Composite membrane assembly based on MABR (Membrane Aerated Baffled Reactor) and denitrification reactor

Abstract

The utility model relates to a composite membrane assembly based on an MABR (Membrane Aerated Baffled Reactor) and a denitrification reactor. The membrane elements are arranged in the frame at intervals, each membrane element is provided with a sheet-shaped supporting layer and a first air pipe and a second air pipe which are installed in the frame, a plurality of transverse membrane wires are arranged on the side wall of the supporting layer from top to bottom, each membrane wire is provided with a plurality of suspension cable-shaped membrane wire sections, and the membrane wires are connected with the side face of the supporting layer through the two ends of the membrane wire sections; the first air pipe and the second air pipe are located on the two sides of the supporting layer respectively and connected with the edges of the corresponding supporting layer, the first end of the two ends of each membrane wire is in sealed connection with the first air pipe, the second end of the two ends of each membrane wire is in sealed connection with the second air pipe, and an inner cavity of each membrane wire is communicated with inner cavities of the first air pipe and the second air pipe respectively. The problems that in an existing MABR membrane assembly, the density of hollow fiber membrane filaments is too high, a biological membrane grows fast, the membrane assembly is prone to being blocked, the mass transfer rate of a matrix and metabolites in the biological membrane is affected, and the nitration reaction efficiency is not high are solved.

Description

Technical Field

[0001] The utility model relates to sewage treatment, in particular to a composite membrane component and a denitrification reactor based on MABR. Background Art

[0002] Membrane aerated biofilm reactor (MABR) is a new type of sewage treatment process, which organically integrates the traditional biofilm method with the gas separation membrane technology, uses an oxygen-permeable membrane to supply oxygen to the bioreactor, and microorganisms can easily attach and grow on the membrane surface to form a biofilm, thereby efficiently degrading pollutants in the water. MABR technology has unique advantages. First, it uses bubble-free aeration to supply oxygen, and the oxygen utilization rate is high; second, due to the heterogeneous mass transfer of oxygen and pollutants, a unique microbial community stratification is formed in the biofilm, which helps to achieve the simultaneous nitrification and denitrification process; third, MABR has obvious advantages in efficient biological denitrification of sewage; in addition, its sludge production is low and the energy-saving effect is significant. Compared with the traditional activated sludge method, it can reduce the operating energy consumption by 40-80%.

[0003] The shortcomings of existing composite or combined MABR membrane components: The alternating arrangement of MABR membrane filaments and traditional biofilm fillers helps to increase the amount of attached microorganisms, but the two have not been organically integrated, and have not been able to solve the problems of easy balling and clogging of biofilm fillers and the difficulty in optimizing and controlling the amount of microorganisms on MABR membrane filaments. If forced de-membrane treatment is performed by increasing the airflow and backwashing intensity, the biofilm on the surface of the MABR membrane will fall off in pieces, reducing the treatment efficiency of the reactor. The membrane filaments in the MABR membrane component are arranged in parallel with the water flow, and the mass transfer rate of the matrix and metabolites through the membrane cannot be effectively improved, which is not conducive to the efficient degradation of pollutants. The MABR membrane component and the filter tank, contact oxidation and other modules of the biofilm method are arranged in the same reactor in an upper and lower manner. There is a risk of overlapping shortcomings of the two types of treatment modules during long-term operation. The problem of biofilm clogging or membrane filament pollution is still serious, and the membrane component is very inconvenient to backwash, maintain and overhaul. Directly applying porous materials or fiber fillers on the surface of MABR membrane fibers will affect the oxygen mass transfer area to a certain extent, reduce the oxygen transfer flux, and affect the working efficiency of MABR membrane components. In addition, the processing and manufacturing are complex and the cost is high. MABR membrane components use a vertical installation method for membrane fibers, and the inlet and outlet pipes are located at the upper and lower ends of the membrane components. Therefore, the only way to perform offline maintenance is to lift the entire membrane component out of the reactor, and online maintenance cannot be achieved, which increases the difficulty of maintenance. Utility Model Content

[0004] The purpose of the utility model is to provide a composite membrane assembly and denitrification reaction device based on MABR to solve the problems that the density of hollow fiber membrane filaments in the existing MABR membrane assembly is too high, the biofilm grows fast, and the membrane assembly is easily blocked; the distribution direction of the membrane filaments is parallel to the water flow direction, which affects the mass transfer rate of the matrix and metabolites in the biofilm, and the nitrification reaction efficiency is not high; the bottom air cleaning process is easy to cause the biofilm at the bottom of the membrane assembly to fall off in pieces, and the cleaning effect of the upper part of the membrane assembly is not good, and the membrane filaments are easy to break and leak, and it is not easy to repair and replace. The utility model can significantly increase the number of microorganisms on the surface of the membrane element and the types of microorganisms of different functional types by distributing the membrane filaments horizontally and attaching them to the surface of the support layer to form a membrane element. The cross-flow mode formed by the membrane filament direction and the water flow direction effectively improves the mass transfer rate through the membrane, and ensures the flushing effect of the over-thick biofilm on the surface of the membrane element, and improves the treatment efficiency of the MABR reactor. At the same time, the composite membrane assembly proposed by the utility model can realize online maintenance, and can realize the online disassembly, replacement and installation of a single membrane element, which greatly reduces the difficulty of maintenance and management.

[0005] The purpose of the utility model is achieved as follows: a composite membrane component based on MABR, comprising:

[0006] A frame having openings at upper and lower ends;

[0007] A plurality of membrane elements are arranged at intervals in the frame, the membrane element comprises a sheet-shaped support layer and a first and a second air pipe installed in the frame, a plurality of transverse membrane threads are arranged from top to bottom on the side wall of the support layer, the membrane threads comprise a plurality of suspension cable-shaped membrane thread segments, both ends of the membrane thread segments are connected to the side surface of the support layer,

[0008] The first and second air tubes are respectively located on both sides of the support layer and connected to the edges of the corresponding support layers. Both ends of each membrane thread are respectively sealed and connected to the first and second air tubes. The inner cavity of each membrane thread is respectively connected to the inner cavities of the first and second air tubes.

