Operation and maintenance method of aerobic granular sludge under low-temperature condition

Abstract

The invention relates to the field of sludge maintenance, in particular to an operation maintenance method for aerobic granular sludge under a low-temperature condition, which comprises the following steps: placing a sludge sample in a transparent observation box, analyzing the deformation flow sensitivity of the sludge sample based on the change condition of sludge contour characteristics, and carrying out ventilation verification; the method comprises the following steps: determining an internal passage diffusion characterization value of a sludge sample, calculating a deformation flow aggregation characterization parameter, dividing a sensitive category of the sludge sample, and controlling an aeration parameter based on the sensitive category in subsequent adaptability. The aeration parameters are adaptively adjusted, the influence of the difference between the expansion trend and the interaction on the sludge maintenance is reduced, the reliability of maintaining the sludge from different sources is improved, the sludge maintenance effect is improved, the microorganism quality is ensured, and the sludge maintenance efficiency is improved. The flocculation probability is reduced, and the forming effect of sludge particles after aeration is ensured.

Description

Technical Field

[0001] The invention relates to the field of sludge maintenance, and in particular to an operation and maintenance method of aerobic granular sludge under low temperature conditions. Background Art

[0002] With the advancement of global industrialization and urbanization, sewage treatment has become an important topic in the field of advanced environmental protection. The sewage treatment system not only needs to efficiently remove organic pollutants, nitrogen, phosphorus and other nutrients in sewage, but also ensure that the treated water quality meets strict emission standards to reduce pollution to natural water bodies. At present, aerobic sludge treatment technology is valued by people because of its high efficiency degradation ability and good sedimentation performance. Aerobic sludge treatment technology has high requirements for the maintenance process, which directly affects the final sludge treatment effect and the quality of microorganisms in the sludge. Therefore, the relevant operation and maintenance methods are valued by people.

[0003] For example, Chinese patent publication number, CN119285147A, discloses an aerobic granular sludge sewage treatment process, including the following steps: S1: ultrasonic treatment of raw sewage; S2: preliminary screening of the sewage treated with ultrasound; S3: adjusting the pH value of the sewage after screening and adding nutrients; S4: injecting the adjusted sewage into a biological reaction zone containing pre-cultured aerobic granular sludge, and performing intermittent aeration operation; S5: performing microwave treatment regularly during the biological reaction process; S6: chemical precipitation of the biologically treated sewage; S7: microfiltration of the biologically and chemically treated sewage; S8: ozone and ultraviolet light treatment of the microfiltered water; S9: terminal disinfection of the treated water; the present invention effectively promotes the formation and stabilization of aerobic granular sludge, improves the removal efficiency of pollutants such as organic matter, nitrogen and phosphorus in sewage, and ensures that the effluent water quality meets the standards.

[0004] However, there are still the following problems in the prior art The existing technology does not take into account that the difference in sludge sources leads to different sludge properties, which affects the expansion trend during sludge maintenance and the mutual aggregation caused by internal stress of the sludge. In particular, the low temperature environment aggravates the above phenomenon. If the aeration parameters are not adaptively adjusted in time, the diffusion path of oxygen in the sludge may be blocked due to expansion and stress, resulting in uneven oxygen distribution, affecting sludge maintenance and the quality of microorganisms in the sludge. Summary of the invention

[0005] To this end, the present invention provides an operation and maintenance method for aerobic granular sludge under low temperature conditions, which is used to overcome the problems in the prior art that the sludge properties are different due to the difference in sludge sources, affecting the expansion trend during the sludge maintenance process and the mutual aggregation phenomenon caused by the internal stress of the sludge, which may lead to the obstruction of the diffusion path of oxygen in the sludge under low temperature environment and the occurrence of uneven oxygen distribution, thus affecting the sludge maintenance and the quality of microorganisms in the sludge.

[0006] To achieve the above object, the present invention provides an operation and maintenance method of aerobic granular sludge under low temperature conditions, which comprises: Step S1, extracting a sludge sample from a sludge storage tank and placing it in a transparent observation box to simulate a low-temperature environment, continuously collecting side images of the transparent observation box, marking sludge contour features, and analyzing the deformation flow sensitivity of the sludge sample based on changes in the sludge contour features; Step S2, inserting a ventilation pipeline into the transparent observation box to perform ventilation verification, and determining an internal passage diffusion characterization value for the sludge sample based on the verification result; Step S3, based on the deformation flow sensitivity of the sludge sample and the internal path diffusion characterization value, calculating the deformation flow aggregation characterization parameter of the sludge sample, and classifying the sludge sample into a sensitive category to deformation flow; Step S4, transferring the sludge in the sludge storage tank to the biological reaction area after pretreatment, and controlling the aeration parameters according to the sensitive category of the sludge sample, including: According to the deformation flow aggregation characterization parameters, the aeration volume and stirring rate of the biological reaction zone are controlled, the sludge image on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and whether the stable aggregation standard is met is analyzed according to the change of the flow aggregation characteristics, so as to adjust the heat in the biological reaction zone; or, maintaining aeration parameters in the biological reaction zone; The flow aggregation characteristics include the discreteness of the sludge contour characteristics in the sludge image on the surface of the biological reaction area and the average area of ​​the sludge contour characteristics.

