A sewage treatment system for in-situ recovery of magnetic catalyst

Abstract

The invention relates to a sewage treatment system for in-situ recovery of magnetic catalysts, comprising at least one reactor, a sludge treatment device and a water collection tank, wherein a drainage port and a sludge discharge port at the bottom of the reactor are respectively connected to the water collection tank and the sludge treatment device; the reactor is provided with an oxidant inlet and a coagulant inlet, which are respectively used to input the oxidant and the coagulant into the reactor; a liftable porous plate is provided at the bottom of the reactor for carrying fluidized fillers and catalysts, a magnetic coating device is provided outside the lower part of the reactor, when catalytic oxidation is performed, the magnetic coating device is opened, the catalyst is not attracted and can flow freely, an aeration device is provided below the porous plate, so that the catalyst is in a fluidized state; when coagulation and sedimentation are performed, the magnetic coating device is closed and tightly wrapped around the reactor, and can attract the catalyst on the porous plate.

Description

Technical Field

[0001] The invention belongs to the technical field of water pollution treatment, and in particular relates to a sewage treatment system for in-situ recovery of magnetic catalysts. Background Art

[0002] As common water treatment processes, catalytic oxidation and coagulation sedimentation have good removal effects on pollutants in wastewater. Among them, catalytic oxidation technology has a fast reaction speed and a short treatment cycle, which can meet the needs of rapid degradation of pollutants. Coagulation sedimentation technology is simple to operate, the treatment method is mature, and the treatment effect is relatively stable. Both have been widely used.

[0003] The current sewage treatment process mainly involves chemical catalytic oxidation followed by coagulation and sedimentation, which requires at least two reactors, as well as pumps, pipelines and other auxiliary equipment between the two reactors, which occupies a large area. In addition, the current catalytic oxidation process generally requires catalyst recovery and catalyst reuse, and these two processes are independent, requiring not only additional equipment, but also additional management and maintenance, which increases operating time and costs. Summary of the invention

[0004] In view of the above problems, the present invention provides a sewage treatment system for in-situ recovery of magnetic catalysts, which integrates catalytic oxidation and coagulation sedimentation into an integrated design, saving construction costs. While efficiently treating organic wastewater, it solves the problem that the existing magnetic catalysts cannot be continuously utilized after recovery.

[0005] The sewage treatment system for in-situ recovery of magnetic catalysts comprises at least one reactor, a sludge treatment device and a water collection tank, wherein the drainage port and the sludge discharge port at the bottom of the reactor are connected to the water collection tank and the sludge treatment device respectively;

[0006] The reactor is provided with an oxidant inlet and a coagulant inlet, which are used to input the oxidant and the coagulant into the reactor respectively;

[0007] The lower part of the reactor is provided with a liftable porous plate for carrying fluidized filler and catalyst. The outside of the lower part of the reactor is provided with a magnetic coating device. When catalytic oxidation is performed, the magnetic coating device is open, the catalyst is not attracted and can flow freely, and an aeration device is provided under the porous plate to keep the catalyst in a fluidized state; when coagulation and sedimentation are performed, the magnetic coating device is closed and tightly wrapped around the reactor, and can attract the catalyst on the porous plate.

[0008] Optionally, the reactor is cylindrical and comprises an upper reaction zone and a lower mud discharge zone, and a porous plate is provided between the reaction zone and the mud discharge zone;

[0009] The top side wall of the reaction zone is provided with a water inlet and a cleaning nozzle, and the upper part is provided with a real-time monitor that can be raised and lowered to monitor the water level and water quality of the reactor in real time;

[0010] An oxidant dosing circulation device and a coagulant dosing circulation device are arranged outside the reaction zone for adding oxidant and coagulant to the reactor.

[0011] Further optionally, the oxidant dosing circulation device includes an oxidant circulation outlet, an oxidant tank and an oxidant inlet connected in sequence, the oxidant circulation outlet is arranged at the upper part of the reaction zone and is connected to the inlet of the oxidant tank through a first oxidant pump, and the oxidant inlet is arranged at the lower part of the reaction zone and is connected to the outlet of the oxidant tank through a second oxidant pump.

