A water pollution source tracing method and system based on material conservation and time history similarity

Abstract

The present invention relates to a water pollution source tracing method and system based on material conservation and time history similarity. By obtaining the layout diagram of the drainage pipe network and the water flow direction data of the pipe network, a spatial topological relationship is established, and water quality monitoring nodes are set outside the drainage pipe network to monitor the water quality of the water quality monitoring nodes. It is judged whether the water quality factors of the water quality monitoring nodes exceed the standard. When it is determined that they do not exceed the standard, the water quality monitoring of the water quality monitoring nodes continues. When it is determined that they exceed the standard, the tracing boundary is determined based on the water quality monitoring data of the exceeded water quality factors. At this time, the water quality monitoring data of the water quality nodes outside the drainage pipe network within the tracing boundary is continuously monitored, and reverse tracing is carried out based on the monitoring data to determine the pollution source range. The present invention constructs a reverse tracing model for water pollution in urban sewage pipe networks, dynamically arranges monitoring points, gradually narrows the tracing range, requires a small sample size of water quality monitoring data, maximally utilizes the monitoring information, and improves the tracing efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of water pollution source tracing, and particularly to a water pollution source tracing method and system based on material conservation and time series similarity. Background Art

[0002] With the rapid development of the economic society, high-intensity production and living activities have brought a high-throughput pollution load to the urban water environment. As the main confluence channel, the drainage pipe network collects most of the production and domestic sewage in the urban area. The drainage pipe network is a topological network composed of multiple pipelines, which are connected to different drainage households through branch lines, and each drainage household is a node of the network. When the drainage quality of a drainage household does not meet the standard, such as the sewage treatment facility is ineffective, there is illegal discharge or an accident, the excessive pollutants will spread along the "node - branch line - main line" channel, thus triggering water pollution incidents in the urban sewage pipe network, and further leading to the deterioration of the water quality of the water body and the serious damage to the water ecological environment.

[0003] Pollution source tracing is the premise for solving water pollution incidents. In the prior art, the main source tracing methods include water quality fingerprint method, isotope tracing method, mitochondrial DNA source tracing method, etc. Although these methods have been applied in the work of pollutant source tracing, there are still certain deficiencies in these methods, that is, a large number of monitoring points need to be arranged for continuous monitoring, which is costly, time-consuming and laborious, and there are also phenomena of insufficient utilization of monitoring information and low source tracing efficiency. There is an urgent need for an efficient source tracing method for urban pipe network water pollution incidents. Summary of the Invention

[0004] The purpose of the present invention is to provide a water pollution source tracing method and system based on material conservation and time series similarity, which can reduce the number of monitoring points arranged, and lock the range of the pollution source with low cost and high efficiency.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] The present invention provides a water pollution source tracing method based on material conservation and time series similarity, and the water pollution source tracing method includes:

[0007] Step 1: Obtain the layout diagram of the drainage pipe network and the data of the water flow direction in the pipe network;

[0008] Step 2: Establish a spatial topological relationship based on the layout diagram of the drainage pipe network and the data of the water flow direction in the pipe network;

[0009] Step 3: Based on the spatial topological relationship, set water quality monitoring nodes outside the drainage pipe network, and obtain the water quality monitoring data outside the drainage pipe network, which is recorded as the first water quality monitoring data;

[0010] Step 4: Determine whether the water quality factors exceed the standard based on the first water quality monitoring data outside the drainage network; if the first water quality monitoring data is greater than the first preset threshold, it is determined that the standard is exceeded, and the exceeded water quality factor is the traceability factor, and step 5 is executed; if the first water quality monitoring data is less than or equal to the first preset threshold, it is determined that the standard is not exceeded, and return to step 3;

[0011] Step 5: Determine the location of the exceeded section based on the water quality monitoring data of the exceeded water quality factor;

[0012] Step 6: Determine the traceability boundary based on the location of the exceeded section;

[0013] Step 7: Obtain the water quality monitoring data outside the drainage network within the traceability boundary, denoted as the second water quality monitoring data;

[0014] Step 8: Conduct reverse tracing based on the second water quality monitoring data to determine the pollution source range;

[0015] Optionally, the drainage network includes a main pipeline and branch pipelines.

[0016] Optionally, after step 8, the traceability method further includes: obtaining the list of factories and enterprises within the pollution source range and locking the illegal discharge source.

[0017] Optionally, the specific steps of conducting reverse tracing based on the second water quality monitoring data to determine the pollution source range are as follows:

[0018] Step 801: Establish a material balance model;

[0019] Step 802: Based on the material balance model and the second water quality monitoring data, calculate the water volume of the water quality monitoring nodes within the traceability boundary, and calculate the balance error of the traceability factor based on the water volume;

[0020] Step 803: Calculate the leakage rate of the drainage network within the traceability boundary based on the balance error;

[0021] Step 804: Based on the leakage rate of the drainage network within the traceability boundary, determine whether the traceability progress is normal;

[0022] The specific steps of determining whether the traceability progress is normal include:

[0023] When the leakage rate of the drainage network within the traceability boundary is less than the second preset threshold, it indicates that the traceability progress is normal, and the next step is carried out; when the leakage rate of the drainage network within the traceability boundary is greater than or equal to the second preset threshold, it indicates that the traceability progress is abnormal. At this time, adjust the water quality monitoring nodes until the leakage rate of the drainage network within the traceability boundary is less than the second preset threshold;

