Fractional atmosphere mercury monitoring equipment

Abstract

The invention relates to the technical field of environment detection, and provides morphological atmospheric mercury monitoring equipment, which comprises a calibration device and a dual-channel morphological mercury measuring device, and is characterized in that an outlet of a zero gas preparation assembly in the calibration device is connected to a first main gas carrying pipeline, and the zero gas preparation assembly is used for preparing atmosphere into zero air; the gaseous mercuric oxide generation assembly is used for preparing gaseous mercuric oxide with target concentration and adding the gaseous mercuric oxide to zero air; the gaseous elemental mercury generation assembly is used for preparing gaseous elemental mercury and supplementing the gaseous elemental mercury to zero air; the interference assembly is used for adding interference gas into zero air and adjusting the humidity of the zero air; and the dual-channel fractional mercury measuring device is connected with a total outlet of the second main gas carrying pipeline and is used for capturing and analyzing gaseous mercury oxide contained in calibration gas generated by the calibration device. According to the invention, various conditions in an actual atmospheric environment can be simulated, so that the reliability of the dual-channel morphological mercury measuring device in actual monitoring is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental detection, and in particular to a form-fractionated atmospheric mercury monitoring device. Background Art

[0002] Mercury is a global pollutant that poses a significant threat to the ecological environment and human health. Mercury exists in the atmosphere primarily in three forms: gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate mercury (PBM). GEM, chemically stable and capable of long-distance transport, is the primary component of atmospheric mercury. GOM and PBM are present in relatively low concentrations in the atmosphere, but their chemical properties are relatively active, allowing them to rapidly settle to the surface through dry and wet deposition. There, they are further converted into highly toxic methylmercury, posing a serious threat to ecological security and human health.

[0003] Currently, simultaneous online observation systems for the three forms of mercury in the atmosphere primarily employ a form-by-form separation method: GOM is captured using a dissolution tube, PBM is captured using a quartz filter, and the remainder is considered GEM. The specific measurement process is as follows: While sampling GOM and PBM, GEM continuously flows through the mercury analyzer for real-time measurement. After GOM and PBM accumulate for a certain period of time, sampling is stopped. The captured GOM and PBM are converted to GEM by heating the dissolution tube and then the quartz filter, respectively. The GEM and PBM are then purged with zero gas into the mercury analyzer, where the concentrations of GOM and PBM are measured.

[0004] While the above method can measure the concentrations of GOM and PBM, it only ensures the accuracy of GEM measurements and cannot verify the reliability of the sampling process. It wasn't until 2010 that a study discovered that under laboratory conditions (using zero gas as the carrier gas), the dissolution tube can almost completely capture GOM. However, when ozone and water vapor are added to the carrier gas (simulating actual atmospheric conditions), the capture efficiency of the dissolution tube drops significantly, resulting in inaccurate GOM measurements. This study demonstrates that traditional methods have significant limitations in actual ambient air monitoring and cannot meet the requirements for accurate monitoring of mercury species.

[0005] To address these issues, researchers proposed a dual-channel subtraction method for atmospheric mercury detection based on a cation exchange membrane (CEM). By introducing a second CEM channel, GOM and PBM are completely intercepted, thereby improving the accuracy and reliability of GEM measurements. By calculating the difference between the GEM measurement value from the first channel (GEM+) and the GEM measurement value from the second channel (GEM), the underestimation of GOM by the corrosion tube is obtained and added to the GEM measurement value, resulting in a more accurate GOM concentration.

[0006] The feasibility of the above system has been theoretically confirmed. However, when the dual-channel subtraction method using a cation exchange membrane (CEM) is applied to atmospheric mercury detection under actual atmospheric sampling conditions, the potential impact of different sampling conditions (such as atmospheric environmental changes, different sampling flow settings, sampling pressure differences caused by gas path resistance, and the impact of switching between the first and second channels) on the measurement results is unclear. This makes it impossible to verify the reliability of the sampling process, leading to doubts about the reliability of the system in practical applications and significantly limiting its dissemination. Summary of the Invention

[0007] The present invention provides a form-specific atmospheric mercury monitoring device to address the above-mentioned technical defects in the prior art. It can simulate various conditions in the actual atmospheric environment, including the presence of mercury forms of different concentrations and interfering gases, so as to improve the reliability of the dual-channel form-specific mercury measurement device in actual monitoring, better adapt to complex atmospheric environments, and maintain stable measurement performance during long-term operation.

[0008] The present invention provides a form-specific atmospheric mercury monitoring device, comprising: Calibration device, comprising: a first main carrier gas pipeline and a second main carrier gas pipeline; a zero air preparation component, the outlet of which is connected to the first main carrier gas pipeline, and the zero air preparation component is used to prepare zero air from atmospheric air; a gaseous mercury oxide generating assembly connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline, the gaseous mercury oxide generating assembly being used to prepare gaseous mercury oxide of a target concentration and add gaseous mercury oxide to the zero air; a gaseous elemental mercury generating assembly connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline, the gaseous elemental mercury generating assembly being used to prepare gaseous elemental mercury and replenish the gaseous elemental mercury into the zero air; an interference component connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline, the interference component being used to add interference gas to the zero air and adjust the humidity of the zero air; A dual-channel mercury form measurement device is connected to the total outlet of the second main carrier gas pipeline and is used to capture and analyze gaseous mercury oxide contained in the calibration gas generated by the calibration device.

[0009] According to the morphological atmospheric mercury monitoring device provided by the present invention, the zero gas preparation component includes: An air supply pipeline, suitable for connecting to an atmosphere purification device, wherein the air supply pipeline is connected to the inlet of the zero air preparation component; a pump body, provided in the air supply pipeline, for pumping the purified atmosphere to the air supply pipeline; The zero air preparation element is provided in the air supply pipeline and is used to remove mercury and active substances in the atmosphere transmitted by the air supply pipeline to generate zero air.

[0010] According to the morphological atmospheric mercury monitoring device provided by the present invention, the gaseous mercury oxide generating component includes: a first mercury vapor generating element, the inlet of which is connected to the outlet of the first main carrier gas pipeline, and the outlet of which is connected to the inlet of the second main carrier gas pipeline, the first mercury vapor generating element being used to generate mercury oxide vapor; a first mass flow controller, provided on the pipeline between the inlet of the first mercury vapor generating element and the outlet of the first main carrier gas pipeline, for controlling the zero air flow at the inlet end of the first mercury vapor generating element; The first control valve is provided at the outlet end of the first mercury vapor generating element and is used for controlling the outlet of the first mercury vapor generating element to be on or off.

[0011] According to the form-specific atmospheric mercury monitoring equipment provided by the present invention, the gaseous mercury oxide generating component also includes an exhaust gas treatment device, which is arranged in parallel with the first mercury vapor generating element. The exhaust gas treatment device is connected to the first control valve and is used to discharge excess mercury oxide vapor generated by the first mercury vapor generating element and perform exhaust gas treatment.

[0012] According to the morphological atmospheric mercury monitoring device provided by the present invention, the tail gas treatment device includes: an exhaust gas treatment pipeline, the inlet of which is connected to the first control valve and is used to discharge excess mercury oxide vapor generated by the first mercury vapor generating element; An exhaust gas treatment element is connected to the outlet end of the exhaust gas treatment pipeline, and is used to perform exhaust gas treatment on the discharged mercury oxide vapor; The second mass flow controller is provided in the exhaust gas treatment pipeline and is located at the inlet end of the exhaust gas treatment element. The second mass flow controller is used to control the exhaust gas output flow of the exhaust gas treatment pipeline.

