Generation, balancing and co-exposure system for bioaerosol and volatile organic compounds, and use method therefor

Abstract

A generation, balancing and co-exposure system for bioaerosol and volatile organic compounds, and a use method therefor. The system comprises a co-exposure and balancing box (1), a volatile organic compound gas balancing box (2) and a bioaerosol balancing box (3) which are connected to the co-exposure and balancing box (1) by means of a pipe system, a bioaerosol collection device (6), etc. By regulating and controlling the gas path ratio of gaseous VOCs to bioaerosol, the types and concentrations of microorganisms in bioaerosol and VOCs, etc., can be changed, and the generation and balancing of multi-component multi-gradient VOCs and multi-type multi-concentration bioaerosol can be controlled rapidly in real time, so as to achieve real-time regulation and control of the exposure of VOCs to bioaerosol, and simulate the release of multiple VOCs of different concentrations and different types as well as the generation of bioaerosol of different types in different natural scenarios, thus evaluating the interaction between VOCs and bioaerosol on this basis, and facilitating the subsequent treatment of VOCs and bioaerosol.

Description

A system for the generation, equilibrium, and co-exposure of bioaerosols and volatile organic compounds, and its method of use.

[0001] Technical Field

[0002] This invention belongs to the field of ecological and environmental technology. More specifically, it relates to a system for the generation, equilibrium, and co-exposure of bioaerosols and volatile organic compounds, and a method for using the same. Background Technology

[0003] Bioaerosols refer to aerosols containing biological ions such as bacteria and viruses. In addition to the characteristics of general aerosols, they can easily cause various respiratory diseases. Volatile organic compounds (VOCs) include industrially produced halogenated hydrocarbons, unsaturated hydrocarbons resulting from incomplete combustion, and benzene compounds, which can damage the nervous system and organs such as the liver and kidneys.

[0004] Bioaerosols and VOCs pollution are both key areas of focus for researchers in the field of atmospheric environmental science. However, current research typically only assesses the emission characteristics of bioaerosols or VOCs, evaluating health risks based on the emission levels and types of individual bioaerosols and VOCs. The interaction mechanisms between bioaerosols and VOCs are unclear, and there are very few reported studies related to the interaction between VOCs exposure and bioaerosols. However, in areas such as municipal solid waste disposal, wastewater treatment, and industrial production, the simultaneous release of bioaerosols and VOCs is common. For example, during aeration treatment in wastewater treatment plants and waste decomposition in landfills, not only are large amounts of VOCs with irritating odors generated, but also large amounts of bioaerosols containing pathogens such as Staphylococcus aureus, Escherichia coli, Legionella, Salmonella, and Mycobacterium tuberculosis are released. These mixed pollutants diffuse into the surrounding environment due to atmospheric diffusion and meteorological conditions, adversely affecting human health.

[0005] When bioaerosols and VOCs coexist, on the one hand, microorganisms and VOCs interact, and exploring this interaction is beneficial for subsequent treatment of mixed pollutants. On the other hand, VOCs can act as environmental stressors, leading to microbial evolution and potentially causing more serious health risks. In addition to short-term observations of their interaction, long-term impact assessments are necessary to avoid greater safety hazards. While there are reports of devices capable of simultaneously capturing aerosols and VOCs, these only collect data and cannot be used to observe the interaction between bioaerosols and VOCs. In other words, there is currently a lack of usable systems for balanced exposure to both bioaerosols and volatile organic compounds. Summary of the Invention

[0006] To address the technical problems existing in the prior art, the present invention provides a system for the co-generation, equilibrium, and exposure of bioaerosols and volatile organic compounds, and a method for using the same.

[0007] The first objective of this invention is to provide a system for the generation, equilibrium, and co-exposure of bioaerosols and volatile organic compounds.

[0008] A second objective of this invention is to provide an application of the system.

[0009] The above-mentioned objective of this invention is achieved through the following technical solution:

[0010] This invention provides a system for the generation, equilibrium, and co-exposure of bioaerosols and volatile organic compounds (VOCs). Using this system, the co-generation and dynamic equilibrium of different types and concentrations of bioaerosols and VOCs can be simulated. Furthermore, the type, concentration, and exposure time of VOCs can be flexibly adjusted to construct a VOCs-exposed bioaerosol interaction system. This allows for the assessment of the physiological state and activity of bioaerosols under VOCs exposure, facilitating the treatment of mixed pollutants from bioaerosols and VOCs.

[0011] Specifically, the bioaerosol and volatile organic compound generation, equilibrium and co-exposure system of the present invention includes a co-exposure equilibrium chamber, a volatile organic compound gas equilibrium chamber and a bioaerosol equilibrium chamber respectively connected to the co-exposure equilibrium chamber through a pipeline system, and a control device for controlling the operation of the system.