[0007] Furthermore, the process of marking the sludge contour features and analyzing the deformation flow sensitivity of the sludge sample based on the change of the sludge contour features includes: Record the sludge profile characteristics corresponding to the start point and the end point of the time period in the reference coordinate system; Constructing a number of reference lines perpendicular to the horizontal axis of the reference coordinate system, and determining the intersection of the reference lines and the sludge contour features as reference points; determining an average distance between reference points on each reference line during a time period, and determining a displacement velocity during the time period based on the average distance; The average displacement velocity corresponding to each time period is determined as the deformation flow sensitivity.

[0008] Further, the ventilation verification is performed, and the process of determining the internal path diffusion characterization value for the sludge sample based on the verification result includes: In each aeration cycle, gas is introduced into the sludge at a predetermined aeration flow rate to perform aeration verification; Record the maximum air pressure of the corresponding ventilation circuit during each ventilation cycle; The average value of the maximum air pressure of the ventilation circuit corresponding to each ventilation cycle is determined as the internal passage diffusion characterization value.

[0009] Furthermore, the process of calculating the deformation flow aggregation characterization parameters of the sludge sample includes: Determining a ratio of the deformation flow sensitivity to a preset deformation flow sensitivity threshold as a deformation flow factor; Determine the ratio of a preset internal pathway diffusion threshold to the internal pathway diffusion characterization value as an aggregation diffusion factor; The deformation flow factor and the aggregation diffusion factor are weighted and summed to obtain the deformation flow aggregation characterization parameter.

[0010] Furthermore, the deformation flow aggregation characterization parameter is compared with a preset deformation flow aggregation characterization parameter standard threshold value to classify the sludge sample into sensitive categories to deformation flow generation, wherein: If the deformation flow aggregation characterization parameter is greater than or equal to a preset deformation flow aggregation characterization parameter standard threshold, the sludge sample is classified as a highly sensitive category; If the deformation flow aggregation characterization parameter is less than a preset deformation flow aggregation characterization parameter standard threshold, the sludge sample is classified as a weakly sensitive category.

[0011] Further, controlling aeration parameters according to the sensitive category of the sludge sample includes: If the sludge sample is a highly sensitive category, the aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, the sludge image on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and whether the stable aggregation standard is met is analyzed according to the change of the flow aggregation characteristics, so as to adjust the heat in the biological reaction zone; If the sludge sample is of the weakly sensitive category, the aeration parameters of the biological reaction zone are maintained.

[0012] Further, controlling the aeration volume and stirring rate of the biological reaction zone according to the deformation flow aggregation characterization parameters includes: The aeration volume and stirring rate of the biological reaction zone are increased, and the increase is positively correlated with the deformation flow aggregation characterization parameters.

[0013] Furthermore, the process of collecting sludge images on the surface of the biological reaction area and extracting flow aggregation features includes: Determine a plurality of sludge contour features in the sludge image on the surface of the biological reaction zone, and determine the edge distance between each sludge contour feature and the nearest other sludge contour features; Solving the edge spacing mean value, and determining the edge spacing mean value as the discreteness of the sludge profile feature; Solve for the average area of ​​each sludge profile feature.

[0014] Furthermore, the analysis of whether the stable aggregation standard is met based on the change of the flow aggregation characteristics includes: If the aggregation conditions are met, it is determined that the stable aggregation standard is not met and the heat in the bioreaction zone is adjusted; The aggregation condition is that the discreteness of the sludge profile feature within the supervision period is less than a predetermined discreteness reference threshold value or / and the average area of ​​the sludge profile feature within the supervision period is greater than a predetermined area threshold value.

[0015] Further, adjusting the heat in the bioreaction zone includes increasing the heat in the bioreaction zone.