[0013] According to the morphological atmospheric mercury monitoring device provided by the present invention, the gaseous elemental mercury generating component includes: a second mercury vapor generating element, the inlet of which is connected to the outlet of the first main carrier gas pipeline, and the outlet of which is connected to the inlet of the second main carrier gas pipeline, the second mercury vapor generating element being configured to evaporate liquid elemental mercury at a preset temperature to generate gaseous elemental mercury; a third mass flow controller, provided on the pipeline between the inlet of the second mercury vapor generating element and the outlet of the first main carrier gas pipeline, for controlling the gas flow at the inlet end of the second mercury vapor generating element; a second control valve, provided at the inlet end of the second mercury vapor generating element, for controlling the inlet of the second mercury vapor generating element to be on or off; The third control valve is provided at the outlet end of the second mercury vapor generating element and is used to control the on-off of the outlet of the second mercury vapor generating element.

[0014] According to the morphological atmospheric mercury monitoring device provided by the present invention, the interference component includes at least one of an ozone generator and a humidity regulating element; The ozone generator is connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline, and a fourth mass flow controller is provided on the pipeline connected to the inlet of the ozone generator. The ozone generator is used to generate interfering gas ozone; The humidity regulating element is connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline. A fifth mass flow controller is provided on the pipeline connected to the inlet of the humidity regulating element. The humidity regulating element is used to regulate humidity.

[0015] According to the morphological atmospheric mercury monitoring device provided by the present invention, the interference component further includes: an interference carrier gas pipeline, one end of which is connected to the outlet of the first main carrier gas pipeline through a fourth control valve, and the other end of the interference carrier gas pipeline is provided with a fifth control valve, the fifth control valve is connected to the pipeline provided with the fourth mass flow controller, and the fifth control valve is connected to the pipeline provided with the fifth mass flow controller; The outlet end of the ozone generator is provided with a sixth control valve, and the outlet end of the humidity regulating element is provided with a seventh control valve.

[0016] The morphological atmospheric mercury monitoring device provided by the present invention further includes: a heating jacket, provided on the second main carrier gas pipeline and located near the dual-channel mercury form measuring device; and / or, The adopting device is arranged at the outlet end of the second main carrier gas pipeline. The adopting device is provided with a funnel-shaped sampling port. An annular gap is provided between the sampling port and the sampling port of the dual-channel mercury form measuring device.

[0017] According to the morphological atmospheric mercury monitoring equipment provided by the present invention, the dual-channel morphological mercury measuring device includes: A gaseous mercury oxide capture and thermal desorption component is used to capture and decompose a portion of the gaseous mercury oxide contained in the ambient atmospheric sample; A gaseous oxidized mercury removal component, used for removing gaseous oxidized mercury contained in an ambient air sample, so as to retain gaseous elemental mercury in the ambient air sample; The atmospheric mercury analyzer based on atomic spectroscopy is used to detect the concentration of mercury in atmospheric samples.

[0018] The morphological atmospheric mercury monitoring device provided by the present invention and the morphological atmospheric mercury monitoring device provided by the embodiment of the present invention establish a full-process calibration system by arranging a calibration device before the dual-channel morphological mercury measuring device, so as to achieve calibration in each link from sampling to analysis, reduce system errors, and improve the accuracy of the measurement results. The zero gas preparation component in the calibration device provides accurate zero air, and the gaseous oxidized mercury generating component, the gaseous elemental mercury generating component, and the interference component can control the composition and concentration of the calibration gas, so that the dual-channel morphological mercury measuring device can more accurately measure the mercury form in the atmosphere. Such a setting can simulate various situations in the actual atmospheric environment, including the presence of mercury forms and interfering gases of different concentrations, so as to improve the reliability of the dual-channel morphological mercury measuring device in actual monitoring, better adapt to complex atmospheric environments, and maintain stable measurement performance in long-term operation, ensure the accuracy of the measurement results, and improve the accuracy and reliability of environmental monitoring data.

[0019] Furthermore, precise control of the calibration gas composition facilitates in-depth research into the chemical transformation processes of atmospheric mercury. For example, the chemical reaction rates and transformation mechanisms of gaseous oxidized mercury and gaseous elemental mercury in the presence of different interfering gases can be studied, providing a scientific basis for the control and management of atmospheric mercury pollution. Furthermore, the full-process calibration system ensures comparability of measurement results across different monitoring sites and time periods. This is of great significance for establishing spatiotemporal distribution models of atmospheric mercury pollution and evaluating the effectiveness of mercury emission reductions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 The invention provides a device for monitoring atmospheric mercury in different forms.

[0022] Figure 2 It is a schematic diagram of an embodiment of a dual-channel mercury form measurement device in a mercury form atmospheric mercury monitoring device provided by an embodiment of the present invention.

[0023] Figure 3 It is a schematic diagram of another embodiment of a dual-channel speciation mercury measurement device in a speciation atmospheric mercury monitoring device provided by an embodiment of the present invention.

[0024] Figure 4This is a schematic diagram of the coordination of the sampling port and the injection port in the form-based atmospheric mercury monitoring device provided by an embodiment of the present invention.

[0025] Figure 5 This is a graph showing the measured concentration and the calibrated concentration of the mercury monitoring device for the atmosphere provided by the embodiment of the present invention.

[0026] Reference numerals: 10. Calibration device; 11. First main carrier gas pipeline; 12. Second main carrier gas pipeline; 13. Zero gas preparation component; 131. Gas supply pipeline; 132. Pump body; 133. Zero gas preparation element; 14. Gaseous mercury oxide generating component; 141. First mercury vapor generating element; 142. First mass flow controller; 143. First control valve; 144. Exhaust gas treatment pipeline; 145. Exhaust gas treatment element; 146. Second mass flow controller; 15. Gaseous elemental mercury generating component; 151. Second Mercury vapor generating element; 152, third mass flow controller; 153, second control valve; 154, third control valve; 16, interference component; 161, ozone generator; 162, humidity adjustment element; 163, fourth mass flow controller; 164, fifth mass flow controller; 165, interference carrier gas line; 166, fourth control valve; 167, fifth control valve; 168, sixth control valve; 169, seventh control valve; 17, heating jacket; 18, sampling device; 181, sampling port; 20. Dual-channel mercury speciation measurement device; 21. First channel; 22. Second channel; 23. Gaseous oxidized mercury capture and thermal desorption component; 24. Gaseous oxidized mercury removal component; 25. Atmospheric mercury analyzer based on atomic spectroscopy; 26. Sampling control device; 27. Switching valve; 28. Inlet valve. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0028] In the description of the embodiments of this application, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on the specific circumstances.

[0029] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0030] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0031] Figure 1 The invention provides a device for monitoring atmospheric mercury in different forms. Figure 2 It is a schematic diagram of an embodiment of a dual-channel mercury form measurement device in a mercury form atmospheric mercury monitoring device provided by an embodiment of the present invention. Figure 3 It is a schematic diagram of another embodiment of a dual-channel speciation mercury measurement device in a speciation atmospheric mercury monitoring device provided by an embodiment of the present invention.

[0032] See Figure 1 Embodiments of the present invention provide a speciation-based atmospheric mercury monitoring device for calibrating environmental monitoring equipment (such as a dual-channel speciation-based mercury measuring device 20) to ensure the accuracy of its detection of gaseous oxidized mercury and gaseous elemental mercury. The device comprises a calibration device 10 and a dual-channel speciation-based mercury measuring device 20. The dual-channel speciation-based mercury measuring device 20 can utilize existing systems for detection. The core of the present invention lies in the placement of the calibration device 10 before the dual-channel speciation-based mercury measuring device 20, establishing a full-process calibration system from sampling to analysis, ensuring the accuracy and reliability of measurement results.

[0033] The calibration device 10 includes a first main carrier gas pipeline 11 , a second main carrier gas pipeline 12 , a zero gas preparation component 13 , a gaseous mercury oxide generating component 14 , a gaseous elemental mercury generating component 15 and an interference component 16 .

