a cylindrical body 11a having a throttle 11b in the middle thereof, and a conduit 11c communicating with the vicinity of the downstream side of the throttle 11b.
The one with and is used. The conduit 11c is connected to an ozone generator (not shown).

A filth removal mechanism 13 is provided near the tank-shaped main body 1, especially at a height level equal to or higher than the ceiling portion 1b.
The filth removal mechanism 13 includes at least one foamy filth discharge pipe that connects the container 13a having an opening / closing plug 130 for cleaning and the container 13a and an annular closed space 14 created in the top area of the annular chamber. The discharge pipe 13c is provided with a discharge pipe 13c for discharging foamy waste from the storage container 13a, and the discharge pipe 13c is provided with an opening / closing valve 131 at several levels. The discharge pipe 13c is directly guided to the waste container 13e arranged outside the water tank D, or is connected to the secondary treatment mechanism 9 as shown in FIG.

Further, the tank-shaped body 1 is provided with a circulation system 15 for further enhancing the efficiency of removing dirt. This circulatory system 15
Is a pipe 15a for circulation whose discharge side is connected to the lower region of the annular chamber 3 and whose discharge side is guided to substantially the same region as the tip 60 of the raw water extraction system 6, and at a position higher than the water level WL of the water tank D. A small circulation pump 15b supported by the tank-shaped body 1 is provided, and the middle of the circulation pipe 15a is at a higher level than the upper end of the second cylindrical body 4 as shown in FIGS. 3 and 5. A gas mixing mechanism 11 'is interveningly connected to the level. The gas mixing mechanism 11 'has the same structure as that of the raw water extraction system 6 described above.

In this embodiment, the biological treatment mechanisms B ₁ and B ₂ are supported by the tank-shaped body 1 or the final treatment mechanism C by brackets or the like. The biological treatment mechanisms B ₁ and B ₂ may be one, but in this embodiment, two vertical treatment units are used and are connected to the treated water extraction system 10 and the branch pipes 10 a and 10 b. The biological treatment mechanisms B ₁ and B ₂ are composed of a sealed tank 19a, and one biological treatment mechanism B ₁ is a water-permeable cylinder 19d made of a mesh or the like leading to the branch pipe 10a, and a sealed container with this. Tank 19a
A filter medium 19e filled between the inner walls, for example, a multi-element ceramic mainly composed of barite stone or a water-permeable cylinder.
The water-permeable member 19f containing activated carbon is provided on 19d. Further, a push-in pipe 19g whose downstream communicates with the main body 30 of the trickle treatment mechanism C is connected to the upper portion of the closed tank 19a.

Further, the other biological treatment mechanism B ₂ comprises a water-permeable cylinder 19d made of a mesh or the like and an activated sludge forming member 19h such as glass wool filled between the water-permeable cylinder 19d and the inner wall of the closed tank 19a,
A push-in pipe 19g 'whose downstream communicates with the main body 30 of the final processing mechanism D is connected to the upper portion of the closed tank 19a. An air vent 19i and an opening / closing plug 19j are provided on the ceiling of the closed tank 19a, and the opening / closing plug 19j facilitates replacement of the filter medium 19e and the activated sludge forming member 19h.

FIG. 6 shows an embodiment in which the biological treatment mechanisms B ₁ and B ₂ are connected not in parallel but in series. In this case the push-in pipe
19g is guided to the lower part of the biological processing mechanism B ₂ and pushed into the push-in pipe 19
The g'is connected downstream to the main body 30 of the final processing mechanism C.

The final processing mechanism C has the closed tank-shaped or box-shaped main body 30 as described above, and at least one unit is provided in the inside thereof at a position separated from the discharge ports of the push-in pipes 19g and 19g 'as shown in FIG.
A retaining structure is created by providing the partition walls 31a and 31b, and the filter material 31c such as coral and diatomaceous earth is filled therein. Then, the clear water outlet holes 31d having a required pitch and number are arranged on the peripheral surface of the main body 30. Also, at the top of the main body 30, there is an air vent 31 that opens above the water level WL.
Figures 8 and 8a, in which the proximal end of e is connected, show another embodiment of the present invention. In this embodiment, there is only one biological treatment mechanism B, and it is interposed between the pretreatment mechanism A and the final treatment mechanism C in the height direction. The biological processing mechanism B has a short cylindrical main body 19a having a relatively low height, and a porous member 19d and a partition wall inside.
19i and 19i are provided, and a filter medium 19e is arranged between them. The filter medium 19e is the same as that used in the above embodiment.
The treated water take-out system 10 communicates with the first chamber defined by the porous member 19d, and the water that has dipped under the partition wall 19i is dropped into the final treatment mechanism C from the upwardly formed push-in pipe 19g. There is.

