Wastewater treatment system and method for waste incineration power plant

Abstract

The present invention relates to the field of sewage treatment technology, specifically a sewage treatment system and method for a waste incineration power plant, comprising a preliminary treatment unit, a sedimentation treatment unit, a biochemical treatment unit, a filtration treatment unit, and a disinfection treatment unit arranged in sequence along the flow direction of the sewage; the sedimentation treatment unit comprises an annular coagulation sedimentation tank, an annular flotation tank, and a circular regulating tank arranged in sequence from the outside to the inside, a collection well being provided in the annular flotation tank, and a slag scooping mechanism for scooping slag into the collection well being provided on the annular flotation tank. The present invention first uses a coagulant to treat the sewage in the annular coagulation sedimentation tank; then the sewage is sent to the annular flotation tank, and by generating a large number of fine bubbles, pollutants such as suspended matter, grease, etc. that are difficult to settle in the sewage are attached to the bubbles and float to the water surface, thereby being effectively removed. This helps to reduce the burden of subsequent treatment processes and improve overall treatment efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a sewage treatment system and method for a waste incineration power plant. Background Art

[0002] The wastewater treatment system of a waste-to-energy plant is primarily responsible for treating wastewater generated during the incineration process, including boiler dust removal and washing wastewater, boiler blowdown wastewater, exhaust gas soot blowing and washing wastewater, flue gas condensate, and ash washing wastewater. These wastewaters typically contain high concentrations of organic matter, heavy metal ions, and other pollutants, requiring specialized treatment processes to meet discharge standards or be reused.

[0003] Currently, wastewater treatment processes at waste-to-energy plants typically include three stages: physical, chemical, and biological treatment, ensuring that wastewater generated by these plants meets specified emission standards. The chemical treatment stage typically utilizes coagulation and sedimentation, adding chemicals to aggregate colloidal particles and suspended solids in the wastewater into larger flocs, which are then precipitated and separated. This process effectively removes pollutants such as organic matter and heavy metal ions from the wastewater.

[0004] However, during use, it was discovered that coagulation and sedimentation alone were inadequate for removing suspended solids, grease, and other difficult-to-sediment pollutants from wastewater. To remove these pollutants, existing technologies generally utilize flotation machines. However, these separate flotation machines require pipes and pumps to transport the coagulated and sedimented wastewater to the flotation machines, which undoubtedly increases wastewater treatment costs. Therefore, we have proposed a wastewater treatment system and method for waste-to-energy plants that effectively address these drawbacks. Summary of the Invention

[0005] The object of the present invention is to provide a wastewater treatment system and method for a waste incineration power plant, so as to solve the problems raised in the above background technology.

[0006] The present invention is achieved through the following technical solutions: A wastewater treatment system for a waste incineration power plant, comprising a preliminary treatment unit, a sedimentation treatment unit, a biochemical treatment unit, a filtration treatment unit and a disinfection treatment unit arranged in sequence along the flow direction of the wastewater;

[0007] The sedimentation treatment unit includes an annular coagulation sedimentation tank, an annular flotation tank and a circular regulating tank arranged in sequence from the outside to the inside, the annular coagulation sedimentation tank is connected to the preliminary treatment unit through a pipeline, and the circular regulating tank is connected to the biochemical treatment unit through a pipeline;

[0008] A releaser is provided inside the annular air flotation tank, and an air dissolving mechanism is provided outside the annular air flotation tank, and an output end of the air dissolving mechanism is connected to the releaser;

[0009] A collection well is provided in the annular flotation pool, and the liquid level in the annular flotation pool is lower than the top surface height of the collection well; a slag scooping mechanism for scooping slag into the collection well is provided on the annular flotation pool.

[0010] Optionally, the slag scooping mechanism includes two concentrically distributed annular vertical baffles, which are respectively arranged on the inner and outer sides of the top surface of the annular flotation tank, and an annular chute is provided on the sides of the two annular vertical baffles close to each other, and a slide rod slides in each annular chute, and a connecting shaft arranged along the radial direction of the annular flotation tank is fixedly connected between the two slide rods;

[0011] A connecting plate arranged in a vertical direction is fixedly connected to the connecting shaft, and an arc-shaped slag scooping box adapted to the annular flotation tank is fixedly connected to the lower end of the connecting plate;

[0012] A vehicle body which moves along the circumference of the annular air flotation pool is arranged on the top of the annular vertical partition, and a guide frame which is rotatably connected with the connecting shaft is movably penetrated on the vehicle body along the vertical direction.

