Method for identifying characteristic pollutants of an impacted wastewater treatment plant

Abstract

This invention relates to a method for identifying characteristic pollutants in impacted wastewater treatment plants. The method includes upstream multi-dimensional pollution source tracing and candidate pollutant database construction, precise detection of physicochemical indicators across multiple sections throughout the entire process, dual analysis of activated sludge microbial function and community, and a ternary coupled determination based on physicochemical, microbiological, and toxicological effects. This invention constructs a ternary coupled determination system integrating upstream discharge characteristics, water quality physicochemical indicators, microbial community composition, microbial functional response, and pollutant toxicological effects. This avoids misjudgments caused by single-dimensional diagnosis, improving the accuracy of characteristic pollutant identification compared to existing technologies. Through upstream source tracing and database construction, multi-section detection and screening, and ternary coupled determination, the time for locating characteristic pollutants is significantly shortened. All detection methods comply with national standards and industry specifications, and the required instruments and equipment are commonly used in wastewater treatment plants and conventional environmental testing institutions, making it suitable for rapid on-site diagnosis.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically a method for identifying characteristic pollutants in a wastewater treatment plant under impact. Background Technology

[0002] Industrial park-type wastewater treatment plants receive industrial wastewater from the park and domestic sewage from the surrounding areas. The influent water has a complex composition and fluctuates greatly in quantity and quality. It is highly susceptible to the impact of characteristic pollutants in industrial wastewater, which can lead to problems such as unstable total phosphorus removal, interruption of denitrification process, imbalance of activated sludge microbial community, and suppression of microbial function. In severe cases, it can cause the effluent quality to exceed the standard and the activated sludge to become completely ineffective, requiring sludge replacement to restore system operation.

[0003] In existing technologies, the methods for investigating abnormal operating conditions in wastewater treatment plants mostly rely on the detection of single physicochemical indicators or the judgment of staff based on experience. These methods can only detect "abnormal" system operation but cannot quickly identify the specific characteristic pollutants causing the abnormality. Although some technologies have introduced pollutant source tracing, multi-indicator water quality analysis, or microbial community sequencing, these methods are scattered and fail to integrate and analyze the characteristics of upstream enterprise discharge, the toxic effects of pollutants, multi-section physicochemical data of the wastewater treatment process, and the microbial community and functional response of activated sludge. This results in one-sided diagnostic results, slow identification of characteristic pollutants, and insufficient targeted process adjustments.

