Landfill leachate treatment system

Abstract

The utility model discloses a landfill leachate treatment system, and particularly relates to the field of sewage treatment, the landfill leachate treatment system comprises a grating, a regulating reservoir, a hydrocyclone, a moving bed bio-membrane reactor, a bag filter, a nanofiltration and a pipeline, and all units in the system are connected in sequence. Compared with a traditional sedimentation tank, the hydrocyclone in the system disclosed by the utility model is small in occupied area, free of external power, simple in structure, strong in durability, free of manpower maintenance and low in operation cost; compared with a membrane bioreactor, the moving bed biological membrane filter generally does not need sludge backflow and does not need regular backwashing; compared with a traditional filter, the bag type filter is wide in filtering precision, simple in structure and convenient to maintain; the whole system is simple in structure, short in construction period and low in operation and maintenance cost, and produced water can reach the standard to be discharged or recycled.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, and more specifically, to a landfill leachate treatment system. Background Art

[0002] At present, three processes are widely used in leachate treatment, namely:

[0003] (1) Biological treatment + membrane advanced treatment process: low investment and good treatment effect, but the membrane unit needs backwashing and chemical cleaning, with a short replacement cycle, and slightly higher energy consumption and operation and maintenance costs;

[0004] (2) Full membrane adsorption and filtration treatment process: simple process operation and high degree of automation, but sensitive to raw water quality, high energy consumption, high replacement frequency of reverse osmosis membranes, and high operation costs;

[0005] (3) Low - consumption evaporation + ion exchange treatment process: high energy consumption, high maintenance costs, high requirements for equipment materials, and high chemical agent costs;

[0006] The current landfill leachate treatment processes have problems such as high operation and maintenance costs, complex equipment maintenance, and treatment effects being sensitive to water quality. Therefore, the utility model provides a landfill leachate treatment system to solve the problems of high energy consumption, high maintenance costs, and unstable treatment effects in the prior art. Summary of the Utility Model

[0007] In order to overcome the above - mentioned defects of the prior art, an embodiment of the utility model provides a landfill leachate treatment system, which uses a hydrocyclone for centrifugal separation, a moving bed biofilm reactor for efficient biological treatment, a bag filter for fine filtration, and a nanofiltration device for advanced purification to solve the problems raised in the above - mentioned background art.

[0008] To achieve the above - mentioned purpose, the utility model provides the following technical solution: a landfill leachate treatment system, including a grille, an adjustment tank, a hydrocyclone, a moving bed biofilm reactor (MBBR), a bag filter, and a nanofiltration (NF) connected in sequence. The leachate is transported to the grille for pretreatment and then enters the adjustment tank. The outlet end of the adjustment tank is connected to the inlet end of the hydrocyclone. The overflow water outlet end of the hydrocyclone is connected to the inlet end of the moving bed biofilm reactor (MBBR). The water production outlet end of the moving bed biofilm reactor (MBBR) is connected to the inlet end of the bag filter. The outlet end of the bag filter is connected to the inlet end of the nanofiltration (NF) device.

[0009] In a preferred embodiment, the grille includes a stepped type and is divided into a coarse grille and a fine grille. The gap of the coarse grille is 15 mm, and the gap of the fine grille is 3 mm.

[0010] In a preferred embodiment, the regulating tank provides an organic load buffer for stabilizing the water volume, equalizing the water quality, and storing the sewage simultaneously.

[0011] In a preferred embodiment, the sewage at the upper inlet of the hydrocyclone enters tangentially. Under the action of centrifugal force, impurities are discharged downward, and the treated water passes upward through the overflow pipe into the subsequent system.

[0012] In a preferred embodiment, when the temperature of the moving bed biofilm reactor (MBBR) is 20 °C, the surface load of BOD5 can be 5 - 15 g BOD5 / (m2·d), and the surface nitrification load can be 0.5 - 2 g NH3-N / (m2·d); the moving bed biofilm reactor is equipped with an aeration device, and the filling rate of the suspended packing can be 20% - 60%.

[0013] In a preferred embodiment, the working pressure of the bag filter is 0.3 - 0.5 MPa, and when the water pressure difference between the inlet and outlet of the bag filter is greater than 0.1 MPa, cleaning or replacement is carried out.

[0014] In a preferred embodiment, when the indexes such as COD, BOD, NH4-N, and SS of the effluent after the final treatment of nanofiltration (NF) meet the treatment requirements, it is recycled or discharged.

