JP2005334679A - Membrane separator - Google Patents

Abstract

By providing an additional treatment mechanism in a membrane separation device used in microfiltration, it is possible to obtain better treated water as a microfiltration treatment than before without providing another treatment device in the subsequent stage, and To provide a membrane separation apparatus that does not complicate the operation method as compared with the prior art.
In a membrane separation apparatus that is disposed in a water treatment system for treating sewage such as sewage and separates treated water from a mixed solution of activated sludge and sewage by a filtration membrane, the inside of a unit container 9 whose inner surface is coated with a photocatalyst In addition, a light source device of a photocatalyst and a filtration membrane tube 8 formed into a tubular shape are disposed.
[Selection] Figure 1

Description

  The present invention relates to a membrane separation apparatus, and in particular, it is possible to obtain better treated water as a microfiltration process without providing a separate treatment apparatus in the subsequent stage, and the operation method is complicated even compared with the conventional one. The present invention relates to a membrane separation apparatus that never happens.

As a method of adsorbing and decomposing organic substances contained in sewage by microorganisms in activated sludge, there has been a standard activated sludge method. However, in recent years, a membrane separation system using a microfiltration membrane has been put into practical use.
Patent documents 1-6 shown below are mentioned as an example of the property of such a microfiltration membrane, and the operation method using the same.

In microfiltration, there are organic flat membranes or organic hollow fiber membranes made from high molecular organic materials, metal membranes using stainless steel, ceramic membranes, etc., and pores existing on the membrane surface (usually about 0.4 μm pore size) ) Can be filtered and separated into sludge microorganisms and clean water, and the clean water can be discharged into public water as treated water.
That is, it is possible to remove solids and bacteria such as Escherichia coli, which are generally referred to as SS components, having a size of 1 μm or more, and it is possible to obtain better treated water quality than the conventional standard activated sludge method.
However, conversely, it can be said that components smaller than the pore diameter, that is, dissolved organic matter, some bacteria, viruses and the like cannot be removed. Among those that cannot be sufficiently removed by the microfiltration membrane, there are some that can be harmful in the water area of the discharge destination, or there may be a problem when the treated water is reused.
In this way, when microfiltration alone is not sufficient, conventionally, sand filtration, ultrafiltration or reverse osmosis filtration is carried out in the subsequent stage, and by using this, removal of dissolved organic matter, etc., further improved treated water can be obtained. It has gained.

However, as described above, the method of providing another processing device such as sand filtration or ultrafiltration as the third processing after the microfiltration has problems that the entire processing system becomes large and the operation method becomes complicated. It was.
Japanese Patent No. 2664110 Japanese Patent No. 3255521 Japanese Patent No. 3376733 Japanese Patent No. 3486451 Japanese Patent Application Laid-Open No. 07-132213 JP 2000-033371 A

  In view of the problems of the above conventional membrane separation apparatus, the present invention provides an additional processing mechanism in the conventional membrane separation apparatus used in microfiltration, thereby providing a precision without providing another processing apparatus in the subsequent stage. An object of the present invention is to provide a membrane separation apparatus that can obtain better treated water as a filtration treatment and that does not complicate the operation method as compared with the conventional treatment.

  In order to achieve the above object, a membrane separation apparatus of the present invention is disposed in a water treatment system for treating sewage such as sewage, and in a membrane separation apparatus for separating treated water from a mixture of activated sludge and sewage by a filtration membrane. In the unit container whose inner surface is coated with a photocatalyst, a light source device for the photocatalyst and a filtration membrane tube formed in a tubular shape are arranged.

  In this case, the unit container has a sealed structure provided with a treated water pipe for collecting treated water, and the filtration membrane pipe is disposed so that both ends penetrate the unit container, and the activated sludge introduced into the inside of the filtration membrane pipe. And the sewage mixed liquid can be filtered by a pressure difference or a water level difference with the unit container, and the filtered treated water can be recovered from the treated water pipe through the unit container.

  Further, the membrane separation device can be immersed in the biological reaction tank or disposed outside the biological reaction tank.

  In addition, titanium dioxide can be used as a photocatalyst, and an ultraviolet lamp can be used as a light source for the photocatalyst.

  In addition, a microfiltration membrane tube or an ultrafiltration membrane tube can be used as the filtration membrane tube.