[0012] The piping system includes an input path that is connected to a volatile organic compound (VOC) gas balance chamber and a bioaerosol balance chamber, respectively, and an output path that connects the VOC gas balance chamber and the bioaerosol balance chamber to a co-exposure balance chamber, respectively. An air compressor, a flow controller, and an air filter are sequentially installed on the input path. A VOC generator is also installed in the input path connected to the VOC gas balance chamber, and a bioaerosol generator is also installed in the input path connected to the bioaerosol balance chamber 3.

[0013] The co-exposure balance chamber is also connected to a bioaerosol collection device; the volatile organic compound gas balance chamber is also connected to a volatile organic compound detector; and the bioaerosol balance chamber 3 is also connected to a real-time bioaerosol particle monitor.

[0014] Specifically, in the pipeline system, the input path and / or output path contains at least one branch. That is, in the most basic pipeline system of this invention, the input path and output path contain only one path, but for purposes such as increasing flow rate, technicians can add branches.

[0015] In a specific embodiment of the present invention, the input path of the pipeline system includes at least one branch. Specifically, the branch of the input path branches off from the air compressor, and a flow controller and an air filter are sequentially installed on the branch. Clean air is input into the balance box connected to the branch for dilution or adjustment of the concentration of bioaerosols or VOCs gases.

[0016] Optionally, the addition of branches in the pipeline system is achieved by using multi-port pipes and connectors connected to multi-port pipes, which can flexibly adjust the number of input or output channels to construct a branched pipeline system.

[0017] Specifically, the pipeline system is also equipped with a valve for controlling the entry and exit of aerosols or gases.

[0018] Optionally, the valve is a ball valve.

[0019] Specifically, each pipe in the pipeline system is connected to the housing through a fluid inlet and outlet.

[0020] Specifically, the co-exposure balance chamber, the volatile organic compound gas balance chamber, and the bioaerosol balance chamber are all equipped with turbulence devices.

[0021] Specifically, the co-exposure balance chamber, the volatile organic compound gas balance chamber, and the bioaerosol balance chamber are all equipped with exhaust and pressure relief devices.

[0022] Optionally, the turbulence device is a fan located inside the balance box. By turbulently dispersing the gas inside the balance box, VOCs and bioaerosols are rapidly and evenly distributed within the balance box.

[0023] Optionally, the fan is a magnetic fan.

[0024] Preferably, the fan blades are covered with an anti-stick coating that reduces the adhesion / adsorption of microorganisms and VOCs, reduces the loss of bioaerosols and VOCs, and maintains the activity of bioaerosols.

[0025] Similarly, the inner walls of each balance box are covered with an anti-stick coating.

[0026] Optionally, the coating is a polytetrafluoroethylene coating or a silicone coating.

[0027] Optionally, the exhaust pressure relief device is an exhaust pressure relief valve; a portion of the gas is discharged through the exhaust pressure relief valve to control the gas pressure in the balance box, and the discharged VOCs and bioaerosols are discharged after being treated to render them harmless.

[0028] Specifically, the bioaerosol generator is a liquid microbial aerosol generator.

[0029] Optionally, the liquid microbial aerosol generator is a three-well bioaerosol generator, a six-well bioaerosol generator, or a twenty-four-well bioaerosol generator.

[0030] Specifically, the VOCs detector is connected to the housing via fluid inlet and outlet (used as sampling ports, hereinafter referred to as sampling ports for easy distinction) and is used to monitor the concentration of VOCs in the VOCs balance chamber in real time, and to monitor whether the balance chamber is in a balanced state; similarly, the bioaerosol particle real-time monitor is also connected to the housing via fluid inlet and outlet and is used to monitor the concentration of bioaerosol particles in real time, and to monitor whether the balance chamber is in a balanced state.

[0031] Specifically, when the readings of the VOCs detector at multiple sampling ports equidistantly distributed on the vertical side of the chamber remain stable and consistent, it indicates that the chamber is in a balanced state. Similarly, when the readings of the real-time bioaerosol particle monitor at multiple sampling ports equidistantly distributed on the vertical side of the chamber remain stable and consistent, it indicates that the chamber is in a balanced state.

[0032] Specifically, the number of sampling ports is at least three.

[0033] Specifically, the control device is a circuit-controlled switch.

[0034] The present invention also provides a method for using the system, or a method for testing the interaction between microbial aerosols and volatile organic compounds using the system of the present invention, comprising the following steps:

[0035] S1. Add the solution of the volatile organic compound to be tested to the injection needle of the volatile organic compound generator. Use the pipeline system to make the volatile organic compound generator produce volatile organic compounds and enter the volatile organic compound gas balance box. After the box is full of volatile organic compounds, turn off the volatile organic compound generator and wait for the volatile organic compounds in the box to reach dynamic equilibrium.

[0036] S2. Place the suspension of the microorganism to be tested into the liquid bottle of the bioaerosol generator, use the pipeline system to make the bioaerosol generator produce microbial aerosols and enter the bioaerosol balance chamber. After the chamber is full of microbial aerosols, turn off the bioaerosol generator and wait for the aerosols in the chamber to reach dynamic balance.

