A kind of MABR sewage treatment device and method based on A+B composite membrane

Abstract

The application discloses a kind of MABR sewage treatment device and method based on A+B composite film, belong to river sewage treatment technical field.The device includes composite film component, membrane shell and support frame.Composite film component is composed of multiple layer bubbleless aeration membrane (A membrane) and a layer of micro-nano aeration membrane (B membrane), bubbleless aeration membrane is spaced distribution from top to bottom, and micro-nano aeration membrane is arranged in the bottom layer.Support frame is fixed with membrane shell on both sides, and each layer of membrane is communicated with membrane shell on both sides.Air enters from top membrane shell, and passes through left and right alternating flow path and flows from top to bottom in multiple layer membrane, to increase the contact area of air and membrane.Bubbleless aeration membrane is used as microbial carrier to degrade pollutants, and micro-nano aeration membrane generates micro-nano bubble to release pressure, oxygenation and clean residual substances on the surface of bubbleless aeration membrane.The application can effectively alleviate membrane pollution, prolong the service life of bubbleless aeration membrane, effectively avoid membrane wire from being damaged due to excessive pressure, and ensure long-term stable operation of system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of river sewage treatment, and particularly relates to a MABR sewage treatment device and method based on A+B composite membranes. BACKGROUND

[0002] With the rapid development of urbanization, a large amount of sewage and industrial wastewater is discharged into rivers, resulting in the destruction of the river ecosystem. According to statistics, 90% of urban surface water in China is polluted, and river management is imminent. Ammonia nitrogen is one of the main causes of river pollution. Ammonia nitrogen mainly comes from industrial wastewater, farmland drainage and domestic sewage. Excessive ammonia nitrogen in water bodies can cause water eutrophication and reduce the oxygen content in water bodies, threatening the survival of aquatic organisms and thus causing harm to human survival.

[0003] MABR membrane aeration biofilm reactor is a new type of water treatment process combining membrane technology and biofilm technology. It utilizes the synergistic effect between gas permeable membranes and attached biofilms to transfer oxygen to the biofilm layer attached to the surface of the gas permeable membrane, while organic matter (COD, BOD) and ammonia and other substrates diffuse from the wastewater to the biofilm layer, thereby consuming and degrading water pollutants to meet water pollution prevention standards. This technology is a new and efficient ecological management technology for water management, and has broad application prospects.

[0004] In the prior art, the MABR membrane assembly used in the MABR membrane aeration biofilm reactor is made of a semi-hydrophobic high molecular composite material. This membrane filament not only has good biocompatibility, but also has high membrane filament strength and oxygenation efficiency. Therefore, it is not only suitable for municipal and domestic sewage treatment, industrial wastewater treatment, but also can quickly and efficiently oxygenate and purify sponge city construction, lakes, landscape water bodies and rivers. However, the traditional MABR membrane still has some shortcomings. First, these membranes are easily contaminated and difficult to clean. In addition, high aeration pressure often occurs inside the membrane filament, which not only reduces the ammonia nitrogen removal efficiency, but also greatly shortens the service life of the membrane filament.

[0005] Therefore, there is an urgent need to develop a MABR sewage treatment device that can prolong the service life of the aeration membrane assembly to solve the technical problem of efficient removal of ammonia nitrogen in rivers. SUMMARY

[0006] The purpose of the present application is to solve the problems of easy contamination and difficult cleaning of the membrane of the MABR sewage treatment device in the prior art, high aeration pressure inside the membrane filament, and short service life of the membrane filament, and to provide a MABR sewage treatment device and method based on A+B composite membranes.

