Intelligent modular membrane-process integrated treatment apparatus for rural domestic wastewater, and method

Abstract

Provided in the present invention are an intelligent modular membrane-process integrated treatment apparatus for rural domestic wastewater, and a method. The apparatus comprises: a water intake regulating tank, which is configured to accommodate untreated wastewater; a water intake tank, a liquid inlet of which is in communication with a liquid outlet of the water intake regulating tank by means of a first variable-frequency pump; and an MBR membrane tank, which is in communication with the water intake tank, wherein a plurality of aeration assemblies are provided at the bottom of the MBR membrane tank, each aeration assembly is correspondingly provided with an MBR module, a water output pipe of each MBR module is provided with a valve, and the water output pipe of each MBR module is in communication with a main water output pipe by means of a second variable-frequency pump. The present invention has the following beneficial effects: by means of determining the number of MBR modules to be turned on and the flow of the first variable-frequency pump on the basis of the amount of incoming water, and by intelligently adjusting the aeration rate on the basis of food-to-microorganism ratio data of the MBR membrane tank, the power consumption of the operation of devices in a system is greatly reduced, the stability of a biochemical reaction and the treatment effect are improved, and carbon emissions are reduced.

Description

An intelligent modularized membrane-based integrated treatment device and method for rural domestic sewage Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to an intelligent modularized membrane-based integrated treatment device and method for rural domestic sewage. Background Art

[0002] Rural domestic sewage primarily refers to the wastewater generated by villagers in rural areas through production and daily life. It primarily consists of four categories: kitchen wastewater, toilet flushing wastewater, laundry wastewater, and bathing wastewater. In rural domestic sewage treatment, inflow is significantly affected by seasonal variations, population size, and lifestyle. The inflow volume and pollutant concentrations generally fluctuate significantly over time. Furthermore, the inflow is intermittent and unstable. The MBR process, with its advantages of a small footprint, high resistance to shock loads, low excess sludge production, high effluent quality, and ease of automated control, has become a significant component of rural domestic sewage treatment. However, existing MBR processes generally operate under stable inflow conditions under design conditions. All MBR membrane modules at the site operate in a coordinated manner. Even with low inflows, all membrane modules and aeration systems must operate in concert. In reality, rural domestic sewage inflows often fall below the designed inflow volume, forcing sewage treatment plants to process this inflow in a short period of time. Afterward, either the entire sewage treatment plant is shut down or the MBR membrane tanks are left empty, resulting in overexposure and energy waste. On the other hand, the MBR process itself is a treatment process that combines biological treatment technology with membrane separation. The feed-to-microorganism ratio is a key parameter for determining sludge loading. It is the amount of organic matter that a unit weight of activated sludge can withstand per unit time. As the name suggests, it is the ratio of food (F value) to microorganism (M value). When the MBR membrane tank is operating at a high feed-to-microorganism ratio, maintaining a relatively high dissolved oxygen level is beneficial, as it can accelerate the degradation rate of organic matter in the wastewater. When the MBR membrane tank is operating at a low feed-to-microorganism ratio, if the dissolved oxygen level is still maintained, insufficient food will accelerate the endogenous metabolism of the activated sludge, ultimately leading to deflocculation of the activated sludge, commonly known as over-aeration. Therefore, in the operation of the MBR aeration membrane tank, the aeration rate should be closely related to the control of the feed-to-microorganism ratio. A high feed-to-microorganism ratio can be controlled according to a higher dissolved oxygen concentration, promoting the effective degradation of organic pollutants. On the contrary, when the feed-microorganism ratio is insufficient, the dissolved oxygen concentration should be kept relatively low to reduce the rate of endogenous metabolism to avoid sludge aging and sludge deflocculation, while also reducing power consumption and operating costs. Current processes generally rely on operators' empirical knowledge of sludge color and properties to determine sludge loading capacity. Dissolved oxygen in the MBR membrane tank is controlled by manually adjusting the fan frequency, operating time, or the size of the vent valve. This lack of accuracy in determining the feed-microorganism ratio significantly reduces treatment effectiveness, and offline sampling and testing methods are unable to resolve the problem in a timely manner.Furthermore, the matching of activated sludge concentration control value with influent concentration is a key factor influencing sewage treatment effectiveness. The food-microorganism ratio is closely related to activated sludge concentration. In the practical operation of rural domestic sewage treatment plants, sludge discharge control still relies primarily on the experience of operators to determine the timing of sludge discharge and regulate sludge concentration. This often results in a poor match between activated sludge concentration control value and influent concentration, and the operational stability of the plant is significantly affected by the experience of operators. To achieve scientific and rational sludge discharge and control sludge concentration within a reasonable range, an intelligent decision-making aid is urgently needed to further improve the standardization and accuracy of sludge discharge timing. Summary of the Invention

[0003] In view of this, the present invention aims to propose an intelligent modular rural domestic sewage membrane integrated treatment device and method, in order to solve at least one of the above-mentioned technical problems.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] On one hand, the present invention provides an intelligent modular integrated membrane treatment device for rural domestic sewage, comprising:

[0006] an influent regulating tank configured to hold raw sewage;

[0007] The liquid outlet of the water inlet regulating tank is connected to the liquid inlet of the water inlet tank through a first variable frequency pump;

[0008] An MBR membrane pool is connected to the water inlet pool. A plurality of aeration components are provided at the bottom of the MBR membrane pool. Each aeration component corresponds to a group of MBR modules. Each group of MBR modules is composed of a plurality of MBR membranes.

