System and method for monitoring water-soluble ions in air

Abstract

The present invention relates to environmental monitoring, and in particular to a system and method for monitoring water-soluble ions in air. The monitoring system includes a separation device, a detection unit, a first concentration pipeline, a particulate matter collection device, a second concentration pipeline and a calculation device. The first concentration pipeline and the second concentration pipeline both include an absorption bottle, a reverse osmosis filter, a pump and a solvent bottle connected in sequence. The pipeline between the absorption bottle and the reverse osmosis filter is connected to the detection unit. The absorption bottle is used to accommodate an input target solution. The pump is used to allow the solvent of the target solution to enter the solvent bottle through the reverse osmosis filter so that the target solution in the absorption bottle is concentrated. The calculation device obtains the concentration C1 of the gaseous soluble target in the air and the concentration C2 of the ions in the solid particulate matter in the air based on the output result of the detection unit and the working parameters in the monitoring system.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection, and in particular to a system and method for monitoring water-soluble ions in air. Background Art

[0002] Atmospheric particulate matter (such as PM 10 , PM 2.5 Water-soluble ions are an important component of atmospheric particulate matter, and monitoring their concentration is crucial for air pollution control.

[0003] The traditional method for analyzing the water-soluble ion content of atmospheric particulate matter involves collecting the particles through a filter membrane, then transporting them to the laboratory for weighing, dissolution, extraction, and analysis using ion chromatography. This method suffers from drawbacks such as large errors in particle sampling, easy sample loss during storage, labor-intensive and time-consuming processes, and an inability to reflect the high-frequency variations in the water-soluble components of atmospheric particulate matter. The recently introduced continuous automatic monitoring system and method for water-soluble ions in air effectively address these issues. This system typically has a sampling and analysis cycle of one hour, with a single solution change, and can operate continuously for 10-50 days. It is a powerful tool for environmental monitoring and atmospheric environmental protection agencies to monitor and analyze ion content in aerosols and gases.

[0004] In recent years, my country's ambient air quality has improved significantly, with pollutant concentrations significantly reduced and PM 2.5 Concentration of several μg / m 3 -20 μg / m 3 This kind of clean weather is more common, and the concentration of water-soluble ions in the air remains at a low level for a long time. - 、Na + , K + Mg 2+ , Ca 2+ The plasma concentration can be as low as 10 -2 μg / m 3 Even 10 -3 μg / m 3 The concentration level, while the existing online monitoring products for water-soluble ions in air have a detection limit of the above ion components at 10 -2 μg / m 3 -10 -1 μg / m 3 The magnitude range is too small to accurately monitor lower concentrations of water-soluble ions, resulting in poor measurement data quality.

[0005] Current online monitoring products for water-soluble ions in the air have a wide range of measurement concentrations, and the calibration curve spans from low concentrations to high concentrations. However, low concentrations are more common, and PM in summer is2.5 Sometimes only a few μg / m 3 , ion concentrations remain in a low range, and high concentrations only occur during periods of exceptionally polluted weather. Current water-soluble ion monitoring systems, however, mostly use the same set of calibration curves to measure both low- and high-concentration samples, which results in poor applicability and, in turn, large measurement errors. Summary of the Invention

[0006] To address the deficiencies in the above-mentioned prior art solutions, the present invention provides a system for monitoring water-soluble ions in air, comprising:

[0007] a separation device for capturing gaseous soluble target matter in the input sample gas to form a first portion of the target matter solution and allowing solid particulate matter in the sample gas to pass through;

[0008] A detection unit, used for analyzing the components of the input solution;

[0009] a first concentration pipeline, connected to the separation device and the detection unit, respectively, for concentrating the first portion of the target solution and then inputting the concentrated solution into the detection unit;

[0010] a particle collecting device connected to the separation device and configured to absorb the solid particles to form a second portion of the target solution;

[0011] a second concentration pipeline, connected to the particle collection device and the detection unit, respectively, for concentrating the second portion of the target solution and then inputting it into the detection unit;

[0012] The first concentration pipeline and the second concentration pipeline each include an absorption bottle, a reverse osmosis filter, a pump, and a solvent bottle connected in sequence. The pipeline between the absorption bottle and the reverse osmosis filter is connected to the detection unit. The absorption bottle is used to accommodate the input target solution. The pump is used to allow the solvent of the target solution to enter the solvent bottle through the reverse osmosis filter, so that the target solution in the absorption bottle is concentrated.