[0034] The first main carrier gas pipeline 11 is used for transmitting zero air, and the second main carrier gas pipeline 12 is used for transmitting mixed calibration gas.

[0035] The outlet of the zero air preparation component 13 is connected to the first main carrier gas pipeline 11. The zero air preparation component 13 is used to prepare the atmosphere into zero air. Zero air refers to The same ratio as the atmosphere, without mercury and other pollutants.

[0036] The zero air preparation component 13 can utilize multi-layer filtration and purification technology, including a pump, a filtration module (HEPA filter, activated carbon adsorption layer), and a drying tube. For example, a high-efficiency particulate matter (HEPA) filter is first used to remove dust, particulate matter, and other impurities from the atmosphere. An activated carbon adsorption column is then used to remove volatile organic compounds (VOCs) and some gaseous mercury from the atmosphere. Next, a chemical absorbent, such as a potassium permanganate-sulfuric acid solution, is used to remove sulfur dioxide and other gases that may interfere with mercury measurement. Finally, a dehumidification device, such as a silica gel drying tube, is used to reduce the atmospheric humidity to an appropriate level, thereby preparing zero air.

[0037] The gaseous mercury oxide generating assembly 14 is connected between the outlet of the first main carrier gas pipeline 11 and the inlet of the second main carrier gas pipeline 12 . The gaseous mercury oxide generating assembly 14 is used to prepare gaseous mercury oxide of target concentration and add gaseous mercury oxide to zero air.

[0038] The gaseous mercuric oxide generating assembly 14 can utilize a constant temperature permeation method (maintaining a constant temperature of 5°C in a permeation tube containing mercuric chloride), with the concentration precisely adjusted using a mass flow controller (MFC). For example, the gaseous mercuric oxide generating assembly 14 can consist of a mercury source, a heating device, and a mixing chamber. A quartz glass container with precise liquid level control is used as the mercury storage container to ensure a stable supply of mercury. The heating device utilizes a high-precision temperature controller, which precisely controls the mercury source temperature within a specific range, ensuring stable mercury evaporation. The mass flow controller precisely controls the carrier gas flow rate. The mixing chamber utilizes a special internal structure, such as a spiral mixing channel, to ensure thorough mixing of the gaseous mercuric oxide with zero air, resulting in the target concentration of gaseous mercury oxide.

[0039] The gaseous elemental mercury generating assembly 15 is connected between the outlet of the first main carrier gas pipeline 11 and the inlet of the second main carrier gas pipeline 12 . The gaseous elemental mercury generating assembly 15 is used to prepare gaseous elemental mercury and replenish the gaseous elemental mercury to the zero air.

[0040] The gaseous elemental mercury generator assembly 15 can generate mercury using a mercury permeation tube (which releases mercury vapor at a constant temperature) or a mercury lamp UV excitation method, similar to the configuration of the gaseous mercury oxide generator assembly 14. For example, liquid mercury is contained in a tubular device containing a permeable membrane (such as a quartz glass container), and the evaporation rate of the elemental mercury is regulated by temperature control. A flow control valve and mass flow controller are used to precisely control the output concentration of the elemental mercury.

[0041] In order to prevent condensation and adsorption of elemental mercury, the pipeline of the entire gaseous elemental mercury generating assembly 15 may adopt heating and heat preservation measures, such as winding heating wires and wrapping them with heat-insulating materials such as glass wool.

[0042] The interference component 16 is connected between the outlet of the first main carrier gas pipeline 11 and the inlet of the second main carrier gas pipeline 12 . The interference component 16 is used to add interference gas to the zero air and adjust the humidity of the zero air.

[0043] The interfering gases can come from a variety of sources. For example, to simulate ozone interference in the atmosphere, ozone is produced using an ozone generator 161. This ozone generator 161 can be based on the principle of ultraviolet radiation irradiating oxygen, with ozone production controlled by adjusting the UV intensity and oxygen flow rate. Other interfering gases, such as nitrogen oxides, can be supplied from gas cylinders, with their flow rates precisely regulated using mass flow controllers. The humidity of the zero air can be adjusted to simulate different atmospheric humidity environments.

[0044] The dual-channel mercury form measurement device 20 is connected to the total outlet of the second main carrier gas pipeline 12 and is used to capture and analyze gaseous mercury oxide contained in the calibration gas generated by the calibration device 10.

[0045] See Figure 2 The dual-channel morphological mercury measuring device 20 in the morphological atmospheric mercury monitoring device provided by an embodiment of the present invention may include a first channel 21 and a second channel 22. The first channel 21 and the second channel 22 share a first air inlet through an air inlet valve 28. One of the first channel 21 and the second channel 22 is provided with a first air outlet, and the other is provided with a second air outlet.

[0046] A gaseous mercury oxide capture and thermal desorption assembly 23 is provided on the first channel 21. This assembly is used to capture and desorb a portion of the gaseous mercury oxide contained in the ambient air sample. A gaseous mercury oxide removal assembly 24 is provided on the second channel 22. This assembly is used to remove all gaseous mercury oxide from the ambient air sample, leaving only gaseous elemental mercury in the ambient air sample.

[0047] The atmospheric mercury analyzer 25 based on atomic spectroscopy is used to detect the concentration of mercury contained in an atmospheric sample. The atmospheric mercury analyzer 25 based on atomic spectroscopy includes a high-precision mercury analysis instrument such as an atomic fluorescence spectrometer or a cold atomic absorption spectrometer.

[0048] The cold atomic fluorescence mercury analyzer is used to detect the concentration of mercury in an atmospheric sample. It has a third air inlet and a third air outlet, which are connected to both the first and second air outlets. A switching valve 27 controls the connection between the first and second air outlets and the third air inlet.

[0049] To remove gaseous mercury oxide, the gaseous mercury oxide removal assembly 24 can utilize a filter membrane with sulfonic acid groups on its surface. When calibration gas containing gaseous mercury oxide passes through the filter membrane, the gaseous mercury oxide undergoes ion exchange with the reagent and is immobilized on the filter membrane. After the gaseous mercury oxide is removed, only gaseous elemental mercury remains in the calibration gas. This gaseous elemental mercury in the ambient air sample is detected using high-precision instruments such as atomic fluorescence spectrometers or cold atomic absorption spectrometers.

[0050] To capture gaseous mercury oxide, the gaseous mercury oxide capture and thermal desorption assembly 23 can utilize a quartz tube with a potassium chloride-plated inner wall. When calibration gas containing gaseous mercury oxide passes through the quartz tube, the gaseous mercury oxide undergoes ion exchange with the potassium chloride, becoming fixed to the inner wall. The calibration gas, after mercury oxide capture, contains gaseous elemental mercury and some gaseous mercury oxide, and is analyzed using high-precision instruments such as atomic fluorescence spectrometers or cold atomic absorption spectrometers.

[0051] Thermal desorption is used to desorb the captured gaseous mercury oxide. The quartz tube containing the trapped gaseous mercury oxide is heated. By precisely controlling the temperature and time, the gaseous mercury oxide is desorbed from the inner wall and converted into gaseous elemental mercury. The desorbed mercury is then analyzed using high-precision instruments such as atomic fluorescence spectrometers or cold atomic absorption spectrometers.

[0052] The sampling control device 26 is electrically connected to the gaseous mercury oxide capture and thermal desorption component 23, the gaseous mercury oxide removal component 24, the air inlet valve 28, the atmospheric mercury analyzer based on atomic spectroscopy, and the switching valve 27, thereby realizing automatic control of the sampling procedure and ensuring that each process proceeds in an orderly manner.

