Low-concentration high-water-level drainage pipeline treatment method

Abstract

The invention discloses a treatment method for a low-concentration and high-water-level drainage pipeline, which comprises the following steps of: accurately diagnosing the reason causing the low-concentration and high-water-level operation problem of a sewage pipeline through various technical means including water quality and water quantity monitoring, pumping and drainage capability improvement and temporary plugging, and quickly and effectively treating at the same time, so that the water quality reaches the standard and the stable operation of a drainage system is realized. The method can be applied to complex and changeable water quality environments.

Description

Technical Field

[0001] The invention relates to a method for treating a low-concentration high-water-level drainage pipeline, belonging to the technical field of water environment treatment. Background Art

[0002] Low-concentration, high-water-level drainage pipes are those with a BOD5 (biochemical oxygen demand) concentration of less than 100 mg / L but a fullness greater than 75%. BOD5 is a crucial parameter in water quality monitoring and wastewater treatment, directly reflecting the organic matter content in the water and its impact on the ecological environment. The fullness of a drainage pipe is the ratio of the volume of water or wastewater in the pipe to its total volume. A reasonable fullness ensures smooth operation of the drainage system, prevents sewage backflow, improves drainage efficiency, and reduces the burden on sewage treatment plants.

[0003] Due to the complexity and operational peculiarities of low-concentration, high-water-level drainage pipelines, existing drainage management technologies face numerous challenges and limitations. First, traditional low-concentration wastewater management methods mostly target pipelines operating at normal water levels, relying primarily on pipeline network mapping, inspection techniques, and water quality and quantity monitoring to detect external water intrusion or other factors contributing to low concentrations. However, when dealing with low-concentration, high-water-level drainage pipelines, traditional inspection and monitoring methods are not accurate or effective enough in identifying internal pipeline information, due to the lack of visibility, uneven distribution of pollutants, and unstable sewage flow patterns. Furthermore, traditional high-water-level drainage pipeline management methods primarily rely on desilting or repair measures to restore the pipeline's flow capacity, but fail to address the presence of low-concentration issues. This can result in sewage flow exceeding the pipeline's flow capacity or other flow bottlenecks. Pipeline flow capacity refers to the maximum flow rate a pipeline can allow under certain conditions (such as pressure, flow velocity, and pipe diameter); it determines the pipeline's drainage capacity. The overflow bottleneck problem mainly refers to the problem that during the drainage, water supply or water transmission process, due to the limitations of certain links in the pipelines, channels, hydraulic structures and other facilities, the water cannot flow smoothly, thus affecting the operating efficiency and stability of the entire system. This makes it difficult to completely solve the relevant problems and has limited effect on improving the efficiency of the sewage treatment plant. Finally, the traditional drainage system management involves multiple professional fields such as investigation, design, construction, operation and maintenance. Each profession is responsible for the corresponding work content and hands over the work results in sequence. When encountering low-concentration and high-water-level drainage pipe problems, the internal problems of the pipes are difficult to accurately identify through the technology of a single professional field, and therefore cannot be solved efficiently. Therefore, in view of the hiddenness and complexity of the internal environment of low-concentration and high-water-level drainage pipes, it is urgent to propose a new comprehensive, multi-level governance solution that integrates technologies from different professional fields to achieve scientific governance. Summary of the Invention

[0004] The present invention aims to provide a method for treating low-concentration and high-water-level drainage pipes, which can accurately diagnose the causes of low-concentration and high-water-level operation problems in sewage pipes, and at the same time quickly and effectively treat them, so as to achieve water quality standards and stable operation of the drainage system.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: a method for treating a low-concentration high-water-level drainage pipeline, characterized in that the method comprises the following steps:

[0006] Step 1: Collect basic information about the drainage pipes and draw a drainage system diagram based on the basic information; based on the drainage system diagram, determine the scope of the high-water-level pipes and determine whether the high-water-level pipes meet the dredging detection conditions. If so, proceed to step 5; if not, proceed to step 2.

[0007] Step 2: Increase the sewage transfer capacity downstream of the high water level pipe. At the same time, pump sewage to the downstream of the high water level pipe at the end of the high water level pipe or the bottleneck point. Observe the water level and concentration changes in the high water level pipe to determine whether the dredging detection conditions are met. If the dredging detection conditions are met, proceed to step 5; if not, proceed to step 3.

