JP7339726B2 - Renewal method of water treatment tank - Google Patents

Description

The present invention relates to a method for renewing a water treatment tank.

In general, a plurality of treatment processes are performed in wastewater treatment, and water treatment facilities are provided with water treatment tanks suitable for each treatment process.
For example, in coagulation sedimentation treatment, which is one of wastewater treatment, there is a reaction tank in which an inorganic coagulant is added to raw water, a coagulation tank in which a polymer coagulant is added, and solids are removed from the water to be treated to which the coagulant has been added. A plurality of water treatment tanks such as a coagulation sedimentation tank for separating water to be treated is provided, and wastewater treatment is performed through these water treatment tanks. In such wastewater treatment, not only is the water treatment facility as a whole becoming large in size, but also the water treatment tank itself is becoming large as an individual device due to the large amount of raw water to be treated. In particular, it can be said that there has been a remarkable tendency from the viewpoint of treatment technology to increase the size of water treatment tanks that have been put into service several decades ago in order to achieve a certain level of treatment.

For example, Patent Literature 1 describes unitizing a plurality of water treatment tanks for coagulating sedimentation for the purpose of space saving of the water treatment tank.

JP 2017-87089 A

As described in Patent Document 1, it is known to downsize a water treatment tank as a new wastewater treatment facility. On the other hand, many of the existing water treatment tanks currently in operation are not only large-sized but also extremely aged. In addition, since more advanced treatment is required in recent years for wastewater treatment, it is very important to renew existing water treatment tanks. However, there is a problem that if there is not enough installation space for adding a new water treatment tank at the time of renewal, the water treatment tank must be stopped for a long period of time before the renewal can be carried out. For example, it is difficult to secure a sufficient installation space in a flat place with a small available site area, such as a mountainous area or an area where many factories are concentrated. At this time, in a water treatment facility consisting of multiple water treatment tanks, when one water treatment tank subject to renewal stops, all wastewater treatment related to other water treatment tanks that are not scheduled to be renewed must also be stopped. There is also the problem of not

The object of the present invention is to update the existing water treatment tank without stopping the water treatment function of the water treatment tank, and to update the water treatment tank even in a small installation space. To provide a method for renewing a water treatment tank.

As a result of intensive studies on the above problems, the present inventors have found that as a method for updating the water treatment tank, a temporary water treatment tank is installed adjacent to the existing water treatment tank, and then the existing water treatment tank is replaced. The present invention has been completed by finding that the water treatment tank can be updated without stopping the water treatment function by updating the above.
That is, the present invention is the following method for renewing a water treatment tank.

A method for renewing a water treatment tank according to the present invention for solving the above problems is a method for renewing a water treatment tank, comprising a step of installing a temporary water treatment tank at a position adjacent to an existing water treatment tank. , a step of switching treatment from an existing water treatment tank to a temporary water treatment tank, and a step of renewing the existing water treatment tank.
In the water treatment tank renewal method of the present invention, by installing a temporary water treatment tank at a position adjacent to the existing water treatment tank, it is possible to provide an alternative water treatment tank even in a place with little installation space. By switching to a temporary water treatment tank, it is possible to upgrade the existing water treatment tank without stopping the water treatment function.

Further, as one embodiment of the water treatment tank renewal method of the present invention, the temporary water treatment tank is characterized in that it can be treated with a higher load than the existing water treatment tank.
According to this feature, the temporary water treatment tank has a higher treatment capacity than the existing water treatment tank, so that even during the renewal of the existing water treatment tank, the water that has been treated in the existing water treatment tank until then can be treated. Updates can be made without slowing down processing power.

Further, as one embodiment of the water treatment tank renewal method of the present invention, the temporary water treatment tank is characterized by being smaller than the existing water treatment tank.
According to this feature, it is possible to deal with the replacement of the water treatment tank especially in a place with a small installation space.

