Wastewater discharge system and method for coal-fired power plant

Abstract

The invention discloses a coal-fired power plant wastewater discharge system and method. The discharge system comprises a primary physical treatment module, a secondary chemical treatment module, a tertiary biological treatment module, a deep filtration treatment module, a marsh filtration module, an energy recovery module and a circular treatment module. The marsh filtering module comprises a movable base, a marsh filtering tower, a marsh filtering device, a water inlet pipe and a marsh overflow pipe; according to the discharging method, large-particle solids are filtered through the primary physical treatment module, small-particle solids are condensed into large particles through the secondary chemical treatment module, organic matter is decomposed through the third-stage biological treatment module, soluble pollutants are removed through the deep filtration treatment module, natural purification is provided through the marsh filtration module, and waste water can be directly discharged. The circular treatment module is used for guiding the wastewater into the previous treatment module for repeated filtration; according to the invention, high efficiency and stability of desulfurization wastewater treatment are realized, fluctuation of a filtering treatment effect is reduced, and pollution to the environment and harm to a human body are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater purification in coal-fired power plants, and in particular to a wastewater discharge system and method for coal-fired power plants. Background Art

[0002] During the operation of coal-fired power plants, a large amount of desulfurization wastewater is generated. These desulfurization wastewaters also contain high concentrations of inorganic salts, heavy metal ions and organic pollutants. If the desulfurization wastewater is discharged directly without proper treatment, it will cause great harm to the human body and the environment. Although traditional wastewater treatment methods can remove some pollutants, the filtering effect of existing processes fluctuates greatly and the operating stability is poor. After filtration, it will still contain suspended matter, inorganic salts, heavy metals and organic matter, etc. There are problems such as unstable treatment effect, incomplete treatment and low resource recovery rate. Summary of the invention

[0003] In order to improve the defects of the existing desulfurization wastewater treatment system of coal-fired power plants, such as unstable desulfurization treatment effect and incomplete treatment, the present application provides a coal-fired power plant wastewater discharge system and method.

[0004] The present application provides a coal-fired power plant wastewater discharge system and method using the following technical solutions: A wastewater discharge system for a coal-fired power plant, comprising a primary physical treatment module for filtering large solid particles, a secondary chemical treatment module connected to the primary physical treatment module and used for agglomeration and precipitation of small particles in wastewater, a tertiary biological treatment module connected to the secondary chemical treatment module and used for decomposing organic matter in wastewater, a deep filtration treatment module connected to the tertiary biological treatment module, a swamp filtration module connected to the deep filtration treatment module, an energy recovery module, and a circulation treatment module; The energy recovery module is respectively connected to the primary physical treatment module, the secondary chemical treatment module and the tertiary biological treatment module; The circulation treatment modules are respectively arranged between the primary physical treatment module and the secondary chemical treatment module, between the secondary chemical treatment module and the tertiary biological treatment module, and between the tertiary biological treatment module and the deep filtration treatment module; The swamp filtration module includes a mobile base, a swamp filtration tower arranged on the mobile base, a swamp filtration device inserted in the swamp filtration tower, an inlet pipe for connecting the deep filtration treatment module and the bottom of the swamp filtration tower, and a swamp overflow pipe for connecting the top of the swamp filtration tower with the external space.

[0005] By adopting the above technical scheme, the primary physical treatment module filters the large particles of solid in the desulfurization wastewater, the secondary chemical treatment module promotes the small particles of solid in the desulfurization wastewater to condense into large particles and precipitate through chemical agents, the tertiary biological treatment module decomposes the organic matter in the wastewater, and the deep filtration treatment module further removes soluble pollutants and suspended matter. The swamp filtration module provides natural purification through the swamp filtration device in the mobile base and the swamp filtration tower, so that the wastewater can be directly discharged into the natural environment; the circulation treatment modules are respectively arranged between the treatment modules to ensure that the wastewater can meet the filtration requirements of each treatment module. When the filtration requirements of the wastewater are not met, the wastewater is introduced into the previous treatment module for repeated filtration treatment through the circulation treatment module; the present application realizes the high efficiency and stability of desulfurization wastewater treatment, reduces the fluctuation of the subsequent filtration treatment effect of desulfurization wastewater, can efficiently filter the suspended matter, inorganic salts, heavy metals and organic matter in the desulfurization wastewater, and reduce pollution to the environment and harm to the human body.

[0006] Preferably, the swamp filtering device includes a water inlet layer arranged at the bottom of the swamp filtering tower and connected to the water inlet pipe, a swamp filtering layer arranged above the water inlet layer, and a plant overflow layer arranged above the swamp filtering layer and connected to the swamp overflow pipe.

[0007] By adopting the above technical scheme, the water inlet layer is located at the bottom of the swamp filter tower and is connected to the water inlet pipe, which is responsible for receiving the wastewater filtered by the deep filtration treatment module; the swamp filtration layer is located above the water inlet layer, and uses the swamp environment and microbial activities to further degrade organic matter and remove pollutants; the plant overflow layer is arranged above the swamp filtration layer and is connected to the swamp overflow pipe, and the water quality is further improved through the adsorption and filtration effect of the plant roots. At the same time, the swamp overflow pipe ensures that the treated clean water can overflow and discharge smoothly. The configuration of the entire swamp filtration device helps to improve the efficiency of wastewater treatment, achieve better purification effects, and promote the natural ecological restoration of water.

[0008] Preferably, the swamp filtering device further comprises a grid support frame arranged between the water inlet layer and the swamp filtering layer, and between the swamp filtering layer and the plant overflow layer, and the grid support frame is fixedly connected to the side wall of the swamp filtering tower.

[0009] By adopting the above technical scheme, the grid support frame is arranged between the water inlet layer and the swamp filter layer, and between the swamp filter layer and the plant overflow layer, and the grid support frame is fixedly connected to the side wall of the swamp filter tower. Such structural design not only enhances the stability and structural integrity of the entire swamp filter device, but also the grid support frame provides support and microbial attachment surface for the swamp filter layer, which is conducive to the increase of biodiversity and further improvement of water quality, while ensuring the healthy growth of plant roots in the plant overflow layer and the effective absorption of nutrients, thereby improving the efficiency and effect of the entire swamp filter system in treating wastewater.

[0010] Preferably, the swamp filter layer includes a mesh filter frame for movably inserting between the two mesh support frames, a filter assembly inserted in the mesh filter frame, a sealing side plate arranged on one side of the mesh filter frame and used for sealingly connecting to the side wall of the swamp filter tower, and a handle connected to the sealing side plate.

[0011] By adopting the above technical solution, a stable platform is provided between two adjacent grid support frames to accommodate the filter assembly, which is responsible for removing suspended solids and pollutants in the wastewater; in order to ensure the sealing inside the swamp filter tower and the convenience of operation, a sealing side panel is provided on one side of the grid filter frame, and the sealing side panel is detachably sealed with the side wall of the swamp filter tower, and the sealing side panel is also connected with a handle, so that the installation, maintenance and replacement process of the entire swamp filter layer is simpler and safer; the present application enhances the structural stability of the swamp filter device, improves the filtration efficiency, and optimizes the convenience and sealing of operation, which helps to improve the performance and service life of the entire wastewater treatment system.

