An in-situ online monitoring system and method for groundwater VOCs

Abstract

The application discloses an underground water VOC in-situ online monitoring system and method, which comprises a workbench, a moving assembly is installed at the bottom of the workbench, a first conveying mechanism is installed at the top of the workbench and is used for conveying headspace bottles, a wheel rotation assembly is installed at the middle position of the first conveying mechanism, a second conveying mechanism comprises a conveying assembly and a turnover positioning assembly, the conveying assembly is installed on the workbench, and the turnover positioning assembly is installed at the end of the conveying assembly, a filling mechanism is installed at the top of the workbench and is used for injecting collected underground water into the headspace bottles, a cover pressing assembly is installed on the top surface of the workbench, and a detection system is connected in series at the end of the first conveying mechanism. The application is helpful for discovering and processing underground water pollution problems in time and protecting water resource environment.

Description

Technical Field

[0001] This invention relates to the field of groundwater monitoring technology, and in particular to a groundwater VOC in-situ online monitoring system and method. Background Technology

[0002] VOC (volatile organic compound) detection is a crucial link in environmental monitoring and water quality safety assurance, and is of great significance for the prevention and control of soil and groundwater pollution. However, current VOC pollution monitoring in soil and groundwater still faces many challenges, mainly stemming from the current reliance on manual sampling and detection methods. Manual sampling has the following technical problems:

[0003] 1. Long monitoring cycle and poor timeliness.

[0004] Manual sampling needs to be carried out in stages according to plan, from sampling point deployment and sample collection to laboratory analysis, and the entire process is time-consuming. For sudden pollution events or short-term pollution spread processes, traditional monitoring methods are difficult to quickly capture pollution dynamics, leading to the expansion of the pollution range or the lag in control measures, which increases environmental risks.

[0005] 2. The sampling operation has high requirements and a high risk of error.

[0006] VOCs are volatile and easily affected by external interference, requiring strict adherence to standardized procedures during sampling. For example, specialized samplers must be used to avoid cross-contamination, sampling depth and flow rate must be precisely controlled, and samples must be quickly sealed to minimize evaporation loss. However, manual operation is susceptible to variations in personnel skills and experience, as well as site conditions, leading to sampling errors and impacting data accuracy.

[0007] 3. The sample preservation environment has stringent requirements and carries a high risk of distortion.

[0008] VOC samples are extremely sensitive to storage conditions and must be transported and stored in a low-temperature, light-protected, and sealed environment to prevent volatilization, degradation, or chemical reactions. In actual monitoring, due to limitations in field conditions or transportation time, samples may be exposed to high temperatures, light, or vibration, leading to changes in VOC concentrations and even false positive or false negative results.

[0009] 4. High monitoring costs and limited coverage.

[0010] Manual sampling requires significant investment of manpower, resources, and time, especially for large-scale regional monitoring, where costs increase substantially. Furthermore, resource constraints limit the density of sampling points, making full coverage difficult and potentially leading to missed detections or misjudgments of pollution trends.

[0011] To address the aforementioned technical issues, this invention provides an in-situ online monitoring system and method for VOCs in groundwater. Summary of the Invention

[0012] The purpose of this invention is to provide an in-situ online monitoring system and method for groundwater VOCs to solve the problems existing in the prior art.

[0013] To achieve the above objectives, the present invention provides the following solution: The present invention provides an in-situ online monitoring system for VOCs in groundwater, comprising:

[0014] A workbench, wherein a movable component is mounted on the bottom of the workbench;

[0015] A first conveying mechanism is installed on the top of the workbench and is used to convey headspace bottles.

[0016] A rotating assembly is installed at the middle position of the first conveying mechanism, and the rotating assembly is used to switch headspace bottles;

[0017] The second conveying mechanism includes a conveying component and a flipping and positioning component. The conveying component is mounted on the worktable, and the flipping and positioning component is mounted at the end of the conveying component.

[0018] A collection mechanism is installed on the top of the workbench and is used to collect groundwater.

[0019] A filling mechanism is installed on the top of the workbench and is disposed between the flipping positioning component and the rotating component. The filling mechanism is used to inject the collected groundwater into the headspace bottle.

[0020] A capping assembly is mounted on the top surface of the workbench, and the conveying assembly and the capping assembly are arranged sequentially along the rotation direction of the wheel assembly;

[0021] A detection system is connected in series at the end of the first conveying mechanism.

