Method and system for evaluating biodegradability of new pollutants in wastewater

Abstract

The invention discloses an evaluation method and system for biodegradability of new pollutants in wastewater, and the method comprises the steps: carrying out the clustering of multi-dimensional features of a wastewater biological treatment process, and screening a biotransformation index and an adsorption and desorption index which are potentially associated with microbial community data; and simultaneously quantifying the contribution of the biotransformation index and the adsorption and desorption index to the concentration change of the target pollutant through VPA analysis to obtain the biotransformation proportion. And finally, correcting the biodegradation rate of the new pollutants through the bioconversion proportion, thereby determining the biodegradability of the new pollutants in the wastewater biological treatment process. According to the method, the occurrence characteristics and the conversion path ratio of different new pollutants in the wastewater biological treatment process can be analyzed, and the deviation caused by evaluating the biodegradability of the new pollutants in the wastewater only through the apparent removal rate is overcome.

Description

Technical Field

[0001] This invention relates to a method and system for assessing the biodegradability of new pollutants in wastewater, and particularly to a method and system for assessing the biodegradability of new pollutants in wastewater biological treatment processes. Background Technology

[0002] Emerging contaminants (ECs) pose potential ecological risks due to their persistence and bioaccumulation. Wastewater treatment is a crucial barrier to prevent these ECs from entering the environment. Among wastewater treatment processes, biological wastewater treatment is one of the core methods for wastewater purification. However, because biological wastewater treatment processes were initially designed to remove conventional pollutants such as carbon, nitrogen, and phosphorus, their removal efficiency for emerging contaminants is poor. Furthermore, the desorption and decoupling of these emerging contaminants can lead to their accumulation in the wastewater effluent, subsequently entering the ecosystem. Therefore, it is necessary to accurately assess the degradation efficiency of biological wastewater treatment processes for emerging contaminants and to identify key toxic emerging contaminants in wastewater.

[0003] Currently, traditional assessment methods often rely on removal rates calculated from influent and effluent concentrations to characterize the biodegradability of new pollutants in wastewater biological treatment processes. However, changes in the concentration of new pollutants in wastewater biological treatment processes involve not only biotransformation caused by activated sludge microbial communities but also adsorption and desorption in the solid phase. Solid-phase adsorption only temporarily isolates new pollutants from the aqueous phase; they may be released during sludge recirculation into the treatment process or enter the environment with residual sludge, posing a potential risk of re-release. Therefore, this may lead to misjudgments of the degradation efficiency of biological treatment processes for new pollutants, further resulting in incorrect assessments of their biodegradability. Therefore, there is an urgent need to develop a method that can quantify the proportion of new pollutant transformation pathways in wastewater biological treatment processes, thereby correcting the biodegradability rate of new pollutants in wastewater biological treatment processes and determining their biodegradability. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a method and system for assessing the biodegradability of new pollutants in wastewater, thereby solving the problem of inaccurate biodegradability assessment caused by using only removal rate to represent biodegradability rate in the prior art.

[0005] Technical solution: The method for assessing the biodegradability of new pollutants in wastewater according to the present invention includes the following steps:

[0006] (1) Collect multi-dimensional characteristics and new pollutant concentrations of wastewater treatment plants. The multi-dimensional characteristics include water quality information, sludge characteristics, operating parameters and microbial community data.

[0007] (2) The multi-dimensional features are divided into two categories by clustering algorithm. The features contained in the cluster containing microbial community data, excluding microbial community data, are biotransformation indicators, while the features in the other clusters are adsorption and desorption indicators.

[0008] (3) The contribution ratio of biotransformation indicators and adsorption-desorption indicators to the change in the concentration of new pollutants was calculated by VPA analysis to obtain the biotransformation ratio;

[0009] (4) The removal rate of new pollutants is corrected by the bioconversion ratio to assess the biodegradability of new pollutants in the wastewater treatment process, and the biodegradability of new pollutants is determined by the biodegradability rate.

[0010] Furthermore, step (3) also includes: calculating the pure effect of bioconversion, the synergistic effect and the pure adsorption-desorption effect by VPA analysis, and allocating the synergistic effect to the pure effect of bioconversion by proportion to obtain the bioconversion ratio.

[0011] Furthermore, the formula for calculating the bioconversion ratio in step (3) is a′=a+bw a ,

[0012] Where a represents the pure effect of bioconversion, b represents the combined effect, c represents the pure effect of adsorption and desorption, and a′ represents the bioconversion ratio.

[0013] Further, step (4) specifically involves multiplying the bioconversion ratio by the removal rate of the new pollutant to obtain the biodegradation rate of the new pollutant.

