WO2010104097A1

WO2010104097A1 - Filtration membrane, membrane module, and water treatment device

Info

Publication number: WO2010104097A1
Application number: PCT/JP2010/053948
Authority: WO
Inventors: 千尋井
Original assignee: パナソニック電工株式会社
Priority date: 2009-03-13
Filing date: 2010-03-10
Publication date: 2010-09-16
Also published as: JP2010214235A; TW201043578A

Abstract

A filtration membrane (10) comprises a membrane body (1) having multiple pores (3) for filtering raw water, and a particle layer (6) for removal of impurities contained in raw water that adhere to and accumulate on a surface (8) of the membrane body (1). Moreover, membrane modules (20) and (40) optionally comprise a vessel (18) having an intake port (12) and a discharge port (13), and the filtration membrane (10) housed inside the vessel (18) as a single unit therewith. In addition, water treatment devices (100) and (100A) optionally comprise the membrane modules (20) and (40) and have a configuration whereby raw water is introduced to the membrane modules (20) and (40) and purified to obtain purified water.

Description

Filtration membrane, membrane module and water treatment apparatus

TECHNICAL FIELD The present invention relates to a filtration membrane, a membrane module, and a water treatment apparatus that remove impurities contained in raw water such as tap water.

As a conventional water purification structure, there is known one in which activated carbons having different specific gravities are packed in layers to form a filter bed, and raw water is allowed to permeate the filter bed to remove impurities contained in the raw water. (E.g., Patent Document 1).

Japanese Patent Application Laid-Open No. 60-071081

However, in the configuration in which activated carbons having different specific gravities are simply stacked in layers as in the above-described prior art, there are some types of impurities that are not adsorbed by activated carbon.

An object of the present invention is to provide a filtration membrane, a membrane module, and a water treatment apparatus capable of improving the accuracy of removing impurities.

According to a first aspect of the present invention, there is provided a membrane body having a plurality of pores for filtering raw water, and a particle layer for adhering and laminating on the surface of the membrane body and removing impurities in the raw water. The gist is that it is a filtration membrane.

According to the first aspect, there is provided a filtration membrane comprising: a membrane main body provided with a plurality of pores; and a particle layer for removing impurities in raw water by attaching to a surface of the membrane main body in advance and laminating the same. In addition to being able to adsorb the impurities in the particle layer and using the film body, it is possible to filter out the impurities, so that the removal accuracy of the impurities can be improved.

Further, the particle layer may include a first particle layer laminated on the surface of the film main body, and a second particle layer laminated on the surface of the first particle layer.

According to the above configuration, since the particle layer includes the first particle layer laminated on the surface of the membrane body and the second particle layer laminated on the surface of the first particle layer, By making the particle layer different depending on the type, a multifunctional film capable of removing various types of impurities contained in the raw water can be obtained.

The first particle layer may be made of carbon particles, and the second particle layer may be made of ion exchange resin.

According to the above configuration, the first particle layer is composed of carbon particles, and the second particle layer is composed of ion exchange resin, so that heavy metal ions contained in the raw water can be reliably removed. .

A second aspect of the present invention is a container having an inlet and an outlet, and a filtration membrane integrally housed inside the container, the membrane body having a plurality of pores for filtering raw water; A gist of the present invention is a filtration module including: a particle layer for removing impurities in raw water deposited and stacked on the surface of the film body.

According to the second aspect, it is possible to obtain a membrane module that exhibits the above-described effects. Further, modularization makes it possible to easily inspect and replace the filtration membrane.

According to a third aspect of the present invention, there is provided a container having an inlet and an outlet, and a membrane body integrally accommodated in the container and having a plurality of pores for filtering raw water, and a surface of the membrane body. A membrane module comprising a filtration membrane including a particle layer for removing impurities in raw water deposited and stacked, and a water treatment apparatus for obtaining purified water purified by introducing raw water into the membrane module As the abstract.

According to the third aspect, it is possible to obtain a water treatment apparatus using a membrane module having the above-described effects.

Further, the water treatment apparatus is connected to a first water channel for guiding introduced raw water from the upstream side of the membrane module to the membrane module, and the first water path, and the introduced raw water is downstream of the membrane module A second water channel for guiding water to the membrane module, and a water channel switching part which is provided at a branch point between the first water channel and the second water channel and feeds raw water to either the first water channel or the second water channel; May further be provided.

