Probe type soil detection sensor and soil layer pollution detection device

Abstract

The invention provides a probe type soil detection sensor and a soil layer pollution detection device, and belongs to the technical field of sensors. Comprising a probe assembly and a detection device, the probe assembly is provided with a shell, and an inner cavity and a middle insulating layer attached to the inner wall of the shell are arranged in the shell; the lower end of the inner cavity is a solution containing space, and the lower end of the shell is used for being inserted into soil and provided with tiny holes to allow a soil solution to enter the solution containing space. The detection devices are arranged in the inner cavity and are used for detecting soil; the sensor is in a plug-in type and is convenient to use and high in detection efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensors, and more specifically, relates to a probe-type soil detection sensor and a soil layer pollution detection device. Background Art

[0002] The risk control and remediation of soil pollution are important aspects of soil pollution prevention and control. The pollution investigation and remediation control of soil and groundwater in industrial enterprises are the key points and difficulties of the current and future soil pollution prevention and control battles in China. Industrial enterprises not only undertake production tasks but also environmental protection tasks. Traditional soil pollution investigation technologies mainly use mechanical drilling sampling and laboratory testing technologies for investigation, which often have problems such as large site disturbance, prominent potential safety hazards in production, long working cycles, and high requirements for construction conditions. At present, traditional soil layer pollution detection devices generally have difficulty meeting the needs of safe production in industrial enterprises and green and low-carbon pollution investigations with "low cost and long-term effect". Therefore, it is urgent to design a soil pollution micro-disturbance detection sensor that meets the requirements of "production while investigation" in industrial enterprises. Summary of the Invention

[0003] The purpose of the present invention is to provide a probe-type soil detection sensor and a soil layer pollution detection device to solve the problem in the prior art that the soil detection device cannot meet the requirements of enterprises for production while investigation.

[0004] To achieve the above object, the technical solution adopted by the present invention is: to provide a probe-type soil detection sensor including a probe assembly and a detection device; the probe assembly has a housing, an inner cavity is provided in the housing, and an intermediate insulating layer is attached to the inner wall of the housing; the lower end of the inner cavity is a solution accommodation space, the lower end of the housing is for inserting into the soil and is provided with minute pores to allow soil solution to enter the solution accommodation space; the detection devices are all arranged in the inner cavity for detecting the soil. Among them, the detection device includes an electrochemical detection unit, a micro light source, a light detector, an optical fiber, a micro temperature sensor, and a micro pressure sensor; the electrochemical detection unit is arranged at one end of the housing for inserting into the soil and is used for detecting pollutants in the soil by electrochemical means; the micro light source is used for emitting a light signal required for detection; the light detector is used for receiving the light signal after the action of the soil solution and converting it into an electrical signal; the optical fiber includes an outgoing optical fiber and an incoming optical fiber, one end of the outgoing optical fiber is connected to the micro light source, and the other end extends into the solution accommodation space; one end of the incoming optical fiber is connected to the light detector, and the other end extends into the solution accommodation space and has a gap with one end of the outgoing optical fiber located in the solution accommodation space to detect the solution between the two; the micro temperature sensor is connected to the housing for detecting the soil temperature; the micro pressure sensor is arranged at the lower end of the housing, and the detection end passes through the housing to detect the resistance of inserting into the soil.

[0005] Combined with the above technical solutions, in a possible implementation, the electrochemical detection unit includes a nano-material modified electrode for detecting heavy metals. The nano-material modified electrode includes a working electrode, a reference electrode, and a counter electrode. The surface of the working electrode is modified with a nano-material that has selective adsorption and reaction capabilities for specific heavy metal ions.

[0006] Combined with the above technical solutions, in a possible implementation, the electrochemical detection unit includes an enzyme-modified electrode for detecting organic pollutants. The surface of the enzyme-modified electrode is immobilized with an enzyme that has a specific reaction to the target organic pollutant.

[0007] Combined with the above technical solutions, in a possible implementation, the needle-type soil detection sensor further includes a communication module, which is installed inside the needle assembly and is used to receive the data collected by the sensor and send it to an external receiving device.

[0008] Combined with the above technical solutions, in a possible implementation, the intermediate insulating layer is a grid structure composed of an insulating and elastic material, and the surface has hydrophobicity through the material's own properties or a hydrophobic coating to reduce the retention of water and make the remaining water more likely to form droplets, avoiding the remaining water from flowing in a stream or adhering to form a conductive path; the intermediate insulating layer is fixedly pasted on the inner wall of the housing through an adhesive.

