Membrane bioreactor and use method thereof

Abstract

The invention belongs to the field of membrane bioreactors, and particularly relates to a membrane bioreactor and a use method thereof. The membrane bioreactor comprises a curtain type membrane assembly, an intermittent aeration device arranged below the curtain type membrane assembly and a micro aeration device arranged below the intermittent aeration device, and the intermittent aeration device provides intermittent aeration for the curtain type membrane assembly; and the micro-aeration device is used for providing continuous aeration for the curtain type membrane component. Compared with a continuous aeration mode in the prior art, the method has the advantages that the energy consumption is comprehensively saved by about 50%, and the dissolved oxygen in the water body is reduced to be less than 1 / 2 of that in the prior art due to the fact that the gas supply amount in the MBR membrane bioreactor filtering process is reduced, so that the sludge refluxed to the front end of the biochemical process is more beneficial to the sewage treatment effect.

Description

Technical Field

[0001] The invention belongs to the field of membrane bioreactors, and in particular relates to a membrane bioreactor and a use method thereof. Background Art

[0002] With the widespread application of membrane technology in the field of water treatment, especially the continuous popularization of membrane bioreactor technology in the field of sewage treatment, the high energy consumption defect of membrane bioreactor technology has gradually become prominent, and has restricted the market promotion of membrane bioreactor technology. The defects are as follows:

[0003] 1. Since a high concentration of activated sludge is maintained in the bioreactor, a large amount of air is required to purge the membrane assembly to ensure that there is no sludge attached to the surface of the membrane assembly, thereby ensuring the effective filtration area and water permeability of the membrane assembly, which results in high energy consumption.

[0004] 2. In order to ensure the effective nitrification and denitrification process, the activated sludge cannot show sedimentation and other phenomena. Therefore, a large amount of air is required to ensure the balance of the activated sludge in the water body, which consumes a lot of energy.

[0005] 3. Under normal circumstances, the high dissolved oxygen wastewater concentrated by the membrane bioreactor needs to be returned to the denitrification section to enter the entire biochemical process again. The return of high dissolved oxygen wastewater is not conducive to the denitrification process, so it is most beneficial to require no dissolved oxygen in the water body. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a membrane bioreactor and a method for using the same.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A membrane bioreactor comprises a curtain membrane assembly, an intermittent aeration device arranged below the curtain membrane assembly and a micro-aeration device arranged below the intermittent aeration device, wherein the intermittent aeration device provides intermittent aeration for the curtain membrane assembly; and the micro-aeration device provides continuous aeration for the curtain membrane assembly.

[0009] The aeration frequency of the intermittent aeration device is 30-60 seconds of aeration every 5-30 minutes.

[0010] The aeration capacity of the micro-aeration device is 1-3m 3 / h; preferably 2m 3 / h.

[0011] The curtain membrane assembly comprises membrane shells arranged at the upper and lower ends and a curtain membrane arranged between the membrane shells; preferably, water outlets are arranged on the membrane shells at the upper and lower ends.

[0012] The micro-aeration device comprises a micro-aeration pipe arranged at the bottom of the curtain membrane assembly and a Roots blower connected to the micro-aeration pipe.

[0013] The intermittent aeration device comprises an aeration plate arranged at the bottom of the curtain membrane assembly and an air compressor connected to the aeration plate.

[0014] The curtain membrane assembly also includes a filtering system, a backwashing system and a vacuum system.

[0015] The present invention also includes a method for using the membrane bioreactor, comprising the following steps: 1) installing a curtain membrane assembly in a reaction tank; 2) installing an intermittent aeration device and a micro-aeration device below the curtain membrane assembly; 3) sewage enters the reaction tank; 4) turning on the intermittent aeration device and the micro-aeration device to aerate the curtain membrane assembly; 5) producing water is collected from the water outlet of the curtain membrane assembly.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The MBR membrane bioreactor of the present invention realizes the air scrubbing process of the membrane bioreactor by performing aeration every 5-30 minutes or 30-60 seconds through the intermittent aeration device below, which greatly reduces the gas consumption in the operation process of the membrane bioreactor. At the same time, in order to ensure that the sludge in the sewage will not settle, the micro-aeration device is used to perform continuous and uninterrupted aeration to ensure the balance of the sludge in the sewage. Compared with the continuous aeration method in the original technology, the present invention saves about 50% of energy consumption comprehensively, and because the air supply during the filtration process of the MBR membrane bioreactor is reduced, the dissolved oxygen in the water body is also reduced to less than 1 / 2 of the original technology, and the sludge refluxed to the front end of the biochemical process is more conducive to the sewage treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the curtain membrane assembly of the present invention;

[0019] Figure 2 It is a schematic diagram of the structure of the membrane bioreactor of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and the best embodiments.

[0021] Figure 1-2A membrane bioreactor is shown, comprising a curtain membrane assembly 3, an intermittent aeration device 5 arranged below the curtain membrane assembly, and a micro-aeration device 6 arranged below the intermittent aeration device, wherein the intermittent aeration device provides intermittent aeration for the curtain membrane assembly; and the micro-aeration device provides continuous aeration for the curtain membrane assembly.

[0022] The aeration frequency of the intermittent aeration device is 30-60 seconds of aeration every 5-30 minutes.

[0023] The aeration capacity of the micro-aeration device is 1-3m 3 / h; preferably 2m 3 / h.

[0024] The curtain membrane assembly comprises membrane shells arranged at the upper and lower ends and a curtain membrane arranged between the membrane shells; preferably, water outlets 31 are arranged on the membrane shells at the upper and lower ends.

