CN112763588A

CN112763588A - Device and method for combining concentration enrichment of atmospheric fine particulate matters and toxicity detection of chemical components

Info

Publication number: CN112763588A
Application number: CN202011465361.5A
Authority: CN
Inventors: 陈建民; 尚晓娜; 康慧慧; 孙剑峰; 李丹; 李凌
Original assignee: Fudan University
Current assignee: Fudan University
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2021-05-07

Abstract

The invention belongs to the technical field of environmental protection, in particular to a multifunctional device and method for combining concentration enrichment of atmospheric particulate matter and chemical component toxicity detection. The device of the invention includes: float flowmeter, concentrated airflow vacuum pump, main airflow vacuum pump, drying tube, mass flow controller, collision type PM2.5 cutting head, condensation system machine, water tank, electric heating rod, virtual cutter, biological sampling bottle , Two micro-injection pumps, automatic sampler, online ion chromatography monitoring system, inductively coupled plasma mass spectrometry, total toxicity measurement analyzer, ultra-high pressure liquid chromatography time-of-flight mass spectrometer, etc. The device integrates the particulate matter into the liquid through sampling, condensation, concentration and other links, so that the concentration of the particulate matter is increased by an order of magnitude, the concentration effect is better than that of similar products, and it also effectively avoids the traditional filter membrane collection and monitoring method. ; Determination of various toxic chemical components and total biological toxicity by combining concentration technology with various advanced chemical components determination instruments can greatly improve the detection rate and reduce the sampling time, and can be widely used in environmental monitoring.

Description

Device and method for combining concentration enrichment of atmospheric fine particulate matters and toxicity detection of chemical components

Technical Field

The invention belongs to the technical field of environmental protection, and particularly relates to a multifunctional device and a method for concentration enrichment and chemical component toxicity detection of atmospheric fine particulate matters.

Background

PM2.5 refers to particles having an aerodynamic equivalent diameter of less than or equal to 2.5 microns in the atmosphere, also known as respirable particles. Although PM2.5 is only a component that is present in small amounts in the earth's atmospheric constituents, it has a significant effect on air quality and visibility, among other things. The PM2.5 particle size of the atmosphere is small, the specific surface area is large, toxic and harmful chemical components such as heavy metal, water-soluble inorganic ions, organic matters and the like are easily enriched, the suspension time in the atmosphere is long, and the transmission distance is long, so that the negative effects on the human health and the atmospheric environment quality are not ignored.

There has been a great deal of epidemiological evidence that PM2.5 has acute and chronic health effects. Toxic and harmful heavy metals such as Pb, Cd, Ni, Mn, V, Zn and the like are mainly adsorbed on the particles with the particle size of less than 2.5 microns. Research shows that heavy metals can directly enter alveoli of a human body along with PM2.5 through respiration and are greatly enriched in the human body. As, Cr, Ni and Cd have certain carcinogenic effect on human body, and Zn, Cu and Pb accumulation can increase teratogenic effect of human body. Sulfite enters a human body easily and forms sulfur trioxide anion free radicals (SO3) through electronic oxidation, and SO3 can rapidly react with O2 to generate superoxide anion free radicals O2. Nitrite (NO-2) is a precursor for the formation of N-nitroso compounds, which are highly mutagenic and carcinogenic and pose potential health risks to humans. Meanwhile, the small molecular organic acid is the most important organic acid in the near-ground atmospheric particulates, and plays an extremely important role in the formation of global acid rain, liquid phase reaction related to pH in the atmosphere, OH free radical reaction in cloud and the like. Meanwhile, the small molecular organic acid plays an important role in cloud nucleation, and indirectly influences ground surface radiation compelling to cause global climate change. Therefore, the research on the biotoxicity of the haze aerosol particles also becomes one of the research hotspots and frontiers. However, the determination of the biotoxicity of the atmospheric particulates is limited by detection technologies and instruments (such as a higher detection limit), and currently, the determination still remains in an off-line detection stage, and needs to be performed under the conditions of heavy pollution and a longer continuous sampling time, and the requirements of monitoring the concentration of the atmospheric particulates and the characteristics of toxic chemical components in real time cannot be met.