[0022] According to the groundwater VOC in-situ online monitoring system provided by the present invention, the first conveying mechanism includes a first conveyor belt, which is installed on the top surface of the workbench. A first baffle and a second baffle are fixed on both sides of the first conveyor belt, and through slots are respectively opened at the middle positions of the first baffle and the second baffle. The through slots are correspondingly arranged with the rotating assembly.

[0023] According to the groundwater VOC in-situ online monitoring system provided by the present invention, the rotating assembly includes an arc-shaped plate fixedly connected to the top surface of the workbench. A rotating disk is rotatably connected to the top surface of the arc-shaped plate. The rotating disk is correspondingly arranged with a through groove on the first baffle and a through groove on the second baffle. A gap is provided between the two sides of the same groove on the second baffle and the outer side of the rotating disk. A third baffle is fixedly connected to the top surface of the arc-shaped plate. The third baffle has an arc-shaped structure and is coaxially arranged with the rotating disk. A gap is provided between the third baffle and the rotating disk. A plurality of arc-shaped grooves are axially evenly spaced on the outer wall of the rotating disk. The arc-shaped grooves are correspondingly arranged with the headspace bottle. A driving assembly is installed at the bottom of the workbench, and the driving assembly is in transmission cooperation with the rotating disk.

[0024] According to the groundwater VOC in-situ online monitoring system provided by the present invention, the drive assembly includes a drive motor and a gearbox. The drive motor and the gearbox are both fixed to the bottom of the workbench. The output shaft of the drive motor is connected to the input shaft of the gearbox. An installation shaft is fixedly connected to the center of the turntable. The installation shaft passes through the workbench. The output shaft of the gearbox is connected to the installation shaft.

[0025] According to the groundwater VOC in-situ online monitoring system provided by the present invention, the collection mechanism includes a collection box, which is fixed on the top of the workbench. A delivery pipe is installed on one side of the collection box and is connected to the filling mechanism. A switching box is installed on one side of the collection box. Two sets of collection pipes are installed on the side of the switching box away from the collection box. A filter screen is installed inside the collection pipe. Two sets of water inlets are opened on the side wall of the switching box. Both sets of water inlets are connected to the collection box and are respectively arranged in correspondence with the collection pipes. A switching component is installed inside the switching box.

[0026] The switching assembly includes a cylinder that is horizontally fixed to the top of the switching box. A slot is provided on the side of the switching box. A switching plate is slidably connected in the slot. A set of switching holes is provided on the switching plate. The switching holes are corresponding to the acquisition tube located near the slot opening.

[0027] The collection box is equipped with a backwash assembly, which includes a backwash water tank and a backwash pump. The backwash pump is installed at the outlet of the backwash water tank, and two sets of backwash pipes are installed at the output end of the backwash pump. The two sets of backwash pipes are respectively connected to the side walls of the two sets of collection pipes.

[0028] A water collection pump is installed on the delivery pipe.

[0029] According to the groundwater VOC in-situ online monitoring system provided by the present invention, the filling mechanism includes a support frame fixedly connected to the top of the workbench, a first electrically controlled telescopic rod fixedly connected vertically to the support frame, an injection joint fixedly connected to the bottom of the first electrically controlled telescopic rod, and the injection joint being connected to the delivery pipe.

[0030] According to the groundwater VOC in-situ online monitoring system provided by the present invention, the conveying assembly includes a second conveyor belt, which is fixed to the top surface of the workbench. One end of the conveyor belt passes through the support frame, and one end of the second conveyor belt is located above the turntable.

[0031] According to the groundwater VOC in-situ online monitoring system provided by the present invention, the flipping positioning component includes a hydraulic lifter symmetrically and vertically fixedly connected to the top surface of the workbench. A clamping plate is fixedly connected to the top of the hydraulic lifter. The two clamping plates are arranged opposite each other. An installation platform is rotatably connected between the top of the two clamping plates. A flipping motor is fixedly connected to the clamping plate. The flipping motor is fixedly connected to the installation platform. A sliding plate is symmetrically slidably connected to the bottom of the installation platform. Positioning blocks are respectively provided on the opposite surfaces of the two sliding plates. A through groove is opened at the center of the installation platform. An electrically controlled push rod is fixedly connected to the top surface of the installation platform. The electrically controlled push rod is fixedly connected to the sliding plate respectively.

