Sludge concentration mass selection system, control method, sewage treatment system and method

Abstract

The application provides a sludge concentration and separation system, a control method, a sewage treatment system and a method. The sludge concentration and separation system is applied to an integrated reaction and precipitation device inoculated with activated sludge, is used to receive sludge discharged from the integrated reaction and precipitation device and concentrate or separate the sludge, and comprises a sludge pre-concentration tank and a sludge separation device. The sludge concentration and separation system has at least two working modes including a sludge separation mode and a sludge concentration mode. The sludge concentration and separation system, the control method, the sewage treatment system and the method can concentrate and discharge the sludge of the integrated reaction and precipitation device, improve the residual sludge concentration, and improve the subsequent sludge treatment efficiency. The sludge in the integrated reaction and precipitation device can be directionally separated and screened, the sludge with poor settling performance is discharged, and the water treatment efficiency and effect are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, and in particular to a sludge concentration and quality selection system, a control method, a sewage treatment system and a method. BACKGROUND

[0002] The integrated reaction and sedimentation device is a sewage treatment device integrating aeration and sedimentation, that is, aeration and sedimentation are performed in the same device or reaction tank. When sewage is treated by using the existing integrated reaction and sedimentation device, the sedimentation time is limited, and no sedimentation tank is additionally provided, so that there is a problem of low residual sludge concentration of discharge. When the residual sludge concentration is low, further treatment of the sludge is required, which causes problems of long treatment process, long time, large energy consumption and the like. At the same time, when the sludge concentration in the reaction system is low, the denitrification and phosphorus removal efficiency in the system is low, which affects the sewage treatment efficiency and effect. SUMMARY

[0003] Therefore, the present application aims to provide a sludge concentration and quality selection system, a control method, a sewage treatment system and a method, so as to solve the above technical problems.

[0004] In a first aspect, the present application provides a sludge concentration and quality selection system applied to an integrated reaction and sedimentation device inoculated with activated sludge; the sludge concentration and quality selection system is used to receive sludge discharged from the integrated reaction and sedimentation device and concentrate or screen the sludge, and comprises:

[0005] A sludge pre-concentration tank is used to separate and pre-concentrate sludge, and is in communication with the integrated reaction and sedimentation device through a first sludge discharge pipeline, and an upper portion is in communication with a pre-concentration effluent pipeline used to discharge supernatant from the sludge pre-concentration tank;

[0006] A sludge quality selection device is used to separate and concentrate sludge or perform cyclone screening, and a side wall is provided with a first inlet, a bottom portion is provided with an underflow port, and a top portion is provided with an overflow port; the first inlet is in communication with the integrated reaction and sedimentation device and the sludge pre-concentration tank through the second sludge discharge pipeline and the pre-concentration sludge discharge pipeline, respectively; the underflow port is in communication with the integrated reaction and sedimentation device and an external sludge storage tank through the first reflux pipeline and the third sludge discharge pipeline, respectively; and the overflow port is in communication with the integrated reaction and sedimentation device and the external sludge storage tank through the second reflux pipeline and the fourth sludge discharge pipeline, respectively;

[0007] The sludge concentration and separation system has at least two working modes including a sludge separation mode and a sludge concentration mode; in the sludge separation mode, the first sludge discharge pipeline, the sludge pre-concentration tank, the pre-concentration sludge discharge pipeline, the pre-concentration effluent pipeline, the third sludge discharge pipeline and the second backflow pipeline are in an inactivated state; in the sludge concentration mode, the second sludge discharge pipeline, the first backflow pipeline and the fourth sludge discharge pipeline are in an inactivated state.

[0008] Further, the sludge concentration and separation system further comprises:

[0009] a dosing device in communication with the first sludge discharge pipeline through a dosing pipeline, configured to add flocculants into the sludge pre-concentration tank;

[0010] and / or a backwashing device in communication with the third sludge discharge pipeline through a backwashing pipeline, configured to backwash the sludge separation device.

[0011] In a second aspect, the present application provides a control method of a sludge concentration and separation system, applied to the sludge concentration and separation system of the first aspect; the control method comprises:

[0012] monitoring the sludge concentration, the sludge age, the sludge settling ratio, the sludge level and the reaction cycle of the integrated reaction and sedimentation device during the wastewater treatment process;

[0013] in response to that the sludge concentration in the integrated reaction and sedimentation device is greater than a first concentration threshold or the sludge age is greater than a preset number of days, and the reaction cycle of the integrated reaction and sedimentation device is in a first preset cycle, starting the sludge concentration and separation system and operating the sludge concentration mode;

[0014] in response to that the ratio of the sludge settling ratio to the sludge concentration in the integrated reaction and sedimentation device is greater than a first preset ratio or the sludge level is greater than a first preset height, and the reaction cycle is in a second preset cycle, starting the sludge concentration and separation system and operating the sludge separation mode.

[0015] Further, the operating step of the sludge concentration mode comprises:

[0016] starting the sludge pre-concentration tank and controlling the integrated reaction and sedimentation device to discharge sludge to the sludge pre-concentration tank through the first sludge discharge pipeline;

[0017] controlling the sludge to stay in the sludge pre-concentration tank for a certain period of time for water separation and sedimentation, monitoring the sludge level in the sludge pre-concentration tank and the sludge concentration of the sludge entering the sludge pre-concentration tank, and opening the pre-concentration effluent pipeline to discharge the supernatant through the sludge pre-concentration tank;

[0018] in response to the sludge level in the sludge pre-concentration tank being greater than or equal to a second preset height and the sludge concentration of the sludge entering the sludge pre-concentration tank being greater than or equal to a second concentration threshold, starting the sludge quality selection device and controlling the sludge pre-concentration tank to discharge sludge through the pre-concentration sludge discharge pipeline, the first inlet, and the sludge quality selection device;

[0019] concentrating the sludge by sludge-water separation using the sludge quality selection device, the concentrated sludge being discharged into an external sludge storage tank through the underflow port and the third sludge discharge pipeline, and the upper sludge-water mixture being returned to the integrated reaction and precipitation device through the overflow port and the second return pipeline.

[0020] Further, the operation steps of the sludge concentration mode further include:

[0021] in response to the sludge staying in the sludge pre-concentration tank for more than a preset time, the sludge level in the sludge pre-concentration tank still being less than the second preset height, or the sludge concentration of the sludge entering the sludge pre-concentration tank still being less than the second concentration threshold, starting a dosing device to add flocculants into the sludge pre-concentration tank.

[0022] Further, the operation steps of the sludge quality selection mode include:

[0023] starting the sludge quality selection device and controlling the integrated reaction and precipitation device to discharge sludge through the second sludge discharge pipeline and the first inlet and the sludge quality selection device;

[0024] concentrating the sludge by sludge-water separation using the sludge quality selection device, the concentrated sludge being discharged into an external sludge storage tank through the underflow port and the third sludge discharge pipeline, and the upper sludge-water mixture being returned to the integrated reaction and precipitation device through the overflow port and the second return pipeline.

[0025] Further, the operation steps of the sludge quality selection mode further include:

[0026] monitoring the sludge concentration, flow rate, and pressure of the underflow port and the first inlet during the operation of the sludge quality selection device;

[0027] in response to the sludge concentration ratio of the underflow port to the first inlet being less than a second preset ratio, the flow rate ratio of the underflow port to the first inlet being greater than a third preset ratio or less than a fourth preset ratio, or the pressure difference between the first inlet and the underflow port being greater than or equal to a preset difference, controlling the backwashing device to be turned on and backwashing the sludge quality selection device through the backwashing pipeline.

[0028] Further, the operation steps of the sludge quality selection mode further include:

[0029] monitoring the sludge particle size in the integrated reaction and precipitation device;

[0030] After the sludge concentration and quality selection device operates for a target period, the ratio of the sludge settling ratio to the sludge concentration in the integrated reaction and sedimentation device is still greater than the first preset ratio;

[0031] Microbial carriers are added to the integrated reaction and sedimentation device until the sludge particle size in the integrated reaction and sedimentation device meets a preset particle size value, or the ratio of the sludge settling ratio to the sludge concentration is less than or equal to a preset ratio.

[0032] The third aspect of the present application also provides a sewage treatment system, which comprises an integrated reaction and sedimentation device and the sludge concentration and quality selection system of the first aspect, and further comprises:

[0033] A water inlet pipeline and a water outlet pipeline that are in communication with the integrated reaction and sedimentation device, respectively, the water inlet pipeline being used to pass untreated sewage into the integrated reaction and sedimentation device, and the water outlet pipeline being used to discharge treated sewage to a next process.

[0034] The fourth aspect of the present application also provides a sewage treatment method, which is applied to the sewage treatment system of the third aspect, and the method comprises:

[0035] Untreated sewage is passed into the integrated reaction and sedimentation device inoculated with activated sludge through a water inlet pipeline, and treated sewage is discharged to a next process through a water outlet pipeline;

[0036] During the treatment process of the integrated reaction and sedimentation device, the sludge concentration and quality selection system is controlled by using the control method of the sludge concentration and quality selection system of the second aspect, so as to concentrate or screen sludge according to the state of the activated sludge in the integrated reaction and sedimentation device.

[0037] From the above, it can be seen that the present application provides a sludge concentration and quality selection system, a control method, a sewage treatment system and a method. By providing a sludge pre-concentration tank and a sludge quality selection device, the sludge in the integrated reaction and precipitation device can be concentrated and cyclone screened. When the integrated reaction and precipitation device needs to discharge residual sludge, the sludge concentration and screening system is started in the sludge concentration mode, the residual sludge discharged from the integrated reaction and precipitation device is separated and concentrated, and then discharged to the external sludge storage tank, so as to improve the concentration of the residual sludge, reduce the subsequent residual sludge treatment process and energy consumption, and improve the subsequent residual sludge removal efficiency. When the settling performance of the integrated reaction and precipitation device is poor, the sludge concentration and screening system is started in the sludge quality selection mode, the sludge in the integrated reaction and precipitation device is cyclone screened, the sludge with poor settling performance and poor flocculation performance is discharged from the system, and the sludge with good settling performance and good flocculation performance is reflowed to the integrated reaction and precipitation device to continue treating the sewage, so as to improve the settling performance and concentration of the activated sludge in the integrated reaction and precipitation device, and further improve the sewage treatment efficiency and treatment effect. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the present application or related art, the following will briefly introduce the drawings needed to be used in the embodiments or related art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0039] Figure 1 It is a schematic diagram of the sludge concentration and quality selection system in the embodiments of the present application.

