Sludge film symbiotic denitrification reaction device

Abstract

The utility model relates to a kind of mud film symbiosis denitrification reaction device, including reaction pool, mixer, flow guide cylinder and biological membrane filler unit;The biological membrane filler unit is set between the outside of flow guide cylinder and the pool body of reaction pool, vertically suspended biological rope filler is set in biological membrane filler unit, water flow passage is left between adjacent biological rope filler, clearance is left between the inner wall of flow guide cylinder and the outer periphery of stirring paddle blade;By setting reaction pool, mixer, flow guide cylinder and biological membrane filler unit, biological rope filler is vertically suspended in biological membrane filler unit and water flow passage is left, when mixer operates, carbon source is in full contact with raw water, mixed liquor, while flow guide cylinder guides water flow to form circulation, biological membrane filler unit is suspended in pool, microorganism is attached to the surface of filler, water flow and filler are in full contact mass transfer, form mud film symbiosis system, promote pollutant degradation, improve denitrification efficiency, solve the problem of low mass transfer efficiency of conventional suspended filler, anaerobic fermentation of activated sludge on the surface of filler.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment technology, specifically relating to a mud-film symbiotic denitrification reaction device. Background Technology

[0002] The statements herein provide only background information related to this invention and do not necessarily constitute prior art.

[0003] Wastewater treatment plants commonly use conventional denitrification processes such as A / O (anaerobic-aerobic / oxygenic) and A2O (anaerobic-anoxic-oxygenic). Under aerobic conditions, nitrifying bacteria in the wastewater convert nitrogenous substances (including organic and inorganic nitrogen) into nitrates. Then, under anoxic conditions (dissolved oxygen <0.5 mg / L), denitrifying bacteria in the wastewater reduce the nitrates into gaseous nitrogen.

[0004] As wastewater treatment plant effluent standards for total nitrogen become increasingly stringent, and with the ongoing renovation of rainwater and wastewater separation pipelines, the total nitrogen content in influent is rising year by year. Conventional biological denitrification processes are beginning to be unable to meet current denitrification demands. To address this issue, methods such as increasing recirculation and carbon sources or constructing new denitrification filters are commonly used. However, this leads to increased operating costs, construction investment, and land acquisition issues. Other methods involve adding suspended packing, bio-rope packing, or three-dimensional fiber packing to the anoxic tank to enhance denitrification. However, these methods suffer from problems such as difficulty in biofilm formation and easy accumulation of suspended packing, and low mass transfer efficiency and excessive sludge adhesion of bio-rope packing and three-dimensional fiber packing. Utility Model Content

[0005] The purpose of this invention is to provide a mud-film symbiotic denitrification reactor that can at least solve one of the above-mentioned technical problems.

[0006] To achieve the above objectives, an embodiment of this utility model provides a mud-film symbiotic denitrification reaction device, including a reaction tank, a mixer, a flow guide tube, and a biofilm packing unit; the mixer is installed on the reaction tank and is used for frequency conversion control, the mixer's mixing shaft is equipped with mixing blades, the outer periphery of the mixing blades is provided with a flow guide tube, the outer side of the flow guide tube is provided between the tank body and the tank body of the reaction tank, the biofilm packing unit is provided with vertically suspended biological rope packing, and water flow channels are left between adjacent biological rope packing.

[0007] Furthermore, the reaction tank has a circular cross-section, and the upper part of the reaction tank is provided with an inlet, a mixed liquid inlet, and a carbon source inlet in sequence from top to bottom. An outlet is provided on the side opposite to the inlet, and the inlet, the mixed liquid inlet, and the carbon source inlet are all connected to the guide tube.

[0008] Furthermore, the guide tube has a structure with flared ends and a straight middle section, and a gap is left between the inner wall of the guide tube and the outer periphery of the stirring blade.

[0009] Furthermore, the guide tube is fixedly connected to the wall of the reaction tank via a connector, which is spaced apart along the outer periphery of the guide tube.

