Environment-friendly sewage purification system

Abstract

The invention relates to the technical field of sewage purification, in particular to an environment-friendly sewage purification system which comprises a pretreatment unit, a detection unit, an analysis unit, a reaction unit, a cleaning unit, an aeration unit and a recovery unit. The detection unit detects the flow of the water inlet and outlet, the water inlet and outlet pressure of the bioreactor and the water level of the reaction tank; the analysis unit is used for adjusting the flow of the water inlet, judging the running state of the membrane biological component, adjusting the backwashing period, determining each pressure difference curve section, judging the pollution degree of sewage and adjusting the aeration mode of the aeration unit; the reaction unit comprises a water pump, an anaerobic tank, a reaction tank and a plurality of membrane biological components; the cleaning unit periodically performs reverse cleaning on the membrane biological component; and the aeration unit introduces air into the sewage according to the determined working mode. According to the invention, efficient solid-liquid separation is carried out on sewage, such that a disadvantage that sludge bulking easily occurs in a traditional activated sludge method is overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage purification, and in particular to an environmentally friendly sewage purification system. Background Art

[0002] With the acceleration of modern urbanization, human activities have exerted increasing pressure on the urban ecological environment. In particular, sewage problems have become one of the focuses of environmental protection in my country, posing a serious threat to human survival and urban sustainable development. Sewage treatment is one of the key points in the field of urban environmental engineering. It aims to effectively purify urban sewage and improve the reuse rate of water resources through advanced technical means, and provide practical scientific research support for the practice of urban ecological and environmental protection concepts.

[0003] Chinese patent publication number: CN117303480A discloses a sewage collection and purification system based on ceramic membrane, including a sedimentation heating unit, which includes a sedimentation tank for sedimentation treatment of sewage after coarse filtration and a heating component for heating sewage; a filtration unit for fine filtration of sewage after sedimentation; a data acquisition unit for collecting demand information; a data analysis unit for determining the heating components that need to be turned on and the operating power of the heating components of the sedimentation heating unit according to the proportion of colloidal sewage collection; a temperature compensation unit for adjusting the operating power of the heating components in the turned-on state according to the ambient temperature; a membrane filtration compensation unit for determining the membrane filtration compensation method according to the membrane flux state; It can be seen that the sewage collection and purification system based on ceramic membrane has the following problems: A large amount of sludge is generated during the sewage treatment process. Improper sludge treatment will become a secondary pollution source. If the harmful substances in the sludge are not effectively treated, they will pose a threat to the environment and human health. Summary of the invention

[0004] To this end, the present invention provides an environmentally friendly sewage purification system to overcome the problem that a large amount of sludge is generated during sewage treatment in the prior art, improper sludge treatment will become a secondary pollution source, and harmful substances in the sludge will pose a threat to the environment and human health if not effectively treated.

[0005] To achieve the above object, the present invention provides an environmentally friendly sewage purification system, comprising: Pretreatment unit, including screens and primary sedimentation tanks, used to remove large debris, sand and suspended solids from sewage; The detection unit includes a flow meter, a pressure sensor, and a water level meter, which is used to detect the flow rate of the water inlet and outlet, the water inlet and outlet pressure of the bioreactor, and the water level of the reaction tank, and transmit the data to the analysis unit; The analysis unit is used to calculate the change rate of the water level in the reaction tank and adjust the flow rate of the water inlet; determine the operating state of the membrane biological component in the bioreactor according to the current inlet and outlet water pressure difference of the bioreactor, and adjust the cycle of the cleaning unit to backwash the membrane biological component; determine each pressure difference curve segment based on the preset pressure difference slope interval, determine the pollution degree of the sewage according to the duration of the pressure difference curve segment, and adjust the aeration mode of the aeration unit according to the pollution degree of the sewage and the inlet flow rate; The reaction unit includes a pump, an anaerobic tank, a reaction tank and several membrane biological components. The reaction tank includes an inlet regulating valve and an outlet. The pump is used to pass the sewage from the primary sedimentation tank into the anaerobic tank. The anaerobic tank is connected to the reaction tank through the inlet. The membrane biological component is placed inside the reaction tank to intercept the activated sludge and macromolecular organic matter in the sewage. A cleaning unit, including a backwash pump and a reagent tank, is used to periodically perform backwash cleaning on the membrane biological component; an aeration unit, including a blower and a regulating valve, for introducing air into the sewage according to the working mode determined by the analysis unit; The recovery unit, including a storage tank, a return pump, and a centrifugal pump, is used to store the purified sewage and recover the sludge generated during the sewage purification process.