[0012] Preferably, the filter assembly includes a microbial eco-stone layer, an activated carbon layer, and a magnetic medium layer.

[0013] By adopting the above technical solution, the filter component achieves efficient wastewater purification effect through a multi-layer combination design, in which the microbial eco-stone layer uses the attached microbial community to degrade organic pollutants, the activated carbon layer removes odors and harmful substances through high adsorption performance, and the magnetic medium layer further removes suspended solids and heavy metal ions in the water through adsorption. This combination not only improves the removal efficiency of various pollutants in the wastewater, but also enhances the stability and durability of the system, ensuring the continuity and efficiency of the purification process; and different filter components can be replaced and combined according to different filtration requirements, which improves the flexibility and scalability of the wastewater treatment system and facilitates customized adjustments according to the specific composition and treatment requirements of different wastewaters.

[0014] Preferably, the plant overflow layer includes an aquatic plant root absorption layer and an overflow layer arranged above the aquatic plant root absorption layer.

[0015] By adopting the above technical scheme, the aquatic plant root absorption layer utilizes the roots of aquatic plants to effectively absorb and adsorb nutrients and residual pollutants in the wastewater, thereby enhancing the biological purification effect; and the overflow layer allows the purified water to overflow smoothly and enter the subsequent treatment stage or be used for recycling. Such a structure not only improves the water purification effect, but also reduces the use of chemicals through the natural purification mechanism of plants, promotes the balance of the ecosystem, and provides the water body with necessary ecological functions and landscape values; the water quality can also be judged by the state of aquatic plants in the aquatic plant root absorption layer, which is convenient for simply judging the water quality after filtration.

[0016] Preferably, the primary physical treatment module comprises a coarse grid unit, a micro screen unit, and a sedimentation tank unit connected in sequence; The secondary chemical treatment module includes a coagulation sedimentation unit connected to the sedimentation tank unit, a flotation unit connected to the coagulation sedimentation unit, and an oxidation-reduction unit connected to the flotation unit; The tertiary biological treatment module includes an anaerobic biological treatment unit connected to the redox unit, and an aerobic biological treatment unit connected to the anaerobic biological treatment unit; The deep filtration treatment module includes a microfiltration unit connected to the aerobic biological treatment unit, an ultrafiltration unit connected to the microfiltration unit, a nanofiltration unit connected to the ultrafiltration unit, and a reverse osmosis unit connected to the nanofiltration unit.

[0017] By adopting the above technical scheme, the primary physical treatment module removes large solid particles through the coarse screen unit, intercepts fine particles through the micro-screen unit, and settles smaller particles in the sedimentation tank unit, thereby effectively separating solid impurities in the wastewater; the secondary chemical treatment module further condenses tiny particles through the coagulation and sedimentation unit, removes grease and suspended matter through the flotation unit, and converts or removes specific pollutants through the oxidation-reduction unit to deepen the purification of the wastewater; the tertiary biological treatment module utilizes anaerobic biological treatment units and aerobic biological treatment units to decompose organic matter; the deep filtration treatment module gradually filters and improves water quality, removes soluble pollutants and suspended matter through microfiltration units, ultrafiltration units, nanofiltration units and reverse osmosis units, and ultimately achieves high-standard wastewater recycling and discharge goals; the present application improves the efficiency and effectiveness of wastewater purification treatment through an integrated filtration treatment process.

[0018] Preferably, the energy recovery module comprises a biogas recovery unit connected to the anaerobic biological treatment unit, and a heat recovery unit connected to the anaerobic biological treatment unit and the aerobic biological treatment unit, respectively.

[0019] By adopting the above technical solution, the energy recovery module effectively captures the biogas generated in the anaerobic biological treatment unit through the biogas recovery unit. This combustible gas can be used for power generation or as fuel, thereby realizing the recycling of energy; at the same time, the heat recovery unit is connected to the anaerobic biological treatment unit and the aerobic biological treatment unit, and can recover the heat energy generated in these two processes, providing the required part of the heat for the primary physical treatment module and the secondary chemical treatment module, thereby reducing the consumption of external energy; this energy recovery mechanism not only improves the energy efficiency of the entire wastewater treatment system, reduces operating costs, but also reduces greenhouse gas emissions, and has important environmental and economic benefits.

[0020] Preferably, the circulation treatment module includes a primary circulation unit disposed between the primary physical treatment module and the secondary chemical treatment module and used for the reflow of wastewater in the primary physical treatment module, a secondary circulation unit disposed between the secondary chemical treatment module and the tertiary biological treatment module and used for the reflow of wastewater in the secondary chemical treatment module, and a tertiary circulation unit disposed between the tertiary biological treatment module and the deep filtration treatment module and used for the reflow of wastewater in the tertiary biological treatment module; The primary circulation unit comprises a solid content sensor disposed at the outlet end of the primary physical treatment module, a secondary water inlet valve disposed between the solid content sensor and the secondary chemical treatment module, and a primary return valve disposed between the solid content sensor and the inlet end of the primary physical treatment module, the primary return valve being connected to the inlet end of the primary physical treatment module, and the solid content sensor being electrically connected to the primary return valve and the secondary water inlet valve, respectively; The secondary circulation unit comprises a particle detection sensor disposed at the outlet end of the secondary chemical treatment module, a tertiary water inlet valve disposed between the particle detection sensor and the tertiary biological treatment module, and a secondary reflux valve disposed between the particle detection sensor and the inlet end of the secondary chemical treatment module, the secondary reflux valve being connected to the inlet end of the secondary chemical treatment module, and the particle detection sensor being electrically connected to the secondary reflux valve and the tertiary water inlet valve, respectively; The tertiary circulation unit includes an organic matter sensor arranged at the outlet end of the tertiary biological treatment module, a deep filtration water inlet valve arranged between the organic matter sensor and the deep filtration treatment module, and a tertiary reflux valve arranged between the organic matter sensor and the inlet end of the tertiary biological treatment module. The tertiary reflux valve is connected to the inlet end of the tertiary biological treatment module, and the organic matter sensor is electrically connected to the tertiary reflux valve and the deep filtration water inlet valve, respectively.

[0021] By adopting the above technical scheme, the primary circulation unit uses a solid content sensor to monitor the solid content of the wastewater, and the primary return valve and the secondary water inlet valve control the water flow, so that the wastewater with unsatisfactory solid content returns to the primary physical treatment module for circulation filtration, thereby optimizing the filtration effect of the primary physical treatment module; the secondary circulation unit uses a particle detection sensor to monitor the particle content of the wastewater, and adjusts the water flow through the secondary return valve and the tertiary water inlet valve, so that the wastewater with unsatisfactory particle content returns to the secondary chemical treatment module for circulation filtration, thereby improving the treatment effect of the secondary chemical treatment module; the tertiary circulation unit uses an organic matter sensor to detect the content of organic matter in the wastewater, and cooperates with the tertiary return valve and the deep filtration water inlet valve to return the wastewater with unsatisfactory organic content to the tertiary biological treatment module for circulation filtration, thereby enhancing the efficiency of the tertiary biological treatment module; the design of the entire circulation treatment module improves the flexibility and adaptability of wastewater treatment through precise sensor monitoring and valve control, thereby ensuring the stability of water quality and the high efficiency of the treatment process.