[0025] The micro-aeration device 6 comprises a micro-aeration tube arranged at the bottom of the curtain membrane assembly and a Roots blower (not shown) connected to the micro-aeration tube; the Roots blower and the micro-aeration tube are connected using a micro-aeration connecting air pipe 7.

[0026] The intermittent aeration device 5 comprises an aeration plate arranged at the bottom of the curtain membrane assembly and an air compressor (not shown) connected to the aeration plate through an aeration pipeline 8 .

[0027] The curtain membrane assembly further includes a filtering system 5 , a backwashing system 9 and a vacuum system 10 .

[0028] The present invention also includes a method for using the membrane bioreactor, comprising the following steps: 1) installing a curtain membrane assembly 3 in a reaction tank 1; 2) installing an intermittent aeration device 5 and a micro-aeration device 6 below the curtain membrane assembly 3; 3) sewage enters the reaction tank 1 through a water inlet pipe 2; 4) turning on the intermittent aeration device and the micro-aeration device to aerate the curtain membrane assembly 3; 5) producing water is collected from a water outlet 31 of the curtain membrane assembly.

[0029] The following is an explanation with a specific implementation method.

[0030] The dissolved oxygen of the sewage entering the reaction tank 1 is 4-6 mg / l, the sludge concentration is 8000 mg / l, and the sludge return ratio of the MBR system is 300%; the intermittent aeration device 5 of the present invention is used for aeration, the aeration time is 30 seconds, the aeration interval is 5 minutes, and the aeration volume of each membrane is 4m 3 / h, the air volume of the micro-aeration device is 2m 3 / h, the dissolved oxygen of the monitored return sewage was 3-5mg / l, and the sludge concentration was 8200mg / l;

[0031] Through the analysis of the data in the embodiment, it can be obtained that the actual gas consumption of the technical solution of this application is 2.7m 3 / h, compared with the existing technology of continuous aeration 4m 3 / h was greatly reduced; at the same time, the dissolved oxygen in the return sewage was detected to be 5-7mg / l, which greatly reduced the dissolved oxygen content in the return sludge;

[0032] At the same time, the test found that the combined aeration capacity of the intermittent aeration device and the micro-aeration device of the present application was 2.7m 3 / h, the transmembrane pressure difference has been stable at -15kpa; however, if the intermittent aeration device is used alone for sewage treatment, when the aeration volume drops to 2.7m 3 / h, the transmembrane pressure difference is initially -15kpa, but it will rise to above -25kpa in a short time, and a higher negative pressure suction is required to produce water. Therefore, the technical solution of the present invention can not only ensure the stable operation of the MBR membrane bioreactor, but also ensure the stability of energy consumption;

[0033] Table 1 shows a comparison between different prior arts and the present invention.

[0034] Table 1

[0035]

[0036]

[0037] In summary, the MBR membrane bioreactor of the present invention realizes the air scrubbing process of the membrane bioreactor by performing an aeration action every 5-30 minutes or 30-60 seconds through the intermittent aeration device below, which greatly reduces the gas consumption in the operation process of the membrane bioreactor. At the same time, in order to ensure that the sludge in the sewage will not settle, the micro-aeration device is used to perform continuous and uninterrupted aeration to ensure the balance of the sludge in the sewage. Compared with the continuous aeration method in the original technology, the present invention saves about 50% of energy consumption comprehensively, and because the air supply is reduced during the filtration process of the MBR membrane bioreactor, the dissolved oxygen in the water body is also as low as less than 1 / 2 of the original technology, and the sludge refluxed to the front end of the biochemical process is more conducive to the sewage treatment effect.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A membrane bioreactor, characterized in that: It comprises a curtain membrane assembly, an intermittent aeration device arranged below the curtain membrane assembly and a micro-aeration device arranged below the intermittent aeration device. The intermittent aeration device provides intermittent aeration for the curtain membrane assembly; the micro-aeration device provides continuous aeration for the curtain membrane assembly.

2. The membrane bioreactor according to claim 1, characterized in that The aeration frequency of the intermittent aeration device is 30-60 seconds of aeration every 5-30 minutes.

3. The membrane bioreactor according to claim 1, characterized in that The aeration capacity of the micro-aeration device is 1-3m 3 / h; preferably 2m 3 / h.

4. The membrane bioreactor according to claim 1, characterized in that The curtain membrane assembly comprises membrane shells arranged at the upper and lower ends and a curtain membrane arranged between the membrane shells; preferably, water outlets are arranged on the membrane shells at the upper and lower ends.

5. The membrane bioreactor according to claim 1, characterized in that: The micro-aeration device comprises a micro-aeration pipe arranged at the bottom of the curtain membrane assembly and a Roots blower connected to the micro-aeration pipe.

6. The membrane bioreactor according to claim 1, characterized in that: The intermittent aeration device comprises an aeration plate arranged at the bottom of the curtain membrane assembly and an air compressor connected to the aeration plate.

7. The membrane bioreactor according to claim 1, characterized in that: The curtain membrane assembly also includes a filtering system, a backwashing system and a vacuum system.

8. A method for using the membrane bioreactor according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: 1) installing a curtain membrane assembly in a reaction tank; 2) Install an intermittent aeration device and a micro-aeration device under the curtain membrane module; 3) The sewage enters the reaction tank; 4) The intermittent aeration device and the micro-aeration device are turned on to aerate the curtain membrane module; 5) The produced water is collected from the water outlet of the curtain membrane module.

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