CN111397977B - System and method for sampling and testing selenium and selenium compounds in waste gas of fixed pollution source - Google Patents
System and method for sampling and testing selenium and selenium compounds in waste gas of fixed pollution source Download PDFInfo
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Abstract
The system comprises a nozzle, a filter, a three-way valve, an absorption system, a suction pump, a gas accumulation flowmeter and a rotameter, wherein if the measured flow or the total sampling volume of gaseous selenium and granular selenium is different; the nozzle is connected with the filter, the filter is communicated with the inlet of the three-way valve through a conveying pipeline, one outlet of the three-way valve is connected with the first conveying pipe, the other outlet of the three-way valve is connected with the inlet of the adsorption system, the outlet of the adsorption system is communicated with the second conveying pipe, and the first conveying pipe and the second conveying pipe are respectively provided with a pressure gauge, a thermometer, a gas accumulation flowmeter and a rotameter. The method has strong dust interference resistance and SO resistance 2 The method has strong interference capability, is accurate and reliable, and can realize the sampling and measurement of selenium and selenium compounds under the complex smoke conditions of coal-fired power plants, glass kilns, garbage incineration plants, coking industry, cement industry, nonferrous metal smelting and the like.
Description
Technical Field
The invention relates to a sampling and measuring system of heavy metals, in particular to a sampling and measuring system and method of selenium and selenium compounds in waste gas with fixed pollution sources, which are suitable for sampling and measuring the selenium and selenium compounds in coal-fired power plants, glass kilns, garbage burning plants, coking industries, cement industries, nonferrous metal smelting and the like.
Background
Coal is a very complex solid hydrocarbon fuel which is formed by mixing various organic compounds and inorganic minerals and is converted by long-term complex biochemical, geochemical, physical and chemical actions. The extreme complexity of the structural composition of coal, known as trace elements (trace elements), is less than 100ppm in coal, including a variety of toxic trace elements such as Hg, cr, as, se. Trace heavy metal elements and compounds thereof have quite large toxicity even under the condition of low concentration, can cause serious pollution to ecological environments such as water, atmosphere, soil and the like, and are closely related to the health of human beings, plants and animals. Trace elements are released from coal in the combustion process and undergo a series of physical and chemical changes, and finally, as flue gas, fly ash and slag are discharged into the environment, the environment including the atmosphere, water and soil is polluted, most of the trace elements are not degraded by microorganisms, can be precipitated in human bodies and converted into metal organic compounds with great toxicity, and the direct or indirect harm is generated to the health of human bodies. Trace elements of greatest concern in environmental pollution are mercury, cadmium, lead, chromium, arsenic, selenium, and the like.
Researches show that a proper amount of selenium has the functions of preventing and resisting cancer, preventing and treating cardiovascular diseases, keshan disease and major bone diseases, resisting aging, resisting radiation, enhancing organism immunity and the like. However, high selenium causes selenium poisoning, which causes alopecia, nail loss, hemiplegia, etc., and the selenium intake must be controlled within a narrow range, and excessive or insufficient selenium content can cause diseases and poisoning. Selenium and selenium compounds have different toxicity depending on the existence forms, simple substance selenium is non-toxic in practice, the toxicity of sodium selenite is greater than that of sodium selenate, and the toxicity of hydrogen selenide is five times greater than that of selenium dioxide, so that the selenium and selenium compounds are the most toxic of all the currently known selenium compounds. There are two sources of selenium in the environment: artificial and natural sources. Combustion of fossil fuels is mainly caused by human activities, followed by nonferrous metal smelting, glass and ceramic products and machining. Selenium smoke dust and selenium-containing wastewater pollute the surrounding environment, and endanger animals, plants and human beings. After the selenium smoke dust is discharged into the atmosphere, dust particles with diameters larger than 10 microns generally settle in places with short distances, and dust particles with diameters smaller than 10 microns can float in the air for a long time. The selenium-containing wastewater is discharged into the lake sea, so that the water quality in local areas can be polluted, the aquatic organisms are damaged, and the fishery production is lost. Selenium has obvious accumulation phenomenon in soil and animals and plants. It has been found that when the selenium concentration in water is greater than 0.05ppm, 4 to 5ppm can be accumulated in soil and feed, when the selenium content in soil is 45ppm, the selenium content in grown rice, corn is 15 to 40ppm, and vegetables can reach 54 to 72ppm. Early in the 30 s in alaska, usa, livestock caused chronic poisoning by ingestion of selenium-containing plants in grassland areas. Selenium produced by coal burning has resulted in a wide range of fish deaths in north carolina and texas in the united states. Selenium poisoning is caused by utilization of high-selenium stone coal of sun of Shaanxi and Hubei, 477 cases of selenium poisoning events are found in southwest China.