Further, as one embodiment of the water treatment tank renewal method of the present invention, the temporary water treatment tank is characterized by removing the existing water treatment tank after renewal.
According to this feature, when installing a temporary water treatment tank, it can be installed on the assumption that it will be removed later. As a result, it becomes possible to install a temporary water treatment tank on a road or the like, which originally requires a space as an installation location. In addition, it is also possible to use a simple means different from that of a permanent water treatment tank as a fixing means for installing the water treatment tank.

Further, one embodiment of the water treatment tank renewal method of the present invention is characterized in that the existing water treatment tank is a coagulating sedimentation tank or an aeration tank.
According to this feature, among the water treatment tanks, the coagulation sedimentation tank or the aeration tank, which are particularly large water treatment tanks, are targeted for renewal, so that even for water treatment tanks that have been difficult to renew in the past, the water treatment function can be updated without stopping

According to the present invention, when updating an existing water treatment tank, the water treatment tank can be updated without stopping the water treatment function of the water treatment tank, and the water treatment tank can be updated even in a small installation space. It is possible to provide a method for renewing a water treatment tank.

It is process explanatory drawing of the renewal method of the water-treatment tank which concerns on the 1st embodiment of this invention. It is process explanatory drawing of the renewal method of the conventional water-treatment tank. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing which shows an example of the temporary water treatment tank which concerns on the 1st embodiment of this invention. It is process explanatory drawing of the renewal method of the water-treatment tank which concerns on the 2nd embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing which shows an example of the temporary water treatment tank which concerns on the 1st embodiment of this invention.

Preferred embodiments of the present invention will now be described in detail with reference to the drawings.
It should be noted that this embodiment does not limit the present invention.

The water treatment tank may be of any type as long as it is a known apparatus for water treatment. For example, in water treatment tanks used for organic wastewater treatment equipment such as sewage treatment plants, wastewater treatment plants, food factories, pharmaceutical factories, etc., inorganic wastewater treatment equipment such as plating factories, and water treatment equipment such as water purification plants. be. More specifically, sedimentation tank equipment, sedimentation tank equipment, aeration tank, aerobic reaction tank, anaerobic reaction tank, oxidation ditch tank, flocculation tank, sedimentation tank, sludge concentration tank, sludge digestion tank, storage tank, disinfection equipment and other wastewater treatment facilities.

[First embodiment]
FIG. 1 is a process explanatory diagram showing a method of renewing a water treatment tank in the first embodiment of the present invention. FIG. 1(A) shows the process of installing a temporary water treatment tank at a position adjacent to the existing water treatment tank, and FIG. 1(B) shows the process of switching the treatment from the existing water treatment tank to the temporary water treatment tank. , FIG. 1(C) shows a process of renewing an existing water treatment tank.
A water treatment facility 100 according to this embodiment has a plurality of water treatment tanks 10 . Here, the water treatment facility 100 is assumed to be a coagulation-sedimentation treatment facility, and the water treatment tanks 10 are respectively assumed to be a reaction tank 10a, a coagulation tank 10b, and a coagulation-sedimentation tank 10c. The water treatment facility 100 also includes a flocculant tank T that stores a flocculant to be added to the reaction tank 10a and the flocculation tank 10b. Here, when the water treatment tank 10' to be renewed is the coagulation sedimentation tank 10c, a temporary water treatment tank 20 is provided adjacent to the coagulation sedimentation tank 10c. FIG. 1 shows an arrangement example of the water treatment tanks 10a to 10c in the water treatment facility 100, and also shows an arrangement example of the temporary water treatment tank 20. As shown in FIG. The water treatment tanks 10a, 10b and 10c are connected by lines L10 and L11, respectively. In FIG. 1, thick lines indicate elements added in the process, and dashed lines indicate elements reduced in the process.