[0009] The outlet pipes of each group of MBR modules are provided with valves, and the outlet pipes of each group of MBR modules are connected to the outlet main pipe, and the outlet main pipe is connected to the second variable frequency pump.

[0010] Furthermore, a valve is provided on the air inlet end of each group of the aeration components, and the air inlet end of the aeration component is connected to the air outlet end of the variable frequency fan.

[0011] Furthermore, a second liquid level sensor is provided in the MBR membrane tank;

[0012] A first liquid level sensor is provided in the water inlet regulating tank;

[0013] A BOD sensor is provided in the water inlet tank;

[0014] The MBR membrane tank is provided with an online sludge concentration detector;

[0015] The valve on the outlet pipe of the MBR module and the valve on the air inlet end of the aeration assembly are both solenoid valves.

[0016] Furthermore, an intermediate tank is provided between the water inlet regulating tank and the water inlet tank, and the inlet and outlet of the intermediate tank are respectively connected to the outlet of the first variable frequency pump and the liquid inlet of the water inlet tank;

[0017] The intermediate tank is an anaerobic tank or an anoxic tank or a combination of an anaerobic tank and an anoxic tank.

[0018] Furthermore, the first liquid level sensor, the second liquid level sensor, the BOD sensor, and the sludge concentration online detector are all electrically connected to the controller, and the electromagnetic valves are all electrically connected to the controller via a driver.

[0019] Another aspect of the present invention provides a method for applying the intelligent modular rural domestic sewage membrane integrated treatment device described in the first aspect, characterized in that it includes the following steps:

[0020] S1. Collecting liquid level information of the water inlet regulating tank through a first liquid level sensor;

[0021] The liquid level information of the MBR membrane tank is collected through the second liquid level sensor;

[0022] S2. Regulate the flow of the first variable frequency pump and the second variable frequency pump according to the liquid level information of the water inlet regulating tank and the liquid level information of the MBR membrane tank, and adjust the opening state of the valve on the outlet pipe of the MBR module and the valve on the air inlet end of the aeration assembly.

[0023] Furthermore, the water inlet regulating tank is provided with four liquid level thresholds, which are, from high to low, high liquid level A, middle level B, low liquid level C, and bottom liquid level D;

[0024] The MBR membrane tank is equipped with three liquid level thresholds, from high to low, namely high liquid level G, middle level F, and low liquid level E;

[0025] In step S1, the first liquid level sensor is used to collect liquid level information of the water inlet regulating tank and determine within which threshold range the liquid level of the water inlet regulating tank is located;

[0026] The second liquid level sensor collects the liquid level information of the MBR membrane pool and determines within what threshold range the liquid level of the MBR membrane pool is;

[0027] Step S2 includes the following operating modes:

[0028] In the minimum liquid level operation mode, when the liquid level in the regulating tank is lower than the guaranteed bottom liquid level D, the first and second variable frequency pumps do not work;

[0029] In the low-level operation mode, when the liquid level in the inlet regulating tank is between the low liquid level C and the guaranteed bottom liquid level D, the flow rate of the first variable frequency pump is adjusted to match the critical flux water production of a group of MBR modules. When the liquid level in the MBR membrane tank reaches the intermediate level F, the electromagnetic valve of the outlet pipe of a group of MBR modules is opened, the flow rate of the second variable frequency pump is adjusted to match the critical flux water production of a group of MBR modules, and the aeration components corresponding to the MBR modules in operation are turned on.

[0030] If the liquid level in the MBR membrane pool continues to rise to the high liquid level G, the first variable frequency water pump will be turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump will be turned on again. If the liquid level in the MBR membrane pool drops to the low liquid level E, the second variable frequency water pump will be turned off, and the corresponding aeration components will be turned off at the same time. When the liquid level returns to the middle level F, the second variable frequency water pump and the corresponding aeration components will be turned on again.

