KR20160009091A - Air diffuser and membrane bio-reactor - Google Patents

Abstract

The present invention relates to an air diffuser in which at least two pore groups including two to six pores are formed, distance between neighboring pore groups of the pore groups is 30-120 mm, the pore groups are linearly arranged, and distance between pores included in a single pore group is 1-20 mm, and to a membrane bio-reactor comprising the air diffuser.

Description

TECHNICAL FIELD [0001] The present invention relates to an air diffuser and a membrane bioreactor,

The present invention relates to an anaerobic apparatus and a separation membrane bioreactor, and more particularly, to an apparatus and a method for separating and purifying biomass which are capable of effectively discharging and dispersing air or bubbles even with a small amount of air, Which is capable of reducing the amount of air and power consumed by the separation membrane bioreactor and increasing the operation efficiency of the separation membrane bioreactor, and a separator bioreactor including the above-described anaerobic reactor.

Membrane bioreactor (MBR) process is called activated sludge membrane separation process or membrane bound activated sludge process and is a method of sewage or wastewater treatment including high concentration organic or inorganic matter.

Such a membrane bioreactor can be used to culture a mixed liquor suspended solid (MLSS) by replacing solid-liquid separation by sedimentation, which is used in a previously known standard activated sludge process or standard activated sludge process, Accordingly, it is possible to greatly reduce the site area required for installation of the apparatus or the whole system, and it is possible to secure stable water quality while improving the treatment efficiency.

However, since the separation membrane bioreactor utilizes the inhalation action to conduct the solid-liquid separation in the separation membrane, in order to mitigate the contamination of the separation membrane or to remove contaminants from the separation membrane, an air diffuser for air injection is installed under the reaction vessel, .

Previously, there have been known methods for solving the problem of pressure distribution occurring in the operation of the air diffusers or methods for generating air bubbles more evenly in the air diffuser, but the use of a smaller amount of air, Or a method for removing contaminants has not been commercialized.

The present invention can effectively release air or bubbles even with a small air volume and can disperse the air or bubbles effectively, thereby achieving an excellent cleaning effect in applications such as separation membrane bioreactors, reducing the amount of air to be used and power consumption, And to provide a diffuser which can increase efficiency.

Further, the present invention is to provide a separation membrane bioreactor including the above-described acidifier.

The present invention relates to a honeycomb structure including at least two pore groups including two to six pores, wherein a distance between neighboring pore groups of the pore groups is 30 mm to 120 mm and the pore groups are arranged in series And a distance between the pores included in the one pore group is 1 mm to 20 mm.

Further, the present invention provides a bioreactor comprising: a bioreactor; At least one separation membrane module installed in the bioreactor; And a diffusion device installed at a lower end of the separation membrane module.

Hereinafter, the anaerobic device and the separation membrane bioreactor according to specific embodiments of the present invention will be described in detail.

According to an embodiment of the present invention, the pore group includes at least two pore groups including two to six pores, the distance between neighboring pore groups of the pore groups is 30 mm to 120 mm, Are arranged in series, and the distance between the pores included in the one pore group is 1 mm to 20 mm.

Previously known air diffusers have typically had air pockets distributed at regular intervals or unevenly distributed. However, in such an air diffuser, it is not easy to control the shape and flow of the air discharged from the pores or the air bubbles generated from the air bubbles, and the apparatus applied due to the flow of air bubbles generated from the discharged air It was not easy to distribute the pressure in the separation membrane of the separation membrane bioreactor.

Accordingly, the inventors of the present invention have conducted researches on an acidifier, and if a plurality of pore groups composed of two or more pores are formed on the acid generator, air or bubbles can be effectively released and dispersed even with a small amount of air, Etc., it is possible to reduce the amount of air to be used and power consumption, and to increase the operation efficiency of the membrane bioreactor.

The 'pore group' means a group consisting of two or more pores formed on the acidifier, and since the distance between the pores included in one pore group is smaller than the distance to the pores included in the other pore group, And can be divided into one group on the above-described diffuser.

