Quantitative evaluation method and system for rain and sewage diversion effect of drainage pipe network based on water quality monitoring

Abstract

The invention discloses a drainage pipe network rain and sewage diversion effect quantitative evaluation method and system based on water quality monitoring. Relates to the technical field of rain and sewage drainage pipe network system evaluation. The method comprises the following steps: step 1, acquiring source drainage data, and confirming a rain and sewage diversion range according to the drainage data; 2, monitoring parameters and monitoring frequency are determined according to the rain and sewage diversion range; 3, performing data analysis on the monitoring parameters and the frequency to obtain a quantitative evaluation index; 4, the rain and sewage diversion effect is judged according to the quantitative evaluation index, and a judgment result is obtained; and 5, a rectification suggestion is given according to a judgment result. According to the method, the source-pipe network-pump station-river channel whole chain is covered through quantitative indexes such as the COD threshold value and the K value, and the drought and rain working conditions are distinguished, so that the pollution recognition rate is increased; and the method can also guide rectification in a targeted manner, and efficiently support rain and sewage diversion optimization and water pollution control.

Description

Technical Field

[0001] This invention relates to the field of stormwater and sewage pipe network system evaluation technology, and more specifically to a quantitative evaluation method and system for the effect of stormwater and sewage separation in drainage pipe networks based on water quality monitoring. Background Technology

[0002] Two core problems still exist in the operation of urban stormwater and sewage separation systems: First, pollution overflows on sunny days, with frequent sewage outflows from stormwater outlets along rivers (e.g., COD at stormwater outlets on dry days is ≥50mg / L, far exceeding the requirement of ≤30mg / L for Class IV surface water in the "Surface Water Environmental Quality Standard"), directly polluting rivers; Second, pollution is out of control on rainy days, with prominent overflows from sewage interception outlets and overflows from manhole covers (e.g., system monitoring revealed that rainwater mixed with sewage at a certain sewage collection system's pumping station accounted for 57.47% of the total amount of sewage on rainy days, causing the COD concentration of the pumping station's influent to plummet from 271mg / L on non-rainy days to 121mg / L), which both reduced the influent concentration to the sewage treatment plant and exacerbated the pollution of the receiving water bodies due to sewage overflows.

[0003] Existing methods for evaluating the effectiveness of rainwater and sewage separation are significantly inadequate and fail to support the requirements of "source control, precise control, and systemic control." 1. Limited assessment dimensions: Existing technologies mostly focus on municipal pipe networks or single source plots, failing to form a comprehensive assessment linking "source drainage users - municipal pipe networks - pumping stations - sewage treatment plants - river outlets", making it impossible to pinpoint pollution sources (e.g., monitoring only the water quality of the pipe network cannot determine whether the pollution originates from mixed connections at the source or from defects in the pipe network itself). 2. Insufficient quantification: The evaluation mainly adopts the qualitative evaluation of "qualified / unqualified" and lacks quantitative indicators (such as the lack of clear threshold for changes in sewage discharge volume during rainy days and the quantitative proportion of external water intrusion into the municipal pipe network), which leads to ambiguity in the direction of rectification; 3. Incomplete coverage of operating conditions: The two core operating conditions of dry weather (72 hours after the rain stops) and rainy weather (from the start of rainfall to 3 hours after the rain stops) are not systematically distinguished, and there is a lack of targeted assessment of rainwater intrusion during rainy weather and groundwater infiltration during dry weather. 4. Limited monitoring targets: Insufficient classification and assessment of source drainage users (e.g., failure to distinguish between the different standards for "complete separation of rainwater and sewage" and "interception of main discharge outlet"), and failure to cover pollution sources that are easily overlooked, such as idle plots and small scattered drainage users; 5. Weak data application: Monitoring data is disconnected from rectification measures, and a closed loop of "monitoring data - problem diagnosis - rectification verification" has not been established. For example, it is not possible to accurately locate mixed connection sections through the COD difference ratio (K value) of key nodes in the pipeline network.

