A method for locating sewage mixing points in high-water-level rainwater pipe networks based on isotopes

Abstract

The present invention discloses a method for locating sewage mixing points in a high-water-level rainwater pipe network based on isotopes, and the method comprises the following steps: determining drainage pipe water quality monitoring points and tap water water quality monitoring points based on rainwater pipe network information in a research area; sampling drainage pipe water quality monitoring points and tap water water quality monitoring points continuously for several times after rain to obtain water samples at several monitoring points; obtaining several isotope indicators based on the water samples at several monitoring points; removing abnormal data of several isotope indicators and loading them into a MixSIAR model, and calculating the sewage mixing rate at the water quality monitoring points of the rainwater pipe network to obtain the mixing rate; calculating the mixing amount of the rainwater pipe network based on the mixing rate and the isotope indicator and locating the mixing point position; checking the mixing point position based on a sonar detector to obtain the connection status of the well wall pipe under the well water. The present invention can relatively accurately calculate the sewage mixing amount of the high-water-level rainwater pipe network and locate the mixing point.

Description

Technical Field

[0001] The present invention belongs to the technical field of rainwater-sewage mixing investigation and diagnosis in drainage pipe networks, and in particular relates to a method for locating sewage mixing points in high-water-level rainwater pipe networks based on isotopes. Background Art

[0002] Due to the long construction period, the overlap or lag between drainage pipeline construction and urban construction, and the incomplete diversion transformation, most drainage systems are facing problems such as continuous fullness of sewage and rainwater pipes, black and smelly water on rainy days, and overflow of sewage treatment plants on rainy days. The root cause of these problems is the obvious mixing of rainwater and sewage in the diversion drainage system.

[0003] At present, the main detection methods for rainwater pipe sewage mixing include intuitive detection method, instrument online monitoring method and tracer method. Among them, the only detection methods include CCTV detection, pipeline periscope detection and sonar detection. The instrument online monitoring method usually monitors the liquid level, flow rate and some traditional water quality indicators of the inspection well. The tracer method usually uses water quality characteristic factors, isotopes, microorganisms, etc. as tracer indicators to calculate the mixing amount in the pipe network and analyze the mixing points. Recently, there are also rainwater and sewage mixing identification methods using emerging technologies such as fluorescence spectroscopy and electrochemical spectroscopy. At present, there is a large room for improvement in the tracer indicators used in the tracer method. Commonly used traditional water quality characteristic factors, such as COD, ammonia nitrogen, fluoride, chloride, total phosphorus, total nitrogen, etc., may react and digest during the sewage transmission process, thereby affecting the accuracy of the rainwater and sewage mixing results inferred based on these factors. At the same time, due to the uncertainty caused by the volatility and variability of sewage water quality, the accuracy of existing rainwater and sewage mixing diagnosis technology is also facing challenges. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a method for locating sewage mixing points in a high-water-level operating rainwater pipe network based on isotopes to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides a method for locating sewage mixing points in a high water level running rainwater pipe network based on isotopes, comprising:

[0006] Determine the drainage pipe water quality monitoring points and tap water quality monitoring points based on the rainwater pipe network information in the study area;

[0007] After the rain, the drainage pipe water quality monitoring point and the tap water quality monitoring point are continuously sampled several times to obtain several monitoring point water samples; and several isotope indicators are obtained based on the several monitoring point water samples;

[0008] After eliminating abnormal data of several isotope indicators, the data are loaded into the MixSIAR model and the sewage mixing rate at the water quality monitoring point of the rainwater pipe network is calculated to obtain the mixing rate;

[0009] Calculate the mixing amount of the rainwater pipe network based on the mixing rate and the isotope index and locate the mixing point;

[0010] The position of the mixing point is checked based on a sonar detector to obtain the connection status of the well wall pipeline under the well water.

[0011] Optionally, the process of determining drainage pipe water quality monitoring points includes:

[0012] Obtain the rainwater pipe network information of the study area based on design data analysis and field survey information;

[0013] Determine the effective water sample well location based on the rainwater pipe network information;

[0014] The drainage pipe water quality monitoring point is obtained based on the effective water sample well location.

