A water pollution monitoring method and system based on spectral analysis

Abstract

The application relates to the technical field of water pollution monitoring, and particularly discloses a water pollution monitoring method and system based on spectrum analysis, which comprises the following steps: according to the coupling degree between the evaluated flow velocity uniformity and content uniformity, the non-uniform water flow velocity change is regularly explored, the water flow velocity rule is determined, the predicted non-monitoring value is obtained, the content non-monitoring period is determined, the appearance frequency of the content non-monitoring period is extracted, the monitoring frequency adjustment amount is obtained, the water pollution monitoring operation at the water outlet in the urban sewage treatment plant is completed, and the monitoring is carried out according to the adjusted frequency; the capture precision of the key nodes of the content change can be improved; the monitoring omission or excessive monitoring caused by the fixed frequency monitoring can be avoided; for the case that the flow velocity change is stable, the overall situation of the water pollution can be obtained in time; for the case that the flow velocity change fluctuates, the content non-monitoring period is accurately predicted, the monitoring is arranged in a targeted manner, and the monitoring efficiency can be improved.

Description

Technical Field

[0001] This invention relates to the field of water pollution monitoring technology, and specifically to a water pollution monitoring method and system based on spectral analysis. Background Technology

[0002] In the operation and management of urban wastewater treatment plants, monitoring the effluent water quality is a crucial step in ensuring that wastewater treatment meets discharge standards and safeguarding water environmental safety. Currently, spectroscopic analysis technology, with its advantages of speed, accuracy, and non-destructiveness, is widely used in wastewater monitoring. Through spectroscopic analysis, the content of various trace elements (such as lead, cadmium, mercury, and trace polycyclic aromatic hydrocarbons) in wastewater can be obtained in real time, providing important data for the operation and control of wastewater treatment plants and water quality assessment.

[0003] In actual wastewater monitoring, although the water quality discharged from the outlet undergoes a series of treatments and is relatively stable overall, the outlet typically uses weir flow or orifice discharge methods for drainage. This drainage method results in a slow flow velocity at the weir edge, which easily accumulates incompletely settled flocs (PAC / PAM flocs) and a small amount of suspended sludge; while the flow velocity at the center of the weir is fast, and the water is mixed relatively uniformly. When the drainage velocity at the outlet changes, resulting in uneven flow velocity, the velocity difference will further exacerbate the local concentration stratification phenomenon—the concentration of suspended solids or flocs is higher in the low-velocity zone and lower in the high-velocity zone.

[0004] More importantly, trace elements in urban sewage are readily adsorbed onto the surface of flocs or embedded within the particles. In low-velocity zones (such as at the edge of a weir), the concentration of adsorbed trace elements is much higher than that dissolved in the water due to the enrichment of flocs; in high-velocity zones (such as at the center of a weir), the strong turbulence disperses the flocs, resulting in a relatively uniform concentration of trace elements. This spatial stratification of flocs or suspended sludge caused by uneven flow velocity makes it difficult for collected water samples to accurately represent the overall water quality at the outlet. If traditional fixed-frequency monitoring methods are used, key changes may be missed, making it impossible to detect water quality anomalies in a timely manner; over-monitoring may also lead to resource waste and increased monitoring costs.

[0005] Therefore, accurately locating problematic areas and conducting more detailed monitoring and analysis of these areas through spectral analysis to identify the specific causes of abnormal trace element content, while also rationally adjusting the monitoring frequency based on the coupling between flow velocity uniformity and content uniformity, to avoid the collected water samples failing to represent the overall water quality at the outlet and to improve the accuracy of water pollution monitoring at the outlet of urban sewage treatment plants, has become an important technical problem that urgently needs to be solved in the field of sewage monitoring.

[0006] Therefore, the present invention provides a water pollution monitoring method and system based on spectral analysis. Summary of the Invention

[0007] The purpose of this invention is to provide a water pollution monitoring method and system based on spectral analysis to solve the aforementioned background problems.

[0008] The objective of this invention can be achieved through the following technical solutions: A water pollution monitoring method based on spectral analysis, comprising: A uniform monitoring cycle was set, and the trace element content in the outlet monitoring area was analyzed for uniformity within each monitoring period to identify the uniform and non-uniform content periods. During the content uniformity monitoring period, the change of effluent flow velocity in the effluent monitoring area was analyzed to screen out the periods of uniform flow velocity and periods of non-uniform flow velocity, and the coupling degree between flow velocity uniformity and content uniformity was analyzed. When the coupling between flow velocity uniformity and content uniformity is close, the regularity of the non-uniform effluent flow velocity variation is investigated to determine the effluent flow velocity regularity. Based on the determined effluent flow rate pattern, the predicted non-monitoring value is obtained, the non-monitoring period of content is determined, and the occurrence frequency of the non-monitoring period of content is extracted to obtain the monitoring frequency adjustment amount, thus completing the water pollution monitoring operation at the effluent outlet of the urban sewage treatment plant.

