JPH02303587A - Device and method for cleaning water - Google Patents

Abstract

PURPOSE:To effectively remove harmful low boiling halogen compds., etc., and to facilitate maintenance and control by passing the water to be treated to one side of a hydrophobic hollow yarn membrane having the oxygen permeation rate of a specific numerical value or above and reducing the pressure on the other side by a vacuum pump. CONSTITUTION:The membrane is the hydrophobic hollow yarn membrane and is required to have >=1X10<-5> [cm<3>(STP)/cm<2>, sec, cmHg] oxygen permeation rate at about 25 deg.C. Further, the membrane type is preferably a heterogeneous membrane or composite membrane having >=1.0 sepn. coefft. of oxygen/nitrogen or a porous membrane of an open cell type having i1.0 [kg/cm<2>G] bubble point. The water to be treated is passed to one side of the hollow yarn membrane of a membrane module 1 formed by assembling this hollow yarn membrane into a housing and the pressure on the other side is reduced by the vacuum pump 2 to remove the harmful low boiling halogen compds., etc., from the water to the outside of the system of the membrane module 1. The treated water is thus obtd. The way of passing the water to the membrane module may be either of internal reflux or external reflux.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a water purification device and a deodorization device for clean water used for drinking and eating, and in particular to a device for eliminating volatile halogen compounds, chlorine odor, and mold contained in water. The present invention relates to a device and method for removing odor-causing substances. The present invention relates to a diaphragm vacuum deaeration type deodorizing water purification device.The present invention is suitable for use in deodorizing and purifying tap water, for example, for household use, the restaurant industry, and the food manufacturing industry.

[Conventional technology]

In recent years, due to the concentration of population in cities and the increase in wastewater, eutrophication of rivers and lakes has progressed, and the quality of raw water for drinking water has deteriorated. On the other hand, people's eating habits have become richer and richer, as is said to be the era of gourmet food, and there has been an increasing demand for delicious drinking water.On the other hand, the addition of chlorine to tap water As the amount of water increases, the increase in trihalomethanes, which are said to be carcinogenic, and the contamination of groundwater by trichlorethylene and other low-boiling halogen compounds have become social problems, and there is a strong demand for ``water that is safe to drink.''

Against this background, the popularity of water purification devices for home use and restaurants has been remarkable, but all of these water purification devices currently on the market are either adsorption types using activated carbon, or nine types that combine adsorption and filtration. It is. Although these types are mainly used to remove odors, they are inferior in their ability to remove low-boiling point compounds such as trihalomethane and trichloroethylene. Furthermore, even if larger-scale equipment is included, the reality is that there is no known effective method for removing low-boiling point (volatile) compounds that exist in tap water.

From a deodorizing perspective, the lifespan of the adsorbent in these water purification devices is short, and the deodorizing effect disappears after a month, and the adsorbent needs to be replaced frequently, making maintenance and management time-consuming. It has the disadvantage of being expensive to maintain and maintain, and its ability to remove tasteless and odorless harmful substances decreases without you noticing, and there is a danger that you may continue to ingest them. .

[Problem to be solved by the invention]

The developed fJA has an excellent removal effect on low-boiling halogen compounds harmful to health such as trihalomethane contained in 1 ct of tap water, and is easy to maintain and has low maintenance costs. The present invention aims to provide a water purification device and a water purification method based on the method.

[Means to solve the problem]

In the present invention, the tR elementary permeation rate is 0-'[cm'/C1
It consists of a membrane module incorporating a hydrophobic hollow fiber membrane with a diameter of 1l" gm @e + ydig) or more into a housing, and a vacuum ring, and the water to be treated is placed on one side of the hollow fiber membrane. This is a deodorizing water purification device that uses a vacuum pump to reduce the pressure on the other side.