[0013] Optionally, the annular chute is composed of a long arc groove provided at the proximal end of the lower end of the annular vertical partition, a short arc groove provided at the proximal end of the upper end of the annular vertical partition, and a first inclined groove and a second inclined groove respectively connected to both ends of the short arc groove and communicating with the long arc groove;

[0014] When the slide bar slides in the long arc groove, the arc-shaped slag scoop box is located below the liquid surface of the annular flotation tank; when the slide bar slides in the short arc groove, the arc-shaped slag scoop box is located above the collection well.

[0015] Optionally, the arc-shaped slag scooping box is composed of a fixed half box and a movable half box that cooperate with each other;

[0016] The fixed half box is fixed to the lower end of the connecting plate. A contraction groove adapted to the movable half box is provided in the fixed half box. A telescopic spring for applying an outward elastic force to the movable half box is provided in the contraction groove.

[0017] Optionally, the movable half box is rotatably connected to an outer side surface away from the fixed half box with a roller, and the roller is distributed along the radial direction of the annular flotation tank.

[0018] Optionally, an incomplete gear is fixedly connected to the proximal end of one end of the connecting shaft, and an arc-shaped rack located below the short arc groove and matching the incomplete gear is fixed on the side of the corresponding annular vertical partition, and the corresponding central angle of the teeth of the incomplete gear is between 90° and 180°.

[0019] Optionally, the guide frame includes a plurality of guide rods that move vertically through the vehicle body, and a sleeve that is movably mounted on the connecting shaft is fixedly connected to the lower end of each guide rod, and a torsion spring is arranged in each sleeve, one of the torsion arms of the torsion spring is connected to the sleeve, and the other torsion arm of the torsion spring is connected to the connecting shaft. In the natural state, the arc-shaped slag box is in a horizontal posture.

[0020] Optionally, the top of the annular vertical partition is integrally formed with a flange, and the vehicle body includes a vehicle plate arranged along the radial direction of the annular flotation tank, and a first side plate and a second side plate are fixedly connected to both ends of the vehicle plate respectively;

[0021] Two first wheels are distributed on the first side plate, respectively located on the upper and lower sides of the corresponding flange; a connecting rod is fixedly connected to the outer side of the first side plate, and a support platform is provided at the central axis of the annular flotation tank, and the end of the connecting rod away from the first side plate is rotatably connected to the support platform.

[0022] Optionally, the second side panel is provided with a second wheel and a driving gear respectively located on the upper and lower sides of the corresponding flange, a gear ring is fixedly connected to the bottom surface of one of the flanges, the driving gear is meshed with the gear ring, and a motor connected to the driving gear is installed on the second side panel.

[0023] The present invention also proposes a wastewater treatment method for a waste incineration power plant, comprising the following steps:

[0024] Step 1: The wastewater in the waste incineration power plant enters the primary treatment unit and undergoes coarse screening;

[0025] Step 2: The sewage after coarse screening enters the sedimentation treatment unit for solid-liquid separation;

[0026] Step 3: The wastewater after solid-liquid separation enters the biochemical treatment unit, where microorganisms are used to degrade organic matter in the wastewater;

[0027] Step 4: The degraded sewage enters the filtration treatment unit to remove tiny particles and microorganisms in the sewage;

[0028] Step 5: Disinfect the sewage treated above by a disinfection treatment unit.