[0016] Compared with the prior art, the present invention places the sludge sample in a transparent observation box to simulate a low-temperature environment, analyzes the deformation flow sensitivity of the sludge sample based on the changes in the sludge contour characteristics, and performs ventilation verification to determine the internal pathway diffusion characterization value of the sludge sample, and subsequently calculates the deformation flow aggregation characterization parameters, divides the sludge sample into sensitive categories for generating deformation flow, and subsequently adaptively controls the aeration parameters based on the sensitive categories. Through the above process, the present invention takes into account the property differences caused by different sludge sources, which in turn affects the subsequent expansion trend and the mutual aggregation phenomenon caused by the internal stress of the sludge, and timely and adaptively adjusts the aeration parameters to reduce the impact of the expansion trend and the difference in interaction on sludge maintenance, improves the reliability of maintenance for sludge from different sources, improves the sludge maintenance effect, avoids water quality deterioration, ensures the quality of microorganisms, and ensures the formation effect of sludge particles after aeration.

[0017] In particular, the present invention considers obtaining the deformation flow sensitivity and internal path diffusion characterization value of the sludge sample in advance. In actual situations, different sources of sewage lead to differences in the properties of the sludge contained therein. The sludges with different properties are affected by microorganisms and the external environment to produce different sensitivities to mutual aggregation, which leads to different sludge aggregation and different diffusion paths of oxygen inside the sludge, affecting the maintenance of the sludge. For example, in some cases, the sludge is more sensitive to the influence of microorganisms and the external environment, and is prone to sludge aggregation and internal expansion. When the sludge expands, a large number of bubbles are attached to the sludge flocs, which reduces the density of the sludge. These bubbles not only increase the volume of the sludge, but also hinder the transmission of oxygen from the gas phase to the liquid phase. The presence of bubbles will increase the mass transfer resistance at the gas-liquid interface, making it difficult for oxygen to be effectively transferred to the inside of the sludge, and the sludge expansion will cause the sludge structure to become loose, and the binding force between the flocs will be weakened. This loose structure makes the transmission path of oxygen in the sludge longer, increasing the resistance to oxygen transmission. At the same time, the loose sludge structure is also prone to cause oxygen to escape on the sludge surface and cannot be effectively transferred to the microbial cells. If the aeration parameters are not adaptively changed, the oxygen penetration and diffusion are affected, which affects the growth of aerobic microorganisms, and easily leads to uneven activity of microorganisms in different areas of the sludge, affecting the maintenance effect. Therefore, the present invention considers collecting deformation flow sensitivity, which is determined based on the change of sludge contour characteristics, and characterizes the sensitivity or tendency of the current sludge to be affected to produce interaction and expansion. In addition, the present invention performs ventilation verification to determine the internal passage diffusion characterization value, and the internal passage diffusion characterization value is determined by the average of the maximum air pressure of the ventilation pipeline corresponding to each ventilation cycle, which characterizes the diffusion of oxygen in the internal passage of the sludge. By determining the deformation flow sensitivity and the internal passage diffusion characterization value, data support is provided for the subsequent classification of sensitive categories of sludge samples, thereby facilitating adaptive adjustment of aeration parameters, reducing the influence of sludge expansion trend and interaction differences on sludge maintenance, improving the reliability of maintenance for sludge from different sources, improving sludge maintenance effect, ensuring microbial quality, and ensuring the formation effect of sludge particles after aeration.

[0018] In particular, the present invention divides sensitive categories and subsequently adaptively controls aeration parameters. For the highly sensitive category, it characterizes the sensitivity of the current sludge to the deformation flow caused by the influence of microorganisms and the environment, resulting in aggregation. In this case, it is necessary to adaptively increase the aeration volume and stirring speed of the biological reaction zone to adapt to the properties of the current sludge so that the aggregation is stable, and the oxygen diffusion adapts to the diffusion channel of the current sludge to reduce the situation of uneven diffusion or hypoxia. At the same time, the adaptive adjustment also avoids excessive aeration volume, which leads to sludge aging and excessive expansion, and the impact on sludge maintenance. At the same time, under this category, since the sludge is more sensitive to microbial and environmental influences and is easy to aggregate and combine, the flow aggregation characteristics are continuously monitored, and the heat of the biological reaction zone is adjusted in time for maintenance when the flow aggregation characteristics are abnormal, thereby reducing the impact of sludge expansion trends and differences in interactions on sludge maintenance, improving the reliability of maintenance for sludge from different sources, improving the sludge maintenance effect, and ensuring the quality of microorganisms. At the same time, since the sludge maintenance volume is generally large, selectively increasing the heat of the biological reaction zone can effectively save energy.