On the other hand, FIG. 2 is a process explanatory diagram showing a method of renewing a water treatment tank in a conventional water treatment facility 110. As shown in FIG. FIG. 2A is an example of the arrangement of existing water treatment tanks. 2(B) and 2(C) show the process of renewing an existing water treatment tank. In addition, the structure common to the water treatment facility 100 of the present invention is given the same number and the explanation is omitted Conventionally, when updating the water treatment tank 10, as shown in FIG. The tank 10' is once dismantled, the land is cleared, and a new water treatment tank 30 is installed. Alternatively, a means of searching for a completely different site and updating the entire water treatment facility 110 is taken. In this case, as shown in FIG. 2(B), by dismantling the water treatment tank 10' to be replaced, the operation of the water treatment tanks 10a and 10b other than the water treatment tank 10' is also stopped. .
On the other hand, in the water treatment tank renewal method according to the present invention, a temporary water treatment tank 20 is provided adjacent to the water treatment tank 10' to be renewed, and the existing water treatment tank 10' is replaced with the temporary water treatment tank. 20, the existing water treatment tank can be replaced with a new water treatment tank 30 without stopping the water treatment function of the water treatment facility 100. FIG.
Each process related to renewal of the water treatment tank will be described below.

As shown in FIG. 1A, first, a temporary water treatment tank 20 is installed at a position adjacent to the water treatment tank 10' (coagulating sedimentation tank 10c) to be replaced. At this time, as shown in FIG. 1A, the temporary water treatment tank 20 is preferably smaller than the existing water treatment tank 10'. For example, it is preferable that the temporary water treatment tank 20 can be installed in an area of 1/2 or less of the existing water treatment tank 10'. As a result, it is possible to install a temporary water treatment tank 20 on the premises even if a space for installing a water treatment tank of the same scale as the existing water treatment tank 10' cannot be secured. Become. In this case, even if the size of the temporary water treatment tank 20 exceeds the site, it is sufficient that there is no problem in operation as the water treatment facility 100. Regarding the upper limit of the size of the temporary water treatment tank 20 is not particularly limited.

Moreover, it is preferable that the temporary water treatment tank 20 is capable of processing with a higher load than the existing water treatment tank 10'. To reduce the size of a device without reducing the water treatment function performed in an existing water treatment tank 10' by using a water treatment tank capable of processing with a high load as a temporary water treatment tank 20.例文帳に追加becomes possible.

Therefore, as the temporary water treatment tank 20, it is preferable to use a high-load treatment tank that can be installed in an area of 1/2 or less of the existing water treatment tank 10'. Specific examples of such a temporary water treatment tank 20 include a distribution-type high-speed coagulation-sedimentation tank using a distributor and a sludge blanket-type ultra-high-speed coagulation-sedimentation tank.

As an example of the temporary water treatment tank 20, FIG. 3 shows a schematic illustration of a sludge blanket type ultra-high speed coagulation sedimentation tank.
As shown in FIG. 3, the sludge blanket type ultra-high speed coagulation sedimentation tank as a temporary water treatment tank 20 according to this embodiment includes a treatment tank 1, a water introduction part 2 for introducing water W to be treated, and , a sludge blanket unit 3 that captures flocs (solids) in the water W to be treated and separates the flocs from the treated water W1, a water quality detection unit 4 that measures the quality of the treated water W1, and discharges the treated water W1. A clarification layer C composed of treated water W1 is formed above the sludge blanket portion 3 with a treated water discharge line L1.
In addition, the treatment tank 1 has a concentrating part 5 in which the flocs aggregated by passing through the sludge blanket part 3 overflow the upper end of the sludge blanket part 3 and precipitate and concentrate at the bottom of the treatment tank 1, A sludge discharge line L2 is provided for discharging flocs (sludge) precipitated in the thickening section 5 to the outside of the system. In addition, the sludge discharge line L2 may be provided with sludge treatment equipment for treating sludge (not shown).