[0015] The technical effects and advantages of the present utility model:

[0016] 1. The initial investment is relatively low, the overall energy consumption of the system is not high, the chemical consumption is low, and it has good economic feasibility. By setting up a hydrocyclone and a moving bed biofilm reactor (MBBR), this system reduces the dependence on external power and chemical agents. The hydrocyclone does not require external power drive and uses centrifugal force for impurity separation, reducing energy consumption. At the same time, the moving bed biofilm reactor does not require sludge reflux during the biological treatment process, reducing the dosage of chemical agents, with low overall operating costs and significantly improved economy;

[0017] 2. The structure of each monomer equipment is simple, easy to repair and maintain, and the maintenance cost is relatively low. The equipment such as the hydrocyclone, bag filter, and nanofiltration device in the system has a simple design structure, reducing the complexity of mechanical components, reducing the failure rate and maintenance difficulty. For example, the hydrocyclone realizes impurity separation through a tangential inlet, reducing the complex structure and maintenance work required by traditional sedimentation tanks; the bag filter adopts a simple filter bag replacement method, which is convenient for maintenance, reducing downtime and maintenance costs;

[0018] 3. The hydrocyclone, bag filter, and nanofiltration device have a large unit volume throughput and a small floor area. The equipment of this system is compact and occupies little space, making it particularly suitable for waste treatment plants with limited space. Compared with traditional sedimentation tanks, the hydrocyclone occupies less land and has high treatment efficiency. The moving bed biofilm reactor (MBBR) increases the biological treatment area by filling suspended packing, improving the treatment capacity. The bag filter and nanofiltration device further improve the water quality through efficient filtration. The overall system design is compact and can achieve efficient treatment in a limited space, meeting the requirements under different site conditions. Description of the Drawings

[0019] Figure 1 It is a process schematic diagram of the garbage leachate treatment system of the present utility model.

[0020] The reference numerals in the drawings are: grille (1), regulating tank (2), hydrocyclone (3), moving bed biofilm reactor (4), bag filter (5), nanofiltration (6). Detailed Embodiments

[0021] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0022] Referring to the attached Figure 1 drawings, an embodiment of the present utility model provides a garbage leachate treatment system, which includes: a grille 1, a regulating tank 2, a hydrocyclone 3, a moving bed biofilm reactor 4, a bag filter 5, a nanofiltration 6, and pipelines. Each unit in the system is connected in sequence, and the connection relationship is as follows:

[0023] The leachate is transported to the grille 1 for pretreatment and then enters the regulating tank 2. After water quality adjustment and pre-sedimentation in the regulating tank 2, the water outlet end is connected to the inlet end of the hydrocyclone 3. The overflow water outlet end of the hydrocyclone 3 is connected to the inlet end of the moving bed biofilm reactor 4. The water production outlet end of the moving bed biofilm reactor 4 is connected to the inlet end of the bag filter 5. The outlet end of the bag filter 5 is connected to the inlet end of the nanofiltration 6 device. The treated water produced at the outlet end of the nanofiltration 6 device can meet the wastewater discharge requirements or can be reused according to needs.

[0024] Specifically, the grille 1 is a stepped grille, divided into two channels of a coarse grille and a fine grille, with grille gaps of 15 mm and 3 mm respectively, for filtering inert substances such as debris, plastics, and sand that are difficult to remove by the subsequent units.

[0025] Specifically, the regulating tank 2 can not only stabilize the influent water quality, but also add coagulants and flocculants to pre-precipitate suspended solids and colloids.

[0026] Specifically, when the temperature of the water in the moving bed biofilm reactor 4 is 20°C, the BOD5 surface load can be 5-15 g BOD5 / m2·d, the surface nitrification load can be 0.5-2 g NH3-N / m2·d, an aeration device needs to be installed inside, and the filling rate of the suspended packing can be 20%-60%.

[0027] Specifically, the working pressure of the bag filter 5 is 0.3-0.5 MPa, and the suspended solids in the water after passing through the bag filter are not more than 100 mg / L.

[0028] Specifically, the nanofiltration membrane aperture of the nanofiltration 6 device is 0.02 μm. Through nanofiltration, refractory substances can be further separated, so that the indexes such as effluent COD, BOD, NH4-N, and SS meet the treatment requirements, and can be recycled or discharged according to needs.