[0012] Further optionally, the coagulant addition circulation device includes a coagulant circulation outlet, a coagulant tank and a coagulant inlet connected in sequence, the coagulant circulation outlet is arranged at the upper part of the reaction zone and is connected to the inlet of the coagulant tank through a first coagulant pump, and the coagulant inlet is arranged at the lower part of the reaction zone and is connected to the outlet of the coagulant tank through a second coagulant pump.

[0013] Optionally, the real-time monitor is connected to a first telescopic rod above, the top of the first telescopic rod passes through the top plate of the reactor and is connected to a first driving device above the reactor, and the first driving device controls the length of the first telescopic rod, thereby realizing the lifting and lowering of the real-time monitor.

[0014] Optionally, the porous plate is circular, and includes a central through hole, an isolation ring, a recessed area and a platform area in sequence from the center of the circle along the radial direction outward, the isolation ring is a vertical cylindrical curved surface and surrounds the periphery of the central through hole, and the top of the isolation ring is higher than the upper surface of the recessed area, which is used to prevent the fluidized filler and catalyst on the porous plate from falling from the central through hole;

[0015] The upper surface of the depression area is lower than the upper surface of the platform area, that is, the thickness of the depression area is less than the thickness of the platform area, and the ratio of the area of ​​the depression area to the area of ​​the platform area is (2-4):1.

[0016] Optionally, the upper surface of the porous plate is covered with a layer of flexible screen, the center of the screen passes through the central through hole and extends to the bottom of the porous plate.

[0017] Optionally, a circle of inwardly protruding fixed platforms is provided at the position of the porous plate corresponding to the inner wall at the bottom of the reaction zone, and matching overlapping steps are provided at the overlapping position of the fixed platform and the porous plate. When the porous plate is between the reaction zone and the mud discharge zone, the fixed platform supports the edge of the platform area of ​​the porous plate, and the platform area is flush with the upper surface of the fixed platform.

[0018] Optionally, the porous plate is connected to a second driving device above the reactor through a second telescopic rod passing through the reactor top plate to achieve the up and down movement of the porous plate. Specifically, the bottom of the second telescopic rod includes a limit block, a thin rod and a thick rod from bottom to top, and the size of the limit block is larger than the central through hole, so that the limit block is always below the porous plate and drives the porous plate to move up and down;

[0019] The thin rod is provided with a circle of retractable tooth hooks, and there is a hole in the center of the screen, and the bottom of the second telescopic rod passes through the hole; when the tooth hook is extended, it can hook the screen below the porous plate when the second telescopic rod rises, and drive the screen to move up together, thereby pulling the screen on the surface of the porous plate into a cone shape, so that the fluidized filler and catalyst on the porous plate fall to the edge of the porous plate, which is convenient for the magnetic coating device to attract; when the tooth hook is retracted to the inside of the thin rod, the screen is not pulled, and the screen is laid flat on the porous plate;

[0020] The radius of the thick rod is larger than the radius of the thin rod, and slightly smaller than the inner diameter of the central through hole and the isolation ring, so that the thick rod can move in the central through hole and the isolation ring.

[0021] Optionally, the magnetic coating device includes at least two magnet coating frames, each magnet coating frame is provided with a hydraulic rod on the side away from the reactor, the hydraulic rod is connected to the hydraulic cylinder, and is used to drive the magnet coating frame to move. After all the magnet coating frames are combined, they can be docked and assembled with each other and tightly surround the outside of the reactor and cling to the side wall of the reactor, so as to attract the magnetic catalyst on the porous plate to the inner wall of the reactor; when the hydraulic rod pulls the magnet coating frame away from the reactor, the magnet coating frame opens and detaches from the side wall of the reactor, and the catalyst is not attracted.

[0022] Optionally, a drainage port is provided at the bottom of the reaction zone, the mud discharge zone is conical, the mud discharge port is provided at the bottom of the mud discharge zone, and the aeration device is connected to an aeration device outside the reactor;

[0023] The water collection tank is connected to the cleaning nozzle through a pipeline, and the treated produced water is used to clean the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of a sewage treatment system for in-situ recovery of magnetic catalysts;

[0025] Figure 2 It is a schematic diagram of the structure of the porous plate and the fixed platform;

[0026] Figure 3 is a schematic diagram of the connection structure between the porous plate and the second telescopic rod;

[0027] Figure 4 Schematic diagram of the structure of the thin rod.

