Full-quantification deep treatment system for landfill leachate

Abstract

The utility model discloses a full-quantification advanced treatment system for landfill leachate, which comprises a coagulative precipitation tank, a primary biochemical treatment system, an advanced oxidation unit, a secondary biochemical treatment system, an adsorption unit and a sludge separation system. Wastewater sequentially passes through a coagulative precipitation tank, a primary biochemical treatment system, an advanced oxidation unit, a secondary biochemical treatment system and an adsorption unit, colloidal particles, tiny suspended solids, ammonia nitrogen, total nitrogen and organic matters in water are sequentially removed, then a flocculating agent is added to remove precipitates generated by a Fenton reaction, and the organic matters, ammonia nitrogen and total nitrogen in the water are degraded again. And finally, the effluent of the tubular ultrafiltration membrane enters an active coke adsorption system, and the sewage sequentially passes through three stages of active coke adsorption tanks to adsorb residual organic matters in the water, so that the effluent is discharged up to the standard.

Description

Technical Field

[0001] The utility model belongs to the field of environmental protection technology and relates to a method for treating landfill leachate. Background Art

[0002] For the two-stage DTRO reverse osmosis treatment technology, the principle is that the original leachate of the landfill enters the high-pressure pump via the regulating tank, and then enters the first-stage DTRO reverse osmosis membrane filtration via the circulating high-pressure pump. The effluent enters the second-stage DTRO reverse osmosis system, and after two-stage reverse osmosis filtration, the effluent meets the discharge standards. The first-stage concentrated liquid is re-injected into the landfill area for centralized treatment, and the second-stage concentrated liquid is refluxed to the total water inlet.

[0003] For the biochemical combined with traditional RO membrane technology, the principle is that most of the COD, ammonia nitrogen and total nitrogen are removed by biochemical treatment first, and the biochemical effluent then enters the back-end medium and low-pressure membrane system. The membrane is a clean production technology, mainly playing a separation role, mainly divided into ultrafiltration UF, nanofiltration NF and reverse osmosis RO. Its function is to separate one substance from another. The separation of the membrane is simply screening, that is, using the principle of mechanical screening of the pores on the membrane surface to separate substances of different sizes to achieve the purpose of separation.

[0004] For the membrane + evaporation treatment technology, the principle is that the front-end uses membrane technology to pre-treat the landfill leachate, and the concentrated liquid generated by the membrane system then enters the evaporation concentration unit for treatment. In practical applications, the evaporation process is used to treat high-salt wastewater, organic wastewater, etc. By evaporation crystallization, the harmful substances in the wastewater are converted into harmless substances or recycled for reuse, realizing the reduction, harmlessness and resource utilization of the wastewater.

[0005] The membrane separation technology is widely used in the landfill leachate treatment process. Compared with traditional treatment methods such as precipitation and filtration, the membrane separation process does not require the addition of chemical agents and will not produce secondary pollution. At the same time, the membrane separation technology has low energy consumption, significantly reducing the treatment cost. Through the filtration of the ultrafiltration membrane, the pollutant concentration in the leachate can be significantly reduced, providing a purer raw material for the subsequent treatment process. Secondly, the nanofiltration membrane separation technology can be used for the advanced treatment of landfill leachate. The pore size of the nanofiltration membrane is extremely small, and it can remove harmful substances such as organic matter with a small molecular weight and heavy metal ions. Through the filtration of the nanofiltration membrane, the pollutant concentration in the leachate can be further reduced, improving the treatment efficiency. In addition, in the reverse osmosis membrane process, by using the pressure difference on both sides of the reverse osmosis membrane, the osmotic pressure of ions can be effectively overcome, and the solvent is selectively permeated to effectively intercept ionic substances, thus achieving separation. Due to the high precision of the technology itself, the interception accuracy can also reach between 0.1nm and 1nm, and it can even effectively separate organic matter with a relative molecular weight above 100, concentrating and intercepting all suspended substances and soluble salts of water molecules, thus meeting the effluent water quality requirements.

