JPH05154470A - Membrane filter - Google Patents

Abstract

PURPOSE:To provide a membrane filter having a new compact treating system where an adsorbent is effectively and economically used and soluble and insoluble materials are removed with high efficiency and the conventional treating process is made an overall revision of. CONSTITUTION:A membrane filter 1 consists of a tank 3 into which raw water 2 introduced, an outer pressure type membrane module 14 immersed and arranged in the tank 3 and a mixing device by which an powder adsorbent, for example, activated carbon 6 introduced into the raw water 2 is agitated and mixed. Soluble materials are adsorbed and removed by the activated carbon 6 and insoluble materials, such as SS are filtered and removed by the membrane module 4 to get clear treated water.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is for filtering soluble and insoluble suspensions contained in liquids such as river water, well water, lake water, human waste, sewage, water, waste water and the like. The present invention relates to a membrane filtration device.

[0002]

2. Description of the Related Art It is common practice to use a powdery adsorbent (generally activated carbon) for the purpose of removing soluble substances. A general flow when using powdered coal can be shown in FIG. That is, the powdered coal and the raw water 2 are sufficiently mixed and brought into contact with each other in the activated carbon contact tank 25 to adsorb the soluble substance. The powdered coal is coagulated and precipitated in the downstream coagulation sedimentation tank 26 together with the insoluble substance in the raw water, that is, mainly SS content, and most of it is discharged from the lower part of the coagulation sedimentation tank 27 as sludge.

The fine activated carbon and SS components remaining in the coagulation-sedimentation-treated water 28 are removed by filtration in the next filtration tank 29.

[0004]

SUMMARY OF THE INVENTION In the conventional method,
The fine coal in the powdered activated carbon is not completely removed in the coagulation sedimentation tank, but flows into the filtration tank 29, hastening the clogging of the filtration tank and increasing the frequency of cleaning the filtration tank. In addition, the powdered activated carbon that has been charged often flows out of the contact tank 25 and is discharged as mud due to a short-circuit flow or the like while the adsorption capacity remains.
Therefore, not only the powdered activated carbon more than necessary for removing the soluble substances is added to increase the running cost of the powdered activated carbon itself, but also the increase in the amount of the sludge solids increases the load of the exhaust treatment 30 in the subsequent stage.

Therefore, an object of the present invention is to solve the above problems, to efficiently and economically utilize an adsorbent, to remove soluble and insoluble substances with high efficiency, and to eliminate the conventional treatment steps. It is an object of the present invention to provide a membrane filtration device having a novel and compact treatment system with an overall improvement.

[0006]

SUMMARY OF THE INVENTION The present invention comprises a tank into which water to be treated is introduced, an external pressure type membrane module disposed in the tank, and a powder adsorbent introduced into the water to be treated or into the tank. A membrane filtration device comprising a stirring device for stirring and mixing, which can solve the above problems. The principle of the present invention is to dispose an external pressure type membrane module in a tank and introduce a powder adsorbent into the tank so that a soluble and / or insoluble substance by the powder adsorbent (hereinafter, both substances are simply adsorbed substances). (2) and the filtration treatment of the insoluble substance mainly composed of SS by the membrane of the membrane module in a single tank in parallel. Clear treated water from which soluble substances have been removed is obtained, and there is no waste because the powder adsorbent does not move between steps as in the past.
In addition, it can be used until the adsorption capacity becomes saturated.

That is, in the present invention, the powder adsorbent is stirred and mixed with raw water until the adsorbability of the powder adsorbent is exhausted in the tank in order to maximize the adsorbability of the powder adsorbent. Remove. In the conventional contact tank, the outflow of fine coal was a problem, but in the present invention, in order to prevent this and to remove mainly SS components in the raw water, the membrane module is immersed in the tank and passed through the membrane module. To obtain treated water.

In the present invention, the substance to be adsorbed and removed by the powder adsorbent is not particularly limited and includes any soluble and / or insoluble chemical substance, and various inorganic compounds, organic compounds and ions thereof are included. , Suspended particles, etc. are included. Stirring of the powder adsorbent is performed in order to sufficiently contact with the water to be treated to enhance the adsorption effect. A pump device that circulates may be used. The circulation pump can also serve as a means for inducing a filtration differential pressure of the membrane module.

The membrane of the membrane module is an external pressure type, that is,
The type in which the water to be treated is filtered from the outside of the membrane to the inside of the membrane is used. The means for generating the filtration differential pressure is arbitrary and may be a pump or a siphon. The material, shape, configuration, etc. of the membrane module used in the present invention are arbitrary. For example, as a membrane, a known microfiltration membrane (MF
Membrane), ultrafiltration membrane (UF membrane), hollow fiber membranes, ceramic membranes, etc. are used, and the desired material, pore size, membrane size (membrane thickness, length, surface area, etc.), membrane density are appropriately used. (Membrane gap), filtration differential pressure, etc. can be selectively used.