[0019] In particular, for the weakly sensitive category, which is not sensitive to microbial and environmental influences, is not easy to aggregate, and the diffusion path of oxygen in the sludge is relatively smooth, so the aeration parameters are maintained to ensure the maintenance effect of the sludge. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the steps of the operation and maintenance method of aerobic granular sludge under low temperature conditions according to an embodiment of the invention; Figure 2 A logic block diagram for classifying sludge samples into sensitive categories for generating deformation flow according to an embodiment of the invention; Figure 3 A logic block diagram of controlling aeration parameters according to the sensitive category of sludge samples according to an embodiment of the invention; Figure 4 This is a logic block diagram of an embodiment of the invention for analyzing whether changes in flow aggregation characteristics meet stable aggregation standards. 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 Figures 1 to 4 As shown, Figure 1 This is a schematic diagram of the steps of the operation and maintenance method of aerobic granular sludge under low temperature conditions according to an embodiment of the invention. Figure 2 The logic block diagram of the embodiment of the invention for classifying the sludge samples into sensitive categories for generating deformation flow is shown in FIG. Figure 3 This is a logic block diagram of controlling aeration parameters according to the sensitive category of sludge samples according to an embodiment of the invention. Figure 4 This is a logic block diagram of analyzing whether the stable aggregation standard is met according to the change of the flow aggregation characteristics of the embodiment of the invention. The operation and maintenance method of aerobic granular sludge under low temperature conditions of the present invention includes: Step S1, extracting a sludge sample from a sludge storage tank and placing it in a transparent observation box to simulate a low-temperature environment, continuously collecting side images of the transparent observation box, marking sludge contour features, and analyzing the deformation flow sensitivity of the sludge sample based on changes in the sludge contour features; Step S2, inserting a ventilation pipeline into the transparent observation box to perform ventilation verification, and determining an internal passage diffusion characterization value for the sludge sample based on the verification result; Step S3, based on the deformation flow sensitivity of the sludge sample and the internal path diffusion characterization value, calculating the deformation flow aggregation characterization parameter of the sludge sample, and classifying the sludge sample into a sensitive category to deformation flow; Step S4, transferring the sludge in the sludge storage tank to the biological reaction area after pretreatment, and controlling the aeration parameters according to the sensitive category of the sludge sample, including: According to the deformation flow aggregation characterization parameters, the aeration volume and stirring rate of the biological reaction zone are controlled, the sludge image on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and whether the stable aggregation standard is met is analyzed according to the change of the flow aggregation characteristics, so as to adjust the heat in the biological reaction zone; or, maintaining aeration parameters in the biological reaction zone; The flow aggregation characteristics include the discreteness of the sludge contour characteristics in the sludge image on the surface of the biological reaction area and the average area of ​​the sludge contour characteristics.

[0026] Specifically, the present invention does not impose any specific limitation on the structure of the transparent observation box, which only needs to provide a space for accommodating sludge samples. In practice, a transparent glass plate can be used to construct a cube with an opening on one side for placing sludge samples as a transparent observation box, which will not be described in detail.

[0027] Specifically, there is no limitation on the method of collecting the side image of the observation box, and a photographic device may be used to capture the side image of the observation box, which will not be described in detail here.

[0028] Specifically, there is no limitation on the specific method of identifying sludge contour features. For example, it can be implemented using existing image processing algorithms, such as image segmentation algorithms, etc. Technical personnel in this field can also train image processing models that can implement corresponding functions by themselves, and implement corresponding functions after importing logical components. Logical components include field programmable processors, computers, or microprocessors in computers.

[0029] Specifically, there is no limitation on the specific structure of the biological reaction zone. It can be understood that the biological reaction zone only needs to provide a storage space for sludge maintenance. The core structure in the storage space of the biological reaction zone is an aeration device, which can aerate the sludge and provide sufficient dissolved oxygen so that the microorganisms react to form aerobic sludge particles. At the same time, a stirring device can be set in the biological reaction zone to facilitate the combination of oxygen and sludge. Those skilled in the art can adopt any aeration device and stirring device in the prior art that can achieve the corresponding functions, as long as they can meet the remote control requirements. This will not be repeated.

[0030] Specifically, there is no limitation on the method of obtaining the sludge image on the surface of the biological reaction zone, and the sludge image on the surface of the biological reaction zone can be obtained by installing an overhead photographic device, which will not be described in detail here.

[0031] Specifically, there is no limitation on the specific method of simulating a low-temperature environment. The required temperature for simulation can be determined based on the temperature in the current biological reaction area. When simulating a low-temperature environment, a transparent observation box can be placed in a constant temperature box. The required temperature can be simulated by adjusting the temperature of the constant temperature box. Of course, other methods can also be used, which will not be repeated here.

[0032] Specifically, there is no limitation on the method of pre-treating the sludge in the sludge storage tank. The pre-treatment generally includes concentrating the sludge by sedimentation or centrifugation, improving the flocculation performance of the sludge by adding flocculants, inoculating microorganisms, etc., which will not be elaborated here.