[0053] See Figure 3 The dual-channel mercury measurement device 20 in the mercury-in-a-morphology atmospheric mercury monitoring device provided by an embodiment of the present invention may include a first channel 21 and a second channel 22 arranged in parallel, and the first channel 21 and the second channel 22 share an air inlet through an air inlet valve 28.

[0054] A heating jacket or heating tube is provided on the first channel 21 . The outlet of the first channel 21 is connected to an air pump via a switching valve 27 . The air pump is connected to an atmospheric mercury analyzer 25 based on atomic spectroscopy.

[0055] A gaseous mercury oxide removal component 24 is provided on the second channel 22. The gaseous mercury oxide removal component 24 is used to remove all gaseous mercury oxide in the ambient atmosphere sample, so that only gaseous elemental mercury remains in the ambient atmosphere sample. The outlet of the second channel 22 is connected to an air pump through a switching valve 27, and the air pump is connected to an atmospheric mercury analyzer 25 based on atomic spectroscopy.

[0056] The working process of the atmospheric mercury monitoring device provided by the embodiment of the present invention is as follows: During the calibration gas preparation phase, the zero gas preparation component 13 first operates, processing the local atmosphere through multiple layers of processing to create zero air. The gaseous mercury oxide generation component 14 is activated, and the mercury source evaporates under the action of a heating device. The carrier gas channel carries the gaseous mercury oxide and mixes it with the zero air output by the zero gas preparation component 13 in a mixing chamber, producing a gaseous mercury oxide calibration gas with the target concentration. Simultaneously, the gaseous elemental mercury generation component 15 operates to replenish the zero air with gaseous elemental mercury. The interference component 16 adds interfering gases, such as ozone and nitrogen oxides, to the zero air as needed.

[0057] Measurement phase: The capture section of the dual-channel mercury form measurement device 20 begins operation. A mixture of calibration gases (including gaseous mercury oxide, gaseous elemental mercury, and interfering gases) enters its corresponding capture unit. In the first channel 21, the gaseous mercury oxide is heated and converted into gaseous elemental mercury. All converted gaseous elemental mercury is then sent to the detection instrument for detection. In the second channel 22, the gaseous mercury oxide is intercepted by a filter membrane with sulfonic acid groups on its surface, and the remaining gaseous elemental mercury enters the detection instrument for detection. The concentration of gaseous mercury oxide is calculated by subtracting the concentration of gaseous elemental mercury after removing the gaseous mercury oxide from the concentration of the total gaseous mercury (including gaseous mercury oxide and gaseous elemental mercury) in the calibration gas.

[0058] The instrument measurement value is calculated according to formula (1) and formula (2), and the average value of multiple measurements is taken as the final result.

[0059] (1); (2); The true concentration of GOM in the calibration gas is determined by formula (3), and the calibration coefficient (η) under each working condition is determined by formula (4).

[0060] (3); (4); When observing the atmosphere in the field, the calibrated GOM atmospheric concentration GOM under the same working conditions is 大气浓度 Calculated by formula (5).

[0061] (5); Among them, in each of the above formulas, Indicates the total mercury concentration in the calibration gas measured by channel 1. It indicates the remaining GEM concentration after GOM is intercepted by the filter membrane.

[0062] GOM i,测量浓度 represents the i-th measurement result of the same concentration; J GOM is the occurrence rate of GOM, ng min -1 ;GOM j,校准浓度 and GOM j,测量浓度 Indicates the jth calibration and measurement concentration under the same working conditions.

[0063] During the entire calibration process, the dual-channel mercury speciation measurement device 20 is calibrated by comparing the known gaseous mercury oxide concentration in the calibration gas with the measured gaseous mercury oxide concentration to ensure the accuracy of the measurement results, thereby improving the accuracy and reliability of the environmental monitoring data.

[0064] It is understood that the speciation atmospheric mercury monitoring device provided in the embodiment of the present invention establishes a full-process calibration system by setting up a calibration device 10 before the dual-channel speciation mercury measuring device 20, so as to achieve calibration at every stage from sampling to analysis, reduce system errors, and improve the accuracy of measurement results. The zero gas preparation component 13 in the calibration device 10 provides accurate zero air, and the gaseous oxidized mercury generating component 14, the gaseous elemental mercury generating component 15, and the interference component 16 can control the composition and concentration of the calibration gas, so that the dual-channel speciation mercury measuring device 20 can more accurately measure the mercury speciation in the atmosphere. This setting can simulate various conditions in the actual atmospheric environment, including the presence of mercury speciation of different concentrations and interfering gases, to improve the reliability of the dual-channel speciation mercury measuring device 20 in actual monitoring, better adapt to complex atmospheric environments, and maintain stable measurement performance during long-term operation, ensuring the accuracy of measurement results and improving the accuracy and reliability of environmental monitoring data.

[0065] Furthermore, because the presence of interfering gases can affect the filter's ability to intercept and capture GOM, resulting in lower GOM measurements, the present invention precisely controls the composition of the calibration gas to identify and correct for mercury chemical transformations caused by the presence of interfering gases during the sampling and measurement process, thereby reducing measurement errors and more accurately reflecting the true distribution of mercury in the atmosphere. Furthermore, the full-process calibration system makes measurement results from different monitoring sites and over different time periods comparable. This is of great significance for establishing a spatiotemporal distribution model of atmospheric mercury pollution and evaluating the effectiveness of mercury emission reductions.

[0066] Continue reading Figure 1 In some embodiments of the present invention, the zero air preparation assembly 13 includes an air supply pipeline 131 , a pump body 132 and a zero air preparation element 133 .

[0067] Air supply line 131 is adapted to connect to an atmospheric purification device and is connected to the inlet of zero-air preparation assembly 13. Pump 132 is provided on air supply line 131 and is used to pump purified atmospheric air into air supply line 131. Zero-air preparation element 133 is provided on air supply line 131 and is used to remove mercury and reactive substances from the atmospheric air transmitted by air supply line 131 to generate zero-air.

[0068] The zero-gas preparation element 133 uses activated carbon with high adsorption capacity and good adsorption selectivity, ensuring strong adsorption of target pollutants while weakly adsorbing background gas components. The activated carbon can be pretreated, such as through high-temperature activation or chemical modification, to improve its adsorption performance and stability. The pretreated activated carbon is placed in a specially designed activated carbon tube. By controlling the gas flow rate, temperature, pressure, and other conditions, the pollutant-laden gas is passed through the tube. The activated carbon adsorbs the pollutants, resulting in zero gas free of the target pollutants.

[0069] In addition to using activated carbon tube adsorption to prepare zero gas on-site, the embodiments of the present invention can also use chemical absorption, catalytic oxidation, low-temperature plasma (low-temperature plasma is generated by high-voltage discharge, and high-energy electrons, free radicals and other active substances in the plasma collide and decompose with pollutants in the air to remove the pollutants and then prepare zero gas).

[0070] During operation, pump 132 starts, drawing air from the ambient atmosphere through air supply line 131. The negative pressure generated by pump 132 causes ambient air to be continuously drawn into air supply line 131. The drawn air first passes through a high-efficiency air filter (HEPA), intercepting particulate matter. The air then enters the activated carbon fiber (ACF) adsorption zone, where mercury atoms and some volatile organic compounds are adsorbed by the microporous structure of the activated carbon fibers. After physical adsorption, the air continues to flow through air supply line 131 and enters the chemical absorption zone. If the air contains acidic active substances such as sulfur dioxide, they are absorbed by the glass fiber filter material impregnated with sodium hydroxide solution. Simultaneously, the mercury-containing air comes into contact with the activated carbon impregnated with sulfur compounds, where the mercury and sulfur react chemically and are absorbed, thereby removing the mercury and other active substances.

