System and method for monitoring water-soluble ions in air

Abstract

The invention relates to environmental protection monitoring, in particular to a monitoring system and method for water-soluble ions in air, and the monitoring system comprises a separation device, a detection unit, a first concentration pipeline, a particulate matter collection device, a second concentration pipeline and a calculation device, each of the first concentration pipeline and the second concentration pipeline comprises an absorption bottle, a reverse osmosis filter, a pump and a solvent bottle which are sequentially connected, a pipeline between the absorption bottle and the reverse osmosis filter is communicated with the detection unit, and the absorption bottle is used for accommodating an input target solution; the pump is used for enabling a solvent of a target solution to enter the solvent bottle through the reverse osmosis filter, so that the target solution in the absorption bottle is concentrated, and the calculation device obtains the concentration C1 of a gaseous soluble target in air according to an output result of the detection unit and working parameters in the monitoring system. And the ion concentration C2 in the solid particulate matters in the air.

Description

Technical Field

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

[0002] Atmospheric particulate matter (such as PM 10 , PM 2.5 , etc.) has adverse effects on air quality, human health, atmospheric visibility, and global climate change. Water-soluble ions are an important component of atmospheric particulate matter. Monitoring the concentration changes of water-soluble ion components in atmospheric particulate matter is of great significance for air pollution control.

[0003] The traditional analysis method for water-soluble ion components in atmospheric particulate matter is to collect particulate matter through a filter membrane and then send it to a laboratory for weighing, dissolving, extracting, and analyzing using ion chromatography. This method has disadvantages such as large sampling errors for particulate matter, easy loss during sample storage, time-consuming and laborious, and inability to reflect the high-frequency change law of water-soluble components in atmospheric particulate matter. The continuously automatic monitoring system and method for water-soluble ions in the air introduced in recent years have well solved the above problems. The general sampling and analysis period of the above system is 1h, and the solution is replaced once, and it can work continuously for 10 - 50 days. It is a powerful tool for environmental monitoring departments and atmospheric environmental protection departments to monitor and analyze ion components in aerosols and gases.

[0004] In recent years, the environmental air quality in China has been significantly improved, and the pollutant concentration has been greatly reduced. The concentration of PM 2.5 is several μg / m 3 -20 μg / m 3 There are more such clean weather conditions, and the concentration of water-soluble ions in the air remains at a relatively low level for a long time. The concentrations of ions such as Cl - , Na + , K + , Mg 2+ , Ca 2+ can reach a minimum of 10 -2 μg / m 3 or even 10 -3 μg / m 3 concentration level. However, the detection limit levels of the above ion components in the existing on-line monitoring products for water-soluble ions in the air are in the range of 10 -2 μg / m 3 -10 -1 μg / m 3 magnitude range, and cannot accurately monitor water-soluble ions at lower concentrations, resulting in poor quality of measurement data.

[0005] Current on-line monitoring products for water-soluble ions in the air have a large measurement concentration range, and the calibration curve spans a large range from low concentration to high concentration. Currently, the low-concentration situation is more common. In summer, PM2.5 Sometimes, it is only a few μg / m for a long time 3 , and the ion concentration remains in a low range continuously. Only when there are special polluted weather conditions will high concentration occur. In the current water-soluble ion monitoring system, most use the same set of calibration curves to measure low-concentration and high-concentration samples, which will lead to poor applicability and further result in relatively large measurement errors. Summary of the Invention

[0006] To solve the deficiencies in the above-mentioned prior art solutions, the present invention provides an air water-soluble ion monitoring system, including:

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

[0008] A detection unit for performing component analysis on the input solution;

[0009] A first concentration pipeline, connected to the separation device and the detection unit respectively, for concentrating the first part of the target substance solution and then inputting it into the detection unit;

[0010] A particulate matter collection device, connected to the separation device, for absorbing the solid particulate matter to form a second part of the target substance solution;

[0011] A second concentration pipeline, connected to the particulate matter collection device and the detection unit respectively, for concentrating the second part of the target substance solution and then inputting it into the detection unit;

[0012] Both the first concentration pipeline and the second concentration pipeline 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 communicates with the detection unit. The absorption bottle is used to hold the input target substance solution, and the pump is used to make the solvent of the target substance solution pass through the reverse osmosis filter and enter the solvent bottle, so as to concentrate the target substance solution in the absorption bottle

[0013] A calculation device, which obtains the concentration C1 of gaseous soluble target substances in the air and the ion concentration C2 in solid particulate matter 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. The pipeline between the first absorption bottle and the first reverse osmosis filter communicates with 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;

[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 communicates with 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.

