KR101367229B1 - Operating method of advanced treatment process use of submerged membrane and advanced treatment apparatus thereof - Google Patents

Abstract

The present invention is to remove the contaminants and sand contained in the sewage in the advanced treatment process using a submerged membrane bioreaction tank: when the level of the flow adjustment tank is above the set value, the flow adjustment tank pump automatically operates Starting and transferring the sewage to the mixing stabilizer in a constant amount, but stopping the operation when the level of the membrane filtration tank is 5 cm higher than the planned value or the level of the flow adjusting tank is lower than the planned minimum value; Mixing the internal transport liquid and the sewage returned from the simultaneous nitrification denitrification tank or the nitrification tank in the mixing stability tank, depleting the trace amount of nitrate nitrogen and dissolved oxygen contained in the internal transport liquid, and transferring the mixed liquid to the anaerobic tank ; Mixing the mixed liquid transferred to the anaerobic tank under complete mixing conditions, releasing the phosphorus accumulated in the microorganism body in the anaerobic state into the mixed liquid, and transferring the mixed liquid to a simultaneous nitrification denitrification tank or nitrification tank; In the simultaneous nitrification denitrification tank, the mixed solution is stirred under the conditions of complete mixing, while maintaining the dissolved oxygen concentration in the range of 0.3 to 0.7 mg / L, simultaneously performing nitrification and denitrification to remove nitrogen, and the phosphorus-removing microorganism absorbs excess phosphorus. Or by supplying air to the mixed solution to keep the dissolved oxygen concentration at 0.5 to 1.0 mg / L, and repeatedly operating the aerobic operation period for stirring and the anoxic operation period for stopping the air supply to the mixture solution and stirring, alternately Simultaneously performing denitrification to remove nitrogen, causing the phosphorus removing microorganism to absorb phosphorus in excess during the exhalation operation period, and transferring the mixed solution to the membrane filtration tank; Alternatively, the mixed solution is stirred in the nitrification tank under complete mixing conditions, nitrification is performed while maintaining the dissolved oxygen concentration in the range of 1.0 to 2.0 mg / L, and the mixed solution is returned to the anoxic tank and the anaerobic tank to remove nitrogen, and the phosphorus removing microorganism The mixed liquor is operated in an oxygen-free tank while repeatedly operating the aerobic operation period in which excess phosphorus is absorbed or air is supplied to the mixed liquid to increase the dissolved oxygen concentration and the aerobic operation period in which the air is supplied to the mixed liquid is stopped while stirring. Returning to remove nitrogen, causing the phosphorus removing microorganism to absorb excess phosphorus during the exhalation operation period and transferring the mixed solution to the membrane filtration tank; Optionally returning the mixed liquor to the anaerobic tank during anoxic operation in a simultaneous nitrification tank or a simultaneous nitrification tank; The outside of the membrane filter is continuously cleaned while supplying air to the membrane filter from the lower part of the membrane filter, the suction pump is operated to transfer the membrane filtrate to the membrane filter water reservoir, and purified by a trapping gas circulation regulator installed at the top of the membrane filter. Adjusting the inflow rate of gas and external air to maintain the dissolved oxygen concentration of the membrane filtration tank in the range of 0.5 to 3.0 mg / L, and returning the mixed liquid to the simultaneous nitrification denitrification tank or nitrification tank; Periodically washing the countercurrent with the membrane filtrate and the chemical with the chemical to the degree of contamination of the membrane filter; And extracting part of the mixed solution of the membrane filtration tank and discarding the resultant in excess sludge, thereby providing an operation method of the submerged membrane advanced processing step and a submerged membrane advanced processing apparatus using the method.
Accordingly, by returning the mixed solution of the membrane filtration tank to the simultaneous nitrification denitrification tank, the dissolved oxygen concentration of the simultaneous nitrification denitrification tank can be properly maintained and the simultaneous nitrification denitrification can be performed to increase the nitrogen removal rate. By returning the mixed solution of the simultaneous nitrification denitrification tank with low temperature to the anaerobic tank, it is possible to increase the phosphorus removal efficiency, eliminate the use of coagulant required for phosphorus removal, save the energy, and obtain the clean effluent, thereby protecting the water quality of the discharged water. Can be.

Description

Operating Method of Advanced Treatment Process Use of Submerged Membrane and Advanced Treatment Apparatus

The present invention relates to an operation method of the submerged membrane advanced treatment process and a submerged membrane advanced treatment apparatus using the same, and more particularly, to a submerged membrane advanced treatment process used in sewage, wastewater, and livestock wastewater treatment plants. And a submerged membrane advanced treatment apparatus using the method.

The present inventors have applied for "Operation Patent 10-1044826 (June 21, 2011) Operation method for improving the high processing efficiency of membrane filtration bioreactor and advanced processing apparatus using the method" and "Registered Patent No. 10-1050375 (July 13, 2011) Submerged membrane bioreactors that can easily cope with load fluctuations and sewage treatment methods using the same are useful inventions with high processing efficiency and easy to cope with load fluctuations. Because of the limited description, it was difficult to apply according to various site conditions.

In addition, since a separate large-capacity degassing tank is required to lower the dissolved oxygen and nitrate nitrogen concentrations in the returning liquid, wasteful factor of the facility has occurred.

The present invention was created to solve the above problems, by controlling the dissolved oxygen concentration of the bioreactor in an appropriate range over a wide load variation range, by lowering the concentration of dissolved oxygen and nitrate nitrogen contained in the return liquid, Reduce the size of the mixed stabilizer or degassing tank, reduce the consumption of organic matter in the mixed stabilizer, maintain the anaerobic tank in the complete anaerobic state, increase the efficiency of phosphorus removal, increase the removal rate of nitrogen and organic matter, It is an object of the present invention to provide an operation method and a submerged membrane advanced treatment apparatus using the method.