[0009] Combined with the above technical solutions, in a possible implementation, the needle-type soil detection sensor further includes a fixing bracket. The edge of the fixing bracket is in interference fit with the intermediate insulating layer to be fixed inside the housing by squeezing through the intermediate insulating layer. The electrochemical detection unit, the micro light source, the photodetector, the optical fiber, and the micro temperature sensor are all installed on the fixing bracket; The lower end of the housing has a conical head. Tiny pores are provided on the conical head, and a through hole for the detection end of the micro pressure sensor to pass through is provided at the top of the conical head; a spring and a sealing ring are provided between the micro pressure sensor and the conical head. The sealing ring is provided on the micro pressure sensor or the outer periphery of the through hole. The spring is connected to the micro pressure sensor and the outer periphery of the through hole respectively to push the micro pressure sensor away from the through hole in the natural state; a pressure rod is provided on the fixing bracket, and the pressure rod extends to the micro pressure sensor to press the micro pressure sensor when the fixing bracket is installed in place, compressing the spring and making the micro pressure sensor and the outer periphery of the through hole sealed by the sealing ring to prevent large particle sediment from entering the solution accommodation space when inserted into the soil, affecting the detection accuracy, and making the detection end of the micro pressure sensor pass through the through hole.

[0010] Combined with the above technical solutions, in a possible implementation, the head of the needle assembly is conical, and the angle of the conical surface is between 30° and 45°.

[0011] Combined with the above technical solutions, in a possible implementation, the probe-type soil detection sensor further includes a general power supply, which is electrically connected to the communication module, the electrochemical detection unit, the micro light source, the light detector, the micro temperature sensor, and the micro pressure sensor.

[0012] To achieve the above object, the technical solution adopted by the present invention is: to provide a soil layer pollution detection device including a probe-type soil detection sensor and a processor; The above probe-type soil detection sensor device; the processor is configured to perform the following operations: receive the electrochemical signal sent by the electrochemical detection unit, the electrical signal transmitted by the light detector, the temperature data detected by the micro temperature sensor, and the pressure data detected by the micro pressure sensor; call the pre-stored calibration algorithm library to match the calculation model of the target pollutant; output a comprehensive report on the type, concentration, spatial distribution of pollutants, and soil physical and chemical parameters.

[0013] The beneficial effects of the probe-type soil detection sensor provided by the present invention are as follows: compared with the traditional soil detection method, first, by using materials sensitive to different pollutants as detection electrodes and combining with the optical detection principle, the present invention can more accurately detect the content of heavy metals and organic pollutants in the soil, improving the accuracy and pertinence of detection. For example, the high-sensitivity detection of specific heavy metal ions by the nano-material modified electrode and the specific reaction detection of organic pollutants by the enzyme-modified electrode can more accurately determine the soil pollution situation.

[0014] Second: The soil detection sensor of the present invention is designed as an insertable type, which can be directly detected on-site without complex sampling and sample transportation. At the same time, the soil layer pollution detection device can process and display the detection results in real time, greatly simplifying the detection process, realizing on-site rapid detection, and improving the detection efficiency.

[0015] Third, previous detection technologies often can only obtain single or a few index data, making it difficult to comprehensively evaluate the soil environmental quality. The probe-type soil detection sensor provided by the present invention can not only detect pollutants, but also obtain soil temperature and insertion resistance data through the temperature sensor and the pressure sensor. Combining these data with the pollutant detection data can more comprehensively understand the soil environmental conditions, providing richer and more accurate data support for soil pollution control and ecological restoration. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 Schematic structural diagram of the probe-type soil detection sensor provided by an embodiment of the present invention; Figure 2 Provided by an embodiment of the present invention Figure 1 Schematic structural diagram of A described therein; Figure 3 Schematic structural diagram of the positions of the housing, the intermediate insulating layer, and the inner cavity of the probe assembly provided by an embodiment of the present invention; Figure 4 Schematic structural diagram of the positions of the micro light source, the optical fiber, and the light detector provided by an embodiment of the present invention; Figure 5 Provided by an embodiment of the present invention Figure 4 Schematic structural diagram of B described therein; Figure 6 Schematic structural diagram of the positions of the soil layer pollution detection device provided by another embodiment of the present invention; Wherein, the reference numerals in the figure are as follows: 10. Probe assembly; 101. Housing; 102. Intermediate insulating layer; 103. Inner cavity; 104. Sealing cover; 11. Electrochemical detection unit; 12. Micro light source; 13. Light detector; 14. Optical fiber; 15. Micro temperature sensor; 16. Micro pressure sensor; 17. Thermal conductive silica gel; 18. Spring; 19. Sealing ring; 20. Communication module; 30. Fixed bracket; 31. Pressing rod; 40. General power supply; 50. Processor; Detailed implementation manners In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0018] It should be further noted that the drawings and embodiments of the present invention mainly describe and explain the concept of the present invention. On the basis of this concept, the specific forms and settings of some connection relationships, position relationships, power mechanisms, power supply systems, hydraulic systems, and control systems may not be completely described. However, on the premise that those skilled in the art understand the concept of the present invention, those skilled in the art can implement the above specific forms and settings in a well-known manner.

[0019] When an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0020] The orientation terms "inside" and "outside" refer to the inside and outside relative to the contour of each component itself. The terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0021] The terms "first" and "second" are only used for descriptive purposes and cannot be construed 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 invention, the meaning of "a plurality" is two or more, and the meaning of "several" is one or more, unless otherwise specifically defined.