[0009] As a further aspect of the present invention, the screening process for the period of uniform content and the period of non-uniform content is as follows: The outlet monitoring area is divided into several outlet monitoring sub-areas by grid pattern. The outlet monitoring sub-area located in the center of the outlet monitoring area and the outlet monitoring sub-area located at the edge of the outlet monitoring area are extracted as the central monitoring sub-area and the edge monitoring sub-area, respectively. The uniform monitoring period is divided into several monitoring periods. Within each monitoring period, the micro-element content in the central monitoring sub-region and the micro-element content in the edge monitoring sub-region are obtained. The difference between the micro-element content in the central monitoring sub-region and the micro-element content in each edge monitoring sub-region is calculated, and the absolute value is taken to obtain the sub-region content difference. The average of the content differences in all sub-regions is summed to obtain the content analysis value for a time period. If the content analysis value for a time period is less than or equal to the content analysis threshold for that time period, it is marked as a time period with uniform content. If the content analysis value of a time period is greater than the content analysis threshold of a time period, it is marked as a time period with uneven content.

[0010] As a further aspect of the present invention, the screening process for uniform flow velocity periods and non-uniform flow velocity periods is as follows: The outflow velocity in the central monitoring sub-region and the outflow velocity in each edge monitoring sub-region are obtained separately and used as the central outflow velocity and the edge outflow velocity. During the content monitoring period, the difference between the central effluent velocity and the effluent velocity at each edge is calculated, and the absolute value is taken to obtain the sub-region velocity difference. The average of the velocity differences in all sub-regions is summed to obtain the velocity analysis value for a given time period. If the velocity analysis value for a given time period is greater than the velocity analysis threshold for that time period, it is marked as a time period with non-uniform velocity. If the flow velocity analysis value for a given period is less than or equal to the flow velocity analysis threshold for that period, it is marked as a period with uniform flow velocity.

[0011] As a further aspect of the present invention, the process for analyzing flow rate uniformity and content uniformity is as follows: The non-uniform content period and the non-uniform flow rate period within the uniform content monitoring period were extracted separately, and the overlapping periods were compared. The overlapping non-uniform content period and the non-uniform flow rate period were extracted and marked as non-uniform content and flow rate periods. During periods of non-uniform content flow rate, the ratio of the corresponding content analysis value to the content analysis threshold for that period is calculated to obtain the content analysis ratio for that period. The ratio of the corresponding time period flow velocity analysis value to the time period flow velocity analysis threshold is calculated to obtain the time period flow velocity analysis ratio. The ratio of content analysis ratio to flow velocity analysis ratio within each period of content-flow velocity non-uniformity is calculated to obtain the period non-uniformity ratio. The standard deviation of the time period non-uniformity ratio corresponding to all non-uniform content and flow rate periods is calculated to obtain the non-uniformity correlation value; The proportion of non-uniform content flow rate periods to the total number of content monitoring periods within a uniform content monitoring cycle is used to obtain the non-uniform period ratio.

[0012] As a further aspect of the present invention, the process for determining the degree of coupling between flow rate uniformity and content uniformity is as follows: The ratio of the non-uniform time period quantity to the non-uniformity correlation value is calculated to obtain the velocity content correlation value. If the velocity content correlation value is greater than or equal to the velocity content correlation threshold, it is displayed as a velocity content closely correlated signal.

[0013] As a further aspect of the present invention, the process of investigating the regularity of non-uniform outflow velocity changes is as follows: When the signal is closely related to the flow velocity content, within the content uniformity monitoring period, the number of uniform flow velocity periods between adjacent non-uniform flow velocity periods is counted as a group of uniform flow velocity periods. The ratio of the number of uniform flow velocity periods to the number of content monitoring periods is calculated to obtain the ratio of adjacent non-uniform interval periods. The standard deviation of the adjacent non-uniform interval time period is calculated for all groups of average flow velocity segments. The interval between adjacent non-uniform flow velocity periods is obtained as a group of non-uniform flow velocity intervals. The ratio of the interval between adjacent non-uniform flow velocity periods to the content uniformity monitoring cycle is calculated to obtain the adjacent non-uniform interval ratio. The standard deviation of the adjacent non-uniform interval duration is calculated by performing a standard deviation calculation on the ratio of the duration of adjacent non-uniform intervals corresponding to all non-uniform velocity interval groups.

[0014] As a further aspect of the present invention, the process for determining the outflow velocity pattern is as follows: The non-uniform speed investigation value is obtained by summing the standard deviation of the adjacent non-uniform interval time period and the standard deviation of the adjacent non-uniform interval duration. If the non-uniform speed investigation value is greater than the non-uniform speed investigation threshold, it is displayed as a non-uniform speed change fluctuation signal. If the non-uniform speed investigation value is less than or equal to the non-uniform speed investigation threshold, it is displayed as a non-uniform speed change stable signal.