[0004] Therefore, based on the "source-network-plant-river" system thinking, integrating water quality and quantity monitoring technologies with quantitative evaluation indicators, and designing a quantitative evaluation method and system for the rainwater and sewage separation effect of drainage pipe networks based on water quality monitoring, so as to achieve "accurate identification of pollution, quantitative evaluation of effect, and targeted guidance for rectification", and support the improvement of urban sewage treatment efficiency and river water pollution control, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a quantitative evaluation method and system for the effect of rainwater and sewage separation in drainage pipe networks based on water quality monitoring. Through quantitative indicators such as COD threshold and K value, it covers the entire chain from source to pipe network to pumping station to river, distinguishes between dry and rainy conditions to improve the pollution identification rate; it can also provide targeted guidance for rectification, and efficiently support the optimization of rainwater and sewage separation and the control of water pollution.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for quantitatively evaluating the effect of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, comprising: Step 1: Obtain source drainage data and determine the scope of rainwater and sewage separation based on the drainage data; Step 2: Confirm monitoring parameters and monitoring frequency based on the scope of rainwater and sewage separation; Step 3: Analyze the monitoring parameters and frequencies to obtain quantitative evaluation indicators; Step 4: Determine the effectiveness of rainwater and sewage separation based on quantitative evaluation indicators and obtain the determination result; Step 5: Provide rectification suggestions based on the judgment results.

[0007] Preferably, the source drainage data includes source drainage users and municipal pipeline network nodes; Source drainage users include those with complete rainwater and sewage separation, those with partial interception of rainwater and sewage separation, those with main outlet interception of drainage, small and scattered drainage users, and drainage users on idle land plots. Municipal pipeline network nodes include coverage of main sewage pipes, important branch pipes, sewage pumping stations, and river overflow outlets.

[0008] Preferably, the monitoring parameters include: COD and flow rate Q of sewage and stormwater outlets of source drainage users; nodal COD and upstream background COD of municipal pipeline nodes; COD and flow rate Q of sewage pumping stations; overflow frequency and duration of river overflow outlets; The monitoring frequency is determined based on the dry and rainy weather conditions. In dry weather, monitoring begins 72 hours after the rain stops and continues for 72 hours. In rainy weather, monitoring begins from the start of rainfall until 3 hours after the rain stops.

[0009] Preferably, the quantitative assessment includes source drainage user assessment and municipal pipeline network assessment; The source wastewater assessment compares the detected COD and flow rate Q levels with a first preset value to determine whether the wastewater is up to standard. The municipal pipeline network assessment includes a difference ratio K, which is calculated and compared with a second preset value to determine whether the COD and Q content within the municipal pipeline network nodes is up to standard.

[0010] Preferably, the quantitative assessment also includes system-level quantitative indicators, which include rainwater intrusion and overflow pollution load. The formula for calculating rainwater intrusion is as follows: Q 雨水 =Q 雨天总 -Q 旱天总 ×1.2; Among them, Q 雨天总 Q represents the total water inflow to the pumping station during rainy weather. 旱天总 This represents the total water intake of the pumping station during dry weather. The formula for calculating overflow pollution load is as follows: COD 溢流负荷 = Overflow frequency × Single overflow amount × Overflow COD浓度 .

[0011] Preferably, the determination results include: source non-compliance, municipal pipeline non-compliance, and overflow non-compliance.

[0012] Preferably, a quantitative evaluation system for the effectiveness of rainwater and sewage separation in drainage pipe networks based on water quality monitoring includes: a monitoring equipment combination module and a data processing module.

[0013] The monitoring equipment module includes flow monitoring equipment, water quality monitoring equipment, and liquid level and overflow monitoring equipment; The data processing module is used to calculate quantitative indicators such as the COD compliance rate of source drainage users, the K-value of municipal pipe network, and the amount of rainwater intrusion on rainy days, and to generate an assessment report.

[0014] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method and system for quantitatively evaluating the effect of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, with the following beneficial effects: 1. Improved accuracy of quantitative assessment Compared with existing qualitative methods, this invention reduces the assessment error from ±20~30% to ±5~10% by using quantitative indicators such as COD threshold (e.g., 300mg / L in dry weather and 240mg / L in rainy weather), water volume ratio (≤1.2 times that of dry weather in rainy weather), and K value (≤10%). For example, in the Jingkou case, the proportion of rainwater intrusion at the Guyang Road pumping station on rainy days was accurately identified as 57.47%, providing a quantitative basis for rectification.

