A magnetic coagulation magnetic seed recovery system for sewage treatment and a method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA THREE GORGES CORPORATION
- Filing Date
- 2024-07-30
- Publication Date
- 2026-07-03
Smart Images
Figure CN119118312B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wastewater treatment technology, and in particular to a magnetic coagulation and magnetic seed recovery system for wastewater treatment, and a method for magnetic coagulation and magnetic seed recovery using this system. Background Technology
[0002] Magnetic enhanced separation technology is an innovative development based on traditional coagulation and sedimentation technology. By adding recyclable magnetic seeds during the chemical flocculation reaction, high-density magnetic flocs are formed. These flocs then rapidly separate from the water through gravity settling or the application of an external magnetic field, significantly shortening the treatment cycle and thus greatly improving the treatment capacity per unit area and the quality of the effluent. Therefore, magnetic enhanced separation technology is now widely used in wastewater treatment plant upgrading and overflow pollution control projects.
[0003] The recycling of magnetic seeds is the key to ensuring the treatment efficiency of magnetically enhanced separation technology. Currently, the magnetic seed sludge is mainly broken up by the high-speed operation of a shearing machine to achieve the crushing and deflocculation of magnetic flocs. Then, the magnetic seeds and sludge are separated by a magnetic powder separator. The separated magnetic seeds are recycled into a coagulation tank, while the sludge is sent to the subsequent treatment process.
[0004] However, the magnetically seeded sludge causes severe wear and tear on equipment such as shearing machines and sludge transfer pumps, increasing equipment maintenance costs. Furthermore, using shearing machines to disperse magnetically seeded sludge not only results in high energy consumption for the shearing machine but also poor dispersion, easily leading to the loss of magnetic seeds. Especially when magnetically enhanced separation technology is used in biofilm process effluent, the magnetic flocs are tightly bound, resulting in low magnetic seed recovery rates. Simultaneously, while magnetically coagulated sludge contains a certain amount of organic matter, which can provide a carbon source for subsequent treatment stages, the influent concentration in some wastewater treatment plants is low, leading to insufficient utilization of the internal carbon source. Summary of the Invention
[0005] To address the aforementioned technical problems, this invention provides a magnetic coagulation and magnetic seed recovery system for wastewater treatment that enables efficient recovery of magnetic seeds and reduces energy consumption.
[0006] The present invention adopts the following technical solution:
[0007] This invention provides a magnetic coagulation and magnetic seed recovery system for wastewater treatment, comprising a coagulation tank, a sedimentation tank, a hydrolysis acidification tank, a shearing machine, and a magnetic powder separator. The outlet of the coagulation tank is connected to the sedimentation tank via a pipeline. The sedimentation area at the bottom of the sedimentation tank is connected to the hydrolysis acidification tank via a sludge transfer pump. The top opening of the sedimentation tank is connected to a subsequent treatment unit via a water pump. The bottom opening of the hydrolysis acidification tank is connected to the shearing machine via a sludge transfer pump. The top opening of the hydrolysis acidification tank is connected to the subsequent treatment unit via a water pump. The outlet of the shearing machine is connected to the magnetic powder separator via a sludge transfer pump. The magnetic seed outlet of the magnetic powder separator is connected to the coagulation tank via a water pump. The sludge outlet of the magnetic powder separator is connected to a sludge branch and a carbon source recovery branch. The sludge branch is connected to the sludge treatment unit via a sludge transfer pump, and the carbon source recovery branch is connected to the subsequent treatment unit via a sludge transfer pump.
[0008] Preferably, the ratio of the inner diameter to the depth of the hydrolysis acidification tank is 1:1.5 to 1:2, the rotation speed of the stirring device at the top of the hydrolysis acidification tank opening is 60 to 600 r / min, and the concentration of sludge introduced into the hydrolysis acidification tank is 10 g / L to 20 g / L.
