JPH0760264A - Pparatus and method for purification of water - Google Patents

Abstract

PURPOSE:To improve circulation and purification properties of pool water by installing a rotating drum type solid-liq. separation apparatus wherein a filter material of which a base material made of woven fabric or knit fabric is made piled and pile of ultrafine fiber is laid to cover the surface of the base material is mounted, on the upstream side and an oxidation apparatus on the downstream side. CONSTITUTION:A filter material wherein pile of ultrafine fiber with a thickness of about 0.1-10mum formed by making a base material piled is laid in one direction on the surface of the base material consisting of woven fabric or knit fabric is mounted on a cylindrical filter drum 4. A raw water such as a pool water is continuously fed into the inside of the cylindrical filter drum 4 under rotating condition through a pipeline and it is filtered when it passes through the filter drum 4. The solid substance separated from the raw water and attached on the inner wall of a filter drum 4 is washed reversely with a part of filtrate water sent to a nozzle 8 by means of a circulation pump 7 and the back washing water is discharged out of the system through a discharging pipeline 9. Purified water is sent to an oxidation apparatus 2 mounted with an ultraviolet lamp 10, wherein water-soluble impurities remaining in the water are removed by decomposition and sterilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pool, a cooling tower, circulating water for industrial use, recycled water of a building's tap water, etc., for purifying water containing water-soluble impurities in addition to solid matters. An apparatus and a purification method. In particular, it is suitable for circulation purification of pool water for swimming, which is highly contaminated by water-soluble impurities.

[0002]

2. Description of the Related Art For many years, most of the purification of water, that is, water treatment has been carried out mainly by a sand filter, a sedimentation device, chlorine addition and the like. Recently, with the deterioration of water quality and the diversification of its causes, and with the recycle use of water, the development of water purification equipment has been promoted, and filtration equipment using biological membranes and biological treatment have been developed. Came to be used. But,
These water purification devices are not all-purpose. As the types of substances in the water to be removed increase, the properties and morphology become uneven, and the targets to be purified become complicated, the unit process is no longer able to handle it. For this reason, recently, it has become important to appropriately combine and use various devices based on the conditions of water to be purified. A typical example of water whose target to be purified is complicated is a swimming pool. Conventionally, in swimming pools, pool water is circulated for sand filtration and disinfection with chlorine or chlorine dioxide, and if necessary, chlorine is used together with ozone or ultraviolet treatment to purify water.

[0003]

By the way, the conventional water purification method has the following problems when the pool water is taken as an example. (1) If a filter is used as the main body of purification, water-soluble impurities accumulate and potassium permanganate consumption increases. A large amount of new water is needed to suppress this. (2) Even if ultraviolet rays are irradiated to promote the purification of water, the lamp surface is easily soiled and frequent cleaning is required. (3) The amount of residual chlorine changes greatly with each measurement and is not stable. (4) The fluctuation of pH is large, and when a pH adjusting agent is added, the residual chlorine concentration, turbidity, etc. change and it is difficult to control. (5) When the number of swimmers increases, turbidity and white turbidity are significant and it is difficult to remove. (6) An unpleasant odor is generated by water treatment. In addition to these, there were problems such as pool wall dirt, equipment corrosion, and ventilation. Not only swimming pools, but also cooling tower water, industrial water, tap water in buildings, etc., had similar problems. The water purifying apparatus and the water purifying method of the present invention have been completed to solve the above problems.

[0004]

In order to solve the above-mentioned problems, the present invention is based on the fact that a woven or knitted base material is napped on the upstream side and napped fibers of ultrafine fibers having a thickness of 0.1 to 10 μm lie on the upstream side. Provided is a rotary drum type solid-liquid separation device equipped with a filter material covering the surface of a material, and an oxidizing device equipped with an ultraviolet lamp on the downstream side. . In this water purification device, the above-mentioned problems can be more sufficiently solved by providing a hollow fiber membrane filtration device further downstream of the oxidation device or between the rotary drum type solid-liquid separation device and the oxidation device. It can be a water purification device. These water purification devices can be preferably used as pool purification devices.

Further, the present invention provides a filter material obtained by first fluffing raw water into a woven or knitted base material and laying naps of ultrafine fibers having a thickness of 0.1 to 10 μm to cover the surface of the base material. A method for purifying water, characterized by irradiating filtered water with ultraviolet rays to purify the filtered water after filtering with a mounted rotary drum type solid-liquid separator. In the present invention, raw water is filtered by the rotary drum type solid-liquid separator to obtain primary filtered water,
After filtering a part or all of the primary filtered water with a hollow fiber membrane filtration device to obtain secondary filtered water, the remaining primary filtered water and the secondary filtered water are irradiated with ultraviolet rays to make the water highly advanced. Can be purified. The filtration with the hollow fiber membrane filtration device may be carried out on a part or the whole amount of the obtained water after irradiating the primary filtered water with ultraviolet rays. In addition, water can be purified more completely by adding an appropriate oxidizing agent to the water to be irradiated with ultraviolet rays. The above water purification method can be preferably used as a pool purification method.

