Urban sewage collection rate accounting method based on conservation of pollutant amount

Abstract

The invention discloses a town sewage collection rate accounting method based on pollutant amount conservation, relates to the technical field of town sewage collection, treatment and supervision, and aims to solve the problem that the town sewage collection rate seriously deviates from reality due to mixing, leakage and the like of an existing town sewage pipe network on the basis of material conservation. The urban domestic sewage pollutant background concentration is determined through differentiation, the urban domestic water consumption in the water collection range of an urban sewage treatment plant is refined in combination with the water supply and drainage space boundary relation, and a method for measuring and calculating the influences of sewage pipe network degradation, external water infiltration and the like is defined. Meanwhile, the influence of external water such as industrial wastewater, livestock and poultry breeding wastewater, rainwater and underground water in the sewage pipe network on town sewage collection rate accounting is considered, measures such as multi-pollutant index quantitative treatment are adopted, and the accuracy of sewage pipe network collection efficiency evaluation is improved.

Description

Technical Field

[0001] This invention relates to the field of urban sewage collection and treatment monitoring technology, and in particular to a method for calculating urban sewage collection rate based on the conservation of pollutant quantity. Background Technology

[0002] Accurate assessment and dynamic accounting of urban wastewater collection rates are crucial for selecting strategies to improve the quality and efficiency of wastewater collection and treatment. Internationally, the United Nations Statistics Division has long used the "population connected to wastewater collecting system" metric to statistically analyze its member states. This indicator is also widely used in many developed countries and regions, such as the EU and the US, as an important measure for evaluating wastewater collection levels. The population connected to a wastewater collecting system refers to the proportion of the population whose wastewater is connected to the city's municipal drainage network or pipe network. However, my country's urban drainage situation is highly complex. Insufficient information on wastewater connection makes it difficult to accurately count the population covered by the wastewater collection system. Furthermore, network defects leading to ineffective connections, poor correlation between the service area of ​​the wastewater network and the population, and difficulty in statistically analyzing non-residential wastewater discharge further complicate the situation. Therefore, the "population connected to wastewater collecting system" indicator is not entirely applicable in my country at present.

[0003] Currently, "sewage treatment rate," "pollutant collection efficiency," and "centralized collection rate of urban domestic sewage" are the main indicators for assessing urban sewage collection rates in my country. Jiangsu Province has also explored and implemented the "centralized collection rate of domestic sewage" indicator. However, these indicator calculation methods still have shortcomings in refining the assessment of urban sewage collection levels, mainly in the following aspects: (1) The impact of non-domestic sources connected to the sewer system was not considered. Some indicators equate the total amount of pollutants in the wastewater influent to the domestic source with the contribution of domestic sources. In areas where the proportion of industrial wastewater connected to the sewer system is high, especially in industrial parks that integrate industry and city, and in areas where industrial enterprises agree on the concentration of wastewater connected to the sewer system with downstream wastewater treatment plants, the calculation results have a large deviation.

[0004] (2) The urban domestic pollution generation coefficient does not reflect regional differences. In the calculation method of "centralized collection rate of urban domestic sewage", the "per capita daily domestic pollutant discharge" is selected from the five-day biochemical oxygen demand index, which is a nationally unified standard. The parameter value is determined to be 45 g / (person•day) according to the "Outdoor Drainage Design Code". In the calculation method of "centralized collection rate of domestic sewage" in Jiangsu Province, the chemical oxygen demand index is selected, which is a provincially unified standard. The parameter value is selected as the high-order verification concentration of 350 mg / L and the low-order verification concentration of 260 mg / L. However, there are significant differences in the development level and wastewater use habits among different regions in my country. Even within the same type of city, differences in the proportion of different types of urban wastewater users, the construction and operation of septic tanks, etc., can lead to significant differences in the per capita daily domestic pollutant discharge.

[0005] (3) Single accounting factor. Due to the differences in the concentration of various pollutant indicators in domestic sewage from different regions and different types of urban drainage users, the distribution of defects such as damage, leakage, misconnection, siltation and blockage in sewage collection pipe networks or the distribution of blank areas in the pipe network are also irregular. If the amount of sewage that is not effectively collected in two areas is the same, the impact of direct discharge of sewage in high-concentration areas on the collection rate is greater than that in low-concentration areas. As a result, the collection rate results calculated by a single factor are difficult to objectively reflect the collection efficiency of the pipe network.

[0006] (4) The degradation of pollutants in the pipe network and the amount of pollutants carried by external water infiltration were not quantitatively calculated. The sewage collection pipe network is equivalent to an anaerobic bioreactor. During the migration of various pollutants in sewage from the discharger to the sewage treatment plant, they will undergo degradation, transformation, sedimentation, and scouring to varying degrees. The infiltration of external water such as rainwater and groundwater into the sewage pipe network will increase the amount of pollutants collected by the sewage treatment plant.

[0007] (5) The data on urban domestic water consumption is not precise. The amount of domestic sewage generated is converted into the actual domestic water consumption, but the water consumption is mostly counted based on administrative regions. Traditional methods are difficult to completely match the coverage of the urban sewage treatment plant's water collection network.

[0008] Therefore, those skilled in the art are dedicated to developing a method for calculating urban sewage collection rates based on the conservation of pollutant levels, in order to address the shortcomings of the aforementioned technologies. Summary of the Invention

[0009] The purpose of this invention is to provide a method for calculating urban sewage collection rate based on the conservation of pollutants. Based on the conservation of matter, this method differentiates and determines the background concentration of pollutants in urban domestic sewage, refines the water collection range of urban sewage treatment plants and urban domestic water consumption by combining the spatial boundary relationship of water supply and drainage, clarifies the calculation methods for the impact of sewage network degradation and external water infiltration, and considers the impact of external water such as industrial wastewater, livestock and poultry breeding wastewater, rainwater, and groundwater in the sewage network on the calculation of urban sewage collection rate. It also adopts methods such as multi-pollutant index equivalent treatment to improve the accuracy of sewage network collection efficiency assessment.