[0006] Furthermore, the analysis unit calculates the change rate of the water level in the reaction pool per unit time according to the change of the water level in the reaction pool, and compares the water level and the change rate of the water level in the reaction pool with the preset water level and the change rate of the water level. If the water level in the reaction tank is lower than the preset water level, and the falling speed of the water level is greater than the preset falling speed, the analysis unit determines that the falling speed of the water level in the reaction tank is faster and the flow rate of the water inlet is smaller, and the flow rate of the water inlet is increased by increasing the valve opening of the regulating valve in the water inlet. The valve opening of the regulating valve is positively correlated with the ratio of the water level falling speed to the preset falling speed and the ratio of the preset water level to the water level in the reaction tank. If the water level in the reaction tank is higher than the preset water level and the rising speed of the water level is greater than the preset rising speed, the analysis unit determines that the membrane bioreactor assembly in the bioreactor may be blocked and determines the blockage condition of the membrane bioreactor assembly.

[0007] Furthermore, the analysis unit calculates the current inlet and outlet water pressure difference of the bioreactor, and compares the current inlet and outlet water pressure difference with the initial inlet and outlet water pressure difference. If the difference between the current inlet and outlet water pressure difference and the initial inlet and outlet water pressure difference is less than or equal to the pressure difference evaluation value, the analysis unit determines that the membrane biological component in the bioreactor is not blocked or is in a normal operating state range; If the difference between the current inlet and outlet water pressure difference and the initial inlet and outlet water pressure difference is greater than the pressure difference evaluation value, the analysis unit determines that the membrane biological component in the bioreactor is clogged.

[0008] Furthermore, when the membrane biological component is not blocked or is in a normal operating state, the analysis unit reduces the flow rate of the water inlet by reducing the valve opening of the regulating valve in the water inlet; When the membrane biological component is clogged, the analysis unit sends a signal to the cleaning unit to backwash the membrane biological component, and adjusts the backwashing cycle of the cleaning unit on the membrane biological component according to the ratio of the current inlet and outlet water pressure difference to the initial inlet and outlet water pressure difference and the pressure difference evaluation value.

[0009] Furthermore, the analysis unit determines the segmentation points of the pressure difference change curve on the pressure difference change curve based on the preset pressure difference slope interval to determine each pressure difference curve segment. If the slopes of several consecutive time-series pressure difference monitoring points on the pressure difference change curve are not within the range of the preset pressure difference slope, the analysis unit will use the initial point and the end point of the corresponding consecutive time-series pressure difference monitoring points according to the time series process as the segmentation points of the pressure difference curve segment, and use the curve segment formed by the segmentation points on the pressure difference change curve as a single pressure difference curve segment.

[0010] Furthermore, the analysis unit compares the duration corresponding to the pressure difference curve segment with a preset duration. If the duration of the pressure difference curve segment is less than or equal to the preset duration, the analysis unit determines that the change in the pressure difference between the inlet and outlet water of the bioreactor is small, and the pollution degree of the sewage is low; If the duration of the pressure difference curve segment is greater than the preset duration, the analysis unit determines that the change in the inlet and outlet pressure difference of the bioreactor is small and the pollution degree of the sewage is high.

[0011] Furthermore, the analysis unit calculates the water inlet flow rate according to the flow rate of the water inlet per unit time, and adjusts the aeration mode of the aeration unit according to the sewage pollution degree and the water inlet flow rate. If the sewage pollution level and the inlet flow rate are low, the aeration unit adopts the second aeration mode; If the sewage pollution degree and the water inlet flow rate are high, the aeration unit adopts the first aeration mode.

[0012] Furthermore, in the first aeration mode, the analysis unit reduces the initial closing time of the aeration unit in the aeration cycle according to the sewage pollution degree and the inlet flow rate, and the initial closing time is inversely proportional to the sewage pollution degree and the inlet flow rate.

