Pretreatment device capable of treating landfill leachate and starting anaerobic ammonia oxidation reaction

Abstract

The utility model discloses a pretreatment device capable of treating landfill leachate and starting anaerobic ammonia oxidation reaction, and relates to the field of wastewater treatment. The device comprises an anaerobic tank, an aerobic tank, a short-range denitrification tank, a water storage tank, filler devices, a stirring device, an aeration device and a PLC (programmable logic controller), the anaerobic tank, the aerobic tank, the short-range denitrification tank and the water storage tank are sequentially connected from front to back, and the filler devices are respectively placed in the anaerobic tank, the aerobic tank and the short-range denitrification tank. The stirring device is arranged in the aerobic tank and the short-cut denitrification tank, and the stirring device and the aeration device are both connected with the PLC; the pretreatment device for treating the landfill leachate and starting the anaerobic ammonia oxidation reaction not only can efficiently treat landfill leachate wastewater with high nitrogen and high chemical oxygen demand, but also can provide a substrate required by the anaerobic ammonia oxidation reaction, realizes harmless utilization of resources, and has important environmental protection and economic benefits.

Description

Technical Field

[0001] The utility model relates to the field of wastewater treatment, in particular to a pretreatment device which can effectively degrade toxic and harmful difficult-to-treat substances, alleviate the impact of organic load on subsequent reaction pools, and thus always maintain a stable operating environment while taking into account the treatment of garbage leachate and the start-up of anaerobic ammonia oxidation reactions. Background Art

[0002] Landfill leachate usually presents extremely high concentrations of chemical oxygen demand (COD) and ammonia nitrogen (NH4 + -N) and contain inhibitors such as heavy metals or organic pollutants, making it difficult for conventional biological wastewater treatment technologies to effectively treat them.

[0003] Existing technologies for treating this wastewater often use "advanced oxidation or adding chemicals + biological treatment" to treat it. The equipment construction and operation costs required are high and difficult to maintain continuously. However, if the leachate is directly subjected to biological treatment of biochemical reactions without pretreatment reaction, it will be affected by organic load and erosion by toxic substances, and the effluent quality will inevitably be difficult to meet the Class A standard of "GB 18918-2002". Therefore, a convenient, low-cost pretreatment reaction device is needed. Anaerobic ammonia oxidation technology does not require aeration or external carbon source, and the sludge output is extremely low. It only needs to provide ammonia nitrogen NH4 + -N and nitrite nitrogen NO2 - -N substrate can react, the denitrification path of this method is short, and compared with the traditional biological nitrification and denitrification process, the denitrification capacity is strong, and it has a strong pollution interception and emission reduction efficiency. However, the promotion of anaerobic ammonium oxidation process is affected by NO2 - -N provides restraints for matrix stabilization. Summary of the invention

[0004] The utility model is to overcome the above technical problems, aiming at the difficulty in treating landfill leachate wastewater and the high operating cost, while providing the required ammonia nitrogen and nitrite nitrogen substrates for the anaerobic ammonium oxidation process, and providing a pretreatment device that takes into account both landfill leachate treatment and the start-up of the anaerobic ammonium oxidation reaction.

[0005] The utility model is a pretreatment device for treating landfill leachate and starting anaerobic ammonia oxidation reaction, characterized in that the pretreatment device comprises an anaerobic tank, an aerobic tank, a short-range denitrification tank, a storage water tank, a filler device, a stirring device, an aeration device and a PLC controller, wherein the anaerobic tank, the aerobic tank, the short-range denitrification tank and the storage water tank are sequentially connected from front to back, the filler device is respectively placed in the anaerobic tank, the aerobic tank and the short-range denitrification tank, the stirring device is arranged in the aerobic tank and the short-range denitrification tank, and the stirring device and the aeration device are both connected to the PLC controller; wherein:

[0006] The anaerobic tank, aerobic tank, short-range denitrification tank and storage water tank are all hollow tanks. Two adjacent tanks are connected by outlet pipes, and the outlet pipes are respectively arranged at the upper part of the tanks. A water inlet is arranged at the front end of the anaerobic tank, and the water inlet is arranged at the lower part of the anaerobic tank.