In addition, as more than two pores are gathered to form one pore group, and as more than two of these pore groups are present in the above-described acidifier, the air bubbles discharged through the pores are bundled And such coalesced air bubbles form giant air bubbles and these giant air bubbles rise or flow in the apparatus (eg, membrane bioreactor) where the air diffuser is installed (slug flow). The air diffuser allows the giant foam to be uniformly formed in a uniform size.

The pore group may include two or more pores, specifically, two to six pores, or three to five pores.

A schematic view of an anomaly devices according to an embodiment of the present invention is shown in Fig. However, FIG. 6 is merely an example of the anomaly devices of the embodiment, and the detailed contents of the anomaly device of the embodiment of the present invention are not limited thereto.

FIG. 9 schematically shows a plan view of the diffuser of an embodiment of the present invention. However, FIG. 9 shows an example of a plan view of the aeration apparatus of the above embodiment and content of the pores included in the aerosolization apparatus, and the details of the aeration apparatus of an embodiment of the present invention are not limited thereto.

As shown in Fig. 10, in the case where one of the previously known diffusers, for example, one pore on the diffuser, is formed in one column or two columns at regular intervals, the bubble coalescence, It is difficult to realize a slug flow of the air bubbles, so that it is not easy to achieve the above-mentioned effect.

As the pore groups include two to six or three to five pores, the air bubbles emitted through the pores can easily be combined into one, and the flow of large air bubbles (slug flow, slug flow) can be stably and balancedly formed.

The distance between the pores included in the one pore group may be 1 mm to 20 mm, or 4 mm to 12 mm, or 5 mm to 10 mm. The distance between pores included in the one pore group may be defined as a distance between a center point of each pore and a center point of the adjacent pore. The center point of the pores may be a center point of the circle including the entire surface of the pores.

As the distance between the pores included in the one pore group is specified in the above range, the air bubbles emitted through the pores can be easily combined into one, and the large air bubbles can be stably and balanced .

On the other hand, the distance between neighboring pore groups in the air diffuser may be 25 mm to 150 mm, or 30 mm to 120 mm, or 40 mm to 100 mm.

If the distance between the neighboring pore groups is too small, the pores do not substantially form a group, and it is difficult to realize the above-described bubble coalescence or slug flow of macro air bubbles, It is not easy to do.

In addition, if the distance between adjacent pore groups is too large, a slug flow can not be uniformly formed on the entire membrane, and the cross flow in a direction perpendicular to the permeated water on the membrane surface cross flow) or an upflow velocity formed upwardly from below may not be smoothly performed, thereby leading to localized separation membrane contamination and the efficiency of the acid catalyst may be reduced.

The maximum diameter of the pores may be 0.5 mm to 10 mm, or 1 mm to 5 mm.

If the size of the pores is too small, the pressure applied to the air generated through the pores is increased to increase the energy loss, and the size of the air bubbles released from the pores becomes too small to form large air bubbles, The bubbles may not be able to make the above-mentioned slug flow.

In addition, if the pore size is too large, the air at the air diffuses suddenly from the pores close to the injection port, thereby causing a problem in the pressure distribution of the air diffuser as a whole, and is likely to become unevenly distributed. In addition, if the pore size is too large, the action and effect of forming the pore group can be reduced, and it is difficult to realize the bubble coalescence or the slug flow of the large air bubble. It is not easy to achieve.

The cross section of the pores on the surface of the diffuser may be circular, elliptical or polygonal with 3 to 30 internal angles.

Meanwhile, the specific shape and size of the air diffuser may vary depending on the apparatus to be actually used, but the diffuser may be in the form of a pipe having an outer diameter of 10 mm to 100 mm or an inner diameter of 1 mm to 90 mm.

The specific material of the air diffuser is not limited to a specific one. For example, thermoplastic plastic such as PVC or metal may be used for the production of the air diffuser.