[0029] Compared with the prior art, the present invention provides a wastewater treatment system and method for a waste incineration power plant, which has the following beneficial effects:

[0030] 1. The present invention comprises an annular coagulation sedimentation tank, an annular flotation tank, and a circular regulating tank. A coagulant is first used to treat sewage in the annular coagulation sedimentation tank, causing colloidal particles and suspended matter in the sewage to condense into larger flocs for sedimentation and separation. The sewage is then fed into the annular flotation tank, where a large number of fine bubbles are generated. These bubbles cause pollutants such as suspended matter and grease that are difficult to settle in the sewage to adhere to the bubbles and float to the water surface, where they are effectively removed. Therefore, the coagulation sedimentation tank and the annular flotation tank are integrated into one design, eliminating the need for long-distance sewage transportation and significantly reducing the treatment cost of the present invention.

[0031] 2. The sedimentation treatment unit of the present invention adopts an annular design, which can achieve a larger treatment capacity within a limited floor area, thereby improving land utilization; and due to its compact structure, it is convenient for centralized management and maintenance.

[0032] 3. The present invention provides a collection well and a slag scooping mechanism. Under normal conditions, the arc-shaped slag scooping box is horizontal and located below the liquid surface of the annular flotation tank. It moves circumferentially along the annular flotation tank, thereby gathering the slag on the liquid surface of the annular flotation tank toward the collection well. Then, through the cooperation of the slide rod and the first chute, the arc-shaped slag scooping box can automatically move upward to the top of the collection well. Subsequently, through the cooperation of the incomplete gear and the arc-shaped rack, the arc-shaped slag scooping box can be driven to flip, and the slag scooped out of the arc-shaped slag scooping box can be poured into the collection well, thereby achieving effective separation of solids. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a block diagram of the sewage treatment system of the present invention;

[0034] Figure 2 is a top view of the precipitation treatment unit of the present invention;

[0035] Figure 3 This is a partial cross-sectional view of the annular flotation tank of the present invention;

[0036] Figure 4 This is a schematic structural diagram of the arc-shaped slag scooping box of the present invention;

[0037] Figure 5 Schematic diagram of the structure of the slide bar of the present invention;

[0038] Figure 6 It is a structural schematic diagram of the annular chute of the present invention;

[0039] Figure 7 This is a cross-sectional view of the structure of the fixed half box of the present invention;

[0040] Figure 8 It is a structural schematic diagram of the guide frame of the present invention;

[0041] Figure 9 for Figure 3A local enlarged schematic diagram of point A in the middle.

[0042] In the figure: 1. Preliminary treatment unit; 2. Sedimentation treatment unit; 201. Annular coagulation sedimentation tank; 202. Annular flotation tank; 203. Circular regulating tank; 3. Biochemical treatment unit; 4. Filtration treatment unit; 5. Disinfection treatment unit; 6. Collection well; 7. Slag scooping mechanism; 701. Annular vertical partition; 702. Annular chute; 7021. Long arc chute; 7022. Short arc chute; 7023. First chute; 7024. Second chute; 703. Sliding rod; 704. Connecting shaft; 705. Connecting plate; 706. Arc scooping box; 707. 061. Fixed half box; 7062. Movable half box; 707. Vehicle body; 7071. Vehicle plate; 7072. First side plate; 7073. Second side plate; 7074. First wheel; 7075. Connecting rod; 7076. Driving gear; 7077. Motor; 7078. Second wheel; 708. Guide frame; 7081. Guide rod; 7082. Sleeve; 7083. Torsion spring; 709. Incomplete gear; 7010. Arc rack; 8. Contraction groove; 9. Telescopic spring; 10. Flanging; 11. Roller; 12. Gear ring. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] Example 1: Please refer to Figures 1 to 9 A wastewater treatment system and method for a waste incineration power plant comprises a preliminary treatment unit 1, a sedimentation treatment unit 2, a biochemical treatment unit 3, a filtration treatment unit 4, and a disinfection treatment unit 5, which are sequentially arranged along the flow direction of the wastewater. The preliminary treatment unit 1 comprises a water collection well and a screen machine, which are sequentially arranged along the flow direction of the wastewater. The wastewater generated in the waste incineration power plant enters the water collection well for collection and is then coarsely filtered through the screen machine to remove larger impurities in the wastewater. The biochemical treatment unit 3 comprises an anaerobic tank, an anoxic tank, and an aerobic tank, which are sequentially arranged along the flow direction of the wastewater. These tanks utilize microorganisms to degrade organic matter in the wastewater. The filtration treatment unit 4 comprises a bag filter, an ultrafilter, and a reverse osmosis filter, which are sequentially arranged along the flow direction of the wastewater. These filter units effectively remove tiny particles and microorganisms from the wastewater. The disinfection treatment unit 5 comprises an activated carbon adsorption tank, an ultraviolet disinfection tank, and a clear water tank, which are sequentially arranged along the flow direction of the wastewater. The activated carbon is first used to adsorb the wastewater, and then ultraviolet rays are used to sterilize and disinfect the wastewater, so that the wastewater entering the clear water tank meets national emission standards.