[0007] The specific technical solutions adopted by the present application are as follows:

[0008] In a first aspect, the present application provides a wastewater treatment device based on A+B composite membrane MABR, comprising a composite membrane assembly, a membrane shell and a support frame; wherein the composite membrane assembly comprises bubbleless aeration membranes and micro-nano aeration membranes, wherein the bubbleless aeration membranes are arranged in multiple layers and are spaced apart from top to bottom in the middle of the support frame, and a layer of micro-nano aeration membranes is arranged below the bottommost bubbleless aeration membrane; a plurality of membrane shells are fixed on both sides of the support frame from top to bottom, and the bubbleless aeration membranes and the micro-nano aeration membranes of each layer are in communication with the membrane shells on both sides; the membrane shell on one side of the topmost bubbleless aeration membrane is in communication with an external air blowing device, air enters from one side of the topmost bubbleless aeration membrane and flows to the other side, then enters the next layer of bubbleless aeration membrane downward, and then flows to the other side, and so on until the bottommost micro-nano aeration membrane; air flows through the multiple layers of aeration membranes from top to bottom through the left-right alternating flow path, increasing the contact area of air and membranes.

[0009] Preferably, the material of the bubbleless aeration membranes and the micro-nano aeration membranes is any one or a combination of polytetramethyl pentene, polypropylene, polyethylene, polytetrafluoroethylene, polyether ether ketone, poly silicone resin, polyvinylidene fluoride, polyurethane, polyester, polyamide, nylon and glass fiber; the inner diameter of the membrane filaments of the bubbleless aeration membranes and the micro-nano aeration membranes is 0.5 mm, and the outer diameter of the membrane filaments is 0.8 mm.

[0010] Preferably, the membrane shell is made of unplasticized polyvinyl chloride material, and the diameter of each membrane shell is 25 mm.

[0011] Preferably, the membrane shells are fixed on both sides of the support frame by screw connection.

[0012] Preferably, the membrane shells and the bubbleless aeration membranes or the micro-nano aeration membranes on both sides are glued.

[0013] Preferably, the support frame is made of Q235 steel material with outer galvanizing, and is fixed as a frame by welding.

[0014] Preferably, the length, width and height of the support frame are 2 m, 2 m and 0.8 m, respectively.

[0015] Further, in the vertical direction, three layers of bubbleless aeration membranes and one layer of micro-nano aeration membranes are arranged from top to bottom in the composite membrane assembly; in the horizontal direction, eight groups of membranes are arranged in each layer of the composite membrane assembly, totaling thirty-two groups of single membrane groups.

[0016] Further, the air flow rate of the bubbleless aeration membranes is 0.1 m 3 / h / group, and the air flow rate of the micro-nano aeration membranes is 0.8 m 3 / h / group.

[0017] In the second aspect, the application provides a method using the MABR sewage treatment device in the first aspect, the MABR sewage treatment device is placed in the sewage to be treated, and the direction of the membrane wire is parallel to the direction of the water flow; the air is introduced into the bubble-free aeration membrane by using the air blowing device, the air flows through the multi-layer aeration membrane from top to bottom through the left-right alternating flow path, and the contact area of the air and the membrane is increased; the bubble-free aeration membrane serves as a microbial carrier, and the microorganism degrades the pollutants in the sewage; the micro-nano aeration membrane generates micro-nano bubbles for pressure relief, and the generated micro-nano bubbles oxygenate the water body and clean the residual substances on the upper bubble-free aeration membrane.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] The application innovatively introduces the micro-nano aeration membrane (B membrane) aiming at the two problems of membrane pollution and membrane wire damage in the existing MABR technology, effectively improves the stability and service life of the MABR sewage treatment device through the specific setting mode of the bubble-free aeration membrane (A membrane) and the micro-nano aeration membrane (B membrane), and has the following beneficial effects:

[0020] (1) effectively alleviating membrane pollution and prolonging the service life of the A membrane:

[0021] In the traditional MABR sewage treatment device, the A membrane is easily polluted by inorganic substances, insoluble substances and microbial metabolites in the river environment, resulting in membrane hole blockage, affecting the treatment efficiency and service life. In the application, a B membrane is arranged below the A membrane, the micro-nano bubbles released by the B membrane can effectively carry away the pollutants attached to the surface of the A membrane when flowing through the surface of the A membrane, prevent the membrane holes from being completely blocked, thereby delaying the membrane pollution process and significantly prolonging the service life of the A membrane.