High dust interference resistance and SO resistance 2 The method for sampling and measuring selenium with strong interference capability and accuracy and reliability has great significance, and is a precondition for grasping the emission level of the actual selenium and further carrying out pollution control and related research.
Disclosure of Invention
The invention aims to provide a dust-interference-resistant and SO-resistant material with strong dust-interference-resistant capability 2 The system and the method for sampling and testing the selenium and selenium compounds in the waste gas of the fixed pollution source, which have strong interference capability, are accurate and reliable, can accurately grasp the emission level of the selenium and the selenium compounds, and provide a reliable testing means for pollution control and related research.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
the system comprises a nozzle, a filter, an absorption system, a suction pump, a gas accumulation flowmeter and a rotameter, wherein the sampling and testing system is used for sampling selenium and selenium compounds in waste gas of a fixed pollution source; the nozzle is connected with the filter, the filter is connected with the inlet of the absorption system through a conveying pipeline, and a pressure meter, a thermometer, a gas accumulation flowmeter and a rotameter are arranged on the pipeline of the outlet of the absorption system;
if the measured flow or total sampling volume of the gaseous selenium and the granular selenium are different, the system comprises a nozzle, a filter, a three-way valve, an absorption system, a suction pump, a gas accumulation flowmeter and a rotameter; the nozzle is connected with the filter, the filter is communicated with the inlet of the three-way valve through a conveying pipeline, one outlet of the three-way valve is connected with the first conveying pipe, the other outlet of the three-way valve is connected with the inlet of the adsorption system, the outlet of the adsorption system is communicated with the second conveying pipe, and the first conveying pipe and the second conveying pipe are respectively provided with a pressure gauge, a thermometer, a gas accumulation flowmeter and a rotameter.
A further improvement of the invention is that the absorption system comprises HNO connected in sequence 3 /H 2 O 2 Absorption bottle, absorption bottle and drying device.
A further improvement of the invention is that HNO 3 /H 2 O 2 The number of the absorption bottles is 3, HNO 3 /H 2 O 2 The absorption bottle is filled with absorption liquid, the concentration of nitric acid in the absorption liquid is 0.4-1mol/L, and the concentration of hydrogen peroxide is 2-4mol/L.
The invention is further improved in that the drying device is a drying tube or a silica gel column.
The invention is further improved in that a getter pump is arranged between the thermometer and the gas accumulation flow meter.
A method for testing selenium and selenium compounds in waste gas of a fixed pollution source based on the system comprises the following steps:
1) Preparation of gaseous selenium sample:
HNO of 3 /H 2 O 2 Transferring the solution in the absorption bottle to a volumetric flask, adding water to a constant volume, and recording the volume of the solution in the volumetric flask to obtain a recovered sample; taking 25mL of recovered sample into a beaker, and adding 1mL of concentrated sulfuric acid and 2mL of concentrated nitric acid; heating until white smoke is generated, cooling, adding 20mL of hydrochloric acid solution with the concentration of 6mol/L, heating for 1h at 363K, transferring into a 25mL volumetric flask, adding water to fix the volume to 25mL, and obtaining a gaseous selenium sample;
preparing a particle selenium sample:
drying the filter element and the filter screen of the filter, taking down the sample on the filter element and the filter screen, and weighing; then placing the mixture in a closed pressurized container, adding 2mL of concentrated nitric acid and 3mL of concentrated hydrofluoric acid solution, and heating the mixture at 383K for 1 hour; transferring into a beaker, heating and drying until hydrofluoric acid is evaporated completely, then adding 20mL of hydrochloric acid solution with the concentration of 6mol/L, heating at 363K for 1 hour, filtering the solution with filter paper, and adding water to dilute to 25mL to obtain a granular selenium sample;
2) Analytical testing
And determining the selenium content in the gaseous selenium sample or the granular selenium sample by adopting an inductively coupled plasma emission spectrometry, an inductively coupled plasma mass spectrometry or a graphite furnace atomic absorption spectrometry.