[0031] In the medium liquid level operation mode, when the liquid level in the inlet regulating tank is between the middle level B and the low liquid level C, the flow rate of the first variable frequency pump is adjusted to match the critical flux water production of the two groups of MBR modules. When the liquid level in the MBR membrane tank reaches the middle level F, the electromagnetic valves of the outlet pipes of the two groups of MBR modules are opened, the flow rate of the second variable frequency pump is adjusted to match the critical flux water production of the two groups of MBR modules, and the two groups of aeration components corresponding to the MBR modules in operation are opened;

[0032] If the liquid level in the MBR membrane pool continues to rise to the high liquid level G, the first variable frequency water pump will be turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump will be turned on again. If the liquid level in the MBR membrane pool drops to the low liquid level E, the second variable frequency water pump will be turned off, and the corresponding aeration components will be turned off at the same time. When the liquid level returns to the middle level F, the second variable frequency water pump and the corresponding aeration components will be turned on again.

[0033] In high liquid level operation mode, when the liquid level in the inlet regulating tank is between the high liquid level A and the intermediate level B, the flow rate of the first variable frequency pump is adjusted to match the critical flux water production of all MBR modules. When the liquid level in the MBR membrane tank reaches the intermediate level F, the electromagnetic valves of the outlet pipes of all MBR modules are opened, the flow rate of the second variable frequency pump is adjusted to match the critical flux water production of all MBR modules, and all aeration components corresponding to the MBR modules in operation are turned on.

[0034] If the liquid level in the MBR membrane pool continues to rise to the high liquid level G, the first variable frequency water pump will be turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump will be turned on again. If the liquid level in the MBR membrane pool drops to the low liquid level E, the second variable frequency water pump will be turned off, and the corresponding aeration components will be turned off at the same time. When the liquid level returns to the middle level F, the second variable frequency water pump and the corresponding aeration components will be turned on again.

[0035] Furthermore, in the low liquid level operation mode, multiple groups of MBR modules and corresponding aeration components are opened alternately, and different MBR modules and corresponding aeration components are opened every 8 hours;

[0036] In the medium liquid level operation mode, two groups of MBR modules and corresponding aeration components are selected from multiple groups of MBR modules without duplication as a module combination. The module combinations are opened alternately, and a different module combination is opened every 8 hours.

[0037] Furthermore, in all the operation modes of step S2, before starting the aeration assembly, it is necessary to determine whether the aeration assembly can be started based on the food-microorganism ratio of the sewage in the MBR membrane tank.

[0038] The formula for calculating the food-micro ratio is:

[0039] F / M=Q×BOD5 / (MLSS×Va);

[0040] Wherein, F / M is the feed-microorganism ratio, Q is the influent flow rate, BOD5 is the BOD5 value of the influent, Va is the effective volume of the MBR membrane tank, and MLSS is the activated sludge concentration in the MBR membrane tank;

[0041] When the food-microorganism ratio is lower than the set food-microorganism ratio lower limit threshold, the aeration component is turned off;

[0042] In all operation modes of step S2, by comparing the daily average activated sludge concentration with the upper threshold of the activated sludge concentration, it is determined whether sludge discharge is required;

[0043] Activated sludge concentration upper threshold MLSS S The calculation formula is:

[0044] MLSS S =Q×BOD5 / (F / M I ×Va);

[0045] Among them, F / M I is the lower limit threshold of the feed microbial ratio, Q is the influent flow rate, BOD5 is the BOD5 value of the influent, Va is the effective volume of the MBR membrane tank, and MLSS is the activated sludge concentration in the MBR membrane tank;

[0046] When the daily average activated sludge concentration (MLSS) in the aeration tank exceeds the upper threshold value (MLSS) of activated sludge concentration S When the mud volume reaches 30%, an alarm message will be issued to indicate that mud needs to be discharged.

[0047] Furthermore, the low liquid level E of the MBR membrane pool is not less than 20 cm above the upper surface of the MBR module.

[0048] Compared with the prior art, the intelligent modularized membrane-based integrated treatment device and method for rural domestic sewage described in the present invention has the following beneficial effects:

[0049] (1) The intelligent modular integrated membrane treatment device for rural domestic sewage described in the present invention determines the number of MBR modules to be opened and the flow rate of the first variable frequency pump according to the amount of incoming water, which greatly reduces the power consumption of the equipment operation and reduces carbon emissions.

[0050] (2) The present invention discloses an integrated membrane treatment method for rural domestic sewage. This method adopts a combination of an online BOD sensor and an online sludge concentration meter. Through the site intelligent management platform, the MBR membrane pool food-microorganism ratio data is obtained at all times, and the aeration time and aeration air volume are intelligently adjusted to avoid sludge aging and sludge deflocculation. By analyzing the relationship between the food-microorganism ratio and the activated sludge concentration, the activated sludge concentration value can be better adjusted to find the appropriate ratio that matches the activated sludge concentration with the influent organic matter concentration, thereby improving the stability of the biochemical reaction and the treatment effect, and effectively improving the effluent compliance rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0052] FIG1 is a schematic diagram of the structure of the device according to an embodiment of the present invention.

