JP2011212542A - Method for backwashing filter treatment means and water treatment apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for backwashing a filter treatment means that can supply clear treated water to a rear-stage reverse osmosis membrane treatment means and efficiently backwashes a hardly blocked and inexpensive filter treatment means and a water treatment apparatus therefor.SOLUTION: The method for backwashing a filter treatment means performs filter treatment on the treated water in parallel before a reverse osmosis membrane treatment where the treated water is treated with a reverse osmosis membrane, wherein the filter treatment means has a filter body where a sheet-like member is spirally wound and a filtration tank where the filter body is filled inside so the shaft center of the filter body as to be along the direction of passing water, the sheet-like member is one in which sheet surfaces of a sheet-like mesh-sheet having vacant holes through which the treated water passes and a sheet-like spacer through which the treated water more hardly passes than the mesh sheet are overlapped, and the filter treatment means is backwashed by passing the concentrated water discharged through the reverse osmosis membrane treatment to the filter treatment means through which the treated water is not allowed to pass from a reverse direction to the direction of passing the treated water.

Description

The present invention relates to a filtration treatment means provided in the preceding stage of a reverse osmosis membrane treatment means for subjecting treated water containing suspended substances such as industrial water, city water, well water, river water, lake water, and factory wastewater to membrane separation treatment. The present invention relates to a backwashing method and a water treatment apparatus to which the backwashing method is applied.

As a method of treating treated water such as industrial water, city water, well water, river water, lake water, and factory wastewater, for example, an inorganic flocculant and an anionic polymer flocculant are added to the treated water. There is a method of removing turbidity by sand filtration or pressurized flotation treatment after flocculation treatment such as adsorption or condensation of the turbidity contained in the treated water. However, sand filtration and pressure levitation processing have a problem that the apparatus becomes large. Moreover, when the turbidity of to-be-processed water is high, there exists a possibility that removal of a turbidity may become inadequate.

Recently, in order to solve such a problem, application of membrane separation processing means, specifically, an ultrafiltration membrane (UF) device or a microfiltration membrane (MF) device has been spreading as a filtration device. However, the ultrafiltration membrane device and the microfiltration membrane device have a problem that clogging occurs due to suspended substances, inorganic substances, and organic substances, and a problem that the cost of the membrane is high.

Moreover, in order to manufacture pure water etc., there exists a technique which processes to-be-processed water with a reverse osmosis membrane (RO) apparatus. And in a reverse osmosis membrane apparatus, it is necessary to use the water to be treated to a certain degree that has been treated by the sand filtration, the pressure levitation treatment, the ultrafiltration apparatus, the microfiltration membrane apparatus or the like in the previous stage. However,
As described above, sand filtration, pressure levitation treatment, ultrafiltration device, microfiltration membrane device, and the like have problems such as insufficient removal of turbidity and occurrence of blockage.

Here, although the filtration apparatus using a long fiber bundle as a filter body is disclosed on the upstream side of the reverse osmosis membrane apparatus, a power plant make-up water production apparatus is disclosed (see Patent Document 1), There is a problem that the reverse osmosis membrane device and the filtration device are clogged and the quality of the treated water is deteriorated.

In addition, in order to suppress clogging due to the turbidity of the filtration device provided on the upstream side of such a reverse osmosis membrane device, so-called backwashing in which wash water is passed in a direction opposite to the direction of water to be treated is passed. However, for example, when permeated water (treated water) that has permeated through a reverse osmosis membrane is used as washing water, the recovery rate of the permeated water is deteriorated, and the water treatment efficiency is lowered.

JP-A-6-134490

In view of the above-described circumstances, the present invention provides a backwashing method and a water treatment apparatus for a filtration treatment unit that can supply clear treatment water to a subsequent reverse osmosis membrane treatment unit and efficiently backwash an inexpensive filtration treatment unit that is difficult to block. The purpose is to provide.

An aspect of the present invention that solves the above-described problem is a backwashing method of a filtration means for filtering the treated water in parallel before the reverse osmosis membrane treatment for treating the treated water with a reverse osmosis membrane, wherein the filtration The treatment means includes a filter body having a sheet-like member wound in a spiral shape, and water to be treated is passed, and the filter body is placed in the interior so that the axis of the filter body is along the direction of water passage. The sheet-like member includes a sheet-like mesh sheet having pores through which the water to be treated passes, and a sheet-like spacer in which the water to be treated is difficult to pass compared to the mesh sheet. The sheet surfaces are overlapped, and the concentrated water discharged in the reverse osmosis membrane treatment is in a direction opposite to the direction of water to be treated to the filtration treatment means in which the water to be treated is not passed. The filtration means is back-washed by passing water through In backwash method of filtration means.

And the said reverse osmosis membrane process may perform a reverse osmosis membrane process in parallel with the to-be-processed water discharged | emitted from the said filtration process means.

