An operation and maintenance method for aerobic granular sludge under low temperature conditions

Abstract

The present invention relates to the field of sludge maintenance, and in particular to an operation and maintenance method for aerobic granular sludge under low-temperature conditions. The method comprises placing a sludge sample in a transparent observation box, analyzing the deformation flow sensitivity of the sludge sample based on changes in sludge contour characteristics, performing ventilation verification, determining the internal pathway diffusion characterization value of the sludge sample, calculating the deformation flow aggregation characterization parameter, dividing the sludge sample into sensitive categories, and subsequently adaptively controlling aeration parameters based on the sensitive categories. The above process takes into account the property differences caused by different sludge sources, thereby affecting the subsequent expansion trend and the mutual aggregation phenomenon caused by the internal stress of the sludge, adaptively adjusting the aeration parameters, reducing the influence of the expansion trend and the interaction difference on sludge maintenance, improving the reliability of maintenance for sludge from different sources, improving the sludge maintenance effect, ensuring the quality of microorganisms, reducing the probability of flocculence, and ensuring the formation effect of sludge particles after aeration.

Description

Technical Field

[0001] The present 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, wastewater treatment has become a key issue in the field of advanced environmental protection. Wastewater treatment systems must not only efficiently remove organic pollutants, nitrogen, phosphorus, and other nutrients from wastewater, but also ensure that the treated water quality meets strict emission standards to reduce pollution to natural water bodies. Currently, aerobic sludge treatment technology is valued for its efficient degradation capabilities and excellent sedimentation performance. However, aerobic sludge treatment technology has high maintenance requirements, which directly affect the final sludge treatment results and the quality of the microorganisms in the sludge. Therefore, related operation and maintenance methods are valued.

[0003] For example, Chinese patent publication number CN119285147A discloses an aerobic granular sludge sewage treatment process, which includes the following steps: S1: ultrasonic treatment of raw sewage; S2: preliminary screening of the ultrasonically treated sewage; S3: adjusting the pH value of the screened sewage 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, the prior art still has the following problems

[0005] The existing technology does not take into account the differences in sludge sources, which lead to different sludge properties, affecting the expansion trend during sludge maintenance and the mutual aggregation phenomenon caused by internal stress of the sludge. In particular, the low temperature environment exacerbates 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 the influence of expansion and stress, resulting in uneven oxygen distribution, affecting sludge maintenance and the quality of microorganisms in the sludge. Summary of the Invention

[0006] 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 differences in the 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 oxygen diffusion path inside the sludge under low temperature environment and the occurrence of uneven oxygen distribution, thereby affecting the sludge maintenance and the quality of microorganisms in the sludge.

[0007] To achieve the above objectives, the present invention provides an operation and maintenance method for aerobic granular sludge under low temperature conditions, which comprises:

[0008] 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 capturing 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.

[0009] Step S2, inserting a ventilation pipe into the transparent observation box to perform ventilation verification, and determining an internal path diffusion characterization value for the sludge sample based on the verification result;

[0010] Step S3, calculating deformation flow aggregation characterization parameters of the sludge sample based on the deformation flow sensitivity and internal path diffusion characterization value of the sludge sample, and classifying the sludge sample into sensitive categories to deformation flow;

[0011] Step S4, transferring the sludge in the sludge storage tank to the biological reaction zone after pretreatment, and controlling the aeration parameters according to the sensitivity category of the sludge sample, including:

[0012] The aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, sludge images on the surface of the biological reaction zone are collected, flow aggregation characteristics are extracted, and whether the flow aggregation characteristics meet the stable aggregation standards is analyzed according to the changes in the flow aggregation characteristics, so as to adjust the heat in the biological reaction zone;

[0013] or, maintaining aeration parameters in the biological reaction zone;

[0014] 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.

[0015] Furthermore, the process of marking the sludge profile features and analyzing the deformation flow sensitivity of the sludge sample based on the changes in the sludge profile features includes:

[0016] Record the sludge profile characteristics corresponding to the starting point and the ending point of the time period in the reference coordinate system;

[0017] Constructing several 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;

[0018] 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;

[0019] The average displacement velocity corresponding to each time period is determined as the deformation flow sensitivity.