[0028] In the accompanying drawings, 1-reactor, 2-hydraulic rod, 3-magnet coating frame, 4-drain outlet, 5-mud outlet, 6-oxidant inlet, 7-coagulant inlet, 8-porous plate, 9-aeration device, 10-water inlet, 11-cleaning nozzle, 12-real-time monitor, 13-oxidant circulation outlet, 14-oxidant tank, 15-coagulant circulation outlet, 16-coagulant tank, 17-first telescopic rod, 18-center through hole, 19-isolation ring, 20-depression area, 21-platform area, 22-screen, 23-fixed platform, 24-second telescopic rod, 25-limiting block, 26-thin rod, 27-thick rod, 28-tooth hook. DETAILED DESCRIPTION

[0029] This embodiment provides a wastewater treatment system for in-situ recovery of magnetic catalysts, such as Figure 1-Figure 4 As shown, it includes at least one reactor 1, a sludge treatment device and a water collection tank, and the drain port 4 and the sludge discharge port 5 at the bottom of the reactor 1 are connected to the water collection tank and the sludge treatment device respectively;

[0030] The reactor 1 is provided with an oxidant inlet 6 and a coagulant inlet 7, which are used to input the oxidant and the coagulant into the reactor 1 respectively;

[0031] The lower part of the reactor 1 is provided with a liftable porous plate 8 for carrying fluidized filler and catalyst. The outer part of the lower part of the reactor 1 is provided with a magnetic coating device. When catalytic oxidation is performed, the magnetic coating device is open, the catalyst is not attracted and can flow freely, and an aeration device 9 is provided below the porous plate 8 to keep the catalyst in a fluidized state; when coagulation and sedimentation are performed, the magnetic coating device is closed and tightly wrapped around the reactor 1, and can attract the catalyst on the porous plate 8.

[0032] Optionally, the reactor 1 is cylindrical and includes an upper reaction zone and a lower mud discharge zone, and a porous plate 8 is provided between the reaction zone and the mud discharge zone;

[0033] The top side wall of the reaction zone is provided with a water inlet 10 and a cleaning nozzle 11, and the upper part is provided with a real-time monitor 12 that can be raised and lowered for real-time monitoring of the water level and water quality of the reactor 1;

[0034] An oxidant dosing circulation device and a coagulant dosing circulation device are provided outside the reaction zone for adding oxidant and coagulant to the reactor 1 .

[0035] Further optionally, the oxidant dosing circulation device comprises an oxidant circulation outlet 13, an oxidant tank 14 and an oxidant inlet 6 connected in sequence, the oxidant circulation outlet 13 is arranged at the upper part of the reaction zone, and is connected to the inlet of the oxidant tank 14 through a first oxidant pump, and the oxidant inlet 6 is arranged at the lower part of the reaction zone, and is connected to the outlet of the oxidant tank 14 through a second oxidant pump. The oxidant is selected from one or a mixture of hydrogen peroxide, potassium permonosulfate, potassium peroxydisulfate, sodium peroxymonosulfate, sodium peroxydisulfate, ammonium peroxymonosulfate, ammonium peroxydisulfate, calcium peroxide, calcium percarbonate, peracetic acid, and sodium perborate.

[0036] Further optionally, the coagulant dosing circulation device comprises a coagulant circulation outlet 15, a coagulant tank 16 and a coagulant inlet 7 connected in sequence, the coagulant circulation outlet 15 is arranged at the upper part of the reaction zone, and is connected to the inlet of the coagulant tank 16 through a first coagulant pump, and the coagulant inlet 7 is arranged at the lower part of the reaction zone, and is connected to the outlet of the coagulant tank 16 through a second coagulant pump. The coagulant can be added sequentially, for example, first add polyferric chloride, polyferric sulfate, polyaluminum chloride, polyaluminum sulfate, polyaluminum ferric chloride, polyaluminum ferric sulfate, etc., and then add polyacrylamide, polyvinyl alcohol, etc.