- The module is an internal four-flow type that flows the feed water to be treated inside the hollow fiber membrane and reduces the pressure in the space between the outside of the hollow fiber and the housing, and the inner diameter of the hollow fiber is 20 to 350 μm. The deodorizing water purification device is equipped with a membrane module and a membrane module.
Hollow fiber membranes to be incorporated are connected to each other (i9) to other yarns (K)
Therefore, it is incorporated into the housing in the state of a stack or convergence of organized sheet-like materials, or in the state of a three-dimensional braided body organized by hollow fiber membranes or with other threads, and the outside of the hollow fiber membrane is It is a deodorizing water purification device characterized by an external FI flow chamber that flows the feed water to be treated through the leap space of the hollow fiber membrane and reduces the pressure inside the hollow fiber membrane. A deodorizing water purification device characterized by having certain characteristics, and a deodorizing water purification device characterized by a specific combination of type 81 of vacuum pumps and hollow fiber membrane types and characteristics, and , oxygen permeation rate is lX
l0-5(i/i.

In a membrane module in which a hydrophobic hollow fiber membrane of 1.e, mHg or higher is incorporated into a housing, the water to be treated with IIK is passed through one of the hollow fiber membranes, and the pressure is reduced using a vacuum pump on the other side. The present invention is a method for removing low-boiling point halogen compounds or substances that cause malodors such as chlorine odor and slight odor from water to the outside of the membrane module system.

Discussing the main parts of the present invention in more detail, the membrane used in the present invention has an oxygen permeation rate, which is a representative value of gas permeation rate, at 25°C.
TP) 7 cm", soe s mHg) or more. If the object to be removed from water is a gas such as oxygen or carbon dioxide, the oxygen permeation rate of the membrane must be 1
0-' (alM”(STP)7m” r s@ewm
Although it is possible to remove at a practical level even if the amount is as low as 1X10-'
(yg” (5TP)/W” l I@e txHg
), the removal rate of low boiling point compounds and malodorous substances becomes impractically slow.

In the present invention, it is necessary that the material be hydrophobic.

If the membrane is hydrophilic, water will enter the membrane and the rate of removal of malodorous substances will be drastically reduced, and water will permeate through the membrane, rendering the diaphragm useless. That is, the membrane used in the present invention may partially contain a hydrophilic portion, but is a membrane through which only volatile substances can pass through without allowing water to pass therethrough in the form of a liquid. Examples of such materials include poly 4-methyl base/
Ten-1° polyolefins such as polyethylene and polyethylene, 7-wood polymers such as vinylidene litz, polytetra 70 ethylene, and PFA, polyacetal,
Illustrative examples include I-reathers and polythioethers such as ppo and pps, chlorine-containing polymers such as I-vinyl chloride, I-trichloropinyline, polyetheretherketone, polysulfone, I-reathersulfone, silicone resin, etc. Other copolymers may also be used.

Preferred membrane types for the present invention are firstly heterogeneous membranes or composite membranes having a separation coefficient of m/nitrogen of 10 or more. The separation coefficient of tR element/S1 element is the oxygen permeation rate divided by the nitrogen permeation rate. If the diaphragm is a porous membrane with open pores, the value of the al/nitrogen separation coefficient will be α935. An oxygen/nitrogen fraction factor of 10 or more means that a non-porous layer is present in the membrane. Porous membranes, cine homogeneous membranes, and composite membranes are superior to porous membranes in that water does not leak even after long-term use. Such films are disclosed in, for example, Japanese Patent Application Laid-open No. 59-196706 and Japanese Patent Laid-open No. 59-59209.
, JP-A-57-122906, JP-A-63-27443
It can be manufactured by the method described in 3. In the case of such a membrane with a non-porous layer, selective permeability may appear depending on the material, but it is possible to select and use a material that has good permeability to the target substance to be removed. In the present invention, a heterogeneous film made of I-4-methylinthene-1 exhibits excellent properties.