[0006]

OPERATION AND EXAMPLE OF THE INVENTION The present invention is a combination of a rotary drum type solid-liquid separation device equipped with a special filter material and provided on the upstream side, and an oxidizing device provided on the downstream side using an ultraviolet lamp. The purifying device and the method for purifying water using such a device are basic techniques. Regarding the present invention,
An embodiment will be described with reference to the drawings. Figure 1
It is a schematic flow sheet showing an embodiment example in which the present invention is applied to a swimming pool, and is also an embodiment example of an apparatus for carrying out the water purification method of the present invention.

The rotary drum type solid-liquid separation device 1 provided on the upstream side is equipped with a special filter material and has a function of separating biological slime and small solids contained in water. For example, Japanese Patent Publication No. 4-1647 and Japanese Patent Publication No. 4-908.
The filter cloth and device described in Japanese Patent No. 1 correspond to this. Furthermore, it is possible to prevent the surface of the ultraviolet lamp 10 mounted on the oxidation device 2 provided on the downstream side from being soiled and to exert a great effect of sustaining the effect of ultraviolet irradiation.

An example of the rotary drum type solid-liquid separation device 1 used in the present invention will be described with reference to FIG. 1. First, the inside of a cylindrical filtration drum 4 having a filter medium attached thereto and rotating,
Raw water such as pool water is continuously fed through the pipe 5. Then, the fed raw water passes through the filtration drum 4 and reaches the receiving tank 6 by the differential pressure Δp between the liquid surface in the filtering drum 4 and the filtered liquid surface in the receiving tank 6 lower than this, and is filtered. . The solid matter separated from the raw water and attached to the inner wall of the filtration drum 4 is backwashed with a part of the filtered water sent to the nozzle 8 by the circulation pump 7, and discharged through the drainage pipe 9 to the outside of the system.

In the present invention, the filter material mounted on the rotary drum type solid-liquid separation device 1 is important. In this filter material, naps of ultrafine fibers having a thickness of 0.1 to 10 μm formed by raising the base are laid in one direction on the surface of the base made of a woven or knitted fabric, and the naps of the filtration layer are formed. It works. Lying means not standing upright or lying down. As the woven or knitted material to be the filtering material, usually, a fine fiber made of synthetic fiber such as polyamide, polyester, polyolefin, polyvinyl alcohol, polyfluoroethylene, polyacrylonitrile having a thickness of 0.1 to 10 μm is used. To do. The type of weaving or knitting is not particularly limited, but a satin woven fabric is preferable for the woven fabric, and a half-knit tricot fabric is preferable because it is easily raised. The ultrafine fibers having a thickness of 0.1 μm or less have insufficient strength, and the fibers having a thickness of 10 μm or more are liable to stand upright after being raised, and it is difficult to form a good filtration layer. As a raising method, a conventionally known means may be used. By using this filter material, it is possible to easily separate fine solid components of 5 to 10 μm which could not be separated by sand filtration in the past. Further, by using this filtering material, the rotary drum type solid-liquid separator 1 can be efficiently attached to a cooling tower or the like to efficiently separate agar-like biological slime, which has been a problem in the past. Moreover, even when such a filtered material is separated, this filter material is different from the conventional filter cloth in that the filtered material is easily peeled off from the surface, backwashing is easy, and clogging is not caused for a long time.

In the present invention, the oxidizer 2 equipped with the ultraviolet lamp 10 which is provided downstream of the rotary drum type solid-liquid separator 1 cannot be separated by the rotary drum type solid-liquid separator 1 and is submerged in water. It has an action of decomposing and removing the remaining water-soluble impurities and a bactericidal action. The type of ultraviolet lamp used and its capacity are selected depending on the state of the raw water, but the wavelength is preferably 184.9 mμ or 253.7 mμ. When used to purify swimming pool water for swimming, the irradiation dose should generally be about 1 W / person / day. There is no need for a special oxidizing tank, for example, a device in which an ultraviolet lamp is immersed in an open storage tank,
A device in which an ultraviolet lamp is immersed in a closed cylindrical reaction tube can be used. Water purified by being irradiated with ultraviolet rays is returned to the pool via the return pipe 11. In the swimming pool, chlorine is supplied from the chlorine supply device 12 in order to maintain the chlorine concentration in the pool water at a specified amount.