In order to achieve the above object, the present invention is to remove the contaminants and sand contained in the sewage in the advanced treatment process using a submerged membrane bioreaction tank: when the level of the flow adjustment tank is more than the set value The pump automatically starts operation and transfers the sewage to the mixing stabilizer in a certain amount, but the operation stops when the level of the membrane filtration tank is 5cm higher than the planned value or when the level of the flow controller is lower than the planned minimum value. Making; Mixing the internal transport liquid and the sewage returned from the simultaneous nitrification denitrification tank or the nitrification tank in the mixing stability tank, depleting the trace amount of nitrate nitrogen and dissolved oxygen contained in the internal transport liquid, and transferring the mixed liquid to the anaerobic tank ; Mixing the mixed liquid transferred to the anaerobic tank under complete mixing conditions, releasing the phosphorus accumulated in the microorganism body in the anaerobic state into the mixed liquid, and transferring the mixed liquid to a simultaneous nitrification denitrification tank or nitrification tank; In the simultaneous nitrification denitrification tank, the mixed solution is stirred under the conditions of complete mixing, while maintaining the dissolved oxygen concentration in the range of 0.3 to 0.7 mg / L, simultaneously performing nitrification and denitrification to remove nitrogen, and the phosphorus-removing microorganism absorbs excess phosphorus. Or by supplying air to the mixed solution to keep the dissolved oxygen concentration at 0.5 to 1.0 mg / L, and repeatedly operating the aerobic operation period for stirring and the anoxic operation period for stopping the air supply to the mixture solution and stirring, alternately Simultaneously performing denitrification to remove nitrogen, causing the phosphorus removing microorganism to absorb phosphorus in excess during the exhalation operation period, and transferring the mixed solution to the membrane filtration tank; Alternatively, the mixed solution is stirred in the nitrification tank under complete mixing conditions, nitrification is performed while maintaining the dissolved oxygen concentration in the range of 1.0 to 2.0 mg / L, and the mixed solution is returned to the anoxic tank and the anaerobic tank to remove nitrogen, and the phosphorus removing microorganism The mixed liquor is operated in an oxygen-free tank while repeatedly operating the aerobic operation period in which excess phosphorus is absorbed or air is supplied to the mixed liquid to increase the dissolved oxygen concentration and the aerobic operation period in which the air is supplied to the mixed liquid is stopped while stirring. Returning to remove nitrogen, causing the phosphorus removing microorganism to absorb excess phosphorus during the exhalation operation period and transferring the mixed solution to the membrane filtration tank; Optionally returning the mixed liquor to the anaerobic tank during anoxic operation in a simultaneous nitrification tank or a simultaneous nitrification tank; The outside of the membrane filter is continuously cleaned while supplying air to the membrane filter from the lower part of the membrane filter, the suction pump is operated to transfer the membrane filtrate to the membrane filter water reservoir, and purified by a trapping gas circulation regulator installed at the top of the membrane filter. Adjusting the inflow rate of gas and external air to maintain the dissolved oxygen concentration of the membrane filtration tank in the range of 0.5 to 3.0 mg / L, and returning the mixed liquid to the simultaneous nitrification denitrification tank or nitrification tank; Periodically washing the countercurrent with the membrane filtrate and the chemical with the chemical to the degree of contamination of the membrane filter; And removing a portion of the mixed solution of the membrane filtration tank and disposing of the mixed liquid into excess sludge, thereby providing an operation method of the submerged membrane advanced treatment process.

In addition, the present invention is to remove the contaminants and sand contained in the sewage in the advanced treatment process using the submerged membrane bioreaction tank: when the level of the flow adjustment tank is more than the set value, the flow adjustment tank pump automatically Starting the operation and transferring the sewage to the mixing stabilizer in a fixed amount, but stopping the operation when the level of the membrane filtration tank is 5 cm or more higher than the planned value or the level of the flow adjusting tank is lower than the planned minimum value; Mixing the internal transport liquid and the sewage returned from the simultaneous nitrification denitrification tank or the nitrification tank in a mixing stability tank, depleting the trace amount of nitrate nitrogen and dissolved oxygen contained in the internal transport liquid and transferring the mixed solution to the anaerobic tank; Mixing the mixed liquid transferred to the anaerobic tank under complete mixing conditions, releasing the phosphorus accumulated in the microorganism body in the anaerobic state into the mixed liquid, and transferring the mixed liquid to a simultaneous nitrification denitrification tank or nitrification tank; In the simultaneous nitrification denitrification tank, the mixed solution is stirred under the conditions of complete mixing, and the nitrogen removal is carried out by simultaneously performing nitrification and denitrification while maintaining the dissolved oxygen concentration in the range of 0.3 to 0.7 mg / L. Or nitrification and denitrification by alternately operating the aerobic operation period in which the dissolved oxygen concentration is adjusted to 0.5 to 1.0 mg / L by supplying air to the mixed liquid and the anoxic operation period in which the air is supplied to the mixed liquid is stopped while stirring. Carrying out simultaneous nitrogen removal, causing phosphorus removal microorganisms to absorb phosphorus in excess during the exhalation operation period and transferring the mixed solution to the membrane filtration tank; Alternatively, the mixed solution is stirred under complete mixing conditions in the nitrification tank, nitrification is performed while maintaining the dissolved oxygen concentration in the range of 1.0 to 2.0 mg / L, and the mixed solution is returned to the anoxic tank and the anaerobic tank to remove nitrogen, and the phosphorus removing microorganism is phosphorus. The mixed liquid is returned to the anoxic tank while operating the aerobic operation period in which the excess liquid is absorbed excessively or the air is supplied to the mixed liquid to increase the dissolved oxygen concentration, and the aerobic operation period in which the mixed liquid is Removing nitrogen, causing the phosphorus removing microorganism to absorb phosphorus excessively during the exhalation operation period, and transferring the mixed solution to the membrane filtration tank; Optionally in a simultaneous nitrification tank or a simultaneous nitrification tank, returning the mixed liquor to the anaerobic tank during anoxic operation; The outside of the membrane filter is continuously washed while supplying air to the membrane filter from the bottom of the membrane filter, the suction pump is operated to transfer the membrane filtrate to the membrane filtrate reservoir, and the dissolved oxygen concentration of the membrane filter tank is maintained at 2 mg / L or more. And returning the mixed liquid to the simultaneous nitrification denitrification tank or nitrification tank; Periodically backwashing the membrane with filtered water and chemicals using the chemical based on the degree of contamination of the membrane filter; And removing a portion of the mixed solution of the membrane filtration tank and disposing of the mixed liquid into excess sludge, thereby providing an operation method of the submerged membrane advanced treatment process.