[0071] After the aforementioned series of physical filtration, adsorption, and chemical absorption processes, the atmosphere in gas supply line 131 is essentially free of mercury and reactive substances, resulting in zero-air. This air can be used for subsequent calibrations or as a contaminant-free background gas for other atmospheric monitoring experiments and operations, ensuring that the calibration environment is consistent with actual atmospheric conditions.

[0072] The zero air preparation assembly 13 provided in this embodiment of the present invention generates zero air that can be used as a precise calibration gas. Because the zero air preparation assembly 13 effectively removes mercury and reactive substances, the calibration process is unaffected by these interfering substances, thereby improving calibration accuracy and ensuring that atmospheric monitoring equipment can accurately measure mercury content and other related parameters in the atmosphere.

[0073] It should be noted that before preparing zero air, high-efficiency air filters and dust removal equipment can be used to remove atmospheric particulate matter, such as dust, pollen, and smoke, from the zero air preparation assembly 13 to prevent interference with subsequent analysis and calibration processes. A dehumidifier or desiccant can be used to remove moisture from the atmosphere, reducing the humidity to an appropriate level to minimize its impact on instrumentation and analytical results. Adsorbents can be used to further remove harmful atmospheric gas components, such as sulfur dioxide, nitrogen oxides, and volatile organic compounds, to ensure that the purified atmosphere meets calibration requirements.

[0074] During the atmosphere purification process, select purification methods and materials that minimize the impact on background gas composition to avoid excessive purification that could lead to loss of background gas components. Based on actual needs, precisely control the degree of atmosphere purification to remove contaminants while preserving background gas components to the greatest extent possible, ensuring that the calibration environment is consistent with actual atmospheric conditions.

[0075] Therefore, the prepared zero gas and purified atmosphere can be calibrated using standard gases of known concentration to verify their accuracy and reliability. The calibrated results are then compared with those measured under actual atmospheric conditions to ensure consistency within the allowable error range. Regular verification and adjustment of the calibration environment is performed to adapt to changes in the atmospheric environment and ensure the accuracy and reliability of the calibration results.

[0076] Continue reading Figure 1 In some embodiments of the present invention, the gaseous mercury oxide generating assembly 14 includes a first mercury vapor generating element 141 , a first mass flow controller 142 and a first control valve 143 .

[0077] The inlet of the first mercury vapor generating element 141 is connected to the outlet of the first main carrier gas pipeline 11, and its outlet is connected to the inlet of the second main carrier gas pipeline 12. The first mercury vapor generating element 141 is used to generate mercury oxide vapor. In this embodiment of the present invention, the first mercury vapor generating element 141 uses a constant temperature evaporation method to generate mercury oxide vapor. Specifically, a mercury source is placed inside a quartz tube constant temperature box and the temperature is adjusted to ensure that the mercury oxide vapor generation rate meets the calibration requirements, approximately 0.1-0.01 ng min. -1 .

[0078] The first mass flow controller 142 is provided on the pipeline between the inlet of the first mercury vapor generating element 141 and the outlet of the first main carrier gas pipeline 11, and is used to control the zero air flow at the inlet end of the first mercury vapor generating element 141 to ensure the stability of the gaseous mercury oxide concentration.

[0079] The first control valve 143 is provided at the outlet of the first mercury vapor generating element 141 to control the outlet of the first mercury vapor generating element 141. The first control valve 143 comprises a solenoid valve or a pneumatic valve, and the valve body is made of polytetrafluoroethylene (PTFE) to prevent mercury oxide vapor from being absorbed or corroded.

[0080] In the initial state, the first control valve 143 is closed to block mercury oxide vapor from entering the second main carrier gas pipeline 12. The first mass flow controller 142 is in standby mode, with the carrier gas flow rate being zero, to prevent impurities from entering the gaseous mercury oxide generating assembly 14 when not heated.

[0081] Open the first mass flow controller 142 to introduce carrier gas (e.g., 2 L / min of zero-pressure air) to the first mercury vapor generating element 141. Start the thermostat and set the temperature to a set value (e.g., 5°C). The mercury source is heated and decomposed into vapor. Open the first control valve 143 to mix the gaseous mercury oxide with the carrier gas and deliver it to the second main carrier gas line 12.

[0082] In the embodiment of the present invention, the output concentration of gaseous mercury oxide (eg, 0.05-1 ppt) is controlled by controlling the flow rates of the first mass flow controller 142 and the second mass flow controller 146 and the temperature of the first mercury vapor generating element 141 .

[0083] The gaseous mercury oxide generating assembly 14 can efficiently generate stable and controllable gaseous mercury oxide calibration gas, significantly improving the calibration efficiency and accuracy of the mercury speciation analyzer.

[0084] Continue reading Figure 1 In some embodiments of the present invention, the gaseous mercury oxide generating component 14 further includes an exhaust gas treatment device, which is arranged in series with the first mercury vapor generating element 141. The exhaust gas treatment device is connected to the first control valve 143 and is used to discharge the excess mercury oxide vapor generated by the first mercury vapor generating element 141 and perform exhaust gas treatment.

[0085] The embodiment of the present invention uses a branch design to discharge excess gaseous mercury oxide and perform tail gas treatment, thereby accurately eliminating excess gaseous mercury oxide and ensuring the relative stability of the concentration of gaseous mercury oxide in the calibration gas. This solves the problem of difficulty in achieving or instability in low occurrence rates, further ensures the stability and accuracy of low-concentration calibration, and provides strong support for the calibration of low-concentration gaseous mercury oxide.

[0086] Specifically, the exhaust gas treatment device includes an exhaust gas treatment pipeline 144 , an exhaust gas treatment element 145 and a second mass flow controller 146 .

[0087] The inlet of the exhaust gas treatment pipeline 144 is connected to the first control valve 143, which is used to discharge the excess mercury oxide vapor generated by the first mercury vapor generating element 141. The first control valve 143 can be a three-way solenoid valve, and the inlet end is connected in series with the outlet of the first control valve 143 through a three-way joint to form an independent branch, which is used to directionally discharge the excess GOM vapor generated by the first mercury vapor generating element 141.

[0088] Tail gas treatment element 145 is connected to the outlet of tail gas treatment pipeline 144. It is used to treat the exhausted mercuric oxide vapor. Integrated into the end of the pipeline, tail gas treatment element 145 can employ a two-stage purification design. Primary treatment utilizes an activated carbon adsorption layer to capture GOM, while further treatment utilizes a palladium-supported catalyst module to catalyze and immobilize residual mercury compounds.

[0089] The second mass flow controller 146 is provided in the exhaust gas treatment pipeline 144 and is located at the inlet end of the exhaust gas treatment element 145 . The second mass flow controller 146 is used to monitor and adjust the exhaust gas output flow rate of the exhaust gas treatment pipeline 144 .

[0090] As can be appreciated, the embodiments of the present invention precisely remove excess gaseous mercury oxide through a branch line, thereby ensuring a relatively low and stable concentration of gaseous mercury oxide in the calibration gas. This approach not only addresses the difficulty or instability of achieving low generation rates, but also further ensures the stability and accuracy of low-concentration calibrations, providing strong support for the calibration of low-concentration gaseous mercury oxide.

[0091] In essence, this embodiment of the present invention introduces a second mass flow controller 146 into the gaseous mercuric oxide generating assembly 14, forming a dual closed-loop flow control system alongside the existing first mass flow controller 142. The first mass flow controller 142 (MFC1) controls the carrier gas input flow rate, while the second mass flow controller 146 (MFC2) monitors and regulates the exhaust gas output flow rate. These two controllers collaborate in real time via a PID algorithm. The flow rate entering the second main carrier gas pipeline 12 is calculated based on the flow difference (ΔQ = MFC1 input flow rate - MFC2 output flow rate). This dynamically compensates for flow losses caused by pipeline pressure fluctuations or leakage, ensuring the stability of the gaseous mercuric oxide output flow rate.