[0004] Meanwhile, existing technologies do not consider the toxic effects of pollutants on activated sludge, easily misidentifying non-toxic but highly concentrated pollutants as characteristic pollutants. Furthermore, they lack a dynamically updated pollutant fingerprint database, failing to provide a continuous and effective basis for subsequent influent pretreatment and anomaly early warning. Therefore, there is an urgent need to develop a method for identifying characteristic pollutants in impacted wastewater treatment plants. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for identifying characteristic pollutants in impacted wastewater treatment plants. This method integrates multi-dimensional information on physicochemical indicators, microbial communities, microbial function, and pollutant toxicity, offering advantages such as high operability and high identification accuracy. It solves the technical problems of existing technologies, including slow location of abnormal operating conditions, inaccurate identification of characteristic pollutants, limited diagnostic dimensions, failure to consider pollutant toxicity effects, and lack of long-term early warning evidence. By constructing a ternary coupled judgment system of physicochemical, microbiological, and toxicological effects, rapid and accurate identification of characteristic pollutants is achieved. Simultaneously, a dynamically updated pollutant fingerprint information database is established, providing a scientific basis for process control and abnormal early warning in wastewater treatment plants.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for identifying characteristic pollutants in a wastewater treatment plant under impact, comprising the following steps: S1. Upstream multi-dimensional pollution source tracing and candidate pollutant database construction: Conduct on-site visits to the target wastewater treatment plant and upstream polluting enterprises, review environmental impact assessment data, production process flow, raw and auxiliary material usage lists, historical wastewater quality data and pollutant discharge ledgers, screen potential characteristic pollutants in combination with the industry type of upstream enterprises, and at the same time measure the inhibition rate of oxygen consumption rate of activated sludge by the wastewater of upstream enterprises, convert the inhibition rate into the equivalent concentration of the standard toxic substance 3,5-dichlorophenol, eliminate pollutants with no toxic effect, and establish a candidate pollutant database with toxicity weights; S2. Precise detection of physicochemical indicators across multiple sections throughout the entire process: Select at least three continuous treatment sections in the wastewater treatment process, including industrial influent, pre-treated effluent, anaerobic section, anoxic section, aerobic section, secondary sedimentation section, and advanced treatment effluent, and collect water samples simultaneously. Detect chemical oxygen demand, total nitrogen, nitrate nitrogen, nitrite nitrogen, total phosphorus, different phosphorus forms, and the concentration of pollutants in the candidate pollutant pool to obtain the variation characteristics of each indicator along the process flow and the migration and transformation patterns of pollutants. S3. Dual analysis of activated sludge microbial function and community: Activated sludge samples were collected from each treatment section, total DNA was extracted from the samples, 16S rDNA hypervariable regions were amplified and sequenced using a high-throughput sequencing platform, and bioinformatics analysis was used to obtain information on microbial community composition, α / β diversity, and differences between samples; at the same time, the specific oxygen consumption rate, nitrification rate, and phosphorus release and uptake rate of activated sludge were measured to obtain the functional response characteristics of microorganisms. S4. Physicochemical, microbiological, and toxicological effects ternary coupling judgment: Integrate the physicochemical indicators of step S2 and the microbial community and functional information of step S3. First, use the carbon-nitrogen ratio and carbon-phosphorus ratio to rule out process abnormalities caused by insufficient carbon source. Then, use correlation analysis, cluster analysis, and redundancy analysis to compare the degree of influence of different candidate pollutants on the structure and function of the microbial community. Combine the pollutant concentration distribution characteristics along the process and toxicity weight to screen pollutants that are significantly related to abnormal operating conditions and determine characteristic pollutants. S5. Output of Characteristic Pollutant Identification Results and Construction of Fingerprint Database: Output the types, concentration ranges, migration patterns along the process, and toxic effects of characteristic pollutants, and construct a fingerprint database of characteristic pollutants. This fingerprint database can be dynamically updated based on subsequent new impact condition data and is used for wastewater pretreatment, real-time control of process operation, and early warning of abnormal conditions.

[0007] Furthermore, in step S1, the candidate pollutants include one or more of polyphosphate pollutants, titanium-containing pollutants, lithium-containing pollutants, aromatic organic pollutants, and heavy metal pollutants. The toxicity weight is determined based on the equivalent concentration of the standard toxic substance 3,5-dichlorophenol, with an equivalent concentration ≥1.0 mg / L indicating high toxicity, 0.5-1.0 mg / L indicating moderate toxicity, and <0.5 mg / L indicating low toxicity.

[0008] Furthermore, in step S2, total phosphorus is determined by potassium persulfate digestion-molybdate spectrophotometry, total nitrogen is determined by alkaline potassium persulfate digestion-ultraviolet spectrophotometry, nitrate nitrogen and nitrite nitrogen are determined by ultraviolet spectrophotometry, chemical oxygen demand is determined by potassium dichromate reflux titration, organophosphates are determined by solid phase extraction-gas chromatography-tandem mass spectrometry, and heavy metal pollutants are determined by inductively coupled plasma mass spectrometry. When the concentrations of nitrate nitrogen / nitrite nitrogen in the aerobic section decrease compared to the upstream anoxic section, and the total phosphorus concentration increases or remains basically unchanged, while the phosphorus uptake rate of activated sludge decreases by ≥30% compared to normal operating conditions, the wastewater treatment system is deemed to have been subjected to an abnormal shock and enters the characteristic pollutant precision screening process.

