CN-122022156-A - Quantitative analysis method for inflow and outflow water of municipal sewage plant in dry days

CN122022156ACN 122022156 ACN122022156 ACN 122022156ACN-122022156-A

Abstract

The invention discloses a quantitative analysis method of inflow and outflow water in dry days of municipal sewage plants, which belongs to the technical field of sewage treatment and comprises the steps of respectively obtaining concentration values of conventional monitoring indexes of primary sewage, outflow water and inflow water; the method comprises the steps of obtaining a primary selection index set by primary screening of conventional monitoring indexes based on concentration stability, obtaining a plurality of characteristic indexes by secondary screening of the primary selection index set based on concentration difference, constructing a multi-index mass balance matrix equation of primary sewage, external water and water in a factory, respectively obtaining daily average concentration statistics of the characteristic indexes of the primary sewage, the external water and the water in the factory, solving and carrying out statistical analysis on the multi-index mass balance matrix equation through random sampling assignment and a least square method to obtain the water volume proportion of the external water in the factory, and completing quantitative analysis of the external water according to the total water volume of the water in the factory. The invention can accurately and quantitatively analyze the inflow and outflow water of the dry days of the sewage plant according to the conventional monitoring data of the sewage plant.

Inventors

LI MENG
SHI QIANYUN
FANG QING
WU YUHAO
BAI ZHONGQIANG
FANG HUA

Assignees

江苏环保产业技术研究院股份公司
南京信息工程大学

Dates

Publication Date: 20260512
Application Date: 20260128

Claims (10)