[0022] A method for discharging wastewater from a coal-fired power plant, comprising the above-mentioned wastewater discharge system for a coal-fired power plant, further comprising the following steps: S1: intercepting large solid particles in wastewater through the primary physical treatment module; S2: Detecting the solid large particle content n discharged from the primary physical treatment module through the circulation treatment module 固 , the preset solid large particle content is n 预 ; When n 固 >n 预 When the wastewater discharged from the primary physical treatment module is discharged, the circulation treatment module guides the wastewater discharged from the primary physical treatment module back into the primary physical treatment module; When n 固 ≤n 预 When the primary physical treatment module introduces the wastewater into the secondary chemical treatment module through the circulation treatment module; S3: adding a coagulant to the wastewater through the secondary chemical treatment module to cause tiny particles in the wastewater to condense into large particles and precipitate; S4: Detecting the solid small particle content p discharged from the secondary chemical treatment module through the circulation treatment module 固 , the preset solid small particle content is p 预 ; When p 固 >p 预 When the wastewater discharged from the secondary chemical treatment module is discharged, the circulation treatment module guides the wastewater discharged from the secondary chemical treatment module back into the secondary chemical treatment module; When p 固 ≤p 预When the secondary chemical treatment module introduces the wastewater into the tertiary biological treatment module through the circulation treatment module; S5: The tertiary biological treatment module decomposes organic matter in the wastewater by microorganisms; S6: Recovering the heat and biogas generated when microorganisms decompose organic matter in the tertiary biological treatment module through the energy recovery module, and introducing the heat into the secondary chemical treatment module and the primary physical treatment module; S7: Detecting the organic matter concentration m of the wastewater discharged from the tertiary biological treatment module through the circulation treatment module 有 , the preset organic matter concentration range is m 预 ; When m 有 >m 预 When the wastewater discharged from the tertiary biological treatment module is discharged, the circulation treatment module guides the wastewater discharged from the tertiary biological treatment module back into the tertiary biological treatment module; When m 有 ≤m 预 When the tertiary biological treatment module guides the wastewater into the deep filtration treatment module through the circulation treatment module; S8: filtering soluble pollutants and suspended solids in the wastewater through the deep filtration treatment module; S9: The wastewater is denitrified and dephosphorized, and heavy metals are removed through the swamp filtration module, and then discharged to the outside.

[0023] By adopting the above technical scheme, the primary physical treatment module intercepts large particles of solids; the circulation treatment module guides the wastewater back to the primary physical treatment module or pushes it to the secondary chemical treatment module according to the test results of the solid content; the secondary chemical treatment module uses a coagulant to condense and precipitate tiny particles; the circulation treatment module determines the flow direction of the wastewater based on the detection of the small particle content to ensure the treatment efficiency; the tertiary biological treatment module uses microorganisms to decompose organic matter; the energy recovery module recovers heat and biogas to optimize energy use; the circulation treatment module determines whether the wastewater of the tertiary biological treatment module is circulated or pushed to the deep filtration treatment module according to the concentration of organic matter; the deep filtration treatment module further removes soluble pollutants and suspended solids; the swamp filtration module completes nitrogen and phosphorus removal and heavy metal removal to ensure the safe discharge of wastewater; it not only improves the efficiency and environmental protection of wastewater treatment, but also reduces energy consumption through energy recovery.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. A wastewater discharge system for a coal-fired power plant, wherein the primary physical treatment module filters large solid particles in the desulfurization wastewater, the secondary chemical treatment module promotes the small solid particles in the desulfurization wastewater to condense into large particles and precipitate through chemical agents, the tertiary biological treatment module decomposes organic matter in the wastewater, the deep filtration treatment module further removes soluble pollutants and suspended matter, and the swamp filtration module provides natural purification through a swamp filtration device in a mobile base and a swamp filtration tower, so that the wastewater can be directly discharged into the natural environment; the circulation treatment modules are respectively arranged between the treatment modules to ensure that the wastewater can meet the filtration requirements of each treatment module, and when the filtration requirements of the wastewater are not met, the wastewater is introduced into the previous treatment module through the circulation treatment module for repeated filtration treatment; the present application realizes the high efficiency and stability of desulfurization wastewater treatment, reduces the fluctuation of the subsequent filtration treatment effect of desulfurization wastewater, can efficiently filter suspended matter, inorganic salts, heavy metals and organic matter in desulfurization wastewater, and reduces pollution to the environment and harm to human body; 2. A wastewater discharge system for a coal-fired power plant, wherein a stable platform is provided between two adjacent grid support frames to accommodate a filter assembly, which is responsible for removing suspended solids and pollutants in the wastewater; in order to ensure the sealing inside the swamp filter tower and the convenience of operation, a sealing side plate is provided on one side of the grid filter frame, and the sealing side plate is detachably sealed and connected to the side wall of the swamp filter tower, and a handle is also connected to the sealing side plate, so that the installation, maintenance and replacement process of the entire swamp filter layer is simpler and safer; 3. A method for discharging wastewater from a coal-fired power plant, wherein the primary physical treatment module intercepts large solid particles; the circulation treatment module guides the wastewater back to the primary physical treatment module or pushes it to the secondary chemical treatment module according to the detection result of the solid content; the secondary chemical treatment module causes tiny particles to condense and precipitate through a coagulant; the circulation treatment module determines the flow direction of the wastewater based on the detection of the small particle content to ensure the treatment efficiency; the tertiary biological treatment module utilizes microorganisms to decompose organic matter; the energy recovery module recovers heat and biogas to optimize energy use; the circulation treatment module determines whether the wastewater from the tertiary biological treatment module is circulated or pushed to the deep filtration treatment module according to the concentration of organic matter; the deep filtration treatment module further removes soluble pollutants and suspended solids; the swamp filtration module completes nitrogen and phosphorus removal and heavy metal removal to ensure the safe discharge of wastewater; it not only improves the efficiency and environmental protection of wastewater treatment, but also reduces energy consumption through energy recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a connection block diagram of an embodiment of a wastewater discharge system of a coal-fired power plant of the present application.

[0026] Figure 2 It is a connection block diagram of a circulation treatment module of an embodiment of a wastewater discharge system of a coal-fired power plant of the present application.

[0027] Figure 3 It is a schematic cross-sectional structure diagram of a swamp filtration module of an embodiment of a wastewater discharge system of a coal-fired power plant of the present application.

[0028] Figure 4 It is a schematic diagram of the plug-in cross-sectional structure of the swamp filter layer and the swamp filter tower of the coal-fired power plant wastewater discharge system embodiment of the present application.

[0029] Figure 5 It is a schematic diagram of the steps of an embodiment of the method for discharging wastewater from a coal-fired power plant of the present application.