[0006] Disadvantages of the prior art:

[0007] Concentrate residue: Ultrafiltration, nanofiltration, and reverse osmosis processes cannot effectively treat all landfill leachate, and 20-30% of the concentrate will still remain in the regulation tank or continue to be recycled. The landfill leachate membrane concentrate produced after membrane treatment has complex components, high pollutant concentrations, contains a large amount of refractory pollutants and salt compounds, and is very difficult to treat. Improper treatment will cause more serious pollution. Currently, most landfill / incineration plants choose to recycle or spray back for treatment, or temporarily store it in the regulation tank. The above treatment methods all pose potential threats to the surrounding environment.

[0008] Clogging problem: Since the membrane system is a simple separation process rather than treatment, refractory substances still remain in the system. When treating landfill leachate, pollutants in the wastewater will continuously accumulate on the membrane surface. Over time, subsequent treatment will be difficult to digest, gradually accumulate to form dirt, and cause the problem of membrane clogging. In addition, in the evaporation process, high-concentration organic matter enters the evaporation system, resulting in easy clogging of the evaporation tubes and increasing the difficulty of subsequent operation.

[0009] Salinity accumulation: Salinity accumulates severely during the membrane treatment process. When it reaches a certain level, the membrane process can no longer be used, and the residual liquid can only be treated by physical methods such as evaporation and drying. The operating cost is extremely high, and hazardous waste is generated, which cannot completely solve the harm problem of landfill leachate.

[0010] High investment and operating costs: The reverse osmosis process uses high-pressure membrane technology. Not only is the price of the device itself relatively high, but the membrane loss, electricity cost, and chemical agent cost during operation are also higher than those of traditional processes. In addition, in the evaporation process, the evaporation system itself consumes a large amount of steam or electricity, and subsequent evaporation concentrate and hazardous waste also require disposal costs, which greatly increase the operating cost. In addition, due to the relatively high salinity and chloride ion content of the leachate water quality, the material requirements for the entire evaporation system are very high, increasing the equipment investment cost. Summary of the Invention

[0011] The present utility model aims to solve one of the technical problems existing in the prior art.

[0012] The present application provides a full-quantification and in-depth treatment system for landfill leachate, including:

[0013] A coagulation sedimentation tank, a primary biochemical treatment system, an advanced oxidation unit, a secondary biochemical treatment system, and an adsorption unit connected in series, as well as a sludge separation system connected to the coagulation sedimentation tank and the advanced oxidation unit. The primary biochemical treatment system and the secondary biochemical treatment system are used to degrade the biodegradable part of the landfill leachate, reducing the concentrations of COD, ammonia nitrogen, and total nitrogen in the landfill leachate. The advanced oxidation unit is used to remove the organic pollutants that are difficult to biodegrade in the landfill leachate, and at the same time convert some macromolecular pollutants into small molecular pollutants, improving the biodegradability of the sewage.

[0014] Both the primary biochemical treatment system and the secondary biochemical treatment system include:

[0015] Biochemical treatment tanks, bag filters, and tubular ultrafilters connected in series;

[0016] Among them, an anoxic tank connected to the coagulation sedimentation tank / advanced oxidation unit and an aerobic tank connected to the bag filter are provided inside the biochemical treatment tank, and the other end of the tubular ultrafilter is connected to the advanced oxidation unit or the adsorption unit.

[0017] Both the primary biochemical treatment system and the secondary biochemical treatment system also include:

[0018] A submersible mixer, which is arranged in the anoxic tank.

[0019] Both the primary biochemical treatment system and the secondary biochemical treatment system also include:

[0020] A Roots blower and an aeration system for aerating the aerobic tank to control the dissolved oxygen in the aerobic tank to be greater than 2 mg / L.

[0021] The sludge intercepted in the tubular ultrafilter is returned to the coagulation sedimentation tank through a pipeline.

[0022] The advanced oxidation unit includes:

[0023] A primary Fenton oxidation tower, a primary neutralization sedimentation tank, a primary Fenton oxidation tower, and a secondary neutralization sedimentation tank connected in series;

[0024] Among them, both the primary neutralization sedimentation tank and the secondary neutralization sedimentation tank are connected to the coagulation sedimentation tank through pipelines.

[0025] The sludge separation device includes:

[0026] A sludge tank, which is connected to the coagulation sedimentation tank, the primary neutralization sedimentation tank, and the secondary neutralization sedimentation tank through pipelines;

[0027] A plate and frame filter press for dehydrating the sludge in the sludge tank, and the filtrate generated is returned to the coagulation sedimentation tank through a pipeline.