1. A quantitative analysis method for inflow and outflow water in a dry day of a municipal sewage plant, wherein the inflow water of the municipal sewage plant comprises raw sewage and outflow water, is characterized by comprising the following steps: respectively acquiring concentration values of conventional monitoring indexes of raw sewage, external water and water in factories at a plurality of sampling time points of a plurality of drought sampling days; based on concentration difference between the conventional monitoring indexes of the primary sewage and the external water, carrying out secondary screening on the primary screening index set to obtain a plurality of characteristic indexes; Constructing a multi-index mass balance matrix equation of the primary sewage, the external water and the water in the factory, respectively obtaining daily average concentration statistics of characteristic indexes of the primary sewage, the external water and the water in the factory, and then solving and statistically analyzing the multi-index mass balance matrix equation by randomly sampling, assigning the characteristic indexes and a least square method to obtain the water quantity proportion of the external water in the factory; and obtaining the external water quantity according to the total water quantity of the water entering the factory and the proportion of the external water to the water quantity of the water entering the factory, and completing the quantitative analysis of the external water.
2. The method for quantitatively analyzing the dry-weather inflow and outflow water of the municipal sewage plant according to claim 1, wherein the conventional monitoring indexes comprise dissolved oxygen, COD, BOD 5 , ammonia nitrogen, nitrate nitrogen, total phosphorus, orthophosphate and total suspended matters.
3. The quantitative analysis method of the dry-weather inflow and outflow water of the municipal sewage plant according to claim 1, wherein the preliminary screening is performed on the conventional monitoring indexes based on concentration stability to obtain a preliminary selection index set, specifically: And respectively acquiring concentration data sets of each conventional monitoring index of the primary sewage at different residence times, acquiring variation coefficients of each concentration data set, and screening out the conventional monitoring indexes exceeding a set variation coefficient threshold value to obtain a primary selection index set.
4. The quantitative analysis method of the dry-weather inflow and outflow water of the municipal sewage plant according to claim 1, wherein the secondary screening is performed on the primary selection index set based on the concentration difference of the conventional monitoring indexes of the primary sewage and the outflow water to obtain a plurality of characteristic indexes, specifically: Aiming at each primary selection index in the primary selection index set, respectively acquiring a concentration data set of each primary selection index of the primary sewage and the external water, and comparing the concentration difference of each primary selection index by adopting a non-parameter test method; Sorting all the primary selection indexes according to the difference strength sequence, and selecting the primary selection indexes before The first selected index is used as a characteristic index, 。
5. The quantitative analysis method for the dry-weather inflow and outflow water of the municipal sewage plant according to claim 1, wherein the daily average concentration statistics of the raw sewage, the outflow water and the inflow water characteristic indexes are respectively obtained, specifically comprising the following steps: Counting the daily average concentration values of all the characteristic indexes of the primary sewage on sampling days to obtain a primary sewage daily average concentration set, and taking the maximum value, the minimum value, the mean value and the standard deviation of the characteristic indexes in the set as the daily average concentration statistic of the characteristic indexes of the primary sewage; counting the daily average concentration values of all the sampled daily external water characteristic indexes to obtain an external water daily average concentration set, and taking the maximum value, the minimum value, the mean value and the standard deviation of the characteristic indexes in the set as the daily average concentration statistic of the external water characteristic indexes; And counting the daily average concentration values of all the characteristic indexes of the water entering the factory on sampling days to obtain a daily average concentration set of the water entering the factory, and taking the maximum value, the minimum value, the mean value and the standard deviation of the characteristic indexes in the set as the daily average concentration statistic of the characteristic indexes of the water entering the factory.
6. The quantitative analysis method for the dry-day inflow and outflow water of the municipal sewage plant according to claim 5, wherein the statistics of the daily average concentration values of all the raw sewage characteristic indexes on sampling days specifically comprises the following steps: Dividing a zone for generating the primary sewage into a living zone and a business zone according to the source of the primary sewage, and determining the proportion of sewage generation amounts of the living zone and the business zone according to the total water consumption data and the water consumption of each type of zone; For each sampling day, according to the single-day average concentration of the characteristic indexes of each primary sewage sampling point, the single-day average concentrations of the characteristic indexes of the residential area and the commercial area are respectively obtained in an arithmetic average mode, and the daily average concentration value of the characteristic indexes of the primary sewage is obtained in a water weight mode by combining the ratio of the sewage production amounts of the residential area and the commercial area.
7. The quantitative analysis method for the dry-weather external water inflow and outflow of the municipal sewage plant according to claim 5, wherein the statistics of the daily average concentration values of all the characteristic indexes of the external water at sampling days is characterized in that the daily average concentration values of the characteristic indexes of the external water are obtained in an arithmetic average mode according to the single-day average concentration of the characteristic indexes of the sampling points of each sampling day.
8. The quantitative analysis method of the dry-weather inflow and outflow water of the municipal sewage plant according to claim 1, wherein the multi-index mass balance matrix equation of the raw sewage, the outflow water and the inflow water is specifically as follows: ; Wherein, the 、 And Respectively the characteristic indexes of raw sewage, external water and water entering into factories Is a daily average concentration sampling value of (1), , Is the number of the characteristic index(s), And The ratio of the primary sewage to the water in the factory and the ratio of the external water to the water in the factory are respectively.
9. The quantitative analysis method of the dry-weather inflow and outflow water of the municipal sewage plant according to claim 8, wherein after the daily average concentration statistics of the characteristic indexes of the raw sewage, the outflow water and the inflow water are respectively obtained, the characteristic indexes are assigned by random sampling, and the multi-index mass balance matrix equation is solved and statistically analyzed by a least square method to obtain the ratio of the outflow water to the inflow water, specifically: According to the daily concentration statistic distribution characteristics of all sampling days, a uniformly distributed random sampling mode or a normal distributed random sampling mode is selected, and daily concentration sampling values of the characteristic indexes of the raw sewage, the external water and the water in the factory are obtained from the daily concentration statistic of the characteristic indexes of the raw sewage, the external water and the water in the factory; Repeatedly sampling for a plurality of times, solving a multi-index mass balance matrix equation by adopting a least square method based on a daily average concentration sampling value of each sampling to obtain the water quantity proportion of the water in the plant water of each sampling, and putting the water into an external water proportion data set X Ⅰ ; Dividing the data set X Ⅰ into a plurality of groups, calculating the average value of each group, constructing an external water proportion average value data set X Ⅱ , counting the frequency distribution of the external water proportion average value data set X Ⅱ , fitting a normal distribution curve, and outputting the optimization result of the proportion of the external water to the water quantity of the water in the factory in the form of 95% confidence interval.
10. The quantitative analysis method for the dry-weather inflow and outflow water of the municipal sewage plant according to claim 9, wherein when the least square method is adopted to solve a multi-index mass balance matrix equation, the constraint conditions are as follows: , wherein, Is the relative error of the settings.

