Natural evaporation enhanced treatment system and treatment method for landfill leachate

Abstract

The invention discloses a landfill leachate natural evaporation enhanced treatment system and a treatment method, and belongs to the technical field of garbage treatment. The system is suitable for landfill leachate treatment in areas with high evaporation capacity and small leachate yield, and the problem that landfill leachate treatment cost in remote areas is high is solved; the system specifically comprises a leachate adjusting tank, an evaporation intensifying device, an air purifying device, a biochemical treatment unit and a sludge drying tank, wherein the leachate adjusting tank is connected with the evaporation intensifying device; the evaporation intensifying device is connected with the sludge drying tank; the evaporation strengthening device is connected with the air purification device; the bottom of the air purifier is connected with the biochemical treatment unit through a condensate pipe. According to the invention, the evaporation intensifying device accelerates the evaporation of water in the landfill leachate, the evaporated steam is discharged after being purified by the air purifying device, and the generated condensed water is sent to the biochemical treatment unit for treatment, so that the separation and treatment of sludge, waste gas and wastewater in the landfill leachate are realized; the process is simple and the operation cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of garbage treatment, and in particular to a natural evaporation enhanced treatment system and method for garbage leachate. Background Art

[0002] With the development of cities and the improvement of people's quality of life, more and more domestic waste is generated in daily life. Domestic waste mainly includes kitchen waste, recyclable waste, hazardous waste and other waste; if these wastes are not properly handled, they will cause serious pollution to the environment and affect people's health. Landfills are waste treatment sites used to treat domestic waste. When landfills treat garbage, they will produce leachate, which is a high-concentration organic wastewater. It contains moisture carried by the garbage itself, moisture produced by the anaerobic decomposition of organic components in the garbage by microorganisms in the landfill, and moisture such as precipitation and external surface water; therefore, the composition of leachate is relatively complex, and the treatment of leachate is very important.

[0003] At present, the existing technologies for treating landfill leachate mainly include evaporation treatment, biological oxidation treatment, advanced chemical oxidation treatment, reverse osmosis treatment, etc. These processes are mature and reliable, and the leachate treatment effect is obvious. However, the cost of treating landfill leachate is relatively high, and it is suitable for large landfills, but it is not economical for some landfills with small leachate production, such as closed landfills. In some areas, re-injection or natural evaporation processes are usually used to treat landfill leachate. This treatment method does not treat landfill leachate thoroughly, has a long treatment cycle, and has prominent environmental pollution risks. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a natural evaporation enhanced treatment system for landfill leachate, which can reduce the landfill leachate treatment cost in areas with high evaporation and low leachate production, and solve the problem of high landfill leachate treatment cost in remote areas.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A natural evaporation enhanced treatment system for landfill leachate comprises a leachate regulating tank, an evaporation enhanced device, an air purification device, a biochemical treatment unit and a sludge drying tank, wherein the leachate regulating tank is connected to the evaporation enhanced device through a leachate inlet pipe; the bottom of the evaporation enhanced device is connected to the sludge drying tank through a sludge pipe; the top of the evaporation enhanced device is connected to the air purification device through an air outlet pipe; and the bottom of the air purification device is connected to the biochemical treatment unit through a condensed water pipe.

[0006] In this scheme, the landfill leachate in the leachate regulating tank enters the evaporation enhancement device, which accelerates the evaporation of water in the landfill leachate, and the sludge produced after evaporation is sent to the sludge drying tank for drying; the evaporated steam is purified by the air purification device and then discharged, and the condensed water produced during the purification is sent to the biochemical treatment unit for treatment, thereby realizing the separation of sludge, waste gas and wastewater in the landfill leachate, and the waste gas and wastewater are treated and discharged separately; the landfill leachate is treated thoroughly, avoiding the hidden danger of environmental pollution, and the process is simple, the operating cost is low, and the maintenance and management are convenient.