[0015] As a further aspect of the present invention, the process for predicting and obtaining non-monitoring values ​​based on the determined effluent flow velocity pattern is as follows: When the signal is displayed as a non-uniform velocity fluctuation, the interval between adjacent non-uniform velocity periods is extracted and compared. The minimum and maximum intervals are selected and the summation and average are calculated to obtain the predicted value of the non-monitoring duration. The predicted non-monitoring duration is calculated by comparing the predicted non-monitoring duration with the duration corresponding to the content monitoring period. When the signal is displayed as a non-uniformly changing stable signal, the number of uniform flow periods between adjacent non-uniform flow periods is extracted and the average value is calculated to obtain the predicted non-monitored value.

[0016] A further aspect of this invention is as follows: the process of determining the non-monitoring period for content and extracting the frequency of occurrence of the non-monitoring period to obtain the monitoring frequency adjustment amount is as follows: Extract the current content monitoring period and calculate it in conjunction with the predicted non-monitoring value to obtain the content non-monitoring period. Statistically count the occurrence frequency of the content non-monitoring period as the content non-monitoring frequency. Extract the current spectral analysis monitoring frequency and calculate the difference between it and the content non-monitoring frequency. Take the absolute value to obtain the monitoring frequency adjustment amount.

[0017] A water pollution monitoring system based on spectral analysis, comprising: Time Period Analysis and Screening Module: Set a uniformity monitoring period for content, perform uniformity analysis of trace elements in the outlet monitoring area within each content monitoring period, and screen out time periods with uniform content and time periods with non-uniform content. Flow velocity content analysis module: During the content uniformity monitoring period, the changes in the effluent flow velocity in the outlet monitoring area are analyzed, the time periods with uniform flow velocity and the time periods with non-uniform flow velocity are screened, and the coupling degree between flow velocity uniformity and content uniformity is analyzed. Flow velocity pattern investigation module: When the coupling between flow velocity uniformity and content uniformity is close, the pattern of non-uniform effluent flow velocity variation is investigated to determine the effluent flow velocity pattern; Monitoring frequency adjustment module: Based on the determined effluent flow rate pattern, it obtains the predicted non-monitoring value, determines the non-monitoring period of content, extracts the occurrence frequency of the non-monitoring period of content, obtains the monitoring frequency adjustment amount, and completes the water pollution monitoring operation at the effluent outlet of the urban sewage treatment plant.

[0018] The beneficial effects of this invention are as follows: 1. This invention sets a uniformity monitoring cycle for trace elements, performs uniformity analysis on the trace element content in the effluent monitoring area within each monitoring period, and screens out periods with uniform and non-uniform content. Furthermore, within the uniformity monitoring cycle, it performs mean analysis on the effluent flow velocity in the effluent monitoring area, screening out periods with uniform and non-uniform flow velocity, and analyzes the coupling degree between flow velocity uniformity and content uniformity. This helps to accurately locate problematic areas. Through spectral analysis, more detailed monitoring and analysis of these areas can be conducted to identify the specific causes of abnormal trace element content. Moreover, based on the coupling between flow velocity uniformity and content uniformity, the monitoring frequency can be reasonably adjusted to avoid the collected water samples failing to represent the overall water quality at the effluent outlet, thus improving the accuracy of water pollution monitoring at the effluent outlet of urban wastewater treatment plants.

[0019] 2. This invention investigates the patterns of non-uniform effluent flow velocity changes based on the assessed coupling degree between flow velocity uniformity and content uniformity, determines the effluent flow velocity pattern, obtains predicted non-monitoring values, identifies non-monitoring periods for content, and extracts the frequency of occurrence of these non-monitoring periods to obtain the monitoring frequency adjustment amount. This completes the water pollution monitoring operation at the effluent outlet of urban wastewater treatment plants. Monitoring according to the adjusted frequency can improve the accuracy of capturing key nodes of content changes, avoid monitoring omissions or over-monitoring that may occur due to fixed-frequency monitoring, and reduce unnecessary monitoring times for stable flow velocity changes. While ensuring monitoring quality, it can obtain the overall water pollution situation in a timely manner. For fluctuating flow velocity changes, it can also improve monitoring efficiency by accurately predicting non-monitoring periods for content and arranging monitoring in a targeted manner. Attached Figure Description

[0020] The invention will now be further described with reference to the accompanying drawings.