[0045] In this embodiment, the sedimentation treatment unit 2 includes an annular coagulation sedimentation tank 201, an annular flotation tank 202 and a circular regulating tank 203 arranged in sequence from the outside to the inside. The annular coagulation sedimentation tank 201 is connected to the preliminary treatment unit 1 through a pipeline, and the circular regulating tank 203 is connected to the biochemical treatment unit 3 through a pipeline.

[0046] Specifically, the annular flotation tank 202 is equipped with a releaser inside and an air dissolving mechanism outside. The output end of the air dissolving mechanism is connected to the releaser, generating a large number of fine bubbles in the water. This is prior art and will not be described in detail here. The annular flotation tank 202 is provided with a collection well 6, the liquid level of which is lower than the top surface of the collection well 6. The annular flotation tank 202 is also provided with a slag scooping mechanism 7 for collecting slag into the collection well 6. First, the sewage is treated with a coagulant in the annular coagulation sedimentation tank 201, so that the colloidal particles and suspended matter in the sewage are condensed into larger flocs for sedimentation and separation. The sewage is then sent to the annular flotation tank 202, which generates a large number of fine bubbles. Pollutants such as suspended matter and grease that are difficult to settle in the sewage are attached to the bubbles and float to the water surface, thereby being effectively removed. Finally, the sewage is sent to the subsequent treatment process through the circular regulating tank 203, which helps to reduce the burden of the subsequent treatment process and improve the overall treatment efficiency.

[0047] It should be noted that an overflow hole is located at the top of the sidewall between the annular coagulation sedimentation tank 201 and the annular flotation tank 202. A gate is located within the overflow hole. When the gate is closed, the annular coagulation sedimentation tank 201 and the annular flotation tank 202 are disconnected. When the gate is open, water in the annular coagulation sedimentation tank 201 automatically flows into the annular flotation tank 202 through the overflow hole. Therefore, the present invention eliminates the need for numerous pipelines to pump sewage, helping to reduce sewage treatment costs.

[0048] In existing technology, flotation machines typically generate a large number of fine bubbles in water. These highly dispersed air bubbles attach to suspended particles, creating a state with a density lower than that of water. Buoyancy then causes these particles to float to the surface, achieving solid-liquid separation. Furthermore, a scraper is often used in conjunction with the flotation machine to scrape the scum layer from the water surface into a scum tank or collection container.

[0049] However, the existing flotation machine is generally long and narrow, and the scraper used is also long and narrow, which cannot adapt to the annular flotation tank 202 of this application. Therefore, a unique design is made for the slag removal mechanism 7, and the specific design is as follows:

[0050] The slag scooping mechanism 7 includes two annular vertical baffles 701 distributed in a concentric circle. The two annular vertical baffles 701 are respectively arranged on the inner and outer sides of the top surface of the annular flotation tank 202, and the two annular vertical baffles 701 coincide with the central axis of the annular flotation tank 202. An annular chute 702 is provided on the side surfaces of the two annular vertical baffles 701 close to each other. A slide rod 703 slides in each annular chute 702. A connecting shaft 704 arranged along the radial direction of the annular flotation tank 202 is fixedly connected between the two slide rods 703. Figures 3 to 6 As shown, when the slide rod 703 slides within the annular chute 702, it drives the connecting shaft 704 to move circumferentially along the annular flotation tank 202. A vertically disposed connecting plate 705 is fixedly connected to the connecting shaft 704. An arc-shaped slag scooping box 706 adapted for the annular flotation tank 202 is fixedly attached to the lower end of the connecting plate 705. The upper end of the arc-shaped slag scooping box 706 is open, allowing it to scoop up slag within the annular flotation tank 202.