[0010] To achieve the above objectives, this invention provides a method for calculating urban sewage collection rate based on pollutant conservation, the steps of which are as follows: S1. Determine the scope of accounting. Based on the influent volume and pollutant concentration of urban sewage treatment facilities within the scope of accounting, calculate the amount of pollutants collected by all urban sewage treatment plants and decentralized sewage treatment facilities within the scope of accounting. S2. Based on the calculated pollutant collection volume of urban sewage treatment facilities, and considering the degradation coefficient of pollutants in the pipe network, calculate the degradation volume of pollutants during the transportation process of urban sewage collection pipe network. S3. Based on the urban domestic water consumption, domestic sewage discharge coefficient, total influent volume of urban sewage treatment facilities and average pollutant concentration of surface water monitoring sections within the accounting scope, calculate the amount of pollutants carried by external water infiltration. S4. Based on the urban domestic water consumption, domestic sewage discharge coefficient and background concentration of pollutants in urban domestic sewage within the accounting scope, calculate the amount of pollutants from urban domestic sources that are discharged into the sewer system. S5. Calculate the amount of wastewater pollutants discharged into the sewer system from industrial enterprises within the scope of the calculation. S6. Calculate the amount of pollutants from other pollution sources besides urban domestic and industrial sources that are included in the management system within the scope of the accounting. S7. For each type of pollutant involved in the accounting, calculate the total amount of pollutant collected and the total amount of pollutant generated. The total amount of pollutant collected is the sum of the amount of pollutant collected by urban sewage treatment facilities and the amount of pollutant degraded by the pipe network, minus the amount of pollutants carried by external water infiltration. The total amount of pollutant generated is the sum of the amount of pollutants from domestic sources, industrial sources, and other sources that are connected to the pipe network. S8. For each type of pollutant involved in the accounting, normalization is performed separately, and the normalized total collection amount and normalized total generation amount are calculated. The ratio of the normalized total collection amount to the normalized total generation amount is taken as the urban sewage collection rate.

[0011] Preferably, in S1, the formula for calculating the amount of pollutants collected by the urban wastewater treatment facility is: (1) (2) In the formula, M 污染物收集量 The amount of pollutants collected by all urban wastewater treatment plants and decentralized urban wastewater treatment facilities within the scope of the calculation is in tons; n To calculate the number of urban wastewater treatment plants and decentralized wastewater treatment facilities within the scope of the calculation; M 污染物收集量i Q represents the amount of pollutants collected by the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facilities within the calculation scope, expressed in tons. 进水i C represents the influent volume of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facilities, expressed in tens of thousands of tons. 进水i The concentration of pollutants in the influent of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facility is expressed in milligrams per liter. Inlet water volume Q 进水i and the concentration of pollutants in the influent C 进水i The methods of obtaining it include: Priority should be given to using monitoring data from the online water intake monitoring facility. If the monitoring data is abnormal, manual monitoring data from the same day should be used instead. When there are no online water inflow monitoring facilities, daily manual monitoring data is used; When daily influent volume and pollutant concentration data are unavailable, monthly monitoring data from law enforcement or environmental protection departments, or valid data obtained by the discharging entity through manual monitoring in accordance with monitoring standards or by a commissioned monitoring agency, shall be used.

[0012] Preferably, in S2, the formula for calculating the amount of pollutant degradation in the urban sewage collection network is: (3) In the formula, N 污染物降解量 K represents the average degradation rate of pollutants during their intermediate transport from the point of entry into the urban sewage collection network to the point of entry into the urban sewage treatment facility, expressed in tons. 降解系数 This refers to the percentage of pollutant degradation in urban sewage collection networks relative to the total amount of pollutants collected by urban sewage treatment facilities.

[0013] Preferably, in S3, the formula for calculating the amount of pollutants carried by external water infiltration is: (4) In the formula, M 外水入渗携带污染物量 To calculate the amount of pollutants infiltrated into the urban sewage pipe network by external water sources such as rainwater, groundwater, and river water within the specified area, the unit is tons; Q 进水i The influent volume of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facility is expressed in tens of thousands of tons. The calculation is based on the sum of influent volumes from all urban wastewater treatment plants and decentralized wastewater treatment facilities within the scope, expressed in tens of thousands of tons; Q 生活用水量 To calculate urban domestic water consumption within the scope, the unit is 10,000 cubic meters; K 生活污水排放系数 The ratio of urban domestic sewage volume to water volume is taken as 0.85; C 地表水浓度 The average concentration of pollutants at national, provincial, and municipal surface water monitoring sections within the calculation area is expressed in milligrams per liter.

[0014] Preferably, in S4, the formula for calculating the amount of urban domestic sewage pollutants discharged into the sewer system is: (5) In the formula, M 生活源污染物纳管量 The amount of pollutants discharged into the urban sewage network by urban domestic wastewater users within the accounting scope is expressed in tons; K 生活污水排放系数 The ratio of urban domestic sewage to water volume is taken as 0.85; C 生活污水本底浓度 To calculate the pollutant concentration in urban domestic sewage within the scope, expressed in milligrams per liter, the highest value among the following methods is used: Select drainage zones in the local or nearby areas with diverse drainage user types, no industrial wastewater discharge into the pipe network or a small proportion of industrial wastewater discharge into the pipe network, short construction time and high quality of sewage pipes, and few rainwater and sewage mixed connection damages, and conduct synchronous monitoring of sewage main pipe flow and water quality for at least 1 day, and obtain the weighted average. The urban drainage users within the accounting scope are classified by type, and the total water consumption of each type is counted. More than 10 drainage users are randomly selected from each type, and the pollutant concentration of the main outlet pipe is monitored in the morning, noon and evening three time periods. The arithmetic average is then calculated and the average is obtained by weighting the total water consumption. Select the highest monthly average concentration of pollutants in the influent from local or nearby urban wastewater treatment plants with short pipeline service time, no industrial wastewater discharge, or a small proportion of industrial wastewater discharge. Select local or nearby urban wastewater treatment plants with short pipeline service life, no industrial wastewater discharge or a small proportion of industrial wastewater discharge, and take the highest daily average concentration of pollutants in their influent during the Spring Festival period.