[0092] Continue reading Figure 1 In some embodiments of the present invention, the gaseous elemental mercury generating assembly 15 includes a second mercury vapor generating element 151 , a third mass flow controller 152 , a second control valve 153 and a third control valve 154 .

[0093] The inlet of the second mercury vapor generating element 151 is connected to the outlet of the first main carrier gas pipeline 11, and the outlet is connected to the inlet of the second main carrier gas pipeline 12. The second mercury vapor generating element 151 is used to evaporate liquid elemental mercury at a preset temperature to generate gaseous elemental mercury.

[0094] In the embodiment of the present invention, the second mercury vapor generating element 151 uses a constant temperature evaporation method to generate gaseous elemental mercury. That is, a mercury permeation tube is used as the core component, which is sealed in a constant temperature tank, and liquid elemental mercury (Hg 0 ) slowly releases mercury vapor at 0-40 ℃, and the release rate is precisely controlled by temperature.

[0095] The third mass flow controller 152 is provided on the pipeline between the inlet of the second mercury vapor generating element 151 and the outlet of the first main carrier gas pipeline 11 , and is used to control the zero air flow at the inlet end of the second mercury vapor generating element 151 .

[0096] The second control valve 153 (inlet valve) is provided at the inlet end of the second mercury vapor generating element 151 and is used to control the inlet opening and closing of the second mercury vapor generating element 151. The second control valve 153 is a normally closed three-way solenoid valve with a valve body made of PTFE to prevent mercury adsorption.

[0097] The third control valve 154 (outlet valve) is provided at the outlet end of the second mercury vapor generating element 151 and is used to control the on / off of the outlet of the second mercury vapor generating element 151. The third control valve 154 may be a double-sealed ball valve.

[0098] In the initial state, the second control valve 153 (inlet) and the third control valve 154 (outlet) are both in a closed state, blocking the risk of mercury vapor leakage.

[0099] The second control valve 153 is opened to allow zero air to flow in, with the flow rate precisely controlled by the third mass flow controller 152. Once the thermostatic bath reaches the set temperature (e.g., 40°C), liquid mercury permeates to produce gaseous elemental mercury. The thermostatic bath maintains the set temperature to ensure a stable mercury permeation rate. The third control valve 154 is opened to mix the gaseous elemental mercury with zero air (i.e., carrier gas) and deliver it to the second main carrier gas line 12.

[0100] In this embodiment of the present invention, flow regulation by the third mass flow controller 152 is coordinated with the constant temperature bath temperature control to achieve precise mercury concentration output, improving calibration efficiency. Furthermore, a double barrier, formed by the inlet valve (second control valve 153) and the outlet valve (third control valve 154), prevents gas leakage.

[0101] Continue reading Figure 1 In some embodiments of the present invention, the interference component 16 includes at least one of an ozone generator 161 and a humidity regulating element 162, that is, the interference component 16 includes an ozone generator 161 or a humidity regulating element 162, and the interference component 16 may also include an ozone generator 161 and a humidity regulating element 162 at the same time.

[0102] The ozone generator 161 is connected between the outlet of the first main carrier gas pipeline 11 and the inlet of the second main carrier gas pipeline 12. A fourth mass flow controller 163 is provided on the pipeline connected to the inlet of the ozone generator 161. The ozone generator 161 is used to generate interfering gas ozone.

[0103] The humidity regulating element 162 is connected between the outlet of the first main carrier gas pipeline 11 and the inlet of the second main carrier gas pipeline 12. A fifth mass flow controller 164 is provided on the pipeline connected to the inlet of the humidity regulating element 162. The humidity regulating element 162 is used to regulate humidity.

[0104] The embodiment of the present invention uses ozone generator 161 to generate interfering gas ozone and a humidity-regulating washing bottle to adjust the humidity, thereby simulating different atmospheric oxidation conditions and humidity environments. This is used to evaluate the changing characteristics of the measurement accuracy of gaseous mercury oxide under different atmospheric oxidation conditions and humidity environments. This helps to further study and optimize the measurement method of gaseous mercury oxide (GOM) and improve the reliability and accuracy of the measurement.

[0105] Ozone generator 161 converts oxygen into ozone through high-voltage discharge or ultraviolet radiation. To accurately add ozone to a standard calibration gas, ozone generator 161 must first be calibrated to determine the relationship between its ozone production efficiency and concentration and input parameters (such as voltage, current, and gas flow).

[0106] For example, for the high-voltage discharge ozone generator 161, the amount of ozone generated can be precisely controlled by adjusting parameters such as the power and oxygen flow rate of the generator.

[0107] To precisely control the concentration of added ozone, a high-precision ozone concentration monitoring instrument, such as a UV absorption ozone analyzer, is required. During the addition process, the ozone concentration is monitored in real time. The parameters of ozone generator 161 are adjusted based on the monitoring results to ensure that the added ozone concentration meets the preset values, thereby simulating the ozone concentration levels under different atmospheric oxidation conditions.

[0108] When adding ozone to the standard calibration gas, it is important to ensure that the gas is mixed evenly. This can be achieved using a special gas mixing device, such as a static mixer or a dynamic mixer, to ensure that the ozone and standard calibration gas are fully mixed to achieve accurate addition.

[0109] The humidity-regulating wash bottle contains a certain amount of ultrapure water. When the standard calibration gas passes through the wash bottle, it exchanges water vapor with the water, increasing the water vapor content in the gas. The balance between the dissolution and volatilization of the gas in the water determines the water vapor content in the gas. The water vapor content in the gas can be adjusted by controlling factors such as the wash bottle temperature, the gas flow rate through the wash bottle, and the initial amount of water in the wash bottle.

[0110] To precisely regulate humidity, real-time humidity measurement is also necessary. This can be achieved using a high-precision humidity sensor, such as a capacitive humidity sensor or a dew point meter. Based on the humidity sensor's measurement results, bottle washing parameters, such as temperature and gas flow rate, can be adjusted to simulate varying humidity environments, ensuring that the water vapor content in the gas accurately simulates atmospheric humidity conditions.

[0111] A mercury oxide gas measurement instrument can be used to perform multiple measurements on a processed standard calibration gas, recording the results under varying atmospheric oxidation conditions (as indicated by ozone concentration) and humidity (as indicated by water vapor content). By comparing the measurement results under different conditions with known reference values, the accuracy of the mercury oxide gas measurement can be analyzed. For example, the deviation between the measured value and the reference value, as well as repeatability, linearity, and other indicators, can be observed to vary with ozone concentration and humidity.

[0112] Continue reading Figure 1In some embodiments of the present invention, the interference component 16 also includes an interference carrier gas pipeline 165, one end of the interference carrier gas pipeline 165 is connected to the outlet of the first main carrier gas pipeline 11 through a fourth control valve 166, and the other end of the interference carrier gas pipeline 165 is provided with a fifth control valve 167, the fifth control valve 167 is connected to the pipeline provided with the fourth mass flow controller 163, and the fifth control valve 167 is connected to the pipeline provided with the fifth mass flow controller 164.

[0113] In other words, this connection method of the interference carrier gas line 165 allows it to operate independently of the other main carrier gas lines. For example, during different experimental or production stages, when the interference carrier gas needs to be introduced for special processing (such as adding specific gas components or changing the gas flow ratio to influence the reaction process), this can be achieved by controlling the relevant control valves without affecting the normal operation of the first main carrier gas line 11.

[0114] In the experimental setup for simulating atmospheric pollution processes, the first main carrier gas line 11 can deliver zero gas. The interference carrier gas line 165 can be used to introduce zero gas for interference. The humidity adjustment element 162 can simulate humidity changes in the atmosphere, and the humidity entering the simulated environment is adjusted via the seventh control valve 169. The ozone generator 161 can produce ozone to simulate photochemical processes in the atmosphere. By controlling the various control valves, atmospheric environments with varying pollution levels, humidity, and photochemical conditions can be accurately simulated to study the generation, transformation, and removal mechanisms of atmospheric pollutants.