[0051] The slag scooping mechanism 7 also includes a vehicle body 707 disposed atop an annular vertical baffle 701, which is configured to move circumferentially along the annular flotation tank 202. In this embodiment, a flange 10 is integrally formed on the top of the annular vertical baffle 701, with a gear ring 12 fixedly connected to the bottom of one of the flanges 10. The vehicle body 707 includes a vehicle plate 7071 radially disposed along the annular flotation tank 202, with a first side plate 7072 and a second side plate 7073 fixedly connected to each end of the vehicle plate 7071. The first side plate 7072 is provided with two first wheels 7074, located on the upper and lower sides of the corresponding flange 10, respectively, and capable of circumferential movement along the flange. Furthermore, a connecting rod 7075 is fixedly connected to the outer surface of the first side plate 7072. A support platform is provided at the central axis of the annular flotation tank 202. The end of the connecting rod 7075, which is away from the first side plate 7072, is rotatably connected to the support platform. Through the cooperation between the connecting rod 7075 and the support platform, the vehicle plate 7071 can stably move along the circumference of the annular flotation tank 202. Finally, the second side plate 7073 is provided with second wheels 7078 and drive gears 7076, respectively located on the upper and lower sides of the corresponding flange 10. The drive gears 7076 mesh with the ring gear 12. A motor 7077, drivingly connected to the drive gears 7076, is mounted on the second side plate 7073. When the motor 7077 drives the driving gear 7076 to rotate, the driving gear 7076 is engaged with the ring gear 12 , so that the vehicle plate 7071 can move circumferentially along the flange 10 , thereby enabling the arc-shaped slag box 706 to move circumferentially within the annular flotation tank 202 .

[0052] In addition, a guide frame 708 movably penetrates the vehicle body 707 in the vertical direction and is rotatably connected to the connecting shaft 704. The guide frame 708 allows the connecting shaft 704 to move along with the vehicle body 707 and simultaneously allows the connecting shaft 704 to move up and down along with the slide bar 703. In this embodiment, the guide frame 708 includes a plurality of guide rods 7081 that movably penetrate the vehicle body 707 in the vertical direction. A sleeve 7082 movably sleeved on the connecting shaft 704 is fixedly connected to the lower end of each guide rod 7081, and the connecting shaft 704 can rotate within the sleeve 7082. A torsion spring 7083 is provided in each sleeve 7082. One of the torsion arms of the torsion spring 7083 is connected to the sleeve 7082, and the other torsion arm of the torsion spring 7083 is connected to the connecting shaft 704. Figure 8 In a normal state, the torsion force of the torsion spring 7083 keeps the connecting plate 705 in a vertical state.

[0053] It is worth mentioning that the annular chute 702 is composed of a long arc groove 7021 provided at the proximal end of the lower end of the annular vertical partition 701, a short arc groove 7022 provided at the proximal end of the upper end of the annular vertical partition 701, and a first inclined groove 7023 and a second inclined groove 7024 respectively connected to both ends of the short arc groove 7022 and communicating with the long arc groove 7021. Figure 6 As shown. When the slide bar 703 slides within the long arc groove 7021, the connecting plate 705 is at its lowest point, positioning the arc-shaped slag scoop box 706 below the liquid level in the annular flotation tank 202. Simultaneously, the torsion spring 7083 maintains the arc-shaped slag scoop box 706 horizontally. When the slide bar 703 moves within the first chute 7023, it drives the connecting shaft 704 upward, thereby driving the arc-shaped slag scoop box 706 upward, thereby scooping up the slag in the annular flotation tank 202. When the slide bar 703 slides within the short arc groove 7022, the arc-shaped slag scoop box 706 is located above the collection well 6. When the slide bar 703 slides within the second chute 7024, it drives the arc-shaped slag scoop box 706 downward until the slide bar 703 slides into the long arc groove 7021, whereupon the arc-shaped slag scoop box 706 re-enters the liquid level in the annular flotation tank 202.