In order to fill the technical blank, the on-line concentration and collection device for the PM2.5 in the medium-flow atmosphere, which is developed by the invention, can concentrate and enrich aerosol to a level which is enough to obviously detect the toxicity of the aerosol on the premise of not changing any physicochemical characteristics except the concentration. Meanwhile, the device can be used together with an on-line chemical component analysis instrument and a biotoxicity detection device, particles are blended into liquid through links such as sampling, saturation, condensation, concentration and collection, the concentration of the particles can be improved by one order of magnitude, the concentration effect is better than that of the like, the problems of sample pollution, high loss of samples and reagents and the like existing in the traditional filter membrane collection monitoring method are effectively solved, the organic components are easily determined by using a flight time mass spectrometry technology, the inorganic components are determined by using an ion chromatograph, the heavy metals are determined by using an inductive coupling plasma mass spectrometry, the air flow demand is greatly reduced, and the air flow demand is reduced to 50 liters/min from the original 1000 liters/min. The realization of artificial intelligent atmospheric particulate matter on-line detection in the future becomes possible, and the method can be widely applied to environmental monitoring and health risk assessment.

The international reference for Air Quality is Air Quality Index (AQI), which is mainly embodied in daily weather forecast by the comprehensive numerical value of PM2.5 and pollution gas, but it cannot directly reflect the biological toxicity of Air. Because the components of the particles are different and the toxicity is completely different, the particles which really have toxic action to human bodies are only a small amount of organic matters with teratogenic and carcinogenic effects, such as polycyclic aromatic hydrocarbons, and the like, and heavy metals and the like. The invention can monitor the air quality and the human health toxicity in real time and can identify the toxic components in the atmospheric particulates, thereby providing a scientific support for the government department to make valuable optimal control pollutant decisions.

Disclosure of Invention

The invention aims to provide a multifunctional device and a method for combining concentration enrichment of atmospheric fine particulate matters and toxicity detection of chemical components, so that the concentration degree of the particulate matters is greatly improved, and the problems of sample pollution, high reagent loss and the like are effectively avoided.

The multifunctional device for concentration enrichment and toxicity detection of chemical components of atmospheric fine particulate matters, provided by the invention, has a structure shown in figure 1, and comprises: the system comprises a float flowmeter 1, a concentrated airflow vacuum pump 2, a main airflow vacuum pump 3, a drying pipe 4, a large-flow mass flow controller 5, a condensing agent circulating pipe 6, a collision type PM2.5 cutting head 7, a condenser 8, a water tank 9, a water tank heat insulation layer 10, a visible window 11, a U-shaped electric heating rod 12 with a temperature sensor, a temperature control digital display device 13, a condensation inner pipe 14, a condensation outer spiral pipe 15, a heat insulation layer 16, a virtual cutter 17, a main airflow outlet 18, a nozzle 19, a nozzle connecting pipe 20, a biological sampling bottle 21, a micro-injection pump 22, an automatic sample injector 23, an online ion chromatography monitoring system 24, an inductive coupling plasma mass spectrum 25, a total toxicity measurement analyzer 26 and an ultrahigh pressure liquid chromatography flight time mass spectrometer 27; wherein:

a heat insulation layer 10 is sleeved outside the water tank 9, and a quartz glass visible window 11 is arranged at the upper left two thirds of the front wall of the water tank;

the U-shaped heating rod 12 is arranged at the bottom end inside the water tank 9, and an external power line of the U-shaped electric heating rod 12 is connected with the temperature control digital display device 13;

the upper part of the water tank 9 is provided with two ports, one of which is connected with a cyclone PM2.5 cutting head and an erosion device 7 by a quick-connection flange; secondly, a condensing inner pipe 14 which is coaxially arranged is connected by a quick-connection flange;