[0028] The adsorption unit includes:

[0029] A primary activated coke adsorption tank, a secondary activated coke adsorption tank, and a tertiary activated coke adsorption tank connected in series in sequence.

[0030] The beneficial effects of the present utility model are as follows:

[0031] The method adopted by this device is to treat landfill leachate by a biochemical + advanced oxidation + adsorption process. Its basic principle is to pre-treat landfill leachate by chemical precipitation method, and then conduct biochemical treatment on the precipitated sewage to remove biodegradable pollutants. Then the sewage is introduced into the advanced oxidation unit, and the strong oxidation ability of hydroxyl radicals is used to oxidize the refractory pollutants in the landfill leachate. Some organic pollutants are completely mineralized and removed. In addition, the refractory macromolecular pollutants become small molecule substances, improving the biodegradability of the landfill leachate. After the sewage exits from the advanced oxidation treatment unit, biochemical treatment is carried out again. Finally, the sewage enters the adsorption unit, and multi-stage adsorption is adopted to ensure the up-to-standard discharge of the sewage, with strong resistance to water quality and water volume impact, reduced operating costs, no membrane concentrate generated, and the full-volume discharge of landfill leachate is realized. During the actual operation process, pay attention to technical details and adjust operating conditions to improve treatment efficiency and reduce costs. Description of the Drawings

[0032] Figure 1 It is a process diagram of a full-quantification and in-depth treatment system for landfill leachate in the embodiments of this application. Specific Embodiments

[0033] Next, the technical solutions in the embodiments of this application will be clearly described in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art belong to the scope protected by this application.

[0034] The terms "primary", "secondary", etc. in the description and claims of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances, so that the embodiments of this application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "primary", "secondary", etc. are usually of the same category, and the number of objects is not limited. For example, the primary object can be one or multiple. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.

[0035] The following will, in conjunction with the accompanying drawings, provide a detailed description of the full - quantification and in - depth treatment system for landfill leachate provided by the embodiments of the present application through specific embodiments and their application scenarios.

[0036] Embodiment 1:

[0037] As Figure 1 shown, the embodiments of the present application provide a full - quantification and in - depth treatment system for landfill leachate, including a coagulation sedimentation tank, a primary biochemical treatment system, an advanced oxidation unit, a secondary biochemical treatment system, and an adsorption unit connected in series in sequence, and a sludge separation system connected to the coagulation sedimentation tank and the advanced oxidation unit. The primary biochemical treatment system and the secondary biochemical treatment system are used to degrade the biodegradable part in the landfill leachate, reducing the concentrations of COD, ammonia nitrogen, and total nitrogen in the landfill leachate. The advanced oxidation unit is used to remove the organic pollutants that are difficult to biodegrade in the landfill leachate, and at the same time convert some macromolecular pollutants into small - molecular pollutants, improving the biodegradability of the sewage.

[0038] Furthermore, both the primary biochemical treatment system and the secondary biochemical treatment system include a biochemical treatment tank, a bag - type filter, and a tubular ultra - filter connected in series. An anoxic tank connected to the coagulation sedimentation tank / advanced oxidation unit and an aerobic tank connected to the bag - type filter are arranged inside the biochemical treatment tank. The other end of the tubular ultra - filter is connected to the advanced oxidation unit or the adsorption unit.

[0039] Furthermore, both the primary biochemical treatment system and the secondary biochemical treatment system also include a submersible agitator, which is arranged in the anoxic tank.

[0040] Furthermore, both the primary biochemical treatment system and the secondary biochemical treatment system also include a Roots blower and an aeration system for aerating the aerobic tank to control the dissolved oxygen in the aerobic tank to be greater than 2 mg / L.

[0041] Preferably, the sludge intercepted in the tubular ultra - filter is returned to the coagulation sedimentation tank through a pipeline.

[0042] Furthermore, the advanced oxidation unit includes a first - stage Fenton oxidation tower, a first - stage neutralization sedimentation tank, a second - stage Fenton oxidation tower, and a second - stage neutralization sedimentation tank connected in series in sequence. Both the first - stage neutralization sedimentation tank and the second - stage neutralization sedimentation tank are connected to the coagulation sedimentation tank through pipelines.