[0054] The structure of the arc-shaped slag box 706 is described below:

[0055] The arc-shaped slag scooping box 706 is composed of a fixed half-box 7061 and a movable half-box 7062 that cooperate with each other. The movable half-box 7062 can retract within the fixed half-box 7061. When the slide bar 703 slides within the first chute 7023, the movable half-box 7062 contacts the collection well 6, thereby causing the arc-shaped slag scooping box 706 to retract, allowing the arc-shaped slag scooping box 706 to move smoothly upward. At the same time, a large gap is not left between the arc-shaped slag scooping box 706 and the collection well 6, effectively scooping all slag in the annular flotation tank 202. Specifically, the fixed half-box 7061 is fixed to the lower end of the connecting plate 705. A retraction groove 8 is defined within the fixed half-box 7061 to accommodate the movable half-box 7062. The movable half-box 7062 can retract within the retraction groove 8. A telescopic spring 9 is provided in the contraction groove 8 to apply an outward elastic force to the movable half box 7062, so that the movable half box 7062 is in an extended state under normal conditions. A protrusion located in the contraction groove 8 is fixed to the movable half box 7062 to prevent the movable half box 7062 from disengaging from the fixed half box 7061.

[0056] Preferably, the movable half-box 7062 is rotatably connected to a roller 11 on an outer side away from the fixed half-box 7061. The roller 11 is distributed radially along the annular flotation tank 202. The provision of the roller 11 prevents the movable half-box 7062 from directly contacting the collection well 6, thereby preventing wear on the movable half-box 7062. During use, when the slide bar 703 slides within the first chute 7023, it drives the arc-shaped slag scooping box 706 upward. Simultaneously, the roller 11 contacts the outer surface of the collection well 6, causing the arc-shaped slag scooping box 706 to retract, thereby preventing friction between the movable half-box 7062 and the collection well 6.

[0057] It should be noted that one of the proximal ends of the connecting shaft 704 is fixedly connected to an incomplete gear 709. An arc-shaped rack 7010 is fixed on the side of the corresponding annular vertical partition 701 and is located below the short arc groove 7022 and matches the incomplete gear 709. The central angle of the teeth of the incomplete gear 709 is between 90° and 180°. In the natural state, under the action of the torsion spring 7083, the arc-shaped slag box 706 is in Horizontal posture When the slide bar 703 slides within the short arc groove 7022 and the incomplete gear 709 meshes with the arc-shaped rack 7010, it drives the connecting shaft 704 to rotate clockwise, causing the arc-shaped slag scoop box 706 to flip, thereby emptying the slag inside the arc-shaped slag scoop box 706 into the collection well 6. Furthermore, the arc-shaped slag scoop box 706 can rotate an angle greater than 90° and less than 180°, thereby completely emptying the slag inside the arc-shaped slag scoop box 706 and preventing it from accumulating. When the incomplete gear 709 completely passes the arc-shaped rack 7010, the torsion spring 7083 returns the arc-shaped slag scoop box 706 to a horizontal position.

[0058] Example 2: This application proposes a wastewater treatment method for a waste incineration power plant, which is applicable to the wastewater treatment system for a waste incineration power plant in Example 1, and includes the following steps:

[0059] Step 1: The wastewater in the waste incineration power plant enters the preliminary treatment unit 1 and undergoes coarse screening;

[0060] The sewage generated in the waste incineration power plant is first collected in the collection well through pipes, and then coarsely filtered through equipment such as screen machines to remove larger impurities in the sewage.

[0061] Step 2: The sewage after coarse screening enters the sedimentation treatment unit 2 for solid-liquid separation;

[0062] The wastewater first enters the annular coagulation and sedimentation tank 201, where a coagulant is added to aggregate impurities into larger flocs, which then settle. The wastewater then enters the annular flotation tank 202, where a large number of fine bubbles are generated. These bubbles cause pollutants such as suspended solids and grease in the wastewater to adhere to the bubbles and rise to the surface, forming scum.