[0024] Step 805: Analyze the traceability factors and water quality factors to obtain the correlation ranking result of the traceability factors and the water quality factors;

[0025] Step 806: Obtain the top k water quality factors in the correlation ranking result;

[0026] Step 807: Based on the second water quality monitoring data, obtain the concentrations of the traceability factors and water quality factors of the water quality monitoring nodes outside the drainage pipe network within the traceability boundary;

[0027] Step 808: Based on the concentrations of the traceability factors and water quality factors of the water quality monitoring nodes outside the drainage pipe network within the traceability boundary, calculate the concentration mean of the traceability factors and the concentration means of the top k water quality factors in the ranking result;

[0028] Step 809: Compare the concentration of the traceability factor at the position of the water quality monitoring node outside the drainage pipe network within the traceability boundary with the concentration mean of the traceability factor to obtain the first deviation;

[0029] Step 810: Compare the concentration of the water quality factor at the position of the water quality monitoring node outside the drainage pipe network within the traceability boundary with the concentration mean of the water quality factor to obtain the second deviation;

[0030] Step 811: Determine the key area based on the first deviation and the second deviation;

[0031] Step 812: Calculate the leakage rate of the drainage pipe network in the key area and judge whether the traceability progress is normal;

[0032] Step 813: Conduct real-time monitoring on the water quality of the drainage pipe network in the key area to obtain the third water quality monitoring data;

[0033] Step 814: Based on the third water quality monitoring data, conduct a time-history analysis on the drainage pipe network in the key area to determine the pollution source range.

[0034] Optionally, the calculation formula of the material balance model is:

[0035]

[0036] M n+1 ′ = Q n+1 C n+1

[0037] where M n+1 is the theoretical value of the pollutant mass at the (n + 1)-th water quality monitoring node, M n+1 ' is the actual value of the pollutant mass at the (n + 1)-th water quality monitoring node, Q i is the flow rate of the i-th water quality monitoring node flowing into the drainage pipe network, C iis the concentration of pollutants flowing into the drainage network at the i-th water quality monitoring node, Q n+1 is the flow rate of the (n + 1)-th water quality monitoring node flowing into the drainage network, C n+1 is the concentration of pollutants flowing into the drainage network at the (n + 1)-th water quality monitoring node.

[0038] Optionally, the calculation formula for the leakage rate of the drainage network of the water quality monitoring node is:

[0039]

[0040] where β is the leakage rate of the sewage network, M n+1 is the theoretical value of the pollutant mass at the (n + 1)-th water quality monitoring node, M n+1 ' is the actual value of the pollutant mass at the (n + 1)-th water quality monitoring node.

[0041] Optionally, the second preset threshold is 5%.

[0042] Optionally, the calculation formula for the average concentration deviation is: deviation = (measured value - average value)^2 / average value^2 * 100%.

[0043] Optionally, the time series analysis specifically includes:

[0044] Determine the water quality monitoring points, and the monitoring frequency of the water quality monitoring points is m times;

[0045] Select the monitoring data of the determined water quality monitoring points from the third water quality monitoring data;

[0046] Based on the monitoring data of the water quality monitoring points, judge whether the tracing factors of the water quality monitoring points, the trend of the concentration change curves of the water quality factors for m times of monitoring are consistent with the trend of the concentration change curves of m times of monitoring at the location of the exceeded standard section;

[0047] If they are consistent, the source of the exceedance is upstream of the drainage network where the water quality monitoring point is located;

[0048] Continue to conduct time series analysis on the upstream drainage network section in the key area;

[0049] If they are not consistent, it is determined that the pollution source is in the downstream branch pipeline of the drainage network where the water quality monitoring point is located.

[0050] The present invention also provides a water pollution tracing system based on material conservation and time series similarity. The water pollution tracing system includes:

[0051] A data acquisition module, which is used to acquire the layout diagram of the drainage network and the data of the water flow direction in the network;

[0052] A spatial topological relationship establishment module, configured to establish a spatial topological relationship based on the layout diagram of the drainage pipe network and the pipe network water flow direction data;

[0053] A first water quality monitoring data acquisition module, configured to, based on the spatial topological relationship, set water quality monitoring nodes outside the drainage pipe network and acquire water quality monitoring data outside the drainage pipe network, denoted as first water quality monitoring data;

[0054] A water quality factor exceeding standard judgment module, configured to judge whether a water quality factor exceeds the standard based on the first water quality monitoring data outside the drainage pipe network; if the first water quality monitoring data is greater than a first preset threshold, it is determined that the standard is exceeded, and the next module is executed, and the exceeded water quality factor is a traceability factor; if the first water quality monitoring data is less than or equal to the first preset threshold, it is determined that the standard is not exceeded, and the first water quality monitoring data acquisition module is returned;

[0055] An exceeded section position determination module, configured to determine the position of the exceeded section based on the water quality monitoring data of the exceeded water quality factor;

[0056] A traceability boundary determination module, configured to determine a traceability boundary based on the position of the exceeded section;

[0057] A second water quality monitoring data acquisition module, configured to acquire water quality monitoring data outside the drainage pipe network within the traceability boundary, denoted as second water quality monitoring data;

[0058] A pollution source range determination module, configured to perform reverse tracing based on the second water quality monitoring data to determine the pollution source range.