[0007] The filler device comprises a hanging filler and a fluidized bed filler. The hanging filler is arranged in the anaerobic tank, and the fluidized bed filler is filled in the aerobic tank and the short-range denitrification tank.

[0008] The stirring device comprises a stirring motor and stirring blades. The two stirring motors are respectively arranged above the aerobic pool and the short-range denitrification pool. The aerobic pool and the short-range denitrification pool are respectively provided with stirring blades. The stirring blades are installed on the rotating shaft of the stirring motor. The stirring motor drives the stirring blades to rotate.

[0009] The aeration device comprises an aeration pump, an air inlet pipe and an aeration plate. The air inlet pipe is closely attached to the inner wall of the bottom of the aerobic pool. The aeration plate is installed on the air inlet pipe in the aerobic pool. The other end of the air inlet pipe is connected to the aeration pump.

[0010] The hanging filler is vertically hung in the anaerobic tank, and several hanging fillers are hung at equal intervals of 5 cm; the fluidized bed filler is filled in the aerobic tank and the short-range denitrification tank, and the volume of the filled fluidized bed filler accounts for 30-35% of the internal volume of the aerobic tank and the short-range denitrification tank.

[0011] The utility model is a pretreatment device that takes into account both the treatment of landfill leachate and the start-up of anaerobic ammonium oxidation reaction. It can not only efficiently treat landfill leachate wastewater with high nitrogen and high chemical oxygen demand, but also provide the substrate required for anaerobic ammonium oxidation reaction, realize the harmless utilization of resources, and has important environmental protection and economic benefits. The specific beneficial effects also include:

[0012] 1) Treating wastewater with complex water quality, high chemical oxygen demand and high ammonia nitrogen can effectively degrade toxic and harmful substances that are difficult to treat, and alleviate the impact of organic load on subsequent reaction pools, thereby maintaining a stable operating environment;

[0013] 2) Separating each reaction pool realizes the continuous denitrification of functional bacteria such as digestive bacteria, polyphosphate bacteria, nitrifying bacteria and short-range denitrifying bacteria, and there is no need to add external carbon source and add alkaline solution to adjust pH, saving the cost of adding chemicals and labor costs. The effluent produced also provides the necessary NH4 for the anaerobic ammonia oxidation reaction. + and NO2 - Reaction matrix, effectively improving resource utilization in wastewater treatment process;

[0014] 3) By adding suspended fillers and fluidized bed fillers, key functional microorganisms are enriched and retained to form a biofilm, which effectively improves the treatment effect. The device has simple and convenient process operation and easy maintenance, and can achieve the dual effects of treating landfill leachate and realizing the harmless utilization of resources, with important environmental and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the utility model.

[0016] Among them: 1-aerobic tank; 2-anaerobic tank; 3-short-range denitrification tank; 4-storage water tank; 5-water inlet; 6-hanging filler; 7-sludge outlet; 8-water outlet; 9-stirring motor; 10-stirring blade; 11-aeration pump; 12-air inlet pipe; 13-aeration plate; 14-fluidized bed filler K3; 15-PLC controller. DETAILED DESCRIPTION

[0017] Embodiment 1: A pretreatment device for treating landfill leachate and starting anaerobic ammonium oxidation reaction, comprising an anaerobic tank, an aerobic tank, a short-range denitrification tank, a storage water tank, a filler device, a stirring device, an aeration device and a PLC controller. The anaerobic tank, the aerobic tank, the short-range denitrification tank and the storage water tank are sequentially connected from front to back. The filler device is respectively placed in the anaerobic tank, the aerobic tank and the short-range denitrification tank. The stirring device is arranged in the aerobic tank and the short-range denitrification tank. The stirring device and the aeration device are both connected to the PLC controller, and the PLC controller uses the Siemens S7-1200 controller; wherein:

[0018] The anaerobic tank, aerobic tank, short-range denitrification tank and storage water tank are all hollow tanks. Two adjacent tanks are connected by outlet pipes, and the outlet pipes are respectively arranged at the upper part of the tanks. A water inlet is arranged at the front end of the anaerobic tank, and the water inlet is arranged at the lower part of the anaerobic tank.