[0015] 2. Enhanced full-chain coverage capability

[0016] Breaking through the limitations of existing "single-link monitoring", we can construct a full-chain assessment of "source-pipeline network-pumping station-river". For example, by linking "source COD background value-pipeline node COD-K value", we can locate whether the pollution comes from "source mixing" or "pipeline defects", thus solving the problem that existing methods "know what but not why".

[0017] 3. Optimization of operating conditions

[0018] It specifically distinguishes between dry weather (72 hours after the rain stops) and rainy weather (the entire rainfall process), covering core pollution scenarios such as groundwater infiltration and rainwater mixing. For example, in dry weather, the focus is on monitoring the sewage outflow from rainwater outlets (COD≤30mg / L), and in rainy weather, the focus is on monitoring the change in sewage outflow (≤1.2 times). Compared with the existing "single-condition monitoring", the pollution identification rate is improved by 40-60%.

[0019] 4. Strengthening of rectification guidance

[0020] Establish a closed loop of "assessment-rectification-verification". For example, if the source is unqualified, it corresponds to "mixed connection rectification". If the pipeline Kh is ≥20%, it corresponds to "functional defect repair". If Ky is ≥20%, it corresponds to "structural defect repair". In the Jingkou case, after rectification based on this method, the COD of the pumping station's non-rainy day influent increased from 139 mg / L (2018) to 271 mg / L (2022), an increase of 95%.

[0021] 5. Improved equipment and cost adaptability

[0022] We offer multiple equipment alternatives (such as cross-correlation flow meters / electromagnetic flow meters / Doppler flow meters) to adapt to different pipe diameters (DN150~DN6000) and operating conditions (full pipe / partial pipe). Compared with purely imported equipment solutions, the cost is reduced by 30~40%, and the maintenance frequency is reduced from "once a week" (Doppler) to "once a month" (cross-correlation), reducing operation and maintenance costs by 60%. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 The method flowchart provided by the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] See Figure 1 As shown in the figure, this invention discloses a method for quantitatively evaluating the effectiveness of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, including: Step 1: Obtain source drainage data and determine the scope of rainwater and sewage separation based on the drainage data; Step 2: Confirm monitoring parameters and monitoring frequency based on the scope of rainwater and sewage separation; Step 3: Analyze the monitoring parameters and frequencies to obtain quantitative evaluation indicators; Step 4: Determine the effectiveness of rainwater and sewage separation based on quantitative evaluation indicators and obtain the determination result; Step 5: Provide rectification suggestions based on the judgment results.

[0027] Specifically, the source drainage data includes source drainage users and municipal pipeline network nodes; Source drainage users include those with complete rainwater and sewage separation, those with partial interception of rainwater and sewage separation, those with main outlet interception of drainage, small and scattered drainage users, and drainage users on idle land plots. Municipal pipeline network nodes include coverage of main sewage pipes, important branch pipes, sewage pumping stations, and river overflow outlets.

[0028] In a specific embodiment of the present invention, the classification of source wastewater users includes Category 1, Category 2, and supplementary objects, as detailed below: Category 1: Drainage users designed according to "complete separation of rainwater and sewage" or "partial interception of rainwater and sewage" (such as residential communities and enterprises); Category 2: Drainage users designed according to the "total discharge outlet interception" principle (such as industrial enterprises and old urban areas); Supplementary targets: Small-scale drainage users (street-side shops) and vacant plots of land (temporary drainage points); Municipal pipeline network nodes: Select key nodes from the "source-process-end" line, covering sewage trunk lines (DN800~DN1500), important branch lines (DN400~DN700), sewage pumping stations, and river overflow outlets (rainwater outlets, combined sewer outlets); Specifically, the monitoring parameters include: COD and flow rate Q of sewage and stormwater outlets of source drainage users; nodal COD and upstream background COD of municipal pipeline nodes; COD and flow rate Q of sewage pumping stations; overflow frequency and duration of river overflow outlets; The monitoring frequency is determined based on the dry and rainy weather conditions. In dry weather, monitoring begins 72 hours after the rain stops and continues for 72 hours. In rainy weather, monitoring begins from the start of rainfall until 3 hours after the rain stops.

[0029] In a specific embodiment of the present invention, when formulating a differentiated monitoring scheme, the working conditions are first divided, including: Dry weather: Monitoring begins 72 hours after the rain stops and continues for 72 hours. Rainy weather: From the start of rainfall to 3 hours after the rain stops, covering the entire rainfall process; The monitoring parameters and frequencies are shown in Table 1.