[0043] Furthermore, the sludge separation device includes a sludge tank, which is connected to the coagulation sedimentation tank, the first - stage neutralization sedimentation tank, and the second - stage neutralization sedimentation tank through pipelines; a plate - and - frame filter press for dewatering the sludge in the sludge tank, and the filtrate generated is returned to the coagulation sedimentation tank through a pipeline.

[0044] In this embodiment of the present application, due to the adoption of the above - mentioned structure, the specific operation steps are as follows:

[0045] S1: Pump the landfill leachate into the coagulation sedimentation tank. The coagulation sedimentation tank includes a reaction zone and a sedimentation zone. The front end is the reaction zone with 3 compartments. The sewage passes through the first compartment, the second compartment, and the third compartment in sequence. First, add sodium hydroxide to the first compartment to adjust the pH, and use a stirrer to mix evenly to maintain the pH between 6.5 and 8.5. Then, add a coagulant aluminum salt polymer or iron salt polymer to the second compartment to destabilize the colloids in the water and form tiny aggregates. Next, add a flocculant PAM to the third compartment to cause the destabilized colloids or tiny suspended solids to aggregate into large flocs. Finally, the effluent from the third compartment enters the sedimentation zone for solid-liquid separation, and the generated physicochemical sludge enters the sludge tank for treatment.

[0046] S2: The effluent from the coagulation sedimentation tank enters the anoxic tank of the primary biochemical treatment system.

[0047] S3: Control the dissolved oxygen in the anoxic tank between 0.2 and 0.5 mg / L, and place a submersible agitator in the anoxic tank for stirring.

[0048] S4: The effluent from the anoxic tank enters the aerobic tank.

[0049] S5: Aerate the aerobic tank using a Roots blower and an aeration system, and control the dissolved oxygen in the aerobic tank to be greater than 2 mg / L.

[0050] S6: The effluent from the aerobic tank enters a bag filter for filtration.

[0051] S7: The effluent from the bag filter enters a tubular ultrafiltration membrane for filtration. The sludge intercepted by the tubular ultrafiltration membrane is refluxed to the aerobic tank of the primary biochemical treatment system process.

[0052] S8: The effluent from the tubular ultrafiltration membrane enters the first-stage Fenton catalytic oxidation tower. First, add sulfuric acid to adjust the pH and control the pH to be maintained between 3 and 4. Then, add Fe2+ and H2O2 in sequence to initiate the Fenton reaction. Use the generated strong oxidizing substances to oxidize and remove the refractory substances in the sewage.

[0053] S9: The effluent from the first-stage Fenton catalytic oxidation tower enters the first-stage neutralization sedimentation tank. First, add sodium hydroxide to adjust the pH to alkaline, and then add PAM to cause the tiny suspended solids generated by the Fenton reaction to aggregate into larger flocs and be removed.

[0054] S10: The physicochemical sludge generated by the neutralization sedimentation tank enters the sludge tank for treatment.

[0055] S11: The effluent from the neutralization sedimentation enters the second-stage Fenton catalytic oxidation tower, and repeat the operations of S8, S9, and S10.

[0056] S12: The effluent from the second-stage neutralization sedimentation tank enters the anoxic tank of the secondary biochemical treatment system process.

[0057] S13: Control the dissolved oxygen in the anoxic tank to be maintained between 0.2 - 0.5 mg / L, and place a submersible agitator in the anoxic tank for agitation.

[0058] S14: The effluent from the anoxic tank enters the aerobic tank.

[0059] S15: Use a Roots blower and an aeration system to aerate the aerobic tank, and control the dissolved oxygen in the aerobic tank to be greater than 2 mg / L.

[0060] S16: The effluent from the aerobic tank enters a bag filter for filtration.

[0061] S17: The effluent from the bag filter enters a tubular ultrafiltration membrane for filtration, and the sludge intercepted by the tubular ultrafiltration membrane flows back to the aerobic tank of the secondary biochemical treatment system process.