The treatment tank 1 includes a bottomed cylindrical outer cylinder water tank 11 and a bottomed cylindrical inner cylinder water tank 12 smaller in diameter and height than the outer cylinder water tank 11 . As shown in FIG. 3 , the inner cylinder water tank 12 is erected inside the outer cylinder water tank 11 so as to be concentric with the outer cylinder water tank 11 . In addition, the bottom of the inner cylinder water tank 12 is separated upward from the bottom of the outer cylinder water tank 11 by a predetermined distance, thus presenting a double water tank structure. A center shaft 13 driven to rotate by a motor M is arranged on the axis L of the outer cylinder water tank 11 and the inner cylinder water tank 12 . The center shaft 13 is connected to the bottom of the inner cylinder water tank 12 by a rotary joint 14 . In addition, the outer cylinder water tank 11 and the inner cylinder water tank 12 are not limited to a cylindrical shape, and may be a square cylinder shape.

The to-be-treated water introduction part 2 includes an introduction pipe 21 for introducing the to-be-treated water W into the treatment tank 1 and a feed pipe 22 for supplying the to-be-treated water W introduced from the introduction pipe 21 into the inner cylinder water tank 12. It has

As shown in FIG. 3, the introduction pipe 21 is inserted through the side wall of the outer cylindrical water tank 11 and protrudes outside the tank, and is connected to the supply source of the water W to be treated. In addition, in this embodiment, the supply source of the to-be-processed water W is the aggregation tank 10b. Here, the introduction pipe 21 is provided with a connection portion 21a for connecting with the coagulation tank 10b instead of the coagulation sedimentation tank 10c of the existing water treatment tank 10'. The connection part 21a is not particularly limited as long as it can introduce the water to be treated W supplied from the aggregation tank 10b into the introduction pipe 21 . For example, an attachment that cuts or removes the pipe (line L11) connecting between the coagulation tank 10b and the coagulation sedimentation tank 10c and connects the introduction pipe 21 so as to fit the line L11 on the side of the coagulation tank 10b, For example, a branch pipe or the like having a switching valve may be provided between the line L11 and the introduction pipe 21 .

Further, as shown in FIG. 3 , the feed pipe 22 is connected to the introduction pipe 21 so as to allow water flow, and is provided outside the center shaft 13 so as to surround the center shaft 13 . In the solid-liquid separator according to this embodiment, the outer cylinder water tank 11, the inner cylinder water tank 12, the center shaft 13, and the feed pipe 22 all have a common axis L. As shown in FIG.

The feed pipe 22 is vertically divided into an upper portion 22a and a lower portion 22b, and the upper portion and the lower portion are connected by a rotary joint 23 such as a labyrinth structure. An introduction pipe 21 is connected to a side surface of an upper portion 22a of the feed pipe 22, and a dispersing pipe 24 is provided to a lower portion 22b of the feed pipe 22. As shown in FIG. The dispersion pipe 24 is arranged in the lower part of the inner cylindrical water tank 12 and has a plurality of water discharge ports 24a. As the center shaft 13 rotates, the lower part of the feed pipe 22 rotates. The upper end of the feed pipe 22 may be closed or may be open upward.

The to-be-treated water W introduced from the to-be-treated water introduction part 2 is waste water containing solid matter, for example, organic waste water mixed with a coagulant. In this embodiment, since the reaction tank 10a and the coagulation tank 10b for mixing the coagulant with the raw water W0 in advance are provided on the upstream side of the coagulation sedimentation tank 10c, the water to be treated W supplied from the coagulation tank 10b is Although what is introduced into the introduction pipe 21 is illustrated in FIG. 3, it is not limited to this. For example, in order to mix the raw water W0 and the coagulant, a coagulant supply line for supplying the coagulant is directly connected to the introduction pipe 21, and the temporary water treatment tank 20 in this embodiment includes the coagulant tank 10b. It is good also as what attaches about the function which concerns on.