[0030] Table 1 Monitoring Parameters and Frequency

[0031] Specifically, the quantitative assessment includes assessment of source drainage users and assessment of municipal pipe networks; The source wastewater assessment compares the detected COD and flow rate Q levels with a first preset value to determine whether the wastewater is up to standard. The municipal pipeline network assessment includes a difference ratio K, which is calculated and compared with a second preset value to determine whether the COD and flow rate Q content within the municipal pipeline network nodes are up to standard.

[0032] Specifically, the quantitative assessment also includes system-level quantitative indicators, which include rainwater intrusion and overflow pollution load. The formula for calculating rainwater intrusion is as follows: Q 雨水 =Q 雨天总 -Q 旱天总 ×1.2; Among them, Q 雨天总 Q represents the total water inflow to the pumping station during rainy weather. 旱天总 This represents the total inflow to the pumping station during dry weather; it also represents the amount of rainwater that enters the sewage system during rainy weather. This is calculated by subtracting the amount of rainwater that is considered acceptable to enter the sewage network during rainy weather from the total amount of sewage during rainy weather. The acceptable amount of rainwater is roughly calculated as 1.2 times the amount of sewage during sunny weather.

[0033] The formula for calculating overflow pollution load is as follows: COD 溢流负荷 = Overflow frequency × Single overflow amount × Overflow COD浓度 .

[0034] In the specific embodiments provided by the present invention, COD can be replaced by BOD (biological oxygen demand) and TOC (total organic carbon). For example, the BOD threshold can be set to ≥120mg / L in dry weather and ≥96mg / L in rainy weather (calculated according to COD:BOD≈2.5:1) to adapt to different water quality monitoring needs. The K value can be replaced with the "concentration decay rate" ((C0-Ch) / C0×100%). The calculation logic is the same, but the expression is different, which does not affect the evaluation results.

[0035] Core areas (such as downtown residential areas and main pipeline networks): monitoring should be conducted continuously for 72 hours during dry weather and throughout the rainy season (optimal solution); For general areas (such as suburban communities and branch pipes): the method can be adjusted to "24-hour continuous sampling in dry weather + 2 sampling times in rainy weather" (efficiency increased by 50%, suitable for large-scale census). For remote areas (such as idle land): "Monthly drought monitoring + temporary monitoring during rainfall" can be adopted (cost reduction of 60-70%, suitable for low priority areas).

[0036] Furthermore, system-level quantitative indicators comprehensively reflect the health of the system. Municipal pipeline network indicators are only one aspect of these indicators; in addition, source indicators and other indicators are also included.

[0037] Specifically, the judgment results include: unqualified source, unqualified municipal pipeline network, and unqualified overflow.

[0038] In a specific embodiment of the present invention, the qualification criteria for Category 1 are as follows: For wastewater discharge outlets, COD ≥ 280~320 mg / L on dry days (optimal 300 mg / L), and COD ≥ 220~260 mg / L on rainy days (optimal 240 mg / L), with Q on rainy days ≤ 1.2 times Q during the same period on dry days; for rainwater discharge outlets, COD ≤ 25~35 mg / L (optimal 30 mg / L) when Q = 0 or Q > 0 on dry days. Category 1 Basic Compliance Criteria: Wastewater discharge outlet COD 240~280mg / L on dry days (optimal 260mg / L), COD 190~230mg / L on rainy days (optimal 208mg / L), or rainwater discharge outlet COD 30~55mg / L on dry days when Q>0 (optimal 30~50mg / L). Category 1 non-compliance criteria: Wastewater discharge outlet with dry day COD ≤ 240 mg / L, rainy day COD ≤ 190 mg / L, or rainy day Q ≥ 1.2 times dry day Q, or rainwater discharge outlet with dry day Q > 0 and COD ≥ 55 mg / L (optimal 50 mg / L); Category 2 qualification criteria: After the interception weir, the dry day Q=0, and the rainy day Q at the total discharge outlet ≤1.2 (first preset value) times the dry day Q during the same period; Category 2 non-compliance criteria: Dry day Q > 0 after the interception weir, or rainy day Q ≥ 1.2 times dry day Q at the main discharge outlet; 3.2 Municipal Pipeline Network Evaluation Indicators: Calculation of the difference ratio K: In dry weather, Kh = (C0 - Ch) / C0 × 100%, and in rainy weather, Ky = (C0y - Cy) / C0y × 100% (where C0 is the upstream background COD, Ch is the node COD in dry weather, C0y is the upstream background COD in rainy weather, and Cy is the node COD in rainy weather). Qualified judgment: Kh ≤ 8 - 12% (optimal 10%) and Ky ≤ 8 - 12% (optimal 10%). Basically qualified judgment: Kh ≤ 10% and 10% < Ky < 22% (optimal 20%), or 10% < Kh < 22% and Ky ≤ 10%, or 10% < Kh < 22% and 10% < Ky < 22%. Unqualified judgment: Kh ≥ 22% (the second preset value) or Ky ≥ 22%.