[0013] A calculation device is provided for obtaining the concentration C1 of the gaseous soluble target substance in the air and the concentration C2 of the ions in the solid particles in the air according to the output result of the detection unit and the working parameters in the monitoring system.

[0014] In some embodiments, the first concentration pipeline includes a first pump, a first switching valve, a first absorption bottle, a first reverse osmosis filter, and a first solvent bottle connected in sequence, a pipeline between the first absorption bottle and the first reverse osmosis filter is connected to the detection unit, and the first switching valve is used to selectively connect the outlet of the first pump to the first absorption bottle or the outside world;

[0015] The second concentration pipeline includes a second pump, a second switching valve, a second absorption bottle, a second reverse osmosis filter and a second solvent bottle connected in sequence. The pipeline between the second absorption bottle and the second reverse osmosis filter is connected to the detection unit. The second switching valve is used to selectively connect the outlet of the second pump to the second absorption bottle or the outside world.

[0016] In some embodiments, it is characterized in that

[0017] C 10 is the ion concentration output by the detection unit when the first concentration pipeline is connected to the detection unit, L2 is the pipe volume between the first absorption bottle and the first reverse osmosis filter, L3 is the pipe volume between the first reverse osmosis filter and the first solvent bottle, when the liquid in the first absorption bottle is sent to the detection unit in each sampling cycle, V1 is the sampling volume of air in each cycle, V2 is the volume of liquid delivered by the first pump in each cycle, the liquid volume in the first absorption bottle is V3, and the liquid volume in the first solvent bottle is V4; C 20 It is the ion concentration output by the detection unit when the second concentration pipeline is connected to the detection unit, L6 is the pipe volume between the second absorption bottle and the second reverse osmosis filter, L7 is the pipe volume between the second reverse osmosis filter and the second solvent bottle, when the liquid in the second absorption bottle is sent to the detection unit in each sampling cycle, V5 is the sampling volume of air in each cycle, V6 is the volume of liquid delivered by the second pump in each cycle, the liquid volume in the second absorption bottle is V7, and the liquid volume in the second solvent bottle is V8.

[0018] In some embodiments, the separation device uses a dissolver, the particle collection device includes a steam generator, a particle growth cavity, a condenser and an impactor connected in sequence, the particle growth cavity is connected to the separation device, and the detection unit uses an ion chromatograph.

[0019] The present invention further provides a method for monitoring water-soluble ions in air, using the monitoring system described in any of the above embodiments, the monitoring method comprising:

[0020] The sample gas passes through the separation device and the particle collection device in sequence. The separation device captures the gaseous soluble target in the sample gas to form a first portion of the target solution. The particle collection device absorbs the solid particles in the sample gas to form a second portion of the target solution.

[0021] The first concentrating pipeline concentrates the first part of the target solution and then inputs it into the detection unit, and the detection unit outputs the measured concentration C of the ions in the first part of the target solution. 10 ;

[0022] The second concentrating pipeline concentrates the second part of the target solution and then inputs it into the detection unit, and the detection unit outputs the measured concentration C of the ions in the second part of the target solution. 20 ;

[0023] The calculation device obtains the concentration C1 of the gaseous soluble target matter in the air and the concentration C2 of the ions in the solid particles in the air according to the output result of the detection unit and the working parameters in the monitoring system.