[0037] Optionally, the real-time monitor 12 is connected to the first telescopic rod 17 above, and the top of the first telescopic rod 17 passes through the top plate of the reactor 1 to connect to the first driving device above the reactor 1. The first driving device controls the length of the first telescopic rod 17, thereby realizing the lifting and lowering of the real-time monitor 12.

[0038] Optionally, the porous plate 8 is circular, and includes a central through hole 18, an isolation ring 19, a recessed area 20 and a platform area 21 in sequence from the center of the circle along the radial direction outward, the isolation ring 19 is a vertical cylindrical curved surface and surrounds the periphery of the central through hole 18, and the top of the isolation ring 19 is higher than the upper surface of the recessed area 20, which is used to prevent the fluidized filler and the granular catalyst on the porous plate 8 from falling from the central through hole 18;

[0039] The upper surface of the recessed area 20 is lower than the upper surface of the platform area 21, that is, the thickness of the recessed area 20 is less than the thickness of the platform area 21, and the ratio of the area of ​​the recessed area 20 to the area of ​​the platform area 21 is (2-4):1.

[0040] Optionally, the upper surface of the porous plate 8 is covered with a layer of flexible screen 22 , the center of the screen 22 passes through the central through hole 18 and extends to the bottom of the porous plate 8 . Figure 2 and Figure 3 In order to clearly show the screen 22, the screen 22 in the recessed area 20 is not in close contact with the upper surface of the recessed area 20. In actual use (when magnetically attracting the catalyst), it can be in close contact with the upper surface of the recessed area 20.

[0041] Optionally, a circle of inwardly protruding fixed platforms 23 is provided at the position of the porous plate 8 on the inner wall at the bottom of the reaction zone, and matching overlapping steps are provided at the overlapping positions of the fixed platforms 23 and the porous plate 8. When the porous plate 8 is between the reaction zone and the mud discharge zone, the fixed platforms 23 support the edge of the platform area 21 of the porous plate 8, and the platform area 21 is flush with the upper surface of the fixed platforms 23.

[0042] Optionally, the porous plate 8 is connected to the second driving device above the reactor 1 through the second telescopic rod 24 through the top plate of the reactor 1 to achieve the up and down movement of the porous plate 8. Specifically, the bottom of the second telescopic rod 24 includes a limit block 25, a thin rod 26 and a thick rod 27 from bottom to top, and the size of the limit block 25 is larger than the central through hole 18, so that the limit block 25 is always below the porous plate 8 and drives the porous plate 8 to move up and down;

[0043] The thin rod 26 is provided with a circle of retractable tooth hooks 28, and there is a hole in the center of the screen 22, through which the bottom of the second telescopic rod 24 passes; when the tooth hooks 28 are extended, they can hook the screen 22 below the porous plate 8 when the second telescopic rod 24 rises, and drive the screen 22 to move up together, thereby pulling the screen 22 on the surface of the porous plate 8 into a cone shape, so that the fluidized filler and catalyst on the porous plate 8 fall to the edge of the porous plate 8, which is convenient for the magnetic coating device to attract; when the tooth hooks 28 are retracted to the inside of the thin rod 26, the screen 22 is not pulled, and the screen 22 is laid flat on the porous plate 8;

[0044] The radius of the thick rod 27 is larger than the radius of the thin rod 26 , and slightly smaller than the inner diameter of the central through hole 18 and the isolation ring 19 , so that the thick rod 27 can move in the central through hole 18 and the isolation ring 19 .

[0045] In the present invention, the fluidized filler is granular, and the catalyst is a mixture of granular and powdery. The plate hole diameter of the porous plate 8 and the mesh diameter of the screen 22 are both smaller than the particle diameter of the fluidized filler and the granular catalyst, so that the fluidized filler and the granular catalyst are above the screen 22. The powdery catalyst can pass through the screen and the porous plate and be attracted by the magnet-coated frame.