[0013] Furthermore, the analysis unit compares the flow rate of the water outlet with a preset flow rate value. If the outlet flow rate is less than the preset flow rate value, and the flow difference between the outlet flow rate and the preset flow rate value is greater than the flow evaluation value, the analysis unit determines that the outlet flow rate is small and the current sewage purification efficiency does not meet the sewage purification requirements.

[0014] Furthermore, when the current sewage purification efficiency does not meet the sewage purification demand, the analysis unit sends out an alarm signal, reduces the spacing between membrane bio-assemblies in the bioreactor, and increases the number of membrane bio-assemblies.

[0015] Compared with the prior art, the beneficial effect of the present invention is that the frequency of chemical cleaning of the membrane bio-assembly and the operating conditions are related to the water quality of the sewage. Under normal circumstances, chemical cleaning should be carried out after running for 1 to 3 months or when the pressure difference through the membrane bio-assembly increases by more than 0.5 bar compared with the initial pressure difference under the same operating conditions; the present invention determines whether to detect the inlet and outlet water pressure difference of the bioreactor according to the change of the water level, judges the blockage of the membrane bio-assembly according to the change of the inlet and outlet water pressure difference of the bioreactor and the initial inlet and outlet water pressure difference, and combines the principle that organic pollution is obviously affected by alkaline washing and salt scaling is obviously affected by acid washing, introduces the chemical enhanced backwashing procedure into the operation process of the membrane bio-assembly; through an operation similar to low-intensity chemical cleaning, the pollution of the membrane bio-assembly is eliminated at the stage of its formation, preventing the membrane pollution from being restored in time and forming a synergistic deterioration effect.

[0016] Furthermore, sewage contains many kinds of organic matter, and the concentration of organic matter is difficult to calculate, and it is difficult to accurately calculate the pollution degree of sewage. The present invention reflects the pollution degree of sewage through the change of the inlet and outlet water pressure difference of the bioreactor, draws the pressure difference change curve according to the inlet and outlet water pressure difference of the bioreactor, divides the pressure difference curve segments according to the slope of the pressure difference change curve, determines the duration of the pressure difference curve segment, and compares it with the preset duration, so as to avoid judging the changing speed of the pressure difference change curve only by the slope of the pressure difference change curve, which leads to misjudgment of the changing speed due to fluctuation of the pressure difference change curve, thereby improving the accuracy of judging the pollution degree of sewage.

[0017] Furthermore, the aeration unit introduces air into the sewage through a blower, so that the organic matter in the sewage comes into contact with oxygen, thereby promoting the growth and metabolism of microorganisms; the main purpose of aeration is to increase the dissolved oxygen concentration in the sewage and provide sufficient oxygen for aerobic microorganisms so that they can effectively degrade the organic matter in the sewage; this system adjusts the opening and closing time of the aeration unit according to the pollution degree of the sewage and the water inlet speed, thereby reducing unnecessary consumption of the aeration unit due to excessive aeration intensity and improving the economic benefits of sewage purification.

[0018] Furthermore, the inlet flow has a direct impact on the outlet flow, and because the sewage purification process needs to be stopped when the membrane biological components in the bioreactor are backwashed, the backwashing cycle of the membrane biological components will also indirectly affect the outlet flow; the system accurately determines the outlet flow to avoid misjudgment due to flow fluctuations, thereby quantifying the current system's sewage purification efficiency, and improving the sewage purification efficiency by adjusting the number of membrane biological components in the bioreactor, further increasing the stability of the system.