a soft copper spiral pipe 15 is tightly wound outside the condensation inner pipe 14, a heat insulation layer 16 is wrapped outside the spiral pipe 15, and an inlet at the upper part and an outlet at the lower part of the spiral pipe 15 are respectively connected to an outlet and an inlet of the condenser 8 through anti-freezing hoses; forming a circulating flow of condensate;

the upper end of the condensation inner pipe 14 is connected with a virtual cutter 17 by a quick-connection flange, the lower end of the interior of the condensation inner pipe is provided with a nozzle 19 which is coaxial with the inner pipe, and the upper end of the condensation inner pipe is provided with a nozzle connecting pipe 20 which is coaxial with the nozzle 19 and is spaced at a certain distance;

a main air outlet 18 is arranged beside the outlet of the nozzle connecting pipe 20, is connected with the drying pipe 4 and then is connected with the mass flow controller 5 with large flow and then is connected with the main air flow vacuum pump 3 to form a main air path; the upper part of the outlet of the nozzle connecting pipe 20 is connected with the air inlet of the biological sampling bottle 21;

the air outlet of the biological sampling bottle 21 is connected with a float flowmeter 1, and then is connected with a concentrated airflow vacuum pump 2 to form a concentrated air path;

the bottom of the biological sampling bottle 21 is provided with a sample inlet and a sample outlet which are respectively connected with the sample outlet and the sample inlet of the two channels of the two micro-injection pumps 22; one channel at the other end of the concentrated gas flow vacuum pump 2 is connected with a sample inlet of a sampling bottle 21, the other channel is connected with an automatic sample injector 23, and then the other channel is simultaneously injected into an online ion chromatography monitoring system 24, an inductively coupled plasma mass spectrometer 25, a total toxicity measurement analyzer 26 and an ultrahigh pressure liquid chromatography flight time mass spectrometer 27.

The working process of the device comprises the following steps:

(1) the original atmosphere is introduced into a cyclone PM2.5 cutting head 7, the PM2.5 cutting head 7 screens out atmospheric particulate matters with aerodynamic equivalent diameter less than or equal to 2.5 microns, then the atmospheric aerosol gas-solid separation is realized through an erosion apparatus by means of system suction, and the separated particulate matters enter a water tank 9;

(2) under the observation of a visual window 11, adding deionized water to two thirds of the height of the water tank, heating the deionized water by using an electric heating rod 12 with a temperature sensor, and controlling the temperature to be 45 +/-2 ℃ by using a temperature control digital display device 13;

(3) the water vapor generated by heating makes the particles reach a saturated state, and then flows through the condensation inner pipe 14; circulating to make the condensate condense and grow the saturated particles; wherein the aerodynamic diameter of most PM2.5 particles can be increased to 3-4 microns; the external circulation temperature control mode of the condenser controls the temperature to be minus 19 +/-1 ℃; wherein the condensate is 80% ethanol;

(4) condensing the long particles into the virtual cutter 17, and obtaining acceleration at the nozzle 19; the accelerating power comes from two gas paths: a main gas path and a concentration gas path; in the main gas path, the flow is controlled to be 50 +/-2 liters/minute and is accurately controlled by a mass flow controller 5 with the flow rate of 0-200 liters/minute; the concentration gas path is the main path for the particles to pass through; in the concentration gas path, the flow of the concentration gas is controlled to be 5 +/-0.2 liter/min and is controlled by a float flowmeter 1 of 0-10 liters/min;

(5) in the virtual cutter 17, the particles accelerated by the nozzle 19 are received by a nozzle connecting pipe 20 which is arranged coaxially and spaced above the nozzle; under the condition that the concentration of the particulate matters is the same, the gas flow is changed into one tenth of the original gas flow, and the concentration of the particulate matters in the original atmosphere is changed into ten times of the original concentration, so that the concentration effect is achieved; collecting the concentrated saturated particles on line by a biological sampling bottle 21, wherein the collecting solvent is deionized water or other organic solvents;