[0033] Specifically, the process of marking the sludge contour features and analyzing the deformation flow sensitivity of the sludge sample based on the changes in the sludge contour features includes: Record the sludge profile characteristics corresponding to the start point and the end point of the time period in the reference coordinate system; Constructing a number of reference lines perpendicular to the horizontal axis of the reference coordinate system, and determining the intersection of the reference lines and the sludge contour features as reference points; Determine the average distance between the reference points on each reference line within the time period, and determine the displacement speed of the time period based on the average distance. It can be understood that the sludge contour features corresponding to the starting point and the end point of the period are constructed in the reference coordinate system. Due to the interaction within the sludge, the sludge contour features change, which in turn causes the two sludge contour features to not overlap, and at least two reference points are generated on a single reference line.

[0034] The average displacement velocity corresponding to each time period is determined as the deformation flow sensitivity.

[0035] It is understood that the spacing between the reference lines should be equal.

[0036] It will be appreciated that displacement velocity is the ratio of average distance to time period.

[0037] In practice, the purpose of setting the time period is to observe the changes in the sludge samples, so the time period should not be too short. Preferably, the time period should be greater than 48 hours.

[0038] Specifically, the process of performing ventilation verification and determining the internal path diffusion characterization value for the sludge sample based on the verification result includes: In each aeration cycle, gas is introduced into the sludge at a predetermined aeration flow rate to perform aeration verification; Record the maximum air pressure of the corresponding ventilation circuit during each ventilation cycle; The average value of the maximum air pressure of the ventilation circuit corresponding to each ventilation cycle is determined as the internal passage diffusion characterization value.

[0039] In implementation, the ventilation cycle is set to 10s, the ventilation flow rate in each ventilation cycle remains unchanged, and there is no limitation on the method of obtaining the air pressure in the ventilation pipeline. A pressure gauge can be set to obtain the air pressure in the pipeline in real time. Of course, other methods in the prior art can also be used, which will not be repeated here.

[0040] The present invention considers obtaining the deformation flow sensitivity and internal path diffusion characterization value of the sludge sample in advance. In actual situations, different sewage sources lead to differences in the properties of the sludge contained therein. The sludges under different properties are affected by microorganisms and the external environment to produce different sensitivities to mutual aggregation, which leads to different aggregation of sludge and different diffusion paths of oxygen inside the sludge, affecting the maintenance of the sludge. For example, in some cases, the sludge is more sensitive to the influence of microorganisms and the external environment, and is prone to sludge aggregation and internal expansion. When the sludge expands, a large number of bubbles are attached to the sludge flocs, which reduces the density of the sludge. These bubbles not only increase the volume of the sludge, but also hinder the transmission of oxygen from the gas phase to the liquid phase. The presence of bubbles will increase the mass transfer resistance of the gas-liquid interface, making it difficult for oxygen to be effectively transferred to the inside of the sludge, and the sludge expansion will cause the sludge structure to become loose, and the binding force between the flocs will be weakened. This loose structure makes the transmission path of oxygen in the sludge longer, increasing the resistance to oxygen transmission. At the same time, the loose sludge structure is also prone to cause oxygen to escape on the sludge surface and cannot be effectively transferred to the microbial cells. If the aeration parameters are not adaptively changed, the oxygen penetration and diffusion are affected, which affects the growth of aerobic microorganisms, and easily leads to uneven activity of microorganisms in different areas of the sludge, affecting the maintenance effect. Therefore, the present invention considers collecting deformation flow sensitivity, which is determined based on the change of sludge contour characteristics, and characterizes the sensitivity or tendency of the current sludge to be affected to produce interaction and expansion. In addition, the present invention performs ventilation verification to determine the internal passage diffusion characterization value, and the internal passage diffusion characterization value is determined by the average of the maximum air pressure of the ventilation pipeline corresponding to each ventilation cycle, which characterizes the diffusion of oxygen in the internal passage of the sludge. By determining the deformation flow sensitivity and the internal passage diffusion characterization value, data support is provided for the subsequent classification of sensitive categories of sludge samples, thereby facilitating adaptive adjustment of aeration parameters, reducing the influence of sludge expansion trend and interaction differences on sludge maintenance, improving the reliability of maintenance for sludge from different sources, improving sludge maintenance effect, ensuring microbial quality, and ensuring the formation effect of sludge particles after aeration.

[0041] Specifically, the process of calculating the deformation flow aggregation characterization parameters of the sludge sample includes: Determining a ratio of the deformation flow sensitivity to a preset deformation flow sensitivity threshold as a deformation flow factor; Determine the ratio of a preset internal pathway diffusion threshold to the internal pathway diffusion characterization value as an aggregation diffusion factor; The deformation flow factor and the aggregation diffusion factor are weighted and summed to obtain the deformation flow aggregation characterization parameter.

