Method for assessing a sewage system based on collection efficiency

Abstract

The application discloses a sewage system evaluation method based on collection efficiency, comprising the following steps: step S1, obtaining basic information of a target sewage treatment system; step S2, obtaining required observation data and analyzing and processing; step S3, calculating various data; step S4, calculating a sewage system collection efficiency value; step S5, calculating a sewage collection inefficiency contribution value of each drainage partition; step S6, calculating a sewage collection overall evaluation value of each drainage partition; and step S7, determining treatment operation and priority of each drainage partition. The method determines treatment operation and priority of each drainage partition by establishing sewage collection efficiency evaluation grades, sewage collection inefficiency contribution evaluation grades and drainage partition sewage collection overall evaluation grades, accurately judges the urgency of problems, and realizes further comprehensive investigation, systematic management and maintenance of the drainage partition in steps and with priorities.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage discharge pipe network system evaluation, in particular to a sewage system evaluation method based on collection efficiency. BACKGROUND

[0002] The sewage discharge underground pipe network system (hereinafter referred to as sewage system in the rest of the article) is a pipe network system arranged underground for discharging sewage. Whether the system is unobstructed is related to whether the urban sewage can be normally collected and treated and whether the social production and living activities can be normally carried out. However, the system is arranged underground, so it is difficult to timely and accurately find the pipe network nodes that need to be maintained, and it is also difficult to comprehensively evaluate the operation status of the system. Once a local failure occurs, the function of the entire sewage system cannot be normally operated, which seriously affects the urban environment and the physical and mental health of residents.

[0003] Scientific and accurate evaluation of the built sewage discharge system is the premise and key of implementing the systematized treatment of "one plant one strategy".

[0004] At present, the analysis and evaluation methods for the sewage system include: evaluation after monitoring the concentration values of the sewage entering the plant, evaluation after monitoring the pipe network defects, evaluation after geophysical prospecting the existing pipe network system, and evaluation after observing the operation of the pipe network. These methods are all from a single angle to analyze the obtained observation results to evaluate the operation status of the sewage system. The analysis methods have wide range of investigation, large resource investment, long time period and low work efficiency. The analysis results cannot comprehensively and systematically reflect the overall situation of the sewage system, and it is difficult to scientifically and accurately support the quality improvement and efficiency increase of the sewage system and the system treatment.

[0005] At present, there is no scientific and systematic analysis and evaluation method and index system for the efficiency of the sewage system, which makes it difficult to relatively quantitatively analyze and evaluate the collection efficiency of the overall sewage system and each drainage partition in the system.

[0006] Therefore, there is an urgent need for a simple, fast, systematic and relatively quantitative scientific evaluation method that can quickly diagnose and evaluate the collection efficiency of the sewage system. SUMMARY

[0007] The present application provides a sewage system evaluation method based on collection efficiency, which is used to solve the technical problems in the prior art that the observation index of the sewage system is single, the evaluation results lack comprehensive system, and the overall situation of the sewage system cannot be comprehensively reflected. The existing evaluation method has wide range of investigation, large resource investment, long time period and low work efficiency.

[0008] The present application provides a sewage system evaluation method based on collection efficiency, which includes the following steps:

[0009] Step S1: Collecting basic information of the target sewage system to obtain theoretical sewage discharge in each drainage partition and theoretical pollution discharge in each drainage partition; the basic information in the present application includes: area of the sewage system, land attribute, population number; sewage pipe network direction, pipe diameter; interception and overflow of the drainage pipe network; scale and operation data of the sewage plant and pump station; area, land use, and population of each drainage partition.

[0010] Step S2: Obtaining flow, COD concentration value, BOD5 concentration value, and NH3-N concentration value of the flow at each water quality and quantity monitoring point of the sewage system as processing data; the water quality and quantity monitoring points are arranged in the inspection well at the most downstream of the sewage main pipe of each sewage drainage partition, and at the interception and overflow of each drainage partition; the sewage collection and water collection range of the main pipe and branch pipe in the sewage pipe network system are taken as the drainage partition;

[0011] Step S3: Obtaining each item of data in Table 4 according to the calculation method and data source in Table 4:

[0012] Table 4

[0013]

[0014] The sewage collection rate, clean water intrusion rate, sewage leakage contribution degree, and clean water intrusion contribution degree are calculated according to the processing data of the sewage system and the following formula respectively:

[0015] The sewage collection rate obtained according to Table 4 is standardized according to the following formula:

[0016]

[0017] Wherein a is 50%, and b is 90%;

[0018] The clean water intrusion rate obtained according to Table 4 is standardized according to the following formula:

[0019]

[0020] Wherein c is 15%, and d is 80%;