[0032] The slide plate is located above the second conveyor belt and is spaced apart from the second conveyor belt;

[0033] The support frame is provided with a clearance groove, which is corresponding to the second conveyor belt. Installation grooves are provided on both sides of the clearance groove. A flap is rotatably connected in the installation groove through a rotating shaft, and a torsion spring is installed on the rotating shaft.

[0034] According to the groundwater VOC in-situ online monitoring system provided by the present invention, the capping assembly includes a mounting frame fixedly connected to the top surface of the workbench, a capping motor fixedly connected to the mounting frame, a second electrically controlled telescopic rod fixedly connected to the bottom end of the capping motor, and a tightening head fixedly connected to the bottom end of the second electrically controlled telescopic rod.

[0035] A method for in-situ online monitoring of VOCs in groundwater includes the following steps:

[0036] Step 1: Move the device to the designated position using the moving component and fix the worktable;

[0037] Step 2: The headspace bottle is transported by the first conveying mechanism, and after being transported to the rotating assembly, it is transferred to the bottom of the filling mechanism. The filling mechanism is connected to the water pump in the collection well, and the collected groundwater is injected into the headspace bottle through the filling mechanism until the water level in the headspace bottle reaches the preset height.

[0038] Step 3: The bottle cap is conveyed to the flipping and positioning component via the conveying component, and the position and orientation of the bottle cap are adjusted by the flipping and positioning component.

[0039] Step 4: The flipping positioning component releases the bottle cap, and the conveying component continues to convey the bottle cap until it reaches the top of the headspace bottle. The filling mechanism then pushes the bottle cap to engage with the headspace bottle.

[0040] Step 5: The rotating mechanism rotates the headspace bottles, replaces the headspace bottles with caps, and tightens the caps using the capping assembly to complete the water sample collection.

[0041] Step 6: The collected samples are tested using a GC-MS, GC-FID, or GC-MSD equipped with an automatic headspace sampler. The headspace bottle containing the water sample is delivered to the sample slot of the automatic headspace sampler through the delivery assembly. The headspace, sample injection, and testing process is carried out according to the preset program. Finally, the test data are summarized and archived.

[0042] The present invention discloses the following technical effects:

[0043] 1) This invention realizes an automated and continuous monitoring process, greatly improving monitoring efficiency. The system can automatically complete steps such as headspace bottle delivery, groundwater collection and injection, headspace bottle flipping and positioning, and capping and sealing, reducing manual intervention and waiting time.

[0044] 2) The system ensures consistent groundwater sample volume in each headspace via precise flow control, injection time setting, and capping operation, improving monitoring accuracy. Furthermore, the system can be equipped with temperature and pressure sensors to monitor and record environmental conditions in real time, further guaranteeing the reliability of the monitoring results.

[0045] 3) The design of the mobile components allows the system to move flexibly between different monitoring points, adapting to the wide range of groundwater monitoring needs. Whether it is urban groundwater monitoring, industrial pollution monitoring, or agricultural irrigation water quality monitoring, the system can be quickly deployed and put into use.

[0046] 4) The system can be equipped with a remote monitoring module and a data management system to achieve real-time transmission, storage, and analysis of monitoring data. Users can view monitoring results anytime via mobile phones, computers, and other terminal devices, enabling timely detection and handling of potential water quality problems.

[0047] 5) This invention helps to promptly detect and address groundwater pollution problems, protecting water resources and the environment. At the same time, the system's automated and continuous monitoring methods reduce the cost and time of manual sampling and analysis, promoting the sustainable development of environmental protection. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the structure of the groundwater VOC in-situ online monitoring system of the present invention. Figure I ;

[0050] Figure 2 This is a schematic diagram of the structure of the groundwater VOC in-situ online monitoring system of the present invention. Figure II ;

[0051] Figure 3 This is a schematic diagram of the structure of the groundwater VOC in-situ online monitoring system of the present invention. Figure III ;

[0052] Figure 4 for Figure 1 Enlarged view of point A in the middle;

[0053] Figure 5 for Figure 2 Enlarged view of point B in the middle;

[0054] Figure 6 This is a schematic diagram of the data acquisition mechanism of the present invention;

[0055] Figure 7 This is a flowchart of the in-situ online monitoring method for VOCs in groundwater according to the present invention.