[0008] Step 3: Temporarily block the branch pipe at the connecting node of the main and branch pipes of the high-water-level pipe, observe the water level and concentration changes in the high-water-level pipe, and determine whether the silt removal detection conditions are met: if the silt removal detection conditions are met, proceed to step 7; if not, proceed to step 4;

[0009] Step 4: For the high-water-level pipeline, simultaneously carry out steps 2 and 3, observe the water level and concentration changes in the high-water-level pipeline, and determine whether the silt removal detection conditions are met: if the silt removal detection conditions are met, proceed to step 5; if the silt removal detection conditions are not met, determine that one of the problem points that causes the high-water-level pipeline to operate at a low concentration and high water level is located in the pipeline that was not blocked in step 3, add a temporary blocking point in the unblocked pipeline, obtain the specific location of the problem point in the unblocked pipeline, update the drainage system diagram, and perform treatment by abolishing the unblocked pipeline and building a new pipeline;

[0010] Step 5: Prepare a dredging inspection plan and carry out dredging work in the areas that meet the dredging inspection conditions.

[0011] The method provided by the present invention is applicable to low-concentration, high-water-level drainage pipelines that do not meet the requirements for desilting detection. For drainage pipelines that meet the requirements for desilting detection, treatment can be carried out according to traditional methods. The essence of the operation of low-concentration, high-water-level drainage pipelines is that the water flow load exceeds the pipeline's flow capacity. Desilting detection is used to determine the specific cause of the low-concentration, high-water-level situation, such as pipeline defects or external water intrusion. The method provided by the present invention creates a condition in which the drainage capacity of the high-water-level pipeline exceeds the water flow load within the pipeline.

[0012] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:

[0013] In one of the preferred embodiments, determining whether the high water level pipeline meets the dredging detection conditions specifically includes: determining whether the water level of the high water level pipeline can be reduced to less than 20% of the diameter of the high water level pipeline by pumping and drainage and the water depth does not exceed 300 mm.

[0014] In one preferred embodiment, in step 1, if the dredging detection conditions are not met, before entering step 2, the following steps are further included:

[0015] a. Determine the rainwater and sewage zones and the layout of the main and branch pipes based on the drainage system diagram, establish water quality and quantity monitoring points, and monitor the water quality and quantity of the rainwater and sewage zones; based on the water quality and quantity monitoring data, conduct external water source tracing operations on the high-water-level pipes that are not suitable for dredging and inspection, and identify the points of external water intrusion;

[0016] b. Based on the basic information, formulate a modification plan for the external water intrusion point and implement the modification to reduce the external water ratio of the high water level pipe section;

[0017] Reducing the external water ratio can alleviate the problem of low-concentration and high-water-level operation and create favorable conditions for the implementation of step 2.

[0018] In one preferred embodiment, the basic information includes the pipe material, diameter, elevation and flow direction of the drainage pipe.

[0019] Basic information can be obtained through pipeline endoscopy (CCTV) inspection: CCTV cameras capture the interior of the pipeline to obtain information such as the internal condition, diameter, and material. CCTV technology is one of the most commonly used pipeline inspection methods, providing high-resolution image and video data.

[0020] In one of the preferred embodiments, the method further includes the following steps: Step 6, inspecting the drainage pipe after dredging; measuring the drainage pipe after dredging inspection, obtaining basic information of the drainage pipe, and updating the drainage system diagram.

[0021] In one of the preferred embodiments, the method further includes the following steps: Step 7, according to the drainage system diagram updated in Step 6, the problem points that cause low concentration and high water level in the drainage pipe are incorporated into the renovation design plan, the problem points are renovated on site, the renovated drainage pipe is inspected and measured, the final basic information is obtained, the drainage system diagram is updated, and the drainage system diagram and the drainage pipe are handed over for operation and maintenance.

[0022] Compared with the existing technology, the beneficial effects of the present invention are: the method for treating low-concentration and high-water-level drainage pipes provided by the present invention gradually investigates the specific causes of low-concentration and high-water-level pipeline problems through a variety of technical means including water quality and quantity monitoring, pumping capacity improvement and temporary blocking, ensuring that the treatment measures are accurate and effective; through a series of measures, it effectively responds to the complex inducements of low-concentration and high-water-level operating pipe sections, so that the drainage system as a whole can operate stably, and can be applied in complex and changeable water quality environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a workflow diagram of the low-concentration high-water-level drainage pipeline treatment method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other.