Further, according to another aspect of the present invention, the filter body having the sheet-like member wound in a spiral shape, the water to be treated is passed, and the shaft core of the filter body is along the water passing direction. The filter body has a filtration tank filled therein, and the sheet-like member has a sheet-like mesh sheet having pores through which the water to be treated passes, and the water to be treated passes compared to the mesh sheet. Filtration processing means in which sheet surfaces of difficult sheet-like spacers are overlapped with each other, a plurality of filtration processing means arranged in parallel for filtering the water to be treated, and provided after the filtration processing means Reverse osmosis membrane treatment means for treating the treated water discharged from the filtration treatment means with a reverse osmosis membrane,
Concentrated water introduction means for introducing the concentrated water discharged from the reverse osmosis membrane treatment means into the filtration treatment means through which the water to be treated is not passed from the direction opposite to the water flow direction of the water to be treated. It is in the water treatment apparatus characterized by this.

A filter body in which the sheet-like member is wound in a spiral shape, a filtration tank in which the water to be treated is passed, and the filter body is filled therein so that the axial core of the filter body is along the water passing direction; The sheet-like member has a sheet-like mesh sheet having pores through which the water to be treated passes, and the sheet surfaces of the sheet-like spacer in which the water to be treated is difficult to pass compared to the mesh sheet. Filtration treatment means (filtration treatment apparatus), which is a product, can provide clear treated water, and can prevent clogging of subsequent reverse osmosis membrane treatment means (reverse osmosis membrane apparatus) and filtration treatment means itself, and is inexpensive. is there. Therefore, the water to be treated can be suitably treated for a long period of time by the reverse osmosis membrane treatment means in the subsequent stage. Since the concentrated water discharged from the reverse osmosis membrane treatment means is used as the washing water for the filtration treatment means, the water treatment efficiency is not reduced, and no liquid feed means such as a pump is required. Cost can be reduced.

It is a schematic system diagram of the example of a water treatment apparatus. It is a longitudinal cross-sectional view which shows the structure of a filtration apparatus. It is a cross-sectional view of a filtration apparatus. It is a perspective view which shows the filter body of a filtration processing apparatus. It is a principal part enlarged view of a mesh sheet. It is a figure which shows the measuring method of the differential pressure | voltage of a reverse osmosis membrane.

Hereinafter, the present invention will be described in detail based on embodiments.
The present invention relates to a backwashing method for filtration treatment means for performing filtration treatment of water to be treated in parallel before the reverse osmosis membrane treatment for treating the water to be treated with a reverse osmosis membrane, wherein the filtration treatment means comprises a sheet-like member. A filter body that is wound in a spiral shape, and a filtration tank in which the water to be treated is passed and in which the filter body is filled so that the axial center of the filter body is along the water passing direction, The sheet-like member is a sheet-like mesh sheet having pores through which the water to be treated passes, and sheet surfaces of sheet-like spacers where the water to be treated is difficult to pass compared to the mesh sheet, By passing the concentrated water discharged by the reverse osmosis membrane treatment from the direction opposite to the direction in which the water to be treated is passed through the filtration means to which the water to be treated is not passed, the filtration means is backwashed. To do.

Examples of water to be treated include water containing a humic acid / fulvic acid organic substance, a biological metabolite such as sugar produced by algae, or a synthetic chemical substance such as a surfactant, specifically, industrial water. ,
Examples include, but are not limited to, city water, well water, river water, lake water, and factory wastewater (particularly, biologically treated water obtained by biologically treating wastewater from a factory). The humic substance refers to a corrosive substance generated by the decomposition of plants and the like into microorganisms, and includes humic acid, and the water containing the humic substance is derived from humic substance and / or humic substance. Soluble COD
Contains ingredients, suspended matter and chromaticity components.

The backwashing method for the filtration treatment means of the present invention will be described with reference to FIG. 1 which is an example of a water treatment apparatus to which the filtration treatment means for the filtration treatment means of the present invention is applied. FIG. 1 is a schematic system diagram of a water treatment apparatus.

As shown in FIG. 1, the water treatment apparatus 10 includes filtration treatment means 12A and 12B that are introduced in parallel from the raw water tank 11 or the like in which the water to be treated (raw water) is stored. The filtration means 12A and 12B will be described later in detail, but turbidity (S
It has a filter body that captures S). And this filtration means 12A and 12B
At the subsequent stage, reverse osmosis membrane processing means 13A and 13B having reverse osmosis membranes are provided. The raw water tank 11, the filtration treatment means 12A and 12B, and the reverse osmosis membrane treatment means 13A and 13B are as shown by the arrows in FIG. 1 so that the water to be treated, concentrated water and the like are passed as described later. Connected by piping.