According to the said structure, the water treatment apparatus of the structure which backwashes a membrane module can be obtained easily. In addition, by backwashing the membrane module, the filtration membrane to which the impurities are attached can be reused, and the life of the membrane module can be prolonged.

In the water treatment apparatus, when the raw water is introduced to the second water channel by the water channel switching unit on the upstream side of the membrane module and the membrane module is backwashed, the filtration membrane of the membrane module is You may further provide the particle collection | recovery part which collect | recovers the particle | grains which had adhered.

According to the above configuration, since the particles attached to the filtration membrane of the membrane module can be recovered by the particle recovery unit, the particles can be reused to reduce the cost of the water treatment apparatus such as the running cost.

The membrane module may also include an electrode for energizing the particle layer.

According to the above configuration, since the membrane module is provided with an electrode capable of energizing the particle layer, particularly when using the ion exchange resin charged in the particle layer, the ion exchange resin is used to adsorb impurities. Since the lost charge can be compensated, the accuracy of removing impurities and the performance of the membrane module can be improved.

According to the present invention, it is possible to provide a filtration membrane, a membrane module, and a water treatment device with an improved accuracy of removing impurities.

FIG. 1 is a view showing a water treatment apparatus according to a first embodiment of the present invention. FIG. 2 is a view showing a membrane module according to a first embodiment of the present invention. FIGS. 3 (a) to 3 (c) are schematic views showing a filtration membrane according to a first embodiment of the present invention. FIG. 3A shows a state in which the particle layer is laminated on the surface of the membrane main body. FIG.3 (b) shows the normal time which filters raw water with a filter membrane. FIG.3 (c) shows the time of the backwashing which backs up water from the downstream side of a membrane module, and wash | cleans a filtration membrane. FIG. 4 is a view showing a water treatment apparatus according to a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same component is contained in several following embodiments. In the following, those similar components are given the same reference numerals, and duplicate explanations are omitted.

First Embodiment
The schematic configuration of the water treatment apparatus according to the present embodiment will be described with reference to FIG.

The water treatment apparatus 100 of the present embodiment includes a raw water tank 21, a raw water pump 22, a membrane module 20, and a treated water tank 23. The raw water tank 21 temporarily stores raw water led by a water conveyance pump (not shown). The raw water pump 22 supplies the raw water in the raw water tank 21 to the membrane module 20. The membrane module 20 filters the raw water led by the raw water pump 22. The treated water tank 23 stores treated water filtered by the membrane module 20. A raw water tank 21, a raw water pump 22, a membrane module 20, and a treated water tank 23 are connected by a water channel 25. V1 to V4 in the figure are valves provided in each water channel 25 and are connected to a control unit (not shown).

The water channel 25 includes a first water channel 25a and a second water channel 25b. The first water channel 25a can conduct water from the upstream side of the membrane module 20 to the membrane module 20 via the raw water pump 22 from the raw water tank 21 at a normal time when the raw water in the raw water tank 21 is filtered by the membrane module 20. The second water channel 25b is provided to be connected to the first water channel 25a, and can feed raw water to the membrane module 20 from the downstream side of the membrane module 20 via the raw water pump 22.

In the water treatment apparatus 100 of this embodiment having such a configuration, the side of the first water passage 25 a of the valve V 2 provided at the branch point between the first water passage 25 a and the second water passage 25 b is opened normally. Raw water is introduced into the suction port 12 of the membrane module 20 via the valve V3. Then, the raw water is filtered by the filtration membrane 10 of the membrane module 20, and the filtered treated water is sent from the discharge port 13 of the membrane module 20 to the treated water tank 23 through the valve V4.

Then, the raw water is made to flow backward from the downstream side of the membrane module 20 according to a preset cycle or the like to wash the filtration membrane 10 (reverse washing).

When the filtration membrane 10 is reversely washed, the second water passage 25b side of the valve V2 provided at the branch point between the first water passage 25a and the second water passage 25b is opened, and the raw water pump 22 presses the raw water through the valve V4. It is introduced into the discharge port 13 of the membrane module 20. Then, the filtration membrane 10 of the membrane module 20 is washed with the raw water, and the washed waste water is discharged from the suction port 12 of the membrane module 20 through the valve V3.

That is, in the present embodiment, the valve V2 provided at the branch point between the first water passage 25a and the second water passage 25b functions as a water passage switching unit, and receives signals from a control unit (not shown) to filter raw water The water channel 25 is switched between the first water channel 25a and the second water channel 25b at the time of backwashing for washing the filtration membrane 10.