[0009] Preferably, the hydrolysis acidification tank is an anaerobic hydrolysis acidification tank.
[0010] Preferably, the magnetic powder separator includes a magnetic drum, a guide plate, a rubber roller, a geared motor, a scraper, and a housing. The guide plate, rubber roller, geared motor, and scraper are all disposed inside the housing. One end of the guide plate is located at the inlet of the housing, and the other end extends downward at an angle to the lower half of the magnetic drum. The rubber roller is disposed near the upper half of the magnetic drum, and the roller shaft of the rubber roller is parallel to the roller shaft of the magnetic drum. The geared motor drives the magnetic drum and the rubber roller to rotate synchronously, and the rotation direction of the rubber roller is opposite to the rotation direction of the magnetic drum. One end of the scraper is located at the upper half of the magnetic drum, and the other end extends downward at an angle to the magnetic seed outlet of the housing. The sludge outlet of the housing is located directly below the magnetic drum.
[0011] Preferably, a wetting water tank is installed directly below the magnetic seed outlet of the shell, and the wetting water tank is connected to the coagulation tank via a water pump.
[0012] Preferably, the magnetic field strength of the magnetic drum is 3000-5000 Gs, and the rotational speed of the magnetic drum is 60-120 rad / min.
[0013] Preferably, three coagulation tanks are arranged consecutively. The foremost coagulation tank is connected to the middle coagulation tank through a top outlet. The middle coagulation tank is connected to the last coagulation tank through a bottom outlet. The last coagulation tank is connected to a sedimentation tank through a pipeline. The magnetic seed outlet of the magnetic powder separator is connected to the middle coagulation tank through a water pump.
[0014] The present invention also provides a method for recovering magnetic seeds from magnetic coagulation in wastewater treatment, employing any of the above-mentioned magnetic coagulation and magnetic seed recovery systems for wastewater treatment, and comprising the following steps:
[0015] S1: The magnetic sludge containing magnetic seeds in the sedimentation area at the bottom of the sedimentation tank is fed into the hydrolysis acidification tank by the sludge transfer pump. The magnetic flocs undergo preliminary crushing and deflocculation in the hydrolysis acidification tank, and the organic matter in the magnetic flocs is decomposed at the same time, so that they can be easily utilized by microorganisms in the subsequent treatment unit.
[0016] S2: The magnetic sludge containing magnetic seeds at the bottom of the hydrolysis acidification tank is fed into the shearing machine by the sludge conveying pump, so that the magnetic flocs are further broken and deflocculated under the rotation of the shearing machine, while the supernatant in the hydrolysis acidification tank is connected to the subsequent treatment unit by the water pump.
[0017] S3: The magnetic seed-containing sludge in the shearing machine is fed into the magnetic powder separator by the sludge transfer pump, so that the magnetic powder and sludge are separated. The separated magnetic powder is discharged through the magnetic seed outlet and returned to the coagulation tank by the water pump. The separated sludge is discharged through the sludge outlet. Part of the sludge enters the sludge branch and is discharged into the sludge treatment unit by the sludge transfer pump to wait for subsequent treatment. The other part of the sludge is used as a supplementary carbon source and enters the carbon source recovery branch and is fed into the subsequent treatment unit by the sludge transfer pump.
[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0019] The magnetic coagulation and magnetic seed recovery system for wastewater treatment of this invention involves continuously installing a hydrolysis acidification tank, a shearing machine, and a magnetic powder separator after the sedimentation tank. This allows the hydrolytic and acidifying bacteria in the hydrolysis acidification tank to initially break down and deflocculate the magnetic flocs. The flocs then undergo secondary breaking down and deflocculation in the shearing machine. Finally, the magnetic powder separator separates the magnetic seeds from the sludge, and the separated magnetic seeds are recycled back into the coagulation tank. Because both the hydrolysis acidification tank and the shearing machine can break down and deflocculate the magnetic flocs throughout the process, efficient recovery of the magnetic seeds is achieved. Furthermore, the shearing machine is only used for secondary breaking down and deflocculation of the magnetic flocs, thus reducing its energy consumption.
