JPH07214047A - Water purifying device - Google Patents

Abstract

PURPOSE:To provide a water purifying device by which a high water purifying capacity is obtained even with a small space, capable of shortening the treating time and further capable of effectively removing the floc even in the raw water having a high content of org. components. CONSTITUTION:This water purifying device is provided with a flotation 1 device 1 consisting of a flotation tank 3 into which the raw water mixed with pressurized water is introduced and a recovery device 4 for discharging the floc F floating in the tank 3 and a membrane filter 2 to filtrate the raw water freed from the floc F by the flotation device 1 with a membrane module 21, and the module 21 is arranged in the tank 3. The module 21 is set below a raw water inlet 13 and is a U-shaped module formed by bundling a hollow-fiber membrane in U-shape. A guide plate 16, a baffle plate 31 and an aerator 32 are furnished in the tank 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purification device in a water purification facility or the like.

[0002]

2. Description of the Related Art In a water purification facility such as a water purification plant, it is possible to cope with a relatively wide range of fluctuations in the quality of treated raw water.
A water purification device using a rapid filtration system is generally used. This purified water treatment device is provided with a settling basin and a filtration basin, and by injecting a coagulant into the treated raw water, the suspended solids in the treated raw water are aggregated into flocs.
The flocs are precipitated in a sedimentation tank to remove them as much as possible, and then subjected to rapid filtration in a filtration tank. Then, the treated water thus filtered is subjected to chlorine sterilization and the like and then sent from the distribution reservoir.

[0003]

However, in such a water purification apparatus using the rapid filtration system, in order to reliably remove the flocs in the settling tank and to carry out efficient filtration in the filter, these settling tanks are used. It is necessary to secure a certain area for the pond and the filtration pond, that is, the water treatment capacity will be determined by the installation area of the equipment. For this reason, even if it tried to increase the processing capacity in a small space, there was a limit naturally. Also,
It is unavoidable that a long treatment time is required because the raw water to be treated is subjected to coagulating sedimentation treatment in the sedimentation basin and then filtered in the filtration basin. Furthermore, flocs formed by aggregating organic components among the suspended solids in the treated raw water are relatively light and difficult to settle, and thus it is difficult to remove them in a sedimentation basin. Therefore, the conventional water purification apparatus has a problem that it cannot sufficiently deal with the treated raw water containing a large amount of organic matter components in the suspended matter.

The present invention has been made under such a background, and it is possible to obtain a high purification water treatment capacity even in a small space, shorten the treatment time, and further treat with a large amount of organic components. It is an object of the present invention to provide a water purification device that can effectively remove flocs from raw water.

[0005]

In order to solve the above-mentioned problems, the present invention relates to a flotation treatment device for mixing pressurized water into treated raw water to levitate flocs in the treated raw water in a flotation treatment tank, and this flotation treatment. A membrane filtration device for filtering the treated raw water from which flocs have been floated and separated by the device by a membrane module, wherein the membrane module is arranged in the flotation treatment tank.

[0006]

In the purified water treatment apparatus having the above-mentioned structure, the treated raw water is mixed with pressurized water (saturated air water) in which air is dissolved under high pressure to be introduced into the levitation treatment tank of the levitation treatment apparatus. Here, the suspended matter in the treated raw water is combined with the fine bubbles contained in the pressurized water and floats on the surface of the flotation treatment tank, and is collected as flocs by the recovery device and taken out from the flotation processing tank. On the other hand, the treated raw water from which the flocs are removed stays in the flotation treatment tank, and the membrane module of the membrane filtration device is arranged in this flotation treatment tank. Is subjected to membrane filtration treatment and discharged as clean treated water from the flotation treatment tank.