[0019] Furthermore, the sludge discharged from the reaction tank is transported to the regulating tank through a reflux pump, and the sewage purification system regularly discharges the sludge and stores it in a sludge tank. After adding a filter agent, the sludge can be pumped into a filter press for dehydration to form a mud cake; the mud cake can be made into sidewalk tiles for reuse without causing secondary pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of an environmentally friendly sewage purification system in an embodiment of the present invention; Figure 2 This is a unit connection diagram of an environmentally friendly sewage purification system in an embodiment of the present invention; Figure 3 A flow chart for determining the working state of a membrane bioreactor assembly in an embodiment of the present invention; Figure 4 This is a flow chart for determining sewage purification efficiency in an embodiment of the present invention; In the figure: 11-grid, 12-primary sedimentation tank, 21-water pump, 22-anaerobic tank, 23-reaction tank, 24-membrane biological component, 31-backwash pump, 32-agent tank, 41-blower, 42-regulating valve, 51-water storage tank, 52-reflux pump, 53-centrifugal pump. DETAILED DESCRIPTION

[0021] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0023] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0024] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] See also Figure 1-Figure 4 As shown, Figure 1 It is a structural schematic diagram of an environmentally friendly sewage purification system in an embodiment of the present invention; Figure 2 This is a unit connection diagram of an environmentally friendly sewage purification system in an embodiment of the present invention; Figure 3 A flow chart for determining the working state of a membrane bioreactor assembly in an embodiment of the present invention; Figure 4 This is a flow chart of determining sewage purification efficiency in an embodiment of the present invention.

[0026] The present invention provides an environmentally friendly sewage purification system, comprising: Pretreatment unit, including screens and primary sedimentation tanks, used to remove large debris, sand and suspended solids from sewage; The detection unit includes a flow meter, a pressure sensor, and a water level meter, which is used to detect the flow rate of the water inlet and outlet, the water inlet and outlet pressure of the bioreactor, and the water level of the reaction tank, and transmit the data to the analysis unit; The analysis unit is used to calculate the change rate of the water level in the reaction tank and adjust the flow rate of the water inlet; determine the operating state of the membrane biological component in the bioreactor according to the current inlet and outlet water pressure difference of the bioreactor, and adjust the cycle of the cleaning unit to backwash the membrane biological component; determine each pressure difference curve segment based on the preset pressure difference slope interval, determine the pollution degree of the sewage according to the duration of the pressure difference curve segment, and adjust the aeration mode of the aeration unit according to the pollution degree of the sewage and the inlet flow rate; The reaction unit includes a pump, an anaerobic tank, a reaction tank and several membrane biological components. The reaction tank includes an inlet regulating valve and an outlet. The pump is used to pass the sewage from the primary sedimentation tank into the anaerobic tank. The anaerobic tank is connected to the reaction tank through the inlet. The membrane biological component is placed inside the reaction tank to intercept the activated sludge and macromolecular organic matter in the sewage. A cleaning unit, including a backwash pump and a reagent tank, is used to periodically perform backwash cleaning on the membrane biological component; an aeration unit, including a blower and a regulating valve, for introducing air into the sewage according to the working mode determined by the analysis unit; The recovery unit, including a storage tank, a return pump, and a centrifugal pump, is used to store the purified sewage and recover the sludge generated during the sewage purification process.

[0027] It is understandable that the membrane bio-assembly can adopt three common membrane assemblies according to specific needs, including hollow fiber curtain-like immersed membrane assembly, hollow fiber column immersed membrane assembly and flat-plate curtain-like immersed membrane assembly.

[0028] In this embodiment, the sewage is filtered through the grille in the pretreatment unit to remove large debris in the sewage and then passed into the primary sedimentation tank. Through gravity sedimentation, the suspended solid particles in the sewage are settled in the tank, thereby achieving solid-liquid separation. The grille can be a circular hole type or a mesh type, and the aperture of the grille is less than 2 mm.

[0029] After entering the primary sedimentation tank, the sewage is pumped into the anaerobic tank. The microorganisms in the anaerobic tank use anaerobic metabolism to convert the organic matter in the sewage into gases such as methane and carbon dioxide, thereby achieving the degradation of organic matter. During the anaerobic digestion process, the cell material of the microorganisms will be decomposed, thereby reducing the production of sludge as well as reducing energy consumption and operating costs.

[0030] The sewage in the anaerobic tank is introduced into the reaction tank through the water inlet regulating valve of the reaction tank. The membrane biological component is placed inside the bioreactor. The sewage enters the bioreactor, most of the pollutants in the sewage are removed by the activated sludge in the mixed liquid, and then the water is filtered out by the membrane under the action of negative pressure.