[0025] Example 1

[0026] This embodiment 1 proposes a comprehensive and systematic treatment method that integrates professional field technologies such as investigation, design, construction, and operation and maintenance based on the causes of low-concentration and high-water-level operation. The treatment method is mainly used for low-concentration and high-water-level drainage pipes that do not have dredging and detection conditions. For drainage pipes that have dredging and detection conditions, traditional treatment methods can be used for treatment [References: Lu Wenlin, Qian Duohuai, Huang Haohui, et al. Research on external water intrusion investigation and remediation countermeasures in the sewage pipe network in the water town area of Dongguan City [J]. Water Supply and Drainage, 2023, 49 (S01): 433-438.]. According to "CJJ181-2012 Urban Drainage Pipeline Inspection and Evaluation Technology", pipeline CCTV inspection should comply with the following regulations: CCTV inspection should not be carried out with water, and it should be ensured that the water level in the pipeline is not greater than 20% of the pipeline diameter and does not exceed 300mm. The steps of the treatment method include:

[0027] Step 1) Pipeline measurement and drainage system diagram drawing

[0028] First, basic information about the drainage pipes is obtained, including pipe material, pipe diameter, elevation, flow direction, etc. The following existing technologies can be used to obtain this basic information.

[0029] Pipeline endoscope (CCTV) inspection: CCTV cameras capture the interior of pipelines to obtain information such as internal conditions, diameter, and material. CCTV technology is one of the most commonly used pipeline inspection methods, providing high-resolution images and video data.

[0030] After completing the basic information collection, the results are analyzed and studied to form a drainage system diagram. This diagram is used to clarify the scope of high-water-level pipe sections and determine areas that are not suitable for dredging and detection, and areas that are suitable for dredging and detection, providing a basic basis for subsequent treatment work. Commonly used technical means include:

[0031] Data integration and processing: Integrate data from different sources such as CCTV, laser scanning, sonar, etc., and use data processing software (such as AutoCAD, ArcGIS, etc.) to perform data cleaning, format conversion and spatial analysis.

[0032] Hydraulic model construction: Based on the collected pipeline information, a hydraulic model of the drainage system is constructed to simulate the pipeline parameters such as flow rate, flow velocity, and pressure.

[0033] Drainage system diagram drawing: Use CAD or GIS software to draw a drainage system diagram, marking pipe material, diameter, elevation, flow direction and other information. Drainage system diagrams usually include plan views, cross-section views and 3D models.

[0034] Risk assessment and optimal design: Through hydraulic models and drainage system diagrams, risk assessments can be conducted to identify potential drainage problems (such as water accumulation, overflow, etc.) and propose optimal design solutions.

[0035] Formation of drainage system diagram: The drainage system diagram is the final result of the collection and analysis of basic information of drainage pipes, and usually includes the following contents:

[0036] Floor plan: shows the plan layout of the drainage pipes, marking the pipe direction, pipe diameter, pipe material and other information.

[0037] Section drawing: displays the longitudinal section of the pipeline, marking the pipeline's elevation, slope and other information.

[0038] 3D model: A 3D model generated based on laser scanning or CCTV data that intuitively displays the spatial distribution and internal conditions of the pipeline.

[0039] Data report: includes basic pipeline information, test results, risk assessment, and optimization suggestions.

[0040] Step 2) External water source investigation and water quality and quantity monitoring

[0041] Further investigations into the source of external water flow, identified in step 1 as unsuitable for desilting inspection, are conducted to identify intrusion points. Based on the drainage system diagram, the rainwater and sewage zones and the layout of the main and branch pipes are clearly defined. Water quality and quantity monitoring points are established [Reference: Zhou Mei, Li Zheng, Xiong Wen, Min Zhicheng, Huang Yu, Zhang Yi. Research on the Application of Zoning Monitoring and Diagnosis Methods in Urban Drainage Network Inspection [J / OL]. Water Resources and Hydropower Express, 20240420.], and regional water quality and quantity monitoring is conducted. Water quality and quantity monitoring data is used to guide intrusion source investigations, improve their accuracy, and ensure that intrusion points are identified as thoroughly as possible in pipe sections operating at low concentrations and high water levels and their upstream tributaries.

