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

Abstract

The invention discloses an MABR sewage treatment device and method based on an A + B composite membrane, and belongs to the technical field of river sewage treatment. The device comprises a composite membrane assembly, a membrane shell and a support frame, the composite membrane assembly is composed of multiple layers of bubble-free aeration membranes (A membranes) and a layer of micro-nano aeration membranes (B membranes), the bubble-free aeration membranes are distributed at intervals from top to bottom, and the micro-nano aeration membranes are arranged on the bottommost layer. Membrane shells are fixed on the two sides of the support frame; and each layer of membrane is communicated with the membrane shells on the two sides. Air enters from the top membrane shell and circulates from top to bottom in the multiple layers of membranes through left-right alternate flowing paths, and the contact area of the air and the membranes is increased. The bubble-free aeration membrane serves as a microbial carrier to degrade pollutants, and the micro-nano aeration membrane generates micro-nano bubbles for pressure relief, oxygenation and cleaning of residual substances on the surface of the bubble-free aeration membrane. Membrane pollution can be effectively relieved, the service life of the bubble-free aeration membrane is prolonged, membrane filaments are effectively prevented from being damaged due to too large pressure, and long-term stable operation of the system is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of river sewage treatment, and specifically relates to a MABR sewage treatment device and method based on an A+B composite membrane. Background Art

[0002] With the rapid development of urbanization, a large amount of sewage and industrial wastewater is discharged into rivers, causing damage to the river ecosystem. According to statistics, 90% of urban surface water in my country 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 will cause eutrophication of water bodies and reduce the oxygen content in water bodies, threatening the survival of aquatic organisms and causing harm to human survival.

[0003] MABR membrane aerated biofilm reactor is a new water treatment process that combines membrane technology with biofilm technology. It uses the synergistic effect between the breathable membrane and the attached growth type biofilm, and uses the breathable membrane to transfer oxygen to the biofilm layer attached to the surface of the breathable membrane. At the same time, organic matter (COD, BOD) and ammonia and other matrices diffuse from the sewage to the biofilm layer, thereby consuming and degrading water pollutants to meet water pollution prevention and control standards. This technology is a new and efficient ecological governance technology for water body governance and has broad application prospects.

[0004] In the prior art, the MABR membrane assembly used in the MABR aerated membrane bioreactor adopts a hollow fiber oxygen permeable membrane made of a semi-hydrophobic polymer composite material. This membrane filament not only has good biophilicity, 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, traditional MABR membranes still have some shortcomings. First of all, these membranes are easily contaminated and inconvenient to clean. In addition, a 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 extend the service life of the aeration membrane assembly to solve the technical problem of efficient removal of ammonia nitrogen in the river. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the prior art that the membrane of the MABR sewage treatment device is easily contaminated and difficult to clean, the aeration pressure inside the membrane filaments is high, and the service life of the membrane filaments is short, and to provide a MABR sewage treatment device and method based on an A+B composite membrane.

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

[0008] In a first aspect, the present invention provides a MABR sewage treatment device based on an A+B composite membrane, comprising a composite membrane assembly, a membrane shell and a support frame; wherein the composite membrane assembly comprises a bubble-free aeration membrane and a micro-nano aeration membrane, wherein the bubble-free aeration membrane is provided in multiple layers and is spaced from top to bottom in the middle of the support frame, and a layer of micro-nano aeration membrane is provided below the bottom bubble-free aeration membrane; a plurality of membrane shells are fixed on both sides of the support frame from top to bottom, and each layer of the bubble-free aeration membrane and the micro-nano aeration membrane are connected to the membrane shells on both sides thereof; the membrane shell on one side of the top bubble-free aeration membrane is connected to an external blowing device, and air enters from one side of the top bubble-free aeration membrane and flows to the other side, then enters downward into the next layer of bubble-free aeration membrane, and then flows to the other side, and so on until the bottom layer of micro-nano aeration membrane; the air circulates from top to bottom in the multi-layer aeration membrane through left and right alternating flow paths, thereby increasing the contact area between the air and the membrane.

[0009] Preferably, the material of the bubble-free aeration membrane and the micro-nano aeration membrane is any one of polytetramethylpentene, polypropylene, polyethylene, polytetrafluoroethylene, polyetheretherketone, polysilicone resin, polyvinylidene fluoride, polyurethane, polyester, polyamide, nylon and glass fiber, or a combination of more thereof; the inner diameter of the membrane wire of the bubble-free aeration membrane and the micro-nano aeration membrane is 0.5 mm, and the outer diameter of the membrane wire is 0.8 mm.