[0062] S18: The effluent from the tubular ultrafiltration membrane enters a primary activated coke adsorption tank, set the residence time to 1 h, and use activated coke to perform primary adsorption on the pollutants remaining in the sewage.

[0063] S19: The effluent from the primary activated coke adsorption tank enters a secondary activated coke adsorption tank, set the residence time to 1 h, and use activated coke to perform secondary adsorption on the pollutants remaining in the sewage.

[0064] S20: The effluent from the secondary activated coke adsorption tank enters a tertiary activated coke adsorption tank, set the residence time to 1 h, and use activated coke to perform tertiary adsorption on the pollutants remaining in the sewage.

[0065] S21: The effluent from the tertiary activated coke adsorption tank meets the discharge standards.

[0066] S22: The sludge in the sludge tank is dehydrated by a plate and frame filter press and then transported for external treatment. The filtrate generated during the dehydration process flows back to the front-end coagulation sedimentation tank. Before entering the plate and frame filter press, a polymer flocculant is added using a flocculant dosing device. The polymer flocculant uses cationic PAM to improve the sludge dehydration effect.

[0067] After the wastewater is collected, it enters the coagulation sedimentation tank through a centrifugal pump. Flocculants and coagulants are added to the coagulation sedimentation tank to cause the colloidal particles and tiny suspended solids in the water to aggregate and settle, thereby being removed. The effluent from the coagulation sedimentation tank enters the first-stage biochemical treatment system for biochemical treatment, that is, the sewage passes through the anoxic tank and the aerobic tank in sequence, and denitrifying and nitrifying microorganisms are used to remove ammonia nitrogen, total nitrogen and organic matter in the water. The effluent from the aerobic tank passes through a bag filter to intercept larger suspended solids and particulate matters in the water, which is used before the ultrafiltration membrane equipment to protect the safety of the ultrafiltration membrane equipment. The effluent from the bag filter enters the tubular ultrafiltration membrane for filtration, and the intercepted sludge is refluxed to the first-stage biochemical treatment system section, so that the first-stage biochemical treatment system always maintains a high sludge concentration.

[0068] The effluent from the tubular ultrafiltration membrane enters the first-stage Fenton oxidation tower. The first-stage Fenton reaction uses advanced oxidation technology to oxidize and decompose the refractory organic matter in the sewage, mineralize some organic matter into carbon dioxide and water, and at the same time convert the macromolecular refractory organic pollutants into small-molecule substances. The effluent from the first-stage Fenton oxidation tower enters the neutralization sedimentation tank, and the water quality is made weakly alkaline by adding alkali, and then a flocculant is added to remove the precipitate generated by the Fenton reaction. The effluent from the first-stage Fenton treatment enters the second-stage Fenton treatment, repeating the operation of the first-stage Fenton to further remove the refractory organic matter in the water. At the same time, the biodegradability of the wastewater is improved through two-stage Fenton treatment.

[0069] The effluent from the neutralization sedimentation tank of the second-stage Fenton treatment enters the second-stage biochemical treatment system for re-biochemical treatment. The denitrifying / nitrifying bacteria are used again to degrade the organic matter, ammonia nitrogen and total nitrogen in the water, and the effluent passes through a bag filter and a tubular ultrafiltration membrane for filtration in sequence to reduce the SS concentration in the effluent. Finally, the effluent from the tubular ultrafiltration membrane enters the activated coke adsorption system, and the sewage passes through three-stage activated coke adsorption tanks in sequence to adsorb the residual organic matter in the water to ensure that the effluent meets the discharge standards.

[0070] The components in the landfill leachate are complex, there are many types of pollutants and its biodegradability is poor, and its color is mostly dark brown. It is one of the refractory wastewaters. It contains refractory substances such as humus and fatty acids, and the concentrations of organic pollutants, ammonia nitrogen and total nitrogen in it are high. Conventional treatment methods are difficult to completely remove it. Therefore, the present invention combines biochemical treatment technology, advanced oxidation technology and activated coke adsorption technology and applies them to the treatment of leachate. By fully quantifying the treatment of landfill leachate, the landfill leachate is discharged up to standard.