[0007] Furthermore, the evaporation enhancement device includes a spray tower, the leachate inlet pipe is connected to the water inlet pipe of the spray tower, and a plurality of spray heads are arranged on the water inlet pipe located inside the spray tower; the top of the spray head is a gas-liquid separation zone, and the bottom of the spray head is filled with a water spray filler; a hot air pipe is connected to the side wall of the spray tower at the bottom of the water spray filler, and a hot air device is connected to the end of the hot air pipe away from the spray tower; The bottom of the spray tower is connected to a concentrate collecting tank, and the bottom of the concentrate collecting tank is a sludge collecting chamber; the bottom of the sludge collecting chamber is connected to a sludge drying tank through a sludge pipe, and the top of the sludge drying tank is connected to an air inlet pipe of a hot air device through an exhaust pipe.

[0008] In this scheme, the landfill leachate sent to the spray tower is sprayed out from the spray head, and after spraying, it is fully contacted with the hot air provided by the hot air device; the spray tower is filled with water filling, which can increase the contact area between the landfill leachate and the hot air, improve the evaporation efficiency, and can also buffer and disperse the landfill leachate so that it is evenly distributed in the spray tower. The sprayed landfill leachate is heated by the rising hot air in the spray tower, which can enhance the evaporation of water in the landfill leachate and avoid the pipeline blockage problem caused by direct heating of the landfill leachate. The role of the gas-liquid separation zone is to use the inertial collision separation principle to block the larger droplets in the steam, so that they are collected in the gas-liquid separation zone and then flow back to the concentrated liquid collection tank. The exhaust pipe is connected to the air inlet pipe of the hot air device to form a negative pressure inside the sludge drying tank and draw the odor inside the sludge drying tank into the spray tower for treatment.

[0009] Furthermore, it also includes a concentrate circulation pool, which is connected to the overflow hole at the top of the concentrate collecting tank through a concentrate reflux pipe; a concentrate circulation pump is arranged in the concentrate circulation pool, the concentrate circulation pump is connected to one end of the concentrate circulation pipe, and the other end of the concentrate circulation pipe is connected to the leachate inlet pipe.

[0010] In this scheme, the landfill leachate in the concentrate collection tank flows into the concentrate circulation pool by overflow, and the concentrate circulation pump in the concentrate circulation pool sends it to the concentrate circulation pipe, and then sends it to the spray tower again through the concentrate circulation pipe for circulation evaporation; this design can ensure that all the landfill leachate can be fully evaporated, and the treatment of the landfill leachate is more thorough.

[0011] Furthermore, the air purification device includes a purification tower, the air outlet pipe is connected to the air inlet pipe of the purification tower, and the air inlet pipe is located inside the purification tower and has a plurality of air outlets on the pipe body; above the air outlets are an air condensation area and a biological filler area in sequence; the top of the biological filler area is provided with an air discharge port; A condensate collection tank is provided at the bottom of the purification tower, and the condensate collection tank is connected to the biochemical treatment unit through a condensate pipe.

[0012] In this scheme, after the steam enters the purification tower, the air condensation area cools the steam, and the cooled condensed water is collected in the condensed water collection tank; while the odorous gas is biologically oxidized through the biological filler area to eliminate odorous substances and achieve standard emissions.

[0013] Furthermore, a plurality of condensation tubes are transversely arranged inside the air condensation zone; and the biological filler zone is filled with biological ceramsite filler.

[0014] In this scheme, the surface of the bioceramsite filler provides a place for microorganisms to attach and grow, forming a biofilm. The microorganisms use organic pollutants in the air as a carbon source and energy source to decompose organic pollutants in the gas into carbon dioxide, water and other harmless substances, so that the gas meets the emission standards.

[0015] Furthermore, the biochemical treatment unit is an A / O tank, an oxidation ditch or an ecological wetland.

[0016] Furthermore, sun sheds are provided on the tops of the leachate regulating tank, the sludge drying tank and the concentrate circulation tank.

[0017] In this solution, the sun shed can accelerate the natural drying process of the landfill leachate while preventing rainwater from entering.