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

[0011] Preferably, the membrane shell is fixed on both sides of the support frame by threaded connection.

[0012] Preferably, the membrane shell and the bubble-free aeration membranes or micro-nano aeration membranes on both sides are bonded by gluing.

[0013] Preferably, the support frame is made of Q235 steel with external galvanized steel and is fixed into a frame by welding.

[0014] Preferably, the support frame is 2 m long, 2 m wide and 0.8 m high.

[0015] Furthermore, in the vertical direction, the composite membrane assembly is provided with three layers of bubble-free aeration membrane and one layer of micro-nano aeration membrane from top to bottom; in the horizontal direction, each layer of the composite membrane assembly is provided with eight groups of membranes, for a total of thirty-two groups of single membrane groups.

[0016] Furthermore, the air flow rate of the bubble-free aeration membrane is 0.1m 3 / h / group, the ventilation capacity of micro-nano aeration membrane is 0.8m 3 / h / group.

[0017] In a second aspect, the present invention provides a method for utilizing the MABR sewage treatment device described in the first aspect, wherein the MABR sewage treatment device is placed in sewage to be treated to ensure that the direction of the membrane fibers is parallel to the direction of the water flow; air is introduced into the bubble-free aeration membrane using an air blowing device, and the air flows from top to bottom in the multi-layer aeration membrane through left and right alternating flow paths, thereby increasing the contact area between the air and the membrane; the bubble-free aeration membrane serves as a microbial carrier, and the microorganisms degrade 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 while cleaning the residual substances of the upper bubble-free aeration membrane.

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

[0019] The present invention aims to solve the two major problems of membrane pollution and membrane fiber fragility in the existing MABR technology, innovatively introduces a micro-nano aeration membrane (B membrane), and effectively improves the stability and service life of the MABR sewage treatment device through the specific setting of the bubble-free aeration membrane (A membrane) and the micro-nano aeration membrane (B membrane). The specific beneficial effects are as follows:

[0020] (1) Effectively alleviate membrane pollution and extend the service life of membrane A:

[0021] The A membrane in the traditional MABR sewage treatment device is easily polluted by inorganic substances, insoluble substances and microbial metabolites in the river environment, resulting in blockage of the membrane pores, affecting the treatment efficiency and service life. In the present invention, a layer of B membrane is arranged under the A membrane. When the micro-nano bubbles released by the B membrane flow through the surface of the A membrane, they can effectively carry away the pollutants attached to the surface of the A membrane, prevent the membrane pores from being completely blocked, thereby delaying the membrane pollution process and significantly extending the service life of the A membrane.

[0022] (2) Stabilize aeration pressure and protect the integrity of membrane fiber structure:

[0023] Improper aeration pressure control in traditional MABR sewage treatment devices can lead to excessive pressure inside the membrane fibers, which is not conducive to microbial enrichment and may even cause membrane fiber breakage, affecting the stable operation of the system. The B membrane in the present invention can release excess air in the membrane assembly in a timely manner, stabilize the air pressure within the optimal range of the MABR reaction device, effectively prevent the membrane fibers from being damaged due to excessive pressure, and ensure long-term stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a MABR sewage treatment device based on an A+B composite membrane provided in an embodiment;

[0025] Figure 2 for Figure 1 A top view of

[0026] Figure 3 for Figure 1 The main view of

[0027] Figure 4 for Figure 1 Left view of

[0028] Figure 5 This is an operating effect diagram of removing ammonia nitrogen using the MABR sewage treatment device provided in the embodiment;

[0029] Figure 6 This is an operating effect diagram of removing phosphate using the MABR sewage treatment device provided in the embodiment;

[0030] In the figure: 1. Bubble-free aeration membrane; 2. Micro-nano aeration membrane; 3. Membrane shell; 4. Support frame. DETAILED DESCRIPTION

[0031] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0032] like Figure 1 and Figure 2 As shown, as a preferred embodiment of the present invention, this embodiment provides a MABR sewage treatment device based on an 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 bubble-free aeration membrane 1 and a micro-nano aeration membrane 2, wherein the bubble-free aeration membrane 1 is provided with multiple layers and is spaced from top to bottom in the middle of the support frame 4, and a layer of micro-nano aeration membrane 2 is provided below the bottom bubble-free aeration membrane 1.

