Full-amount treatment system for landfill leachate

Abstract

The utility model relates to the technical field of sewage treatment, and discloses a full-amount treatment system for landfill leachate. Comprising a regulating tank, a coagulation coupling advanced oxidation reaction system, a double-alkali hardness removal system, a primary denitrification tank, a primary nitrification tank, a secondary denitrification tank, a secondary nitrification tank, an external ultrafiltration membrane, an electrochemical catalytic oxidation system, a supportability biochemical reaction system and a water outlet tank which are connected in sequence, the aeration system is respectively connected with the primary denitrification tank and the secondary denitrification tank; the defoaming agent tank is respectively connected with the primary nitrification tank and the secondary nitrification tank; the input end of the primary denitrification tank is connected with a nitrogen source tank; and a chemical sludge discharge port of the primary denitrification tank is sequentially connected with a cooling system, a sludge concentration tank and a sludge dewatering system. According to the utility model, the processes of pretreatment, biochemical treatment, electrocatalytic oxidation and deep treatment are adopted, the treatment system is stable, no concentrated solution is generated in the treatment process, the treatment flow is short, the cost is low, and the full-amount treatment of the leachate is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of sewage treatment, specifically relates to a landfill leachate full quantity treatment system. BACKGROUND

[0002] Garbage leachate refers to the moisture contained in garbage itself, rain and snow water and other moisture entering the landfill, deducting the saturated water holding capacity of garbage and soil cover, and forming a kind of high concentration organic wastewater after experiencing garbage layer and soil cover.Garbage leachate is a kind of wastewater containing high concentration of refractory organic matter and high ammonia nitrogen, and the treatment of garbage leachate is an important problem that cannot be ignored in garbage sanitary landfill system.

[0003] Among the relatively mature garbage leachate treatment processes in the market, the "pretreatment+ biochemical treatment+ double membrane method (nanofiltration+ reverse osmosis) " treatment process has become the mainstream combined process for landfill leachate treatment because of its good effluent effect and high integration degree.But membrane treatment will produce concentrated liquid, which cannot realize the full quantity treatment of garbage leachate, which brings huge environmental protection pressure to garbage treatment enterprises.Therefore, there is an urgent need for low-cost garbage leachate full quantity treatment technology.

[0004] CN 112456728 A discloses a kind of garbage leachate full quantity treatment system and process, including the grid pool, adjusting pool, first anoxic tank, first aerobic tank, second anoxic tank, second aerobic tank, external ultrafiltration membrane group device, electro-catalytic oxidation tank, sedimentation tank, photocatalytic oxidation tank and biological aerated filter by pipeline sequentially connected, it adopts electro-catalytic oxidation, sedimentation, photocatalytic oxidation treatment+ aeration biological treatment process to the concentrated liquid obtained by external ultrafiltration membrane group device, effluent discharge reaches standard.But the full quantity treatment system still has the following deficiencies: sludge is not effectively treated;Biochemical treatment system does not adjust carbon-nitrogen ratio, because organic matter is due to long-term hydrolysis fermentation leads to leachate ammonia nitrogen concentration is too high, causes C / N imbalance in leachate, thereby inhibiting the microorganism in biochemical treatment, poor biodegradability, leading to biochemical treatment system cannot be stably operated;A large amount of foam is generated in nitrification tank, which can cause the gas exchange efficiency to decrease and affect the nitrification process;After electro-catalytic oxidation treatment, multiple steps of treatment are still needed, the process flow of sewage treatment process is longer, and the capital construction cost and maintenance cost are higher. UTILITY MODEL CONTENTS

[0005] The utility model aims at the above problems, provides a landfill leachate full quantity treatment system, and the treatment system is stable, concentrated liquid is not generated in the treatment process, the treatment flow is short, the cost is low, and the full quantity treatment of leachate is realized.