[0042] Step 3) Check and correct major water intrusion issues immediately

[0043] For external water intrusion points discovered during the inspection, a strategy of immediate inspection and rectification is adopted. Based on the basic information of the drainage network such as pipe material, pipe diameter, elevation and flow direction obtained in step 1), a renovation plan is formulated and specific renovation measures are implemented [Reference: Zhou Lei, Shen Xiaohua. Practice of sewage network inspection in the main urban area of Nanjing [J]. Water Supply and Drainage, 2022, 48(9):5.]. After the renovation is completed, reducing the proportion of external water in the sewage system can alleviate the low-concentration high-water level operation problem to a certain extent, creating favorable conditions for the implementation of the next step.

[0044] Step 4) Pumping capacity improvement experiment

[0045] First, maximize the sewage transfer capacity downstream of the drainage system, for example, by increasing the sewage treatment plant or sewage pumping station to full capacity. Simultaneously, at the end of the high-water-level pipe section or other flow bottlenecks, use a mobile pump truck (sewage pump) to lift sewage downstream. Observe the water level and concentration changes within the drainage pipe to assess whether the pumping effect meets the dredging test conditions. If the dredging test conditions are met, proceed to step 7). If not, proceed to step 5.

[0046] Step 5) Temporary blocking test of branch pipe

[0047] At the junctions connecting the main and branch pipes in high-water-level sections, temporary plugging of branch pipes (e.g., using air bags, masonry walls, or steel plates) is performed using divers. This measure aims to reduce the amount of water flowing into the high-water-level sections and monitor changes in the water level and concentration within the drainage pipes. The process then assesses whether the desilting test conditions are met. If so, proceed to step 7; if not, proceed to step 6.

[0048] Step 6) Combined experiment of pumping capacity improvement and temporary branch pipe blocking

[0049] Combine steps 4) and 5) and carry out them simultaneously. The pipe section drained in step 4) is the same section that was not blocked in step 5). Observe the water level and concentration changes in the drainage pipe to assess whether the desilting test conditions are met. If the desilting test conditions are met, proceed to step 7).

[0050] If the conditions for dredging detection are not met, it can be clearly determined that one of the problem points causing the low concentration and high water level in the drainage pipe is located in an unblocked pipe. At this time, it is only necessary to add temporary blocking points in the unblocked pipe to shorten the length of the unblocked pipe section. Eventually, the specific location of the problem point in the unblocked pipe section can be found and updated in the drainage system diagram. The corresponding treatment plan is to abolish this section of pipe and replace it with a new drainage pipe. In order to investigate whether there are other factors in other pipe sections that cause the low concentration and high water level problem in the drainage pipe, it is still necessary to proceed to step 7 for other pipe sections that meet the conditions for dredging detection.

[0051] Step 7) Drainage pipe desilting inspection

[0052] By implementing the aforementioned steps in this embodiment, a dredging detection plan is prepared, and dredging work is carried out on the pipe sections that meet the dredging detection conditions. After dredging is completed, detection work is immediately carried out to understand the internal quality status of the pipeline and assist in analyzing and studying the causes of high water level problems and low concentration problems.

[0053] Step 8) Pipeline measurement and updated drainage system diagram

[0054] After dredging to eliminate interference factors such as siltation, obstacles, and abnormal pipe diameters in the inspection well, the pipe sections after dredging inspection need to be accurately measured, and the drainage system diagram needs to be updated based on the newly obtained basic information such as pipe material, diameter, elevation, and flow direction to ensure the accuracy and reliability of the drawing information.

[0055] Step 9) Renovation of problem areas

[0056] According to the above steps, the drainage system diagram is modified and improved, and the problem points found are deeply analyzed. The problem points that lead to low concentration and high water level in the drainage pipes are incorporated into the renovation design plan to ensure the pertinence and feasibility of the design [Reference: Zhou Lei, Shen Xiaohua. Practice of sewage pipe network inspection in the main urban area of Nanjing [J]. Water Supply and Drainage, 2022, 48(9):5]. According to the design plan, the problem points are renovated on the spot, and the renovated drainage pipes are inspected and measured to obtain the final basic information such as pipe material, pipe diameter, elevation and flow direction, and the drainage system diagram is updated. Finally, the drainage system diagram and the drainage pipes are handed over for subsequent operation and maintenance.

