JP4551650B2 - Biological treatment equipment - Google Patents

Description

  The present invention relates to a biological treatment apparatus such as a wastewater treatment apparatus and a sludge treatment apparatus, and more particularly to a biological treatment apparatus that performs treatment of wastewater, sewage, surplus sludge, and the like with activated sludge added with magnetic powder.

Conventionally, the activated sludge method has been widely used as a treatment method for sewage and organic wastewater. In this method, basically, organic substances contained in sewage etc. are decomposed by activated sludge in a treatment tank such as an aeration tank, and then activated sludge is settled and separated by gravity in the final sedimentation tank, and the activated sludge separated here is treated. The model is to return to the tank. In such an activated sludge method, in recent years, as a means for separating treated water and activated sludge, magnetism is imparted to the activated sludge by adding magnetic powder to the activated sludge, and this activated sludge is used as a permanent magnet. There has been proposed a magnetic separation method and apparatus that is magnetically attached and separated from treated water (for example, see Patent Document 1).
Japanese Patent Publication No. 63-59759

  However, if the excess sludge generated in the system is extracted as it is in the biological treatment equipment to which the magnetic separation method is applied, the magnetic powder added to the activated sludge is extracted out of the system together with the excess sludge. Powder has to be added, leading to an increase in operating costs.

  Therefore, an object of the present invention is to provide a biological treatment apparatus that can draw excess sludge out of the system while retaining the magnetic powder in the system.

In order to achieve the above object, the biological treatment apparatus of the present invention includes a biological reaction tank that performs biological treatment with an activated sludge containing magnetic powder to which magnetic powder is added, and an activated sludge suspension that flows out of the biological reaction tank. is the biological treatment device having a magnetic separation means for a portion of the magnetic powder-containing activated sludge separated from the liquid in the magnetic force, the magnetic powder collecting means for separating and recovering the magnetic powder-containing active sludge or al magnetic powder, the A magnetic powder return path for returning the magnetic powder separated and recovered by the magnetic powder recovery means to the biological reaction tank; and a sludge discharge path for discharging residual sludge after the magnetic powder is separated by the magnetic powder recovery means. In particular, the magnetic powder recovery means is a hydrocyclone.

Further, the biological treatment apparatus of the present invention, the magnetic powder collecting means, and solubilization and volume reduction means for performing solubilization and volume reduction treatment for the magnetic powder containing active sludge, solubilized and reduction magnetic powder containing active sludge which in iodide means doing solubilization and volume reduction treatment, Or, the magnetic powder contained after the solubilization and volume reduction treatment in the solubilization-volume reduction means activity sludge or al magnetic powder is characterized by comprising a manual stage you separate and recover magnetic powder by the liquid cyclone or a magnetic separating and recovering the solubilized-volume reduction means, the magnetic powder-containing active It is an ultrasonic treatment apparatus that irradiates an activated sludge suspension containing sludge with ultrasonic waves.

According to the biological treatment device of the present invention, to separate and recover the magnetic powder of a magnetic powder-containing active sludge or al magnetic powder collection means is circulated through the bioreactor, for discharging only the remaining residual sludge in the system The consumption of magnetic powder can be suppressed, and the operating cost of the biological treatment apparatus to which the magnetic separation method is applied can be reduced.

  In particular, before separating magnetic powder from activated sludge containing magnetic powder, etc. with a hydrocyclone or magnetic separation means, solubilization / volume reduction treatment, specifically ultrasonic irradiation, etc. is performed on activated sludge containing magnetic powder. Thus, the separation of the magnetic powder-containing activated sludge and the like from the magnetic powder can be performed more effectively.

  Furthermore, according to the present invention, since the residual sludge after separating and recovering the magnetic powder can be mainly discharged, the outflow of the magnetic powder, particularly in a system where it is necessary to discharge the inorganic matter that is difficult to biological treatment together with the excess sludge. Can be effectively prevented.

