Polluted water body tracing identification device and method

Abstract

The invention provides a polluted water source tracing identification device and method, and the device comprises a separation column which is provided with an inlet and an outlet; the driving unit is used for driving the separation column to move forwards or backwards, and the forward direction is the direction from the inlet to the outlet; exciting light emitted by the light source enters the separation column, the detector is used for receiving lateral fluorescence in the separation column, and converted electric signals are sent to the analysis module; and the analysis module is used for obtaining characteristic peak information according to the electric signal and obtaining pollutant information according to the characteristic peak information. The device has the advantages of simple structure and the like.

Description

Technical Field

[0001] The invention relates to fluorescence spectroscopy technology, and in particular to a polluted water source tracing and identification device and method. Background Art

[0002] Monitoring the illegal discharge of sewage and diagnosing pollution sources in water quality monitoring are the key and difficult points of current early warning monitoring. Wastewater discharged by different enterprises contains a large amount of fluorescent substances, such as oils, proteins, surfactants, aromatic compounds such as phenols, pesticide residues, etc. The fluorescence spectra of compounds with different structures are different and have fingerprint characteristics. Three-dimensional fluorescence spectroscopy technology is suitable for the detection of fluorescent organic matter in water bodies. In the process of characteristic fingerprint peak extraction and fingerprint library comparison, the source of each component is clarified to realize the function of pollution tracing.

[0003] The analysis of three-dimensional fluorescence spectra generally uses the peak identification method, using the location of the maximum fluorescence intensity to determine the excitation and emission wavelengths, and then determine the type of fluorescence peak. However, the components in actual water samples are complex, and the fluorescence peaks overlap in some areas, as well as the shielding effect of strong fluorescence peaks on weak fluorescence peaks, resulting in the loss of some fluorescence peak information; when the concentration of the target fluorescent substance in the discharged wastewater is low, the fluorescence peak is further weakened due to dilution by surface water. These weak fluorescence peaks are often easily overlooked in the higher humic acid / tryptophan base peaks, which has a certain impact on the accuracy of traceability identification of actual water samples.

[0004] For example: the common tryptophan spectral components in water bodies have two main characteristic peaks at 220 / 350 and 275 / 350; while the characteristic peak positions of aniline (Ex / Em) are 230 / 340 and 280 / 340; the peak coordinates of the two are relatively close, with a difference of only 5-10nm; if the water body contains both tryptophan and aniline, when the tryptophan concentration is high, it can mask the characteristic peak of aniline, making it difficult to identify and distinguish the two components.

[0005] .

[0006] Existing patents use algorithms alone to improve characteristic peak recognition. For example, the PARAFAC method is based on the three-line decomposition theory and uses an alternating least squares algorithm to achieve "mathematical separation" of fluorescent substances. However, it can only identify some characteristic fluorescent components and cannot separate all characteristic peaks, resulting in poor accuracy. Summary of the invention

[0007] In order to solve the deficiencies in the above-mentioned prior art solutions, the present invention provides a device for tracing and identifying the source of polluted water.

[0008] The objective of the present invention is achieved through the following technical solutions: A polluted water source identification device comprises a separation column, wherein the separation column has an inlet and an outlet; the polluted water source identification device further comprises: A driving unit, the driving unit is used to drive the separation column to move in a forward direction or a reverse direction, the forward direction is a direction from the inlet to the outlet; A light source and a detector, wherein the excitation light emitted by the light source is incident into the separation column, and the detector is used to receive the side fluorescence in the separation column and the converted electrical signal is sent to the analysis module; An analysis module is used to obtain characteristic peak information of each separated component according to the electrical signal, sort the characteristic peak information of the separated components by importance and assign weights, and compare the characteristic peak information and importance weights with a database to obtain pollutant information.