[0046] Optionally, the magnetic coating device includes at least two magnet coating frames 3, each magnet coating frame 3 is provided with a hydraulic rod 2 on the side away from the reactor 1, the hydraulic rod 2 is connected to the hydraulic cylinder, and is used to drive the magnet coating frame 3 to move. After all the magnet coating frames 3 are combined, they can be docked and assembled with each other and tightly surround the outside of the reactor 1, and cling to the side wall of the reactor 1, so as to attract the magnetic catalyst on the porous plate 8 to the inner wall of the reactor 1 without affecting the subsequent coagulation treatment; when the hydraulic rod 2 pulls the magnet coating frame 3 away from the reactor 1, the magnet coating frame 3 opens and detaches from the side wall of the reactor 1, the catalyst is not attracted, and naturally falls on the porous plate 8, and can be catalytically oxidized again.

[0047] The magnet coating frame 3 is provided with through holes at positions corresponding to the drain port 4 and the aeration device 9, so as to facilitate the passage of the drainage pipe and the gas path. The telescopic mechanism of the tooth hook 28 can use a conventional telescopic mechanism, for example, the tops of several tooth hooks 28 are gathered, and the bottom hooks can diverge and form a circle, with the hooks facing outward, and a fixed ring with a smaller inner diameter is inserted from the top of the tooth hook 28. The opening and closing of a circle of tooth hooks 28 is controlled by moving the position of the fixed ring. When the fixed ring moves downward and constrains the tooth hooks 28, all the tooth hooks 28 are contracted in the thin rod 26. When the fixed ring moves upward, the bottom edge of the tooth hook 28 is released from the constraint and diverges, and the thin rod 26 is extended.

[0048] When the magnetic coating device of the present invention attracts the catalyst, there is also a fluidized filler on the porous plate 8. After aeration in the oxidation catalytic stage, the fluidized filler and the catalyst are fully mixed. It is difficult to fully attract most of the catalyst by the magnetic coating device. In view of this problem, the present invention covers the surface of the porous plate 8 with a screen 22, and drives the center of the screen 22 to rise through the tooth hook 28 at the bottom of the second telescopic rod 24 that can move up and down, and the fluidized filler and the granular catalyst roll down along the inclined surface of the screen 22 to the fixed platform 23 or the edge of the porous plate 8, so as to be attracted by the magnetic coating device.

[0049] Specifically, in the oxidation catalytic stage, the screen 22 is laid flat on the porous plate 8, penetrates into the central through hole 18 along the isolation ring 19, and extends to the bottom of the porous plate 8. At this time, the screen 22 does not form any inclined surface on the upper surface of the porous plate 8, but is laid along the upper surface of the porous plate 8; at this time, the second telescopic rod 24 is inside the reactor 1, and the bottom passes through the isolation ring 19 and the central through hole 18, and the thick rod 27 stays in the isolation ring 19 and the central through hole 18, and squeezes the screen 22 there to prevent the fluidized filler and the catalyst screen from leaking from the central through hole 18 to the mud discharge area during aeration, and at the same time fixes the screen 22 to prevent the screen 22 from escaping from the central through hole 18; the thin rod 26 and the limit block 25 pass through the hole in the center of the screen 22 and are located below the porous plate 8.

[0050] When the catalyst needs to be attracted, aeration is stopped, the tooth hook 28 extends the thin rod 26, and during the upward movement of the second telescopic rod 24, a circle of tooth hooks 28 hooks the screen 22 and drives the screen 22 to move upward, so that the screen 22 forms a cone on the porous plate 8, and the fluidized filler and the granular catalyst roll down along the inclined surface of the screen 22 to the edge of the fixed platform 23 or the porous plate 8 and are attracted by the magnetic coating device. When the limit block 25 contacts the lower surface of the porous plate 8, the second telescopic rod 24 stops moving upward.

[0051] If one wishes to improve the catalyst recovery rate and increase the amount of catalyst magnetically attracted, the second telescopic rod 24 can be moved downward to reset, and the tooth hook 28 can be retracted to reset the screen 22. A small amount of aeration can be performed for a short period of time to mix and reset the catalyst remaining on the screen 22 and the fluidized filler. Then, aeration can be stopped and the operation of moving the second telescopic rod 24 upward can be repeated to attract the catalyst again.