[0022] (2) stabilizing the aeration pressure and protecting the structure of the membrane wire:

[0023] In the traditional MABR sewage treatment device, improper control of the aeration pressure will cause excessive internal pressure of the membrane wire, which is not conducive to microbial enrichment, and even cause the membrane wire to break, affecting the stable operation of the system. In the application, the B membrane can release the excess air in the membrane assembly in time, stabilize the air pressure in the best range of the MABR reaction device, effectively avoid the damage of the membrane wire due to excessive pressure, and ensure the long-term stable operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A+B composite membrane-based MABR sewage treatment device schematic diagram provided for the embodiment;

[0025] Figure 2 is a top view of Figure 1 ;

[0026] Figure 3 isFigure 1 the front view of the MABR sewage treatment device provided by the embodiment;

[0027] Figure 4 the front view of the MABR sewage treatment device provided by the embodiment; Figure 1 the left view of the MABR sewage treatment device provided by the embodiment;

[0028] Figure 5 the operation effect diagram of the MABR sewage treatment device provided by the embodiment for removing ammonia nitrogen;

[0029] Figure 6 the operation effect diagram of the MABR sewage treatment device provided by the embodiment for removing phosphate;

[0030] In the figure: 1, bubbleless aeration membrane; 2, micro-nano aeration membrane; 3, membrane shell; 4, support frame. DETAILED DESCRIPTION

[0031] The present application will be further described and explained with the accompanying drawings and specific embodiments. The technical features of each embodiment in the present application can be combined accordingly without conflict.

[0032] As shown in Figure 1 and Figure 2 , as a preferred embodiment of the present application, the present embodiment provides a MABR sewage treatment device based on A+B composite membrane.

[0033] The treatment device comprises a composite membrane assembly, a membrane shell 3 and a support frame 4. The composite membrane assembly comprises a bubbleless aeration membrane 1 and a micro-nano aeration membrane 2, wherein the bubbleless aeration membrane 1 is arranged in multiple layers and is spaced and distributed in the middle of the support frame 4 from top to bottom, and a layer of micro-nano aeration membrane 2 is arranged below the bubbleless aeration membrane 1 at the bottom.

[0034] In the present embodiment, as shown in Figure 4 , in the vertical direction, i.e. the direction perpendicular to the water flow direction, the composite membrane assembly is arranged with three layers of bubbleless aeration membranes 1 and one layer of micro-nano aeration membrane from top to bottom. In the horizontal direction, each layer of composite membrane assembly is arranged with eight groups of membranes, a total of thirty-two groups of single membrane groups.

[0035] The bubbleless aeration membrane 1 and the micro-nano aeration membrane 2 used in the present embodiment are reinforced modified polymer composite materials with polyether ether ketone as the main material. The inner diameter of the membrane wire of the bubbleless aeration membrane 1 and the micro-nano aeration membrane 2 is 0.5mm, and the outer diameter of the membrane wire is 0.8mm. It should be noted that the material of the bubbleless aeration membrane 1 and the micro-nano aeration membrane 2 can use any one or a combination of multiple of polytetramethylpentene, polypropylene, polyethylene, polytetrafluoroethylene, polyether ether ketone, polyorganosilicon resin, polyvinylidene fluoride, polyurethane, polyester, polyamide, nylon and glass fiber.

[0036] The support frame 4 in the embodiment is made of Q235 steel material with external galvanizing, and is fixed as a frame by welding. The length of the support frame 4 is 2 m, the width is 2 m, and the height is 0.8 m. As shown in Figure 3 the drawing, the support frame 4 in the embodiment is fixed with four membrane shells 3 from top to bottom on both sides, and the membrane shells 3 are fixed on both sides of the support frame 4 by threaded connection. The bubbleless aeration membrane 1 and the micro-nano aeration membrane 2 of each layer are in communication with the membrane shells 3 on both sides. The membrane shells 3 are made of unplasticized polyvinyl chloride (UPVC) material, and the diameter of each membrane shell 3 is 25 mm. Eight interfaces are provided on each membrane shell 3, and correspond to eight groups of membranes of the layer. The membrane shells 3 and the bubbleless aeration membrane 1 or the micro-nano aeration membrane 2 on both sides are glued.

