JPH08257581A - Immersion membrane separator using floating body - Google Patents

Abstract

(57) [Summary] [Structure] The submerged membrane separation device 2 is installed inside the biological reaction tank 1, the air diffuser 3 is installed below the submerged membrane separation device 2, and the activated sludge mixed solution 4 is placed in the tank. Add activated carbon 5. The air diffusing pipe 3 allows the activated sludge mixed liquid 4 and the activated carbon 5 to flow in the tank. [Effect] The membrane can be efficiently washed with the amount of air that does not affect the biological treatment due to the collision of activated carbon, and the biological treatment efficiency and the membrane separation performance are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submerged membrane-using submerged membrane separation device used in the treatment of organic waste water.

[0002]

2. Description of the Related Art Conventionally, as a wastewater treatment apparatus used for treating organic wastewater such as human waste, there is, for example, one in which a submerged membrane separation apparatus is installed inside a biological reaction tank.
In such wastewater treatment equipment, the water to be treated is introduced into the biological reaction tank, mixed with the activated sludge in the tank, and the aerated air is supplied under aerobic conditions to activate the treated water by the action of the activated sludge. The organic substances, etc. are removed by decomposition. At the same time,
Solid-liquid separation of the activated sludge mixed liquid in the tank is performed by the membrane separation device so that solids such as activated sludge remain in the tank and the permeated water that has passed through the separation membrane of the membrane separation device is treated water outside the tank. Leading to. At this time, inside the biological reaction tank,
An air diffuser is installed so as to supply aerated air in excess of the amount of air required for biological treatment, and the air flow flowing out from the air diffuser and the activated sludge mixed liquid flow generated by this air flow causes the membrane separation device to operate. The film surface is self-cleaning.

Further, a water tank provided with a submerged rotary membrane separation device is provided outside the biological reaction tank, and the biologically treated activated sludge mixed liquid is allowed to flow into the water tank to perform solid-liquid separation by the membrane separation device. There is a wastewater treatment device. In this wastewater treatment device, by rotating the membrane separation device itself, the activated sludge mixed liquid in the tank is subjected to solid-liquid separation in a state where a water flow is formed, and the membrane surface of the membrane separation device is washed by this water flow. ing.

Further, there is a wastewater treatment device in which a hollow fiber membrane having a flexible and flexible structure is installed inside a biological reaction tank. In this device, membrane cleaning is performed by vibrating the hollow fiber membrane with aerated air.

There is also a waste water treatment device in which the above-mentioned membrane separation devices and hollow fiber membranes are installed inside and outside the chemical aggregation reaction tank to separate aggregates and the like.

[0006]

However, in the case of a wastewater treatment apparatus having an immersion type membrane separator inside the above-mentioned biological reaction tank (or chemical aggregation reaction tank), the amount of air and the membrane surface required for biological treatment are required. Depending on the balance with the amount of air required for cleaning, a sufficient amount of air for biological treatment may not be supplied, which causes a problem of unstable biological treatment.

Further, in the above-mentioned immersion type rotary membrane separation device or hollow fiber membrane cleaning method, the cleaning effect is unstable, and the amount of permeated liquid per unit area tends to be low due to insufficient cleaning, etc. Since it is necessary to use chemical cleaning together, there is a problem that the membrane area must be designed excessively in order to obtain sufficient membrane separation performance.

The present invention solves the above problems, and enables efficient cleaning of a membrane separation device with an air amount that does not affect biological treatment, thereby improving biological treatment efficiency and membrane separation performance. The purpose is.

[0009]

In order to solve the above problems, the present invention installs a submerged membrane separator inside a reaction tank, and introduces a minute floating body capable of floating in the water to be treated into the tank. In addition, there is provided an immersion membrane separation apparatus using a floating body, which is provided with an agitation flow means for causing the floating body to flow together with the water to be treated in the tank.