[0059] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0060] The present invention provides a water pollution source tracing method and system based on material conservation and time series similarity. By obtaining the layout diagram of the drainage pipe network and the water flow direction data of the pipe network, a spatial topological relationship is established, and water quality monitoring nodes are set outside the drainage pipe network. The water quality of the water quality monitoring nodes is monitored to obtain the first water quality monitoring data. It is judged whether the water quality factors of the water quality monitoring nodes exceed the standard. When it is determined that they do not exceed the standard, the water quality monitoring of the water quality monitoring nodes continues. When it is determined that they exceed the standard, the exceeding section is determined based on the water quality monitoring data of the exceeding water quality factors, and the tracing boundary is determined based on the position of the exceeding section. At this time, the water quality monitoring data of the water quality nodes outside the drainage pipe network within the tracing boundary is continuously monitored to obtain the second water quality monitoring data, and reverse tracing is carried out based on the second water quality monitoring data to determine the pollution source range. Based on the material conservation and time series similarity principles, on the basis of data tracing and manual investigation results, the present invention constructs a reverse tracing model for water pollution in urban sewage pipe networks, dynamically arranges monitoring points, gradually narrows the tracing range, requires a small sample size of water quality monitoring data, maximally utilizes monitoring information, improves the tracing efficiency, and provides a new idea and method for the water pollution source tracing work of urban sewage pipe networks. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0062] Figure 1 It is a flowchart of a water pollution source tracing method based on material conservation and time series similarity provided by the present invention;

[0063] Figure 2 It is a spatial topological relationship diagram of the layout of the drainage pipe network and the water flow direction of the pipe network in the embodiment provided by the present invention;

[0064] Figure 3 It is a distribution diagram of the positions of water quality monitoring nodes of the drainage pipe network in the embodiment provided by the present invention;

[0065] Figure 4 It is a comparison diagram of the correlation between CODcr and BOD5 in the embodiment provided by the present invention;

[0066] Figure 5 It is a comparison diagram of the correlation between CODcr and conductivity in the embodiment provided by the present invention;

[0067] Figure 6 It is a comparison diagram of the correlation between CODcr and ammonia nitrogen in the embodiment provided by the present invention;

[0068] Figure 7Comparison chart of the correlation between CODcr and sulfate in the embodiments provided by the present invention;

[0069] Figure 8 Comparison chart of the correlation between CODcr and volatile phenol in the embodiments provided by the present invention;

[0070] Figure 9 Comparison chart of the correlation between CODcr and oxides in the embodiments provided by the present invention;

[0071] Figure 10 Comparison chart of the deviation of CODcr at each monitoring point from the mean value in the embodiments provided by the present invention;

[0072] Figure 11 Comparison chart of the deviation of sulfate at each monitoring point from the mean value in the embodiments provided by the present invention;

[0073] Figure 12 Comparison chart of the deviation of BOD5 at each monitoring point from the mean value in the embodiments provided by the present invention;

[0074] Figure 13 Comparison chart of the deviation of ammonia nitrogen at each monitoring point from the mean value in the embodiments provided by the present invention;

[0075] Figure 14 Location map of water quality monitoring points in key areas of the embodiments provided by the present invention;

[0076] Figure 15 Curve graph of the change in the concentration of chloride monitored 4 times in the key area of the embodiments provided by the present invention and curve graph of the change in the concentration monitored 4 times at the location of the exceeded standard section;

[0077] Figure 16 Curve graph of the change in the concentration of CODcr monitored 4 times in the key area of the embodiments provided by the present invention and curve graph of the change in the concentration monitored 4 times at the location of the exceeded standard section;

[0078] Figure 17 Reduced location map of water quality monitoring points in key areas of the embodiments provided by the present invention;

[0079] Figure 18 Curve graph of the change in the concentration of CODcr monitored 4 times in the reduced key area of the embodiments provided by the present invention and curve graph of the change in the concentration monitored 4 times at the location of the exceeded standard section;

[0080] Figure 19 Curve graph of the change in the concentration of chloride monitored 4 times in the reduced key area of the embodiments provided by the present invention and curve graph of the change in the concentration monitored 4 times at the location of the exceeded standard section;

[0081] Figure 20 Location map of the source of illegal discharge in the embodiments provided by the present invention;

[0082] Figure 21 Schematic structural diagram of a water pollution source tracing system based on material conservation and time history similarity provided by the present invention. Specific embodiments

[0083] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0084] The purpose of the present invention is to provide a water pollution source tracing method and system based on material conservation and time history similarity, which can reduce the number of monitoring points arranged and lock the scope of the pollution source at low cost and high efficiency.

[0085] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0086] See the accompanying drawings Figure 1 , the present invention provides a water pollution source tracing method based on material conservation and time history similarity, and the water pollution source tracing method includes:

[0087] Step 1: Obtain the drainage network layout diagram and the network water flow direction data, and the drainage network includes a main pipeline and branch pipelines.

[0088] Step 2: See the accompanying drawings Figure 2 , establish a spatial topological relationship based on the drainage network layout diagram and the network water flow direction data.

[0089] Step 3: Based on the spatial topological relationship, set water quality monitoring nodes outside the drainage network, obtain the water quality monitoring data outside the drainage network, and record it as the first water quality monitoring data.

