JPH1147747A - Immersion type membrane processing equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In an immersion type membrane treatment apparatus in which an activated carbon adsorption treatment tank and an immersion type membrane module are integrated, the activated carbon adsorption capacity is sufficiently exhibited to reduce the amount of activated carbon used and increase Obtain treated water. SOLUTION: A plurality of tank portions 1 to 3 in which raw water is sequentially circulated.
The raw water is supplied to the first-stage tank section 1, and the immersion type membrane module 8 is provided in the last-stage tank section 3, and the permeated water is taken out as treated water. The activated carbon is supplied to the tank 3 at the last stage, the activated carbon mixed solution in each stage is sequentially transferred to the upstream tank, and the used activated carbon is discharged from the tank 1 at the first stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an immersion type membrane treatment apparatus for adsorbing raw water with activated carbon and subjecting the adsorbed water to membrane filtration.

[0002]

2. Description of the Related Art An adsorption treatment using powdered activated carbon has been widely used for the purpose of removing hardly decomposable substances, chromaticity, odor and the like in wastewater. In recent years, a method has been developed in which an MF (microfiltration) membrane or a UF (ultrafiltration) membrane module is combined with the powdered activated carbon adsorption treatment apparatus, and the adsorption treatment and the membrane filtration treatment of the adsorption treatment water are simultaneously performed.

[0003] By combining the activated carbon adsorption treatment with the membrane filtration treatment, treated water of good water quality from which SS has been removed to a high degree can be obtained. Therefore, this method is highly evaluated as a promising treatment method. In particular, an immersion type membrane treatment apparatus in which an external pressure type membrane module is immersed in an activated carbon adsorption treatment tank is extremely advantageous for downsizing the apparatus.

[0004]

In the activated carbon adsorption treatment, whether or not the adsorbing capacity of the added powdered activated carbon is sufficiently utilized is an important factor which affects the treatment efficiency.

However, in a conventional immersion type membrane processing apparatus provided with an immersion type membrane module in an activated carbon adsorption treatment tank,
In many cases, the activated carbon is discharged while retaining its adsorption capacity. For this reason, the use efficiency of activated carbon is poor,
Further, a part of the treated water (membrane permeated water) may be discharged in a state where the adsorption treatment with the activated carbon is insufficient.

[0006] As described above, the conventional immersion type membrane treatment apparatus in which the activated carbon adsorption treatment tank and the immersion type membrane module are integrated has advantages in that the apparatus is compact and SS-free treated water can be obtained. , The utilization efficiency of the activated carbon is poor, and this requires more than the theoretical amount of activated carbon.
There was a drawback that activated carbon cost increased.

[0007] The present invention solves the above-mentioned conventional problems and is an immersion type membrane treatment apparatus in which an activated carbon adsorption treatment tank and an immersion type membrane module are integrated. It is an object of the present invention to provide a type membrane processing apparatus.

[0008]

According to the present invention, there is provided an immersion type membrane processing apparatus comprising: a plurality of tanks through which raw water is sequentially passed; a means for supplying raw water to a first-stage tank; A submerged membrane module provided in the tank, a means for supplying activated carbon to the last tank, a means for transferring the activated carbon mixture in each tank to the upstream tank, Means for discharging activated carbon from the tank of the stage.

According to the present invention, while the activated carbon added to the tank in the final stage is sequentially transferred to the tank on the upstream side, the activated carbon is sufficiently brought into contact with the raw water to adsorb contaminants in the raw water. Can be fully exhibited.

In particular, the activated carbon is first added to the tank at the last stage and comes into contact with sufficiently purified water while passing through the tank at the previous stage. Contaminants can be highly adsorbed and removed on their fresh adsorption surfaces.

The activated carbon is sequentially transferred to the tanks on the upstream side, and comes into contact with raw water in each of the tanks to adsorb the contaminants.
Since it sequentially comes into contact with water having a high contaminant content, the contaminants in the raw water can be sufficiently adsorbed by the adsorption ability remaining on the activated carbon.

As described above, the activated carbon is brought into contact with raw water in a stepwise manner to carry out the adsorption treatment, whereby the adsorption capacity of the activated carbon can be sufficiently exerted, the amount of activated carbon used can be reduced, and highly treated water can be obtained. be able to.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of an immersion type film processing apparatus according to the present invention.