[0018] In a second aspect, the present invention provides a method for enhancing the natural evaporation of landfill leachate based on the natural evaporation enhanced treatment system for landfill leachate provided in the first aspect, comprising the following steps: S1: Regulate the pH of the landfill leachate in the leachate regulating tank; and send the landfill leachate into the evaporation enhancement device through the leachate inlet pipe; S2: The evaporation enhancement device evaporates the landfill leachate, and the evaporated steam is sent to the air purification device through the air outlet pipe; the excess landfill leachate and sludge after evaporation fall into the concentrated liquid collection tank and the sludge collection chamber respectively; S3: The landfill leachate in the concentrate collection tank flows into the concentrate return pipe in an overflow manner, flows back to the concentrate circulation pool through the concentrate return pipe, and then is sent to the leachate inlet pipe through the concentrate circulation pipe. The landfill leachate following the leachate inlet pipe enters the evaporation enhancement device for evaporation again; S4: The air purification device purifies the steam, and the clean gas after purification is directly discharged. The condensed water generated during purification is sent to the biochemical treatment unit through the condensed water pipe; S5: The biochemical treatment unit treats the condensed water.

[0019] In this scheme, the landfill leachate is first evaporated using an evaporation enhancement device to separate the steam and sludge precipitation, and then the steam obtained after evaporation is purified, and the purified air meets the emission standards; the landfill leachate treatment method has simple steps, low implementation cost, and high treatment efficiency.

[0020] Furthermore, S2 includes: S201: The garbage leachate enters the spray tower from the water inlet pipe and is sprayed out from the spray head on the water inlet pipe; the hot air device transports hot air to the bottom of the spray head through the hot air pipe; S202: the landfill leachate sprayed from the spray head is fully contacted with the hot air in the water spraying filler, and the hot air heats and evaporates the landfill leachate; S203: The steam generated after heating in the spray tower rises with the hot air to reach the gas-liquid separation zone, and the liquid droplets carried in the steam are separated in the gas-liquid separation zone; the steam continues to rise and enters the air purification device from the air outlet pipe; S204: the excess landfill leachate after evaporation in the spray tower falls into a concentrated liquid collection tank; S205: The sludge generated after evaporation in the spray tower is deposited in the sludge collection chamber and transported to the sludge drying tank through the sludge pipe.

[0021] Furthermore, S4 includes: S401: The steam in the spray tower enters the air inlet pipe through the air outlet pipe, and enters the purification tower from the air outlet of the air inlet pipe; S402: After the steam in the purification tower rises to the air condensation area, the condensed water generated by the cooling of the water in the steam falls into the condensed water collection tank; S403: The gas in the steam in the purification tower continues to rise, and after rising to the biological filler area, it is purified by the biological ceramsite filler in the biological filler area, and is discharged through the air discharge port after purification.

[0022] The beneficial effects of the present invention are: In the natural evaporation enhanced treatment system for landfill leachate provided by the present invention, a water spray filler is designed inside the evaporation enhancement device, and the landfill leachate is fully contacted with the rising hot air after being sprayed from the spray head, accelerating the evaporation of water in the landfill leachate; a gas-liquid separation zone is designed on the top of the water spray filler, and when the steam passes through the gas-liquid separation zone, the larger droplets inside are blocked due to inertia, so that the droplets flow back to the concentrated liquid collection tank, and the droplets are prevented from following the hot air into the air purification device. The concentrated liquid collection tank is connected to the concentrated liquid circulation tank through a concentrated liquid reflux pipe, and the excess landfill leachate that has not been evaporated inside the spray tower can flow back to the concentrated liquid circulation tank, and then be sent to the spray tower again through the concentrated liquid circulation pipe for circulation evaporation, thereby ensuring the sufficient evaporation of the landfill leachate.

[0023] The natural evaporation enhanced treatment method for landfill leachate provided by the invention has simple process and low operation cost, and is suitable for the natural evaporation enhanced treatment of landfill leachate in areas with high evaporation amount and small leachate output. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a schematic diagram of the structure of a natural evaporation enhanced treatment system for landfill leachate.