[0020] The magnetic coagulation and magnetic seed recovery method for wastewater treatment of the present invention utilizes the above-mentioned magnetic coagulation and magnetic seed recovery system for wastewater treatment. It can not only improve the efficient recovery of magnetic seeds and reduce the energy consumption of the shearing machine through the combined action of the hydrolysis acidification tank and the shearing machine, but also decompose the organic matter in the magnetic flocs into small molecule organic matter that is easy for subsequent microorganisms to utilize, thereby improving the utilization efficiency of carbon sources in wastewater. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of a magnetic coagulation and magnetic seed recovery system for wastewater treatment in an embodiment of the present invention.
[0022] The reference numerals in the attached figures are explained as follows:
[0023] 1. Coagulation tank
[0024] 2. Sedimentation tank
[0025] 3. Hydrolysis acidification tank
[0026] 4. Shearing machine
[0027] 5. Magnetic powder separator
[0028] 6. Sludge branch road
[0029] 7. Carbon source recovery branch Detailed Implementation
[0030] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.
[0031] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0033] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0034] See Figure 1This embodiment provides a magnetic coagulation and magnetic seed recovery system for wastewater treatment, including a coagulation tank 1, a sedimentation tank 2, a hydrolysis acidification tank 3, a shearing machine 4, and a magnetic powder separator 5. The outlet of the coagulation tank 1 is connected to the sedimentation tank 2 through a pipeline. The sedimentation area at the bottom of the sedimentation tank 2 is connected to the hydrolysis acidification tank 3 through a sludge transfer pump. The top opening of the sedimentation tank 2 is connected to a subsequent treatment unit through a water pump. The bottom opening of the hydrolysis acidification tank 3 is connected to the shearing machine 4 through a sludge transfer pump. The top opening of the hydrolysis acidification tank 3 is connected to the subsequent treatment unit through a water pump. The outlet of the shearing machine 4 is connected to the magnetic powder separator 5 through a sludge transfer pump. The magnetic seed outlet of the magnetic powder separator 5 is connected to the coagulation tank 1 through a water pump. The sludge outlet of the magnetic powder separator 5 is connected to a sludge branch line 6 and a carbon source recovery branch line 7. The sludge branch line 6 is connected to the sludge treatment unit through a sludge transfer pump, and the carbon source recovery branch line 7 is connected to the subsequent treatment unit through a sludge transfer pump.
[0035] The magnetic coagulation and magnetic seed recovery system for wastewater treatment in this embodiment continuously installs a hydrolysis acidification tank 3, a shearing machine 4, and a magnetic powder separator 5 after the sedimentation tank 2. This allows the hydrolytic and acidifying bacteria in the hydrolysis acidification tank 3 to initially break down and deflocculate the magnetic flocs. The flocs then undergo secondary breaking down and deflocculation in the shearing machine 4. Finally, the magnetic powder separator 5 separates the magnetic seeds from the sludge, and the separated magnetic seeds are recycled back into the coagulation tank 1. Because both the hydrolysis acidification tank 3 and the shearing machine 4 can break down and deflocculate the magnetic flocs throughout the process, efficient recovery of the magnetic seeds is achieved. Furthermore, the shearing machine 4 is only used for secondary breaking down and deflocculation of the magnetic flocs, thus reducing its energy consumption.
[0036] In addition, by connecting the sludge branch 6 and the carbon source recovery branch 7 to the sludge outlet of the magnetic powder separator 5, a portion of the sludge can be recycled as a carbon source through the carbon source recovery branch 7, while the remaining sludge is discharged to the sludge treatment unit.