[0022] Now, the probe-type soil detection sensor and the soil layer pollution detection device provided by the present invention will be described.

[0023] Such as Figure 1 And Figure 5As shown in the figure, the first embodiment of the present invention provides a probe-type soil detection sensor, which includes a probe assembly and a detection device; the probe assembly has a housing 101, an inner cavity 103 is provided in the housing 101, and an intermediate insulating layer 102 is attached to the inner wall of the housing 101; the lower end of the inner cavity 103 is a solution accommodation space, the lower end of the housing 101 is used to be inserted into the soil, and is provided with minute pores to allow the soil solution to enter the solution accommodation space; the detection devices are all arranged in the inner cavity 103 for detecting the soil; among them, the detection devices include an electrochemical detection unit 11, a micro light source 12, a light detector 13, an optical fiber 14, a micro temperature sensor 15 and a micro pressure sensor 16; the electrochemical detection unit 11 is arranged at one end of the housing 101 for inserting into the soil for detecting pollutants in the soil by an electrochemical method; the micro light source 12 is used to emit the optical signal required for detection; the light detector 13 is used to receive the optical signal after being affected by the soil solution and convert it into an electrical signal; the optical fiber 14 includes an outgoing optical fiber and an incoming optical fiber, one end of the outgoing optical fiber is connected to the micro light source 12, and the other end extends into the solution accommodation space; one end of the incoming optical fiber is connected to the light detector 13, and the other end extends into the solution accommodation space and has a gap with one end of the outgoing optical fiber located in the solution accommodation space to detect the solution between the two; the micro temperature sensor 15 is connected to the housing 101 for detecting the soil temperature; the micro pressure sensor 16 is arranged at the lower end of the housing 101, and the detection end passes through the housing 101 to detect the resistance of inserting into the soil. The head of the probe assembly is conical, and the angle of the conical surface is between 30° and 45°. The probe-type soil detection sensor further includes a general power supply 40, and the general power supply 40 is electrically connected to the communication module, the electrochemical detection unit 11, the micro light source 12, the light detector 13, the micro temperature sensor 15 and the micro pressure sensor 16. The probe-type soil detection sensor further includes a communication module, which is installed inside the probe assembly for receiving the data collected by the sensor and sending it to an external receiving device.

[0024] Before work, the staff will select a series of detection points according to the actual situation. During work, the staff will insert the head of the probe assembly 10 into the soil to a certain depth (10 - 50 cm). After the head of the probe assembly 10 is inserted into the soil, it will be left standing for a period of time (5 - 10 minutes) to allow enough time for the soil solution to enter the lower end of the inner cavity 103 of the probe assembly 10, and the lower end of the inner cavity 103 is used to accommodate the soil solution. Specifically, the probe assembly 10 has a housing 101, and an inner cavity 103 and an intermediate insulating layer 102 attached to the inner wall of the housing 101 are provided inside the housing 101. The lower end of the housing 101 is used to be inserted into the soil and has minute pores, and these minute pores are used to allow the soil solution to enter the solution accommodation space, but can block the sand and gravel from entering the interior, facilitating subsequent detection work, and the intermediate insulating layer 102 is used to prevent signal interference. The detection devices are all arranged in the inner cavity 103 to detect the soil. The inner cavity 103 of the probe assembly 10 integrally installs an electrochemical detection unit 11, a micro light source 12, a light detector 13 and an optical fiber 14. Among them, the electrochemical detection unit 11 is arranged at one end of the housing 101 for inserting into the soil to detect pollutants in the soil by an electrochemical method. The type of the micro light source 12 is: a micro LED light source, and its wavelength range is 300 - 800 nm, which is used to emit the optical signal required for detection. The light detector 13 is used to receive the optical signal after being affected by the soil solution and convert it into an electrical signal. The diameter range of the optical fiber 14 is 0.1 - 0.5 mm. The optical fiber 14 includes an outgoing optical fiber and an incoming optical fiber. One end of the outgoing optical fiber is connected to the micro light source 12, and the other end extends into the solution accommodation space. One end of the incoming optical fiber is connected to the light detector 13, and the other end extends into the solution accommodation space and has a gap with one end of the outgoing optical fiber located in the solution accommodation space to detect the solution between the two. The head of the probe assembly 10 is designed with a sharp conical shape, and the angle of the conical surface is between 30° - 45°, which is convenient for inserting into the soil. And a micro pressure sensor 16 is arranged at the lower end of the housing 101. The detection end of the micro pressure sensor 16 passes through the housing 101 and is used to detect the resistance of inserting into the soil. The micro pressure sensor 16 is connected to the housing 101 and is used to detect the soil temperature. The micro temperature sensor 15 and the micro pressure sensor 16 can monitor the soil temperature and the insertion resistance at the insertion depth in real time, providing data support for judging the soil texture. Specifically, the micro temperature sensor 15 is integrated on the side wall of the probe assembly 10 and contacts the soil through the heat-conducting silica gel 17 to monitor the temperature at the insertion depth in real time. The micro pressure sensor 16 is embedded in the lower end of the probe assembly 10 and passes through the housing 101. The detection end of the micro pressure sensor 16 directly acts on the soil to measure the resistance of inserting into the soil.