This immersion type membrane processing apparatus comprises a partition wall 10A,
One processing tank 10 is divided into three by 10B, and first to third tank sections 1, 2, 3 are formed.

Draft pipes 4, 5, 6 are provided in each of the tank sections 1 to 3, and a submerged membrane module 8 is provided together with the draft pipe 6 in the third tank section 3 in the final stage. A partition wall 7 is provided between the draft tube 6 and the membrane module 8, and one side is an activated carbon adsorption section 3A and the other side is a membrane filtration section 3B.

Air is diffused below the draft pipes 4 to 6 in each tank section, whereby the activated carbon in each tank section is fluidized and stirred, and the activated carbon and the liquid to be treated are mixed. Further, the draft pipes 4 to 6 are blown by air blown from below the draft pipes 4 to 6.
An air lift is created in the draft tube 4
活性 6 rises inside the draft tubes 4〜6. Then, in the draft pipes 5, 6, the activated carbon mixed liquid is transferred to the preceding tank sections 1, 2 via the transfer pipes 5A, 6A connected to the upper side thereof. This transfer pipe 5A,
A flow control valve (not shown) is provided in the middle of 6A so that the liquid transfer amount can be adjusted. In the draft pipe 4, the activated carbon mixed liquid that has risen in the pipe overflows again into the first tank outside the pipe and circulates.

Air is also diffused in the lower portion of the immersion type membrane module 8 in the third tank section 3, and the SS diffuses and removes activated carbon and carbon adhering to the membrane surface.

The raw water is introduced into the first tank 1 and sequentially flows into the tanks 2 and 3 at the subsequent stage. After being mixed with activated carbon in each tank and subjected to adsorption treatment, the permeated water filtered by the membrane module 8 is taken out as treated water.

The activated carbon is added to the activated carbon adsorbing section 3A of the third tank section 3 and is sequentially transferred to the preceding tank sections 2 and 1 by an air lift in the draft tube, during which the liquid to be treated is adsorbed. The used activated carbon is withdrawn from the bottom of the first tank 1.

The first tank 1 has a cone-shaped bottom so that the used activated carbon can be easily pulled out.

Submerged membrane module 8 provided in third tank section 3
May be an external pressure type in which the permeated water is taken out by a suction pump 9 connected to the permeated water side (secondary side) of the membrane, or the permeated water is taken out by the water pressure of the third tank portion 3. The shape may be any of a hollow fiber shape, a tubular shape, a flat membrane shape and the like. The material of the film may be any of an organic film and a ceramic film, and the type of the film may be any of an MF film and a UF film.

In the immersion type membrane module, from the viewpoint of preventing SS and activated carbon from adhering to the surface, it is necessary to perform aeration from the lower part of the membrane and to constantly carry out membrane cleaning while keeping the liquid on the membrane surface in a fluid state. Alternatively, a method of intermittently injecting treated water or working water from the permeated water side of the membrane together with aeration from the lower part of the membrane module is also an effective method of membrane cleaning. Further, after the operation is continued for a certain period, it is necessary to wash with an alkali, an acid, an oxidizing agent such as sodium hypochlorite, hydrogen peroxide, a suitable surfactant, an enzyme agent and the like.

The shape of the suction pump 9 is arbitrary as long as suction from the membrane is possible, and a siphon other than the pump can be used.

Draft pipes 4 to 4 installed in the tank sections 1 to 3
No. 6 needs to be able to sufficiently flow and stir the activated carbon in each of the tank portions 1 to 3. As a means for transferring a part of the activated carbon from each post-tank to each pre-tank, it is convenient to use an air lift mechanism attached to the draft tube, but it is also possible to use a pump instead of the air lift. It is possible. Although the amount of activated carbon to be transferred varies depending on the amount of activated carbon to be charged, it is preferable to adjust the amount of activated carbon to be transferred to each tank so that the concentration of activated carbon in each tank is uniform.

With such an immersion type membrane treatment apparatus, in performing the activated carbon adsorption treatment of the raw water and the membrane filtration treatment of the activated carbon adsorption treatment water, the utilization efficiency of the activated carbon is increased, and the advanced treated water is used with a small amount of activated carbon. Can be obtained.

In FIG. 1, one processing tank is divided into three, but an independent processing tank may be connected. In addition, there is no particular limitation on the number of connected tank parts,
Two or four or more tanks may be used. Generally, from the viewpoint of increasing the utilization efficiency of activated carbon by repeating the stepwise adsorption treatment with activated carbon, it is preferable to provide three or more tanks, and in consideration of economy and the like, three to five tanks are suitable. .