In addition, the present invention is a pretreatment apparatus for removing the fine solids in the influent in the advanced treatment process using a submerged membrane bioreactor; A flow rate adjusting tank for storing the inflow water that has passed the pretreatment step for a predetermined period of time and supplying the flow rate evenly; A mixing stabilizer for mixing the inflow water conveyed from the flow rate control tank with the return water returned from the simultaneous nitrification denitrification tank to achieve uniform water quality and depleting nitrate nitrogen and dissolved oxygen contained in the return water; An anaerobic tank in which a mixed solution of the inflow water and the return water passing through the mixing stabilizer flows in, and the phosphorus removing microorganism releases phosphorus in a complete anaerobic state while staying for a certain period of time, and maintains a completely mixed state by the action of an anaerobic stirrer; It has aeration and agitation means inside, and it is equipped with dissolved oxygen concentration meter and redox potentiometer, and performs nitrification and denitrification at the same time while maintaining low dissolved oxygen concentration. Simultaneous nitrification denitrification tank to maintain; A variable capacity aeration blower for supplying air to the aeration and agitation means installed in the simultaneous nitrification denitrification tank; A membrane filter for filtering the mixed liquid passed through the simultaneous nitrification denitrification tank to separate the solids and the membrane filtrate; A membrane filtration tank having the membrane filter installed therein; A membrane cleaning diffuser for cleaning the outside of the filtration membrane of the membrane filter; A membrane cleaning blower for supplying a mixed gas to the membrane cleaning diffuser; The upper end of the membrane filter is installed so that the lower end is immersed, the gas passing through the membrane filter is collected, the collected gas is returned to the inlet of the membrane cleaning blower, and the ratio of the return gas to the outside air amount is adjusted. A collection gas circulation control device for adjusting the dissolved oxygen concentration of the membrane filtration tank; A membrane filtration tank mixed liquid conveying pump of a variable capacity for conveying the mixed liquid of the membrane filtration tank to the simultaneous nitrification denitrification tank or nitrification tank; A variable capacity internal conveying pump for conveying the mixed solution of the simultaneous nitrification denitrification tank or nitrification tank to the mixing stabilizer or the mixing stabilizer and the anoxic tank; A membrane filtrate reservoir for storing filtrate that has passed through the membrane filtrate pump; An air supersaturated water washing apparatus for making water in the membrane filtered water reservoir into air supersaturated water to backwash the membrane of the membrane filter; A chemical cleaning device for cleaning the membrane filter with a chemical; And a control panel for automatically controlling the operation of the pretreatment device, aeration blower, membrane cleaning blower, collection gas circulation control device, mixed liquid return pump, variable capacity internal return pump, air supersaturated water cleaning device, and chemical cleaning device. Provide a membrane advanced processing device.

In addition, the present invention is a high-precision fixing using a submerged membrane bioreactor, pre-treatment apparatus for removing the fine solids in the influent; A flow rate adjusting tank for storing the inflow water that has passed through the pretreatment step for a predetermined period of time and supplying the flow rate evenly; A mixing stabilizer for mixing the inflow water conveyed from the flow rate adjusting tank with the return water conveyed from the simultaneous nitrification denitrification tank to have an equal water quality, and depleting nitrate nitrogen and dissolved oxygen contained in the return water; An anaerobic tank in which the mixed solution of the inflow water and the return water passing through the mixing stabilizer flows in and stays there for a period of time, and is maintained in a fully mixed state by the function of an anaerobic stirrer releasing phosphorus in the completely anaerobic state; It has aeration and agitation means inside, and it is equipped with dissolved oxygen concentration meter and redox potentiometer, performs nitrification and denitrification at the same time while maintaining low dissolved oxygen concentration. Simultaneous nitrification denitrification tank to maintain; A membrane filter for filtering the mixed solution passed through the simultaneous nitrification denitrification tank to separate the solids and the filtered water; A membrane filtration tank having the membrane filter installed therein; A membrane cleaning tube for cleaning the outside of the filtration membrane of the membrane filter; A membrane cleaning blower for supplying a mixed gas to the membrane cleaning diffuser; Electric fluid door adjusting the conveyance amount of the mixed liquid conveyed to the simultaneous nitrification denitrification tank or the nitrification tank from the mixed liquid conveying pump or the membrane filtration tank partitioned by the partition wall to adjust the conveyed amount of the mixed liquid conveyed from the membrane filtration tank to the simultaneous nitridation tank or nitrification tank ; A variable-capacity internal conveying pump for conveying the mixed liquid of the simultaneous nitrification denitrification tank or the mixed liquid of the mixed stabilizer tank or the nitrification tank to the mixed stabilizer and the oxygen-free furnace; A membrane filtrate reservoir for storing filtrate that has passed through the membrane filtrate pump; An air supersaturated water washing apparatus for making water in the membrane filtered water reservoir into supersaturated water to backwash the membrane of the membrane filter; A chemical cleaning device for cleaning the membrane filter with a chemical; And a control panel for automatically controlling the operation of the pretreatment device, aeration blower, membrane cleaning blower, electric sluice, mixed liquid conveying pump, variable capacity internal return pump, air supersaturated water cleaning device, and chemical cleaning device. Provide the device.

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The operation method of the submerged membrane advanced treatment process and the submerged membrane advanced treatment apparatus using the method have the following effects.
First, by returning the mixed solution of the membrane filtration tank to the simultaneous nitrification denitrification tank for the contaminant load fluctuations of the sewage, it is possible to increase the nitrogen removal rate by performing simultaneous nitrification denitrification by maintaining the dissolved oxygen concentration of the simultaneous nitrification denitrification tank.
Second, by returning the mixed solution of the simultaneous nitrification denitrification tank with low dissolved oxygen concentration to the anaerobic tank, the use of coagulant required for phosphorus removal by increasing phosphorus removal efficiency is unnecessary, economical effect of saving energy, and clean effluent can be obtained. It can protect the quality of the water.