According to the membrane separation apparatus of the present invention, a membrane separation apparatus that is disposed in a water treatment system for treating sewage such as sewage and separates treated water from a mixed liquid of activated sludge and sewage by a filtration membrane, the inner surface is a photocatalyst. Since the light source device of the photocatalyst and the tubular filter membrane tube are arranged in the coated unit container, by using this membrane separation device, solid-liquid separation of the mixed liquid of activated sludge and sewage is performed. In addition to obtaining filtered water with a filtration membrane tube, soluble organic matter, bacteria, and viruses remaining in the filtrate can be further decomposed or sterilized by the catalytic action of a combination of a photocatalyst and a light source. In addition, it is possible to obtain treated water with good water quality.
And this membrane separator uses the catalytic action by a photocatalyst together, and operation management does not become complicated especially compared with the conventional microfiltration alone.
In this way, when the treated water is reused, the use of the membrane separation device of the present invention eliminates the need for providing a tertiary treatment device such as a sand filtration tank, which has been conventionally required, and the arrangement thereof. In addition to eliminating the need for consideration of location, cost, and the like, it is also possible to facilitate operation management that has been apt to be complicated in the past.

  In this case, the unit container has a sealed structure with a treated water pipe for collecting treated water, and the filtration membrane pipe is disposed so that both ends penetrate the unit container, and the activated sludge introduced into the filtration membrane pipe and The mixed liquid of sewage is filtered by the pressure difference or the water level difference with the unit container, and the filtered treated water is recovered from the treated water pipe through the unit container, thereby efficiently filtering the mixed liquid of activated sludge and sewage. be able to.

  Moreover, by immersing the membrane separation apparatus in a biological reaction tank or disposing it outside the biological reaction tank, any of them can suitably perform solid-liquid separation of a mixed liquid of activated sludge and sewage.

  In addition, when titanium dioxide is used as a photocatalyst and an ultraviolet lamp is used as a light source of the photocatalyst, a strong oxidation-reduction action is exhibited, so that dissolved organic matter can be decomposed and bacteria can be sterilized.

  Further, by using a microfiltration membrane tube or an ultrafiltration membrane tube as the filtration membrane tube, the mixed liquid of activated sludge and sewage can be efficiently filtered.

  Hereinafter, embodiments of the membrane separation apparatus of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the membrane separation apparatus of the present invention.
This membrane separation device is disposed in a water treatment system for treating sewage such as sewage, and separates treated water from a mixed liquid of activated sludge and sewage by a filtration membrane, in the unit container 9 whose inner surface is coated with a photocatalyst. In addition, a light source device (not shown) of a photocatalyst and a filtration membrane tube 8 formed into a tubular shape are disposed.
In addition, this membrane separation device has a unit container 9 having a sealed structure including a treated water pipe 16 for collecting treated water, and a filtration membrane pipe 8 is disposed so that both ends penetrate the unit container 9, The mixed liquid of activated sludge and sewage introduced into the pipe 8 is filtered by a pressure difference (or water level difference) from the unit container 9, and the filtered treated water is recovered from the treated water pipe 16 through the unit container 9. I have to.

Specifically, a unit container 9 in which a part or the whole of the inner surface is coated with a photocatalyst is used as an outer frame, and a light source device (not shown) is provided therein.
Although not specified as a photocatalyst and a light source device, a combination of titanium dioxide and ultraviolet rays exhibits a strong oxidation-reduction action, and can decompose dissolved organic substances and sterilize bacteria.

On the other hand, with respect to the filtration membrane tube 8 obtained by forming the filtration membrane into a tubular shape, for example, as shown in FIG. 1, a plurality of filtration membrane tubes 8 are held in a unit container 9 coated with a photocatalyst. 10 to hold.
The holder 10 is made of a hollow disk-like material, and also acts as a stopper for sealing the unit container 9 and also serves as a sludge distributor / collector when a mixed liquid consisting of activated sludge and sewage is charged and discharged. Also works.

In other words, the mixed liquid is introduced from the mud pipe 14 into the filtration membrane tube 8, but temporarily stays in the hollow holder 10, and then guided to the plurality of filtration membrane tubes 8.
Further, the mixed solution passes through the inside of the filtration membrane tube 8, but the inside of the unit container 9 is set to a low pressure different from that in the filtration membrane tube 8, and the mixed solution is moved to the outside of the filtration membrane tube 8 by the pressure difference. Force to push out acts.
Since the filtration membrane tube 8 has pores with very small pore diameters, solid matter is retained in the tube, but clean water accumulates in the unit container 9 as filtered water, and is processed when it reaches a certain water level. The water pipe 16 discharges the system.