(6) one of the two micro-injection pumps 22 is used for injecting a solvent into the biological sampling bottle 21, the solvent injection speed is 5-10 ml/min, the operation lasts for 1 min, and the dormancy lasts for 59 min; the other is used for extracting the collected concentrated solution from the biological sampling bottle, the extraction speed of the concentrated solution is 5-10 ml/min, the operation lasts for 1 min, and the dormancy lasts for 59 min;

(7) the concentrated solution extracted by the micro-injection pump 22 is pumped into an automatic sample injector 23 on line, and then is simultaneously pumped into an on-line ion chromatography monitoring system 24, an inductively coupled plasma mass spectrum 25, a total toxicity measurement analyzer 26 and an ultrahigh pressure liquid chromatography flight time mass spectrometer 27 to analyze water-soluble ions, heavy metals, total biological toxicity and organic components of the concentrated solution.

In the present invention, the diameter of the inner condensation pipe 14 is 2.5 cm, and the length is 80 cm; the condensate is ethanol with a certain concentration, for example, the concentration can be 70-90%, and the condensate can be adjusted, so that the effects of refrigerating and reducing the volatilization amount are only achieved.

In the invention, the diameter of the nozzle 19 is 0.37 +/-0.01 cm, the spacing gap between the nozzle 19 and the nozzle connecting pipe 20 is 0.45 +/-0.01 cm, and the diameter of the connecting pipe 20 is 2.5 +/-0.1 cm.

The invention has the beneficial effects that:

(1) the device can realize gas-solid separation of the atmospheric aerosol in a real atmospheric environment, and avoids the influence of gas components on the quantitative determination of the chemical components of atmospheric particulates;

(2) the device can concentrate actual atmospheric particulates by 7 to 10 times (the size of the particulates is related), the concentration efficiency is high and can reach 75 to 99 percent (the size of the particulates is related), and the concentration performance is stable;

(3) the device has low requirements on the flow of sampled inlet air, and the actual atmospheric particulate matters can be efficiently concentrated when the medium flow is 50 liters/minute;

(4) the particles concentrated by the device do not need to be dried, and can be directly collected and used for subsequent on-line or off-line analysis;

(5) the device realizes the on-line collection of the concentrated sample, simultaneously realizes the on-line measurement of nitrite, sulfite, heavy metal, total biotoxicity and organic components, has high automation of equipment, and is simple and convenient to operate, reliable, stable and easy to maintain.

Drawings

FIG. 1 is a schematic structural diagram of a multifunctional device combining concentration enrichment of atmospheric particulates and toxicity detection of chemical components.

Reference numbers in the figures: the device comprises a float flowmeter 1, a concentrated airflow vacuum pump 2, a main airflow vacuum pump 3, a drying pipe 4, a mass flow controller 5, a condensing agent circulating pipe 6, a cyclone PM2.5 cutting head 7, a condensing machine 8, a water tank 9, a water tank thermal insulation layer 10, a visible window 11, an electric heating rod with a temperature sensor 12, a temperature control digital display device 13, a condensing inner pipe 14, a condensing outer spiral pipe 15, a thermal insulation layer 16, a virtual cutter 17, a main airflow outlet 18, a nozzle 19, a nozzle adapter 20, a biological sampling bottle bubble 21, a microinjection pump 22, an automatic sample injector 23, an online ion chromatography monitoring system 24, an inductively coupled plasma mass spectrometer 25, a total toxicity measurement analyzer 26 and an ultrahigh pressure liquid chromatography flight time mass spectrometer 27.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