[0020] Furthermore, 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:

[0021] In each aeration cycle, gas is introduced into the sludge at a predetermined aeration flow rate to perform aeration verification;

[0022] Record the maximum air pressure of the corresponding ventilation circuit during each ventilation cycle;

[0023] The average value of the maximum air pressure of the ventilation line corresponding to each ventilation cycle is determined as the internal passage diffusion characterization value.

[0024] Furthermore, the process of calculating the deformation flow aggregation characterization parameters of the sludge sample includes:

[0025] Determining a ratio of the deformation flow sensitivity to a preset deformation flow sensitivity threshold as a deformation flow factor;

[0026] determining a ratio of a preset internal pathway diffusion threshold to the internal pathway diffusion characterization value as an aggregation diffusion factor;

[0027] The deformation flow factor and the aggregation diffusion factor are weighted and summed to obtain the deformation flow aggregation characterization parameter.

[0028] 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, wherein:

[0029] 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;

[0030] 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.

[0031] Furthermore, controlling aeration parameters according to the sensitivity category of the sludge sample includes:

[0032] If the sludge sample is a highly sensitive type, the aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, an image of the sludge on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and the change in the flow aggregation characteristics is analyzed to determine whether it meets the stable aggregation standard, so as to adjust the heat in the biological reaction zone;

[0033] If the sludge sample is of the weakly sensitive category, the aeration parameters of the biological reaction zone are maintained.

[0034] Furthermore, controlling the aeration volume and stirring rate of the biological reaction zone according to the deformation flow aggregation characterization parameters includes:

[0035] Increasing the aeration volume and stirring rate in the biological reaction zone is positively correlated with the deformation flow aggregation characterization parameters.

[0036] Furthermore, the process of collecting sludge images on the surface of the biological reaction area and extracting flow aggregation features includes:

[0037] Determining a plurality of sludge contour features in the sludge image on the surface of the biological reaction zone, and determining the edge distance between each sludge contour feature and the nearest other sludge contour features;

[0038] Calculating the mean value of the edge spacing, and determining the mean value of the edge spacing as the discreteness of the sludge profile feature;

[0039] Calculate the average area of each sludge profile feature.

[0040] Furthermore, the analysis of whether the stable aggregation standard is met based on the changes in the flow aggregation characteristics includes:

[0041] 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;

[0042] The aggregation condition is that the discreteness of the sludge profile feature within the supervision period is less than a predetermined discreteness reference threshold and / or the average area of the sludge profile feature within the supervision period is greater than a predetermined area threshold.

[0043] Furthermore, adjusting the heat in the bioreaction zone includes increasing the heat in the bioreaction zone.

[0044] 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. Subsequently, the deformation flow aggregation characterization parameters are calculated, and the sludge sample is divided into sensitive categories for generating deformation flow. Subsequently, the aeration parameters are adaptively controlled 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 interaction differences on sludge maintenance, thereby improving the reliability of maintenance for sludge from different sources, improving the sludge maintenance effect, avoiding water quality deterioration, ensuring microbial quality, and ensuring the formation effect of sludge particles after aeration.

[0045] 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. Sludges with different properties are affected by microorganisms and the external environment and have different sensitivities to mutual aggregation, which in turn 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 adhere to the sludge flocs, reducing 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 interior of the sludge, and 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 also easily causes oxygen to escape from the sludge surface and be unable to be effectively transferred to the microbial cells. If the aeration parameters are not changed adaptively, the oxygen penetration and diffusion will be affected, affecting the growth of aerobic microorganisms, which can easily lead to uneven activity of microorganisms in different areas of the sludge, affecting the maintenance effect. Therefore, the present invention considers collecting deformation flow sensitivity. This parameter is determined based on the changes in the sludge profile characteristics and characterizes the sensitivity or tendency of the current sludge to be affected by the interaction and expansion. In addition, the present invention performs ventilation verification to determine the internal path diffusion characterization value. The internal path 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 path of the sludge. By determining the deformation flow sensitivity and the internal path diffusion characterization value, data support is provided for the subsequent classification of the sensitive categories of sludge samples, thereby facilitating the adaptive adjustment of aeration parameters, reducing the impact of sludge expansion trends and interaction differences on sludge maintenance, improving the reliability of maintenance for sludge from different sources, improving the sludge maintenance effect, ensuring microbial quality, and ensuring the formation effect of sludge particles after aeration.