[0090] Specifically, the water quality monitoring nodes are mainly set at different sewage junctions of the drainage network and key pollution discharge enterprises that discharge characteristic pollutants related to the tracing factors.

[0091] Specifically, the monitoring elements of the water quality monitoring nodes are: basic conventional water quality monitoring indicators, characteristic pollutant factors of the connected pollution discharge enterprises, and water quality over-standard factors. In this embodiment, they are set as pH, water temperature, CODcr (chemical oxygen demand), BOD5 (biochemical oxygen demand in five days), ammonia nitrogen, total phosphorus, suspended solids, SO4 2- (sulfate radical), volatile phenol, cyanide, total lead, total zinc, total mercury, total vanadium, total arsenic, total nickel, total chromium, hexavalent chromium, total cadmium, conductivity, total hardness.

[0092] The monitoring frequency of the water quality monitoring node is: three times of monitoring are carried out at 8:00 / 12:00 / 18:00 every day.

[0093] Step 4: Judge whether the water quality factors exceed the standard based on the first water quality monitoring data outside the drainage network; if the first water quality monitoring data is greater than the first preset threshold, it is determined to exceed the standard, and the exceeded water quality factor is the traceability factor, and step 5 is executed; if the first water quality monitoring data is less than or equal to the first preset threshold, it is determined not to exceed the standard, and return to step 3.

[0094] The exceeded water quality factor in this embodiment is CODcr (chemical oxygen demand).

[0095] Step 5: Determine the position of the exceeded section based on the water quality monitoring data of the exceeded water quality factor.

[0096] Step 6: Determine the traceability boundary based on the position of the exceeded section, and obtain the list of industrial enterprises, drainage volume, and pollutant types within the traceability range above the exceeded section by referring to the list of enterprises connected to the sewage treatment plant and conducting on-site supplementary investigations.

[0097] Step 7: Obtain the water quality monitoring data outside the drainage network within the traceability boundary, which is recorded as the second water quality monitoring data.

[0098] Step 8: Based on the second water quality monitoring data, conduct reverse tracing to determine the pollution source range, which specifically includes the following steps:

[0099] Step 801: Establish a material balance model, and the calculation formula of the material balance model is:

[0100]

[0101] M n+1 ′=Q n+1 C n+1

[0102] Among them, M n+1 is the theoretical value of the pollutant mass at the (n + 1)th water quality monitoring node (kg / h), M n+1 ' is the actual value of the pollutant mass at the (n + 1)th water quality monitoring node (kg / h), Q i is the flow rate of the water flowing into the drainage network at the ith water quality monitoring node (m 3 / s), C i is the concentration of the pollutant in the water flowing into the drainage network at the ith water quality monitoring node (mg / L), Q n+1 is the flow rate of the water flowing into the drainage network at the (n + 1)th water quality monitoring node (m 3 / s), C n+1 is the concentration of the pollutant in the water flowing into the drainage network at the (n + 1)th water quality monitoring node (mg / L).

[0103] Step 802: Based on the material balance model and the second water quality monitoring data, calculate the water volume of the water quality monitoring nodes within the traceability boundary, and calculate the balance error of the traceability factors based on the water volume.

[0104] See the attached drawings Figure 3 Distribution map of the positions of the water quality monitoring nodes in the drainage network. In this embodiment, calculate the material balance of the water quality monitoring nodes numbered 02, 08, 13, and 17. The calculation formula is:

[0105] Q 02 ×C 02 = 4.765 g / s

[0106] Q 01 ×C 01 +Q 02-01 ×C 02-01 +Q 02-02 ×C 02-02 +Q 02-03 ×C 02-03 = 4.886 g / s

[0107] Q 02 ×C 02 = 0.975 * (Q 01 ×C 01 +Q 02-01 ×C 02-01 +Q 02-02 ×C 02-02 +Q 02-03 ×C 02-03 )

[0108] Q 08 ×C 08 = 43.678 g / s

[0109] Q 07 ×C 07 +Q 07-01 ×C 07-01 +Q 07-02 ×C 07-02 +Q 07-03 ×C 07-03 = 45.641 g / s

[0110] Q 08 ×C 08 = 0.957 * (Q 07 ×C 07 +Q 07-1 ×C 07-1 +Q 07-2 ×C 07-2 +Q 07-3 ×C 07-3 )

[0111] Q 13 ×C 13 = 10.580 g / s

[0112] Q 14 ×C 14 +Q 13-01 ×C 13-01 +Q 13-02 ×C 13-02 +Q 13-03 ×C 13-03 = 11.032 g / s

[0113] Q 13 ×C 13 = 0.959 * (Q 14 ×C 13 +Q 13-01 ×C 13-01 +Q 13-02 ×C 13-02 +Q 13-03 ×C 13-03 )

[0114] Q 17 ×C 17 = 227.993 g / s

[0115] Q 16 ×C 16 +Q 16-01 ×C 16-01 +Q 16-02 ×C 16-02 +Q 17-01 ×C 17-01 +Q 17-02 ×C 17-02 = 236.262 g / s

[0116] Q 17 ×C 17 = 0.965 * (Q 16 ×C 16 +Q 16-01 ×C 16-01 +Q 16-02 ×C 16-02 +Q 17-01 ×C 17-01 +Q 17-02 ×C 17-02 )

[0117] Step 803: Calculate the leakage rate of the drainage pipe network within the traceability boundary based on the balance error. The calculation formula for the leakage rate of the drainage pipe network of the water quality monitoring node is as follows:

[0118]

[0119] Among them, β is the leakage rate of the sewage pipe network, and M n+1 is the theoretical value of the pollutant mass (kg / h) at the (n + 1)-th water quality monitoring node, and M n+1 ′ is the actual value of the pollutant mass (kg / h) at the (n + 1)-th water quality monitoring node.

