Underground water pollutant fluorescence in-situ detection device and method

Abstract

The invention discloses an underground water pollutant fluorescence in-situ detection device and method. The device comprises an excitation assembly, a fluorescence detection assembly, a turbidity correction assembly and a competitive absorption correction assembly, the excitation assembly, the turbidity correction assembly and the competitive absorption correction assembly are arranged around the underground water monitoring site by adopting an annular structure and are positioned on the same horizontal plane; meanwhile, light emitted by the excitation assembly can be used as a light source for exciting and inducing the to-be-detected sample to generate a fluorescence signal, and can also be used as a correction light source for competitively absorbing the correction assembly; the fluorescence detection assembly and the excitation assembly are vertically arranged and are located on different horizontal planes, a fluorescence signal is propagated in the vertical direction of an excitation light path formed by the excitation assembly, and the fluorescence detection assembly is arranged in the propagation direction of the fluorescence signal. According to the invention, benzene and phenol toxic organic pollutants in the underground water of the chemical industrial park can be detected in situ in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of ultraviolet-induced fluorescence spectroscopy detection, and specifically to a fluorescence in-situ detection device for groundwater pollutants. Background Technique

[0002] At present, the monitoring of organic pollutants in groundwater in chemical industrial parks mainly relies on the traditional method of "on-site sampling - laboratory analysis", such as the combined analysis of a fully automatic purge and trap device and gas chromatography / mass spectrometry. This method has disadvantages such as time-consuming sampling, difficult sample preservation, complex operation, and loss of in-situ spatio-temporal information. In addition, on-site off-site monitoring methods such as portable chromatography, mass spectrometry, and colorimetry also have similar problems and may cause secondary environmental pollution. Therefore, there is an urgent need to develop efficient in-situ monitoring methods and equipment that can overcome the above problems to achieve accurate and rapid monitoring of organic pollutants in groundwater.

[0003] As a non-destructive detection technology, ultraviolet-induced fluorescence has high sensitivity, does not require sample pretreatment, and has a fast response speed, and has great potential for in-situ monitoring of benzene and phenol pollutants in the groundwater of chemical industrial parks. The fluorescence excitation wavelength range of benzene is usually between 250 - 280 nm, and the fluorescence emission wavelength range is concentrated around 270 - 350 nm. The fluorescence excitation wavelength range of phenols is usually between 260 - 290 nm, and its fluorescence emission wavelength range is between 280 - 340 nm. There is a significant overlap in the fluorescence spectrum information of the two major types of pollutants.

[0004] Foreign in-situ fluorescence sensors for detecting benzene series usually use 255 nm to excite benzene series and detect the fluorescence signal at 290 nm, and measure the concentration of benzene series according to the measured signal value. The existing problems include: (1) Usually, benzene and phenol pollutants coexist in chemical industrial parks, and phenols also have a weak 290 nm fluorescence signal under 255 nm excitation. With only one characteristic wavelength of 255 nm, it is impossible to remove the influence of phenols on the detection of benzene; (2) In the groundwater of chemical industrial parks with a complex environment, suspended particles, sulfates, chlorides, etc. will cause light scattering and absorption, weakening the intensity of the fluorescence signals of benzene and phenols, affecting the accuracy and reliability of monitoring. In the complex physical and chemical environment of groundwater in chemical industrial parks, when using 255 nm excitation and 290 nm fluorescence in-situ detection of benzene series, some interfering substances such as sulfates and chlorides may absorb the excitation light near 255 nm, resulting in a decrease in the intensity of the fluorescence signal detected by the detector. In addition, suspended particles will cause light scattering, weakening the intensity of the benzene fluorescence signal and affecting the accuracy and reliability of monitoring; (3) Since the diameter of groundwater monitoring wells is usually 5 - 10 cm, this physical size limits the volume of the detection device. In this limited space, the excitation light source, fluorescence detector, and related optical components need to be reasonably arranged, and it is difficult for the existing technology to meet the size requirements while ensuring the detection performance.