[0009] The present invention also aims to provide a method for tracing and identifying the source of polluted water, which is achieved through the following technical solutions: A method for tracing and identifying the source of polluted water comprises the following steps: (A1) The water sample enters the separation column and the various components are separated; (A2) The light source and the separation column move relative to each other, so that the excitation light emitted by the light source is incident on the various components after separation in different time periods, emitting fluorescence, and the detector receives the lateral fluorescence, and the converted electrical signal is sent to the analysis module; (A3) The analysis module obtains characteristic peak information according to the electrical signal, and obtains pollutant information according to the characteristic peak information.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. Accurate results; The water sample is introduced into the solid phase separation column for separation. Due to different polarities, the fluorescent components in the water sample form fluorescent bands of different components in the stationary phase. Each fluorescent band corresponds to a substance, which realizes the effective separation of each fluorescent component to be tested. The three-dimensional fluorescence spectrometer is used to perform spectrum detection on the fluorescence peaks in the stationary phase one by one, and the spectrum of each fluorescent component can be obtained. The overlapping and masking of the fluorescence peaks of some components that may appear when the water sample is directly subjected to spectrum detection without separation is avoided, thereby avoiding the loss of some important fluorescence characteristic information. At the same time, the classification PSO-RF algorithm is used to analyze the weights of each fluorescent component, thereby realizing further analysis of the components of the mixed water sample and ensuring the accuracy of traceability identification. 2. Low detection limit; After the water sample is separated by the stationary phase, different components are separated and enriched in the stationary phase, which improves the detection limit of the fluorescence peak; 3. Low cost; The separation column has a small single injection volume, is easy to regenerate and clean, and can be reused many times; 4. Good reliability; The 0.45um cross-flow filtration used in water sample pretreatment uses the high-speed shear force during water sample filtration to continuously flush the filter membrane surface, reducing the clogging of the filter membrane by particulate matter in the water sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The disclosure of the present invention will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. In the drawings: Figure 1 This is a simplified structural diagram of the device for tracing and identifying the source of polluted water according to the present invention; Figure 2 Schematic diagram of the separation column according to the present invention. DETAILED DESCRIPTION

[0012] Figure 1-Figure 2 The following description describes optional specific embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to teach the technical solution of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art will understand that variations or replacements derived from these specific embodiments will be within the scope of the present invention. Those skilled in the art will understand that the following features can be combined in various ways to form multiple variations of the present invention. Thus, the present invention is not limited to the following optional specific embodiments, but is only limited by the claims and their equivalents.

[0013] Example 1.

[0014] like Figure 1 As shown, a polluted water source identification device according to an embodiment of the present invention includes: A separation column 11, wherein the separation column 11 has an inlet 12 and an outlet 13, so that various components in the water sample entering the separation column 11 are separated; A driving unit, the driving unit is used to drive the separation column 11 to move in a forward direction or a reverse direction, wherein the forward direction is a direction from the inlet 12 to the outlet 13; A light source 61 and a detector, wherein the excitation light 31 emitted by the light source 61 is incident on various substances separated in the separation column 11, and the detector is used to receive the side fluorescence 32 in the separation column and convert the electrical signal to an analysis module; An analysis module is used to obtain characteristic peak information according to the electrical signal, and obtain pollutant information according to the characteristic peak information.

[0015] In order to accurately obtain the components in the water sample, the analysis module further compares the characteristic peak information with the standard database and the pollutant emission database of the upstream enterprises of the sampling point, calculates the matching degree, and gives a similarity ranking result.

[0016] In order to separate multiple components in the water sample, the separation column 11 is further filled with light-transmitting porous microspheres 18 with chemically modified surfaces.

[0017] In order to detect the separated multiple components, further, the driving unit includes: A guide rail, on which the separation column 11 is arranged; A driving module 41, the driving module 41 is used to drive the separation column 11 to move forward or reverse along the guide rail; A control module is used to send movement and stop instructions to the driving module.

[0018] In order to remove particulate matter from the water sample, the polluted water source identification device further includes: A filter is provided upstream of the inlet 12 and is used for filtering out particles in the water sample.

[0019] A method for tracing and identifying the source of polluted water according to an embodiment of the present invention comprises the following steps: (A1) The water sample enters the separation column 11 and the various components are separated; Since the fluorescent components have different polarities, when they move and migrate in the stationary phase, the interaction forces with the stationary phase are different, and the migration rates are different, and finally they are separated to form different component bands. For example, when silica gel is used as the stationary phase, the components with stronger polarity in the water sample, such as acetic acid and aniline, have stronger interaction forces with the stationary phase, and migrate slower during separation and stay longer; while the components with weak polarity, such as toluene and p-xylene, have weaker interaction forces with the stationary phase, and migrate faster during separation and stay shorter, thus achieving separation. When the water sample passes through the solid phase, the components with different polarities migrate at different speeds, forming mutually separated component bands, corresponding to different fluorescent bands.