[0009] The supporting layer is a mesh cloth made of nylon; the membrane filament is a dense transparent silicone rubber tube made of polydimethylsiloxane or methylphenyl silicone rubber.

[0010] The air pipe is connected to the inner wall of the frame through a clamping plate. The cross-section of the clamping slot of the clamping plate is a small-bottom structure. The body of the air pipe is installed in the clamping slot. The membrane filaments and the supporting layer connected to the air pipe are passed through the lateral opening of the clamping slot. The limiting piece abuts against the upper end of the clamping slot or the frame to limit the air pipe. The membrane elements are coaxially and laterally arranged in the frame.

[0011] The root of each membrane wire segment is vertically connected to the support layer so that the membrane wire segment bends outward from both side ends away from the support layer.

[0012] The two ends of the membrane wire segment are connected to the support layer by binding with a flexible nylon line, or the two ends of the membrane wire segment are connected to the support layer by welding or bonding;

[0013] The edge of the support layer is bonded or welded to the corresponding air pipe;

[0014] The end of the membrane thread extends into the trachea through the mounting hole on the trachea, and the membrane thread is fixed to the mounting hole by welding or bonding.

[0015] A denitrification reactor, comprising:

[0016] A cell body, wherein the interior of the cell body is divided into a reflux mixing zone and a membrane reaction zone which are connected at the bottom by a guide plate, and an air distribution plate is arranged at the bottom of the membrane reaction zone;

[0017] Any of the MABR-based composite membrane modules, wherein the MABR-based composite membrane modules are mounted on the air distribution plate, the first air pipe of each composite membrane module is sealed and connected to the aeration pipe, and the second air pipe of each membrane module is sealed and connected to the exhaust pipe,

[0018] A reactor mud outlet pipe arranged at the lower part of the tank body;

[0019] A water inlet pipe and a water outlet pipe, wherein the water inlet pipe is connected to the reflux mixing zone, and the water outlet pipe is connected to the membrane reaction zone.

[0020] An air stirring transverse pipe is arranged at the bottom of the membrane reaction zone, and a plurality of air stirring perforated pipes extending laterally are sealed and connected to the outer side wall of the air stirring transverse pipe.

[0021] A plurality of mixed liquid outlet pipes are arranged in the middle and / or upper part of the membrane reaction zone, and the mixed liquid outlet pipes are connected to the mixed liquid reflux pump, and the mixed liquid reflux pump is connected to the reflux mixing zone through the mixed liquid reflux pipe.

[0022] A mud discharge pump is arranged on the mud outlet pipe of the reactor, the downstream end of the mud outlet pipe of the reactor is connected to the mud discharge pipe and the mud return pipe, the mud discharge pipe is connected to the outside, the mud return pipe is connected to the return mixing zone, a mud discharge valve is arranged on the mud discharge pipe, and a mud return valve is arranged on the mud return pipe.

[0023] A stirrer is arranged in the reflux mixing zone, and an online dissolved oxygen meter and an online ORP meter are also arranged in the middle and upper part of the membrane reaction zone.

[0024] The above scheme has the following beneficial effects: the composite MABR membrane assembly and the biological denitrification reaction device constructed with the membrane assembly as the core solve the problems that the density of hollow fiber membrane filaments in the existing MABR membrane assembly is too high, the biofilm grows fast, and the membrane assembly is easily blocked; the distribution direction of the membrane filaments is parallel to the water flow direction, which affects the mass transfer rate of the matrix and metabolites in the biofilm, and the nitrification reaction efficiency is not high; the biofilm at the bottom of the membrane assembly is prone to fall off in pieces during the bottom air cleaning process, and the cleaning effect of the upper part of the membrane assembly is not good; the membrane filaments are easy to break and leak, and are not easy to repair or replace. The utility model proposes a new type of composite membrane assembly and denitrification reactor, which can significantly increase the number of microorganisms on the surface of the membrane element and the types of microorganisms of different functional types by distributing dense membrane filaments horizontally and attaching them to the surface of the support layer to form a membrane element. The cross-flow between the membrane fibers and the water flow direction effectively improves the mass transfer rate through the membrane and ensures the flushing effect of the excessively thick biofilm on the surface of the membrane elements, thereby improving the treatment efficiency of the MABR reactor. At the same time, the membrane elements arranged at intervals are easy to inspect and replace without affecting the work of other membrane elements, and can be inspected and replaced online. A single membrane element can be disassembled, replaced and installed online, greatly reducing the difficulty of maintenance and management.

[0025] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cross-sectional schematic diagram of the membrane assembly in the front view direction;

[0027] Figure 2 It is a cross-sectional schematic diagram of the membrane assembly in the rearward direction;

[0028] Figure 3 It is a schematic diagram of the matching structure of the pallet and the air pipe;

[0029] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0030] Figure 5 It is a schematic diagram of the longitudinal cross-sectional structure of a denitrification reactor;

[0031] Figure 6 Schematic diagram of the top view of the denitrification reactor;

[0032] Figure 7 This is a schematic diagram of the installation structure of the gas distribution plate in the denitrification reactor.