[0030] Description of reference numerals: 1. Primary physical treatment module; 11. Coarse grid unit; 12. Micro screen unit; 13. Sedimentation tank unit; 2. Secondary chemical treatment module; 21. Coagulation sedimentation unit; 22. Flotation unit; 23. Redox unit; 3. Tertiary biological treatment module; 31. Anaerobic biological treatment unit; 32. Aerobic biological treatment unit; 4. Deep filtration treatment module; 41. Microfiltration unit; 42. Ultrafiltration unit; 43. Nanofiltration unit; 44. Reverse osmosis unit; 5. Swamp filtration module; 51. Mobile base; 52. Swamp filtration tower; 53. Swamp filtration device; 54. Water inlet pipe; 55. Swamp overflow pipe; 56. Grid support frame; 531. Water inlet layer; 532. Swamp filtration layer; 533. Plant overflow layer; 551. Water pump; 5321. Grid filtration frame; 5322. Filter assembly; 5323. Sealing side panel; 5324. Handle; 5325. Microbial ecological stone layer; 5326. Activated carbon layer; 5327. Magnetic medium layer; 5331. Aquatic plant root absorption layer; 5332. Overflow layer; 6. Energy recovery module; 61. Biogas recovery unit; 62. Heat recovery unit; 7. Circulation processing module; 71. Primary circulation unit; 72. Secondary circulation unit; 73. Tertiary circulation unit; 711. Solid content sensor; 712. Secondary water inlet valve; 713. Primary return valve; 721. Particle detection sensor; 722. Tertiary water inlet valve; 723. Secondary return valve; 731. Organic matter sensor; 732. Deep filtration water inlet valve; 733. Tertiary return valve. DETAILED DESCRIPTION

[0031] The following is combined with Figure 1-5 This application is described in further detail.

[0032] The present application embodiment discloses a wastewater discharge system and method for a coal-fired power plant. Figures 1 to 3A wastewater discharge system of a coal-fired power plant includes a primary physical treatment module 1 for filtering large solid particles, a secondary chemical treatment module 2 connected to the primary physical treatment module 1 and used for agglomeration and precipitation of small particles in the wastewater, a tertiary biological treatment module 3 connected to the secondary chemical treatment module 2 and used for decomposing organic matter in the wastewater, a deep filtration treatment module 4 connected to the tertiary biological treatment module 3, a swamp filtration module 5 connected to the deep filtration treatment module 4, an energy recovery module 6, and a circulation treatment module 7; The energy recovery module 6 is connected to the primary physical treatment module 1, the secondary chemical treatment module 2 and the tertiary biological treatment module 3 respectively; The circulation treatment modules 7 are respectively arranged between the primary physical treatment module 1 and the secondary chemical treatment module 2, between the secondary chemical treatment module 2 and the tertiary biological treatment module 3, and between the tertiary biological treatment module 3 and the deep filtration treatment module 4; The swamp filtration module 5 includes a mobile base 51, a swamp filtration tower 52 arranged on the mobile base 51, a swamp filtration device 53 inserted in the swamp filtration tower 52, an inlet pipe 54 for connecting the deep filtration treatment module 4 and the bottom of the swamp filtration tower 52, and a swamp overflow pipe 55 for connecting the top of the swamp filtration tower 52 and the external space.

[0033] The present application filters large solid particles in the desulfurization wastewater through the primary physical treatment module 1, the secondary chemical treatment module 2 promotes the small solid particles in the desulfurization wastewater to condense into large particles and precipitate through chemical agents, decomposes organic matter in the wastewater through the tertiary biological treatment module 3, and further removes soluble pollutants and suspended matter through the deep filtration treatment module 4. The swamp filtration module 5 provides natural purification through the swamp filtration device 53 in the mobile base 51 and the swamp filtration tower 52, so that the wastewater can be directly discharged into the natural environment; the circulation treatment module 7 is respectively arranged between each treatment module to ensure that the wastewater can meet the filtration requirements of each treatment module. When the filtration requirements of the wastewater are not met, the wastewater is introduced into the previous treatment module through the circulation treatment module 7 for repeated filtration treatment; the present application realizes the high efficiency and stability of desulfurization wastewater treatment, reduces the fluctuation of the subsequent filtration treatment effect of desulfurization wastewater, and can efficiently filter suspended matter, inorganic salts, heavy metals and organic matter in desulfurization wastewater, reducing pollution to the environment and harm to human body; Moreover, the existing wastewater treatment systems lack flexibility and scalability, and are difficult to customize according to the specific composition and treatment requirements of different wastewaters. The present application can customize according to the specific composition and treatment requirements of different wastewaters through the combination and position adjustment of the primary physical treatment module 1, the secondary chemical treatment module 2, the tertiary biological treatment module 3, the deep filtration treatment module 4, and the swamp filtration module 5. The swamp filter tower 52 can also be moved by the mobile base 51, and the water inlet pipes 54 and the swamp overflow pipes 55 on different swamp filter modules 5 are connected to enable multiple swamp filter modules 5 to be connected in series or in parallel, which not only improves the wastewater filtration efficiency, but also improves the flexibility and scalability of wastewater filtration and discharge.

[0034] The swamp overflow pipe 55 of the present application is also provided with a water pump 551. When a plurality of swamp filter modules 5 are interconnected, the water pump 551 is used to guide and flow the wastewater after filtration, thereby improving the filtration efficiency.

[0035] Furthermore, if Figure 1 and Figure 3 As shown, the swamp filtering device 53 includes an inlet layer 531 disposed at the bottom of the swamp filtering tower 52 and connected to the inlet pipe 54, a swamp filtering layer 532 disposed above the inlet layer 531, and a plant overflow layer 533 disposed above the swamp filtering layer 532 and connected to the swamp overflow pipe 55.

[0036] The water inlet layer 531 of the present application is located at the bottom of the swamp filter tower 52 and is connected to the water inlet pipe 54, and is responsible for receiving the wastewater filtered by the deep filtration treatment module 4; the swamp filter layer 532 is located above the water inlet layer 531, and uses the swamp environment and microbial activities to further degrade organic matter and remove pollutants; the plant overflow layer 533 is arranged above the swamp filter layer 532 and is connected to the swamp overflow pipe 55, and the water quality is further improved through the adsorption and filtration effect of the plant roots. At the same time, the swamp overflow pipe 55 ensures that the treated clean water can overflow and discharge smoothly. The configuration of the entire swamp filter device 53 helps to improve the efficiency of wastewater treatment, achieve better purification effects, and promote the natural ecological restoration of water.

[0037] Furthermore, if Figure 3 As shown, the swamp filtering device 53 also includes a grid support frame 56 arranged between the water inlet layer 531 and the swamp filtering layer 532, and between the swamp filtering layer 532 and the plant overflow layer 533, and the grid support frame 56 is fixedly connected to the side wall of the swamp filtering tower 52.

[0038] The grid support frame 56 of the present application is arranged between the water inlet layer 531 and the swamp filter layer 532, and between the swamp filter layer 532 and the plant overflow layer 533, and the grid support frame 56 is fixedly connected to the side wall of the swamp filter tower 52. Such a structural design not only enhances the stability and structural integrity of the entire swamp filter device 53, but also the grid support frame 56 provides support and an attachment surface for microorganisms for the swamp filter layer 532, which is conducive to the increase of biodiversity and further improvement of water quality, while ensuring the healthy growth of plant roots in the plant overflow layer 533 and the effective absorption of nutrients, thereby improving the efficiency and effect of the entire swamp filter system in treating wastewater.

[0039] Specifically, Figure 3 As shown, the swamp filter layer 532 includes a mesh filter frame 5321 for movably inserting between two mesh support frames 56, a filter assembly 5322 inserted in the mesh filter frame 5321, a sealing side plate 5323 provided on one side of the mesh filter frame 5321 and used for sealingly connecting to the side wall of the swamp filter tower 52, and a handle 5324 connected to the sealing side plate 5323.