[0014] Furthermore, the clustering algorithm described in step (2) is a Gaussian mixture model clustering algorithm.

[0015] Furthermore, in step (1), the water quality information includes: total organic carbon, total phosphorus, total nitrogen, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, water temperature, and pH value;

[0016] Sludge characteristics include: sludge volume index, sludge settling ratio, volatile suspended solids concentration in mixed liquor, and mixed liquor suspended solids concentration;

[0017] Operating parameters include: dissolved oxygen, hydraulic retention time, and sludge retention time;

[0018] Microbial community data include: α-diversity and β-diversity.

[0019] Furthermore, in step (1), the concentration of the new pollutant is calculated by liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry.

[0020] The wastewater biodegradability assessment system of the present invention includes:

[0021] The data acquisition unit is used to collect multi-dimensional characteristics of the wastewater treatment plant and the concentration of new pollutants. The multi-dimensional characteristics include water quality information, sludge characteristics, operating parameters and microbial community data.

[0022] The biotransformation index screening unit is used to divide multi-dimensional features into two categories using a clustering algorithm. Features other than microbial community data contained in the cluster are biotransformation indicators, while features in the other clusters are adsorption and desorption indicators.

[0023] The bioconversion ratio calculation unit is used to calculate the contribution ratio of bioconversion indicators and adsorption-desorption indicators to the change in the concentration of new pollutants using the VPA analysis method, and obtain the bioconversion ratio.

[0024] The biodegradability assessment unit is used to assess the biodegradability of new pollutants during wastewater treatment by correcting the removal rate of new pollutants through bioconversion ratio, and to determine the biodegradability of new pollutants through the biodegradability rate.

[0025] The electronic device of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded onto the processor, it implements the method for assessing the biodegradability of new pollutants in the wastewater.

[0026] The computer-readable storage medium of the present invention stores a computer program, which, when executed by a processor, implements the method for assessing the biodegradability of new pollutants in wastewater.

[0027] Beneficial effects: Compared with the prior art, the advantages of the present invention are: 1. The present invention is based on data-driven evaluation of the biodegradability of new pollutants in wastewater, and can analyze the occurrence characteristics and transformation pathway ratio of different new pollutants in wastewater biological treatment processes; 2. The present invention quantifies the bioconversion ratio of new pollutants and corrects the biodegradation rate of new pollutants in wastewater biological treatment processes, and evaluates the biodegradability of new pollutants. Attached Figure Description

[0028] Figure 1 This is a flowchart of the method for assessing the biodegradability of novel pollutants according to the present invention.

[0029] Figure 2 This is a graph illustrating the performance evaluation of unsupervised machine learning in an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the clustering results of multi-dimensional features in an embodiment of the present invention.

[0031] Figure 4A graph showing the quantitative results of the transformation pathways of new pollutants.

[0032] Figure 5 This is a comparison chart of the biodegradability of personal medicines and care products before and after correction in an embodiment of the present invention. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0034] Biotransformation, based on the degradation and reduction of new pollutants by activated sludge microorganisms, as well as the decoupling or generation of parent new pollutants, reflects the biodegradability of new pollutants in wastewater biological treatment processes. However, concentration changes caused by reversible adsorption are only temporary removals. Due to the complex nonlinear relationship between the two, it is impossible to distinguish their contributions to the concentration changes of new pollutants in wastewater biological treatment. To address this issue, this invention proposes a method for assessing the biodegradability of new pollutants based on machine learning combined with statistical analysis, such as... Figure 1 As shown, it includes the following steps.

[0035] Step 1: Obtain multi-dimensional characteristics of different stages of the wastewater treatment plant and detect the concentration of new pollutants.

[0036] The acquisition of multi-dimensional characteristics of wastewater treatment plants includes water quality information, sludge characteristics, operating parameters, and microbial community data. Water quality information includes: Total Organic Carbon (TOC), Total Phosphorus (TP), Total Nitrogen (TN), Ammonia Nitrogen (NH3-N), Nitrate Nitrogen (NO3-N), Nitrite Nitrogen (NO2-N), Water Temperature (T), and pH value. Sludge characteristics include: Sludge Volume Index (SVI), Sludge Settling Ratio (SV), Mixed Liquor Volatile Suspended Solids Concentration (MLVSS), and Mixed Liquor Suspended Solids Concentration (MLSS). Operating parameters include: Dissolved Oxygen (DO), Hydraulic Retention Time (HRT), and Sludge Retention Time (SRT). Microbial community data includes: α-diversity and β-diversity.

[0037] The concentration of new pollutants at different stages of wastewater treatment can be quantitatively determined by liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry.

[0038] Step 2: Measure the microbial data of the wastewater biological treatment system.