[0006] In order to achieve the above object, the utility model adopts the technical scheme as follows: A landfill leachate full quantity treatment system, including the regulating pool, coagulation coupling advanced oxidation reaction system, double alkali hardness removal system, primary denitrification tank, primary nitrification tank, secondary denitrification tank, secondary nitrification tank, external ultrafiltration membrane, electrochemical catalytic oxidation system, guaranteeing biochemical reaction system and effluent tank that are connected in proper order through pipeline, and the aeration system is connected with primary denitrification tank and secondary denitrification tank respectively, and provides oxygen for primary denitrification tank and secondary denitrification tank, and the defoaming agent tank is connected with primary nitrification tank and secondary nitrification tank respectively, and provides defoaming agent for primary denitrification tank and secondary denitrification tank, and the input end of primary denitrification tank is connected with nitrogen source tank, which is used for adjusting the carbon-nitrogen ratio of primary denitrification tank, and the biochemical sludge discharge port of primary denitrification tank is connected with cooling system, sludge concentration tank and sludge dewatering system in proper order, and the chemical sludge discharge port of coagulation coupling advanced oxidation reaction system, double alkali hardness removal system and guaranteeing biochemical reaction system is communicated with sludge concentration tank, and the mud cake is sent to the designated landfill site for landfill after dewatering treatment by sludge dewatering system, and the supernatant after dewatering is collected by water collecting well.

[0007] Preferably, the primary nitrification tank is backflowed to the primary denitrification tank through a nitrification liquid backflow pipeline.

[0008] Preferably, the primary nitrification tank is backflowed to the primary denitrification tank through an internal backflow pipeline.

[0009] Preferably, the external ultrafiltration membrane is connected with the primary denitrification tank through an ultrafiltration concentrated liquid backflow pipeline.

[0010] Preferably, the residual sludge discharge ports of the primary nitrification tank and the external ultrafiltration membrane are communicated with the sludge concentration tank.

[0011] Due to the adoption of the above technical scheme, the utility model has the following beneficial effects:

[0012] The leachate full quantity treatment system of the utility model adopts the process of "pretreatment + biochemical treatment + electrochemical catalytic oxidation + advanced treatment", and no concentrated liquid is generated in the leachate treatment process, and the residual sludge can be filled after dewatering, the treatment system is stable, the whole system process is short, the operation cost is low, the operation is stable and the treatment efficiency is high, and the full quantity treatment of landfill leachate is realized. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a structural schematic view of the utility model landfill leachate full quantity treatment system;

[0014] In the figure: 101 - conditioning tank, 102 - coagulation coupled advanced oxidation reaction system, 103 - dual-alkali hardness removal system, 104 - primary denitrification tank, 105 - primary nitrification tank, 106 - secondary denitrification tank, 107 - secondary nitrification tank, 108 - external ultrafiltration membrane, 109 - electrochemical catalytic oxidation system, 110 - guaranteeing biochemical reaction system, 111 - effluent tank, 112 - cooling system, 113 - sludge concentration tank, 114 - sludge dewatering system, 115 - water collecting well, 116 - aeration system, 117 - defoaming agent tank, 116 - nitrogen source tank. DETAILED DESCRIPTION

[0015] In order to make the personnel in the technical field better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Unless otherwise defined, all the technical and scientific terms used in the present application have the same meanings as those commonly understood by the person skilled in the art of the present application. The terms used in the present application in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. The terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects and are not used to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed or can optionally include other steps or units inherent to the process, method, product or device.

