JPH11207343A - Treatment of ozone-containing water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform a membrane separation treatment of ozone- containing water with a spiral type membrane module. SOLUTION: This treatment method refers to a treating method of the ozone- containing water with the spiral type membrane module. The spiral type membrane module consists of a wound body formed by winding a bag shaped separation membrane 10 around a shaft 20, and feeds raw water from one end face of the wound body and takes out transmitted water and concentrated water from the other end face of the wound body. Thus, the ozone-containing water can be efficiently subjected to a membrane separation treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for treating ozone-containing water with a spiral membrane module.

[0002]

2. Description of the Related Art In the case of membrane separation treatment of groundwater, river water or various kinds of wastewater, ozone is added to raw water to prevent the membrane surface from being clogged with organic substances, and the membrane has excellent ozone resistance. The use of such a fluororesin film is described in JP-A-6-335622 and JP-A-6-343843.

[0003] Japanese Patent Application Laid-Open No. 7-39872 describes that ozone is added to groundwater to convert manganese into an insoluble oxide, followed by membrane permeation treatment.

Japanese Patent Application Laid-Open No. 7-158297 describes that swimming pool water is sterilized with ozone and treated with an ultrafiltration membrane.

The above-mentioned JP-A-6-335622, JP-A-6-343843 and JP-A-7-15829
Patent Document 7 discloses that a hollow fiber module is used as a membrane module. However, this hollow fiber module has a disadvantage that power consumption for membrane permeation processing is large.

In the present invention, the ozone-containing water is treated by the improved spiral-type membrane module. The configuration of the conventional spiral-type membrane module will now be described with reference to the drawings.

FIG. 5 is a partially exploded perspective view showing the structure of a conventional spiral type membrane module. A plurality of bag-shaped separation membranes 2 are wound around a water collecting pipe 1 via a mesh spacer 3.

The water collecting pipe 1 is provided with a slit-shaped opening communicating with the inside and outside of the pipe. The separation membrane 2 has a bag shape,
The central part surrounds the water collection pipe 1. A channel material 4 made of a mesh spacer or the like is inserted inside the bag-shaped separation membrane 2, and the inside of the bag-shaped separation membrane (bag-shaped membrane) 2 is a permeated water channel.

A top ring 6 and an end ring 7 are provided at both ends of the wound body 5 of the bag-like membrane 2, and a brine seal 8 is provided around the outer periphery thereof.

The raw water flows into the raw water flow path between the bag-like membranes 2 from the front end face of the wound body 5 and flows in the longitudinal direction of the wound body 5 as it is, and the concentrated water flows from the rear end face of the wound body 5 Leaked as. While flowing through the raw water flow path, water permeates the bag-like membrane 2 and enters the inside thereof, flows into the water collecting pipe 1, and is taken out of the module from the rear end side of the water collecting pipe 1.

[0011]

The conventional spiral type membrane module shown in FIG. 5 has the following problems to be solved.

In order to increase the flow rate of the permeated water in the water collecting pipe 1, it is necessary to increase the diameter of the water collecting pipe 1, but in such a case, the diameter of the spiral membrane module also becomes large. The permeated water that has permeated into the bag-shaped membrane 2 flows to the water collecting pipe 1 while spirally flowing through the bag-shaped membrane 2.
The flow resistance in the bag-like membrane 2 is large. Moreover, the flow resistance near the slit portion of the water collecting pipe flowing into the water collecting pipe 1 from the inside of the bag-shaped membrane 2 is large. The flow rate of the raw water flowing through the raw water flow path decreases toward the downstream side. (The flow rate of raw water decreases as much as the raw water is concentrated.)
For this reason, the raw water flow velocity is low in the downstream of the raw water flow path,
Dirt easily adheres.

[0013] The present invention solves the above-mentioned conventional problems, and does not require a water collecting pipe and treats ozone-containing water efficiently by a spiral-type membrane module having low permeated water flow resistance. The purpose is to provide a method.

[0014]

The method for treating ozone-containing water according to the present invention is a method for treating ozone-containing water with a spiral membrane module, wherein the spiral membrane module has a fluororesin membrane wound around a shaft. It is turned into a wound body, raw water is supplied from one end face of the wound body, and permeated water is taken out from the other end face of the wound body.