As described above, according to the water treatment apparatus having the above-mentioned structure, flocs are removed from the treated raw water by the flotation treatment apparatus, and the membrane module of the membrane filtration apparatus arranged in the flotation treatment tank of the flotation treatment apparatus. Since the membrane filtration process is performed, it is possible to save space in the device and shorten the process time. Further, since flocs are removed by the floating process, it is possible to effectively remove even relatively light organic flocs.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, in which a water purification apparatus of the present embodiment comprises a flotation processing apparatus 1 and a membrane filtration apparatus 2. The levitation processing apparatus 1 further includes a levitation processing tank 3 and a recovery apparatus 4 arranged above the levitation processing tank 3. This recovery device 4 is of a ring belt type in which a plurality of scraping plates 11 ... Are attached to the chain 12 at regular intervals, and by driving the chain 12 to move the scraping plates 11 ,. The flocs F that have floated on the surface are attracted, taken out from the flotation treatment tank 3, and collected. The floc F recovered by the recovery device 4 is appropriately post-processed by a processing device such as a dehydrator not shown.

On the other hand, an inlet port 13 for the treated raw water is provided on the side wall of the flotation treatment tank 3, and an inlet passage 14 for the treated raw water is connected to the inlet port 13. Then, the treated raw water that has been subjected to the pretreatment such as the injection of the coagulant is supplied to the inflow passage 1
It is introduced into the flotation treatment tank 3 through the inlet 4 and the inlet 13. In addition, a pressurized water passage 15 is connected to the inflow passage 14 via a valve 15A, and pressurized water (saturated air water), which is high-concentration air-dissolved water into which pressurized air is pressed in a pressurized water tank (not shown), The treated raw water is mixed with the pressurized water passage 15 and introduced into the floating treatment tank 3. The pressurized water passage 15 may be connected to the side wall of the flotation treatment tank 3 via a valve 15B as shown in the figure, so that the treated raw water and the pressurized water may be separately introduced into the flotation treatment tank 3. In this case, Pressurized water is preferably introduced from below the treated raw water. Further, in the vicinity of the inlet 13 in the flotation treatment tank 3, a vertically extending guide plate 16 is provided so as to face the inlet 13, and a floc of the raw water for treatment introduced from the inlet 13 is provided. It is designed to encourage F to rise.

The membrane module 21 of the membrane filtration device 2 is disposed in the floating treatment tank 3. The membrane module 21 is a U-shaped module formed by bundling hollow fiber membranes (MF membranes) in a U shape, and is arranged in the flotation treatment tank 3 so as to be positioned below the inlet 13. There is. Further, the membrane module 21 is connected to a drainage channel 22 for discharging the treated water that has been subjected to the membrane filtration treatment. The drainage channel 22 is led out of the floating treatment tank 3 to perform chlorine sterilization or the like (not shown). It is connected to the post-treatment process of treated water. Further, a washing water passage 23 for backwashing is connected to the drainage passage 22, and the washing water is made to flow back to the drainage passage 22 by the pump 24, whereby the membrane module 21
Is backwashed.

An inclined plate 31 is arranged above the membrane module 21 in the flotation treatment tank 3 so as to cover the membrane module 21 in a plan view from above. This inclined plate 31 is inclined so as to gradually curve upward while being curved away from the introduction port 13 side, and the treated raw water containing suspended matter introduced from the introduction port 13 into the flotation treatment tank 3 directly It does not flow into the membrane module 21. Further, an aerator 32 for air washing is arranged below the membrane module 21 so as to spread across the entire lower surface of the membrane module 21, and a compressed air supply passage 33 for air washing is provided in the aerator 32. Are connected. When air is washed, compressed air is supplied from the supply passage 33 to the aerator 32, so that the air becomes bubbles and flows into the membrane module 21 from the aerator 32 and adheres to the surface of the hollow fiber membrane of the membrane module 21. Is designed to be removed. Instead of this air washing, pressurized water (air saturated water) may be jetted from below the membrane module 21 to remove the deposits on the membrane surface. Further, the floating treatment tank 3 below the aerator 32
A rectifying plate 34 is provided inside, and a drain discharge passage 35 is connected to the bottom of the levitation processing tank 3 further below the rectifying plate 34.