[0039] In another specific embodiment of the present invention, the comprehensive grade judgment includes qualified, basically qualified, and unqualified, which are specifically as follows: Qualified: The qualified rate of the source drainage households ≥ 90%, the proportion of qualified nodes in the municipal pipe network ≥ 90%, and there is no overflow pollution. Basically qualified: The qualified rate of the source drainage households is 70 - 90%, the proportion of qualified nodes in the municipal pipe network is 70 - 90%, or there is a slight overflow (the duration of a single overflow ≤ 1h). Unqualified: The qualified rate of the source drainage households < 70%, the proportion of qualified nodes in the municipal pipe network < 70%, or there is a serious overflow (the duration of a single overflow ≥ 3h). Targeted rectification suggestions include: Unqualified at the source: If it is a mixed connection, rectify the connection of the rain - sewage pipe network within a time limit; if it is groundwater infiltration, repair the damaged pipe network. Unqualified in the pipe network: When Kh ≥ 20%, it is necessary to check for functional defects (such as siltation), and when Ky ≥ 20%, it is necessary to check for structural defects (such as wrong connection). Unqualified in overflow:改造截流设施或提升泵站输送能力。

[0040] Specifically, a quantitative evaluation system for the rain - sewage separation effect of a drainage pipe network based on water quality monitoring includes: a monitoring equipment combination module and a data processing module

[0041] The monitoring equipment combination module includes a flow monitoring equipment, a water quality monitoring equipment, and a liquid level and overflow monitoring equipment. The data processing module is used to calculate the COD compliance rate of the source drainage households, the K value of the municipal pipe network, and the quantitative index of the rainwater intrusion volume in rainy weather, and generate an evaluation report.

[0042] In a specific embodiment of the present invention, the flow monitoring device is preferably a Nivos portable cross-correlation flow meter (measurement error ±1~3%, suitable for pipe diameters of DN150~DN6000, battery life ≥250 days). Alternative options are an electromagnetic flow meter (suitable for full pipe conditions, pipe diameters of DN400~DN1500, measurement error ±0.5~1%) and a Doppler flow meter (suitable for small diameter non-full pipes, measurement error ±10~15%). Water quality monitoring equipment: Online COD analyzer (using potassium dichromate digestion spectrophotometry, detection range 0~1000 mg / L, detection limit ≤5 mg / L), auxiliary equipment for BOD and N... -N, TP manual sampling and detection device; Liquid level and overflow monitoring equipment: hydrostatic level gauge (measuring range 0~4m) O, accuracy ±0.25%FSO, protection level IP68); flow direction meter (monitors overflow frequency and duration, supports downstream / reverse flow signal transmission, protection level IP67); 2. Data Processing Module It integrates the functions of "data collection - indicator calculation - level determination - report output", supports access to "digital water supply and drainage platform" or "smart sponge city system platform", and can automatically calculate quantitative indicators such as COD compliance rate of source drainage users, K value of municipal pipe network, rainwater intrusion on rainy days, and generate evaluation reports.

[0043] In a specific embodiment of the present invention, flow monitoring: when the pipe diameter is ≤ DN400 and the pipe is not full, a Doppler flow meter can be used to replace the cross-correlation flow meter (cost reduction of 50-60%, suitable for budget-limited scenarios); when the pipe diameter is ≥ DN1000 and the pipe is full, an electromagnetic flow meter can be used to replace it (measurement accuracy improved to ±0.5%, suitable for long-term monitoring of core nodes). Water quality monitoring: When real-time data is not required, a "COD rapid detection kit" (detection time 15~30min, accuracy ±10%) can be used to replace the online COD detector (cost reduction of 70~80%, suitable for spot checks of small and scattered wastewater dischargers). Overflow monitoring: When the number of outlets is small, a "liquid level sensor + video monitoring" can be used to replace the flow meter (cost reduction of 40-50%, suitable for temporary monitoring).