Another type of membrane preferred for the present invention is a continuous pore type porous membrane with a bubble point of 1.0 (kg/cm
"G:) The bubble point referred to here was measured according to ASTM F'-316 using low viscosity silicone oil with a surface tension of 17 to 19 dyn/cm as the wetting liquid. If the bubble point is less than 0 [an'G], water will easily penetrate into the pores even if the membrane material is hydrophobic and weak.

When the membrane is a porous membrane with open pores, the gas permeation rate of the membrane needs to be higher than that of a heterogeneous membrane or a composite membrane, and the gas permeation rate of the membrane must be higher than that of a heterogeneous membrane or a composite membrane. lol
see + txHg ] or more, such a membrane can be produced, for example, by methods described in Japanese Patent Publication No. 56-52123, Japanese Patent Publication No. 60-14844, Japanese Patent Application Laid-open No. 56-56202, and the like.

The membrane of the present invention has a hollow fiber shape. Compared to film-like membranes, hollow fiber membranes have the advantage of allowing a larger membrane area per device volume, allowing the device to be built into a shed. The dimensions of the hollow fiber in the present invention are determined when water is allowed to flow inside (inner layer fl
fli) IIC has an inner diameter of 20 to 350 μm, and
~200 μm is preferred.

20A! If it is less than 1, it will be difficult to manufacture, and if it exceeds 350 μm, the removal efficiency per membrane area will deteriorate significantly. In the present invention, when the module is an internal perfusion type,
The inner diameter of the hollow fiber is a factor greater than or equal to the permeation rate of the membrane, Kti', and the smaller the inner diameter of the hollow fiber, the lower the residual concentration of the substance to be removed.

In the case of flowing water outside the hollow fiber (external perfusion), the dimensions of the hollow fiber are not an important factor in the case of internal perfusion, but an outer diameter of 50 to 1000 is preferable, and if it is less than 50 μm, it will be difficult to manufacture. When the thickness exceeds 1000 μm, the volumetric efficiency deteriorates.

The hollow fiber membrane is used in the form of a housing (referred to as a module). In the case of usage in which water flows inside the hollow fiber (internal perfusion), the module shape is not particularly limited;
For example, a shape commonly used for artificial kidneys as shown in FIG. 2 can be used.

That is, raw water is introduced into the module via the water inlet (8),
It flows from the end face of the hollow fiber membrane sealed (6) with resin to the inside of the hollow fiber membrane (5) loaded in a bundle, and flows through the discharge port (9).
) is discharged as treated water. - 10,000, the space between the outside of the hollow fiber membrane and the) suction port (10)
Reduce the pressure (by vacuum 4 pump).

In the case of usage in which water flows outside the hollow fiber (external perfusion),
In order to prevent the removal efficiency from decreasing due to uneven water flow (channeling) caused by uneven filling of hollow fibers, etc.
The hollow fibers are in the state of a superimposed body or convergence body of foot-like structures organized by hollow fibers or with other threads, or in the state of a three-dimensional braided body organized by hollow fibers or with other threads. It is necessary to incorporate it into Haunong. Specific examples of this include, for example, Japanese Patent Application No. 63-255938,
Special 11111fi63-257364, Japanese Patent Publication No. 52-1
43974, etc. - An example is shown in FIG. The raw water introduced into the module through the water inlet (8) is braided in a straight manner as shown in Fig. 4, is laminated and filled, twists and flows over the outer surface of the nine hollow fibers (5), and flows through the outlet. (9)) It is discharged as treated water. On the other hand, the inside of the hollow fiber membrane is depressurized from the suction port (10) using a vacuum pump.

The principle of the water purifier of the present invention is that the water to be treated is depressurized through a membrane and brought into contact with the gas phase, thereby removing volatile malodorous substances and harmful substances contained in the water to the gas phase. The degree of pressure reduction at that time is preferably 60 Torr or less, more preferably 40 Tc1rr or less. In the present invention, a vacuum pump is used as the pressure reducing means. Generally speaking, as vacuum pumps, there are oil rotary vacuum pumps, piston pumps, water ring types, dry types, and 7-diameter pumps.
Any type can be used, but water-ring type vacuum ponder and gas palust pump (oil rotary vacuum I7 equipped with general KFi gas palust pulp) are suitable in terms of degree of pressure reduction, lifespan, water vapor resistance, etc. ing.