[0040] Figure 2 It is a structural schematic diagram of the hydrocyclone in the embodiments of the present application.

[0041] Figure 3 It is a schematic diagram of an electronic device in the embodiments of the present application.

[0042] Legend: 1-integrated reaction and precipitation device; 2-sludge pre-concentration tank; 201-second inlet; 202-center cylinder; 203-baffle; 3-sludge quality selection device; 301-first inlet; 302-underflow port; 303-overflow port; 4-first sludge discharge pipeline; 5-pre-concentration sludge discharge pipeline; 6-second sludge discharge pipeline; 7-third sludge discharge pipeline; 8-first reflux pipeline; 9-fourth sludge discharge pipeline; 10-second reflux pipeline; 11-backwashing device; 12-backwashing pipeline; 13-dosing device; 14-dosing pipeline; 15-water inlet pipeline; 16-water outlet pipeline; 17-pre-concentration water outlet pipeline. DETAILED DESCRIPTION

[0043] For purposes of the present application, technical and scientific terms can have the following meanings unless otherwise defined:

[0044] It should be noted that unless otherwise defined, technical and scientific terms used in the present application should have the meanings commonly understood by one of ordinary skill in the art to which this application pertains. The meaning and definition of the term "first", "second" and similar terms in the present application do not connote any order, quantity, or importance, but are used to distinguish one element from another. The terms "including", "containing" and similar terms are intended to be inclusive and mean that elements or objects prior to the term encompass elements or objects listed thereafter and equivalents thereof, but do not exclude other elements or objects. The terms "connected" or "coupled" and similar terms are not limited to a physical or mechanical connection or linkage to either other, but also include an electrical connection, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like are used only to indicate relative positions, and when the absolute position of the described object is changed, the relative positional relationship can also be changed accordingly.

[0045] The activated sludge method is a method of biological treatment of wastewater with activated sludge as the main body. It has a history of research and application of more than 100 years, can remove dissolved and colloidal biodegradable organic matter and suspended solids and other substances that can be adsorbed by activated sludge from wastewater, has the characteristics of wide adaptability to water quality and quantity, flexible and diverse operation mode, good controllability, high treatment efficiency, low cost, etc., and has become the main method of biological treatment of wastewater.

[0046] Activated sludge is a flocculent sludge particle formed by mixing microorganisms such as bacteria, fungi, protozoa, metazoan, suspended matter and colloidal matter in wastewater, which has strong adsorption and decomposition of organic matter and good settling performance. Because of its biochemical activity, it is called activated sludge. The activated sludge method is a biological treatment method that uses organic pollutants in wastewater as culture medium, continuously cultures activated sludge under dissolved oxygen conditions, and uses its adsorption, coagulation and oxidation decomposition functions to purify organic pollutants in wastewater.

[0047] The activated sludge process has been developed for many years. Its process has been continuously improved, innovated and proliferated, and various activated sludge process types and reaction devices have been derived. The integrated reaction and sedimentation device 1 is a device that integrates aeration and sedimentation into one, i.e., aeration is first performed, then sedimentation is performed, and finally supernatant after sedimentation is discharged, and activated sludge is left in the reaction device to continue treating the next batch of wastewater. During the operation of the integrated reaction and sedimentation device 1, the operation mode consists of four basic processes of water inflow, aeration, standing, and water discharge to form a cycle, i.e., different operations for different purposes are performed at different time periods in a single reaction device. Although it is completely mixed in terms of flow state, it is plug flow in terms of pollutant degradation. The integrated reaction and sedimentation device 1 reduces the land occupation area of the treatment process, reduces the pipe connection between various treatment equipment in the traditional AAO process, and reduces the use of various consumables, and is a saving and intensive wastewater treatment process.

[0048] During the reaction process of the integrated reaction and sedimentation device 1, the types and growth rates of microorganisms in the activated sludge are affected by process parameters such as aeration amount and concentrations of nutrients in the wastewater. After the device has been operated for a period of time, in order to maintain the sludge in the integrated reaction and sedimentation device 1 at a good treatment performance, it is necessary to periodically or irregularly discharge a part of the sludge in the integrated reaction and sedimentation device 1. The discharged excess sludge usually contains a high water content, has a large volume and is inconvenient to transport, and also contains volatile substances, ash, pathogens, toxic substances and other substances. Therefore, a series of subsequent treatments are also needed for the discharged excess sludge, including reducing the volume of the sludge, reducing the water content of the sludge, facilitating transportation, digestion, dewatering and comprehensive utilization; carrying out sanitization and stabilization treatment to remove organic matter, pathogens and other harmful substances, prevent "secondary pollution source" and environmental pollution; improving the composition and properties of the sludge for resource utilization, etc.

[0049] Since the sedimentation process is directly completed in the integrated reaction and sedimentation device 1, when the sedimentation time is too long, the wastewater treatment efficiency is low; and when the sedimentation time is too short, it will lead to low sludge concentration and low concentration of the discharged excess sludge. When the sludge concentration of the discharged excess sludge is too low, the following problems will be caused to the subsequent excess sludge treatment: (1) affecting the subsequent sludge removal efficiency, i.e., it can not meet the demand of the water content of the excess sludge, resulting in that the excess sludge can not be transported out; (2) causing the lengthening of the excess sludge treatment process, requiring a larger land occupation area, and increasing the consumption of chemicals; (3) causing the capacity of the sludge dewatering machine to be insufficient, causing the solid recovery rate of the dewatering machine to be less than 80% for a long time, resulting in the generation of a large amount of leachate, increasing the power consumption of the dewatering machine and energy consumption. The above problems greatly limit the subsequent treatment and disposal of the excess sludge.

[0050] In addition, the settling performance of the activated sludge of the integrated reaction and sedimentation device 1 is affected by the water quality of the incoming water, the aeration time, etc. When the settling performance of the sludge decreases, the sludge is difficult to settle, which also causes the problem of a decrease in the sludge concentration; on this basis, the compaction of the sludge is poor, the discharge of the supernatant is limited, the sludge ratio decreases, and the amount of sewage treated per operating cycle decreases, thereby affecting the sewage treatment efficiency; at the same time, when the sludge concentration decreases, the nitrogen and phosphorus removal efficiency of the sewage decreases, which easily leads to a high nitrogen and phosphorus content in the effluent, thereby affecting the sewage treatment effect.

[0051] The sequencing batch reactor is a typical integrated reaction and sedimentation device 1. The activated sludge process realized by the sequencing batch reactor (SBR) is usually referred to as the sequencing batch activated sludge process (SBR process). The SBR process adopts intermittent aeration and is one of the important methods for urban sewage treatment, industrial (petroleum, chemical, food, pharmaceutical, etc.) sewage treatment, and nutrient element removal. In addition to the sequencing batch reactor, the integrated reaction and sedimentation tank is also a typical integrated reaction and sedimentation device 1. In order to further improve the sewage treatment effect in the biochemical system, an integrated reaction and sedimentation tank is added in the secondary sedimentation tank in some processes, aeration is performed in the integrated reaction and sedimentation tank, the activated sludge is promoted to react with the sewage, then the treated sewage is discharged from the system after sedimentation. Whether it is an integrated reaction and sedimentation tank or a sequencing batch reactor, the aforementioned problems exist.

[0052] Therefore, the present application provides a sludge concentration and selection system, as shown in Figure 1 which is applied to an integrated reaction and sedimentation device 1 inoculated with activated sludge, can simultaneously improve the sludge concentration, the sewage treatment efficiency, and the sewage treatment effect of the integrated reaction and sedimentation device 1, and is used to receive the sludge discharged from the integrated reaction and sedimentation device 1 and concentrate or select the sludge, and comprises:

[0053] The sludge pre-concentration tank 2 is used for sludge-water separation pre-concentration of the sludge, is communicated with the integrated reaction and sedimentation device 1 through a first sludge discharge pipeline 4, and the upper portion is communicated with a pre-concentration effluent pipeline 17 for discharging the supernatant out of the sludge pre-concentration tank 2;

[0054] The sludge concentration and separation device 3 is used for sludge water separation concentration or cyclone screening, and is provided with a first inlet 301 on the side wall, a underflow port 302 on the bottom, and an overflow port 303 on the top. The first inlet 301 is communicated with the integrated reaction and precipitation device 1 and the sludge pre-concentration tank 2 through the second sludge discharge pipeline 6 and the pre-concentration sludge discharge pipeline 5 respectively. The underflow port 302 is communicated with the integrated reaction and precipitation device 1 and an external sludge storage tank through the first reflux pipeline 8 and the third sludge discharge pipeline 7 respectively. The overflow port 303 is communicated with the integrated reaction and precipitation device 1 and an external sludge storage tank through the second reflux pipeline 10 and the fourth sludge discharge pipeline 9 respectively.

[0055] The sludge concentration and separation system has at least two working modes including a sludge concentration mode and a sludge separation mode. In the sludge concentration mode, the first sludge discharge pipeline 4, the sludge pre-concentration tank 2, the pre-concentration sludge discharge pipeline 5, the pre-concentration water outlet pipeline 17, the third sludge discharge pipeline 7 and the second reflux pipeline 10 are in an inactivated state. In the sludge separation mode, the second sludge discharge pipeline 6, the first reflux pipeline 8 and the fourth sludge discharge pipeline 9 are in an inactivated state.