Example 1:

atmospheric particulates are screened by a cyclone type PM2.5 cutting head 7, particulates with the particle size smaller than 2.5 micrometers enter an erosion device 7 to remove acid-base gas, the passing particulates enter a water tank 9 set to be at a constant temperature of 45 +/-2 ℃ to wrap water vapor and reach a supersaturation state, saturated ions ascend to a condensation pipe 14 set to be at a constant temperature of-19 +/-1 ℃ to condense and grow into droplets of 3-4 micrometers under the suction force of a main airflow vacuum pump 350 +/-2 liters/minute under the control of a mass flow controller 5, the droplets pass through a nozzle 19 in a virtual cutter 17 to enter a concentration gas path in an accelerating manner, and gas enters a bypass gas outlet to be discharged, so that the concentration of the particulates is improved ten times. The concentrated liquid drops are pumped to a biological sampling bottle 21 by a concentrated gas flow vacuum pump 2 which is controlled by 5 +/-0.2 liters/minute through a float flow meter 1, and are sprayed on the wall of the bottle in a radial mode from three needle eye nozzles to be captured by liquid phase solvent which is vigorously swirled. Notably, the droplet-like particulate matter trapping efficiency is higher, and therefore, the concentrated particulate matter does not need to be dried. The concentrated solution collected by the liquid phase is simultaneously pumped to an online ion chromatography monitoring system 24, an inductively coupled plasma mass spectrometer 25, a total toxicity measurement analyzer 26 and an ultrahigh pressure liquid chromatography flight time mass spectrometer 27 at regular time by controlling two micro-injection pumps 22 through online software, and water-soluble ions, heavy metals, total biological toxicity and organic components are analyzed on line according to a set program and a sample list. Through the process and the operation, the simultaneous online analysis of various chemical components and biological toxicity in the atmospheric particulates is realized, and compared with the traditional filter membrane analysis, the detection rate is improved, and the complexity, pollution and loss of pretreatment are effectively avoided.

Claims

1. A combined device for concentration enrichment of atmospheric fine particulate matter and chemical component toxicity detection, characterized in that it comprises: a float flowmeter (1), a concentrated airflow vacuum pump (2), a main airflow vacuum pump (3), a drying tube ( 4), large flow mass flow controller (5), condensate circulation pipe (6), collision type PM2.5 cutting head (7), condenser (8), water tank (9), water tank insulation layer (10) , visual window (11), U-shaped electric heating rod with temperature sensor (12), temperature control digital display device (13), condensation inner tube (14), condensation outer spiral tube (15), insulation layer ( 16), virtual cutter (17), main airflow outlet (18), nozzle (19), nozzle nozzle (20), biological sampling bottle (21), two microinjection pumps (22), automatic sampler (23) ), online ion chromatography monitoring system (24), inductively coupled plasma mass spectrometry (25), total toxicity measurement analyzer (26), ultra-high pressure liquid chromatography time-of-flight mass spectrometer (27); of which:

The outer layer of the water tank (9) is provided with a temperature insulating layer (10), and a quartz glass viewing window (11) is arranged at the upper left two-thirds of the front wall;

The U-shaped electric heating rod (12) is arranged at the inner bottom end of the water tank (9), and the external power cord of the U-shaped heating rod (12) is connected to the temperature control digital display device (13);

There are two openings on the upper part of the water tank (9). One is to connect the cyclone PM2.5 cutting head and the corroder (7) with a quick-connect flange; );

A soft copper spiral tube (15) is tightly wound on the outside of the condensation inner tube (14). The hose is connected to the outlet and inlet of the condenser (8); it forms a circulating flow of condensate;

The upper end of the condensing inner pipe (14) is connected with the virtual cutter (17) by a quick-connect flange, the inner lower end is a nozzle (19) arranged coaxially with the inner pipe, and the upper end is arranged coaxially with the nozzle (19) but and nozzle nozzles (20) spaced at a certain distance;

An air outlet is provided next to the outlet of the nozzle nozzle (20), the air outlet is connected to the drying pipe (4) and then connected to the large-flow mass flow controller (5), and then connected to the main air flow vacuum pump (3) to form the main air path; the nozzle; The upper part of the outlet of the connecting pipe (20) is connected to the air inlet of the biological sampling bottle (21);

The air outlet of the biological sampling bottle (21) is connected to the rotameter (1), and then connected to the concentrated gas flow vacuum pump (2) to form a concentrated gas path;

The bottom of the biological sampling bottle (21) is provided with a sample inlet and outlet, which are respectively connected to the sample outlet and the sample inlet of the two channels of the two micro-syringe pumps (22); a channel at the other end of the concentrated airflow vacuum pump (2) is connected to The injection port of the sampling bottle (21), another channel automatic sampler (23), and simultaneously connected to the online ion chromatography monitoring system (24), the inductively coupled plasma mass spectrometer (25), and the total toxicity measurement analyzer (26), ultra-high pressure liquid chromatography time-of-flight mass spectrometer (27).