1 is a flowchart illustrating a method of operating a submerged membrane advanced treatment process according to an embodiment of the present invention.
2 is a view schematically showing the configuration of an embodiment of the submerged membrane advanced processing apparatus using the operation method of the submerged membrane advanced processing process according to the present invention.
3 is a view schematically showing the configuration of another embodiment of the submerged membrane advanced processing apparatus using the operation method of the submerged membrane advanced processing process according to the present invention.
4 is a view schematically showing a state in which internal conveyance is performed in an oxygen-free state.
5 is a view showing a modified example of the submerged membrane advanced processing apparatus shown in FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately The present invention should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention.
1 is a flow chart showing the operation method of the submerged membrane advanced processing process according to an embodiment of the present invention, Figure 2 is an embodiment of the submerged membrane advanced processing apparatus operating method of the submerged membrane advanced processing process according to the present invention Figure 3 schematically shows the configuration of the example, Figure 3 is a schematic view showing the configuration of another embodiment of the submerged membrane advanced processing apparatus operating method of the submerged membrane advanced processing process according to the present invention, Figure 4 is in an anoxic state It is a figure which shows schematically the state in which internal conveyance is carried out.
Referring to the drawings, the operation method of the submerged membrane advanced treatment process according to an embodiment of the present invention and the submerged membrane advanced processing apparatus using the method are as follows.

First, in the pretreatment apparatus 10 for removing fine solids in the influent, after the step S10 of removing sand and large impurities and fine impurities contained in the influent (sewage, wastewater, etc.), the influent is stored for a period of time. It transfers to the flow volume adjusting tank 20 for supplying a flow volume evenly.

While staying in the flow regulating tank 20 for 6 to 12 hours, it buffers against fluctuations in flow rate, and the flow regulating tank pump 80 supplies water inflows with equal quality and quantity to the subsequent treatment, and adjusts the flow regulating tank 20. When the water level is between the high water level and the low water level, it is automatically operated and goes through a 10-minute operation, repeating the 2-minute stop operation or performing a continuous operation according to the characteristics of the membrane filter 61.

When the water level of the flow adjustment tank 20 is lower than the low water level, the flow adjustment tank pump 80 stops operation, and when the water level of the flow adjustment tank reaches a high water level, operation starts again and operates as described above.

The flow rate adjusting tank pump 80 stops operation when the water level of the membrane filtration tank 60, which will be described later, becomes 5 cm (not limited to this value) higher than the planned value, and when the water level of the membrane filtration tank 60 becomes lower than the value. Start driving automatically. The planned value of the water level of the membrane filtration tank 60 is not limited to exactly 5 cm, and may be slightly lower or higher than this.

The inflow water transferred to the flow adjustment tank pump 80 is introduced into the drum screen 90 to remove fine contaminants at a high removal rate.

The membrane filter 61 of the membrane filtration tank 60 has a filtration capability that is difficult to remove even when washed if a disorder such as a hairy fiber-like contaminant is wound around the membrane (hollow fiber membrane) during long-term use. In order to prevent such a failure and to shorten the life of the membrane, it is more preferable to remove impurities of 0.5 mm or more from the drum screen 90 and to remove small impurities of 0.2 mm to 0.3 mm or less.

The mixing stabilizer 30 is fed to the inflow water from which the fine contaminants have been removed from the drum screen 90, and mixed with the return water returned from the simultaneous nitrification denitrification tank 50 to be uniform water quality (hereinafter referred to as "mixed liquid"). And depleting the nitrate nitrogen and dissolved oxygen contained in the return water. The mixed liquid depleted of nitrate nitrogen and dissolved oxygen contained in the returned water is subjected to the step (S30) to be transferred to the anaerobic tank (40).

The anaerobic tank 40 is introduced into the mixed liquid passed through the mixing stabilizer 30, and generally stays for 1 to 2 hours, in a complete anaerobic state in which all the nitrate nitrogen and dissolved oxygen is depleted and the organic matter is sufficient, While maintaining a fully mixed state by the action of the stirrer 45, the phosphorus-removing microorganisms sufficiently release the phosphorus stored in the body into the mixed liquid.

When phosphorus release occurs well in the anaerobic tank 40, the concentration of phosphorus in the mixed solution in the anaerobic tank is increased.

The mixed liquid passed through the anaerobic tank 40 is subjected to the step (S40) to be transferred to the simultaneous nitrification denitrification tank 50 or the nitrification tank 50A, the simultaneous nitrification denitrification tank 50 is sufficient dissolved oxygen concentration therein Aeration and agitation means (51) are provided for securing and ensuring complete mixing conditions, and a dissolved oxygen concentration meter (54) and a redox potentiometer (55) for measuring an appropriate low dissolved oxygen concentration to facilitate simultaneous nitrification and denitrification. And maintain a low dissolved oxygen concentration in the range of 0.3-0.7 mg / L.

When the redox potential of the redox potentiometer 55 is maintained at a specific value of +, the nitrification rate of the nitrifying microorganisms and the denitrification rate of the denitrifying microorganisms (bacteria) are balanced, while nitrification and denitrification occur simultaneously at the same place. Nitrogen is removed at a high removal rate of 90 to 95% or more, and the phosphorus removal microorganism excessively absorbs phosphorus and organic matter is also removed.

Air is supplied to the aeration and agitating means 51 installed inside the simultaneous nitrification denitrification tank 50 from the outside by using the aeration blower 52 of variable capacity.

Preferably, the aeration and agitation means 51 may use an underwater aeration device supplied with air from the outside, and a combination of a mechanical stirrer and a microbubble diffuser installed at the bottom of the simultaneous nitrification denitrification tank 50 may be used. Do.

Nitrogen and organic matters are removed from the simultaneous nitrification denitrification tank 50, and the mixed solution including the phosphorus removing microorganism that excessively absorbed phosphorus is passed to the membrane filtration tank 60 (S50), and the membrane filter 61 ) Filter out the solids in the mixture and produce a clean filtrate.