[0115] A sixth control valve 168 is provided at the outlet end of the ozone generator 161 , and a seventh control valve 169 is provided at the outlet end of the humidity adjustment element 162 .

[0116] When the system is operating, gas in the first main carrier gas pipeline 11 is continuously delivered. The zero-vacuum in the interference carrier gas pipeline 165 enters through the fourth control valve 166 and the fifth control valve 167. Under the control of the fourth mass flow controller 163, it enters the ozone generator 161 at a set flow rate. The ozone generated by the ozone generator 161 enters the second main carrier gas pipeline 12 through the sixth control valve 168. Under the control of the fifth mass flow controller 164, the ozone enters the humidity control element 162 at a set flow rate. The gas conditioned by the humidity control element 162 enters the second main carrier gas pipeline 12 through the sixth control valve 168.

[0117] Figure 4 It is a schematic diagram of the coordination between the sampling port 181 and the injection port in the form-based atmospheric mercury monitoring device provided by an embodiment of the present invention.

[0118] Continue reading Figure 1 , and also see Figure 4In some embodiments of the present invention, the spectroscopic atmospheric mercury monitoring device further includes a heating jacket 17 and / or an employing device 18 .

[0119] A heating jacket 17 is installed on the second main carrier gas pipeline 12, near the dual-channel mercury speciation measurement device 20. Mercury easily adsorbs to walls at room temperature, especially in relatively low temperatures. Installing the heating jacket 17 on the second main carrier gas pipeline 12 and heating it to 120°C raises the gas temperature, preventing mercury condensation within the pipeline and ensuring accurate measurements.

[0120] The sampling device 18 is located at the outlet of the second main carrier gas pipeline 12. It is equipped with a funnel-shaped sampling port 181. An annular gap is defined between sampling port 181 and the inlet of the dual-channel mercury speciation measurement device 20. A 0.8 mm annular gap is defined between the funnel-shaped sampling port 181 and the inlet. When the calibration gas transmitted from the second main carrier gas pipeline 12 flows through this annular gap, the gas flow state changes due to the gap. The Venturi-like effect generated by the gas flow maintains a constant pressure near atmospheric pressure at the sampling port 181, eliminating the positive pressure accumulation caused by volumetric delivery in traditional driven injection modes. This ensures the stability and accuracy of the injection process and further improves the reliability of the calibration.

[0121] The embodiment of the present invention adopts an optimized funnel-shaped sampling port 181 design and adjusts the calibration gas flow rate (slightly higher than the sampling flow rate). By adjusting the calibration gas flow rate to be slightly higher than the sampling flow rate, it can be ensured that there is enough gas entering the injection system, and at the same time, conditions are created for utilizing the Venturi effect. This flow regulation requires the use of a precise flow control device, such as a mass flow controller. The mass flow controller can accurately adjust the flow rate of the gas according to the set flow value. For example, it can control the gas flow rate by measuring the mass flow rate of the gas and adjusting the opening of the control valve according to the built-in algorithm and feedback mechanism. This completely simulates the negative pressure injection condition under atmospheric pressure, rather than the positive pressure of the injection port caused by the pumping operation, thereby avoiding the deviation in the calibration and measurement of the injection flow rate caused by the difference between positive and negative pressure.

[0122] Figure 5 This is a graph showing the measured concentration and the calibrated concentration of the mercury monitoring device for the atmosphere provided by the embodiment of the present invention.

[0123] See Figure 5 Since the actual concentration of gaseous oxidized mercury (GOM) in the atmosphere is usually less than 0.1 ng m -3, far below the detection limit of mercury analyzers, necessitates simultaneous measurement of both GOM and GEM in atmospheric measurements to ensure that total mercury concentrations exceed the instrument's detection limit. However, this approach presents calibration challenges, as direct calibration of GOM measurements at atmospheric concentrations is difficult in the absence of GEM. Existing calibration systems can only calibrate within a concentration range above the detection limit, which is far higher than the actual concentration of GOM in the atmosphere. Therefore, the accuracy of GOM measurements at atmospheric concentrations has not been verified through calibration.

[0124] The embodiment of the present invention provides a mercury speciation atmospheric mercury monitoring device, which is designed for a GOM concentration calibration method for a dual-channel atmospheric mercury speciation measurement device. This method establishes a full-process calibration system from sampling to analysis to ensure the accuracy and reliability of the measurement results. It also verifies the applicability and stability of the dual-channel GOM measurement method under real atmospheric conditions. It also achieves breakthroughs in low-concentration GOM (<0.1 ng m -3 ) calibration technology bottleneck, providing high-precision and high-reliability technical support for atmospheric mercury pollution monitoring; at the same time, promoting the standardization and regularization of atmospheric mercury speciation monitoring technology.

[0125] The calibration device 10 uses the same GOM measurement and calculation method as the actual atmospheric measurement, as shown in the following formula (1). Considering that the total mercury concentration in the actual atmospheric measurement contains a higher concentration of GEM (3-5 ng m -3 ), ensuring that the measured concentration was above the instrument detection limit, while lower GOM concentrations (0.01-0.5 ng m -3 ) was obtained by subtraction. To avoid the detection limit problem during GOM calibration, GOM (0.01-0.5 ng m -3 ) and GEM (3-5 ngm -3 ), which not only breaks through the instrument detection limit, but also ensures that the calculation method is completely consistent with the actual measurement, and at the same time verifies the separation efficiency of CEM for GOM and GEM.

[0126] For low concentrations of GOM (0.01-0.5 ng m -3 ) generation needs, the system is equipped with an exhaust gas treatment device, which can accurately remove excess GOM and ensure a relatively stable concentration.

[0127] At least two concentration calibrations are performed for each working condition, and each calibration concentration needs to be repeated for at least six times (refer to EPAMethod IO-5 recommendations) to obtain reliable statistical results. The instrument measurement value is calculated according to formula (1), and the average value of multiple measurements is taken as the final result. The true concentration of GOM in the calibration gas is determined by formula (2), and the calibration coefficient (η) under each working condition is determined by formula (3). When observing in the atmospheric field, the atmospheric concentration of GOM after calibration under the same working condition is GOM. 大气浓度Calculated by formula (4).

[0128] (1); (2); (3); (4); Where, GOM i,测量浓度 represents the i-th measurement result of the same concentration; J GOM is the occurrence rate of GOM, ng min -1 ;GOM j,校准浓度 and GOM j,测量浓度 Indicates the jth calibration and measurement concentration under the same working conditions.

[0129] Therefore, the form-specific atmospheric mercury monitoring equipment provided in the embodiment of the present invention adopts the same GOM measurement and calculation method as the actual atmospheric measurement, and the calibration concentration is equivalent to the real atmospheric GOM concentration level. By adding GOM and GEM to the calibration gas at the same time, it not only breaks through the instrument detection limit, but also ensures that the calculation method is completely consistent with the actual measurement, effectively solving the detection limit problem during low-concentration GOM calibration, and improving the accuracy and reliability of calibration.

[0130] By using local atmospheric purification to prepare zero gas, the background gas composition is retained to the greatest extent possible, ensuring the consistency of the calibration environment with the actual atmospheric conditions. This provides an environmental basis that is closer to actual application for the calibration process, making the calibration results more valuable for reference.

[0131] The interfering gas simulation system can accurately add ozone and water vapor as interfering components, and can systematically evaluate the changing characteristics of GOM measurement accuracy under different atmospheric ozone and humidity environments. This will help to further study and optimize the GOM measurement method and improve the reliability and accuracy of the measurement.