In addition, in this embodiment, the raw water has two systems 6,
6 ', and one system 6 pumps the bottom side sewage from the pump 7 as described above, but the remaining one system 6'
Pumps water near the water surface with the pump 7'and uses the hose 6
It is connected to the annular chamber 3 from 1'through a cartridge type filter 8 '. The connection level is preferably substantially the same as that of one system 6. Normally, this system 6'has a gas mixing mechanism 11
Is omitted.

The secondary processing mechanism 9 is used as needed. That is,
In the case of fish tanks, the contamination of water d does not proceed linearly, but rather the type of food (for example, the degree of water pollution when squid and horse mackerel are used and the time when pollution starts are completely different), It changes from moment to moment due to various factors such as the time required for digestion. Therefore, in relation to this, the properties (the amount of water content is large or the amount is small) and the amount of the foamy soil removed by the soil removal mechanism 13 are also changing every moment, and when the foamy soil contains a lot of water, This is because the water in the water tank D is taken out to the outside. The secondary treatment mechanism 9 has a mechanism for further separating the taken out foamy waste, taking out only the foam content, purifying the water and returning it to the water tank D. Therefore, it is suitable for use when it is difficult or troublesome to supply water to the water tank D.

8 to 10 show a first embodiment of the secondary processing mechanism 9, and FIG. 11 shows a second embodiment. The secondary processing mechanism 9 includes a foam separation unit 9a that collects foam from the foamy waste,
It is provided with a filtering unit 9b for moisture that has passed through the bubble separating unit 9a.
The separating portion 9a has a tubular body 90 made of transparent plastic, and the longitudinal direction of the tubular body 90 is closed by a wall plate 91 which also serves as a mounting member. Inside the tubular body 90, a perforated plate 92 is stretched close to the bottom, and the perforated plate 92 divides the chamber into an upper chamber 93 and a lower chamber 94. The perforated plate 92 is made of glass wool, sponge, matte filter cloth, or the like. The different filter member 9c is attached over several layers, and can be inserted and removed through the lid-equipped cleaning opening 9d.

The conduit 13d is inserted into the upper chamber 93 so as to face the wall plate 91, and the base end of the take-out pipe 9e is connected to the conduit 13d at a position equal to or higher than the conduit 13d and collected in the upper chamber 93. It is designed to take out foamy filth that is light and has a low specific gravity.

The lower chamber 94 communicates with a flat water collecting tube 96 opposite to the tubular body 90 through a through hole 95 penetrating the wall plate 91.
Is connected to the intake port 97 of the filtration unit 9b.

The filtering unit 9b is provided with a cylindrical main body 98 made of transparent plastic and a porous water-passing plate 99 forming the bottom thereof, and the inside thereof is filled with a filter medium 9f, for example, a multi-element ceramic or a mixture thereof with activated carbon, which is formed by a biofilm. Has a purification function.

FIG. 11 shows the second embodiment. In this embodiment, the intake port 97 of the filtering portion 9b directly communicates with the lower chamber 93 of the tubular body 90. Others are the same as those in the previous embodiment.

In addition, other than around the tank-shaped main body 1 or on the main body 30, several small sub-pre-stage treatment mechanisms having the same structure as those of the above which do not have the circulation system 15 are arranged, and the treated water extraction system 10 is treated in multiple stages. It may lead to the biological processing mechanism B ₁ . The present invention also includes this aspect.

[Operation of Example]

The device of the present invention has a final treatment device D in a water tank D as shown in FIG.
Is installed as a base, and the main body 30 is submerged in water d.