[0044] When there is no platform access, the "Excel formula calculation template" can be used to replace the "data processing module". After manually inputting monitoring data, indicators such as K value and pass rate are automatically generated, which is suitable for small projects or temporary evaluation scenarios.

[0045] In a specific embodiment provided by the present invention, an assessment of the source dischargers of a certain sewage collection system (taking Ocean Phase I as an example).

[0046] 1. Monitoring objects: Category 1 (complete separation of rainwater and sewage) residential communities, sewage outlet DN500, rainwater outlet DN600; 2. Monitoring conditions: dry weather (June 10-12, 2022, 72 hours after the rain stopped), rainy weather (June 15, 2022, with a rainfall duration of 4 hours); 3. Monitoring data are shown in Table 2. Table 2 Monitoring Data

[0047] 4. Indicator Calculation: Rainy day Q / Dry day Q = 920 / 850 ≈ 1.08 < 1.2; Wastewater discharge outlet COD on dry days: 312 mg / L ≥ 300 mg / L; COD on rainy days: 255 mg / L ≥ 240 mg / L. For rainwater drainage outlets, Q=0 in dry weather and COD=28mg / L≤30mg / L in rainy weather; 5. Assessment result: The rainwater and sewage separation effect of this community is qualified.

[0048] In a specific embodiment provided by the present invention, an assessment of the municipal pipeline network of a sewage collection system in Zhenjiang is conducted (taking the inlet main pipe of Guyang Pumping Station as an example).

[0049] 1. Monitoring object: Municipal sewage trunk line (DN1000), covering 5 residential communities upstream (background COD sampling rate 35%); 2. Monitoring conditions: dry days (June 10-12, 2022), rainy days (June 15, 2022); 3. Monitoring data are shown in Table 3. Table 3 Monitoring Data

[0050] 4. Indicator Calculation: Dry weather Kh = (305-282) / 305×100%≈7.5%≤10%; Rainy day Ky = (242-225) / 242×100%≈7.0%≤10%; 5. Evaluation results: The rainwater and sewage separation effect of this pipeline node is qualified.

[0051] In a specific embodiment of the present invention, an assessment of rainwater overflow in a wastewater collection system is conducted (taking the receiving water body outlet as an example):

[0052] 1. Monitoring targets: 78 rainwater outfalls of the receiving water body, monitored in real time using flow direction meters; 2. Monitoring conditions: Rainfall on June 15, 2022 (35 mm); 3. Monitoring data: There were 12 overflow outlets, with a single overflow duration of 0.5 to 1.2 hours and an average overflow COD concentration of 42 mg / L; 4. Indicator Calculation: Overflow outlet percentage = 12 / 78 ≈ 15.4% < 20%; The maximum duration of a single overflow is 1.2 hours to 3 hours. 5. Assessment results: The overflow control effect in this area is basically satisfactory. It is recommended to modify the three intercepting weirs at the discharge outlets with a duration of more than 1 hour.

[0053] In another specific embodiment of the present invention, two comparative embodiments are also included.

[0054] Comparative Example 1: Existing qualitative assessment methods vs. the quantitative method of this invention (taking an old residential community as an example)

[0055] 1. Existing method: Only the COD of the sewage outlet during dry weather was measured to be 270 mg / L, which was judged as "basically qualified". The operating conditions and rainwater outlets during rainy weather were not monitored. 2. The method of this invention: Dry weather: Wastewater discharge outlet COD=270mg / L (260~300mg / L, basically qualified); Rainwater discharge outlet Q=50m³ / d, COD=45mg / L (30~50mg / L, basically qualified). Rainy days: Wastewater discharge outlet COD=200mg / L (≤208mg / L, unqualified), Q=320m³ / d (dry days Q=250m³ / d, 320 / 250=1.28≥1.2, unqualified). 3. Result differences: Existing methods fail to identify "unqualified in rainy weather", while this invention accurately locates the problem of "mixed connection of rainwater in rainy weather" and guides the rectification of pipeline interfaces.