[0025] After the probe assembly 10 is inserted into the soil, the soil solution enters the solution accommodation space through the tiny pores at the lower end of the outer shell 101. For heavy metal detection, on the one hand, by using the electrochemical stripping voltammetry method, a specific potential is applied to the working electrode modified with nanomaterials, causing the redox reaction of the heavy metal ions adsorbed on the electrode surface, and the heavy metal content is determined by detecting the current signal; on the other hand, by using the fluorescence probe technology of heavy metal ions based on optics, a fluorescence probe that can selectively bind to specific heavy metal ions and produce a fluorescence response is pre-loaded inside the probe. When the heavy metal ions in the soil solution bind to the fluorescence probe, under the excitation of the specific wavelength light emitted by the micro light source 12, a characteristic fluorescence signal is generated. The light detector 13 receives the fluorescence signal and converts it into an electrical signal. For organic pollutant detection, on the one hand, based on the specific reaction between the enzyme and the substrate, the enzyme on the enzyme-modified electrode reacts with the target organic pollutant to produce a change in the electrical signal; on the other hand, the spectrophotometry method is used. The micro light source 12 emits composite light. After the light passes through the soil solution, the organic pollutants in the soil will absorb the light of a specific wavelength. The light detector 13 receives the transmitted light, and according to the Lambert-Beer law, the concentration of the organic pollutants is determined by detecting the change in the absorbance of the light. The data of the temperature sensor and the pressure sensor are transmitted to the processor 50 of the soil pollution detection device together with the detection electrode signal and the optical detection signal through the built-in circuit.

[0026] Specifically, with the insertion direction of the probe assembly 10 as the reference, the head of the probe assembly 10 is at the lower end, the tail of the probe assembly 10 is at the upper end, the micro light source 12 is above, and the photoelectric detector is below. The light emitted by the micro light source 12 is transmitted downward through the light-emitting optical fiber 14 in the optical fiber to the solution accommodation space. When the light signal emitted by the micro light source 12 acts on the soil solution between the light-emitting optical fiber and the light-receiving optical fiber, the light signal reflected or transmitted by the soil solution is received by the photoelectric detector through the light-receiving optical fiber.

[0027] Furthermore, the probe-type soil detection sensor further includes a general power supply 40 and a communication module 20. The general power supply 40 is electrically connected to the communication module 20, the electrochemical detection unit 11, the micro light source 12, the light detector 13, the micro temperature sensor 15, and the micro pressure sensor 16. The communication module 20 is installed inside the probe assembly 10 and is used to receive the data collected by the sensor and send it to an external receiving device.

[0028] Among them, the general power supply 40 can be selected as a lithium-ion battery, and a stable voltage is output through a DC-DC converter. The battery life ≥ 100 hours supports fast charging via a USB-C interface.

[0029] Compared with the prior art, by using materials sensitive to different pollutants as detection electrodes and combining with the optical detection principle, the present invention can more accurately detect the contents of heavy metals and organic pollutants in soil, improving the accuracy and pertinence of detection. For example, the highly sensitive detection of specific heavy metal ions by the nano-material modified electrode and the specific reaction detection of organic pollutants by the enzyme modified electrode can more precisely determine the soil pollution situation.

[0030] Second: The soil detection sensor of the present invention is designed as an insertable type, which can be directly detected on-site without complex sampling and sample transportation. At the same time, the host of the soil layer pollution detection device can process and display the detection results in real time, greatly simplifying the detection process, realizing on-site rapid detection, and improving the detection efficiency.

[0031] Third, previous detection technologies often can only obtain data of single or a few indicators, making it difficult to comprehensively evaluate the soil environmental quality. The needle-type soil detection sensor provided by the present invention can not only detect pollutants, but also obtain soil temperature and insertion resistance data through a temperature sensor and a pressure sensor. Combining these data with the pollutant detection data can more comprehensively understand the soil environmental conditions and provide richer and more accurate data support for soil pollution control and ecological restoration.

[0032] A specific embodiment provided by the present invention on the basis of the first embodiment is as follows: The electrochemical detection unit 11 includes a nano-material modified electrode for detecting heavy metals. The nano-material modified electrode includes a working electrode, a reference electrode, and a counter electrode. The surface of the working electrode is modified with a nano-material having selective adsorption and reaction capabilities for specific heavy metal ions.

[0033] In order to detect heavy metals in soil pollutant species, the electrochemical detection unit 11 includes a nano-modified electrode for detecting heavy metals. The nano-material modified electrode includes a working electrode, a reference electrode, and a counter electrode. The surface of the working electrode is modified with a nano-material having selective adsorption and reaction capabilities for specific heavy metal ions, such as graphene oxide nano-material, which can be used to selectively adsorb lead ions, chromium ions, or arsenic ions in the soil solution.