The ozone-containing water is always in a sterile state, can suppress the growth of biological slime, and can perform efficient membrane filtration. In addition, the chromaticity and the trihalomethane precursor can be oxidatively decomposed by the oxidizing power of ozone, and advanced processing that cannot be achieved by only microfiltration or ultrafiltration is possible.

In the present invention, the fluororesin film is used as the film, and the ozone-containing water can be treated without deterioration for a long time.

The spiral membrane module employed in the present invention is a spiral membrane module in which a permeated water flow path material is disposed inside a bag-like membrane, and a raw water flow path material is disposed between the bag-like membranes. The bag-like membrane is substantially rectangular with first, second, third and fourth sides, and the first, second and third sides are sealed and the fourth A part of the side part is an open part and the remaining part is a closed part, and a first side part orthogonal to the fourth side part is applied to a shaft to wind a bag-like membrane to form a wound body, The fourth side faces the rear end face of the wound body, the second side facing the fourth side faces the front end face of the wound body, between the bag-shaped films. The raw water flow path of the third
The entire side of the bag-shaped membrane is sealed, and in the fourth side, a portion overlapping with the open portion of the bag-shaped film is a closed portion, and a portion overlapping with the closed portion of the bag-shaped film is open. It is preferably a part.

In this spiral type membrane module, raw water flows into the raw water flow path from the front end face of the wound body. The raw water flows through the raw water flow path in a direction substantially parallel to the axis of the wound body, and then flows out as concentrated water from the raw water flow path opening at the rear end face of the wound body.

The water that has passed through the bag-like membrane flows in the bag-like membrane in a direction substantially parallel to the axis of the wound body, and flows out of the bag-shaped membrane opening at the rear end face of the wound body.

As described above, since the permeated water flows in the bag-shaped membrane in a direction parallel to the axis of the wound body, the water collecting pipe used in the conventional spiral membrane module becomes unnecessary. Then, there is no flow resistance when flowing into the water collecting pipe from inside the bag-shaped membrane, and the flow resistance of permeated water is reduced.

Since the water collecting pipe is eliminated, the length of the bag-like membrane in the winding direction can be increased by that much.
The membrane area can be expanded. And even if the length in the winding direction of the bag-like membrane is increased, the flow resistance of the permeated water does not increase,
The amount of permeated water can be increased.

Further, since the raw water flow path is opened only at a part of the rear end face of the wound body, the flow rate of the raw water (concentrated water) at the downstream side of the raw water flow path can be increased more than before. In addition, the adhesion of dirt in the downstream area of the raw water flow path can be prevented.

In the present invention, in addition to polytetrafluoroethylene (PTFE), the film may be made of fluorine such as polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer or chlorotrifluoroethylene-ethylene copolymer. A resin film is preferred.
This fluororesin film has high ozone resistance and can treat ozone-containing water for a long time. PTFE is particularly excellent in this ozone resistance, is water repellent, and is hardly stained.

According to the method of the present invention, water such as groundwater or river water to which ozone is added for removal of COD or chromaticity, sterilization, or oxidative precipitation of metal ions, various cleaning steps, and manufacturing steps Various types of ozone-containing water film treatment, such as ozone-containing water drainage discharged from a treatment step or the like, can be performed. This membrane may be any of an ultrafiltration membrane, a microfiltration membrane, and a reverse osmosis filtration membrane, and is preferably an ultrafiltration membrane or a microfiltration membrane.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A spiral type membrane module used in an embodiment of the present invention will be described below with reference to the drawings. FIG. 1A is a perspective view of a bag-like membrane of the spiral membrane module and a shaft around which the bag-like membrane is wound. FIGS. 1B and 1C are cross-sectional views taken along lines BB and CC of FIG. 1A, respectively. FIG. 2 is a sectional view showing a method of winding a bag-like membrane around a shaft, and FIG.
Is a perspective view showing an engagement relationship between the wound body and the socket, and FIG. 4 is a side view of the spiral membrane module.

As shown in FIG. 1, the bag-like film 10 made of a fluororesin has a square or rectangular shape, and has a first side 11, a second side 12, a third side 13 and It has a fourth side 14. 1st side part 11, 2nd side part 1
In the second and third sides 13, the separation membrane films are adhered to each other with an adhesive or the like, and only a part of the fourth sides 14 is adhered. In addition, as the bag-like film 10, one long film is folded in two at the second side 12, and the first side 11, the third side 13, and the fourth side 1 are folded.
4 may be bonded.