[0132] The gas sampling system adopts an optimized funnel-shaped sampling port 181 design and utilizes a quasi-Venturi effect to keep the pressure of the sampling port 181 stable near atmospheric pressure, effectively eliminating the pressure difference problem between the pumping injection method and atmospheric measurement, ensuring the stability and accuracy of the injection process and further improving the reliability of calibration.

[0133] During the generation of low-concentration GOM, since it is difficult for the GOM generator to directly reach the required low generation rate or to maintain stability at a low generation rate, the present invention adopts a split flow design. In the system, the GOM generator produces a higher concentration of GOM and then discharges the excess GOM through a branch. This branch is equipped with an exhaust gas treatment device that can accurately remove excess GOM, thereby ensuring the relative stability of the GOM concentration in the calibration gas. In this way, the system not only solves the problem of low generation rate being difficult to achieve or unstable, but also further ensures the stability and accuracy of low-concentration calibration, providing strong support for the calibration of low-concentration GOM.

[0134] The atmospheric mercury monitoring equipment utilizes a modular design, with each module clearly defined and interoperable. The overall system structure is clear and easy to assemble, maintain, and upgrade. For example, a centrifugal pump provides power, activated carbon tubes provide deep purification, and flow control devices divide the purified zero air into multiple channels for generating target GOM concentrations, replenishing GEM components, generating interfering ozone gas, and adjusting humidity. These modules work together to ensure the efficient operation of the entire calibration system. The system's modular design also enhances its flexibility and scalability, allowing for easy adjustment and optimization of the system to meet diverse calibration requirements, enhancing its adaptability and versatility.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A morphological atmospheric mercury monitoring device, characterized in that: include: Calibration device, comprising: a first main carrier gas pipeline and a second main carrier gas pipeline; a zero air preparation component, the outlet of which is connected to the first main carrier gas pipeline, and the zero air preparation component is used to prepare zero air from atmospheric air; a gaseous mercury oxide generating assembly connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline, the gaseous mercury oxide generating assembly being used to prepare gaseous mercury oxide of a target concentration and add gaseous mercury oxide to the zero air; a gaseous elemental mercury generating assembly connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline, the gaseous elemental mercury generating assembly being used to prepare gaseous elemental mercury and replenish the gaseous elemental mercury into the zero air; an interference component connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline, the interference component being used to add interference gas to the zero air and adjust the humidity of the zero air; A dual-channel mercury form measurement device is connected to the total outlet of the second main carrier gas pipeline and is used to capture and analyze gaseous mercury oxide contained in the calibration gas generated by the calibration device.

2. The atmospheric mercury monitoring device according to claim 1, characterized in that: The zero gas preparation component includes: An air supply pipeline, suitable for connecting to an atmosphere purification device, wherein the air supply pipeline is connected to the inlet of the zero air preparation component; a pump body, provided in the air supply pipeline, for pumping the purified atmosphere to the air supply pipeline; The zero air preparation element is provided in the air supply pipeline and is used to remove mercury and active substances in the atmosphere transmitted by the air supply pipeline to generate zero air.

3. The atmospheric mercury monitoring device according to claim 1, characterized in that: The gaseous mercury oxide generating assembly comprises: a first mercury vapor generating element, the inlet of which is connected to the outlet of the first main carrier gas pipeline, and the outlet of which is connected to the inlet of the second main carrier gas pipeline, the first mercury vapor generating element being used to generate mercury oxide vapor; a first mass flow controller, provided on the pipeline between the inlet of the first mercury vapor generating element and the outlet of the first main carrier gas pipeline, for controlling the zero air flow at the inlet end of the first mercury vapor generating element; The first control valve is provided at the outlet end of the first mercury vapor generating element and is used for controlling the outlet of the first mercury vapor generating element to be on or off.

4. The atmospheric mercury monitoring device according to claim 3, characterized in that: The gaseous mercury oxide generating assembly further includes an exhaust gas treatment device, which is arranged in parallel with the first mercury vapor generating element and connected to the first control valve for discharging excess mercury oxide vapor generated by the first mercury vapor generating element and performing exhaust gas treatment.

5. The atmospheric mercury monitoring device according to claim 4, characterized in that: The tail gas treatment device comprises: an exhaust gas treatment pipeline, the inlet of which is connected to the first control valve and is used to discharge excess mercury oxide vapor generated by the first mercury vapor generating element; An exhaust gas treatment element is connected to the outlet end of the exhaust gas treatment pipeline, and is used to perform exhaust gas treatment on the discharged mercury oxide vapor; The second mass flow controller is provided in the exhaust gas treatment pipeline and is located at the inlet end of the exhaust gas treatment element. The second mass flow controller is used to control the exhaust gas output flow of the exhaust gas treatment pipeline.

6. The atmospheric mercury monitoring device according to claim 1, characterized in that: The gaseous element mercury generating assembly comprises: a second mercury vapor generating element, the inlet of which is connected to the outlet of the first main carrier gas pipeline, and the outlet of which is connected to the inlet of the second main carrier gas pipeline, the second mercury vapor generating element being configured to evaporate liquid elemental mercury at a preset temperature to generate gaseous elemental mercury; a third mass flow controller, provided on the pipeline between the inlet of the second mercury vapor generating element and the outlet of the first main carrier gas pipeline, for controlling the zero air flow at the inlet end of the second mercury vapor generating element; a second control valve, provided at the inlet end of the second mercury vapor generating element, for controlling the inlet of the second mercury vapor generating element to be on or off; The third control valve is provided at the outlet end of the second mercury vapor generating element and is used to control the on-off of the outlet of the second mercury vapor generating element.

7. The atmospheric mercury monitoring device according to claim 1, characterized in that: The interference component includes at least one of an ozone generator and a humidity conditioning element; The ozone generator is connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline, and a fourth mass flow controller is provided on the pipeline connected to the inlet of the ozone generator. The ozone generator is used to generate interfering gas ozone; The humidity regulating element is connected between the outlet of the first main carrier gas pipeline and the inlet of the second main carrier gas pipeline. A fifth mass flow controller is provided on the pipeline connected to the inlet of the humidity regulating element. The humidity regulating element is used to regulate humidity.

8. The atmospheric mercury monitoring device according to claim 7, characterized in that: The interference component also includes: an interference carrier gas pipeline, one end of which is connected to the outlet of the first main carrier gas pipeline through a fourth control valve, and the other end of the interference carrier gas pipeline is provided with a fifth control valve, the fifth control valve is connected to the pipeline provided with the fourth mass flow controller, and the fifth control valve is connected to the pipeline provided with the fifth mass flow controller; The outlet end of the ozone generator is provided with a sixth control valve, and the outlet end of the humidity regulating element is provided with a seventh control valve.

9. The equipment for monitoring atmospheric mercury in a morphological manner according to any one of claims 1 to 8, characterized in that: Also includes: a heating jacket, provided on the second main carrier gas pipeline and located near the dual-channel mercury form measuring device; and / or, The adopting device is arranged at the outlet end of the second main carrier gas pipeline. The adopting device is provided with a funnel-shaped sampling port. An annular gap is provided between the sampling port and the sampling port of the dual-channel mercury form measuring device.

10. The equipment for monitoring atmospheric mercury in a morphological manner according to any one of claims 1 to 8, characterized in that: The dual-channel mercury form measurement device comprises: A gaseous mercury oxide capture and thermal desorption component is used to capture and decompose a portion of the gaseous mercury oxide contained in the ambient atmospheric sample; A gaseous oxidized mercury removal component, used for removing gaseous oxidized mercury contained in an ambient air sample, so as to retain gaseous elemental mercury in the ambient air sample; The atmospheric mercury analyzer based on atomic spectroscopy is used to detect the concentration of mercury in atmospheric samples.

Images