[0034] A specific embodiment provided by the present invention on the basis of the first embodiment is as follows: The electrochemical detection unit 11 includes an enzyme modified electrode for detecting organic pollutants. The surface of the enzyme modified electrode is fixed with an enzyme having a specific reaction to the target organic pollutant.

[0035] Specifically, for detecting organic pollutants in soil, the electrochemical detection unit 11 further includes an enzyme-modified electrode for detecting organic pollutants. The working electrode surface of the enzyme-modified electrode is immobilized with laccase or peroxidase, and the content of organic pollutants is detected by catalyzing the redox reaction of the target pollutants to generate current or voltage signals. Among them, the laccase-modified electrode can detect bisphenol A, phenol or p-nitrophenol in wastewater; while the peroxidase electrode detects phenolic and aromatic compounds (such as pentachlorophenol, etc.) and organophosphorus pesticide residues (such as parathion).

[0036] Furthermore, in the international academic journal Sens. Actuators B: Chem., a paper titled "Electrochemical detection of organophosphorus pesticides based on amino acids conjugated nanoenzyme modified electrodes" DOI: 10.1016 / i.snb.2019.02.007. In the paper, it was found that nanoenzymes attached with amino acids (AAs) serine (S), histamine (H) and glutamate (E) contribute to catalyzing the hydrolysis of organophosphorus pesticides (OPs) to form electroactive p-nitrophenol (PNP). This phenomenon follows the proton transfer relay mechanism found in biomimetic hydrolases. Therefore, an electrochemical method for detecting organophosphorus pesticides with S, H, E conjugated TiO2 NPs (NPs) modified electrodes was proposed. Using TiO2 NPs as a carrier, the attached S, H, E have hydrolytic activity towards organophosphorus, so the behavior of TiO2 NPS-AAs is similar to that of a nanoenzyme with hydrolytic activity. OPs (methyl paraoxon, methyl parathion and ethyl paraoxon) can generate electrochemically active PNP on the surface of this nanoenzyme-modified electrode, and OPs can be quantified by the electrochemical signal of PNP. This technique is selective for organophosphorus pesticides with p-nitrophenol groups. The detection limits of methyl paraoxon, methyl parathion and ethyl paraoxon are about 0.2 mM, and the working range is two orders of magnitude. This detection technique can be applied to detect organophosphorus pesticides in soil pollution and has high detection accuracy. Therefore, the working electrode surface of the enzyme-modified electrode can also use amino acid-conjugated nanoenzymes to generate electroactive substances by catalyzing the hydrolysis of organic pollutants, realizing electrochemical detection.

[0037] Such as Figure 3As shown in the figure, a specific implementation manner provided by the present invention on the basis of the first embodiment is as follows: The middle insulating layer 102 is a grid structure composed of an insulating and elastic material, and its surface has hydrophobicity through the material's own characteristics or a hydrophobic coating, so as to reduce the retention of water and make the remaining water more likely to form droplets, avoiding the remaining water flowing in a stream or adhering to form a conductive path; the middle insulating layer 102 is fixedly pasted on the inner wall of the outer shell 101 through an adhesive.

[0038] The middle insulating layer 102 is made of elastic polytetrafluoroethylene (PTFE) material to form a three-dimensional grid structure, with a grid density of 20 mesh / inch, a wire diameter of 0.15 mm, and a porosity of 75%. This material itself has excellent chemical stability and hydrophobicity, with a surface contact angle greater than 110°, and can effectively reduce water retention without an additional coating. To further enhance the hydrophobic performance, a fluorocarbon coating with a thickness of 5 - 10 μm is deposited on the grid surface through a plasma polymerization process, increasing the contact angle to more than 135°. The coating is firmly bonded to the PTFE matrix and shows no peeling after 500 bending tests.

[0039] The middle insulating layer 102 is fixedly pasted on the inner wall of the outer shell 101 through a two-component epoxy resin adhesive. Before construction, the inner wall of the outer shell 101 is sandblasted and roughened to Ra 3.2 - 6.3 μm and degreased with acetone. After the adhesive is mixed in a 1:1 ratio, an automatic dispensing device is used to evenly coat the inner wall of the outer shell 101 at a spacing of 0.5 mm. The prefabricated insulating layer grid structure is stretched axially by 5% along the outer shell 101 and then fitted, and a pressure of 0.08 MPa is applied through a vacuum adsorption device and maintained for 30 minutes to ensure that the adhesive fully penetrates the grid gaps. After curing, a bonding layer with a uniform thickness is formed, meeting the requirements for long-term use.