When the submersible pump 7 is operated, the water in the water tank is pumped up by the submersible pump 7 through the intake basin 62 as shown in FIG.
Solid matter is removed by the filter 8 of the raw water extraction system 6,
Next, air is added when passing through the ozone mixing mechanism 11. That is, since the raw water passes through the throttle 11b, a pressure difference is generated between the front and rear, so that the conduit 11 that is open to the low pressure side is
Ozone is sucked into the cylinder 11a from c, disperses and dissolves in raw water. The flow rate of the tank raw water passing through the raw water extraction system 6 is restricted by the throttle 11b, and the resulting differential pressure causes ozone to be sucked into the turbulent raw water immediately after passing through the throttle 11b. , Mixing is performed, whereby ozone becomes finer and becomes fine water in which fine bubbles of ozone are mixed to pass through the raw water extraction system 6, during which the ozone and the raw water are reliably contacted, and therefore, the oxygen is dissolved. The rates can be very high.

In this way, the raw water containing a large amount of fine ozone bubbles per unit amount of water is pushed into the annular chamber 3 from the tip 60, whereby the ozone-mixed raw water once rises spirally in the annular chamber 3, loses its lift, and descends. When mixed, it mixes violently with the subsequent flow of ozone-mixed raw water.
As a result, ozone becomes finer bubbles and comes into sufficient contact with raw water.

As a result, the raw water is reliably sterilized by ozone, and even if the suspended solids contained in the raw water are difficult-to-decompose substances such as male sperm and squid smears, they are entangled with fine ozone bubbles, and By virtue of the adsorption action and the wetting action, they are vigorously combined, the apparent specific gravity is reduced, and they rise in the annular chamber 3. Therefore, colloidal substances such as proteins that are hard to settle can be collected reliably and in large amounts. In addition, volatile dissolved substances such as ammonia, nitrous acid, and hydrogen sulfide are surely and promptly oxidized and rise in contact with fine ozone bubbles, and they are accumulated in the closed space 14 as a foam, which is a closed space.
The foamy waste exceeding the storage capacity of 14 flows into the container 13a.

On the other hand, the raw water from which the suspended solids and the volatile dissolved substances have been removed descends and dives under the lower end of the first tubular body 2 and the second tubular body 4 and the first tubular body 4.
Flow into the annular flow path 5 between the cylindrical bodies 2 and rise, and then descend from the upper end of the second cylindrical body 4 into the second cylindrical body 4 to obtain the treated water extraction system 10
Through the branch pipes 10a, 10b from the biological treatment mechanism B ₁ , B ₂
Flow into.

In order to raise and lower raw water in a complicated curved flow path as described above,
The raw water is reliably separated from ozone, the flow rate and the flow rate are controlled, and it is possible to reliably adsorb and oxidize the suspended substances and volatile dissolved substances in the annular chamber 3 described above.
No need for special aeration gas agitation means, small ozone generator, yet efficient separation and removal of suspended solids and volatile dissolved substances, and excessive load on the biological treatment mechanism in the next stage Instead, it is possible to maintain a highly efficient and stable purification capacity for a long period of time.

In the biological treatment mechanism B ₁ , while flowing up the water-permeable cylinder 19d, it flows in the radial direction and comes into contact with the filter medium 19e, and a biological film is formed on the filter medium surface by oxygen in the treated water. Upon contact, organic matter is adsorbed and diffused into the membrane, aerobic and anaerobic microorganisms and food chain ecosystems appear due to the difference in oxygen concentration in the membrane, and floating organic matter and soluble organic matter flow Removed by slow speed. Further, in the biological treatment mechanism B ₂ , the activated sludge forming member 19h produces aerobic microorganisms, and the pollutants are decomposed by the biooxidation reaction.

The water treated by the biological treatment mechanisms B ₁ and B ₂ is pushed into the main body of the final treatment mechanism D by the push-in pipes 19g and 19g '. The treated water contacts the filter medium 31e filled inside the main body while staying at the partition walls 31a and 31b, and a biofilm is partially generated there, so that the treated water remains by the physical / biological treatment. The pollutants present are completely removed. Then, the clear water is diffused into the water through the outlet 31d of the main body 30.