  FIG. 1 is a system diagram of a wastewater treatment apparatus showing an embodiment of a biological treatment apparatus according to the present invention, and FIG. 2 is a cross-sectional view showing an example of magnetic separation means. The wastewater treatment apparatus shown in this embodiment is a non-chemical injection type pressure flotation separation apparatus 11 for separating and removing suspended components in inflow wastewater and inflow sewage (raw water), and activated sludge to which magnetic powder is added. Biological reaction tank 12 that performs water treatment with (magnetic powder-containing activated sludge), and magnetic separation that separates part of the activated sludge contained in the activated sludge suspension flowing out of the biological reaction tank 12 from the liquid by magnetic force. Means 13, final sedimentation basin 14 as solid-liquid separation means for separating the remaining activated sludge in the activated sludge suspension flowing out from magnetic separation means 13 from the liquid, and magnetic powder extracted from biological reaction tank 12 A liquid cyclone 15 is provided as magnetic powder recovery means for recovering the magnetic powder by separating the activated sludge of the contained activated sludge from the magnetic powder.

  In the magnetic separation means 13 and the final sedimentation basin 14, the magnetic separation sludge return path 17 and the sedimentation separation for extracting the activated sludge magnetically separated and the activated sludge separated and settled into the sludge receiving tank 16 and returning them to the biological reaction tank 12. Each sludge return path 18 is provided. The sludge return path 19 between the sludge receiving tank 16 and the biological reaction tank 12 has a solubilization / volume reduction means 20 for return sludge that performs solubilization / volume reduction (sterilization) treatment of activated sludge, A bypass path 21 that bypasses the solubilization / volume reduction means 20 is provided. The final sedimentation basin 14 is provided with a treated water outflow path 22 for extracting treated water from which activated sludge has been separated.

  The liquid cyclone 15 includes a suspension extraction path 23 for extracting a part of the activated sludge suspension in the biological reaction tank 12 toward the liquid cyclone 15 through a pump, and the activity separated from the magnetic powder by the liquid cyclone 15. An upper discharge port 24 for discharging sludge (residual sludge) out of the system as surplus sludge and a lower discharge port 25 for returning and circulating the magnetic powder separated from the surplus sludge to the biological reaction tank 12 are provided. The extraction path 23 is provided with a solubilization / volume reduction means 26 that performs solubilization processing and volume reduction processing on the activated sludge flowing into the hydrocyclone 15.

  In this embodiment, the liquid cyclone 15 and the solubilizing / volume reducing means 26 correspond to the magnetic powder collecting means, but depending on the properties of the activated sludge and the operating conditions, only the liquid cyclone 15 may be sufficient. In the present embodiment, the magnetic powder is recovered by the liquid cyclone 15 after the solubilization / volume reduction treatment is performed on the activated sludge. However, the present invention is not limited to this example. For example, the solubilizing / volume-reducing means 26 and the liquid cyclone 15 are integrally provided, and the activated sludge in the solubilizing / volume-reducing treatment process is subjected to this treatment while the liquid is applied. The magnetic powder can be separated and recovered by a cyclone.

  The pressurized levitation separator 11 mixes the raw water flowing in from the raw water inflow path 31 and the pressurized air dissolved water supplied from the pressurized water path 32 and introduces them into the tank, and generates from the pressurized air dissolved water. Floating matters, suspended components, and foaming components in raw water are lifted and separated by fine bubbles. Floating matters and suspended components in raw water adhere to fine bubbles generated from pressurized air-dissolved water. As a result, the apparent specific gravity is reduced and floats as floating sludge (floss) on the upper part of the tank of the pressurized flotation separation device 11. At the same time, the foaming component in the raw water is foamed by the fine bubbles and floats on the upper part of the tank.

  The floss and foam that have floated to the top of the tank are scraped off by a scraper or the like and extracted to the floating material collection path 33. In addition, the solid matter (primary sedimentation sludge) that has settled at the bottom of the pressurized flotation separation device 11 is extracted to the sediment collection path 34. Such a pressure levitation separation device 11 has a higher removal rate of suspended components than ordinary precipitation treatment, and also has foam components, oil, scum, etc., in addition to coarse suspended matter and threadlike suspended hair. This has the advantage that it can be removed almost completely in a short time. Furthermore, since the foaming component and suspended solids can be separated and removed without using chemicals by using the non-chemical injection type pressure rising and separating apparatus 11, there is no adverse effect on biological treatment.