[0053] Description of reference numerals:

[0054] 1. Water inlet regulating tank; 2. Water inlet tank; 3. MBR membrane tank; 4. MBR module; 5. Aeration assembly. DETAILED DESCRIPTION

[0055] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0057] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0058] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0059] As shown in Figure 1, an intelligent modular integrated membrane treatment device for rural domestic sewage includes:

[0060] an influent regulating tank 1 configured to receive untreated sewage;

[0061] The liquid outlet of the water inlet regulating tank 1 is connected to the liquid inlet of the water inlet tank 2 through the first variable frequency pump;

[0062] An MBR membrane pool 3 is connected to the water inlet pool 2. Three aeration components 5 are provided at the bottom of the MBR membrane pool 3. Each aeration component 5 is provided with a corresponding MBR module 4.

[0063] Each MBR module 4 has a valve installed on its outlet pipe, which is connected to the main outlet pipe, which is connected to the second variable frequency pump. A valve is installed on the air inlet of each aeration assembly 5, which is connected to the air outlet of the variable frequency fan.

[0064] A second liquid level sensor is provided in the MBR membrane tank 3;

[0065] A first liquid level sensor is provided in the water inlet regulating tank 1;

[0066] A BOD sensor is provided in the water inlet tank 2;

[0067] An online sludge concentration detector is provided in the MBR membrane tank 3;

[0068] The valve on the outlet pipe of the MBR module 4 and the valve on the air inlet end of the aeration assembly 5 are both solenoid valves.

[0069] An intermediate tank is provided between the water inlet regulating tank 1 and the water inlet tank 2, and the inlet and outlet of the intermediate tank are respectively connected to the outlet of the first variable frequency pump and the liquid inlet of the water inlet tank 2;

[0070] In some embodiments, the middle tank is an anaerobic tank, in other embodiments, the middle tank is an anoxic tank, and in other embodiments, the middle tank is a combination of an anaerobic tank and an anoxic tank.

[0071] MBR module 4 is a membrane bioreactor (MBR) composed of multiple MBR membranes. The MBR (Membrane Bio-Reactor) is a novel wastewater treatment system that organically combines membrane separation and biological treatment technologies. Membrane modules replace the secondary settling tank at the end of traditional biological treatment technology. This maintains a high activated sludge concentration within the bioreactor, increasing the organic load of biological treatment, thereby reducing the wastewater treatment facility footprint and reducing excess sludge volume by keeping the sludge load low. The system primarily utilizes activated sludge and macromolecular organic matter within the retention tank of the membrane separation equipment immersed in the aerobic biotank. The activated sludge concentration (MLSS) within the MBR system can be increased to 8,000-10,000 mg / L, or even higher, and the sludge age (SRT) can be extended to over 30 days. MBRs are currently available, and their specific structure and connection configuration are not detailed here.

[0072] The first liquid level sensor, the second liquid level sensor, the BOD sensor, and the sludge concentration online detector are all electrically connected to the controller, and the electromagnetic valves are all electrically connected to the controller through the driver.

[0073] The aeration assembly 5 is a plurality of straight pipes connected to the variable frequency blower, and through holes are opened on the straight pipes for gas to flow out.

[0074] The first liquid level sensor and the second liquid level sensor both adopt but are not limited to existing radio frequency admittance / capacitance liquid level meters; the BOD sensor adopts but is not limited to existing optical, electronic and microbiological technologies; the biochemical oxygen demand (BOD) microbial sensor rapid tester product model is JXSZ-1001-BOD. The sludge concentration online detector adopts but is not limited to the existing sludge concentration online analyzer model TSS-6212, the solenoid valve adopts but is not limited to the existing flying saucer piston solenoid valve model HOPE91, the first variable frequency water pump and the second variable frequency water pump both adopt but are not limited to the existing variable frequency water pump, the controller controls the frequency converter to change the speed of the variable frequency water pump and thus change the flow of the variable frequency water pump, which is the existing technology, the variable frequency fan adopts but is not limited to the axial flow fan driven by the variable frequency motor, the controller controls the frequency converter to change the speed of the variable frequency fan and thus change the fan flow, which is the existing technology, the controller adopts but is not limited to the existing industrial computer or PLC controller, the program set in the industrial computer or PLC controller adjusts the opening of the solenoid valve according to the liquid level information, and controls the first variable frequency water pump and the second variable frequency water pump, which is the existing technology and will not be repeated here.

[0075] Working process:

[0076] A method for treating rural domestic sewage by membrane integrated method using the above-mentioned intelligent modular rural domestic sewage membrane integrated treatment device is characterized by comprising the following steps:

[0077] S1, collecting liquid level information of the water inlet regulating tank 1 through the first liquid level sensor;

[0078] The liquid level information of the MBR membrane tank 3 is collected by the second liquid level sensor;

[0079] S2. Regulate the flow of the first variable frequency pump and the second variable frequency pump according to the liquid level information of the water inlet regulating tank 1 and the liquid level information of the MBR membrane tank 3, and adjust the opening state of the valve on the outlet pipe of the MBR module 4 and the valve on the air inlet end of the aeration assembly 5.