[0056] The components are as follows: 1. Workbench; 2. First conveyor belt; 3. First baffle; 4. Second baffle; 5. Arc plate; 6. Rotary disc; 7. Third baffle; 8. Drive motor; 9. Gearbox; 10. Support frame; 11. First electrically controlled telescopic rod; 12. Injection joint; 13. Second conveyor belt; 14. Hydraulic lifter; 15. Clamping plate; 16. Mounting platform; 17. Tilting motor; 18. Slide plate; 19. Positioning block; 20. Through groove; 21. Clearance groove; 22. Mounting frame; 23. Cover motor; 24. Second electrically controlled telescopic rod; 25. Collection box; 26. Conveying pipe; 27. Switching box; 28. Collection pipe; 29. ​​Cylinder; 30. Switching plate; 31. Backflush pump; 32. Backflush pipe. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0059] Reference Figure 1-7 This invention provides an in-situ online monitoring system for VOCs in groundwater, comprising:

[0060] Workbench 1, with a movable component installed at the bottom of workbench 1;

[0061] The first conveying mechanism is installed on the top of the workbench 1 and is used to convey headspace bottles.

[0062] A rotating assembly is installed in the middle of the first conveying mechanism and is used to switch headspace bottles.

[0063] The second conveying mechanism includes a conveying component and a tilting and positioning component. The conveying component is mounted on the worktable 1, and the tilting and positioning component is mounted on the end of the conveying component.

[0064] The collection mechanism is installed on the top of the workbench 1 and is used to collect groundwater.

[0065] A filling mechanism is installed on top of the workbench 1 and is located between the flip positioning component and the rotating component. The filling mechanism is used to inject the collected groundwater into the headspace bottle.

[0066] A capping assembly is installed on the top surface of the workbench 1. The conveying assembly and the capping assembly are arranged sequentially along the rotation direction of the wheel assembly.

[0067] The detection system is connected in series at the end of the first conveying mechanism.

[0068] In operation, the entire system is first moved to the predetermined monitoring position by a moving component at the bottom of the workbench 1. The moving component may be an electric wheel, track, or other suitable mobile device to ensure the system can move flexibly between different monitoring points. Once at the monitoring point, the system enters standby mode, ready to begin the monitoring process. The first conveying mechanism is activated, transporting empty headspace vials from the storage area to the rotating assembly. The rotating assembly receives the headspace vials and prepares to send them into the subsequent collection process. The filling mechanism is activated, collecting samples from groundwater using a pump or suction tube. The collected groundwater samples are injected into the headspace vials on the rotating assembly. By controlling the flow rate and injection time, the sample volume in each headspace vial is ensured to be consistent. The cap is positioned by a flipping positioning component to ensure it aligns with the headspace vial. The conveying component continues to transport the cap until it reaches the top of the headspace vial, at which point the filling mechanism pushes the cap to engage with the headspace vial. The rotating mechanism rotates the headspace vials, replacing the vials with the caps, and the capping component tightens the caps, completing the water sample collection. The sealed headspace bottles are then transported back to the storage area or sent to subsequent analysis equipment. The system repeats these steps according to a preset monitoring cycle and frequency to achieve continuous, online monitoring of groundwater.

[0069] Further optimization of the scheme: the first conveying mechanism includes a first conveyor belt 2, which is installed on the top surface of the workbench 1. A first baffle 3 and a second baffle 4 are fixed on both sides of the first conveyor belt 2, respectively. A through groove 20 is opened in the middle position of the first baffle 3 and the middle position of the second baffle 4, respectively. The through groove 20 is set in correspondence with the wheel assembly.

[0070] The first conveyor belt 2 is installed on the top surface of the workbench 1 for horizontal transport of headspace bottles. The conveyor belt is typically made of durable materials, such as rubber or plastic, to withstand long-term, high-frequency use.

[0071] The first baffle 3 is fixed to one side of the first conveyor belt 2 to prevent headspace bottles from slipping or shifting during the conveying process.

[0072] The second baffle 4 is fixed on the other side of the first conveyor belt 2, and is also used for positioning the headspace bottle and preventing it from shifting.

[0073] The channels 20 are respectively opened in the middle of the first baffle 3 and the second baffle 4, corresponding to the rotating assembly. These channels 20 allow the headspace bottles to pass smoothly during the conveying process and be accurately received by the rotating assembly.

[0074] When the first conveyor belt 2 starts, it moves horizontally along a predetermined path. The headspace bottle is placed on the conveyor belt and moves forward under the drive of the conveyor belt.