[0063] The vehicle body 707 moves circumferentially along the annular flotation tank 202, driving the slide bar 703 to slide in the annular chute 702. When the slide bar 703 slides in the long arc groove 7021, the arc-shaped slag scooping box 706 is located below the liquid surface of the annular flotation tank 202, so the slag can be gathered together through the connecting plate 705.

[0064] When the slide bar 703 slides in the first chute 7023 , it can drive the arc-shaped slag scooping box 706 to move upward. At the same time, the roller 11 contacts the collection well 6 , driving the arc-shaped slag scooping box 706 to contract, thereby scooping up the slag.

[0065] When the slide bar 703 slides in the short arc groove 7022 and the incomplete gear 709 engages with the arc rack 7010, it can drive the connecting shaft 704 to rotate clockwise, so that the arc-shaped slag box 706 is turned over, thereby pouring the slag in the arc-shaped slag box 706 into the collection well 6.

[0066] When the slide bar 703 slides in the second chute 7024 , the arc-shaped slag scooping box 706 is gradually turned to a horizontal state under the action of the torsion spring 7083 and extends below the liquid surface of the annular flotation tank 202 .

[0067] This process is repeated until all the scum in the annular flotation tank 202 is scooped into the collection well 6 .

[0068] Step 3: After solid-liquid separation, the wastewater enters the biochemical treatment unit 3 and is treated in sequence by the oxygen pressure tank, the anoxic tank and the aerobic tank, where microorganisms can be used to degrade organic matter in the wastewater.

[0069] Step 4: The degraded sewage enters the filtration treatment unit 4, and passes through the bag filter, ultrafilter and reverse osmosis filter to effectively remove the tiny particles and microorganisms in the sewage;

[0070] Step 5: The treated sewage is disinfected by the disinfection treatment unit 5. Specifically, the bacteria and pathogens remaining in the water are firstly killed by activated carbon adsorption and then by ultraviolet rays, so that the water meets the environmental discharge standards.

[0071] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0072] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A wastewater treatment system for a waste incineration power plant, characterized in that: It comprises a preliminary treatment unit (1), a sedimentation treatment unit (2), a biochemical treatment unit (3), a filtration treatment unit (4) and a disinfection treatment unit (5) which are arranged in sequence along the flow direction of the sewage; The sedimentation treatment unit (2) comprises an annular coagulation sedimentation tank (201), an annular flotation tank (202), and a circular regulating tank (203) arranged in sequence from the outside to the inside, the annular coagulation sedimentation tank (201) is conductively connected to the preliminary treatment unit (1) via a pipeline, and the circular regulating tank (203) is conductively connected to the biochemical treatment unit (3) via a pipeline; A releaser is provided inside the annular air flotation tank (202), and an air dissolving mechanism is provided outside the annular air flotation tank (202), wherein the output end of the air dissolving mechanism is connected to the releaser; A collection well (6) is provided in the annular flotation tank (202), and the liquid level in the annular flotation tank (202) is lower than the top surface of the collection well (6); a slag scooping mechanism (7) for scooping slag into the collection well (6) is provided on the annular flotation tank (202); The slag scooping mechanism (7) comprises two concentrically distributed annular vertical baffles (701), the two annular vertical baffles (701) being respectively arranged on the inner and outer sides of the top surface of the annular flotation tank (202), annular chutes (702) being arranged on the sides of the two annular vertical baffles (701) close to each other, a slide bar (703) sliding in each annular chute (702), and a connecting shaft (704) arranged along the radial direction of the annular flotation tank (202) being fixedly connected between the two slide bars (703); A connecting plate (705) arranged in a vertical direction is fixedly connected to the connecting shaft (704), and an arc-shaped slag scooping box (706) adapted to the annular flotation tank (202) is fixedly connected to the lower end of the connecting plate (705); A vehicle body (707) that moves circumferentially along the annular flotation tank (202) is provided on top of the annular vertical partition (701), and a guide frame (708) that is rotatably connected to the connecting shaft (704) is movably provided on the vehicle body (707) in the vertical direction. The annular chute (702) is composed of a long arc groove (7021) provided at the proximal end of the lower end of the annular vertical partition (701), a short arc groove (7022) provided at the proximal end of the upper end of the annular vertical partition (701), and a first inclined groove (7023) and a second inclined groove (7024) respectively connected to both ends of the short arc groove (7022) and communicating with the long arc groove (7021); When the slide bar (703) slides in the long arc groove (7021), the arc-shaped slag scooping box (706) is located below the liquid surface of the annular flotation tank (202); when the slide bar (703) slides in the short arc groove (7022), the arc-shaped slag scooping box (706) is located above the collection well (6); The arc-shaped slag scooping box (706) is composed of a fixed half box (7061) and a movable half box (7062) that cooperate with each other; The fixed half box (7061) is fixed to the lower end of the connecting plate (705), and a contraction groove (8) adapted to the movable half box (7062) is provided in the fixed half box (7061). A telescopic spring (9) for applying an outward elastic force to the movable half box (7062) is provided in the contraction groove (8).