[0057] The primary cause of low-concentration, high-water-level problems in sewage networks is essentially an overloaded network. Step 4) applies to situations where the overload is not particularly severe. In these cases, implementing Step 4) can meet the prerequisites for implementing Step 7). Step 5) applies to situations where implementing Step 4) still fails to meet the prerequisites for Step 7. For example, when a branch pipe is connected to a river channel and the water level is consistent with the river level, pumping the river water to meet the test conditions is impossible. Therefore, it is necessary to block the branch pipe to isolate the critical water load source and lower the water level in the network. After isolating the branch pipe, the water stored in the main pipe will drain downstream over time. However, the critical water load in Step 5) does not necessarily originate from the branch pipe; it may also be due to a rupture in the sewage main pipe itself, resulting in low-concentration, high-water-level conditions. Therefore, it is possible that implementing Step 4) or Step 5) independently will fail to meet the test conditions. Step 6 involves aligning the implementation time of Steps 4) and 5) to observe whether the requirements for Step 7) can be met. If the main pipe rupture is not severe, the desilting test conditions in step 7) can be met. If the main pipe rupture is severe, causing the water level to approach the groundwater level or river level, in an extreme case where the test conditions cannot be met, further implementing the temporary plugging measures in step 6) can further narrow the scope and ultimately locate the problematic pipe section.

[0058] Compared with the prior art, the treatment method for low-concentration high-water-level drainage pipes provided in Example 1 has the following advantages:

[0059] 1. Comprehensiveness: Combining technical means in four professional fields of investigation, design, construction, and operation and maintenance, a comprehensive treatment plan is formed to ensure that the problem of low-concentration high-water level drainage pipes is thoroughly solved from multiple angles and levels;

[0060] 2. Systematic: Through multi-step and multi-link systematic management, we ensure that problems are fully identified and effectively addressed. Not only do we solve individual problem points, but we also ensure the overall stable operation of the drainage system through a series of measures;

[0061] 3. Accuracy: Utilizing a variety of technical means, such as water quality and quantity monitoring, pumping capacity enhancement experiments, and temporary plugging experiments, we gradually identify the specific causes of the problem and ensure that the remediation measures are accurate and effective;

[0062] 4. Flexibility: Based on different situations and the complexity of the root causes of the problems, a step-by-step approach is adopted, such as experiments to improve the pumping capacity and temporary plugging of branch pipes, to flexibly deal with different types of problem pipe sections;

[0063] 5. Efficiency: Immediate investigation and correction measures make the treatment process more efficient, reduce waiting time, quickly deal with external water intrusion problems, and improve treatment efficiency;

[0064] 6. Innovation: Comprehensively apply technologies in the fields of investigation, design, construction, operation and maintenance to form a systematic governance method that organically combines time and space, thereby improving the scientific nature and effectiveness of governance;

[0065] 7. Adaptability to complex environments: Aiming at the particularity of low-concentration, high-water-level drainage pipes, a multi-step, multi-technical systematic treatment method is proposed. It can be applied in complex and changeable water quality environments and effectively address problems that are difficult to solve with traditional methods.

[0066] 8. Dynamically adjust the treatment plan: During the treatment process, by observing changes in water level and concentration, the treatment plan is dynamically adjusted to ensure that each step is optimized and improved based on the latest test results;

[0067] 9. Economy: The investigation measures should be implemented gradually according to their workload and cost, with priority given to measures with less workload and cost. This can not only ensure that all problems are discovered, but also avoid waste of resources during the investigation process.

[0068] In summary, the treatment method for low-concentration, high-water-level drainage pipes provided in Example 1 can effectively solve the complex causes of low-concentration, high-water-level operation pipe sections.

[0069] Example 2

[0070] The design scale of a certain city sewage treatment plant is 30,000 m 3 / d. After the plant was put into operation, the actual water inflow reached the maximum treatment capacity of the sewage treatment plant, about 36,000 m 3 / d, the size of its sewage trunk culvert is 1.6×1.6m, the operating water level depth is an average of 4.1m, and sewage frequently overflows the ground; the monthly average BOD5 water quality concentration of the sewage treatment plant influent is only 36mg / L, which has attracted the attention of environmental protection inspectors. Due to the deep water level in the full pipe operation section and the large sewage flow, the local government has used conventional investigation technology for three consecutive years and has failed to find out the reason why the sewage trunk culvert is running at a low concentration and high water level. The process of treatment according to the treatment method provided in Example 1 is as follows:

[0071] 1) Pipeline measurement and drainage system diagram drawing

[0072] Pipeline measurements of approximately 20.1 km were carried out on the above-mentioned low-concentration and high-water-level pipe sections and the surrounding drainage network to obtain basic information such as drainage pipe material, diameter, elevation, flow direction, and draw a drainage system diagram.