[0042] The weight for the deformation flow factor is 0.45, and the weight for the aggregation diffusion factor is 0.55.

[0043] Specifically, the deformation flow sensitivity threshold and the internal pathway diffusion characterization value are pre-set, wherein several sludge samples from different sources are tested in advance, the corresponding deformation flow sensitivity and the internal pathway diffusion characterization value are recorded, the deformation flow sensitivity mean and the internal pathway diffusion characterization value mean are solved, the deformation flow sensitivity threshold is set to the product of the deformation flow sensitivity mean and the deformation flow precision coefficient, the deformation flow precision coefficient is selected within the interval [1.15, 1.3], the internal pathway diffusion characterization value is set to the product of the internal pathway diffusion characterization value mean and the internal pathway diffusion precision coefficient, the internal pathway diffusion precision coefficient is selected within the interval [1.25, 1.5].

[0044] Specifically, the deformation flow aggregation characterization parameter is compared with a preset deformation flow aggregation characterization parameter standard threshold value to classify the sludge sample into sensitive categories to deformation flow, wherein: If the deformation flow aggregation characterization parameter is greater than or equal to a preset deformation flow aggregation characterization parameter standard threshold, the sludge sample is classified as a highly sensitive category; If the deformation flow aggregation characterization parameter is less than a preset deformation flow aggregation characterization parameter standard threshold, the sludge sample is classified as a weakly sensitive category.

[0045] Specifically, in the implementation, the standard threshold of the deformation flow aggregation characterization parameter is selected within the interval [1.25, 1.35].

[0046] Specifically, the aeration parameters controlled according to the sensitive category of the sludge sample include: If the sludge sample is a highly sensitive category, the aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, the sludge image on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and whether the stable aggregation standard is met is analyzed according to the change of the flow aggregation characteristics, so as to adjust the heat in the biological reaction zone; If the sludge sample is of the weakly sensitive category, the aeration parameters of the biological reaction zone are maintained.

[0047] It is understandable that aeration parameters include aeration volume and stirring rate, which will not be elaborated here.

[0048] Specifically, the aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, including: The aeration volume and stirring rate of the biological reaction zone are increased, and the increase is positively correlated with the deformation flow aggregation characterization parameters.

[0049] In implementation, optionally, The deformation flow aggregation characterization parameter is compared with a preset first deformation flow aggregation reference threshold and a second deformation flow aggregation reference threshold, wherein: If the deformation flow aggregation characterization parameter is greater than or equal to the second deformation flow aggregation reference threshold, the aeration volume of the biological reaction zone is increased to between 1.5 and 1.6 times the initial aeration volume, and the stirring speed is increased to between 1.65 and 1.75 times the initial stirring speed; If the deformation flow aggregation characterization parameter is greater than the first deformation flow aggregation reference threshold and the deformation flow aggregation characterization parameter is less than the second deformation flow aggregation reference threshold, the aeration volume of the biological reaction zone is increased to between 1.3 and 1.4 times the initial aeration volume, and the stirring speed is increased to between 1.45 and 1.55 times the initial stirring speed; If the deformation flow aggregation characterization parameter is less than or equal to the first deformation flow aggregation reference threshold, the aeration volume of the biological reaction zone is increased to between 1.1 and 1.2 times the initial aeration volume, and the stirring speed is increased to between 1.25 and 1.35 times the initial stirring speed; Among them, the first deformation flow aggregation reference threshold is 1.25 times the standard threshold of the deformation flow aggregation characterization parameter, and the second deformation flow aggregation reference threshold is 1.5 times the standard threshold of the deformation flow aggregation characterization parameter.

[0050] Specifically, the process of collecting sludge images on the surface of the biological reaction area and extracting flow aggregation features includes: Determine a plurality of sludge contour features in the sludge image on the surface of the biological reaction zone, and determine the edge distance between each sludge contour feature and the nearest other sludge contour features; Solving the edge spacing mean value, and determining the edge spacing mean value as the discreteness of the sludge profile feature; Solve for the average area of ​​each sludge profile feature.

[0051] It can be understood that the edge spacing is the minimum spacing between sludge contour features. By solving the mean value of the edge spacing, the aggregation of the sludge can be quickly determined and the discreteness of the sludge contour features can be characterized.

[0052] Specifically, the analysis of whether the stable aggregation standards are met based on the changes in the flow aggregation characteristics includes: If the aggregation conditions are met, it is determined that the stable aggregation standard is not met and the heat in the bioreaction zone is adjusted; The aggregation condition is that the discreteness of the sludge profile feature within the supervision period is less than a predetermined discreteness reference threshold value or / and the average area of ​​the sludge profile feature within the supervision period is greater than a predetermined area threshold value.