[0056] The sludge pre-concentration tank 2 and the sludge concentration and separation device 3 are arranged to realize the concentration and cyclone screening of the sludge in the integrated reaction and precipitation device 1. When the integrated reaction and precipitation device 1 needs to discharge the residual sludge, the sludge concentration and separation system is started in the sludge concentration mode, the residual sludge discharged from the integrated reaction and precipitation device 1 is concentrated and separated, and then discharged to the external sludge storage tank, so as to improve the concentration of the residual sludge, reduce the subsequent residual sludge treatment process and energy consumption, and improve the subsequent residual sludge removal efficiency. When the settling performance of the integrated reaction and precipitation device 1 is poor, the sludge concentration and separation system is started in the sludge separation mode, the sludge in the integrated reaction and precipitation device 1 is cyclone screened, the sludge with poor settling performance and poor flocculation performance is discharged from the system, and the sludge with good settling performance and good flocculation performance is reflowed to the integrated reaction and precipitation device 1 to continue treating the sewage, so as to improve the settling performance and concentration of the activated sludge in the integrated reaction and precipitation device 1, and further improve the sewage treatment efficiency and treatment effect.

[0057] In the sludge concentration mode, the second sludge discharge pipeline 6, the first reflux pipeline 8, and the fourth sludge discharge pipeline 9 are in a non-enabled state, the sludge discharged from the integrated reaction and precipitation device 1 is introduced into the sludge pre-concentration tank 2 through the first sludge discharge pipeline 4, preliminary separation of sludge and water is performed in the sludge pre-concentration tank 2, pre-concentration is realized, the upper clear liquid is discharged through the pre-concentration effluent pipeline 17, and the bottom sludge is introduced into the sludge quality selection device 3 through the pre-concentration sludge discharge pipeline 5 for further separation of sludge and water, realizing secondary concentration. In the sludge quality selection device 3, due to high-speed rotation, the heavier sludge is thrown to the outer wall and sinks, and then is discharged through the underflow port 302 and the third sludge discharge pipeline 7 to an external sludge storage tank for subsequent treatment; while the sewage and the sludge with lower concentration overflow through the overflow port 303 and are returned to the integrated reaction and precipitation device 1 through the second reflux pipeline 10 to continue to participate in the reaction, thereby realizing concentration and dewatering of the remaining sludge during the sludge discharge of the integrated reaction and precipitation device 1, improving the sludge concentration, reducing the subsequent sludge treatment process and energy consumption, and further improving the subsequent sludge removal efficiency.

[0058] In the sludge concentration mode, the second sludge discharge pipeline 6, the first reflux pipeline 8, and the fourth sludge discharge pipeline 9 are in a non-enabled state, the sludge discharged from the integrated reaction and precipitation device 1 is introduced into the sludge pre-concentration tank 2 through the first sludge discharge pipeline 4, preliminary separation of sludge and water is performed in the sludge pre-concentration tank 2, pre-concentration is realized, the upper clear liquid is discharged through the pre-concentration effluent pipeline 17, and the bottom sludge is introduced into the sludge quality selection device 3 through the pre-concentration sludge discharge pipeline 5 for further separation of sludge and water, realizing secondary concentration. In the sludge quality selection device 3, due to high-speed rotation, the heavier sludge is thrown to the outer wall and sinks, and then is discharged through the underflow port 302 and the third sludge discharge pipeline 7 to an external sludge storage tank for subsequent treatment; while the sewage and the sludge with lower concentration overflow through the overflow port 303 and are returned to the integrated reaction and precipitation device 1 through the second reflux pipeline 10 to continue to participate in the reaction, thereby realizing concentration and dewatering of the remaining sludge during the sludge discharge of the integrated reaction and precipitation device 1, improving the sludge concentration, reducing the subsequent sludge treatment process and energy consumption, and further improving the subsequent sludge removal efficiency.

[0059] In some embodiments, the sludge quality selection device 3 is a hydrocyclone. As shown in FIG. 1, the sludge quality selection device 3 is a hydrocyclone. Figure 2As shown, the hydrocyclone is a high-efficiency separation device using centrifugal field to separate mixtures with different densities, which can be used for concentration and dewatering. The sludge enters the hydrocyclone from the first inlet 301 in a tangential direction, forming a rotating flow from top to bottom inside the hydrocyclone. Based on the differences in density, particle size, weight, etc. of different components in the sludge, the rotating motion inside the hydrocyclone is divided into outer vortex and inner vortex motion. The sludge with large density and mass in the sludge moves along the radial direction to the wall under the action of centrifugal force, and at the same time moves downward, forming an outer vortex, and in this process, the light components with small density in the sludge are separated, and finally discharged from the underflow outlet. Affected by the uneven radial pressure distribution in the hydrocyclone, a low pressure area or even a vacuum area is formed at the center position, and the light components with small density in the sludge gradually separate from the outer vortex and migrate to the center position, and the migration amount is larger as it is closer to the underflow outlet, so that the light components cannot be discharged from the underflow outlet 302. The light components perform upward rotating motion to form an inner vortex, and are finally discharged from the overflow outlet 303.

[0060] In some embodiments, the dosing device 13 communicates with the first sludge discharge pipeline 4 through the dosing pipeline 14 to add flocculants to the sludge pre-concentration tank 2. During the sludge pre-concentration process, the pre-concentration condition is monitored, and whether to add flocculants is determined according to the pre-concentration condition, thereby improving the pre-concentration effect.

[0061] In some embodiments, the backwashing device 11 communicates with the third sludge discharge pipeline 7 through the backwashing pipeline 12 to backwash the sludge quality selection device 3. During the long-term operation of the sludge quality selection device 3, sludge may be left in the sludge quality selection device 3 to block the underflow outlet 302, the first inlet 301, etc., thereby affecting the concentration and screening effect. Therefore, the backwashing device 11 is arranged to periodically or irregularly backwash the sludge quality selection device 3, to ensure the separation effect of the sludge quality selection device 3. When backwashing is needed, the backwashing pipeline 12 and the backwashing device 11 are opened, and the backflushing liquid (generally sludge supernatant) in the backwashing device 11 enters the sludge quality selection device 3 from the underflow outlet 302 through the backwashing pipeline 12 and the third sludge discharge pipeline 7, to realize backflushing of the sludge quality selection device 3. The backflushing time is 30 minutes each time, and after completing a backflushing, if the sludge quality selection device 3 can continue to operate normally, the backflushing is closed, and if there is still an abnormality, a backflushing is performed again.

[0062] Specifically, the sludge pre-concentration tank 2 is provided with a central cylinder 202, and a second inlet 201 is arranged at the top of the sludge pre-concentration tank 2, and the central cylinder 202 is located below the second inlet 201. A baffle 203 is arranged on the outer side wall of the central cylinder 202, and the included angle between the baffle 203 and the central cylinder 202 is 30-60°, and the gap between the baffle 203 and the side wall of the sludge pre-concentration tank 2 is 5-20 cm. The sludge enters the sludge pre-concentration tank 2 through the central cylinder 202 for sludge-water separation, and the sludge is settled at the bottom of the tank. After pre-concentration for a certain period of time, the sludge is introduced into the sludge quality selection device 3 through the pre-concentration sludge discharge pipeline 5 for further concentration. The upper clear liquid slowly rises from the edge through the two side baffles 203, and finally flows out through the pre-concentration water outlet pipeline 17. A booster pump can be arranged on the second sludge discharge pipeline 6 and the pre-concentration sludge discharge pipeline 5 to pressurize the sludge, so that the sludge enters the sludge quality selection device 3 at a higher pressure, thereby achieving better separation and concentration.

[0063] In some embodiments, the integrated reaction precipitation device 1 is provided with a sludge concentration meter A1, a sludge level meter L1, and a sludge settling ratio online detector SV for detecting the sludge concentration X1, the sludge level h1, and the sludge settling ratio SV in the integrated reaction precipitation device 1, respectively. A flow meter F1 is also provided to detect the inflow Q1. The sludge pre-concentration tank 2 is provided with a sludge level meter L2 and a sludge concentration meter A2 for detecting the sludge level h2 in the sludge pre-concentration tank 2 and the sludge concentration X2 of the sludge entering the sludge pre-concentration tank 2, respectively. The first inlet 301 of the sludge quality selection device 3 is provided with a sludge concentration meter A3, a pressure gauge P1, and a flow meter F2 for detecting the sludge concentration X3, the pressure p1, and the flow Q2 of the first inlet 301, respectively. The underflow port 302 of the sludge quality selection device 3 is provided with a sludge concentration meter A4, a pressure gauge P2, and a flow meter F4 for detecting the sludge concentration X4, the pressure p2, and the flow Q3 of the underflow port 302, respectively. The overflow port 303 is provided with a flow meter F3 for detecting the flow Q3 of the overflow port. Through the above arrangement, the automatic control of the sludge concentration and quality selection system is realized.

[0064] The application also provides a control method of a sludge concentration and quality selection system, which applies the sludge concentration and quality selection system of any of the above embodiments. The control method comprises:

[0065] monitoring the sludge concentration, sludge age, sludge settling ratio, and reaction period during the sewage treatment process of the integrated reaction precipitation device 1;

[0066] in response to the sludge concentration in the integrated reaction precipitation device 1 being greater than a first concentration threshold or the sludge age being greater than a preset number of days, and the reaction period of the integrated reaction precipitation device 1 being in a first preset period, starting the sludge concentration and quality selection system and operating in the sludge concentration mode;

[0067] In response to the ratio of sludge settling ratio to sludge concentration in the integrated reaction and sedimentation device 1 being greater than a first preset ratio or the sludge level being greater than a first preset height, and the reaction period being in a second preset period, the sludge concentration and quality selection system is started and operated in the sludge concentration and quality selection mode.