[0073] 2) External water source investigation and water quality and quantity monitoring

[0074] For drainage pipes with dredging and inspection conditions, external water source tracing and water quality and quantity monitoring were carried out, and 35 points of external water intrusion into the sewage system were preliminarily identified, including 28 groundwater infiltration problem points, 4 construction drainage and mis-discharge problem points, and 3 river water backflow problem points.

[0075] 3) Major external water intrusion problem points are checked and corrected immediately

[0076] A renovation plan for external water intrusion points was issued and implemented. Trenchless repair and temporary plugging measures were adopted to rectify the above 35 external water intrusion points, reducing the external water volume by approximately 16,000 m 3 / d, at this time the water level of the sewage main culvert drops by an average of about 0.1m.

[0077] 4) Pumping capacity improvement experiment

[0078] Propose the demand for increasing the scale of drainage capacity, propose the drainage capacity point, and call for 1 18,000 m 3 / d mobile pump truck, combined with temporary sewage pumping station in sewage system (44,000 m 3 / d) and sewage treatment plant (30,000 m 3 / d) to its maximum capacity, increasing the terminal pumping capacity of the high-water-level pipe section to a total of 92,000 m 3 / d, the water level dropped by 1.0-1.5m overall. However, at this time, the conditions for desilting and testing the low-concentration, high-water-level operating sections were still not met.

[0079] 5) Branch pipe temporary blocking test

[0080] The temporary blocking points of branch pipes were analyzed and implemented, and 8 main branch pipe nodes upstream of the sewage trunk culvert were temporarily blocked and drained, and the overall water level was reduced by about 0.8 to 1.0m.

[0081] 6) Combined experiment on pumping capacity improvement and temporary branch pipe blocking

[0082] By referring to steps 4) and 5), temporary branch pipe blocking was combined with measures to increase drainage capacity, successfully lowering the main sewage culvert water level by 2.0 to 3.0 meters. For the first time, the sewage culvert liquid level dropped below the top plate, initially enabling the implementation of pipeline Quick View Inspection (QV) inspections. Pipeline Quick View Inspection (QV) is a technique that uses a periscope to inspect pipelines within sewage manholes or other fixed spaces. Its advantage lies in its ability to clearly visualize and record all conditions within the pipeline from a distance.

[0083] 7) Drainage pipe desilting inspection

[0084] Formulate desilting and inspection plans, inspect drainage pipes, carry out precipitation desilting, maintain pumping capacity improvement and temporary branch pipe blocking measures, quickly carry out pipeline QV inspection operations, and find other sewage systems (500,000 m 3 / d) sewage and the gate separating the sewage system was damaged, resulting in 500,000 m 3 / d of sewage continuously flowed into this sewage system, and eventually the water levels of the two sewage systems remained the same, resulting in a high water level operation problem. After repairing the gate, the sewage trunk culvert water level dropped to 0.5-2.1m, but the BOD5 water quality concentration of the sewage treatment plant influent was still only 40-60mg / L, and the sewage treatment plant influent water volume was reduced to 32,000m 3 / d or so.

[0085] According to the subsequent drainage pipe dredging and inspection work, 58 groundwater infiltration defect points, 2 problem points of tap water bursting and infiltration into the sewage system, 1 problem point of incorrect drainage of precipitation in the foundation pit of the construction site and 11 problem points of river water backflow were further discovered.

[0086] 8) Pipeline measurement and updated drainage system diagram

[0087] Obtain basic data on drainage pipes, compile them into a book, improve the inspection results to the drainage network database, and update and improve the drainage system diagram.

[0088] 9) Renovation and construction of problem spots

[0089] A renovation plan was issued and implemented, and measures such as trenchless repair, temporary blocking, and excavation and buried pipes were adopted to address the above-mentioned problem points, ultimately reducing the area by approximately 12,000 m 3 / d external water, the water inlet scale of the sewage treatment plant is reduced to 20,000 m 3 / d or so.