[0052] Before the coagulation and sedimentation stage, the second telescopic rod 24 is moved down and reset, and the screen 22 is reset. Through a short period of aeration, the fluidized filler is evenly distributed on the porous plate 8, and then the coagulant is input and aeration is started. The filler is fluidized, which promotes mass transfer and performs coagulation. Before the formation of a large amount of flocculent precipitation, the porous plate 8 is moved up, the second telescopic rod 24 is moved up, the tooth hook 28 remains contracted and does not extend, the screen 22 is basically immobile, and the limit block 25 is stuck under the central through hole 18 and drives the porous plate 8 to move up. During the process of moving up and cleaning, the fluidized filler can be basically distributed in the recessed area 20, and will neither fall from the central through hole 18 nor fall from the outer edge of the porous plate 8.

[0053] Optionally, a drain port 4 is provided at the bottom of the reaction zone for discharging produced water after catalytic oxidation and coagulation treatment.

[0054] Optionally, the mud discharge area is conical, and the mud discharge port 5 is arranged at the bottom of the mud discharge area for discharging the coagulated sludge.

[0055] Optionally, the aeration device 9 is connected to an aeration device outside the reactor 1, and the aeration device 9 may be an aeration pipe, and the aeration device may be a blower or a compressed gas cylinder; the aeration gas is selected from one or more of air, oxygen, ozone, and chlorine dioxide;

[0056] The sludge treatment device is a common sludge treatment equipment in the art; the water collection tank is connected to the cleaning nozzle 11 through a pipeline, and the treated produced water is used to clean the reactor 1.

[0057] The working principle of the sewage treatment system for in-situ recovery of magnetic catalysts described in the present invention is as follows:

[0058] Before the reactor 1 is started, the porous plate 8 is on the fixed table 23, and the nano-magnetic catalyst is placed on the porous plate 8. The hydraulic cylinder pulls the magnet coating frame 3 through the hydraulic rod 2, so that several magnet coating frames 3 are separated and detached from the side wall of the reactor 1 without affecting the catalyst in the reactor 1. The oxidant and the coagulant are added to the oxidant tank 14 and the coagulant tank 16 respectively.

[0059] Sewage is injected into the reactor 1 from the water inlet 10, and the first telescopic rod 17 is extended to move the real-time monitor 12 down to the height of the preset water level. When the sewage water level reaches the real-time monitor 12, the water inlet is stopped. The aeration device 9 is turned on to make the fluidized filler and catalyst on the porous plate 8 in a fluidized state. The oxidant circulation outlet 13, the oxidant inlet 6, the first oxidant pump and the second oxidant pump are turned on, and the oxidant in the oxidant tank 14 is input into the reactor 1. The sewage, the catalyst and the oxidant are fully contacted to generate a large number of free radicals to oxidize and degrade the pollutants. The sewage at the top of the reactor 1 carries a small amount of residual oxidant, which flows back to the oxidant tank 14 through the oxidant circulation outlet 13 and is used as a solvent for dissolving the oxidant.

[0060] After the real-time monitor 12 detects that the sewage meets the standard, the first telescopic rod 17 contracts, so that the real-time monitor 12 rises to the top of the reactor 1, and the injection of the oxidant is stopped. The hydraulic cylinder pushes the magnet coating frame 3 through the hydraulic rod 2, so that several magnet coating frames 3 are combined and close to the side wall of the reactor 1, and the granular catalyst on the porous plate 8 and the powdered catalyst above and below the porous plate are attracted to the side wall of the reactor 1.

[0061] The coagulant circulation outlet 15, the coagulant inlet 7, the first coagulant pump and the second coagulant pump are opened, and the coagulant in the coagulant tank 16 is input into the reactor 1. Under aeration conditions, the sewage and the fluidized filler are fully in contact with the coagulant.

[0062] After coagulation treatment and before a large amount of flocculent precipitation is formed, that is, before or while aeration is stopped, the second telescopic rod 24 lifts the porous plate 8 above the liquid level, opens the cleaning nozzle 11, and uses the last treated water in the water collection tank to clean the real-time monitor 12, the porous plate 8 and the fluidized filler.