[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 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 period, V1 is the sampling volume of air in each period, V2 is the liquid volume transported by the first pump in each period, the liquid volume in the first absorption bottle is V3, and the liquid volume in the first solvent bottle is V4; C 20 is the ion concentration output by the detection unit when the second concentration pipeline is connected to the detection unit. 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 period, V5 is the sampling volume of air in each period, V6 is the liquid volume transported by the second pump in each period, 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 an eroder. The particulate matter collection device includes a steam generator, a particulate matter growth chamber, a condenser, and an impactor connected in sequence. The particulate matter growth chamber is connected to the separation device. The detection unit uses an ion chromatograph.

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

[0020] The sample gas sequentially passes through the separation device and the particulate matter collection device. The separation device captures the gaseous soluble target substances in the sample gas to form a first part of the target substance solution. The particulate matter collection device absorbs the solid particulate matter in the sample gas to form a second part of the target substance solution;

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

[0022] The second concentration pipeline concentrates the second part of the target solution and 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 in the air and the ion concentration C2 in the solid particulate matter 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 the detection unit to measure the concentration of the target solution includes:

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

[0026] Input the target solution into the detection unit, and the detection unit outputs a detection signal;

[0027] Based on the detection signal and the calibration curve, determine the calibration curve segment corresponding to the detection signal;

[0028] Based on the determined calibration curve segment and the detection signal, determine the concentration value.

[0029] In some embodiments, the 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, then compare the measurement errors of the critical concentrations of the two calibration curve segments adjacent to the detection signal to select the corresponding calibration curve segment, and use the calibration curve segment with the relatively smaller measurement error as the corresponding calibration curve segment.

[0031] In some embodiments, the 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, then judge the magnitude of the correlation coefficients of the two calibration curve segments adjacent to the detection signal, and use the calibration curve segment with the relatively larger correlation coefficient as the corresponding calibration curve segment.

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

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

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

[0036] Adjust the interval division based on the proportion so that the proportion meets a preset ratio; establish a new calibration curve segment for each concentration interval based on the adjusted interval division.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. A filter using the reverse osmosis principle and a flow path of a new type of water-soluble ion monitoring system are used to achieve the concentration of the sample solution. The concentration multiple is the improvement multiple of the detection limit level. After improvement, for the weather with very low pollutant concentration, the measurement accuracy is greatly improved;

[0039] 2. According to the measurement signals of each ion, the calibration curves in different concentration ranges are intelligently matched, which can greatly improve the measurement accuracy. Brief Description of the Drawings

[0040] Referring to the accompanying drawings, the disclosure of the present invention will become more understandable. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention. In the drawings:

[0041] Figure 1 is a schematic structural diagram of the monitoring system according to an embodiment of the present invention. Detailed Description of the Embodiments

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

[0043] Example 1:

[0044] An air water-soluble ion monitoring system according to an embodiment of the present invention, as Figure 1 shown, includes:

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

[0046] The first concentration pipeline 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 that are connected in sequence. The first switching valve 31 is used to selectively connect the outlet of the first pump 21 to the first absorption bottle 41 or the outside. The third switching valve 33 is used to selectively connect 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 arranged 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 bucket 91.

[0047] The monitoring system further includes a particulate matter collection device and a second concentration pipeline that are connected in sequence. The particulate matter collection device is connected to the separation device 12 and is used to collect particulate matter. The liquid after absorbing particulate matter output by the second concentration pipeline is sent to the detection unit. The particulate matter collection device includes a steam generator 82, a particulate matter growth chamber 13, a condenser 14, and an impactor 15 that are connected in sequence. The particulate matter growth chamber 13 is connected to the separation device 12. The second concentration pipeline includes a 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 that are connected in sequence. 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. 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. A tenth pump 72 and a sixth switching valve 36 are arranged between the fourth switching valve 34 and the detection unit 81. The sixth switching valve 36 selectively connects the outlet of the tenth pump 72 to the detection unit 81 or the waste liquid bucket 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 result of the detection unit and the working parameters in the monitoring system. Specifically:

[0049]

[0050] Among them, the output result of the detection unit includes 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, and 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 period, V1 is the sampling volume of air in each period, V2 is the liquid volume transported by the first pump in each period, 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, and 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 period, V5 is the sampling volume of air in each period, V6 is the liquid volume transported by the second pump in each period, the liquid volume in the second absorption bottle is V7, and the liquid volume in the second solvent bottle is V8.

[0052] Specifically, first, the ambient air passes through the cutter 11. After screening out particulate matters of a certain particle size, it enters the sampling pipeline of the monitoring system. The air sample in the sampling pipeline includes solid particulate matters and gaseous soluble target substances. The absorbent liquid is pumped into the denuder by the peristaltic pump, and the air sample enters the denuder. The denuder captures the soluble gaseous pollutants into the denuder and converts them into a liquid solution. At this time, the water-soluble ions in the gas dissolve in the absorbent liquid. The first pump 21 pumps the gas sample absorbent liquid out of the denuder, 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 while the solute cannot pass through. Therefore, the liquid after passing through the first reverse osmosis filter 51 is the solvent liquid, and this liquid is continuously pumped into the first solvent bottle 61 by the fourth pump 23.