[0015] Optionally, the process of taking water samples from several monitoring points after rain includes:

[0016] Determine the fixed interval time;

[0017] After rain, the drainage pipe water quality monitoring point and the tap water quality monitoring point are continuously sampled several times at the fixed intervals to obtain water samples of several monitoring points;

[0018] The fixed interval time includes but is not limited to half a day and a day.

[0019] Optionally, the plurality of isotope indicators include isotope indicators δ 18 O and isotope index δ 2 H.

[0020] Optionally, the process of calculating the mixing rate based on the MixSIAR model includes:

[0021] The data corresponding to the isotope index after eliminating abnormal data is converted into a csv file, and the csv file is input into the MixSIAR algorithm model;

[0022] The mixing rate is obtained by calculating based on the uncertain algorithm JAGS function in the MixSIAR algorithm model.

[0023] Optionally, the process of performing calculation based on the uncertain algorithm JAGS function includes performing iterative calculation based on a Monte Carlo Markov chain; wherein the calculation chain length of the Monte Carlo Markov chain is 100,000.

[0024] Optionally, the process of calculating the mixing volume of the rainwater pipe network and locating the mixing point position includes:

[0025] Obtaining an average value of the pipe network mixing rate based on the mixing rates of the plurality of monitoring points;

[0026] Calculating the mixing amount based on the mean value of the pipe network mixing rate and the pipe network volume;

[0027] The locations of the mixing points are located based on the changes in the mixing rates and isotope indicators of the monitoring points over time and space.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] The method for locating sewage mixing points in a high-water-level rainwater pipe network based on hydrogen and oxygen isotopes proposed in the present invention solves the problems in existing rainwater-sewage mixing diagnosis technologies that the tracing indicators are unstable and the mixing diagnosis results are greatly affected by sewage quality fluctuations. Compared with traditional water quality characteristic factors, hydrogen and oxygen isotopes are not only natural tracers of water, but also the hydrogen and oxygen isotope contents of water from different sources are stable and will not react or decompose during pipeline transportation, which can effectively solve the problem of low stability of traditional tracers. In addition, MixSIAR is a model based on an uncertainty algorithm, which is used to calculate the mixing rate of single-source external water, which can effectively reduce the impact of water quality fluctuations on the uncertainty of the calculation results, making the mixing diagnosis results more effective and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] Figure 1 A technical roadmap of a method for locating sewage mixing points in a high-water-level rainwater pipe network based on isotopes according to an embodiment of the present invention;

[0032] Figure 2 A rainwater pipe selected according to an embodiment of the present invention;

[0033] Figure 3 It is the average value of the mixed connection rate calculation results of different water quality monitoring points in a rainwater pipe in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0036] Embodiment 1

[0037] like Figure 1 As shown, in this embodiment, a method for locating sewage mixing points in a high-water-level operating rainwater pipe network based on isotopes is provided, and the implementation process includes: determining rainwater pipe network water quality monitoring points and tap water quality monitoring points in the study area; performing continuous sampling at the water quality monitoring points after rain to obtain a number of isotope indicators in the water samples at the monitoring points; eliminating abnormal data from the obtained several isotope indicators, loading the data into the MixSIAR model and calculating the sewage mixing rate at the rainwater pipe network water quality monitoring points; according to the mixing rate and its changes at each monitoring point, as well as the changes in hydrogen and oxygen isotopes, calculating the mixing amount of the rainwater pipe network and locating the mixing point; using a sonar detector to detect the connection of the underwater well wall pipes in the inspection well at the analyzed mixing point. In view of the two problems in the traditional rainwater-sewage mixing diagnosis technology, namely the low stability of traditional tracers and the great influence of sewage quality fluctuations on the results, this invention proposes a method for locating sewage mixing points in a high-water-level rainwater pipe network based on isotopes. By combining sampling at monitoring points after rain, using isotopes as tracers and the MixSIAR algorithm model as a mixing rate calculation method, the sewage mixing amount in a high-water-level rainwater pipe network can be calculated more accurately and the mixing points can be located. Specifically, the following steps are included:

[0038] Step 1: Determine the physical connection relationship of the rainwater pipe network in the study area by consulting design data or on-site investigation;