[0075] The first baffle 3 and the second baffle 4 ensure that the headspace bottle maintains a stable position during the transport process, preventing it from slipping or shifting due to bumps or external forces.

[0076] When the headspace bottles move to the position corresponding to the rotating assembly, they will pass through the through slots 20 on the first baffle 3 and the second baffle 4.

[0077] The rotating assembly then accurately picks up the headspace bottle from the conveyor belt and sends it into the subsequent collection or processing flow.

[0078] With this design, the first conveying mechanism can continuously and stably convey headspace bottles, ensuring the efficient operation of the system.

[0079] The combined use of baffles and channels 20 not only ensures the stability of headspace bottles during the conveying process, but also facilitates docking with rotating components, thereby improving the automation and reliability of the entire system.

[0080] Further optimization of the scheme: the rotary assembly includes an arc-shaped plate 5 fixedly connected to the top surface of the workbench 1. A rotary disk 6 is rotatably connected to the top surface of the arc-shaped plate 5. The rotary disk 6 is correspondingly arranged with the through groove 20 on the first baffle 3 and the through groove 20 on the second baffle 4. There is a gap between the two sides of the same groove on the second baffle 4 and the outer side of the rotary disk 6. A third baffle 7 is fixedly connected to the top surface of the arc-shaped plate 5. The third baffle 7 has an arc-shaped structure and is coaxially arranged with the rotary disk 6. There is a gap between the third baffle 7 and the rotary disk 6. Several arc-shaped grooves are axially evenly spaced on the outer wall of the rotary disk 6. The arc-shaped grooves are correspondingly arranged with the headspace bottles. A drive assembly is installed at the bottom of the workbench 1. The drive assembly is in transmission cooperation with the rotary disk 6.

[0081] When the first conveying mechanism delivers the headspace bottle to the corresponding position on the rotary table 6, the headspace bottle is accurately transferred to the arc-shaped groove of the rotary table 6 through the through grooves 20 on the first baffle 3 and the second baffle 4.

[0082] The arc-shaped groove design ensures the stable positioning of the headspace bottle on the rotary table 6, preventing it from slipping or shifting even during rotation.

[0083] The drive assembly starts, transmitting power to the turntable 6 via the transmission mechanism, causing it to begin rotating.

[0084] The rotary disk 6 rotates around its axis, causing the headspace bottle placed in the arc-shaped groove to move together.

[0085] The presence of the third baffle 7 restricts the radial movement of the headspace bottle, ensuring its stability during rotation.

[0086] As the rotary table 6 rotates, the headspace bottles are sequentially conveyed to different workstations;

[0087] At each workstation, headspace bottles can be accurately docked and processed, enabling an automated and continuous monitoring process.

[0088] The design of the rotating assembly allows headspace bottles to be continuously and stably transported and processed on the rotating disk 6, improving the overall operating efficiency of the system.

[0089] By adjusting the speed of the drive components and the rotation direction of the turntable 6, different monitoring needs and scenarios can be flexibly adapted.

[0090] The scheme is further optimized. The drive components include a drive motor 8 and a gearbox 9. Both the drive motor 8 and the gearbox 9 are fixed at the bottom of the worktable 1. The output shaft of the drive motor 8 is connected to the input shaft of the gearbox 9. A mounting shaft is fixedly connected to the center of the turntable 6. The mounting shaft passes through the worktable 1. The output shaft of the gearbox 9 is connected to the mounting shaft.

[0091] The scheme is further optimized. The collection mechanism includes a collection box 25, which is fixed on the top of the workbench 1. A conveying pipe 26 is installed on one side of the collection box 25 and is connected to the filling mechanism. A switching box 27 is installed on one side of the collection box 25. Two sets of collection pipes 28 are installed on the side of the switching box 27 away from the collection box 25. A filter screen is installed inside the collection pipe 28. Two sets of water inlets are opened on the side wall of the switching box 27. Both sets of water inlets are connected to the collection box 25 and are respectively set to correspond one-to-one with the collection pipes 28. A switching component is installed inside the switching box 27.

[0092] The switching assembly includes a cylinder 29 that is horizontally fixed to the top of the switching box 27. A slot is provided on the side of the switching box 27. A switching plate 30 is slidably connected in the slot. A set of switching holes is provided on the switching plate 30. The switching holes are corresponding to the acquisition tube 28 located near the slot opening.