Further, in the present embodiment, on the upstream side of the membrane module 20, there is provided a particle recovery unit 30 for recovering the particles stacked on the filtration membrane 10 which will be described in detail later. Waste water from the backwashing of the filtration membrane 10 by switching the valve V2 is sent to the particle collection unit 30. The particle recovery unit 30 separates the particles stacked on the filtration membrane 10 from the impurities contained in the waste water, recovers the particles, and sends the recovered particles to the valve V1 via the third water channel 25c. It is made to be able to make it re-laminate on 20 filtration membranes 10, and to utilize.

As a method for collecting particles by the particle collection unit 30, for example, separation by a filter suitable for the particle diameter, separation by specific gravity difference, electrical separation, collection by an electromagnet, etc. are appropriately adopted depending on the type and water quality of particles to be stacked. And it is possible to change. Also, particles that have deteriorated in accordance with the number of times the filter membrane 10 is reversely washed, a preset cycle, or the like may be collected without drainage and drained, and new particles may be stacked.

As described above, the water treatment apparatus 100 according to the present embodiment includes the first water channel 25a capable of supplying raw water from the upstream side of the membrane module 20, the second water channel 25b capable of transmitting water from the downstream side of the membrane module 20, and The membrane module 20 is provided with a valve V2 as a water channel switching unit which is provided at a branch point between the first water channel 25a and the second water channel 25b and feeds raw water to either the first water channel 25a or the second water channel 25b. It is possible to easily obtain the water treatment apparatus 100 configured to backwash.

Further, in the present embodiment, since the particles that have been attached to the filtration membrane 10 of the membrane module 20 can be recovered by the particle recovery unit 30, the particles are reused to reduce the cost of the water treatment apparatus 100 such as running cost. It can be done.

In the present embodiment, the reverse cleaning of the filtration membrane 10 is performed using the raw water, but the reverse cleaning may be performed using, for example, treated water stored in the treated water tank 23 or purified water for cleaning. .

Next, the membrane module 20 according to the present embodiment will be described in detail with reference to FIGS. 2 and 3A to 3C.

The membrane module 20 according to the present embodiment includes a filtration membrane 10 for filtering raw water, and a cylindrical casing (container) 18 having an inlet 12 and an outlet 13 and having the filtration membrane 10 housed therein.

The filtration membrane 10 comprises a membrane body provided with a plurality of pores 3 for filtering raw water. In the present embodiment, a thin straw-like hollow fiber membrane 1 is used as the membrane main body, and a large number of hollow fiber membranes 1 are bundled and accommodated in the casing 18 in a substantially U-shape. Raw water that passes through the fine holes 3 of the hollow fiber membrane 1 from the suction port 12 of the casing 18 and permeates into the membrane flows out into the water collecting portion 15 through the membrane, and is processed from the discharge port 13 via the valve V4. It is sent to the water tank 23. When the raw water passes through the hollow fiber membrane 1, the impurities contained in the raw water are filtered.

Here, in the present embodiment, the filtration membrane 10 is configured by adhering and laminating in advance the particle layer 6 for removing the impurities in the raw water on the outer surface (surface) 8 of the membrane wall 7 of the hollow fiber membrane 1 doing.

Specifically, as shown in FIG. 3A, the particle layer 6 of the filtration membrane 10 is formed by laminating carbon particles having a particle diameter larger than that of the pores 3 on the outer surface 8 of the hollow fiber membrane 1 An ion exchange resin layer 5 formed by laminating particles of a cation exchange resin having an alkali metal type exchange group such as Na on the surface of the carbon particle layer 4 (first particle layer) and the carbon particle layer 4 concerned. And (second particle layer).

In the present embodiment, a hollow fiber 1 as a membrane main body provided with a plurality of pores 3 is supplied with a solution containing carbon particles having a larger particle size than the pores 3 to allow the carbon particles to be hollow fibers. The carbon particle layer 4 is formed by laminating on the membrane 1 to form a carbon particle layer 4 and then passing a solution in which particles of cation exchange resin having a particle diameter smaller than that of the carbon particles are mixed. The ion exchange resin layer 5 is formed by laminating on the layer 4.