[0015] Preferably, in S3 and S4, the urban domestic water consumption Q 生活用水量 The statistical objects include: residential water users, non-residential water users who pay residential prices, and non-residential water users such as industrial enterprises, business service water users, and administrative and public institution water users whose water is used for employees' domestic life and whose domestic sewage is directly discharged into the pipe network without pretreatment; the urban domestic water consumption is obtained by spatial matching and division of the geographical location of water users according to the service range of urban sewage collection pipe network through a geographic information system, combined with smart water meter data or manual meter reading data.

[0016] Preferably, in S5, the amount of industrial source pollutants discharged into the system... Calculate using any of the following methods: For industrial enterprises that have installed automatic water quantity and water quality monitoring facilities, or that have automatic water quantity monitoring and periodic manual water quality monitoring, the calculation formula is as follows: After calculating the pollutant quantity of each individual enterprise, the total amount is summed. (6) (7) For industrial enterprises without sufficient monitoring data, the pollutant quantities of individual or similar packaged enterprises are calculated using the pollution generation coefficient method and then summed. The calculation formula is as follows: (8) For industrial enterprises without sufficient monitoring data, the pollutant amounts of individual or similar packaged enterprises are calculated using the water consumption extrapolation method, and then summed. The calculation formula is as follows: (9) In the formula, Q 纳管水量i C represents the amount of wastewater discharged from the i-th industrial enterprise into the urban sewage network, expressed in tens of thousands of tons.纳管浓度i W represents the concentration of pollutants in the wastewater discharged from the i-th industrial enterprise into the urban sewage network, expressed in milligrams per liter. 产品产量i P represents the product output of the i-th industrial enterprise during its accounting period, expressed in tons. 产污系数i Let η be the pollutant production coefficient of the i-th industrial enterprise during the product manufacturing process; 去除率i Let Q be the pollutant removal rate of the i-th industrial enterprise after adopting different pretreatment processes; 工业用水i K represents the industrial water consumption of the i-th industrial enterprise during its product manufacturing process, expressed in tens of thousands of tons. 工业废水排放系数i This represents the ratio of wastewater discharge to water volume for the i-th industrial enterprise.

[0017] Preferably, in S6, the formula for calculating the amount of other source pollutants entering the sewer system is: (10) (11) In the formula, M 其他源污染物纳管量 This is to calculate the amount of pollutants discharged into the urban sewage network from sources other than urban domestic and industrial sources, expressed in tons; M 其他源污染物纳管量i The amount of pollutants discharged into the urban sewage network from the i-th other source is expressed in tons. m To calculate the number of pollution sources other than urban residential and industrial sources within the scope of the calculation; Q 纳管水量i C represents the amount of water discharged into the urban sewage network from the i-th other source, expressed in tens of thousands of tons; 纳管浓度i The concentration of pollutants emitted from the i-th other source into the urban sewage network is expressed in milligrams per liter. Other pollution sources include livestock and poultry farming, aquaculture, and other sources connected to the water supply system. For pollution sources with water quantity and quality monitoring facilities installed at the pipe connection points, the calculation is based on the monitoring data. For pollution sources without monitoring facilities, mobile metering equipment is used to measure water quantity, and water quality is estimated based on monitoring data from law enforcement or ecological and environmental departments, valid data obtained by the discharging unit through manual monitoring in accordance with monitoring specifications or by a commissioned monitoring agency, or the total amount of pollutants discharged as approved in the project's environmental impact assessment, discharge permit, and other documents.

[0018] Preferably, in S7, the total amount of pollutants collected is... The calculation formula is: (12) Total amount of pollutants generated The calculation formula is: (13).

[0019] Preferably, in S8, the normalization process specifically includes: If the total number of pollutant types involved in the accounting is m, then for each of them, the pollution equivalent value is... The j Pollutant type, assuming its total collection volume is Then the normalized collection amount of the pollutant is: (14) Let its total production be Then the normalized production amount of the pollutant is: (15) Total collection amount after normalization The calculation formula is: (16) Total output after normalization The calculation formula is: (17) Obtain urban sewage collection rate The calculation formula is: (18).

[0020] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: (1) From the perspective of pollutant quantity, accounting is carried out based on the principle of conservation of matter.

[0021] (2) All urban domestic pollution sources within the coverage area of ​​the sewage pipe network, as well as other non-domestic pollution sources such as industrial enterprises and livestock and poultry breeding, are included in the accounting scope.

[0022] (3) A localized method for determining the background concentration of urban domestic sewage under different conditions was proposed, which makes the amount of pollutants in urban domestic sewage more accurate.

[0023] (4) Based on the spatial boundary relationship of water supply and drainage, a method for obtaining urban domestic water consumption in a refined manner is proposed.

[0024] (5) Considering the universality and accessibility of monitoring data, and in line with the assessment indicators of surface water environmental quality, chemical oxygen demand, ammonia nitrogen and total phosphorus are used as accounting factors. The collection rate evaluation results are more comprehensive and more in line with the needs of water ecological environment management.

[0025] (6) A quantitative method for the degradation of pollutants in sewage pipe networks and the amount of pollutants carried by external water infiltration is proposed to reduce the calculation error.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram illustrating the calculation principle of an embodiment of the urban sewage collection rate calculation method based on pollutant conservation according to the present invention. Detailed Implementation

[0029] 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.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example like Figure 1 As shown, a method for calculating urban sewage collection rate based on pollutant conservation is described, with the following steps: S1. Determine the accounting scope and objects. The accounting objects include all urban wastewater treatment plants and decentralized urban wastewater treatment facilities within the accounting scope. Based on the influent flow and pollutant concentration of urban wastewater treatment facilities within the accounting scope, calculate the pollutant collection volume of all urban wastewater treatment plants and decentralized wastewater treatment facilities within the accounting scope. The pollutant collection volume should be calculated daily and then accumulated to obtain the annual collection volume. The formula for calculating the pollutant collection volume of urban wastewater treatment facilities is: (1) (2) In the formula, M 污染物收集量 The amount of pollutants collected by all urban wastewater treatment plants and decentralized urban wastewater treatment facilities within the scope of the calculation is in tons; n To calculate the number of urban wastewater treatment plants and decentralized wastewater treatment facilities within the scope of the calculation; M 污染物收集量i Q represents the amount of pollutants collected by the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facilities within the calculation scope, expressed in tons. 进水i C represents the influent volume of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facilities, expressed in tens of thousands of tons. 进水iThe concentration of pollutants in the influent of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facility is expressed in milligrams per liter. Inlet water volume Q 进水i and the concentration of pollutants in the influent C 进水i The methods of obtaining it include: Priority should be given to using monitoring data from the online water intake monitoring facility. If the monitoring data is abnormal, manual monitoring data from the same day should be used instead. When there are no online water inflow monitoring facilities, daily manual monitoring data is used; When daily influent volume and pollutant concentration data are unavailable, monthly monitoring data from law enforcement or ecological departments should be used, or valid data obtained by the discharging entity through manual monitoring in accordance with monitoring standards or by a commissioned monitoring agency.