[0037] S3. The volatile organic compounds and microbial aerosols in dynamic equilibrium are simultaneously introduced into the co-exposure equilibrium chamber through the output of the pipeline system for dynamic equilibrium. Microbial aerosol samples are collected and enriched using a bioaerosol collection device. The enriched microorganisms are then serially diluted and plated for culture. The culturable number of microorganisms in the samples is calculated based on the dilution factor, and the changes in the culturable number of microorganisms are observed to observe the effect of volatile organic compounds on microbial aerosols.

[0038] The formula for calculating the number of culturable individuals is as follows:

[0039] ;

[0040] Among them, C 液体浓度 The culturable number of microorganisms to dilute the plate count.

[0041] Specifically, the method for preparing the microbial suspension is as follows: the preserved microbial strain is inoculated into a culture medium and cultured until the microorganisms enter the logarithmic growth phase. The supernatant is discarded by centrifugation, the precipitate is washed with buffer solution, and then vortexed again with buffer solution to obtain the microbial suspension. The concentration of the microbial suspension is 0–10. 10 CFU / mL.

[0042] Specifically, the buffer solution is a phosphate solution.

[0043] Specifically, in S3, the collected microbial aerosol samples are enriched through an ultrafiltration tube, and the enriched samples are eluted from the ultrafiltration membrane using physiological saline.

[0044] More specifically, the collected bioaerosol samples were enriched using a centrifugal ultrafiltration tube, centrifuged at 3000–6000× for 1–30 min, and then eluted from the ultrafiltration membrane with 0.9% physiological saline solution.

[0045] Specifically, the microorganisms include bacteria, fungi, and viruses.

[0046] Specifically, the bacteria are one or more of Escherichia coli, Bacillus, Bacillus aeruginosa, and Staphylococcus aureus.

[0047] Specifically, the constant flow rate mentioned in S2 is 0–50 L / min, and the rinsing time is 0–30 min.

[0048] Specifically, the VOCs are one or more of the following: aromatic hydrocarbons, aliphatic hydrocarbons, halogenated hydrocarbons, oxygen-containing hydrocarbons, and organic sulfur compounds.

[0049] Specifically, the temperature of the generator in S2 is 0–300°C, the injection flow rate is 0–500 µL / min, and the constant flow rate is 0–100 L / min.

[0050] Specifically, the common equilibration time described in S3 is 0–120 min, and the acquisition time is 0–200 min.

[0051] Specifically, the sampler in S3 can be a liquid impactor sampler. After the sample is collected by the liquid impactor sampler, the bioaerosol sample is continuously diluted with 0.9% physiological saline solution and incubated on a nutrient agar plate at 37°C for 1–24 h.

[0052] Specifically, the gradient dilution is performed at a volume ratio of 1:10.

[0053] The present invention has the following beneficial effects:

[0054] 1. This invention provides a bioaerosol and volatile organic compound co-generation equilibrium exposure system, including a co-exposure equilibrium chamber, a volatile organic compound gas equilibrium chamber and a bioaerosol equilibrium chamber connected to the co-exposure equilibrium chamber via a piping system, and a bioaerosol collection device, etc. The system can be used to assess the interaction between VOCs and bioaerosols, thereby facilitating subsequent treatment of VOCs and bioaerosols.

[0055] 2. Based on the system described in this invention, by adjusting the gas path ratio of VOCs and bioaerosols, the types and concentrations of VOCs, as well as parameters such as the release and atomization of bioaerosols, can be changed. This allows for rapid and real-time control of the generation balance of multi-component, multi-gradient VOCs and various types and concentrations of bioaerosols, achieving real-time regulation of VOCs exposure to bioaerosols. It simulates the release of different concentrations, types, and multiple types of VOCs and the generation of different types of bioaerosols in natural scenarios, and can achieve real-time dynamic balance between bioaerosols and VOCs. This allows for a systematic and comprehensive evaluation of the effects of VOCs on bioaerosols in the natural environment.

[0056] 3. The system described in this invention is simple to operate and produces accurate and intuitive results, making it easy to simulate the interaction between VOCs and bioaerosols in natural scenarios (such as landfills, industrial emissions, sewage treatment plants, and nature). Attached Figure Description

[0057] Figure 1 is a schematic diagram of the system described in Embodiment 1 of the present invention; in the figure, 1 is a co-exposure balance box, 2 is a VOCs gas balance box, 3 is a bioaerosol balance box, 4 is a VOCs generator, 5 is a bioaerosol generator, 6 is a bioaerosol collection device, 7 is a VOCs detector, 8 is a bioaerosol particle real-time monitor, 9 is an air compressor, 10 is a flow turbulence device, 11 is a flow controller, 12 is an air filter, 13 is a fluid inlet and outlet, and 14 is an exhaust pressure relief valve.