The water ring type vacuum d:/f cannot reduce the pressure to a high degree of vacuum, but it has nine advantages: it can suck in a large amount of water vapor, and it does not require periodic oil changes. This is suitable when a porous membrane with high water vapor permeability is used as the diaphragm. The water seal type vacuum 4/F removes harmful substances from the water and discharges them when the water seal drains, so they are not dispersed into the air. There is no need for exhaust gas cleaning, toggling, suction operations, etc. as in the case of using this oil rotary vacuum pump. In this way, the water ring type ponder is suitable as a vacuum ring for water purification equipment. In addition, the displacement is larger than that of an aspirator, making it suitable for water purification devices that can process water at a rate of 1 liter per minute or more.

According to theoretical considerations, when a water ring pump is used as a pressure reduction means and the water to be treated is diverted to the seal water, the volatile substances to be removed from the seal water also transfer to the gas phase. For,
It is presumed that there is no partial pressure difference between the front and back sides of the membrane, and that the substance does not permeate through the membrane and be removed. However, in reality, effective removal is unexpected and should be expected.

Gas ballast pumps have the disadvantage of requiring periodic oil changes, but they have the ability to reduce pressure to a high degree of vacuum, so they have a high removal effect, and they can withstand some water vapor inhalation.
If a heterogeneous membrane or a composite membrane with an oxygen/nitrogen partition coefficient of 10 or more is used as a diaphragm, these membranes have a low water vapor permeation rate, so even if the pressure is reduced to below the boiling point of water, a large amount of water vapor will be released. Water vapor does not pass through the pump, allowing the gas ballast pump to take full advantage of its features. Using an ordinary oil rotary vacuum I ring without gas ballast pulp (instead of a gas ballast pump) and providing a separate gas ballast pulp is simply separating the two, and this is also within the scope of the present invention. included.

The configuration of this water purification device is as shown in Fig. 741, and is made up of a membrane membrane (1) and a vacuum tube (2), and the water to be treated is passed through one side of the hollow fiber membrane. It is characterized by reducing the pressure on the other side using a vacuum pump. If necessary, install a shut pulp or flow rate adjustment pal 2 (3) on the water inlet side.
A pal f (4) can be provided at the #9 treated water outlet. The purified water outlet from the water purification device can be in the form of a faucet, hose, or other suitable form for use.

The target substances to be removed from water in the present invention are volatile hazardous substances, especially low-boiling halogen compounds. For example, chloroform, promonochloromethane, sogromochloromethane, bromoform, carbon tetrachloride, and! Examples include J/DH ethylene, tetrachloroethylene, and LLI-trihalomethane chloropicrin. Although suction cup water purifiers have poor removal efficiency for these substances, the present invention can effectively remove these substances.

Examples of malodor-causing substances that can be removed from water in the present invention include chlorine, ozone, 2-methylisoborneol, diosmin, amines, and ammonia. However, the objects to be removed are not limited to these known substances, but also include odor-causing substances whose names have not been identified. It is surprising that substances that can be removed, including those with boiling points higher than water, can be effectively removed by the apparatus of the present invention.

The present invention is based on the discovery that a diaphragm vacuum degassing type can have effective performance as a deodorizing water purification device, which until now has only been known as an adsorption type. Looking back, it seems to be well known that volatile substances such as low-boiling point compounds and odor-causing substances can be removed from water using a Ni6 type vacuum deaerator. It looks like. However, in order to remove malodorous substances to below the detection limit, it is necessary to remove the residual concentration to below the ppm order in many cases, and in some cases to the PPb order a degree.