In the present invention, the concentrated water discharged from the reverse osmosis membrane treatment means 13A and 13B is supplied to the filtration treatment means 12A and the filtration treatment means 12B through which the treatment water is not passed. Concentrated water introduction means for introducing from the opposite direction. In the present embodiment, the concentrated water introduction means is a pipe for supplying concentrated water from the concentrated water discharge ports of the reverse osmosis membrane treatment means 13A and 13B from which the concentrated water is discharged to the filtration treatment means 12A and the filtration treatment means 12B. And valves 17A to 17I that regulate the flow path of water that is automatically opened and closed and allowed to flow. In addition,
In FIG. 1, the valves 17 </ b> A to 17 </ b> I are arranged so that the pipes 17 </ b> A are not cut off.
A delay timer is incorporated into the program at ~ 17I. And the frequency of backwashing of the filtration means 12A and 12B, which will be described later, is the water treatment time of the treatment means 12A and 12B,
It is controlled by the processing amount and differential pressure, etc., so that it can be operated completely automatically. Of course, each of the valves 17A to 17I may be a manual valve instead of an automatic valve.

In such a water treatment device 10, first, the water to be treated is introduced into the filtration means 12A from the raw water tank 11 in which the water to be treated is stored. And the turbidity contained in to-be-processed water is capture | acquired by the filter body which 12A of filtration process means has, and the to-be-processed water from which the turbidity was removed to some extent is the filtration process means 1.
Discharged from 2A. The treated water discharged from the filtration means 12A is supplied to the reverse osmosis membrane treatment means 13A and 13B and subjected to membrane separation treatment by the reverse osmosis membrane. The permeated water that has permeated through the reverse osmosis membranes of the respective reverse osmosis membrane treatment means 13A and 13B is discharged as treated water. Further, from each reverse osmosis membrane treatment means 13A and 13B, water to be treated that has not been treated with the reverse osmosis membrane, that is, so-called concentrated water that does not permeate the reverse osmosis membrane and contains more impurities than the permeated water. Discharged. During such water treatment, the valve 17A provided in the pipe connecting the raw water tank 11 and the filtration treatment means 12A, and the pipe connecting the filtration treatment means 12A and the reverse osmosis membrane treatment means 13A were provided. Valve 17B and reverse osmosis membrane treatment means 13A and reverse osmosis membrane treatment means 1
The valve 17I provided in the pipe through which the concentrated water discharged from 3B is passed is opened, and the other valves 17C to 17H are closed.

And if the filtration processing means 12A has been contaminated by turbidity, for example, after passing the water to be treated,
When a predetermined time has elapsed, the filtration processing means 12A is back-washed, and the filtration processing is performed by the filtration processing means 12
Perform by B. Specifically, the valves 17C, 17D, 17E, and 17F are opened, and the other valves 17A, 17B, 17G, 17H, and 17I are closed. In this state, first, the water to be treated is introduced into the filtration means 12B from the raw water tank 11 in which the water to be treated is stored. At this time, since the valve 17A is closed, the water to be treated from the raw water tank 11 is not supplied to the filtration means 12A. And the turbidity contained in to-be-processed water is capture | acquired by the filter body which the filtration process means 12B has, and the to-be-processed water from which the turbidity was removed to some extent is the filtration process means 12B.
Discharged from. The water to be treated discharged from the filtration means 12B is boosted by a boosting means such as a pump (not shown), supplied to the reverse osmosis membrane treatment means 13A and 13B, and subjected to membrane separation treatment by the reverse osmosis membrane. The permeated water that has permeated through the reverse osmosis membranes of the reverse osmosis membrane treatment means 13A and 13B is discharged as treated water. Further, the concentrated water discharged from the reverse osmosis membrane treatment means 13A and 13B is introduced into the filtration treatment means 12A via the valve 17F from the side opposite to the water flow direction of the water to be treated. The means 12A is backwashed. Here, since this concentrated water has a high pressure, the reverse osmosis membrane treatment means 13A and 13A can be provided without providing a liquid feeding means such as a pump.
The liquid can be fed from B to the filtration means 12A. Therefore, the cost and power consumption of a pump etc. are unnecessary. Moreover, installation space for a pump or the like is not necessary. The concentrated water discharged from the filtration processing means 12A by this back washing is returned to the raw water tank 11 via the valve 17E. Thereafter, when the back washing of the filtration means 12A is completed, the valve 17E and the valve 17F are closed and the valve 17I is closed.
The concentrated water discharged from the reverse osmosis membrane treatment means 13A and 13B
Discharge via 7I.