[0080] The water inlet regulating tank 1 is provided with four liquid level thresholds, which are high liquid level A, middle level B, low liquid level C and bottom liquid level D from high to low;

[0081] The MBR membrane pool 3 is provided with three liquid level thresholds, which are high liquid level G, middle level F, and low liquid level E from high to low;

[0082] In step S1, the liquid level information of the water inlet regulating tank 1 is collected by the first liquid level sensor to determine within what threshold range the liquid level of the water inlet regulating tank 1 is;

[0083] The second liquid level sensor collects the liquid level information of the MBR membrane pool 3 and determines within what threshold range the liquid level of the MBR membrane pool 3 is;

[0084] Step S2 includes the following operating modes of the device:

[0085] In the minimum liquid level operation mode, when the liquid level in the regulating tank is lower than the guaranteed bottom liquid level D, the first and second variable frequency pumps do not work;

[0086] In the low-liquid-level operation mode, when the liquid level in the inlet regulating tank 1 is between the low liquid level C and the guaranteed bottom liquid level D, the flow rate of the first variable-frequency pump is adjusted to match the critical flux water production of a group of MBR modules 4. When the liquid level in the MBR membrane tank 3 reaches the intermediate level F, the electromagnetic valve of the outlet pipe of a group of MBR modules 4 is opened, the flow rate of the second variable-frequency pump is adjusted to match the critical flux water production of a group of MBR modules 4, and the aeration assembly 5 corresponding to the MBR module 4 in operation is turned on.

[0087] If the liquid level in the MBR membrane pool 3 continues to rise to the high liquid level G, the first variable frequency water pump is turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump is turned on again. If the liquid level in the MBR membrane pool 3 drops to the low liquid level E, the second variable frequency water pump is turned off, and the corresponding aeration component 5 is turned off at the same time. When the liquid level returns to the middle level F, the second variable frequency water pump and the corresponding aeration component 5 are turned on again.

[0088] In the medium liquid level operation mode, when the liquid level in the inlet regulating tank 1 is between the intermediate level B and the low liquid level C, the flow rate of the first variable frequency pump is adjusted to match the critical flux water production of the two groups of MBR modules 4. When the liquid level in the MBR membrane tank 3 reaches the intermediate level F, the electromagnetic valves of the outlet pipes of the two groups of MBR modules 4 are opened, the flow rate of the second variable frequency pump is adjusted to match the critical flux water production of the two groups of MBR modules 4, and the two groups of aeration components 5 corresponding to the MBR modules 4 in operation are opened;

[0089] If the liquid level in the MBR membrane pool 3 continues to rise to the high liquid level G, the first variable frequency water pump is turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump is turned on again. If the liquid level in the MBR membrane pool 3 drops to the low liquid level E, the second variable frequency water pump is turned off, and the corresponding aeration component 5 is turned off at the same time. When the liquid level returns to the middle level F, the second variable frequency water pump and the corresponding aeration component 5 are turned on again.

[0090] In the high liquid level operation mode, when the liquid level in the inlet regulating tank 1 is between the high liquid level A and the intermediate level B, the flow rate of the first variable frequency pump is adjusted to match the critical flux water production of all the MBR modules 4. When the liquid level in the MBR membrane tank 3 reaches the intermediate level F, the electromagnetic valves of the outlet pipes of all the MBR modules 4 are opened, the flow rate of the second variable frequency pump is adjusted to match the critical flux water production of all the MBR modules 4, and all the aeration components 5 corresponding to the MBR modules 4 in operation are opened;

[0091] If the liquid level in the MBR membrane pool 3 continues to rise to the high liquid level G, the first variable frequency water pump is turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump is turned on again. If the liquid level in the MBR membrane pool 3 drops to the low liquid level E, the second variable frequency water pump is turned off, and the corresponding aeration component 5 is turned off at the same time. When the liquid level returns to the middle level F, the second variable frequency water pump and the corresponding aeration component 5 are turned on again.

[0092] In the low liquid level operation mode, one of the three groups of MBR modules 4 and the corresponding aeration components 5 is opened alternately, and a different MBR module 4 and the corresponding aeration component 5 are opened every 8 hours;

[0093] In the medium liquid level operation mode, two groups of MBR modules 4 and corresponding aeration components 5 are selected from the three groups of MBR modules 4 without duplication as a module combination, and the module combinations are opened alternately, and a different module combination is opened every 8 hours.

[0094] In all operation modes of step S2 , before starting the aeration assembly 5 , it is necessary to determine whether the aeration assembly 5 can be started based on the food-microorganism ratio of the sewage in the MBR membrane tank 3 .