Flocculants to be mixed include inorganic flocculants and organic polymer flocculants. As the flocculant, only an inorganic flocculant or an organic polymer flocculant may be used, or an inorganic flocculant and an organic polymer flocculant may be used in combination. In addition, when an inorganic flocculant and an organic polymer flocculant are used together, it is preferable to add the inorganic flocculant and the organic polymer flocculant to the water W to be treated in this order. This enables stable floc formation.
Specific examples of the coagulant include Al-based inorganic coagulants such as aluminum sulfate and PAC, and Fe-based inorganic coagulants such as polyiron sulfate. Alternatively, crystals can be formed by adding pH adjusters such as alkalis such as NaOH and Ca(OH) ₂ or acids such as H ₂ SO ₄ and HCl, addition of Ca, Al and Fe compounds, addition of oxidizing agents and reducing agents, and the like. It may be deposited. Examples of organic polymer flocculants include cationic polymer flocculants such as polyaminoalkyl methacrylate, polyethyleneimine, polydiallylammonium halide, chitosan, urea-formalin resin, sodium polyacrylate, partial hydrolysates of polyacrylamide, Partially sulfomethylated polyacrylamide, anionic polymer flocculants such as poly(2-acrylamide)-2-methylpropane sulfate, nonionic polymer flocculants such as polyacrylamide and polyethylene oxide, acrylamide, aminoalkyl methacrylate and acrylic acid Examples include amphoteric polymer flocculants such as sodium copolymers.

The sludge blanket section 3 introduces the water W to be treated containing the coagulant from the water to be treated introduction section, grows the flocculated flocs, and then separates the flocculated flocs from the treated water W1.
The separated treated water W1 is discharged out of the system through a treated water discharge line L1 provided in the upper portion of the treatment tank 1. FIG. In addition, the flocculated flocs overflowing from the upper end of the sludge blanket part 3 settle in the thickening part 5 provided at the bottom of the sludge blanket part 3, and through the sludge discharge line L2 provided at the bottom of the treatment tank 1, the system discharged outside.

As shown in FIG. 3, the sludge blanket portion 3 in this embodiment refers to the inner region of the bottomed cylindrical inner cylinder water tank 12 in the treatment tank 1 . The sludge blanket section 3 has a floc growth zone Z1 and a separation zone Z2 formed above the floc growth zone. In the floc growth zone Z1, a fluidized bed of aggregated flocs is formed by the upward flow of the water W flowing into the inner cylinder water tank 12 from the water introduction part 2. As shown in FIG. Further, the separation zone Z2 is for solid-liquid separation of the flocculated flocs (solids) and the treated water W1.

The water to be treated W containing the flocculant is uniformly jetted to the lower part of the inner cylindrical water tank 12 from the distribution pipe 24 of the water introduction portion of the inner cylindrical water tank 12, and the stirring force, shearing force, etc. of this jetted water flow are applied. are mixed to form flocs. The flocs formed in the inner cylindrical water tank 12 accumulate on the bottom of the inner cylindrical water tank 12, and the water to be treated W further supplied forms a fluidized bed in the floc growth zone Z1. Small flocs contained in the water W to be treated contact and are captured by flocs that have been previously generated during the process of moving up the fluidized bed, and the particle size of the flocs grows large. Thus, the water W to be treated grows flocs while rising in the floc growth zone Z1.

Since the specific gravity of the flocs is higher than that of water, the flocs tend to deposit on the bottom of the floc growth zone Z1. In the process in which the water W to be treated rises in the floc growth zone Z1, the flocs in the water W to be treated grow and become larger and heavier. Therefore, as shown in FIG. 3, larger and heavier flocs gather in the upper part of the inner cylinder water tank 12, and the rising force due to the upward flow of the water W to be treated and the sedimentation property (self-weight) of the flocs are in equilibrium. As a result, a virtual boundary layer K is formed in which the floc concentration changes discontinuously. Here, the imaginary boundary layer K and its lower vicinity are defined as a separation zone Z2. A high concentration of flocs is retained in the separation zone Z2. Further, part of the flocs collected in the separation zone Z2 overflows from the upper edge of the inner cylinder water tank 12 to the outer cylinder water tank 11 side due to the fluidized bed of the water W to be treated. In addition, since the overflowed aggregated flocs have a higher specific gravity than water, they naturally settle toward the thickening portion 5 at the bottom of the outer cylinder water tank 11 . The flocculated flocs that have settled and accumulated in the thickening section 5 are thickened to become thickened sludge, which is discharged from the sludge discharge line L2 provided at the bottom of the outer cylinder water tank 11 .