  Further, the floss and solids separated by the pressurized flotation separation apparatus 11 are introduced into the methane fermentation means 35 from the float collection path 33 and the precipitate collection path 34 and subjected to methane fermentation treatment, followed by initial precipitation. After being introduced into the sludge solubilization / volume reduction treatment means 36 and subjected to the solubilization treatment and volume reduction treatment, it is introduced into the biological reaction tank 12 through the initial sedimentation sludge path 37.

  In this way, by performing methane fermentation treatment with the methane fermentation means 35 on the floss and solid matter separated by the pressurized flotation separation device 11, it is possible to use primary fertilized sludge having good fermentability as a raw material. While improving the efficiency of fermentation, the amount of excess sludge after methane fermentation can also be reduced. Further, by applying solubilization and volume reduction treatment such as ozone treatment, alkali treatment, ultrasonic treatment, etc., to the surplus sludge and then throwing it into the biological reaction tank 12, The generation of excess sludge from the pressurized flotation separator 11 can be eliminated.

  In order to make the activated sludge subjected to water treatment in the biological reaction tank 12 magnetically separated by the magnetic separation means 13, magnetic powder is added and mixed in advance, and the magnetic sludge is adsorbed to the activated sludge. It is necessary to keep it held. As the magnetic powder to be used, an appropriate one can be selected. However, since magnetic powder having a size of 10 μm or more is too heavy for activated sludge, it is often separated from activated sludge by gravity. Smaller ones are preferred, and usually those in the range of 0.05 to 2 μm are optimal. Although it is possible to use ultrafine magnetic powder, it is not preferable because the cost of the magnetic powder increases.

  Further, the coercive force of the magnetic powder is suitably 0 to 200 Oe, and the magnetic powder having an excessively large coercive force has the disadvantage that it aggregates due to its own magnetic force and separates from the activated sludge and settles. Furthermore, in consideration of long-term use, it is preferable to use an oxide-based magnetic powder that hardly dissolves or deteriorates in water at room temperature. 0.1 to 1.0 μm, for example, about 0.4 μm of iron trioxide powder is optimal.

  If the concentration (addition amount) of the magnetic powder is too low, a strong magnet such as a superconducting magnet is required to separate the activated sludge. Conversely, if the concentration is too high, the cost of the magnetic powder will increase. The MLVSS of the activated sludge is preferably in a concentration range of 0.01 to 10 with respect to 1, and normally, it may be set to have a concentration similar to that of the activated sludge MLVSS.

  When such magnetic powder is put into the activated sludge suspension at an appropriate position in the biological reaction tank 12 or the like, it is immediately adsorbed and held by the activated sludge, and the magnetic powder-containing activated sludge attracted to the magnet Become. Since most or all of this magnetic powder-containing activated sludge circulates with the return sludge, the addition and mixing of the magnetic powder to the activated sludge suspension usually only needs to be performed once before starting the magnetic separation. However, it can be added as appropriate according to the situation of the water treatment facility. Also, when adding magnetic powder, add an appropriate amount of magnetic powder at appropriate intervals while circulating the activated sludge so that the magnetic powder is evenly adsorbed to the entire activated sludge circulating in the system. Is preferred.

  The biological reaction tank 12 is divided into an anaerobic treatment tank 42 on the inflow side and an aerobic treatment tank 43 on the outflow side by a partition plate 41, and an agitator 44 is provided in the anaerobic treatment tank 43. Each is provided with a diffuser tube 45. The anaerobic treatment tank 42 adsorbs the foaming component remaining in the floating separation water flowing from the pressurized floating separation device 11 through the floating separation water inflow path 38 to the activated sludge (microbe floc) or decomposes it with the activated sludge. This prevents the foam component from flowing into the aerobic treatment tank 43 on the downstream side and foaming. In the aerobic treatment tank 43, by aeration from the air diffuser 45, an aerobic treatment (aeration treatment) by a normal activated sludge method is performed to purify the raw water.