[0033] In the accompanying drawings, 1 is a denitrification reactor, 2 is a reflux mixing zone, 3 is a membrane reaction zone, 4 is a guide plate, 5 is a support beam, 6 is an air distribution plate, 7 is an air stirring main pipe, 8 is a composite membrane module based on MABR, 9 is an air stirring horizontal pipe, 10 is an air stirring perforated pipe, 11 is a sludge pump, 12 is a reactor mud outlet pipe, 13 is a reactor mud outlet valve, 14 is a sludge reflux valve, 15 is a sludge reflux flowmeter, 16 is a sludge reflux pipe, 17 is a sludge valve, 18 is a sludge pipe, 19 is a mixed liquor reflux valve, 20 is a mixed liquor outlet pipe, 21 is a mixed liquor reflux pump, 22 is a mixed liquor reflux flowmeter, 23 is a mixed liquor reflux pipe, 24 is a water inlet pipe, 25 is a water outlet pipe, 26 is an aeration fan, 27 is an aeration air duct main valve, 28 is an aeration flowmeter, 29 is an aeration main pipe, and 30 is an aeration main pipe valve, 31 is an aeration main pipe, 32 is an aeration branch pipe, 33 is an aeration branch pipe valve, 34 is an air stirring fan, 35 is an air stirring main pipe valve, 36 is an air stirring flow meter, 37 is a mixer, 38 is an exhaust branch pipe valve, 39 is an exhaust branch pipe, 40 is an exhaust main pipe, 41 is an exhaust main pipe valve, 42 is an exhaust outlet, 43 is an online dissolved oxygen meter, 44 is an online ORP meter, 45 is an aeration main pipe air pressure gauge, 46 is an aeration main pipe air flow meter, 47 is an exhaust main pipe air pressure gauge, 48 is an exhaust main pipe air flow meter, 800 is a frame, 801 is a card board, 802 is a first air pipe, 804 is a supporting layer, 805 is a membrane wire, 807 is a supporting column, 808 is a second air pipe, 809 is an embedded plug, 810 is a limiter, 811 is a membrane element, 8051 is the membrane wire segment, 8101 is the slot, and 8102 is the lateral opening. DETAILED DESCRIPTION

[0034] With reference to the accompanying drawings, specific embodiments of the present invention will be described in detail.

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms center, up, down, front, back, left, right, vertical, horizontal, top, bottom, inside, outside, etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, the terms first and second are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as first and second can be used to explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of multiple is two or more. It should be noted that in practical applications, due to the limitations of equipment accuracy or installation errors, absolute parallel or vertical effects are difficult to achieve. The description of vertical, parallel or same direction in this application is not an absolute limiting condition, but means that a vertical or parallel structural setting can be achieved within a preset error range and the corresponding preset effect can be achieved. In this way, the technical effect of the limited features can be maximized, and the corresponding technical solution can be easy to implement and has high feasibility.

[0037] In the description of this specification, the description of reference terms such as one embodiment, some embodiments, examples, specific examples, or some examples means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples without contradiction.

[0038] See also Figures 1 to 7 An embodiment of a composite membrane assembly based on MABR, the composite membrane assembly based on MABR includes a frame 800, a plurality of membrane elements 811, a first air pipe 802 and a second air pipe 808.

[0039] The frame 800 may be a rectangular frame 800, with openings at the upper and lower ends for water to flow in and out; the frame is made of 304 or higher grade stainless steel, and its length, width and height may be set according to the needs of the MABR denitrification reactor 1. The main function of the frame 800 is to support and fix the multiple membrane elements 811, and to facilitate the lifting and disassembly of the membrane assembly.

[0040] A plurality of membrane elements 811 are arranged at intervals in the frame 800, and flow channels are formed between adjacent membrane elements 811. The membrane element 811 has a sheet-like support layer 804 and a first and a second air pipe 808 installed in the frame 800. The support layer 804 is used to support the membrane filaments 805. At the same time, the surface of the support layer 804 also forms a film hanging area for forming an anaerobic membrane and an aerobic membrane in the adjacent membrane filament area. In this embodiment, the membrane element 811 is a composite body composed of a plurality of membrane filaments 805 and a whole piece of mesh cloth serving as the support layer 804, wherein the mesh cloth can be made of nylon with a square mesh of 6 to 10 meshes. The mesh cloth has a larger surface area and a lighter weight, and is also convenient for water flow.

[0041] The membrane wire 805 includes a plurality of membrane wire segments 8051 in the form of suspension cables, and the entire membrane wire 805 is divided into a plurality of membrane wire segments 8051 through the connection points between the membrane wire 805 and the support layer 804, that is, the end of the membrane wire segment 8051 is connected to the side of the support layer 804. The connection method of the membrane wire 805 may include binding, welding or bonding. When the fixation is achieved by binding. For example, a flexible nylon rope can be used to bind the mesh cloth. In the binding method, the membrane wire 805 can be attached to the warp tissue or weft tissue of the mesh cloth and tied by the nylon rope, and limited by the vertical weft tissue or warp tissue; of course, the membrane wire 805 can also be passed through one of the mesh holes of the mesh cloth, and the other mesh hole is passed through and wrapped around at least one weft tissue. In this embodiment, the two horizontal sides of the mesh cloth in the vertical direction are the selvedges, and the weft direction is the direction perpendicular to the selvedges.

[0042] Preferably, the membrane filament 805 is fixed to the support layer 804 by welding. The welding fixation method can realize automated production through mechanical equipment, which can improve work efficiency and improve product consistency. Figure 1As shown, the spacing between adjacent connections of the membrane filaments 805 is 20 to 30 cm. Each membrane filament 805 in a single membrane element 811 is arranged horizontally, and different membrane filaments 805 are evenly distributed in parallel from top to bottom on the surface of the mesh cloth. The membrane filament 805 between the connections of two adjacent membrane filaments 805 maintains an appropriate relaxation state, and the arc length of its membrane filament segment 8051 is 1.2 to 1.4 times the linear spacing between adjacent connections. The membrane filament segment 8051 droops in a suspended cable shape, and the entire membrane filament 805 is arranged in a wavy shape on the mesh cloth. By adopting this structure, the arc length of the entire membrane filament is longer, and it can provide a larger film-forming area. The membrane filament swings in the water flow. Due to the swinging, the position of the membrane filament 805 changes greatly. The part of the membrane filament 805 facing away from the water flow direction can contact the sewage to be treated, and the biofilm grows well; it has a larger effective horizontal action area. When swinging, the membrane filament 805 can extend to a deeper position in the flow channel between adjacent membrane components. At the same time, during the whole process, the membrane filament 805 swings, and the swinging part has a sweeping area, which can also treat the sewage to be treated that is contacted by the sweeping part. The swinging speed is changing, and the water flow speed and the speed of the membrane filament 805 synthesize different actual membrane filament 805 relative water flow speeds and speed directions. The angle of the actual water flow direction is constantly changing, and the membrane filament 805 is in contact with different directions, so that the biofilm grows more evenly. At the same time, the swing of the membrane filament 805 can control the thickness of the biofilm on the membrane filament 805 and keep it within an appropriate range. When flushing, the water flow impacts the membrane filament 805. Since the membrane filament 805 can swing, the surface of the membrane filament 805 is easier to clean. At the same time, due to the swing of the membrane filament 805, the position of the swinging part is unstable. The membrane filament 805 on the back side of the flushing water flow is easily flushed due to the change in position.