Furthermore, in order to bring carcinogenic substances such as trihalomethane below regulatory limits, it is necessary to remove them to the order of D ppb. In the diaphragm vacuum degassing method known so far, apart from removing gas, it has not been possible to remove substances that are liquid at room temperature to extremely trace amounts of residual concentration below pp-order. However, it was not known that it could be used for such purposes. In addition, there is no known deodorizing device using a diaphragm vacuum degassing method (90) The present invention can extract low vapor pressure substances that are liquid at room temperature from water depending on the diaphragm, the configuration of the device, and other conditions. pp
The inventors completed the invention by discovering that it can be removed at mpp order or less and that it has a clear deodorizing effect.

〔effect〕

The water purification device of the present invention has excellent performance in deodorizing water, and has a high ability to remove malodorous substances and volatile harmful substances that tend to be mixed into tap water or underground water.

The present invention is capable of effectively removing harmful substances such as trihalomethane compared to adsorption water purification devices, and it is also possible to remove nine silver ions, which are added to the adsorbent to prevent bacterial growth, from dissolving. do not have. In addition, there is no danger that the removal ability of the adsorbent will decrease without you noticing, and you will continue to ingest tasteless and odorless harmful substances.In this way, the present invention is superior to conventional water purification devices in terms of safety. It is better than the next one.

The present invention has the advantage that it does not require frequent replacement of consumable parts such as adsorbent, and there is no cost for consumable parts, and there is no maintenance cost, compared to adsorption water purification devices.

Because of these features, the water purifier of the present invention is suitable as a water purifier for home use, restaurants, and the food industry.

〔Example〕

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples.

Example 1 Poly4-methylpentene-1 with melt index 26
Melt spinning was carried out at a spinning temperature of 290°C and a draft of 200 using
Heat treatment for 60 seconds, cold stretching at 25°C, draw ratio (DR) L2, hot stretching at 150°C, DR-L5, and 180°C,
Please heat set the DR-α9), outer diameter 252,
A hollow fiber membrane with an inner diameter of 200 mm was obtained. When this membrane was observed under a scanning electron microscope, both the inner and outer surfaces of the hollow fiber membrane had a diameter of about 0. Many I Itm pores were observed. mercury
The average pore diameter measured with a la simeter is α0811a
Met. When 701 ethanol (aqueous solution) was introduced into the inside of this membrane under α5 kli/ex"GO positive pressure, the ethanol permeated at a rate of 200 cxa"7 m", mi. From this, this exchange connects the inner and outer surfaces. Silicone oil (manufactured by PETRACHBYBTEMB, P8-03) was used as the ma liquid.
6. Surface tension 18 dyQ/3, viscosity L 5 dt)
Bubble point measured using (Mu8TM, F-3
16) was greater than 10 #/cs"G (measurement limit).

tiThe gas permeation rate of this membrane in the gas-gas system (Mu8TM
, F-316, by Dry method) is the oxygen permeation rate IE
(Qo2) &20 X 10-'(3I' (8T
P) 15I", I@@t5LH11;], nitrogen permeation rate (QN2) & 42 X 10-5 (same unit),
The acid lA/nitrogen separation factor was α936.

This membrane was assembled into a mole having an inner surface area of 12 m'' as shown in FIG. 2 to construct the water purification device shown in FIG.

However, pulp (4) is not provided.

As the vacuum pump/f, a water-pair vacuum pump (manufactured by Kobe Steel, 8
W25-8 shop, displacement 450 4/f! lim, vacuum degree of 32 Torr).

This water purification device was connected to the water supply system, and the system was operated so that the amount of water treated was 3 torr per minute. According to the color analysis method, the chlorine mix α7 pprm of raw water is about α3
It had decreased to PPII. Also, as raw water, 10
A sensory test of water treated at 3 liters per minute with distilled water to which ppt of 2-methylisoluneol was added showed that the ink odor of the raw water was hardly felt in the treated water.