[0010] Furthermore, the stirring blades are installed at a clockwise horizontal angle.

[0011] Furthermore, the mixer is mounted on the top of the reaction tank via a fixed base, which is fixedly connected to the top of the reaction tank.

[0012] Furthermore, the axis of the stirring shaft coincides with the central axis of the reaction tank.

[0013] Furthermore, the bio-rope packing is installed inside the biofilm packing unit via a suspension bracket.

[0014] Furthermore, the suspension bracket is fixedly connected to the wall of the reaction tank.

[0015] Furthermore, the water flow within the biofilm packing unit is from bottom to top.

[0016] The beneficial effects of the above technical solutions are as follows: This invention features a reaction tank, a mixer, a flow guide tube, and a biofilm packing unit. The biofilm packing unit contains vertically suspended biological rope packing with a water flow channel. When the mixer operates, the carbon source fully contacts the raw water and the mixed liquor. Simultaneously, the flow guide tube guides the water flow to form a circulation. The biofilm packing unit is suspended in the tank, and microorganisms adhere to the surface of the packing. The water flow and packing fully contact each other for mass transfer, forming a sludge-film symbiotic system. This promotes pollutant degradation, improves denitrification efficiency, and solves the problems of low mass transfer efficiency and anaerobic fermentation of activated sludge accumulated on the packing surface in conventional suspended packing systems.

[0017] The design of the guide tube with its flared ends, straight middle section, and gap with the agitator blades, combined with the variable frequency control of the agitator, allows for control of the circulation ratio of the mixed liquid in the reaction tank. This enables rapid dilution of the influent, making it highly adaptable to influent shock loads. Furthermore, it controls the upward flow velocity in the biofilm packing area, preventing packing blockage, improving mass transfer efficiency, and utilizing water flow shearing to remove aged biofilm from the packing surface, thereby maintaining biofilm activity. Ultimately, this enhances denitrification and reduces operating costs. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0019] Figure 1 This is a schematic diagram of the overall structure of the reaction device in an embodiment of this utility model.

[0020] In the diagram, 1 is the reaction tank; 2 is the agitator; 3 is the flow guide tube; 4 is the biofilm packing unit; 5 is the water inlet; 6 is the mixed liquor inlet; 7 is the carbon source inlet; and 8 is the water outlet. Detailed Implementation

[0021] like Figure 1 As shown, this embodiment provides a mud-film symbiotic denitrification reaction device, comprising a reaction tank 1, a mixer 2, a guide tube 3, and a biofilm packing unit 4.

[0022] The mixer 2 is installed on the top of the reaction tank 1 via a fixed base. The fixed base is fixedly connected to the top of the reaction tank 1. The mixer 2 has a stirring blade installed on its stirring shaft. A guide tube 3 is set around the stirring blade. A biofilm packing unit 4 is set between the outside of the guide tube 3 and the tank body of the reaction tank 1. Vertically suspended biological rope packing is set inside the biofilm packing unit 4. A water flow channel is left between adjacent biological rope packing.

[0023] Specifically, reaction tank 1 serves as the main container, used to hold the mixture and provide reaction space. Agitator 2 drives fluid movement. The agitator blades are installed at an angle of 30° to 60° with the horizontal plane. The horizontal angle setting causes the blades to generate a downward force when rotating, causing the liquid in the guide tube 3 to move downward under the downward pressure of the agitator blades. At the same time, the downward water flow speed can be controlled by adjusting the angle.

[0024] The guide tube 3 has a structure with flared ends and a straight middle section. A gap is left between the inner wall of the guide tube 3 and the outer periphery of the stirring blade. The guide tube 3 is used to constrain the water flow direction in the stirring area. The annular area between the outer wall of the guide tube 3 and the inner wall of the reaction tank 1 constitutes the biofilm packing unit 4. Biofilm packing is vertically suspended in the biofilm packing unit 4 by a suspension bracket, and water flow channels are left between adjacent biofilm packing.