[0009] Furthermore, in step S3, the high-throughput sequencing platform is HiSeq, MiSeq, or NovaSeq, and the determination of microbial functional response characteristics includes the quantitative detection of anaerobic phosphorus release rate, aerobic phosphorus uptake rate, ammonia oxidation rate, and nitrite oxidation rate.

[0010] Furthermore, in step S4, the redundancy analysis is used to quantify the explanatory power of each candidate pollutant on changes in the microbial community structure. Pollutants with an explanatory power ≥ 20% are included in the candidate range of characteristic pollutants, and the final determination is made by combining toxicity weight and concentration change characteristics along the route.

[0011] Furthermore, in step S5, the characteristic pollutant fingerprint information database includes pollutant name, characteristic absorption spectrum, typical concentration range, impact characteristics on microbial community, inhibition threshold of microbial function, migration and transformation patterns along the wastewater treatment process, and targeted pretreatment process information.

[0012] Furthermore, in step S1, the temperature of the activated sludge oxygen consumption rate inhibition test is controlled at 25±2℃, the dissolved oxygen concentration is maintained at 2.0-3.0mg / L, and the test reaction time is 30-60min.

[0013] Furthermore, in step S3, after the activated sludge sample is collected, it needs to be stored at 4°C for no more than 24 hours to avoid changes in the microbial community structure.

[0014] Furthermore, in step S4, if the candidate pollutant is a composite pollutant, a combined toxicity test is required to analyze the synergistic inhibitory effect between the pollutants. When the inhibition rate of microbial function after synergistic inhibition is ≥50%, the composite pollutant combination is determined to be a characteristic pollutant.

[0015] Furthermore, in step S5, the characteristic pollutant fingerprint information database can be linked with the wastewater treatment plant's online monitoring system. When a signal matching the characteristic pollutant in the fingerprint database is detected online, an abnormality warning is automatically triggered.

[0016] Compared with the prior art, the technical solution of this application has the following beneficial effects: 1. This invention constructs a three-dimensional coupled judgment system of physicochemical, microbiological, and toxicological effects, integrating multi-dimensional information such as upstream sewage discharge characteristics, water quality physicochemical indicators, microbial community composition, microbial functional response, and pollutant toxicity effects. This avoids misjudgments caused by single-dimensional diagnosis, and improves the accuracy of characteristic pollutant identification compared to existing technologies. Through the process of upstream source tracing and database construction, multi-section detection and screening, and three-dimensional coupled judgment, the time for locating characteristic pollutants is significantly shortened. Moreover, all detection methods comply with national standards and industry specifications, and the required instruments and equipment are commonly used in sewage treatment plants and conventional environmental testing agencies. The system is easy to operate and suitable for rapid diagnosis in engineering sites.

[0017] This invention introduces an activated sludge oxygen consumption rate inhibition test in the upstream source tracing stage, converting pollutant inhibition rates into equivalent concentrations of standard toxic substances. This establishes a candidate pollutant library with toxicity weights, eliminating interfering pollutants with no toxic effects and significantly improving the accuracy of characteristic pollutant identification. It not only outputs the characteristic pollutant identification results for a single impact but also constructs a dynamically updated characteristic pollutant fingerprint information database. This provides continuous and effective scientific evidence for subsequent influent pretreatment, real-time process control, and early warning of abnormal operating conditions in wastewater treatment plants, achieving a shift from passive treatment to proactive prevention.