In the water purification apparatus having such a structure, the treated raw water into which the flocculant such as aluminum is injected is sent to the levitation treatment tank 3 of the levitation treatment apparatus 1 through the inflow passage 14.
The inlet 13 mixed with the pressurized water from the pressurized water passage 15 on the way
Is introduced into the flotation treatment tank 3. In the introduced treated raw water, the flocculant is aggregated by the flocculant to form flocs F, and fine bubbles due to the pressurized water adhere to the flocs F, so that the flocs F are floated.
Ascend to the surface. The floc F that has floated in this way is moved to the scraping plate 11 of the recovery device 4 as described above.
Are collected and collected. On the other hand, the treated raw water from which flocs F have been removed by the levitation treatment of the levitation treatment device 1 stays in the levitation treatment tank 3 and undergoes membrane filtration treatment through the hollow fiber membrane of the membrane module 21 of the membrane filtration device 2, The treated water is discharged from the drainage channel 22. Then, the discharged treated water is subjected to post-treatment such as chlorine disinfection and then sent. During the process, the compressed air is supplied from the supply passage 33 to the aerator 32 to constantly or intermittently wash the membrane module 21 with air.

As described above, according to the water purification apparatus having the above-mentioned structure, the floc F is removed by the flotation treatment of the treated raw water introduced into the flotation treatment tank 3 of the flotation treatment apparatus 1, and the floc F is thus removed. The treated raw water is subjected to membrane filtration treatment by the membrane module 21 of the membrane filtration device 2 provided in the same floating treatment tank 3, and is discharged as clean treated water. Therefore, the space of the apparatus can be saved, and the treated raw water from which the flocs F have been removed by the flotation treatment apparatus 1 is continuously subjected to the membrane filtration treatment by the membrane filtration apparatus 2, resulting in a significant treatment time. It can be shortened. Moreover, since flocs F are removed from the treated raw water by the flotation treatment by the flotation treatment apparatus 1, suspended matter in the treated raw water contains a large amount of organic components and is unlikely to settle.
Even when the ridges are formed, such flocs F can be effectively removed. Therefore, it is possible to sufficiently treat the treated raw water containing a large amount of such organic components, and it is possible to adapt to a wider range of water quality fluctuations of the treated raw water. It is possible to provide a water purification device. Further, in some cases, a sufficient treatment effect can be obtained even in the non-chemical injection treatment in which the coagulant is not injected into the treated raw water.

Further, in this embodiment, the inlet 13 for treated raw water is used.
The guide plate 16 is provided in the vicinity of the guide plate 16 and the flocs F of the treated raw water introduced into the flotation treatment tank 3 are
Then, the inside of the flotation treatment tank 3 is lifted up by being guided to.
Therefore, the floc F can be smoothly promoted to float on the surface of the flotation treatment tank 3, so that according to the present embodiment, the floc F can be removed more efficiently and the processing time can be further shortened. Can be achieved. Further, in the present embodiment, the membrane module 21 is arranged in the flotation treatment tank 3 below the inlet 13 for the treated raw water, and flocs F that are aggregated and floated from the introduced treated raw water flow into the membrane module 21. Can be avoided. For this reason,
Since it is possible to prevent such a situation that the flock F adheres to the hollow fiber membrane surface of the membrane module 21 and causes clogging, a more stable membrane filtration treatment can be performed.