[0040] The elastic design of the grid structure enables it to adapt to the thermal expansion and contraction of the outer shell 101 in the temperature range of -20°C to 60°C, with a maximum deformation of 2% without debonding. When water seeps into the outer shell 101 through its tiny pores, the hydrophobic grid surface forces the water to quickly form droplets with a diameter ≥ 2 mm, which slide down along the grid pores to the solution accommodation space under the action of gravity. After testing, in an environment with a relative humidity of 95% for 24 hours, the residual water volume on the surface of the insulating layer is ≤ 0.1 g / m², and no flowing water in a stream or conductive path is found. This design effectively avoids the risks of electrochemical corrosion and leakage caused by water accumulation, ensuring the long-term stable operation of the internal detection devices.

[0041] As Figure 1 and Figure 4As shown in the figure, a specific implementation manner provided by the present invention on the basis of the first embodiment is as follows: The probe-type soil detection sensor further includes a fixing bracket 30. The edge of the fixing bracket 30 is in interference fit with the middle insulating layer 102, so as to be fixed in the outer shell 101 by extrusion through the middle insulating layer 102. The electrochemical detection unit 11, the micro light source 12, the light detector 13, the optical fiber 14, and the micro temperature sensor 15 are all installed on the fixing bracket 30; The lower end of the outer shell 101 has a conical head. The micro pores are provided on the conical head, and a through hole for the detection end of the micro pressure sensor 16 to pass through is provided at the top of the conical head; A spring 18 and a sealing ring 19 are provided between the micro pressure sensor 16 and the conical head. The sealing ring 19 is provided on the micro pressure sensor 16 or the outer periphery of the through hole. The spring 18 is respectively connected to the micro pressure sensor 16 and the outer periphery of the through hole, so as to push the micro pressure sensor 16 away from the through hole in the natural state; A pressure rod 31 is provided on the fixing bracket 30. The pressure rod 31 extends to the micro pressure sensor 16, and is used to press the micro pressure sensor 16 when the fixing bracket 30 is installed in place, so that the spring 18 is compressed, and the micro pressure sensor 16 and the outer periphery of the through hole are sealed through the sealing ring 19, so as to avoid large particle sediment entering the solution accommodating space when inserted into the soil, affecting the detection accuracy, and enabling the detection end of the micro pressure sensor 16 to pass through the through hole.

[0042] The fixing bracket 30 is injection molded from high-strength polycarbonate, with an outer diameter of 18.5 mm and an inner diameter of the middle insulating layer 102 of 18 mm. The fixing bracket 30 and the middle insulating layer 102 are in interference fit; a circular groove with a width of 1.5 mm and a depth of 0.8 mm is machined on the edge of the fixing bracket 30, and a nitrile rubber O-ring is embedded, which can effectively prevent the soil solution from seeping into the upper part of the inner cavity 103 along the gap between the bracket and the insulating layer, and avoid corrosion of precision electronic components such as the micro light source 12 and the light detector 13; during assembly, the outer diameter of the fixing bracket is compressed to 17.8 mm by applying an axial force through a special tooling and then pushed into the outer shell 101, and the radial clamping force is generated by the elastic deformation of the middle insulating layer 102 to ensure no loosening in the vibration environment.

[0043] Further, a top cover 104 is provided at the upper end of the outer shell 101. Vent holes are provided on the top cover 104 to facilitate the entry of the soil solution into the solution accommodation space at the lower end of the inner cavity 103. The top cover 104 is screwed onto the upper end of the outer shell 101 through a threaded structure. After the top cover 104 is tightened, the inside of the top cover 104 abuts against the upper end of the fixing bracket 30, and the pressing rod 31 at the bottom of the fixing bracket 30 abuts against the micro pressure sensor 16. At this time, the position of the micro pressure sensor 16 is fixed, and its detection end extends out of the lower end of the outer shell 101. At the same time, the spring 18 between the micro pressure sensor 16 and the through hole is in a compressed state. Under the action of the elastic force of the spring 18, the micro pressure sensor 16 is further pressed out of the lower end of the outer shell 101. In addition, such a design is mainly to, after one detection, when the operator unscrews the top cover 104 and conveniently takes out the fixing bracket 30, the micro pressure sensor 16 is pushed open under the action of the spring 18, so that the inner cavity 103 communicates with the through hole. Then, the inner cavity 103, especially the solution accommodation space and the tiny pores on the conical head, is directly flushed with flushing water or high-pressure flushing water. The flushing water can directly flow out of the through hole and the tiny pores with impurities, avoiding affecting the detection effect during the next use.

[0044] At the same time, a waterproof structure is provided outside the micro pressure sensor 16 to protect the detection devices inside the probe assembly 10 from moisture intrusion. The waterproof structure can be made of resin sealant material, that is, resin sealant is coated at the place where the micro pressure sensor 16 contacts the outer shell 101, or a waterproof rubber sleeve can be provided outside the micro pressure sensor 16.

[0045] Detection devices such as the electrochemical detection unit 11, the micro light source 12, and the light detector 13 are installed on the fixing bracket 30 through threaded holes. The optical fiber 14 is hermetically connected to the fixing bracket 30 by a metal ferrule joint to ensure that the optical path collimation error ≤ 0.05°.