[0025] Reference numerals: 1. Leachate regulating tank; 2. Evaporation enhancement device; 21. Gas-liquid separation area; 22. Sprinkler head; 23. Water spraying filler; 24. Hot air device; 25. Sludge collection chamber; 26. Concentrate collection tank; 3. Air purification device; 31. Air discharge port; 32. Air condensation area; 33. Biological filler area; 34. Condensate collection tank; 4. Biochemical treatment unit; 5. Sludge drying tank; 6. Concentrate circulation tank; 71. Leachate inlet pipe; 72. Air outlet pipe; 73. Sludge pipe; 74. Condensate pipe; 75. Concentrate reflux pipe; 76. Concentrate circulation pipe; 77. Air extraction pipe; 8. Sun shed; DETAILED DESCRIPTION The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. The specific implementation of the present invention is described below to facilitate the understanding of the present invention by those skilled in the art, but it should be clear that the present invention is not limited to the scope of the specific implementation. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

[0026] Example 1 like Figure 1 As shown, this embodiment provides a natural evaporation enhanced treatment system for landfill leachate, which can separate sludge precipitation, waste gas and waste water in the landfill leachate, and then purify the waste gas and waste water respectively; it specifically includes: leachate regulating tank 1, evaporation enhancement device 2, air purification device 3, biochemical treatment unit 4, sludge drying tank 5 and concentrated liquid circulation tank 6; The leachate regulating tank 1 is connected to the evaporation enhancement device 2 through the leachate inlet pipe 71, and the garbage leachate in the leachate regulating tank 1 can flow into the evaporation enhancement device 2 through the leachate inlet pipe 71. The evaporation enhancement device 2 is used to accelerate the evaporation of water in the garbage leachate. The bottom of the evaporation enhancement device 2 is connected to the concentrated liquid circulation tank 6 through the concentrated liquid return pipe 75; the bottom of the evaporation enhancement device 2 is connected to the sludge drying tank 5 through the sludge pipe 73, and the evaporated sludge is sent to the sludge drying tank 5 for drying; the top of the evaporation enhancement device 2 is connected to the air purification device 3 through the air outlet pipe 72, and the evaporated steam is sent to the air purification device 3 through the air outlet pipe 72 for purification. The bottom of the air purification device 3 is connected to the biochemical treatment unit 4 through the condensed water pipe 74, and the condensed water generated during purification can be sent to the biochemical treatment unit 4 through the condensed water pipe 74 for treatment.

[0027] The evaporation enhancement device 2 includes a spray tower, a spray head 22, a water spray filler 23, a hot air device 24, a concentrate collection tank 26 and a sludge collection chamber 25; the leachate inlet pipe 71 is connected to the water inlet pipe of the spray tower, and the water inlet pipe is located on the pipe body inside the spray tower and is provided with a plurality of spray heads 22, and the garbage leachate sent to the spray tower is sprayed out from the spray head 22; the top of the spray head 22 is a gas-liquid separation zone 21, and the bottom of the spray head 22 is filled with a water spray filler 23; a hot air pipe is connected to the side wall of the spray tower located at the bottom of the water spray filler 23, and a hot air device 24 is connected to the end of the hot air pipe away from the spray tower; the hot air device 24 is used to provide hot air into the spray tower, and the hot air heats the garbage leachate sprayed from the spray head 22 during the rising process to evaporate it.

[0028] In this embodiment, the hot air device 24 is preferably a hot air blower, which can be powered by the power grid or a solar panel. The hot air pipe is preferably an aluminum alloy pipe with a rectangular cross section, and a heat-absorbing coating is applied around the hot air pipe, such as SS-WL80 dark blue nano tungsten oxide, to improve the heat absorption efficiency; the heat-absorbing coating absorbs solar energy to generate heat and transfers it to the aluminum alloy pipe to assist in heating the air inside the pipe body.

[0029] In this embodiment, the water spray filler 23 can be selected from multi-faceted hollow balls or corrugated plates made of ceramic material or high-temperature resistant plastic material; the multi-faceted hollow balls or corrugated plates can increase the contact area between the leachate and the hot air, improve the evaporation efficiency, and can also buffer and disperse the leachate so that it is evenly distributed in the spray tower.

[0030] In this embodiment, a plurality of baffles are provided in the gas-liquid separation zone 21 , and the baffles are used to block larger liquid droplets in the steam so that they are collected in the gas-liquid separation zone 21 and flow back to the concentrated liquid collection tank 26 .