From the middle of the fourth side portion 14 to the third side portion 13
The separation membrane films of the bag-like membrane 10 are not adhered to each other, and the opening portion 30 for permeated water outflow is formed. Further, from the middle of the fourth side portion 14 to the first side portion 11, the separation membrane films of the bag-like membrane 10 are adhered to each other, forming a closing portion 31 for preventing outflow of permeated water. I have.

A permeated water flow path material (for example, a mesh spacer) 15 is inserted into the bag-shaped membrane 10.

On one surface of the bag-like film 10, an adhesive 1
6 is adhered and adhesives 17 and 18 are adhered to the other surface, and the bag-like film 10 is wound around the shaft 20. The adhesive 16 is applied along the first side 11, and the adhesive 17 is applied along the third side 13. The adhesive 18 is applied along the opening 30 for outflow of permeated water from the intermediate portion in the longitudinal direction of the fourth side portion 14 to the third side portion 13.

By winding a plurality of bag-like films 10 around the shaft 20, the overlapping bag-like films 10 are joined to each other at the adhesives 17 and 18 in a water-tight manner. Thus, a raw water flow path through which raw water (and concentrated water) flows is formed between the bag-shaped membranes 10. As the adhesive 18 cures, an open portion for flowing out the raw water (concentrated water) is formed on the rear end surface of the wound body on the inner peripheral side, and a closing portion for preventing raw water outflow is formed on the outer peripheral side. You.

Fins 19 extend from the boundary between the open portion 30 for permeate outflow and the closed portion 31 for permeate outflow prevention in the fourth side portion 14 toward the rear of the wound body. I have. The fins 19 are made of, for example, a synthetic resin film or sheet, and are preferably bonded to the bag-like film 10 by adhesion or the like.

By winding the bag-like membrane 10 around the shaft 20 via a raw water flow path material (mesh spacer) 29 as shown in FIG. 2, a wound body 24 is formed as shown in FIG. The fin 19 extends from the rear end face of the wound body 24. By providing the fins 19 at the same location on the fourth side portion 14 of each bag-like film 10, the fins 19
Are located equiradially from the axis of the winding body 24 and
The fins 19 form a ring-shaped protrusion by overlapping the 9. The rear end of the cylindrical socket 25 is inserted into the ring-shaped protrusion, and the socket 25 and the fin 19 are joined with an adhesive or the like. Note that the socket 25 may be externally fitted to the fin 19. Also, fin 1
A cutting groove may be formed on the rear end face of the wound body 24 along the line 9 by a lathe, and the end of the socket 25 may be embedded in the groove.

By joining the socket 25 and the fins 19 in this manner, a permeated water outflow area on the outer peripheral side of the rear end face of the wound body 24 and a concentrated water outflow area on the inner peripheral side of the socket 25 are defined. .

When the bag-like film 10 is wound around the shaft 20, as shown in FIG.
A raw water flow path material (mesh spacer) 29 is interposed between them. The raw water flow path is formed by interposing these mesh spacers 29.

As shown in FIG. 4, a top ring 26 and an end ring 27 are provided on the leading edge and the trailing edge of the wound body 24, respectively.
Is formed by a synthetic resin mold or the like, and the top ring 26 is formed.
A brine seal 28 is provided around the outer periphery of.

The method for treating ozone-containing water according to the present invention treats ozone-containing water with the spiral membrane module configured as described above. As shown in FIG. 4, the ozone-containing water flows from the front end surface of the wound body 24 as raw water into the raw water flow path between the bag-shaped membranes 10. This raw water flows through the raw water flow path in a direction substantially parallel to the axis of the wound body 24, and is taken out from the end face inside the socket 25 at the rear end of the wound body 24. Then, while the raw water flows through the raw water flow path, the water permeates into the bag-like membrane 10, and the permeated water flows out from the outer peripheral side of the socket 25 on the rear end surface of the wound body 24.

In this spiral type membrane module, the permeated water flows in the bag-like membrane 10 in a direction parallel to the axis of the wound body 24 and is taken out from the rear end face. The used collecting pipe is unnecessary. For this reason, the flow resistance when flowing from the bag-like membrane into the water collecting pipe is eliminated, and the permeated water flow resistance is significantly reduced.