A further improvement of the invention is that the pore size of the acid-resistant filter paper is 0.45 μm.
The invention is further improved in that the mass concentration of the concentrated sulfuric acid is 6%, the mass concentration of the concentrated nitric acid is 68%, and the mass concentration of the concentrated hydrofluoric acid solution is 40%.
Compared with the prior art, the invention has the beneficial effects that:
1) Under the condition that the measured flow and the total sampling amount of the gaseous selenium and the granular selenium are the same, the invention comprises the steps of arranging a nozzle, a filter, an absorption system, a suction pump, a gas accumulation flowmeter and a rotameter; the nozzle is connected with the filter, the filter is connected with the inlet of the absorption system through a conveying pipeline, and a pressure meter, a thermometer, a gas accumulation flowmeter and a rotameter are arranged on the pipeline of the outlet of the absorption system;
under the condition that the measured flow or the total sampling volume of the gaseous selenium and the granular selenium are different, a nozzle, a filter, a three-way valve, an absorption system, a suction pump, a gas accumulation flowmeter and a rotameter are arranged; the nozzle is connected with the filter, the filter is communicated with the inlet of the three-way valve through a conveying pipeline, one outlet of the three-way valve is connected with the first conveying pipe, the other outlet of the three-way valve is connected with the inlet of the adsorption system, the outlet of the adsorption system is communicated with the second conveying pipe, and the first conveying pipe and the second conveying pipe are respectively provided with a pressure gauge, a thermometer, a gas accumulation flowmeter and a rotameter.
Aiming at the situation that if the measured flow and the total sampling amount of the gaseous selenium and the granular selenium are the same and if the measured flow or the total sampling volume of the gaseous selenium and the granular selenium are different, whether the measurement of the content of the gaseous selenium and the content of the granular selenium are realized or not, the method has strong dust interference resistance and SO resistance 2 The interference capability is strong, accurate and reliable.
2) The sampling and measuring method of gaseous selenium and solid selenium provided by the invention can realize the sampling and measuring of selenium and selenium compounds under complex flue gas conditions of coal-fired power plants, glass kilns, garbage incineration plants, coking industries, cement industries, nonferrous metal smelting and the like, and provides a basic condition for grasping the real selenium emission level.
Drawings
FIG. 1 is a schematic diagram of the strip side-stream sampling system of the present invention.
FIG. 2 is a schematic diagram of the structure of a sidestream free sampling system of the present invention.
In the figure, 1 is a nozzle, 2 is a filter, 3 is a conveying pipeline, 4 is a three-way valve, 5 is HNO 3 /H 2 O 2 The absorption bottle is 6, and 7 is drying device, and 8 is the manometer, and 9 is the thermometer, and 10 is the suction pump, and 11 is gas accumulation flowmeter, 12 is the rotameter.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings.
The system for sampling and measuring selenium and selenium compounds mainly comprises a sampling system, a sample preparation and analysis instrument. The sampling system extracts a certain volume of flue gas from the chimney or pipeline at a proper flow rate, and effectively captures gaseous selenium and particulate selenium through the sampling system. Samples are recovered from the sampling system, prepared for analysis as needed, and analyzed for selenium and selenium compound concentrations by an analytical instrument.
As shown in fig. 1 and 2, the sampling system may be of two types, one being a strip side-stream sampling system and the other being a sidestream-free sampling system. In a sidestream free sampling system, all of the sampled flue gas passes through the absorbent bottle solution, whereas in a strip sidestream sampling system, only a portion of the sampled flue gas passes through the absorbent bottle solution of the absorbent system. If the measured flow and the total sampling amount of the gaseous selenium and the granular selenium are the same, sampling is performed by adopting a sidestream-free sampling system. If the measured flow rates or total sample volumes of gaseous selenium and particulate selenium are different, a tape lateral flow sampling system is employed for sampling.
If the measured flow rates and the total sampling amounts of the gaseous selenium and the particulate selenium are the same, referring to fig. 2, the system includes a nozzle 1, a filter 2, an absorption system, a getter pump 10, a gas accumulation flow meter 11, and a rotameter 12; the nozzle 1 is connected with the filter 2, the filter 2 is connected with an inlet of an absorption system through a conveying pipeline 3, and a pressure gauge 8, a thermometer 9, a gas accumulation flowmeter 11 and a rotameter 12 are arranged on a pipeline of an outlet of the absorption system; the nozzle 1 is for the direction of the incoming flow of the flue gas.