Description

Quantitative analysis method for inflow and outflow water of municipal sewage plant in dry days Technical Field The invention belongs to the technical field of sewage treatment, and particularly relates to a quantitative analysis method for inflow and outflow water in a dry day of a municipal sewage plant. Background Municipal wastewater treatment plants are an essential infrastructure for maintaining safe operation of modern cities, and have important functions of controlling water pollution, maintaining water ecological environment quality and protecting crowd health. Because the attached sewage collection pipe network of sewage plant is laid underground, is influenced by factors such as long service life, high ground load, improper work progress, and the like, a large number of defects and damages commonly exist in the existing sewage pipe network, and further the problem that exogenous low-concentration water (external water) such as groundwater infiltration, rainwater inflow in rainy days and the like invades the sewage pipe network is caused. On one hand, the sewage treatment system greatly reduces the concentration of pollutants in the inflow water of the sewage plant, causes unmatched design parameters of the inflow water and the sewage plant, has high stable operation difficulty and high operation cost of the sewage plant, and on the other hand, causes the false impression of high sewage collection efficiency and virtual high operation load of the sewage plant, directly influences the accuracy of regional water environment management decision and water pollution protection measures, and even generates the false results of blindly expanding the sewage treatment scale and wasting a large amount of financial resources and material resources. The external water entering the municipal sewage plant mainly comprises two parts, namely groundwater infiltration at the defective and damaged part of the sewage pipe network and rainwater inflow at the rain-sewage staggered joint part. The inflow rainwater occurs in a rainfall period, and for the same sewage plant, the inflow rainwater amount in a rainy day can be obtained through the difference value of the inflow flows of the sewage plant in the rainy day and the sewage plant in a dry day, and the result is accurate; on the other hand, the inflow rainwater quantity and the rainfall intensity in the rainy days are highly correlated, and the rainfall intensity and inflow rainwater quantity correlation curve of the water collecting sheet area of the sewage plant can be conveniently obtained. Therefore, calculating the dry-day external water quantity (i.e., the infiltration underground water quantity) is an important point and a difficult point in the evaluation work of the external water quantity of the municipal sewage plant. The existing evaluation and calculation work of the external water invasion amount in the sewage system is mainly carried out aiming at the sewage pipe network system, the external water invasion scale in a pipe section is estimated according to the changes of factors such as the liquid level, the water amount, the water quality and the temperature between the downstream associated nodes on the sewage pipe network, and the evaluation of the pipe network health degree and the pipe network defect investigation and repair are carried out. The common external water quantitative method mainly comprises a water quantity method, a distributed temperature sensor method, a characteristic factor method and the like. The flow method is a simple estimation method, the result accuracy is low, a large number of temperature sensors are required to be distributed along a pipeline by the distributed temperature sensor method, and the cost is high and the efficiency is low. The characteristic factor method takes substances with obvious concentration difference between sewage and external water as characteristic factors, and substitutes the substances into a mass balance equation among the sewage, the external water and water samples at monitoring points for calculation, so that a relatively accurate calculation result can be obtained theoretically. The characteristic factor method has the following limitations in practical application, namely (1) common characteristic factors such as acesulfame potassium, caffeine, a surfactant, oxyhydrogen isotopes and the like are all unconventional indexes, the analysis and detection requirements are high, the cost is high, a screening method which is matched with the daily operation management of a sewage plant and takes the conventional pollution indexes as the characteristic factors is lacked, (2) calculation is carried out by adopting a single characteristic factor, the accuracy of basic data is highly dependent, the fault tolerance is low, large deviation is easy to occur, and (3) the external water quantity estimation is carried out mainly aiming at pipe sections of a small-range pipe network and an upstream-downstr