[0031] The detection unit uses a water level meter to detect the water level of the reaction pool. The analysis unit calculates the change rate of the water level of the reaction pool per unit time according to the change of the water level of the reaction pool, and compares the water level of the reaction pool and the change rate of the water level with the preset water level and the change rate of the water level. It can be understood that the change rate of the water level includes a falling rate and a rising rate. If the water level of the reaction pool is lower than the preset water level, and the falling rate of the water level is less than or equal to the preset falling rate, the analysis unit determines that the water level of the reaction pool is within the normal fluctuation range of the water level. If the water level in the reaction tank is lower than the preset water level, and the falling speed of the water level is greater than the preset falling speed, the analysis unit determines that the falling speed of the water level in the reaction tank is faster and the flow rate of the water inlet is smaller, and the flow rate of the water inlet is increased by increasing the valve opening of the regulating valve in the water inlet. The valve opening of the regulating valve is positively correlated with the ratio of the water level falling speed to the preset falling speed and the ratio of the preset water level to the water level in the reaction tank. If the water level of the reaction tank is higher than the preset water level, and the rising speed of the water level is greater than the preset rising speed, the analysis unit determines that the water level of the reaction tank is within the normal fluctuation range of the water level; If the water level in the reaction tank is higher than the preset water level and the rising speed of the water level is greater than the preset rising speed, the analysis unit determines that the membrane bioreactor assembly in the bioreactor may be blocked and determines the blockage condition of the membrane bioreactor assembly.

[0032] The detection unit detects the actual inlet and outlet water pressures of the bioreactor in real time through pressure sensors arranged at both ends of the bioreactor. The analysis unit calculates the current inlet and outlet water pressure difference of the bioreactor according to the actual inlet and outlet water pressures detected by the detection unit, and compares the current inlet and outlet water pressure difference with the initial inlet and outlet water pressure difference. If the difference between the current inlet and outlet water pressure difference and the initial inlet and outlet water pressure difference is less than or equal to the pressure difference evaluation value, the analysis unit determines that the membrane biological component in the bioreactor is not blocked or is in a normal operating state range, and reduces the flow rate of the water inlet by reducing the valve opening of the regulating valve in the water inlet; If the difference between the current inlet and outlet water pressure difference and the initial inlet and outlet water pressure difference is greater than the pressure difference evaluation value, the analysis unit determines that the membrane biological component in the bioreactor is blocked, sends a signal to the cleaning unit to backwash the membrane biological component, and adjusts the cleaning unit's backwashing cycle for the membrane biological component based on the ratio of the difference between the current inlet and outlet water pressure difference and the initial inlet and outlet water pressure difference to the pressure difference evaluation value.

[0033] The pressure difference evaluation value in this embodiment is 0.5 bar.

[0034] Specifically, the frequency of chemical cleaning of the membrane bio-assembly and the operating conditions are related to the water quality of the sewage. Under normal circumstances, chemical cleaning should be carried out after running for 1 to 3 months or when the pressure difference through the membrane bio-assembly increases by more than 0.5 bar compared with the initial pressure difference under the same operating conditions. The present invention determines whether to detect the inlet and outlet water pressure difference of the bioreactor according to the change of the water level, and judges the blockage of the membrane bio-assembly according to the change of the inlet and outlet water pressure difference of the bioreactor and the initial inlet and outlet water pressure difference. In combination with the principle that organic pollution is obviously affected by alkaline washing and salt scaling is obviously affected by acid washing, a chemical enhanced backwashing procedure is introduced into the operation process of the membrane bio-assembly. Through an operation similar to low-intensity chemical cleaning, the pollution of the membrane bio-assembly is eliminated at the stage of its formation, preventing the membrane pollution from being restored in time and forming a synergistic deterioration effect.