[0039] Step 2: Arrange drainage pipe water quality monitoring points on inspection wells on the rainwater pipe network that are convenient for obtaining stable and effective water samples;

[0040] Step 3: Select tap water quality monitoring points in the study area that are convenient for water collection;

[0041] Step 4: After the rain, take samples from the above water quality monitoring points five times at intervals of half a day or a day, and measure the isotope index δ 18 O and isotope index δ 2 H;

[0042] Step 5: Eliminate abnormal data from several isotope indicators, process the data into csv file format and load it into the MixSIAR model. Based on the uncertain algorithm JAGS function in the MixSIAR algorithm model, perform iterative calculations through the Monte Carlo Markov chain in the JAGS function, set the calculation chain length to 100,000, and obtain the sewage mixing rate of the rainwater pipe network water quality monitoring point based on the final output results.

[0043] Step 6: Calculate the mixing amount based on the mean mixing rate of the pipeline network and the volume of the pipeline network, and locate the mixing point based on the changes in the mixing rate and isotope indicators of the monitoring point over time and space.

[0044] The process of calculating the mixing volume of the rainwater pipe network and locating the mixing point position includes: obtaining the average mixing rate of the pipe network based on the mixing rates of several monitoring points; calculating the mixing volume based on the average mixing rate of the pipe network and the pipe network volume; locating the mixing point position based on the mixing rate of the monitoring point and the change of isotope index over time and space.

[0045] Step 7: Use a sonar detector to detect the connection status of the underwater well wall pipelines at the analyzed mixed connection points.

[0046] Aiming at the two problems of low stability of traditional tracers in traditional rainwater-sewage mixing diagnosis technology and the great influence of sewage quality fluctuation on the results, the present invention proposes a method for locating sewage mixing points in a rainwater pipe network with high water level based on isotopes. By combining sampling at monitoring points after rain, using isotopes as tracers and the MixSIAR algorithm model as a mixing rate calculation method, the sewage mixing amount in the rainwater pipe network with high water level can be calculated more accurately and the mixing points can be located.

[0047] Embodiment 2

[0048] like Figure 2-3 As shown, this example takes a high-water-level rainwater pipe network as an example, calculates the sewage mixing amount of the rainwater pipe network and locates the mixing points. The specific steps are as follows: determine the drainage pipe water quality monitoring points and tap water water quality monitoring points based on the rainwater pipe network information in the study area; continuously sample the drainage pipe water quality monitoring points and tap water water quality monitoring points several times after the rain to obtain several monitoring point water samples; obtain several isotope indicators based on the several monitoring point water samples; remove the abnormal data of several isotope indicators and load them into the MixSIAR model, and calculate the sewage mixing rate of the rainwater pipe network water quality monitoring points to obtain the mixing rate; calculate the rainwater pipe network mixing amount based on the mixing rate and isotope indicators and locate the mixing point; check the mixing point position based on the sonar detector to obtain the connection status of the well wall pipe under the well water.

[0049] Step 1: By consulting the design data of the rainwater pipe network, determine the physical connection relationship of the rainwater pipe network pipes, such as Figure 2 As shown;

[0050] Step 2: Arrange drainage pipe water quality monitoring points on inspection wells on the rainwater pipe network that are convenient for obtaining stable and effective water samples;

[0051] Step 3: Select tap water quality monitoring points in the study area that are convenient for water collection;

[0052] Step 4: After the rain, take samples from the above water quality monitoring points five times at intervals of half a day or a day, and measure the isotope index δ 18 O and isotope index δ 2 H;

[0053] Step 5: According to the isotope indicators of the water quality monitoring points measured, the abnormal data are eliminated and the data is processed into a csv file format. The csv file is loaded into the MixSIAR model. Based on the uncertain algorithm JAGS function in the MixSIAR algorithm model, iterative calculations are performed through the Monte Carlo Markov chain in the JAGS function. The calculation chain length is set to 100000. According to the final output results, the sewage mixing rate of the rainwater pipe network water quality monitoring point is obtained, as shown in Figure 3 shown.