[0043] Furthermore, the root of each membrane filament segment 8051 is vertically connected to the support layer 804 so that the membrane filament segment 8051 is bent outward from the two side ends away from the support layer 804. In this way, the membrane filament segment 8051 is bent outward from the two side ends away from the support layer 804. Due to the existence of gravity, the membrane filament segment extends from its end toward the outside of the support layer and downward, which can make the membrane filament segment 8051 deviate closer from the support layer 804 and extend to a deeper position in the flow channel between adjacent membrane components, so as to have a larger reaction area, significantly increase the reaction area, and have a larger aerobic membrane generation area.

[0044] The first air pipe 802 and the second air pipe 808 are arranged in the frame 800. In this embodiment, the first air pipe 802 and the second air pipe 808 are both made of ABS material, and the nominal diameter is DN32-DN65. This embodiment does not limit this. In practice, it can be determined according to the length and number of the membrane wires 805 in the membrane element 811. The air pipe includes a pipe body, and a plug is arranged at the lower end of the pipe body. The plug is fixed in a way that the bottom end of the pipe of the air pipe is sealed by bonding with an embedded plug 809. The upper end of the pipe body has a pipe opening connected to the outside, which can be used to connect the intake branch pipe or the exhaust branch pipe 39. One of the two air tubes is used as an air inlet tube, and the other air tube is used as an air outlet tube. The first and second air tubes 808 are respectively located on both sides of the support layer 804 and connected to the edges of the corresponding support layer 804. The first end of each membrane thread 805 is sealed and connected to the first air tube 802, and the second end of each membrane thread 805 is sealed and connected to the second air tube 808. The inner cavity of each membrane thread 805 is respectively connected to the inner cavities of the first and second air tubes 808. The inner cavity of the membrane thread 805, the first air tube 802 cavity, and the second air tube 808 cavity form a closed cavity for gas circulation.

[0045] The sealed connection between the membrane thread 805 and the trachea can be achieved in the following manner: the end of the membrane thread 805 is inserted into the trachea through the mounting hole on the trachea, and the membrane thread 805 is welded or bonded to the mounting hole. More specifically, first, a hole is opened in the first trachea 802 or the second trachea 808 at the connection point 803 between the membrane thread 805 and the trachea, and the hole diameter is larger than the outer diameter of the membrane thread 805 by 1mm; then one end of the membrane thread 805 is inserted into the trachea for at least 5mm; then the two are connected by ultrasonic welding, and the membrane thread 805 is well sealed at the connection point 803 between the trachea and the inner cavity of the trachea while ensuring good communication between the inner cavity of the membrane thread 805 and the inner cavity of the trachea, and no leakage occurs under the maximum working pressure of the membrane element 811 of 10 to 200Kpa.

[0046] The left and right sides of the support layer 804 are respectively bonded or welded to the first air tube 802 and the second air tube 808 . The bonding and fixing part can be a continuous strip and maintain a distance of more than 5 mm between it and the membrane wire 805 and the air tube connection point 803 .

[0047] In the above implementation, the membrane filament 805 preferably adopts a dense transparent silicone rubber tube, which has the advantages of high pressure resistance, no bubble point, and low cost. The material can be polydimethylsiloxane or methylphenyl silicone rubber, with an inner diameter of 0.5mm to 1.2mm and a wall thickness of 0.25mm to 0.5mm. The oxygen permeable membrane material mainly includes a hydrophobic microporous membrane, a non-porous dense membrane, and a mixed membrane composed of the two. The microporous membrane has a small mass transfer resistance and a large membrane flux, but the selectivity for oxygen is poor, the bubble point pressure is low, and it is easily blocked by microbial contamination; the dense membrane has high mechanical strength, good chemical stability, and strong selectivity for oxygen, but the microbial attachment and growth performance is poor, and it is difficult to form a membrane; the mixed membrane has the advantages of the first two, but the production is difficult and the cost is high, and the uniformity and stability of the surface modification layer directly affect the performance and life of the membrane.

[0048] To facilitate the replacement of the membrane assembly, in some embodiments, the air pipe is connected to the inner wall of the frame 800 through a clamping plate 801. The cross-section of the clamping slot 8101 of the clamping plate 801 is a small-bottom structure. The body of the air pipe is installed in the clamping slot 8101. The membrane filament 805 and the supporting layer 804 connected to the air pipe are led out through the lateral opening 8102 of the clamping slot 8101. A limiting member 810 is set at the upper end of each air pipe, and the limiting member 810 abuts against the upper end of the clamping slot 8101 or the frame to limit the air pipe.

[0049] Among them, at least one card board 801 can be set, or multiple cards can be set in the height direction. The card board 801 is made of ABS or PP material. The cross-section of the card slot 8101 of the card board 801 is a small bottom structure. Exemplarily, the card board 801 is evenly opened with multiple circular holes, each circular hole corresponds to a first air pipe 802 or a second air pipe 808, and the diameter of the circular hole is 4 to 5 mm larger than the diameter of the first air pipe 802 or the second air pipe 808. At the same time, each circular hole is opened on the same side. The length of the notch is 0.5 times to 0.7 times the diameter of the first air pipe 802 or the second air pipe 808 to ensure that the membrane filament 805 and the mesh cloth can pass through the notch smoothly, wherein the circular hole part and the notch part jointly constitute the card slot 8101 structure. The stopper 810 may be a flange, and the stopper 810 may also be a pipe clip, which is used to limit the first air pipe 802 or the second air pipe 808 of each membrane wire 805. The stopper is limited by the frame or the topmost card plate. For example, the pipe clip can be connected to the frame to form abutment in the vertical direction. When connected to the air pipe, it is clamped on the air pipe. Each membrane element 811 is coaxial and arranged horizontally in the frame 800, that is, the axis of the entire membrane element is on the same straight line, and each membrane element is arranged neatly for easy management; of course, multiple membrane elements can share a horizontally arranged card plate on one side, and multiple installation slots can be set on a card plate, and the pipes in each installation slot are arranged at the same height.