Depending on the conditions of the raw water to be purified,
A hollow fiber membrane filtration device is installed between the rotating drum type solid-liquid separation device and the oxidation device, and some or all of the filtered water (primary filtered water) of the rotating drum type solid-liquid separation device is filtered to leave a fine residue. After the particles are separated by filtration, the filtered water (secondary filtered water) and the rest of the primary filtered water are sent to an oxidizer and irradiated with ultraviolet rays, whereby highly purified water can be obtained. A hollow fiber membrane filtering device may be provided on the downstream side of the oxidizing device, and a part or the whole amount of the water discharged from the oxidizing device may be filtered with this. The hollow fiber membrane to be used is, for example, JP-A-61 / 1986.
The hollow fiber of the polysulfone-based resin porous membrane described in JP-A-238834 is suitable because of its high mechanical strength and excellent resistance to clogging and contamination. The one described in the specification attached to the -270581 application is compact and convenient.

In the embodiment shown in FIG. 1, the hollow fiber membrane filtration device 3 is provided on the downstream side of the oxidizing device 2, and a part of the treated water treated by the oxidizing device 2 is pumped through a pipe 13 using a pump 14 It has been fed into the membrane filter 3. The water filtered by the hollow fiber membrane filtering device 3 is sent to the backwash water tank 16 through the pipe 15. The water that overflows from the backwash water tank 16 is mixed with the water that has been irradiated with ultraviolet rays, and is circulated to the pool via the reflux pipe 11. Each of 17 is a pipe used for backwashing the hollow fiber membrane filtration device 3. The backwash water is discharged from the drainage pipe 18.

In carrying out the method for purifying water according to the present invention, an oxidizing agent may be added to raw water or filtered water before irradiation with ultraviolet rays. The added oxidizing agent has a function of greatly increasing the effect of ultraviolet irradiation. As the oxidizing agent, sodium hypochlorite, calcium hypochlorite, hydrogen peroxide, ozone, chlorine and the like can be used. The amount used is required to be more than the amount that can theoretically decompose water-soluble impurities in raw water.

[0014]

EXAMPLES AND COMPARATIVE EXAMPLES Next, the present invention was applied to the purification of pool water for swimming, and the results will be described.

Examples and Comparative Examples The water purifying apparatus of the present invention was installed in a hot water pool and operated, and the effect of the present invention was confirmed by comparison with a conventional purifying apparatus. The volume of the warm water pool used was 275 m ³ ,
Conventionally, 900 m ³ of pool water was sand filtered per day, and chlorine was injected to circulate it. The water purification apparatus of the present invention was installed in parallel with the conventional purification apparatus for this pool. On the upstream side, a rotary drum type solid-liquid separator (“Trelom” R
D-750-A3 type: manufactured by Toray Industries, Inc. is attached, and the filter material is made of polyester fiber having a thickness of 10 μm.
A woven fabric in which the bundled warp is used as the warp, and about 2000 microfibers of polyester with a thickness of about 2.4 μm are used as the weft is manufactured by raising the weft mainly with a raising machine. A napped satin fabric having a number of naps of about 1000 / mm was attached. Further, a 110 W ultraviolet lamp (ST-110NF type: manufactured by Sen Special Light Source Co., Ltd.) was mounted on the downstream side of 0.7 x 0.95 x (depth) 1.3 m and a capacity of 0.
A 78 m ³ oxidation tank was provided. UV irradiation thickness is 350
mm. The effect of the present invention was confirmed by circulating 900 m ³ of pool water per day and injecting chlorine into the purifying apparatus of the present invention as in the conventional case. An example of the relationship between the swimming population measured at this time and the residual chlorine and potassium permanganate consumption is shown in FIG. In addition to the results shown in FIG. 2, when the present invention was carried out, the conventional peculiar odor of the pool disappeared. On the other hand, as a comparative example, under the same conditions,
FIG. 3 shows a state in which conventional sand filtration was performed and chlorine was injected to circulate. The downflow pressure type sand filter used for comparison was a closed cylindrical type having a diameter of 2.4 m and a height of 2.5 m, and an effective filtration area of 4.5 m ² . The amount of residual chlorine is based on the notification of the Ministry of Health and Welfare (May 25, 1978), and consumption of potassium permanganate (abbreviated as KM consumption in the figure)
Was measured in accordance with water supply test method 12 (Japan Waterworks Association).