[0120] Specifically, the leakage rates of the drainage pipe networks with the water quality monitoring node numbers 02, 08, 13, and 17 are respectively:

[0121] β 02 = 2.5%

[0122] β 08 = 4.3%

[0123] β 13 = 4.1%

[0124] β 17 = 3.5%

[0125] Step 804: Based on the leakage rate of the drainage pipe network within the tracing boundary, determine whether the tracing progress is normal. The specific determination of whether the tracing progress is normal includes:

[0126] When the leakage rate of the drainage pipe network within the tracing boundary is less than the second preset threshold, it indicates that the tracing progress is normal, and the next step is carried out; when the leakage rate of the drainage pipe network within the tracing boundary is greater than or equal to the second preset threshold, it indicates that the tracing progress is abnormal. At this time, the water quality monitoring node is adjusted until the leakage rate of the drainage pipe network within the tracing boundary is less than the second preset threshold; the second threshold is 5%.

[0127] It can be seen that β 02 , β 08 , β 13 , β 17 are all less than the second threshold of 5%, indicating that the tracing progress of the water quality monitoring node numbers 02, 08, 13, and 17 is normal.

[0128] Step 805: Refer to the attached drawings Figure 4 CODcr and BOD5 correlation comparison chart, Figure 5 CODcr and conductivity correlation comparison chart, Figure 6 CODcr and ammonia nitrogen correlation comparison chart, Figure 7 CODcr and sulfate correlation comparison chart, Figure 8 CODcr and volatile phenol correlation comparison chart, and Figure 9 CODcr and oxide correlation comparison chart, analyze the tracing factor and the water quality factor to obtain the correlation ranking result of the tracing factor and the water quality factor.

[0129] Correlation analysis is to study the strength of the linear correlation between two variables through sample data, reflecting the convergence relationship between the two variables. The commonly used Pearson correlation coefficient method is adopted in the present invention:

[0130]

[0131] where r is the correlation coefficient; X i is the i-th sample value of variable X; is the sample mean of variable X; Y i is the i-th sample value of variable Y; is the sample mean of variable Y.

[0132] According to the numerical value, the degree of closeness of incomplete linear correlation is divided into four levels: 0 ≤ |r| ≤ 0.3 is weak correlation; 0.3 < |r| ≤ 0.5 is low correlation; 0.5 < |r| ≤ 0.8 is medium correlation; 0.8 < |r| ≤ 1 is high correlation. In this embodiment, the sorting of the 6 correlation analyses is: BOD5, sulfate, ammonia nitrogen, conductivity, chloride, volatile phenol.

[0133] Step 806: Obtain the first k water quality factors in the correlation sorting result. Specifically, k is taken as 3, and the first 3 water quality factors are: BOD5, sulfate, ammonia nitrogen.

[0134] Step 807: Based on the second water quality monitoring data, obtain the tracing factors and the concentrations of water quality factors of the water quality monitoring nodes outside the drainage pipe network within the tracing boundary.

[0135] Step 808: Based on the tracing factors and the concentrations of water quality factors of the water quality monitoring nodes outside the drainage pipe network within the tracing boundary, calculate the mean concentration of the tracing factors and the mean concentration of the first k water quality factors in the sorting result; the calculation formula for the mean concentration deviation is: deviation = (measured value - mean) 2 / mean 2 * 100%.

[0136] Step 809: Compare the concentration of the tracing factor at the position of the water quality monitoring node outside the drainage pipe network within the tracing boundary with the mean concentration of the tracing factor to obtain the first deviation.

[0137] Step 810: Compare the concentration of the water quality factor at the position of the water quality monitoring node outside the drainage pipe network within the tracing boundary with the mean concentration of the water quality factor to obtain the second deviation.

[0138] Step 811: Determine the key area based on the first deviation and the second deviation, that is, the key over-standard area with an obvious deviation from the overall mean. Specifically, refer to the attached drawings Figure 10 Comparison chart of the deviation of CODcr at each monitoring point from the mean value, Figure 11Comparison chart of the deviation of sulfate at each monitoring point from the average value, Figure 12 comparison chart of the deviation of BOD5 at each monitoring point from the average value, and Figure 13 comparison chart of the deviation of ammonia nitrogen at each monitoring point from the average value to determine the key area.

[0139] Step 812: Calculate the leakage rate of the drainage pipeline network in the key area and judge whether the tracing progress is normal.