[0031] The bottom of the spray tower is connected to a concentrate collecting tank 26, and a concentrate circulation tank 6 is connected to the overflow hole at the top of the concentrate collecting tank 26 through a concentrate return pipe 75; a concentrate circulation pump is provided in the concentrate circulation tank 6, and the concentrate circulation pump is connected to one end of the concentrate circulation pipe 76, and the other end of the concentrate circulation pipe 76 is connected to the leachate inlet pipe 71; the bottom of the concentrate collecting tank 26 is a sludge collection chamber 25. In this embodiment, the concentrate collecting tank 26 and the sludge collection chamber 25 can be an integrated design, and the sludge generated during the evaporation process is deposited in the sludge collection chamber 25 at the bottom, and the excess garbage leachate that is not evaporated is collected at the top of the sludge. When the liquid level of the excess garbage leachate reaches the overflow hole position, it flows out from the overflow hole and flows into the concentrate circulation tank 6 through the concentrate return pipe 75.

[0032] The bottom of the sludge collection chamber 25 is connected to the sludge drying tank 5 through the sludge pipe 73, and a valve and a sludge pump can be set on the sludge pipe 73; the sludge in the sludge collection chamber 25 enters the sludge drying tank 5 through the sludge pipe 73; the top of the sludge drying tank 5 is connected to the air inlet pipe of the hot air blower through the exhaust pipe 77, so as to form a negative pressure inside the sludge drying tank and draw the odor inside the sludge drying tank into the spray tower for treatment.

[0033] The air purification device 3 includes a purification tower, an air condensation area 32, a biological filler area 33, an air discharge port 31 and a condensed water collection tank 34; the air outlet pipe 72 is connected to the air inlet pipe of the purification tower, and the air inlet pipe is located in the purification tower. The pipe body has multiple air outlets; the air condensation area 32 and the biological filler area 33 are arranged above the air outlet; the air discharge port 31 is arranged at the top of the biological filler area 33; the condensed water collection tank 34 is arranged at the bottom of the purification tower, and the condensed water collection tank is connected to the biochemical treatment unit 4 through the condensed water pipe 74. After the steam enters the purification tower, the air condensation area 32 cools the steam, and the cooled condensed water is collected in the condensed water collection tank 34; and the gas carrying the odor is biologically oxidized through the biological filler area 33 to eliminate the odorous substances and achieve standard emission.

[0034] A plurality of condensing pipes connected end to end are arranged transversely inside the air condensation area 32, and the two ends of the condensing pipes can be connected to circulating cooling water. The biological filler area 33 is filled with biological ceramsite filler; the surface of the biological ceramsite filler provides a place for microorganisms to attach and grow, forming a biofilm. The microorganisms use organic pollutants in the air as carbon sources and energy sources, and decompose organic pollutants in the gas into carbon dioxide, water and other harmless substances, so that the gas meets the emission standards.

[0035] The biochemical treatment unit 4 uses a biological oxidation process to treat the condensed water, mainly to remove low-concentration ammonia nitrogen and COD; therefore, the biochemical treatment unit 4 can be an A / O pool, an oxidation ditch or an ecological wetland.

[0036] The tops of the leachate regulating tank 1, the sludge drying tank 5 and the concentrated liquid circulation tank 6 are all provided with sun sheds 8, which can accelerate the natural drying process of the garbage leachate and prevent rainwater from entering.

[0037] Example 2 This embodiment provides a method for enhancing the natural evaporation of landfill leachate based on the natural evaporation enhanced treatment system of landfill leachate provided in Embodiment 1, comprising the following steps: S1: Regulate the pH of the landfill leachate in the leachate regulating tank 1 so that the landfill leachate is in a weakly alkaline condition of pH 7-8 to reduce the diffusion of hydrogen sulfide; and send the landfill leachate into the evaporation enhancement device 2 through the leachate inlet pipe 71.