On the other hand, the tip of the second cylindrical body 4 is the ceiling plate 1b of the tank-shaped main body 1.
Since they face each other at a predetermined distance, the water level is automatically set, and a ring-shaped closed space 14 is created at the top of the annular chamber between this and the ceiling plate 1b. The fine air bubbles that adsorb and collect the dirt as described above accumulate in the form of foam on the water surface of the closed space 14, and the dirt is concentrated due to the interface phenomenon between this foam and the water surface, and the foam exceeds the capacity of the closed space 14. Waste container 13
It flows into a, is appropriately defoamed here, and is discharged from the discharge pipe 13c.

If the secondary treatment mechanism 9 is also used, the foamy waste will be pipe 13
It is discharged from d, diffuses into the upper chamber 93 by colliding with the wall plate 91, and is shattered into small volumes even if there are many bubbles. Since the filter member 9c is arranged in this region, only the bubbles are collected by the filter member 9c, the water passes through the filter member 9c, and flows down from the perforated plate 92 to the lower chamber 93,
From the intake port 97, the filter material 9f of the separation part 9b is brought into contact with the filter material 9f, and the organic matter is removed by the biofilm that appears there, so that it becomes clear water and is returned from the water passage plate 99 to the water tank D. On the other hand, the filter member 9c
The water content is removed from the bubbles accumulated in the upper part, the specific gravity becomes lighter, and the bubbles are discharged together with the air from the take-out pipe 9e.

If the circulation pump 15b is operated during operation, raw water is taken out from the lower part of the annular chamber 3, air or the like is added from the gas mixing mechanism 11 'and introduced into the annular chamber 3, and the ozone from the raw water intake system 6 is used. Stir with mixed raw water. Therefore, the efficiency of separating pollutants is further increased.

In the embodiment of Figures 8 and 8a, the raw water is pumped 7,
7'is pumped up, the water on the bottom side is mixed with gas as described above and sent to the pretreatment mechanism A, and the water near the water surface is supplied to the pretreatment mechanism A after removing coarse foreign matters.

The present invention is mainly applied to tanks for stocking or aquaculture of fish and shellfish, but can also be applied to water facilities such as pools, domestic and industrial water storage tanks, water pools such as golf courses, etc. Of course.

[Effect of device]

According to the present invention described above, the three stages of the pretreatment mechanism A, the biological treatment mechanism, and the final treatment mechanism C are combined, and the raw water extraction system that pumps the water in the water tank and sends it to the pretreatment mechanism A. 6 has an ozone mixing mechanism 11 including a throttle 11b and a conduit 11c communicating with the downstream side in the vicinity of the throttle 11b on the upstream side of the tip portion 60.
It is possible to create raw water mixed with a large amount of finely divided bubbles of ozone until reaching the stage and introduce it into the pretreatment mechanism A,
Moreover, the pretreatment mechanism A forms a ring-shaped chamber 3 between itself and the inner surface of the tank-shaped main body 1, and the first cylindrical body 2 descends from the inner top of the tank-shaped main body 1 and an annular flow communicating with the lower part of the ring-shaped chamber 3. A second tube which is inserted into the inside of the first tube body 2 so as to form the passage 5 and whose upper end stops at a limit not reaching the top of the tank to form a closed space 14 at the top of the annular chamber 3. Since it has the body 4, the raw water containing a large amount of fine ozone bubbles per unit amount of water is spirally moved up in the annular chamber 3 once, loses its lift, and is lowered to be vigorously mixed. Since it is possible to make sufficient contact with ozone, colloidal substances that are difficult to settle can be collected reliably and in large amounts, and volatile dissolved substances can also be oxidized and floated reliably and quickly, and they can be enclosed in a closed space. Since it will be accumulated as foam on the container 13a, It can be discharged smoothly.
Then, the raw water dives under the lower end of the first tubular body 2, flows into the annular flow path 5 between the second tubular body 4 and the first tubular body 2, rises, and from the upper end of the second tubular body 4. The flow rate and flow rate are controlled because the flow passes through the curved flow path that is downward in the second cylindrical body 4, so that the suspended substances and volatile dissolved substances in the annular chamber 3 can be surely adsorbed and oxidized. .