[0046] The conical head of the outer shell 101 is integrally formed by a molding process, and the cone angle is strictly controlled within 35° ± 1° to balance the insertion resistance and the structural strength. Multiple tiny pores are evenly distributed on the conical surface. A through hole is opened at the top of the head, and a sealing groove is machined on the inner wall of the through hole for installing the sealing ring 19. The inner diameter of the sealing ring 19 is 2.5 mm, the wire diameter is 1.8 mm, and the compression ratio is set to 25% to ensure reliable sealing.

[0047] The micro pressure sensor 16 is a ceramic piezoresistive sensor. A cylindrical boss is designed at the tail of the sensor, which has a clearance fit with the inner diameter of the spring 18.

[0048] A pressing rod 31 extends vertically from the bottom of the fixed bracket 30, and the contact area between the end of the pressing rod 31 and the tail of the micro pressure sensor 16 is ≥ 3 mm². When the fixed bracket 30 is pressed in place, the axial displacement of the pressing rod 31 is 4 mm, compressing the spring 18 to the working height of 12 mm. At this time, the spring force is 14.4 N, ensuring that the detection end of the sensor extends 1 mm outside the through hole and forms an effective seal. After testing, this sealing structure can withstand a water pressure of 0.3 MPa, meeting the requirements of high-pressure flushing.

[0049] To achieve the above object, the technical solution adopted by the present invention is: to provide a soil pollution detection device including a needle-type soil detection sensor and a processor 50; the processor 50 is configured to perform the following operations: receive the electrochemical signal sent by the electrochemical detection unit 11, the electrical signal transmitted by the photodetector 13, the temperature data detected by the micro temperature sensor 15, and the pressure data detected by the micro pressure sensor 16; call the pre-stored calibration algorithm library to match the calculation model of the target pollutant; and output a comprehensive report on the types, concentrations, spatial distributions of pollutants and soil physical and chemical parameters.

[0050] As Figure 6 shown, the soil pollution detection device provided by the present invention mainly consists of a needle-type soil detection sensor and a processor 50. The needle-type soil detection sensor, as the front-end detection device, is responsible for collecting various data in the soil; the processor 50, as the core processing unit, analyzes and processes the data collected by the sensor and finally outputs the detection results.

[0051] The detection principle of the soil pollution detection device in the present invention is: when the needle is inserted into the soil, the soil solution comes into contact with the electrochemical detection unit 11 and starts to work. For heavy metal detection, the working electrode of the nano-material modified electrode selectively adsorbs and reacts with specific heavy metal ions by virtue of the nano-materials modified on the surface, generating an electrochemical signal; for organic pollutant detection, the enzyme immobilized on the surface of the enzyme modified electrode specifically reacts with the target organic pollutant, triggering a change in the electrochemical signal. At the same time, the micro light source 12 emits the optical signal required for detection, which is transmitted to the soil solution through the optical fiber 14. After interacting with the pollutant, the photodetector 13 receives the optical signal and converts it into an electrical signal. The micro temperature sensor 15 detects the soil temperature in real time, and the micro pressure sensor 16 detects the soil insertion resistance. All these data provide important bases for subsequent analysis.

[0052] The processor 50 is connected to the needle-type soil detection sensor and receives the electrochemical signals sent by the electrochemical detection unit 11, the electrical signals transmitted by the photodetector 13, the temperature data detected by the micro temperature sensor 15, and the pressure data detected by the micro pressure sensor 16. A calibration algorithm library is pre-stored inside the processor 50. After receiving the data, according to the data characteristics and preset rules, relevant algorithms in the library are called to match the calculation model of the target pollutant. For example, for the electrochemical signals and optical signals, comprehensive analysis is carried out in combination with the temperature and pressure data to determine the types and concentrations of pollutants. After determining the types and concentrations of pollutants, the processor 50, based on a certain spatial distribution algorithm and in combination with the position information of the detection points, obtains the spatial distribution of pollutants. At the same time, using the temperature and pressure data, as well as the preset calculation model of soil physical and chemical parameters, the physical and chemical parameters of the soil are calculated. Finally, the processor 50 integrates the pollutant types, concentrations, spatial distributions, and soil physical and chemical parameters and outputs a comprehensive report to visually present the pollution status and physical and chemical properties of the soil.

[0053] Through such a design, the native layer pollution detection device can achieve comprehensive and accurate detection of soil pollution. The needle-type soil detection sensor is directly inserted into the soil for on-site detection, avoiding the complex sampling and transportation processes and reducing errors. The powerful data processing ability of the processor 50 and the pre-stored algorithm library ensure the accuracy and reliability of the detection results. The output comprehensive report provides comprehensive and accurate data support for soil pollution control, ecological restoration, and agricultural production, etc., and has high practical value.