[0035] The analysis unit draws a pressure difference change curve of the inlet and outlet water pressure difference over time according to the inlet and outlet water pressure difference of the bioreactor, obtains the derivative function of the pressure difference change curve, and calculates the slope of the pressure difference change curve through the derivative function; The analysis unit determines the segmentation points of the pressure difference change curve on the pressure difference change curve based on the preset pressure difference slope interval to determine each pressure difference curve segment. If the slopes of several consecutive time-series pressure difference monitoring points on the pressure difference change curve are not within the range of the preset pressure difference slope, the analysis unit uses the initial point and the end point of the corresponding consecutive time-series pressure difference monitoring points according to the time series process as the segmentation points of the pressure difference curve segment, and uses the curve segment formed by the segmentation points on the pressure difference change curve as a single pressure difference curve segment; If the duration of the pressure difference curve segment is less than or equal to the preset duration, the analysis unit determines that the change in the pressure difference between the inlet and outlet water of the bioreactor is small, and the pollution degree of the sewage is low; If the duration of the pressure difference curve segment is greater than the preset duration, the analysis unit determines that the change in the pressure difference between the inlet and outlet water of the bioreactor is small, and the pollution degree of the sewage is high.

[0036] Among them, the several time-series pressure difference monitoring points are several analysis points selected on the pressure difference change curve according to the time-series process; the value of the preset pressure difference slope is equal to the preset pressure difference change rate, and the preset pressure difference change rate is determined according to the characteristics of the membrane biocomponent.

[0037] It can be understood that the value of the slope of the pressure difference change curve is equal to the change rate of the inlet and outlet water pressure difference of the bioreactor, and the change rate of the inlet and outlet water pressure difference is the change amount of the inlet and outlet water pressure difference within a preset time length. The preset time length is determined according to actual production and actual requirements, and the value should be as small as possible to obtain an accurate change rate and slope of the inlet and outlet water pressure difference, so as to improve the accuracy of determining the pressure difference change curve; Specifically, sewage contains many kinds of organic matter, and the concentration of organic matter is difficult to calculate, and it is difficult to accurately calculate the pollution degree of sewage. The present invention reflects the pollution degree of sewage through the change of the inlet and outlet water pressure difference of the bioreactor, draws the pressure difference change curve according to the inlet and outlet water pressure difference of the bioreactor, divides the pressure difference curve segments according to the slope of the pressure difference change curve, determines the duration of the pressure difference curve segment, and compares it with the preset duration, so as to avoid judging the changing speed of the pressure difference change curve only by the slope of the pressure difference change curve, resulting in misjudgment of the changing speed due to fluctuation of the pressure difference change curve, thereby improving the accuracy of judging the pollution degree of sewage.

[0038] The analysis unit determines the degree of sewage pollution, calculates the water inlet flow rate according to the flow rate of the water inlet per unit time, and adjusts the aeration mode of the aeration unit according to the degree of sewage pollution and the water inlet flow rate. If the sewage pollution level and the inlet flow rate are low, the aeration unit adopts the second aeration mode; If the sewage pollution level and the inlet flow rate are high, the aeration unit adopts the first aeration mode; In the second aeration mode, the closing time of the aeration unit in the aeration cycle is three times the opening time, and the initial opening and closing time is 10s / 30s; In the first aeration mode, the analysis unit reduces the initial closing time of the aeration unit in the aeration cycle according to the sewage pollution degree and the inlet flow rate, and the initial closing time is inversely proportional to the sewage pollution degree and the inlet flow rate.

[0039] It is understandable that there are many methods of aeration, including forced aeration, mechanical aeration and microporous aeration, etc. Different aeration devices and methods can be used according to the specific needs of sewage purification, as long as enough air can be introduced into the sewage.

[0040] Specifically, the aeration unit introduces air into the sewage through a blower, so that the organic matter in the sewage comes into contact with oxygen, thereby promoting the growth and metabolism of microorganisms; the main purpose of aeration is to increase the dissolved oxygen concentration in the sewage and provide sufficient oxygen for aerobic microorganisms so that they can effectively degrade the organic matter in the sewage; this system adjusts the opening and closing time of the aeration unit according to the pollution degree of the sewage and the water inlet speed, reducing unnecessary consumption of the aeration unit due to excessive aeration intensity, and improving the economic benefits of sewage purification.

[0041] The detection unit uses a flow meter to detect the flow rate of the water outlet, and the analysis unit compares the flow rate of the water outlet with a preset flow rate value. If the outlet flow rate is less than the preset flow rate value, and the flow difference between the outlet flow rate and the preset flow rate value is greater than the flow evaluation value, the analysis unit determines that the outlet flow rate is small, and the current sewage purification efficiency does not meet the sewage purification requirements. The analysis unit sends an alarm signal, reduces the spacing between membrane bio-assemblies in the bioreactor, and increases the number of membrane bio-assemblies.