Next, if the filtration means 12B is contaminated with turbidity, for example, after passing the water to be treated,
When the predetermined time has elapsed, the filtration processing means 12B is back-washed, and the filtration processing is performed by the filtration processing means 12
Do this by A. Specifically, the valves 17A, 17B, 17G, and 17H are opened, and the other valves 17C to 17F and the valve 17I are closed. In this state,
Water to be treated is introduced into the filtration means 12A from the raw water tank 11 in which the water to be treated is stored. At this time, since the valve 17C is closed, the water to be treated from the raw water tank 11 is not supplied to the filtration means 12B. Then, turbidity contained in the water to be treated is captured by the filter body of the filtration means 12A, and the water to be treated from which the turbidity has been removed to some extent is discharged from the filtration means 12A. The water to be treated discharged from the filtration means 12A is boosted by a boosting means such as a pump (not shown), supplied to the reverse osmosis membrane treatment means 13A and 13B, and subjected to membrane separation treatment by the reverse osmosis membrane. The permeated water that has permeated through the reverse osmosis membranes of the reverse osmosis membrane treatment means 13A and 13B is discharged as treated water. Further, the concentrated water discharged from the reverse osmosis membrane treatment means 13A and 13B is introduced into the filtration treatment means 12B via the valve 17H from the opposite side to the water flow direction of the treated water.
The filtration means 12B is backwashed from the concentrated water. Here, since this concentrated water is high-pressure, it can be fed from the reverse osmosis membrane treatment means 13A and 13B to the filtration treatment means 12B without providing a liquid feed means such as a pump. The concentrated water discharged from the filtration means 12B by this back washing is returned to the raw water tank 11 via the valve 17G. Thereafter, when the backwashing of the filtration means 12B is completed, the concentrated water discharged from the reverse osmosis membrane treatment means 13A and 13B is passed through the valve 17I by closing the valve 17G and the valve 17H and opening the valve 17I. Try to drain.

By repeating the above, the permeated water (treated water) is not used to wash the filtration treatment means 12A and 12B using unnecessary concentrated water discharged from the reverse osmosis membrane treatment means 13A and 13B. High efficiency. Moreover, since it is not necessary to provide liquid feeding means such as a pump for backwashing, cost reduction can be achieved. And since the filtration processing means which performs a filtration process can be wash | cleaned, continuing the water treatment which consists of a filtration process and a reverse osmosis membrane process, a water treatment can be performed continuously.

In the above example, two reverse osmosis membrane treatment means are provided, but three or more may be used,
One may be sufficient. For example, when there is one reverse osmosis membrane treatment means, when washing the filtration treatment means 12A, the water to be treated is passed through the filtration treatment means 12B and the reverse osmosis membrane treatment means 13A for water treatment, The concentrated water discharged from the osmotic membrane treatment means 13A may be passed through the filtration means 12A in the direction opposite to the direction of water to be treated, and when the filtration means 12B is washed, The treated water is passed through the filtration treatment means 12A and the reverse osmosis membrane treatment means 13A for water treatment, and the concentrated water discharged from the reverse osmosis membrane treatment means 13A is passed through the filtration treatment means 12B. It is only necessary to pass water in the opposite direction.

In the above-described example, only the concentrated water discharged from the reverse osmosis membrane treatment means 13A and 13B is used as a washing liquid, and the filtration treatment means 12A and 12B are backwashed. However, the bactericide such as sodium hypochlorite is added to the concentrated water. The liquid to which the additive such as is added is supplied to the filtration means 12A and 12B,
The filtration means 12A and 12B may be backwashed. For example, when a bactericidal agent is added, blockage of the filtration means 12A and 12B due to biological contaminants can be suppressed.

In the above-described example, the concentrated water discharged from the filtration treatment means 12A and 12B by backwashing is returned to the raw water tank 11, and the filtration treatment and the reverse osmosis membrane treatment are performed again so that the water treatment efficiency becomes higher. However, the turbidity etc. of the concentrated water may contaminate the piping in the water treatment system, the reverse osmosis membrane treatment means and the filtration treatment means, so the filtration treatment means 12A and 1 by backwashing.
The concentrated water discharged from 2B may be discharged out of the system of the water treatment apparatus 10 without returning to the raw water tank 11.

In the present invention, the filtration means 12A and 12B have a predetermined filter body. An example of the filtration means 12A and 12B will be described with reference to FIGS. FIG. 2 is a longitudinal sectional view in the direction of water flow of the water to be treated showing the configuration of the filtration device as the filtration means, FIG. 3 is a transverse sectional view, and FIG. 4 shows the filter body of the filtration device. It is a perspective view.

As shown in FIG.2 and FIG.3, the filtration apparatus (filtration process means) 12 is the filtration which capture | acquires the turbidity in the cylindrical filtration tank 41 into which the to-be-processed water flows, and the to-be-processed water to flow through And a body 42. The filter body 42 includes a core member 43 connected to both ends of the filtration tank 41 in the water passage direction, and a filter body main body 44 including a sheet-like member wound around the core member 43 in a spiral shape. In this sheet-like member, the sheet-like mesh sheet 45 having holes through which the water to be treated passes and the sheet surfaces of the sheet-like spacer 46 where the water to be treated is difficult to pass compared to the mesh sheet 45 are overlapped. Is.