In addition, as shown in FIG. 3, the treated water that has passed through the sludge blanket portion 3 rises due to the upward flow of the water to be treated W, and above the sludge blanket portion 3, a clarified layer C composed of the treated water W1 is formed. be. That is, a virtual boundary layer K is formed at the boundary between the clarified layer C and the sludge blanket portion 3 . The treated water W1 in the clarified layer C is discharged outside the tank through a treated water discharge line L1 provided in the upper portion of the outer tube water tank 11 .

On the other hand, the thickened sludge accumulated in the thickening section 5 is scraped to the center of the bottom surface of the outer cylinder water tank 11 provided with the sludge discharge line L2 by the thickened sludge scraper 51 provided at the lower end of the center shaft 13 . The thickened sludge scraper 51 is not particularly limited as long as it has a structure capable of rotating with the rotation of the center shaft 13 and scraping the thickened sludge to the central portion of the bottom surface of the outer cylinder water tank 11 . For example, as shown in FIG. 3, a plurality of scraping members may be provided on a support vertically intersecting the center shaft 13, instead of providing the scraping members perpendicular to the center shaft 13. Alternatively, a scraping member having a curved surface may be provided on the center shaft 13 so as to form an S shape when viewed from above the tank.

The water quality detection unit 4 is for measuring the water quality of the treated water W that has undergone solid-liquid separation in the sludge blanket unit 3 .
As the water quality, turbidity, chromaticity, water temperature, pH, concentration of organic substances, etc., may be measured. Further, examples of detectors for detecting a measurement target include a turbidity meter, a chromaticity meter, a water temperature meter, a pH meter, a COD meter, a BOD meter, a TOD meter, and a TOC meter.

Here, in order not to reduce the water treatment function of the water treatment facility 100 in this embodiment, the reaction tank 10a and the coagulation tank 10b increase the amount of chemicals such as flocculants used to increase the treatment efficiency. may be It is conceivable that an increase in the amount of chemicals used will lead to an increase in cost, but since the wastewater treatment by the temporary water treatment tank 20 is temporary, the impact of the increase in cost can be kept low. At this time, based on the measurement result of the water quality detection unit 4 provided in the temporary water treatment tank 20, a control device is provided for controlling the amount of coagulant added in the reaction tank 10a and the coagulant tank 10b. is preferably controlled. Thereby, sufficient treatment effect can be exhibited in the temporary water treatment tank 20 even during renewal of the coagulating sedimentation tank 10c.

As shown in FIGS. 1(B) and 3, by connecting the connecting portion 21a of the introduction pipe 21 of the temporary water treatment tank 20 to the line L11 on the flocculation tank 10b side, the existing water treatment tank 10' Processing is switched to the temporary water treatment tank 20 . After the treatment is switched, the existing water treatment tank 10' is updated. After that, as shown in FIG. 1(C), the connecting portion 21a of the introduction pipe 21 of the temporary water treatment tank 20 is removed from the line L11, and the renewed water treatment tank 30 is reconnected to the flocculation tank 10b.

Further, as shown in FIG. 1(C), the temporary water treatment tank 20 is removed after the existing water treatment tank 10' has been renewed. Therefore, the temporary water treatment tank 20 can be installed on the assumption that it will be removed. As a result, it becomes possible to install the temporary water treatment tank 20 on a road or the like, which originally requires a space as an installation location.

In addition, it is also possible to use relatively simple fixing means for installing the water treatment tank, unlike a permanent water treatment tank.
For example, the temporary water treatment tank 20 may be mounted on a movable pedestal that has fixing means to the ground. As a result, it is possible to quickly remove the existing water treatment tank 10' after the completion of the renewal work. Also, after being removed, it can be reused at another site.
Moreover, the temporary water treatment tank 20 may be dismantled on the spot. In this case, there is no need to make arrangements for the relocation destination.