If the measured flow rates or total sampling volumes of gaseous selenium and particulate selenium are different, referring to fig. 1, the system includes a nozzle 1, a filter 2, a three-way valve 4, an absorption system, a getter pump 10, a gas accumulation flow meter 11, and a rotameter 12; wherein, nozzle 1 links to each other with filter 2, and filter 2 is linked together with three way valve 4 entry through transfer line 3, and one export of three way valve 4 links to each other with first conveyer pipe, and another export links to each other with the entry of adsorption system, and the export of adsorption system is linked together with the second conveyer pipe, all is provided with manometer 8, thermometer 9, gas accumulation flowmeter 11 and rotameter 12 on first conveyer pipe and the second conveyer pipe.
If representative sampling is allowed, two sidestream-free sampling systems are used to collect the particulate selenium and gaseous selenium, respectively. The filter collects the particulate selenium sample at constant speed. After removal of the dust particles, the gaseous selenium sample is absorbed in the absorption liquid at a constant or non-constant speed.
The system comprises a sampling probe consisting of a heatable nozzle 1 and a filter 2, and the absorption system comprises five absorption bottles, which are HNO respectively 3 /H 2 O 2 Absorption bottle 5, absorption bottle 6 and drying tube 7, HNO 3 /H 2 O 2 The number of the absorption bottles 5 is 3, namely a first absorption bottle, a second absorption bottle and a third absorption bottleOne each of the absorption bottle 6 and the drying device 7. The absorption bottle 6 serves as a fourth absorption bottle, and the drying device 7 serves as a fifth absorption bottle. The drying device 7 is a drying tube or a silica gel column. HNO (HNO) 3 /H 2 O 2 The absorption bottle 5 is filled with absorption liquid containing nitric acid, hydrogen peroxide and water, the concentration of the nitric acid is 0.4-1mol/L HNO 3 The concentration of the hydrogen peroxide is 2-4mol/L.
For efficient absorption of gaseous selenium, three absorption bottles 5 are filled with an absorption liquid containing nitric acid and hydrogen peroxide and are connected in series. The fourth absorbent bottle was left empty to collect any residue of absorbent. The drying device 7 is used for drying and is placed before the suction pump 10, the gas accumulation flow meter 11 and the rotameter 12. HNO filled with absorption liquid 3 /H2O 2 An absorption bottle 5 (for capturing gaseous selenium), a pressure gauge 8, a getter pump 10, a gas accumulation flow meter 11 and a rotameter 12. A thermometer 9 and a pressure gauge 8 should be included in the sampling system to measure the temperature and pressure of the sampled gas. During the test, barometer should be used to measure the atmospheric pressure in order to scale the volume of the sampled gas to a standard volume at 273.15K and 101.325 kPa.
The respective components are described in detail below.
1) And (3) a nozzle: the nozzle diameter is selected to be consistent with the required gas sampling volume flow rate, and the nozzle material can be, but is not limited to, silicon glass, polytetrafluoroethylene and titanium.
2) Filter 2: the filter 2 is arranged in a filter housing, the filter 2 being able to withstand temperatures above the sampling temperature 40K for a long period of time in order to prevent changes in the filter quality. At the expected maximum flow rate, the filtration efficiency of an aerosol with an average particle size of 0.3 μm should be better than 99.5%.
3) Conveying pipeline 3: the material of the conveying pipeline 3 can be, but not limited to, quartz glass and polytetrafluoroethylene. The transfer line should have a heating system capable of maintaining the gas temperature at its outlet at least 423K or at least 20K above the dew point temperature, whichever is higher.
4) Absorption system: the absorption system consists of five absorption bottles. In order to efficiently absorb gaseous selenium, three absorption bottles should be placed in series.The first three absorption bottles are filled with absorption liquid which is HNO 3 、H 2 O 2 The concentration of the nitric acid is 0.4-1mol/L and the concentration of the hydrogen peroxide is 2-4mol/L. The fourth absorbent bottle was left empty to collect any residue of absorbent. The fifth absorption bottle (i.e., the drying device) is used for drying, and is filled with silica gel before the suction pump 10, the gas accumulation flow meter 11 and the rotameter 12 to dry the sample gas. The material of the absorbing bottle can be, but is not limited to, silicon glass, borosilicate glass or polytetrafluoroethylene. If the selenium mass concentration of the third absorption bottle exceeds 10% of the total concentration of selenium in the sampled gas, the measurement should be invalidated.