[0038] S2: The evaporation enhancement device 2 evaporates the landfill leachate, and the evaporated steam is sent to the air purification device 3 through the air outlet pipe 72; the excess landfill leachate and sludge after evaporation fall into the concentrated liquid collection tank 26 and the sludge collection chamber 25 respectively; specifically includes: S201: The garbage leachate enters the spray tower from the water inlet pipe, and is sprayed out from the spray head 22 on the water inlet pipe by dripping water; the hot air device 24 delivers hot air to the bottom of the spray head 22 through the hot air pipe; S202: The landfill leachate sprayed from the spray head 22 is fully in contact with the hot air in the water spray filler 23, and the hot air heats and evaporates the landfill leachate; S203: The steam generated after heating in the spray tower rises with the hot air to the gas-liquid separation zone 21, and the liquid droplets carried in the steam are separated in the gas-liquid separation zone 21; the steam continues to rise and enters the air purification device 3 from the air outlet pipe 72; S204: the excess landfill leachate after evaporation in the spray tower falls into the concentrate collection tank 26; S205: The sludge generated after evaporation in the spray tower is deposited in the sludge collection chamber 25 and transported to the sludge drying tank 5 through the sludge pipe 73.

[0039] S3: The landfill leachate in the concentrate collecting tank 26 flows into the concentrate reflux pipe 75 in an overflow manner, flows back to the concentrate circulation pool 6 through the concentrate reflux pipe 75, and is then sent to the leachate inlet pipe 71 through the concentrate circulation pipe 76. The landfill leachate following the leachate inlet pipe 71 enters the evaporation enhancement device 2 again for evaporation.

[0040] S4: The air purification device 3 purifies the steam, and the clean gas after purification is directly discharged. The condensed water generated during purification is sent to the biochemical treatment unit 4 through the condensed water pipe 74; specifically including: S401: The steam in the spray tower enters the air inlet pipe through the air outlet pipe 72, and enters the purification tower from the air outlet of the air inlet pipe; S402: The steam rises in the purification tower, and after rising to the air condensation area 32, the water in the steam is cooled, and the condensed water generated after cooling falls into the condensed water collection tank 34; S403: The gas in the steam in the purification tower continues to rise, and after rising to the biological filler area 33, it is purified by the biological ceramsite filler in the biological filler area 33, and is discharged through the air discharge port 31 after purification.

[0041] S5: The biochemical treatment unit 4 treats the condensed water.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A natural evaporation enhanced treatment system for landfill leachate, characterized in that: The invention comprises a leachate regulating tank (1), an evaporation enhancing device (2), an air purification device (3), a biochemical treatment unit (4) and a sludge drying tank (5), wherein the leachate regulating tank (1) is connected to the evaporation enhancing device (2) via a leachate inlet pipe (71); the bottom of the evaporation enhancing device (2) is connected to the sludge drying tank (5) via a sludge pipe (73); the top of the evaporation enhancing device (2) is connected to the air purification device (3) via an air outlet pipe (72); and the bottom of the air purification device (3) is connected to the biochemical treatment unit (4) via a condensed water pipe (74).

2. The natural evaporation enhanced treatment system for landfill leachate according to claim 1 is characterized by: The evaporation enhancement device (2) comprises a spray tower, the leachate inlet pipe (71) is connected to the water inlet pipe of the spray tower, and a plurality of spray heads (22) are provided on the pipe body of the water inlet pipe located inside the spray tower; the top of the spray head (22) is a gas-liquid separation zone (21), and the bottom of the spray head (22) is filled with a water spray filler (23); a hot air pipe (74) is connected to the side wall of the spray tower located at the bottom of the water spray filler (23), and the end of the hot air pipe (74) away from the spray tower is connected to a hot air device (24); The bottom of the spray tower is connected to a concentrated liquid collection tank (26), and the bottom of the concentrated liquid collection tank (26) is a sludge collection chamber (25); the bottom of the sludge collection chamber (25) is connected to the sludge drying tank (5) via a sludge pipe (73); the top of the sludge drying tank (5) is connected to the air inlet pipe of the hot air device (24) via an exhaust pipe (77).

3. The natural evaporation enhanced treatment system for landfill leachate according to claim 2 is characterized in that: It also includes a concentrate circulation pool (6), the concentrate circulation pool (6) being connected to the overflow hole at the top of the concentrate collection tank (26) via a concentrate return pipe (75); a concentrate circulation pump is provided in the concentrate circulation pool (6), the concentrate circulation pump is connected to one end of a concentrate circulation pipe (76), and the other end of the concentrate circulation pipe (76) is connected to the leachate inlet pipe (71).