[0053] As the sampling time increases, the liquid volumes in the first absorption bottle 41 and the first solvent bottle 61 will gradually increase. There are liquid level sensors (or pressure sensors) in both bottles. After the amount of the solution in any one of the two bottles reaches the maximum set value, the first switching valve 31 is switched to let the gas sample solution coming out of the denuder flow into the waste liquid bucket, and stop pumping the solution into the first absorption bottle 41. At the same time, the third switching valve 33 is switched to turn on the plunger pump. The software synchronously records the air sampling volume V1 (unit: m 3 ) at this time, the liquid volume V2 (unit: ml) pumped out by the first pump 21, the liquid volume V3 (unit: ml) in the first absorption bottle 41, and the solution volume V4 (unit: ml) in the first solvent bottle 61.

[0054] It is understandable 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 (unit: 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 (unit: ml). Technicians can easily determine the actual values of L0, L1, L2, and L3 according to the existing technology; according to the above volume information, it can be obtained that V2 = L0 + L1 + L2 + L3 + V3 + V4. Therefore, as long as any one of the values of V3 and 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, according to the parameters in the second concentration pipeline and the above formula, the ion concentration C2 in the particulate matter of the air sample can be calculated.

[0056] In some embodiments, the gaseous soluble ions in the air sample and the soluble ion NO3 in the particulate matter - are used as the target substances for monitoring, and the monitoring results are shown in Table 1 and Table 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 of air samples within 24 hours

[0061]

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

[0063] The present invention also provides a method for monitoring water-soluble ions in the air based on the monitoring system of the embodiments of the present invention. The monitoring method includes:

[0064] The sample gas sequentially passes through a separation device and a particulate matter collection device. The separation device captures the gaseous soluble target substances in the sample gas to form a first part of the target substance solution, and the particulate matter collection device absorbs the solid particulate matter in the sample gas to form a second part of the target substance solution;

[0065] The first concentration 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 concentration 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 in the air and the ion concentration C2 in the solid particulate matter 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, then the corresponding calibration curve segment is selected by comparing the measurement errors of the critical concentrations of the two adjacent calibration curve segments of the detection signal, and the calibration curve segment with the relatively smaller measurement error of 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, then the correlation coefficients of the two adjacent calibration curve segments of the detection signal are judged, and the calibration curve segment with the relatively larger correlation coefficient of the two is used as the corresponding calibration curve segment

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

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

[0074] Obtaining the proportion of the concentration detection data within each interval during the statistical time;

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

[0076] Based on the adjusted interval division, a new calibration curve segment is established for each concentration interval

[0077] Specifically, the detection unit 81 outputs the measured concentration C of the gaseous soluble ions 10, the measured concentration C of soluble ions in particulate matter 20 . The way to obtain the concentration is as follows: The detection unit 81 outputs a signal, searches for the calibration curve corresponding to this signal among multiple segmented calibration curves, and uses this calibration curve to obtain the concentration corresponding to the signal. The calibration curve is the mapping relationship between concentration and signal.

[0078] The way to obtain the segmented calibration curve can be: According to past measurement data, divide each ion concentration range into n concentration ranges. For example, n = 4, and divide it into 4 concentration ranges S1, S2, S3, S4 in ascending order of concentration, corresponding to concentrations: 0 - s1, s1 - s2, s2 - s3, 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 this period can be statistically analyzed. For example, analyze the concentration data of each week to see the distribution of the concentration data, and find out what the proportion of the data falling into each concentration range is. If the proportion has not changed significantly compared to before, then continue to use the original concentration range and calibration curve. If the proportion of the data in several ranges has changed significantly compared to the previous week, then the concentration interval can be adjusted and a new calibration curve can be made. Among them, new calibration curve segments are established for each concentration interval based on the adjusted interval division, that is, according to past measurement data, calibration curve fitting is performed on the data in the re - divided concentration intervals respectively.

[0080] Among them, adjusting the interval division based on the proportion so that the proportion meets the preset ratio means refining the monitoring granularity of the main distribution range of the data in the current environment according to the actual pollution situation. For example, the concentration ranges S10, S20, S30, S40, corresponding 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 proportions are 20%, 30%, 30%, 20%. It is considered that this proportion is reasonable. Therefore, the same calibration curve is used in the second week. After the second week, the concentration data of the second week is statistically analyzed. If the proportion change of a certain gear exceeds 10%, then the calibration curve needs to be adjusted again. For example, if according to the previous concentration range, the proportion becomes 40%, 30%, 20%, 10%, it means that there are more low - concentration data points this week and the overall pollution becomes 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, S41 are re - adjusted, corresponding to 0 - s 11 , s 11 - s 21, s 21 -s 31 , s 31 -s 41 , such that the concentration distribution ratio in the second week is about 20%, 30%, 30%, 20%, which is equivalent to making the demarcation point of the low concentration range smaller and the calibration points in the low concentration range denser, being more conducive to the measurement of low concentration data. Similarly, if the proportion of high concentration data suddenly increases, after corresponding adjustment, the calibration points in the high concentration range will be denser and the high concentration measurement accuracy will be higher.