[0021] The sewage leakage contribution degree index is standardized by using a negative index:

[0022]

[0023] Wherein minP is the minimum value of the sewage leakage contribution degree of each drainage partition; and maxP is the maximum value of the sewage leakage contribution degree of each drainage partition;

[0024] The clean water intrusion contribution degree index is standardized by using a negative index

[0025]

[0026] wherein, minw is the minimum value of the water intrusion contribution degree of each drainage subarea; maxw is the maximum value of the water intrusion contribution degree of each drainage subarea;

[0027] Step S4: calculate the sewage system collection efficiency value according to the following formula, and establish an evaluation grade according to the calculation result;

[0028] S i = X i × K x + Y i × K y Formula (5)

[0029] wherein, S i is the collection efficiency value of the i-th sewage subarea; X i is the sewage collection rate of the i-th sewage subarea; Y i is the clean water intrusion rate of the i-th sewage subarea; K x is the sewage collection rate weight; K y is the clean water intrusion rate weight, K x and K y are determined as K x = 0.5, and K y = 0.5 by expert scoring method;

[0030] The sewage system collection efficiency is sorted in descending order, and the evaluation grade shown in Table 1 is obtained by grade division. The collection efficiency value of the sewage system is evaluated according to Table 1:

[0031] Table 1

[0032]

[0033]

[0034] According to the collection efficiency evaluation grade of the sewage system to be evaluated, the priority of implementing the management measures is determined. The worse the grade in Table 1 is, the higher the priority of the management measures is;

[0035] Step S5: calculate the sewage collection inefficiency contribution degree value of each drainage subarea according to the following formula, and establish an evaluation grade according to the calculation result;

[0036] D i = P i × K p + Q i × K q Formula (6)

[0037] wherein, D i is the sewage collection inefficiency contribution degree, P iY is the sewage leakage contribution degree of the i-th sewage subarea i K is the clean water intrusion contribution degree of the i-th sewage subarea p K is the sewage leakage contribution degree weight q K is the clean water intrusion contribution degree weight p and K q K is determined by expert scoring method p K is taken as 0.5 q K is taken as 0.5

[0038] The sewage collection inefficiency contribution degrees of the drainage subareas are ranked in descending order and graded to obtain the evaluation grades shown in Table 2, and the sewage collection inefficiency contribution degree values of the sewage system are evaluated according to Table 2:

[0039] Table 2

[0040] level grade Sewage collection inefficiency contribution (D i )]]> 1 large D i ≥0.8]]> 2 relatively large 0.6 < D < 0.8 i <0.8 3 medium 0.4 < D < 0.6 i <0.6 4 relatively small 0.2 < D i <0.4 5 small D i <0.2]]>

[0041] According to the sewage collection inefficiency contribution degrees of the drainage subareas, the grades are determined as the urgency grades of the sewage system treatment, and the higher the grade in Table 2, the more urgent the sewage system treatment is;

[0042] Step S6: the sewage collection overall evaluation value of each drainage subarea is calculated by using the following formula, and an evaluation grade is established according to the calculation result:

[0043] A i = S i ×K s +(1-D i )×K d Formula (7)

[0044] Wherein, A i is the sewage collection overall evaluation value of the drainage subarea, K s is the sewage system collection efficiency value weight; K q is the sewage collection inefficiency contribution degree weight; K s and K q K is determined by expert scoring method s K is taken as 0.5 q K is taken as 0.5

[0045] The sewage collection overall evaluation values of the drainage subareas are ranked in descending order and graded to obtain the evaluation grades shown in Table 3, and the sewage collection overall evaluation values of the sewage system are evaluated according to Table 3:

[0046] Table 3

[0047] level grade Overall collection performance rating (A i )]]> 1 not urgent A i ≥0.75]]> 2 generally urgent 0.5 < A i <0.75 3 relatively urgent 0.25 < A i <0.5]] 4 very urgent A i <0.25]]>

[0048] The higher the grade obtained according to Table 3 is, the lower the sewage collection rate is, the greater the external water invasion rate is, the higher the proportion of the total pollutant leakage and external water invasion in the entire large sewage system is, and the more urgent the sewage system treatment is;

[0049] Step S7: According to the grade results of each drainage partition obtained in steps S4-S6, determine the treatment operation of each drainage partition and the treatment priority thereof.

[0050] For the evaluation grades obtained according to Tables 1-3, targeted sewage system treatment guidance schemes are developed, so as to achieve targeted treatment, improve treatment efficiency and targeting, avoid misjudgment of treatment opportunities, and improve the accuracy and reliability of the implementation of treatment measures.