[0037] It should be noted that the magnetic coagulation and magnetic seed recovery system for sewage treatment in this embodiment is built on the basis of the original sewage treatment system. In the original sewage treatment system, sewage is introduced into the inlet of the coagulation tank 1 and the outlet is connected to the sedimentation tank 2 through a pipeline. Coagulant is added to the coagulation tank 1. After the sewage with coagulant enters the sedimentation tank 2, the magnetic flocs and sludge are deposited in the sedimentation area at the bottom of the sedimentation tank 2. The purified sewage is then pumped from the top opening of the sedimentation tank 2 to the subsequent treatment unit.
[0038] Preferably, in this embodiment, the outlet of the coagulation tank 1 is connected to a water distributor located in the sedimentation tank 2 via a pipeline.
[0039] Preferably, the ratio of the inner diameter to the depth of the hydrolysis acidification tank 3 is 1:1.5 to 1:2, the rotation speed of the agitator at the top of the hydrolysis acidification tank 3 is 60 to 600 r / min, and the concentration of sludge introduced into the hydrolysis acidification tank 3 is 10 g / L to 20 g / L. The agitator at the top of the hydrolysis acidification tank 3 is used to mix the sludge in the hydrolysis acidification tank 3. The use of the above parameters for the ratio of the inner diameter to the depth of the hydrolysis acidification tank 3, the rotation speed of the agitator at the top of the hydrolysis acidification tank 3, and the concentration of sludge introduced into the hydrolysis acidification tank 3 is beneficial to ensuring the crushing and deflocculation effect of the magnetic flocs in the hydrolysis acidification tank 3.
[0040] Preferably, the hydrolysis acidification tank 3 is an anaerobic hydrolysis acidification tank, which can promote the anaerobic hydrolysis acidification of sludge by means of the presence of magnetic powder in the magnetic flocculant, further utilize the carbon source in the wastewater, and reduce the amount of external carbon source added; at the same time, it can also suppress the gas production stage of sludge digestion, avoid carbon source loss, and improve the recovery efficiency of internal carbon source.
[0041] Preferably, the magnetic powder separator 5 includes a magnetic drum, a guide plate, a rubber roller, a geared motor, a scraper, and a housing. The guide plate, rubber roller, geared motor, and scraper are all disposed inside the housing. One end of the guide plate is located at the inlet of the housing, and the other end extends downward at an angle to the lower half of the magnetic drum. The rubber roller is disposed near the upper half of the magnetic drum, and the roller shaft of the rubber roller is parallel to the roller shaft of the magnetic drum. The geared motor drives the magnetic drum and the rubber roller to rotate synchronously, and the rotation direction of the rubber roller is opposite to the rotation direction of the magnetic drum. One end of the scraper is located at the upper half of the magnetic drum, and the other end extends downward at an angle to the magnetic seed outlet of the housing. The sludge outlet of the housing is located directly below the magnetic drum.
[0042] After being transported by the sludge conveying pump, the sludge containing magnetic seeds enters the inlet of the upper shell of the magnetic powder separator 5 from the shearing machine 4. The sludge entering the shell is guided to the magnetic drum by the guide plate. While the magnetic drum is rotating, it continuously adsorbs magnetic powder from the sludge. The rubber pressure roller is used to squeeze out the water adsorbed on the magnetic powder on the magnetic drum. The magnetic powder with squeezed water comes into contact with the scraper as the magnetic drum rotates. Then, the scraper scrapes off the magnetic powder adsorbed on the outer circumference of the magnetic drum. The scraped magnetic powder is discharged from the magnetic seed outlet of the shell.
[0043] Preferably, a wetting water tank is installed directly below the magnetic seed outlet of the shell, and the wetting water tank is connected to the coagulation tank 1 via a water pump. The magnetic powder discharged from the magnetic seed outlet of the shell falls into the wetting water tank and mixes with the clean water in the wetting water tank. Then, the separated magnetic powder is returned to the coagulation tank 1 by the water pump.