5) Suction pump: a diaphragm pump may be used, but is not limited to.
6) A thermometer: it should be installed between the drying device 7 of the sampling system and the gas accumulation flow meter 11.
7) A pressure gauge: for measuring the pressure difference between the gas entering the gas accumulation flow meter and the atmosphere. The accuracy of the manometer is within 1% of the differential pressure.
8) Gas accumulation flow meter: the sample gas volume should be measured using a calibrated gas accumulation flow meter. The accuracy of the gas accumulation flow meter should be within 2% of the volume determined by the sampling system flow.
9) Rotameter: its measuring accuracy is within + -10% of the actual flow.
10 Barometer: the local atmospheric pressure is measured in kilopascals (kPa) with an accuracy within 1% of absolute pressure.
(2) Sample preparation for analysis
1) Preparation of gaseous selenium samples for analysis
Selenium contained in the absorption bottles should be recovered as soon as possible after sampling, and the solutions of the first and second absorption bottles are quantitatively transferred to volumetric flasks of appropriate volume, each absorption bottle using about 20mL of 0.4-1mol/L HNO 3 2-4mol/LH 2 O 2 The washes were added to a volumetric flask, water was added to a constant volume, and the volume of solution in the flask was recorded to obtain a recovered sample. 25mL of recovered sample was taken to 100mL beakerTo this, 1mL of concentrated sulfuric acid and 2mL of concentrated nitric acid were added. Heating the solution on a heating plate to generate H 2 SO 4 White smoke. After cooling, 20mL of a hydrochloric acid solution with a concentration of 6mol/L was added, heated at 363K for 1h, then the solution was transferred into a 25mL volumetric flask, and water was added to a constant volume of 25mL to obtain a gaseous selenium sample.
2) Preparation of particulate selenium samples for analysis
The filter cartridge and screen of filter 2 were dried (without heating to accelerate drying) and the dried sample was weighed.
Placing the dried sample into a closed pressurizing fluoroplastic container made of PTFF, PFA or FEP, adding 2mL of concentrated HNO 3 And 3mL of concentrated hydrofluoric acid solution, then heated at 383K for 1 hour.
The digested solution was transferred to a plastic beaker, heated and dried until the hydrofluoric acid evaporated, then 20mL of 6mol/L hydrochloric acid solution was added and heated at about 363K for 1 hour.
The solution was filtered through acid-resistant filter paper (0.45 μm), diluted with water to 25mL (or to a volume appropriate for the selenium concentration), and the sample volume was measured and recorded to give a particulate selenium sample.
The mass concentration of the concentrated sulfuric acid is 6%, the mass concentration of the concentrated nitric acid is 68%, and the mass concentration of the concentrated hydrofluoric acid solution is 40%.
3) Analytical testing
Standard methods for determining selenium in gaseous or particulate selenium samples are ICP-OES (inductively coupled plasma emission spectrometry), ICP-MS (inductively coupled plasma mass spectrometry) or GFAAS (graphite furnace atomic absorption spectrometry). The method has high sensitivity to selenium determination by an atomic absorption spectrophotometry, an atomic fluorescence spectrometry, an inductively coupled plasma emission spectrometry or an inductively coupled plasma mass spectrometry.
The invention has the following advantages:
1) The sampling and measuring method of the gaseous selenium and the solid selenium provided by the invention has the following characteristics: high dust interference resistance and SO resistance 2 The interference capability is strong, accurate and reliable.
2) The sampling and measuring method of gaseous selenium and solid selenium provided by the invention can realize the sampling and measuring of selenium and selenium compounds under complex flue gas conditions of coal-fired power plants, glass kilns, garbage incineration plants, coking industries, cement industries, nonferrous metal smelting and the like, and provides a basic condition for grasping the real selenium emission level.