[0025] When the stirring blades rotate, the top flare smoothly guides the fluid into the straight section, while the bottom flare evenly diffuses the fluid into the biofilm packing area.

[0026] like Figure 1 As shown, the reaction tank 1 has a circular cross-section. The upper part of the reaction tank 1 is provided with an inlet 5, a mixed liquid inlet 6, and a carbon source inlet 7 from top to bottom. An outlet 8 is provided on the side opposite to the inlet 5. The inlet 5, the mixed liquid inlet 6, and the carbon source inlet 7 are all connected to the guide tube 3.

[0027] The circular pool structure allows the water flow to form a stable swirling motion under stirring, eliminating stagnation in the corner areas of the rectangular pool. The three inlets are distributed from top to bottom in the order of inlet water, mixed liquor, and carbon source, forming a stratified injection pattern in the vertical direction. The connection design between each inlet and the guide tube 3 allows reactants to directly enter the high-velocity zone inside the guide tube 3, achieving rapid diffusion through the forced circulation effect of the guide tube 3. The outlet 8 is located opposite the inlet 5, forming a plug flow path to avoid short-circuiting of the water.

[0028] The guide tube 3 is fixedly connected to the wall of the reaction tank 1 via connecting parts, which are spaced apart along the outer periphery of the guide tube 3. The connecting parts are rigid support structures used to fix the guide tube 3 to the tank wall, and can be made of metal or polymer materials as rods, plates, or flanges. Their ends are welded or bolted to the outer wall of the guide tube 3 and the inner wall of the reaction tank 1, respectively, thus forming a stable mechanical connection. The spaced arrangement means that multiple connecting parts are distributed at uniform or non-uniform intervals around the outer periphery of the guide tube 3, which can be achieved using a ring array or a symmetrical layout.

[0029] Furthermore, during the operation of the mixer 2, the mixing shaft drives the blades to rotate, generating vortices and creating a downward forced circulation of water inside the guide tube 3. The connectors, by rigidly connecting the guide tube 3 to the pool wall, counteract the lateral displacement effects of water flow impact and mechanical vibration on the guide tube 3, preventing the gap between the guide tube 3 and the mixing blades from shifting due to vibration, thus ensuring the stability of the water circulation path. The spacing of the connectors along the outer circumference of the guide tube 3 evenly transmits the stress on the guide tube 3 to the pool wall, preventing localized stress concentration that could lead to structural deformation. Simultaneously, it reduces obstruction of the water flow channels within the biofilm packing unit 4 by the connectors, ensuring sufficient contact between the water flow and the biofilm packing.

[0030] The axis of the stirring shaft coincides with the central axis of the reaction tank 1. The centrifugal force field generated by the rotation of the stirring blades forms a symmetrically distributed circulation inside and outside the guide tube 3. The fluid inside the guide tube 3 moves downward under the driving force of the blades, while the fluid outside the tube is guided downward by the bell mouth of the guide tube 3 to replenish it, forming a stable vertical circulation flow. This flow pattern ensures that the water flow in the biofilm packing unit 4 flows evenly through the channels between all the biofilm packing materials, avoiding local stagnation or insufficient shear caused by uneven flow velocity.

[0031] The bio-rope packing material is installed within the biofilm packing unit 4 via a suspension bracket. The suspension bracket is a rigid support structure used to support and fix the bio-rope packing material, which can be implemented using a stainless steel frame or an engineering plastic mesh structure. The mesh size can be adjusted according to the packing material diameter. This structure is connected to the tank wall of reaction tank 1 through multi-point anchoring, forming a stable three-dimensional spatial distribution system to ensure that the packing material does not shift during dynamic water flow.

[0032] The water flow within the biofilm packing unit 4 flows from bottom to top, achieved by setting the inlet 5 at the bottom of the guide tube 3 and the outlet 8 at the top of the reaction tank 1, thus forming a continuous upward flow pattern using fluid dynamics principles. This flow direction can overcome the packing blockage problem caused by gravity settling of sludge in traditional horizontal or downward flow patterns, while also promoting the uniform distribution of dissolved substances in the packing layer.