[0056] Comparative Example 2: Single Node Monitoring vs. the "Source-Network" Linkage Assessment of this Invention (Taking a Pumping Station as an Example)

[0057] 1. Existing method: Only monitoring the COD of the pump station influent is 180 mg / L (non-rainy day), which is used to determine "low pollution load in the pipeline network", but the source cannot be traced. 2. The method of this invention: Source: The average COD of sewage outlets in 10 upstream residential areas was 302 mg / L (compliant); Pipeline network: Node Kh = (302-180) / 302×100%≈40.4%≥20% (unqualified); 3. Differences in results: Existing methods misjudge "insufficient pollution at the source". This invention uses the Kh value to locate "groundwater infiltration in the pipeline network" (infiltration rate of approximately 1200 m³ / d) and guides pipeline network repair.

[0058] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0059] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A quantitative evaluation method for the effectiveness of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, characterized in that, include: Step 1: Obtain source drainage data and determine the scope of rainwater and sewage separation based on the drainage data; Step 2: Confirm monitoring parameters and monitoring frequency based on the scope of rainwater and sewage separation; Step 3: Analyze the monitoring parameters and frequencies to obtain quantitative evaluation indicators; Step 4: Determine the effectiveness of rainwater and sewage separation based on quantitative evaluation indicators and obtain the determination result; Step 5: Provide rectification suggestions based on the judgment results.

2. The method for quantitatively evaluating the effectiveness of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, as described in claim 1, is characterized in that... The source drainage data includes source drainage users and municipal pipeline network nodes; Source drainage users include those with complete rainwater and sewage separation, those with partial interception of rainwater and sewage separation, those with main outlet interception of drainage, small and scattered drainage users, and drainage users on idle land plots. Municipal pipeline network nodes include coverage of main sewage pipes, important branch pipes, sewage pumping stations, and river overflow outlets.

3. The method for quantitatively evaluating the effectiveness of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, as described in claim 2, is characterized in that... The monitoring parameters include: COD and flow rate Q of sewage and stormwater outlets of source drainage users; nodal COD and upstream background COD of municipal pipeline nodes; COD and flow rate Q of sewage pumping stations; overflow frequency and duration of river overflow outlets; The monitoring frequency is determined based on the dry and rainy weather conditions. In dry weather, monitoring begins 72 hours after the rain stops and continues for 72 hours. In rainy weather, monitoring begins from the start of rainfall until 3 hours after the rain stops.

4. The method for quantitatively evaluating the effect of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, as described in claim 3, is characterized in that... The quantitative assessment includes assessment of source drainage users and assessment of municipal pipe networks; The source wastewater assessment compares the detected COD and flow rate Q levels with a first preset value to determine whether the wastewater is up to standard. The municipal pipeline network assessment includes a difference ratio K, which is calculated and compared with a second preset value to determine whether the COD and Q content within the municipal pipeline network nodes is up to standard.

5. The method for quantitatively evaluating the effect of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, as described in claim 4, is characterized in that... The quantitative assessment also includes system-level quantitative indicators, which include rainwater intrusion and overflow pollution load. The formula for calculating rainwater intrusion is as follows: Q 雨水 =Q 雨天总 -Q 旱天总 ×1.2; Among them, Q 雨天总 Q represents the total water inflow to the pumping station during rainy weather. 旱天总 This represents the total water intake of the pumping station during dry weather. The formula for calculating overflow pollution load is as follows: COD 溢流负荷 = Overflow frequency × Single overflow amount × Overflow COD浓度 .

6. The method for quantitatively evaluating the effect of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, as described in claim 1, is characterized in that... The judgment results include: unqualified source, unqualified municipal pipeline network, and unqualified overflow.

7. A quantitative evaluation system for the effectiveness of rainwater and sewage separation in drainage pipe networks based on water quality monitoring, characterized in that, include: Monitoring equipment assembly module and data processing module; The monitoring equipment module includes flow monitoring equipment, water quality monitoring equipment, and liquid level and overflow monitoring equipment; The data processing module is used to calculate quantitative indicators such as the COD compliance rate of source drainage users, the K-value of municipal pipe network, and the amount of rainwater intrusion on rainy days, and to generate an assessment report.

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