Further, the present invention provides a submerged membrane-utilizing submerged membrane separation apparatus in which the reaction tank is a biological reaction tank and the floating body has a function of supporting microorganisms. The present invention also provides an immersion membrane separation device using a floating body, wherein the reaction tank is a coagulation reaction tank and the floating body has a function of adhering a suspended matter in the water to be treated.

The present invention further provides a floating body-utilizing submerged membrane separation device in which the floating body is activated carbon.

[0012]

According to the above construction, the floating body charged in the reaction tank flows in the tank together with the water to be treated by the action of the stirring and flowing means, and during this time, the floating body collides with the separation membrane of the membrane separation device and Since the accumulation of suspended solids on the membrane surface is prevented, the amount of permeated water per unit area in the membrane separation device increases.

In the biological reaction tank, since the microorganisms in the water to be treated are carried by the floating bodies, the amount of floating microorganisms is reduced and the accumulation of microorganisms on the membrane surface is reduced. Therefore,
Since the amount of air used for cleaning the membrane may be small, the influence on the biological treatment is small, and the biological treatment is performed in a state where the aerated air supplied into the tank is sufficiently utilized, so that the biological treatment efficiency is improved.

In the flocculation reaction tank, floating substances such as flocculates in the water to be treated adhere to the floating bodies, so that the amount of floating substances decreases and the deposition of the floating substances on the film surface is reduced. By using activated carbon as a floating body, not only the microorganisms and suspended matter in the water to be treated are carried or attached, but also other pollutants to be treated are physically adsorbed, so better treated water can be obtained. Obtainable.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a submerged membrane separation device 2 is installed inside a biological reaction tank 1, and a diffusing tube 3 is provided below the membrane separation device 2.
Is installed, and powdered or granular activated carbon 5 as a floating body is put into the activated sludge mixed solution 4 in the tank 1. Reference numeral 6 is a treated water supply pipe, and 7 is a sludge drawing pipe.

The biological reaction tank 1 has R at the boundary portion 2a between the bottom surface and the side surface and the side surface and the upper surface, and is formed so that the activated sludge mixed liquid 4 easily flows in the whole area of the tank. The submerged membrane separation device 2 has a flat plate-shaped membrane cartridge 9 in which an organic membrane is arranged inside a casing 8 at appropriate intervals, and a permeated water channel (not shown) formed in each membrane cartridge 9 is sucked by a suction pump 10 Is communicated with the permeated water pipe 11. The lower portion of the casing 8 has an opening 8a.

The air diffuser 3 is arranged below the membrane cartridge 9 and is connected to an air supply means such as a blower 12 outside the tank. The air diffuser 3 supplies aeration air 13 to the activated sludge mixed liquid 4. In addition, the upward flow of the activated sludge mixed solution 4 generated by the aerated air 13 is changed to the membrane cartridges 9, 9
It is designed to feed the gap between them.

The operation of the above configuration will be described below.
The treated water is introduced from the treated water supply pipe 6 into the biological reaction tank 1 and mixed with the activated sludge mixed solution 4 in the tank, and the blower 12
The organic sludge and the like contained in the water to be treated are decomposed and removed by the action of activated sludge under aerobic conditions in which the aerated air 13 is supplied through the air diffuser 3. Further, a suction pressure is applied from the suction pump 10 to perform solid-liquid separation of the activated sludge mixed liquid 4 by the submerged membrane separation device 2 so that solids such as microorganisms forming the activated sludge remain in the tank and the membrane cartridge 9
The permeated water that has permeated the separation membrane is guided to the outside of the tank through the permeated water pipe 11.

At this time, the activated sludge mixed liquid 4 supplied as an upward flow into the gap between the membrane cartridges 9 and 9 is inverted above the submerged membrane separation device 2 to face the outside of the submerged membrane separation device 2 downward. Depending on the shape of the tank having the flow R, the fluid flows in the entire area of the tank as indicated by arrow A. The charged activated carbon 5 flows in the tank while floating in the activated sludge mixed solution 4, and during this period, the microorganisms in the activated sludge mixed solution 4 are carried to reduce the amount of suspended microorganisms and the membrane cartridge 9 is used.
It prevents the accumulation of microorganisms on the membrane surface of the membrane cartridge 9 by colliding with the membrane surface.