  The aerated treated water and activated sludge purified in the aerobic treatment tank 43 can be separated only by the magnetic separation means 13, but in this embodiment, the magnetic separation means 13 and the final sedimentation basin 14 are separated. The separation process is performed in two stages. Therefore, it is not necessary for the magnetic separation means 13 to magnetically separate the entire amount of the magnetic powder-containing activated sludge in the activated sludge suspension, and depending on the concentration of the magnetic powder-containing activated sludge and the load of the final sedimentation tank 14, What is necessary is just to be able to isolate | separate 50 to 99.5% or more of the magnetic powder containing activated sludge which exists in it.

  Various types of magnetic separation means 13 for separating the magnetic powder-containing activated sludge from the suspension can be used. For example, as shown in the sectional view of FIG. 2, the magnetic separation tank 53 having the inflow portion 51 and the outflow portion 52 of the activated sludge suspension, the rotating drum 54 having the magnet disposed on the outer peripheral surface, and the rotating drum 54 are attached. A magnetic separator provided with a scraper 56 that scrapes off the magnetic sludge containing activated sludge 55 and a sludge recovery trough 57 that collects the magnetic sludge containing activated sludge 55 scraped off by the scraper 56 can be used. The rotary drum 54 is connected to a driving motor (not shown), the sludge recovery trough is connected to the magnetic separation sludge return path 17, and a sludge delivery pump is installed as necessary. The

  The magnet provided in the rotating drum 54 can be a special magnet such as a superconducting magnet or an electromagnet, but it is not necessary to separate all of the magnetic powder-containing activated sludge from the suspension. Permanent magnets that can be obtained at low cost, such as ferrite magnets, can be used. The arrangement of the magnetic poles on the drum peripheral surface is preferably in a state where N poles and S poles are alternately arranged at a magnetization interval of 2 to 20 mm. When this magnetization interval is narrowed, the saturated adhesion amount of the magnetic powder-containing activated sludge is reduced, and when the magnetization interval is widened, the adhesion force of the magnetic powder-containing activated sludge is weakened. The size (diameter and length) of the rotating drum 54 and the number of rotations during the magnetic separation process are arbitrary and can be selected according to the processing amount, taking into consideration the installation space, manufacturing cost, operating cost, etc. You only have to set it.

  Collection of the magnetic powder-containing activated sludge separated from the suspension by magnetic force can be performed by any method depending on the structure and shape of the magnet, and various shapes of magnets such as plates, disks, rods, etc. The sludge collecting means can be combined with the shape of these magnets, etc., but the magnetic powder-containing activated sludge 55 magnetically separated can be easily collected in a continuous state by the combination of the rotating drum 54 and the scraper 56. Can do. In addition, by using a rotating drum-shaped magnet, the configuration of the apparatus can be simplified, the manufacturing cost of the magnetic separation apparatus can be reduced, and maintenance and inspection can be easily performed.

  Among the microorganisms constituting the activated sludge, most of the floc-forming bacteria that easily hold magnetic powder are separated by the magnetic separation means 13, but the filamentous fungi and dispersible microorganisms that cannot hold magnetic powder alone are Most of them pass through the magnetic separation means 13 and settle and separate in the final settling tank 14. Therefore, by combining the magnetic separation means 13 and the final sedimentation basin 14, the activated sludge can be more reliably separated from the treated water.

  On the other hand, since only the floc-forming bacteria separated and recovered by the magnetic separation means 13 are returned to the biological reaction tank 12, the activated sludge in the biological reaction tank 12 can be mainly composed of floc-forming bacteria. However, in this case, excess sludge is generated from the final settling tank 14. In order to prevent the generation of this excess sludge, the solubilizing / volume-reducing means 20 is used for the part or all of the returned sludge returned from the sludge receiving tank 16 to the biological reaction tank 12 in accordance with the activated sludge concentration in the system. The activated sludge is solubilized and volume-reduced using ozone, chlorine, hydrogen peroxide, ultrasonic waves, or the like.