4. The natural evaporation enhanced treatment system for landfill leachate according to claim 3 is characterized by: The air purification device (3) comprises a purification tower, the air outlet pipe (72) is connected to the air inlet pipe of the purification tower, and the air inlet pipe is provided with a plurality of air outlets on a pipe body located inside the purification tower; above the air outlets are an air condensation area (32) and a biological filler area (33) in sequence; and an air discharge port (31) is provided at the top of the biological filler area (33); A condensed water collection tank (34) is provided at the bottom of the purification tower, and the condensed water collection tank (34) is connected to the biochemical treatment unit (4) via the condensed water pipe (74).

5. The natural evaporation enhanced treatment system for landfill leachate according to claim 4 is characterized in that: A plurality of condensation pipes are arranged transversely inside the air condensation area (32); The biological filler area (33) is filled with biological ceramsite filler.

6. The natural evaporation enhanced treatment system for landfill leachate according to claim 3 is characterized by: The biochemical treatment unit (4) is an A / O pool, an oxidation ditch or an ecological wetland.

7. The natural evaporation enhanced treatment system for landfill leachate according to any one of claims 3 to 6, characterized in that: Sunshades (8) are provided on the tops of the leachate regulating tank (1), the sludge drying tank (5) and the concentrated liquid circulation tank (6).

8. A method for treating landfill leachate by natural evaporation enhanced treatment system according to claim 5, characterized in that: The following steps are involved: S1: Regulating the pH of the landfill leachate in the leachate regulating tank (1); and sending the garbage leachate into the evaporation enhancement device (2) through the leachate inlet pipe (71); S2: The evaporation enhancement device (2) evaporates the landfill leachate, and the evaporated steam is sent to the air purification device (3) through the air outlet pipe (72); after evaporation, the excess landfill leachate and sludge fall into the concentrated liquid collection tank (26) and the sludge collection chamber (25) respectively; S3: the landfill leachate in the concentrate collection tank (26) flows into the concentrate return pipe in an overflow manner, flows back into the concentrate circulation pool (6) through the concentrate return pipe (75), and then is sent into the leachate inlet pipe (71) through the concentrate circulation pipe (76). The landfill leachate following the leachate inlet pipe (71) enters the evaporation enhancement device (2) again for evaporation; S4: The air purification device (3) purifies the steam, and the clean gas after purification is directly discharged. The condensed water generated during the purification is sent to the biochemical treatment unit (4) through the condensed water pipe (74); S5: The biochemical treatment unit (4) treats the condensed water.

9. The method for treating landfill leachate by natural evaporation enhanced treatment system according to claim 8, characterized in that: The S2 includes: S201: The garbage leachate enters the spray tower from the water inlet pipe and is sprayed out from the spray head (22) on the water inlet pipe; the hot air device (24) delivers hot air to the bottom of the spray head (22) through the hot air pipe (74); S202: the landfill leachate sprayed from the spray head (22) is fully contacted with the hot air in the water spraying filler (23), and the hot air heats and evaporates the landfill leachate; S203: The steam generated after heating in the spray tower rises with the hot air to reach the gas-liquid separation zone (21), and the liquid droplets carried in the steam are separated in the gas-liquid separation zone (21); the steam continues to rise and enters the air purification device (3) from the air outlet pipe (72); S204: after evaporation in the spray tower, the excess landfill leachate falls into a concentrated liquid collection tank (26); S205: The sludge generated after evaporation in the spray tower is deposited in the sludge collection chamber (25) and transported to the sludge drying tank (5) through the sludge pipe (73).

10. The method for treating landfill leachate by natural evaporation enhanced treatment system according to claim 9, characterized in that: The S4 includes: S401: The steam in the spray tower enters the air inlet pipe through the air outlet pipe (72), and enters the purification tower from the air outlet of the air inlet pipe; S402: After the steam in the purification tower rises to the air condensation area (32), the condensed water generated by the cooling of the water in the steam falls into the condensed water collection tank (34); S403: The gas in the steam in the purification tower continues to rise, and after rising to the biological filler area (33), it is purified by the biological ceramsite filler in the biological filler area (33), and is discharged through the air discharge port (31) after purification.

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