[0140] Specifically, calculate the material balance of water quality monitoring nodes numbered 1-4. The calculation formula is:

[0141] Q 1-4 ×C 1-4 = 32.856 g / s

[0142] Q 1-3 ×C 1-3 +Q 1-3-1 ×C 1-3-1 +Q 1-3-2 ×C 1-3-2 +Q 1-3-3 ×C 1-3-3 = 34.118 g / s

[0143] Q 1-4 ×C 1-4 = 0.963 * (Q 1-3 ×C 1-3 +Q 1-3-1 ×C 1-3-1 +Q 1-3-2 ×C 1-3-2 +Q 1-3-3 ×C 1-3-3 )

[0144] β 1-4 = 3.7% < 5%

[0145] It can be seen that the tracing progress of nodes 1-4 is good.

[0146] Step 813: Conduct real-time monitoring on the water quality of the drainage pipeline network in the key area to obtain the third water quality monitoring data.

[0147] Step 814: Based on the third water quality monitoring data, conduct a time history analysis on the drainage pipeline network in the key area to determine the pollution source range. The time history analysis specifically includes:

[0148] Refer to the attached drawings Figure 14Location map of water quality monitoring points in key areas, determining water quality monitoring points. The water quality monitoring points are located at the confluence of branch pipelines into the main pipeline within the key area. The monitoring frequency of the water quality monitoring points is m times. In this embodiment, the monitoring frequency is 4 times. This embodiment adopts continuous monitoring for 4 days. When the water quality monitoring points and frequencies do not meet the requirements, supplementary continuous monitoring will be carried out. Specifically, 7 water quality monitoring points are set, and the monitoring factors are CODcr and chloride. Specifically, online monitoring data and on-site monitoring data can be obtained simultaneously. The on-site monitoring data is monitored by on-site staff.

[0149] Select the monitoring data of the determined water quality monitoring points from the third water quality monitoring data.

[0150] Based on the monitoring data of the water quality monitoring points, judge whether the tracing factors of the water quality monitoring points, the trend of the concentration change curves of the water quality factors in m times of monitoring, are consistent with the trend of the concentration change curves in m times of monitoring at the location of the exceeded standard section.

[0151] If they are consistent, it can be preliminarily judged that the exceeded standard source is in this area, and the exceeded standard source is upstream of the drainage pipe network where the water quality monitoring point is located. Continue to conduct time-course analysis on the cross-sections of the upstream drainage pipe network within the key area.

[0152] If they are inconsistent, it is determined that the pollution source is in the downstream branch pipeline of the drainage pipe network where the water quality monitoring point is located. For the finally screened exceeded standard pipelines, if there are more than 5 exceeded standard pipeline enterprises after tracing, continue to set water quality monitoring points in the branch pipelines under the pipeline, and use time-course analysis to accelerate tracing. The tracing scope is reduced to less than 5, and the pollution source can be locked through on-site investigation.

[0153] Specifically, refer to the attached drawings Figure 15 Curve of the concentration change of chloride in 4 times of monitoring in the key area and the curve of the concentration change in 4 times of monitoring at the location of the exceeded standard section, Figure 16 Curve of the concentration change of CODcr in 4 times of monitoring in the key area and the curve of the concentration change in 4 times of monitoring at the location of the exceeded standard section. The water quality concentration change trends of cross-sections 1-3 to 1-7 are basically consistent with that of the exceeded standard section, while the water quality concentration change trends of cross-sections 1-1 and 1-2 are inconsistent with that of the exceeded standard section. It is determined that the exceeded standard source is in the branch pipe network between cross-sections 1-3 and 1-2.

[0154] Specifically, the scope of the pollution source can be further narrowed. When it is determined that the exceeded standard source is in the branch pipe network between cross-sections 1-3 and 1-2, refer to the attached drawings Figure 17Location map of water quality monitoring points in the reduced key area. Three monitoring points, namely 1-3-1, 1-3-2, and 1-3-3, are arranged between section 1-2 and section 1-3. The monitoring factors are CODcr (chemical oxygen demand) and chloride, and the monitoring frequency is set to 4 times. Specifically, online monitoring data and on-site monitoring data can be obtained simultaneously. The on-site monitoring data is monitored by on-site staff.

[0155] Specifically, calculate the material conservation of the tributary pipe network and calculate the material balance of the water quality monitoring node numbered 1-2. The calculation formula is:

[0156] Q 1-3 ×C 1-3 =19.869g / s

[0157] Q 1-2-1 ×C 1-2-1 +Q 1-2-2 ×C 1-2-2 +Q 1-2-3 ×C 1-2-3 =20.348g / s

[0158] Q 1-3 ×C 1-3 =0.976(Q 1-2-1 ×C 1-2-1 +Q 1-2-2 ×C 1-2-2 +Q 1-2-3 ×C 1-2-3 )

[0159] β=2.4%<5%

[0160] It can be seen that the tracing progress of node 1-2 is good.

[0161] Specifically, based on the third water quality monitoring data, continue the time-course analysis of the drainage pipe network in the key area to determine the reduced pollution source range.

[0162] See the attached figure Figure 18 Change curve of 4-time monitoring concentration of CODcr in the reduced key area and change curve of 4-time monitoring concentration at the location of the exceeded standard section, Figure 19 Change curve of 4-time monitoring concentration of chloride in the reduced key area and change curve of 4-time monitoring concentration at the location of the exceeded standard section. It can be seen that the water quality concentration change trends of section 1-2-1 and section 1-2-2 are basically the same as that of section 1-3, while the water quality concentration change trends of section 1-2-3 and section 1-3 are inconsistent with those of the exceeded standard section. It is determined that the exceeded standard source is in the branch pipe network between section 1-2-2 and section 1-2-3.