[0032] The influent flow rate and pollutant concentration should be measured as raw urban sewage, and should be measured at the inlet of the plant. At the same time, interference from external carbon sources, internal backflow of sewage treatment plant, and repeated measurement should be avoided.

[0033] S2. Based on the calculated pollutant collection volume of urban wastewater treatment facilities, and considering the degradation coefficient of pollutants in the pipe network, calculate the degradation amount of pollutants during transportation in the urban wastewater collection pipe network; the calculation formula for the pollutant degradation amount in the urban wastewater collection pipe network is as follows: (3) In the formula, N 污染物降解量 K represents the average degradation rate of pollutants during their intermediate transport from the point of entry into the urban sewage collection network to the point of entry into the urban sewage treatment facility, expressed in tons. 降解系数 This refers to the percentage of pollutant degradation in urban sewage collection networks relative to the total amount of pollutants collected by urban sewage treatment facilities.

[0034] The selection principles for relevant parameters are explained as follows: ① The pollutant degradation coefficient of urban sewage collection pipe networks is affected by various factors such as the distribution of drainage users, the diameter of sewage pipes, the fullness of the pipes, and the concentration of sewage, making it difficult to measure accurately. However, considering that the flow environment and average residence time of sewage in the pipes are similar to those of septic tanks, the coefficient value is obtained by referring to the degradation efficiency of pollutants in septic tanks. ② The degradation coefficient is compared with the direct discharge and septic tank discharge coefficients of sewage in different regional zones and different city categories in the first pollution source census urban domestic pollution source emission coefficient manual.

[0035] S3. Based on the urban domestic water consumption, domestic sewage discharge coefficient, and total influent volume of urban sewage treatment facilities within the accounting scope, calculate the amount of pollutants carried by external water infiltration; the formula for calculating the amount of pollutants carried by external water infiltration is as follows: (4) In the formula, M 外水入渗携带污染物量To calculate the amount of pollutants infiltrated into the urban sewage pipe network by external water sources such as rainwater, groundwater, and river water within the specified area, the unit is tons; Q 进水i The influent volume of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facility is expressed in tens of thousands of tons. The calculation is based on the sum of influent volumes from all urban wastewater treatment plants and decentralized wastewater treatment facilities within the scope, expressed in tens of thousands of tons; Q 生活用水量 To calculate urban domestic water consumption within the scope, the unit is 10,000 cubic meters; K 生活污水排放系数 The ratio of urban domestic sewage volume to water volume is taken as 0.85; C 地表水浓度 The average concentration of pollutants at national, provincial, and municipal surface water monitoring sections within the calculation area is expressed in milligrams per liter.

[0036] The selection principles for relevant parameters are explained as follows: ① Urban domestic water consumption includes tap water consumption, domestic self-supplied water consumption, and domestic water consumption. Water consumption is based on the actual amount of water sold to users, not the amount supplied by waterworks or reclaimed water plants. ② The statistical objects of urban domestic water consumption include urban residential buildings, public buildings, and industrial enterprises that use water for employee domestic purposes and whose factory wastewater is directly discharged into the pipe network without pretreatment. Based on the classification of water users in the "Urban Water Supply Price Management Measures," the statistical objects can be determined according to Table 1:

[0037] Table 1. Urban water users as statistical subjects in the calculation of urban sewage collection rate ③ The statistical scope of urban domestic water consumption should match the accounting scope. The geographical location of users should be spatially divided according to the service area of ​​the urban sewage collection network defined in the geographic information system to obtain refined urban domestic water consumption data. When water users use smart water meters with location information, water consumption within the accounting scope can be directly filtered and statistically analyzed through the geographic information system; if there is no smart water meter system to support it, the correspondence between water users and the accounting scope can be established by manual identification by meter readers, based on the accounting scope boundaries, and water consumption meter reading data can be statistically analyzed. ④ The urban domestic sewage discharge coefficient should refer to the "Urban Drainage Engineering Planning Code" (GB50318-2017). The comprehensive urban domestic sewage discharge coefficient is 0.8-0.9, generally selected as 0.85.

[0038] S4. Based on the urban domestic water consumption, domestic sewage discharge coefficient, and background concentration of pollutants in urban domestic sewage within the accounting scope, calculate the amount of pollutants discharged into the urban sewer system from domestic sources; the formula for calculating the amount of pollutants discharged into the urban sewer system from domestic sources is as follows: (5) In the formula, M 生活源污染物纳管量 The amount of pollutants discharged into the urban sewage network by urban domestic wastewater users within the accounting scope is expressed in tons; K 生活污水排放系数The ratio of urban domestic sewage to water volume is taken as 0.85; C 生活污水本底浓度 The concentration of pollutants in urban domestic sewage within the calculation scope is expressed in milligrams per liter.