[0058] Figure 2 is a schematic diagram of the system described in Embodiment 2 of the present invention; in the figure, 1 is a co-exposure balance box, 2 is a VOCs gas balance box, 3 is a bioaerosol balance box, 4 is a VOCs generator, 5 is a bioaerosol generator, 6 is a bioaerosol collection device, 7 is a VOCs detector, 8 is a bioaerosol particle real-time monitor, 9 is an air compressor, 10 is a flow turbulence device, 11 is a flow controller, 12 is an air filter, 13 is a fluid inlet and outlet, and 14 is an exhaust pressure relief valve.

[0059] Figure 3 shows the culturable number of Escherichia coli bioaerosols exposed to different types of VOCs.

[0060] Figure 4 shows the number of culturable Escherichia coli bioaerosols exposed to different concentrations of dimethyl trisulfide. Embodiments of the present invention

[0061] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0062] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0063] Example 1

[0064] This embodiment provides a system for the generation, equilibration, and co-exposure of bioaerosols and VOCs, as shown in Figure 1. As shown in Figure 1, the system for the generation, equilibration, and co-exposure of bioaerosols and volatile organic compounds according to this invention includes a co-exposure equilibration chamber 1, a volatile organic compound gas equilibration chamber 2 and a bioaerosol equilibration chamber 3 respectively connected to the co-exposure equilibration chamber 1 via a piping system, and a control device for controlling the operation of the system.

[0065] The piping system includes an input path that connects to the volatile organic compound gas balance chamber 2 and the bioaerosol balance chamber 3 respectively, and an output path that connects the volatile organic compound gas balance chamber 2 and the bioaerosol balance chamber 3 to the co-exposure balance chamber 1 respectively. An air compressor 9, a flow controller 11 and an air filter 12 are sequentially provided on the input path. A volatile organic compound generator 4 is also provided in the input path connected to the volatile organic compound gas balance chamber 2, and a bioaerosol generator 5 is also provided in the input path connected to the bioaerosol balance chamber 3.

[0066] The co-exposure balance chamber 1 is connected to a bioaerosol collection device 6 and an exhaust pressure relief valve 14, and is equipped with a flow disturbance device 10 inside; the volatile organic compound gas balance chamber 2 is connected to a volatile organic compound detector 7 and an exhaust pressure relief valve 14, and is equipped with a flow disturbance device 10 inside; the bioaerosol balance chamber 3 is connected to a real-time bioaerosol particle monitor 8 and an exhaust pressure relief valve 14, and is equipped with a flow disturbance device 10 inside.

[0067] In this embodiment, the turbulence device is a magnetic fan. Simultaneously, to reduce the adhesion / adsorption of microorganisms and VOCs, minimize the loss of bioaerosols and VOCs, and maintain the activity of bioaerosols, this embodiment also coats the fan blades and the inner walls of each balance box with a polytetrafluoroethylene coating.

[0068] Based on functional zoning, the system described in this invention can be divided into a bioaerosol generation and balancing system, a VOCs gas generation and balancing system, a co-exposure balancing system, a piping system for air distribution, and a control system. The bioaerosol generation and balancing system generates controllable and stable bioaerosols and VOCs gases. The co-exposure balancing system enables research on the environmental behavior, exposure, and prevention and control of bioaerosols under different concentrations, types, and multiple VOCs exposures.

[0069] The bioaerosol generation and balancing system includes a bioaerosol generator 5, a pipeline system input for supplying pure air to the bioaerosol generator 5, a bioaerosol balancing chamber 3 connected to the bioaerosol generator 5, a real-time bioaerosol particle monitor 8 connected to the bioaerosol balancing chamber 3, a turbulence device 10 installed in the bioaerosol balancing chamber 3, and a control device connected to the bioaerosol generator 5, the pipeline system, and the bioaerosol balancing chamber 3. The pipeline system input delivers filtered and disinfected clean air stably and evenly to the bioaerosol generator 5. The bioaerosol generator 5 evenly disperses the biologically active microbial suspension into the clean air to form active bioaerosols. The generated bioaerosols are then introduced into the bioaerosol balance chamber 3. The bioaerosol generator 5 can regulate the particle size distribution, concentration, and population of active bioaerosols in the system. The turbulence device 10 allows the aerosols in the bioaerosol balance chamber 3 to flow, forming a uniform and stable bioaerosol gas. The bioaerosol particle real-time monitor 8, connected to the bioaerosol balance chamber 3, can monitor the stable balance of the bioaerosol particle concentration in the bioaerosol balance chamber 3 in real time. The operation of the entire device is controlled and regulated by the control device system. The bioaerosol balance chamber 3 has at least three equidistantly distributed fluid inlets and outlets 13 on its vertical side for use as sampling ports. The bioaerosol particle real-time monitor 8 is connected to the bioaerosol balance chamber 3 through the fluid inlets and outlets 13. When the detection readings of the bioaerosol particle real-time monitor 8 at each fluid inlet and outlet 13 are consistent, it indicates that the bioaerosol balance chamber 3 is in a balanced state.