[0054] Step 6: Calculate the mixing amount based on the mean mixing rate of the pipeline network and the volume of the pipeline network, and locate the mixing point based on the changes in the mixing rate and isotope indicators of the monitoring point over time and space.

[0055] The process of calculating the mixing volume of the rainwater pipe network and locating the mixing point position includes: obtaining the average mixing rate of the pipe network based on the mixing rates of several monitoring points; calculating the mixing volume based on the average mixing rate of the pipe network and the pipe network volume; locating the mixing point position based on the mixing rate of the monitoring point and the change of isotope index over time and space.

[0056] Step 7: Use a sonar detector to detect the connection status of the underwater well wall pipelines at the analyzed mixed connection points.

[0057] The results show that the sewage mixing volume of the high-water-level rainwater pipe network is 237 m / d. Each water quality monitoring point has a certain proportion of sewage mixing, among which 21.7% of the monitoring points have a sewage mixing rate of more than 40%. The sewage mixing situation in Branch 1 is the most serious, followed by Branch 6 and Branch 4. The sonar detection results confirm that there are sewage mixing points in Branch 1, Branch 4 and Branch 6.

[0058] Although the functions and working processes of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific functions and working processes. The above-mentioned specific implementation methods are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

[0059] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for locating sewage mixing points in a high-water-level rainwater pipe network based on isotopes, characterized in that: include: Determine the drainage pipe water quality monitoring points and tap water quality monitoring points based on the rainwater pipe network information in the study area; After the rain, the drainage pipe water quality monitoring point and the tap water quality monitoring point are continuously sampled several times to obtain several monitoring point water samples; and several isotope indicators are obtained based on the several monitoring point water samples; After eliminating abnormal data of several isotope indicators, the data are loaded into the MixSIAR model and the sewage mixing rate at the water quality monitoring point of the rainwater pipe network is calculated to obtain the mixing rate; Calculate the mixing amount of the rainwater pipe network based on the mixing rate and the isotope index and locate the mixing point; The position of the mixing point is checked based on a sonar detector to obtain the connection status of the well wall pipeline under the well water; The process of calculating the mixing rate based on the MixSIAR model includes: The data corresponding to the isotope index after eliminating abnormal data is converted into a csv file, and the csv file is input into the MixSIAR algorithm model; The mixing rate is calculated based on the uncertain algorithm JAGS function in the MixSIAR algorithm model; The process of calculating the amount of mixing in the stormwater pipe network and locating the mixing point location includes: Obtaining an average value of the pipe network mixing rate based on the mixing rates of the plurality of monitoring points; Calculating the mixing amount based on the mean value of the pipe network mixing rate and the pipe network volume; The locations of the mixing points are located based on the changes in the mixing rates and isotope indicators of the monitoring points over time and space.

2. The method for locating sewage mixing points in a high-water-level rainwater pipe network based on isotopes according to claim 1 is characterized in that: The process of determining drainage pipe water quality monitoring points includes: Obtain the rainwater pipe network information of the study area based on design data analysis and field survey information; Determine the effective water sample well location based on the rainwater pipe network information; The drainage pipe water quality monitoring point is obtained based on the effective water sample well location.

3. The method for locating sewage mixing points in a high-water-level rainwater pipe network based on isotopes according to claim 1 is characterized in that: The process of taking water samples from several monitoring points after rain includes: Determine the fixed interval time; After rain, the drainage pipe water quality monitoring point and the tap water quality monitoring point are continuously sampled several times at the fixed intervals to obtain water samples of several monitoring points; The fixed interval time includes but is not limited to half a day and a day.

4. The method for locating sewage mixing points in a high-water-level rainwater pipe network based on isotopes according to claim 3 is characterized in that: Some of the isotope indicators include the isotope indicators of tap water and rainwater monitoring point water samples δ 18 O and isotope index δ 2 H.

5. The method for locating sewage mixing points in a high-water-level rainwater pipe network based on isotopes according to claim 1 is characterized in that: The process of performing calculation based on the uncertain algorithm JAGS function includes performing iterative calculation based on the Monte Carlo Markov chain; wherein the calculation chain length of the Monte Carlo Markov chain is 100,000.

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