[0021] Figure 1 This is a functional block diagram of a water pollution monitoring method based on spectral analysis according to the present invention; Figure 2 This is a flowchart illustrating the judgment process of a water pollution monitoring method based on spectral analysis in this invention. Figure 3This is a flowchart of a water pollution monitoring system based on spectral analysis according to the present invention. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0023] Example 1 In the process of monitoring wastewater at the effluent outlet of urban wastewater treatment plants using spectral analysis, although the water quality discharged from the outlet is relatively stable after treatment, the outlet is usually drained using methods such as weir flow or orifice discharge. This can result in slow flow velocity at the weir edge, making it easy for incompletely settled flocs (PAC / PAM) to accumulate. The wastewater contains flocs and a small amount of suspended sludge. The flow velocity at the center of the weir is high, and the water is relatively uniformly mixed (or when the drainage velocity at the outlet changes, resulting in uneven flow velocity). This velocity difference causes local concentration stratification—higher concentrations of suspended solids or flocs in low-velocity zones and lower concentrations in high-velocity zones. Furthermore, uneven flow velocity at the outlet causes spatial stratification of flocs or suspended sludge. Trace elements in urban wastewater (such as lead, cadmium, mercury, and trace polycyclic aromatic hydrocarbons) are easily adsorbed onto the floc surface or embedded within the particles. In low-velocity zones (such as the weir edge), flocs are enriched, and the adsorbed trace element concentration is much higher than the dissolved state in the water. In high-velocity zones (such as the weir center), strong turbulence disperses the flocs, resulting in a relatively uniform trace element concentration. This makes it difficult for collected water samples to represent the overall water quality at the outlet. Therefore, if… Figure 1 - Figure 2 As shown, this embodiment provides a water pollution monitoring method based on spectral analysis, including: Step 1: Set a monitoring cycle for uniform content, perform content uniformity analysis on trace elements in the monitoring area of ​​the outlet, determine the degree of uniformity of trace element content in the entire monitoring area of ​​the outlet, and mark the time periods with uniform content and the time periods with non-uniform content if the content uniformity is low. In some embodiments, the content uniformity monitoring cycle is equally divided into several content monitoring periods, wherein the duration of each content monitoring period is equal. The outlet monitoring area is divided into several outlet monitoring sub-areas by grid pattern, wherein each outlet monitoring sub-area has an equal area; The water outlet monitoring sub-area located at the center of the water outlet monitoring area and the water outlet monitoring sub-area located at the edge of the water outlet monitoring area are extracted respectively as the central monitoring sub-area and the edge monitoring sub-area; It should be noted that the edge monitoring sub-region can be the water outlet monitoring sub-region located on the edge line of the water outlet monitoring region, or it can be the water outlet monitoring sub-region located at the apex of the water outlet monitoring region. During the content monitoring period, the micro-element content in the central monitoring sub-region and the micro-element content in the edge monitoring sub-region are obtained respectively. The difference between the micro-element content in the central monitoring sub-region and the micro-element content in each edge monitoring sub-region is calculated, and the absolute value is taken to obtain the sub-region content difference. The average value of the content differences in all sub-regions is calculated to obtain the content analysis value for the time period. If the content analysis value of a time period is greater than the content analysis threshold of a time period, it indicates that the content of trace elements in the central monitoring sub-area differs significantly from the content of trace elements in each edge monitoring sub-area during the content monitoring period. The content of trace elements in each content monitoring sub-area is uneven, which is displayed as a content unevenness signal. The content monitoring period is marked as a content unevenness period. If the content analysis value of a time period is less than or equal to the content analysis threshold of a time period, it indicates that the content of trace elements in the central monitoring sub-area is not significantly different from the content of trace elements in each edge monitoring sub-area during the content monitoring period. The content of trace elements in each content monitoring sub-area is uniform, and the content is displayed as a uniform content signal. The content monitoring period is then marked as a uniform content period.

