JPH08206467A - Counter contamination preventing membrane module - Google Patents

Abstract

PURPOSE: To prevent the counter contamination of stagnated purified water caused by a contaminant such as bacteria penetrating from a purified water outlet in a water passing stop state by arranging a fiber layer to which an antibacterial agent containing antibacterial metal ions is held on the end surface of the purified water outlet of a water purifying membrane module obtained by housing hollow yarn membranes in a cylindrical case. CONSTITUTION: The membrane module of a water purifier is constituted by fixing the ends of bundles consisting of hollow yarn membranes 1 with a potting agent such as a polyurethane resin to house the bundles in a cylindrical case to fix them. In this case, a fiber layer 3 having an antibacterial agent containing antibacterial metal ions, pref., zeolite having silver ions supported and held thereon is arranged to the end surface of the purified water outlet of the membrane module. The fiber layer 3 having the antibacterial agent held thereon may be arranged when or after the membrane module is formed and is pref. attached to the membrane module in a freely detachable manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane module for preventing reverse pollution in water purification equipment.

[0002]

[Prior art]

Conventionally, hollow fiber membranes in the form of membrane modules have been widely used in water purification equipment such as household water purifiers, industrial wash water production apparatuses, water purification apparatuses, and filtration apparatuses.
The membrane module focuses the hollow fiber membrane and fixes the converging end with a potting agent such as polyurethane resin so as not to block the open end of the hollow fiber, thereby airtightly partitioning the hollow portion of the hollow fiber membrane and It is formed by being housed and fixed in a circular case, and is used by being mounted in a case arranged according to the intended use of the water purification device.

The membrane module has a function of obtaining purified water by passing only water through the fine pores of the hollow fiber membrane to remove bacteria and fine particles contained in the raw water when the raw water is flowing. There is. However, in the stopped state of water flow where the membrane module does not exhibit its function,
There is a risk of reverse contamination by contaminants such as bacteria invading and propagating from the purified water outlet into the purified water that stays near the purified water outlet of the membrane module in the released state.

Therefore, there is a possibility that purified water that is reversely contaminated will be mixed in the purified water when water is restarted to the membrane module, and the accumulated water is sufficiently removed when the membrane module is used again. It is necessary to discharge the new purified water as waste water.

[0006] In order to prevent reverse contamination of the membrane module when the water flow is stopped, it is proposed that the surface of the water channel of the mounting case on the downstream side of the membrane module be subjected to antibacterial treatment (Japanese Patent Laid-Open No. 3-2.
No. 62593 and Japanese Patent Laid-Open No. 6-7617). However, when an antibacterial treatment is applied to the wearing case, the effect is initially obtained, but the effect is reduced due to repeated use over a long period of time, and when a large amount of antibacterial agent is added in anticipation of a decrease in effect, dissolution occurs, There is a problem with the safety of beverages or water used for washing.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reverse pollution prevention membrane module for preventing reverse pollution of purified water due to contaminants such as bacteria that enter from the purified water outlet when the water flow to the membrane module is stopped. To do.

[0008]

According to the present invention, an antibacterial agent containing an antibacterial metal ion is held on the purified water outlet end face of a water purification membrane module constructed by housing a hollow fiber membrane in a cylindrical case. The reverse pollution prevention membrane module is characterized in that a fiber layer is arranged.

Examples of the hollow fiber membrane used in the membrane module of the present invention include hollow fiber membranes made of materials such as cellulosics, polyolefins, polysulfones, polyvinyl alcohols and pomethylmethacrylates.
These hollow fiber membranes may be hydrophilized.

In the membrane module of the present invention, a hollow fiber membrane is obtained by any known method, and the hollow fiber membrane is fixed with a potting agent so that the focusing end of the hollow fiber membrane does not block the open end of the hollow fiber membrane. As long as the hollow part is airtightly partitioned and is housed and fixed in the cylindrical case, its size and shape may be arbitrary. Further, the tubular case may be filled with activated carbon.

In the present invention, it is necessary to dispose a fiber layer holding an antibacterial agent containing antibacterial metal ions on the end face of the purified water outlet of the membrane module. The fiber layer holding the antibacterial agent containing antibacterial metal ions is disposed at the purified water outlet end of the membrane module in a state of conforming to the surface shape of the outlet surface, and preferably the purified water outlet surface in the case of the membrane module. Alternatively, it is arranged on the purified water outlet surface of the case of the membrane module.

The fiber layer holding the antibacterial agent containing antibacterial metal ions may be installed and arranged at the time of forming the membrane module, or may be installed and arranged after the formation of the membrane module. It is preferable to attach it to the membrane module and dismount it so that only the fiber layer can be exchanged or it can be applied to an existing membrane module.

When the hollow fiber membrane is fixed at one end, the fiber layer holding the antibacterial agent containing the antibacterial metal ion is arranged at one of the purified water outlet ends, and the hollow fiber membrane is at both ends. If it is fixed at, it is preferable to place it at both purified water outlet ends, and if a plurality of membrane modules are coupled, it may be placed at the purified water outlet end of each membrane module, It may be placed at the purified water outlet end of the final membrane module.

In the present invention, the fiber layer arranged on the end face of the purified water has an antibacterial metal in which an antibacterial metal ion such as silver, copper or zinc is carried on an inorganic material, preferably silver ion is carried on a zeolite. An antibacterial agent containing 0.1 to 50% by weight of ions is composed of fibers such as synthetic fibers such as polyester fibers, polypropylene fibers, polyamide fibers, and fibers such as cellulose fibers, ceramic fibers, and glass fibers.