[0037] Since the length of the support frame 4 in the embodiment is 2 m, the size of each single membrane group is set to 210*2140 mm, the effective length of the single membrane group is 2 m, and the effective area is 3.5 m 2 . The breaking strength of the membrane wire of the bubbleless aeration membrane 1 and the micro-nano aeration membrane 2 is greater than 50 N, the membrane working air pressure is 0.005-0.085 MPa, and the membrane unit oxidation capacity is 15 g / m 2 / day.

[0038] The membrane shell 3 on one side of the top bubbleless aeration membrane 1 is in communication with the external air blowing device, and the air enters from one side of the top bubbleless aeration membrane 1 and flows to the other side, then enters the next layer of bubbleless aeration membrane 1 downward, and then flows to the other side, and so on until the bottom micro-nano aeration membrane 2. The air flows through the left and right alternating flow paths in the multi-layer aeration membrane from top to bottom, increasing the contact area of the air and the membrane.

[0039] The bubbleless aeration membrane 1 is used as an A membrane, and the air supply is 0.1 m 3 / h / group. The A membrane is used as a microbial carrier, which is more suitable for microbial biofilm formation, and the pollutants in the wastewater are degraded by the microorganisms. The micro-nano aeration membrane 2 is used as a B membrane, and the air supply is 0.8 m 3 / h / group. The B membrane can quickly produce micro-nano bubbles to release the excess air in the membrane wire, and the generated nano bubbles not only can quickly oxygenate the water body, but also can clean the residual substances on the A membrane, slow down the membrane pollution problem, and prolong the service life of the device.

[0040] The MABR sewage treatment device based on the A+B composite membrane is placed in the sewage to be treated, the direction of the membrane is parallel to the water flow direction, and the shearing force of the water flow on the microorganisms is reduced. Air is introduced into the bubble-free aeration membrane 1 by using a blowing device, the air flows through the multi-layer aeration membrane from top to bottom through the left-right alternating flow path, and the contact area of the air and the membrane is increased. The bubble-free aeration membrane 1 serves as a microbial carrier, and the microorganisms degrade the pollutants in the sewage. The micro-nano aeration membrane 2 generates micro-nano bubbles for pressure relief, avoids excessive air pressure in the membrane, and generates micro-nano bubbles to quickly oxygenate the water body and clean the residual substances on the upper bubble-free aeration membrane 1. The treatment effect is as shown in Figure 5 and Figure 6 .

[0041] As shown in Figure 5 , under a short hydraulic retention time (about 4-8 min), the MABR sewage treatment device still has a good effect on the removal of ammonia nitrogen in the river: the ammonia nitrogen in the influent and effluent is detected, and it is found that under the condition of high ammonia nitrogen concentration in the influent, the removal effect is good, and under the condition of low ammonia nitrogen concentration in the influent, the removal effect decreases, and as the MABR sewage treatment device gradually stabilizes, the ammonia nitrogen in the effluent is obviously improved, and in November, the ammonia nitrogen in the effluent can be stabilized at 1.5 NH3-N mg / L, reaching the surface water environmental quality Class IV standard.

[0042] As shown in Figure 6 , under a short hydraulic retention time (about 4-8 min), the MABR sewage treatment device has a good effect on the removal of phosphate in the river, and the phosphate in the effluent is detected within 30 days of operation, and a continuous phosphorus removal effect is found, and the phosphate in the effluent is maintained below 0.05 PO4-P mg / L.

[0043] The MABR sewage treatment device provided in the embodiment includes a composite membrane assembly of a bubble-free aeration membrane (A membrane) and a micro-nano aeration membrane (B membrane). The sewage treatment device is installed in the river to be treated, does not agitate the sediment, and does not affect the water flow area. The micro-nano aeration membrane realizes efficient oxygenation, the bubble-free aeration membrane realizes rapid biofilm formation, can efficiently remove nitrogen and phosphorus, rapidly purify water quality, and eliminate black and stench. In addition, the micro-nano bubbles generated by the micro-nano aeration membrane can clean the bubble-free aeration membrane, prolong the service life of the membrane, slow down the occurrence of membrane pollution, and can realize continuous operation for many years.