[0039] The selection principles for relevant parameters are explained as follows: The background concentration of urban domestic sewage is the comprehensive water quality after mixed discharge from all urban wastewater users within the calculation scope. Influenced by factors such as the proportion of different types of wastewater users, wastewater discharge habits, and the quality and quantity of wastewater, the concentration varies greatly across different regions. Even within the same region, differences in development level and the intensity of daily life activities among permanent residents lead to significant variations in concentration. Where feasible, the background concentration of urban domestic sewage should be determined separately for cities, counties, and towns based on their respective development levels, and the amount of pollutants discharged into the sewer system for each city, county, and town should be calculated separately. The background concentration of urban domestic sewage can be obtained using one of the following methods or by selecting the highest value from multiple methods: a. Select drainage zones in the local or nearby areas with diverse types of drainage users, no industrial wastewater discharge into the pipe network or a small proportion of industrial wastewater discharge into the pipe network, short construction time and high quality of sewage pipes, and few damages to rainwater and sewage mixed connections. Conduct simultaneous monitoring of flow and water quality in the main sewage pipes. The monitoring period is at least 1 day, and the weighted average is used to obtain the background concentration of urban domestic sewage. b. Based on local conditions, different types of urban wastewater users within the accounting scope are divided into major categories such as residential buildings, commercial complexes, office buildings, higher education institutions, schools, catering establishments, accommodation facilities, and hospitals. The total water consumption of each major category is simultaneously calculated. Within each major category, at least 10 wastewater users are randomly selected, and the pollutant concentration in the main outlet pipe is monitored during three time periods: morning (06:30-08:30), noon (11:30-13:30), and evening (17:30-19:30). The arithmetic average is then combined with a weighted average of the total water consumption of each major category to obtain the background concentration of urban domestic sewage. c. Select local or nearby urban sewage treatment plants with short pipeline service time, no industrial wastewater discharge or small proportion of industrial wastewater discharge, and take the highest monthly average concentration of pollutants in their influent as the background concentration of urban domestic sewage. d. Select urban sewage treatment plants in the local area or nearby areas with short pipeline service time, no industrial wastewater discharge, or a small proportion of industrial wastewater discharge, and take the highest daily average concentration of pollutants in the influent during the Spring Festival period as the background concentration of urban domestic sewage.

[0040] In S3 and S4, the urban domestic water consumption Q 生活用水量The statistical objects include: residential water users, non-residential water users who pay residential prices, and non-residential water users such as industrial enterprises, business service water users, and administrative and public institution water users whose water is used for employees' domestic life and whose domestic sewage is directly discharged into the pipe network without pretreatment; the urban domestic water consumption is obtained by spatially dividing the service area of ​​urban sewage collection pipe network with the geographical location of water users through geographic information system, and combining smart water meter data or manual meter reading data.

[0041] S5. Calculate the amount of industrial source pollutants discharged into the sewer system from industrial enterprises within the scope of the accounting. The following methods shall be used for accounting: ① For industrial enterprises that have installed automatic water quantity and water quality monitoring facilities, or that have automatic water quantity monitoring and periodic manual water quality monitoring, the pollutant quantity of each individual enterprise is calculated and then summed. The calculation formula is as follows: (6) (7) ② For industrial enterprises without sufficient monitoring data, calculate the pollutant amounts of a single enterprise or similar packaged enterprises using the pollution generation coefficient method, and then sum them up. The calculation formula is as follows: (8) The pollution generation coefficient and average removal rate are taken from the industrial sector pollution generation coefficient manual in the "Emission Source Statistical Survey Pollution Generation and Discharge Accounting Methods and Coefficients Manual".

[0042] ③ For industrial enterprises without sufficient monitoring data, calculate the pollutant amounts of a single or similar packaged enterprise based on water consumption estimation method, and then sum them up. The calculation formula is as follows: (9) The total industrial water consumption is the sum of water consumption from public water supply, self-supplied water sources, and other water consumption (such as purchased steam). For water users with water metering facilities, the actual measured water consumption should be used as the statistical basis for water consumption. For water users without metering facilities, mobile metering equipment can be used to measure at the water intake, or water consumption quotas can be obtained through typical water user samples to estimate the total water consumption within the accounting unit. The industrial wastewater discharge coefficient can refer to the environmental statistics data of the region in the previous year, pollution source census, production and discharge coefficient manual, or survey data of typical samples. The wastewater discharge concentration is the average value of data from pollution source census, production and discharge coefficient manual, or survey data of typical samples.

[0043] In the formula, Q 纳管水量i C represents the amount of wastewater discharged from the i-th industrial enterprise into the urban sewage network, expressed in tens of thousands of tons. 纳管浓度i W represents the concentration of pollutants in the wastewater discharged from the i-th industrial enterprise into the urban sewage network, expressed in milligrams per liter. 产品产量iP represents the product output (in tons) of the i-th industrial enterprise during its accounting period. 产污系数i Let η be the pollutant production coefficient of the i-th industrial enterprise during the product manufacturing process; 去除率i Let Q be the pollutant removal rate of the i-th industrial enterprise after adopting different pretreatment processes; 工业用水i K represents the industrial water consumption of the i-th industrial enterprise during its product manufacturing process, expressed in tens of thousands of tons. 工业废水排放系数i This represents the ratio of wastewater discharge to water volume for the i-th industrial enterprise.

[0044] S6. Calculate the amount of pollutants discharged into the sewer system from sources other than urban residential and industrial sources within the scope of the accounting; the formula for calculating the amount of pollutants discharged into the sewer system from other sources is as follows: (10) (11) In the formula, M 其他源污染物纳管量 This is to calculate the amount of pollutants discharged into the urban sewage network from sources other than urban domestic and industrial sources, expressed in tons; M 其他源污染物纳管量i The amount of pollutants discharged into the urban sewage network from the i-th other source is expressed in tons. m To calculate the number of pollution sources other than urban residential and industrial sources within the scope of the calculation; Q 纳管水量i Let C be the amount of water discharged into the urban sewage network from the i-th other source, in tons; 纳管浓度i The concentration of pollutants emitted from the i-th other source into the urban sewage network is expressed in mg / L. Other pollution sources include livestock and poultry farming, aquaculture, and other sources connected to the water supply system. For pollution sources with water quantity and quality monitoring facilities installed at the pipe connection points, the calculation is based on the monitoring data. For pollution sources without monitoring facilities, mobile metering equipment is used to measure water quantity, and water quality is estimated based on monitoring data from law enforcement or ecological and environmental departments, valid data obtained by the discharging unit through manual monitoring in accordance with monitoring specifications or by a commissioned monitoring agency, or the total amount of pollutants discharged as approved in the project's environmental impact assessment, discharge permit, and other documents.