The tank used in the present invention may be an open tank or a closed tank. The pressure required for passing the membrane may be either a suction pump or a circulation pump, but it is desirable to use the suction pump in an open tank for maintenance. It is preferable that the powdered activated carbon be mixed with the water to be treated in the tank until it loses its adsorption capacity, and then discharged out of the system when its adsorption capacity is lost. The amount and timing of discharging the used powder adsorbent can be set as desired.

The fine powder adsorbent and the SS component are removed by the filtering action of the membrane module installed in the tank, and clear treated water is obtained. Since the water quality of the treated water of the present invention is equivalent to that of the conventional coagulating sedimentation filtration method, the present invention does not require the conventional sedimentation tank and filtration tank after the conventional contact tank, as described above. As the membrane module continues to be treated, SS etc. adheres to the membrane surface, so regular cleaning is required, but the cleaning method is by bubbling, or the method of passing treated water from the inner surface to the outer surface is known. It ’s fine.

If the amount of SS adhering to the membrane module in the tank and the sludge component such as the fine powder adsorbent increases due to continuous washing and processing, the efficiency of each processing in the tank decreases, so these are discharged to the outside of the system. There must be. These discharges may be the same as or different from the discharge of the powder adsorbent, and it is preferable to configure the inside of the tank so that the sludge component can be selectively discharged from the powder adsorbent.

When the SS content of the water to be treated is low, the fine powder adsorbent separated from the membrane surface by cleaning and the SS content are recirculated in the tank and can coexist in the tank until the powder adsorbent reaches saturation. When the powder adsorbent reaches saturation, it is preferable to discharge it together with it. If the SS content of the water to be treated is high, a large amount of SS content will be retained in the tank in the above method, and the treatment efficiency will decrease. It is preferable to drain only the waste water.

In order to determine the adsorption capacity of the powder adsorbent, the amount of water passing through the powder adsorbent with respect to the raw water to be treated is grasped in advance, and when the integrated value of the treated water amount or the raw water amount is close to that value. The method can be adopted. A known method can be used for charging the powder adsorbent after sludge discharge, whether it is a dry method using a quantitative feeder or a slurry method. The powder adsorbent used in the present invention is optional as long as it has the above-mentioned adsorption action, and examples thereof include activated carbon and ion exchange resins. The particle size of the powder adsorbent may be appropriately selected, but, for example, a particle size finer than 0.15 mm is usually used. In the present invention, it is possible to use the fine powder adsorbent without intentionally removing it from the powder adsorbent, but it is preferable to use a product obtained by removing these because the treatment efficiency can be improved.

[0015]

EXAMPLES Hereinafter, specific examples of the present invention will be described.
The present invention is not limited to this. Example 1 An example of an open-tank type membrane filtration device when the SS concentration of raw water is relatively low will be described below with reference to FIG.

The membrane filtration apparatus 1 of the present invention comprises a tank 3 into which raw water 2 is introduced, an external pressure type membrane module 4 immersed in the tank, and a stirrer 5 for stirring and mixing a powder adsorbent. Composed. In this example, powdered activated carbon (hereinafter simply referred to as activated carbon) is used as the powder adsorbent. The activated carbon 6 is introduced into the tank by the activated carbon injection device 7, and is uniformly dispersed by the stirrer 5 in the raw water introduced via the raw water valve 8 to adsorb and remove the adsorbate in the raw water. on the other hand,
In parallel with this adsorption treatment, the raw water is filtered by the membrane module 3. The activated carbon may be added to the raw water and then introduced into the tank.

It is desirable to determine the capacity of the membrane filtration device and the concentration of activated carbon in the device depending on the quality of the raw water, but generally, the residence time is 10 minutes or more, and the higher the activated carbon concentration, the longer the saturation time. It is necessary to adjust the concentration so that the mixture is completely freed by mixing with a stirrer and does not settle. The treated water is suctioned from the membrane module 4 by operating the suction pump 9, and flows out to the treated water tank 10.

Since the membrane module 4 is clogged with filtration, it is washed at regular intervals. This example shows an example of air cleaning. At the time of cleaning, an air source such as the blower 11 is activated, air is diffused from the air diffuser 12, and the rising bubbles cause the membrane module 4 to vibrate, and the adhered fine carbon and SS components are separated. Raw water SS
When the concentration is low, the separated fine charcoal or the like is circulated again in the membrane filtration device. For saturated activated carbon, sludge, etc.,
Discharged from.

A flow rate accumulator 14 is installed in the treated water pipe, and when the water passage ratio with respect to a predetermined activated carbon input amount is reached, the suction pump 9 is stopped, the sludge discharge valve 13 is opened, and the raw water valve 8 is opened. Is closed, and all the activated carbon in the device is pulled out. After that, the mud discharge valve 13 is closed, and the raw water 2 flows in.
Activated carbon 6 is thrown in, suction pump 9 is started, and processing is restarted.