[0051] Preferably, the monitoring method used in each monitoring point in step S2 is any one of manual monitoring, automatic monitoring by sensors, or a combination of manual monitoring and automatic monitoring by sensors.

[0052] Preferably, the monitoring frequency of manual monitoring is at least 1 data collection per 4 hours; the monitoring frequency of automatic monitoring is 1 data collection per 1-5 minutes; and at least 5 days of monitoring are performed on dry days. Obtaining data at this frequency can effectively improve the accuracy of data acquisition while reducing the data acquisition frequency.

[0053] Preferably, the sewage collection efficiency value is used to reflect the sewage collection efficiency and level of the drainage partition or the entire sewage system; and the sewage collection inefficiency contribution degree index is used to reflect the contribution degree of each drainage partition in the sewage system to the collection inefficiency of the entire sewage system due to sewage leakage and clean water invasion.

[0054] Preferably, the sewage collection efficiency value includes a sewage collection rate index and a clean water invasion rate index.

[0055] Preferably, the sewage collection inefficiency contribution degree includes a sewage leakage contribution degree and a clean water invasion amount contribution degree.

[0056] Preferably, in step S7, when the grade of the collection efficiency value of the drainage partition is extremely poor, the grade of the sewage collection inefficiency contribution degree is small, and the grade of the overall evaluation value of the collection efficiency is very urgent, the drainage partition is preferentially subjected to comprehensive and systematic investigation and treatment.

[0057] Preferably, in step S7, when the grade of the collection efficiency value of the drainage partition is general or poor, the grade of the sewage collection inefficiency contribution degree is medium to small, and the grade of the overall evaluation value of the collection efficiency is general, the outstanding problems of the drainage partition are investigated and treated.

[0058] Preferably, in step S7, when the grade of the collection efficiency value of the drainage partition is excellent or good, the grade of the sewage collection inefficiency contribution degree is small, and the grade of the overall evaluation value of the collection efficiency is not urgent, the drainage partition is subjected to difference and defect supplement and rectification improvement.

[0059] Preferably, the drainage partition area is 0.5-5km 2 ; By this setting, reasonable sewage monitoring data can be obtained.

[0060] The determination of each level in the application is derived from the feedback of a large number of actual detection and maintenance results of the sewage system. For example, when the calculation result of the overall evaluation value of the collection efficiency is ≥0.75, the pipe network condition of the drainage partition is checked by opening the inspection well for many times and using endoscopic detection means, and it is determined that the pipe network condition belongs to not urgent, thereby obtaining the grading result.

[0061] The beneficial effects that can be produced by the application include:

[0062] 1) The sewage system evaluation method based on collection efficiency provided by the application, by obtaining the basic data of the area to be evaluated, monitoring the water quantity, COD concentration value, BOD5 concentration value, and NH3-N concentration value of the flowing water at the monitoring points of each drainage partition, obtaining the sewage collection rate, clean water intrusion rate, sewage leakage contribution degree, and clean water intrusion contribution degree according to the monitoring results, and sorting the calculation results according to the values from large to small, the grading is divided, and the management, maintenance operation priority of the drainage partition is determined according to the grading division result, thereby realizing accurate and targeted timely and reliable maintenance or management of the underground sewage system, and avoiding the occurrence of local paralysis of the sewage system.

[0063] 2) The sewage system evaluation method based on collection efficiency provided by the application establishes the sewage collection efficiency evaluation level, the sewage collection low-efficiency contribution degree evaluation level, and the overall evaluation level of the sewage system of the drainage partition. According to the evaluation level, when problems such as insufficient pipe network coverage, inadequate source collection, serious pipe network damage defects, and external water (mountain water, underground water, and river water) intrusion occur, the problem can be accurately judged in terms of urgency, and further comprehensive and systematic investigation of the drainage partition can be realized in steps and with emphasis, so as to accurately find the problem and quickly take comprehensive measures for management, realize timely diagnosis of the sewage system with problems, and effectively carry out investigation and management work according to the evaluation results. BRIEF DESCRIPTION OF DRAWINGS

[0064] fig. 1 The sewage system evaluation method based on collection efficiency provided by the application is shown in the figure;

[0065] fig. 2 The sewage drainage system of a certain area in the embodiment of the application is divided into eleven drainage partitions, which are shown in the figure. DETAILED DESCRIPTION

[0066] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0067] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0068] The technical means not described in detail in the present application and not used to solve the technical problems of the present application are set according to the common knowledge in the art, and various common knowledge setting modes can be implemented.