[0042] In this embodiment, the flow evaluation value is 1.5% of the preset flow value; It is understandable that, in order to meet the efficiency requirements of sewage purification, the preset flow value of the water outlet is a fixed value, which is determined according to the requirements of sewage purification; Specifically, the inlet flow has a direct impact on the outlet flow, and because the sewage purification process needs to be stopped when the membrane biological components in the bioreactor are backwashed, the backwashing cycle of the membrane biological components will also indirectly affect the outlet flow; this system accurately determines the outlet flow to avoid misjudgment due to flow fluctuations, thereby quantifying the current system's sewage purification efficiency, and improving the sewage purification efficiency by adjusting the number of membrane biological components in the bioreactor, further increasing the stability of the system.

[0043] Understandably, the membrane bioreactor components in the bioreactor can use the vibrating membrane bioreactor (V-MBR) technology, which can achieve the reciprocating motion of the membrane filaments and the water body through mechanical transmission, effectively control membrane fouling, and further reduce energy consumption. Compared with traditional membrane bioreactors, mechanical vibration can reduce the entanglement of fibrous substances on the membrane filaments and ensure the stable operation of the membrane system.

[0044] The sludge discharged from the reaction tank is transported to the regulating tank through a reflux pump. The sewage purification system regularly discharges the sludge and stores it in a sludge tank. After adding a filter agent, the sludge can be pumped into a filter press for dehydration to form a mud cake; the mud cake can be made into sidewalk tiles for reuse without causing secondary pollution.

[0045] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An environmentally friendly sewage purification system, characterized in that: include: Pretreatment unit, including screens and primary sedimentation tanks, used to remove large debris, sand and suspended solids from sewage; The detection unit includes a flow meter, a pressure sensor, and a water level meter, which is used to detect the flow rate of the water inlet and outlet, the water inlet and outlet pressure of the bioreactor, and the water level of the reaction tank, and transmit the data to the analysis unit; The analysis unit is used to calculate the change rate of the water level in the reaction tank and adjust the flow rate of the water inlet; determine the operating state of the membrane biological component in the bioreactor according to the current inlet and outlet water pressure difference of the bioreactor, and adjust the cycle of the cleaning unit to backwash the membrane biological component; determine each pressure difference curve segment based on the preset pressure difference slope interval, determine the pollution degree of the sewage according to the duration of the pressure difference curve segment, and adjust the aeration mode of the aeration unit according to the pollution degree of the sewage and the inlet flow rate; The reaction unit includes a pump, an anaerobic tank, a reaction tank and several membrane biological components. The reaction tank includes an inlet regulating valve and an outlet. The pump is used to pass the sewage from the primary sedimentation tank into the anaerobic tank. The anaerobic tank is connected to the reaction tank through the inlet. The membrane biological component is placed inside the reaction tank to intercept the activated sludge and macromolecular organic matter in the sewage. A cleaning unit, including a backwash pump and a reagent tank, is used to periodically perform backwash cleaning on the membrane biological component; an aeration unit, including a blower and a regulating valve, for introducing air into the sewage according to the working mode determined by the analysis unit; The recovery unit, including a storage tank, a return pump, and a centrifugal pump, is used to store the purified sewage and recover the sludge generated during the sewage purification process.

2. The environmentally friendly sewage purification system according to claim 1, characterized in that: The analysis unit calculates the change rate of the water level in the reaction pool per unit time according to the change of the water level in the reaction pool, and compares the water level and the change rate of the water level in the reaction pool with the preset water level and the change rate of the water level. If the water level in the reaction tank is lower than the preset water level, and the falling speed of the water level is greater than the preset falling speed, the analysis unit determines that the falling speed of the water level in the reaction tank is faster and the flow rate of the water inlet is smaller, and the flow rate of the water inlet is increased by increasing the valve opening of the regulating valve in the water inlet. The valve opening of the regulating valve is positively correlated with the ratio of the water level falling speed to the preset falling speed and the ratio of the preset water level to the water level in the reaction tank. If the water level in the reaction tank is higher than the preset water level and the rising speed of the water level is greater than the preset rising speed, the analysis unit determines that the membrane bioreactor assembly in the bioreactor may be blocked and determines the blockage condition of the membrane bioreactor assembly.