In addition, a circular plate 47 made of resin or the like provided with a plurality of holes to allow water to be treated containing turbidity (suspended substance) or the like to freely pass therethrough at both ends of the filtration tank 41 in the direction of water flow. Provided, and both ends of the core member 43 are fixed to the center of each plate 47. And as for the filter body 42, the filter body 42 is filled with the whole inside of the filtration tank 41 so that the axial center of the filter body main body 44 may follow the water flow direction of to-be-processed water. Further, the gap between the inner wall of the filtration tank 41 and the outer periphery of the filter body main body 44 and the gap near the core member 43 are filled with a water-impermeable member 48 through which the water to be treated such as an adhesive does not pass. Cannot pass through. The shaft core of the filter body 44 is the center of the spiral of the filter body 44 wound in a spiral shape, and the core material 43 corresponds to this embodiment.

When the water to be treated is passed through such a filtration device 12, the spacer 46 becomes the mesh sheet 4.
Since the water to be treated is less likely to pass than 5, most of the water to be treated passes through the pores of the mesh sheet 45 and substantially passes through the mesh sheet 45, that is, passes through the mesh sheet 45 in the surface direction. The turbidity contained in the water is trapped in the mesh sheet 45, and the water to be treated from which the turbidity has been removed is discharged from the filtration tank 41. In this way, the water to be treated is passed through the mesh sheet 45 that has pores through which the water to be treated passes and can capture turbidity, not vertically across the thickness direction but in a longitudinal direction. By setting it as the filtration apparatus 12 of a structure, clear treated water is obtained.
Therefore, as shown in FIG. 1 described above, the filtration device 12 can be used in the preceding stage of the reverse osmosis membrane device (reverse osmosis membrane treatment means) 13 having the reverse osmosis membrane (RO membrane). Can be prevented. The filtration device 12 is not filtered using a membrane as in the case of an ultrafiltration membrane device or a microfiltration membrane device, so it is difficult to block and is inexpensive.

Here, the mesh sheet 45 is not particularly limited as long as the mesh sheet 45 has pores through which the water to be treated can pass and can remove the turbidity contained in the water to be treated to a desired extent. For example, FIG. Examples thereof include a woven fabric formed of warp yarns 49a and weft yarns 49b. 5 is an enlarged plan view of the main part of the mesh sheet 45 (FIG. 5A) and a cross-sectional view taken along the line AA ′ in FIG.
b)).

The distance between adjacent warp yarns 49a and adjacent weft yarns 49b of the mesh sheet 45, that is, the opening (indicated by OP in FIG. 5) is preferably about 200 to 4000 μm, and air holes (indicated by diagonal lines in FIG. 5) ), That is, the space ratio (opening area) in a plan view of the mesh sheet 45 is preferably about 40 to 90%, and the height of the intersection (thickness indicated by T in the figure) Is preferably 500 to 1200 μm. As a specific product, for example, a product of about 100th to 8th (NBC) may be used.
If it is this range, a turbidity can be removed especially suitably. Further, in a reverse osmosis membrane device, for example, a spiral type reverse osmosis membrane device having a shape in which a reverse osmosis membrane is wound, the height of the intersection is usually 0.
Since a mesh sheet of about 65 to 1.2 mm is used as the raw water flow path spacer, it is used as a filtration device used in the preceding stage of the reverse osmosis membrane device, that is, as a filtration device for supplying treated water to the reverse osmosis membrane device. This is because it is preferable to use a mesh sheet having a lower intersection portion than the reverse osmosis membrane device when blocking the membrane device.

Moreover, the diameter D of the fiber used as the warp 49a or the weft 49b is 0.1-0.6 m in diameter, respectively.
m is preferable, and more preferably about 0.1 to 0.4 mm. Depending on the turbidity and the amount of water to be treated, in order to be able to cut the water to be treated substantially vertically, it is necessary to form holes through which the water to be treated passes with fibers of a certain thickness, Moreover, if the thickness is too large, the formed pores become too large, and the suspended matter cannot be removed.

Examples of the material constituting the mesh sheet 45 include synthetic resins such as polyolefin, polyester, nylon, and polyvinylidene fluoride (PVDF), and metal fibers. From the viewpoint of chemical resistance and economy. Polyolefins are preferred. In addition, although the woven fabric was illustrated in FIG. 5, the nonwoven fabric which has a comparatively big void | hole formed with the fiber may be sufficient.