[0046] In particular, the present invention divides sludge into sensitive categories and subsequently adaptively controls aeration parameters. For the highly sensitive category, this characterizes the sensitivity of the current sludge to deformation and flow caused by microbial and environmental influences, leading to aggregation. In this case, the aeration volume and stirring speed in the biological reaction zone need to be adaptively increased to adapt to the current sludge properties and stabilize aggregation. In addition, oxygen diffusion should be adapted to the current sludge diffusion channels to reduce uneven diffusion or hypoxia. At the same time, adaptive adjustment also avoids excessive aeration volume, which leads to sludge aging and excessive expansion, which affects sludge maintenance. At the same time, in this category, because the sludge is more sensitive to microbial and environmental influences and is prone to aggregation, the flow and aggregation characteristics are continuously monitored. When the flow and aggregation characteristics are abnormal, the heat of the biological reaction zone is promptly adjusted for maintenance. In this way, the impact of sludge expansion trends and interaction differences on sludge maintenance is reduced, the reliability of maintenance for sludge from different sources is improved, the sludge maintenance effect is improved, and the microbial quality is guaranteed. At the same time, because the sludge maintenance volume is generally large, selectively increasing the heat of the biological reaction zone can effectively save energy.

[0047] In particular, for the weakly sensitive category, this category is not sensitive to microbial and environmental influences, is not easy to aggregate, and the oxygen diffusion path inside the sludge is relatively smooth, so the aeration parameters are maintained to ensure the maintenance effect of the sludge. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] 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;

[0049] Figure 2 A logic block diagram for classifying sludge samples into sensitive categories to deformation flow according to an embodiment of the present invention;

[0050] Figure 3 A logic block diagram of controlling aeration parameters according to the sensitivity category of sludge samples according to an embodiment of the present invention;

[0051] Figure 4 This is a logic diagram of an embodiment of the present invention for analyzing whether changes in flow aggregation characteristics meet stable aggregation standards. DETAILED DESCRIPTION

[0052] 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 merely used to explain the present invention and are not intended to limit the present invention.

[0053] 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 scope of protection of the present invention.

[0054] 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 accompanying drawings. This is only 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.

[0055] Furthermore, it should be noted that, in the description of the present invention, 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.

[0056] 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 This is a logic diagram for classifying sludge samples into sensitive categories that are sensitive to deformation flow according to an embodiment of the invention. Figure 3 This is a logic block diagram of controlling aeration parameters according to the sensitivity 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 the stable aggregation standard is met based on the change of flow aggregation characteristics. The operation and maintenance method of aerobic granular sludge under low temperature conditions of the present invention includes:

[0057] 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 capturing 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.

[0058] Step S2, inserting a ventilation pipe into the transparent observation box to perform ventilation verification, and determining an internal path diffusion characterization value for the sludge sample based on the verification result;

[0059] Step S3, calculating deformation flow aggregation characterization parameters of the sludge sample based on the deformation flow sensitivity and internal path diffusion characterization value of the sludge sample, and classifying the sludge sample into sensitive categories to deformation flow;

[0060] Step S4, transferring the sludge in the sludge storage tank to the biological reaction zone after pretreatment, and controlling the aeration parameters according to the sensitivity category of the sludge sample, including:

[0061] The aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, sludge images on the surface of the biological reaction zone are collected, flow aggregation characteristics are extracted, and whether the flow aggregation characteristics meet the stable aggregation standards is analyzed according to the changes in the flow aggregation characteristics, so as to adjust the heat in the biological reaction zone;

[0062] or, maintaining aeration parameters in the biological reaction zone;

[0063] 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.

[0064] Specifically, the present invention does not impose any specific restrictions on the structure of the transparent observation box. It 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 the transparent observation box. This will not be repeated here.