[0033] During operation, the mixed liquid enters the biofilm packing unit 4 from the bottom of the guide tube 3 and continues to move upward under the driving force of the circulating flow field formed by the agitator 2. The rising water flow exerts a shearing effect on the surface of the biofilm packing, peeling off the aging biofilm and maintaining the thickness of the active layer on the packing surface; the carbon source and nitrate carried by the water flow form a concentration gradient, enhancing the diffusion and mass transfer of pollutants into the biofilm.

[0034] The working principle of this utility model: Inside reaction tank 1, agitator 2 drives the impeller to rotate, generating a downward force that propels the liquid inside guide tube 3 to form a forced circulation flow. Guide tube 3 constrains the water flow direction, allowing the influent, mixed liquor, and carbon source to be injected into the high-velocity zone of guide tube 3 from top to bottom, rapidly diffusing with the help of eddies inside the tube. The fluid inside the tube moves downward under the propulsion of the impeller, while the fluid outside the tube is replenished downward through the funnel, driving the water flow in the biofilm packing unit 4 from bottom to top. Channels are left between the vertically suspended bio-rope packing materials, and the upward flow overcomes sludge settling and clogging, while simultaneously shearing and stripping away excessively thick biofilm to maintain the thickness of the active layer. The carbon source carried by the water flow forms a concentration gradient with nitrate, enhancing the diffusion and mass transfer of pollutants into the biofilm.

[0035] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A mud-film symbiotic denitrification reactor, characterized in that, The system includes a reaction tank, a mixer, a flow guide tube, and a biofilm packing unit. The mixer is installed on the reaction tank and is controlled by frequency conversion. The mixer's mixing shaft is equipped with mixing blades, and a flow guide tube is provided around the mixing blades. A biofilm packing unit is provided between the outside of the flow guide tube and the tank body of the reaction tank. Vertically suspended bio-rope packing is provided inside the biofilm packing unit, and water flow channels are left between adjacent bio-rope packing.

2. The mud-film symbiotic denitrification reactor according to claim 1, characterized in that, The reaction tank has a circular cross-section. From top to bottom, the upper part of the reaction tank is provided with a water inlet, a mixed liquid inlet, and a carbon source inlet. An outlet is provided on the side opposite to the water inlet. The water inlet, the mixed liquid inlet, and the carbon source inlet are all connected to the guide tube.

3. The mud-film symbiotic denitrification reactor according to claim 1, characterized in that, The guide tube has a structure with flared ends and a straight middle section, and there is a gap between the inner wall of the guide tube and the outer periphery of the stirring blade.

4. The mud-film symbiotic denitrification reactor according to claim 1, characterized in that, The guide tube is fixedly connected to the wall of the reaction tank via connectors, which are spaced apart along the outer periphery of the guide tube.

5. The mud-film symbiotic denitrification reactor according to claim 1, characterized in that, The stirring blades are installed at a clockwise horizontal angle.

6. The mud-film symbiotic denitrification reactor according to claim 1, characterized in that, The mixer is mounted on the top of the reaction tank via a fixed base, which is fixedly connected to the top of the reaction tank.

7. The mud-film symbiotic denitrification reactor according to claim 1, characterized in that, The axis of the stirring shaft coincides with the central axis of the reaction tank.

8. The mud-film symbiotic denitrification reactor according to claim 1, characterized in that, The bio-rope packing material is installed inside the biofilm packing unit via a suspension bracket.

9. A mud-film symbiotic denitrification reactor according to claim 8, characterized in that, The suspension bracket is fixedly connected to the wall of the reaction tank.

10. The mud-film symbiotic denitrification reactor according to claim 1, characterized in that, The water flow within the biofilm packing unit is from bottom to top.

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