[0163] Specifically, after the step 8, it further includes: obtaining the list of factories and enterprises within the scope of the pollution source and locking the source of illegal discharge.

[0164] Specifically, refer to the attached drawings Figure 20 Location map of the source of illegal discharge. After narrowing down the pollution scope, there are a total of 2 enterprises in the over-standard branch pipe network. Through on-site investigation, the pollution source was locked to one of the enterprises, and the pollution source was found.

[0165] Refer to the attached drawings Figure 21 Schematic structural diagram of a water pollution source tracing system based on material conservation and time series similarity. Based on the water pollution source tracing method based on material conservation and time series similarity provided above by the present invention, the present invention also provides a water pollution source tracing system based on material conservation and time series similarity. The system includes: a data acquisition module, a spatial topological relationship establishment module, a first water quality monitoring data acquisition module, a water quality factor over-standard judgment module, an over-standard section location determination module, a source tracing boundary determination module, a second water quality monitoring data acquisition module, and a pollution source range determination module.

[0166] The data acquisition module is used to obtain the layout map of the drainage pipe network and the data of the water flow direction in the pipe network.

[0167] The spatial topological relationship establishment module is used to establish a spatial topological relationship based on the layout map of the drainage pipe network and the data of the water flow direction in the pipe network.

[0168] The first water quality monitoring data acquisition module is used to set water quality monitoring nodes outside the drainage pipe network based on the spatial topological relationship and obtain the water quality monitoring data outside the drainage pipe network, which is recorded as the first water quality monitoring data.

[0169] The water quality factor over-standard judgment module is used to judge whether the water quality factors exceed the standard based on the first water quality monitoring data outside the drainage pipe network; if the first water quality monitoring data is greater than the first preset threshold, it is determined to exceed the standard, and the next module is executed. The over-standard water quality factor is the source tracing factor; if the first water quality monitoring data is less than or equal to the first preset threshold, it is determined not to exceed the standard, and the first water quality monitoring data acquisition module is returned.

[0170] The over-standard section location determination module is used to determine the location of the over-standard section based on the water quality monitoring data of the over-standard water quality factors.

[0171] The source tracing boundary determination module is used to determine the source tracing boundary based on the location of the over-standard section.

[0172] The second water quality monitoring data acquisition module is used to obtain the water quality monitoring data outside the drainage pipe network within the source tracing boundary, which is recorded as the second water quality monitoring data.

[0173] The pollution source range determination module is used to perform reverse tracing based on the second water quality monitoring data to determine the pollution source range.

[0174] In the present specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method part.

[0175] In this article, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A water pollution source tracing method based on material conservation and time history similarity, characterized in that The described method for tracing the source of water pollution includes: Step 1: Obtain the layout map of the drainage pipe network and the data of the water flow direction in the pipe network; Step 2: Establish a spatial topological relationship based on the layout map of the drainage pipe network and the data of the water flow direction in the pipe network; Step 3: Based on the spatial topological relationship, set water quality monitoring nodes outside the drainage pipe network to obtain the water quality monitoring data outside the drainage pipe network, denoted as the first water quality monitoring data; Step 4: Determine whether the water quality factors exceed the standard based on the first water quality monitoring data outside the drainage pipe network; if the first water quality monitoring data is greater than the first preset threshold, it is determined to exceed the standard, and the exceeded water quality factor is the tracing factor, and proceed to Step 5; if the first water quality monitoring data is less than or equal to the first preset threshold, it is determined not to exceed the standard, and return to Step 3; Step 5: Determine the position of the exceeded section based on the water quality monitoring data of the exceeded water quality factor; Step 6: Determine the tracing boundary based on the position of the exceeded section; Step 7: Obtain the water quality monitoring data outside the drainage pipe network within the tracing boundary, denoted as the second water quality monitoring data; Step 8: Based on the second water quality monitoring data, conduct reverse tracing to determine the range of the pollution source; Based on the second water quality monitoring data, conduct reverse tracing to determine the range of the pollution source, which specifically includes the following steps: Step 801: Establish a material balance model; Step 802: Based on the material balance model and the second water quality monitoring data, calculate the flow rate of the water quality monitoring nodes within the tracing boundary, and calculate the balance error of the tracing factor based on the flow rate; Step 803: Calculate the leakage rate of the drainage pipe network within the tracing boundary based on the balance error; Step 804: Based on the leakage rate of the drainage pipe network within the tracing boundary, determine whether the tracing progress is normal; The determination of whether the tracing progress is normal specifically includes: When the leakage rate of the drainage pipe network within the tracing boundary is less than the second preset threshold, it indicates that the tracing progress is normal, and proceed to the next step; when the leakage rate of the drainage pipe network within the tracing boundary is greater than or equal to the second preset threshold, it indicates that the tracing progress is abnormal. At this time, adjust the water quality monitoring nodes until the leakage rate of the drainage pipe network within the tracing boundary is less than the second preset threshold; Step 805: Analyze the tracing factor and the water quality factor to obtain the correlation ranking result of the tracing factor and the water quality factor; Step 806: Obtain the top k water quality factors in the correlation ranking result; Step 807: Based on the second water quality monitoring data, obtain the concentration of the tracing factor and the water quality factor of the water quality monitoring nodes outside the drainage pipe network within the tracing boundary; Step 808: Based on the concentration of the tracing factor and the water quality factor of the water quality monitoring nodes outside the drainage pipe network within the tracing boundary, calculate the average concentration of the tracing factor and the average concentration of the top k water quality factors in the ranking result; Step 809: Compare the concentration of the tracing factor at the position of the water quality monitoring nodes outside the drainage pipe network within the tracing boundary with the average concentration of the tracing factor to obtain the first deviation; Step 810: Compare the concentration of the water quality factor at the position of the water quality monitoring nodes outside the drainage pipe network within the tracing boundary with the average concentration of the water quality factor to obtain the second deviation; Step 811: Determine the key area based on the first deviation and the second deviation; Step 812: Calculate the leakage rate of the drainage pipe network in the key area and determine whether the progress of source tracing is normal; Step 813: Real-time monitor the water quality of the drainage pipe network in the key area to obtain the third water quality monitoring data; Step 814: Based on the third water quality monitoring data, conduct a time-course analysis of the drainage pipe network in the key area to determine the scope of the pollution source; The calculation formula of the material balance model is: Among them, is the theoretical value of the pollutant mass at the (n + 1)-th water quality monitoring node, is the actual value of the pollutant mass at the (n + 1)-th water quality monitoring node, is the i flow rate of the water quality monitoring node flowing into the drainage pipe network, is the i concentration of pollutants in the water quality monitoring node flowing into the drainage pipe network, is the flow rate of the (n + 1)-th water quality monitoring node flowing into the drainage pipe network, is the concentration of pollutants in the (n + 1)-th water quality monitoring node flowing into the drainage pipe network; Based on the Pearson correlation coefficient method, determine the correlation ranking result. The calculation formula of the correlation coefficient is: Among them, is the correlation coefficient, is the th sample value of the variable is the sample mean of the variable ; is the th sample value of the variable is the sample mean of the variable ; The specific time-course analysis includes: Determine the water quality monitoring points, and the monitoring frequency of the water quality monitoring points is m times; Select the monitoring data of the determined water quality monitoring points from the third water quality monitoring data; Based on the monitoring data of the water quality monitoring points, judge whether the trend of the concentration change curves of the source tracing factors and water quality factors monitored m times at the water quality monitoring points is consistent with the trend of the concentration change curves monitored m times at the location of the exceeded standard section; If they are consistent, the source of the exceedance is upstream of the drainage pipe network where the water quality monitoring point is located; Continue to conduct a time-course analysis on the cross-section of the upstream drainage pipe network in the key area; If they are not consistent, it is determined that the pollution source is in the downstream branch pipeline of the drainage pipe network where the water quality monitoring point is located.