[0018] This invention can selectively screen candidate pollutants based on the industry type of different industrial parks, and is applicable to the diagnosis of shock-induced abnormal operating conditions in wastewater treatment plants in various industrial parks such as chemical, electroplating, pharmaceutical, and new materials industries. At the same time, it can provide synergistic inhibition effect analysis for operating conditions with combined pollutant shocks, making process regulation more targeted. Attached Figure Description

[0019] Figure 1 This is a flowchart of the method for identifying characteristic pollutants in an impacted wastewater treatment plant according to the present invention; Figure 2 This is a flowchart illustrating the implementation of the method for identifying characteristic pollutants in an impacted wastewater treatment plant according to the present invention. Figure 3 This is a flowchart illustrating the implementation of the microbial dual analysis method for identifying characteristic pollutants in an impacted wastewater treatment plant according to the present invention. Figure 4 This is a schematic diagram showing the changes in the main physicochemical indicators at each treatment section of the method for identifying characteristic pollutants in a wastewater treatment plant under impact, as presented in this invention. Figure 5This is a schematic diagram showing the changes in tripolyphosphate concentration at various treatment sections of the method for identifying characteristic pollutants in an impacted wastewater treatment plant according to the present invention. Figure 6 This is a schematic diagram showing the changes in hexapolyphosphate concentration at various treatment sections of the method for identifying characteristic pollutants in an impacted wastewater treatment plant according to the present invention. Detailed Implementation

[0020] 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.

[0021] Please see Figure 1-6 The method for identifying characteristic pollutants in a wastewater treatment plant under impact, as described in this embodiment, specifically includes the following steps: S1. Upstream multi-dimensional pollution source tracing and candidate pollutant database construction On-site visits were conducted to the target wastewater treatment plant and all upstream discharging enterprises. Environmental impact assessment documents, production processes, raw material usage lists, historical wastewater quality data, and pollutant discharge ledgers were reviewed. Potential characteristic pollutants were preliminarily screened based on the industry type of the upstream enterprises (e.g., chemical, electroplating, pharmaceutical, new materials, etc.). Simultaneously, wastewater samples were collected from upstream enterprises, and activated sludge oxygen consumption rate inhibition tests were used to determine their inhibition rate on the activated sludge of the wastewater treatment plant. The inhibition rate was converted into the equivalent concentration of the standard toxic substance 3,5-dichlorophenol. Pollutants without toxic effects were eliminated, and a candidate pollutant library with toxicity weights was established. The toxicity weights were based on equivalent concentrations: ≥1.0 mg / L was considered high toxicity, 0.5-1.0 mg / L was moderate toxicity, and <0.5 mg / L was low toxicity.

[0022] S2, Precise Detection of Physicochemical Indicators Across Multiple Sections Throughout the Entire Process At least three continuous treatment sections were selected from the industrial influent, pretreatment effluent, anaerobic stage, anoxic stage, aerobic stage, secondary sedimentation stage, and advanced treatment effluent of the wastewater treatment process. Water samples were collected simultaneously, and conventional physicochemical indicators and candidate pollutant concentrations were measured. Conventional physicochemical indicators included chemical oxygen demand (COD), total nitrogen, nitrate nitrogen, nitrite nitrogen, total phosphorus, and different phosphorus forms (orthophosphate, tripolyphosphate, hexametaphosphate, etc.). Candidate pollutant concentrations were specifically measured based on the pollutant types in the candidate pollutant database. The variation characteristics of each indicator along the process flow and the migration and transformation patterns of pollutants were obtained, providing physicochemical data support for subsequent identification of characteristic pollutants.

[0023] When the concentrations of nitrate nitrogen / nitrite nitrogen in the aerobic section are detected to decrease rather than increase compared to the upstream anoxic section, and the total phosphorus concentration increases rather than decreases or remains basically unchanged, while the phosphorus uptake rate of activated sludge decreases by ≥30% compared to normal operating conditions, it is directly determined that the wastewater treatment system has been subjected to an abnormal impact and enters the characteristic pollutant precise screening process.