[0095] The formula for calculating the food-micro ratio is:

[0096] F / M=Q×BOD5 / (MLSS×Va);

[0097] Wherein, F / M is the feed-microorganism ratio; Q is the influent flow rate; BOD5 is the BOD5 value of the influent, which is collected by the BOD sensor; Va is the effective volume of the MBR membrane tank; MLSS is the activated sludge concentration in the MBR membrane tank, which is collected by the sludge concentration online detector;

[0098] When the MBR membrane tank 3 operates within the appropriate feed-to-microorganism ratio, the activated sludge flocs have a good structure, excellent settling performance, and clear, transparent effluent. When the MBR membrane tank 3 operates at a high feed-to-microorganism ratio, or even at overload, the excess feed causes the activated sludge to settle poorly, resulting in turbid effluent and difficulty in completely degrading the BOD in the wastewater. Maintaining a relatively high dissolved oxygen level is beneficial in this situation, accelerating the degradation of organic matter in the wastewater. When the MBR membrane tank 3 operates at a low feed-to-microorganism ratio, insufficient feed can cause the activated sludge to age. Long-term operation at a low feed-to-microorganism ratio can cause sludge deflocculation and even induce bulking of activated sludge filamentous bacteria. When activated sludge ages and deflocculates, the floc structure becomes looser, and the effluent carries many fine sludge fragments, reducing effluent clarity and deteriorating water quality. In this case, aeration should be reduced, the dissolved oxygen concentration should be kept relatively low, and sludge discharge should be initiated appropriately.

[0099] Conduct process tests on the treatment unit to obtain the range of the food-microorganism ratio under which the effluent from the unit meets the discharge standards for a considerable period of time. The upper and lower limits of this range are used as the lower and upper thresholds of the food-microorganism ratio.

[0100] When the food-microorganism ratio is lower than the set food-microorganism ratio lower limit threshold, the aeration component 5 is closed;

[0101] When the food-microorganism ratio is higher than the set food-microorganism ratio upper limit threshold, all aeration components 5 are turned on;

[0102] The closing and opening operation of the aeration component 5 has the highest priority. That is, when the closing or opening instruction of the aeration component 5 of the food micro-ratio conflicts with other aeration opening and closing instructions, the closing or opening instruction of the aeration component 5 of the food micro-ratio will be executed first.

[0103] At the same time, considering that the aeration component 5 of the MBR membrane pool 3 also has the function of disturbing the attachment of pollutants, the logic setting of closing the aeration component 5 cycle can be set to a timer length according to actual conditions.

[0104] In all operation modes of step S2, by comparing the daily average activated sludge concentration with the upper threshold of the activated sludge concentration, it is determined whether sludge discharge is required;

[0105] Activated sludge concentration upper threshold MLSS S The calculation formula is:

[0106] MLSS S =Q×BOD5 / (F / M I ×Va);

[0107] Among them, F / M I is the lower limit threshold of the feed microbial ratio, Q is the influent flow rate, BOD5 is the BOD5 value of the influent, Va is the effective volume of the MBR membrane tank, and MLSS is the activated sludge concentration in the MBR membrane tank;

[0108] When the daily average activated sludge concentration (MLSS) in the aeration tank exceeds the upper threshold value (MLSS) of activated sludge concentration S When the mud volume reaches 30%, an alarm message will be issued to indicate that mud needs to be discharged.

[0109] The low liquid level E of the MBR membrane pool 3 is not less than 20 cm above the upper surface of the MBR module 4 . Beneficial effects

[0110] 1) Since this process optimizes the operation mode of the membrane module, the number of MBR modules 4 to be opened and the rotation frequency of the first variable frequency pump are determined according to the amount of water inflow, which greatly reduces the power consumption of equipment operation and reduces carbon emissions.

[0111] 2) This process adopts a combination of online BOD sensor and online sludge concentration meter. Through the site intelligent management platform, it can obtain the 3-micronutrient ratio data of the MBR membrane pool in real time, intelligently adjust the aeration time and aeration air volume to avoid sludge aging and sludge deflocculation. At the same time, it can scientifically and intelligently remind the sludge discharge time of the activated sludge in the membrane pool, thereby improving the stability of the biochemical reaction and the treatment effect.

[0112] 3) Compared with the original process, after group operation, the number of membrane modules in operation depends on the amount of incoming water, which can keep the entire sewage treatment system in a long-term stable operation state, avoiding frequent shutdowns or air exposure due to insufficient incoming water to support the processing capacity of the entire system. This has a good effect on maintaining the balance of mud bacteria in the biochemical pool and the properties of the MBR biofilm.

[0113] 4) Extend the MBR membrane offline cleaning cycle

[0114] Over-aeration can damage sludge flocs, change sludge particle size and distribution, and release more colloids and dissolved organic matter (EPS and SMP), which can exacerbate membrane fouling. This process uses intelligent control of aeration volume, adjusting it based on changes in the food-microorganism ratio to keep it within a more scientific and reasonable range.

[0115] Due to the modular operation, during the alternating operation, the MBR module 4 that does not produce water has no suction effect on the sewage, and the pollutants on the membrane surface are loosened and fall off due to gravity. Under the action of aeration disturbance, it is more conducive to the shedding of pollutants attached to the membrane fibers and aged biofilm, which has a positive effect on extending the membrane fiber pollution cycle.