[0093] The collection box 25 is equipped with a backwash assembly, which includes a backwash water tank and a backwash pump 31. The backwash pump 31 is installed at the outlet of the backwash water tank. Two sets of backwash pipes 32 are installed at the output end of the backwash pump 31. The two sets of backwash pipes 32 are respectively connected to the side walls of the two sets of collection pipes 28.

[0094] A water collection pump is installed on the delivery pipe 26.

[0095] Two sampling pipelines are used. While one pipeline is sampling, the other is backflushing and cleaning to avoid false positives in subsequent samples due to pollutants remaining in the sampling system when the groundwater is heavily polluted.

[0096] The scheme is further optimized. The filling mechanism includes a support frame 10 fixedly connected to the top of the workbench 1. A first electrically controlled telescopic rod 11 is vertically fixedly connected to the support frame 10. A filling connector 12 is fixedly connected to the bottom of the first electrically controlled telescopic rod 11. The filling connector 12 is connected to the delivery pipe 26.

[0097] The scheme is further optimized. The conveying component includes a second conveyor belt 13, which is fixed to the top surface of the workbench 1. One end of the conveyor belt passes through the support frame 10, and one end of the second conveyor belt 13 is located above the turntable 6.

[0098] The scheme is further optimized. The flipping and positioning component includes a hydraulic lifter 14 that is symmetrically and vertically fixedly connected to the top surface of the workbench 1. The top of the hydraulic lifter 14 is fixedly connected to a clamping plate 15. The two clamping plates 15 are arranged opposite each other. The top of the two clamping plates 15 is rotatably connected to a mounting platform 16. A flipping motor 17 is fixedly connected to the clamping plate 15. The flipping motor 17 is fixedly connected to the mounting platform 16. The bottom of the mounting platform 16 is symmetrically slidably connected to a sliding plate 18. Positioning blocks 19 are respectively provided on the opposite surfaces of the two sliding plates 18. A through groove 20 is opened at the center of the mounting platform 16. An electric control push rod is fixedly connected to the top surface of the mounting platform 16. The electric control push rod is fixedly connected to the sliding plate 18 respectively.

[0099] The slide plate 18 is located above the second conveyor belt 13 and is spaced apart from the second conveyor belt 13;

[0100] The support frame 10 is provided with a clearance groove 21, which is correspondingly set with the second conveyor belt 13. The clearance groove 21 is provided with mounting grooves on both sides. A flap is rotatably connected in the mounting groove through a rotating shaft, and a torsion spring is installed on the rotating shaft.

[0101] The second conveyor belt 13 transports the headspace bottle cap to the underside of the tilting and positioning assembly. When the headspace bottle reaches the predetermined position, the hydraulic lifter 14 drives the clamping plate 15 to descend, bringing the mounting platform 16 closer to the headspace bottle cap. An electrically controlled push rod drives the sliding plate 18 to slide, causing the positioning block 19 to clamp the headspace bottle cap. The positioning block 19 ensures the headspace bottle cap remains in a stable position on the mounting platform 16. The tilting motor 17 starts, driving the mounting platform 16 to rotate. The mounting platform 16 tilts the headspace bottle together to the desired position. After tilting, the electrically controlled push rod drives the sliding plate 18 to retract, releasing the headspace bottle cap. The hydraulic lifter 14 drives the clamping plate 15 to rise, moving the mounting platform 16 away from the headspace bottle cap. The headspace bottle cap continues to be conveyed through the clearance slot 21, where the tilting plate may provide additional support or guidance as the headspace bottle passes, before returning to its initial position (due to the action of the torsion spring). The entire tilting and positioning process is automatic and controlled by the control system. The coordinated operation of the hydraulic lifter 14, the electrically controlled push rod, and the tilting motor 17 ensures the accurate tilting and positioning of the headspace bottle cap.

[0102] Further optimization of the scheme: the capping assembly includes a mounting bracket 22 fixedly connected to the top surface of the workbench 1, a capping motor 23 fixedly connected to the mounting bracket 22, a second electrically controlled telescopic rod 24 fixedly connected to the bottom end of the capping motor 23, and a tightening head fixedly connected to the bottom end of the second electrically controlled telescopic rod 24.

