Full-scale separation treatment system and method for landfill leachate

Abstract

The application discloses a landfill leachate full-quantitative separation treatment system and method, and the system comprises a DTRO system, a seed pretreatment system, a sludge filter pressing system, a material separation membrane system, an evaporation system, a secondary RO system, a mother liquor solidification system and an electro-catalytic oxidation system. The main process of adopting the DTRO+material membrane+electro-catalytic oxidation+evaporator can realize full-quantity discharge up to the standard, especially for ammonia nitrogen and total nitrogen. The system is a pure physical and chemical process, has high stability, occupies small area and has low equipment energy consumption.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment technology, specifically to a system and method for the full-volume separation and treatment of landfill leachate. Background Technology

[0002] Landfill leachate is a black or yellowish-brown liquid with a foul odor. It contains large amounts of organic and inorganic matter, including various aromatic compounds and recalcitrant organic matter such as humic substances, as well as inorganic salts such as ammonium, carbonate, and sulfate. Due to the complex composition of landfill waste, the most prominent characteristic of landfill leachate is its high pollutant content and strong toxicity. The COD concentration can reach over 15,000 mg / L, containing benzene and its various derivatives, and ammonia nitrogen concentration can reach 7,000 mg / L. This wastewater containing toxic organic matter and high ammonia nitrogen presents significant challenges for its treatment, especially biological treatment. In addition to toxic aromatic compounds, leachate also contains large amounts of humic substances and humic acids, which are large molecular weight organic compounds. Although these organic compounds are not biologically toxic, their large molecular weight and excellent chemical stability make them difficult for microorganisms to effectively degrade. Therefore, traditional biological treatment methods are insufficient for the effective removal of COD from leachate.

[0003] In recent years, most aging landfills have implemented extensive volume reduction projects for leachate, almost all of which utilize disc tube reverse osmosis (DTRO) technology. However, the large-scale recirculation of membrane concentrate from these projects leads to the continuous accumulation of organic pollutants and inorganic salts, further deteriorating the leachate quality. The conductivity often exceeds 50 mS / cm, causing the biological system to collapse and become inoperable. Even the current mainstream "membrane system + evaporation system" for full-volume leachate treatment still largely suffers from the recirculation of ammonia nitrogen and low-boiling-point VOCs, resulting in their continuous accumulation and substandard effluent quality after prolonged operation. Furthermore, current full-volume leachate treatment technologies also suffer from excessive energy consumption. Summary of the Invention

[0004] In order to address the aforementioned deficiencies in the field, this application aims to provide a system and method for the full-volume separation and treatment of landfill leachate.

[0005] According to one aspect of this application, a landfill leachate full-volume separation and treatment system is provided, characterized in that it includes: a DTRO system, a seed crystal pretreatment system, a sludge dewatering system, a material separation membrane system, an evaporation system, a secondary RO system, a mother liquor solidification system, and an electrocatalytic oxidation system;

[0006] The DTRO system is connected to the seed crystal pretreatment system and the secondary RO system; the seed crystal pretreatment system is connected to the sludge dewatering system and the material separation membrane system; the material separation membrane system is connected to the evaporation system and the electrocatalytic oxidation system; the evaporation system is connected to the secondary RO system and the mother liquor solidification system; and the secondary RO system is connected to the electrocatalytic oxidation system.

[0007] The seed crystal pretreatment system includes: a dosing unit, a suspension unit, a sedimentation unit, an aeration unit, and a multi-media filter unit.

[0008] According to some embodiments of this application, the DTRO system includes: a high-pressure plunger-type inlet pump, a circulating booster pump, and a disc tube DTRO membrane module.

[0009] According to some embodiments of this application, the anode of the electrocatalytic oxidation system is one or a combination of several of the following: titanium-based ruthenium-iridium-tantalum-tin coated electrode plate, titanium-based ruthenium-iridium-tantalum coated electrode plate, and titanium-based ruthenium-iridium coated electrode plate; the cathode is one or a combination of several of the following: 304 stainless steel electrode plate, 316L stainless steel electrode plate, 2205 duplex stainless steel electrode plate, 2507 duplex stainless steel electrode plate, and titanium electrode plate.