[0063] Stop aeration, a large amount of flocculent precipitation is formed and condensed and sank, and at the same time, a small part of the powdered catalyst and coagulant that are not attracted by the magnetic coating device form a magnetic coagulation effect to a certain extent, which accelerates the sinking speed of the flocculent precipitation. The solid precipitation sinks to the conical mud discharge area, and the drainage port 4 is opened to discharge the supernatant of the reactor 1 into the water collection tank, and then the mud discharge port 5 is opened to discharge the sludge into the sludge treatment device for further treatment. The small amount of catalyst mixed in the sludge can be separated by magnetic separation. The water in the upper part of the water collection tank is used as cleaning water for the next cleaning, and the rest can be reused as reclaimed water.

[0064] The porous plate 8 is lowered onto the fixed platform 23 by the second telescopic rod 24, and the magnet coating frame 3 is pulled by the hydraulic rod 2, so that several magnet coating frames 3 are separated and detached from the side wall of the reactor 1, releasing the attracted catalyst and waiting for the next batch of sewage to enter.

[0065] The present invention can make the catalyst immediately attached to the side of the reactor 1 after recovery, and reused in the next oxidation catalysis, which can fully utilize the catalyst, save manpower, shorten the operation time, reduce the storage space occupied by the recovered catalyst, and realize the connection between the in-situ recovery and reuse of the catalyst.

[0066] The present invention realizes the integrated treatment of catalytic oxidation and coagulation and sedimentation, does not need additional coagulation and sedimentation tanks, and saves construction costs; at the same time, a small part of the magnetic catalyst that is not fully recovered can work synergistically with the coagulant to achieve a certain magnetic coagulation effect, thereby achieving a better treatment effect.

[0067] Optionally, the sewage treatment system further includes a control unit, which includes a controller, a display and an alarm. The controller is electrically connected to the display and the alarm. The controller is communicatively connected to each opening of the reactor 1, each pump, the first drive device, the real-time monitor 12, the second drive device, the telescopic mechanism of the tooth hook 28, and the hydraulic cylinder. The operation of each component is controlled according to the above-mentioned process method, and the real-time status and data of each component are displayed on the display. The controller performs analysis and calculation, and automatically issues instructions to each valve and water pump to keep the reaction going, so as to realize the effective automatic operation of the treatment system and guide the technicians to control the status of the reactor 1.

[0068] The function of the alarm is to sound an alarm and give a corresponding report for reference by operation and maintenance personnel when the system has abnormal operation and the controller cannot adjust itself.

[0069] When the sewage treatment system includes two or more reactors 1, the sewage can be treated in one reactor while water is supplied to the next reactor 1, thereby shortening the overall process time.