[0024] In some embodiments, the method for measuring the concentration of a target solution by the detection unit includes:

[0025] Calibrate the detection unit to establish a calibration curve, wherein the calibration curve includes a plurality of calibration curve segments, each of which includes a linear correspondence curve between a concentration in a specific concentration range and an output signal of the detection unit;

[0026] Inputting the target solution into the detection unit, and the detection unit outputting a detection signal;

[0027] determining a calibration curve segment corresponding to the detection signal based on the detection signal and the calibration curve;

[0028] A concentration value is determined based on the determined calibration curve segment and the detection signal.

[0029] In some embodiments, determining the calibration curve segment corresponding to the detection signal based on the detection signal and the calibration curve includes:

[0030] If the detection signal does not belong to the signal interval corresponding to any calibration curve segment or the detection signal corresponds to more than two calibration curve segments, the corresponding calibration curve segment is selected by comparing the measurement errors of the critical concentrations of two adjacent calibration curve segments of the detection signal, and the calibration curve segment with the relatively smaller measurement error among the two is used as the corresponding calibration curve segment.

[0031] In some embodiments, determining the calibration curve segment corresponding to the detection signal based on the detection signal and the calibration curve includes:

[0032] If the detection signal does not belong to the signal interval corresponding to any calibration curve segment or the detection signal corresponds to more than two calibration curve segments, the size of the correlation coefficient of the two adjacent calibration curve segments of the detection signal is determined, and the calibration curve segment with the relatively larger correlation coefficient is used as the corresponding calibration curve segment.

[0033] In some embodiments, calibrating the detection unit to establish a calibration curve comprises:

[0034] Divide the total concentration range of specific ions into intervals;

[0035] Obtain the proportion of concentration detection data in each interval within the statistical time;

[0036] The interval division is adjusted based on the proportion so that the proportion conforms to a preset ratio; and a new calibration curve segment is established for each concentration interval based on the adjusted interval division.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. Using a filter based on the reverse osmosis principle and a new water-soluble ion monitoring system flow path, the sample solution is concentrated. The concentration factor is the same as the improvement factor of the detection limit. After the improvement, the measurement accuracy is greatly improved in weather with very low pollutant concentrations.

[0039] 2. Based on the measurement signal of each ion, intelligent matching of calibration curves in different concentration ranges can greatly improve measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The disclosure of the present invention will become more easily understood with reference to the accompanying drawings. Those skilled in the art will readily appreciate that these drawings are merely used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0041] Figure 1 FIG. 4 is a simplified structural diagram of a monitoring system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] Figure 1 The following description describes optional embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to explain the technical solution of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art will understand that variations or substitutions derived from these embodiments will be within the scope of the present invention. Those skilled in the art will understand that the following features can be combined in various ways to form multiple variations of the present invention. Therefore, the present invention is not limited to the following optional embodiments, but is only limited by the claims and their equivalents.

[0043] Example 1:

[0044] A system for monitoring water-soluble ions in air according to an embodiment of the present invention is as follows: Figure 1 Shown, including:

[0045] The cutter 11, the separation device (using a dissolver) 12, the first concentration pipeline and the detection unit (in this embodiment, an ion chromatograph) 81 are connected in sequence.

[0046] The first concentration circuit includes a first pump 21, a first switching valve 31, a first absorption bottle 41, a third switching valve 33, a first reverse osmosis filter 51, a fourth pump 23, a first solvent bottle 61, and a sixth pump 25, which are connected in sequence. The first switching valve 31 selectively connects the outlet of the first pump 21 to the first absorption bottle 41 or the outside world, while the third switching valve 33 selectively connects the outlet of the first absorption bottle 41 to the detection unit 81 or the first reverse osmosis filter 51. A ninth pump 71 and a fifth switching valve 35 are located between the third switching valve 33 and the detection unit 81. The fifth switching valve 35 selectively connects the outlet of the ninth pump 71 to the detection unit 81 or the waste liquid tank 91.