The membrane filter 61 is filtered by the head difference generated by the suction force of the membrane filtration pump 120, the head difference for the membrane filtration is different depending on the type of membrane, but in the MF (precision) membrane is usually 3 to 5m Filtration and re-suspension are repeated for 10 minutes to prevent clogging and elastic recovery of the membrane, which is preferably in accordance with membrane manufacturer requirements.

In order to prevent microorganisms or other foreign matter from adhering to the outside of the membrane filter 61, a membrane cleaning diffuser 62 is provided below the membrane filter 61, and the gas supplied from the membrane cleaning blower 63 is provided. Spraying to clean the outside of the membrane filter 61 by the cleaning force by the vibration of the air and buoyancy.

The amount of gas for external cleaning of the membrane filter 61 varies slightly depending on the membrane manufacturer, but in general, 75 to 100 m 3 / hr or 150 m 3 / hr or more per horizontal projection area of the membrane filter 61 is preferable. There is also.

The amount of gas for cleaning the membrane filter 61 as described above is very large, and if the gas is all air, in the advanced biological treatment process, when the influent BOD concentration is 150 mg / L or less, it is over-aerated and anaerobic or Due to the nature of the advanced treatment process, which requires an anoxic state, the dissolved oxygen concentration in the returned water is high, which prevents the formation of anaerobic or anoxic states, making it impossible to perform advanced biotreatment to remove total nitrogen and total phosphorus, or extremely high treatment efficiency. Will be low.

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2 and 3 show an embodiment using different collected gas circulation control device (64).

The collecting gas circulation adjusting device 64 installs a gas collecting tube so that the lower end is locked on the upper surface of the membrane filter 61, collects the gas passing through the membrane filter 61, and collects the collected gas. It conveys to the inlet of the said membrane washing blower 63 via a gas piping, adjusts the opening degree of a control valve (not shown), and adjusts the ratio of the conveyed collection gas and the quantity of air which flows in into the membrane washing blower 63 from the outside. Thus, the dissolved oxygen concentration of the membrane washing filtration tank 60 is adjusted to 0.5 to 3.0 mg / L, but the total amount of gas passing through the membrane filter 61 is always kept constant, thereby ensuring the cleaning power of the membrane filter 61. It was made.

After the variable volume of the membrane filtration tank mixed liquid conveying pump 100, the mixed liquid of the membrane filtration tank 60 is returned to the simultaneous nitrification denitrification tank 50 or the nitrification tank 50A (S60), and then the inflow water When the BOD concentration is higher than 200 mg / L and the amount of inflow is large, the MLSS concentration in the simultaneous nitrification denitrification tank 50 is high and there is no fear of supersaturation. Therefore, in order to make maximum use of the dissolved air in the membrane filtration tank 60. The amount of circulating gas is reduced in the collected gas circulation adjusting device 64, and the amount of air supplied from the outside to the membrane cleaning blower 63 is adjusted to be the maximum, and the membrane filtration tank 60 having a high dissolved oxygen concentration of about 5 to 7 mg / L is operated. The mixed liquor) is returned to the simultaneous nitrification denitrification tank 50 at a rate of up to 60 times the amount of the influent.

When conveying as mentioned above, since the amount of oxygen required for the simultaneous nitrification denitrification tank 50 can be supplied sufficiently, power is saved because there is no need to supply air separately.

If the BOD concentration of the influent is reduced or the pollution load is reduced due to the reduction of the influent, the amount of dissolved oxygen required for the bioreactor is reduced and the required MLSS concentration of the bioreactor is reduced. The amount of air is reduced and the amount of circulating gas is adjusted to keep the dissolved oxygen concentration of the membrane filtration tank 60 at a low range of 0.5 to 2.0 mg / L, and the amount of the mixed liquid conveying pump is adjusted to adjust the amount of the mixed liquid in the membrane filtration tank. The amount is appropriately adjusted in the range of 30 to 200%, and adjusted so that the dissolved oxygen concentration of the co-nitridation denitrification tank 50 is an appropriate value in the range of 0.3 to 0.7 mg / L.

When the dissolved oxygen concentration of the simultaneous nitrification denitrification tank can be maintained only by conveying the mixed liquid, the operation of the aeration blower 52 is stopped and only the stirring means is operated.

In order to maintain the concentration of the mixed solution with respect to the influent, and to supply the phosphorus removing microorganism to the mixing stabilizer 30 and the anaerobic tank 40, internal conveyance should be performed.

In the internal conveyance, the mixed liquid of the simultaneous nitrification denitrification tank 50 having low dissolved oxygen concentration is operated by operating the internal conveying pump 110 so that nitrate nitrogen and dissolved oxygen can be depleted in the mixing stabilizer 30 in a short time. Return to 30.

Although the internal conveyance ratio is 100% as a standard, it is operated with a variable adjustment in the range of 10 to 150% according to the variation of the pollution load.

The simultaneous nitrification denitrification tank 50 is preferably operated at a low dissolved oxygen concentration range, but in another embodiment, the aeration blower 52 is periodically supplied to the aeration and agitation means 51 of the simultaneous nitrification denitrification tank 50. It is also preferable to operate by dividing the operation and stopping repeatedly, and the aerobic operation to operate in aerobic state by supplying air and the anaerobic operation period to stop the air supply and operate in an anaerobic state.

The aerobic and anaerobic operating periods are preferably adjusted within the range of 20 to 60 minutes.

During the exhalation period, the dissolved oxygen concentration of the nitrification nitrification tank may be operated in the range of 0.3 to 0.7 mg / L (when the hydraulic residence time is long) and in the range of 0.5 to 1.5 mg / L as described in detail above. desirable.

Nitrogen nitrogen and dissolved oxygen depletion occur in a short time in the mixing stabilizer 30, the consumption of organic matter due to nitrate nitrogen and dissolved oxygen in the mixing stabilizer 30 is minimized, the anaerobic tank 40 is nitrate nitrogen In order to maintain the complete anaerobic condition without dissolved oxygen and to increase phosphorus removal efficiency, in the aerobic anaerobic repetitive operation condition, the internal transfer is preferably performed only during the anaerobic operation period as shown in FIG. The pump 110 needs to increase the capacity because it needs to return the required amount in a short time.