2. A wastewater treatment system for a waste incineration power plant according to claim 1, characterized in that: The movable half box (7062) is rotatably connected to a roller (11) on an outer side surface away from the fixed half box (7061), and the roller (11) is distributed along the radial direction of the annular flotation tank (202).

3. The wastewater treatment system for a waste incineration power plant according to claim 1, characterized in that: An incomplete gear (709) is fixedly connected to the proximal end of one end of the connecting shaft (704), and an arc-shaped rack (7010) is fixed on the side of the corresponding annular vertical partition (701) and is located below the short arc groove (7022) and matched with the incomplete gear (709). The central angle of the teeth of the incomplete gear (709) is between 90° and 180°.

4. The wastewater treatment system for a waste incineration power plant according to claim 1, characterized in that: The guide frame (708) includes a plurality of guide rods (7081) that are movable along the vertical direction and pass through the vehicle body (707). A sleeve (7082) that is movably sleeved on the connecting shaft (704) is fixedly connected to the lower end of each guide rod (7081). A torsion spring (7083) is provided in each sleeve (7082). One torsion arm of the torsion spring (7083) is connected to the sleeve (7082), and the other torsion arm of the torsion spring (7083) is connected to the connecting shaft (704). In a natural state, the arc-shaped slag scooping box (706) is in a horizontal posture.

5. The wastewater treatment system for a waste incineration power plant according to claim 1, characterized in that: The top of the annular vertical partition (701) is integrally formed with a flange (10), and the vehicle body (707) comprises a vehicle plate (7071) radially arranged along the annular flotation tank (202), with a first side plate (7072) and a second side plate (7073) fixedly connected to both ends of the vehicle plate (7071). Two first wheels (7074) are distributed on the first side plate (7072), respectively located on the upper and lower sides of the corresponding flange (10); a connecting rod (7075) is fixedly connected to the outer side surface of the first side plate (7072); a support platform is provided at the central axis of the annular flotation tank (202); and one end of the connecting rod (7075) away from the first side plate (7072) is rotatably connected to the support platform.

6. A wastewater treatment system for a waste incineration power plant according to claim 5, characterized in that: The second side plate (7073) is provided with a second wheel (7078) and a driving gear (7076) respectively located on the upper and lower sides of the corresponding flange (10). A ring gear (12) is fixedly connected to the bottom surface of one of the flanges (10). The driving gear (7076) is meshed with the ring gear (12). A motor (7077) is installed on the second side plate (7073) and is transmission-connected to the driving gear (7076).

7. A method for treating wastewater in a waste incineration power plant, applicable to the wastewater treatment system for a waste incineration power plant according to any one of claims 1 to 6, characterized in that: The steps include: Step 1: The wastewater in the waste incineration power plant enters the preliminary treatment unit (1) and undergoes coarse screening; Step 2: The sewage after coarse screening enters the sedimentation treatment unit (2) for solid-liquid separation; Step 3: The wastewater after solid-liquid separation enters the biochemical treatment unit (3), where microorganisms are used to degrade organic matter in the wastewater; Step 4: The degraded sewage enters the filtration treatment unit (4) to remove tiny particles and microorganisms in the sewage; Step 5: disinfect the sewage after the above treatment through the disinfection treatment unit (5).

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