[0070] The VOCs generation and balancing system includes a VOCs generator 4, a pipeline system input for supplying clean air to the VOCs generator, a VOCs balancing box 2 connected to the VOCs generator 4, a VOCs detector 7 connected to the VOCs balancing box 2, a turbulence device 10 installed on the VOCs balancing box 2, and a control device connected to the VOCs generator 4, the pipeline system, and the VOCs balancing box 2. The pipeline system input line stably and evenly delivers filtered and disinfected clean air to the VOCs generator 4. The VOCs generator 4 heats and vaporizes liquid organic matter to form VOCs gas. The generated VOCs are introduced into the VOCs balancing chamber 2. The VOCs generator 4 can adjust the concentration and type of VOCs in the system by changing the quantity, type, and injection volume of liquid organic matter. The turbulence device 10 causes the aerosol in the VOCs balancing chamber 2 to flow, forming a uniform and stable VOCs gas. The VOCs detector 7 connected to the VOCs balancing chamber 2 can monitor the stability of the VOCs concentration in the VOCs balancing chamber in real time. The operation of the entire device is controlled and adjusted by the control device system. The vertical side of the VOCs balancing chamber 2 is provided with at least three equidistantly distributed fluid inlets and outlets 13 for use as sampling ports. The VOCs detector 7 is connected to the VOCs balancing chamber 2 through the fluid inlets and outlets 13. When the detection readings of the VOCs detector at each fluid inlet and outlet 13 are consistent, it indicates that the VOCs balancing chamber 2 is in a balanced state.

[0071] The co-exposure balancing system includes a co-exposure balancing chamber 1 connected to a bioaerosol balancing chamber 3 and a VOCs balancing chamber 2. A turbulence device 10 is installed on the co-exposure balancing chamber 1 to ensure uniform distribution of aerosols and VOCs in the balancing chamber. A fluid inlet and outlet 13 is provided on the vertical side of the co-exposure balancing chamber 1. A bioaerosol collection device 6 connected to the fluid inlet and outlet 13 of the co-exposure balancing chamber 1 collects the bioaerosols after co-exposure for subsequent analysis.

[0072] The piping system includes an air compressor 9, a flow controller 11 connected in sequence to the air compressor 9, and a high-efficiency air filter 12. The high-efficiency air filter 12 is connected to the bioaerosol generator 5 and the VOCs generator 4 via a quick-connect air connector. The air compressor 9 pumps in air, and the gas pressure supplied by the air compressor 9 is stabilized by adjusting the exhaust pressure relief valve 14. The flow controller 11 changes the flow rate of the incoming air into the bioaerosol generator 5 or the VOCs generator 4, thereby regulating the concentration of bioaerosols and VOCs in the bioaerosol generator 5 and the VOCs generator 4. The air filter 12 filters out pollutants such as dust, microorganisms, and VOCs from the air to prevent contamination of the bioaerosols and VOCs in the bioaerosol balance chamber 3 and the VOCs balance chamber 2.

[0073] Example 2

[0074] Based on the system described in Example 1, this embodiment further improves upon it. Specifically, a branch line equipped with a flow controller 11 and a high-efficiency air filter 12 is added to each of the pipeline input lines connected to the VOCs balance box 2 and the bioaerosol balance box 3, respectively. This branch line is used to input clean air into the balance box it is connected to, thereby adjusting the concentration of bioaerosol or VOCs gas. A schematic diagram of the bioaerosol and VOCs generation, balance, and co-exposure system described in this embodiment is shown in Figure 2.

[0075] Example 3

[0076] This embodiment uses the system described in Example 2 to test the interaction between Escherichia coli and different species of VOCs, and also illustrates the method of using the system of the present invention, including the following steps:

[0077] S1. Using an inoculation loop, pick up E. coli culture stored at -80℃ and inoculate it into 50 mL of prepared nutrient broth. Incubate at 37℃ and 140 rpm on a shaker until E. coli is in the logarithmic growth phase. Centrifuge the bacterial culture at 8000 rpm for 2 min, discard the supernatant, wash the bacterial precipitate twice with 0.9% NaCl solution, resuspend the bacterial precipitate, and adjust the bacterial concentration using a microplate reader to an OD600 of 1.0, indicating that the concentration of E. coli at this point is 10⁻⁶. 9 CFU / mL.

[0078] S2. In a clean bench, transfer the E. coli suspension prepared in S1 to a bioaerosol generator (six-nozzle Collison). Adjust the relative height between the internal device of the generator and the liquid surface. Use clean air at a flow rate of 12.5 L / min to aerosolize the bacterial suspension into the balance chamber. Connect an air microbial sampling pump to the exhaust gas and draw the exhaust gas into the fume hood at the same flow rate of 12.5 L / min to maintain a stable balance in the balance chamber. Suspend the generated bioaerosol in the balance chamber. Rinse the entire system continuously with bioaerosol for 5 minutes until the chamber is full of bioaerosol.

