JP2525701B2 - Membrane filtration device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. 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. The general flow when using powdered coal can be shown in FIG. That is, sufficiently mix the powder coal and raw water 2 at activated carbon contact tank 2 1, to adsorb the soluble substance is contacted. Charcoal powder downstream of coagulating sedimentation tank 2 2 in raw water insoluble substance, that is, mainly coagulation sedimentation with SS component, most are waste sludge 2 3 from the coagulating sedimentation tank bottom.

[0003] fine activated carbon remaining on the coagulation sedimentation process water 2 4, SS component is filtered out in the next filtration tank 2 6.

[0004]

SUMMARY OF THE INVENTION In the conventional method,
The fine coal in the powdered activated carbon is not completely removed by the coagulation sedimentation tank, but flows into the filtration tank 26 , hastening the clogging of the filtration tank and increasing the cleaning frequency of the filtration tank. Further, charged powder activated carbon flows out from the contact vessel 2 1 causes a short circuit current or the like in a state where the remaining adsorption capacity, waste sludge is often.
Not only therefore solubility powdered activated carbon, such unnecessarily material removal increases the running cost of powdered activated carbon itself is turned on, the increase in the waste sludge solid content increases the subsequent loading of the wastewater treatment 2 5.

Therefore, an object of the present invention is to solve the above-mentioned problems, to efficiently and economically utilize an adsorbent, to remove soluble and insoluble substances with high efficiency, and to use 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]

DISCLOSURE OF THE INVENTION The present invention is directed to an open tank into which water to be treated is introduced and an external suction provided in the open tank.
An external pressure type membrane module communicating with a pump and a powder adsorbent introduced into the water to be treated or into the open tank are provided in the open tank.
A membrane filtration device comprising an agitation device provided in the open tank for agitating and mixing in the inside, whereby the above problems can be solved. The principle of the present invention is that an open tank (hereinafter, also simply referred to as “tank”)
The external pressure type membrane module is placed inside the container, and the powder adsorbent is introduced into the tank to improve the solubility and / or
Alternatively, the adsorption / removal of insoluble substances (hereinafter, both substances are simply referred to as adsorbates) and the filtration treatment of insoluble substances mainly composed of SS by the membrane of the membrane module are performed in parallel. By performing in a tank, clear treated water from which soluble substances and insoluble substances have been removed can be obtained in one step, and since the powder adsorbent does not move between steps as in the conventional case, there is no waste, and It can be used until the adsorption capacity is saturated.

That is, in the present invention, in order to make maximum use of the adsorption capacity of the powder adsorbent, the powder adsorbent is agitated and mixed with the raw water until the adsorbability of the powder adsorbent is exhausted in the tank. 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 content 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 their ions are included. , Suspended particles, etc. are included. Stirring of the powder adsorbent is carried out 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 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.

[0010] The film pressure required to pass through the membrane element is open
Since it is installed in the discharge tank, it uses a suction pump . 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 the 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 similar to that of the conventional coagulating sedimentation filtration system, the present invention does not require the conventional settling tank or filtration tank after the contact tank as described above. As the membrane module continues to be treated, SS etc. adheres to the membrane surface, so periodic cleaning is required, but the cleaning method is by bubbling, 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. Therefore, while maintaining the powder adsorbent in the tank, It is preferable to drain only the waste water.

In order to determine the adsorption capacity of the powder adsorbent, it is necessary to know in advance the amount of water passing through the powder adsorbent with respect to the raw water to be treated, and when the integrated value of the treated water amount or 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 in the case where the raw water SS concentration is relatively low will be described below with reference to FIG.

The membrane filtration device 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 sediment. The treated water is sucked 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, the 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. Saturated activated carbon, sludge, etc. should be drained 13
Emitted 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 mud 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 drain valve 13 is closed and the raw water 2 is flown 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 replenishing with new carbon 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 device shown in FIG. 1 of the first embodiment in that a partition wall 15, a discharge beam 16 and a discharge valve 17 are provided. That is, the raw water 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. After the membrane module 4 is washed, the washing wastewater can be discharged from the drainage beam 16 together with the raw water by opening the drainage valve 17 to remove the separated fine coal and SS components. Prevents reduction in processing efficiency and maintains high processing efficiency.

The timing of discharging saturated activated carbon and the like and adding fresh activated carbon is the same as in Example 2. Example 3 This example is an example in which a circulation pump is 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 as in the first embodiment, 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 under pressure by a circulation pump to wastewater treatment.

Further, the circulation pump of the present example, you can use instead of the stirrer membrane filtration apparatus according to the second embodiment.

[0025]

[0026]

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 sedimentation tank in the activated sludge treatment process, or by immersing the membrane module in a biological treatment tank. Can be used as a processing method.

[0028]

According to the present invention, since 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 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 Activated carbon contact tank 22 Coagulation sedimentation tank 23 Waste mud 24 Coagulation sedimentation treated water 25 Wastewater treatment 26 Filtration tank

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C02F 9/00 503 C02F 9/00 503A

Claims (1)

(57) [Claims] 1. A an open tank water to be treated is introduced, and an external pressure type membrane module in communication with the outside of the suction pump to be deployed in the open <br/> tank, the treated water or the open tank The open tank for stirring and mixing the powder adsorbent introduced into the open tank
A membrane filtration device consisting of an agitator installed inside .