The spacer 46 is not particularly limited as long as the water to be treated is less likely to pass through than the mesh sheet 45. For example, the water impervious sheet does not have any holes and does not allow the water to be treated to pass through. Or it may be a non-woven fabric formed of fibers having a diameter of 0.1 to 100 [mu] m, preferably about 0.5 to 30 [mu] m, or the like, or those laminated by integrally bonding them by heat fusion or the like. In addition, since the to-be-processed water can be made to contact the mesh sheet 45 uniformly if the spacer 46 is a water-impermeable sheet which does not allow the to-be-processed water to pass through, the spacer 46 may have a water-impermeable sheet. preferable. And if a nonwoven fabric is used as the spacer 46, the turbidity of the to-be-processed water can be captured at the fluffing part of the nonwoven fabric surface, and the turbidity capture property of the filtration apparatus 12 can be improved. It is preferable to use a spacer consisting of

Examples of the material of the spacer 46 include polyolefin, polyester, nylon,
Examples thereof include polyvinylidene fluoride (PVDF), metal fibers, activated carbon fibers, and the like. Polyolefins are preferred from the viewpoint of chemical resistance and economy. NaCl contained in the water to be treated
From the viewpoint that reduction treatment of O or the like can be performed and an apparatus such as an activated carbon tower can be eliminated, activated carbon fibers are preferable.

The form in which the mesh sheet 45 and the spacer 46 are overlapped is not particularly limited, and the sheet surfaces may be bonded together or integrally formed by heat fusion. In addition, although the magnitude | size of the mesh sheet 45 and the spacer 46 does not need to be the same, in order to process a to-be-processed water uniformly, it is preferable that it is substantially the same. The length of the mesh sheet 45 and the spacer 46 in the water flow direction depends on the turbidity of the water to be treated, the amount of treatment, and the turbidity of the treated water to be obtained.
What is necessary is just about -1000 mm.

The material of the core member 43 around which the sheet member on which the mesh sheet 45 and the spacer 46 are superimposed is wound is not particularly limited, and plastic, metal, or the like can be used, but from the viewpoint of economy, vinyl chloride piping (CVP) Piping). Also, the core material 43
The shape is not particularly limited, and may be, for example, cylindrical or prismatic. The method for winding the sheet-like member around the core member 43 is not particularly limited. For example, the end of the sheet-like member is bonded to the core member 4 with an adhesive or the like.
3, the sheet member is wound around the core member 43 in a roll shape, and wound to have an arbitrary diameter according to the amount of water to be treated, turbidity, and the like.

The filter tank 41 is not limited. For example, the material can be made of stainless steel or fiber reinforced plastic (FRP), and if the size is a hollow cylindrical shape (tubular shape), the diameter is 1
It can be set to 00 to 1000 mm and a height of 200 to 1000 mm. In FIG.
Although it was set as the cylindrical filtration tank 41, it does not need to be a cylinder and what is necessary is just the shape which can permeate | transmit water, ie, a hollow, for example, the shape which provided the cavity in the prism.

In FIG. 2, the filter body 42 having the filter body main body 44 wound three times around the core material 43 is used. However, the number of windings is not limited, and the treatment amount, turbidity, etc. of the water to be treated May be adjusted as appropriate. Therefore, the filter body 42 may be the filter body 42 wound only once, but the shape of the mesh sheet 45 is more easily held by the spacer 46 as the number of times of winding is increased, and the water to be treated is uniformly distributed in the mesh sheet. 45 can be cut longitudinally, and the water treatment is stable, which is preferable.

In FIG. 2, a filter body 42 in which a filter body main body 44 is wound around a core material 43 is used as the filter body 42, but the core material 43 may be omitted. For example, the mesh sheet 45 may be passed by a spacer 46 or the like. The filter body 42 including only the filter body main body 44 may be used as long as the water shape is maintained and the water to be treated can pass (vertically cut) the mesh sheet 45 in the surface direction.

Moreover, in FIG. 2, the filtration apparatus 1 which filled the filter body 42 in the hollow cylindrical filtration tank 41 is shown.
However, the filter 42 may be wound around a sheet of FRP or the like so that the water to be treated does not leak. Moreover, the spacer 46 may be made to serve as the filtration tank 41 by making the spacer 46 a water-impermeable material so that the water to be treated does not leak.

Further, the reverse osmosis membrane device 13 provided at the subsequent stage of the filtration device 12 has a cross-sectional area of the water passage of the treated water larger than the cross-sectional area of the mesh sheet 45 in the water passage direction of the treated water. What has the width | variety of a raw | natural water flow path larger than the height of the intersection part of the mesh sheet 45 is preferable. The form of the reverse osmosis membrane device 13 is not particularly limited. For example, a so-called spiral-type device in which a reverse osmosis membrane bound in a bag is wound around a hollow core member having a water passage hole on its side surface is increased in size. Since it is easy to respond to, it is preferable. In particular, a spiral type reverse osmosis membrane device having the same diameter as the filtration device 12 is preferable. When the spiral type reverse osmosis membrane device 13 is used, treated water (permeated water) obtained by separation of impurities by the reverse osmosis membrane is discharged from the hollow core material, and the reverse osmosis membrane is used from other than the core material. So-called concentrated water containing a large amount of impurities not subjected to membrane separation is discharged.