On the other hand, the liquid mixture that has passed through the filtration membrane tube 8 temporarily stays in another holder 10 provided on the side opposite to the inflow side, and is then discharged out of the system separately from the filtered water through the drainage pipe 15. .
The filtration membrane constituting the filtration membrane tube 8 is not specified, but a metal membrane is preferable in view of ease of molding and strength.

2 to 4 show a second embodiment of the membrane separation apparatus of the present invention.
FIG. 2 is a process flow diagram when the membrane separation apparatus is immersed in a biological reaction tank.
The sewage that has flowed into the sewage treatment facility such as a sewage treatment plant passes through the fine screen 1, during which large impurities are removed.
The sewage from which contaminants have been removed flows down into the biological reaction tank 2 and is mixed and aerated with the activated sludge microorganisms held in the tank, so that the organic matter in the sewage is adsorbed and decomposed by the activated sludge microorganisms. .
On the other hand, a membrane separation device 3 is immersed in the biological reaction tank 2, and solid-liquid separation is performed thereby.

As shown in FIGS. 3 to 4, the membrane separation device includes a photocatalyst light source device 7 and a tubular filter membrane tube 8 formed in a unit container 9 whose inner surface is coated with a photocatalyst 12. .
In addition, the membrane separation device has a unit container 9 with a sealed structure including a suction pipe 11 for collecting treated water, and a filtration membrane pipe 8 is disposed so that both ends penetrate the unit container 9, and the filtration membrane The mixed liquid of activated sludge and sewage introduced into the pipe 8 is filtered by a pressure difference (or water level difference) from the unit container 9, and the filtered treated water is recovered from the suction pipe 11 through the unit container 9. I have to.
Specifically, an ultraviolet lamp 7 is disposed at the center of the unit container 9 whose inside is coated with titanium dioxide 12, and a plurality of filtration membrane tubes 8 are disposed so as to surround the ultraviolet lamp 7, The ultraviolet lamp 7 and the filtration membrane tube 8 are held by a holder 10.
As shown in FIG. 3, the membrane separation device is disposed in the biological reaction tank 2 so that the filtration membrane tube 8 is in the vertical direction.

An air diffuser 4 is provided below the membrane separator 3, and air is sent from the blower 6 to generate an upward flow in the filtration membrane tube 8.
The mixed liquid of activated sludge microorganisms and sewage flows from the bottom to the top through the filtration membrane tube 8, but is filtered by the suction pressure by the suction pump 5 provided in the middle of the suction tube 11 connected to the unit container 9. The
The filtration membrane tube 8 is provided with pores having a pore diameter of 1 μm or less, and almost all solid substances and bacteria are removed by passing through the pores.

The filtrate filtered by the filtration membrane tube 8 contains some soluble organic matter, but the organic matter is decomposed and removed by the photocatalytic action of the combination of the titanium dioxide 12 and the ultraviolet lamp 7 while temporarily staying in the unit container 9. After that, it is discharged out of the system as treated water through the suction pipe 11.
In the filtration membrane tube 8, bubbled air is provided by the air diffuser 4, which not only generates an upward flow in the filtration membrane tube 8 but also the surface of the filtration membrane tube 8. The membrane surface can be prevented from being clogged.

5 to 8 show a third embodiment of the membrane separation apparatus of the present invention.
FIG. 5 shows a processing flow chart when the membrane separation apparatus is disposed outside the biological reaction tank.
Sewage that has flowed into a sewage treatment facility such as a sewage treatment plant is mixed with aerated microorganisms and activated sludge microorganisms that have been removed from the sewage while passing through the fine screen 1. As a result, the organic matter in the sewage is adsorbed and decomposed by the activated sludge microorganisms. The mixed liquid of activated sludge microorganisms and sewage that has flowed out of the biological reaction tank 2 is introduced into a membrane separation device 3 provided at a later stage.

