Landfill leachate treatment system

Abstract

The utility model discloses a landfill leachate treatment system which comprises a sedimentation tank, a biological treatment tank and a membrane filtration tank which are connected in sequence, and further comprises an aeration pipe extending into the sedimentation tank, the biological treatment tank and the membrane filtration tank, the second aeration assembly is positioned in the biological treatment tank; the third aeration assembly is positioned in the membrane filtration tank; an umbrella-shaped flow guide screen plate is arranged above the first aeration assembly in the sedimentation tank, and a blanking gap is reserved between the peripheral edge of the flow guide screen plate and the tank wall of the sedimentation tank; a step plate extending downwards is arranged below the water inlet in the biological treatment tank, a drainage hole is formed in the horizontal part of the step plate, and a biological rotating cage corresponding to the drainage hole is transversely and rotationally connected to the vertical part of the step plate through a rotating shaft; and an ultrafiltration membrane assembly is arranged in the membrane filtration tank. The device has the characteristics of combined treatment in various modes and improvement of the treatment efficiency and effect.

Description

Technical Field

[0001] This utility model relates to a wastewater treatment system, and more particularly to a landfill leachate treatment system. Background Technology

[0002] Landfill leachate is a high-concentration organic / inorganic liquid produced during the storage, transfer, landfilling, or incineration of waste through biochemical degradation, rainwater / groundwater infiltration, or the release of moisture from the waste itself. It is one of the main secondary pollutants in waste treatment. Landfill leachate contains large amounts of organic matter, ammonia nitrogen, total nitrogen, heavy metals, phosphorus, etc., and is classified as high-concentration organic wastewater with complex composition. Its water quality and quantity vary greatly and are non-periodic, which undoubtedly poses significant challenges to its effective and stable treatment.

[0003] Currently, leachate from waste-to-energy plants is generally treated using chemical precipitation, biological treatment, or membrane filtration. Chemical precipitation mainly involves adding precipitants or flocculants to react with pollutants in the wastewater, forming water-insoluble precipitates, thus achieving solid-liquid separation. Biological treatment is used to remove large amounts of biodegradable organic matter. Membrane treatment is used to retain organic matter that is difficult to biodegrade and other inorganic pollutants. However, in current chemical precipitation treatments, the dosage of individual chemical treatments is relatively large, resulting in high reagent costs. Turbulence created by stirring can easily affect the precipitation effect, and the precipitation efficiency of recalcitrant organic matter is low. In biological treatment, the biofilm in the biological treatment tank is generally fixed. After a period of use, the aging biofilm remains on the carrier, affecting the growth of new biofilm and thus reducing the treatment efficiency of the biofilm. In membrane filtration treatment, the filter membrane needs to be cleaned after a period of use to ensure its permeability. Currently, backwashing devices are mostly used to clean the filter membrane. However, using backwashing devices requires shutdown during the process, which prolongs the treatment cycle of landfill leachate and reduces the treatment efficiency of landfill leachate. Utility Model Content

[0004] The purpose of this invention is to provide a landfill leachate treatment system. This invention features a combination of multiple treatment methods, improving treatment efficiency and effectiveness.

[0005] The technical solution of this utility model is as follows: A landfill leachate treatment system includes a sedimentation tank, a biological treatment tank, and a membrane filtration tank connected in sequence. It also includes an aeration pipe extending into the sedimentation tank, the biological treatment tank, and the membrane filtration tank. The aeration pipe is equipped with a first aeration component located in the sedimentation tank, a second aeration component located in the biological treatment tank, and a third aeration component located in the membrane filtration tank. An umbrella-shaped guide net plate is provided above the first aeration component in the sedimentation tank, with a material drop gap between the periphery of the guide net plate and the tank wall. A downwardly extending stepped plate is provided below the inlet in the biological treatment tank. The horizontal part of the stepped plate has drainage holes, and the vertical part of the stepped plate is laterally rotatably connected to a biological rotating cage corresponding to the drainage holes via a rotating shaft. An ultrafiltration membrane module is provided in the membrane filtration tank.

[0006] In the aforementioned landfill leachate treatment system, the second aeration component includes multiple rotating pipes rotatably connected to the aeration pipes. The top of the rotating pipes is provided with a swirl aeration disc. The upper surface, lower surface, and side circumferential surface of the swirl aeration disc are all provided with cutting teeth. The upper surface of the swirl aeration disc is also provided with aeration holes.