[0010] According to some embodiments of this application, the distance between the anode and the cathode is 10-20 mm, and the operating current density is 200-500 A / m2.

[0011] According to some embodiments of this application, the evaporation system includes primary evaporation and secondary evaporation;

[0012] According to some embodiments of this application, the primary evaporation is falling film evaporation; the secondary evaporation is negative pressure forced circulation MVR.

[0013] According to some embodiments of this application, the dosing unit contains a pharmaceutical agent;

[0014] According to some embodiments of this application, the reagent includes: calcium sulfate seed crystals, calcium carbonate seed crystals, calcium hydroxide, sodium hydroxide, and sodium carbonate.

[0015] According to another aspect of this application, a method for the full-volume separation and treatment of landfill leachate using the above-described full-volume separation and treatment system is also provided, comprising:

[0016] The landfill leachate is fed into the DTRO system for concentration treatment to obtain first permeate and first concentrate.

[0017] The first concentrated water is sent to the seed crystal pretreatment system, where it is mixed and suspended with the reagent from the dosing unit in the suspension unit. After sufficient reaction, it enters the sedimentation unit to separate sludge and liquid. The sludge enters the sludge depressurization system, and the liquid is sequentially sent to the aeration unit and the multi-media filter unit for treatment to obtain the second permeate.

[0018] The second permeate is fed into the material separation membrane system to obtain the third permeate and the second concentrate.

[0019] The second concentrated water is fed into the evaporation system to obtain mother liquor and fourth product water;

[0020] The mother liquor is fed into the mother liquor solidification system;

[0021] The first permeate and the fourth permeate are mixed and fed into the secondary RO system to obtain the fifth permeate and the third concentrate.

[0022] The third concentrated water is mixed with the third product water and sent into the electrocatalytic oxidation system to obtain the sixth product water, which is then discharged together with the fifth product water.

[0023] According to some embodiments of this application, the reagent includes: calcium sulfate seed crystals, calcium carbonate seed crystals, calcium hydroxide, sodium hydroxide, and sodium carbonate;

[0024] According to some embodiments of this application, based on the volume of the first concentrated water, the dosage of the calcium sulfate seed crystals is 50-100 mg / L, the dosage of the calcium carbonate seed crystals is 50-100 mg / L, and the dosage of the sodium carbonate is 2-5 g / L; the dosage of the sodium hydroxide is to adjust the pH of the first concentrated water to 11.2-11.5.

[0025] According to some embodiments of this application, the mass ratio of the calcium hydroxide dosage to the bicarbonate in the first concentrated water is 1 to 0.8:1.

[0026] According to some embodiments of this application, the reagent further includes PAM 1-5 mg / L.

[0027] According to some embodiments of this application, the first concentrated water and the agent are mixed and suspended in the suspension unit for 10 to 20 minutes;

[0028] The upward flow velocity of the first concentrated water in the sedimentation unit is 3-5 m / h;

[0029] The aeration unit has an air-to-water ratio of 5 to 10:1 and a residence time of 30 to 60 minutes.

[0030] According to some embodiments of this application, the operating pressure of the material separation membrane system is 0.5-1.5 MPa.

[0031] According to some embodiments of this application, a curing agent is added to the mother liquor curing system;

[0032] According to some embodiments of this application, the curing agent component includes the following parts by weight: 0.15 to 0.20 parts of heavy metal stabilizer component, 0.10 to 0.17 parts of thickener component, 0.008 to 0.05 parts of alkaline activator component, and 0.08 to 0.10 parts of reinforcing curing agent.

[0033] According to some embodiments of this application, the solidified material after the mother liquor is solidified and the sludge from the sludge dewatering system are packaged in ton bags.

[0034] Compared with the prior art, this application has at least the following beneficial effects:

[0035] This application provides a comprehensive separation and treatment system for landfill leachate, including: a DTRO system, a seed crystal pretreatment system, a sludge dewatering system, a material separation membrane system, an evaporation system, a secondary RO system, a mother liquor solidification system, and an electrocatalytic oxidation system.