[0047] The monitoring system also includes a sequentially connected particulate matter collection device and a second concentration pipeline. The particulate matter collection device is connected to the separation device 12 and is used to collect particulate matter. The liquid output from the second concentration pipeline after absorbing particulate matter is sent to the detection unit. The particulate matter collection device includes a sequentially connected steam generator 82, a particulate matter growth chamber 13, a condenser 14, and an impactor 15. The particulate matter growth chamber 13 is connected to the separation device 12. The second concentration pipeline includes a sequentially connected second pump 22, a second switching valve 32, a second absorption bottle 42, a fourth switching valve 34, a second reverse osmosis filter 52, a fifth pump 24, a second solvent bottle 62, and a seventh pump 26. The second switching valve 32 is used to selectively connect the outlet of the second pump 22 to the second absorption bottle 42 or the outside world. The fourth switching valve 34 is used to selectively connect the outlet of the second absorption bottle 42 to the detection unit 81 or the second reverse osmosis filter 52. The tenth pump 72 and the sixth switching valve 36 are provided between the fourth switching valve 34 and the detection unit 81 . The sixth switching valve 36 allows the outlet of the tenth pump 72 to selectively connect to the detection unit 81 or the waste liquid tank 91 .

[0048] The calculation device obtains the gaseous ion concentration C1 in the air and the ion concentration C2 in the particulate matter in the air according to the output results of the detection unit and the working parameters in the monitoring system, specifically:

[0049]

[0050] Among them, the output results of the detection unit include C 10 and C 20 , C 10 is the ion concentration output by the detection unit when the first concentration pipeline is connected to the detection unit; C 20 is the ion concentration output by the detection unit when the second concentration pipeline is connected to the detection unit;

[0051] Among them, the working parameters of the monitoring system include: in the first concentration pipeline, L2 is the pipeline volume between the first absorption bottle and the first reverse osmosis filter, L3 is the pipeline volume between the first reverse osmosis filter and the first solvent bottle, when the liquid in the first absorption bottle is sent to the detection unit in each sampling cycle, V1 is the sampling volume of air in each cycle, V2 is the volume of liquid delivered by the first pump in each cycle, the liquid volume in the first absorption bottle is V3, and the liquid volume in the first solvent bottle is V4; in the second concentration pipeline, L6 is the pipeline volume between the second absorption bottle and the second reverse osmosis filter, L7 is the pipeline volume between the second reverse osmosis filter and the second solvent bottle, when the liquid in the second absorption bottle is sent to the detection unit in each sampling cycle, V5 is the sampling volume of air in each cycle, V6 is the volume of liquid delivered by the second pump in each cycle, the liquid volume in the second absorption bottle is V7, and the liquid volume in the second solvent bottle is V8.

[0052] Specifically, the ambient air first passes through the cutter 11, filters out particles of a certain size, and then enters the sampling pipeline of the monitoring system. The air sample in the sampling pipeline includes solid particles and gaseous soluble target substances. The absorption liquid is pumped into the dissolver by the peristaltic pump. The air sample enters the dissolver, and the dissolver captures the soluble gaseous pollutants into the dissolver, converting them into a liquid solution. At this time, the water-soluble ions in the gas are dissolved in the absorption liquid. The first pump 21 pumps the gas sample absorption liquid out of the dissolver, passes through the first switching valve 31 and enters the first absorption bottle 41. The solution in the first absorption bottle 41 then passes through the third switching valve 33 and enters the first reverse osmosis filter 51. The characteristic of the first reverse osmosis filter 51 is that it allows the solvent to pass through, but the solute cannot pass through. Therefore, the liquid after passing through the first reverse osmosis filter 51 is a solvent liquid, which is further pumped into the first solvent bottle 61 by the fourth pump 23.

[0053] As the sampling time increases, the amount of liquid in the first absorption bottle 41 and the first solvent bottle 61 will gradually increase. Both bottles have liquid level sensors (or pressure sensors). When the amount of solution in any of the two bottles reaches the maximum setting value, the first switching valve 31 is switched to allow the gas sample solution from the dissolver to flow into the waste liquid bucket, and the pumping of solution into the first absorption bottle 41 is stopped. At the same time, the third switching valve 33 is switched to start the plunger pump. The software synchronously records the air sampling volume V1 (unit: m 3 ), the volume V2 (unit ml) of liquid pumped out by the first pump 21, the volume V3 (unit ml) of liquid in the first absorption bottle 41, and the volume V4 (unit ml) of solution in the first solvent bottle 61.