[0007] In the aforementioned landfill leachate treatment system, the third aeration component includes multiple first branch pipes fixedly connected to the aeration pipe. Second branch pipes are movably connected to the interior of the first branch pipes, and air nozzles are provided on the second branch pipes. The multiple second branch pipes are connected to each other through a lifting frame, which is driven to move up and down by a lifting driver.

[0008] In the aforementioned landfill leachate treatment system, the lifting drive includes a winch located outside the membrane filtration tank, a guide wheel on the membrane filtration tank, and a lifting frame with a lifting rope that passes around the guide wheel and is connected to the winch.

[0009] In the aforementioned landfill leachate treatment system, flow control valves are provided on the aeration pipe at the first aeration component, the second aeration component, and the third aeration component.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0011] This invention comprises a first aeration component, a second aeration component, and a third aeration component located respectively in a sedimentation tank, a biological treatment tank, and a membrane filtration tank. The first aeration component introduces microbubbles into the sedimentation tank, which facilitates the sedimentation or filtration of pollutants in the landfill leachate. It also efficiently adheres to oil droplets in the leachate, removing oily pollutants. A guide plate is installed above the first aeration component. This guide plate directs the settled pollutants along the material droplet gap, preventing them from affecting the aeration of the first aeration component. Furthermore, it cuts, intercepts, and stabilizes the large bubbles generated by the first aeration component, making the bubbles finer and more evenly dispersed, preventing turbulence from affecting sedimentation, thus better treating the landfill leachate.

[0012] A stepped plate is installed in the biological treatment tank. The leachate falls on the stepped plate and generates a certain impact force. It impacts the biological rotating cage through the drainage hole, causing the biological rotating cage to rotate, renewing the biofilm on the biological rotating cage, and improving the biofilm's treatment efficiency of the leachate.

[0013] The third aeration component introduces microbubbles into the membrane filtration tank, which drive the water flow to generate strong turbulence, flushing the surface of the ultrafiltration membrane module and adsorbing and removing oil droplets, colloidal particles, etc. from the membrane surface. This provides continuous and uniform dynamic cleaning of the membrane surface without the need for shutdown, thereby maintaining the cleanliness of the membrane surface and preserving the membrane's permeability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model.

[0015] Figure 2 This is a schematic diagram of the second aeration component.

[0016] The labels in the attached diagram are as follows: 1. Sedimentation tank; 11. Guide mesh plate; 12. Material drop gap; 13. Dosing device; 2. Biological treatment tank; 21. Stepped plate; 22. Drainage hole; 23. Biological rotating cage; 3. Membrane filtration tank; 31. Ultrafiltration membrane module; 4. Aeration pipe; 41. First aeration module; 42. Second aeration module; 421. Rotary pipe; 422. Swirl aeration disc; 423. Cutting teeth; 424. Aeration hole; 43. Third aeration module; 431. First branch pipe; 432. Second branch pipe; 433. Lifting frame; 51. Winch; 52. Guide wheel; 53. Lifting rope; 6. Backwash box; 7. Flow control valve. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0018] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, a hinged connection, a rotating connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0019] Example:

[0020] like Figures 1-2 As shown, a landfill leachate treatment system includes a sedimentation tank 1, a biological treatment tank 2, and a membrane filtration tank 3 connected in sequence. It also includes an aeration pipe 4 extending into the sedimentation tank 1, biological treatment tank 2, and membrane filtration tank 3. The aeration pipe 4 is connected to an aerator. The aeration pipe 4 is equipped with a first aeration component 41 located in the sedimentation tank 1, a second aeration component 42 located in the biological treatment tank 2, and a third aeration component 43 located in the membrane filtration tank 3. An umbrella-shaped guide net plate 11 is provided above the first aeration component 41 in the sedimentation tank 1, with a material drop gap 12 between the periphery of the guide net plate 11 and the tank wall of the sedimentation tank 1. A downwardly extending stepped plate 21 is provided below the inlet and above the second aeration component 42 in the biological treatment tank 2. The horizontal part of the stepped plate 21 has drainage holes 22, and the vertical part of the stepped plate 21 is rotatably connected to a biological rotating cage 23 corresponding to the drainage holes 22 via a rotating shaft. An ultrafiltration membrane component 31 is provided in the membrane filtration tank 3.