[0068] In the present application, by monitoring the state of the sludge in the integrated reaction and sedimentation device 1 and the reaction period, it is determined whether to start the sludge concentration and quality selection system and the operation mode of the sludge concentration and quality selection system, realizing the automatic intelligent control of the sludge concentration and quality selection system. When the sludge concentration in the integrated reaction and sedimentation device 1 is greater than a first concentration threshold or the sludge age is greater than a preset number of days, and the reaction period is in a first preset period, at this time, the remaining sludge in the integrated reaction and sedimentation device 1 needs to be discharged, that is, the sludge concentration and quality selection system is started and operated in the sludge concentration mode. When the ratio of sludge settling ratio to sludge concentration in the integrated reaction and sedimentation device 1 is greater than a first preset ratio or the sludge level therein is greater than a first preset height, and the reaction period is in a second preset period, it indicates that the settling performance of the activated sludge in the integrated reaction and sedimentation device 1 is poor and the concentration is low, so the sludge needs to be screened, at this time, the sludge concentration and quality selection system is started and operated in the sludge concentration and quality selection mode. The start and operation of the sludge concentration and quality selection system are determined according to the state of the sludge in the integrated reaction and sedimentation device 1 and the reaction period, so that the operation of the system is more in line with the actual needs of the integrated reaction and sedimentation device 1, the activated sludge can be concentrated and discharged or cyclone screened in time, the degree of intelligence and automation is higher, the processing efficiency is higher, and the scope of application is wider.

[0069] The integrated reaction and sedimentation device 1 contains the following four stages in each treatment period when treating wastewater: water inlet stage, aeration stage, standing stage and water outlet stage. In the water inlet stage, the wastewater to be treated is introduced into the integrated reaction and sedimentation device 1. After the water inlet is completed, the aeration stage begins, the microorganisms in the activated sludge decompose and remove the pollutants in the wastewater. Then the standing stage is entered, the solid substances are precipitated to realize solid-liquid separation. At this time, the upper clear liquid in the integrated reaction and sedimentation device 1 is the treated wastewater, and finally the upper clear liquid is discharged from the reactor to the next treatment process in the water outlet stage, completing the treatment of the wastewater to be treated. The activated sludge stays in the integrated reaction and sedimentation device 1 and continues to treat the next batch of wastewater to be treated according to the process of water inlet-aeration-standing-water outlet. In the above process, that is, in the process of treating wastewater by using the integrated reaction and sedimentation device 1, the sludge concentration, sludge age, sludge settling ratio and reaction period in the integrated reaction and sedimentation device 1 are monitored, and the start and operation mode of the sludge concentration and quality selection system are determined according to the monitoring results.

[0070] Specifically, the first concentration threshold is 5000 mg / L, the preset number of days is 20 days, and the first preset period is the effluent stage. When the integrated reaction and precipitation device 1 is in the effluent stage, it is in the state after standing and precipitation at this time. The upper clear liquid is discharged to the next process at this time. If the sludge concentration is greater than 5000 mg / L is monitored at this time, it indicates that the sludge concentration in the integrated reaction and precipitation device 1 is too high at this time, and the sludge and water separation needs a longer time, thereby affecting the sewage treatment efficiency. At the same time, as the sludge concentration increases, the oxygen consumption increases, the aeration requirement increases, and the treatment cost of unit sewage increases. Therefore, at this time, the integrated reaction and precipitation device 1 can be concentrated and sludge discharged, that is, a part of the sludge is discharged from the integrated reaction and precipitation device 1, the sludge content in the integrated reaction and precipitation device 1 is reduced, the sewage treatment efficiency is improved, and the cost is reduced.

[0071] During the long-time operation of the integrated reaction and precipitation device 1, when the sludge age reaches a certain length of time, the sludge activity, microbial dominant species, and treatment performance in the sludge will change to a certain extent, so it is necessary to regularly discharge sludge, so that the activated sludge can always be in the best treatment state. In this application, the preset number of days is set to 20 days. When the sludge age is greater than 20 days, the sludge concentration and selection system of the integrated reaction and precipitation device 1 is started in the effluent stage, and runs in the sludge concentration mode, so as to concentrate and discharge sludge. In addition, the sludge is discharged in the effluent stage, which does not affect the normal operation of the integrated reaction and precipitation device 1, and the operation efficiency is high. Alternatively, the first concentration threshold can also be other values, such as 4800, 4500, 4200, 4000, 5200, 5500 mg / L, etc. It can be adjusted according to the specific characteristics of the activated sludge, the characteristics of the treated sewage, etc., and the specific limitations are not limited. The preset number of days can be 19, 18, 17, 16, 15, 12, 10, 8, 6, 5, 4, 22, 25, 26, 27, 28, 29, 30 days. It can be adjusted according to the specific characteristics of the activated sludge, the microbial species, the characteristics of the treated sewage, etc., and the specific limitations are not limited. Specifically, the first preset height is 4 / 5 of the liquid level of the integrated reaction and precipitation device 1. When the sludge level in the integrated reaction and precipitation device 1 is greater than 4 / 5 of the liquid level of the integrated reaction and precipitation device 1, it indicates that the sludge has expanded at this time, and the settling performance is poor. Therefore, the sludge concentration and selection system needs to be started to screen the sludge in the integrated reaction and precipitation device 1, and the sludge with poor performance is discharged, so as to improve the sludge performance, treatment efficiency and effect in the integrated reaction and precipitation device 1.

[0072] Specifically, the first preset ratio is 120, and the second preset period is the aeration stage. The sludge settling ratio (Sludge Settling Velocity, SV) is also called 30 min settling rate, which represents the percentage of the volume of the settled sludge formed after the mixed liquid is left for 30 min to the volume of the original mixed liquid. The SV value can effectively reflect the sludge amount and the coagulation and settling performance of the sludge during normal operation of the aeration. The smaller the SV value is, the better the settling performance of the sludge is. The occurrence of the sludge bulking phenomenon can be judged and found by the change of the SV value. However, the SV value of the activated sludge is affected by the sludge concentration, and the two are positively correlated. Therefore, the SV value of the activated sludge can only roughly reflect the settling performance of the sludge. When the sludge concentration also changes, the sludge settling ratio at this time cannot accurately reflect the structure and accurate settling performance of the sludge. Therefore, in the present application, the sludge settling ratio and the sludge concentration are used to determine the settling performance of the sludge in the integrated reaction and precipitation device 1, which can avoid the influence of the sludge concentration on the sludge settling. When the ratio of the sludge settling ratio to the sludge concentration is greater than 120, it indicates that the settling performance of the sludge in the integrated reaction and precipitation device 1 is poor. If the current state continues to run, it is easy to cause the content of pollutants such as nitrogen and phosphorus in the final effluent to be high, the water quality to be poor, the treatment effect to be affected, and the concentration of the sludge to be low. Therefore, at this time, the sludge concentration and quality selection system is started and runs in the sludge quality selection mode. The sludge with poor settling performance is screened out and discharged from the system, the settling performance and quality of the sludge in the integrated reaction and precipitation device 1 are improved, and the sewage treatment effect and efficiency are improved, so as to realize efficient phosphorus removal and nitrogen removal.

[0073] In some embodiments, the sludge SRT is calculated by the following formula:

[0074]

[0075] wherein V is the effective tank volume of the integrated reaction and precipitation device 1, Q x is the sludge discharge amount of the integrated reaction and precipitation device 1 per hour, X1 is the sludge concentration of the integrated reaction and precipitation device 1, and X2 is the sludge concentration of the sludge pre-concentration tank 2.

[0076] In some embodiments, the operation steps of the sludge concentration mode include:

[0077] starting the sludge pre-concentration tank 2, and controlling the integrated reaction and precipitation device 1 to discharge sludge to the sludge pre-concentration tank 2 through the first sludge discharge pipeline 4;

[0078] controlling the sludge to stay in the sludge pre-concentration tank 2 for a certain period of time for water separation and precipitation, monitoring the sludge level in the sludge pre-concentration tank 2 and the sludge concentration of the sludge pre-concentration tank 2, and opening the pre-concentration effluent pipeline 17 to discharge the supernatant through the sludge pre-concentration tank 2;

[0079] In response to the sludge level in the sludge pre-concentration tank 2 being greater than or equal to a second preset height, and the sludge concentration of the sludge entering the sludge pre-concentration tank 2 being greater than or equal to a second concentration threshold, the sludge quality selection device 3 is started, and the sludge pre-concentration tank 2 is controlled to discharge sludge to the sludge quality selection device 3 through the pre-concentration sludge discharge pipeline 5, the first inlet 301.

[0080] The sludge is concentrated by sludge-water separation in the sludge quality selection device 3, and the concentrated sludge is discharged into an external sludge storage tank through the underflow port 302 and the third sludge discharge pipeline 7, and the upper sludge-water mixture is returned to the integrated reaction and precipitation device 1 through the overflow port 303 and the second return pipeline 10.