[0054] It is understood that the volume of the pipeline between the first pump 21 and the first switching valve 31 is a fixed value, L0; the volume of the pipeline between the first switching valve 31 and the first absorption bottle 41 is a fixed value, L1; the volume of the pipeline between the first absorption bottle 41 and the first reverse osmosis filter 51 is a fixed value, L2 (in ml); and the volume of the pipeline between the first reverse osmosis filter 51 and the first solvent bottle 61 is a fixed value, L3 (in ml). Based on existing technology, technicians can easily determine the actual values of L0, L1, L2, and L3. Based on this volume information, it can be concluded that V2 = L0 + L1 + L2 + L3 + V3 + V4. Therefore, as long as any one value of V3 or V4 is known, the other value can be calculated. Finally, the gaseous ion concentration C1 in the air sample can be calculated according to the above formula.

[0055] Similarly, the ion concentration C2 of the particulate matter in the air sample can be calculated based on the parameters in the second concentration pipeline and the above formula.

[0056] In some embodiments, the gaseous soluble ions in the air sample and the soluble ions in the particulate matter NO3 - The target objects were monitored, and the monitoring results were shown in Tables 1 and 2 below.

[0057] Table 1 Monitoring data of gaseous soluble ions in air samples within 24 hours

[0058]

[0059]

[0060] Table 2 Monitoring data of soluble ions in particulate matter in air samples within 24 hours

[0061]

[0062] The present invention utilizes a filter based on the reverse osmosis principle and a novel water-soluble ion monitoring system flow path to achieve the concentration of the sample solution. The concentration multiple is the multiple of improvement in the detection limit level. After the improvement, the measurement accuracy is greatly improved for weather with very low pollutant concentrations.

[0063] The present invention also provides a method for monitoring water-soluble ions in air based on the monitoring system of an embodiment of the present invention, the monitoring method comprising:

[0064] The sample gas passes through the separation device and the particle collection device in sequence. The separation device captures the gaseous soluble target in the sample gas to form a first portion of the target solution. The particle collection device absorbs the solid particles in the sample gas to form a second portion of the target solution.

[0065] The first concentrating pipeline concentrates the first part of the target solution and then inputs it into the detection unit, and the detection unit outputs the measured concentration C of the ions in the first part of the target solution. 10 ;

[0066] The second concentrating pipeline concentrates the second part of the target solution and then inputs it into the detection unit, and the detection unit outputs the measured concentration C of the ions in the second part of the target solution. 20 ;

[0067] The calculation device obtains the concentration C1 of the gaseous soluble target matter in the air and the concentration C2 of the ions in the solid particles in the air according to the output result of the detection unit and the working parameters in the monitoring system.

[0068] In some embodiments, determining the calibration curve segment corresponding to the detection signal based on the detection signal and the calibration curve includes:

[0069] If the detection signal does not belong to the signal interval corresponding to any calibration curve segment or the detection signal corresponds to more than two calibration curve segments, the corresponding calibration curve segment is selected by comparing the measurement errors of the critical concentrations of two adjacent calibration curve segments of the detection signal, and the calibration curve segment with the relatively smaller measurement error among the two is used as the corresponding calibration curve segment.

[0070] In some embodiments, determining the calibration curve segment corresponding to the detection signal based on the detection signal and the calibration curve includes:

[0071] If the detection signal does not belong to the signal interval corresponding to any calibration curve segment or the detection signal corresponds to more than two calibration curve segments, the size of the correlation coefficient of the two adjacent calibration curve segments of the detection signal is determined, and the calibration curve segment with the relatively larger correlation coefficient is used as the corresponding calibration curve segment.