The antibacterial agent containing an antibacterial metal ion may be retained on the fiber by a kneading method added at the time of spinning the synthetic fiber, but preferably by a post-processing method in which the fiber is fixed with a binder such as polyurethane. Be seen.
The post-processing method is a preferable method since it can be applied after the fibers are formed into a layered form, the layer form can be maintained, and the post-processing can be performed after shaping into the arrangement shape. Use a binder that is safe and does not elute.

The amount of the antibacterial agent containing antibacterial metal ions contained in the fiber may be any amount as long as the antibacterial effect is exerted during the mounting period of the membrane module, since the membrane module is replaced after the lapse of a predetermined use period, Depending on the content of the antibacterial metal ion in the antibacterial agent, the antibacterial agent is held at 5 to 100% by weight.

The form of the fiber layer includes the thickness of the constituent fibers,
There is no particular limitation on the length and the like, as long as it does not cause a pressure loss when water is passed through the membrane module, and it may be a sheet material such as a web, a woven fabric, a knitted fabric or a nonwoven fabric. It is preferably used.

[0018]

The anti-contamination membrane module of the present invention has the antibacterial fiber layer disposed on the purified water outlet surface of the tubular membrane module, so that the purified water passes through the antibacterial fiber layer during water passage. The purified water becomes stagnant water when it stops flowing and is not used.However, the antibacterial fiber layer on the outlet side of the purified water blocks the ingress of contaminants such as bacteria and reversely contaminates the stagnant purified water. Is prevented.

[0019]

EXAMPLES Hereinafter, the present invention will be described by way of examples. FIG. 1 is a schematic cross-sectional view of a reverse pollution preventing membrane module in which an antibacterial fiber layer is arranged on the purified water outlet surface in the case of the membrane module. FIG. 2 shows a schematic cross-sectional view of a reverse pollution prevention membrane module in which an antibacterial fiber layer is arranged on the purified water outlet surface of the case of the membrane module. In the figure, 1 is a hollow fiber membrane, 2 is a potting agent fixing part, 3 is an antibacterial fiber layer, 4 is an activated carbon filled layer,
5 represents a cylindrical case.

In the following examples, the antibacterial fiber layer was arranged on the membrane module as shown in FIG. The disposed antibacterial fiber layer has a thickness of 5.5 mm and a basis weight of 240 g, which is made of polyester fiber having a thickness of 15 denier and a fiber length of 51 mm.
An antibacterial non-woven fabric obtained by fixing 30% by weight of Zeomic (zeolite containing 2.5% by weight of silver ion manufactured by Shinagawa Fuel Co., Ltd.) to a non-woven fabric of / m ² by a polyurethane resin by post-processing was used.

Three membrane modules with antibacterial non-woven fabric and three membrane modules without antibacterial non-woven fabric were prepared. For the membrane module with antibacterial non-woven fabric and the membrane module without anti-bacterial non-woven fabric, the number of E. coli bacteria was 2.4 x 1
Add 1 ml of the bacterial solution adjusted to 0 ⁴ cells / ml to the purified water outlet end surface of each membrane module (antibacterial nonwoven surface for membrane modules with antibacterial nonwoven fabric, potting agent fixing part surface for membrane modules without antibacterial nonwoven fabric) Then, after leaving it in a constant temperature bath at 30 ° C. for 24 hours, using Nagoya city water as raw water, water was passed through each membrane module to collect 30 ml of the first flow of purified water, and the viable cell count was measured.

Also, for each of the remaining other membrane modules, 1 ml of the same bacterial solution as above was added to the purified water outlet end face of each membrane module after passing 4 m ^{3 of} raw water and 8 m ^{3 of} raw water. After being left to stand for 24 hours, water was passed through each membrane module, and 30 ml of the first flow of purified water was sampled to measure the viable cell count. The results of the above antibacterial test are shown in Table 1.

[0023]

[Table 1]

Even when the bacteria are positively attached to the membrane module to contaminate the membrane module as described above, the membrane module having the antibacterial nonwoven fabric has a very high antibacterial effect. In addition, the invasion of bacteria from the outside can be effectively prevented.

[0025]

INDUSTRIAL APPLICABILITY The reverse pollution prevention membrane module of the present invention prevents reverse contamination of purified water that remains by contaminants such as bacteria that enter from the purified water outlet in a water flow stopped state, and restarts water passage. It is possible to obtain purified water without pollution immediately, and since the antibacterial fiber layer is exchanged at the same time when the membrane module is replaced, it is possible to obtain purified water that always exhibits an antibacterial effect and is free of pollution. It is possible.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an example of a reverse pollution prevention membrane module of the present invention.

FIG. 2 is a schematic cross-sectional view of another example of the reverse pollution prevention membrane module of the present invention.

[Explanation of symbols]

 1 Hollow fiber membrane 2 Potting agent fixing part 3 Antibacterial fiber layer 4 Activated carbon filling layer 5 Cylindrical case

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area C02F 1/50 F 540 F 550 H 560 EB

Claims (2)

[Claims] 1. A fiber layer holding an antibacterial agent containing an antibacterial metal ion is disposed on the purified water outlet end face of a water purifying membrane module constructed by housing a hollow fiber membrane in a cylindrical case. Characteristic reverse pollution prevention membrane module. 2. The reverse pollution prevention membrane module according to claim 1, wherein a fiber layer holding an antibacterial agent containing an antibacterial metal ion is detachably arranged.