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

[0035] The bubble-free aeration membrane 1 and the micro-nano aeration membrane 2 used in this embodiment are mainly made of a reinforced modified polymer composite material of polyetheretherketone. The inner diameter of the membrane wire of the bubble-free 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. It should be noted that the material of the bubble-free aeration membrane 1 and the micro-nano aeration membrane 2 can be any one or a combination of polytetramethylpentene, polypropylene, polyethylene, polytetrafluoroethylene, polyetheretherketone, polysilicone resin, polyvinylidene fluoride, polyurethane, polyester, polyamide, nylon and glass fiber.

[0036] In this embodiment, the support frame 4 is made of Q235 steel with external galvanization and is fixed into a frame by welding. The support frame 4 is 2m long, 2m wide and 0.8m high. Figure 3 As shown, four membrane shells 3 are fixed from top to bottom on both sides of the support frame 4 provided in this embodiment, and the membrane shells 3 are fixed on both sides of the support frame 4 by threaded connection. Each layer of bubble-free aeration membrane 1 and micro-nano aeration membrane 2 are connected to the membrane shells 3 on both sides. The membrane shell 3 is made of non-plasticized polyvinyl chloride UPVC material, and the diameter of each membrane shell 3 is 25mm. Eight interfaces are provided on each membrane shell 3, corresponding to the eight groups of membranes set in this layer. The membrane shell 3 and the bubble-free aeration membrane 1 or micro-nano aeration membrane 2 on both sides are glued.

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

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

[0039] The bubble-free aeration membrane 1 is used as membrane A, and the ventilation volume is 0.1m 3 / h / group. A membrane is used as a microbial carrier and is more suitable for microbial biofilm formation, which can degrade pollutants in sewage through microorganisms. Micro-nano aeration membrane 2 is used as B membrane, with a ventilation volume of 0.8m 3 / h / group. The B membrane can quickly generate micro-nano bubbles to release excess air in the membrane fibers. The generated nano-bubbles can not only quickly oxygenate the water, but also clean the residual substances on the A membrane, reduce membrane pollution problems, and extend the service life of the device.

[0040] The above-mentioned MABR sewage treatment device based on the A+B composite membrane is placed in the sewage to be treated to ensure that the direction of the membrane fibers is parallel to the direction of the water flow, thereby reducing the shear force of the water flow on the microorganisms. Use an air blowing device to introduce air into the bubble-free aeration membrane 1. The air flows from top to bottom in the multi-layer aeration membrane through alternating left and right flow paths, increasing the contact area between the air and the membrane. 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 to avoid excessive air pressure inside the membrane. The generated micro-nano bubbles quickly oxygenate the water body while cleaning the residual substances on the upper bubble-free aeration membrane 1. The treatment effect is as follows: Figure 5 and Figure 6 shown.

[0041] like Figure 5 As shown in the figure, under a shorter hydraulic retention time (about 4 to 8 minutes), the MABR sewage treatment device still has a good effect on removing ammonia nitrogen in the river: the detection of inlet and effluent ammonia nitrogen found that under the condition of high inlet ammonia nitrogen concentration, the removal effect was good, and under the condition of low inlet ammonia nitrogen concentration, the removal effect decreased. As the MABR sewage treatment device gradually stabilized, the effluent ammonia nitrogen improved significantly. In November, the effluent ammonia nitrogen could be stabilized at 1.5NH3-Nmg / L, meeting the fourth category standard of surface water environmental quality.

[0042] like Figure 6 As shown, under a shorter hydraulic retention time (about 4 to 8 minutes), the MABR sewage treatment device has a good effect on removing phosphate in the river. During the 30-day operation, the phosphate at the outlet was tested and a continuous phosphorus removal effect was found. The phosphate at the outlet was kept below 0.05PO4-P mg / L.

[0043] The MABR sewage treatment device provided in this 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, without stirring the bottom mud and affecting the small footprint of the water flow. The micro-nano aeration membrane realizes efficient oxygenation, and the bubble-free aeration membrane realizes rapid film hanging, which can efficiently remove nitrogen and phosphorus, quickly purify water quality, and eliminate black and odor. In addition, the micro-nano bubbles generated by the micro-nano aeration membrane can clean the bubble-free aeration membrane, extend the service life of the membrane, slow down the occurrence of membrane pollution, and achieve continuous operation for many years.