  Thereby, while the activated sludge density | concentration in a system can be maintained in a suitable range, the filamentous fungi etc. which are the causative bacteria of a bulking can be extinguished, and an excess sludge does not generate | occur | produce from the final sedimentation basin 14. The solubilization / volume reduction means 20 is installed in the sedimentation / separation sludge return path 18 so that the activated sludge is solubilized / volume-reduced only for the sedimentation / separation sludge separated in the final sedimentation tank 14. May be.

  If the activated sludge concentration in the system tends to increase even after performing the normal solubilization treatment and volume reduction treatment in the solubilization / volume reduction means 20 due to the properties of raw water, etc., the liquid cyclone 15 separates the activated sludge having a relatively small specific gravity and the magnetic powder having a relatively large specific gravity, and discharges the separated activated sludge (residual sludge) as excess sludge to the outside of the system. Return to the inside and circulate. Thus, by separating activated sludge and magnetic powder with the hydrocyclone 15, only excess sludge is discharged out of the system from the upper outlet 24, and the magnetic powder is returned to the system from the lower outlet 25 and circulated. Therefore, even when the activated sludge concentration becomes high and it is necessary to discharge excess sludge, the magnetic powder can be kept in the system, and the loss of the magnetic powder can be minimized.

  At this time, the liquid cyclone 36 is provided with a solubilizing / volume-reducing means 26 in front of the liquid cyclone 15 and irradiating the activated sludge suspension introduced into the liquid cyclone 15 with ultrasonic waves. The activated sludge and magnetic powder can be effectively separated from each other. Furthermore, an ultrasonic transmitter is provided in the hydrocyclone 36 itself or its inflow pipe, and the activated sludge suspension in the liquid cyclone 36 or immediately before the inflow is irradiated with ultrasonic waves, whereby the activity in the hydrocyclone 15 is increased. Separation of sludge and magnetic powder can be performed more effectively.

  The solubilization / volume reduction means 26 is not limited to an ultrasonic treatment device that irradiates ultrasonic waves, but may be an ozone treatment device, a heat treatment device, an alkali treatment device, a mechanical treatment device such as a crusher or a ball mill, or the like. Can be used.

  As the liquid cyclone 15, those generally used for liquids can be used, and the treatment capacity may be set according to the degree of fluctuation of the activated sludge concentration in the system, and the structure and shape of the cyclone main body. Further, by appropriately selecting the flow rate of the magnetic powder-containing activated sludge flowing from the suspension extraction path 23, a desired amount of excess sludge can be separated from the magnetic powder and discharged out of the system. Further, in the liquid cyclone 15, it is not necessary to completely separate the activated sludge and the magnetic powder, and the magnetic powder-containing activated sludge that has not been separated may be returned to the system from the lower discharge port 25. Furthermore, the installation position of the liquid cyclone 15 is arbitrary, and the suspension extraction position and the magnetic powder return position may be different.

  The raw water flowing into the wastewater treatment apparatus formed in this way flows into the anaerobic treatment tank 42 of the biological reaction tank 12 through the pressurized flotation separator 11 and circulates from the sludge return path 19 (the activated sludge containing magnetic powder). ) And the initial settling sludge from the initial settling sludge path 37. The organic matter in the raw water is purified by being treated with activated sludge in the anaerobic treatment tank 42 and the aerobic treatment tank 33. The activated sludge suspension after the aeration treatment flows out from the biological reaction tank 12 and flows into the magnetic separation means 13, and a part of the magnetic powder-containing activated sludge in the suspension is magnetically separated.

  The amount of activated sludge separated in the magnetic separation means 13 is set in accordance with the balance between the activated sludge growth and auto-oxidation in the biological reaction tank 12 and the load on the final sedimentation basin 14. It is preferable to set the activated sludge concentration in the activated sludge suspension flowing into the final sedimentation basin 14 to 3000 mg / L or less, preferably 2000 mg / L or less, particularly 1500 mg / L or less.

  Generally, the BOD concentration of sewage flowing into the aerobic treatment tank 43 of the sewage treatment plant is about 100 to 200 mg / L. In the aerobic treatment tank 43 under this load condition, when the activated sludge concentration is in the range of 5000 to 10000 mg / L, the activated sludge is balanced with the auto-oxidation, and surplus sludge is hardly generated. . Therefore, by separating 80% of the activated sludge by the magnetic separation means 13, the activated sludge concentration flowing into the final sedimentation basin 14 can be 1000 to 2000 mg / L. Within this activated sludge concentration range, it is possible to perform sufficient sedimentation separation in the final sedimentation tank 14.