[0044] The above-described embodiments are only a preferred scheme of the present application, and are not intended to limit the present application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, any technical scheme obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. An A+B composite membrane-based MABR wastewater treatment device, characterized in that, The application relates to a composite membrane module, which comprises a bubbleless aeration membrane (1), a micro-nano aeration membrane (2), a membrane shell (3) and a support frame (4). The bubbleless aeration membrane (1) is arranged in multiple layers and is spaced apart from top to bottom in the middle of the support frame (4), and a layer of the micro-nano aeration membrane (2) is arranged below the bubbleless aeration membrane (1) at the bottom. A plurality of membrane shells (3) are fixed on both sides of the support frame (4) from top to bottom, and the bubbleless aeration membrane (1) and the micro-nano aeration membrane (2) of each layer are communicated with the membrane shells (3) on both sides. The membrane shell (3) on one side of the bubbleless aeration membrane (1) at the top is communicated with an external air blowing device, air enters from one side of the bubbleless aeration membrane (1) at the top and flows to the other side, then enters the bubbleless aeration membrane (1) at the next layer downwards, and flows to the other side again, and the process is repeated until the micro-nano aeration membrane (2) at the bottom layer. The air flows from top to bottom in the multiple layers of aeration membranes through the left-right alternating flow path, thereby increasing the contact area of the air and the membranes.

2. The A+B composite membrane based MABR wastewater treatment device according to claim 1, characterized in that, The material of the bubbleless aeration membrane (1) and the micro-nano aeration membrane (2) is any one or a combination of multiple kinds of polytetramethylpentene, polypropylene, polyethylene, polytetrafluoroethylene, polyether ether ketone, polyorganosilicon resin, polyvinylidene fluoride, polyurethane, polyester, polyamide, nylon and glass fiber. The inner diameter of the membrane wire of the bubbleless aeration membrane (1) and the micro-nano aeration membrane (2) is 0.5 mm, and the outer diameter of the membrane wire is 0.8 mm.

3. The A+B composite membrane based MABR wastewater treatment device of claim 1, wherein, The membrane shell (3) is made of non-plasticized polyvinyl chloride material, and the diameter of each membrane shell (3) is 25 mm.

4. The A+B composite membrane based MABR wastewater treatment device of claim 1, wherein, The membrane shell (3) is fixed on both sides of the support frame (4) through threaded connection.

5. The A+B composite membrane based MABR wastewater treatment device of claim 1, wherein, The membrane shell (3) and the bubbleless aeration membrane (1) or the micro-nano aeration membrane (2) on both sides are glued.

6. The A+B composite membrane based MABR wastewater treatment device of claim 1, wherein, The support frame (4) is made of Q235 steel material with zinc plating, and is fixed into a frame through welding.

7. The A+B composite membrane based MABR wastewater treatment device of claim 1, wherein, The length, width and height of the support frame (4) are 2 m, 2 m and 0.8 m respectively.

8. The A+B composite membrane based MABR wastewater treatment device of claim 7, wherein, In the vertical direction, three layers of bubbleless aeration membranes (1) and one layer of micro-nano aeration membranes are arranged from top to bottom in the composite membrane module; and in the horizontal direction, eight groups of membranes are arranged in each layer of the composite membrane module, and a total of thirty-two groups of single membrane groups are arranged.

9. The A+B composite membrane based MABR wastewater treatment device of claim 8, wherein, The bubbleless aeration membrane (1) has a ventilation rate of 0.1 m 3 / h / group, and the micro-nano aeration membrane (2) has a ventilation rate of 0.8 m 3 / h / group.

10. A method of using the MABR wastewater treatment device of any one of claims 1-9, wherein, The MABR wastewater treatment device is placed in the wastewater to be treated, and the membrane wire direction is parallel to the water flow direction; air is introduced into the bubbleless aeration membrane (1) through an air blowing device, the air flows from top to bottom in the multiple layers of aeration membranes through the left-right alternating flow path, thereby increasing the contact area of the air and the membranes; the bubbleless aeration membrane (1) serves as a microbial carrier, and the microorganisms degrade the pollutants in the wastewater; the micro-nano aeration membrane (2) generates micro-nano bubbles for pressure relief, the generated micro-nano bubbles oxygenate the water body and clean the residual substances on the upper bubbleless aeration membrane (1).

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