[0044] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A MABR sewage treatment device based on A+B composite membrane, characterized in that: The invention comprises a composite membrane assembly, a membrane shell (3) and a support frame (4); wherein the composite membrane assembly comprises a bubble-free aeration membrane (1) and a micro-nano aeration membrane (2); wherein the bubble-free aeration membrane (1) is provided in multiple layers and is spaced from top to bottom in the middle of the support frame (4); and a layer of micro-nano aeration membrane (2) is provided below the bottom bubble-free aeration membrane (1); and a plurality of membrane shells (3) are fixed from top to bottom on both sides of the support frame (4); and each layer of the bubble-free aeration membrane (1) and the micro-nano aeration membrane (2) are provided on the support frame (4). The membranes (2) are connected to the membrane shells (3) on both sides thereof; the membrane shell (3) on one side of the topmost bubble-free aeration membrane (1) is connected to an external blowing device, and air enters from one side of the topmost bubble-free aeration membrane (1) and flows to the other side, then enters downward into the next layer of bubble-free aeration membrane (1), and flows to the other side, and so on until it reaches the bottom layer of micro-nano aeration membrane (2); the air circulates from top to bottom in the multi-layer aeration membrane through the left-right alternating flow path, thereby increasing the contact area between the air and the membrane.

2. The MABR sewage treatment device based on A+B composite membrane according to claim 1 is characterized in that: The material of the bubble-free aeration membrane (1) and the micro-nano aeration membrane (2) is any one of polytetramethylpentene, polypropylene, polyethylene, polytetrafluoroethylene, polyetheretherketone, polysilicone resin, polyvinylidene fluoride, polyurethane, polyester, polyamide, nylon and glass fiber, or a combination of multiple thereof; the inner diameter of the membrane wire of the bubble-free 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 MABR sewage treatment device based on A+B composite membrane according to claim 1 is characterized in that: 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 MABR sewage treatment device based on A+B composite membrane according to claim 1 is characterized in that: The membrane shell (3) is fixed on both sides of the support frame (4) through threaded connection.

5. The MABR sewage treatment device based on A+B composite membrane according to claim 1 is characterized in that: The membrane shell (3) and the bubble-free aeration membranes (1) or micro-nano aeration membranes (2) on both sides are bonded by gluing.

6. The MABR sewage treatment device based on A+B composite membrane according to claim 1 is characterized in that: The support frame (4) is made of Q235 steel with external galvanizing and is fixed into a frame by welding.

7. The MABR sewage treatment device based on A+B composite membrane according to claim 1 is characterized in that: The support frame (4) is 2 m long, 2 m wide and 0.8 m high.

8. The MABR sewage treatment device based on A+B composite membrane according to claim 7 is characterized in that: In the vertical direction, the composite membrane assembly is provided with three layers of bubble-free aeration membranes (1) and one layer of micro-nano aeration membrane from top to bottom; in the horizontal direction, each layer of the composite membrane assembly is provided with eight groups of membranes, for a total of thirty-two groups of single membrane groups.

9. The MABR sewage treatment device based on A+B composite membrane according to claim 8 is characterized in that: The air flow rate of the bubble-free aeration membrane (1) is 0.1m 3 / h / group, the ventilation volume of micro-nano aeration membrane (2) is 0.8m 3 / h / group.

10. A method for using the MABR sewage treatment device according to claims 1 to 9, characterized in that: The MABR sewage treatment device is placed in the sewage to be treated, ensuring that the membrane filament direction is parallel to the water flow direction; air is introduced into the bubble-free aeration membrane (1) by using an air blowing device, and the air flows from top to bottom in the multi-layer aeration membrane through left and right alternating flow paths, thereby increasing the contact area between the air and the membrane; the bubble-free aeration membrane (1) serves as a microbial carrier, and the microorganisms degrade pollutants in the sewage; the micro-nano aeration membrane (2) generates micro-nano bubbles for pressure relief, and the generated micro-nano bubbles oxygenate the water body and clean the residual substances of the upper bubble-free aeration membrane (1) at the same time.

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