[0044] Preferably, the magnetic field strength of the magnetic drum is 3000-5000 Gs, and the rotation speed of the magnetic drum is 60-120 rad / min, so as to ensure the magnetic seed recovery amount and recovery efficiency of the magnetic powder separator 5.
[0045] Preferably, see Figure 1 There are three coagulation tanks 1 in succession. The coagulation tank 1 at the front end is connected to the middle coagulation tank 1 through the top outlet. The middle coagulation tank 1 is connected to the end coagulation tank 1 through the bottom outlet. The end coagulation tank 1 is connected to the sedimentation tank 2 through a pipeline. The magnetic seed outlet of the magnetic powder separator 5 is connected to the middle coagulation tank 1 through a water pump, thereby ensuring the magnetic enhancement separation effect of the magnetic powder.
[0046] This embodiment also provides a method for recovering magnetic seeds from magnetic coagulation in wastewater treatment, combined with... Figure 1 The above-mentioned magnetic coagulation and magnetic seed recovery system for wastewater treatment is adopted, and includes the following steps:
[0047] S1: The magnetic sludge containing magnetic seeds in the sedimentation area at the bottom of the sedimentation tank 2 is fed into the hydrolysis acidification tank 3 by the sludge transfer pump, so that the magnetic flocs are initially broken and deflocculated in the hydrolysis acidification tank 3, and the organic matter in the magnetic flocs is decomposed at the same time, so that it is easy for the microorganisms in the subsequent treatment unit to utilize.
[0048] S2: The magnetic sludge at the bottom of the hydrolysis acidification tank 3 is fed into the shearing machine 4 by the sludge conveying pump, so that the magnetic flocs are further broken and deflocculated under the rotation of the shearing machine 4, while the supernatant in the hydrolysis acidification tank 3 is connected to the subsequent treatment unit by the water pump.
[0049] S3: The magnetic seed-containing sludge in the shearing machine 4 is fed into the magnetic powder separator 5 by the sludge transfer pump, so that the magnetic powder and sludge are separated. The separated magnetic powder is discharged through the magnetic seed outlet and returned to the coagulation tank 1 by the water pump. The separated sludge is discharged through the sludge outlet. Part of the sludge enters the sludge branch 6 and is discharged into the sludge treatment unit by the sludge transfer pump to wait for subsequent treatment. The other part of the sludge is used as a supplementary carbon source and enters the carbon source recovery branch 7 and is fed into the subsequent treatment unit by the sludge transfer pump.
[0050] The magnetic coagulation and magnetic seed recovery method for wastewater treatment in this embodiment utilizes the aforementioned magnetic coagulation and magnetic seed recovery system for wastewater treatment. This not only improves the efficient recovery of magnetic seeds and reduces the energy consumption of the shearing machine 4 through the combined action of the hydrolysis acidification tank 3 and the shearing machine 4, but also decomposes the organic matter in the magnetic flocs into small molecule organic matter that is easily utilized by subsequent microorganisms, thereby improving the utilization efficiency of carbon sources in wastewater.
[0051] The following are data from two specific embodiments of municipal wastewater treatment using the above-described magnetic coagulation and magnetic seed recovery method:
[0052] Example 1
[0053] The wastewater to be treated is municipal wastewater from a region in northern China. Its typical water quality indicators are: COD (Chemical Oxygen Demand) = 200–300 mg / L, SS (Suspended Solids) concentration = 180–230 mg / L, and NH4+ concentration = 100–200 mg / L. + The concentration of -N (ammonia nitrogen) is 30-50 mg / L, the concentration of TN (total nitrogen) is 40-60 mg / L, and the concentration of TP (total phosphorus) is 3-7 mg / L.