[0072] In some embodiments, calibrating the detection unit to establish a calibration curve comprises:

[0073] Divide the total concentration range of specific ions into intervals;

[0074] Obtain the proportion of concentration detection data in each interval within the statistical time;

[0075] Adjusting the interval division based on the proportion so that the proportion meets a preset ratio;

[0076] A new calibration curve segment is established for each concentration interval based on the adjusted interval division.

[0077] Specifically, the detection unit 81 outputs the measured concentration C of gaseous soluble ions. 10, measured concentration of soluble ions in particulate matter C 20 The concentration is obtained by: the detection unit 81 outputs a signal, a calibration curve corresponding to the signal is found in a plurality of segmented calibration curves, and the concentration corresponding to the signal is obtained using the calibration curve. The calibration curve is a mapping relationship between concentration and signal.

[0078] The segmented calibration curve can be obtained by dividing the concentration range of each ion into n concentration ranges based on previous measurement data, for example, n=4, and dividing the concentration ranges S1, S2, S3, and S4 from low to high, corresponding to the concentrations of 0-s1, s1-s2, s2-s3, and s3-s4, respectively.

[0079] Furthermore, since the ambient air quality will change to a certain extent in different seasons, a certain time period can be set and the data within the period can be statistically analyzed. For example, the concentration data of the week can be analyzed every week to see the distribution of the concentration data and the proportion of data falling into each concentration range. If the proportion has not changed significantly compared with the previous period, the original concentration range and calibration curve will continue to be used. If the proportion of data in several ranges has changed significantly compared with the past week, the concentration interval can be adjusted and the calibration curve can be re-produced, wherein a new calibration curve segment is established for each concentration interval based on the adjusted interval division, that is, based on the previous measurement data, the calibration curve is fitted for the data in the re-divided concentration interval.

[0080] Among them, adjusting the interval division based on the proportion so that the proportion conforms to the preset ratio means refining the monitoring granularity of the main distribution range of data in the current environment according to the actual pollution situation. For example, the concentration range S10, S20, S30, S40 corresponds to 0-s 10 、s 10 -s 20 、s 20 -s 30 、s 30 -s 40 , four concentration ranges. In the first week, the data accounted for 20%, 30%, 30%, and 20%. It is believed that the proportion is reasonable, so the same calibration curve is used in the second week. After the end of the second week, the concentration data of the second week are counted. If the proportion of a certain gear changes by more than 10%, the calibration curve needs to be readjusted. For example, if the proportion changes to 40%, 30%, 20%, and 10% according to the previous concentration range, it means that the number of low-concentration data points has increased this week and the overall pollution has become lighter. At this time, the concentration range can be adjusted according to the data of the second week, and the concentration ranges S11, S21, S31, and S41 can be readjusted to correspond to 0-s 11 、s 11 -s 21、s 21 -s 31 、s 31 -s 41 , resulting in a concentration distribution of approximately 20%, 30%, 30%, and 20% in the second week. This is equivalent to adjusting the cutoff point in the low-concentration range to a smaller value, making the low-concentration range calibration points more densely populated, which is more conducive to low-concentration data measurement. Similarly, if the proportion of high-concentration data suddenly increases, making corresponding adjustments, the high-concentration range calibration points will be more densely populated, resulting in higher high-concentration measurement accuracy.

[0081] In the above four ranges, select n different concentration solutions including the upper and lower limits to establish the calibration curve. For example, n = 3. In the range of S1, three concentration points can be selected: 0, the middle concentration point between 0 and s1, and the s1 concentration point for calibration. According to this calibration point selection requirement, four calibration curves Q1, Q2, Q3, and Q4 are established under the four concentration ranges S1, S2, S3, and S4. The measurement errors of the upper and lower concentration points are measured respectively under the four calibration curves. Q1 △0 、Q1 △1 、Q2 △1 、Q2 △2 、Q3 △2 、Q3 △3 、Q4 △3 、Q4 △4 .