As described above, by laminating carbon particles on the hollow fiber membrane 1 and laminating particles of cation exchange resin on the carbon particle layer 4, it has pores smaller than the pores 3 of the hollow fiber membrane 1. A filtration membrane 10 is formed. The pore diameter of the filtration membrane 10 can be appropriately set by changing the particle size to be laminated or the thickness to be laminated.

When raw water is filtered using the filtration membrane 10 having such a configuration, as shown in FIG. 3 (b), not only can filtration of the algae 9 present in the raw water and the organic matter 9 having a property gathered in the colloid is possible. Soils smaller than the pores 3 of the hollow fiber membrane 1 which can not be filtered by the membrane 1 can also be filtered. Furthermore, when the raw water passes through the ion exchange resin layer 5, ion exchange is carried out between the raw water and the ion exchange resin layer 5 when the raw water passes through the ion exchange resin layer 5, and sodium ions are heavy metal ions 11. It is captured by being replaced by the ion 11. That is, by forming the ion exchange resin layer 5, the heavy metal ions 11 dissolved in the raw water can be removed.

Then, as described above, when the raw water is reversely flowed from the downstream side of the membrane module 20 and the filtration membrane 10 is washed according to a preset cycle or the like, as shown in FIG. As the carbon particles and the particles of the cation exchange resin that have been stacked separate from the filtration membrane 10, the impurities captured by the filtration membrane 10 separate from the carbon particles and the particles of the cation exchange resin. Then, the particles of carbon particles and cation exchange resin were separated from the impurities contained in the waste water by the particle recovery unit 30 (see FIG. 1), and the particles of carbon particles and cation exchange resin membrane were recovered and recovered. The carbon particles and the particles of the cation exchange resin can be sent to the valve V1 and can be laminated again on the hollow fiber membrane 1 of the membrane module 20 for use. At this time, the particles of the cation exchange resin may be regenerated by passing the solution through a salt solution such as a saline solution so as to be reusable as a cation exchange resin.

As described above in detail, in the present embodiment, the hollow fiber membrane (membrane main body) 1 provided with a plurality of pores 3 for filtering raw water and the outer surface 8 of the hollow fiber membrane 1 are attached in advance. The membrane module 20 is configured using the filtration membrane 10 provided with the particle layer 6 for removing the impurities in the raw water by stacking the layers. Therefore, the particle layer 6 stacked on the hollow fiber membrane 1 can adsorb the impurities in the raw water, and the hollow fiber membrane 1 can also filter the impurities, so the impurity removal accuracy is improved. be able to.

Further, since only the particle layer 6 is laminated on the outer surface 8 of the hollow fiber membrane 1, it is possible to easily obtain the filtration membrane 10 capable of improving the removal accuracy of the impurities.

Further, the particle layer 6 of the filtration membrane 10 comprises a first particle layer 4 laminated on the outer surface 8 of the hollow fiber membrane 1 and a second particle layer 5 laminated on the surface of the first particle layer 4. Therefore, by changing the particle layer according to the type of impurity to be removed, a multifunctional film capable of removing various types of impurities contained in the raw water can be obtained. In the present embodiment, the first particle layer 4 is made of carbon particles, and the second particle layer 5 is made of ion exchange resin. Therefore, the heavy metal ions 11 contained in the raw water are reliably removed. can do.

Further, in the present embodiment, since the membrane module 20 is configured by storing and integrating such a filtration membrane 10 inside the casing (container) 18, inspection and replacement of the filtration membrane 10 can be facilitated. While being able to carry out, the particle layer 6 can be easily laminated on the filtration membrane 10.

In the present embodiment, the thin straw-like hollow fiber membrane 1 is used as the membrane body of the filtration membrane 10, but is not limited thereto. For example, a spiral membrane, a tubular membrane, or a flat membrane may be used. And as a kind of these membranes, it is also possible to use MF membrane (microfiltration membrane), UF membrane (ultrafiltration membrane), and NF membrane.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a view showing a water treatment apparatus according to the present embodiment.

The water treatment apparatus 100A according to the present embodiment differs from the water treatment apparatus 100 according to the first embodiment in the membrane module 40.

Specifically, in the present embodiment, in place of the ion exchange resin layer constituting the filtration membrane 10, an ionizable resin formed by negatively charging an ion exchange resin is laminated on the surface of the carbon particle layer 4 to form ions. As the conductive resin layer, the

electrodes

17 and 18 are provided on the upstream side and the downstream side of the filtration membrane 10 so that the ionic resin layer is continuously or intermittently energized by the power supply device 50.