[0005] The invention patent with the publication number of CN107389644A discloses a rapid fluorescence quantitative device, including an excitation light source A located on the left side of the sample cell and an excitation light source B located on the right side of the sample cell, which are used to excite the fluorescent substances in the sample; an excitation light detection unit A is located between the excitation light source A and the sample cell, and an excitation light detection unit B is located between the excitation light source B and the sample cell. The excitation light detection unit B and the sample cell are both lower in height than the excitation light source B to ensure that the excitation light can irradiate the sample in the sample cell; the fluorescence detection units A and B are respectively vertically located on both sides of the sample cell and the excitation light optical path, welded on the circuit board and embedded in the light transmission channel, which can provide dual-band excitation light and realize free switching. The application technical field of this patent is biological detection. Although the excitation optical path and the detection optical path are vertically arranged around the sample, the laser optical path and the detection optical path form a cross structure, and the sample cell is located in the middle of the cross. The laser optical path and the detection optical path are arranged on the same horizontal plane, which increases the cross-sectional area of the device. When applied to a groundwater monitoring well, it is difficult for the device to be lowered into the well.

[0006] The utility model patent with the publication number of CN220340054U discloses a disc-type multi-channel optical detection system. Although it is mentioned in this patent that the excitation optical path and the detection optical path are perpendicular, it refers to the perpendicularity in structure, not the perpendicularity of the fluorescence and the excitation light on the optical path. And the fluorescence measured in this patent is in the opposite direction to the excitation light. Only the detection optical path is deflected by a dichroic mirror to reduce the volume size, rather than measuring the fluorescence at 90 degrees to the excitation light. It is difficult to eliminate the influence of the excitation light and the scattered light on the fluorescence measured by this optical path. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a detection device for underground toxic organic pollutants suitable for groundwater monitoring wells in chemical industrial parks, with real-time correction of turbidity and competitive absorption.

[0008] To solve the above technical problem, the present invention provides the following technical solutions: A fluorescence in-situ detection device for groundwater pollutants, including: an excitation component 100, a fluorescence detection component 200, a turbidity correction component 300, and a competitive absorption correction component 400; The excitation component 100, the turbidity correction component 300, and the competitive absorption correction component 400 are arranged in an annular structure around the groundwater monitoring site 500 and are on the same horizontal plane; Meanwhile, the light emitted by the excitation component 100 can both be used as a light source to excite and induce the sample to be measured to generate a fluorescence signal, and can also be used as a correction light source for the competitive absorption correction component 400; The fluorescence detection component 200 is vertically arranged with the excitation component 100 and is at different horizontal levels, and the fluorescence signal propagates in the direction perpendicular to the excitation optical path formed by the excitation component 100. The fluorescence detection component 200 is arranged in the propagation direction of the fluorescence signal.

[0009] Technical effect: The present invention adopts an innovative optical structure design, vertically arranges the fluorescence detection component and the excitation component and they are at different horizontal levels, accurately arranges the fluorescence detection component in the propagation direction of the fluorescence signal, and at the same time makes the fluorescence signal maintain a strict perpendicular relationship with the excitation optical path formed by the excitation component. This vertically crossed optical path layout not only realizes the miniaturization of the device structure, but also utilizes the physical property that the scattered light in the vertical direction is the smallest, effectively reducing the interference of the excitation light scattering on the fluorescence signal, improving the signal-to-noise ratio, and thus significantly improving the accuracy and reliability of the fluorescence detection of groundwater pollutants while having a compact structure design.

[0010] Furthermore, the present invention adopts a highly integrated annular layout design, forms a compact annular structure with the excitation component, the turbidity correction component and the competitive absorption correction component around the groundwater monitoring site and they are at the same horizontal level, and at the same time innovatively realizes resource sharing, enabling the competitive absorption correction component to directly use the excitation component as its light source, avoiding the setting of redundant light sources. This annular integration and resource sharing design of multi-functional components significantly optimizes the space utilization rate, greatly reduces the overall device size, enables it to easily adapt to the narrow space limitation of the standard monitoring well, and solves the technical bottleneck that the equipment is too large to be lowered into the well for detection.