Furthermore, nine tests were conducted using distilled water to which chloroform and tric aa ethane were added as raw water. When raw water and water treated at 3 s/min were measured using gas chromatography (Water Test Methods 1985 Edition, edited by Keiji Iwamoto, published by Japan Water Works Association, p. 482), riproform was found to be
A15ppm decreased to α03ppm, and tricloyl and ethylene decreased to α19ppm to α04ppm.

Example 2 As a hollow fiber membrane, 4 rig ipyrene porous genus (Irigkusnax Co., Ltd., X-10, pore size α2~α3xα4 tns
) was used, but the same water purification device as in Example 1 was manufactured, and the same tests as in Example 1 were conducted. The actual value of this film is
Outer diameter 268μm, inner diameter 207μm.

Pal f4 India λ5 kl/cs"G, gas permeation characteristics are QO2- & 77 X 10-'(3"(s'rp),
"ex"*see+mHg), the oxygen/nitrogen separation factor was α933. The hypochlorine odor that can be felt in the raw water is hardly felt in the treated water, and the results of DPD colorimetric analysis show that the chlorine concentration in the raw water has decreased from α7 ppm to approximately α4 ppm, and regarding 2-methylisoIluneol,
When the same test as in Example 1 was conducted, the nine ink ink odor that was felt in the raw water was almost not felt in the treated water. Furthermore, regarding chloroform and trichlorethylene,
The same test as in Example 1 was conducted, and chloroform was
α17 ppm decreased to α05 pprm, and α2 G ppmm of trichlorethylene decreased by α06 ppm K.

Example 3 Poly 4-methylpente/-1 with melt index 26
Melt spinning was performed using a spinning temperature of 290°C and a draft of 300, and the obtained hollow fiber intermediate was heat-treated at 210°C, drawing ratio (DR) Ll, treatment time 5 seconds, 25°C, DR.
A hollow fiber membrane having an outer diameter of 213 μm and an inner diameter of 167 μm was obtained by performing cold stretching of shoe L2, hot stretching of DR-140 at 150°C, and heat setting of DR-α9 at 180°C. When this membrane was subjected to a scanning electron microscope *St, many pores with a diameter of approximately α1 were observed on the inner surface of the hollow fiber membrane, but almost none were present on the outer surface. Although 70% ethanol (aqueous solution) was introduced into the inside of this membrane at a pressure of α5 #/cm"G, no permeation of ethanol was observed. From this, this membrane has pores that connect the inner and outer surfaces. In addition, the gas permeation rate of this membrane in a gas-gas system is oxygen permeation rate (QO2) L51X10-' (
clR'(137P)151", m @ em
ailg], nitrogen permeation rate (QN2) λ80X10-
5 (same unit), and the oxygen/nitrogen separation coefficient was 97.

This membrane was assembled into a module having an inner surface area of 13 m8 as shown in FIG. 2, and a water purification device similar to that of Example 1 was constructed, except that there was no water seal for the vacuum pump. Oil rotary vacuum pump with gas palust pulp as a vacuum pump (Shinku Kikou, GCD-135XA type, exhaust fit 135
4/m1 m, degree of vacuum L 5 Torr).

A test similar to that in Example 1 was conducted using this water purifier. Regarding chlorine, the DPD method reduces the concentration of chlorine to 0.7 ppm in raw water.
However, the chlorine odor felt in the raw water was not felt in the treated water. As for 2-methyliso〆reneol, the black ink odor that can be felt in the raw water is almost invisible in the treated water. Also,
For chloroform, α15 pprx becomes α02 ppm, and for trichlorethylene, 119 ppm becomes α03 ppm.
It had decreased to m.