[0116] Due to the modular operation, the hydraulic retention time (HRT) is extended, and microorganisms have more time to digest and decompose nutrients, thereby reducing the possibility of membrane fouling.

[0117] The flow rate of each gear of the first variable frequency pump and the second variable frequency pump is equivalent to the critical flux water production of the corresponding module. When each module operates at the critical flux, the membrane fouling rate can be greatly slowed down.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

[0119] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An intelligent modularized membrane integrated treatment method for rural domestic sewage, characterized in that: include: an influent regulating tank (1) configured to receive raw sewage; A water inlet tank (2), wherein the liquid outlet of the water inlet regulating tank (1) is connected to the liquid inlet of the water inlet tank (2) via a first variable frequency pump; An MBR membrane pool (3), wherein the MBR membrane pool (3) is connected to the water inlet pool (2), and a plurality of aeration components (5) are arranged at the bottom of the MBR membrane pool (3), and each aeration component (5) is correspondingly provided with a group of MBR modules (4); A valve is provided on the water outlet pipe of each group of the MBR modules (4), and the water outlet pipe of each group of the MBR modules (4) is connected to a water outlet main pipe, and the water outlet main pipe is connected to a second variable frequency pump; The intelligent module membrane integrated treatment method for rural domestic sewage includes the following steps: S1, collecting liquid level information of the water inlet regulating tank (1) through a first liquid level sensor; Collecting liquid level information of the MBR membrane tank (3) by means of a second liquid level sensor; S2, adjusting the flow rates of the first variable frequency pump and the second variable frequency pump according to the liquid level information of the water inlet regulating tank (1) and the liquid level information of the MBR membrane tank (3), and adjusting the opening state of the valve on the outlet pipe of the MBR module (4) and the valve at the air inlet end of the aeration assembly (5); The water inlet regulating tank (1) is provided with four liquid level thresholds, which are respectively, from high to low, a high liquid level A, an intermediate level B, a low liquid level C, and a bottom liquid level D; The MBR membrane pool (3) is provided with three liquid level thresholds, which are respectively high liquid level G, middle level F, and low liquid level E from high to low; In step S1, the liquid level information of the water inlet regulating tank (1) is collected by a first liquid level sensor to determine within what threshold range the liquid level of the water inlet regulating tank (1) is; Collecting liquid level information of the MBR membrane pool (3) by means of a second liquid level sensor, and determining within what threshold range the liquid level of the MBR membrane pool (3) is; Step S2 includes the lowest liquid level operation mode, the low liquid level operation mode, the middle liquid level operation mode, and the high liquid level operation mode: In the minimum liquid level operation mode, when the liquid level in the regulating tank is lower than the guaranteed bottom liquid level D, the first variable frequency pump and the second variable frequency pump do not work; Low liquid level operation mode, when the liquid level of the water inlet regulating tank (1) is between the low liquid level C and the bottom liquid level D, the flow rate of the first variable frequency pump is adjusted to match the critical flux water production of a group of MBR modules (4); when the liquid level of the MBR membrane tank (3) reaches the intermediate position F, the electromagnetic valve of the outlet pipe of a group of MBR modules (4) is opened, the flow rate of the second variable frequency pump is adjusted to match the critical flux water production of a group of MBR modules (4), and a group of aeration components (5) corresponding to the MBR modules (4) in the operating state is opened; If the liquid level in the MBR membrane pool (3) continues to rise to the high liquid level G, the first variable frequency water pump is turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump is turned on again. If the liquid level in the MBR membrane pool (3) drops to the low liquid level E, the second variable frequency water pump is turned off and the corresponding aeration component (5) is turned off at the same time. When the liquid level rises back to the middle level F, the second variable frequency water pump and the corresponding set of aeration components (5) are turned on again.

2. According to claim 1, an intelligent modularized membrane integrated treatment method for rural domestic sewage is characterized by: A valve is provided on the air inlet end of the aeration component (5), and the air inlet end of the aeration component (5) is connected to the air outlet end of the variable frequency fan.

3. According to claim 2, an intelligent modularized membrane integrated treatment method for rural domestic sewage is characterized by: A second liquid level sensor is provided in the MBR membrane tank (3); A first liquid level sensor is provided in the water inlet regulating tank (1); A BOD sensor is provided in the water inlet pool (2); An online sludge concentration detector is provided in the MBR membrane pool (3); The valves on the water outlet pipes of each group of MBR modules (4) and the valves on the air inlet end of the aeration assembly (5) are both solenoid valves.

4. The intelligent modularized membrane integrated treatment method for rural domestic sewage according to claim 1 is characterized by: An intermediate pool is provided between the water inlet regulating pool (1) and the water inlet pool (2), and the inlet and outlet of the intermediate pool are respectively connected to the outlet of the first variable frequency pump and the liquid inlet of the water inlet pool (2); The intermediate tank is an anaerobic tank or an anoxic tank or a combination of an anaerobic tank and an anoxic tank.