[0020] (A2) The light source 61 and the separation column 11 move relative to each other, so that the excitation light emitted by the light source 61 is incident on the various components after separation in different time periods, emitting fluorescence, and the detector receives the lateral fluorescence, and the converted electrical signal is sent to the analysis module; (A3) an analysis module obtains characteristic peak information according to the electrical signal; (A4) Data preprocessing is performed on the three-dimensional fluorescence signals of pollutants obtained from each substance. In the actual three-dimensional fluorescence spectrum analysis and scanning, interference phenomena such as first-order Rayleigh scattering, second-order Rayleigh scattering, and Raman scattering will occur. Before processing, the Delaunay triangulation algorithm is used to remove Rayleigh and Raman scattering.

[0021] Noise is often unavoidable in the process of three-dimensional fluorescence scanning. Savitzky Golay (SG) smoothing method is used to process the spectrum through a two-dimensional plane method to remove noise. Its mathematical definition formula is: .

[0022] Where: σ is the standard deviation of the Gaussian function, x, y are the horizontal and vertical coordinates of the spectrum.

[0023] After separation by the separation column, substances of different properties will present different three-dimensional fluorescence spectra. In order to confirm the importance of each component in the mixed water body, the random forest algorithm (RF) is selected to construct multiple decision trees for classification or regression problems. The random forest model will assign an importance score to each component and give weights to each component according to the importance score, thereby explaining the impact of each component on the mixed water sample.

[0024] In this patent, the PSO-RF algorithm with the best classification effect is mainly used. The PSO-RF algorithm is a method that combines particle swarm optimization with random forest to improve the performance of the prediction model. The feature importance function is used to select feature indicators that have a greater impact on the recognition results from the three-dimensional fluorescence feature indicators, and can reduce the dimensionality of the data to a certain extent, thereby improving the efficiency and effectiveness of the algorithm. Through multiple algorithm running tests, the importance weights of the feature indicators of each component are ranked.

[0025] In order to continuously improve the classification accuracy, it is necessary to continuously optimize the algorithm parameters. For this purpose, the PSO-RF algorithm model can be established for continuous optimization. The PSO model is introduced to determine the optimal values ​​of the above random forest parameters, and the number of decision trees is optimized by the particle swarm optimization (PSO) method. The basic settings of the PSO-RF model are as follows: the three-dimensional fluorescence characteristic index of the mixed sewage components after pretreatment is used as the input of the random forest, and the output layer is the mixed water sample number; in order to obtain the optimal number of input decision trees ntree and depth ndepth of the random forest, the particle swarm algorithm is used to optimize it. The population number of the PSO algorithm is set to 50, the maximum number of iterations Tmax is set to 50, the learning factors c1 and c2 are set to 1.5, the inertia weight w is 0.8, and the position and speed are randomly initialized. The reference values ​​are shown in the following table:

[0026] By importing three-dimensional fluorescence signals of different water samples, the algorithm model is used to continuously optimize the basic algorithm parameters to obtain the optimal parameters, thereby improving the efficiency and accuracy of the algorithm.

[0027] (A5) A PSO-RF algorithm model is established to continuously optimize the algorithm parameters and determine the most suitable algorithm parameters. The PSO-RF algorithm is used to rank the importance of the components separated by the separation column and determine the importance weight of each component.

[0028] The characteristic peak information and importance weights of each component are compared with the standard database and the pollutant emission database of the upstream enterprises of the sampling point, and the matching degree is calculated to give a similarity ranking result.

[0029] In order to regenerate the separation column, the method for tracing the source of polluted water further includes the following steps: (A6) A volume of V is introduced into the separation column 11 1 Solvent, let stand; 1≤V 1 / V≤2, V is the volume of the packing in the separation column; (A7) A volume of V is introduced into the separation column 11. 2 Bubble-free pure water, clean the packing 18; 3≤V 2 / V≤5; (A8) Pure water is passed into the separation column 11, and characteristic peak information is obtained according to steps (A2) to (A3); If the characteristic peak is related to pure water, the separation column 11 is cleaned; If the characteristic peak is not related to pure water, return to step (A7).

[0030] In order to accurately obtain the components in the water sample, the method for tracing the source of polluted water further includes the following steps before step (A1): (A0) Collect and test wastewater from the discharge outlets of upstream enterprises at the water sampling points, organize and enter enterprise wastewater data, and build a wastewater fingerprint database for upstream enterprises.

[0031] Example 2.

[0032] An application example of the device and method for tracing the source of polluted water in Example 1 of the present invention.