[0024] Step 2: During the content uniformity monitoring period, analyze the changes in the outflow velocity in the outlet monitoring area, screen out the time periods with uniform and non-uniform flow velocities, and analyze the coupling degree between flow velocity uniformity and content uniformity. In some embodiments, the outflow velocity in the central monitoring sub-region and the outflow velocity in each edge monitoring sub-region are obtained respectively, as the central outflow velocity and the edge outflow velocity; During the content monitoring period, the difference between the central effluent velocity and the effluent velocity at each edge is calculated, and the absolute value is taken to obtain the sub-region velocity difference. The average value of the velocity differences in all sub-regions is summed to obtain the velocity analysis value for the time period. If the flow velocity analysis value of a time period is greater than the flow velocity analysis threshold of a time period, it indicates that there is a large difference between the effluent flow velocity in the central monitoring sub-area and the effluent flow velocity in each edge monitoring sub-area during the content monitoring period. The effluent flow velocity in each content monitoring sub-area is uneven, which is displayed as an effluent flow velocity uneven signal and marked as a flow velocity uneven time period. If the flow velocity analysis value of a time period is less than or equal to the flow velocity analysis threshold of a time period, it indicates that during the content monitoring period, the difference between the effluent flow velocity in the central monitoring sub-area and the effluent flow velocity in each edge monitoring sub-area is small, and the effluent flow velocity in each content monitoring sub-area is not uniform. This is displayed as a uniform effluent flow velocity signal and marked as a time period with uniform flow velocity. The non-uniform content period and the non-uniform flow rate period within the uniform content monitoring period were extracted separately, and the overlapping periods were compared. The overlapping non-uniform content period and the non-uniform flow rate period were extracted and marked as non-uniform content and flow rate periods. During periods of non-uniform content flow rate, the ratio of the corresponding content analysis value to the content analysis threshold for that period is calculated to obtain the content analysis ratio for that period. Similarly, the ratio of the corresponding time period flow velocity analysis value to the time period flow velocity analysis threshold is calculated to obtain the time period flow velocity analysis ratio; The ratio of content analysis ratio to flow velocity analysis ratio within each period of content-flow velocity non-uniformity is calculated to obtain the period non-uniformity ratio. The standard deviation of the time period non-uniformity ratio corresponding to all non-uniform content and flow rate periods is calculated to obtain the non-uniformity correlation value; The proportion of non-uniform content flow rate periods to the total number of content monitoring periods within a uniform content monitoring cycle is used to obtain the non-uniform period ratio. The flow velocity content correlation value is obtained by calculating the ratio of the non-uniform time period quantity ratio to the correlation value of the degree of non-uniformity. Understandably, the velocity-content correlation value refers to the degree of correlation between uneven effluent flow velocity and uneven trace element content. On the one hand, it reflects the co-occurrence frequency of these two phenomena within the monitoring period through the ratio of the number of uneven periods. On the other hand, it reflects the relative relationship between the degree of unevenness of content and the degree of unevenness of flow velocity in a single uneven content-flow velocity period, and measures the fluctuation of the degree of unevenness ratio between different periods. Specifically, a larger velocity-content correlation value indicates that uneven flow velocity and uneven content not only occur simultaneously in more periods (larger ratio of uneven periods), but also that the relative relationship of unevenness fluctuates less between different uneven content-flow velocity periods (smaller correlation value). Conversely, a smaller velocity-content correlation value indicates that uneven flow velocity and uneven content not only occur simultaneously in fewer periods (smaller number of uneven periods), but also that the relative relationship of unevenness fluctuates more between different uneven content-flow velocity periods (larger correlation value). If the velocity-content correlation value is greater than or equal to the velocity-content correlation threshold, it indicates that the velocity non-uniformity and content non-uniformity not only occur simultaneously in many time periods, but also that the relative relationship of the degree of non-uniformity between different content and velocity non-uniform time periods fluctuates little, showing a signal of close velocity-content correlation. If the velocity-content correlation value is less than the velocity-content correlation threshold, it indicates that the velocity non-uniformity and content non-uniformity not only occur simultaneously in a few time periods, but also that the relative relationship of the degree of non-uniformity between different content and velocity non-uniform time periods fluctuates greatly, showing a non-close velocity-content correlation signal. It should be noted that the significance of analyzing the coupling degree between flow velocity uniformity and content uniformity is that coupling degree analysis helps to accurately locate the problem area. If a slow flow velocity and high trace element content frequently occur in a certain area (such as the edge of a weir), it indicates that the area is a key area for water quality monitoring. Spectral analysis can be used to monitor and analyze the area in more detail and find out the specific reasons for the abnormal trace element content. Based on the coupling between flow velocity uniformity and content uniformity, the monitoring frequency can be adjusted appropriately. If non-uniform periods of flow velocity and content are frequently found to occur simultaneously, it indicates that the water quality fluctuates significantly during these periods, and the monitoring frequency needs to be increased to promptly capture changes in water quality. Conversely, if the coupling is low and non-uniform periods of flow velocity and content rarely occur simultaneously, the monitoring frequency can be appropriately reduced.

[0025] The specific scheme of this embodiment is as follows: A uniform monitoring cycle is set, and the trace element content in the effluent monitoring area is analyzed for uniformity within each monitoring period. Periods with uniform content and periods with non-uniform content are then identified. Furthermore, within the uniform monitoring cycle, the average flow velocity in the effluent monitoring area is analyzed to identify periods with uniform and non-uniform flow velocity. The coupling degree between flow velocity uniformity and content uniformity is analyzed, which helps to accurately locate problematic areas. Spectral analysis allows for more detailed monitoring and analysis of these areas, identifying the specific causes of abnormal trace element content. Moreover, based on the coupling between flow velocity uniformity and content uniformity, the monitoring frequency can be reasonably adjusted to avoid the collected water samples failing to represent the overall water quality at the effluent outlet, thus improving the accuracy of water pollution monitoring at the effluent outlet of urban sewage treatment plants.