[0024] S3, Dual Analysis of Microbial Function and Community in Activated Sludge Simultaneously with water sampling, activated sludge samples were collected from each treatment section and divided into two parts: one part was used for microbial community analysis, where total DNA was extracted from the sample, 16S rDNA hypervariable regions were amplified, and sequencing was performed using HiSeq, MiSeq, or NovaSeq high-throughput sequencing platforms. Bioinformatics analysis was used to complete sequence quality control, species annotation, and community diversity analysis to obtain information on microbial community composition, α / β diversity, and inter-sample differences; the other part was used for the determination of microbial functional response characteristics, quantitatively detecting the anaerobic phosphorus release rate, aerobic phosphorus uptake rate, ammonia oxidation rate, and nitrite oxidation rate of activated sludge to clarify the degree of inhibition of pollutants on the core nitrogen and phosphorus removal functions of activated sludge.

[0025] S4. Tripartite Coupling Determination of Physicochemical, Microbiological, and Toxicity Effects 1. First, determine the carbon-nitrogen ratio and carbon-phosphorus ratio of the industrial influent. If the carbon-nitrogen ratio is ≥8 and the carbon-phosphorus ratio is ≥20, which meets the carbon source range required for biological nitrogen and phosphorus removal, then process abnormalities caused by insufficient carbon source will be excluded first. 2. Integrate the physicochemical indicators from step S2 and the microbial community and functional information from step S3, and use correlation analysis and cluster analysis to screen candidate pollutants that are significantly related to microbial community imbalance and functional suppression. 3. Redundancy analysis was used to quantify the explanatory power of each candidate pollutant on changes in microbial community structure, and pollutants with an explanatory power ≥20% were included in the candidate range of characteristic pollutants; 4. By combining the toxicity weights of candidate pollutants, the concentration distribution characteristics along the wastewater treatment process, and the inhibition thresholds on microbial function, the characteristic pollutants that cause system abnormalities are finally identified.

[0026] S5. Output of Characteristic Pollutant Identification Results and Construction of Fingerprint Database This system outputs information on the types of characteristic pollutants, their characteristic absorption spectra, typical concentration ranges, impact characteristics on microbial communities, inhibition thresholds of microbial function, migration patterns along the flow path, and toxic effects, constructing a characteristic pollutant fingerprint database. This database can be dynamically updated based on subsequent impact data from the wastewater treatment plant, adding newly identified characteristic pollutants and related information. Simultaneously, it provides wastewater treatment plants with targeted influent pretreatment process recommendations, real-time process operation control parameters, and early warning thresholds for abnormal operating conditions, achieving a shift from passive diagnosis to proactive early warning.

[0027] Specifically, candidate pollutants include one or more of the following: polyphosphate pollutants, titanium-containing pollutants, lithium-containing pollutants, aromatic organic pollutants (biphenyl, phenol, naphthalene, etc.), and heavy metal pollutants. Targeted screening can be carried out based on the industry type of the upstream industrial park.

[0028] Specifically, the detection methods for each physicochemical indicator strictly follow national standards and industry specifications: total phosphorus is determined by potassium persulfate digestion-molybdate spectrophotometry; total nitrogen is determined by alkaline potassium persulfate digestion-ultraviolet spectrophotometry; nitrate nitrogen and nitrite nitrogen are determined by ultraviolet spectrophotometry; chemical oxygen demand is determined by potassium dichromate reflux titration; organophosphates are determined by solid-phase extraction-gas chromatography-tandem mass spectrometry; and heavy metal pollutants are determined by inductively coupled plasma mass spectrometry.

[0029] Specifically, the bioinformatics analysis of microbial community analysis includes sequence quality control using QIIME2 or Mothur software, species annotation using the Silva database, and α / β diversity analysis and visualization using R language.

[0030] Specifically, if the candidate pollutant is a compound pollutant, it is necessary to further analyze the synergistic inhibition effect among the pollutants. The compound pollutant combination with an inhibition rate of ≥50% on microbial function after synergistic inhibition is identified as the characteristic pollutant.

[0031] Specifically, the characteristic pollutant fingerprint information database can be digitally managed through computer software, supporting rapid querying, addition, modification of pollutant information, and dynamic adjustment of early warning thresholds.