[0033] In this application example, Figure 1 As shown, the pollution entity source tracing and identification device includes: The water sample is filtered through a 0.45μm microporous membrane in the filter to remove insoluble particles to detect dissolved organic matter (DOM) in the filtrate. Specifically, the filter uses cross-flow filtration, using the shear force generated by the high-speed influent fluid to flush the surface of the filter membrane to reduce the clogging of the filter membrane by particles in the water sample.

[0034] like Figure 2As shown, the separation column 11 is made of quartz material and is a vertically arranged columnar structure with a square horizontal cross section. The width is required to be greater than the diameter of the excitation light spot, and the length / width ratio is 5:1~10:1. The upper and lower ends of the separation column 11 are connected to the water inlet and outlet interfaces. In order to ensure that the water sample maintains a stable flow rate when entering the inner cavity of the separation column 11 from the inlet / outlet, the entrances at both ends of the inner cavity of the separation column 11 are set as bell-mouth structures.

[0035] The separation column 11 is vertically installed in the fixed bracket 21. A long square hole 22 is hollowed out between two adjacent sides of the bracket 21 to facilitate the transmission of excitation light and (fluorescent) light. An elastic component is provided inside the fixed bracket 21 to fasten the separation column. The elastic component is a spring or elastic filler. A circular hole is provided at the bottom of the bracket 21, and the water inlet of the separation column 11 passes through the circular hole.

[0036] The separation column 11 is filled with light-transmitting, surface-chemically modified porous spherical microspheres, the size of which is 3 to 20 μm. The surface modification groups may be selected from strongly polar silanol, cyano, amino, etc., or non-polar alkyl, phenyl, etc., depending on the polarity of the separated components. The microspheres may be filled with the same type of microspheres, or may be filled with a variety of microsphere fillers of different polarities according to the region, forming separation zones with different polarity gradients such as weak polarity, medium polarity, and strong polarity.

[0037] The following table shows the polarity data of several common organic compounds in chemical wastewater. Generally, alkanes have weak polarity, followed by aromatic hydrocarbons, while molecules containing electron-withdrawing groups such as N, O, and halogens have greater polarity.

[0038] .

[0039] In the drive unit, the drive module 41 uses a motor to drive the screw 42, which is set on the vertical guide rail. There are two fixed structures 33 on one side of the bracket 21 of the separation column 11, which are connected to the movement component of the screw 42. When the motor moves, the screw 42 links the separation column 11 to move vertically up and down. In order to control the limit of the screw 42 when it reciprocates in the vertical direction, limit switches 51 are set at both ends. When the screw 42 moves to the two ends to trigger the limit switches, the motor stops moving.

[0040] The light source 61 uses a xenon lamp. Most of the fluorescence peaks in the water sample are mainly concentrated in the excitation wavelength of 230-450nm. The light emitted by the xenon lamp is split and the wavelength of 230-450nm is retained as the excitation light, and the scanning interval is 5-20nm. The spectrometer includes a detector and uses an electron multiplier tube.

[0041] The analysis module compares the characteristic peak information with the standard database and the pollutant emission database of the upstream enterprises of the sampling point, calculates the matching degree, and gives the similarity ranking results.

[0042] A method for tracing and identifying the source of polluted water according to an embodiment of the present invention comprises the following steps: (A0) Collect and test wastewater from the discharge outlets of upstream enterprises at the water sampling points, organize and enter enterprise wastewater data, and build a wastewater fingerprint database for upstream enterprises.

[0043] (A1) The water sample enters the separation column 11 and the various components are separated; (A2) The positions of the light source 61 and the detector are fixed, and the screw 42 controls the separation column 11 to reciprocate at a uniform speed in the vertical direction, moving vertically downward from the initial position. The initial time t is 0, and the motor speed of the screw 42 is v. According to the degree of water sample pollution (the number of types of organic matter), the effective height of the separation column 11 is subdivided into 8 to 12 equal parts (unit lengths). Every time the screw 42 moves forward one unit length, that is, the residence time Δt (Δt>fluorescence detection time), the spectrometer is turned on for detection to obtain a spectrum diagram, and the screw is started again to move forward one unit length for detection. After all the detections are completed, 8 to 12 component spectra are obtained.

[0044] (A3) After preprocessing the obtained spectra of each component, the analysis module obtains the characteristic peak information according to the electrical signal, and sorts the characteristic important information of the spectrum of each component in the mixed water sample according to the PSO-RF algorithm to obtain the importance weight, and compares the characteristic peak information and the importance weight with the standard database and the pollutant emission database of the upstream enterprises of the sampling point, calculates the matching degree, and gives the similarity ranking result.