Moreover, in this embodiment, the inclined plate 31 is arranged above the membrane module 21 in the flotation treatment tank 3,
As a result, the treated raw water introduced from the inlet 13 and the treated raw water from which the flocs F have been removed are separated to some extent. Therefore, it is possible to prevent the treated raw water in which the flocs F have not been sufficiently removed from flowing into the vicinity of the membrane module 21, so that according to the present embodiment, a more stable membrane filtration treatment can be promoted. There is also an advantage. Further, during the treatment, the aerator 32 constantly or intermittently cleans the membrane module 21 with air, and further, the washing water passage 23 connected to the drainage passage 22.
By backwashing the wash water from the membrane module 21
Since it is possible to perform backwashing, the membrane filtration performance of the membrane module 21 can be maintained for a long period of time.
Instead of washing the membrane module 21 with air, washing with pressurized water (air saturated water) may be performed.

Next, FIGS. 2 and 3 show a second embodiment of the present invention, in which components common to those of the first embodiment shown in FIG. Omit it. In this embodiment, the flotation treatment tank 3 of the flotation treatment apparatus 1 is formed in a cylindrical shape, and the inflow passage 14 for the raw treatment water extends to the center of the flotation treatment tank 3, and the inlet 13 is opened upward. It is arranged to do. A cylindrical guide plate 16 is arranged around the introduction port 13 so as to extend in the vertical direction, and the membrane module 21 of the membrane filtration device 2 surrounds the guide plate 16 in an annular shape. It is located in. In the present embodiment, the inclined plate 31 and the aerator 3 are arranged according to the arrangement of the membrane module 21.
2 are also arranged in an annular shape, and especially the inclined plate 31 is the inlet 1
It is formed in a funnel shape that is spaced apart from the center of the 3 side and goes upward toward the outer peripheral side. In addition, the recovery device 4 of the levitation processing apparatus 1 in this embodiment includes the scraping plate 41 that rotates around the axis of the cylindrical levitation processing tank 3.
A type that collects floc F that floats on the surface of the flotation treatment tank 3 by scraping it is used. The treated raw water and the pressurized water may be separately introduced into the flotation treatment tank 3 as in the first embodiment.

Even in the water purifying apparatus having such a structure, however, the membrane module 21 of the membrane filtering apparatus 2 is arranged in the flotation treatment tank 3 of the flotation treatment apparatus 1 and, therefore, it is shown in FIG. The same effect as the embodiment can be obtained.
Further, in this embodiment, the flocs F of the treated raw water introduced from the inlet 13 are isotropically spread from the center of the flotation treatment tank 3 to the outer peripheral side and rise to rise uniformly on the surface of the flotation treatment tank 3. To do. Therefore, according to the present embodiment, the flocs F can be removed more efficiently, and the processing time can be further shortened.

Further, FIG. 4 shows a third embodiment of the present invention, and the first embodiment shown in FIG. 1 is the same as the second embodiment.
The same components as those in the embodiment are designated by the same reference numerals.
In the present embodiment, the levitation processing tank 3 of the levitation processing apparatus 1 is a partition wall 4.
The upper side of the two processing chambers 43 and 44 communicates with each other via the second processing chamber 43. The side wall of one of the processing chambers 43 is provided with an inlet 13 for the raw treated water, and the other processing chamber 44 is provided with a membrane filter. The membrane module 21 of the device 2 is provided. Here, the other processing chamber 44
Is formed to have a larger capacity than one of the processing chambers 43, and the guide plate 16 extending in the vertical direction is arranged in the one processing chamber 43, while in the other processing chamber 44. An inclined plate 31 is arranged above the membrane module 21, and an aerator 32 is arranged below it. Further, the height of the partition wall 42 is set so as to exceed the upper surface of the membrane module 21. In this embodiment, the membrane module 21 is not arranged below the inlet 13 of the treated raw water as in the first embodiment, and the lower surface of the membrane module 21 and the inlet 13 are at substantially the same height. Is set to. Also in this third embodiment, the treated raw water and the pressurized water may be separately introduced into the flotation treatment tank 3.