[Second embodiment]
FIG. 4 is a process explanatory diagram showing a method for renewing a water treatment tank according to the second embodiment of the present invention. Fig. 4(A) shows the process of installing a temporary water treatment tank at a position adjacent to the existing water treatment tank, and Fig. 4(B) shows the process of switching the treatment from the existing water treatment tank to the temporary water treatment tank. , FIG. 4(C) shows a process of renewing an existing water treatment tank.
The water treatment facility 101 according to this embodiment is an aerobic biological treatment facility, and the water treatment tanks 40 are an aeration tank 40a, a sedimentation tank 40b, and a sludge concentration tank 40c, respectively. Here, when the water treatment tank 40' to be renewed is the aeration tank 40a, a temporary water treatment tank 50 is provided adjacent to the aeration tank 40a. FIG. 4 shows an arrangement example of the water treatment tanks 40 in the water treatment facility 101, and also shows an arrangement example of the temporary water treatment tanks 50. As shown in FIG. The water treatment tanks 40a, 40b and 40c are connected by lines L12 and L13, respectively. In FIG. 4, thick lines indicate elements added in the process, and dashed lines indicate elements reduced in the process.

As an example of the temporary water treatment tank 50, FIG. 5 shows a schematic illustration of a membrane aeration tank.
As shown in FIG. 5, the membrane aeration tank as a temporary water treatment tank 50 according to this embodiment includes an activated sludge tank 6 and an immersed membrane unit (membrane separation means) 7 equipped with a separation membrane. Below the submerged membrane unit 7, an aeration device 8 connected to an aeration line L3 is arranged. The aeration device 8 supplies aeration gas into the activated sludge tank 6 .

At this time, the aerobic microorganisms in the activated sludge decompose the organic matter in the water W to be treated. Aerobic microorganisms produce extracellular polymers in the process of decomposition treatment, and combine with other aerobic microorganisms via the extracellular polymers to form flocs.

The submerged membrane unit 7 selectively filters the treated water W1 from the flocculated activated sludge. The filtered treated water W1 is stored in the treated water storage tank 9 via the treated water recovery line L4. On the other hand, excess sludge is connected to the sedimentation tank 40b or the sludge thickening tank 40c via the sludge discharge line L5.

In the aeration device 8, the aeration gas released via the aeration line L3 and the pump P promotes the activation of the aerobic microorganisms in the activated sludge, and contacts the separation membrane of the microorganism-immersed membrane unit 7 to remove the membrane surface. It also has the effect of cleaning the deposits of

As the separation membrane, a reverse osmosis (RO) membrane, an ultrafiltration (UF) membrane, a microfiltration (MF) membrane, a hollow fiber (HF) membrane, or the like can be appropriately used.

As shown in FIG. 4A, first, a temporary water treatment tank 50 is installed adjacent to the water treatment tank 40' (aeration tank 40a) to be replaced.
Further, as shown in FIGS. 4B and 5, by connecting the temporary water treatment tank 50 to the sedimentation tank 40b or the sludge thickening tank 40c via the sludge discharge line L5 and the line L12, the existing water treatment The treatment is switched from the tank 40' to the temporary water treatment tank 50. FIG. The connection between the temporary water treatment tank 50 and the water treatment tank 40b or 40c and the specific configuration related to the switching of treatment from the existing water treatment tank 40' to the temporary water treatment tank 50 are not particularly limited. . For example, the configuration in the first embodiment can be used. After the treatment is switched, the existing water treatment tank 30' is renewed.
After that, as shown in FIG. 4(C), the activated sludge discharge line L5 of the temporary water treatment tank 40 is removed, and the renewed water treatment tank 60 is reconnected to the sedimentation tank 40b via the line L12.
Further, as shown in FIG. 4(C), the temporary water treatment tank 50 is removed after the renewal work of the existing water treatment tank 40' is completed. Note that the means for removal is not particularly limited. For example, the temporary water treatment tank 50 may be mounted on a movable frame, or may be dismantled on the spot.