[0053] Specifically, the discreteness reference threshold and the area threshold are predetermined. The technicians in this field collect sludge images of the surface of the biological reaction area without abnormal conditions during several maintenance processes in advance, determine the discreteness of the sludge profile features and the average area of ​​the sludge profile features in each supervision cycle, and solve the mean value of the discreteness of the sludge profile features and the mean value of the average area of ​​the sludge profile features. The discreteness reference threshold is set as the product of the discreteness mean of the sludge profile feature and the offset coefficient, and the area threshold is set as the product of the mean of the average area of ​​the sludge profile feature and the offset coefficient. The offset coefficient is selected in the interval [1.5, 2].

[0054] Specifically, the supervision period can be selected in the interval [6h, 12h] to observe the changes in the flow aggregation characteristics.

[0055] The present invention divides sensitive categories and then adaptively controls aeration parameters. For the highly sensitive category, it characterizes the sensitivity of the current sludge to the deformation flow caused by the influence of microorganisms and the environment, resulting in aggregation. In this case, it is necessary to adaptively increase the aeration volume and stirring speed of the biological reaction zone to adapt to the properties of the current sludge so as to stabilize the aggregation. Moreover, at the microscopic level, the oxygen diffusion adapts to the diffusion channel of the current sludge to reduce the situation of uneven diffusion or hypoxia. At the same time, the adaptive adjustment also avoids excessive aeration volume, which leads to sludge aging and excessive expansion, and the impact on sludge maintenance. At the same time, under this category, since the sludge is more sensitive to microbial and environmental influences and is easy to aggregate and combine, the flow aggregation characteristics are continuously monitored, and the heat of the biological reaction zone is adjusted in time for maintenance when the flow aggregation characteristics are abnormal, thereby reducing the impact of sludge expansion trends and differences in interactions on sludge maintenance, improving the reliability of maintenance for sludge from different sources, improving the sludge maintenance effect, and ensuring the quality of microorganisms. At the same time, since the sludge maintenance volume is generally large, selectively increasing the heat of the biological reaction zone can effectively save energy.

[0056] Specifically, adjusting the heat in the bioreaction zone includes increasing the heat in the bioreaction zone.

[0057] Specifically, it is understandable that when heat is added, the heat gradient increases to avoid stimulation of microorganisms. Since the suitable temperature of aerobic sludge is generally between 15°C and 30°C, and below 20°C is a relatively low temperature, and the aerobic tank is usually around 20°C, the temperature increase can be controlled within 5°C. By moderately raising the temperature, the aggregation tendency of the sludge can be reduced, excessive energy consumption can be avoided, and the microorganisms in the link can be ensured to be at a suitable temperature.

[0058] Specifically, there is no limitation on the method of controlling the temperature of the biological reaction zone. A temperature control system is usually provided in the biological reaction zone to adjust the temperature in the biological reaction zone. This is a prior art and will not be described in detail.

[0059] For the weakly sensitive category, it is not sensitive to microbial and environmental influences, is not easy to aggregate, and the diffusion path of oxygen in the sludge is relatively smooth, so the aeration parameters are maintained to ensure the maintenance effect of the sludge.

[0060] Taking a sludge maintenance process as an example, the deformation flow aggregation characterization parameter obtained from the sludge sample collection is 1.7, and the standard threshold value of the deformation flow aggregation characterization parameter set in the implementation is 1.35, so the sludge sample is a highly sensitive category; In the implementation, the second deformation flow aggregation reference threshold is set to 2.025, and the first deformation flow aggregation reference threshold is set to 1.688. If the deformation flow aggregation characterization parameter is greater than the first deformation flow aggregation reference threshold and less than the second deformation flow aggregation reference threshold, the aeration volume of the biological reaction zone is increased to 1.3 times the initial aeration volume, and the stirring speed is increased to 1.45 times the initial stirring speed; Subsequently, the flow aggregation characteristics were extracted, and the discreteness of the collected sludge contour characteristics was 30cm, which was larger than the discreteness benchmark threshold of 20cm. The average area of ​​the sludge contour characteristics was 1.35m², which was smaller than the area threshold of 2m², and it was determined to meet the stable aggregation standards.

[0061] 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.