In order to maintain the performance of the membrane filter (61) over a long period of time through the chemical cleaning step (S70), such as internal backwash of the membrane using a periodic air supersaturated water, periodic chemical cleaning, the step of cleaning the chemical It is preferable to perform periodic out-of-system washing about S70 once a year.

Backwash and chemical cleaning devices are already well known, so detailed description thereof will be omitted.

Since the advanced processing device using the submerged membrane filter is a technology intensive facility, it is impossible to operate it manually.The pretreatment device, the aeration blower, the membrane cleaning blower, the electric water gate, the mixed liquid return pump, the variable capacity internal return pump, the air supersaturation Water scrubbers and chemical scrubbers, for example, chemical scrubber 150 for cleaning the membrane filter with chemicals, air supersaturated water scrubber 130, pretreatment device 10, flow control tank pump 30, A control panel 160 for automatically controlling the measurement and operation of the various mechanical devices and measuring instruments such as the drum screen 90 and the mixing stabilizer stirrer 35 was installed to configure the facility to automatically operate.

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3 shows that the trapped gas circulation control device 64 is removed in the configuration of FIG. 2, and the structure of the facility is relatively simple.

The operation method of FIG. 3 is largely the same as the case of FIG. 2, but the dissolved oxygen concentration of the membrane filtration tank 60 is high at 6-9 mg / L, which is the saturation concentration at low load, so that the mixed liquid in the membrane filtration tank 60 Although denitrification microorganisms are inhibited by the gene, the dissolved oxygen concentration of the simultaneous nitrification denitrification tank 50 is appropriately controlled by controlling the amount of the mixed liquid returned from the membrane filtration tank 60 to the simultaneous nitrification denitrification tank 50. Controllable as is the same as described above.

The mixing stabilizer (30), anaerobic tank (40), simultaneous nitrification denitrification tank (50) and membrane filtration tank (60) and related machinery are operated only during the period in which the flow regulating tank pump (80) is operated or the flow regulating tank pump (80). It is desirable to operate only for 10 minutes after stopping.

If there is no sewage inflow, the continuous operation of the machinery wastes energy due to problems with the advanced processing process due to over-aeration and unnecessary operation.

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FIG. 5 divides the simultaneous nitrification denitrification tank 50 or the nitrification tank 50A and the membrane filtration tank 60 into partitions 501, forms openings in the lower part and the upper part of the partition wall, and the electric water gate 57 in the upper opening part. ) Is installed.

When the size combination of the membrane filtration tank 60 formed by the partition 501 and the membrane filter 61 is appropriate, when the membrane cleaning air is supplied to the membrane cleaning diffuser 62 provided below the membrane filter, the membrane cleaning is performed. A bubble pump is formed in the portion due to the rise of air so that the water surface of the membrane filtration tank 60 is about 10 to 20 cm higher than the water surface of the simultaneous nitrification denitrification tank 50 or the nitrification tank 50A. ).

As described above, when the electric door 57 is opened and the opening degree is increased in the state in which the water surface of the membrane filtration tank 60 is increased, the mixed liquid of the membrane filtration tank 60 is opened at the opening formed by the opening degree of the electric door 57. 50 or the nitrification tank 50A, and the mixed liquid is conveyed, and the conveyed amount of the mixed liquid is proportional to the opening degree of the electric hydrograph 57, and when the mixed liquid is conveyed, the nitrification simultaneous denitrification tank ( 50) or the mixed liquid is transferred to the membrane filtration tank 60 from the nitrification tank 50A.

The excess of the mixed solution of the membrane filtration tank 60 is withdrawn to the outside to dispose of excess sludge to release the phosphorus (S80), when the mixed liquid concentration of the membrane filtration tank 60 is low, the volume of the excess sludge is large Because of this, various problems may occur. To prevent this, when the excess sludge is taken out, the amount of the mixed liquid returned from the membrane filtration tank 60 to the simultaneous nitrification denitrification tank 50 or the nitrification tank 50A is temporarily reduced. Concentration of the mixed liquor is increased, and the volume of excess sludge is reduced.
Accordingly, by returning the mixed solution of the membrane filtration tank to the simultaneous nitrification denitrification tank, the dissolved oxygen concentration of the simultaneous nitrification denitrification tank can be properly maintained and the simultaneous nitrification denitrification can be performed to increase the nitrogen removal rate. By returning the mixed solution of the simultaneous nitrification denitrification tank with low temperature to the anaerobic tank, it is possible to increase the phosphorus removal efficiency, eliminate the use of coagulant required for phosphorus removal, save the energy, and obtain the clean effluent, thereby protecting the water quality of the discharged water. Can be.

10 pretreatment unit
20 Flow Adjustment Tank
30 mixing stabilizer
35 Mixing Stabilizer Stirrer
40 anaerobic tanks
45 anaerobic agitator
46 Anaerobic Tank
50 simultaneous nitrification denitrification tank
50A Nitrification Tank (Aeration Tank)
51 Aeration and stirring means
52 aeration blower
53 air piping
54 dissolved oxygen concentration meter
55 Redox Potentiometer 57 Electric Gate 501 Bulkhead
60 membrane filtration tank
61 membrane filter
62 membrane cleaning diffuser
63 membrane cleaning blower
64 Collected gas circulation regulator
65 Circulating gas pipe
70 membrane filtrate reservoir
80 flow regulator pump
90 drum screen
100 Mixed Liquid Return Pump
110 Internal Transfer Pump
120 membrane filtration pump
130 Air Supersaturated Water Washer
140 surplus sludge pump
150 chemical cleaning device
160 control board

Claims (7)