[0069] Embodiment

[0070] Embodiment 1

[0071] A method for evaluating the collection efficiency of a sewage system, comprising the following steps:

[0072] Step one: collecting basic information of the target sewage system; including: the area of the target sewage system, the land attribute, the population number, the direction and elevation of the sewage pipe network, the pipe diameter, the position of the intercepting and overflow ports of the drainage pipe network, the scale and operation data of the sewage plant and pump station, the area, land use and population of each drainage subarea.

[0073] Step three: data acquisition: acquiring the flow rate, COD concentration value, BOD5 concentration value and NH3-N concentration value of the flowing water at each water quality and quantity monitoring point of the sewage system; the water quality and quantity monitoring mode includes manual monitoring, automatic monitoring by sensors or a combination of manual monitoring and automatic monitoring by sensors, and the frequency of manual monitoring is at least 1 data collection every 4 hours, the frequency of automatic monitoring is 1 data collection every 1-5 minutes, and the monitoring is performed for more than 5 days in dry weather.

[0074] Specifically, the drainage subareas are divided for the sewage system as the object;

[0075] Considering the factors of pollution range, pipe diameter size and bearing function, the sewage pipe network system can be divided into sewage main pipe and sewage branch pipe. The sewage main pipe mainly realizes the transportation of the branch pipe converging sewage, and connects the branch pipe and the treatment terminal (sewage plant). The branch pipe mainly transports the sewage of the drainage unit out of the house pipe, and connects the drainage house and the main pipe. The pollution (water collection) range of the main pipe and the branch pipe is the specific drainage district. According to the needs of the analysis work, the drainage district is generally 0.5-5km 2 The drainage district in the application is the sewage collection range of the branch pipe upstream of the intersection of the branch pipe and the main pipe.

[0076] The water quality and quantity monitoring points are arranged, and the monitoring point arrangement requirements are clear; in order to truly and accurately collect basic data and scientifically and reasonably evaluate the sewage system collection efficiency of each drainage district, the water quality and quantity monitoring points should be arranged at the most downstream inspection well of the sewage main pipe of each sewage drainage district, and at the overflow port and interception port of each drainage district.

[0077] Step four: analysis and processing of data;

[0078] The main data and their sources or calculation methods are shown in the following table:

[0079] Table 4

[0080]

[0081] The application adopts sewage collection efficiency value and sewage collection low efficiency contribution degree as indexes for evaluation;

[0082] In the application, the sewage collection efficiency value includes sewage collection rate and clear water intrusion rate; the sewage collection efficiency value reflects the sewage collection efficiency and level of drainage or the whole sewage system.

[0083] The sewage collection low efficiency contribution degree index reflects the contribution degree of the whole sewage system in terms of collection low efficiency caused by sewage leakage and clear water intrusion in each drainage district. The sewage collection low efficiency contribution degree includes sewage leakage contribution degree and clear water intrusion amount contribution degree. The selection of these two indexes can reflect the influence on the actual treatment of sewage in the sewage system. When there is sewage leakage in the sewage system, the leaked part of the sewage cannot be treated, and when there is clear water intrusion, the treatment of clear water is ineffective.

[0084] The sewage collection rate data is standardized by the following formula:

[0085]

[0086] a is 50%, and b is 90%.

[0087] The clear water intrusion rate data is standardized by the following formula:

[0088]

[0089] wherein c takes 15% and d takes 80%.

[0090] The sewage leakage contribution index is standardized by using a negative index:

[0091]

[0092] wherein minP is the minimum value of the sewage leakage contribution of each obtained drainage partition; maxP is the maximum value of the sewage leakage contribution of each obtained drainage partition;

[0093] The clean water intrusion contribution index is standardized by using a negative index:

[0094]

[0095] wherein minw is the minimum value of the water intrusion contribution of each obtained drainage partition; maxw is the maximum value of the water intrusion contribution of each obtained drainage partition;

[0096] Step five: calculate the sewage system collection efficiency value according to the following formula, and establish an evaluation grade:

[0097] The sewage system collection efficiency value calculation formula is as follows:

[0098] S i = X i × K x + Y i × K y Formula (5)

[0099] wherein S i is the collection efficiency value of the i-th sewage partition; X i is the sewage collection rate of the i-th sewage partition; Y i is the clean water intrusion rate of the i-th sewage partition; K x is the sewage collection rate weight; K y is the clean water intrusion rate weight; K x and K y are determined by expert scoring method as K x = 0.5 and K y = 0.5;

[0100] According to the calculation results of the sewage system collection efficiency value, the sewage system collection efficiency is divided into grades from large to small, and the sewage system obtained collection efficiency value is evaluated according to Table 1:

[0101] Table 1

[0102] level grade The collection efficiency value (S i ) is calculated as follows: 1 excellent