5. The intelligent modularized membrane integrated treatment method for rural domestic sewage according to claim 3 is characterized by: The first liquid level sensor, the second liquid level sensor, the BOD sensor, and the sludge concentration online detector are all electrically connected to the controller, and the electromagnetic valves are all electrically connected to the controller via a driver.

6. The intelligent modularized membrane integrated treatment method for rural domestic sewage according to claim 1 is characterized by: In the middle liquid level operation mode, when the liquid level of the water inlet regulating tank (1) is between the middle level B and the low liquid level C, the flow rate of the first variable frequency pump is adjusted to match the critical flux water production of the two groups of MBR modules (4); when the liquid level of the MBR membrane tank (3) reaches the middle level F, the electromagnetic valves of the outlet pipes of the two groups of MBR modules (4) are opened, the flow rate of the second variable frequency pump is adjusted to match the critical flux water production of the two groups of MBR modules (4), and the two groups of aeration components (5) corresponding to the MBR modules (4) in the operating state are opened; If the liquid level of the MBR membrane pool (3) continues to rise to the high liquid level G, the first variable frequency water pump is turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump is turned on again. If the liquid level of the MBR membrane pool (3) drops to the low liquid level E, the second variable frequency water pump is turned off and the corresponding aeration component (5) is turned off at the same time. When the liquid level rises back to the middle level F, the second variable frequency water pump and the corresponding aeration component (5) are turned on again. High liquid level operation mode, when the liquid level of the water inlet regulating tank (1) is between the high liquid level A and the intermediate level B, the flow rate of the first variable frequency pump is adjusted to match the critical flux water production of all MBR modules (4); when the liquid level of the MBR membrane tank (3) reaches the intermediate level F, the electromagnetic valves of the outlet pipes of all MBR modules (4) are opened, the flow rate of the second variable frequency pump is adjusted to match the critical flux water production of all MBR modules (4), and all aeration components (5) corresponding to the MBR modules (4) in the operating state are opened; If the liquid level in the MBR membrane pool (3) continues to rise to the high liquid level G, the first variable frequency water pump is turned off. When the liquid level drops back to the middle level F, the first variable frequency water pump is turned on again. If the liquid level in the MBR membrane pool (3) drops to the low liquid level E, the second variable frequency water pump is turned off and the corresponding aeration component (5) is turned off at the same time. When the liquid level rises back to the middle level F, the second variable frequency water pump and the corresponding aeration component (5) are turned on again.

7. The intelligent modularized membrane integrated treatment method for rural domestic sewage according to claim 6 is characterized by: In the low liquid level operation mode, a plurality of groups of MBR modules (4) and corresponding aeration components (5) are opened alternately, and a different MBR module (4) and corresponding aeration component (5) are opened every 8 hours; In the medium liquid level operation mode, two groups of MBR modules (4) and corresponding aeration components (5) are selected from multiple groups of MBR modules (4) without duplication as a module combination, and the module combinations are opened alternately, and a different module combination is opened every 8 hours.

8. The intelligent modularized membrane integrated treatment method for rural domestic sewage according to claim 6 is characterized by: In all operation modes of step S2, before the aeration component (5) is turned on, it is necessary to determine whether the aeration component (5) can be turned on based on the food-micro ratio of the sewage in the MBR membrane tank (3); The formula for calculating the food-micro ratio is: F / M=Q×BOD5 / (MLSS×Va); Among them, F / M is the food-microorganism ratio, Q is the influent flow rate, BOD5 is the BOD5 value of the influent, Va is the effective volume of the MBR membrane pool, and MLSS is the activated sludge concentration in the MBR membrane pool; When the food-microorganism ratio is lower than the set food-microorganism ratio lower limit threshold, the aeration component (5) is closed; In all operation modes of step S2, by comparing the daily average concentration of activated sludge with the upper threshold of activated sludge concentration, it is determined whether sludge discharge operation is required; Activated sludge concentration upper threshold MLSS S The calculation formula is: MLSS S =Q×BOD5 / (F / M I ×Va); Among them, F / M I is the lower limit threshold of the food-micro ratio, Q is the influent flow rate, BOD5 is the BOD5 value of the influent, Va is the effective volume of the MBR membrane tank, and MLSS is the activated sludge concentration in the MBR membrane tank; When the daily average activated sludge concentration (MLSS) in the aeration tank exceeds the upper threshold value (MLSS) of activated sludge concentration S When the mud volume reaches 30%, an alarm message will be issued to indicate that mud discharge is required.

9. The intelligent modularized membrane integrated treatment method for rural domestic sewage according to claim 6 is characterized by: The low liquid level E of the MBR membrane pool (3) is not less than 20 cm above the upper surface of the MBR module (4).

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