[0040] The swamp filter layer 532 of the present application includes a mesh filter frame 5321, which is used to be movably inserted between two mesh support frames 56, providing a stable platform to accommodate the filter assembly 5322, and the filter assembly 5322 is responsible for removing suspended solids and pollutants in the wastewater; in order to ensure the sealing inside the swamp filter tower 52 and the convenience of operation, a sealing side plate 5323 is provided on one side of the mesh filter frame 5321, and the sealing side plate 5323 is detachably sealed with the side wall of the swamp filter tower 52, and the sealing side plate 5323 is also connected to a handle 5324, so that the installation, maintenance and replacement process of the entire swamp filter layer 532 is simpler and safer; the present application enhances the structural stability of the swamp filter device 53, improves the filtering efficiency, and optimizes the convenience and sealing of operation, which helps to improve the performance and service life of the entire wastewater treatment system; The sealing side plate 5323 of the present application is plugged into and matched with the side wall of the swamp filter tower 52 through a slot and a sealing rubber gasket, and is fixedly connected by bolts, so as to facilitate disassembly, assembly and replacement.

[0041] More specifically, if Figure 4 As shown, the filter component 5322 includes a microbial eco-stone layer 5325 , an activated carbon layer 5326 , and a magnetic medium layer 5327 .

[0042] The filter component 5322 of the present application achieves efficient wastewater purification through a multi-layer combination design, wherein the microbial eco-stone layer 5325 utilizes the attached microbial community to degrade organic pollutants, the activated carbon layer 5326 removes odors and harmful substances through high adsorption performance, and the magnetic medium layer 5327 further removes suspended solids and heavy metal ions in the water through adsorption. Such a combination not only improves the removal efficiency of various pollutants in the wastewater, but also enhances the stability and durability of the system, ensuring the continuity and efficiency of the purification process; and different filter components 5322 can be replaced and combined according to different filtration requirements, thereby improving the flexibility and scalability of the wastewater treatment system and facilitating customized adjustments according to the specific composition and treatment requirements of different wastewaters.

[0043] In addition, if Figure 4 As shown, the plant overflow layer 533 includes an aquatic plant root absorption layer 5331 and an overflow layer 5332 arranged above the aquatic plant root absorption layer 5331 .

[0044] The plant overflow layer 533 of the present application is composed of two parts: an aquatic plant root absorption layer 5331 and an overflow layer 5332; the aquatic plant root absorption layer 5331 uses the roots of aquatic plants to effectively absorb and adsorb nutrients and residual pollutants in the wastewater, thereby enhancing the biological purification effect; and the overflow layer 5332 allows the purified water to overflow smoothly and enter the subsequent treatment stage or be used for recycling. Such a structure not only improves the water purification effect, but also reduces the use of chemicals through the natural purification mechanism of plants, promotes the balance of the ecosystem, and provides the water body with the necessary ecological functions and landscape value; the water quality can also be judged by the state of aquatic plants in the aquatic plant root absorption layer 5331, which is convenient for simply judging the water quality after filtration.

[0045] And, if Figure 1 As shown, the primary physical treatment module 1 includes a coarse screen unit 11, a micro screen unit 12, and a sedimentation tank unit 13 connected in sequence; The secondary chemical treatment module 2 includes a coagulation sedimentation unit 21 connected to the sedimentation tank unit 13, a flotation unit 22 connected to the coagulation sedimentation unit 21, and a redox unit 23 connected to the flotation unit 22; The tertiary biological treatment module 3 includes an anaerobic biological treatment unit 31 connected to the redox unit 23, and an aerobic biological treatment unit 32 connected to the anaerobic biological treatment unit 31; The deep filtration treatment module 4 includes a microfiltration unit 41 connected to the aerobic biological treatment unit 32 , an ultrafiltration unit 42 connected to the microfiltration unit 41 , a nanofiltration unit 43 connected to the ultrafiltration unit 42 , and a reverse osmosis unit 44 connected to the nanofiltration unit 43 .

[0046] The primary physical treatment module 1 of the present application removes large solid particles through the coarse grid unit 11, intercepts fine particles through the micro-screen unit 12, and settles smaller particles through the sedimentation tank unit 13, so as to effectively separate solid impurities in the wastewater; the coarse grid unit 11 is composed of a group of parallel metal bars or grid sheets, which are installed in the channel through which the wastewater flows to form a physical barrier; the micro-screen unit 12 is a finer metal wire mesh for intercepting finer particles; the sedimentation tank unit 13 is a structure that uses gravity to settle suspended solid particles in the wastewater, and a sludge collection area is designed at the bottom of the sedimentation tank unit 13, and the sludge can be regularly removed by a sludge scraper or a sludge suction truck; The secondary chemical treatment module 2 further condenses tiny particles through the coagulation and sedimentation unit 21, removes grease and suspended matter through the flotation unit 22, and transforms or removes specific pollutants through the redox unit 23, so as to deepen the purification degree of the wastewater; the coagulation and sedimentation unit 21 includes a coagulation tank, which fully mixes the coagulant (such as polyaluminium chloride PAC or polyferric sulfate PFS) with the wastewater to condense the tiny particles into large particles for easy precipitation; the flotation unit 22 includes a flotation tank or a flotation machine, and the flotation unit 22 generates fine bubbles through aeration, so that the flotation agent attached to the pollutants makes the pollutants float to the water surface to form scum, which is used to remove grease, surfactants and other pollutants that are not easy to settle; the redox unit 23 adds an oxidant (such as chlorine, ozone or hydrogen peroxide) or a reducing agent (such as ferrous sulfate) to the wastewater to perform a redox reaction, so as to remove or transform difficult-to-degrade organic matter, heavy metal ions or other specific pollutants; The tertiary biological treatment module 3 utilizes an anaerobic biological treatment unit 31 and an aerobic biological treatment unit 32 to decompose organic matter; the anaerobic biological treatment unit 31 is preferably an upflow anaerobic sludge blanket (UASB), which is composed of a sludge layer at the bottom, a wastewater and sludge mixing zone in the middle, and a three-phase separator at the top. Wastewater enters from the bottom of the upflow anaerobic sludge blanket and flows upward through the sludge blanket. Microorganisms decompose organic matter under anaerobic conditions, and the generated biogas is collected through the three-phase separator; the aerobic biological treatment unit 32 is preferably an activated sludge process, which is carried out in a reactor in an aeration tank, and wastewater is mixed with activated sludge (suspended solids containing a large amount of aerobic microorganisms) to decompose biodegradable organic matter in the wastewater; The deep filtration treatment module 4 gradually filters and improves the water quality, removes soluble pollutants and suspended solids through the microfiltration unit 41, the ultrafiltration unit 42, the nanofiltration unit 43 and the reverse osmosis unit 44, and finally achieves the high standard of wastewater recycling and discharge goals; the microfiltration unit 41 preferably uses a microporous membrane (pore size of about 0.1-10 microns) to filter out bacteria, algae and some viruses; the ultrafiltration unit 42 preferably uses a membrane with a smaller pore size (about 0.01-0.1 microns) to remove smaller particles, such as viruses and large molecular organic matter; the nanofiltration unit 43 preferably uses a semipermeable membrane with a pore size at the nanometer level, which can remove multivalent ions and some monovalent ions in the water; the reverse osmosis unit 44 preferably uses a membrane with a high desalination rate, which can remove most of the soluble salts and organic matter; the present application improves the efficiency and effect of wastewater purification through an integrated filtration treatment process.