[0021] This invention features aeration pipes 4 extending into a sedimentation tank 1, a biological treatment tank 2, and a membrane filtration tank 3, respectively. Air bubbles are introduced into these tanks via a first aeration component 41, a second aeration component 42, and a third aeration component 43. The microbubbles introduced into the sedimentation tank 1 by the first aeration component 41 rise within the sedimentation tank 1, colliding with suspended particles and colloids in the landfill leachate. This reduces the electrostatic repulsion between particles, promoting particle aggregation and the formation of larger flocs, which facilitates the sedimentation or filtration of pollutants in the landfill leachate. Furthermore, the microbubbles efficiently adhere to oil droplets in the landfill leachate, quickly causing them to float to the surface, achieving effective oil-water separation and removing oily pollutants from the landfill leachate. Furthermore, a guide plate 11 is installed above the first aeration component 41. On the one hand, it guides the settled pollutants to fall along the material drop gap 12, so as to avoid affecting the aeration of the first aeration component 41. On the other hand, it cuts, intercepts and stabilizes the large bubbles generated by the first aeration component 41, cuts the large bubbles into smaller microbubbles, makes the bubbles finer, and disperses the bubbles evenly, avoiding bubble aggregation and turbulence affecting sedimentation, thereby better treating landfill leachate.

[0022] The biological rotating cage 23 in the biological treatment tank 2 is covered with a biofilm. Through the biochemical activity of the biofilm, it can further adsorb and decompose pollutants in suspended, colloidal, and dissolved states in the landfill leachate. The landfill leachate entering the biological treatment tank 2 forms a drop on the stepped plate 21, generating a certain impact force. This force is diverted through the drainage holes 22 and impacts the biological rotating cage 23, causing it to rotate. This causes the aging biofilm to detach naturally, while new microorganisms grow, thus renewing the biofilm on the rotating cage 23, maintaining its activity, and ensuring that the biofilm can continuously and efficiently adsorb and degrade organic matter in the landfill leachate, improving the biofilm's treatment efficiency. Furthermore, the varying heights of the biological rotating cage 23 within the biological treatment tank 2 allow for treatment at different depths, further improving treatment efficiency. The second aeration component 42 introduces microbubbles carrying a large amount of oxygen into the biological treatment tank 2, providing sufficient oxygen for the aerobic organisms on the biofilm, which helps enhance the biofilm's ability to remove pollutants such as organic matter and ammonia nitrogen from the landfill leachate.

[0023] The ultrafiltration membrane module 31, installed within the membrane filtration tank 3, efficiently traps landfill leachate, ensuring the effluent meets discharge standards. The third aeration module 43, through microbubbles introduced into the membrane filtration tank 3, generates strong turbulence in the water flow, washing over the membrane surface of the ultrafiltration membrane module 31 and adsorbing and removing oil droplets, colloidal particles, etc., thus providing continuous and uniform dynamic cleaning of the membrane surface, maintaining its cleanliness and permeability.

[0024] The ultrafiltration membrane module 31 is one or more of the following: flat sheet organic ultrafiltration membrane, hollow fiber organic ultrafiltration membrane, tubular organic ultrafiltration membrane, and flat sheet ceramic ultrafiltration membrane.

[0025] The second aeration component 42 includes multiple rotating pipes 421 rotatably connected to the aeration pipe 4 via rotary joints. A swirl-type aeration disc 422 is provided at the top of each rotating pipe 421. Cutting teeth 423 are provided on the upper surface, lower surface, and side circumference of the swirl-type aeration disc 422. Aeration holes 424 are also provided on the upper surface of the swirl-type aeration disc 422. When the leachate entering the biological treatment tank 2 impacts the second aeration component 42, it causes the second aeration component 42 to rotate, thereby driving the swirl-type aeration disc 422 to rotate. The rotating swirl-type aeration disc 422 agitates the water flow through the cutting teeth 423, further promoting the movement of the biological rotating cage 23 and the renewal of the biofilm, improving the biological treatment effect, and accelerating the uniform diffusion of introduced microbubbles, promoting oxygen dissolution, and providing more sufficient oxygen to the biofilm.

[0026] The third aeration component 43 includes multiple first branch pipes 431 fixedly connected to the aeration pipe 4. Second branch pipes 432 are movably connected vertically inside each first branch pipe 431. Each second branch pipe 432 is equipped with a nozzle. The multiple second branch pipes 432 are connected by a lifting frame 433, which moves vertically driven by a lifting driver. The second branch pipes 432 are designed to be movable, allowing the lifting frame 433 to rise and fall with the lifting driver. This, in turn, causes the multiple second branch pipes 432 to rise and fall together as a whole, resulting in good stability. This allows adjustment of the position of the second branch pipes 432 to correspond to the membrane surface of the ultrafiltration membrane component 31, thus improving the rinsing and cleaning of the ultrafiltration membrane component 31. The position of the second branch pipes 432 can be detected by a position sensor installed on the tank wall. When the sensor detects that the second branch pipe 432 has reached the appropriate position, the lifting driver stops operating, thereby better controlling the movement range of the second branch pipes 432.