3. The environmentally friendly sewage purification system according to claim 2, characterized in that: The analysis unit calculates the current inlet and outlet water pressure difference of the bioreactor, and compares the current inlet and outlet water pressure difference with the initial inlet and outlet water pressure difference. If the difference between the current inlet and outlet water pressure difference and the initial inlet and outlet water pressure difference is less than or equal to the pressure difference evaluation value, the analysis unit determines that the membrane biological component in the bioreactor is not blocked or is in a normal operating state range; If the difference between the current inlet and outlet water pressure difference and the initial inlet and outlet water pressure difference is greater than the pressure difference evaluation value, the analysis unit determines that the membrane biological component in the bioreactor is clogged.

4. The environmentally friendly sewage purification system according to claim 3, characterized in that: When the membrane biological component is not blocked or is in a normal operating state, the analysis unit reduces the flow rate of the water inlet by reducing the valve opening of the regulating valve in the water inlet; When the membrane biological component is clogged, the analysis unit sends a signal to the cleaning unit to backwash the membrane biological component, and adjusts the backwashing cycle of the cleaning unit on the membrane biological component according to the ratio of the current inlet and outlet water pressure difference to the initial inlet and outlet water pressure difference and the pressure difference evaluation value.

5. The environmentally friendly sewage purification system according to claim 1, characterized in that: The analysis unit determines the segmentation points of the pressure difference change curve on the pressure difference change curve based on the preset pressure difference slope interval to determine each pressure difference curve segment. If the slopes of several consecutive time-series pressure difference monitoring points on the pressure difference change curve are not within the range of the preset pressure difference slope, the analysis unit will use the initial point and the end point of the corresponding consecutive time-series pressure difference monitoring points according to the time series process as the segmentation points of the pressure difference curve segment, and use the curve segment formed by the segmentation points on the pressure difference change curve as a single pressure difference curve segment.

6. The environmentally friendly sewage purification system according to claim 5, characterized in that: The analysis unit compares the duration corresponding to the pressure difference curve segment with the preset duration. If the duration of the pressure difference curve segment is less than or equal to the preset duration, the analysis unit determines that the change in the pressure difference between the inlet and outlet water of the bioreactor is small, and the pollution degree of the sewage is low; If the duration of the pressure difference curve segment is greater than the preset duration, the analysis unit determines that the change in the inlet and outlet pressure difference of the bioreactor is small and the pollution degree of the sewage is high.

7. The environmentally friendly sewage purification system according to claim 6, characterized in that: The analysis unit calculates the water inlet flow rate according to the flow rate of the water inlet per unit time, and adjusts the aeration mode of the aeration unit according to the sewage pollution degree and the water inlet flow rate. If the sewage pollution level and the inlet flow rate are low, the aeration unit adopts the second aeration mode; If the sewage pollution degree and the water inlet flow rate are high, the aeration unit adopts the first aeration mode.

8. The environmentally friendly sewage purification system according to claim 7, characterized in that: In the first aeration mode, the analysis unit reduces the initial closing time of the aeration unit in the aeration cycle according to the sewage pollution degree and the inlet flow rate, and the initial closing time is inversely proportional to the sewage pollution degree and the inlet flow rate.

9. The environmentally friendly sewage purification system according to claim 1, characterized in that: The analysis unit compares the flow rate of the water outlet with the preset flow rate value. If the outlet flow rate is less than the preset flow rate value, and the flow difference between the outlet flow rate and the preset flow rate value is greater than the flow evaluation value, the analysis unit determines that the outlet flow rate is small and the current sewage purification efficiency does not meet the sewage purification requirements.

10. The environmentally friendly sewage purification system according to claim 9, characterized in that: When the current sewage purification efficiency does not meet the sewage purification demand, the analysis unit sends out an alarm signal, reduces the spacing of the membrane biological components in the bioreactor, and increases the number of membrane biological components.

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