[0029] It should be further noted that the landfill leachate treatment system of the present utility model adopts a multi-stage treatment process, including a grille 1, a regulating tank 2, a hydrocyclone 3, a moving bed biofilm reactor 4, a bag filter 5, and a nanofiltration 6. Each treatment unit is interconnected and treated in sequence to ensure the effective purification of the leachate.

[0030] Grille pretreatment: The leachate is first transported to the grille 1 for preliminary removal of solid particles; the grille is divided into a coarse grille and a fine grille, which respectively treat larger and smaller particles to ensure the smooth operation of the subsequent treatment units;

[0031] Regulating tank regulation: The pretreated leachate enters the regulating tank 2, where the water quality is homogenized. At the same time, coagulants and flocculants can be added to further remove suspended solids and colloidal impurities and stabilize the organic matter load;

[0032] Hydrocyclone separation: The effluent from the regulating tank enters the hydrocyclone 3 in a tangential manner. Under the action of centrifugal force, impurities are separated and discharged, and the treated water enters the subsequent system through the overflow pipe; the hydrocyclone has a simple structure and does not require external power, reducing energy consumption;

[0033] Moving bed biofilm reactor biological treatment: The preliminarily purified water enters the moving bed biofilm reactor 4, where biological degradation treatment is carried out. The suspended packing in the reactor provides a surface for microorganisms to attach and grow, significantly improving the biological treatment efficiency. At the same time, an aeration device is installed in the reactor to maintain a suitable biological degradation environment;

[0034] Fine filtration by bag filter: The biologically treated water enters the bag filter 5 for further removal of suspended solids. The bag filter uses replaceable filter bags, which is easy to operate and maintain, effectively ensuring the filtration accuracy and quality of the effluent.

[0035] Nanofiltration for deep purification: Finally, the water enters the nanofiltration 6 device for deep purification through the nanofiltration membrane, removing refractory organic matters and other trace pollutants to ensure that the effluent meets the relevant discharge or reuse standards.

[0036] Finally, several points should be noted: First, in the description of this application, it should be noted that unless otherwise specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense, which can be mechanical connection or electrical connection, or the communication inside two components, and can be directly connected. The terms "upper", "lower", "left", "right", etc. are only used to represent relative position relationships. When the absolute position of the object being described changes, the relative position relationship may change.

[0037] Second: In the attached drawings of the disclosed embodiments of the present utility model, only the structures related to the disclosed embodiments are involved. Other structures can refer to the general design. Without conflict, the same embodiment and different embodiments of the present utility model can be combined with each other.

[0038] Finally: The above description is only the preferred embodiment of the present utility model and is not used to limit the present utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A landfill leachate treatment system, characterized in that: It includes a grille (1), an adjustment tank (2), a hydrocyclone (3), a moving bed biofilm reactor (4), a bag filter (5), and nanofiltration (6) that are connected in sequence. The leachate is transported to the grille (1) for pretreatment and then enters the adjustment tank (2). The water outlet end of the adjustment tank (2) is connected to the water inlet end of the hydrocyclone (3). The overflow water outlet end of the hydrocyclone (3) is connected to the water inlet end of the moving bed biofilm reactor (4). The water production outlet end of the moving bed biofilm reactor (4) is connected to the inlet end of the bag filter (5). The outlet end of the bag filter (5) is connected to the water inlet end of the nanofiltration (6) device.

2. The garbage leachate treatment system according to claim 1, characterized in that: The grille (1) includes a stepped type and is divided into a coarse grille and a fine grille. The gap of the coarse grille is 15 mm, and the gap of the fine grille is 3 mm.

3. A landfill leachate treatment system according to claim 1, characterized in that: The sewage entering from the upper inlet of the hydrocyclone (3) enters along the tangent. Under the action of centrifugal force, impurities are discharged downward, and the treated water passes upward through the overflow pipe and enters the subsequent system.

4. A garbage leachate treatment system according to claim 1, characterized in that: When the water temperature of the moving bed biofilm reactor (4) is 20 °C, the surface load of BOD5 is 5 - 15 gBOD5 / (m2·d), and the surface nitrification load is 0.5 - 2 gNH3-N / (m2·d). The moving bed biofilm reactor (4) is equipped with an aeration device, and the filling rate of the suspended packing is 20% - 60%.

5. A landfill leachate treatment system according to claim 1, characterized in that: The working pressure of the bag filter (5) is 0.3 - 0.5 MPa. When the pressure difference between the inlet and outlet water of the bag filter (5) is greater than 0.1 MPa, cleaning or replacement is carried out.

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