2 . The device according to claim 1 , characterized in that, the diameter of the condensation inner pipe ( 14 ) is 2.5 cm and the length is 80 cm, and the condensate is ethanol with a certain concentration. 3 .

3. The device according to claim 1, characterized in that the diameter of the nozzle (19) is 0.37±0.01 cm, the interval between the nozzle (19) and the nozzle nozzle (20) is 0.45±0.01 cm, and the nozzle (19) is 0.45±0.01 cm. 20) The diameter is 2.5 ± 0.1 cm.

4. A multifunctional atmospheric fine particle concentration enrichment and chemical component toxicity detection method based on the device described in one of claims 1-3, characterized in that the specific steps are:

(1) The original atmosphere is introduced into the collision type PM2.5 cutting head (7), and the PM2.5 cutting head (7) screens out atmospheric particles whose aerodynamic equivalent diameter is less than or equal to 2.5 microns, and is pumped by the system into the water tank ( 9);

(2) Under the observation of the visual window (11), add deionized water to two-thirds of the height of the water tank (9), and the deionized water is heated by an electric heating rod (12) with a temperature sensor. , the temperature is controlled to be 45±2 degrees Celsius through the temperature control digital display device (13);

(3) The water vapor generated by heating makes the particulate matter reach a saturated state, and then flows through the condensing inner pipe (14); the saturated particulate matter is condensed and grown by circulating condensate, and most of the PM2.5 particulate matter has aerodynamics. The diameter can be increased to 3-4 microns; in addition, the external circulation temperature control mode of the condenser controls the temperature at -19±1 degrees Celsius;

(4) The condensed and grown particles enter the virtual cutter (17) and are accelerated at the nozzle (19); the acceleration power comes from two gas paths: the main gas path and the concentrated gas path; in the main gas path, control the The flow rate is 50±2 liters/min, which is precisely controlled by a large flow mass flow controller (5) of 0-200 liters/min; the concentrated gas path is the main path for the particles to pass through; in the concentrated gas path, the controlled concentrated gas flow is 5±0.2L/min, controlled by 0-10L/min float flowmeter (1);

(5) In the virtual cutter (17), the particles accelerated by the nozzle (19) are received by the nozzle nozzle (20) with a certain interval above the coaxially arranged nozzle; when the particle concentration is the same, the gas flow rate changes. It is one-tenth of the original gas flow rate, and the concentration of particulate matter in the original atmosphere becomes ten times that of the original concentration, thereby achieving the concentration effect; the concentrated saturated particulate matter is collected online through the biological sampling bottle (21), and the collection solvent is Deionized water or other organic solvents;

(6) Among the two micro-injection pumps (22), one is used to inject solvent into the biological sampling bottle (21), the solvent injection rate is 5-10 ml/min, the work is 1 minute, and the sleep is 59 minutes; the other is used to inject solvent into the biological sampling bottle (21). It is used to extract the collected concentrate from the biological sampling bottle. The extraction speed of the concentrate is 5-10 ml/min, the work is 1 minute, and the dormancy is 59 minutes;

(7) The concentrated liquid drawn by the micro-injection pump (22) is injected into the automatic sampler (23), and then injected into the online ion chromatography monitoring system (24), the inductively coupled plasma mass spectrometry (25), and the total toxicity measurement and analysis at the same time. Instrument (26), ultra-high pressure liquid chromatography time-of-flight mass spectrometer (27) to analyze its water-soluble ions, heavy metals, total biological toxicity, and organic components.