Claims

1. A sewage treatment system for in-situ recovery of magnetic catalyst, characterized in that: It comprises at least one reactor, a sludge treatment device and a water collection tank, wherein the drainage port and the sludge discharge port at the bottom of the reactor are connected to the water collection tank and the sludge treatment device respectively; The reactor is provided with an oxidant inlet and a coagulant inlet, which are used to input the oxidant and the coagulant into the reactor respectively; The lower part of the reactor is provided with a liftable porous plate for carrying fluidized fillers and catalysts. The outer part of the lower part of the reactor is provided with a magnetic coating device. When catalytic oxidation is performed, the magnetic coating device is open, the catalyst is not attracted and can flow freely, and an aeration device is provided below the porous plate to keep the catalyst in a fluidized state; when coagulation and sedimentation are performed, the magnetic coating device is closed and tightly wrapped around the reactor, and can attract the catalyst on the porous plate; The porous plate is circular, and includes a central through hole, an isolation ring, a recessed area and a platform area in sequence from the center of the circle along the radial direction outward, the isolation ring is a vertical cylindrical curved surface and surrounds the periphery of the central through hole, and the top of the isolation ring is higher than the upper surface of the recessed area; The upper surface of the depression area is lower than the upper surface of the platform area, the thickness of the depression area is less than the thickness of the platform area, and the ratio of the area of ​​the depression area to the area of ​​the platform area is (2-4):1; The upper surface of the porous plate is covered with a layer of flexible screen, the center of the screen passes through the central through hole and extends to the bottom of the porous plate; A circle of inwardly protruding fixed platforms is provided at the position of the inner wall at the bottom of the reaction zone corresponding to the porous plate, and mutually matching overlapping steps are provided at the overlapping positions of the fixed platforms and the porous plates. When the porous plates are between the reaction zone and the mud discharge zone, the fixed platforms support the edge of the platform area of ​​the porous plates, and the platform area is flush with the upper surface of the fixed platforms; The porous plate is connected to a second driving device above the reactor through a second telescopic rod passing through the reactor top plate, so as to realize the up and down movement of the porous plate; The bottom of the second telescopic rod includes a limit block, a thin rod and a thick rod from bottom to top, and the size of the limit block is larger than the central through hole, so that the limit block is always below the porous plate and drives the porous plate to move up and down; The thin rod is provided with a circle of retractable tooth hooks, and there is a hole in the center of the screen, and the bottom of the second telescopic rod passes through the hole; when the tooth hook is extended, it hooks the screen below the porous plate when the second telescopic rod rises, and drives the screen to move up together, thereby pulling the screen on the surface of the porous plate into a cone shape, so that the fluidized filler and catalyst on the porous plate fall to the edge of the porous plate, which is convenient for the magnetic coating device to attract; when the tooth hook is retracted to the inside of the thin rod, the screen is not pulled, and the screen is laid flat on the porous plate; The radius of the thick rod is larger than the radius of the thin rod, and slightly smaller than the inner diameter of the central through hole and the isolation ring, so that the thick rod can move in the central through hole and the isolation ring; The magnetic coating device includes at least two magnet coating frames, each magnet coating frame is provided with a hydraulic rod on the side away from the reactor, the hydraulic rod is connected to the hydraulic cylinder, and is used to drive the magnet coating frame to move. After all the magnet coating frames are combined, they can be docked and assembled with each other and tightly surround the outside of the reactor and cling to the side wall of the reactor, so as to attract the magnetic catalyst on the porous plate to the inner wall of the reactor; when the hydraulic rod pulls the magnet coating frame away from the reactor, the magnet coating frame opens and detaches from the side wall of the reactor, and the catalyst is not attracted.

2. The sewage treatment system for in-situ recovery of magnetic catalyst according to claim 1, characterized in that: The reactor is cylindrical and includes an upper reaction zone and a lower mud discharge zone, and a porous plate is provided between the reaction zone and the mud discharge zone; The top side wall of the reaction zone is provided with a water inlet and a cleaning nozzle, and the upper part is provided with a real-time monitor that can be raised and lowered to monitor the water level and water quality of the reactor in real time; An oxidant dosing circulation device and a coagulant dosing circulation device are arranged outside the reaction zone for adding oxidant and coagulant to the reactor.

3. The sewage treatment system for in-situ recovery of magnetic catalyst according to claim 2, characterized in that: The oxidant dosing circulation device comprises an oxidant circulation outlet, an oxidant tank and an oxidant inlet which are connected in sequence, wherein the oxidant circulation outlet is arranged at the upper part of the reaction zone and is connected to the inlet of the oxidant tank through a first oxidant pump, and the oxidant inlet is arranged at the lower part of the reaction zone and is connected to the outlet of the oxidant tank through a second oxidant pump; The coagulant dosing circulation device comprises a coagulant circulation outlet, a coagulant tank and a coagulant inlet which are connected in sequence. The coagulant circulation outlet is arranged at the upper part of the reaction zone and is connected to the inlet of the coagulant tank through a first coagulant pump. The coagulant inlet is arranged at the lower part of the reaction zone and is connected to the outlet of the coagulant tank through a second coagulant pump.

4. The sewage treatment system for in-situ recovery of magnetic catalyst according to claim 2, characterized in that: The real-time monitor is connected to a first telescopic rod above, the top of the first telescopic rod passes through the top plate of the reactor and is connected to a first driving device above the reactor, and the first driving device controls the length of the first telescopic rod, thereby realizing the lifting and lowering of the real-time monitor.

5. The sewage treatment system for in-situ recovery of magnetic catalyst according to claim 2, characterized in that: A drainage port is provided at the bottom of the reaction zone, the mud discharge zone is conical, the mud discharge port is provided at the bottom of the mud discharge zone, and the aeration device is connected to the aeration equipment outside the reactor; The water collection tank is connected to the cleaning nozzle through a pipeline, and the treated produced water is used to clean the reactor.

Images