[0019] The filler device comprises a hanging filler and a fluidized bed filler. The hanging filler is arranged in the anaerobic tank, and the fluidized bed filler is filled in the aerobic tank and the short-range denitrification tank.

[0020] The stirring device includes a stirring motor and a stirring blade. The two stirring motors are respectively arranged above the aerobic tank and the short-range denitrification tank. The aerobic tank and the short-range denitrification tank are respectively provided with stirring blades. The stirring blades are installed on the rotating shaft of the stirring motor. The stirring motor drives the stirring blades to rotate. The aeration device includes an aeration pump, an air inlet pipe and an aeration plate. The air inlet pipe is tightly attached to the inner wall of the bottom of the aerobic tank. The aeration plate is installed on the air inlet pipe in the aerobic tank. The other end of the air inlet pipe is connected to the aeration pump. The hanging filler is vertically suspended in the anaerobic tank. Several hanging fillers are hung at equal intervals with a spacing of 5 cm. The fluidized bed filler is filled in the aerobic tank and the short-range denitrification tank. The volume of the filled fluidized bed filler accounts for 30-35% of the internal volume of the aerobic tank and the short-range denitrification tank. The fluidized bed filler adopts MBBR filler to provide a suitable growth environment for microorganisms.

[0021] Among them, the specific process of enriching anaerobic digestion bacteria, polyphosphate bacteria, nitrifying bacteria and short-range denitrifying bacteria is as follows:

[0022] (1) Enrichment of anaerobic digestion bacteria and polyphosphate bacteria in anaerobic tanks: Sludge from anaerobic tanks of municipal sewage treatment plants was inoculated, with a sludge concentration of 5500±500 mg / L, and the sludge volume accounting for 35±5% of the volume of the anaerobic tank. The temperature in the anaerobic tank was controlled to be 30±3°C, the dissolved oxygen concentration to be 0.5±0.3 mg / L, the pH value to be 7.5±0.5, and the sludge age to be 6 days. The landfill leachate was diluted by 20% and continuously injected into the anaerobic tank to enrich anaerobic digestion bacteria and polyphosphate bacteria in the anaerobic tank. When the chemical oxygen demand removal rate was greater than 80%, the enrichment of anaerobic digestion bacteria and polyphosphate bacteria was completed.

[0023] (2) Enrichment of nitrifying bacteria and polyphosphate bacteria in aerobic pools: Inoculate sludge from anaerobic pools of municipal sewage treatment plants with a sludge concentration of 5500±500mg / L, with the sludge volume accounting for 35±5% of the volume of aerobic pools. Control the temperature in the aerobic pool to be 30±3℃, the dissolved oxygen concentration to be 3.5±0.5mg / L, the pH value to be 8.5±0.5, and the sludge age to be 1-3d. The wastewater treated in the anaerobic pool is injected into the aerobic pool along the direction of the water flow. Enrich aerobic nitrifying bacteria and polyphosphate bacteria in the aerobic pool, with ammonia nitrogen removal rate greater than 50%, and nitrate NO3 - -N accumulation rate is greater than 50%, total phosphorus TP removal rate is greater than 80%, and the aerobic nitrifying bacteria and polyphosphate bacteria in the aerobic pool are fully enriched;

[0024] (3) Enrichment of short-distance denitrifying bacteria in the short-distance denitrification pool: inoculate the sludge in the denitrification pool of the municipal sewage treatment plant, the sludge concentration is 5500±500mg / L, the sludge volume accounts for 35±5% of the volume of the short-distance denitrification pool, control the temperature in the short-distance denitrification pool to be 30±3℃, the dissolved oxygen concentration to be 0.5±0.2mg / L, the pH value to be 8.5±0.5, the sludge age to be 1-3d, and the wastewater treated in the aerobic pool is injected into the short-distance denitrification pool along the water flow direction; enrich the short-distance denitrifying bacteria in the short-distance denitrification pool, the nitrate removal rate is greater than 80%, the nitrite nitrogen accumulation rate is greater than 60%, the retention ratio in the short-distance denitrification pool is controlled at ammonia nitrogen: nitrite nitrogen = 1: (1-1.5), and the enrichment of the short-distance denitrifying bacteria in the short-distance denitrification pool is completed;