[0036] The DTRO system described in this application features a unique open flow channel and a fully turbulent flow design, making it more tolerant to SS and COD in the feed water than ordinary RO membranes. This significantly reduces fouling and scaling, common problems in reverse osmosis membrane modules. The DTRO system can withstand pressures up to 12 MPa, thus enabling it to directly treat high-concentration, high-salinity leachate from aging landfills.

[0037] The full-scale separation and treatment system of this application includes a seed crystal pretreatment system. Utilizing the fact that the seed crystal structure is similar to the scale, and the crystal surface has a high affinity for scale, sulfate ions, carbonate ions, and calcium ions in the DTRO membrane concentrate (i.e., concentrate) preferentially precipitate as calcium sulfate and calcium carbonate molecules, adhering to the suspended seed crystal surface. The reaction time is reduced by approximately 40% compared to conditions without seed crystals. Due to the reduced hydraulic retention time, the equipment size can also be reduced by approximately 40%. The seed crystal pretreatment system of this application can reduce the total hardness of the product water to below 100 mg / L, significantly reducing scaling in the downstream special material separation membrane system, evaporation system, and electrocatalytic oxidation system. The seed crystal pretreatment system of this application can achieve a COD removal rate of about 45%. The aeration unit also removes colloids, which alleviates the clogging of the downstream material separation membrane system caused by colloids. At the same time, it can strip and remove some VOCs and ammonia nitrogen. The removal of some ammonia nitrogen in the aeration unit reduces the processing pressure of the downstream system and provides a certain guarantee for the water quality of the final product. The product water from the aeration unit enters the multi-media filter to remove suspended particles that were not removed by the sedimentation unit.

[0038] In this application, the sludge and water mixture of the sedimentation unit of the seed crystal pretreatment system enters the sludge dewatering system, and the moisture content of the dewatered filter cake is <65%. The dewatering liquid is returned to the seed crystal pretreatment system.

[0039] The seed crystal pretreatment water enters the special material separation membrane system. The special material separation membrane operates at a pressure of 0.5-1.5 MPa and has a recovery rate of 50%-75%. The material separation membrane of this application has a COD rejection rate of >70%.

[0040] In this application, the permeate from the material separation membrane system enters the electrocatalytic oxidation system, while the concentrate enters the evaporation system. The material separation membrane effectively separates organic matter and salts from the seed crystal pretreatment permeate. Because the total organic matter content in the permeate is significantly reduced by the material separation membrane, especially since most large, recalcitrant organic molecules are retained by the membrane while maintaining the original inorganic salt concentration, the processing efficiency of the downstream electrocatalytic oxidation system can be greatly improved, thus significantly reducing the energy consumption of the electrocatalytic system. A small amount of concentrate enters the high-efficiency, energy-saving evaporator for treatment. Due to the drastically reduced treatment volume, the investment cost of the evaporator is saved, effectively reducing the energy consumption of the evaporation system. Furthermore, the material separation membrane system itself has very low energy consumption, making the combined process far more energy-efficient than using either electrocatalytic oxidation or a single evaporator process.

[0041] The electrocatalytic oxidation system of this application can degrade ammonia nitrogen, a capability not found in other advanced oxidation systems. Due to the reduction effect at the cathode, nitrate nitrogen can be degraded, allowing total nitrogen in water to be treated to meet discharge standards. Simultaneously, the electrocatalytic oxidation system of this application can treat the concentrate from a secondary RO membrane system, avoiding the accumulation of low-boiling-point VOCs and ammonia nitrogen caused by RO concentrate reflux in conventional processes.

[0042] The evaporation system of this application consists of two stages of evaporators. The first stage of evaporation uses falling film evaporation, which saves energy. The second stage of evaporation uses negative pressure forced circulation MVR, and the low-temperature flash evaporation operation avoids scaling problems caused by excessive hardness of the mother liquor. If the water volume to be treated is small, single-stage evaporation can also meet the overall system requirements. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of a landfill leachate full-volume separation and treatment system, which is an example embodiment of this application.