[0054] When the existing wastewater treatment system was treated using a conventional magnetically enhanced separation-mud membrane composite process (which still involves the combination of a shearing machine and a magnetic powder separator as described in the background technology), the effluent COD from the magnetic powder separator was 126±25 mg / L, the magnetic seed recovery rate was 75%, and the shearing machine speed was 300 r / min. However, when the aforementioned magnetic coagulation and magnetic seed recovery method for wastewater treatment was adopted, the SRT (sludge retention time in the system) was 3 days, the effluent COD from the supernatant in the hydrolysis acidification tank was 400±35 mg / L, the shearing machine speed was 260 r / min, and the magnetic seed recovery rate was 85%.
[0055] Clearly, compared to the conventional magnetically enhanced separation-mud membrane composite process, the magnetic coagulation and magnetic seed recovery method for wastewater treatment in this embodiment is better able to achieve the standard treatment of municipal wastewater in a certain northern region, and the shearing machine has low energy consumption and high magnetic seed recovery rate.
[0056] Example 2
[0057] The wastewater to be treated is municipal wastewater from a region in southern China. Its typical water quality indicators are: COD (Chemical Oxygen Demand) = 200–300 mg / L, SS (Suspended Solids) concentration = 120–180 mg / L, and NH4+ concentration = 100–150 mg / L. + The concentration of -N (ammonia nitrogen) is 20-35 mg / L, the concentration of TN (total nitrogen) is 40-50 mg / L, and the concentration of TP (total phosphorus) is 4-8 mg / L.
[0058] When the existing wastewater treatment system was treated using the conventional pure membrane MBBR-magnetic coagulation sedimentation process (which still uses a combination of shear and magnetic powder separator as described in the background technology), the effluent COD of the magnetic powder separator was 40±4 mg / L, the magnetic seed recovery rate was 80%, and the shear speed was 300 r / min. However, when the above-mentioned magnetic coagulation and magnetic seed recovery method for wastewater treatment was adopted, the SRT (sludge retention time in the system) was 3 days, the effluent COD of the supernatant in the hydrolysis acidification tank was 350±35 mg / L, the shear speed was 250 r / min, and the magnetic seed recovery rate was 86%.
[0059] Clearly, compared to the conventional pure membrane MBBR-magnetic coagulation sedimentation process, the magnetic coagulation and magnetic seed recovery method for wastewater treatment in this embodiment is better able to achieve the standard treatment of municipal wastewater in a certain area in the south, and the shearing machine has low energy consumption and high magnetic seed recovery rate.
[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.
Claims
1. A magnetic coagulation magnetic seed recovery system for sewage treatment, characterized by, The system includes a coagulation tank (1), a sedimentation tank (2), a hydrolysis acidification tank (3), a shearing machine (4), and a magnetic powder separator (5). The hydrolysis acidification tank (3) is an anaerobic hydrolysis acidification tank. The outlet of the coagulation tank (1) is connected to the sedimentation tank (2) through a pipeline. The sedimentation area at the bottom of the sedimentation tank (2) is connected to the hydrolysis acidification tank (3) through a sludge transfer pump. The top opening of the sedimentation tank (2) is connected to a subsequent treatment unit through a water pump. The bottom opening of the hydrolysis acidification tank (3) is connected to the shearing machine (4) through a sludge transfer pump. The top opening of the hydrolysis acidification tank (3) is connected to the subsequent treatment unit via a water pump. The outlet of the shearing machine (4) is connected to the magnetic powder separator (5) via a sludge conveying pump. The magnetic seed outlet of the magnetic powder separator (5) is connected to the coagulation tank (1) via a water pump. The sludge outlet of the magnetic powder separator (5) is connected to a sludge branch (6) and a carbon source recovery branch (7). The sludge branch (6) is connected to the sludge treatment unit via a sludge conveying pump. The carbon source recovery branch (7) is connected to the subsequent treatment unit via a sludge conveying pump.