[0047] Furthermore, if Figure 1 As shown, the energy recovery module 6 includes a biogas recovery unit 61 connected to the anaerobic biological treatment unit 31 , and a heat recovery unit 62 connected to the anaerobic biological treatment unit 31 and the aerobic biological treatment unit 32 , respectively.

[0048] The energy recovery module 6 of the present application effectively captures the biogas generated in the anaerobic biological treatment unit 31 through the biogas recovery unit 61. This combustible gas can be used for power generation or as fuel, thereby realizing the recycling of energy; at the same time, the heat recovery unit 62 is connected to the anaerobic biological treatment unit 31 and the aerobic biological treatment unit 32, and can recover the heat energy generated in these two processes, providing the required part of the heat for the primary physical treatment module 1 and the secondary chemical treatment module 2, thereby reducing the consumption of external energy; this energy recovery mechanism not only improves the energy efficiency of the entire wastewater treatment system, reduces operating costs, but also reduces greenhouse gas emissions, and has important environmental and economic benefits; The heat energy recovery unit 62 is preferably a heat exchanger, a heat pump system or a waste heat boiler; in the tertiary biological treatment module 3, the heat generated by the decomposition of organic matter can be recovered through the heat exchanger and used to preheat the cooled wastewater or heat the primary physical treatment module 1 and the secondary chemical treatment module 2.

[0049] Furthermore, if Figure 1 and Figure 2 As shown, the circulation treatment module 7 includes a primary circulation unit 71 disposed between the primary physical treatment module 1 and the secondary chemical treatment module 2 and used for the wastewater reflow in the primary physical treatment module 1, a secondary circulation unit 72 disposed between the secondary chemical treatment module 2 and the tertiary biological treatment module 3 and used for the wastewater reflow in the secondary chemical treatment module 2, and a tertiary circulation unit 73 disposed between the tertiary biological treatment module 3 and the deep filtration treatment module 4 and used for the wastewater reflow in the tertiary biological treatment module 3; The primary circulation unit 71 includes a solid content sensor 711 disposed at the outlet end of the primary physical treatment module 1, a secondary water inlet valve 712 disposed between the solid content sensor 711 and the secondary chemical treatment module 2, and a primary return valve 713 disposed between the solid content sensor 711 and the inlet end of the primary physical treatment module 1, the primary return valve 713 is connected to the inlet end of the primary physical treatment module 1, and the solid content sensor 711 is electrically connected to the primary return valve 713 and the secondary water inlet valve 712 respectively; The secondary circulation unit 72 includes a particle detection sensor 721 disposed at the outlet end of the secondary chemical treatment module 2, a tertiary water inlet valve 722 disposed between the particle detection sensor 721 and the tertiary biological treatment module 3, and a secondary reflux valve 723 disposed between the particle detection sensor 721 and the inlet end of the secondary chemical treatment module 2, the secondary reflux valve 723 being connected to the inlet end of the secondary chemical treatment module 2, and the particle detection sensor 721 being electrically connected to the secondary reflux valve 723 and the tertiary water inlet valve 722, respectively; The tertiary circulation unit 73 includes an organic matter sensor 731 arranged at the outlet end of the tertiary biological treatment module 3, a deep filtration water inlet valve 732 arranged between the organic matter sensor 731 and the deep filtration treatment module 4, and a tertiary return valve 733 arranged between the organic matter sensor 731 and the inlet end of the tertiary biological treatment module 3. The tertiary return valve 733 is connected to the inlet end of the tertiary biological treatment module 3, and the organic matter sensor 731 is electrically connected to the tertiary return valve 733 and the deep filtration water inlet valve 732, respectively.

[0050] The circulation treatment module 7 of the present application realizes efficient circulation filtration treatment of wastewater by setting a primary circulation unit 71, a secondary circulation unit 72 and a tertiary circulation unit 73; the primary circulation unit 71 uses a solid content sensor 711 to monitor the solid content of the wastewater, and the primary return valve 713 and the secondary water inlet valve 712 control the water flow, so that the wastewater with substandard solid content returns to the primary physical treatment module 1 for circulation filtration, thereby optimizing the filtration effect of the primary physical treatment module 1; The secondary circulation unit 72 uses a particle detection sensor 721 to monitor the particle content of the wastewater, and adjusts the water flow through the secondary return valve 723 and the tertiary water inlet valve 722, so that the wastewater with substandard particle content returns to the secondary chemical treatment module 2 for circulation filtration, thereby improving the treatment effect of the secondary chemical treatment module 2; The tertiary circulation unit 73 uses an organic matter sensor 731 to detect the organic matter content in the wastewater, and cooperates with the tertiary return valve 733 and the deep filtration inlet valve 732 to return the wastewater with substandard organic matter content to the tertiary biological treatment module 3 for circulation filtration, thereby enhancing the efficiency of the tertiary biological treatment module 3; the design of the entire circulation treatment module 7 improves the flexibility and adaptability of wastewater treatment through precise sensor monitoring and valve control, ensures the stability of water quality and the efficiency of the treatment process, while reducing the consumption of energy and water resources, and enhancing the economy and sustainability of the system.

[0051] Specifically, Figure 5 As shown, the present application also discloses a method for discharging wastewater from a coal-fired power plant, including a wastewater discharge system for a coal-fired power plant, and further comprising the following steps: S1: interception of large solid particles in wastewater through primary physical treatment module 1; S2: Detect the solid large particle content n discharged from the primary physical treatment module 1 through the circulation treatment module 7 固 , the preset solid large particle content is n 预 ; When n 固 >n 预 When the wastewater discharged from the primary physical treatment module 1 is discharged, the circulation treatment module 7 guides the wastewater discharged from the primary physical treatment module 1 back into the primary physical treatment module 1; When n 固 ≤n 预 When the primary physical treatment module 1 introduces the wastewater into the secondary chemical treatment module 2 through the circulation treatment module 7; S3: adding a coagulant to the wastewater through the secondary chemical treatment module 2 to cause the tiny particles in the wastewater to condense into large particles and precipitate; S4: Detect the solid small particle content p discharged from the secondary chemical treatment module 2 through the circulation treatment module 7 固 , the preset solid small particle content is p 预 ; When p 固 >p 预 When the wastewater discharged from the secondary chemical treatment module 2 is discharged, the circulation treatment module 7 guides the wastewater discharged from the secondary chemical treatment module 2 back into the secondary chemical treatment module 2; When p 固 ≤p 预 When the secondary chemical treatment module 2 introduces the wastewater into the tertiary biological treatment module 3 through the circulation treatment module 7; S5: The tertiary biological treatment module 3 decomposes organic matter in the wastewater through microorganisms; S6: Recover the heat and biogas generated when microorganisms decompose organic matter in the tertiary biological treatment module 3 through the energy recovery module 6, and introduce the heat into the secondary chemical treatment module 2 and the primary physical treatment module 1; S7: Detect the organic matter concentration m of the wastewater discharged from the tertiary biological treatment module 3 through the circulation treatment module 7 有 , the preset organic matter concentration range is m 预 ; When m 有 >m 预 When the wastewater discharged from the tertiary biological treatment module 3 is discharged, the circulation treatment module 7 guides the wastewater discharged from the tertiary biological treatment module 3 back into the tertiary biological treatment module 3; When m 有 ≤m 预 When the tertiary biological treatment module 3 guides the wastewater into the deep filtration treatment module 4 through the circulation treatment module 7; S8: filtering soluble pollutants and suspended solids in the wastewater through the deep filtration treatment module 4; S9: The wastewater is denitrified and dephosphorized, and heavy metals are removed through the swamp filtration module 5, and then discharged to the outside.