[0026] Example 2 like Figure 1 - Figure 2 As shown, this embodiment provides a water pollution monitoring method based on spectral analysis, which also includes: Step 3: Based on the degree of coupling between the assessed flow velocity uniformity and content uniformity, investigate the pattern of non-uniform effluent flow velocity variation and determine the effluent flow velocity pattern. In some embodiments, when the signal is closely related to the flow velocity content, the number of uniform flow velocity periods between adjacent non-uniform flow velocity periods is counted within the content uniformity monitoring period, and a group of uniform flow velocity periods is formed. The ratio of the number of uniform flow velocity periods to the number of content monitoring periods is calculated to obtain the ratio of adjacent non-uniform interval periods. The standard deviation of the adjacent non-uniform interval time period is calculated for all groups of average flow velocity segments. The interval between adjacent non-uniform flow velocity periods is obtained as a group of non-uniform flow velocity intervals. The ratio of the interval between adjacent non-uniform flow velocity periods to the content uniformity monitoring cycle is calculated to obtain the adjacent non-uniform interval ratio. The standard deviation of the adjacent non-uniform interval duration ratio corresponding to all non-uniform velocity interval groups is calculated to obtain the standard deviation of the adjacent non-uniform interval duration. The non-uniform speed investigation value is obtained by summing the standard deviation of the adjacent non-uniform interval time period and the standard deviation of the adjacent non-uniform interval duration. It is understandable that the non-uniform velocity exploration value represents the fluctuation in the number of time intervals and the duration of intervals between adjacent non-uniform velocity periods. It reflects the regularity and stability of the changes in non-uniform effluent velocity. On the one hand, the standard deviation of the interval between adjacent non-uniform periods reflects the dispersion of the number of uniform velocity periods between adjacent non-uniform velocity periods. On the other hand, the standard deviation of the duration of the interval between adjacent non-uniform periods reflects the dispersion of the duration of the interval between adjacent non-uniform velocity periods. Specifically, if the non-uniform velocity exploration value is larger, it indicates that the fluctuations in the number of time intervals and the duration of intervals between adjacent non-uniform velocity periods are larger. That is, the changes in non-uniform effluent velocity lack regularity and stability, and it is difficult to predict the occurrence time and interval of non-uniform velocity periods. If the non-uniform velocity exploration value is smaller, it indicates that the fluctuations in the number of time intervals and the duration of intervals between adjacent non-uniform velocity periods are smaller. The changes in non-uniform effluent velocity are relatively regular, and the occurrence of non-uniform velocity periods has a certain degree of stability and predictability. If the non-uniform velocity exploration value is greater than the non-uniform velocity exploration threshold, it indicates that the fluctuation between adjacent non-uniform velocity periods is large in terms of the number of periods and the duration of the periods. In other words, the change of non-uniform outflow velocity lacks regularity and stability, making it difficult to predict the occurrence time and interval of non-uniform velocity periods, which is displayed as a non-uniform velocity change fluctuation signal. If the non-uniform velocity exploration value is less than or equal to the non-uniform velocity exploration threshold, it indicates that the fluctuation between adjacent non-uniform velocity periods in terms of the number of periods and the duration of the periods is small, the change of non-uniform outflow velocity is relatively regular, and the occurrence of non-uniform velocity periods has a certain degree of stability and predictability, showing as a stable signal of non-uniform velocity change. Step 4: Based on the determined effluent flow rate pattern, obtain the predicted non-monitoring value, determine the non-monitoring period of content, extract the occurrence frequency of the non-monitoring period of content, obtain the monitoring frequency adjustment amount, and complete the water pollution monitoring operation at the effluent outlet of the urban sewage treatment plant. For example, when the signal is displayed as a non-uniform velocity fluctuation, the interval between adjacent non-uniform velocity periods is extracted and compared. The minimum and maximum intervals are selected and the summation and average are calculated to obtain the predicted value of the non-monitoring duration. The predicted non-monitoring duration is calculated by comparing the predicted non-monitoring duration with the duration corresponding to the content monitoring period. Extract the current content monitoring period and calculate the non-monitoring period by combining it with the predicted non-monitoring value; For example, when the signal is displayed as a non-uniformly changing stable signal, the number of uniform flow periods between adjacent non-uniform flow periods is extracted and the average is calculated to obtain the predicted non-monitored value. Extract the current content monitoring period and calculate the non-monitoring period by combining it with the predicted non-monitoring value; The frequency of occurrence of content in non-monitoring periods is statistically analyzed and used as the non-monitoring frequency. The current spectral analysis monitoring frequency is extracted, and the difference between the current and non-monitoring frequencies is calculated. The absolute value is then taken to obtain the monitoring frequency adjustment amount. The specific scheme of this embodiment is as follows: Based on the degree of coupling between the assessed flow velocity uniformity and content uniformity, the regularity of non-uniform effluent flow velocity changes is investigated to determine the effluent flow velocity pattern, obtain the predicted non-monitoring value, determine the content non-monitoring period, and extract the occurrence frequency of the content non-monitoring period to obtain the monitoring frequency adjustment amount. This completes the water pollution monitoring operation at the effluent outlet of the urban sewage treatment plant. Monitoring according to the adjusted frequency can improve the accuracy of capturing key nodes of content changes, avoid monitoring omissions or over-monitoring that may occur due to fixed frequency monitoring, and reduce unnecessary monitoring times for cases with stable flow velocity changes. Under the premise of ensuring monitoring quality, the overall situation of water pollution can be obtained in a timely manner. For cases with fluctuating flow velocity changes, targeted monitoring can be arranged by accurately predicting the content non-monitoring period, which can also improve monitoring efficiency.