[0082] In some embodiments, when a sample enters an ion chromatograph for measurement, a calibration curve corresponding to the concentration range is selected for calibration based on the sample's measured signal to obtain the final concentration measurement value. However, due to factors such as instrument measurement errors and human manipulation, the calibration curve segments for different concentration ranges are not continuous, resulting in two situations:

[0083] In some embodiments, the detection signal is located between the signal ranges of the calibration curves Q1 and Q2 of the two concentration intervals S1 and S2, and does not belong to the range of any of the calibration curves. In this case, the calibration curve Q1 is used to calibrate the signal point to obtain the concentration x 11 , and x 11 In the S2 range; at this time, the calibration curve Q2 is used to calibrate the signal point to obtain the concentration x 12 , and x 12 In the range of S1. To solve this problem, the present invention has the following two solutions: ① Determine the measurement error Q1 of the two calibration curves Q1 and Q2 for the concentration s1 △1 and Q2 △1 ② Determine the correlation coefficient between the two calibration curves and select the one with the higher correlation coefficient as the calibration curve for signal point x1. The first solution is the best.

[0084] In some embodiments, the detection signal is located in the repeated interval where the calibration curves Q3 and Q4 of the two concentration intervals S3 and S4 intersect, and belongs to both Q3 and Q4. In this case, the calibration curve Q3 is used to calibrate the signal point to obtain the concentration x 23 , x 23 In the range of S3; at this time, the calibration curve Q4 is used to calibrate the signal point to obtain the concentration x 24 , x 24 In view of this problem, the present invention has the following two solutions: ① Determine the measurement error Q3 of the two calibration curves Q3 and Q4 for the concentration s3 △3 and Q4 △3 ② Determine the correlation coefficient between the two calibration curves and select the one with the higher correlation coefficient as the calibration curve for signal point x2. The first solution is the best.

[0085] The embodiment of the present invention can intelligently match calibration curves of different concentration ranges according to the measurement signal of each ion, which can greatly improve the measurement accuracy.

[0086] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A system for monitoring water-soluble ions in air, characterized in that: include: a separation device for capturing gaseous soluble target matter in the input sample gas to form a first portion of the target matter solution and allowing solid particulate matter in the sample gas to pass through; A detection unit, used for analyzing the components of the input solution; a first concentration pipeline, connected to the separation device and the detection unit, respectively, for concentrating the first portion of the target solution and then inputting the concentrated solution into the detection unit; a particle collecting device connected to the separation device and configured to absorb the solid particles to form a second portion of the target solution; a second concentration pipeline, connected to the particle collection device and the detection unit, respectively, for concentrating the second portion of the target solution and then inputting it into the detection unit; The first concentration pipeline and the second concentration pipeline each include an absorption bottle, a reverse osmosis filter, a pump, and a solvent bottle connected in sequence. The pipeline between the absorption bottle and the reverse osmosis filter is connected to the detection unit. The absorption bottle is used to accommodate an input target solution. The pump is used to allow the solvent of the target solution to enter the solvent bottle through the reverse osmosis filter, so that the target solution in the absorption bottle is concentrated. A calculation device, wherein the calculation device obtains the concentration C1 of the gaseous soluble target substance in the air and the concentration C2 of the ions in the solid particulate matter in the air according to the output result of the detection unit and the operating parameters in the monitoring system; The first concentration pipeline includes a first pump, a first switching valve, a first absorption bottle, a first reverse osmosis filter, and a first solvent bottle connected in sequence. The pipeline between the first absorption bottle and the first reverse osmosis filter is connected to the detection unit. The first switching valve is used to selectively connect the outlet of the first pump to the first absorption bottle or the outside world. The second concentration pipeline includes a second pump, a second switching valve, a second absorption bottle, a second reverse osmosis filter, and a second solvent bottle connected in sequence, the pipeline between the second absorption bottle and the second reverse osmosis filter is connected to the detection unit, and the second switching valve is used to selectively connect the outlet of the second pump to the second absorption bottle or the outside world; ， ； C 10 is the ion concentration output by the detection unit when the first concentration pipeline is connected to the detection unit, L2 is the pipe volume between the first absorption bottle and the first reverse osmosis filter, L3 is the pipe volume between the first reverse osmosis filter and the first solvent bottle, when the liquid in the first absorption bottle is sent to the detection unit in each sampling cycle, V1 is the sampling volume of air in each cycle, V2 is the volume of liquid delivered by the first pump in each cycle, the liquid volume in the first absorption bottle is V3, and the liquid volume in the first solvent bottle is V4; C 20 It is the ion concentration output by the detection unit when the second concentration pipeline is connected to the detection unit, L6 is the pipe volume between the second absorption bottle and the second reverse osmosis filter, L7 is the pipe volume between the second reverse osmosis filter and the second solvent bottle, when the liquid in the second absorption bottle is sent to the detection unit in each sampling cycle, V5 is the sampling volume of air in each cycle, V6 is the volume of liquid delivered by the second pump in each cycle, the liquid volume in the second absorption bottle is V7, and the liquid volume in the second solvent bottle is V8.

