Stereoscopic lake cyanobacterial biomass spectral detection system

Abstract

The application provides a kind of three-dimensional lake blue-green algae biomass spectrum detection system, comprising: host computer and probe;Host computer and probe are connected by optical fiber;Light source emits light beam to light source reflection coating, produces diffuse reflection light beam to detection warehouse;Water tower head is arranged on the other side of detection warehouse, for the water body from detection warehouse is extracted after detection is completed;Collimating lens group is arranged on the top surface of detection warehouse, for imaging to the water body to be measured;Collimating lens group is connected with optical fiber through connecting device, and then connected with optical fiber switching structure and optical fiber spectrometer through optical fiber respectively.Diffuse reflection light beam enters the inside of detection warehouse through light inlet hole and irradiates the water body to be measured, and then the image is transmitted to optical fiber spectrometer through optical fiber after collimating lens group imaging, to obtain the spectral data of the water body to be measured.The application has the advantages of practical, portable, low cost and low power consumption.

Description

Technical Field

[0001] This invention relates to the field of spectral analysis technology, and in particular to a three-dimensional spectral detection system for cyanobacterial biomass in lakes. Background Technology

[0002] Algal blooms caused by excessive algal growth are a key characteristic of eutrophication in lakes, and my country has become one of the countries with the most severe and widespread cyanobacterial blooms in the world. In practice, it has been found that the area of ​​algal blooms and the concentration of chlorophyll a on the surface of eutrophic lakes often change drastically within a few days, sometimes even showing large-scale aggregation or disappearance of cyanobacterial blooms within hours. Therefore, conducting three-dimensional monitoring of algal biomass in lakes, accurately grasping the spatiotemporal variation patterns of total algal content, and scientifically interpreting the driving factors and mechanisms of these changes are crucial for accurately understanding the changing trends of cyanobacterial bloom intensity in lakes in my country and globally, and for achieving sustainable development of lake basins.

[0003] Compared with water quality detection and analysis methods such as chemical analysis, electrochemical analysis, chromatographic separation technology, and biosensing technology, lake cyanobacteria detection technology based on spectral analysis is one of the important development directions of modern environmental water quality detection.

[0004] Currently, the main technologies include atomic absorption spectrometry, hyperspectral remote sensing, and molecular absorption spectrometry. Hyperspectral remote sensing, due to its low measurement accuracy, is mostly used for qualitative water quality monitoring and analysis. While atomic absorption spectrometry has been listed as a standard analytical method for determining heavy metal parameters such as total chromium, total lead, total mercury, total zinc, and total manganese in water, offering advantages such as high sensitivity, accuracy, selectivity, and speed, it consumes a lot of energy and is difficult to determine refractory and non-metallic elements. It requires laboratory testing, resulting in expensive equipment and inconvenience, failing to meet the needs of online, real-time, multi-parameter environmental water quality monitoring. In comparison, molecular absorption spectrometry, especially ultraviolet-visible molecular absorption spectrometry, represents a crucial development direction in modern water quality testing. It offers advantages such as ease of operation, low reagent consumption (some water quality parameters may even be reagent-free), good repeatability, high measurement accuracy, and rapid analysis, making it suitable for rapid online detection of environmental water samples. Currently, based on whether sample chemical pretreatment is required, water quality detection technologies based on molecular absorption spectroscopy can be divided into two categories: sample pretreatment spectroscopy and direct spectroscopy. Comparatively, sample pretreatment spectroscopy is a mature technology applicable to online detection of most water quality parameters and represents the main development direction for spectral water quality detection. While direct spectroscopy does not require sample pretreatment, it is susceptible to the anisotropy of different water bodies. Its core intelligent algorithm model is easily affected by interference from different water bodies, resulting in less stable detection and weaker universality. Furthermore, current direct spectroscopy instruments are limited to detecting only a few water quality parameters, such as COD, nitrates, and benzene compounds, and are still in an immature technological development stage. Their application areas are far less extensive than those of sample pretreatment spectroscopy instruments.

[0005] Spectroscopic water environment detection technology is an important development direction in the field of water quality testing. However, the above analysis of the current status and trends of this technology reveals the following problems:

[0006] (1) From the perspective of the nature of the detection method, water environment detection is the unique advantage of the spectral water quality detection technology itself. It can solve the technical problem of realizing multi-parameter detection of water environment by integrating multiple electrochemical sensors, integrating multiple analysis method modules, or combining multiple instruments. However, at present, spectral water environment detection instruments are still mainly based on single-parameter detection, and multi-parameter spectral water environment detection instruments are still in the immature stage of technological development.