[0027] The lifting drive includes a winch 51 located outside the membrane filtration tank 3, a guide wheel 52 inside the membrane filtration tank 3, and a lifting rope 53 on the lifting frame 433 that passes around the guide wheel 52 and connects to the winch 51. Driven by the winch 51 and guided by the guide wheel 52, the lifting rope 53 drives the lifting frame 433 to rise and fall, thereby changing the position of the second branch pipe 432 relative to the ultrafiltration membrane module 31, thus better cleaning different ultrafiltration membrane modules 31.

[0028] The aeration pipe 4 is equipped with flow control valves 7 at the first aeration component 41, the second aeration component 42, and the third aeration component 43. The flow control valves 7 control the amount of air bubbles entering the sedimentation tank 1, the biological treatment tank 2, and the membrane filtration tank 3.

[0029] The ultrafiltration membrane module 31 can also be connected to a backwashing tank 6. A backwashing pump and valve are provided between the backwashing tank 6 and the ultrafiltration membrane module 31 to clean different types of contaminants adhering to the ultrafiltration membrane, thereby ensuring the membrane flux of the ultrafiltration membrane and extending the service life of the ultrafiltration membrane module 31.

[0030] A dosing device 13 can also be connected to the sedimentation tank 1. Coagulants such as PAC and PAM are added to the sedimentation tank 1 through the dosing device 13 to cause suspended solids and colloids in the landfill leachate to aggregate and settle; acid / alkali adjusters can also be added to make the pH of the landfill leachate neutral and remove acid and alkaline pollutants.

[0031] The parts of this utility model not described in detail are existing technologies and therefore will not be specifically described here.

Claims

1. A landfill leachate treatment system, comprising a sedimentation tank (1), a biological treatment tank (2), and a membrane filtration tank (3) connected in sequence, characterized in that: It also includes aeration pipes (4) extending into the sedimentation tank (1), the biological treatment tank (2) and the membrane filtration tank (3). The aeration pipes (4) are equipped with a first aeration component (41) located in the sedimentation tank (1), a second aeration component (42) located in the biological treatment tank (2) and a third aeration component (43) located in the membrane filtration tank (3). An umbrella-shaped guide net plate (11) is provided above the first aeration component (41) in the sedimentation tank (1). A material drop gap (12) is left between the periphery of the guide net plate (11) and the tank wall of the sedimentation tank (1). A downward-extending stepped plate (21) is provided below the inlet in the biological treatment tank (2). The horizontal part of the stepped plate (21) is provided with a drain hole (22). The vertical part of the stepped plate (21) is connected to a biological rotating cage (23) corresponding to the drain hole (22) by a rotating shaft. An ultrafiltration membrane component (31) is provided in the membrane filtration tank (3).

2. The landfill leachate treatment system according to claim 1, characterized in that: The second aeration component (42) includes a plurality of rotating tubes (421) rotatably connected to the aeration tube (4). The top of the rotating tube (421) is provided with a swirl aeration disc (422). The upper surface, lower surface and side circumferential surface of the swirl aeration disc (422) are provided with cutting teeth (423). The upper surface of the swirl aeration disc (422) is also provided with aeration holes (424).

3. The landfill leachate treatment system according to claim 1, characterized in that: The third aeration component (43) includes a plurality of first branch pipes (431) fixedly connected to the aeration pipe (4). The interior of the first branch pipe (431) is movably connected to a second branch pipe (432). The second branch pipe (432) is provided with a jet nozzle. The plurality of second branch pipes (432) are connected to each other by a lifting frame (433). The lifting frame (433) is driven up and down by a lifting driver.

4. The landfill leachate treatment system according to claim 3, characterized in that: The lifting drive includes a winch (51) located outside the membrane filter tank (3), a guide wheel (52) on the membrane filter tank (3), and a lifting rope (53) on the lifting frame (433) that passes around the guide wheel (52) and connects to the winch (51).

5. A landfill leachate treatment system according to claim 1, characterized in that: The aeration pipe (4) is equipped with flow control valves (7) at the first aeration component (41), the second aeration component (42) and the third aeration component (43).

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