[0050] The installation method of the membrane element 811 is to unfold a single membrane element 811 flatly, vertically insert the first air pipe 802 into the clamping plate 801 in the membrane assembly, and vertically insert the second air pipe 808 into the clamping plate 801 on the other side of the membrane assembly, and simultaneously insert the two air pipes downward to the bottom of the membrane assembly. After the two pipes are in place, fix the membrane element 811 with a pipe clip.

[0051] The disassembly method of the membrane element 811 is that if the membrane element 811 is blocked, damaged, or other problems occur during the operation of the reactor, the problematic membrane element 811 can be disassembled online or offline. First, the valve of the aeration branch pipe 32 on the membrane element 811 is closed, the valve of the exhaust branch pipe 38 is closed, and the aeration branch pipe 32 and the exhaust branch pipe 39 are disconnected from the valves thereon; secondly, the pipe clips at the top of the inlet and exhaust branch pipes 39 are opened; finally, the aeration branch pipe 32 and the exhaust branch pipe 39 are synchronously lifted vertically upward, steadily and slowly to the outside of the membrane assembly, and the disassembly is completed. During the disassembly process, other membrane elements 811 can continue to operate without being affected.

[0052] After all membrane elements 811 are correctly installed in the membrane assembly frame 800, the membrane assembly can be hoisted as a whole into the denitrification reactor 1. The installation and disassembly method using the above structure can realize online maintenance of the membrane assembly during operation, and can individually disassemble, replace and install abnormal or damaged membrane elements 811 without affecting the operation of other membrane elements 811, thereby reducing the difficulty of repairing and maintaining the membrane assembly.

[0053] In this embodiment, the composite membrane assembly forms a composite membrane structure through the organic fusion of dense silicone rubber membrane and nylon mesh cloth. Microorganisms are easy to attach to the mesh cloth to form a biofilm, thereby increasing the biofilm formation rate on the surface of the membrane filament 805 and increasing the number and types of microorganisms attached to and growing on the surface of the membrane element 811, which is beneficial to improving the carbon removal and denitrification efficiency of the reactor.

[0054] The distribution direction of the membrane filaments 805 in the composite membrane assembly proposed in this embodiment is perpendicular to the water flow direction. The upper and lower ends of the water flow frame are open to flow in and out, forming a cross-flow pattern with the membrane filaments 805, which helps to increase the mass transfer rate of the matrix and metabolic products across the membrane and improve the processing efficiency of the reactor.

[0055] In the composite membrane assembly proposed in this embodiment, the membrane filaments 805 are arranged horizontally, so that the amount of pollutants received by each membrane filament segment 8051 of a single membrane filament 805 is basically the same, and the thickness of the biofilm on its surface is uniform, which makes it easier to uniformly control the properties of the biofilm. A certain interval is maintained between each membrane element 811 to form a gap, which helps to reduce the clogging problem of the membrane assembly. The membrane filaments 805 can be scrubbed cross-flow by intermittent air stirring and other methods, which can effectively control the thickness of the biofilm.

[0056] The composite membrane assembly proposed in this embodiment, the easily adjustable biofilm thickness and the gentle and effective cleaning method effectively avoid the risk of overlapping disadvantages of membrane pollution and biofiller clogging caused by arranging the MABR membrane assembly and the biofiller up and down.

[0057] The utility model also provides an embodiment of a denitrification reactor, see Figures 1 to 7 The denitrification reactor includes a tank body, which can be composed of a reinforced concrete structure or a steel structure. The interior of the tank body is divided into a reflux mixing zone 2 and a membrane reaction zone 3 connected at the bottom by a guide plate 4. In this embodiment, a space is reserved below the guide plate 4 for the reflux mixing zone and the membrane reaction zone 3 to be connected. The effective volume ratio of the reflux mixing zone 2 to the membrane reactor is 1:3 to 1:5. Of course, the connection method can also be achieved by pipelines and other methods.

[0058] A stirrer 37 is provided in the reflux mixing zone 2. The stirring blade of the stirrer 37 is in the form of a hyperbolic surface, which can generate water flow lifting stirring in the reflux mixing zone 2. The stirring intensity is 0.6-0.8W / m 3 水容积 .

[0059] An air distribution plate 6 is provided at the bottom of the membrane reaction zone 3. In this embodiment, the air distribution plate 6 is supported and fixed by a support beam 5 provided at the bottom end of the guide plate 4 and the lower part of the inner wall of the denitrification reactor 1. The air distribution plate 6 is a porous stainless steel plate or a glass fiber reinforced plastic plate, and the openings are evenly distributed circular holes with an aperture of 10 to 20 mm and an opening rate of 40% to 60%. The water inlet and stirring air at the bottom of the membrane reaction zone 3 are evenly distributed, and the strength thereof meets the support requirements of all membrane components.

[0060] The denitrification reactor 1 further comprises at least one MABR membrane assembly as described in the above embodiment, wherein the MABR membrane assembly is mounted on the air distribution plate 6, the first air pipe of each composite membrane assembly is sealedly connected to the aeration pipe, and the second air pipe 808 of each membrane assembly is sealedly connected to the second air pipe 808.

[0061] The denitrification reactor 1 further includes a reactor mud outlet pipe 12 disposed at the lower part of the tank body for leading out the sludge inside the reactor. The denitrification reactor 1 further includes a water inlet pipe 24 and a water outlet pipe 25, wherein the water inlet pipe 24 is connected to the reflux mixing zone 2, and the water outlet pipe 25 is connected to the membrane reaction zone 3.