[0007] (2) Currently reported multi-parameter spectroscopic instruments for water environment detection all have built-in large-scale spectrophotometric analysis systems, resulting in complex instrument structures, large size, and high cost.

[0008] (3) The complexity of actual environmental water samples and the various interference signals carried by the continuous spectrum itself are among the main factors affecting the accuracy of water quality detection. Therefore, the characteristics of online water environment detection spectral signals should be analyzed, and the spectral signal processing technology for multi-parameter detection of water environment should be studied to improve the accuracy of water quality detection. Summary of the Invention

[0009] In view of the above problems, the purpose of this invention is to propose a three-dimensional spectral detection system for cyanobacterial biomass in lakes. This invention addresses the urgent need for high accuracy, portability, low power consumption, and high-performance online detection capabilities in modern lake cyanobacterial biomass detection. Based on ultraviolet-visible spectroscopy, it constructs an algorithm for inverting the spectral parameters of the three-dimensional distribution of cyanobacteria in eutrophic shallow lakes. It integrates a miniaturized fluorescence detection system, dynamic positioning technology, vacuum sealing technology, real-time data transmission, and cloud sharing technology. This system can meet the requirements of in-situ, online, high-precision, three-dimensional monitoring of cyanobacterial biomass in lakes, and can also detect the thickness of cyanobacterial blooms. It has the advantages of practicality, portability, low cost, and low power consumption.

[0010] To achieve the above objectives, the present invention adopts the following specific technical solution:

[0011] This invention provides a three-dimensional spectral detection system for cyanobacterial biomass in lakes, comprising: a main unit and a probe; the main unit and the probe are connected via optical fiber;

[0012] The main unit includes: a built-in battery, a single-board computer, and a fiber optic spectrometer; the probe includes: a light source and a detection chamber.

[0013] The bottom of the probe is semi-circular, and the inner side of the bottom of the probe is coated with a light source reflective coating; the light beam emitted by the light source is incident on the light source reflective coating, and a diffuse reflection light beam is generated and incident on the detection chamber;

[0014] The testing chamber is a hollow cuboid structure;

[0015] A light inlet is provided on the bottom surface of the testing chamber;

[0016] A water inlet is located on the side of the testing chamber;

[0017] A water pumping tower head is installed on the other side of the testing chamber to pump the tested water out of the testing chamber.

[0018] A collimating lens group is installed on the top surface of the detection chamber for imaging the water body to be tested;

[0019] The collimating lens assembly is connected to the optical fiber via a connecting device, and then connected to the optical fiber switching structure and the optical fiber spectrometer via optical fibers.

[0020] The diffuse reflection beam enters the detection chamber through the light entrance aperture to irradiate the water body to be tested, and after being imaged by the collimating lens group, it is transmitted to the fiber optic spectrometer through the optical fiber to obtain the spectral data of the water body to be tested.

[0021] The single-board computer is used to store the spectral data of the water body to be tested, and the built-in battery is used to power the single-board computer and the fiber optic spectrometer.

[0022] Preferably, it also includes an optical fiber switching structure;

[0023] The probe contains a number of detection chambers of varying sizes, and each detection chamber is connected to a fiber optic switch and a fiber optic spectrometer via an optical fiber.

[0024] At any given moment, a fiber optic spectrometer can only receive spectral data of the water body being measured transmitted through one fiber optic cable.

[0025] The spectral data of the water body to be measured can be selected and received from any optical fiber by controlling the optical fiber switching structure.

[0026] Preferably, a filtration system is installed at the water inlet;

[0027] The filtration system is used to filter the water to different degrees, so that different test chambers contain different water samples, thereby enabling the detection of different water samples.

[0028] Preferably, the optical fiber is placed in a waterproof, sealed corrugated tube.

[0029] Preferably, the main unit is placed on the water surface, and the probe is placed in an underwater working environment of 0m-2m.

[0030] Preferably, the fiber optic switching mechanism includes an electric displacement stage and a double L-shaped structure; the double L-shaped structure includes a first L-shaped structure and a second L-shaped structure;

[0031] The electric displacement table is installed on the bottom of the main unit;

[0032] The first L-shaped structure is installed on the bottom of the main unit; the first L-shaped structure is equipped with fiber optic collimating lenses, which are connected to the detection chamber via optical fibers.