[0044] Figure 2 This is a comparison chart of the energy consumption per ton of water treated by electrocatalytic oxidation and evaporation in an example embodiment of this application. Detailed Implementation

[0045] The technical solution of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] It should be particularly noted that similar substitutions and modifications made to this application are obvious to those skilled in the art, and they are all considered to be included in this application. Those skilled in the art can obviously make modifications or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit, and scope of this application to implement and apply the technology of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0047] Unless otherwise specified, this application is conducted under standard conditions or conditions recommended by the manufacturer. The raw materials or excipients used, as well as the reagents or instruments used, whose manufacturers are not specified, are all conventional products that can be obtained commercially.

[0048] The following is a detailed description of this application.

[0049] The separation and processing system of this application includes a DTRO system, a seed crystal pretreatment system, a sludge dewatering system, a material separation membrane system, an evaporation system, a secondary RO system, a mother liquor solidification system, and an electrocatalytic oxidation system.

[0050] DTRO system: Landfill leachate is first concentrated using the DTRO system, with a water production rate >45%. The DTRO system consists of a high-pressure plunger-type inlet pump, a circulating booster pump, and a disc tube DTRO membrane module.

[0051] DTRO's unique open flow channel and fully turbulent flow design make it more tolerant to SS and COD in the feed water than ordinary RO membranes, which can greatly reduce fouling and scaling that are common in reverse osmosis membrane modules.

[0052] DTRO can withstand pressures of 12 MPa, so it can directly treat leachate from aging landfills with high concentrations and high salinity.

[0053] Seed Pretreatment System: DTRO membrane concentrate enters the seed pretreatment system, which consists of a dosing unit, a suspension unit, a sedimentation unit, an aeration unit, and a multi-media filter unit.

[0054] The DTRO membrane concentrate is first mixed with the reagents added in the dosing unit in the suspension unit and then suspended to allow for a full reaction. The added reagents are calcium sulfate seed crystals, calcium carbonate seed crystals, calcium hydroxide, sodium hydroxide, and sodium carbonate.

[0055] The dosage of calcium sulfate seed crystals is 50–100 mg / L, and the dosage of calcium carbonate seed crystals is 50–100 mg / L. The mass ratio of calcium hydroxide to bicarbonate in the DTRO membrane concentrate is 1–0.8:1. The remaining alkali is adjusted to pH 11.2–11.5 using sodium hydroxide to remove magnesium ions. The dosage of sodium carbonate is 2–5 g / L to remove residual calcium ions. Finally, 1–5 mg / L of PAM is added.

[0056] After mixing, the solution enters the precipitation unit. The residence time of the DTRO membrane concentrate in the suspension unit is 10–20 min.

[0057] After the reaction is complete, the DTRO membrane concentrate enters the sedimentation unit for sludge-water separation. The sludge enters the sludge dewatering system, and the permeate enters the aeration unit. The upward flow velocity of the DTRO membrane concentrate in the sedimentation unit is 3-5 m / h.

[0058] The air-to-water ratio of the aeration unit is 5–10:1, and the residence time is 30–60 min. Aeration removes colloids from the DTRO membrane concentrate, preventing clogging of the downstream material separation membrane system due to colloid fouling; it can also remove some VOCs and ammonia nitrogen by stripping.

[0059] The water produced by the aeration unit enters the multi-media filter to remove suspended particles that were not removed by the sedimentation unit.

[0060] The seed crystal pretreatment system utilizes the fact that the seed crystal structure is the same as the scale, and the crystal surface has a greater affinity for the scale. This causes sulfate ions, carbonate ions, and calcium ions in the DTRO membrane concentrate to preferentially precipitate and adhere to the suspended seed crystal surface in the form of calcium sulfate molecules and calcium carbonate molecules. The reaction time is about 40% shorter than under conditions without seed crystals. Due to the reduction in hydraulic retention time, the equipment size can also be reduced by about 40%.

[0061] The seed crystal pretreatment system can reduce the total hardness of DTRO membrane concentrate to below 100 mg / L, greatly reducing scaling in downstream special material separation membrane systems, evaporation systems, and electrocatalytic oxidation systems.

[0062] The seed crystal pretreatment system can remove COD at a rate of about 45%, while the aeration unit removes colloids at the same time, alleviating the clogging of the downstream material separation membrane system. The aeration unit also removes some ammonia nitrogen, reducing the processing pressure on the downstream system and providing a certain guarantee for the quality of the final produced water.