Moreover, you may make it perform the aggregation process which adds flocculants, such as an inorganic flocculant and a polymer flocculent, to a to-be-processed water before the filtration process. Since flocs (aggregates) are formed by the turbidity contained in the water to be treated by the flocculation treatment, the turbidity is easily captured by the subsequent filtration treatment, and a clearer water to be treated can be obtained. . In addition, when performing a flocculation process, the water treatment apparatus 10 should just provide a flocculation process means between the raw | natural water tank 11 and the filtration process means 12A, or between the raw | natural water tank 11 and the filtration process means 12B. As the coagulation treatment means, a reaction tank into which the water to be treated is introduced, a coagulant introduction means comprising a pump or the like for introducing the coagulant in the reaction tank or the previous stage of the reaction tank, and the water to be treated are stirred if necessary. What is necessary is just to have a stirrer.

Below, the reference example which shows the effect of the filtration process means (filter apparatus) 12 which has the reverse osmosis membrane process means (reverse osmosis membrane apparatus) 13 in the back | latter stage and has the said predetermined filter body is shown.
(Reference Example 1)
As water to be treated (raw water), turbidity 2.0-3.0 degrees, residual chlorine _(as.Cl 2): 0.0
Less than 5 ppm, water temperature: 24.5 to 25.5 ° C. industrial water using a water treatment device provided with a reverse osmosis membrane device 13 at the subsequent stage of the filtration device 12, an inlet pressure of the reverse osmosis membrane device: 0.75 MPa, The water to be treated was passed through and treated with the amount of concentrated water discharged from the reverse osmosis membrane device: 1.35 m ³ / h and the amount of treated water: 0.25 m ³ / h. The configurations of the filtration device 12 and the reverse osmosis membrane device 13 are as follows.

<Filtration device>
Filtration tank ... Cylindrical container (vessel) with an inner diameter of 100 mm
Filter body: mesh sheet made of warp and weft made of polyethylene fibers with a diameter of 0.3 mm, 1 m × 10 m shown in FIG. 5, intersection point height T is 0.85 mm, opening is 3000 μm, opening area A sheet-like member made of 82% woven fabric, a spacer made of PET (polyethylene terephthalate), 1 m × 10 m × 0.1 mm thick film (water impervious film), and the four corners are laminated and heat-sealed. A pipe made of vinyl chloride having a diameter of 20 mm (with a water-impermeable film facing outside)
Filter body with a diameter of 100 mm, water-impermeable member formed by wrapping 10 m around the core material): Adhesion that does not allow the water to be treated to pass through the gap between the inner wall of the filtration tank and the outer periphery of the filter body, or the gap near the core material Flow rate of the filtration device filled with the agent: 1.6 m ³ / h (LV = 200 m / h)

<Reverse osmosis membrane device>
Reverse osmosis membrane: FILMTEC LE-4040 (The Dow Chemical Company)
Spiral type using raw water flow path spacer intersection height (0.85 mm) (diameter 100 mm)
The differential pressure of the reverse osmosis membrane at the time of processing is shown in FIG.
And the pressure P2 at the outlet of the concentrated water (P1−P2 (MPa)), it was confirmed that even when water was passed for 72 hours, the water was almost constant and stable, and blockage was prevented. After that,
The pressure increased to 0.2 MPa, and water passage became impossible.

In addition, the water to be treated (raw water) to be introduced into the filtering device 12 and 72 from the start of water flow of the water to be treated
With respect to the treated water discharged from the reverse osmosis membrane device 13 over time, the number of fine particles was measured with a fine particle counter of a laser light blocking method, and the turbidity was determined by a transmitted light measurement method using a kaolin standard solution. The results shown in Table 1 were obtained. As shown in Table 1, in Reference Example 1, the turbidity of 200 μm or more was removed, and the turbidity was remarkably removed as compared with Reference Comparative Example 1 in which the filtration device 12 was not used. In Reference Example 1, it was confirmed that the treated water discharged from the filtration device 12 was clear, and as a result, the membrane separation treatment in the reverse osmosis membrane device 13 in the subsequent stage was suitably performed.

(Reference Comparative Example 1)
The same operation as in Reference Example 1 was performed except that the filtration device 12 was not provided and only the reverse osmosis membrane device was used. The measurement results of the number of fine particles and turbidity are shown in Table 1. Further, the differential pressure of the reverse osmosis membrane increased immediately after water flow, and after 24 hours became 0.2 MPa, making water flow impossible.