[0054] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A probe-type soil detection sensor, characterized in that, Comprising: A probe assembly (10) having a housing (101) with an inner cavity (103) therein and an intermediate insulating layer (102) adhered to the inner wall of the housing (101); the lower end of the inner cavity (103) is a solution accommodation space, and the lower end of the housing (101) is for insertion into the soil and is provided with minute pores to allow soil solution to enter the solution accommodation space; Detection devices, all disposed in the inner cavity (103) for detecting the soil; Wherein, the detection devices include: An electrochemical detection unit (11), disposed at one end of the housing (101) for insertion into the soil, for detecting pollutants in the soil by an electrochemical method; A micro light source (12) for emitting a light signal required for detection; A light detector (13) for receiving the light signal after being affected by the soil solution and converting it into an electrical signal; An optical fiber (14), including a light-emitting optical fiber and a light-incident optical fiber, one end of the light-emitting optical fiber is connected to the micro light source (12), and the other end extends into the solution accommodation space; one end of the light-incident optical fiber is connected to the light detector (13), and the other end extends into the solution accommodation space and has a gap with one end of the light-emitting optical fiber located in the solution accommodation space to detect the solution therebetween; A micro temperature sensor (15), connected to the housing (101) for detecting the soil temperature; and A micro pressure sensor (16), disposed at the lower end of the housing (101), and the detection end penetrates through the housing (101) to detect the resistance of insertion into the soil.

2. A probe-type soil detection sensor according to claim 1, wherein: The electrochemical detection unit (11) includes a nano-material modified electrode for detecting heavy metals, the nano-material modified electrode includes a working electrode, a reference electrode and a counter electrode, and the surface of the working electrode is modified with a nano-material having selective adsorption and reaction capabilities for specific heavy metal ions.

3. A probe-type soil detection sensor according to claim 1, wherein: The electrochemical detection unit (11) includes an enzyme-modified electrode for detecting organic pollutants, and the surface of the enzyme-modified electrode is immobilized with an enzyme having a specific reaction to the target organic pollutant.

4. A probe-type soil detection sensor according to claim 1, wherein: The probe-type soil detection sensor further includes a communication module (20), installed inside the probe assembly (10), for receiving data collected by the sensor and sending it to an external receiving device.

5. A probe-type soil detection sensor according to claim 1, wherein: The intermediate insulating layer (102) is a grid structure made of an insulating and elastic material, and the surface has hydrophobicity through the material's own properties or a hydrophobic coating to reduce the retention of water and make the remaining water more likely to form droplets, avoiding the remaining water from flowing in a stream or adhering to form a conductive path; The intermediate insulating layer (102) is adhered and fixed to the inner wall of the housing (101) by an adhesive.

6. The needle-type soil detection sensor according to claim 1, wherein: The needle-type soil detection sensor further includes a fixing bracket (30), and the edge of the fixing bracket (30) is in interference fit with the middle insulating layer (102) to be fixed in the housing (101) by extrusion through the middle insulating layer (102). The electrochemistry detection unit (11), the micro light source (12), the photodetector (13), the optical fiber (14) and the micro temperature sensor (15) are all installed on the fixing bracket (30); The lower end of the housing (101) has a conical head, the micro pores are provided on the conical head, and a through hole for the detection end of the micro pressure sensor (16) to pass through is provided at the top of the conical head; A spring (18) and a sealing ring (19) are provided between the micro pressure sensor (16) and the conical head. The sealing ring (19) is provided on the micro pressure sensor (16) or the outer periphery of the through hole. The spring (18) is respectively connected to the micro pressure sensor (16) and the outer periphery of the through hole to push the micro pressure sensor away from the through hole in the natural state; A pressure rod (31) is provided on the fixing bracket (30), and the pressure rod (31) extends to the micro pressure sensor (16) to press the micro pressure sensor (16) when the fixing bracket (30) is installed in place, so that the spring (18) is compressed, and the micro pressure sensor (16) and the outer periphery of the through hole are sealed through the sealing ring (18) to prevent large particle sediment from entering the solution accommodation space when inserted into the soil, affecting the detection accuracy, and the detection end of the micro pressure sensor (16) passes through the through hole.

7. The needle-type soil detection sensor according to claim 6, wherein: The conical head is a conical structure, and the angle of the conical surface is between 30° and 45°.

8. The needle-type soil detection sensor according to claim 4, wherein: The needle-type soil detection sensor further includes a general power supply (40), and the general power supply (40) is electrically connected to the communication module (20), the electrochemistry detection unit (11), the micro light source (12), the photodetector (13), the micro temperature sensor (15) and the micro pressure sensor (16).

9. A soil layer pollution detection device, characterized in that: Comprising: The needle-type soil detection sensor according to any one of claims 1-8; A processor (50), configured to perform the following operations: Receive the electrochemistry signal sent by the electrochemistry detection unit (11), the electrical signal transmitted by the photodetector (13), the temperature data detected by the micro temperature sensor (15) and the pressure data detected by the micro pressure sensor (16); Call the pre-stored calibration algorithm library to match the calculation model of the target pollutant; Output a comprehensive report on the types, concentrations, spatial distributions of pollutants and soil physical and chemical parameters.

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