Since dirt in water and heavy metal ions dissolved in water are basically positively charged, when this filtration membrane 10 is used, these dirt and ions in which heavy metal ions 11 are negatively charged The resin is attracted and removed by being absorbed by the ionic resin. However, when the adsorption of heavy metal ions 11 proceeds, the charge transfer is performed between the heavy metal ions 11 and the ionic resin, and the total charge amount of the ionic resin layer decreases, and eventually, the saturated state occurs. As a result, it becomes uncharged. As described above, the removal ability of heavy metal ions 11 by the ionic resin gradually decreases as water is filtered, but in the present embodiment, the ionic resin layer is energized by the power supply device 50, and the ionic resin layer It is possible to charge the ionic resin layer negatively and make it reusable by supplying electric charge to the

Therefore, in the present embodiment, it is possible to remove heavy metal ions 11 in water until the filtration membrane 10 is physically blocked.

Further, the ionic resin layer can be energized in a state in which the plus and minus of the

electrodes

17 and 18 are inverted, and for example, when the filtration membrane 10 is physically clogged, the ionic resin layer is positively charged. In this case, it is possible to peel off the heavy metal ions 11 and the ionic resin by the repulsive force between the positively charged ones.

Furthermore, also in the present embodiment, since the water channel switching portion (valve V2) is provided as in the first embodiment, when the filtration membrane 10 is reversely washed, the positive and negative of the

electrodes

17 and 18 are reversed. If the ionic resin layer is energized in the state where it has been allowed to pass, in addition to physical washing by reverse washing, washing by electric repulsion can also be performed, and washing of the filtration membrane 10 can be carried out more effectively. .

In addition, a particle collection unit 30 for collecting particles stacked on the filtration membrane 10 is also provided, and the waste water after reverse washing is sent to the particle collection unit 30 and included in the particles and drainage that are stacked on the filtration membrane 10 The impurities can be separated to recover the particles, and the recovered particles can be stacked on the filtration membrane 10 for use.

Therefore, also by the filtration membrane 10 of the present embodiment, the same effects as those of the first embodiment can be exhibited.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, although the cation exchange resin which removes heavy metal ion was illustrated as a particle layer in the said embodiment, this particle layer can be suitably changed according to the substance which it is going to remove. For example, an anion exchange resin may be laminated to remove an anionic substance such as ammonium ion, or a silica particle may be laminated to remove silica colloid. Further, in the above embodiment, the particles are laminated on the hollow fiber membrane (membrane main body) by passing the solution mixed with the particles, but the lamination may be performed using gravity or pressure, or electrochemically. It may be laminated.

It is possible to provide a filtration membrane, a membrane module and a water treatment device with an improved accuracy of removing impurities.

Claims

A membrane body having a plurality of pores for filtering raw water;
A particulate layer attached to and laminated on the surface of the membrane body to remove impurities in the raw water.
The particle layer is
A first particle layer laminated on the surface of the film body;
A second particle layer laminated on the surface of the first particle layer,
The filtration membrane according to claim 1, comprising:
The first particle layer is composed of carbon particles,
The filtration membrane according to claim 2, wherein the second particle layer is composed of an ion exchange resin.
A container having an inlet and an outlet;
A filter membrane integrally contained in the interior of the container, the membrane body having a plurality of pores for filtering raw water, and particles for removing impurities in the raw water deposited on the surface of the membrane body A membrane module comprising: a bed;
A container having an inlet and an outlet, and a membrane body integrally accommodated inside the container and having a plurality of pores for filtering raw water, and attached to the surface of the membrane body and laminated And d) a filter module including a particle layer for removing impurities.
A water treatment apparatus for obtaining purified water purified by introducing raw water into the membrane module.
A first water channel for conveying introduced raw water from the upstream side of the membrane module to the membrane module;
A second water channel which is connected to the first water channel and transfers the introduced raw water from the downstream side of the film module to the film module;
The water treatment device according to claim 5, further comprising: a water channel switching unit provided at a branch point between the first water channel and the second water channel, for guiding raw water to any of the first water channel and the second water channel. .
When raw water is conducted to the second water channel by the water channel switching unit on the upstream side of the membrane module and the membrane module is reversely washed, particles adhering to the filtration membrane of the membrane module are recovered The water treatment apparatus according to claim 6, further comprising a particle recovery unit.
The water treatment apparatus according to claim 5, wherein the membrane module includes an electrode for energizing the particle layer.