[0103] A method for in-situ online monitoring of VOCs in groundwater includes the following steps:

[0104] Step 1: Move the device to the designated position using the moving component and fix the worktable 1;

[0105] Step 2: The headspace bottle is transported by the first conveying mechanism, and after being transported to the rotating assembly, it is transferred to the bottom of the filling mechanism. The filling mechanism is connected to the water pump in the collection well, and the collected groundwater is injected into the headspace bottle through the filling mechanism until the water level in the headspace bottle reaches the preset height.

[0106] Step 3: The bottle cap is conveyed to the flipping and positioning component via the conveying component, and the position and orientation of the bottle cap are adjusted by the flipping and positioning component.

[0107] Step 4: The flipping positioning component releases the bottle cap, and the conveying component continues to convey the bottle cap until it reaches the top of the headspace bottle. The filling mechanism then pushes the bottle cap to engage with the headspace bottle.

[0108] Step 5: The rotating mechanism rotates the headspace bottles, replaces the headspace bottles with caps, and tightens the caps using the capping assembly to complete the water sample collection.

[0109] Step 6: The collected samples are tested using a GC-MS, GC-FID, or GC-MSD equipped with an automatic headspace sampler. The headspace bottle containing the water sample is delivered to the sample slot of the automatic headspace sampler through the delivery assembly. The headspace, sample injection, and testing process is carried out according to the preset program. Finally, the test data are summarized and archived.

[0110] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0111] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A groundwater VOC in-situ online monitoring system, characterized in that, include: Workbench (1), with a movable component installed at the bottom of the workbench (1); A first conveying mechanism is installed on the top of the workbench (1) and is used to convey headspace bottles. A rotating assembly is installed at the middle position of the first conveying mechanism, and the rotating assembly is used to switch headspace bottles; The second conveying mechanism includes a conveying component and a flipping positioning component. The conveying component is installed on the worktable (1), and the flipping positioning component is installed at the end of the conveying component. A collection mechanism is installed on the top of the workbench (1) and is used to collect groundwater. A filling mechanism is installed on the top of the workbench (1) and is located between the flip positioning component and the rotating component. The filling mechanism is used to inject the collected groundwater into the headspace bottle. A capping assembly is installed on the top surface of the workbench (1), and the conveying assembly and the capping assembly are arranged sequentially along the rotation direction of the wheel assembly; A detection system is connected in series at the end of the first conveying mechanism; The first conveying mechanism includes a first conveyor belt (2), which is installed on the top surface of the workbench (1). A first baffle (3) and a second baffle (4) are fixed on both sides of the first conveyor belt (2). A through groove (20) is opened in the middle of the first baffle (3) and the middle of the second baffle (4). The through groove (20) is correspondingly arranged with the wheel assembly. The rotating assembly includes an arc-shaped plate (5) fixedly connected to the top surface of the workbench (1). A rotating disk (6) is rotatably connected to the top surface of the arc-shaped plate (5). The rotating disk (6) is correspondingly arranged with the through groove (20) on the first baffle (3) and the through groove (20) on the second baffle (4). There is a gap between the two sides of the same groove on the second baffle (4) and the outer side of the rotating disk (6). A third baffle (7) is fixedly connected to the top surface of the arc-shaped plate (5). The third baffle (7) has an arc structure. The third baffle (7) is coaxially arranged with the rotating disk (6). There is a gap between the third baffle (7) and the rotating disk (6). Several arc-shaped grooves are axially and evenly spaced on the outer wall of the rotating disk (6). The arc-shaped grooves are correspondingly arranged with the headspace bottle. A driving assembly is installed at the bottom of the workbench (1). The driving assembly is in transmission cooperation with the rotating disk (6). The drive assembly includes a drive motor (8) and a transmission (9). Both the drive motor (8) and the transmission (9) are fixed to the bottom of the worktable (1). The output shaft of the drive motor (8) is connected to the input shaft of the transmission (9). A mounting shaft is fixedly connected to the center of the turntable (6). The mounting shaft passes through the worktable (1). The output shaft of the transmission (9) is connected to the mounting shaft. The collection mechanism includes a collection box (25), which is fixed on the top of the workbench (1). A conveying pipe (26) is installed on one side of the collection box (25), and the conveying pipe (26) is connected to the filling mechanism. A switching box (27) is installed on one side of the collection box (25). Two sets of collection pipes (28) are installed on the side of the switching box (27) away from the collection box (25). A filter screen is installed inside the collection pipe (28). Two sets of water inlets are opened on the side wall of the switching box (27). Both sets of water inlets are connected to the collection box (25) and are respectively set to correspond one-to-one with the collection pipes (28). A switching component is installed inside the switching box (27). The switching assembly includes a cylinder (29) that is horizontally fixed to the top of the switching box (27). The side of the switching box (27) has a slot, and a switching plate (30) is slidably connected in the slot. A set of switching holes is provided on the switching plate (30), and the switching holes are corresponding to the acquisition tube (28) near the slot opening. The collection box (25) is equipped with a backwash assembly, which includes a backwash water tank and a backwash pump (31). The backwash pump (31) is installed at the outlet of the backwash water tank. The output end of the backwash pump (31) is equipped with two sets of backwash pipes (32). The two sets of backwash pipes (32) are respectively connected to the side walls of the two sets of collection pipes (28). A water collection pump is installed on the delivery pipe (26); The filling mechanism includes a support frame (10) fixedly connected to the top of the workbench (1), a first electrically controlled telescopic rod (11) is vertically fixedly connected to the support frame (10), a filling connector (12) is fixedly connected to the bottom of the first electrically controlled telescopic rod (11), and the filling connector (12) is connected to the delivery pipe (26). The conveying assembly includes a second conveyor belt (13), which is fixed to the top surface of the workbench (1). One end of the conveyor belt passes through the support frame (10), and one end of the second conveyor belt (13) is located above the turntable (6). The flipping positioning assembly includes a hydraulic lifter (14) symmetrically and vertically fixedly connected to the top surface of the workbench (1). A clamping plate (15) is fixedly connected to the top of the hydraulic lifter (14). The two clamping plates (15) are arranged opposite each other. A mounting platform (16) is rotatably connected between the top of the two clamping plates (15). A flipping motor (17) is fixedly connected to the clamping plate (15). The flipping motor (17) is fixedly connected to the mounting platform (16). A sliding plate (18) is symmetrically slidably connected to the bottom of the mounting platform (16). Positioning blocks (19) are respectively provided on the opposite surfaces of the two sliding plates (18). A through groove (20) is opened at the center of the mounting platform (16). An electric control push rod is fixedly connected to the top surface of the mounting platform (16). The electric control push rod is fixedly connected to the sliding plate (18) respectively. The slide plate (18) is located above the second conveyor belt (13) and is spaced apart from the second conveyor belt (13); The support frame (10) is provided with a clearance groove (21), which is correspondingly provided with the second conveyor belt (13). Installation grooves are provided on both sides of the clearance groove (21). A flap is rotatably connected in the installation groove through a rotating shaft, and a torsion spring is installed on the rotating shaft.