Claims

1. An operation and maintenance method of aerobic granular sludge under low temperature conditions, characterized in that: include: Step S1, extracting a sludge sample from a sludge storage tank and placing it in a transparent observation box to simulate a low-temperature environment, continuously collecting side images of the transparent observation box, marking sludge contour features, and analyzing the deformation flow sensitivity of the sludge sample based on changes in the sludge contour features; Step S2, inserting a ventilation pipeline into the transparent observation box to perform ventilation verification, and determining an internal passage diffusion characterization value for the sludge sample based on the verification result; Step S3, based on the deformation flow sensitivity of the sludge sample and the internal path diffusion characterization value, calculating the deformation flow aggregation characterization parameter of the sludge sample, and classifying the sludge sample into a sensitive category to deformation flow; Step S4, transferring the sludge in the sludge storage tank to the biological reaction area after pretreatment, and controlling the aeration parameters according to the sensitive category of the sludge sample, including: According to the deformation flow aggregation characterization parameters, the aeration volume and stirring rate of the biological reaction zone are controlled, the sludge image on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and whether the stable aggregation standard is met is analyzed according to the change of the flow aggregation characteristics, so as to adjust the heat in the biological reaction zone; or, maintaining aeration parameters in the biological reaction zone; The flow aggregation characteristics include the discreteness of the sludge contour characteristics in the sludge image on the surface of the biological reaction area and the average area of ​​the sludge contour characteristics.

2. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: The process of marking the sludge contour features and analyzing the deformation flow sensitivity of the sludge sample based on the change of the sludge contour features includes: Record the sludge profile characteristics corresponding to the start point and the end point of the time period in the reference coordinate system; Constructing a number of reference lines perpendicular to the horizontal axis of the reference coordinate system, and determining the intersection of the reference lines and the sludge contour features as reference points; determining an average distance between reference points on each reference line during a time period, and determining a displacement velocity during the time period based on the average distance; The average displacement velocity corresponding to each time period is determined as the deformation flow sensitivity.

3. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: The process of performing aeration verification and determining the internal path diffusion characterization value for the sludge sample based on the verification result includes: In each aeration cycle, gas is introduced into the sludge at a predetermined aeration flow rate to perform aeration verification; Record the maximum air pressure of the corresponding ventilation circuit during each ventilation cycle; The average value of the maximum air pressure of the ventilation circuit corresponding to each ventilation cycle is determined as the internal passage diffusion characterization value.

4. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: The process of calculating the deformation flow aggregation characterization parameters of the sludge sample includes: Determining a ratio of the deformation flow sensitivity to a preset deformation flow sensitivity threshold as a deformation flow factor; Determine the ratio of a preset internal pathway diffusion threshold to the internal pathway diffusion characterization value as an aggregation diffusion factor; The deformation flow factor and the aggregation diffusion factor are weighted and summed to obtain the deformation flow aggregation characterization parameter.

5. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: The deformation flow aggregation characterization parameter is compared with a preset deformation flow aggregation characterization parameter standard threshold value to classify the sludge sample into sensitive categories to deformation flow, wherein: If the deformation flow aggregation characterization parameter is greater than or equal to a preset deformation flow aggregation characterization parameter standard threshold, the sludge sample is classified as a highly sensitive category; If the deformation flow aggregation characterization parameter is less than a preset deformation flow aggregation characterization parameter standard threshold, the sludge sample is classified as a weakly sensitive category.

6. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 5, characterized in that: The aeration parameters controlled according to the sensitivity category of the sludge sample include, If the sludge sample is a highly sensitive category, the aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, the sludge image on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and whether the stable aggregation standard is met is analyzed according to the change of the flow aggregation characteristics, so as to adjust the heat in the biological reaction zone; If the sludge sample is of the weakly sensitive category, the aeration parameters of the biological reaction zone are maintained.

7. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: Controlling the aeration volume and stirring rate of the biological reaction zone according to the deformation flow aggregation characterization parameters includes: The aeration volume and stirring rate of the biological reaction zone are increased, and the increase is positively correlated with the deformation flow aggregation characterization parameters.

8. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: The process of collecting sludge images on the surface of the biological reaction area and extracting flow aggregation characteristics includes: Determine a plurality of sludge contour features in the sludge image on the surface of the biological reaction zone, and determine the edge distance between each sludge contour feature and the nearest other sludge contour features; Solving the edge spacing mean value, and determining the edge spacing mean value as the discreteness of the sludge profile feature; Solve for the average area of ​​each sludge profile feature.

9. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: Analyzing whether the stable aggregation standards are met based on the changes in the flow aggregation characteristics includes: If the aggregation conditions are met, it is determined that the stable aggregation standard is not met and the heat in the bioreaction zone is adjusted; The aggregation condition is that the discreteness of the sludge profile feature within the supervision period is less than a predetermined discreteness reference threshold value or / and the average area of ​​the sludge profile feature within the supervision period is greater than a predetermined area threshold value.

10. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: Adjusting the heat within the bioreaction zone includes increasing the heat within the bioreaction zone.

Images