As a result, the amount of permeated water per unit area in the submerged membrane separation device 2 is increased, the amount of air used for membrane cleaning is reduced, and the aerated air 13 supplied into the tank is sufficiently used. Since biological treatment is carried out in, biological treatment efficiency is improved.

At this time, since the activated carbon 5 is used as the floating body, not only microorganisms and suspended matter are carried or attached to the activated carbon 5, but also other pollutants are physically adsorbed, Good treated water is obtained.

Powder activity as a suspension in the nitrification and denitrification tank
Put charcoal, 1m as treated water³/ Introduce daily excrement
Conventional method where powdered activated carbon is not added
Compared with, the membrane flux (quantity of permeated water) is 0.5m³ 
/ M²・ 0.7m from the day³ / M ²・ Raised day, hypochlorous acid
Soda chemical cleaning cycle extended from 3 months to 6 months
The amount of air for membrane cleaning is 2 times the amount of air required for biological treatment.
What was needed was double the amount to half.

The above structure may be applied to a flocculation reaction tank, in which case floating substances such as flocculates in the water to be treated adhere to the floating bodies. Further, instead of the activated carbon, an inorganic substance such as a granular or powdery ceramic or a plastic may be used, which can float in the water to be treated and has activated sludge or suspended matter on the contact surface with the water to be treated. Any structure may be used as long as it easily adheres. Further, the stirring and fluidizing means can be used without being limited to the air diffusing tube, and a mechanical stirring device may be installed or installed side by side.

[0024]

As described above, according to the present invention, a minute floating body capable of floating in the water to be treated is put into the reaction tank equipped with the submerged membrane separation device, and the floating body is stirred and fluidized. By allowing the water to flow along with the water to be treated by the means, the effect of cleaning the membrane surface can be enhanced by the collision of the floating body with the separation membrane. As a result, the membrane separation performance can be improved and the chemical cleaning cycle can be significantly reduced.

By introducing a floating body carrying microorganisms into the biological reaction tank, the amount of microorganisms floating in the water to be treated can be reduced and the accumulation of microorganisms on the membrane surface can be reduced. As a result, the amount of air required for cleaning the membrane can be reduced as compared with the conventional case, and the biological treatment can be performed in a state where the aerated air supplied into the tank is sufficiently utilized, so that the biological treatment efficiency can be improved.

By introducing a floating material to which a floating material such as an agglomerate adheres into the coagulation reaction tank, the amount of the floating material in the water to be treated can be reduced and the deposition of the floating material on the film surface can be reduced. .

By introducing activated carbon as a suspension, not only can the microorganisms and suspended matter in the water to be treated be carried or attached to the activated carbon, but other contaminants can be physically adsorbed. Better treated water is obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of a floating body-used submerged membrane separation device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Biological reaction tank 2 Immersion membrane separation device 3 Air diffuser 4 Activated sludge mixture 5 Activated carbon

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location C02F 3/10 C02F 3/10 A (72) Inventor Kiyoji Izumi Shiritsuhigashi, Naniwa-ku, Osaka-shi, Osaka 1-chome 2-47 Kubota Co., Ltd.

Claims (4)

[Claims] 1. A submerged membrane separation device is installed inside a reaction tank, and a minute floating body capable of floating in the water to be treated is placed in the tank, and this floating body is made to flow in the tank together with the water to be treated. An immersion membrane separation device using a floating body equipped with a stirring flow means. 2. The immersion membrane separation apparatus using a floating body according to claim 1, wherein the reaction tank is a biological reaction tank, and the floating body has a function of supporting microorganisms. 3. The immersion membrane separation apparatus using a floating body according to claim 1, wherein the reaction tank is a flocculation reaction tank, and the floating body has a function of adhering a suspended matter in the water to be treated. 4. The floating membrane-utilizing immersion membrane separation device according to claim 1, wherein the floating body is activated carbon.