[0052] In the present application, in step S1, the primary physical treatment module 1 intercepts large particles of solids; in step S2, based on the detection result of the solid content, the circulation treatment module 7 decides whether to guide the wastewater back to the primary physical treatment module 1 or push it to the secondary chemical treatment module 2; in step S3, the secondary chemical treatment module 2 causes the tiny particles to condense and precipitate through a coagulant; in step S4, based on the detection of the small particle content, the wastewater flow direction is determined to ensure the treatment efficiency; the tertiary biological treatment module 3 in step S5 uses microorganisms to decompose organic matter; in step S6, the energy recovery module 6 recovers heat and biogas to optimize energy use; in step S7, based on the concentration of organic matter, it is determined whether the wastewater of the tertiary biological treatment module 3 is to be circulated or pushed to the deep filtration treatment module 4; in step S8, the deep filtration treatment module 4 further removes soluble pollutants and suspended solids; in step S9, the swamp filtration module 5 completes nitrogen and phosphorus removal and heavy metal removal to ensure the safe discharge of wastewater; not only the efficiency and environmental protection of wastewater treatment are improved, but also energy consumption is reduced through energy recovery, thereby achieving the discharge target of coal-fired power plant wastewater.

[0053] The implementation principle of a coal-fired power plant wastewater discharge system and method in the embodiment of the present application is: A wastewater discharge system for a coal-fired power plant, wherein a primary physical treatment module 1 is used to filter large solid particles in desulfurized wastewater, a secondary chemical treatment module 2 is used to promote the aggregation of small solid particles in desulfurized wastewater into large particles and precipitation through chemical agents, a tertiary biological treatment module 3 is used to decompose organic matter in the wastewater, a deep filtration treatment module 4 is used to further remove soluble pollutants and suspended matter, a swamp filtration module 5 is used to provide natural purification through a mobile base 51 and a swamp filtration device 53 in a swamp filtration tower 52, so that the wastewater can be directly discharged into the natural environment; a circulation treatment module 7 is respectively arranged between each treatment module to ensure that the wastewater can meet the filtration requirements of each treatment module, and when the filtration requirements of the wastewater are not met, the wastewater is introduced into the previous treatment module through the circulation treatment module 7 for repeated filtration treatment; the present application realizes the high efficiency and stability of desulfurized wastewater treatment, reduces the fluctuation of the subsequent filtration treatment effect of desulfurized wastewater, can efficiently filter suspended matter, inorganic salts, heavy metals and organic matter in desulfurized wastewater, and reduces pollution to the environment and harm to human body; The swamp filter layer 532 includes a mesh filter frame 5321, which is used to be movably inserted between two mesh support frames 56, providing a stable platform to accommodate the filter assembly 5322, and the filter assembly 5322 is responsible for removing suspended solids and pollutants in the wastewater; in order to ensure the sealing inside the swamp filter tower 52 and the convenience of operation, a sealing side plate 5323 is provided on one side of the mesh filter frame 5321, and the sealing side plate 5323 is detachably sealed with the side wall of the swamp filter tower 52, and the sealing side plate 5323 is also connected to a handle 5324, so that the installation, maintenance and replacement process of the entire swamp filter layer 532 is simpler and safer; the present application enhances the structural stability of the swamp filter device 53, improves the filtering efficiency, and optimizes the convenience and sealing of operation, which helps to improve the performance and service life of the entire wastewater treatment system; A method for discharging wastewater from a coal-fired power plant, wherein in step S1, a primary physical treatment module 1 intercepts large solid particles; in step S2, a circulation treatment module 7 is used to determine whether to guide the wastewater back to the primary physical treatment module 1 or to push it to a secondary chemical treatment module 2 based on the detection result of the solid content; in step S3, the secondary chemical treatment module 2 causes tiny particles to condense and precipitate through a coagulant; in step S4, the flow direction of the wastewater is determined based on the detection of the small particle content to ensure the treatment efficiency; in step S5, a tertiary biological treatment module 3 uses microorganisms to decompose organic matter; in step S6, an energy recovery module 6 recovers heat and biogas to optimize energy use; in step S7, based on the concentration of organic matter, it is determined whether the wastewater of the tertiary biological treatment module 3 is circulated or pushed to a deep filtration treatment module 4; in step S8, the deep filtration treatment module 4 is used to further remove soluble pollutants and suspended solids; in step S9, a swamp filtration module 5 completes nitrogen and phosphorus removal and heavy metal removal to ensure safe discharge of wastewater; not only the efficiency and environmental protection of wastewater treatment are improved, but also energy consumption is reduced through energy recovery, thereby achieving the discharge target of coal-fired power plant wastewater.

[0054] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A coal-fired power plant wastewater discharge system, characterized in that: The invention comprises a primary physical treatment module (1) for filtering large solid particles, a secondary chemical treatment module (2) connected to the primary physical treatment module (1) and used for agglomeration and precipitation of small particles in wastewater, a tertiary biological treatment module (3) connected to the secondary chemical treatment module (2) and used for decomposing organic matter in wastewater, a deep filtration treatment module (4) connected to the tertiary biological treatment module (3), a swamp filtration module (5) connected to the deep filtration treatment module (4), an energy recovery module (6), and a circulation treatment module (7); The energy recovery module (6) is respectively connected to the primary physical treatment module (1), the secondary chemical treatment module (2) and the tertiary biological treatment module (3); The circulation treatment module (7) is respectively arranged between the primary physical treatment module (1) and the secondary chemical treatment module (2), between the secondary chemical treatment module (2) and the tertiary biological treatment module (3), and between the tertiary biological treatment module (3) and the deep filtration treatment module (4); The swamp filtration module (5) comprises a mobile base (51), a swamp filtration tower (52) arranged on the mobile base (51), a swamp filtration device (53) inserted in the swamp filtration tower (52), a water inlet pipe (54) for connecting the deep filtration processing module (4) and the bottom of the swamp filtration tower (52), and a swamp overflow pipe (55) for connecting the top of the swamp filtration tower (52) and the external space.

2. A coal-fired power plant wastewater discharge system according to claim 1, characterized in that: The swamp filtering device (53) comprises a water inlet layer (531) disposed at the bottom of the swamp filtering tower (52) and connected to the water inlet pipe (54), a swamp filtering layer (532) disposed above the water inlet layer (531), and a plant overflow layer (533) disposed above the swamp filtering layer (532) and connected to the swamp overflow pipe (55).