As described above, according to the water treatment tank renewal method of this embodiment, even large water treatment tanks, such as coagulation sedimentation tanks or aeration tanks, which have been difficult to renew in the past, can be renewed without stopping the water treatment function. becomes possible.

In addition, the embodiment mentioned above shows an example of the renewal method of a water-treatment tank. The method for renewing a water treatment tank according to the present invention is not limited to the above-described embodiment, and modifications of the method for renewing a water treatment tank according to the above-described embodiment are possible without changing the gist of the claims. may

The water treatment tank to be renewed in this embodiment is not limited to the coagulating sedimentation tank or the aeration tank. For example, a reaction tank or a coagulation tank in a coagulation-sedimentation treatment facility may be subject to renewal. In addition, sedimentation tanks and sludge thickening tanks in aerobic biological treatment facilities may be subject to renewal.

Further, for example, the water treatment facility of the present embodiment is an anaerobic biological treatment facility, the water treatment tank to be renewed is a fixed bed type or fluidized bed type microbial filling tank, and the temporary water treatment tank is a UASB ( A water treatment tank based on the Up flow Anaerobic Sludge Blanket method or a water treatment tank based on EGSB (Expanded Granular Sludge Bed) may be used.

INDUSTRIAL APPLICABILITY The method for renewing a water treatment tank of the present invention is suitably used in renewal work for renewing an existing water treatment tank due to aging and advanced treatment. In particular, when it is difficult to secure an installation space for installing a new water treatment tank in order to update an existing water treatment tank, it is particularly suitable for use.

100, 101 water treatment equipment, 10, 40 water treatment tank, 20, 50 temporary water treatment tank, 30, 60 renewed water treatment tank, 10a reaction tank, 10b coagulation tank, 10c coagulation sedimentation tank, 40a aeration tank, 40b sedimentation tank, 40c sludge thickening tank, 1 treatment tank, 11 outer cylinder water tank, 12 inner cylinder water tank, 13 center shaft, 14 rotary joint, 2 water to be treated introduction part, 21 introduction pipe, 21a connection part, 22 feed pipe, 22a upper part, 22b lower part, 23 rotary joint, 24 dispersion pipe, 24a treated water discharge port, 3 sludge blanket part, 4 water quality detection part, 5 thickening part, 51 thickened sludge scraper, 6 activated sludge tank, 7 immersion membrane unit, 8 aerator, 9 treated water storage tank, L1 treated water discharge line, L2 sludge discharge line, L3 aeration line, L4 treated water recovery line, L5 sludge discharge line, L10 to L13 lines, C clear layer, K virtual boundary layer , L shaft, M motor, P pump, T coagulant tank, W water to be treated, W0 raw water, W1 treated water, Z1 floc growth zone, Z2 separation zone

Claims (5)

A method for renewing a coagulant sedimentation tank, comprising:
A step of installing a temporary coagulation sedimentation tank at a position adjacent to the existing coagulation sedimentation tank;
A step of switching the treatment from the existing coagulating sedimentation tank to the temporary coagulating sedimentation tank;
A step of updating the existing coagulating sedimentation tank ,
A method of renewing a coagulating sedimentation tank, wherein the temporary coagulating sedimentation tank is temporarily treated until the existing coagulating sedimentation tank is renewed . 2. The method of renewing a coagulating sedimentation tank according to claim 1, wherein said temporary coagulating sedimentation tank is capable of processing with a higher load than said existing coagulating sedimentation tank. 3. The method for renewing a coagulating sedimentation tank according to claim 1, wherein said temporary coagulating sedimentation tank is smaller than said existing coagulating sedimentation tank. The method for updating a coagulating sedimentation tank according to any one of claims 1 to 3, wherein the temporary coagulating sedimentation tank is removed after the existing coagulating sedimentation tank is renewed. The coagulating sedimentation tank renewal method according to any one of claims 1 to 4, wherein the coagulating sedimentation tank is used as the temporary coagulating sedimentation tank and is smaller than the existing coagulating sedimentation tank.

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