[0027] Example 3 Please see Figure 3 As shown, this embodiment also provides a water pollution monitoring system based on spectral analysis, including the following modules: Time Period Analysis and Screening Module: Set a uniformity monitoring period for content, perform uniformity analysis of trace elements in the outlet monitoring area within each content monitoring period, and screen out time periods with uniform content and time periods with non-uniform content. Flow velocity content analysis module: During the content uniformity monitoring period, the changes in the effluent flow velocity in the outlet monitoring area are analyzed, the time periods with uniform flow velocity and the time periods with non-uniform flow velocity are screened, and the coupling degree between flow velocity uniformity and content uniformity is analyzed. Flow velocity pattern investigation module: When the coupling between flow velocity uniformity and content uniformity is close, the pattern of non-uniform effluent flow velocity variation is investigated to determine the effluent flow velocity pattern; Monitoring frequency adjustment module: Based on the determined effluent flow rate pattern, it obtains the predicted non-monitoring value, determines the non-monitoring period of content, extracts the occurrence frequency of the non-monitoring period of content, obtains the monitoring frequency adjustment amount, and completes the water pollution monitoring operation at the effluent outlet of the urban sewage treatment plant.

[0028] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A water pollution monitoring method based on spectral analysis, characterized in that: include; A uniform content monitoring cycle was set, and the trace element content in the outlet monitoring area was analyzed for uniformity within each content monitoring period to screen out the periods with uniform content and periods with non-uniform content. During the content uniformity monitoring period, the change of effluent flow velocity in the effluent monitoring area was analyzed to screen out the periods of uniform flow velocity and periods of non-uniform flow velocity, and the coupling degree between flow velocity uniformity and content uniformity was analyzed. When the coupling between flow velocity uniformity and content uniformity is close, the regularity of the non-uniform effluent flow velocity variation is investigated to determine the effluent flow velocity regularity. Based on the determined effluent flow rate pattern, the predicted non-monitoring value is obtained, the non-monitoring period of content is determined, and the occurrence frequency of the non-monitoring period of content is extracted to obtain the monitoring frequency adjustment amount, thus completing the water pollution monitoring operation at the effluent outlet of the urban sewage treatment plant.

2. The water pollution monitoring method based on spectral analysis according to claim 1, characterized in that: The screening process for periods with uniform and non-uniform content is as follows: The outlet monitoring area is divided into several outlet monitoring sub-areas by grid pattern. The outlet monitoring sub-area located in the center of the outlet monitoring area and the outlet monitoring sub-area located at the edge of the outlet monitoring area are extracted as the central monitoring sub-area and the edge monitoring sub-area, respectively. The uniform monitoring period is divided into several monitoring periods. Within each monitoring period, the micro-element content in the central monitoring sub-region and the micro-element content in the edge monitoring sub-region are obtained. The difference between the micro-element content in the central monitoring sub-region and the micro-element content in each edge monitoring sub-region is calculated, and the absolute value is taken to obtain the sub-region content difference. The average of the content differences in all sub-regions is summed to obtain the content analysis value for a time period. If the content analysis value for a time period is less than or equal to the content analysis threshold for that time period, it is marked as a time period with uniform content. If the content analysis value of a time period is greater than the content analysis threshold of a time period, it is marked as a time period with uneven content.

3. The water pollution monitoring method based on spectral analysis according to claim 1, characterized in that: The screening process for uniform and non-uniform flow velocity periods is as follows: The outflow velocity in the central monitoring sub-region and the outflow velocity in each edge monitoring sub-region are obtained separately and used as the central outflow velocity and the edge outflow velocity. During the content monitoring period, the difference between the central effluent velocity and the effluent velocity at each edge is calculated, and the absolute value is taken to obtain the sub-region velocity difference. The average of the velocity differences in all sub-regions is summed to obtain the velocity analysis value for a given time period. If the velocity analysis value for a given time period is greater than the velocity analysis threshold for that time period, it is marked as a time period with non-uniform velocity. If the flow velocity analysis value for a given period is less than or equal to the flow velocity analysis threshold for that period, it is marked as a period with uniform flow velocity.

4. The water pollution monitoring method based on spectral analysis according to claim 3, characterized in that: The process of analyzing flow rate uniformity and content uniformity is as follows: The non-uniform content period and the non-uniform flow rate period within the uniform content monitoring period were extracted separately, and the overlapping periods were compared. The overlapping non-uniform content period and the non-uniform flow rate period were extracted and marked as non-uniform content and flow rate periods. During periods of non-uniform content flow rate, the ratio of the corresponding content analysis value to the content analysis threshold for that period is calculated to obtain the content analysis ratio for that period. The ratio of the corresponding time period flow velocity analysis value to the time period flow velocity analysis threshold is calculated to obtain the time period flow velocity analysis ratio. The ratio of content analysis ratio to flow velocity analysis ratio within each period of content-flow velocity non-uniformity is calculated to obtain the period non-uniformity ratio. The standard deviation of the time period unevenness ratio corresponding to all time periods with uneven content and flow rate is calculated to obtain the unevenness correlation value; The proportion of non-uniform content flow rate periods to the total number of content monitoring periods within a uniform content monitoring cycle is used to obtain the non-uniform period ratio.