[0033] The second L-shaped structure is mounted on the electric displacement stage; the second L-shaped structure is equipped with a fiber optic focusing lens, which is connected to the fiber optic spectrometer.

[0034] The electric displacement stage is moved by a stepper motor, which in turn drives the second L-shaped structure to translate, so that the fiber focusing lens on the second L-shaped structure is aligned with the different fiber collimating lenses on the first L-shaped structure to complete the optical path switching.

[0035] Preferably, the probe has dimensions of 160mm*80mm*80mm.

[0036] Preferably, the detection spectral range of the present invention is 200-800nm.

[0037] Compared with existing technologies, the present invention has the following advantages:

[0038] 1. It has a wide spectral range (200-800nm), high spectral resolution (better than 1nm), can perform continuous spectral analysis, multi-parameter detection spectral signal processing, and adopts a three-beam measurement optical path design to eliminate the influence of lake water turbidity, while also eliminating the influence of light source intensity and detector variations;

[0039] 2. Low cost, easy to carry and deploy (total volume ≤10dm) 2 Total mass ≤10kg), large detection depth: 0-2m, simultaneously capable of in-situ, online, high-precision, three-dimensional detection of cyanobacterial bloom thickness, cyanobacterial Chl-a content and biomass in water, long continuous working time (>24h unmanned vessel cable power supply), autonomous movement distance >1km; high positioning accuracy (<5m);

[0040] 3. It has promoted the shift of monitoring lake cyanobacterial biomass from ex-situ to in-situ, and significantly increased the monitoring frequency and the spatiotemporal scale of monitoring indicators for lake cyanobacteria. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of a three-dimensional lake cyanobacterial biomass spectral detection system provided in an embodiment of the present invention.

[0042] Figure 2 This is a three-dimensional view of the three-dimensional lake cyanobacterial biomass spectral detection system provided in an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram of the probe portion of the three-dimensional lake cyanobacteria biomass spectral detection system provided in an embodiment of the present invention.

[0044] Figure 4 This is a cross-sectional view of the probe portion of the three-dimensional lake cyanobacteria biomass spectral detection system provided in an embodiment of the present invention.

[0045] Figure 5 This is a schematic diagram of the double L-shaped structure of the three-dimensional lake cyanobacteria biomass spectral detection system provided in an embodiment of the present invention.

[0046] The reference numerals in the accompanying drawings include: light source 1, light source reflective coating 2, detection chamber 3, light inlet 31, water inlet 32, water pumping tower head 33, collimating lens group 34, collimating lens group connector 35, connecting device 4, built-in battery 5, single-board computer 6, fiber optic switching structure 7, electric displacement stage 71, double L-shaped structure 72, first L-shaped structure 721, second L-shaped structure 722, and fiber optic spectrometer 8. Detailed Implementation

[0047] In the following description, embodiments of the invention will be described with reference to the accompanying drawings. In the description below, the same modules are denoted by the same reference numerals. Where the same reference numerals are used, their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0049] Figure 1 A schematic diagram of the structure of a three-dimensional lake cyanobacterial biomass spectral detection system provided according to an embodiment of the present invention is shown.

[0050] Figure 2 A three-dimensional view of a three-dimensional lake cyanobacterial biomass spectral detection system provided according to an embodiment of the present invention is shown.

[0051] like Figure 1-2 As shown, the three-dimensional lake cyanobacterial biomass spectral detection system provided in this embodiment of the invention includes a main unit and a probe; the main unit and the probe are connected via optical fiber. The probe dimensions are 160mm*80mm*80mm.

[0052] The main unit includes: a built-in battery 5, a single-board computer 6, an optical fiber switching structure 7, and an optical fiber spectrometer 8.

[0053] The probe assembly includes: a light source 1, a light source reflective coating 2, a detection chamber 3, a light inlet 31, a water inlet 32, a water pumping tower head 33, a collimating lens assembly 34, a collimating lens assembly connector 35, and a connecting device 4.

[0054] The bottom of the probe is semi-circular, and the inner side of the bottom of the probe is coated with a light source reflective coating 2.

[0055] The light beam emitted by the light source 1 is incident on the light source reflective coating 2, and a diffusely reflected light beam is generated and incident on the detection chamber 3.

[0056] The probe contains multiple detection chambers 3 that are evenly placed on the same horizontal plane.

[0057] Figure 3A schematic diagram of the probe portion of the three-dimensional lake cyanobacterial biomass spectral detection system provided according to an embodiment of the present invention is shown.