[0010] S i ≥0.85]]> 2 good 0.7 < S i <0.85 3 fair 0.55 < S i <0.7 4 poor 0.4 < S i <0.55]]> 5 very poor [SA i <0.4]]>

[0103] The priority of implementing treatment measures is determined according to the evaluation grade of the sewage system to be evaluated, and the higher the grade in Table 1, the higher the priority of the treatment measures; and according to the evaluation grade of the sewage system to be evaluated, the sewage system with a grade of general or below is preferentially subjected to comprehensive investigation and system treatment measures;

[0104] Step six: calculating the sewage collection inefficiency contribution degree of the drainage subarea, and establishing an evaluation grade;

[0105] The sewage collection inefficiency contribution degree of the drainage subarea is calculated by the following formula:

[0106] D i =P i ×K p +Q i ×K q Formula (6)

[0107] Wherein, D i is the sewage collection inefficiency contribution degree, P i is the sewage leakage contribution degree of the i-th drainage subarea, Y i is the clean water intrusion contribution degree of the i-th drainage subarea, K p is the sewage leakage contribution degree weight, K q is the clean water intrusion contribution degree weight; K p and K q are determined as K p = 0.5 and K q = 0.5 by expert scoring method;

[0108] The evaluation grades shown in Table 2 are obtained by ranking the sewage collection inefficiency contribution degrees of the drainage subareas in descending order and then grading, and the grade of the sewage system is evaluated according to Table 2:

[0109] Table 2

[0110] level grade Sewage collection inefficiency contribution (D i )]]> 1 large D i ≥0.8]]> 2 relatively large 0.6 < D i <0.8 3 medium 0.4 < D i <0.6]] 4 relatively small 0.2 < D i <0.4]] 5 small D i <0.2]]>

[0111] The greater the sewage collection inefficiency contribution degree of the drainage subarea, the lower the collection efficiency of the drainage subarea in the entire sewage system, the greater the absolute nature of sewage leakage and clean water intrusion, the higher the urgency of treatment, and the higher the treatment priority grade; by directly comparing the grades of two sewage systems, the sewage system that needs to be treated as soon as possible can be determined.

[0112] Step seven: calculating the overall evaluation value of the sewage collection of each drainage subarea by the following formula, and establishing an evaluation grade according to the calculation result;

[0113] The overall evaluation value A i of the sewage collection of the drainage subarea is calculated by the following formula:

[0114] A i =Si xK s +(1-D i )xK d Equation (7)

[0115] wherein, K s is the weight of sewage collection efficiency value; K q is the weight of sewage collection inefficiency contribution degree; K s and K q are determined by expert scoring method as K s = 0.5, K q = 0.5;

[0116] The sewage collection overall evaluation values of each drainage partition are sorted in descending order, and the evaluation grades shown in Table 3 are obtained by grade division. The grade of the sewage system is evaluated according to Table 3:

[0117] Table 3

[0118] level grade (urgency of quality improvement) Sewage collection overall evaluation value (A i )]]> 1 not urgent A i ≥0.75]]> 2 generally urgent 0.5 < A i <0.75 3 relatively urgent 0.25 < A i <0.5]] 4 very urgent A i <0.25]]>

[0119] The evaluation grade is high (4th grade), which represents that the sewage collection rate of the partition is low, the external water intrusion rate is large, the total pollutant leakage amount and external water intrusion amount of the partition account for a high proportion of the entire large sewage system, and the urgency of quality improvement and efficiency enhancement is high, which can be used as a priority partition for management. On the contrary, if the evaluation grade is low (1st grade), it represents that the sewage collection rate of the partition is high, the external water intrusion rate is small, the total pollutant leakage amount and external water intrusion amount of the partition account for a low proportion of the entire large sewage system, and the urgency of quality improvement and efficiency enhancement is high, which does not need management or the urgency of management is relatively low.

[0120] Step eight: proposing a quality improvement and efficiency enhancement guidance scheme for the sewage system;

[0121] According to the sewage collection efficiency evaluation grade, the sewage collection inefficiency contribution degree evaluation grade, and the drainage partition sewage collection overall evaluation grade, a quality improvement and efficiency enhancement guidance scheme for the sewage system is developed;

[0122] According to the sewage collection efficiency evaluation grade, the sewage collection inefficiency contribution degree evaluation grade, and the drainage partition sewage collection overall evaluation grade, in view of the problems that may exist in the sewage system, such as insufficient pipe network coverage, inadequate source collection, serious pipe network damage defects, external water (mountain water, groundwater and river water) intrusion, etc., the drainage partition needs to be further comprehensively and systematically investigated according to the urgency and steps, and the problems need to be accurately found out. Comprehensive measures such as pipe network supplement and improvement, pipe network detection and repair, source rain and sewage separation, and external water extrusion are taken to manage and realize the quality improvement and efficiency enhancement of the sewage system.