Example 4 The same hollow fiber membrane as that used in Example 3 was used as shown in FIG. 4, using 30 denier polyester yarn as the warp.
An original sheet as shown in FIG. 4 was formed with a tangled weave, a hollow fiber density of 25/aR, and a warp density of 1/aR. This sheet has many holes with a diameter of 3m.
The module was layered and wound, loaded into a tube, and the ends were sealed with polyurethane resin to form the module shown in FIG. 3. The effective membrane area (hollow fiber outer surface area) of the module is &8m! Met. Using this module,
A water purification device was constructed as shown in Figure 1. However, there is no water seal for the vacuum pump, and the i9pal f(3) is not provided.

With this water purifier, the same test as in Example 1 was conducted except that the flow rate was adjusted using Pal f (4). As a result, the chlorine concentration was only reduced to 6 ppm from α7 ppm, but in the sensory test, almost no chlorine was felt. In addition, with regard to 2-methylingelneol K, the black ink odor that was felt in the raw water was hardly felt in the 6-ration water. In addition, chloroform (
α15 ppm) was removed to α02 ppmK, and ethylene (0.18 ppm) was removed to α03 ppm.

Brief explanation of the melon drawings Fig. 1 shows an embodiment of the present invention, and is a conceptual diagram showing the structure of a water purifier, and Fig. 2 shows an internal layer I51 used in the embodiment! m
FIG. 3 is a vertical cross-sectional front view of the external four-meteor group module used in the example.
FIG. 4 is a conceptual diagram of the shape of the hollow fiber sheet.

The symbols in the figure are as follows.

1... Membrane module, 2... Vacuum pump, 3...
/4 Lug, 4...Pulp, 5...Hollow fiber membrane, 6...
・Resin sealing part, 7... Housing, 8... Water supply port,
9... Treated water outlet, 10... Suction port, 11...
Porous mother Eve, 12...net.

13... Warp.

Agent: Patent Attorney Katsutoshi Takahashi Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] 1. Oxygen permeation rate is 1×10^-^5 [cm^3/cm]
It consists of a membrane module that incorporates a hydrophobic hollow fiber membrane in a housing with a hydrophobic hollow fiber membrane of ^2, sec, cmHg] or more, and a vacuum pump. A water purification device characterized by reducing the pressure using a vacuum pump. 2. The water purification device according to claim 1, which is a water deodorization device. 3. The membrane module is an internal perfusion type that flows the feed water to be treated inside the hollow fiber membrane and reduces the pressure in the space between the outside of the hollow fiber and the housing, and the inner diameter of the hollow fiber is 20 to 350 μm. The water purification device according to claim 1 or 2. 4. In the membrane module, the hollow fiber membranes to be incorporated are in the state of a stack or convergence of sheet-like materials organized by hollow fiber membranes or with other fibers, or by hollow fiber membranes or with other fibers. It is built into the housing in the form of an organized three-dimensional braided body, and is an external perfusion type in which the feed water to be treated flows through the space between the outside of the hollow fiber membrane and the housing, reducing the pressure inside the hollow fiber membrane. The water purification device according to claim 1 or 2. 5. The hollow fiber diaphragm has a bubble point of 1.0 [kg/
5. The water purification device according to claim 1, wherein the water purification device is a communicating pore type porous membrane having a diameter of 1 cm^2G] or more. 6. Claims 1 and 2, wherein the hollow fiber diaphragm is a heterogeneous membrane or a composite membrane having an oxygen/nitrogen separation coefficient of 1.0 or more.
3 or 4. The water purification device according to 4. 7. The water purification device according to claim 5 or 6, wherein the vacuum pump is a water ring vacuum pump. 8. The water purification device according to claim 6, wherein the vacuum pump is an oil rotary vacuum pump equipped with a gas ballast valve. 9. Oxygen permeation rate is 1 x 10^-^5 [cm^3/cm]
By flowing the water to be treated on one side of the hollow fiber membrane in a membrane module in which a hydrophobic hollow fiber membrane with a pressure of 2, cmHg or more is incorporated into the housing, and reducing the pressure on the other side with a vacuum pump, A water purification method that removes low-boiling point halogen compounds, chlorine odor, faint odor, and other odor-causing substances from water outside the membrane module system.