[0032] Example A wastewater treatment plant that receives industrial wastewater and domestic sewage from a new materials industrial park was selected as the research object. This wastewater treatment plant recently experienced a sharp drop in nitrogen and phosphorus removal efficiency in its aerobic stage and excessive total phosphorus in the effluent. The method of this invention was used to identify characteristic pollutants. The specific steps are as follows: 1. Upstream multi-dimensional pollution source tracing and candidate pollutant database construction On-site visits were conducted to 12 new material enterprises upstream of the wastewater treatment plant to review their production processes and wastewater discharge data. Polyphosphates, titanium-containing, lithium-containing, and chromium-containing pollutants were initially screened as potential pollutants. Wastewater samples were collected from each enterprise to conduct activated sludge oxygen consumption rate inhibition tests. The inhibition rate was converted into the equivalent concentration of 3,5-dichlorophenol. The equivalent concentration of chromium-containing pollutants was 0.3 mg / L (low toxicity weight), while the equivalent concentrations of polyphosphates, titanium, and lithium were 1.2 mg / L, 1.94 mg / L, and 0.85 mg / L, respectively. A candidate pollutant library with toxicity weights was established.

[0033] Precise detection of physicochemical indicators across multiple sections throughout the entire process Water samples were collected from four continuous cross-sections: industrial influent, anoxic zone, aerobic zone, and secondary sedimentation zone. Conventional physicochemical indicators and candidate pollutant concentrations were measured. The industrial influent showed a carbon-to-nitrogen ratio of 19.5 and a carbon-to-phosphorus ratio of 203.7, meeting the carbon source requirements for biological nitrogen and phosphorus removal. From the anoxic to the aerobic zone, nitrate nitrogen decreased from 0.85 mg / L to 0.58 mg / L, while total phosphorus increased from 0.79 mg / L to 0.80 mg / L. The aerobic phosphorus uptake rate of the activated sludge decreased by 45% compared to normal operating conditions, indicating an abnormal shock to the system. Tripolyphosphate, hexametaphosphate, titanium, and lithium were detected at measurable concentrations at all cross-sections, while chromium was only detected at low concentrations in the industrial influent.

[0034] Dual analysis of activated sludge microbial function and community Activated sludge samples were collected from four sections. High-throughput sequencing results showed that the relative abundance of nitrifying bacteria (nitrosomonas, nitrifying spirochetes) and polyphosphate-accumulating bacteria (Acinetobacter, Rawlston) in the aerobic section decreased by more than 50% compared with the anoxic section, and the community diversity was significantly reduced. Microbial function tests showed that the ammonia oxidation rate, nitrite oxidation rate, and phosphorus uptake rate in the aerobic section decreased by 55%, 60%, and 45% respectively compared with normal operating conditions, while the anaerobic phosphorus release rate did not change significantly.

[0035] Physicochemical, microbiological, and toxicological effects combined for determination Redundancy analysis was used to quantify the explanatory power of each candidate pollutant on the microbial community structure. The explanatory powers of titanium, tripolyphosphate, and lithium were 35%, 28%, and 22%, respectively, all ≥20%. Combining the toxicity weights (titanium is highly toxic, tripolyphosphate is highly toxic, and lithium is moderately toxic) and the concentration distribution characteristics along the route, titanium and tripolyphosphate accumulated in the aerobic section, and their inhibition thresholds for polyphosphate-accumulating bacteria and nitrifying bacteria were much lower than the actual detected concentrations. Finally, tripolyphosphate and titanium were determined to be the core characteristic pollutants of this system anomaly, and lithium was a secondary characteristic pollutant.

[0036] Characteristic pollutant identification results output and fingerprint database construction The system outputs characteristic information of tripolyphosphate, titanium, and lithium, including typical concentration ranges, impact characteristics on microbial communities, functional inhibition thresholds, and migration patterns along the process. It constructs a fingerprint information database of characteristic pollutants and develops a targeted process scheme for the wastewater treatment plant, which is "pretreatment of polyphosphate from upstream enterprises + removal of titanium ions from influent". It also sets early warning thresholds to achieve early prevention and control of abnormal operating conditions.