Claims (2)
1. The sampling and testing system for selenium and selenium compounds in the waste gas of the fixed pollution source is characterized in that if the measured flow and the total sampling amount of gaseous selenium and granular selenium are the same, the system comprises a nozzle (1), a filter (2), an absorption system, a suction pump (10), a gas accumulation flowmeter (11) and a rotameter (12); the device comprises a nozzle (1), a filter (2), a conveying pipeline (3), an absorption system inlet, a pressure meter (8), a thermometer (9), a gas accumulation flowmeter (11) and a rotameter (12), wherein the nozzle (1) is connected with the filter (2), the filter (2) is connected with the absorption system inlet through the conveying pipeline (3), and the pipeline at the absorption system outlet is provided with the pressure meter (8), the thermometer (9), the gas accumulation flowmeter (11) and the rotameter (12);
if the measured flow or total sampling volume of the gaseous selenium and the granular selenium are different, the system comprises a nozzle (1), a filter (2), a three-way valve (4), an absorption system, a suction pump (10), a gas accumulation flowmeter (11) and a rotameter (12); the device comprises a nozzle (1), a filter (2), a three-way valve (4), a first conveying pipe, an adsorption system, a second conveying pipe, a pressure gauge (8), a thermometer (9), a gas accumulation flowmeter (11) and a rotameter (12), wherein the nozzle (1) is connected with the filter (2), the filter (2) is communicated with the inlet of the three-way valve (4) through a conveying pipeline (3), one outlet of the three-way valve (4) is connected with the first conveying pipe, the other outlet of the three-way valve is connected with the inlet of the adsorption system, the outlet of the adsorption system is communicated with the second conveying pipe, and the pressure gauge (8), the thermometer (9), the gas accumulation flowmeter (11) and the rotameter (12) are arranged on the first conveying pipe and the second conveying pipe; the thermometer (9) is arranged between the drying device (7) and the gas accumulation flowmeter (11), the filter (2) can bear the temperature higher than the sampling temperature by 40K for a long time,
the absorption system comprises HNO connected in sequence 3 /H 2 O 2 An absorption bottle (5), an absorption bottle (6) and a drying device (7);
HNO 3 /H 2 O 2 the number of the absorption bottles (5) is 3 in series, and HNO 3 /H 2 O 2 An absorption liquid (HNO) is filled in the absorption bottle (5) 3 、H 2 O 2 Nitric acid in the absorption liquidThe concentration of the solution is 0.4-1mol/L, and the concentration of the hydrogen peroxide is 2-4mol/L;
the drying device (7) is a drying pipe or a silica gel column;
a getter pump (10) is arranged between the thermometer (9) and the gas accumulation flowmeter (11).
2. A method for testing selenium and selenium compounds in exhaust gas of stationary pollution sources based on the system of claim 1, comprising the steps of:
1) Preparation of gaseous selenium sample:
HNO of 3 /H 2 O 2 Transferring the solution in the absorption bottle (5) to a volumetric flask, adding water to a constant volume, and recording the volume of the solution in the volumetric flask to obtain a recovered sample; taking 25mL of recovered sample into a beaker, and adding 1mL of concentrated sulfuric acid and 2mL of concentrated nitric acid; heating until white smoke is generated, cooling, adding 20mL of hydrochloric acid solution with the concentration of 6mol/L, heating for 1h at 363K, transferring into a 25mL volumetric flask, adding water to fix the volume to 25mL, and obtaining a gaseous selenium sample;
preparing a particle selenium sample:
drying the filter element and the filter screen of the filter (2), and then taking down the samples on the filter element and the filter screen and weighing; then placing the mixture in a closed pressurized container made of PTFF, PFA or FEP, adding 2mL of concentrated nitric acid and 3mL of concentrated hydrofluoric acid solution, and heating at 383K for 1 hour; transferring into a beaker, heating and drying until hydrofluoric acid is evaporated completely, then adding 20mL of hydrochloric acid solution with the concentration of 6mol/L, heating at 363K for 1 hour, filtering the solution with filter paper, and adding water to dilute to 25mL to obtain a granular selenium sample;
2) Analytical testing
Measuring the selenium content in a gaseous selenium sample or a granular selenium sample by adopting an inductively coupled plasma emission spectrometry, an inductively coupled plasma mass spectrometry or a graphite furnace atomic absorption spectrometry;
the pore diameter of the acid-resistant filter paper is 0.45 mu m;
the mass concentration of the concentrated sulfuric acid is 6%, the mass concentration of the concentrated nitric acid is 68%, and the mass concentration of the concentrated hydrofluoric acid solution is 40%; the method has strong dust interference resistance,SO resistance 2 The interference capability is strong, accurate and reliable.