[0058] Figure 4 A cross-sectional view of the probe portion of the three-dimensional lake cyanobacterial biomass spectral detection system provided according to an embodiment of the present invention is shown.

[0059] like Figure 3-4 As shown, in one embodiment of the present invention, the number of detection chambers 3 is 3, which are placed symmetrically inside the probe.

[0060] The detection chamber 3 is a hollow cuboid structure;

[0061] A light inlet 31 is provided on the bottom surface of the detection chamber 3 facing the light source reflective coating 2;

[0062] A water inlet 32 ​​is provided on the side of the detection chamber 3, and a filtration system is installed in the water inlet 32;

[0063] A water pumping tower head 33 is provided on the other side of the testing chamber 3, which is used to pump out the water after testing from the testing chamber 3;

[0064] A collimating lens group 34 is installed on the top surface of the detection chamber 3 to image the water body to be tested, so as to obtain the spectral data of the water body to be tested through the fiber optic spectrometer 8.

[0065] The collimating lens group 34 is connected to the optical fiber via the collimating lens group connector 35. The optical fiber is placed inside the connecting device 4 and then connected to the optical fiber switching structure 7 and the optical fiber spectrometer 8 via the optical fiber.

[0066] The aforementioned optical fiber is placed in a waterproof, sealed corrugated tube and connected to the optical fiber switching structure 7 and the optical fiber spectrometer 8 inside the main unit.

[0067] Figure 5 A schematic diagram of the double L-shaped structure of the three-dimensional lake cyanobacterial biomass spectral detection system provided in an embodiment of the present invention is shown.

[0068] like Figure 5 As shown, the fiber optic switching structure 7 is installed on the bottom of the host machine. The fiber optic switching mechanism 7 includes an electric displacement stage 71 and a double L-shaped structure 72. The double L-shaped structure 72 includes a first L-shaped structure 721 and a second L-shaped structure 722.

[0069] The electric displacement stage 71 is installed on the bottom of the main unit;

[0070] The first L-shaped structure 721 is installed on the bottom of the main unit; the first L-shaped structure 721 is equipped with multiple fiber optic collimating lenses, which are connected to the detection chamber via optical fibers.

[0071] The second L-shaped structure 722 is mounted on the electric displacement stage 71; the second L-shaped structure 722 is equipped with a fiber optic focusing lens, which is connected to the fiber optic spectrometer 8.

[0072] The electric displacement stage 71 is moved by a stepper motor, which in turn drives the second L-shaped structure 722 to translate, so that the fiber focusing lens on the second L-shaped structure 722 is aligned with the different fiber collimating lenses on the first L-shaped structure 721 to complete the optical path switching.

[0073] The three testing chambers each contain three different types of water:

[0074] The original lake water (containing blue-green algae, inorganic matter, organic matter, and water);

[0075] Water that contains only blue-green algae and organic matter after light filtration;

[0076] Distilled water prepared in the laboratory.

[0077] During the operation of the three-dimensional lake cyanobacterial biomass spectral detection system provided by this invention:

[0078] The main unit is placed on an unmanned surface vessel, while the probe is positioned in an underwater operating environment of 0-2 meters. The entire unit is constructed of 6061 aluminum and encapsulated with rubber O-rings.

[0079] The light source is switched by a stepper motor to emit a preset wavelength. The light beam emitted by the light source at the preset wavelength is reflected by the light source reflective coating to form a diffuse reflection beam. The diffuse reflection beam is simultaneously incident on the detection chambers at different positions through the light entrance aperture to irradiate the water body to be tested.

[0080] When acquiring the spectral data of the first type of water body to be tested:

[0081] The light source emits a light beam of a first preset wavelength, which is reflected by the light source's reflective coating to form a diffuse reflection beam, which then irradiates the three water bodies to be tested in the detection chamber.

[0082] The optical fiber switching structure 7 is controlled to select and receive spectral data from the optical fiber corresponding to the first type of water body to be tested.

[0083] When acquiring spectral data for a second type of water body:

[0084] The light source emits a beam of light with a second preset wavelength. After being reflected by the reflective coating of the light source, it forms a diffuse reflection beam, which illuminates the three water bodies to be tested in the detection chamber.

[0085] The optical fiber switching structure 7 is controlled to select and receive spectral data from the optical fiber corresponding to the second type of water body to be tested.

[0086] In this manner, spectral data of three different water bodies to be tested are obtained in sequence.