[0039] The activated sludge samples used in this embodiment were collected from various biological treatment tanks in 154 wastewater treatment systems across the country. The sludge samples underwent 16S rRNA amplicon sequencing to determine the V3-V4 region of the bacterial 16S rRNA. The 16S primers used for sequencing were:

[0040] 341F(CCTAYGGGRBGCASCAG, SEQ ID NO: 1);

[0041] 806R (GGACTACNNNGGGTATCTAAT, SEQ ID NO: 2).

[0042] Step 3: Select an unsupervised machine learning model through performance evaluation.

[0043] This embodiment uses GMM, OPTICs, SC, and SOM as unsupervised machine learning models, such as Figure 2 As shown, the final unsupervised machine learning model is determined by comparing the silhouette coefficient, CH index, DB index, and noise point ratio. Ultimately, the Gaussian Mixture Model (GMM) clustering was selected as the unsupervised machine learning model in this embodiment because it has the highest CH index and silhouette coefficient, as well as the lowest noise point ratio and relatively low DB index.

[0044] Step 4: Screen biotransformation indicators that affect the biotransformation of new pollutants in wastewater.

[0045] Clustering of multi-dimensional features of wastewater treatment plants using the GMM model, such as Figure 3 The clustering results are shown. Using the α-diversity and β-diversity of the microbial community data as targets, we observed which clusters contained microbial community data. Features related to the microbial community data are considered biotransformation indicators, while other features are called adsorption-desorption indicators. In this embodiment, the final determined biotransformation indicators are: MLVSS, MLSS, TP, DO, and NO2-N.

[0046] Step 5: Quantify the proportion of new pollutant removal pathways in wastewater.

[0047] The effects of biotransformation and adsorption-desorption indicators on the dynamic changes in the concentration of new pollutants in wastewater were analyzed using VPA (Vibration-Activated Polymerization) analysis, yielding the pure biotransformation effect, the combined effect, and the pure adsorption-desorption effect. Subsequently, the combined effect was proportionally allocated to the pure biotransformation and adsorption-desorption effects using a ratio method, resulting in the biotransformation ratio a′, calculated as follows: a′=a+bw a c = c + bw c Where a and c are the pure effects of biotransformation and adsorption / desorption, respectively; a+c is the sum of the pure effects; b is the combined effect; and w a and w c The weight is calculated using the following formula:

[0048]

[0049] The novel contaminants selected in this embodiment are personal medications and care products, such as... Figure 4The figure shown is a quantitative result diagram of the new pollutant transformation pathway based on VPA. The proportion of removal pathways of personal medicines and care products in wastewater after being allocated by the proportional method is shown in Table 1.

[0050] Table 1. Proportions of Personal Medicines and Care Products Conversion Pathways in Wastewater After Proportional Allocation

[0051]

[0052] Step 6: Correct the biodegradability of new pollutants in wastewater based on the bioconversion ratio to determine the biodegradability of the new pollutants.

[0053] The bioconversion rate is used as a weight and multiplied by the conventional removal rate to obtain the corrected biodegradability rate of new pollutants in the wastewater, thus determining the biodegradability of the new pollutants. For example... Figure 5 The figures show the biodegradation rates of personal care products before and after correction. The removal rates and removal efficiencies decrease from top to bottom. Figure 5 The right side shows the uncorrected removal rate, the left side shows the biodegradation rate corrected by the bioconversion ratio, and the dashed line in the middle represents the ranking change of the corresponding substances after correction. Traditional removal rates overestimate the biodegradability of sulfathiazole, sulfaquinoxaline, tetracycline, sulfamethoxazole, acetaminophen, salicylic acid, norfloxacin, ciprofloxacin, ofloxacin, sulfadiazine, and naproxen. They underestimate the biodegradability of roxithromycin, tetracycline, erythromycin, ketorofen, ibuprofen, diclofenac, clarithromycin, and sulfamethoxypyrimidine. These results indicate that this invention can quantify the transformation pathways of new pollutants in wastewater and determine their biodegradability by correcting the biodegradation rate of new pollutants using the bioconversion ratio as a weight.

[0054] The wastewater biodegradability assessment system of the present invention includes:

[0055] The data acquisition unit is used to collect multi-dimensional characteristics of the wastewater treatment plant and the concentration of new pollutants. The multi-dimensional characteristics include water quality information, sludge characteristics, operating parameters and microbial community data.

[0056] The biotransformation index screening unit is used to divide multi-dimensional features into two categories using a clustering algorithm. Features other than microbial community data contained in the cluster are biotransformation indicators, while features in the other clusters are adsorption and desorption indicators.