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| CN112198096A (en) * | 2020-09-30 | 2021-01-08 | 中国工程物理研究院激光聚变研究中心 | Beryllium dust concentration online monitoring equipment and monitoring method thereof |
| CN112683617A (en) * | 2020-12-16 | 2021-04-20 | 华中科技大学 | Device for stably producing gas-phase trace elements or compounds thereof and application thereof |
| CN113432930B (en) * | 2021-05-24 | 2022-11-25 | 中国原子能科学研究院 | Representative sampling system and method for Po-210 in chimney gaseous effluent |
| CN113405865B (en) * | 2021-06-30 | 2023-04-11 | 上海电力大学 | Coal-fired flue gas arsenic sampling device |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439152A (en) * | 2013-08-26 | 2013-12-11 | 上海明华电力技术工程有限公司 | Polymorphic sampling system and method for sulfur trioxide in exhaust of stationary pollution source |
| CN106855472A (en) * | 2017-03-08 | 2017-06-16 | 中国华能集团清洁能源技术研究院有限公司 | A kind of stationary source particulate Hg and gaseous mercury isokinetic sampling device and the method for sampling |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000009609A (en) * | 1998-06-19 | 2000-01-14 | Hitachi Kyowa Engineering Co Ltd | Method and apparatus for collecting sample of exhaust gas |
| US6520033B1 (en) * | 2000-03-29 | 2003-02-18 | Her Majesty The Queen In Right Of Canada, Represented By The Minister Of The Environment | Apparatus for sampling & analysis of thermally-labile species and a method relating thereto |
| AUPR347901A0 (en) * | 2001-03-02 | 2001-03-29 | Parsons Australia Pty Ltd | Particulate and gaseous emission testing method of apparatus |
| US20080168752A1 (en) * | 2006-12-22 | 2008-07-17 | Perma Pure, Llc | Separating particulate-containing gas flow into particulate and non-particulate flow portions |
| CN203053947U (en) * | 2013-01-17 | 2013-07-10 | 清华大学 | Multi-channel multi-component fixed source sampling analysis device |
| CN103149271A (en) * | 2013-03-18 | 2013-06-12 | 中国环境科学研究院 | Method for simultaneously measuring heavy metals with different forms in coal-fired flue gas |
| CN204944901U (en) * | 2015-07-16 | 2016-01-06 | 北京市环境保护监测中心 | Stationary pollution source waste gas constant speed is followed the tracks of and is added shunting sampling apparatus |
| CN105486549B (en) * | 2016-01-20 | 2018-08-03 | 四川大学 | A kind of sampling system that can realize constant flow isokinetic sampling |
| CN108414299A (en) * | 2018-05-17 | 2018-08-17 | 太原海纳辰科仪器仪表有限公司 | A kind of stationary source exhaust gas sampling apparatus and the method for sampling |
| CN109342284A (en) * | 2018-10-22 | 2019-02-15 | 北京清新环境技术股份有限公司 | A kind of detection system and detection method for harmful substances from flue gases |
| CN209470939U (en) * | 2018-11-15 | 2019-10-08 | 天津城建大学 | A kind of particulate matter and gaseous pollutant sampling apparatus |
| CN110849679A (en) * | 2019-11-08 | 2020-02-28 | 华电电力科学研究院有限公司 | Synchronous sampling device for condensable particles and sulfur trioxide in coal-fired flue gas and working method thereof |
| CN110806339A (en) * | 2019-11-18 | 2020-02-18 | 国电南京电力试验研究有限公司 | SO in flue gas of thermal power plant3Sampling method |
| CN110749481A (en) * | 2019-11-18 | 2020-02-04 | 国电环境保护研究院有限公司 | Sampling device and sampling method for low-concentration total particulate matters in flue gas of thermal power plant |
-
2020
- 2020-05-08 CN CN202010382842.3A patent/CN111397977B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439152A (en) * | 2013-08-26 | 2013-12-11 | 上海明华电力技术工程有限公司 | Polymorphic sampling system and method for sulfur trioxide in exhaust of stationary pollution source |
| CN106855472A (en) * | 2017-03-08 | 2017-06-16 | 中国华能集团清洁能源技术研究院有限公司 | A kind of stationary source particulate Hg and gaseous mercury isokinetic sampling device and the method for sampling |
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