[0065] Specifically, there is no limitation on the method of collecting the side image of the observation box. A photographic device may be used to capture the side image of the observation box, which will not be described in detail here.

[0066] 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. Those skilled in the art can also train image processing models that can implement corresponding functions on their own, and implement corresponding functions after importing logical components. The logical components include field programmable processors, computers, or microprocessors in computers.

[0067] 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 of the storage space of the biological reaction zone is an aeration device, which can aerate the sludge and provide sufficient dissolved oxygen to enable microbial reactions 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 existing technology that can achieve the corresponding functions, as long as they can meet the remote control requirements. This will not be repeated.

[0068] Specifically, there is no limitation on the method of obtaining the sludge image on the surface of the biological reaction zone. The sludge image on the surface of the biological reaction zone can be obtained by using an overhead photography device, which will not be described in detail here.

[0069] 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, and 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.

[0070] Specifically, there is no limitation on the method of pre-treating the sludge in the sludge storage tank. 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.

[0071] Specifically, the process of marking sludge contour features and analyzing the deformation flow sensitivity of the sludge sample based on the changes in the sludge contour features includes:

[0072] Record the sludge profile characteristics corresponding to the starting point and the ending point of the time period in the reference coordinate system;

[0073] Constructing several 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;

[0074] 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.

[0075] The average displacement velocity corresponding to each time period is determined as the deformation flow sensitivity.

[0076] It is understood that the spacing between the reference lines should be equal.

[0077] It can be understood that the displacement speed is the ratio of the average distance to the time period.

[0078] In practice, the purpose of setting the time period is to observe the changes in the sludge sample, so the time period should not be too short. Preferably, the time period should be greater than 48 hours.

[0079] 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:

[0080] In each aeration cycle, gas is introduced into the sludge at a predetermined aeration flow rate to perform aeration verification;

[0081] Record the maximum air pressure of the corresponding ventilation circuit during each ventilation cycle;

[0082] The average value of the maximum air pressure of the ventilation line corresponding to each ventilation cycle is determined as the internal passage diffusion characterization value.

[0083] 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 existing technology can also be used, which will not be repeated here.

[0084] The present invention considers obtaining the deformation flow sensitivity and internal path diffusion characterization value of the sludge sample in advance. In actual conditions, different sources of sewage lead to differences in the properties of the sludge contained therein. Sludges with different properties are affected by microorganisms and the external environment to produce different sensitivities to mutual aggregation, which in turn 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 adhere to the sludge flocs, reducing 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 interior of the sludge, and 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 also easily causes oxygen to escape from the sludge surface and be unable to be effectively transferred to the microbial cells. If the aeration parameters are not changed adaptively, the oxygen penetration and diffusion will be affected, affecting the growth of aerobic microorganisms, which can easily lead to uneven activity of microorganisms in different areas of the sludge, affecting the maintenance effect. Therefore, the present invention considers collecting deformation flow sensitivity. This parameter is determined based on the changes in the sludge profile characteristics and characterizes the sensitivity or tendency of the current sludge to be affected by the interaction and expansion. In addition, the present invention performs ventilation verification to determine the internal path diffusion characterization value. The internal path 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 path of the sludge. By determining the deformation flow sensitivity and the internal path diffusion characterization value, data support is provided for the subsequent classification of the sensitive categories of sludge samples, thereby facilitating the adaptive adjustment of aeration parameters, reducing the impact of sludge expansion trends and interaction differences on sludge maintenance, improving the reliability of maintenance for sludge from different sources, improving the sludge maintenance effect, ensuring microbial quality, and ensuring the formation effect of sludge particles after aeration.

[0085] Specifically, the process of calculating the deformation flow aggregation characterization parameters of the sludge sample includes:

[0086] Determining a ratio of the deformation flow sensitivity to a preset deformation flow sensitivity threshold as a deformation flow factor;

[0087] determining a ratio of a preset internal pathway diffusion threshold to the internal pathway diffusion characterization value as an aggregation diffusion factor;

[0088] The deformation flow factor and the aggregation diffusion factor are weighted and summed to obtain the deformation flow aggregation characterization parameter.

[0089] The weight for the deformation flow factor is 0.45, and the weight for the aggregation and diffusion factor is 0.55.