[0057] The bioconversion ratio calculation unit is used to calculate the contribution ratio of bioconversion indicators and adsorption-desorption indicators to the change in the concentration of new pollutants using the VPA analysis method, and obtain the bioconversion ratio.

[0058] The biodegradability assessment unit is used to assess the biodegradability of new pollutants during wastewater treatment by correcting the removal rate of new pollutants through bioconversion ratio, and to determine the biodegradability of new pollutants through the biodegradability rate.

[0059] The electronic device of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded onto the processor, it implements the method for assessing the biodegradability of new pollutants in the wastewater.

[0060] The computer-readable storage medium of the present invention stores a computer program, which, when executed by a processor, implements the method for assessing the biodegradability of new pollutants in wastewater.

[0061] The computer-readable storage medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, flash memory or any other medium that can be used to store program code in the form of instructions or data structures and is accessible by a computer.

[0062] The processor is used to execute a computer program stored in memory to implement the various steps in the methods described in the above embodiments.

Claims

1. A method for assessing the biodegradability of novel pollutants in wastewater, characterized in that, Includes the following steps: (1) Collect multi-dimensional characteristics and new pollutant concentrations of wastewater treatment plants. The multi-dimensional characteristics include water quality information, sludge characteristics, operating parameters and microbial community data. (2) The multi-dimensional features are divided into two categories by clustering algorithm. The features contained in the cluster containing microbial community data, excluding microbial community data, are biotransformation indicators, while the features in the other clusters are adsorption and desorption indicators. (3) The contribution ratio of biotransformation indicators and adsorption-desorption indicators to the change in the concentration of new pollutants was calculated by VPA analysis to obtain the biotransformation ratio; (4) The removal rate of new pollutants is corrected by the bioconversion ratio to assess the biodegradability of new pollutants in the wastewater treatment process, and the biodegradability of new pollutants is determined by the biodegradability rate.

2. The method for assessing the biodegradability of new pollutants in wastewater according to claim 1, characterized in that, Step (3) also includes: calculating the pure effect of biotransformation, the synergistic effect and the pure adsorption-desorption effect by VPA analysis, and allocating the synergistic effect to the pure effect of biotransformation by proportion to obtain the biotransformation ratio.

3. The method for assessing the biodegradability of new pollutants in wastewater according to claim 2, characterized in that, The formula for calculating the bioconversion ratio in step (3) is a′=a+bw a , Where a represents the pure effect of bioconversion, b represents the combined effect, c represents the pure effect of adsorption and desorption, and a′ represents the bioconversion ratio.

4. The method for assessing the biodegradability of new pollutants in wastewater according to claim 1, characterized in that, Step (4) specifically involves multiplying the bioconversion ratio by the removal rate of the new pollutant to obtain the biodegradation rate of the new pollutant.

5. The method for assessing the biodegradability of new pollutants in wastewater according to claim 1, characterized in that, The clustering algorithm described in step (2) is the Gaussian mixture model clustering algorithm.

6. The method for assessing the biodegradability of new pollutants in wastewater according to claim 1, characterized in that, In step (1), the water quality information includes: total organic carbon, total phosphorus, total nitrogen, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, water temperature, and pH value; Sludge characteristics include: sludge volume index, sludge settling ratio, volatile suspended solids concentration in mixed liquor, and mixed liquor suspended solids concentration; Operating parameters include: dissolved oxygen, hydraulic retention time, and sludge retention time; Microbial community data include: α-diversity and β-diversity.

7. The method for assessing the biodegradability of new pollutants in wastewater according to claim 1, characterized in that, In step (1), the concentration of the new pollutant is calculated by liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry.

8. A system for assessing the biodegradability of novel pollutants in wastewater, characterized in that, include: The data acquisition unit is used to collect multi-dimensional characteristics of the wastewater treatment plant and the concentration of new pollutants. The multi-dimensional characteristics include water quality information, sludge characteristics, operating parameters and microbial community data. The biotransformation index screening unit is used to divide multi-dimensional features into two categories using a clustering algorithm. Features other than microbial community data contained in the cluster are biotransformation indicators, while features in the other clusters are adsorption and desorption indicators. The bioconversion ratio calculation unit is used to calculate the contribution ratio of bioconversion indicators and adsorption-desorption indicators to the change in the concentration of new pollutants using the VPA analysis method, and obtain the bioconversion ratio. The biodegradability assessment unit is used to assess the biodegradability of new pollutants during wastewater treatment by correcting the removal rate of new pollutants through bioconversion ratio, and to determine the biodegradability of new pollutants through the biodegradability rate.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer program is loaded into the processor, it implements the method for assessing the biodegradability of new pollutants in wastewater according to any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for assessing the biodegradability of new pollutants in wastewater according to any one of claims 1-7.

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