[0011] In an embodiment of the present invention, the excitation component 100 includes: an LED light source 110, a collimating lens 120, a filter 130, and a focusing lens 140. The band-tunable LED light source 110 emits excitation light, the generated excitation light is collimated by the collimating lens 120, then the stray light is filtered by the filter 130, and finally the excitation light is focused on the groundwater monitoring site 500 through the focusing lens 140 to form an excitation optical path. Multiple groups of excitation components 100 are provided, and the structure of each group of excitation components 100 is the same.

[0012] In an embodiment of the present invention, the fluorescence detection component 200 is successively provided with a window 210, a collimating lens 220, a filter 230, a focusing lens 240, a light-shielding diaphragm 250, and a fluorescence detector 260 along the propagation direction of the fluorescence signal.

[0013] Technical effect: The present invention adopts a carefully optimized optical path design. The fluorescence detection component is arranged in a direction strictly perpendicular to the excitation optical path, and the optical elements are arranged in sequence along the fluorescence signal propagation direction. This structure not only realizes the miniaturization of the device, but more importantly, in view of the stringent requirements for high sensitivity in the groundwater detection scenario, the incident angle of light is effectively reduced through the collimating lens to prevent the blue shift of fluorescence; the focusing lens accurately converges the signal; and the light-shielding diaphragm further filters stray light. This combined design of multiple optical filters significantly improves the signal collection efficiency, minimizes the interference of stray light to the greatest extent, ensures that high-quality fluorescence signals can still be obtained in a complex groundwater environment, and achieves the purpose of high-sensitivity in-situ detection.

[0014] In an embodiment of the present invention, two groups of fluorescence detection components 200 are provided, and the two groups of fluorescence detection components 200 are symmetrically arranged with the groundwater monitoring site 500 as the center; Moreover, the fluorescence receiving bands of the fluorescence detectors 260 in the two groups of fluorescence detection components 200 are different.

[0015] In an embodiment of the present invention, the window opening 210 is in a convex character shape; wherein, the small opening of the convex character-shaped window opening 210 faces the light source, and the large aperture faces the fluorescence detector 260; and the ratio of the small aperture to the large aperture is between 0.2 and 1; Two focusing lenses two 240 are arranged side by side.

[0016] In an embodiment of the present invention, the turbidity correction component 300 includes a turbidity light source component 310 and a turbidity detection component 320; wherein, the turbidity detection component 320 includes a collimating lens four 321, a filter four 322, a focusing lens four 323, and a photodiode one 324; The transmitted light emitted by the turbidity light source component 310 does not generate a fluorescence signal for the sample to be measured; the transmitted light emitted by the turbidity light source component 310 forms a parallel beam after passing through the collimating lens four 321, and then passes through the filter four 322 and the focusing lens four 323, and is focused on the photodiode one 324.

[0017] In an embodiment of the present invention, the turbidity light source component 310 includes an LED light source two 311, a collimating lens three 312, a filter three 313, and a focusing lens three 314; The transmitted light emitted by the band-tunable LED light source two 311 passes through the collimating lens three 312, the filter three 313, and the focusing lens three 314 in sequence and then irradiates the groundwater monitoring site 500 and is simultaneously received by the turbidity detection component 320.

[0018] In an embodiment of the present invention, the competitive absorption correction component 400 includes a competitive absorption detection component 410; The competitive absorption detection component 410 includes a collimating lens V 411, a filter V 412, a focusing lens V 413, and a photodiode II 414; While the excitation light of the excitation component 100 induces a fluorescence signal in the sample to be measured, the transmitted light of the excitation light forms a parallel beam through the collimating lens V 411, and then forms a parallel beam and is focused on the photodiode II 414 after passing through the filter V 412 and the focusing lens V 413.

[0019] In an embodiment of the present invention, multiple sets of competitive absorption detection components 410 are provided; the number of the competitive absorption detection components 410 matches the number of the excitation components 100 and the used wavelength bands match.

[0020] The present invention also provides a method for fluorescence in-situ detection of groundwater pollutants, applying the above-mentioned device for fluorescence in-situ detection of groundwater pollutants, including: Taking the excitation wavelength of the excitation component 100 and the fluorescence reception wavelength received by the fluorescence detection component 200 as the fluorescence characteristic signals; at the same time, taking the transmitted light at the excitation wavelength of the excitation component 100 and the absorbance received by the competitive absorption correction component 400 as the competitive absorption correction signals; Taking the transmitted light wavelength emitted by the turbidity correction component 300 and the received turbidity as the turbidity correction signals; Taking the fluorescence characteristic signals, the competitive absorption correction signals, and the turbidity correction signals as the input feature set of a trained multiple linear regression model, and the model outputs to obtain the pollutant concentration.