[0090] 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 internal pathway diffusion characterization values are recorded, the deformation flow sensitivity mean and the internal pathway diffusion characterization value mean are solved, the deformation flow sensitivity threshold is set as 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 as the product of the internal pathway diffusion characterization value mean and the internal pathway diffusion precision coefficient, and the internal pathway diffusion precision coefficient is selected within the interval [1.25, 1.5].

[0091] Specifically, the deformation flow aggregation characterization parameter is compared with a preset deformation flow aggregation characterization parameter standard threshold to classify the sludge sample into sensitive categories to deformation flow, wherein:

[0092] 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;

[0093] 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.

[0094] Specifically, in the implementation, the standard threshold value of the deformation flow aggregation characterization parameter is selected within the interval [1.25, 1.35].

[0095] Specifically, the aeration parameters controlled according to the sensitivity category of the sludge sample include:

[0096] If the sludge sample is a highly sensitive type, the aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, an image of the sludge on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and the change in the flow aggregation characteristics is analyzed to determine whether it meets the stable aggregation standard, so as to adjust the heat in the biological reaction zone;

[0097] If the sludge sample is of the weakly sensitive category, the aeration parameters of the biological reaction zone are maintained.

[0098] It is understood that the aeration parameters include aeration volume and stirring rate, which will not be described in detail here.

[0099] Specifically, controlling the aeration volume and stirring rate of the biological reaction zone according to the deformation flow aggregation characterization parameters includes:

[0100] Increasing the aeration volume and stirring rate in the biological reaction zone is positively correlated with the deformation flow aggregation characterization parameters.

[0101] In implementation, optionally,

[0102] 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:

[0103] 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 bioreactor 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;

[0104] 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 bioreactor 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;

[0105] 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 bioreactor 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;

[0106] 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.

[0107] Specifically, the process of collecting sludge images on the surface of the biological reaction area and extracting flow aggregation features includes:

[0108] Determining a plurality of sludge contour features in the sludge image on the surface of the biological reaction zone, and determining the edge distance between each sludge contour feature and the nearest other sludge contour features;

[0109] Calculating the mean value of the edge spacing, and determining the mean value of the edge spacing as the discreteness of the sludge profile feature;

[0110] Calculate the average area of each sludge profile feature.

[0111] 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.

[0112] Specifically, the analysis of whether the stable aggregation standards are met based on the changes in the flow aggregation characteristics includes:

[0113] 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;

[0114] The aggregation condition is that the discreteness of the sludge profile feature within the supervision period is less than a predetermined discreteness reference threshold and / or the average area of the sludge profile feature within the supervision period is greater than a predetermined area threshold.

[0115] Specifically, the discreteness reference threshold and the area threshold are predetermined. Those skilled in the art collect sludge images of the surface of the biological reaction area without abnormalities 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 monitoring cycle, and solve for the mean value of the discreteness of the sludge profile features and the mean value of the average area of the sludge profile features;

[0116] 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].

[0117] Specifically, the supervision period can be selected in the interval [6h, 12h] to observe the changes in flow aggregation characteristics.

[0118] The present invention classifies sludge into sensitive categories and then adaptively controls aeration parameters. For the highly sensitive category, this characterizes the sensitivity of the current sludge to deformation and flow caused by microbial and environmental influences, leading to aggregation. In this case, the aeration volume and stirring speed in the bioreactor zone need to be adaptively increased to adapt to the current sludge properties and stabilize aggregation. Furthermore, at the microscopic level, oxygen diffusion adapts to the current sludge diffusion channels, reducing uneven diffusion or hypoxia. Adaptive adjustment also avoids excessive aeration, which can lead to sludge aging and excessive expansion, and thus impact sludge maintenance. Furthermore, in this category, since sludge is more sensitive to microbial and environmental influences and prone to aggregation, flow and aggregation characteristics are continuously monitored. When these flow and aggregation characteristics are abnormal, the bioreactor zone heat is promptly adjusted for maintenance. This reduces the impact of sludge expansion trends and interaction differences on sludge maintenance, improves the reliability of maintenance for sludge from different sources, enhances sludge maintenance effectiveness, and ensures microbial quality. Furthermore, since the sludge maintenance volume is generally large, selectively increasing the heat in the bioreactor zone can effectively save energy.