[0028]

The present invention will be described more specifically below with reference to examples and comparative examples.

Example 1 SS: 5-8 mg / L, COD _Mn : 27-33 mg / L
L, BOD: Activated sludge treated water of 5-12 mg / L comprehensive beer factory effluent was treated as raw water by the immersion type membrane treatment apparatus shown in FIG.

The capacities of the tanks are as follows: the first tank 1:15 L, the second tank 2:15 L, the third tank (membrane immersion tank) 3:30 L.
(A total of 60 L), and the draft tubes 4 to 6 installed in each of the tank portions 1 to 3 have an inner diameter of 50 mm and a height of 500 mm.
Further, as the immersion type membrane module 8 of the third tank section 3, a hollow fiber MF membrane module (“STELAPORE (registered trademark) L” manufactured by Mitsubishi Rayon Co., Ltd., effective area 0.5 m ² , fraction pore diameter 0.1 μm) Was used.

Air was diffused from below the draft pipes 4 to 6 of the tanks 1 to 3 to flow and agitate the activated carbon in the tanks. In addition, air is blown into the lower portions of the draft pipes 4 to 6 to cause an air lift, and the activated carbon mixture in the third tank 3 is supplied to the second tank 2, and the activated carbon mixture in the second tank 2 is supplied to the first tank. Transferred to Part 1 sequentially.

The permeated water side of the membrane module 8 installed in the third tank 3 was suctioned by the suction pump 9 to take out the treated water.
In this membrane module 8, SS and activated carbon adhering to the membrane surface were peeled off by diffusing air from below.

Raw water was introduced into the first tank 1 at a flow rate of 600 L / day. As the powdered activated carbon, “Kuraray Co., Ltd. (registered trademark) PFK” (particle size: 320 mesh or less) manufactured by Kuraray Co., Ltd. was continuously charged into the third tank portion 3 at a rate of 100 g / day (dry powdered activated carbon weight). . The used activated carbon was continuously discharged from the lower part of the first tank unit 1 by an amount equivalent to the input amount.

The quality of the treated water when treated under such conditions was examined, and the results are shown in Table 1.

Further, the CO per activated carbon of the extracted activated carbon is
The D adsorption amount was examined, and the results are shown in Table 1.

Comparative Example 1 A membrane module similar to that used in Example 1 was immersed in a treatment tank with a stirrer having a capacity of 50 L, and air was diffused from the bottom of the membrane module in the same manner as in Example 1. Raw water was introduced into the treatment tank and activated carbon was charged, and used activated carbon was taken out from the bottom of the tank. The quality of the treated raw water, its flow rate, and the amount of activated carbon charged were the same as in Example 1.

At this time, the quality of the treated water and the COD adsorption amount of the extracted activated carbon were examined, and the results are shown in Table 1.

[0038]

[Table 1]

As is clear from Table 1, in Example 1,
Both the treated water COD and BOD are better than that of Comparative Example 1, and the COD adsorption amount of the activated carbon is increased by 23% as compared with Comparative Example 1.

From these results, it can be seen that according to the immersion type membrane treatment apparatus of the present invention, since the adsorbing ability of the charged activated carbon is sufficiently utilized, it is possible to obtain advanced treated water with a small amount of activated carbon used.

[0041]

As described above in detail, according to the immersion type membrane treatment apparatus of the present invention, the immersion type membrane treatment apparatus in which the activated carbon adsorption treatment tank and the immersion type membrane module are integrated has a sufficient ability to adsorb activated carbon. Since it can be exerted, the amount of activated carbon used can be reduced and highly treated water can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an immersion type film processing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st tank part 2 2nd tank part 3 3rd tank part 4,5,6 Draft pipe 7 Partition wall 8 Submersible membrane module 9 Suction pump 10 Processing tank 10A, 10B Partition wall

Claims (1)

[Claims] 1. A plurality of tanks through which raw water is sequentially circulated, means for supplying raw water to a first tank, a submerged membrane module provided in a final tank, Means for supplying activated carbon to the tank section, means for transferring the activated carbon mixture in the tank section of each stage to the tank section on the upstream side, and means for discharging activated carbon from the first tank section. Immersion type membrane processing equipment.