[0079] S3. Take out 99% pure dimethyl trisulfide, dimethyl disulfide, formic acid and ethanethiol liquid from the 4 ℃ refrigerator, and use the injection needle of the VOCs generator to draw 5 mL of each. Fix the injection needle horizontally on the base, set the injection needle orifice diameter to 10 mm, set the VOC gas concentration to 140 ppm, connect the VOCs generator to the air pipeline of the air distribution system and check the air tightness and pipeline flow rate. Then set the reactor temperature to the boiling point of VOCs, and use clean air to atomize and generate each VOCs gas at a constant flow rate of 5 L / min, so that the VOCs gas is suspended in the VOCs balance box. Continuously flush with VOCs until the box is full of VOCs gas and enters dynamic equilibrium.

[0080] S4. Stable bioaerosols and stable VOCs gases are introduced into a sterile co-exposure equilibration chamber for dynamic equilibration. After equilibration for 10 min, bioaerosol samples are collected for 20 min using a liquid impactor sampler. The collected bioaerosol samples are enriched using a centrifugal ultrafiltration tube, centrifuged at 4000× for 30 min, and the samples are eluted from the ultrafiltration membrane with 0.9% physiological saline solution.

[0081] S5. The bioaerosol samples enriched in S4 were serially diluted with 0.9% NaCl solution at a volume ratio of 1:10. The dilution factor was recorded. An equal volume of the diluted solution was inoculated onto a nutrient agar plate and incubated at 37°C for 24 h. The culturable number of microorganisms in the sample was calculated based on the dilution factor.

[0082] The method for calculating the number of culturable individuals is as follows:

[0083] ;

[0084] Among them, C 液体浓度 The culturable number of microorganisms for dilution plate counts is a fixed value in the unit conversion, where 10,000 is the unit conversion.

[0085] Figure 3 shows the statistical chart of the culturable number of *E. coli* bioaerosols exposed to different types of VOCs. During the experiment, all conditions were the same except for the different types of VOCs used. As shown in Figure 3, compared to the blank control, the culturable concentration of *E. coli* bioaerosols exposed to dimethyl disulfide showed very little change, indicating a small impact on *E. coli* bioaerosols. In contrast, dimethyl trisulfide, ethanethiol, and formic acid had significant effects on *E. coli* bioaerosols, decreasing the culturable number by 2 to 3 powers; formic acid had the greatest impact on *E. coli* bioaerosols. This embodiment demonstrates that the system described in this invention can autonomously adjust the exposure to different types of VOCs, meeting the needs of evaluating the co-exposure to different types of VOCs and bioaerosols in various environments.

[0086] Example 4

[0087] The difference between this embodiment and embodiment 3 is that in this embodiment, the VOCs injection flow rate in S3 is set to 0.8, 8.9, and 17.7 µL / min, from which the VOCs concentrations are calculated to be 5 ppm, 50 ppm, and 100 ppm. Escherichia coli is selected as the test strain, and dimethyl trisulfide is selected as the VOCs. The reactor temperature is set to 60°C, and clean air is atomized at a constant flow rate of 5 L / min to generate dimethyl trisulfide gas, which is then equilibrated with Escherichia coli bioaerosol in a co-exposure equilibration chamber for 10 min.

[0088] The sample collection and calculation of the culturable quantity include the following steps:

[0089] S1. Use a bioaerosol sampler to collect bioaerosol samples into 10 mL of 0.9% physiological saline solution for 20 min.

[0090] S2. Dilute the bioaerosol sample by 10-fold serial dilution with 0.9% physiological saline solution and record the dilution factor.

[0091] S3. Spread 100 µL of sample onto a nutrient agar plate and incubate at 37°C for 24 h.

[0092] S4. Calculate the culturable number of E. coli in the sample based on the dilution factor, expressed as CFU / m³. 3 count.

[0093]

[0094] Among them, C 液体浓度 The culturable number of microorganisms for dilution plate counts is a fixed value in the unit conversion, where 10,000 is the unit conversion.

[0095] Figure 4 shows the culturable number of *E. coli* bioaerosols exposed to different concentrations of dimethyl trisulfide. The results are similar to those in Example 3; the culturable number of bioaerosols decreases with increasing VOC concentration. This demonstrates that the system described in this invention can realistically simulate the interaction between bioaerosols and malodorous gases in landfills, and can autonomously adjust the exposure concentration of VOCs, facilitating the analysis of the environmental behavior of different concentrations of VOCs exposed to bioaerosols in different areas.