[0063] Sludge dewatering system: The sludge and water from the sedimentation unit of the seed crystal pretreatment system are mixed and enter the sludge dewatering system. The moisture content of the filter cake obtained by pressing is <65%, and the filtrate is returned to the seed crystal pretreatment system.

[0064] Material separation membrane system: The pretreated water from the seed crystal process enters the special material separation membrane system. The special material separation membrane operates at a pressure of 0.5-1.5 MPa, with a recovery rate of 50%-75%, and a COD rejection rate of >70%.

[0065] The permeate from the material separation membrane enters the electrocatalytic oxidation system, while the concentrate enters the evaporation system. The material separation membrane effectively separates organic matter and salts from the seed crystal pretreatment permeate. Because the total organic matter content in the permeate is significantly reduced, especially since most large, recalcitrant organic molecules are retained by the membrane while maintaining the original inorganic salt concentration, the processing efficiency of the downstream electrocatalytic oxidation system can be greatly improved, thus significantly reducing the energy consumption of the electrocatalytic system. A small amount of concentrate enters a high-efficiency, energy-saving evaporator. Due to the drastically reduced water volume, the investment cost of the evaporator is saved, effectively reducing the energy consumption of the evaporation system. Furthermore, the material separation membrane system itself has very low energy consumption; therefore, the combined process has a much lower energy consumption than using either electrocatalytic oxidation or a single evaporator process.

[0066] Electrocatalytic oxidation system: Permeate from the material separation membrane enters the electrocatalytic oxidation system. The anode used in the electrocatalytic oxidation system is one or a combination of several of the following: titanium-based ruthenium-iridium-tantalum-tin coated electrode, titanium-based ruthenium-iridium-tantalum coated electrode, and titanium-based ruthenium-iridium coated electrode. The cathode is one or a combination of several of the following: 304 stainless steel electrode, 316L stainless steel electrode, 2205 duplex stainless steel electrode, 2507 duplex stainless steel electrode, and titanium electrode. The anode and cathode distance is 10-20 mm, and the operating current density is 200-500 A / m. 2 .

[0067] Electrocatalytic oxidation can degrade ammonia nitrogen, which is not possible with other advanced oxidation processes.

[0068] Because the reduction effect of the cathode can degrade nitrate nitrogen, the total nitrogen in the water can be treated to meet the discharge standards.

[0069] Electrocatalytic oxidation can treat the concentrate of a two-stage RO membrane system, avoiding the problems of low-boiling-point VOCs and ammonia nitrogen enrichment caused by the reflux of RO concentrate in conventional processes.

[0070] Evaporation system: Composed of two-stage evaporators. The first stage uses falling film evaporation, which saves energy. The second stage uses negative pressure forced circulation MVR, and the low-temperature flash evaporation operation avoids scaling problems caused by excessive hardness of the mother liquor. When the water volume to be treated is small, single-stage evaporation can also meet the overall system requirements.

[0071] Mother liquor solidification: The mother liquor produced by the evaporation system enters the mother liquor solidification system. The solidifying agent used in the mother liquor solidification system consists of the following components by weight: 0.15–0.20 parts heavy metal stabilizer, 0.10–0.17 parts thickener, 0.008–0.05 parts alkaline activator, and 0.08–0.10 parts strengthening solidifying agent. The solidified material after mother liquor solidification is packaged in ton bags with the sludge dewatering system.

[0072] Secondary RO membrane system: Permeate from the DTRO membrane system is mixed with condensate from the evaporation system and enters the secondary RO membrane system to ensure permeate quality. The permeate is then mixed with electrocatalytic permeate and discharged after meeting standards. The concentrate from the secondary RO membrane system enters the electrocatalytic oxidation system for further treatment.

[0073] The present application will now be described in detail with reference to specific embodiments.