[0071] Coagulation sedimentation is a process in which chemical agents are added to cause the colloids and tiny suspended solids in water to aggregate and settle. Coagulation sedimentation includes two stages: coagulation and flocculation. In the coagulation stage, a coagulant is added to the sewage for aggregation, mainly referring to the process in which the colloids in water are destabilized and form tiny aggregates. Flocculation refers to the process in which a flocculant is added to cause the destabilized colloids or tiny suspended solids in water to aggregate into large flocs. The coagulation sedimentation method is commonly used as a pretreatment process to remove the fine suspended solids and colloidal particles in sewage, reduce the turbidity and chromaticity of water, and enhance the subsequent biochemical treatment effect. The coagulation sedimentation method is used to pretreat landfill leachate to reduce the turbidity and chromaticity of landfill leachate, and at the same time reduce the concentration of organic matter in water and the organic load of the subsequent treatment process.

[0072] The A / O method is an anoxic / aerobic treatment method. The sewage passes through the anoxic zone and the aerobic zone in sequence, and at the same time, the mixed liquor in the aerobic zone is refluxed to the anoxic zone. In the anoxic zone, through the action of facultative anaerobic denitrifying bacteria, taking the organic pollutants in the sewage as the electron donor and the nitrate nitrogen refluxed from the aerobic zone and the nitrate nitrogen originally in the sewage as the electron acceptor, the nitrate nitrogen in the sewage is reduced to nitrogen gas. At the same time, the heterotrophic bacteria also hydrolyze the soluble organic matter in the sewage into organic acids and decompose the nitrogen-containing organic matter to produce ammonia nitrogen, improving the biodegradability of the sewage. In the aerobic zone, under the condition of sufficient oxygen, the nitrification of aerobic autotrophic microorganisms converts ammonia nitrogen into nitrate nitrogen, and at the same time, the aerobic microorganisms further oxidize and degrade the organic pollutants. Through this zoned operation, the A / O process can simultaneously achieve the efficient degradation and removal of organic substances and pollutants such as nitrogen and phosphorus. Therefore, the first-stage biochemical treatment system process is used to degrade the biodegradable part of landfill leachate and reduce the concentrations of COD, ammonia nitrogen, and total nitrogen in landfill leachate.

[0073] Fenton method is an advanced oxidation technology. Under acidic conditions, H2O2 decomposes under the catalysis of Fe2+ to generate hydroxyl radicals with strong oxidation ability. It has extremely strong oxidation ability, can attack and degrade most organic substances without selectivity, its oxidation potential reaches 2.8V, and initiates a chain reaction to generate more other reactive oxygen species. They oxidize and decompose organic substances into small molecules or completely mineralize them into carbon dioxide and water through electron transfer and other pathways. At the same time, Fe2+ is oxidized to Fe3+ to produce coagulation precipitation. This oxidation process is a chain reaction, starting with hydroxyl radicals as the chain initiation, and other reactive oxygen species and reaction intermediates constitute the nodes of the chain. As the reaction progresses, each reactive oxygen species is consumed, ultimately leading to the termination of the reaction chain. Due to the high electronegativity and electrophilicity of hydroxyl radicals, with an electron affinity as high as 569.3 KJ, having very strong oxidation characteristics, the Fenton reaction can oxidize most organic substances in sewage without selectivity, and is particularly suitable for the treatment of organic wastewater that is difficult to biodegrade or ineffective for general chemical oxidation. Through two-stage Fenton reaction, the organic pollutants that are difficult to biodegrade in landfill leachate can be removed, and at the same time, some macromolecular pollutants can be converted into small molecular pollutants to improve the biodegradability of the sewage.

[0074] The secondary biochemical treatment system further treats the landfill leachate after Fenton treatment. Through anoxic and aerobic conditions, the concentrations of COD, ammonia nitrogen, and total nitrogen in the landfill leachate are further reduced.