[0021] Compared with the prior art, the beneficial effects of the present invention are: The present invention adopts a highly optimized optical system design, achieving the unity of the accuracy of fluorescence detection of groundwater pollutants and the miniaturization of the device. The core innovation lies in the adoption of a ring-shaped LED light source structure, which not only provides multi-wavelength excitation ability to meet the excitation requirements of different pollutants such as benzene series and phenols, but also significantly reduces the device volume, enabling it to smoothly enter the standard monitoring well for in-situ detection. The optical path system is carefully designed, including strategically arranged light-shielding diaphragms to effectively suppress the interference of stray light and improve the signal purity; the precisely matched combination of collimating lenses and filters ensures that only light of the target wavelength is used for sample excitation, greatly improving the quality of fluorescence signals. At the same time, the present invention also integrates multiple correction mechanisms: the adoption of the transmitted light detection technology at a wavelength of 860 nm effectively eliminates the interference of waterborne particulate matter on fluorescence signals; the competitive absorption correction is achieved through the transmitted light detection at wavelengths of 255 nm, 265 nm, and 275 nm, comprehensively improving the accuracy and reliability of fluorescence detection of organic pollutants in complex groundwater environments, and providing an efficient and compact technical solution for real-time monitoring of groundwater pollution.

[0022] The present invention can accurately compensate for the attenuation problem of fluorescence signals caused by the competitive absorption of substances such as ions in groundwater and turbidity scattering caused by suspended particles. This real-time correction technology enables the system to accurately calculate the actual concentrations of organic pollutants such as phenols and benzenes in a complex and changing groundwater environment, significantly improving the data reliability of in-situ monitoring. Especially in the detection scenario of low-concentration pollutants, the unique optical design and correction algorithm of the present invention greatly improve the selective capture efficiency and detection sensitivity of benzene and phenol fluorescence signals, reducing the detection limit to the ppb level, providing high-precision and high-reliability technical support for early warning of groundwater pollution and monitoring of trace pollutants. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of a fluorescence in-situ detection device for groundwater pollutants according to an embodiment of the present invention.

[0024] Figure 2 It is a schematic diagram of an excitation component and a fluorescence detection component according to an embodiment of the present invention.

[0025] Figure 3 It is a schematic diagram of a turbidity correction component according to an embodiment of the present invention.

[0026] Figure 4 It is a schematic diagram of a competitive absorption correction component according to an embodiment of the present invention.

[0027] Figure 5 It is a flowchart of a fluorescence in-situ detection method for groundwater pollutants according to an embodiment of the present invention.

[0028] Description of the Reference Numerals: 100 - Excitation Component; 110 - LED Light Source 1; 120 - Collimating Lens 1; 130 - Filter 1; 140 - Focusing Lens 1; 200 - Fluorescence Detection Component; 210 - Window Opening; 220 - Collimating Lens 2; 230 - Filter 2; 240 - Focusing Lens 2; 250 - Light Shielding Diaphragm; 260 - Fluorescence Detector; 300 - Turbidity Correction Component; 310 - Turbidity Light Source Component; 311 - LED Light Source 2; 312 - Collimating Lens 3; 313 - Filter 3; 314 - Focusing Lens 3; 320 - Turbidity Detection Component; 321 - Collimating Lens 4; 322 - Filter 4; 323 - Focusing Lens 4; 324 - Photoelectric Diode 1; 400 - Competitive Absorption Correction Component; 410 - Competitive absorption detection component; 411 - Collimating lens V; 412 - Filter V; 413 - Focusing lens V; 414 - Photodiode II; 500 - Groundwater monitoring site. Specific implementation manner

[0029] For the convenience of those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings of the specification.