[0087] The three-dimensional lake cyanobacterial biomass spectral detection system provided by this invention can detect the absorption spectra of three different water samples in real time from 200 to 800 nm using the same fiber optic spectrometer, and finally obtain the absorption spectral data of cyanobacteria based on the superposition of absorption spectra.

[0088] The single-board computer 6 is equipped with corresponding control software and programs to realize data acquisition functions. It can store the spectral data of different water bodies to be tested, and can also transmit the spectral data of different water bodies to the cloud via network or cable.

[0089] The device is powered by a built-in battery 5 and a single-board computer 6, and the autonomous data acquisition program is run. The signal is transmitted back to the base station using waterproof connectors and underwater waterproof optical cables.

[0090] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0091] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A three-dimensional spectral detection system for cyanobacterial biomass in lakes, characterized in that, include: Main unit and probe; The main unit and the probe are connected via optical fiber; The host unit includes: a built-in battery, a single-board computer, and a fiber optic spectrometer; the probe includes: a light source and a detection chamber. The bottom of the probe is semi-circular, and the inner side of the bottom of the probe is coated with a light source reflective coating; the light source emits a light beam that is incident on the light source reflective coating, and a diffusely reflected light beam is generated and incident on the detection chamber; The detection chamber is a hollow cuboid structure; A light inlet hole is provided on the bottom surface of the detection chamber; A water inlet is provided on the side of the testing chamber; A water pumping tower head is provided on the other side of the testing chamber for pumping out the tested water from the testing chamber. A collimating lens group is installed on the top surface of the detection chamber for imaging the water body to be tested; The collimating lens group is connected to the optical fiber via a connecting device, and then connected to the optical fiber switching structure and the optical fiber spectrometer via the optical fiber. The diffuse reflection beam enters the detection chamber through the light entrance hole to irradiate the water body to be tested, and after being imaged by the collimating lens group, it is transmitted through the optical fiber to the fiber optic spectrometer to obtain the spectral data of the water body to be tested. The single-board computer is used to store the spectral data of the water body to be tested, and the built-in battery is used to power the single-board computer and the fiber optic spectrometer.

2. The three-dimensional lake cyanobacterial biomass spectral detection system according to claim 1, characterized in that, It also includes fiber optic switching structures; The probe is uniformly provided with a different number of detection chambers, and each detection chamber is connected to the fiber optic switching structure and the fiber optic spectrometer via an optical fiber. At any given time, the fiber optic spectrometer can only receive spectral data of the water body being tested transmitted through one fiber optic cable. The spectral data of the water body to be tested can be selected and received from any optical fiber by controlling the optical fiber switching structure.

3. The three-dimensional lake cyanobacterial biomass spectral detection system according to claim 2, characterized in that, The water inlet is equipped with a filtration system; The filtration system is used to filter water to different degrees, so that different test chambers contain different water samples, thereby enabling the detection of different water samples.

4. The three-dimensional lake cyanobacterial biomass spectral detection system according to claim 3, characterized in that, The optical fiber is placed in a waterproof, sealed corrugated tube.

5. The three-dimensional lake cyanobacterial biomass spectral detection system according to claim 4, characterized in that, The main unit is placed on the water surface, and the probe is placed in an underwater working environment of 0m-2m.

6. The three-dimensional lake cyanobacterial biomass spectral detection system according to claim 5, characterized in that, The fiber optic switching mechanism includes an electric displacement stage and a double L-shaped structure; the double L-shaped structure includes a first L-shaped structure and a second L-shaped structure. The electric displacement table is mounted on the bottom of the main unit; The first L-shaped structure is installed on the bottom of the host; the first L-shaped structure is equipped with an optical fiber collimating lens, which is connected to the detection chamber via optical fiber. The second L-shaped structure is mounted on the electric displacement stage; a fiber optic focusing lens is mounted on the second L-shaped structure and connected to the fiber optic spectrometer; The electric displacement stage is moved by a stepper motor, which in turn drives the second L-shaped structure to translate, so that the fiber focusing lens on the second L-shaped structure is aligned with the different fiber collimating lenses on the first L-shaped structure to complete the optical path switching.

7. The three-dimensional lake cyanobacterial biomass spectral detection system according to claim 6, characterized in that, The probe measures 160mm*80mm*80mm.

8. The three-dimensional lake cyanobacterial biomass spectral detection system according to claim 7, characterized in that, The detection spectral range is 200-800nm.

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