5. The water pollution monitoring method based on spectral analysis according to claim 4, characterized in that: The process for determining the degree of coupling between flow velocity uniformity and content uniformity is as follows: The ratio of the non-uniform time period quantity to the non-uniformity correlation value is calculated to obtain the velocity content correlation value. If the velocity content correlation value is greater than or equal to the velocity content correlation threshold, it is displayed as a velocity content closely correlated signal.

6. The water pollution monitoring method based on spectral analysis according to claim 1, characterized in that: The process of investigating the patterns of non-uniform outflow velocity variations is as follows: When the signal is closely related to the flow velocity content, within the content uniformity monitoring period, the number of uniform flow velocity periods between adjacent non-uniform flow velocity periods is counted as a group of uniform flow velocity periods. The ratio of the number of uniform flow velocity periods to the number of content monitoring periods is calculated to obtain the ratio of adjacent non-uniform interval periods. The standard deviation of the adjacent non-uniform interval time period is calculated for all groups of average flow velocity segments. The interval between adjacent non-uniform flow velocity periods is obtained as a group of non-uniform flow velocity intervals. The ratio of the interval between adjacent non-uniform flow velocity periods to the content uniformity monitoring cycle is calculated to obtain the adjacent non-uniform interval ratio. The standard deviation of the adjacent non-uniform interval duration is calculated by performing a standard deviation calculation on the ratio of the duration of adjacent non-uniform intervals corresponding to all non-uniform velocity interval groups.

7. A water pollution monitoring method based on spectral analysis according to claim 6, characterized in that: The process for determining the outflow velocity pattern is as follows: The non-uniform speed investigation value is obtained by summing the standard deviation of the adjacent non-uniform interval time period and the standard deviation of the adjacent non-uniform interval duration. If the non-uniform speed investigation value is greater than the non-uniform speed investigation threshold, it is displayed as a non-uniform speed change fluctuation signal. If the non-uniform speed investigation value is less than or equal to the non-uniform speed investigation threshold, it is displayed as a non-uniform speed change stable signal.

8. The water pollution monitoring method based on spectral analysis according to claim 7, characterized in that: Based on the determined effluent flow velocity pattern, the process for predicting and obtaining non-monitoring values ​​is as follows: When the signal is displayed as a non-uniform velocity fluctuation, the interval between adjacent non-uniform velocity periods is extracted and compared. The minimum and maximum intervals are selected and the summation and average are calculated to obtain the predicted value of the non-monitoring duration. The predicted non-monitoring duration is calculated by comparing the predicted non-monitoring duration with the duration corresponding to the content monitoring period. When the signal is displayed as a non-uniformly changing stable signal, the number of uniform flow periods between adjacent non-uniform flow periods is extracted and the average value is calculated to obtain the predicted non-monitored value.

9. The water pollution monitoring method based on spectral analysis according to claim 1, characterized in that: The process of determining the non-monitoring periods for content and extracting the frequency of occurrence of these non-monitoring periods to obtain the monitoring frequency adjustment amount is as follows: Extract the current content monitoring period and calculate it in conjunction with the predicted non-monitoring value to obtain the content non-monitoring period. Statistically count the occurrence frequency of the content non-monitoring period as the content non-monitoring frequency. Extract the current spectral analysis monitoring frequency and calculate the difference between it and the content non-monitoring frequency. Take the absolute value to obtain the monitoring frequency adjustment amount.

10. A water pollution monitoring system based on spectral analysis, characterized in that: include: Time Period Analysis and Screening Module: Set a uniformity monitoring period for content, perform uniformity analysis of trace elements in the outlet monitoring area within each content monitoring period, and screen out time periods with uniform content and time periods with non-uniform content. Flow velocity content analysis module: During the content uniformity monitoring period, the changes in the effluent flow velocity in the outlet monitoring area are analyzed, the time periods with uniform flow velocity and the time periods with non-uniform flow velocity are screened, and the coupling degree between flow velocity uniformity and content uniformity is analyzed. Flow velocity pattern investigation module: When the coupling between flow velocity uniformity and content uniformity is close, the pattern of non-uniform effluent flow velocity variation is investigated to determine the effluent flow velocity pattern; Monitoring frequency adjustment module: Based on the determined effluent flow rate pattern, it obtains the predicted non-monitoring value, determines the non-monitoring period of content, extracts the occurrence frequency of the non-monitoring period of content, obtains the monitoring frequency adjustment amount, and completes the water pollution monitoring operation at the effluent outlet of the urban sewage treatment plant.

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