As shown in FIGS. 6 to 8, the membrane separation device 3 includes a photocatalyst light source device 7 and a tubular filter membrane tube 8 formed in a unit container 9 whose inner surface is coated with a photocatalyst 12. Yes.
In addition, the membrane separation device has a unit container 9 with a sealed structure including a suction pipe 11 for collecting treated water, and a filtration membrane pipe 8 is disposed so that both ends penetrate the unit container 9, and the filtration membrane The mixed liquid of activated sludge and sewage introduced into the pipe 8 is filtered by a pressure difference (or water level difference) from the unit container 9, and the filtered treated water is recovered from the suction pipe 11 through the unit container 9. I have to.
Specifically, as shown in FIGS. 6 to 8, a filtration membrane tube 8 is disposed together with an ultraviolet lamp 7 in a unit container 9 whose inside is coated with titanium dioxide 12, and one filtration membrane tube 8 is provided. The two ends of the membrane tube are held in the unit container 9 together with the ultraviolet lamp 7 by the holder 10.

The mixed liquid flowing in from the mud pipe 14 passes through the filtration membrane pipe 8 and flows out of the membrane separation apparatus 3 from the mud pipe 15.
At this time, the inside of the unit container 9 has a negative pressure due to the operation of the suction pump 5 provided in the middle of the suction pipe 11 to be connected, and the mixed liquid passing through the filtration membrane pipe 8 is outside, that is, the unit container 9. Only the clean filtrate is temporarily held in the unit container 9.

The filtered water temporarily held in the unit container 9 is further processed by the catalytic action of the combination of the titanium dioxide 12 and the ultraviolet lamp 7, but is discharged out of the system through the suction pipe 11 as the water level rises.
Note that the mixed liquid discharged from the membrane separation device 3 is returned to the biological reaction tank 2 again by the return sludge pump 13.

  As described above, the membrane separation apparatus of the present invention has been described based on a plurality of examples. However, the present invention is not limited to the configurations described in the above examples, and the configurations described in the respective examples are appropriately combined. The configuration can be changed as appropriate without departing from the spirit of the invention.

  The membrane separation apparatus of the present invention can obtain better treated water as a microfiltration process without providing a separate treatment apparatus in the subsequent stage, and the operation method can be complicated compared to the conventional one. For example, in a sewage treatment facility that treats sewage such as sewage, by mixing and aeration of the influent sewage and activated sludge mainly composed of microorganisms, the organic matter in the sewage is microbial. It can be used for a sewage treatment system that obtains clean treated water by decomposing / treating and then separating the solid and liquid later.

It is a perspective view which shows 1st Example of the membrane separator of this invention. It is a processing flow figure showing the state where the 2nd example of the membrane separation device of the present invention was immersed in the processing tank. It is a longitudinal cross-sectional view of the membrane separator of the same Example. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is a processing flowchart which shows the state which has arrange | positioned the 3rd Example of the membrane separator of this invention out of the processing tank. It is a longitudinal cross-sectional view of the membrane separator of the same Example. It is the BB sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fine screen 2 Biological reaction tank 3 Membrane separator 4 Air diffuser 5 Suction pump 6 Blower 7 Ultraviolet lamp (light source device)
8 Filtration membrane tube 9 Unit container 10 Holder 11 Suction tube (treated water tube)
12 Titanium dioxide (photocatalyst)
13 Return sludge pump 14 Mud pipe 15 Mud pipe 16 Treated water pipe

Claims (5)

  In a membrane separation device that is disposed in a water treatment system that treats sewage such as sewage and separates treated water from a mixture of activated sludge and sewage with a filtration membrane, the light source of the photocatalyst is placed in a unit container whose inner surface is coated with a photocatalyst A membrane separation device comprising a device and a tubular filtration membrane tube.   The unit container has a sealed structure with a treated water pipe for collecting treated water, and the filtration membrane pipe is arranged so that both ends penetrate the unit container, and the activated sludge and sewage mixed in the inside of the filtration membrane pipe are mixed. 2. The membrane separator according to claim 1, wherein the liquid is filtered by a pressure difference or a water level difference with the unit container, and the filtered treated water is recovered from the treated water pipe through the unit container.   The membrane separator according to claim 1 or 2, wherein the membrane separator is immersed in a biological reaction tank or disposed outside the biological reaction tank.   4. The membrane separation apparatus according to claim 1, wherein titanium dioxide is used as a photocatalyst and an ultraviolet lamp is used as a light source of the photocatalyst.   5. The membrane separation device according to claim 1, wherein a microfiltration membrane tube or an ultrafiltration membrane tube is used as the filtration membrane tube.

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