[0074] Example

[0075] This embodiment adopts Figure 1 The system shown here treats leachate from an old landfill. The steps today are as follows:

[0076] (1) The landfill leachate is sent to the DTRO system for concentration treatment to obtain the first permeate and the first concentrate;

[0077] (2) The first concentrated water is sent into the seed crystal pretreatment system for treatment to obtain the second product water;

[0078] (3) The second product water is fed into the material separation membrane system to obtain the third product water and the second concentrate;

[0079] (4) The second concentrated water is fed into the evaporation system to obtain mother liquor and fourth product water; the mother liquor is fed into the mother liquor solidification system;

[0080] (5) The first permeate and the fourth permeate are mixed and sent into the secondary RO system to obtain the fifth permeate and the third concentrate;

[0081] (6) The third concentrated water and the third product water are mixed and sent into the electrocatalytic oxidation system to obtain the sixth product water and the fifth product water, which are then discharged together.

[0082] The specific processing results are shown in the table below:

[0083]

[0084]

[0085] Comparative Example 1

[0086] The comparative treatment of leachate from an aged landfill follows these steps:

[0087] (1) The landfill leachate is sent to the DTRO system for concentration treatment to obtain the first permeate and the first concentrate;

[0088] (2) The first concentrated water is sent into the seed crystal pretreatment system for treatment to obtain the second product water;

[0089] (3) The second product water is fed into the evaporation system to obtain mother liquor and third product water; the mother liquor is fed into the mother liquor solidification system;

[0090] (5) The first permeate and the third permeate are mixed and sent into the secondary RO system to obtain the fourth permeate and the second concentrate.

[0091] (6) The second concentrated water is sent into the evaporation system, treated, and then discharged.

[0092] Comparative Example 2

[0093] The comparative treatment of leachate from an aged landfill follows these steps:

[0094] (1) The landfill leachate is sent to the DTRO system for concentration treatment to obtain the first permeate and the first concentrate;

[0095] (2) The first concentrated water is sent into the seed crystal pretreatment system for treatment to obtain the second product water;

[0096] (3) The second product water is fed into the electrocatalytic oxidation system to obtain mother liquor and third product water; the mother liquor is fed into the mother liquor solidification system;

[0097] (5) The first permeate and the third permeate are mixed and sent into the secondary RO system to obtain the fourth permeate and the second concentrate.

[0098] (6) The second concentrated water is sent into the electrocatalytic oxidation system, treated, and then discharged.

[0099] After treating the above-mentioned landfill leachate, the energy consumption per ton of water treated in Example 1 and Comparative Examples 1 and 2 were calculated respectively, and the results are as follows: Figure 2 As shown, the landfill leachate full-volume separation and treatment system of this application, which employs a material membrane + electrocatalytic oxidation + evaporator separation process, can reduce energy consumption by 56% compared to using electrocatalytic oxidation alone, and by 17.9% compared to using an evaporator alone.

[0100] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of this application. It should be noted that, for those skilled in the art, several improvements and modifications can be made to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A comprehensive separation and treatment system for landfill leachate, characterized in that, include: DTRO system, seed crystal pretreatment system, sludge depressurization system, material separation membrane system, evaporation system, secondary RO system, mother liquor solidification system, and electrocatalytic oxidation system; The concentrate outlet of the DTRO system is connected to the seed crystal pretreatment system; the permeate outlet of the DTRO system is connected to the secondary RO system; the sludge-water mixture outlet of the seed crystal pretreatment system is connected to the sludge dewatering system; the permeate outlet of the seed crystal pretreatment system is connected to the material separation membrane system; the concentrate outlet of the material separation membrane system is connected to the evaporation system; the permeate outlet of the material separation membrane system is connected to the electrocatalytic oxidation system; the permeate outlet of the evaporation system is connected to the secondary RO system; and the mother liquor outlet of the evaporation system is connected to the mother liquor solidification system. The concentrate outlet of the secondary RO system is connected to the electrocatalytic oxidation system. The DTRO system includes: a high-pressure plunger-type inlet pump, a circulating booster pump, and a disc tube DTRO membrane module. The DTRO system features an open flow channel and turbulent flow design.

2. The landfill leachate full-volume separation and treatment system according to claim 1, characterized in that, The seed crystal pretreatment system includes: a dosing unit, a suspension unit, a sedimentation unit, an aeration unit, and a multi-media filter unit.