[0030] The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0031] Please refer to Figure 1 、 2 As shown in, the present invention provides a fluorescence in-situ detection device for groundwater pollutants, including an excitation component 100, a fluorescence detection component 200, a turbidity correction component 300, and a competitive absorption correction component 400. The excitation component 100, the turbidity correction component 300, and the competitive absorption correction component 400 are arranged in a circular structure around the groundwater monitoring site 500 and are on the same horizontal plane. At the same time, the light emitted by the excitation component 100 can both serve as the light source for exciting and inducing the fluorescence signal of the sample to be measured and as the correction light source for the competitive absorption correction component 400. The fluorescence detection component 200 is vertically arranged with respect to the excitation component 100 and is on a different horizontal plane, and the fluorescence signal propagates in the direction perpendicular to the excitation optical path formed by the excitation component 100. The fluorescence detection component 200 is arranged in the propagation direction of the fluorescence signal.

[0032] In an embodiment of the present invention, the excitation component 100 includes: LED light source I 110, collimating lens I 120, filter I 130, and focusing lens I 140.

[0033] In this embodiment, the band-tunable LED light source I 110 emits excitation light. The generated excitation light is collimated by the collimating lens I 120, and then the stray light is filtered by the filter I 130. Finally, the excitation light is focused onto the groundwater monitoring site 500 through the focusing lens I 140 to form an excitation optical path.

[0034] In this embodiment, taking the detection of benzene and phenol pollutants in groundwater as an example, the excitation component 100 is used to efficiently collect the deep ultraviolet light emitted by the first LED light source 110, and after collimation and filtering, it irradiates the groundwater monitoring site 500 at a specific emission angle. The excitation component 100 uses deep ultraviolet LEDs arranged in an annular structure to generate excitation light and form an excitation optical path, which is focused on the groundwater monitoring site 500, thereby exciting the sample to generate a fluorescence signal.

[0035] In this embodiment, multiple groups of excitation components 100 are provided, and the structure of each group of excitation components 100 is the same. In this embodiment, three groups of excitation components 100 are provided. The first LED light sources 110 in each group of excitation components 100 emit lights with wavelengths of 255 nm, 265 nm, and 275 nm respectively. The light source intensity of each first LED light source 110 can be independently controlled, and the excitation lights with different wavelengths excite the characteristic fluorescence of benzene and phenol.

[0036] In an embodiment of the present invention, the fluorescence detection component 200 is sequentially provided with a window opening 210, a second collimating lens 220, a second filter 230, a second focusing lens 240, a light shielding diaphragm 250, and a fluorescence detector 260 along the fluorescence signal propagation direction. The fluorescence signal reaches the fluorescence detector 260 and is converted into an analyzable electrical signal.

[0037] Two groups of fluorescence detection components 200 are provided, and the two groups of fluorescence detection components 200 are symmetrically arranged with the groundwater monitoring site 500 as the center. Moreover, the fluorescence receiving bands of the fluorescence detectors 260 in the two groups of fluorescence detection components 200 are different. In this embodiment, the difference is that the fluorescence receiving wavelength on one side is 290 nm, and the fluorescence receiving wavelength on the other side is 310 nm.

[0038] In this embodiment, the window opening 210 is in a convex character shape. The small opening of the convex character-shaped window opening 210 faces the light source, and the large aperture faces the fluorescence detector 260. Moreover, the ratio of the small aperture to the large aperture is between 0.2 and 1, effectively enhancing the reception efficiency of the fluorescence signal emitted from the sample.

[0039] In this embodiment, two second focusing lenses 240 are arranged side by side. This setting makes the focal length shorter and reduces the optical path size. The fluorescence detection optical path further includes a light shielding diaphragm 250, which is used to filter out non-target light in the fluorescence detection optical path, optimize the beam quality, and ensure that the fluorescence emitted from the groundwater monitoring site 500 is captured to the greatest extent.

[0040] In this embodiment, the fluorescence detection component 200 is used to collect the weak fluorescence signals emitted by benzene and phenol organic pollutants at the groundwater monitoring site 500.