2. The magnetic coagulation magnetic seed recovery system for sewage treatment according to claim 1, characterized by, The ratio of the inner diameter to the depth of the hydrolysis acidification tank (3) is 1:1.5 to 1:
2. The rotation speed of the stirring device at the top of the opening of the hydrolysis acidification tank (3) is 60 to 600 r / min. The concentration of sludge introduced into the hydrolysis acidification tank (3) is 10 g / L to 20 g / L.
3. The magnetic coagulation seed recovery system for sewage treatment according to claim 1, characterized by, The magnetic powder separator (5) includes a magnetic drum, a guide plate, a rubber roller, a geared motor, a scraper, and a housing. The guide plate, the rubber roller, the geared motor, and the scraper are all disposed inside the housing. One end of the guide plate is located at the inlet of the housing, and the other end extends downward at an angle to the lower half of the magnetic drum. The rubber roller is disposed near the upper half of the magnetic drum, and the roller shaft of the rubber roller is parallel to the roller shaft of the magnetic drum. The geared motor drives the magnetic drum and the rubber roller to rotate synchronously, and the rotation direction of the rubber roller is opposite to the rotation direction of the magnetic drum. One end of the scraper is located at the upper half of the magnetic drum, and the other end extends downward at an angle to the magnetic seed outlet of the housing. The sludge outlet of the housing is located directly below the magnetic drum.
4. The magnetic coagulation and magnetic seed recovery system for wastewater treatment according to claim 3, characterized in that, A wetting water tank is installed directly below the magnetic seed outlet of the shell, and the wetting water tank is connected to the coagulation tank (1) by a water pump.
5. The magnetic coagulation and magnetic seed recovery system for wastewater treatment according to claim 3, characterized in that, The magnetic field strength of the magnetic drum is 3000~5000Gs, and the rotation speed of the magnetic drum is 60~120rad / min.
6. The magnetic coagulation and magnetic seed recovery system for wastewater treatment according to claim 1, characterized in that, The coagulation tanks (1) are arranged in three consecutively. The coagulation tank (1) at the front end is connected to the middle coagulation tank (1) through the top outlet. The middle coagulation tank (1) is connected to the last coagulation tank (1) through the bottom outlet. The last coagulation tank (1) is connected to the sedimentation tank (2) through a pipeline. The magnetic seed outlet of the magnetic powder separator (5) is connected to the middle coagulation tank (1) through a water pump.
7. A method for recovering magnetic seeds from magnetic coagulation in wastewater treatment, characterized in that, The wastewater treatment magnetic coagulation and magnetic seed recovery system according to any one of claims 1-6 includes the following steps: S1: The magnetic sludge containing magnetic seeds in the sedimentation area at the bottom of the sedimentation tank (2) is fed into the hydrolysis acidification tank (3) by the sludge transfer pump, so that the magnetic flocs are initially broken and initially deflocculated in the hydrolysis acidification tank (3), and the organic matter in the magnetic flocs is decomposed at the same time, so that it is easy for the microorganisms in the subsequent treatment unit to utilize it. S2: The magnetic sludge at the bottom of the hydrolysis acidification tank (3) is fed into the shearing machine (4) by the sludge conveying pump, so that the magnetic flocs are further broken and deflocculated under the rotation of the shearing machine (4), while the supernatant in the hydrolysis acidification tank (3) is connected to the subsequent treatment unit by the water pump. S3: The magnetic sludge containing magnetic seeds in the shearing machine (4) is fed into the magnetic powder separator (5) by the sludge transfer pump, so that the magnetic powder and sludge are separated. The separated magnetic powder is discharged through the magnetic seed outlet and returned to the coagulation tank (1) by the water pump. The separated sludge is discharged through the sludge outlet, and part of the sludge enters the sludge branch (6) and is discharged into the sludge treatment unit by the sludge transfer pump to wait for subsequent treatment. The other part of the sludge is used as a supplementary carbon source and enters the carbon source recovery branch (7) and is fed into the subsequent treatment unit by the sludge transfer pump.