3. A coal-fired power plant wastewater discharge system according to claim 2, characterized in that: The swamp filtering device (53) further comprises a grid support frame (56) arranged between the water inlet layer (531) and the swamp filtering layer (532), and between the swamp filtering layer (532) and the plant overflow layer (533); the grid support frame (56) is fixedly connected to the side wall of the swamp filtering tower (52).

4. A coal-fired power plant wastewater discharge system according to claim 3, characterized in that: The swamp filter layer (532) includes a mesh filter frame (5321) for movably inserting between the two mesh support frames (56), a filter assembly (5322) inserted in the mesh filter frame (5321), a sealing side plate (5323) provided on one side of the mesh filter frame (5321) and used for sealingly connecting to the side wall of the swamp filter tower (52), and a handle (5324) connected to the sealing side plate (5323).

5. A coal-fired power plant wastewater discharge system according to claim 4, characterized in that: The filtering component (5322) includes a microbial ecological stone layer (5325), an activated carbon layer (5326), and a magnetic medium layer (5327).

6. A coal-fired power plant wastewater discharge system according to claim 4, characterized in that: The plant overflow layer (533) comprises an aquatic plant root absorption layer (5331) and an overflow layer (5332) arranged above the aquatic plant root absorption layer (5331).

7. A coal-fired power plant wastewater discharge system according to claim 1, characterized in that: The primary physical treatment module (1) comprises a coarse grid unit (11), a micro screen unit (12), and a sedimentation tank unit (13) which are connected in sequence; The secondary chemical treatment module (2) comprises a coagulation sedimentation unit (21) connected to the sedimentation tank unit (13), a flotation unit (22) connected to the coagulation sedimentation unit (21), and a redox unit (23) connected to the flotation unit (22); The tertiary biological treatment module (3) comprises an anaerobic biological treatment unit (31) connected to the redox unit (23), and an aerobic biological treatment unit (32) connected to the anaerobic biological treatment unit (31); The deep filtration treatment module (4) comprises a microfiltration unit (41) connected to the aerobic biological treatment unit (32), an ultrafiltration unit (42) connected to the microfiltration unit (41), a nanofiltration unit (43) connected to the ultrafiltration unit (42), and a reverse osmosis unit (44) connected to the nanofiltration unit (43).

8. A coal-fired power plant wastewater discharge system according to claim 7, characterized in that: The energy recovery module (6) comprises a biogas recovery unit (61) connected to the anaerobic biological treatment unit (31), and a heat recovery unit (62) respectively connected to the anaerobic biological treatment unit (31) and the aerobic biological treatment unit (32).

9. A coal-fired power plant wastewater discharge system according to claim 7, characterized in that: The circulation treatment module (7) comprises a primary circulation unit (71) arranged between the primary physical treatment module (1) and the secondary chemical treatment module (2) and used for the wastewater reflow in the primary physical treatment module (1), a secondary circulation unit (72) arranged between the secondary chemical treatment module (2) and the tertiary biological treatment module (3) and used for the wastewater reflow in the secondary chemical treatment module (2), and a tertiary circulation unit (73) arranged between the tertiary biological treatment module (3) and the deep filtration treatment module (4) and used for the wastewater reflow in the tertiary biological treatment module (3); The primary circulation unit (71) comprises a solid content sensor (711) arranged at the outlet end of the primary physical treatment module (1), a secondary water inlet valve (712) arranged between the solid content sensor (711) and the secondary chemical treatment module (2), and a primary return valve (713) arranged between the solid content sensor (711) and the inlet end of the primary physical treatment module (1), wherein the primary return valve (713) is connected to the inlet end of the primary physical treatment module (1), and the solid content sensor (711) is electrically connected to the primary return valve (713) and the secondary water inlet valve (712), respectively; The secondary circulation unit (72) comprises a particle detection sensor (721) arranged at the outlet end of the secondary chemical treatment module (2), a tertiary water inlet valve (722) arranged between the particle detection sensor (721) and the tertiary biological treatment module (3), and a secondary reflux valve (723) arranged between the particle detection sensor (721) and the inlet end of the secondary chemical treatment module (2), the secondary reflux valve (723) being connected to the inlet end of the secondary chemical treatment module (2), and the particle detection sensor (721) being electrically connected to the secondary reflux valve (723) and the tertiary water inlet valve (722), respectively; The tertiary circulation unit (73) comprises an organic matter sensor (731) arranged at the outlet end of the tertiary biological treatment module (3), a deep filtration water inlet valve (732) arranged between the organic matter sensor (731) and the deep filtration treatment module (4), and a tertiary return valve (733) arranged between the organic matter sensor (731) and the inlet end of the tertiary biological treatment module (3), wherein the tertiary return valve (733) is connected to the inlet end of the tertiary biological treatment module (3), and the organic matter sensor (731) is electrically connected to the tertiary return valve (733) and the deep filtration water inlet valve (732), respectively.

10. A method for discharging wastewater from a coal-fired power plant, characterized in that: A coal-fired power plant wastewater discharge system comprising any one of claims 1 to 9, further comprising: The following steps are involved: S1: intercepting large solid particles in the wastewater through the primary physical treatment module (1); S2: Detecting the content of large solid particles n discharged from the primary physical treatment module (1) through the circulation treatment module (7) 固 , the preset solid large particle content is n 预 ; When n 固 >n 预 When the primary physical treatment module (1) is discharged, the circulation treatment module (7) guides the wastewater discharged from the primary physical treatment module (1) back into the primary physical treatment module (1); When n 固 ≤n 预 When the primary physical treatment module (1) guides the wastewater into the secondary chemical treatment module (2) through the circulation treatment module (7); S3: adding a coagulant to the wastewater through the secondary chemical treatment module (2) to cause tiny particles in the wastewater to condense into large particles and precipitate; S4: Detecting the solid small particle content p discharged from the secondary chemical treatment module (2) through the circulation treatment module (7) 固 , the preset solid small particle content is p 预 ; When p 固 >p 预 When the secondary chemical treatment module (2) is discharged, the circulation treatment module (7) guides the wastewater discharged from the secondary chemical treatment module (2) back into the secondary chemical treatment module (2); When p 固 ≤p 预 When the secondary chemical treatment module (2) introduces the wastewater into the tertiary biological treatment module (3) through the circulation treatment module (7); S5: The tertiary biological treatment module (3) decomposes organic matter in the wastewater by microorganisms; S6: recovering heat and biogas generated by microorganisms decomposing organic matter in the tertiary biological treatment module (3) through the energy recovery module (6), and introducing the heat into the secondary chemical treatment module (2) and the primary physical treatment module (1); S7: Detecting the organic matter concentration m of the wastewater discharged from the tertiary biological treatment module (3) through the circulation treatment module (7) 有 , the preset organic matter concentration range is m 预 ; When m 有 >m 预 When the wastewater discharged from the tertiary biological treatment module (3) is discharged, the circulation treatment module (7) guides the wastewater discharged from the tertiary biological treatment module (3) back into the tertiary biological treatment module (3); When m 有 ≤m 预 When the tertiary biological treatment module (3) guides the wastewater into the deep filtration treatment module (4) through the circulation treatment module (7); S8: filtering soluble pollutants and suspended solids in the wastewater through the deep filtration treatment module (4); S9: The wastewater is denitrified and dephosphorized, and heavy metals are removed through the swamp filtration module (5), and then discharged to the outside.

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