(Reference Example 2)
As a spacer, 1 m × 10 made of polyolefin fibers having a diameter of 17.5 μm
One non-woven fabric of mx thickness 0.22mm (FT-330N made by Nippon Vilene) and PET (
Reference Example 1 except that a 1 m × 10 m × 0.1 mm thick film (water impervious film) made of polyethylene terephthalate was superposed and fixed by heat-sealing the four corners. The same operation was performed. The measurement results of the number of fine particles and turbidity are shown in Table 1. As a result, it was confirmed that the differential pressure of the reverse osmosis membrane was almost constant and stable even when water was passed for 30 days, and occlusion was prevented for a long time. Moreover, as shown in Table 1, in Reference Example 2, turbidity of 50 μm or more was removed, and it was significantly more turbid than Reference Comparative Example 1 and Reference Example 1 in which the filtration device 12 was not used. Since the quality was removed, the treated water discharged from the filtration device 12 was remarkably clarified in Reference Example 2, and as a result, the membrane separation treatment in the reverse osmosis membrane device 13 in the subsequent stage was suitably performed. Was confirmed.

(Reference Example 3)
As a spacer, 1 m × 10 m × thickness 0.3 made of activated carbon fiber with a diameter of 15 μm
1 mm × 10 mm non-woven fabric (Unitika activated carbon fiber A-15) and 1 mm × 10 m × 0.1 mm thick film (water impervious film) made of PET (polyethylene terephthalate) The same operation as in Reference Example 1 was performed, except that a material fixed by heat fusion was used. The measurement results of the number of fine particles and turbidity are shown in Table 1. As a result, the differential pressure of the reverse osmosis membrane is 3
It was confirmed that even if water was passed for 0 days, it was almost constant and stable, and occlusion was prevented for a long time.
Moreover, as shown in Table 1, in Reference Example 3, turbidity of 50 μm or more was removed, and turbidity was remarkably removed as compared with Reference Comparative Example 1 and Reference Example 1. Thus, in Reference Example 3, it was confirmed that the treated water discharged from the filtration device 12 was remarkably clarified, and as a result, the membrane separation treatment in the subsequent reverse osmosis membrane device 13 was suitably performed.

And, as a result of passing tap water of Nogi-cho, Tochigi Prefecture having 0.5 ppm (as.Cl ₂ ) residual chlorine through the water treatment apparatus similar to that of Reference Example 3 for 100 hours, the residual chlorine concentration was stable. A treated water of less than 0.05 ppm (as. Cl ₂ ) was obtained.

DESCRIPTION OF SYMBOLS 10 Water treatment apparatus, 11 Raw water tank, 12 Filtration apparatus (filtration treatment means), 13 Reverse osmosis membrane apparatus (reverse osmosis membrane treatment means), 17A-17I valve, 41 Filtration tank, 42 Filter body, 43 Core material, 44 Filtration Body body, 45 mesh sheet, 46 spacer, 47 plate, 48 water impervious member, 49a warp, 49b weft

Claims (3)

A reverse washing method of a filtration means for filtering the treated water in parallel before the reverse osmosis membrane treatment for treating the treated water with a reverse osmosis membrane,
The filtration means includes a filter body having a sheet-like member wound in a spiral shape, water to be treated, and the filter body so that an axis of the filter body is along a water passage direction. The sheet-like member has a sheet-like mesh sheet having pores through which the water to be treated passes, and a sheet-like material through which the water to be treated is difficult to pass compared to the mesh sheet. The sheet surfaces of the spacer are overlapped,
By passing the concentrated water discharged in the reverse osmosis membrane treatment from the direction opposite to the water flow direction of the water to be treated, the filtration treatment means is passed through the filtration treatment means through which the water to be treated is not passed. A backwashing method of the filtration means characterized by backwashing. The reverse washing method of the filtration processing means according to claim 1, wherein the reverse osmosis membrane treatment is a reverse osmosis membrane treatment of water to be treated discharged from the filtration treatment means in parallel. A filter body in which a sheet-like member is spirally wound, and a filter in which water to be treated is passed, and the filter body is filled in such a manner that the shaft core of the filter body is along the water passing direction. The sheet-like member has a sheet-like mesh sheet having pores through which the water to be treated passes, and sheet surfaces of the sheet-like spacer in which the water to be treated is difficult to pass compared to the mesh sheet. A plurality of filtration processing means arranged in parallel for filtering the water to be treated.
A reverse osmosis membrane treatment means which is provided at a subsequent stage of the filtration treatment means and performs a reverse osmosis membrane treatment with a reverse osmosis membrane on the water to be treated discharged from the filtration treatment means;
Concentrated water introduction means for introducing the concentrated water discharged from the reverse osmosis membrane treatment means into the filtration treatment means through which the water to be treated is not passed from the direction opposite to the water flow direction of the water to be treated. Water treatment device characterized by.

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