[0081] Within the above four ranges, select n different concentration solutions including the upper and lower limits to establish a calibration curve. For example, when n = 3, within the range S1, the intermediate concentration point between 0, 0 and s1, and the concentration point s1 can be selected, and three concentration points are used for calibration. According to this calibration point selection requirement, establish four calibration curves Q1, Q2, Q3, Q4 under four concentration ranges S1, S2, S3, S4, and measure the measurement errors of the upper and lower limit concentration points 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 chromatography measurement, according to the measured signal of the sample, select the calibration curve corresponding to the concentration interval for calibration to obtain the final concentration measurement value. However, due to factors such as the measurement error of the instrument and the influence of human operation, the calibration curve segments between different concentration intervals are not continuous, and there will be two situations:

[0083] In some embodiments, the detection signal is between the signal ranges of the calibration curves Q1 and Q2 of two concentration intervals S1 and S2 and does not belong to the range of any one of the calibration curves. At this time, use the calibration curve Q1 to calibrate this signal point to obtain the concentration x 11 , and x 11 is within the range of S2; at this time, use the calibration curve Q2 to calibrate this signal point to obtain the concentration x 12 , and x 12 is within the range of S1. For this problem, there are the following two solutions in the scheme of the present invention: ① Judge the measurement errors Q1 △1 and Q2 △1 of the two calibration curves Q1 and Q2 for the concentration s1, and select the calibration curve with the smaller error as the calibration curve for the x1 point; ② Judge the correlation coefficients of the two calibration curves and select the calibration curve with the higher correlation coefficient as the calibration curve for the signal point x1. The first solution is preferred.

[0084] In some embodiments, the detection signal is within the overlapping range where the calibration curves Q3 and Q4 corresponding to two concentration ranges S3 and S4 intersect, belonging to both Q3 and Q4. In this case, the calibration curve Q3 is used to calibrate this signal point to obtain the concentration x 23 , x 23 which is within the range of S3; in this case, the calibration curve Q4 is used to calibrate this signal point to obtain the concentration x 24 , x 24 which is within the range of S4. To address this issue, the solution of the present invention has the following two methods: ① Judge the measurement errors Q3 △3 and Q4 △3 of the two calibration curves Q3 and Q4 for the concentration s3, and select the calibration curve with the smaller error as the calibration curve for the x2 point; ② Judge the correlation coefficients of the two calibration curves, and select the calibration curve with the higher correlation coefficient as the calibration curve for the signal point x2. The first method is preferred.

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

[0086] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present 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 substances in the input sample gas to form a first portion of the target substance solution, and allowing solid particles 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 part of the target solution and then inputting it into the detection unit; a particle collecting device, connected to the separation device, and used to absorb the solid particles to form a second portion of the target solution; A second concentration pipeline is connected to the particle collection device and the detection unit respectively, and is used to concentrate the second part of the target solution and then input 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 contain the input target solution, and 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 is provided for obtaining the concentration C1 of the gaseous soluble target 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.

2. The monitoring system according to claim 1, characterized in that: The first concentration pipeline comprises 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; 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.

3. The monitoring system according to claim 2, characterized in that: 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 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; 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 pipeline volume from the second absorption bottle to 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.

4. The monitoring system according to claim 1, characterized in that: The separation device adopts a dissolver, the particle collection device comprises 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.

5. A method for monitoring water-soluble ions in air, using the monitoring system according to any one of claims 1 to 4, 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 part of the target solution, and the particle collection device absorbs the solid particles in the sample gas to form a second part 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 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.

6. The monitoring method according to claim 5, characterized in that: The method for measuring the concentration of a 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 a linear correspondence curve between the concentration in a specific concentration range and the output signal of the detection unit; Inputting the target solution into the detection unit, and the detection unit outputs 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.

7. The monitoring method according to claim 6, 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 a relatively small measurement error is used as the corresponding calibration curve segment.

8. The monitoring method according to claim 6, 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 two adjacent calibration curve segments of the detection signal is determined, and the calibration curve segment with a relatively large correlation coefficient is taken as the corresponding calibration curve segment.

9. The monitoring method according to claim 6, characterized in that: The step of calibrating the detection unit to establish a calibration curve comprises: Divide the total concentration range of specific ions 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.

Images