[0045] (A4) A volume of V is introduced into the separation column 11. 1 Solvent (methanol or ethanol), let stand for 5-10min; 1≤V 1 / V≤2, V is the volume of the packing 18 in the separation column; (A5) A volume of V is introduced into the separation column 11 2 Bubble-free pure water to clean the packing; 3≤V 2 / V≤5; (A6) Pure water is passed into the separation column 11, and characteristic peak information is obtained according to steps (A2) to (A3); If the characteristic peak is related to pure water, the separation column is cleaned; If the characteristic peak is not related to pure water, return to step (A5).

[0046] The above embodiment is only an example of a driving unit, and it can certainly be other forms in the prior art, such as a motor driving a synchronous belt, and the synchronous belt drives the separation column 11 to move vertically up and down along the guide rail.

Claims

1. A polluted water source identification device, comprising a separation column, wherein the separation column has an inlet and an outlet; characterized in that: The polluted water source identification device also includes: A driving unit, the driving unit is used to drive the separation column to move in a forward direction or a reverse direction, the forward direction is a direction from the inlet to the outlet; A light source and a detector, wherein the excitation light emitted by the light source is incident into the separation column, and the detector is used to receive the side fluorescence in the separation column and the converted electrical signal is sent to the analysis module; An analysis module is used to obtain characteristic peak information of each separated component according to the electrical signal, sort the characteristic peak information of the separated components by importance and assign weights, and compare the characteristic peak information and importance weights with a database to obtain pollutant information.

2. The polluted water source identification device according to claim 1 is characterized in that: The analysis module compares the characteristic peak information with the standard database and the pollutant emission database of the upstream enterprises of the sampling point, calculates the matching degree, and gives a similarity ranking result.

3. The polluted water source identification device according to claim 2 is characterized in that: The separation column is filled with light-transmitting porous microspheres with chemically modified surfaces.

4. The polluted water source identification device according to claim 1 is characterized in that: The separation column is arranged vertically.

5. The polluted water source identification device according to claim 1 is characterized in that: The driving unit comprises: a guide rail, on which the separation column is arranged; A driving module, the driving module is used to drive the separation column to move forward or reverse along the guide rail; A control module is used to send movement and stop instructions to the driving module.

6. The polluted water source identification device according to claim 1 is characterized in that: The polluted water source identification device also includes: The filter is arranged upstream of the inlet and is used to filter out particulate matter in the water sample.

7. A method for tracing the source of polluted water, comprising the following steps: (A1) The water sample enters the separation column and the various components are separated; (A2) The light source and the separation column move relative to each other, so that the excitation light emitted by the light source is incident on the various components after separation in different time periods, emitting fluorescence, and the detector receives the lateral fluorescence, and the converted electrical signal is sent to the analysis module; (A3) an analysis module obtains characteristic peak information of each separated component according to the electrical signal; (A4) sorting the characteristic peak information of the separated components by importance and assigning weights, and comparing the characteristic peak information and the importance weights with a database to obtain pollutant information.

8. The method for tracing and identifying the source of polluted water according to claim 7, characterized in that: The working mode of the analysis module is as follows: The classification algorithm is used to obtain the weight of the fluorescence signal of each substance and the characteristic peak information, which are compared with the standard database and the pollutant emission database of the upstream enterprises of the sampling point, and the matching degree is calculated to give the similarity ranking result.

9. The method for tracing and identifying the source of polluted water according to claim 7, characterized in that: The method for tracing and identifying the source of polluted water also includes the following steps: (A5) introducing a volume of V1 of solvent into the separation column and allowing to stand; 1≤V1 / V≤2, where V is the volume of the packing in the separation column; (A6) introducing a volume of V2 of bubble-free pure water into the separation column to clean the packing; 3≤V2 / V≤5; (A7) Pure water is passed into the separation column, and characteristic peak information is obtained according to steps (A2) to (A3); If the characteristic peak is related to pure water, the separation column is cleaned; If the characteristic peak is not related to pure water, return to step (A6).

10. The method for tracing and identifying the source of polluted water according to claim 7, characterized in that: The method for tracing the source of polluted water also includes the following steps before step (A1): (A8) Collect and test wastewater from the discharge outlet of the upstream enterprise of the water sample collection point, obtain three-dimensional fluorescence maps of different components of the enterprise wastewater after separation by separation column, and use classification algorithm to assign weights for map arrangement and entry to establish a wastewater fingerprint database of upstream enterprises.

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