[0081] When the sludge concentration and quality selection system is operated in the sludge concentration mode, the second sludge discharge pipeline 6, the first reflux pipeline 8 and the fourth sludge discharge pipeline 9 are in the disabled state. The specific operation of the sludge concentration mode is as follows: the sludge pre-concentration tank 2 is started, and the integrated reaction and sedimentation device 1 is controlled to discharge sludge to the sludge pre-concentration tank 2 through the first sludge discharge pipeline 4; the sludge stays in the sludge pre-concentration tank 2 for a certain period of time for sludge-water separation, and the sludge gradually settles at the bottom, and the upper clear liquid is discharged through the pre-concentration effluent pipeline 17, thereby realizing the pre-concentration of the sludge. When the sludge stays in the sludge pre-concentration tank 2, the sludge level in the sludge pre-concentration tank 2 and the sludge concentration of the sludge entering the sludge pre-concentration tank 2 are monitored; when the sludge level in the sludge pre-concentration tank 2 is greater than or equal to the second preset height, and the sludge concentration of the sludge entering the sludge pre-concentration tank 2 is greater than or equal to the second concentration threshold, it is indicated that the pre-concentration of the sludge achieves the target effect at this time, at which time the pre-concentration sludge discharge pipeline 5 and the sludge quality selection device 3 are started, and the sludge in the sludge pre-concentration tank 2 is introduced into the sludge quality selection device 3 through the pre-concentration sludge discharge pipeline 5; the sludge rotates at high speed in the sludge quality selection device 3, the water in the sludge and the lighter sludge (i.e. sludge-water mixture) flow into the second reflux pipeline 10 through the overflow port 303, thereby returning to the integrated reaction and sedimentation device 1, and the heavier sludge (i.e. concentrated sludge) settles at the bottom and is discharged into the external sludge storage tank through the third sludge discharge pipeline 7 for subsequent treatment. At this time, the sludge entering the external sludge storage tank is the concentrated sludge, which has high sludge concentration, low water content, high density and small volume, thereby facilitating transportation and reducing subsequent treatment process, land occupation, energy consumption and the like, thereby realizing efficient treatment of the residual sludge. Specifically, the sludge can achieve good pre-concentration effect by staying in the sludge pre-concentration tank 2 for 30-90 minutes, and therefore the staying time can be set to 30-90 minutes, such as 35, 45, 50, 60, 70, 80 minutes and the like, or other values less than 30 minutes or greater than 90 minutes, which can be adjusted according to the actual situation, and the specific limitation is not made. Of course, the staying time can not be controlled, and the starting of the pre-concentration sludge discharge pipeline 5 and the sludge quality selection device 3 can be determined only according to the sludge level in the sludge pre-concentration tank 2 and the sludge concentration of the sludge entering the sludge pre-concentration tank 2, and the specific limitation is not made.

[0082] Specifically, the second preset height is 2 / 3 of the liquid level of the sludge pre-concentration tank 2, and the second concentration threshold is 10000 mg / L. When the sludge level in the sludge pre-concentration tank 2 is greater than or equal to 2 / 3 of the liquid level of the sludge pre-concentration tank 2, and the sludge concentration of the sludge entering the sludge pre-concentration tank 2 is greater than or equal to 10000 mg / L, it is indicated that the sludge concentration in the sludge pre-concentration tank 2 is high, and the pre-concentration purpose is achieved, at which time the sludge quality selection device 3 is started to effectively separate the heavier sludge from the lighter sludge and water, and to complete the concentration of the sludge. Meanwhile, the pre-concentration through the sludge pre-concentration tank 2 can greatly improve the concentration efficiency of the subsequent sludge quality selection device 3, and realize efficient concentration of the sludge.

[0083] In some examples, the running step of the sludge concentration mode further comprises:

[0084] In response to the sludge staying in the sludge pre-concentration tank 2 for more than a preset time, the sludge level in the sludge pre-concentration tank 2 still being less than a second preset height, or the sludge concentration of the sludge pre-concentration tank 2 still being less than a second concentration threshold, starting the dosing device 13 to add flocculants into the sludge pre-concentration tank 2.

[0085] When the sludge stays in the sludge pre-concentration tank 2 for more than a preset time, the sludge level in the sludge pre-concentration tank 2 still being less than a second preset height, or the sludge concentration of the sludge pre-concentration tank 2 still being less than a second concentration threshold, the dosing device 13 is started to add flocculants into the sludge pre-concentration tank 2 at this time, improving the sludge sedimentation effect of the sludge pre-concentration tank 2, thereby speeding up the realization of pre-concentration and improving the treatment efficiency. Specifically, the preset time can be 45 minutes, or can be set to less than 45 minutes, such as 40 minutes, 35 minutes, 30 minutes, etc., or more than 45 minutes, such as 50 minutes, 55 minutes, 60 minutes, etc., which can be adjusted according to the actual operation, and the specific limitation is not limited.

[0086] In some embodiments, the additive amount of flocculants is calculated by the following formula: Wherein, C represents the additive amount of flocculants.

[0087] In some examples, the running step of the sludge concentration mode further comprises:

[0088] Starting the sludge quality selection device 3, and controlling the integrated reaction and sedimentation device 1 to discharge sludge to the sludge quality selection device 3 through the second sludge discharge pipeline 6 and the first inlet 301.

[0089] Using the sludge quality selection device 3 to perform cyclone screening on the discharged sludge, the bottom sludge being backflowed to the integrated reaction and sedimentation device 1 through the underflow port 302 and the first backflow pipeline 8; the upper layer sludge being discharged to the external sludge storage tank through the overflow port 303 and the fourth sludge discharge pipeline 9.

[0090] When the sludge concentration and separation system is operated in the sludge concentration and separation mode, the first sludge discharge pipeline 4, the sludge pre-concentration tank 2, the pre-concentration sludge discharge pipeline 5, the pre-concentration effluent pipeline 17, the third sludge discharge pipeline 7 and the second reflux pipeline 10 are in a non-enabled state. The specific operation steps of the sludge concentration and separation mode are as follows: start the sludge concentration and separation device 3, open the second sludge discharge pipeline 6, the first reflux pipeline 8 and the fourth sludge discharge pipeline 9, and then control the integrated reaction and precipitation device 1 to discharge sludge to the sludge concentration and separation device 3 through the second sludge discharge pipeline 6 and the first inlet 301. The sludge rotates at high speed in the sludge concentration and separation device 3, the sludge with low density, light quality, poor settling performance and poor flocculation performance (i.e. upper layer sludge) floats up, is discharged into the external sludge storage tank through the overflow port 303 and the fourth sludge discharge pipeline 9, so that this part of sludge with poor quality is completely discharged from the reaction system; the sludge with high density, heavy quality, good settling performance and good flocculation performance sinks, is refluxed to the integrated reaction and precipitation device 1 through the underflow port 302 and the first reflux pipeline 8 to continue to participate in the reaction, thereby improving the concentration and quality of the activated sludge in the integrated reaction and precipitation device 1, and further improving the efficiency and effect of wastewater treatment.

[0091] In some embodiments, further comprising:

[0092] In the operation of the sludge concentration and separation device 3, the sludge concentration, flow and pressure of the underflow port 302 and the first inlet 301 are monitored;

[0093] In response to the sludge concentration ratio of the underflow port 302 to the first inlet 301 being less than a second preset ratio, or the flow ratio of the underflow port 302 to the first inlet 301 being greater than a third preset ratio or less than a fourth preset ratio, or the pressure difference between the first inlet 301 and the underflow port 302 being greater than or equal to a preset difference, the backwashing device 11 is controlled to be opened to backwash the sludge concentration and separation device 3 through the backwashing pipeline 12.

[0094] When the sludge concentration mode is running, if the sludge quality selection device 3 has an abnormal operation due to blockage, etc., the sludge concentration, flow rate, pressure, etc. of the underflow port 302 and the first inlet 301 of the sludge quality selection device 3 will change, so that the opening of the backwashing device 11 can be controlled through the change of the sludge concentration, flow rate, pressure, etc. of the underflow port 302 and the first inlet 301. When the sludge concentration ratio of the underflow port 302 to the first inlet 301 is less than the second preset ratio, or the flow rate ratio of the underflow port 302 to the first inlet 301 is greater than the third preset ratio or less than the fourth preset ratio, or the pressure difference between the first inlet 301 and the underflow port 302 is greater than or equal to the preset difference, it indicates that the sludge quality selection device 3 has an abnormal operation at this time, which may be blocked, so the backwashing device 11 is enabled to backwash the sludge quality selection device 3 through the backwashing pipeline 12 to clean the blockage, thereby ensuring the normal operation of the sludge quality selection device 3, and ensuring the efficient concentration and screening of the sludge. Specifically, the second preset ratio is 1.5, which can also be set to other values such as 1.4, 1.3, 1.2, 1.6, 1.7, 1.8, 1.9, 2, 3, etc., without limitation; the third preset ratio is 0.5, which can also be set to other values such as 0.4, 0.5, 0.6, 0.7, etc., without limitation; the preset difference is 0.1 MPa, which can also be set to other values such as 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, etc., without limitation; the fourth preset ratio is 0.2, which can also be set to other values such as 0.1, 0.15, 0.25, 0.3, 0.4, etc., without limitation.

[0095] In some embodiments, the sludge quality selection mode further comprises the following steps:

[0096] Monitoring the sludge particle size in the integrated reaction and sedimentation device 1;

[0097] After the sludge quality selection device 3 runs for a target period, the ratio of the sludge settling ratio to the sludge concentration in the integrated reaction and sedimentation device 1 is still greater than the first preset ratio;

[0098] Adding a microbial carrier to the integrated reaction and sedimentation device 1 until the sludge particle size in the integrated reaction and sedimentation device 1 meets the preset particle size value, or the ratio of the sludge settling ratio to the sludge concentration is less than or equal to the preset ratio.

[0099] When the activated sludge in the integrated reaction and precipitation device 1 has poor performance, the sludge quality selection device 3 can be started to operate in the sludge quality selection mode to screen out the activated sludge with poor settling performance and quality. However, when the ratio of the sludge settling ratio to the sludge concentration in the integrated reaction and precipitation device 1 is still greater than the first preset ratio after the sludge quality selection device 3 operates for a period of time, it is indicated that it is difficult to quickly improve the settling performance of the activated sludge by simply relying on the sludge quality selection device 3. Therefore, at this time, the microbial carrier can be added to the integrated reaction and precipitation device 1, so that the pollutants, sludge and the like in the sewage can be aggregated with the microbial carrier to form large-particle flocculation that is easy to precipitate, thereby accelerating the precipitation of the sludge and effectively improving the performance of the activated sludge in the integrated reaction and precipitation device 1, and ensuring the efficiency and effect of the sewage treatment. Specifically, the microbial carrier includes micro-sand, diatomite and the like which are easy to be biologically attached, and the density of the microbial carrier is greater than 1 g / cm 3 When the selected microbial carrier is micro-sand, the particle size of the micro-sand is 60-100 μm, the dosage is 1% of the sludge concentration in the integrated reaction and precipitation device 1, i.e. 1% X1, and the evaluation index of the sludge particle size is D 50 , and the preset particle size value is 100 μm, i.e. when the sludge particle size D 50 > 100 μm or the ratio of the sludge settling ratio to the sludge concentration is less than or equal to the first preset ratio, the micro-sand addition can be stopped. Alternatively, the sludge particle size can be monitored by an online particle size distribution monitor.