[0123] Example 2

[0124] The wastewater system collection efficiency assessment method of Example 1 is adopted. This example uses the assessment method to actually evaluate the wastewater collection efficiency, as detailed below:

[0125] Step 1: Collect basic information on the target wastewater system, including: the area, land type, and population of the target wastewater system's catchment area; the route and diameter of the wastewater pipeline network; the location of interceptor and overflow outlets in the drainage pipeline network; the scale and operational data of the wastewater treatment plant and pumping stations; and the area, land use, and population of each drainage zone. See the wastewater pipeline network data collection results for details. fig. 2 Step Two: Based on the wastewater collection efficiency index and the wastewater collection inefficiency contribution index, observe and obtain data from the wastewater system;

[0126] Among them, the wastewater collection efficiency value reflects the wastewater collection efficiency and level of the drainage analysis or the entire wastewater system. The wastewater collection efficiency value includes the wastewater collection rate index and the clean water intrusion rate. The wastewater collection inefficiency contribution index reflects the contribution of each drainage zone to the overall wastewater system collection inefficiency due to wastewater leakage and clean water intrusion. The wastewater collection inefficiency contribution includes the contribution of wastewater leakage and the contribution of clean water intrusion.

[0127] Step 3: Data Acquisition: Obtain measured data on water quantity and water quality (BOD5) through a combination of manual and automatic sensor monitoring.

[0128] Specifically, such as fig. 2 As shown, the sewage drainage system of a certain area is divided into eleven drainage zones, from BXG001 to BXG0011; water quality and quantity monitoring points are set up in the inspection well at the downstream end of the sewage trunk line in each drainage zone.

[0129] Step 4: Data analysis and processing;

[0130] Specifically, the main data and their sources or calculation methods are shown in the table below:

[0131] Table 4

[0132]

[0133] Specifically, in this embodiment, the actual sewage collection volume q of each drainage zone is obtained based on the measured data of the region, combined with relevant population information, drainage planning and standards, and the measured data. S- i. Actual collected concentration of pollutant BOD5 (c) i-1 Actual collection amount of pollutant BOD5 S S-i-1 Theoretical wastewater discharge q L-i Theoretical emissions of pollutant BOD5 S L-i-1 As shown in the table below. There are no overflow outlets or interception outlets in this area, therefore overflow sewage volume data is not included.

[0134] Table 5

[0135]

[0136] Further, the centralized sewage collection rate x of each drainage partition is calculated i and the external water intrusion rate y i , and the standardization processing is performed according to the following formula:

[0137] When the sewage collection rate is standardized, a is taken as 50%, and b is taken as 90%, and the calculation formula is:

[0138]

[0139] When the clean water intrusion rate data is standardized, c is taken as 15%, and d is taken as 80%, and the calculation formula is:

[0140]

[0141] The sewage leakage contribution degree standardized value Pi index is standardized by using a negative index:

[0142]

[0143] The clean water intrusion contribution degree standardized value Qi is standardized by using a negative index:

[0144]

[0145] According to the above calculation method and data, the centralized sewage collection rate standardized value X i , the external water intrusion rate standardized value Y i , the sewage leakage contribution degree standardized value P i , and the clean water intrusion contribution degree standardized value Q i of each drainage partition are calculated, as shown in the following table:

[0146] Table 6

[0147]

[0148] Step five: calculating the sewage system collection efficiency value and performing evaluation;

[0149] K x is taken as 0.5, and K y is taken as 0.5, then S i = X i × 0.5 + Y i × 0.5, and the sewage system collection efficiency value of each drainage partition is calculated according to the above data, and the rating is performed, as shown in the following table.

[0150] Table 8

[0151]

[0152]

[0153] From the table, it can be seen that the collection efficiency values of BXG001, BXG002 and BXG003 are all less than 0.2, and the rating belongs to the worst. It shows that the sewage collection rate of the three areas is low, and the sewage collection efficiency is low. The pipe network system may have problems such as incomplete coverage, direct discharge of sewage into river, and a large amount of external water intrusion into the pipe network, which needs to be comprehensively managed. The collection efficiency values of BXG007 and BXG0010 are both greater than 0.8, and the rating belongs to the best. It shows that the pipe network coverage and sewage collection rate of the two areas are high, and the collection efficiency of the sewage system is good.