3. The landfill leachate full-volume separation and treatment system according to claim 1, characterized in that, The anode of the electrocatalytic oxidation system is one or a combination of several of the following: titanium-based ruthenium-iridium-tantalum-tin coated electrode plate, titanium-based ruthenium-iridium-tantalum coated electrode plate, and titanium-based ruthenium-iridium coated electrode plate; the cathode is one or a combination of several of the following: 304 stainless steel electrode plate, 316L stainless steel electrode plate, 2205 duplex stainless steel electrode plate, 2507 duplex stainless steel electrode plate, and titanium electrode plate.

4. The landfill leachate full-volume separation and treatment system according to claim 3, characterized in that, The distance between the anode and the cathode is 10-20 mm, and the operating current density is 200-500 A / m. 2 .

5. The landfill leachate full-volume separation and treatment system according to claim 1, characterized in that, The evaporation system includes primary evaporation and secondary evaporation.

6. The landfill leachate full-volume separation and treatment system according to claim 5, characterized in that, The first-stage evaporation is falling film evaporation; the second-stage evaporation is negative pressure forced circulation MVR.

7. The landfill leachate full-volume separation and treatment system according to claim 2, characterized in that, The dosing unit contains a drug.

8. The landfill leachate full-volume separation and treatment system according to claim 7, characterized in that, The reagents include: calcium sulfate seed crystals, calcium carbonate seed crystals, calcium hydroxide, sodium hydroxide, and sodium carbonate.

9. A method for the full-volume separation and treatment of landfill leachate using the full-volume separation and treatment system described in any one of claims 1-8, characterized in that, include: The landfill leachate is fed into the DTRO system for concentration treatment to obtain first permeate and first concentrate. The first concentrated water is sent to the seed crystal pretreatment system, where it is mixed and suspended with the reagent from the dosing unit in the suspension unit. After sufficient reaction, it enters the sedimentation unit to separate sludge and liquid. The sludge enters the sludge depressurization system, and the liquid is sequentially sent to the aeration unit and the multi-media filter unit for treatment to obtain the second permeate. The second permeate is fed into the material separation membrane system to obtain the third permeate and the second concentrate. The second concentrated water is fed into the evaporation system to obtain mother liquor and fourth product water; The mother liquor is fed into the mother liquor solidification system; The first permeate and the fourth permeate are mixed and fed into the secondary RO system to obtain the fifth permeate and the third concentrate. as well as The third concentrated water is mixed with the third product water and sent into the electrocatalytic oxidation system to obtain the sixth product water, which is then discharged together with the fifth product water.

10. The full-scale separation processing method according to claim 9, characterized in that, The reagents include: calcium sulfate seed crystals, calcium carbonate seed crystals, calcium hydroxide, sodium hydroxide, and sodium carbonate.

11. The full-scale separation processing method according to claim 10, characterized in that, Based on the volume of the first concentrated water, the dosage of the calcium sulfate seed crystals is 50-100 mg / L, the dosage of the calcium carbonate seed crystals is 50-100 mg / L, and the dosage of the sodium carbonate is 2-5 g / L; the dosage of the sodium hydroxide is used to adjust the pH of the first concentrated water to 11.2-11.

5.

12. The full-scale separation processing method according to claim 10, characterized in that, The mass ratio of the calcium hydroxide dosage to the bicarbonate in the first concentrated water is 1~0.8:

1.

13. The full-scale separation processing method according to claim 10, characterized in that, The drug also includes PAM 1~5mg / L.

14. The full-scale separation processing method according to claim 9, characterized in that, The first concentrated water and the drug are mixed and suspended in the suspension unit for 10-20 minutes; The upward flow velocity of the first concentrated water in the sedimentation unit is 3~5m / h; The aeration unit has an air-to-water ratio of 5-10:1 and a residence time of 30-60 minutes.

15. The full-scale separation processing method according to claim 9, characterized in that, The operating pressure of the material separation membrane system is 0.5-1.5 MPa.

16. The full-scale separation processing method according to claim 9, characterized in that, A curing agent is added to the mother liquor curing system.

17. The full-scale separation processing method according to claim 16, characterized in that, The curing agent components include the following parts by weight: 0.15~0.20 parts of heavy metal stabilizer, 0.10~0.17 parts of thickener, 0.008~0.05 parts of alkaline activator, and 0.08~0.10 parts of reinforcing curing agent.

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