In an advanced treatment process using a submerged membrane bioreactor,
To remove the dirt and sand contained in sewage:
When the level of the flow adjusting tank is above the set value, the flow adjusting tank pump automatically starts operation and transfers the sewage to the mixing stabilizer in a certain amount, but the level of the membrane filtration tank is 5cm higher than the planned value or Stopping operation when the water level is lower than the planned minimum value;
Mixing the internal transport liquid and the sewage returned from the simultaneous nitrification denitrification tank or the nitrification tank in the mixing stability tank, depleting the trace amount of nitrate nitrogen and dissolved oxygen contained in the internal transport liquid, and transferring the mixed liquid to the anaerobic tank ;
Mixing the mixed liquid transferred to the anaerobic tank under complete mixing conditions, releasing the phosphorus accumulated in the microorganism body in the anaerobic state into the mixed liquid, and transferring the mixed liquid to a simultaneous nitrification denitrification tank or nitrification tank;
In the simultaneous nitrification denitrification tank, the mixed solution is stirred under the conditions of complete mixing, while maintaining the dissolved oxygen concentration in the range of 0.3 to 0.7 mg / L, simultaneously performing nitrification and denitrification to remove nitrogen, and the phosphorus-removing microorganism absorbs excess phosphorus. Or by supplying air to the mixed solution to keep the dissolved oxygen concentration at 0.5 to 1.0 mg / L, and repeatedly operating the aerobic operation period for stirring and the anoxic operation period for stopping the air supply to the mixture solution and stirring, alternately Simultaneously performing denitrification to remove nitrogen, causing the phosphorus removing microorganism to absorb phosphorus in excess during the exhalation operation period, and transferring the mixed solution to the membrane filtration tank;
Alternatively, the mixed solution is stirred in the nitrification tank under complete mixing conditions, nitrification is performed while maintaining the dissolved oxygen concentration in the range of 1.0 to 2.0 mg / L, and the mixed solution is returned to the anoxic tank and the anaerobic tank to remove nitrogen, and the phosphorus removing microorganism The mixed liquor is operated in an oxygen-free tank while repeatedly operating the aerobic operation period in which excess phosphorus is absorbed or air is supplied to the mixed liquid to increase the dissolved oxygen concentration and the aerobic operation period in which the air is supplied to the mixed liquid is stopped while stirring. Returning to remove nitrogen, causing the phosphorus removing microorganism to absorb excess phosphorus during the exhalation operation period and transferring the mixed solution to the membrane filtration tank;
Optionally returning the mixed liquor to the anaerobic tank during anoxic operation in a simultaneous nitrification tank or a simultaneous nitrification tank;
The outside of the membrane filter is continuously cleaned while supplying air to the membrane filter from the lower part of the membrane filter, the suction pump is operated to transfer the membrane filtrate to the membrane filter water reservoir, and purified by a trapping gas circulation regulator installed at the top of the membrane filter. Adjusting the inflow rate of gas and external air to maintain the dissolved oxygen concentration of the membrane filtration tank in the range of 0.5 to 3.0 mg / L, and returning the mixed liquid to the simultaneous nitrification denitrification tank or nitrification tank;
Periodically washing the countercurrent with the membrane filtrate and the chemical with the chemical to the degree of contamination of the membrane filter; And
A method of operating a submerged membrane advanced treatment process, comprising: removing a portion of the mixed solution of the membrane filtration tank and disposing it as excess sludge to remove phosphorus. In an advanced treatment process using a submerged membrane bioreactor,
To remove the dirt and sand contained in sewage:
When the water level in the flow control tank is over the set value, the flow control pump automatically starts operation and transfers the sewage to the mixing stabilizer in a certain amount, but the level of the membrane filtration tank is 5cm higher than the planned value, Stopping operation when the water level is lower than the planned minimum value;
Mixing the internal transport liquid and the sewage returned from the simultaneous nitrification denitrification tank or the nitrification tank in a mixing stability tank, depleting the trace amount of nitrate nitrogen and dissolved oxygen contained in the internal transport liquid and transferring the mixed solution to the anaerobic tank;
Mixing the mixed liquid transferred to the anaerobic tank under complete mixing conditions, releasing the phosphorus accumulated in the microorganism body in the anaerobic state into the mixed liquid, and transferring the mixed liquid to a simultaneous nitrification denitrification tank or nitrification tank;
In the simultaneous nitrification denitrification tank, the mixed solution is stirred under the conditions of complete mixing, and the nitrogen removal is carried out by simultaneously performing nitrification and denitrification while maintaining the dissolved oxygen concentration in the range of 0.3 to 0.7 mg / L. Or nitrification and denitrification by alternately operating the aerobic operation period in which the dissolved oxygen concentration is adjusted to 0.5 to 1.0 mg / L by supplying air to the mixed liquid and the anoxic operation period in which the air is supplied to the mixed liquid is stopped while stirring. Carrying out simultaneous nitrogen removal, causing phosphorus removal microorganisms to absorb phosphorus in excess during the exhalation operation period and transferring the mixed solution to the membrane filtration tank;
Alternatively, the mixed solution is stirred under complete mixing conditions in the nitrification tank, nitrification is performed while maintaining the dissolved oxygen concentration in the range of 1.0 to 2.0 mg / L, and the mixed solution is returned to the anoxic tank and the anaerobic tank to remove nitrogen, and the phosphorus removing microorganism is phosphorus. The mixed liquid is returned to the anoxic tank while operating the aerobic operation period in which the excess liquid is absorbed excessively or the air is supplied to the mixed liquid to increase the dissolved oxygen concentration, and the aerobic operation period in which the mixed liquid is Removing nitrogen, causing the phosphorus removing microorganism to absorb phosphorus excessively during the exhalation operation period, and transferring the mixed solution to the membrane filtration tank;
Optionally in a simultaneous nitrification tank or a simultaneous nitrification tank, returning the mixed liquor to the anaerobic tank during anoxic operation;
The outside of the membrane filter is continuously washed while supplying air to the membrane filter from the bottom of the membrane filter, the suction pump is operated to transfer the membrane filtrate to the membrane filtrate reservoir, and the dissolved oxygen concentration of the membrane filter tank is maintained at 2 mg / L or more. And returning the mixed liquid to the simultaneous nitrification denitrification tank or nitrification tank; Periodically backwashing the membrane with filtered water and chemicals using the chemical based on the degree of contamination of the membrane filter; And