[0090] Implementation Effect

[0091] After the rectification was completed, the annual average BOD5 water quality index of the sewage treatment plant influent increased from 36mg / L to 93mg / L, and the influent volume of the sewage treatment plant increased from 36,000m 3 / d reduced to 20,000 m 3 / d, the operating water level in the sewage trunk box culvert stabilized between 0.2m and 1.2m, returning to normal operation. By resolving the issue of low-concentration, high-water-level operation in the sewage pipeline, the sewage treatment plant saved approximately 20 million yuan in annual sewage treatment fees, and sewage overflows no longer occurred.

[0092] The contents described in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A method for treating a low-concentration high-water-level drainage pipeline, characterized in that: The method comprises the following steps: Step 1: Collect basic information about the drainage pipes and draw a drainage system diagram based on the basic information; based on the drainage system diagram, determine the scope of the high-water-level pipes and determine whether the high-water-level pipes meet the dredging detection conditions. If so, proceed to step 5; if not, proceed to step 2. Step 2: Increase the sewage transfer capacity downstream of the high water level pipe. At the same time, pump sewage to the downstream of the high water level pipe at the end of the high water level pipe or the bottleneck point. Observe the water level and concentration changes in the high water level pipe to determine whether the dredging detection conditions are met. If the dredging detection conditions are met, proceed to step 5; if not, proceed to step 3. Step 3: Temporarily block the branch pipe at the connecting node of the main and branch pipes of the high water level pipe, observe the water level and concentration changes in the high water level pipe, and determine whether the silt removal detection conditions are met: if the silt removal detection conditions are met, proceed to step 5; if not, proceed to step 4; Step 4: For the high-water-level pipeline, simultaneously carry out steps 2 and 3, observe the water level and concentration changes in the high-water-level pipeline, and determine whether the silt removal detection conditions are met: if the silt removal detection conditions are met, proceed to step 5; if the silt removal detection conditions are not met, determine that one of the problem points that causes the high-water-level pipeline to operate at a low concentration and high water level is located in the pipeline that was not blocked in step 3, add a temporary blocking point in the unblocked pipeline, obtain the specific location of the problem point in the unblocked pipeline, update the drainage system diagram, and perform treatment by abolishing the unblocked pipeline and building a new pipeline; Step 5: Prepare a dredging inspection plan and carry out dredging work in the areas that meet the dredging inspection conditions.

2. The method for treating a low-concentration, high-water-level drainage pipeline according to claim 1, characterized in that: In step 1, if the dredging detection conditions are not met, before entering step 2, the following steps are further included: a. Determine the rainwater and sewage zones and the layout of the main and branch pipes based on the drainage system diagram, establish water quality and quantity monitoring points, and monitor the water quality and quantity of the rainwater and sewage zones; based on the water quality and quantity monitoring data, conduct external water source tracing operations on the high-water-level pipes that are not suitable for dredging and inspection, and identify the points of external water intrusion; b. Based on the basic information, a renovation plan for the external water intrusion point is prepared and the renovation is implemented to reduce the proportion of external water in the high water level pipe section.

3. The method for treating a low-concentration high-water-level drainage pipeline according to claim 1, characterized in that: Determining whether the high water level pipeline meets the silt removal detection conditions specifically includes: determining whether the water level of the high water level pipeline can be reduced to less than 20% of the diameter of the high water level pipeline by pumping and drainage and the water depth does not exceed 300mm.

4. The method for treating a low-concentration high-water-level drainage pipeline according to claim 1, characterized in that: The basic information includes the pipe material, diameter, elevation and flow direction of the drainage pipe.

5. The method for treating a low-concentration high-water-level drainage pipeline according to claim 1, characterized in that: The method further comprises the following steps: Step 6: After the dredging is completed, the drainage pipe is inspected; the drainage pipe after the dredging inspection is measured, basic information of the drainage pipe is obtained, and the drainage system diagram is updated.

6. The method for treating a low-concentration, high-water-level drainage pipeline according to claim 2, characterized in that: The method further comprises the following steps: Step 7: Based on the drainage system diagram updated in step 6, the problem points that lead to low concentration and high water level in the drainage pipe are incorporated into the renovation design plan, the problem points are renovated on site, the renovated drainage pipe is inspected and measured, the final basic information is obtained, the drainage system diagram is updated, and the drainage system diagram and the drainage pipe are handed over to operation and maintenance.

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