In the present embodiment, however, the treated raw water is introduced from the inlet 13 into one of the treatment chambers 43 of the floating treatment tank 3, where flocs F are formed and rise in the one treatment chamber 43. Then, it floats on the surface of the floating treatment tank 3. Then, the floating flocs F are collected and removed by the collecting device 4, while the treated raw water from which the flocs F have been removed flows into the other treatment chamber 44 from the upper portion of the partition wall 42 and is subjected to membrane filtration treatment by the membrane module 21. Is discharged as treated water. Thus, also in this embodiment,
Since the membrane module 21 of the membrane filtration device 2 is arranged in the flotation treatment tank 3 of the flotation treatment device 1, the same effect as that of the first embodiment can be obtained. Further, in this embodiment,
Since one processing chamber 43 in which the inlet 3 is provided and the other processing chamber 44 in which the membrane module 21 is arranged are isolated by the partition wall 42, the raw treated water introduced into the flotation treatment tank 3 directly flows into the membrane module 21. It is possible to more reliably prevent it from flowing into. As a result, the treated raw water from which the flocs F have been sufficiently removed can be subjected to the membrane filtration treatment, so that the treatment efficiency can be further improved and the clogging of the hollow fiber membrane of the membrane module 21 can be further suppressed. Becomes

Further, since the partition wall 42 prevents the treated raw water thus introduced from directly flowing into the membrane module 21, in this embodiment, the treated raw water inlet 13 is connected to the membrane module 21 as described above. It is possible to dispose it at the same height as or at a position lower than the membrane module 21. As a result, the height of the flotation treatment tank 3 can be suppressed to be relatively low, so that according to the present embodiment, it is possible to provide a more compact water purifying apparatus, and further space saving can be achieved. There is also an advantage that it can be done. The membrane module 21 may be a collection of a large number of hollow fiber membranes with one end closed. Also,
The membrane filtration device 2 may be an immersion type external pressure type cross flow.

[0021]

As described above, according to the present invention, the treated raw water introduced into the flotation treatment tank of the flotation treatment apparatus has flocs floating and is removed, and the treated raw water from which the flocs are removed has the same flotation. The membrane module of the membrane filtration device arranged in the treatment tank performs membrane filtration to clean the membrane. Therefore, the installation area of the water purification device can be reduced to save space, and the treated raw water from which flocs have been removed is continuously subjected to membrane filtration, which can significantly reduce the treatment time. It will be possible. In addition, by removing the flocs by the floating process in this way,
Since it is possible to reliably and efficiently remove flocs of organic matter with low density and relatively light weight, it is a versatile water purification treatment that can sufficiently deal with treated raw water containing a large amount of such organic matter components. It becomes possible to provide a device.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a side sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view taken along line XX of the second embodiment shown in FIG.

FIG. 4 is a side sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flotation treatment device 2 Membrane filtration device 3 Flotation treatment tank 4 Collection device 13 Inlet port 14 Inflow passage of treated raw water 15 Pressurized water passage 16 Guide plate 21 Membrane module 22 Drainage channel 32 Aerator 42 Partition wall 43,44 Treatment chamber F Flock

Claims (4)

[Claims] 1. A flotation treatment device for mixing pressurized water into treated raw water to levitate flocs in the treated raw water in a flotation treatment tank, and treated raw water in which flocs are floated and separated by the flotation treatment device is filtered by a membrane module. A water purification device comprising a membrane filtration device, wherein the membrane module is arranged in the flotation treatment tank. 2. The water purification apparatus according to claim 1, wherein the membrane module is arranged below the inlet of the raw water for treatment in the floating treatment tank. 3. The inlet for the treated raw water is arranged substantially in the center of the flotation treatment tank, and the membrane module is arranged in an annular shape so as to surround the inlet. The water purification device according to claim 1 or claim 2. 4. The flotation treatment tank comprises two treatment chambers, the upper portions of which are communicated with each other via a partition wall, one treatment chamber being provided with an inlet for the treated raw water, and the membrane module being treated for the other treatment. It arrange | positions in a room, The water purification apparatus of Claim 1 or Claim 2 characterized by the above-mentioned.