[0096] Example 5

[0097] The difference between this embodiment and Embodiment 3 is that in Embodiment S1, the bacterial culture is serially diluted 10-fold using a 0.9% physiological saline solution to obtain 10 5Bacterial suspensions of CFU / mL were used, with Bacillus as the test species. A three-nozzle Collison bioaerosol generator was used, and methanol was selected as the VOC. The injection flow rate was set to 0.2 µL / min, and the VOC gas concentration was set to 0.5 ppm for the interaction exposure experiment. The samples were collected for 20 min using a liquid impactor bioaerosol sampler, and the bioaerosol samples were concentrated using an ultrafiltration tube.

[0098] The sample collection and calculation of the culturable quantity include the following steps:

[0099] S1. Use an impactor liquid bioaerosol sampler to collect bioaerosol samples into 10 mL of 0.9% physiological saline solution for 20 min.

[0100] S2. Add the collected bioaerosol sample to a centrifuge ultrafiltration tube for enrichment and concentration, centrifuge at 4000× for 30 min, and elute the sample from the ultrafiltration membrane with 0.9% physiological saline solution.

[0101] S3. Dilute the bioaerosol sample 10 times with 0.9% physiological saline solution and record the dilution factor.

[0102] S4. Spread 100 µL of sample onto a nutrient agar plate and incubate at 37°C for 24 h.

[0103] S5. Calculate the culturable number of E. coli in the sample based on the dilution factor, expressed as CFU / m³. 3 count.

[0104]

[0105] Among them, C 液体浓度 The culturable number of microorganisms for dilution plate counts is a fixed value in the unit conversion, where 10,000 is the unit conversion.

[0106] The test results show that methanol affects the physiological state of Bacillus bioaerosols, with a slight decrease in the number of culturable bacteria, indicating that the experimental simulation of co-equilibrium exposure to Bacillus bioaerosols with low concentrations of methanol is feasible.

[0107] Example 6

[0108] The difference between this embodiment and embodiment 4 is that in this embodiment, the VOC injection flow rate in S3 is set to 10.8, 21.7 and 37.4 µL / min, and the VOC concentrations are calculated to be 40 ppm, 120 ppm and 200 ppm. Pseudomonas aeruginosa is selected as the test strain, and dimethyl disulfide and dimethyl trisulfide are selected as VOCs. The reactor temperature is set to 85°C, and dimethyl disulfide and dimethyl trisulfide gases are generated by atomizing clean air at a constant flow rate of 5 L / min and then equilibrated with the bioaerosol in the VOCs co-exposure equilibrium chamber for 30 min.

[0109] The sample collection and calculation of the culturable quantity include the following steps:

[0110] S1. Use a bioaerosol sampler to collect bioaerosol samples into 10 mL of 0.9% physiological saline solution for 20 min.

[0111] S2. Dilute the bioaerosol sample by 10-fold serial dilution with 0.9% physiological saline solution and record the dilution factor.

[0112] S3. Spread 100 µL of sample onto a nutrient agar plate and incubate at 37°C for 22 h.

[0113] S4. Calculate the culturable number of E. coli in the sample based on the dilution factor, expressed as CFU / m³. 3 count.

[0114]

[0115] Among them, C 液体浓度 The culturable number of microorganisms for dilution plate counts is a fixed value in the unit conversion, where 10,000 is the unit conversion.

[0116] The test results showed that the mixed sulfide gases dimethyl disulfide and dimethyl trisulfide affected the physiological state of Pseudomonas aeruginosa bioaerosols, reducing the culturable number by 2 to 3 powers. This indicates that the experimental simulation of co-equilibrium exposure to Pseudomonas aeruginosa bioaerosols using the mixed sulfide gases dimethyl disulfide and dimethyl trisulfide is feasible and can be used to assess the effects of VOCs on bioaerosols in real landfills and evaluate the risks of VOCs and bioaerosols in landfills.

[0117] Example 7

[0118] The difference between this embodiment and Embodiment 6 is that, in this embodiment, Staphylococcus aureus is selected as the test strain, and xylene gas is generated by atomizing clean air at a constant flow rate of 8 L / min and equilibrated with bioaerosol in a VOCs co-exposure equilibrium chamber for 30 min, with a VOC gas concentration of 20 ppm.

[0119] The sample collection and calculation of the culturable quantity include the following steps:

[0120] S1. Use a bioaerosol sampler to collect bioaerosol samples into 10 mL of 0.9% physiological saline solution for 30 min.

[0121] S2. Dilute the bioaerosol sample by 10-fold serial dilution with 0.9% physiological saline solution and record the dilution factor.

[0122] S3. Spread 100 µL of sample onto a nutrient agar plate and incubate at 37°C for 22 h.

[0123] S4. Calculate the culturable number of E. coli in the sample based on the dilution factor, expressed as CFU / m³. 3 count.

[0124]

[0125] Among them, C 液体浓度 The culturable number of microorganisms for dilution plate counts is a fixed value in the unit conversion, where 10,000 is the unit conversion.