[0045] There are no other water pollution sources within the scope of the accounting, other than domestic and industrial sources.

[0046] S7. For each type of pollutant involved in the accounting, calculate the total amount of pollutant collected and the total amount of pollutant generated separately. The total amount of pollutant collected is the sum of the amount of pollutant collected and the amount of pollutant degraded, minus the difference in the amount of pollutants carried by external water infiltration. The total amount of pollutant generated is the sum of the amount of pollutants from domestic sources, the amount of pollutants from industrial sources, and the amount of pollutants from other sources. Total amount of pollutants collected The calculation formula is: (12) Total amount of pollutants generated The calculation formula is: (13).

[0047] S8. For each type of pollutant involved in the accounting, normalization is performed separately, and the normalized total collection amount and normalized total generation amount are calculated. The ratio of the normalized total collection amount to the normalized total generation amount is taken as the urban sewage collection rate.

[0048] The normalization process specifically includes: If the total number of pollutant types involved in the accounting is m, then for each of them, the pollution equivalent value is... The j Pollutant type, assuming its total collection volume is Then the normalized collection amount of the pollutant is: (14) Let its total production be Then the normalized production amount of the pollutant is: (15) Total collection amount after normalization The calculation formula is: (16) Total output after normalization The calculation formula is: (17) Obtain urban sewage collection rate The calculation formula is: (18).

[0049] In areas where conditions permit, the amount of urban domestic sewage pollutants collected should be calculated by distinguishing between different levels of cities, county towns, and established towns before calculating the collection rate.

[0050] The following calculation of the urban sewage collection rate is based on the urban built-up area of ​​a certain district in a certain city.

[0051] S1. Calculate the amount of pollutants collected by urban wastewater treatment facilities. The accounting scope was defined as the urban built-up area of ​​the city's district, and the accounting objects were the three urban wastewater treatment plants within the urban built-up area. Based on daily operational monitoring data of the wastewater treatment plants, the total influent volume for the entire year of 2024 was... 10,000 tons.

[0052] According to online monitoring data, the influent pollutant concentrations for chemical oxygen demand (COD), ammonia nitrogen, total phosphorus, and total nitrogen were 310.00 mg / L, 30.00 mg / L, 3.50 mg / L, and 35.00 mg / L, respectively. The total pollutant collection volume for each type of pollutant was calculated using formula (2): COD: ton; Ammonia nitrogen: ton; Total phosphorus: ton; Total nitrogen: ton.

[0053] S2. Calculate the amount of pollutant degradation in urban sewage collection pipe networks.

[0054] Referring to the degradation rate of pollutants by septic tanks in the area covered by the first national pollution source census, the degradation coefficients K of chemical oxygen demand (COD), ammonia nitrogen, total phosphorus, and total nitrogen by the sewage pipe network are 18.8%, 3.4%, 15.2%, and 15.2%, respectively. According to formula (3), the degradation amount of various pollutants by the urban sewage collection pipe network is as follows: COD: ton; Ammonia nitrogen: ton; Total phosphorus: ton; Total nitrogen: ton.

[0055] S3. Calculate the amount of pollutants carried by external water infiltration. Urban domestic water consumption within the accounting scope in 2024 10,000 tons Urban domestic sewage generation = 10,000 tons. The three urban wastewater treatment plants treat approximately 64,003,900 tons of wastewater annually; therefore, the infiltration volume is expressed as:

[0056] In 2024, the average concentrations of chemical oxygen demand (COD), ammonia nitrogen, total phosphorus, and total nitrogen in local surface water at national and provincial monitoring sections were 12.7 mg / L, 0.252 mg / L, 0.067 mg / L, and 1.84 mg / L, respectively. Substituting these values ​​into the above formula, the amounts of COD, ammonia nitrogen, total phosphorus, and total nitrogen pollutants carried by the infiltration of external water are as follows: COD: ; Ammonia nitrogen: ; Total phosphorus: ; Total nitrogen: .

[0057] S4. Calculate the amount of pollutants from urban domestic sources that are included in the management system.

[0058] According to the investigation, the concentrations of chemical oxygen demand (COD), ammonia nitrogen, total phosphorus, and total nitrogen for typical residential, commercial, scientific, educational, cultural, health, and institutional wastewater dischargers in the area covered by the accounting scope were 276.03 mg / L, 41.94 mg / L, 4.80 mg / L, and 66.55 mg / L, respectively.

[0059] For urban wastewater treatment plants where the proportion of industrial wastewater discharged into the sewer system is less than 5%, the highest monthly influent chemical oxygen demand (COD), ammonia nitrogen, total phosphorus, and total nitrogen concentrations were 490.90 mg / L, 50.41 mg / L, 5.95 mg / L, and 57.75 mg / L, respectively.

[0060] During the Spring Festival, the highest influent chemical oxygen demand, ammonia nitrogen, total phosphorus, and total nitrogen concentrations of urban sewage treatment plants were 440.95 mg / L, 29.48 mg / L, 7.03 mg / L, and 43.28 mg / L, respectively.

[0061] The background concentration of urban domestic sewage is taken as the maximum value among the above three. The concentrations of chemical oxygen demand, ammonia nitrogen, total phosphorus and total nitrogen are 490.90 mg / L, 50.41 mg / L, 7.03 mg / L and 66.55 mg / L, respectively.

[0062] According to formula (5), the urban domestic pollutant discharge amounts of chemical oxygen demand, ammonia nitrogen, total phosphorus, and total nitrogen are as follows: COD: ; Ammonia nitrogen: ; Total phosphorus: ; Total nitrogen: .

[0063] The industrial wastewater discharge within the accounting scope in 2024 was directly based on monitoring data: chemical oxygen demand, ammonia nitrogen, total phosphorus, and total nitrogen pollutants were 210.05 tons, 16.85 tons, 2.11 tons, and 50.64 tons, respectively.

[0064] S6. Calculate the amount of other pollutants that are included in the management system.

[0065] There are no other water pollution sources within the accounting scope besides domestic and industrial sources. .