[0062] Specifically, the aeration pipe includes an aeration branch pipe and an aeration main pipe, and the exhaust pipe includes an exhaust main pipe and an exhaust branch pipe. The top of the membrane assembly is rectangular, the long side of the membrane element 811 is parallel to the guide plate 4, and one side of the short side is the membrane element 811 air inlet pipe of each membrane element 811, which is connected to the aeration branch pipe 32 of the membrane assembly through the valve of the aeration branch pipe 32 of the membrane assembly, and the aeration branch pipe 32 of each membrane assembly is connected to the aeration main pipe 31 of the membrane assembly, and the aeration main pipe 31 is connected to the aeration main pipe 29 through the aeration main pipe valve 30; the other short side is the membrane element 811 exhaust pipe of each membrane element 811 in the membrane assembly, which is connected to the exhaust branch pipe 39 of the membrane assembly through the valve of the exhaust branch pipe 39 of the membrane assembly, and the exhaust branch pipe 39 of each membrane assembly is connected to the exhaust main pipe 40 of the membrane assembly, and the exhaust main pipe valve 41 is set on the exhaust main pipe 40, and its downstream end is the exhaust port 42.

[0063] The aeration fan 26 is connected to the aeration main pipe 29 to provide air for the membrane assembly. The aeration main pipe 29 between the aeration fan 26 and the valve 30 of the aeration main pipe 31 is provided with an aeration air pipe main valve 27 and an aeration flow meter 28.

[0064] An air stirring transverse pipe 9 is arranged at the bottom of the membrane reaction zone 3, and a plurality of air stirring perforated pipes 10 extending laterally are sealed and connected to the outer side wall of the air stirring transverse pipe 9. Specifically, the air stirring transverse pipe 9 has a nominal diameter of DN50 to DN80, and is arranged perpendicular to the guide plate 4 and located at the bottom center line of the membrane reaction zone 3. A plurality of horizontal air stirring perforated pipes 10 are evenly distributed on the outer side wall of the air stirring transverse pipe 9, and are sealed and connected to the air stirring transverse pipe 9. Each air stirring perforated pipe 10 is parallel to each other and perpendicular to the air stirring transverse pipe 9, and the spacing between two adjacent air stirring perforated pipes 10 is 500mm to 800mm. The nominal diameter of the air stirring perforated pipe 10 is DN25 to DN50, and holes are evenly opened on it, and the hole opening method is inclined downward at 45°, the hole diameter is 3mm to 5mm, and the spacing between two adjacent groups of holes is 50mm to 150mm. One end of the air stirring transverse pipe 9 is closed, and the other end is connected to the air stirring main pipe 7. The air stirring fan 34 is connected to the air stirring main pipe 7 through the air stirring main pipe valve 35 and provides stirring air for it. The air stirring main pipe 7 is also provided with an air stirring flow meter 36.

[0065] In some embodiments, a sludge pump 11 is provided on the reactor sludge outlet pipe 12, and the downstream end of the reactor sludge outlet pipe 12 is connected to a sludge discharge pipe 18 and a sludge return pipe 16, the sludge discharge pipe 18 is connected to the outside, the sludge return pipe 16 is connected to the reflux mixing zone 2, a sludge discharge valve 17 is provided on the sludge discharge pipe 18, and a sludge return valve 14 is provided on the sludge return pipe 16. The reactor sludge outlet pipes 12 are connected to the sludge discharge pump 11 after being collected, and the sludge discharge of the sludge discharge pump 11 is divided into two ways, one of which is to discharge the sludge in the reactor through the sludge discharge valve 17 and the sludge discharge pipe 18, and the other is to return the sludge to the reflux mixing zone 2 of the denitrification reactor 1 through the sludge return valve 14 and the sludge return pipe 16, and mix with the influent and the mixed liquid. A sludge return flowmeter 15 is provided on the sludge return pipe 16. The upstream of the reactor mud outlet pipe 12 can be connected to the tank bottom and the membrane reaction zone through pipelines provided with a reactor mud outlet valve 13 respectively.

[0066] In some embodiments, a plurality of mixed liquor outlet pipes 20 are provided in the middle or / and upper part of the denitrification reactor 1, on which a mixed liquor reflux valve 19 is provided. The mixed liquor outlet pipes 20 are connected to a mixed liquor reflux pump 21 after being collected, and the mixed liquor is transported to the reflux mixing zone 2 through a mixed liquor reflux pipe 23 to be mixed with the influent and reflux sludge. A mixed liquor reflux flowmeter 22 is provided on the mixed liquor reflux pipe 23.

[0067] In some embodiments, an online dissolved oxygen meter 43 and an online ORP meter are also provided in the middle and upper part of the membrane reaction zone 3 to perform online monitoring of the operating status of the reactor.

[0068] An aeration main pipe air pressure gauge 45 and an aeration main pipe air flow meter 46 are provided on the aeration main pipe 31 of each membrane assembly; an exhaust main pipe air pressure gauge 47 and an exhaust main pipe air flow meter 48 are provided on the exhaust main pipe 40 of each membrane assembly to monitor the operating status of each membrane assembly.

[0069] When the denitrification reactor in the above embodiment is used for sewage treatment, the denitrification reactor 11 adopts a continuous water inlet and outlet operation mode; the membrane assembly 8 adopts a flow-through operation mode; the membrane filaments 805 and the influent are in an efficient cross-flow operation mode, which can optimize the thickness of the biofilm on the membrane filaments 805 while improving the treatment efficiency; there is a high concentration of activated sludge in the mixing recirculation zone 2 of the denitrification reactor 11 and at the bottom of the membrane reaction zone 33, thereby completing the denitrification reaction together with the membrane assembly, forming an operation mode of the mud membrane method.

[0070] The sewage to be treated enters the mixing recirculation zone 2 through the water inlet pipe 24, and the mixed liquid enters the mixing recirculation zone 2 through the mixed liquid recirculation pipe 23 and the return sludge enters the mixing recirculation zone 2 through the sludge return pipe 16. The three are fully mixed under the action of the agitator 37. The mixed liquid is rich in nitrate nitrogen or nitrite nitrogen produced by the nitrification reaction of the membrane module 8, and the return sludge contains a large number of denitrifying bacteria. In the mixing recirculation zone 2, the denitrifying bacteria use the organic matter in the influent to undergo a denitrification reaction, and reduce the nitrate nitrogen in the mixed liquid to nitrogen gas, thereby achieving the purpose of denitrification.