[0016] In the present application, the term "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0017] As Figure 1As shown, a landfill leachate total treatment system includes a conditioning tank 101, a coagulation coupled advanced oxidation reaction system 102, a double alkali hardness removal system 103, a first-stage denitrification tank 104, a first-stage nitrification tank 105, a second-stage denitrification tank 106, a second-stage nitrification tank 107, an external ultrafiltration membrane 108, an electrochemical catalytic oxidation system 109, a guaranteeing biochemical reaction system 110, and a water outlet tank 111 connected in sequence through pipelines; an aeration system 116 is connected with the first-stage denitrification tank 104 and the second-stage denitrification tank 106 respectively to provide oxygen for the first-stage denitrification tank 104 and the second-stage denitrification tank 106; a defoaming agent tank 117 is connected with the first-stage nitrification tank 105 and the second-stage nitrification tank 107 respectively to provide defoaming agents for the first-stage denitrification tank 104 and the second-stage denitrification tank 106; the input end of the first-stage denitrification tank 104 is connected with a nitrogen source tank 116 for adjusting the carbon-nitrogen ratio of the first-stage denitrification tank 104; the biochemical sludge discharge port of the first-stage denitrification tank 104 is connected with a cooling system 112, a sludge concentration tank 113, and a sludge dewatering system 114 in sequence, the chemical sludge discharge ports of the coagulation coupled advanced oxidation reaction system 102, the double alkali hardness removal system 103, and the guaranteeing biochemical reaction system 110 are communicated with the sludge concentration tank 113, and the mud cake after dewatering treatment by the sludge dewatering system 114 is sent to a designated landfill site for landfill, and the supernatant after dewatering is collected through a water collecting well 115. The defoaming agent is added in an amount of 200-300 mg / L in the first-stage denitrification tank 104 and the second-stage denitrification tank 106 to play a defoaming role, avoid a large amount of bubbles from affecting the biochemical treatment efficiency, and ensure the stability of system operation.

[0018] The first-stage nitrification tank 105 is connected with the first-stage denitrification tank 104 through a nitrification liquid reflux pipeline. The nitrification liquid in the first-stage denitrification tank 104 can be refluxed to the first-stage denitrification tank 104 through the reflux action, converted into nitrogen gas under the action of the bacterial flora in the first-stage denitrification tank 104, and total nitrogen removal is realized.

[0019] The external ultrafiltration membrane 108 is connected with the first-stage denitrification tank 104 through an ultrafiltration concentrated liquid reflux pipeline, so that the ultrafiltration concentrated liquid can be refluxed to the first-stage denitrification tank 104 to improve the sludge concentration. The ultrafiltration concentrated liquid improves the sludge concentration in the first-stage denitrification tank 104 through the reflux action.

[0020] The residual sludge discharge ports of the first-stage nitrification tank 105 and the external ultrafiltration membrane 108 are communicated with the sludge concentration tank 113. The residual sludge of the first-stage nitrification tank 105 and the external ultrafiltration membrane 108 can be effectively recycled and treated.

[0021] The treatment process of the leachate total treatment system is as follows:

[0022] 1. The leachate generated in the municipal solid waste landfill site is sent to the conditioning tank 101 for water quality balancing treatment. Since the water quality of the leachate from the landfill site is uneven and the water quantity is unstable, it is easy to reduce the overall sewage treatment effect. The conditioning tank 101 is used to adjust the water quality, so that the water quality and quantity are relatively balanced and stable, and the subsequent treatment effect is ensured;

[0023] 2. Pretreatment: After the water quality balancing treatment, the landfill leachate is pretreated by the coagulation coupled advanced oxidation reaction system 102 and the double-alkali water softening system 103. The coagulation coupled advanced oxidation reaction system 102 combines coagulation and advanced oxidation methods. By adding a coagulant to the water, suspended solids and colloidal particles are aggregated to form large particles, which are convenient for subsequent treatment. Oxidizing agents (such as titanium dioxide) are used to produce active oxygen under light or heating conditions. These active oxygen has strong oxidizing properties and can oxidize and decompose organic pollutants to enhance the removal effect of pollutants. The double-alkali water softening system 103 uses sodium hydroxide and sodium carbonate to react with calcium and magnesium ions in water to generate insoluble precipitates, thereby achieving the effect of softening water quality. In addition, the sludge generated in the coagulation coupled advanced oxidation reaction system 102 and the double-alkali water softening system 103 is collected in the sludge thickening tank 113;