2. The groundwater VOC in-situ online monitoring system according to claim 1, characterized in that: The capping assembly includes a mounting bracket (22) fixedly connected to the top surface of the workbench (1), a capping motor (23) fixedly connected to the mounting bracket (22), a second electrically controlled telescopic rod (24) fixedly connected to the bottom end of the capping motor (23), and a tightening head fixedly connected to the bottom end of the second electrically controlled telescopic rod (24).

3. A method for in-situ online monitoring of VOCs in groundwater, based on the in-situ online monitoring system for VOCs in groundwater according to any one of claims 1-2, characterized in that, Includes the following steps: Step 1: Move the device to the designated position by moving the component and fix the worktable (1); Step 2: The headspace bottle is transported by the first conveying mechanism, and after being transported to the rotating assembly, it is transferred to the bottom of the filling mechanism. The filling mechanism is connected to the water pump in the collection well, and the collected groundwater is injected into the headspace bottle through the filling mechanism until the water level in the headspace bottle reaches the preset height. Step 3: The bottle cap is conveyed to the flipping and positioning component via the conveying component, and the position and orientation of the bottle cap are adjusted by the flipping and positioning component. Step 4: The flipping positioning component releases the bottle cap, and the conveying component continues to convey the bottle cap until it reaches the top of the headspace bottle. The filling mechanism then pushes the bottle cap to engage with the headspace bottle. Step 5: The rotating mechanism rotates the headspace bottles, replaces the headspace bottles with caps, and tightens the caps using the capping assembly to complete the water sample collection. Step 6: The collected samples are tested using a GC-MS, GC-FID, or GC-MSD equipped with an automatic headspace sampler. The headspace bottle containing the water sample is delivered to the sample slot of the automatic headspace sampler through the delivery assembly. The headspace, sample injection, and testing process is carried out according to the preset program. Finally, the test data are summarized and archived.

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