[0037] Alternative implementation methods Without departing from the inventive concept, the following equivalent substitutions can be made to this invention, all of which fall within the protection scope of this invention: In step S1, the standard toxic substance can be replaced with phenol, potassium dichromate, etc., depending on the type of pollutants in the industrial park; In step S2, the detection section can be adjusted according to the process type of the wastewater treatment plant, such as adding deep treatment sections like MBR section or Fenton section; In step S3, the high-throughput sequencing platform can be replaced with other mainstream sequencing platforms depending on the experimental conditions, and other quantitative detection methods in the industry can be used for microbial function determination. In step S4, the statistical methods for determining coupling can be auxiliaryly verified by principal component analysis, canonical correspondence analysis, and correlation network analysis. In step S5, the characteristic pollutant fingerprint information database can be linked with the online monitoring system of the sewage treatment plant to realize automatic early warning of abnormal operating conditions.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for identifying characteristic pollutants of a impacted sewage treatment plant, characterized in that, Includes the following steps: S1. Upstream multi-dimensional pollution source tracing and candidate pollutant database construction: Conduct on-site visits to the target wastewater treatment plant and upstream polluting enterprises, review environmental impact assessment data, production process flow, raw and auxiliary material usage lists, historical wastewater quality data and pollutant discharge ledgers, screen potential characteristic pollutants in combination with the industry type of upstream enterprises, and at the same time measure the inhibition rate of oxygen consumption rate of activated sludge by the wastewater of upstream enterprises, convert the inhibition rate into the equivalent concentration of the standard toxic substance 3,5-dichlorophenol, eliminate pollutants with no toxic effect, and establish a candidate pollutant database with toxicity weights; S2. Precise detection of physicochemical indicators across multiple sections throughout the entire process: Select at least three continuous treatment sections in the wastewater treatment process, including industrial influent, pre-treated effluent, anaerobic section, anoxic section, aerobic section, secondary sedimentation section, and advanced treatment effluent, and collect water samples simultaneously. Detect chemical oxygen demand, total nitrogen, nitrate nitrogen, nitrite nitrogen, total phosphorus, different phosphorus forms, and the concentration of pollutants in the candidate pollutant pool to obtain the variation characteristics of each indicator along the process flow and the migration and transformation patterns of pollutants. S3. Dual analysis of activated sludge microbial function and community: Activated sludge samples were collected from each treatment section, total DNA was extracted from the samples, 16S rDNA hypervariable regions were amplified and sequenced using a high-throughput sequencing platform, and bioinformatics analysis was used to obtain information on microbial community composition, α / β diversity, and differences between samples; at the same time, the specific oxygen consumption rate, nitrification rate, and phosphorus release and uptake rate of activated sludge were measured to obtain the functional response characteristics of microorganisms. S4. Physicochemical, microbiological, and toxicological effects ternary coupling judgment: Integrate the physicochemical indicators of step S2 and the microbial community and functional information of step S3. First, use the carbon-nitrogen ratio and carbon-phosphorus ratio to rule out process abnormalities caused by insufficient carbon source. Then, use correlation analysis, cluster analysis, and redundancy analysis to compare the degree of influence of different candidate pollutants on the structure and function of the microbial community. Combine the pollutant concentration distribution characteristics along the process and toxicity weight to screen pollutants that are significantly related to abnormal operating conditions and determine characteristic pollutants. S5. Output of Characteristic Pollutant Identification Results and Construction of Fingerprint Database: Output the types, concentration ranges, migration patterns along the process, and toxic effects of characteristic pollutants, and construct a fingerprint database of characteristic pollutants. This fingerprint database can be dynamically updated based on subsequent new impact condition data and is used for wastewater pretreatment, real-time control of process operation, and early warning of abnormal conditions.