[0119] Specifically, adjusting the heat in the bioreaction zone includes increasing the heat in the bioreaction zone.

[0120] Specifically, it is understandable that when adding heat, in order to avoid microbial stimulation, the heat gradient increases. 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 to reduce the aggregation tendency between sludges through moderate temperature increase, avoid excessive energy consumption, and ensure that the microorganisms in the link are at a suitable temperature.

[0121] Specifically, there is no limitation on the method for controlling the temperature of the bioreactor zone. A temperature control system is usually provided in the bioreactor zone to adjust the temperature therein. This is a prior art and will not be described in detail.

[0122] For the weakly sensitive category, this category is not sensitive to microbial and environmental influences, is not easy to aggregate, and the oxygen diffusion path inside the sludge is relatively smooth, so the aeration parameters are maintained to ensure the maintenance effect of the sludge.

[0123] Taking a sludge maintenance process as an example, the deformation flow aggregation characterization parameter obtained from the sludge sample collection is 1.7. The standard threshold value of the deformation flow aggregation characterization parameter set in the implementation is 1.35, so the sludge sample is classified as a highly sensitive category;

[0124] In 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 bioreactor is increased to 1.3 times the initial aeration volume, and the stirring speed is increased to 1.45 times the initial stirring speed.

[0125] Subsequently, the flow aggregation characteristics were extracted, and the discreteness of the collected sludge contour characteristics was 30 cm, which was greater than the discreteness benchmark threshold of 20 cm. The average area of the sludge contour characteristics was 1.35 m², which was less than the area threshold of 2 m², and was determined to meet the stable aggregation standard.

[0126] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A method for operating and maintaining 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 capturing 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 pipe into the transparent observation box to perform ventilation verification, and determining an internal path diffusion characterization value for the sludge sample based on the verification result; Step S3, calculating deformation flow aggregation characterization parameters of the sludge sample based on the deformation flow sensitivity and internal path diffusion characterization value of the sludge sample, and classifying the sludge sample into sensitive categories to deformation flow; Step S4, transferring the sludge in the sludge storage tank to the biological reaction zone after pretreatment, and controlling the aeration parameters according to the sensitivity category of the sludge sample, including: The aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, sludge images on the surface of the biological reaction zone are collected, flow aggregation characteristics are extracted, and whether the flow aggregation characteristics meet the stable aggregation standards is analyzed according to the changes in 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 features in the sludge image on the surface of the biological reaction area and the average area of the sludge contour features; The process of marking 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 starting point and the ending point of the time period in the reference coordinate system; Constructing several 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; 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; Determine the average of the maximum air pressure of the ventilation line corresponding to each ventilation cycle as the internal passage diffusion characterization value; The process of collecting sludge images on the surface of the biological reaction area and extracting flow aggregation characteristics includes: Determining a plurality of sludge contour features in the sludge image on the surface of the biological reaction zone, and determining the edge distance between each sludge contour feature and the nearest other sludge contour features; Calculating the mean value of the edge spacing, and determining the mean value of the edge spacing as the discreteness of the sludge profile feature; Calculate the average area of each sludge profile feature.

2. 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; determining a 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.

3. 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 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.

4. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 3, 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 type, the aeration volume and stirring rate of the biological reaction zone are controlled according to the deformation flow aggregation characterization parameters, an image of the sludge on the surface of the biological reaction zone is collected, the flow aggregation characteristics are extracted, and the change in the flow aggregation characteristics is analyzed to determine whether it meets the stable aggregation standard, 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.

5. 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: Increasing the aeration volume and stirring rate in the biological reaction zone is positively correlated with the deformation flow aggregation characterization parameters.

6. The operation and maintenance method of aerobic granular sludge under low temperature conditions according to claim 1, characterized in that: Analyzing whether the changes in flow aggregation characteristics meet the stable aggregation standards 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 and / or the average area of the sludge profile feature within the supervision period is greater than a predetermined area threshold.

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

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