2. The monitoring system according to claim 1, characterized in that The separation device adopts a dissolver, the particle collection device includes a steam generator, a particle growth cavity, a condenser and an impactor connected in sequence, the particle growth cavity is connected to the separation device, and the detection unit adopts an ion chromatograph.

3. A method for monitoring water-soluble ions in air, using the monitoring system according to any one of claims 1 to 2, the monitoring method comprising: The sample gas passes through the separation device and the particle collection device in sequence. The separation device captures the gaseous soluble target in the sample gas to form a first portion of the target solution. The particle collection device absorbs the solid particles in the sample gas to form a second portion of the target solution. The first concentrating pipeline concentrates the first part of the target solution and then inputs it into the detection unit, and the detection unit outputs the measured concentration C of the ions in the first part of the target solution. 10 ; The second concentrating pipeline concentrates the second part of the target solution and then inputs it into the detection unit, and the detection unit outputs the measured concentration C of the ions in the second part of the target solution. 20 ; The calculation device obtains the concentration C1 of the gaseous soluble target matter in the air and the concentration C2 of the ions in the solid particles in the air according to the output result of the detection unit and the working parameters in the monitoring system.

4. The monitoring method according to claim 3, characterized in that: The method for measuring the concentration of the target solution by the detection unit includes: Calibrate the detection unit to establish a calibration curve, wherein the calibration curve includes a plurality of calibration curve segments, and the calibration curve segments include linear correspondence curves between concentrations and output signals of the detection unit within a concentration range; Inputting the target solution into the detection unit, and the detection unit outputting a detection signal; determining a calibration curve segment corresponding to the detection signal based on the detection signal and the calibration curve; A concentration value is determined based on the determined calibration curve segment and the detection signal.

5. The monitoring method according to claim 4, characterized in that: The determining, based on the detection signal and the calibration curve, a calibration curve segment corresponding to the detection signal comprises: If the detection signal does not belong to the signal interval corresponding to any calibration curve segment or the detection signal corresponds to more than two calibration curve segments, the corresponding calibration curve segment is selected by comparing the measurement errors of the critical concentrations of two adjacent calibration curve segments of the detection signal, and the calibration curve segment with the relatively smaller measurement error among the two is used as the corresponding calibration curve segment.

6. The monitoring method according to claim 4, characterized in that: The determining, based on the detection signal and the calibration curve, a calibration curve segment corresponding to the detection signal comprises: If the detection signal does not belong to the signal interval corresponding to any calibration curve segment or the detection signal corresponds to more than two calibration curve segments, the size of the correlation coefficient of the two adjacent calibration curve segments of the detection signal is determined, and the calibration curve segment with the relatively larger correlation coefficient is used as the corresponding calibration curve segment.

7. The monitoring method according to claim 4, characterized in that: The step of calibrating the detection unit to establish a calibration curve comprises: Divide the total concentration range of the ions to be measured into intervals; Obtain the proportion of concentration detection data in each interval within the statistical time; Adjusting the interval division based on the proportion so that the proportion meets a preset ratio; A new calibration curve segment is established for each concentration interval based on the adjusted interval division.

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