As described above, the aeration apparatus of one embodiment can be used in a membrane bioreactor (MBR).

According to another embodiment of the present invention, there is provided a bioreactor; At least one separation membrane module installed in the bioreactor; And a diffusion device installed at a lower end of the separation membrane module.

As described above, by using the air diffuser of the embodiment, it is possible to effectively discharge and disperse air or bubbles even with a small amount of air, and it is possible to realize an excellent cleaning effect in application fields such as a membrane bioreactor, It is possible to reduce the amount of air and power consumption, and to increase the operation efficiency of the membrane bioreactor.

Particularly, by using the air diffuser of the embodiment, the air bubbles emitted through the pores of the diffuser can coalesce, and the air bubbles thus formed form a large air bubble, Such large air bubbles rise or flow in the membrane bioreactor of this embodiment (slug flow). The air diffuser allows the giant foam to be uniformly formed in a uniform size.

According to the cyclic flow of the macro air bubbles, contaminants that can be generated in the separation membrane of the separation membrane bioreactor can be easily removed even with a smaller amount of air, and the accumulation of contaminants in the separation membrane can be minimized .

The detailed description related to the air diffusing apparatus includes all of the above-mentioned contents in the above embodiment.

A schematic view of a separation membrane bioreactor according to another embodiment of the present invention is shown in Fig. However, FIG. 7 schematically shows only one example of the separation membrane bioreactor, and the details of the separation membrane biological reactor according to the embodiment of the present invention are not limited thereto.

The bioreactor is a part that performs biological purification using microorganisms in the treatment of sewage or wastewater. The part where the separation membrane is immersed is called an aeration tank, aeration tank or aerobic tank, and serves as a decomposition part of organic matter. Or circular shape. The size of such a bioreactor is not limited, but may be on the order of 100 m 3 to 20,000 m 3 per unit of an aeration tank, for example.

The one or more separation membrane modules installed in the biological reactor are installed in an aeration tank or in an aeration tank in the aeration tank or outside the tank in a biological reactor represented by a standard activated sludge process or a standard activated sludge process variation process and the activated sludge and purified water Liquid separation, and may be in the form of an immersion type or a pressure type depending on the installation position of the separation membrane, the operation method, and the like. In addition, such a membrane module consists of a constituent part of a unit comprising a membrane, an element (including a panel or a spacer), a module and a module in the form of a flat membrane.

The separator module may include a hollow fiber membrane, and the material of the membrane and the hollow fiber membrane is not particularly limited. Typically, polyvinylidene fluoride (PVDF), which is a hydrophobic material, is subjected to surface treatment, hydrophilization, And a hydrophilic modification may be used. In addition to PVDF, it is also possible to use aromatic polymer materials such as polysulfone (PSf) or polyethersulfone (PES), polyacrylonitrile (PAN), cellulose acetate (CA) or cellulose triacetate , CTA) can be used. The flat membrane and the hollow fiber membrane may have a plurality of pores having a size of 5 mu m to 0.0005 mu m.

The separator module may be installed in an upper space between the pore groups included in the diffuser. Specifically, the separation membrane module may be formed variously according to the designing method of the manifold and the air injection direction perpendicularly or horizontally to the direction of the diffuser of the diffuser.

Meanwhile, a distance between the separation membrane module and the diffusion device may be 5 mm to 400 mm. If the distance between the separator module and the acid generator is too small, the air bubbles released through the pores of the air diffuser may be difficult to accumulate, or the bubble growth due to the foam coalescence may provide a space over the entire separator It is possible to increase the number of installation places of the device for dissipating heat and to lower the energy consumption efficiency. If the distance between the separation membrane module and the acid generator is too large, the stability of the large air bubbles formed by the aggregation of the air bubbles discharged through the pores of the air diffuser may be reduced, or the large air bubbles may flow into the separator module It may not be easy to penetrate. As a result, the effect of large and strong bubble aggregates formed by controlling the ratio of air / water is halved, which hinders the formation of smooth slug flow.