[0154] Step six: Calculate the contribution degree of sewage collection inefficiency of drainage partition and evaluate it;

[0155] K P Take 0.5, K q Take 0.5, then D i = P i ×0.5+Q i ×0.5, the sewage collection inefficiency contribution degree value of each drainage partition can be calculated from the above data, and the rating is shown in Table 8. From Table 8, it can be seen that the sewage collection inefficiency contribution degree of BXG001 and BXG002 is more than 0.6, and the rating belongs to the extremely large. It shows that BXG001 and BXG002 have the greatest impact on the inefficiency of the entire BXG sewage system, and need to be given priority to management.

[0156] Step seven: Analyze the overall evaluation value of sewage collection of drainage partition and evaluate it;

[0157] K s Take 0.5, K d Take 0.5, then A i = S i ×0.5+(1-D i )×0.5, the overall evaluation value of sewage collection of each drainage partition can be calculated from the above data, and the rating is shown in Table 8. From Table 8, it can be seen that the comprehensive evaluation value of BXG002 is only 0.11, and the rating belongs to the extremely urgent; the comprehensive evaluation values of BXG001 and BXG003 are both 0.27, and the rating belongs to the extremely urgent. It shows that to realize the quality improvement and efficiency increase of the entire BXG sewage system, the urgency of management of the three areas is greater.

[0158] Step eight: Propose a guidance scheme for quality improvement and efficiency increase of sewage system;

[0159] According to the above evaluation results, the following guidance suggestions can be proposed for the quality improvement and efficiency increase of the entire BXG sewage system:

[0160] (1) Based on the overall evaluation value of sewage collection in each drainage zone, the improvement of the quality and efficiency of the entire BXG sewage system can be carried out in three stages. First, a comprehensive system investigation and treatment of the three areas BXG001, BXG002, and BXG003 should be initiated. Second, the outstanding problems of the four areas BXG004, BXG005, BXG006, and BXG0011 should be investigated and treated. Finally, the deficiencies and omissions of the four areas BXG007, BXG008, BXG009, and BXG010 should be addressed and improved.

[0161] (2) The overall evaluation of sewage collection in BXG001, BXG002 and BXG003 is extremely poor. It is preliminarily judged that there are problems such as insufficient pipe network coverage, inadequate source collection, serious pipe network damage and defects, and intrusion of external water (mountain water, groundwater and river water) in these three areas.

[0162] (3) The three areas BXG001, BXG002 and BXG003 contribute 56% to the inefficiency of the entire sewage system. After the quality improvement and efficiency enhancement treatment of these three areas is completed, the collection efficiency of the entire sewage system can be greatly improved.

[0163] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wastewater system assessment method based on collection efficiency, characterized in that, Includes the following steps: Step S1: Collect basic data of the target wastewater system to obtain the theoretical wastewater discharge volume and the theoretical pollutant discharge volume in each drainage zone; Step S2: Obtain the flow rate, COD concentration, BOD5 concentration, and NH3-N concentration of the water at each water quality and quantity monitoring point in the sewage system as processing data. The water quality and quantity monitoring points are arranged in the inspection wells at the downstream end of the sewage trunk line of each sewage drainage zone and at each interception outlet and overflow outlet. The sewage drainage zone is defined by the sewage collection and catchment area of ​​the trunk line and branch line in the sewage pipe network system. Step S3: Obtain the data in Table 4 according to the calculation methods and data sources in Table 4: Table 4 The wastewater collection rate, clean water intrusion rate, wastewater leakage contribution, and clean water intrusion contribution were calculated using the obtained wastewater system treatment data and the following formulas, respectively. The wastewater collection rate obtained from Table 4 is standardized using the following formula: Where a is 50% and b is 90%; The water intrusion rate obtained from Table 4 is standardized using the following formula: Where c is 15% and d is 80%; The contribution index to wastewater leakage is standardized using a negative indicator: Wherein, minp is the minimum value of the sewage leakage contribution of each drainage zone; maxp is the maximum value of the sewage leakage contribution of each drainage zone. The contribution index of clean water intrusion is standardized using a negative index. Wherein, minw is the minimum value of water intrusion contribution among the obtained drainage zones; maxw is the maximum value of water intrusion contribution among the obtained drainage zones; Step S4: Calculate the wastewater system collection efficiency value according to the following formula, and establish an evaluation level based on the calculation results; S i =X i ×K x +Y i ×K y Equation (5) Among them, S i X represents the collection efficiency value of the i-th wastewater zone; i Y represents the wastewater collection rate of the i-th wastewater zone; i K represents the clean water intrusion rate of the i-th wastewater zone; x Weighted by wastewater collection rate; K y K is the weight for the water intrusion rate. x and K y It was determined to be K based on expert scoring. x Take 0.5, K y Take 0.5; The wastewater collection efficiency was sorted from highest to lowest and then classified into evaluation levels as shown in Table 1. The wastewater collection efficiency values ​​were evaluated according to Table 1. Table 1 The priority of treatment measures is determined based on the evaluation level of the wastewater system to be evaluated. In Table 1, the worse the evaluation level, the higher the priority of the treatment measures. Step S5: Calculate the contribution value of wastewater collection inefficiency in each drainage zone according to the following formula, and establish an evaluation level based on the calculation results; D i =P i ×K p +Q i ×K q Equation (6) Among them, D i P contributes to the inefficiency of wastewater collection. i Q represents the contribution of wastewater leakage to the i-th wastewater zone. i K represents the contribution of clean water intrusion to the i-th wastewater zone. p K is the weight for the contribution of sewage leakage. q Weighting of the contribution of clean water intrusion; K p and K q It was determined to be K based on expert scoring. p Take 0.5, K q Take 0.5; After ranking the inefficiencies in wastewater collection in each drainage zone from largest to smallest, the evaluation levels are shown in Table 2. The wastewater system is then evaluated according to Table 2. Table 2 Based on the contribution value of inefficient sewage collection in the drainage zone, the level is determined as the urgency level of the need for sewage system treatment. In Table 2, the higher the level, the more urgent the need for sewage system treatment. Step S6: Calculate the overall wastewater collection evaluation value A for each drainage zone using the following formula. i And establish evaluation levels based on the calculation results; A i =S i ×K s +(1-D i )×K d Equation (7) Among them, K s K represents the weight of the wastewater system collection efficiency value. q Weighting of the contribution of inefficient wastewater collection; K s and K q It was determined to be K based on expert scoring. s To take 0.5, K q Take 0.5; The overall evaluation values ​​of wastewater collection in each drainage zone were sorted from largest to smallest and then classified into levels as shown in Table 3. The levels of the wastewater system were evaluated according to Table 3. Table 3 According to Table 3, the higher the level, the lower the sewage collection rate, the higher the external water intrusion rate, and the higher the proportion of total pollutant leakage and external water intrusion in the entire large sewage system, the more urgent the need to treat the sewage system. Step S7: Based on the grade results of each drainage zone obtained in steps S4 to S6, determine the processing operation and processing priority of each drainage zone.