Comparing the results of these two examples, in the example, the residual chlorine concentration is stable at a high concentration, but in the comparative example, chlorine is rapidly consumed and decreased. In the comparative example, it is considered that the nitrogen compounds brought in by the increase in the number of swimmers accumulate and react with chlorine, and partly produces chloramine, which is a source of odor. In the examples, the nitrogen compound is decomposed into nitrogen or the like, reacts with chlorine or is less adsorbed, so that residual chlorine is stable, and
Since the water-soluble organic matter is also decomposed, it is considered that the consumption amount of potassium permanganate is stable at a low value.

[0017]

By using the water purifying apparatus and the water purifying method of the present invention, the water-soluble organic matter is decomposed by the irradiation of ultraviolet rays and the consumption amount of potassium permanganate is suppressed to a low value. Therefore, in the swimming pool, it is not necessary to exchange a large amount of water, and water can be saved. on the other hand,
The UV irradiation lamp uses a high-performance rotary drum type solid-liquid separator installed upstream of the lamp to remove biological slums and fine particles that tend to adhere to the lamp surface. Can be irradiated. The content of water-soluble organic matter is large, and in swimming pools that require chlorine injection, the water-soluble organic matter can be kept low, so the residual chlorine concentration is stable, and the nitrogen compounds in the water-soluble organic matter are fast. As it is decomposed, the production of chloramine, which is the cause of malodor, is suppressed.
When a hollow fiber membrane filtering device is further arranged in the present invention, the colloid component can be removed without adding a coagulant, and fine particles of 1 μm or less can be removed, and a coagulant caused by the coagulant is generated. Since it disappears, it is effective in preventing the occurrence of turbidity or white turbidity. By disposing the hollow fiber membrane filtering device on the upstream side of the oxidizing device, the contamination of the ultraviolet lamp can be further reduced. Therefore, the water purifying apparatus and the water purifying method of the present invention are intended to purify pool water for swimming, cooling tower water, industrial water, etc. which are exclusively used for circulation, and recycled water used for tap water such as buildings and condominiums. It is suitable for purification.

[Brief description of drawings]

FIG. 1 is a schematic flow sheet showing an embodiment example in which the present invention is applied to a swimming pool.

FIG. 2 is a graph showing fluctuations in water quality when the present invention is carried out in a warm water pool.

FIG. 3 is a graph showing changes in conventional water quality of a warm water pool.

[Explanation of symbols]

1: Rotating drum type solid-liquid separation device 2: Oxidation device 3: Hollow fiber membrane filtration device 4: Filtration drum 5: Raw water pipe 6: Receiving tank 7: Circulation pump 8: Nozzle 9: Drainage pipe 1
0: UV lamp 11: Reflux pipe 12: Chlorine supply device 13: Pipe 14: Pump 15: Pipe 16: Backwash water tank 17: Backwash pipe
18: Drainage pipe

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C02F 9/00 N 7446-4D R 7446-4D 503 A 7446-4D 504 B 7446-4D E04H 4 / 12

Claims (9)

[Claims] 1. A rotary drum type in which a base material of a woven or knitted fabric is napped on the upstream side, and a napped fiber of ultrafine fibers having a thickness of 0.1 to 10 μm lies down and covers the surface of the base material. A water purification device, wherein a solid-liquid separation device is provided on the downstream side with an oxidizer equipped with an ultraviolet lamp. 2. The water purifying device according to claim 1, further comprising a hollow fiber membrane filtering device provided on the further downstream side of the oxidizing device. 3. The water purification apparatus according to claim 1, further comprising a hollow fiber membrane filtration device provided between the rotary drum type solid-liquid separation device and the oxidation device. 4. A pool purification apparatus using the water purification apparatus according to claim 1, 2, or 3. 5. A rotary drum equipped with a filter medium, wherein raw water is first raised on a base material of a woven or knitted fabric, and standing fibers of ultrafine fibers having a thickness of 0.1 to 10 μm lie down to cover the surface of the base material. A method for purifying water, characterized by obtaining filtered water by irradiating filtered water with ultraviolet rays after filtering with a solid-liquid separation device. 6. Raw water is filtered by the rotary drum type solid-liquid separator according to claim 5 to obtain primary filtered water, and a part or all of the primary filtered water is filtered by a hollow fiber membrane filtering device to obtain secondary water. A method for purifying water, which comprises obtaining purified water by irradiating the remaining primary filtered water and the secondary filtered water with ultraviolet rays after making the filtered water. 7. A method for purifying water, characterized in that a part or all of the water obtained by the method according to claim 5 is further filtered by a hollow fiber membrane filtration device to obtain purified water. 8. In any step before irradiation with ultraviolet rays,
The method for purifying water according to claim 5, 6 or 7, wherein an oxidizing agent is added to the water to be purified. 9. A pool purification method using the water purification method according to claim 5, 6, 7, or 8.