[0100] The target period of the sludge quality selection device 3 can be determined by the replacement period. The replacement period is the number of days required for the sludge quality selection device 3 to divide and screen all the activated sludge in the integrated reaction and precipitation device 1 once. The replacement period can be calculated by the following formula:

[0101]

[0102] Wherein, n is the replacement period, X1 is the sludge concentration in the integrated reaction and precipitation device 1, V is the effective tank volume of the integrated reaction and precipitation device 1, Q2 is the flow rate of the first inlet 301 of the sludge quality selection device 3, and X3 is the sludge concentration of the first inlet 301 of the sludge quality selection device 3.

[0103] After the replacement period is calculated, the target period can be 5-10 replacement periods, for example, 5n, 6n, 7n, 8n, 9n, 10n, or can be set to more than 10 replacement periods or less than 5 replacement periods, for example, 4n, 3n, 2n, n, 11n, 12n, 13n, 14n, etc., which can be adjusted according to the actual operation, and the specific limitation is not limited. When the sludge quality selection device 3 is to be started, the replacement period is calculated, then the target period is determined according to the replacement period, and then the sludge quality selection device 3 runs at the target period. When the sludge settling ratio and the sludge concentration ratio in the integrated reaction and precipitation device 1 are still greater than the first preset ratio after running for the target period, the microbial carrier can be added to the integrated reaction and precipitation device 1 to improve the sludge settling performance of the integrated reaction and precipitation device 1.

[0104] The sludge concentration, sludge level, flow rate, and pressure of the present application are the average values of continuous multiple values. In sewage treatment, the concentration, level, flow rate, and pressure usually fluctuate with the inflow and outflow, so the average values of continuous multiple values are used in the present application to more truly reflect the actual situation. Specifically, it can be an average value of continuous 2, 3, 4, 5, 6, 7, 8, 9, 10 times, etc., or other number of times, and the specific limitation is not limited. For example, the concentration, level, flow rate, and pressure data can be read every 1 min, and the data obtained continuously for 3 times are averaged, that is, the final sludge concentration, sludge level, flow rate, and pressure data for determination and calculation. The sludge settling ratio is the sludge settling ratio at 30 min of sludge precipitation.

[0105] The present application also provides a sewage treatment system, as shown in Figure 1 The present application also provides a sewage treatment system, as shown in

[0106] The water inlet pipeline 15 and the water outlet pipeline 16 are respectively communicated with the integrated reaction and precipitation device 1, the water inlet pipeline 15 is used to pass the sewage to be treated into the integrated reaction and precipitation device 1, and the water outlet pipeline 16 is used to discharge the treated sewage to the next process.

[0107] The sewage treatment system of the present application comprises an integrated reaction and precipitation device 1 and a sludge concentration and quality selection system. In the integrated reaction and precipitation device 1, active sludge is inoculated to treat sewage. When it is necessary to concentrate and discharge sludge or to screen the sludge in the integrated reaction and precipitation device 1, the sludge concentration and quality selection system is started and runs in the corresponding operation mode, which can effectively improve the sludge concentration, improve the subsequent sludge treatment efficiency and sewage treatment effect.

[0108] The present application also provides a sewage treatment method applied to the sewage treatment system of the above-mentioned embodiments, which comprises:

[0109] The sewage to be treated is introduced into the integrated reaction and sedimentation device 1 inoculated with activated sludge through the water inlet pipeline 15, and the treated sewage is discharged into the next process through the water outlet pipeline 16;

[0110] During the treatment process of the integrated reaction and sedimentation device 1, the sludge concentration and selection system is controlled by the control method of the sludge concentration and selection system of any of the above embodiments, so as to concentrate or select the sludge according to the state of the activated sludge in the integrated reaction and sedimentation device 1.

[0111] When the integrated reaction and sedimentation device 1 needs to be started for sewage treatment, the sewage to be treated is introduced into the integrated reaction and sedimentation device 1 inoculated with activated sludge through the water inlet pipeline 15, and after the aeration stage and the standing stage in the integrated reaction and sedimentation device 1, the water outlet stage is entered, and the integrated reaction and sedimentation device 1 is discharged into the next process through the water outlet pipeline 16.

[0112] The effect of the present application will be described below through a specific example.

[0113] The sequence batch sewage reactor is used as the integrated reaction and sedimentation device 1, the sludge concentration and selection system of the present application is connected with the sequence batch sewage reactor, and a sewage treatment system is formed, as shown in Figure 1 .

[0114] The sequence batch sewage reactor has a water outlet, a water inlet, a sludge discharge outlet and a sludge inlet. The water inlet of the sequence batch sewage reactor is connected with the water inlet pipeline 15, the water outlet is connected with the water outlet pipeline 16, the sludge discharge outlet is connected with the second inlet 201 of the sludge pre-concentration tank 2 through the first sludge discharge pipeline 4, and the sludge discharge outlet is connected with the first inlet 301 of the sludge selection device 3 through the second sludge discharge pipeline 6.

[0115] The second inlet 201 is arranged at the top of the sludge pre-concentration tank 2, and a central cylinder 202 is arranged inside. The central cylinder 202 is located below the second inlet 201, a baffle 203 is arranged on the outer side wall of the central cylinder 202, the included angle between the baffle 203 and the central cylinder 202 is 30-60°, and the gap between the baffle 203 and the side wall of the sludge pre-concentration tank 2 is 5-20 cm. The sludge pre-concentration tank 2 is connected with a pre-concentration water outlet pipeline 17 at the upper portion, so as to discharge the supernatant, and the bottom is connected with the first inlet 301 of the sludge selection device 3 through a pre-concentration sludge discharge pipeline 5. In order to save costs and reasonably use the pipelines, the pre-concentration sludge discharge pipeline 5 can be connected with the first sludge discharge pipeline 4, and the first sludge discharge pipeline 4 is used to realize the connection with the sludge selection device 3.

[0116] The sludge quality selection device 3 is a hydrocyclone device, the side wall is provided with a first inlet 301, the bottom is provided with an underflow port 302, and the top is provided with an overflow port 303; the underflow port 302 is communicated with the sludge inlet of the sequencing batch reactor through a first backflow pipeline 8, and is communicated with the external sludge storage tank through a third sludge discharge pipeline 7; the overflow port 303 is communicated with the water inlet of the sequencing batch reactor through a second backflow pipeline 10, and is communicated with the external sludge storage tank through a fourth sludge discharge pipeline 9.

[0117] The dosing device 13 is communicated with the second inlet 201 of the sludge pre-concentration tank 2 through a dosing pipeline 14, and optionally, the dosing pipeline 14 can be connected with the first sludge discharge pipeline 4, so that the medicament is introduced into the sludge pre-concentration tank while the sludge is discharged from the sludge pre-concentration tank through the first sludge discharge pipeline 4, and the uniform mixing of the medicament can be realized.

[0118] The backwashing device 11 is communicated with the third sludge discharge pipeline 7 through a backwashing pipeline 12. The first sludge discharge pipeline 4, the pre-concentration sludge discharge pipeline 5, the pre-concentration water outlet pipeline 17, the second sludge discharge pipeline 6, the third sludge discharge pipeline 7, the first backflow pipeline 8, the fourth sludge discharge pipeline 9, the second backflow pipeline 10, the water inlet pipeline 15 and the water outlet pipeline 16 are all provided with valves to control the opening and closing of the pipelines, and optionally, the valves are electric valves.

[0119] The water inlet of the sequencing batch reactor is provided with a flow meter F1 to detect the water inlet flow Q1, and is internally provided with a sludge concentration meter A1, a sludge level meter L1 and a sludge settling ratio online detector SV to respectively detect the sludge concentration X1, the sludge level h1 and the sludge settling ratio SV in the integrated reaction precipitation device 1. The first inlet 301 of the sludge pre-concentration tank 2 is provided with a sludge concentration meter A2 to detect the sludge concentration X2 of the sludge inlet, and is internally provided with a sludge level meter L2 to detect the sludge level h2 in the sludge pre-concentration tank 2; the first inlet 301 of the sludge quality selection device 3 is provided with a sludge concentration meter A3, a pressure gauge P1 and a flow meter F2 to respectively detect the sludge concentration X3, the pressure p1 and the flow Q2 of the first inlet 301; the underflow port 302 of the sludge quality selection device 3 is provided with a sludge concentration meter A4, a pressure gauge P2 and a flow meter F4 to respectively detect the sludge concentration X4, the pressure p2 and the flow Q3 of the underflow port 302; and the overflow port 303 is provided with a flow meter F3 to detect the flow Q3 of the overflow port.

[0120] Each reaction cycle of the sequencing batch wastewater reactor comprises a water feeding stage, an aeration stage, a standing stage and a water discharging stage, the total reaction time of each reaction cycle is 240 min, the reaction time is represented by T, the water feeding stage is 0 min < T < 20 min, the aeration stage is 20 min < T < 180 min, the standing stage is 180 min < T < 220 min, and the water discharging stage is 220 min < T < 240 min. The sequencing batch wastewater reactor experiences 6 reaction cycles per day, i.e. 6 batches of wastewater are treated. The number of reaction cycles of the sequencing batch wastewater reactor and the division of the reaction time of each stage in each reaction cycle can be set according to the actual situation of the wastewater to be treated, the water quality, the water discharge requirement and the like, and are not specifically limited.