2. The wastewater system assessment method based on collection efficiency according to claim 1, characterized in that, The monitoring method used at each monitoring point in step S2 is any one of the following: manual monitoring, automatic sensor monitoring, or a combination of manual and automatic sensor monitoring.

3. The wastewater system evaluation method based on collection efficiency according to claim 2, characterized in that, Manual monitoring involves collecting data at least once every 4 hours. The automatic monitoring system collects data every 1 to 5 minutes. Monitoring should be conducted for at least 5 days during dry seasons.

4. The wastewater system evaluation method based on collection efficiency according to claim 1, characterized in that, Wastewater collection efficiency value is used to reflect the efficiency and level of wastewater collection in drainage zones or the entire wastewater system; wastewater collection inefficiency contribution index is used to reflect the contribution of each drainage zone in the wastewater system to the inefficiency of the entire wastewater system collection due to wastewater leakage and clean water intrusion.

5. The wastewater system evaluation method based on collection efficiency according to claim 1, characterized in that, Wastewater collection efficiency values ​​include: wastewater collection rate and clean water intrusion rate.

6. The wastewater system evaluation method based on collection efficiency according to claim 1, characterized in that, The contribution of inefficient wastewater collection includes the contribution of wastewater leakage and the contribution of clean water intrusion.

7. The wastewater system assessment method based on collection efficiency according to claim 1, characterized in that, In step S7, if the collection efficiency value of the drainage zone is extremely poor, the contribution of inefficient sewage collection is small, and the overall evaluation value of sewage collection is very urgent, then a comprehensive investigation and system treatment of the drainage zone will be carried out first.

8. The wastewater system evaluation method based on collection efficiency according to claim 1, characterized in that, In step S7, if the collection efficiency value of the drainage zone is rated as average or poor, the contribution of wastewater collection inefficiency is rated as medium to small, and the overall wastewater collection evaluation value is rated as average and urgent, then the outstanding problems of the drainage zone shall be investigated and addressed.

9. The wastewater system evaluation method based on collection efficiency according to claim 1, characterized in that, In step S7, if the collection efficiency value of the drainage zone is rated as excellent or good, the contribution of inefficient sewage collection is rated as small, and the overall evaluation value of sewage collection is rated as not urgent, then the drainage zone will be improved by making up for deficiencies.

10. The wastewater system evaluation method based on collection efficiency according to claim 1, characterized in that, The area of ​​each drainage zone ranges from 0.5 to 5 km². 2 .

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