The water collecting pipe is omitted, and the length of the bag-like membrane 10 in the winding direction can be increased by that much.
It is possible to increase the film area. Even if the length of the bag-like membrane in the winding direction is increased, the permeated water flow resistance does not increase,
The amount of permeated water can be increased.

In this spiral type membrane module, the outlet portion of the raw water flow path is provided only inside the socket 25, and the outlet (the most downstream portion) of the raw water flow path is narrowed. The flow rate of the raw water (concentrated water) becomes sufficiently large also on the downstream side of the road, and the adhesion of dirt in the downstream area of the raw water flow path can be prevented. The area inside and outside the socket 25 (the length of the adhesive 18 in the side portion 14 direction) is preferably determined according to the water recovery rate of the spiral membrane module.

In the above embodiment, the socket 25
A permeated water outflow portion is arranged on the outer peripheral side of the socket 25, and a concentrated water outflow portion is arranged inside the socket 25. Conversely, the inside of the socket 25 is used as the permeated water outflow portion, and the outer peripheral side of the socket 25 is concentrated water outflow. It may be configured to be a part.

[0041]

EXAMPLES Examples and comparative examples will be described below.

Example 1 A spiral type membrane module having a structure shown in FIGS. 1 to 4 in which a PTFE microfiltration membrane was wound as a membrane material was used. The contained water was treated.

The membrane area of this membrane module is 0.87 m ²
And the diameter is 10 cm and the length is 40 cm.

When raw water was passed at 21 m ³ / m ² / day, the permeated water flux was 20 m ³ / m ² / day.

Comparative Example 1 A spiral type membrane module having the structure shown in FIG. 5 (the membrane area is the same as that of Example 1; diameter 10c)
(m, 100 cm in length) except that ozone-containing water was treated in the same manner as in Example 1, and the permeated water flux was 5 m ³ / m ² / day, which was considerably lower than that in Example 1. Was.

[0046]

As described above, the method for treating ozone-containing water according to the present invention enables highly efficient membrane separation of ozone-containing water, and uses a fluororesin membrane as the membrane. Ozone-containing water can be treated for a long period of time without causing film deterioration.

[Brief description of the drawings]

FIG. 1A is a perspective view of a bag-shaped membrane of a spiral membrane module used in a method for treating ozone-containing water according to an embodiment, and FIG. 1B is a view taken along line BB in FIG. FIG. 3C is a cross-sectional view taken along line C-C in FIG.

FIG. 2 is a cross-sectional view showing a method of winding a bag-like membrane of the spiral membrane module of FIG.

FIG. 3 is a perspective view showing an engagement relationship between a wound body and a socket of the membrane module of FIG. 1;

FIG. 4 is a side view of the spiral membrane module of FIG. 1;

FIG. 5 is a partially exploded perspective view showing the structure of a conventional spiral membrane module.

[Explanation of symbols]

 Reference Signs List 10 bag-like membrane 11 first side 12 second side 13 third side 14 fourth side 15 flow path material 16, 17, 18 adhesive 19 fin 20 shaft 24 wound body 25 socket 29 Mesh spacer 30 Open part for permeate outflow 31 Closed part for permeate outflow prevention

Claims (2)

[Claims] 1. A method of treating ozone-containing water with a spiral-wound membrane module, wherein the spiral-wound membrane module winds a fluororesin film around a shaft to form a roll, and raw water is supplied from one end surface of the roll. A method for treating ozone-containing water, wherein the supplied and permeated water is taken out from the other end surface of the wound body. 2. The bag according to claim 1, wherein the membrane is a bag-like membrane in which a permeated water channel material is disposed, and the bag-like membrane is a first membrane.
It is a substantially rectangular shape having second, third and fourth sides, the first, second and third sides are sealed, the fourth side is partially open, and the remainder is The spiral-type membrane module is a closed part, and the first side part orthogonal to the fourth side part is applied to a shaft to wind a bag-like membrane into a roll, and the fourth side is formed. Part facing the rear end face of the wound body, a second side part facing the fourth side part facing the front end face of the wound body, and a raw water flow path between the bag-shaped membranes. The third side portion is entirely sealed, and in the fourth side portion, a portion overlapping with the open portion of the bag-shaped film is a closed portion, and the closed portion of the bag-shaped film is closed. A method of treating ozone-containing water, characterized in that it is a spiral-wound membrane module in which a portion overlapping with the above is an open part.