[0121] The sequencing batch wastewater reactor inoculated with activated sludge is started, and the wastewater to be treated is introduced into the sequencing batch wastewater reactor through a water pipeline in the water feeding stage, in the process, the sludge concentration X1, the sludge age SRT, the sludge settling ratio SV and the reaction cycle of the sequencing batch wastewater reactor are monitored. When X1 > 5000 mg / L or SRT is 20 days are detected, and at this time the reaction cycle of the sequencing batch wastewater reactor is in the water discharging stage (220 min < T < 240 min), the sludge concentration system is started and operated in the sludge concentration mode.

[0122] The specific operation steps of the sludge concentration mode are as follows: (1) starting the sludge pre-concentration tank 2, the second sludge discharge pipeline 6 is in a closed state, the valve of the first sludge discharge pipeline 4 is opened, and the sludge discharge port of the sequencing batch reactor is opened, so that part of the sludge in the sequencing batch reactor is discharged into the sludge pre-concentration tank 2, the sludge enters the central cylinder 202 through the second inlet 201 and then enters the sludge pre-concentration tank 2 to stay for a certain time, under the hydraulic condition, the sludge is deposited at the bottom of the sludge pre-concentration tank 2, the supernatant is overflowed through the gap between the baffle 203 and the tank wall, and is discharged through the pre-concentration effluent pipeline 17, so that pre-concentration is realized. When the sludge level h2 in the sludge pre-concentration tank 2 is greater than or equal to 2 / 3 of the liquid level (H2) of the sludge pre-concentration tank 2, that is, h2≥2 / 3H2, and the sludge concentration X2 of the sludge pre-concentration tank 2 is greater than or equal to 10000 mg / L, that is, X2≥10000 mg / L, it is indicated that the sludge concentration in the sludge pre-concentration tank 2 is high, and the purpose of pre-concentration is achieved, at this time, the sludge concentration and separation device 3 is started to concentrate the sludge. The first reflux pipeline 8 and the fourth sludge discharge pipeline 9 are closed, the pre-concentration sludge discharge pipeline 5, the sludge concentration and separation device 3, the third sludge discharge pipeline 7 and the second reflux pipeline 10 are opened, the sludge in the sludge pre-concentration tank is discharged into the sludge concentration and separation device 3 through the pre-concentration sludge discharge pipeline 5, the sludge rotates at high speed in the sludge concentration and separation device 3, the heavier sludge is deposited at the bottom and is discharged into the external sludge storage tank through the underflow port 302 and the third sludge discharge pipeline 7, and the lighter sludge and water overflow from the overflow port 303 and are refluxed to the sequencing batch reactor through the second sludge discharge pipeline 6. When the sludge level h2 of the sludge pre-concentration tank 2 is still less than 2 / 3 of the liquid level (H2) of the sludge pre-concentration tank 2 within a preset time, that is, h2<2 / 3H2, or the sludge concentration X2 of the sludge pre-concentration tank 2 is still less than 10000 mg / L, that is, X2<10000 mg / L, the dosing device 13 is started, and the dosing pipeline 14 is opened to add flocculants into the sludge pre-concentration tank 2. Under the action of the flocculants, the sludge in the sludge pre-concentration tank 2 is accelerated to deposit, and the pre-concentration effect is achieved.

[0123] In the reaction process of the sequencing batch reactor, the ratio of the sludge settling ratio SV of the sequencing batch reactor to the sludge concentration X1 in the aeration stage is greater than the first preset ratio, that is, SV / X1>120, or the sludge level h1 of the sequencing batch reactor is greater than 4 / 5 of the liquid level H1 of the sequencing batch reactor, that is, h1>4 / 5H1, and the reaction period of the sequencing batch reactor is the aeration stage (20min<T<180min), the sludge concentration and separation system is started and operated in the sludge concentration and separation mode.

[0124] The operation steps of the sludge quality selection mode are as follows: the sludge quality selection device 3 is started, the second sludge discharge pipeline 6 is opened, the first sludge discharge pipeline 4, the sludge pre-concentration tank 2, the pre-concentration sludge discharge pipeline 5, the second reflux pipeline 10 and the third sludge discharge pipeline 7 are closed, part of the sludge in the sequencing batch wastewater reactor is introduced into the sludge quality selection device 3 through the second sludge discharge pipeline 6 and the first inlet 301, the sludge rotates at high speed in the sludge quality selection device 3, the sludge with poor quality and poor settling performance overflows through the overflow port 303 and is discharged to the external sludge storage tank through the fourth sludge discharge pipeline 9, the sludge with good quality and good settling performance sinks to the bottom and flows into the first reflux pipeline 8 through the underflow port 302, and is re-introduced into the sequencing batch wastewater reactor through the sludge inlet, so that the sludge with high quality and high settling performance is screened. In this process, the sludge particle size D 50 After the sludge quality selection device 3 is operated for a target period, that is, after 10 displacement cycles, the ratio of the sludge settling ratio to the sludge concentration in the sequencing batch wastewater reactor is still greater than the first preset ratio, that is, SV / X1>120, micro-sand is added to the sequencing batch wastewater reactor, and the sludge particle size D 50 in the sequencing batch wastewater reactor is monitored. When the sludge particle size D 50 >100μm or the ratio of the sludge settling ratio to the sludge concentration is less than or equal to the preset ratio, that is, SV / X1≤120, the micro-sand addition is stopped.

[0125] In the operation process of the sludge quality selection device 3, the sludge concentration X4, the flow rate Q4 and the pressure p2 of the underflow port 302 are monitored, and the sludge concentration X3, the flow rate Q2 and the pressure p1 of the first inlet 301 are monitored. When X4 / X3<1.5 or Q4 / Q2>0.5 or Q4 / Q2<0.2 or p1-p2≥0.1Mpa, it indicates that the sludge quality selection device 3 has certain abnormalities and the operation efficiency is reduced, and the backwashing device 11 is controlled to be opened to backwash the sludge quality selection device 3 through the backwashing pipeline 12. Q2 and Q4 are measured by flow meters F2 and F4 respectively, X1, X2, X3 and X4 are measured by sludge concentration meters A1, A2, A3 and A4 respectively, h1 and h2 are measured by sludge level meters L1 and L2 respectively, and p1 and p2 are measured by pressure gauges P1 and P2 respectively.

[0126] After the static standing stage in the sequencing batch wastewater reactor, the water outlet pipeline 16 and the water outlet are opened, the treated wastewater is discharged to the next process, and the treatment of one batch of wastewater is completed. After the water is discharged, the water inlet and the water inlet pipeline 15 are opened again, and the next batch of wastewater to be treated is introduced, and the above process is repeated to continue the wastewater treatment. The residual sludge in the sequencing batch wastewater reactor is treated by the present application, which can reduce the land occupation area of the residual sludge dewatering, and the land occupation area is saved by more than 30%, and the treatment efficiency is high. The concentrated sludge is easier to dewater (the properties are improved), and the reagent is saved; at the same time, the sludge settling performance can be effectively improved, and the in-situ capacity is expanded by more than 30%.

[0127] The technical effects of the present application are further illustrated by the following examples.

[0128] Example 1:

[0129] A 10000m 3 / d SBR core process wastewater treatment plant, before using the system of the present application, has the problems of low residual sludge concentration, large sludge storage pool area without new land, poor thickening effect, and the water content of the dewatered sludge cannot meet the transportation requirements. After using the sludge thickening and quality selection system and the control method thereof in the present application, the scale of the sludge quality selection device 3 is 50m 3 / h, the residence time of the sludge pre-thickening tank 2 is 1.5h, the residence time of the sludge quality selection device 3 is 15-30s, the flow rate of the underflow port 302 accounts for 40%-45% of the flow rate of the first inlet 301, the sludge concentration is thickened from the original 3000-5000mg / L to 10000-12000mg / L, and the sludge storage pool area is saved by more than 1.5 times.

[0130] Example 2:

[0131] CASS is a process integrating reaction, sedimentation, drainage and function, which is realized by using an integrated reaction and sedimentation device 1. A 5000m 3 / d CASS core process wastewater treatment plant also has the problem of poor sludge thickening effect before using the system, which affects the treatment and disposal of residual sludge on the one hand, and the reflux efficiency of the external reflux sludge on the other hand. After using the sludge thickening and quality selection system and the control method thereof in the present application, the scale of the sludge quality selection device 3 is 25m 3 / h, the residence time of the sludge pre-thickening tank 2 is 1h, the residence time of the sludge quality selection device 3 is 10-15s, the flow rate of the underflow port 302 accounts for 30%-35% of the flow rate of the first inlet 301, and the sludge concentration is thickened from the original 4000-5000mg / L to about 10000mg / L, greatly reducing the sludge storage pool area, the dewatering efficiency of the residual sludge, and the external reflux efficiency of the thickened sludge, etc.

[0132] Based on the same inventive concept, the present application also provides an electronic device corresponding to any of the above-mentioned embodiment methods, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to realize the control method of the sludge thickening and quality selection system according to any one of the above-mentioned embodiments.

[0133] Figure 3A more specific electronic device hardware structure schematic diagram provided by the embodiment is shown, and the device can include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other through the bus 1050 for internal communication.

[0134] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits, and is used to execute related programs to implement the technical solutions provided by the embodiments of the present specification.

[0135] The memory 1020 can be implemented by a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory 1020 can store an operating system and other application programs. When the technical solutions provided by the embodiments of the present specification are implemented by software or firmware, the related program codes are stored in the memory 1020 and are called and executed by the processor 1010.

[0136] The input / output interface 1030 is used to connect input / output modules to realize information input and output. The input / output modules can be configured as components in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. The input device can include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device can include a display, a speaker, a vibrator, an indicator light, etc.

[0137] The communication interface 1040 is used to connect a communication module (not shown in the figure) to realize the communication interaction between the device and other devices. The communication module can realize communication through a wired manner (such as USB, network cable, etc.) or a wireless manner (such as mobile network, WIFI, Bluetooth, etc.).