Meanwhile, the separation membrane bioreactor of the embodiment includes an injection unit for injecting wastewater into the bioreactor; An air injection unit for injecting outside air into the bioreactor; An injecting portion of washing air or washing liquid to be introduced for washing the air diffuser; A discharge unit for discharging treated water treated in the bioreactor; A conveying unit for conveying in the bioreactor; As shown in FIG.

According to the present invention, it is possible to effectively discharge and disperse air or bubbles even with a small amount of air, thereby realizing an excellent cleaning effect in applications such as separation membrane bioreactors, etc., And a separator bioreactor including the acid generator can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a photograph showing the operation of a separation membrane bioreactor according to Example 1. FIG.
FIG. 2 is a photograph showing the operation of the separation membrane bioreactor of Example 2. FIG.
FIG. 3 is a photograph of the operation of the separation membrane bioreactor of Examples 3 to 6. FIG.
FIG. 4 is a photograph of the operation of the separation membrane bioreactor of Examples 7 to 10 observed. FIG.
FIG. 5 is a photograph showing the operation of the separation membrane bioreactor of Comparative Example 1 observed. FIG.
Figure 6 schematically shows diffuser devices of one embodiment of the invention.
7 schematically shows a separation membrane bioreactor according to an embodiment of the present invention.
8 shows the results of Experimental Example 2.
Figure 9 schematically shows a top view of the diffuser of one embodiment of the invention.
Fig. 10 schematically shows a plan view of a conventional diffuser.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

< Example 1 to  10 and Comparative Example 1 : Air diffuser and separator Bioreactor  Driving>

In a bioreactor having a volume of 200 liters, four separation membranes each having a size of 150 mm x 300 mm (width x length) were arranged at intervals of 8 mm on both sides, and a total of 8 surfaces were provided, and a diffuser was installed at a predetermined distance from the separation membrane.

As the separation membrane, a polyacrylonitrile (PAN) ultrafiltration membrane (pore size of about 0.07 m) was used, and the maximum diameter of each pore formed in the acidifier, the number of pores contained in the pore group, The distance between the pore groups, and the distance between the membrane module and the diffusion device are as shown in Table 1 below.

The operation was carried out by filling the tap water with 10 L / min (10 L / min) and 10 L / min (unit), and the formation of slug flow and the behavior of bubbles dispersed throughout the membrane And observed with a high-speed camera.

Formation of pores on the air diffuser of Examples and Comparative Examples Pore
Longest diameter Number of pores contained in the pore group Spacing between pores within the pore group Distance between groups Distance between membrane module and diffuser Example 1 About 2 mm 3 7 mm 37.5 mm 40 mm Example 2 About 2 mm 4 7 mm 37.5 mm 40 mm Example 3 About 2 mm 3 8 mm 37.5 mm 40mm Example 4 About 2 mm 3 7 mm 37.5 mm Example 5 About 2 mm 4 8 mm 37.5 mm Example 6 About 2 mm 4 7 mm 37.5 mm Example 7 About 4 mm 3 10 mm 83.3 mm 160 mm Example 8 About 4 mm 3 9 mm 83.3 mm Example 9 About 4 mm 4 10 mm 83.3 mm Example 10 About 4 mm 4 9 mm 83.3 mm Comparative Example 1 About 2 mm 4 No group spacing [pores arranged in series at intervals of 7 mm] No group spacing 120mm

< Experimental Example 1 : Example 1 to  10 and Comparative Example 1  Membrane Bioreactor  Driving observation>

(1) As shown in FIG. 1 and FIG. 2, as the separation membrane bioreactor of Example 1 and Example 2 is operated, the phenomenon of coalescence of air bubbles generated in the air diffuser can be observed (Coalescence) of the air bubbles, and thus, a slug flow occurs in which the large air bubbles formed by the air bubbles are transferred to the membrane module.

As shown in FIGS. 3 and 4, the above phenomenon was also confirmed in the operation of the separation membrane bioreactors of Examples 3 to 10.