When the processing flow rate by the suction pump is constant, the processing amount may be judged from the flow rate and the processing time without installing the flow rate integrating meter. In this example, the method of withdrawing the total amount of activated carbon was described, but a method of periodically withdrawing the amount of saturated activated carbon commensurate with the amount of water flow and supplementing with fresh carbon by that amount may be used. Example 2 An example of an open-tank type membrane filtration device when the raw water SS concentration is relatively high will be described with reference to FIG.

This example is different from the membrane filtration apparatus of the first embodiment shown in FIG. 1 in that a partition wall 15, a discharge beam 16 and a discharge valve 17 are provided. That is, the raw water that has been treated with activated carbon rises from the opening 18 provided in the lower part of the partition wall and is filtered by the membrane module. Further, after the membrane module 4 is washed, the washing wastewater can be drained together with the raw water by the drainage beam 15 by opening the drainage valve 16, so that the treatment efficiency due to the increase of these concentrations. To prevent the deterioration of temperature and maintain high processing efficiency.

The timing of discharging saturated activated carbon and the like and adding fresh activated carbon is the same as in the second embodiment. Example 3 This example is an example in which a circulation pump was used as the stirring device, and the configuration is shown in FIG. The membrane filtration device 1 shows an example in which the circulating pump 19 is used instead of the stirrer in the first embodiment to mix the activated carbon and the raw water.

When the raw water and the activated carbon are mixed, the circulation pump 19 is started, the circulation valve 20 is opened, and the mud discharge valve 13 is closed to circulate the raw water and the activated carbon through the circulation pump. Cleaning
The air diffuser 12 is used in the same manner as in Example 1, and when sludge is discharged,
By closing the circulation valve 20 and opening the sludge discharge valve 13, the slurry of activated carbon can be extracted and sent to the wastewater treatment under pressure by the circulation pump.

Further, the circulation pump of this example can be used instead of the agitator of the membrane filtration device of the second embodiment. Example 4 This example is an example of a closed-tank type membrane filtration device, the configuration of which is shown in FIG. In the membrane filtration device 1 of the present invention, in the third embodiment, the tank is hermetically sealed, the diffuser for cleaning the membrane module 3 is removed, and instead of this, the treated water is passed from the inside of the membrane to the outside. It is characterized by adopting a cleaning method.

The powdered activated carbon in the membrane filtration device is circulated and mixed with the raw water in the device by operating the circulation pump 19. The pressure in the device by the circulation pump acts as the pressure of the membrane module, and the suction pump 9 of the third embodiment is unnecessary. Further, by opening the treated water valve 21, the treated water flows out to the treated water tank. However, the raw water 2 needs to flow into the membrane filtration device at a pressure higher than the pressure in the tank 3 by the circulation pump.

As an example of the cleaning method, in one example of cleaning the treated water by the cleaning pump 22, the raw water valve 8 is closed, the cleaning pump 22 is started, the cleaning valve 23 is opened, and the treated water in the treated water tank 10 is discharged from the inside of the membrane module to the outside. The waste water for cleaning is discharged by opening the drain valve 24. The opening of the drain valve 24 may be adjusted so that the amount of drainage is the same as the amount of wash water.

Further, the introduction of raw water into the tank may be stopped, or the flow of the water flow in the tank by the circulation pump may be made more vigorous than the normal treatment to wash the membrane module. INDUSTRIAL APPLICABILITY The membrane filtration device of the present invention can also be used for treating wastewater by the activated sludge method, and can be used instead of the settling tank in the activated sludge treatment step, or by immersing the membrane module in a biological treatment tank for treatment. Available on the way.

[0028]

According to the present invention, since the insoluble and soluble substances can be removed in the same apparatus, the equipment can be simplified and the installation space can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an example of an open tank type membrane filtration device of the present invention.

FIG. 2 is a diagram for explaining an example of the open tank type membrane filtration device of the present invention.

FIG. 3 is a diagram for explaining an example of the open tank type membrane filtration device of the present invention.

FIG. 4 is a diagram for explaining an example of the closed tank type membrane filtration device of the present invention.

FIG. 5 is a diagram illustrating a general flow when conventional powdered coal is used.

[Explanation of symbols]

 1 Membrane Filtration Device 2 Raw Water 3 Tank 4 Membrane Module 5 Stirrer 6 Activated Carbon 7 Activated Carbon Injection Device 8 Raw Water Valve 9 Suction Pump 10 Treated Water Tank 11 Blower 12 Diffuser 13 Drain Valve 14 Liquid Volume Accumulator 15 Partition 16 Discharge Beam 17 Discharge Valve 18 Opening 19 Circulation pump 20 Circulation valve 21 Treated water valve 22 Wash pump 23 Wash valve 24 Discharge valve 25 Activated carbon contact tank 26 Coagulation sedimentation tank 27 Sludge 28 Coagulation sedimentation treated water 29 Filtration tank 30 Wastewater treatment

Claims (1)

[Claims] 1. A tank for introducing water to be treated, an external pressure type membrane module provided in the tank, and a stirring device for stirring and mixing the water to be treated or a powder adsorbent introduced into the tank. Membrane filtration device.