[0041] In this embodiment, through the combination of 3 excitation wavelengths and 2 fluorescence reception wavelengths, a total of 6 fluorescence characteristic signals are obtained. Further, the ratio calculation is performed pairwise on these 6 fluorescence characteristic signals to generate 15 additional ratio signals. These 6 original fluorescence characteristic signals and 15 ratio signals are integrated into a column of data as the input feature set. Based on the multiple linear regression model, the model is trained using benzene and phenol samples with known concentrations, and a quantitative relationship between the fluorescence characteristic signals and the pollutant concentration is established. The fluorescence characteristic signals are analyzed through the trained multiple linear regression model to achieve the quantitative detection of benzene and phenol pollutants.

[0042] Please refer to Figures 1 to 4 As shown, in an embodiment of the present invention, the device also provides a high-efficiency fluorescence detection optical path for groundwater organic matter that can correct turbidity and competitive absorption interference in real time.

[0043] In an embodiment of the present invention, the turbidity correction component 300 includes a turbidity light source component 310 and a turbidity detection component 320.

[0044] In this embodiment, the turbidity light source component 310 includes an LED light source two 311, a collimating lens three 312, a filter three 313, and a focusing lens three 314. The transmitted light emitted by the band-tunable LED light source two 311 passes through the collimating lens three 312, the filter three 313, and the focusing lens three 314 in sequence and then irradiates the groundwater monitoring site 500 and is simultaneously received by the turbidity detection component 320. Among them, the transmitted light emitted by the turbidity light source component 310 does not generate a fluorescence signal for the sample to be measured.

[0045] In this embodiment, the turbidity detection component 320 includes a collimating lens four 321, a filter four 322, a focusing lens four 323, and a photodiode one 324. The transmitted light emitted by the turbidity light source component 310 forms a parallel beam after passing through the collimating lens four 321, and then passes through the filter four 322 and the focusing lens four 323 and is focused on the photodiode one 324. The light intensity value of the transmitted light detected by the photodiode one 324 is used to calculate the turbidity value of the water body, which reflects the turbidity condition of the groundwater in real time.

[0046] In this embodiment, for turbidity interference, the turbidity value is determined by the transmitted light intensity of the groundwater monitoring site 500. The specific implementation method is as follows: When the LED light source two 311 emitting a wavelength of 860 nm works, the photodiode one 324 synchronously detects the change in the light intensity of the 860 nm transmitted light. Since the suspended particles in the water body will scatter the light, the higher the turbidity of the water body, the lower the transmitted light intensity. Therefore, by measuring the attenuation degree of the transmitted light, the turbidity value of the water body can be calculated.

[0047] Please refer to Figure 1 、 2and Figure 4 As shown, in one embodiment of the present invention, the competitive absorption correction component 400 includes a competitive absorption detection component 410, and the competitive absorption detection component 410 includes a collimating lens five 411, a filter five 412, a focusing lens five 413 and a photodiode two 414.

[0048] In this embodiment, while the excitation light of the excitation component 100 excites and induces the sample to be tested to produce a fluorescent signal, the transmitted light of the excitation light passes through the collimating lens five 411 to form a parallel light beam, and then passes through the filter five 412 and the focusing lens five 413 to form a parallel light beam and focus on the photodiode two 414.

[0049] In this embodiment, the competitive absorption detection components 410 are provided with multiple groups, and the number of competitive absorption detection components 410 matches the number of excitation components 100 and the used bands. It can be understood that the competitive absorption detection components 410 are also provided with three groups. When the LED light sources 110 of 255nm, 265nm and 275nm excite the substance, the transmitted light of the three excitation lights respectively passes through the collimating lens 5 411 of each group to form parallel light beams, and then enters the 255nm filter 5 412, the 265nm filter 5 412, and the 275nm filter 5 412 respectively, and then passes through the focusing lens 5 413 of each group, and finally enters the photodiode 2 414 of each group, and the light intensity value of the transmitted light is measured, and the absorbance is calculated according to the transmitted light intensity at different wavelengths, reflecting the absorption of the excitation light by sulfate, chloride, etc. in the water body.