[0071] The mixed liquid in the mixed reflux zone 2 flows downward through the bottom of the guide plate 44 into the membrane reaction zone 33, and then evenly distributes water to the composite membrane assembly based on MABR after passing through the air distribution plate 66, and flows through the membrane assembly 8 from bottom to top. The aeration fan 26 delivers air to the membrane assembly 8, and enters the air inlet pipe 802 of each membrane element 811 through the aeration branch pipe 32. The oxygen in the air passes through the surface of the membrane filament 805, providing dissolved oxygen for the biofilm attached to the surface of the membrane filament 80 and the biofilm attached and grown on the mesh cloth 804. Under aerobic conditions, the microorganisms in the biofilm oxidize and decompose the organic matter in the sewage into carbon dioxide and water, and at the same time oxidize the ammonia nitrogen in the sewage into nitrate nitrogen or nitrite nitrogen to complete the nitrification reaction. The nitrified mixed liquid rich in nitrate nitrogen or nitrite nitrogen is then transported to the mixed reflux zone through the mixed liquid reflux pump 21 for denitrification and denitrification.

[0072] The aeration air intake mode of the membrane assembly 8 has two operation modes: continuous aeration and intermittent aeration. When the denitrification reactor 11 is operated according to the traditional nitrification and denitrification process, the continuous aeration mode is adopted; when the denitrification reactor 11 is operated according to the short-range nitrification and denitrification or partial nitrite-anaerobic ammonia oxidation process, the intermittent aeration mode is adopted, and the ratio of aeration time to aeration stop time is 1:0.5 to 1:2.

[0073] The air stirring mode of the membrane assembly 8 adopts a timed stirring operation mode, that is, the air stirring is turned on for 10s to 30s every 15min to 30min. After turning on the air stirring fan 34 and the air stirring main pipe valve 35, the stirring air enters the bottom of the membrane reactor through the air stirring main pipe 77, the air stirring cross pipe 99 and the air stirring perforated pipe 10. The stirring air bubbles pass upward through the air distribution plate 66, evenly dispersed into smaller bubbles, and flow upward through the surface of the membrane element 811 to scrub the biofilm on the surface of the membrane filament 805 to remove the excessively thick biofilm. At the same time, the excessively thick biofilm on the mesh cloth 804 can also be scrubbed and removed.

[0074] There is a large amount of activated sludge in the lower part of the denitrification reactor 11, including the activated sludge after proliferation and the aged biofilm detached from the MABR membrane assembly by cleaning. These sludges are returned to the mixing reflux zone 2 through the sludge pump 11, and the excess sludge is discharged out of the reactor through the sludge valve 17 and the reactor sludge outlet pipe 1218.

[0075] The denitrification reactor in the utility model can monitor the dissolved oxygen concentration and redox property of the membrane reaction zone 3 through the online dissolved oxygen meter 43 and the online ORP meter, and thereby adjust the various functional properties of the membrane reaction zone 3 by adjusting the air inlet valve. When the denitrification reactor 1 operates in the traditional nitrification and denitrification mode, the higher dissolved oxygen 1.0mg / L~2.0mg / L and the higher ORP value 200mV~600mV are controlled; when the denitrification reactor 1 operates in the short-range nitrification and denitrification mode, it is controlled in the micro-oxygen state 0.2mg / L~0.5mg / L and the medium ORP range 100mV~300mV; when the denitrification reactor 1 operates in the partial nitrite-anaerobic ammonia oxidation mode, the low dissolved oxygen 0~0.1mg / L and the lower ORP range -100mV~100mV are controlled.

[0076] The utility model proposes a MABR composite membrane assembly, which uses a silicone rubber tube as an oxygen permeable membrane, a single membrane filament 805 is horizontally oriented, and is fixed at multiple points at equal intervals on a nylon mesh cloth, and multiple membrane filaments 805 are parallel and evenly distributed on the mesh cloth to form a single membrane element 811. Multiple membrane elements 811 are evenly distributed horizontally to form a composite MABR membrane assembly. The membrane assembly can realize the symbiotic growth of multiple functional microorganisms, forming a biofilm with aerobic bacteria, ammonia oxidizing bacteria and nitrite oxidizing bacteria as the main body on the surface of the membrane filament 805, and forming a biofilm with denitrifying bacteria and other facultative oxic bacteria as the main body on the mesh cloth, thereby achieving efficient removal of organic matter and nitrogen.

[0077] The denitrification reactor 1 based on the composite membrane assembly includes two relatively independent areas, namely the reflux mixing zone 2 and the membrane reaction zone 3. In the reflux mixing zone 2, the influent, reflux mixed liquor and reflux sludge are fully mixed, and the denitrifying bacteria in the sludge utilize the organic matter in the influent to undergo a denitrification reaction, converting the nitrate nitrogen or nitrite nitrogen in the reflux mixed liquor into nitrogen gas, thereby achieving the effect of removing total nitrogen. In the membrane reaction zone 3, oxygen is provided by the oxygen-permeable membrane in the MABR membrane assembly, and the biofilm on the surface of the membrane filament 805 and the biofilm on the surface of the mesh cloth can complete the removal of organic matter and nitrification reaction, converting ammonia nitrogen into nitrate nitrogen or nitrite nitrogen. At the same time, the biofilm on the surface of the mesh cloth can also produce a certain denitrification effect, thereby achieving the purpose of efficient denitrification.

[0078] The bottom area of ​​the denitrification reactor 1 based on the composite membrane assembly proposed in the utility model, in addition to the water and gas distribution functions, also has a relatively high concentration of activated sludge, which can play a role in denitrification. In addition, inoculating an appropriate amount of anaerobic ammonium oxidizing bacteria in this area can also achieve anaerobic ammonium nitrogen denitrification.