  At this time, even if the total amount of the activated sludge separated by the magnetic separation means 13 and the final sedimentation basin 14 is returned to the biological reaction tank 12, in the case of normal conditions, depending on the balance between the growth of the activated sludge itself and autooxidation. Since the increase in the activated sludge concentration automatically stops, the maintenance and management of the activated sludge concentration can be made unnecessary. Further, the activated sludge concentration in the equilibrium state naturally fluctuates with the load fluctuation, but the activated sludge separation amount in the magnetic separation means 13 so as not to exceed the allowable sludge concentration in the final sedimentation basin 14 even at the maximum load. By setting, water treatment can be continued regardless of load fluctuations.

  Further, by separating most of the activated sludge with the magnetic separation means 13, it is possible to prevent the final sedimentation basin 14 from exceeding the allowable sludge concentration even if the activated sludge concentration in the biological reaction tank 12 increases to some extent. It is also possible to perform a negative emission in which excess sludge from the wastewater is introduced into the biological reaction tank 12 and self-oxidized. On the other hand, when the raw sludge conditions change and the activated sludge concentration increases above the set value, the operation of the activated sludge concentration in the system is stabilized by operating the liquid cyclone 15 and discharging the excess sludge out of the system. Can be maintained within the range of possible.

  Even when the amount of water flowing into the final sedimentation basin 14 increases due to the inflow of rainwater, the activated sludge that has captured the magnetic powder has a higher specific gravity and better sedimentation than ordinary activated sludge. Thus, since floc-forming bacteria can be preferentially grown, sufficient sedimentation separation can be performed in the final sedimentation tank 14. For example, if the capacity of the magnetic separation means 13 is set so that the MLVSS concentration flowing into the final sedimentation basin 14 is about 1000 mg / L even when the flow rate is increased by rainwater, it is usually set to about 3 to 4 hours. Even if the residence time of the final sedimentation basin 14 is about half, the adverse effect on sedimentation separation can be almost eliminated.

  In addition, since the magnetic separation means 13 does not need to separate the entire amount of the magnetic powder-containing activated sludge, the required amount of activated sludge can be separated in an extremely short time, for example, separation and removal of the magnetic powder-containing activated sludge. Even when the rate is 99.5%, the magnetic separation can be performed in several seconds to several tens of seconds, so that the processing can be performed with a volume of about 1/100 to 1/10000 of the volume of the final sedimentation tank 13. Therefore, not only between the biological reaction tank 12 and the final sedimentation basin 14 in the existing water treatment facility, but also as shown in phantom lines in FIG. 1, the outflow part of the aerobic treatment tank 43 and the inflow part of the final sedimentation basin 14. In addition, since the magnetic separation means 13 can be installed with a small scale modification, it can be easily applied not only to a new water treatment facility but also to an existing water treatment facility.

  In the present embodiment, the final sedimentation basin 14 that settles and separates activated sludge by gravity is exemplified as the solid-liquid separation means subsequent to the magnetic separation means. However, even when membrane separation is adopted as the solid-liquid separation means, the membrane Clogging and the interval between cleaning operations can be made wider than before, so that the life of the membrane can be extended and the cost for membrane separation can be reduced.

As mentioned above, although the best form for implementing this invention was demonstrated, this invention is not limited only to the above-mentioned form. For example, a configuration combining a solubilizing / volume reducing unit and a magnetic separation unit may be employed as the magnetic powder collection unit. In this case, to separate the thus magnetic powder and the residual sludge magnetic from activated sludge after treatment solubilization and volume reduction in the solubilization and volume reduction means, to recover only the magnetic powder. Further, in solubilization and volume reduction means, that shall be carried out with respect to activated sludge processes are performed solubilization and volume reduction process, the separation and recovery of the thus magnetic powder magnetic while performing this process You can also.