2. The water pollution source tracing method based on material conservation and time history similarity according to claim 1, characterized in that, The drainage pipe network includes a main pipeline and branch pipelines.

3. A water pollution source tracing method based on material conservation and time-course similarity according to claim 1, characterized in that, After step 8, the source tracing method further includes: obtaining the list of factories and enterprises within the scope of the pollution source and locking the source of illegal discharge.

4. A water pollution source tracing method based on material conservation and time course similarity according to claim 1, characterized in that The calculation formula of the leakage rate of the drainage pipe network at the water quality monitoring node is: Among them, is the leakage rate of the sewage pipe network, is the theoretical value of the pollutant mass at the (n + 1)-th water quality monitoring node, is the actual value of the pollutant mass at the (n + 1)-th water quality monitoring node.

5. A water pollution source tracing method based on material conservation and time-course similarity according to claim 1, characterized in that The second preset threshold is 5%.

6. The water pollution source tracing method based on material conservation and time history similarity according to claim 1, characterized in that, The calculation formula of the mean concentration deviation is: 。 7. A water pollution source tracing system based on material conservation and time history similarity, which is used to implement the water pollution source tracing method based on material conservation and time history similarity described in any one of claims 1-6, and is characterized in that, The water pollution source tracing system includes: A data acquisition module for acquiring the drainage pipe network layout diagram and the network water flow direction data; A spatial topological relationship establishment module for establishing a spatial topological relationship based on the drainage pipe network layout diagram and the network water flow direction data; A first water quality monitoring data acquisition module for, based on the spatial topological relationship, setting water quality monitoring nodes outside the drainage pipe network and acquiring the water quality monitoring data outside the drainage pipe network, denoted as the first water quality monitoring data; A water quality factor exceedance judgment module for judging whether the water quality factor exceeds the standard based on the first water quality monitoring data outside the drainage pipe network; if the first water quality monitoring data is greater than the first preset threshold, it is determined to exceed the standard, and the next module is executed. The exceeded water quality factor is the source tracing factor; if the first water quality monitoring data is less than or equal to the first preset threshold, it is determined not to exceed the standard, and the first water quality monitoring data acquisition module is returned; An exceeded standard section location determination module for determining the location of the exceeded standard section based on the water quality monitoring data of the exceeded water quality factor; A source tracing boundary determination module for determining the source tracing boundary based on the location of the exceeded standard section; A second water quality monitoring data acquisition module for acquiring the water quality monitoring data outside the drainage pipe network within the source tracing boundary, denoted as the second water quality monitoring data; A pollution source range determination module for, based on the second water quality monitoring data, conducting reverse source tracing to determine the range of the pollution source.

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