[0079] The denitrification reactor 1 based on the composite membrane assembly proposed in the utility model can use relatively low-intensity air stirring to perform cross-flow scrubbing on the membrane filaments 805, thereby preventing the biofilm on the surface of the membrane filaments 805 from corrosively falling off in pieces and reducing the reduction in the denitrification performance of the reactor.

[0080] The denitrification reactor 1 based on the composite membrane assembly proposed in the utility model has flexible and diverse operation modes. It can adopt the traditional denitrification operation mode of high-efficiency nitrification of the MABR membrane assembly and denitrification in the mixed recirculation zone; it can also operate the MABR membrane assembly in a short-range nitrification state by adjusting the gas supply pressure, aeration interval length and dissolved oxygen concentration, so that the reactor can perform short-range nitrification and denitrification; in addition, it can also contact the anaerobic ammonia-oxidizing bacteria at the bottom of the membrane reaction zone 3 to realize a new autotrophic denitrification operation mode of partial nitrite-anaerobic ammonia oxidation.

[0081] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Obviously, those skilled in the art can make various changes and modifications to the utility model without departing from the spirit and scope of the utility model. Thus, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and their equivalents, the utility model is also intended to include these modifications and variations.

Claims

1. A composite membrane module based on MABR, characterized in that: include: A frame (800) having openings at its upper and lower ends; A plurality of membrane elements (811) are arranged at intervals in a frame (800), the membrane elements (811) having a sheet-like support layer (804) and first and second air pipes (808) installed in the frame (800), a plurality of transverse membrane threads (805) are arranged on the side wall of the support layer (804) from top to bottom, the membrane threads (805) having a plurality of suspension cable-shaped membrane thread segments (8051), and two ends of the membrane thread segments (8051) are connected to the side surfaces of the support layer (804). The first and second air tubes (808) are respectively located on both sides of the support layer (804) and connected to the edges of the corresponding support layer (804), and both ends of each membrane thread (805) are respectively sealed and connected to the first air tube (802) and the second air tube (808), and the inner cavity of each membrane thread (805) is respectively connected to the inner cavities of the first and second air tubes (808).

2. The MABR-based composite membrane assembly according to claim 1, characterized in that: The support layer (804) is a mesh cloth made of nylon; the membrane filament (805) is a dense transparent silicone rubber tube made of polydimethylsiloxane or methylphenyl silicone rubber.

3. The MABR-based composite membrane assembly according to claim 1, characterized in that The air tube is connected to the inner wall of the frame (800) via a clamping plate (801); the cross section of the clamping slot (8101) of the clamping plate (801) is a small-bottomed structure; the tube body of the air tube is installed in the clamping slot (8101); the membrane filament (805) and the support layer (804) connected to the air tube are led out through the lateral opening (8102) of the clamping slot (8101); a limiting member (810) is provided at the upper end of each air tube; the limiting member (810) abuts against the upper end of the clamping slot (8101) or the frame to limit the air tube; and each membrane element (811) is coaxially and transversely arranged in the frame (800).

4. The MABR-based composite membrane assembly according to any one of claims 1 or 2, characterized in that: The root of each membrane thread segment (8051) is vertically connected to the support layer (804) so ​​that the membrane thread segment (8051) is bent outward from both side ends away from the support layer (804).

5. The MABR-based composite membrane assembly according to any one of claims 1 or 2, characterized in that: The two ends of the membrane thread segment (8051) are tied and connected to the support layer (804) through a flexible nylon line, or the two ends of the membrane thread segment (8051) are connected to the support layer (804) through welding or bonding; The edge of the support layer (804) is bonded or welded to the corresponding air pipe; The end of the membrane thread (805) extends into the trachea through a mounting hole on the trachea, and the membrane thread (805) is fixed to the mounting hole by welding or bonding.

6. A denitrification reactor, characterized in that: include: A cell body, wherein the interior of the cell body is divided into a reflux mixing zone (2) and a membrane reaction zone (3) which are connected at the bottom by a guide plate (4), and an air distribution plate (6) is arranged at the bottom of the membrane reaction zone (3); The MABR-based composite membrane assembly according to any one of claims 1 to 5, wherein the MABR-based composite membrane assembly is installed on the air distribution plate (6), the first air pipe (802) of each composite membrane assembly is sealedly connected to the aeration pipe, and the second air pipe (808) of each membrane assembly is sealedly connected to the exhaust pipe. A reactor mud outlet pipe (12) disposed at the lower part of the tank body; A water inlet pipe (24) and a water outlet pipe (25), wherein the water inlet pipe (24) is connected to the reflux mixing zone (2), and the water outlet pipe (25) is connected to the membrane reaction zone (3).

7. The denitrification reactor according to claim 6, characterized in that: An air stirring transverse pipe (9) is arranged at the bottom of the membrane reaction zone (3), and a plurality of laterally extending air stirring perforated pipes (10) are sealed and connected to the outer side wall of the air stirring transverse pipe (9).

8. The denitrification reactor according to claim 6, characterized in that: A plurality of mixed liquid outlet pipes (25) are arranged in the middle or / and upper part of the membrane reaction zone (3), and the mixed liquid outlet pipes (25) are connected to the mixed liquid reflux pump (21). The mixed liquid reflux pump (21) is connected to the reflux mixing zone (2) via the mixed liquid reflux pipe (23).

9. The denitrification reactor according to claim 6, characterized in that: A mud discharge pump (11) is provided on the reactor mud outlet pipe (12); the downstream end of the reactor mud outlet pipe (12) is connected to a mud discharge pipe (18) and a mud return pipe (16); the mud discharge pipe (18) is connected to the outside; the mud return pipe (16) is connected to the return mixing zone (2); a mud discharge valve (17) is provided on the mud discharge pipe (18); and a mud return valve (14) is provided on the mud return pipe (16).

10. The denitrification reactor according to claim 6, characterized in that: A stirrer (37) is arranged in the reflux mixing zone (2), and an online dissolved oxygen meter (43) and an online ORP meter (44) are also arranged in the middle and upper part of the membrane reaction zone (3).

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