  Furthermore, the activated sludge that is the target of magnetic powder recovery is not limited to that in the activated sludge suspension in the biological reaction tank 12. For example, the activated sludge separated by the magnetic separation means 13 or the final sedimentation basin 14 is used. Magnetic powder can also be recovered from sludge.

  The biological treatment apparatus of the present invention is not limited to the above-described wastewater treatment apparatus, and in the biological treatment apparatus in which the magnetic separation method is applied to the treatment of excess sludge or the anaerobic treatment of sludge, it is necessary to remove excess sludge. Applicable. In particular, according to the biological treatment apparatus of the present invention, the magnetic powder is not discharged together with the excess sludge, which is suitable for a wastewater treatment apparatus in which the conditions of raw water change greatly.

It is a systematic diagram of the biological treatment apparatus which shows one example of this invention. It is sectional drawing which shows an example of a magnetic separation means.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Pressure floating separator, 12 ... Biological reaction tank, 13 ... Magnetic separation means, 14 ... Final sedimentation tank, 15 ... Liquid cyclone, 16 ... Sludge receiving tank, 17 ... Magnetic separation sludge return path, 18 ... Settling separation sludge return Route, 19 ... sludge return route, 20 ... solubilization / volume reduction means, 21 ... bypass route, 22 ... treated water outflow route, 23 ... suspension extraction route, 24 ... upper discharge port, 25 ... lower discharge port 26 ... Solubilization / volume reduction means, 31 ... Raw water inflow path, 32 ... Pressurized water path, 33 ... Floating matter recovery path, 34 ... Sediment recovery path, 35 ... Methane fermentation means, 36 ... Solubilization / volume reduction Treatment means, 37 ... first sedimentation sludge path, 38 ... floating separation water inflow path, 41 ... partition plate, 42 ... anaerobic treatment tank, 43 ... aerobic treatment tank, 44 ... stirrer, 45 ... aeration pipe, 51 ... inflow part 52 ... Outflow part, 53 ... Magnetic separation tank, 54 ... Rotating drum 55 ... magnetic powder containing active sludge, 56 ... scraper, 57 ... sludge collecting trough

Claims (5)

A biological reaction tank that performs biological treatment with activated sludge containing magnetic powder to which magnetic powder is added, and a part of the activated sludge containing magnetic powder contained in the activated sludge suspension flowing out of the biological reaction tank from the liquid by magnetic force. in the biological treatment device having a magnetic separation means for separating said biological reactor with magnetic powder collecting means for separating and recovering the magnetic powder-containing active sludge or al magnetic powder, the separated recovered magnetic powder in the magnetic powder recovery means A biological treatment apparatus, comprising: a magnetic powder return path for returning to the waste water; and a sludge discharge path for discharging residual sludge after the magnetic powder is separated by the magnetic powder recovery means. The biological treatment apparatus according to claim 1, wherein the magnetic powder collecting means is a hydrocyclone. The magnetic powder recovery means includes a solubilization-volume reduction means for performing solubilization and volume reduction treatment for the magnetic powder containing active sludge, solubilization and volume reduction in solubilization-volume reduction means magnetic powder containing active sludge doing the processing, or, separation and recovery of magnetic powder containing active sludge or al magnetic powder after the solubilization and volume reduction treatment in the solubilization-volume reduction means The biological treatment apparatus according to claim 1, further comprising a liquid cyclone. The magnetic powder recovery means includes a solubilization-volume reduction means for performing solubilization and volume reduction treatment for the magnetic powder containing active sludge, solubilization and volume reduction in solubilization-volume reduction means magnetic powder containing active sludge doing the processing, or, the magnetic powder-containing active sludge or al the magnetic powder by the magnetic after the solubilization and volume reduction treatment in the solubilization-volume reduction means biological treatment apparatus according to claim 1, characterized in that it comprises a manual stage you separated and recovered. The organism according to claim 3 or 4, wherein the solubilizing / volume-reducing means is an ultrasonic treatment apparatus that irradiates an activated sludge suspension containing the magnetic powder-containing activated sludge with ultrasonic waves. Processing equipment.

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