(2) On the other hand, when the separation membrane bioreactor of Comparative Example 1 (FIG. 5) was operated, it was hard to observe the accumulation of air bubbles generated in the air diffuser, And it was possible to observe the passage between the membrane modules.

< Example 11  And Comparative Example 2 >

In a bioreactor having a volume of 200 liters, four separation membranes each having a size of 150 mm x 300 mm (width x length) were arranged at intervals of 8 mm on both sides, and a total of 8 surfaces were provided, and a diffuser was installed at a predetermined distance from the separation membrane.

As the separation membrane, a polyacrylonitrile (PAN) ultrafiltration membrane (pore size of about 0.07 m) was used, and the maximum diameter of each pore formed in the acidifier, the number of pores contained in the pore group, The distance between the pore groups, and the distance between the membrane module and the diffusion device are as shown in Table 2 below.

Artificial wastewater containing artificial organic contaminants such as insoluble organic matter, sugar, and lipids was filled in the separation membrane bioreactor and air was injected at a rate of 30 L / min. The pressure applied to the vacuum pump used in the separation membrane , And trans membrane pressure (TMP).

[Operation condition]

(1) Flux: 15.4 LMH (L / m ² / h)

(2) Operation mode: 9 min.

(3) Organic matter concentration (wt%): 0.035

Formation of pores on the acidifier of Example 11 and Comparative Example 2 [Length of the acidifier: 150 mm] Pore
Longest diameter Number of pores contained in the pore group Spacing between pores within the pore group Distance between groups Distance between membrane module and diffuser Example 11 About 2 mm 3
[Total 4 groups] 7 mm 37.5 mm 40 mm Comparative Example 2 About 2 mm - No group spacing [23 pores arranged in series] - 120 mm

< Experimental Example 2 : Example  11 and Comparative Example 2  Membrane Bioreactor  Driving observation>

As shown in FIG. 8, it can be seen that the membrane bioreactor of Comparative Example 2 continuously increases the trans membrane pressure (TMP) by more than 0.2 in the experiment conducted for 100,000 sec.

On the contrary, in the separation membrane bioreactor of Example 11, even when the same flow rate of 30 L / min was introduced and the experiment was carried out at the same time, the rate of rise of the differential pressure was gentle and the time to reach the limit differential pressure (on the average, about 0.5 or more) It has been confirmed that the period of cleaning the separation membrane can be greatly improved, and an economical separation membrane bioreactor operation condition can be formed.

Claims (11)

At least two pore groups containing 2 to 6 pores,
The distance between neighboring pore groups of the pore groups is 30 mm to 120 mm,
The pore groups are arranged in series,
And the distance between the pores included in the one pore group is 1 mm to 20 mm.
The method according to claim 1,
Wherein the maximum diameter of the pores is 0.5 mm to 10 mm.
The method according to claim 1,
Wherein the cross section of the pores is a polygon having a circle, an ellipse or an inner angle of 3 to 30 angles.
The method according to claim 1,
In the form of a pipe having an outer diameter of 10 mm to 100 mm.
The method according to claim 1,
In the form of a pipe having an inner diameter of 1 mm to 90 mm.
The method according to claim 1,
Comprising a thermoplastic or metal.
Bioreactor;
At least one separation membrane module installed in the bioreactor; And
The separator bioreactor according to claim 1, wherein the separator module is installed at the lower end of the separator module.
8. The method of claim 7,
Wherein the separation membrane module is installed in an upper space between pore groups included in the anaerobic device.
8. The method of claim 7,
Wherein the separation membrane module comprises a hollow fiber membrane.
8. The method of claim 7,
Wherein a distance between the separation membrane module and the anaerobic device is 5 mm to 400 mm.
8. The method of claim 7,
An injector injecting wastewater into the bioreactor;
An air injection unit for injecting outside air into the bioreactor; or
And a discharge part for discharging the treated water treated in the bioreactor.

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