[0075] Activated coke adsorption technology is a technology that can remove conventional pollutant indicators in water. It can not only remove components such as COD, ammonia nitrogen, and total nitrogen in water, but also has very good effects on decolorization and deodorization of sewage. Activated coke adsorption technology mainly removes pollutants through physical adsorption and chemical adsorption between activated coke and pollutant molecules. During the adsorption process, the force between activated coke molecules and pollutant molecules is van der Waals force (or electrostatic attraction), which is called physical adsorption; when the force between activated coke molecules and pollutant molecules is a chemical bond, it is called chemical adsorption. When pollutant molecules approach the surface of activated coke solid, physical adsorption occurs first. At this time, the pollutant molecules further approach the surface of activated coke solid. Due to the mutual repulsion of electron movement, the potential energy of pollutant molecules rises sharply; when the potential energy of pollutant molecules rises above its activation energy, chemical adsorption occurs. Activated coke adsorption is a process of intercepting pollutants in water, and the intercepted pollutants fill the pores, surfaces, and voids of activated coke. Activated coke adsorption technology has obvious removal effects on organic pollutants that are difficult to remove by conventional biochemistry and advanced oxidation. Therefore, a three-stage activated coke adsorption device is set at the end of the process to adsorb organic pollutants that are difficult to remove by both biochemistry and advanced oxidation to ensure that the effluent quality meets the discharge standards.

[0076] It should be noted that in this document, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or device comprising that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the reverse order according to the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0077] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Those of ordinary skill in the art, under the inspiration of the present application and without departing from the spirit and scope protected by the claims of the present application, can still make many forms, all of which fall within the protection scope of the present application.

Claims

1. A fully quantitative deep treatment system for landfill leachate, characterized in that: include: A coagulation sedimentation tank, a primary biochemical treatment system, an advanced oxidation unit, a secondary biochemical treatment system and an adsorption unit are connected in series in sequence, and a sludge separation system is connected to the coagulation sedimentation tank and the advanced oxidation unit. The primary biochemical treatment system and the secondary biochemical treatment system are used to degrade the biodegradable part in the landfill leachate and reduce the concentrations of COD, ammonia nitrogen and total nitrogen in the landfill leachate. The advanced oxidation unit is used to remove organic pollutants in the landfill leachate that are difficult to biodegrade, and at the same time convert some large molecular pollutants into small molecular pollutants to improve the biodegradability of sewage.

2. A fully quantitative deep treatment system for landfill leachate according to claim 1, characterized in that: The primary biochemical treatment system and the secondary biochemical treatment system both include: A biochemical treatment tank, bag filter and tubular ultrafilter connected in series; The biochemical treatment tank is provided with an anoxic tank connected to the coagulation sedimentation tank / advanced oxidation unit and an aerobic tank connected to the bag filter, and the other end of the tubular filter is connected to the advanced oxidation unit or the adsorption unit.

3. A fully quantitative deep treatment system for landfill leachate according to claim 2, characterized in that: The primary biochemical treatment system and the secondary biochemical treatment system both further include: A submersible mixer is arranged in the anoxic tank.

4. A fully quantitative deep treatment system for landfill leachate according to claim 2, characterized in that: The primary biochemical treatment system and the secondary biochemical treatment system both further include: Roots blower and aeration system are used to aerate the aerobic pool and control the dissolved oxygen in the aerobic pool to be greater than 2 mg / L.

5. The fully quantitative deep treatment system for landfill leachate according to claim 2 is characterized by: The sludge intercepted in the tubular ultrafilter flows back to the coagulation sedimentation tank through a pipeline.

6. The fully quantitative deep treatment system for landfill leachate according to claim 1 is characterized in that: The advanced oxidation unit comprises: A primary Fenton oxidation tower, a primary neutralization sedimentation tank, a primary Fenton oxidation tower and a secondary neutralization sedimentation tank are connected in series in sequence; Wherein, the primary neutralization sedimentation tank and the secondary neutralization sedimentation tank are both connected to the coagulation sedimentation tank through pipelines.

7. A fully quantitative deep treatment system for landfill leachate according to claim 6, characterized in that: The sludge separation device comprises: A sludge tank, which is connected to the coagulation sedimentation tank, the primary neutralization sedimentation tank and the secondary neutralization sedimentation tank through pipelines; The plate and frame filter press is used to dewater the sludge in the sludge tank, and the generated filtrate flows back to the coagulation sedimentation tank through a pipeline.

8. The fully quantitative deep treatment system for landfill leachate according to claim 1 is characterized in that: The adsorption unit comprises: A primary activated coke adsorption tank, a secondary activated coke adsorption tank and a tertiary activated coke adsorption tank are connected in series in sequence.

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