[0050] In this embodiment, a photodiode 2 414 is used to detect the transmitted light emitted by an LED light source 110 of 255nm, 265nm, and 275nm, and its absorbance is measured after being transmitted through the lens assembly in the competitive absorption detection assembly 410. According to the measured absorbance value, the fluorescence signal is corrected to eliminate the influence of competitive absorption on the fluorescence intensity. The specific correction method is as follows: the absorbance of water samples with different turbidity at 255nm, 265nm, and 275nm is experimentally measured, and the fluorescence signals of phenolic and benzene compounds are measured using standard methods, and a quantitative relationship model between absorbance and fluorescence signal is established. During the detection process, the transmitted light intensity of the three wavelengths is recorded in real time, and the absorbance value A is calculated. 255 , A 265 , A 275 , and simultaneously obtain water sample turbidity data.

[0051] In this embodiment, light rays with wavelengths of 860 nm, 255 nm, 265 nm, and 275 nm are used to detect the scattered light and transmitted light in the water sample, obtain the turbidity data and absorbance data of the water sample, and perform real-time correction on the caused fluorescence signal attenuation to ensure the accuracy of the excitation light and fluorescence signal. For the corrected multi-wavelength fluorescence signal data, the concentrations of benzene series compounds and phenolic compounds in groundwater are quantitatively calculated through a trained multiple linear regression model.

[0052] Please refer to Figures 1 to 4 As shown, in an embodiment of the present invention, the configuration and material of the collimating lenses in the excitation component 100, fluorescence detection component 200, turbidity correction component 300, and competitive absorption correction component 400 are optimized for the purpose of minimizing light loss and improving the beam quality. Specifically, the material of the collimating lens is, for example, quartz or sapphire.

[0053] In this embodiment, the focusing lenses in the excitation component 100, fluorescence detection component 200, turbidity correction component 300, and competitive absorption correction component 400 are designed as high-precision optical components, which can efficiently focus the excitation light to a tiny area.

[0054] In this embodiment, the design of the window opening 210 and the light-shielding diaphragm 250 is optimized for the purpose of improving the quality and accuracy of the fluorescence signal received from the sample.

[0055] In one embodiment, the fluorescence detector 260 is selected to be variable according to application requirements, including a photomultiplier tube PMT or a silicon photodiode SiPD, for the purpose of optimizing the signal capture and conversion efficiency.

[0056] Please refer to Figures 1 to 5 As shown, the present invention also provides a fluorescence in-situ detection method for groundwater pollutants, applying the above-mentioned fluorescence in-situ detection device for groundwater pollutants, including: Taking the excitation wavelength of the excitation component 100 and the fluorescence reception wavelength received by the fluorescence detection component 200 as the fluorescence characteristic signal. At the same time, taking the transmitted light at the excitation wavelength of the excitation component 100 and the absorbance received by the competitive absorption correction component 400 as the competitive absorption correction signal.

[0057] Taking the transmitted light wavelength emitted by the turbidity correction component 300 and the received turbidity as the turbidity correction signal.

[0058] Taking the fluorescence characteristic signal, the competitive absorption correction signal, and the turbidity correction signal as the input feature set of a trained multiple linear regression model, and the model outputs to obtain the pollutant concentration.

[0059] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0060] The above-described embodiments merely represent the implementation manners of the invention. The protection scope of the present invention is not limited to the above embodiments only. For those skilled in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all fall within the protection scope of the present invention.

Claims

1. A fluorescent in-situ detection device for groundwater pollutants, characterized in that: include: An excitation component (100), a fluorescence detection component (200), a turbidity correction component (300) and a competitive absorption correction component (400); The excitation component (100), the turbidity correction component (300) and the competitive absorption correction component (400) are arranged in a ring structure around the groundwater monitoring site (500) and are located on the same horizontal plane; At the same time, the light emitted by the excitation component (100) can be used as a light source for exciting and inducing the sample to be tested to generate a fluorescent signal, and can also be used as a correction light source for the competitive absorption correction component (400); The fluorescence detection component (200) and the excitation component (100) are arranged vertically and at different horizontal planes, and the fluorescence signal propagates in a direction vertical to the excitation light path formed by the excitation component (100), and the fluorescence detection component (200) is arranged in the propagation direction of the fluorescence signal.