2. The method of identifying characteristic pollutants of a impacted wastewater treatment plant according to claim 1, wherein, In step S1, the candidate pollutants include one or more of the following: polyphosphate pollutants, titanium-containing pollutants, lithium-containing pollutants, aromatic organic pollutants, and heavy metal pollutants. The toxicity weight is determined based on the equivalent concentration of the standard toxic substance 3,5-dichlorophenol. An equivalent concentration ≥1.0 mg / L is considered high toxicity, 0.5-1.0 mg / L is considered moderate toxicity, and <0.5 mg / L is considered low toxicity.

3. The method of identifying characteristic pollutants of a impacted wastewater treatment plant according to claim 1, wherein, In step S2, total phosphorus was determined by potassium persulfate digestion-molybdate spectrophotometry, total nitrogen was determined by alkaline potassium persulfate digestion ultraviolet spectrophotometry, nitrate nitrogen and nitrite nitrogen were determined by ultraviolet spectrophotometry, chemical oxygen demand was determined by potassium dichromate reflux titration, organophosphates were determined by solid phase extraction-gas chromatography-tandem mass spectrometry, and heavy metal pollutants were determined by inductively coupled plasma mass spectrometry. When the concentrations of nitrate nitrogen / nitrite nitrogen in the aerobic section decrease compared to the upstream anoxic section, and the total phosphorus concentration increases or remains basically unchanged, while the phosphorus uptake rate of activated sludge decreases by ≥30% compared to normal operating conditions, the wastewater treatment system is deemed to have been subjected to an abnormal shock and enters the characteristic pollutant precision screening process.

4. The method for identifying characteristic pollutants in a wastewater treatment plant under impact according to claim 1, characterized in that, In step S3, the high-throughput sequencing platform is HiSeq, MiSeq, or NovaSeq, and the determination of microbial functional response characteristics includes the quantitative detection of anaerobic phosphorus release rate, aerobic phosphorus uptake rate, ammonia oxidation rate, and nitrite oxidation rate.

5. The method for identifying characteristic pollutants in a wastewater treatment plant under impact according to claim 1, characterized in that, In step S4, the redundancy analysis is used to quantify the explanatory power of each candidate pollutant on changes in the microbial community structure. Pollutants with an explanatory power ≥ 20% are included in the candidate range of characteristic pollutants, and the final determination is made by combining toxicity weight and concentration change characteristics along the route.

6. The method for identifying characteristic pollutants in a wastewater treatment plant under impact according to claim 1, characterized in that, In step S5, the characteristic pollutant fingerprint information database includes pollutant name, characteristic absorption spectrum, typical concentration range, impact characteristics on microbial community, inhibition threshold of microbial function, migration and transformation law along the sewage treatment process, and targeted pretreatment process information.

7. The method for identifying characteristic pollutants in a wastewater treatment plant under impact according to claim 1, characterized in that, In step S1, the temperature of the activated sludge oxygen consumption rate inhibition test is controlled at 25±2℃, the dissolved oxygen concentration is maintained at 2.0-3.0mg / L, and the test reaction time is 30-60min.

8. The method for identifying characteristic pollutants in a wastewater treatment plant under impact according to claim 1, characterized in that, In step S3, after the activated sludge sample is collected, it needs to be stored at 4°C for no more than 24 hours to avoid changes in the microbial community structure.

9. The method for identifying characteristic pollutants in a wastewater treatment plant under impact according to claim 1, characterized in that, In step S4, if the candidate pollutant is a composite pollutant, a combined toxicity test is required to analyze the synergistic inhibitory effect between the pollutants. When the inhibition rate of microbial function after synergistic inhibition is ≥50%, the composite pollutant combination is determined to be a characteristic pollutant.

10. The method for identifying characteristic pollutants in a wastewater treatment plant under impact according to claim 1, characterized in that, In step S5, the characteristic pollutant fingerprint information database can be linked with the wastewater treatment plant's online monitoring system. When a signal matching the characteristic pollutant in the fingerprint database is detected online, an abnormality warning is automatically triggered.

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