A method of operating a submerged membrane advanced treatment process, comprising: removing a portion of the mixed solution of the membrane filtration tank and disposing it as excess sludge to remove phosphorus. In the advanced treatment process using a submerged membrane bioreactor,
A pretreatment device for removing fine solids in the influent;
A flow rate adjusting tank for storing the inflow water that has passed the pretreatment step for a predetermined period of time and supplying the flow rate evenly;
A mixing stabilizer for mixing the inflow water conveyed from the flow rate control tank with the return water returned from the simultaneous nitrification denitrification tank to achieve uniform water quality and depleting nitrate nitrogen and dissolved oxygen contained in the return water;
An anaerobic tank in which a mixed solution of the inflow water and the return water passing through the mixing stabilizer flows in, and the phosphorus removing microorganism releases phosphorus in a complete anaerobic state while staying for a certain period of time, and maintains a completely mixed state by the action of an anaerobic agitator;
It has aeration and agitation means inside, and it is equipped with dissolved oxygen concentration meter and redox potentiometer, and performs nitrification and denitrification at the same time while maintaining low dissolved oxygen concentration. Simultaneous nitrification denitrification tank to maintain;
A variable capacity aeration blower for supplying air to the aeration and agitation means installed in the simultaneous nitrification denitrification tank;
A membrane filter for filtering the mixed liquid passed through the simultaneous nitrification denitrification tank to separate the solids and the membrane filtrate;
A membrane filtration tank having the membrane filter installed therein;
A membrane cleaning diffuser for cleaning the outside of the filtration membrane of the membrane filter;
A membrane cleaning blower for supplying a mixed gas to the membrane cleaning diffuser;
The upper end of the membrane filter is installed so that the lower end is immersed, the gas passing through the membrane filter is collected, the collected gas is returned to the inlet of the membrane cleaning blower, and the ratio of the return gas to the outside air amount is adjusted. A collection gas circulation control device for adjusting the dissolved oxygen concentration of the membrane filtration tank;
A membrane filtration tank mixed liquid conveying pump of a variable capacity for conveying the mixed liquid of the membrane filtration tank to the simultaneous nitrification denitrification tank or nitrification tank;
A variable capacity internal conveying pump for conveying the mixed liquid of the simultaneous nitrification denitrification tank or nitrification tank to the mixing stabilizer or the mixing stabilizer and the anoxic tank;
A membrane filtrate reservoir for storing filtrate that has passed through the membrane filtrate pump;
An air supersaturated water washing apparatus for making water in the membrane filtered water reservoir into air supersaturated water to backwash the membrane of the membrane filter;
A chemical cleaning device for cleaning the membrane filter with a chemical; And
The front end processor, giving blower, membrane washing blower, trapped gas recirculation regulating device, mixed liquid conveying pump, is flooded, including the control panel, which automatically controls the internal return pump, air supersaturated washing unit and driving of the drug cleaning apparatus of a variable capacity type Membrane advanced processing equipment. In the advanced treatment fixing using submerged membrane bioreactor,
A pretreatment device for removing fine solids in the influent;
A flow rate adjusting tank for storing the inflow water that has passed through the pretreatment step for a predetermined period of time and supplying the flow rate evenly;
A mixing stabilizer for mixing the inflow water conveyed from the flow rate adjusting tank with the return water conveyed from the simultaneous nitrification denitrification tank to have an equal water quality, and depleting nitrate nitrogen and dissolved oxygen contained in the return water;
An anaerobic tank in which the mixed solution of the inflow water and the return water passing through the mixing stabilizer flows in and stays there for a period of time, and is maintained in a fully mixed state by the function of an anaerobic stirrer releasing phosphorus in the completely anaerobic state;
It has aeration and agitation means inside, and it is equipped with dissolved oxygen concentration meter and redox potentiometer, performs nitrification and denitrification at the same time while maintaining low dissolved oxygen concentration. Simultaneous nitrification denitrification tank to maintain;
A membrane filter for filtering the mixed solution passed through the simultaneous nitrification denitrification tank to separate the solids and the filtered water;
A membrane filtration tank having the membrane filter installed therein;
A membrane cleaning tube for cleaning the outside of the filtration membrane of the membrane filter;
A membrane cleaning blower for supplying a mixed gas to the membrane cleaning diffuser;
Electric fluid door adjusting the conveyance amount of the mixed liquid conveyed to the simultaneous nitrification denitrification tank or the nitrification tank from the mixed liquid conveying pump or the membrane filtration tank partitioned by the partition wall to adjust the conveyed amount of the mixed liquid conveyed from the membrane filtration tank to the simultaneous nitridation tank or nitrification tank ;
A variable-capacity internal conveying pump for conveying the mixed liquid of the simultaneous nitrification denitrification tank or the mixed liquid of the mixed stabilizer tank or the nitrification tank to the mixed stabilizer and the oxygen-free furnace;
A membrane filtrate reservoir for storing filtrate that has passed through the membrane filtrate pump;
An air supersaturated water washing apparatus for making water in the membrane filtered water reservoir into supersaturated water to backwash the membrane of the membrane filter;
A chemical cleaning device for cleaning the membrane filter with a chemical; And
Submerged membrane advanced processing apparatus including a control panel for automatically controlling the operation of the pretreatment device, aeration blower, membrane cleaning blower, electric sluice, mixed liquid conveying pump, variable capacity internal return pump, air supersaturated water cleaning device and chemical cleaning device . The method according to claim 1 or 2,
A method of operating a submerged membrane advanced treatment process, characterized in that the amount of conveyed liquid mixture is temporarily reduced in the step of removing excess sludge to remove phosphorus, thereby increasing the concentration of the mixed membrane filtration tank to reduce the waste volume of the excess sludge. The method according to claim 1 or 2,
A method of operating a submerged membrane advanced processing process characterized in that the machinery of the advanced processing process is operated only for 10 minutes after the flow regulating pump is operated or stopped. The method according to claim 1 or 2,
An operating method of the submerged membrane advanced treatment process, characterized in that the amount of oxygen supplied to the simultaneous nitrification denitrification tank or the nitrification tank is adjusted by adjusting the conveying amount of the mixed liquid of the membrane filtration tank.

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