2. The fluorescent in-situ detection device for groundwater pollutants according to claim 1 is characterized in that: The excitation component (100) comprises: an LED light source (110), a collimating lens (120), a filter (130), and a focusing lens (140); A band-adjustable LED light source (110) emits excitation light, which is collimated by a collimating lens (120), then filtered out by a filter (130) to remove stray light, and finally focused by a focusing lens (140) to a groundwater monitoring site (500), thereby forming an excitation light path; The excitation components (100) are arranged in a plurality of groups, and each group of excitation components (100) has the same structure.

3. The fluorescent in-situ detection device for groundwater pollutants according to claim 1 is characterized in that: The fluorescence detection component (200) comprises a window opening (210), a second collimating lens (220), a second filter (230), a second focusing lens (240), a light shielding diaphragm (250), and a fluorescence detector (260) which are sequentially arranged along the propagation direction of the fluorescence signal.

4. The fluorescent in-situ detection device for groundwater pollutants according to claim 3 is characterized in that: Two groups of fluorescence detection components (200) are provided, and the two groups of fluorescence detection components (200) are symmetrically arranged with the groundwater monitoring site (500) as the center; Furthermore, the fluorescence receiving wavelength bands of the fluorescence detectors (260) in the two groups of fluorescence detection components (200) are different.

5. The groundwater pollutant fluorescence in-situ detection device according to claim 3, characterized in that: The window opening (210) is in a convex shape; wherein the small opening of the convex window opening (210) faces the light source, and the large opening faces the fluorescence detector (260); and the ratio of the small opening to the large opening is between 0.2 and 1; Two focusing lenses 2 (240) are arranged side by side.

6. The fluorescent in-situ detection device for groundwater pollutants according to claim 1 is characterized in that: The turbidity correction component (300) comprises a turbidity light source component (310) and a turbidity detection component (320); wherein the turbidity detection component (320) comprises a collimating lens four (321), a filter four (322), a focusing lens four (323) and a photodiode one (324); The transmitted light emitted by the turbidity light source assembly (310) does not generate a fluorescent signal for the sample to be tested; the transmitted light emitted by the turbidity light source assembly (310) passes through a collimating lens four (321) to form a parallel light beam, then passes through a filter four (322), a focusing lens four (323), and is focused onto a photodiode one (324).

7. The fluorescent in-situ detection device for groundwater pollutants according to claim 6 is characterized in that: The turbidity light source assembly (310) comprises a second LED light source (311), a third collimating lens (312), a third filter (313), and a third focusing lens (314); The transmitted light emitted by the second LED light source (311) with adjustable wavelength passes through the third collimating lens (312), the third filter (313), and the third focusing lens (314) in sequence, and then irradiates the groundwater monitoring site (500) and is received by the turbidity detection component (320).

8. The groundwater pollutant fluorescence in-situ detection device according to claim 1, characterized in that: The competitive absorption correction component (400) includes a competitive absorption detection component (410); The competitive absorption detection component (410) includes a collimating lens five (411), a filter five (412), a focusing lens five (413) and a photodiode two (414); While the excitation light of the excitation component (100) excites and induces the sample to be tested to produce a fluorescent signal, the transmitted light of the excitation light passes through the collimating lens five (411) to form a parallel light beam, and then passes through the filter five (412) and the focusing lens five (413) to form a parallel light beam and focus on the photodiode two (414).

9. The fluorescent in-situ detection device for groundwater pollutants according to claim 8, characterized in that: A plurality of competitive absorption detection components (410) are provided; the number of competitive absorption detection components (410) matches the number of excitation components (100) and the wavelength bands used match.

10. A method for fluorescent in-situ detection of groundwater pollutants, characterized in that: The fluorescent in-situ detection device for groundwater pollutants according to any one of claims 1 to 9 comprises: The excitation wavelength of the excitation component (100) and the fluorescence receiving wavelength received by the fluorescence detection component (200) are used as fluorescence characteristic signals; and the transmitted light at the excitation wavelength of the excitation component (100) and the absorbance received by the competitive absorption correction component (400) are used as competitive absorption correction signals; Using the wavelength of the transmitted light emitted by the turbidity correction component (300) and the received turbidity as a turbidity correction signal; The fluorescence characteristic signal, competitive absorption correction signal and turbidity correction signal are used as the input feature set of the trained multivariate linear regression model, and the model output obtains the pollutant concentration.

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