For this reason, no special aeration gas stirring means is required, and the ozone generator is small in size, yet the separation and removal efficiency of suspended solids and volatile dissolved substances is good, and the load on the biological treatment mechanism is excessive. Instead, it is possible to maintain a highly efficient and stable purification capacity for a long period of time. In addition, since the treated water that has been subjected to the biological treatment mechanism is further treated by the final treatment mechanism C that accommodates the filter medium 31c installed in the tank and has the clear water discharge hole 31d toward the outside, It can be returned to the tank as activated water from which pollutants have been removed, and thus a large amount of fish can be put into the tank.

In addition, since the final treatment mechanism C is installed in the tank and is used as a stand, the pretreatment mechanism A and the biological treatment mechanisms B ₁ and B ₂ are mounted on the final treatment mechanism C, which is economical. Since the final treatment mechanism C is present in the tank, a migratory path for seafood can be formed naturally, and the moving parts are only pumps, and motors for aeration and stirring are not required, so the structure is simple. In combination with the fact that the ozone generator is small and the ozone generator is small, it is possible to obtain an excellent effect that a relatively inexpensive device can be obtained.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a water tank purification apparatus according to the present invention in use, FIG. 2 is an explanatory view showing the purification system, and FIG. 3 is a partially cutaway perspective view showing an outline of a pretreatment mechanism. 4 and 5 are partially cutaway front views thereof, FIG. 5 is also partially cutaway front view thereof, FIG. 6 is a partially cutaway side view showing another embodiment of the pretreatment mechanism, and FIG. 7 is ozone mixture. FIG. 8 is a sectional view of the mechanism, FIG. 8 is a partial cutaway side view showing another embodiment of the present invention, FIG. 8a is an explanatory view showing the purification system according to FIG. 8, and FIG. 9 is a partial cutaway plane of the secondary treatment mechanism. FIG. 10 is a side view of the same, FIG. 11 is a partially cutaway front view taken along line XI-XI of FIG. 10, and FIG. 12 is a partially cutaway side view of another embodiment. A ... pretreatment mechanism, B _1, B ₂ ... biological processing mechanisms, C ... final processing mechanism, D ... water tank, 1 ... tank-shaped body, 2 ... first cylindrical body, 3 ... annular chamber, 4 ... first 2 cylindrical body, 5 ... annular flow path, 6
... Raw water extraction system, 7 ... Submersible pump, 11 ... Ozone mixing mechanism, 11b ... Throttling, 11c ... Conduit, 13 ... Waste collection mechanism, 13a ...
Container, 13b ... Conduit, 30 ... Main body, 31a, 31b ... Partition wall, 31c
… Filter material, 31d… Clear water outlet, 60… Tip

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C02F 1/78 9045-4D

Claims (2)

[Scope of utility model registration request] 1. A final treatment mechanism C disposed in a tank or the like, containing a filter medium 31c therein, and having a clear water discharge hole 31d facing outward, and a pretreatment mechanism A disposed on the final treatment mechanism C. And a biological treatment mechanism which is disposed in the vicinity of the pretreatment mechanism A and which purifies the treated water from the pretreatment mechanism A with a biofilm and introduces it into the final treatment mechanism C, and water in tanks including the submersible pump 7. To the pretreatment mechanism A, and the pretreatment mechanism A has an annular chamber between the tank-shaped main body 1 installed on the final treatment mechanism C and the inner surface of the tank-shaped main body 1. A first tubular body 2 that descends from the inner top of the tank-shaped main body 1 so as to form an annular flow path 5 that communicates with the lower portion of the annular chamber 3. The closed space 14 is formed at the top of the annular chamber 3 by being installed and stopping at the upper limit to the top of the tank. A second cylindrical body 4 and a foamy filth removal mechanism 13 including a container 13a communicating with a closed space by a conduit 13b, and the raw water extraction system 6 has a tip 60 communicating with the annular chamber 3 and a tip. An ozone mixing mechanism 11 including a throttle 11b and a conduit 11c communicating with the downstream side in the vicinity of the throttle 11b is interposed in the upstream side, and ozone is dispersed and mixed in the raw water passing through the raw water extraction system 6 to form the ring. A water tank purification device characterized by being introduced into the chamber 3. 2. A water tank according to claim 1, wherein the final treatment mechanism C comprises a tank or box having a diameter larger than that of the preceding treatment mechanism A and has partition plates 31a, 31b therein. Purification equipment.