[0066] S7. Calculate the total amount of pollutants collected and the total amount of pollutants generated. According to formula (12), the total collection amounts of chemical oxygen demand, ammonia nitrogen, total phosphorus, and total nitrogen within the calculation range are respectively: COD: ; Ammonia nitrogen: ; Total phosphorus: ; Total nitrogen: .

[0067] According to formula (13), the total production of chemical oxygen demand, ammonia nitrogen, total phosphorus, and total nitrogen within the accounting scope are respectively: COD: ; Ammonia nitrogen: ; Total phosphorus: ; Total nitrogen: .

[0068] S8. Calculate the urban sewage collection rate First, normalization was performed. Referring to the Environmental Protection Tax Law and industry standards, the pollution equivalent value of chemical oxygen demand was determined to be 1 kg, the pollution equivalent value of ammonia nitrogen was 0.8 kg, the pollution equivalent value of total phosphorus was 0.25 kg, and the pollution equivalent value of total nitrogen was 0.8 kg.

[0069] According to formula (14), the normalized collection amounts of the above pollutants are obtained as follows:

[0070]

[0071]

[0072]

[0073]

[0074] According to formula (14), the normalized production amounts of the above pollutants are obtained as follows:

[0075]

[0076]

[0077]

[0078]

[0079] Will and Substituting into formula (18), the final urban sewage collection rate is 61.87%.

[0080] The remaining technical features in the above embodiments can be flexibly selected by those skilled in the art according to actual circumstances to meet different specific practical needs. However, it is obvious to those skilled in the art that these specific details are not necessary to implement the present invention. In other instances, to avoid obscuring the present invention, well-known components, structures, or parts are not specifically described, and all are within the scope of technical protection defined by the claims of the present invention.

[0081] Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this invention should be within the protection scope of the appended claims. In the above description, numerous specific details have been set forth to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, to avoid obscuring the invention, well-known techniques, such as specific construction details, operating conditions, and other technical conditions, have not been specifically described.

[0082] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for calculating urban sewage collection rate based on pollutant conservation, characterized in that, The steps are as follows: S1. Determine the accounting scope of the urban built-up area, and calculate the amount of pollutants collected based on the influent volume and pollutant concentration of urban sewage treatment facilities within the accounting scope; S2. Based on the calculated pollutant collection volume of urban sewage treatment facilities, and considering the degradation coefficient of pollutants in the pipe network, calculate the degradation volume of pollutants during the transportation process of urban sewage collection pipe network. S3. Based on the urban domestic water consumption, domestic sewage discharge coefficient, total influent volume of urban sewage treatment facilities and average pollutant concentration of surface water monitoring sections within the accounting scope, calculate the amount of pollutants carried by external water infiltration. S4. Based on the urban domestic water consumption, domestic sewage discharge coefficient and background concentration of pollutants in urban domestic sewage within the accounting scope, calculate the amount of pollutants from urban domestic sources that are discharged into the sewer system. S5. Calculate the amount of wastewater pollutants discharged into the sewer system from industrial enterprises within the scope of the calculation. S6. Calculate the amount of pollutants from other pollution sources besides urban domestic and industrial sources that are included in the management system within the scope of the accounting. S7. For each type of pollutant involved in the accounting, calculate the total amount of pollutant collected and the total amount of pollutant generated. The total amount of pollutant collected is the sum of the amount of pollutant collected by urban sewage treatment facilities and the amount of pollutant degraded by the pipe network, minus the amount of pollutants carried by external water infiltration. The total amount of pollutant generated is the sum of the amount of pollutants from domestic sources, industrial sources, and other sources that are connected to the pipe network. S8. For each type of pollutant involved in the accounting, normalization is performed separately, and the normalized total collection amount and normalized total generation amount are calculated. The ratio of the normalized total collection amount to the normalized total generation amount is taken as the urban sewage collection rate.

2. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 1, characterized in that: In S1, the formula for calculating the amount of pollutants collected by urban wastewater treatment facilities is as follows: （1） （2） In the formula, M 污染物收集量 The amount of pollutants collected by all urban wastewater treatment plants and decentralized urban wastewater treatment facilities within the scope of the calculation is in tons; n To calculate the number of urban wastewater treatment plants and decentralized wastewater treatment facilities within the scope of the calculation; M 污染物收集量i Q represents the amount of pollutants collected by the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facilities within the calculation scope, expressed in tons. 进水i C represents the influent volume of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facilities, expressed in tens of thousands of tons. 进水i The concentration of pollutants in the influent of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facility is expressed in milligrams per liter. Inlet water volume Q 进水i and the concentration of pollutants in the influent C 进水i The methods of obtaining it include: Priority should be given to using monitoring data from the online water intake monitoring facility. If the monitoring data is abnormal, manual monitoring data from the same day should be used instead. When there are no online water inflow monitoring facilities, daily manual monitoring data is used; When daily influent volume and pollutant concentration data are unavailable, monthly monitoring data from law enforcement or environmental protection departments shall be used, or valid data obtained by the discharging entity through manual monitoring in accordance with monitoring standards or by a commissioned monitoring agency.

3. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 2, characterized in that: In S2, the formula for calculating the degradation amount of pollutants in the urban sewage collection network is: （3） In the formula, N 污染物降解量 K represents the average degradation rate of pollutants during their intermediate transport from the point of entry into the urban sewage collection network to the point of entry into the urban sewage treatment facility, expressed in tons. 降解系数 This refers to the percentage of pollutant degradation in urban sewage collection networks relative to the total amount of pollutants collected by urban sewage treatment facilities.

4. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 3, characterized in that: In S3, the formula for calculating the amount of pollutants carried by external water infiltration is: （4） In the formula, M 外水入渗携带污染物量 To calculate the amount of pollutants infiltrated into the urban sewage pipe network by external water sources such as rainwater, groundwater, and river water within the specified area, the unit is tons; Q 进水i The influent volume of the i-th urban wastewater treatment plant and decentralized urban wastewater treatment facility is expressed in tens of thousands of tons. The calculation is based on the sum of influent volumes from all urban wastewater treatment plants and decentralized wastewater treatment facilities within the scope, expressed in tens of thousands of tons; Q 生活用水量 To calculate urban domestic water consumption within the scope, the unit is 10,000 cubic meters; K 生活污水排放系数 The ratio of urban domestic sewage volume to water volume is taken as 0.85; C 地表水浓度 The average concentration of pollutants at national, provincial, and municipal surface water monitoring sections within the calculation area is expressed in milligrams per liter.

5. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 4, characterized in that: In S4, the formula for calculating the amount of urban domestic sewage pollutants discharged into the sewer system is: （5） In the formula, M 生活源污染物纳管量 The amount of pollutants discharged into the urban sewage network by urban domestic wastewater users within the accounting scope is expressed in tons; K 生活污水排放系数 The ratio of urban domestic sewage to water volume is taken as 0.85; C 生活污水本底浓度 To calculate the pollutant concentration in urban domestic sewage within the scope, expressed in milligrams per liter, the highest value is determined using the following method: Select drainage zones in the local or nearby areas with diverse drainage user types, no industrial wastewater discharge into the pipe network or a small proportion of industrial wastewater discharge into the pipe network, short construction time and high quality of sewage pipes, and few rainwater and sewage mixed connection damages, and conduct synchronous monitoring of sewage main pipe flow and water quality for at least 1 day, and obtain the weighted average. The urban drainage users within the accounting scope are classified by type, and the total water consumption of each type is counted. More than 10 drainage users are randomly selected from each type, and the pollutant concentration of the main outlet pipe is monitored in the morning, noon and evening three time periods. The arithmetic average is then calculated and the average is obtained by weighting the total water consumption. Select the highest monthly average concentration of pollutants in the influent from local or nearby urban wastewater treatment plants with short pipeline service time, no industrial wastewater discharge, or a small proportion of industrial wastewater discharge. Select local or nearby urban wastewater treatment plants with short pipeline service life, no industrial wastewater discharge or a small proportion of industrial wastewater discharge, and take the highest daily average concentration of pollutants in their influent during the Spring Festival period.

6. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 5, characterized in that: In S3 and S4, the urban domestic water consumption Q 生活用水量 The statistical objects include: residential water users, non-residential water users who pay residential prices, and non-residential water users such as industrial enterprises, business service water users, and administrative and public institution water users whose water is used for employees' domestic life and whose domestic sewage is directly discharged into the pipe network without pretreatment; the urban domestic water consumption is obtained by spatial matching and division of the geographical location of water users according to the service range of urban sewage collection pipe network through a geographic information system, combined with smart water meter data or manual meter reading data.

7. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 6, characterized in that: In S5, the amount of industrial source pollutants included in the management system Calculate using any of the following methods: For industrial enterprises that have installed automatic water quantity and water quality monitoring facilities, or that have automatic water quantity monitoring and periodic manual water quality monitoring, the calculation formula is as follows: After calculating the pollutant quantity of each individual enterprise, the total amount is summed. （6） （7） For industrial enterprises without sufficient monitoring data, the pollutant quantities of individual or similar packaged enterprises are calculated using the pollution generation coefficient method and then summed. The calculation formula is as follows: （8） For industrial enterprises without sufficient monitoring data, the pollutant amounts of individual or similar packaged enterprises are calculated using the water consumption extrapolation method, and then summed. The calculation formula is as follows: （9） In the formula, Q 纳管水量i C represents the amount of wastewater discharged from the i-th industrial enterprise into the urban sewage network, expressed in tens of thousands of tons. 纳管浓度i W represents the concentration of pollutants in the wastewater discharged from the i-th industrial enterprise into the urban sewage network, expressed in milligrams per liter. 产品产量i P represents the product output of the i-th industrial enterprise during its accounting period, expressed in tons. 产污系数i Let be the pollutant production coefficient of the i-th industrial enterprise during the product manufacturing process; η 去除率i Let be the pollutant removal rate of the i-th industrial enterprise after adopting different pretreatment processes; Q 工业用水i K represents the industrial water consumption of the i-th industrial enterprise during its product manufacturing process, expressed in tens of thousands of tons. 工业废水排放系数i This represents the ratio of wastewater discharge to water volume for the i-th industrial enterprise.

8. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 7, characterized in that: In S6, the formula for calculating the amount of other source pollutants entering the system is: （10） （11） In the formula, M 其他源污染物纳管量 This is to calculate the amount of pollutants discharged into the urban sewage network from sources other than urban domestic and industrial sources, expressed in tons; M 其他源污染物纳管量i The amount of pollutants discharged into the urban sewage network from the i-th other source is expressed in tons. m To calculate the number of pollution sources other than urban residential and industrial sources within the scope of the calculation; Q 纳管水量i C represents the amount of water discharged into the urban sewage network from the i-th other source, expressed in tens of thousands of tons; 纳管浓度i The concentration of pollutants emitted from the i-th other source into the urban sewage network is expressed in milligrams per liter. Other pollution sources include livestock and poultry farming, aquaculture, and other sources connected to the water supply system. For pollution sources with water quantity and quality monitoring facilities installed at the pipe connection points, the calculation is based on the monitoring data. For pollution sources without monitoring facilities, mobile metering equipment is used to measure water quantity, and water quality is estimated based on monitoring data from law enforcement or ecological and environmental departments, valid data obtained by the discharging unit through manual monitoring in accordance with monitoring specifications or by a commissioned monitoring agency, or the total amount of pollutants discharged as approved in the project's environmental impact assessment, discharge permit, and other documents.

9. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 8, characterized in that: In S7, the total amount of pollutants collected The calculation formula is: （12） Total amount of pollutants generated The calculation formula is: （13）。 10. The method for calculating urban sewage collection rate based on pollutant conservation as described in claim 7, characterized in that: In S8, the normalization process specifically includes: If the total number of pollutant types involved in the accounting is m, then for each of them, the pollution equivalent value is... The j Pollutant type, assuming its total collection volume is Then the normalized collection amount of the pollutant is: （14） Let its total production be Then the normalized production amount of the pollutant is: （15） Total collection amount after normalization The calculation formula is: （16） Total output after normalization The calculation formula is: （17） Obtain urban sewage collection rate The calculation formula is: （18）。

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