[0025] (4) After the above enrichment work is completed, the landfill leachate raw water enters the anaerobic tank of the pretreatment reaction device, and the dissolved oxygen concentration is controlled at 0.5±0.3 mg / L. The pre-enriched anaerobic digestion bacteria are used to degrade and consume a large amount of difficult-to-degrade organic matter in the landfill leachate raw water, and the polyphosphate bacteria perform anaerobic phosphorus release reaction; the wastewater treated in the anaerobic tank is injected into the aerobic tank along the water flow direction, and the dissolved oxygen concentration is controlled at 3.5±0.5 mg / L. The aeration pump is turned on for uniform aeration, and aerobic nitrification and aerobic phosphorus absorption reactions are carried out simultaneously; the wastewater treated in the aerobic tank is injected into the short-cut denitrification tank along the water flow direction, and the dissolved oxygen concentration is 0.5±0.2 mg / L. Short-cut denitrification reaction is carried out, and the effluent ammonia nitrogen concentration is maintained at 80-120 mg / L, the ratio of ammonia nitrogen to nitrite nitrogen is controlled at 1:(1-1.5), and the effluent chemical oxygen demand concentration is controlled at less than 5 mg / L; finally, the treated wastewater is stored in the storage tank by gravity flow.

Claims

1. A pretreatment device for treating landfill leachate and starting anaerobic ammonium oxidation reaction, characterized in that The pretreatment device comprises an anaerobic tank, an aerobic tank, a short-range denitrification tank, a storage water tank, a filler device, a stirring device, an aeration device and a PLC controller. The anaerobic tank, the aerobic tank, the short-range denitrification tank and the storage water tank are sequentially connected from front to back. The filler devices are respectively placed in the anaerobic tank, the aerobic tank and the short-range denitrification tank. The stirring device is arranged in the aerobic tank and the short-range denitrification tank. The stirring device and the aeration device are both connected to the PLC controller; wherein: The anaerobic tank, aerobic tank, short-range denitrification tank and storage water tank are all hollow tanks. Two adjacent tanks are connected by outlet pipes, and the outlet pipes are respectively arranged at the upper part of the tanks. A water inlet is arranged at the front end of the anaerobic tank, and the water inlet is arranged at the lower part of the anaerobic tank. The filler device comprises a hanging filler and a fluidized bed filler. The hanging filler is arranged in the anaerobic tank, and the fluidized bed filler is filled in the aerobic tank and the short-range denitrification tank.

2. The pretreatment device for treating landfill leachate and starting anaerobic ammonium oxidation reaction as claimed in claim 1, characterized in that The stirring device comprises a stirring motor and stirring blades. The two stirring motors are respectively arranged above the aerobic pool and the short-range denitrification pool. The aerobic pool and the short-range denitrification pool are respectively provided with stirring blades. The stirring blades are installed on the rotating shaft of the stirring motor. The stirring motor drives the stirring blades to rotate.

3. The pretreatment device for treating landfill leachate and starting anaerobic ammonium oxidation reaction as claimed in claim 1, characterized in that The aeration device comprises an aeration pump, an air inlet pipe and an aeration plate. The air inlet pipe is closely attached to the inner wall of the bottom of the aerobic pool. The aeration plate is installed on the air inlet pipe in the aerobic pool. The other end of the air inlet pipe is connected to the aeration pump.

4. The pretreatment device for treating landfill leachate and starting anaerobic ammonium oxidation reaction as claimed in claim 1, characterized in that The hanging filler is vertically hung in the anaerobic tank, and several hanging fillers are hung at equal intervals of 5 cm; the fluidized bed filler is filled in the aerobic tank and the short-range denitrification tank, and the volume of the fluidized bed filler filled in accounts for 30-35% of the internal volume of the aerobic tank and the short-range denitrification tank.

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