[0024] 3. Biological treatment: The pretreated landfill leachate is sequentially treated by the first-stage denitrification tank 104, the first-stage nitrification tank 105, the second-stage denitrification tank 106, and the second-stage nitrification tank 107, and then sent to the external ultrafiltration membrane 108 for filtration and separation. The synergistic effect of nitrifying bacteria and denitrifying bacteria is used to biodegrade the pollutants in the leachate, removing most of the biodegradable organic, ammonia nitrogen, and total nitrogen pollutants. During the treatment process, nitrogen is introduced into the first-stage denitrification tank 104 to adjust the carbon-nitrogen ratio in the first-stage nitrification tank 105, avoiding the imbalance of C / N in the leachate, which can inhibit the growth of microorganisms and reduce the biodegradability, ensuring the stable operation of the biological treatment system. Oxygen is introduced into the first-stage nitrification tank 105 and the second-stage nitrification tank 107 to maintain the dissolved oxygen concentration at 4-6 mg / L. The external ultrafiltration membrane 108 uses hollow fiber membrane filaments with high material packing density, which can provide a large amount of water output and separate the biological activated sludge. At the same time, the sludge generated in the first-stage nitrification tank 105 is cooled by the cooling system 112 and then enters the sludge thickening tank 113. The remaining sludge in the first-stage nitrification tank 105 and the external ultrafiltration membrane 108 also enters the sludge thickening tank 113;

[0025] 4. Electro-catalytic oxidation, the wastewater after biochemical treatment enters the electro-catalytic oxidation system 109, the electro-catalytic oxidation system 109 includes reaction tank and multiple serial electrode module groups arranged in the reaction tank, which generates strong oxidizing or reducing substances, such as hydroxyl radical, hydrogen peroxide, ozone, etc., by electrode material under the action of electric field to oxidize or reduce organic pollutants in water body, further degrading organic matter;

[0026] 5. Advanced treatment, the wastewater after electro-catalytic oxidation system 109 treatment enters the guaranteeing biochemical reaction system 110, biochemical treatment is to effectively remove soluble organic matter and part of insoluble organic matter in wastewater by microorganism, so that water is purified, and the purpose of wastewater advanced treatment is achieved, through advanced treatment, water quality is further purified, and the treated water is sent to the effluent tank 111, and is discharged.

[0027] The utility model is described in detail above, but some modifications or improvements can be made on the basis of the utility model, which is obvious to those skilled in the art. Therefore, the modifications or improvements without departing from the spirit of the utility model are within the protection scope of the utility model.

Claims

1. A full-strength landfill leachate treatment system, characterized by: The system comprises a conditioning pool, a coagulation coupling advanced oxidation reaction system, a double-alkali water softening system, a first-stage denitrification pool, a first-stage nitrification pool, a second-stage denitrification pool, a second-stage nitrification pool, an external ultrafiltration membrane, an electrochemical catalytic oxidation system, a guaranteeing biochemical reaction system and a water outlet pool connected in sequence through pipelines. The aeration system is connected with the first-stage denitrification pool and the second-stage denitrification pool respectively to provide oxygen for the first-stage denitrification pool and the second-stage denitrification pool; the defoaming agent tank is connected with the first-stage nitrification pool and the second-stage nitrification pool respectively to provide defoaming agent for the first-stage denitrification pool and the second-stage denitrification pool; the input end of the first-stage denitrification pool is connected with a nitrogen source tank for adjusting the carbon-nitrogen ratio of the first-stage denitrification pool; the biochemical sludge discharge port of the first-stage denitrification pool is connected with a cooling system, a sludge concentration pool and a sludge dewatering system in sequence, the chemical sludge discharge ports of the coagulation coupling advanced oxidation reaction system, the double-alkali water softening system and the guaranteeing biochemical reaction system are communicated with the sludge concentration pool, and the mud cake after dewatering treatment by the sludge dewatering system is sent to a designated landfill site for landfill, and the supernatant after dewatering is collected through a water collecting well.

2. The full-strength landfill leachate treatment system according to claim 1, characterized in that: The first-stage nitrification pool is backflowed to the first-stage denitrification pool through a nitrification liquid backflow pipeline.

3. The full-strength landfill leachate treatment system according to claim 2, wherein: The first-stage nitrification pool is backflowed to the first-stage denitrification pool through an internal backflow pipeline.

4. The full-strength landfill leachate treatment system of claim 1, wherein: The external ultrafiltration membrane is connected with the first-stage denitrification pool through an ultrafiltration concentrated liquid backflow pipeline.

5. The full-strength landfill leachate treatment system of claim 1, wherein: The residual sludge discharge ports of the first-stage nitrification pool and the external ultrafiltration membrane are communicated with the sludge concentration pool.

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