[0138] The bus 1050 includes a channel to transmit information between various components (such as the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040) of the device.

[0139] It should be noted that although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040 and the bus 1050, but in the specific implementation process, the device can also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device can also only contain the components necessary to implement the embodiments of the present application, and does not have to contain all the components shown in the figure.

[0140] The electronic device of the above embodiment is used to implement the control method of the corresponding sludge concentration and quality selection system in any of the preceding embodiments, and has the beneficial effects of the corresponding method embodiments, which are not repeated here.

[0141] Based on the same inventive concept, corresponding to any of the above embodiment methods, the present application also provides a non-transitory computer readable storage medium storing computer instructions for causing the computer to execute the control method of the sludge concentration and quality selection system as described in any of the above embodiments.

[0142] The computer readable medium of the present embodiment includes permanent and non-permanent, removable and non-removable media, which can be realized by any method or technology to store information. The information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device.

[0143] The storage medium of the above embodiment stores computer instructions for causing the computer to execute the control method of the sludge concentration and quality selection system as described in any of the above embodiments, and has the beneficial effects of the corresponding method embodiments, which are not repeated here.

[0144] Those skilled in the art should understand that the above discussion of any of the embodiments is only exemplary and is not intended to imply that the scope of the present application (including claims) is limited to these examples; under the idea of the present application, the above embodiments or technical features in different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the embodiments of the present application as described above. In order to be brief, they are not provided in detail.

[0145] Further, while the exemplary embodiments of the application have been described in the context of a particular implementation, those skilled in the art will appreciate that many alternatives, modifications, and variations will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the appended claims.

[0146] To simplify the illustration and discussion, and so as not to obscure the inventive embodiments of the present application with details that are well known to those skilled in the art, the description herein may not show or describe some of the well-known power / ground connections, signaling, and other details of the devices and systems. Moreover, devices may be shown in block diagram form in order to avoid obscuring the inventive embodiments of the present application, and also in view of the fact that the details in regard to how such devices are implemented are highly dependent on the platform within which the inventive embodiments of the present application are being performed, i.e., such details should be readily apparent to those of ordinary skill in the art having the benefit of the present description. While the present application has been described with respect to a particular implementation, those skilled in the art will appreciate that many alternatives, modifications, and variations will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the appended claims.

[0147] While the present application has been described with respect to a particular implementation, those skilled in the art will appreciate that many alternatives, modifications, and variations will become apparent to those skilled in the art upon reading the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) can use the embodiments discussed.

[0148] The embodiments of the present application are intended to cover all such alternatives, modifications, and variations as fall within the scope of the appended claims. Accordingly, any omission, modification, equivalent replacement, improvement, etc. made in the spirit and principle of the embodiments of the present application should be included in the scope of the present application.

Claims

1. A control method of a sludge concentration mass selection system, characterized by, The sludge concentration and selection system is applied to an integrated reaction and sedimentation device inoculated with activated sludge; The sludge concentration and selection system is used to receive sludge discharged from the integrated reaction and sedimentation device and concentrate or select the sludge, and comprises: A sludge pre-concentration tank is used to separate sludge and water for pre-concentration, and is communicated with the integrated reaction and sedimentation device through a first sludge discharge pipeline, and an upper portion is communicated with a pre-concentration effluent pipeline used to discharge supernatant from the sludge pre-concentration tank; A sludge concentration and selection device is used to separate sludge and water for concentration or cyclone screening, and a sidewall is provided with a first inlet, a bottom portion is provided with an underflow port, and a top portion is provided with an overflow port, the first inlet is respectively communicated with the integrated reaction and sedimentation device and the sludge pre-concentration tank through the second sludge discharge pipeline and the pre-concentration sludge discharge pipeline, the underflow port is respectively communicated with the integrated reaction and sedimentation device and an external sludge storage tank through the first reflux pipeline and the third sludge discharge pipeline, and the overflow port is respectively communicated with the integrated reaction and sedimentation device and the external sludge storage tank through the second reflux pipeline and the fourth sludge discharge pipeline; The sludge concentration and selection system has at least two working modes including a sludge concentration and selection mode and a sludge concentration mode, in the sludge concentration and selection mode, the first sludge discharge pipeline, the sludge pre-concentration tank, the pre-concentration sludge discharge pipeline, the pre-concentration effluent pipeline, the third sludge discharge pipeline and the second reflux pipeline are in a non-enabled state, and in the sludge concentration mode, the second sludge discharge pipeline, the first reflux pipeline and the fourth sludge discharge pipeline are in a non-enabled state; The control method comprises: Monitoring sludge concentration, sludge age, sludge settling ratio, sludge level and reaction period during sewage treatment of the integrated reaction and sedimentation device; In response to that the sludge concentration in the integrated reaction and sedimentation device is greater than a first concentration threshold or the sludge age is greater than a preset number of days, and the reaction period of the integrated reaction and sedimentation device is in a first preset period, the sludge concentration and selection system is started and operated in the sludge concentration mode; In response to that the ratio of the sludge settling ratio to the sludge concentration in the integrated reaction and sedimentation device is greater than a first preset ratio or the sludge level is greater than a first preset height, and the reaction period is in a second preset period, the sludge concentration and selection system is started and operated in the sludge concentration and selection mode; The operation steps of the sludge concentration mode comprise: Starting the sludge pre-concentration tank, and controlling the integrated reaction and sedimentation device to discharge sludge to the sludge pre-concentration tank through the first sludge discharge pipeline; Controlling sludge to stay in the sludge pre-concentration tank for a certain time for water separation and sedimentation, monitoring the sludge level in the sludge pre-concentration tank and the sludge concentration of the sludge entering the sludge pre-concentration tank, and opening the pre-concentration effluent pipeline to discharge supernatant from the sludge pre-concentration tank; In response to that the sludge level in the sludge pre-concentration tank is greater than or equal to a second preset height and the sludge concentration of the sludge entering the sludge pre-concentration tank is greater than or equal to a second concentration threshold, the sludge concentration and selection device is started, and the sludge pre-concentration tank is controlled to discharge sludge to the sludge concentration and selection device through the pre-concentration sludge discharge pipeline and the first inlet; The sludge is concentrated by the sludge concentration and classification device, and the concentrated sludge is discharged into an external sludge storage tank through the underflow port and the third sludge discharge pipeline, and the upper sludge-water mixture is returned to the integrated reaction and precipitation device through the overflow port and the second return pipeline. The operation steps of the sludge concentration and classification mode include: The sludge concentration and classification device is started, and the integrated reaction and precipitation device is controlled to discharge sludge to the sludge concentration and classification device through the second sludge discharge pipeline and the first inlet. The sludge concentration and classification device is used to perform cyclone screening on the discharged sludge, the bottom sludge is returned to the integrated reaction and precipitation device through the underflow port and the first return pipeline, and the upper sludge is discharged into the external sludge storage tank through the overflow port and the fourth sludge discharge pipeline.

2. The control method of a sludge concentration and mass separation system according to claim 1, characterized by, Further comprising: A dosing device in communication with the first sludge discharge pipeline through a dosing pipeline, used to add flocculants to the sludge pre-concentration tank; And / or, a backwashing device in communication with the third sludge discharge pipeline through a backwashing pipeline, used to backwash the sludge concentration and classification device.

3. The control method of a sludge concentration and mass separation system according to claim 1, characterized by, The operation steps of the sludge concentration mode further include: In response to the sludge staying in the sludge pre-concentration tank for more than a preset time, the sludge level in the sludge pre-concentration tank still being less than a second preset height, or the sludge concentration of the sludge entering the sludge pre-concentration tank still being less than a second concentration threshold, the dosing device is started to add flocculants to the sludge pre-concentration tank.

4. The control method of a sludge concentration and mass separation system according to claim 1, characterized by, Further comprising: During the operation of the sludge concentration and classification device, the sludge concentration, flow rate and pressure of the underflow port and the first inlet are monitored; In response to the sludge concentration ratio of the underflow port to the first inlet being less than a second preset ratio, or the flow rate ratio of the underflow port to the first inlet being greater than a third preset ratio or less than a fourth preset ratio, or the pressure difference between the first inlet and the underflow port being greater than or equal to a preset difference, the backwashing device is controlled to be turned on to backwash the sludge concentration and classification device through the backwashing pipeline.

5. The control method of the sludge concentration and classification system according to claim 1, wherein the operation steps of the sludge concentration and classification mode further include: Monitoring the particle size of the sludge in the integrated reaction and precipitation device; After the target period of operation of the sludge concentration and classification device, the ratio of the sludge settling ratio to the sludge concentration in the integrated reaction and precipitation device is still greater than a first preset ratio; Microbial carriers are added to the integrated reaction and precipitation device until the particle size of the sludge in the integrated reaction and precipitation device meets a preset particle size value, or the ratio of the sludge settling ratio to the sludge concentration is less than or equal to a preset ratio.

6. A method of sewage treatment, characterised in that, The application is applied to a sewage treatment system, and the sewage treatment system includes an integrated reaction and precipitation device and a sludge concentration and classification system, and further includes: A water inlet pipeline and a water outlet pipeline in communication with the integrated reaction and precipitation device, respectively, the water inlet pipeline being used to pass untreated sewage into the integrated reaction and precipitation device, and the water outlet pipeline being used to discharge treated sewage to the next process; The method includes: The wastewater to be treated is introduced into the integrated reaction and sedimentation device inoculated with activated sludge through the water inlet pipeline, and the treated wastewater is discharged to the next process through the water outlet pipeline; During the treatment process of the integrated reaction and sedimentation device, the sludge concentration and selection system is controlled by the control method of the sludge concentration and selection system according to any one of claims 1-5, so as to concentrate or select the sludge according to the state of the activated sludge in the integrated reaction and sedimentation device.

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