[0126] The test results show that xylene gas affects the physiological state of Staphylococcus aureus bioaerosols, reducing the number of culturable bacteria by 1 to 2 powers. This indicates that the experimental simulation of co-equilibrium exposure of xylene gas to Staphylococcus aureus bioaerosols is feasible and can be used to assess the effect of VOCs in real dyeing and printing wastewater on bioaerosols and evaluate the risks of VOCs and bioaerosols in real-world scenarios.

[0127] Example 8

[0128] The difference between this embodiment and embodiment 7 is that, in this embodiment, Staphylococcus aureus and Escherichia coli are selected as test strains. Dimethyl disulfide gas is generated by atomizing clean air at a constant flow rate of 5 L / min and is co-equilibrated with bioaerosol in a VOCs co-exposure equilibrium chamber for 60 min, with a VOCs gas concentration of 20 ppm.

[0129] The sample collection and calculation of the culturable quantity include the following steps:

[0130] S1. Use an impactor liquid bioaerosol sampler to collect bioaerosol samples into 10 mL of 0.9% physiological saline solution for 30 min.

[0131] S2. Dilute the bioaerosol sample by 10-fold serial dilution with 0.9% physiological saline solution and record the dilution factor.

[0132] S3. Spread 100 µL of sample onto a nutrient agar plate and incubate at 37°C for 22 h.

[0133] S4. Calculate the culturable number of E. coli in the sample based on the dilution factor, expressed as CFU / m³. 3 count.

[0134]

[0135] Among them, C 液体浓度 The culturable number of microorganisms for dilution plate counts is a fixed value in the unit conversion, where 10,000 is the unit conversion.

[0136] The test results showed that dimethyl disulfide had a slight effect on the physiological state of Staphylococcus aureus and Escherichia coli bioaerosols, reducing the culturable number by 0 to 1 power. This indicates that the experimental simulation of co-equilibrium exposure to Staphylococcus aureus and Escherichia coli bioaerosols with dimethyl disulfide is feasible and can be used to assess the effect of VOCs on bioaerosols in real wastewater treatment plants and evaluate the risks of VOCs and bioaerosols in wastewater treatment plants.

[0137] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

[0138]

Claims

1. A bioaerosol and volatile organic compound generation, equilibration, and co-exposure system, comprising, It includes a co-exposure balance chamber (1), a volatile organic compound gas balance chamber (2) and a bioaerosol balance chamber (3) connected to the co-exposure balance chamber (1) via a piping system, and a control device for controlling the operation of the system. The piping system includes an input path that is connected to the volatile organic compound gas balance box (2) and the bioaerosol balance box (3) respectively, and an output path that connects the volatile organic compound gas balance box (2) and the bioaerosol balance box (3) to the co-exposure balance box (1) respectively; the input path is provided with an air compressor (9), a flow controller (11) and an air filter (12) in sequence, the input path connected to the volatile organic compound gas balance box (2) is also provided with a volatile organic compound generator (4), and the input path connected to the bioaerosol balance box (3) is also provided with a bioaerosol generator (5); The co-exposure balance chamber (1) is also connected to a bioaerosol collection device (6); the volatile organic compound gas balance chamber (2) is also connected to a volatile organic compound detector (7); and the bioaerosol balance chamber (3) is also connected to a bioaerosol particle real-time monitoring instrument (8).

2. The system of claim 1, wherein, The input path and / or output path contains at least one branch.

3. The system of claim 2, wherein, The input path branch is branched off from the air compressor (9), and the branch is provided with a flow controller (11) and an air filter (12) in sequence.

4. The system according to any one of claims 1 to 3, characterized in that The pipeline system is also equipped with a valve for controlling the entry and exit of aerosols or gases.

5. The system of claim 4, wherein, The co-exposure balance chamber (1), the volatile organic compound gas balance chamber (2), and the bioaerosol balance chamber (3) are all equipped with a turbulence device (10).

6. The system of claim 5, wherein, The co-exposure balance chamber (1), the volatile organic compound gas balance chamber (2), and the bioaerosol balance chamber (3) are all equipped with exhaust and pressure relief devices (14).

7. The system of claim 6, wherein, The turbulence device (10) is a fan.

8. The system of claim 6, wherein, The exhaust pressure relief device (14) is an exhaust pressure relief valve.

9. The system of claim 6, wherein, The fan blades and the inner walls of the balance boxes are all covered with an anti-stick coating.

10. Use of the system according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Add the solution of the volatile organic compound to be tested to the injection needle of the volatile organic compound generator (4), and use the pipeline system to make the volatile organic compound generator (4) generate volatile organic compounds and enter the volatile organic compound gas balance box (2). After the box is full of volatile organic compounds, turn off the volatile organic compound generator (4) and wait for the volatile organic compounds in the box to enter dynamic equilibrium. S2. Place the suspension of the microorganism to be tested in the liquid bottle of the bioaerosol generator (5), and use the pipeline system to make the bioaerosol generator (5) generate microbial aerosols and enter the bioaerosol balance box (3). After the box is filled with microbial aerosols, turn off the bioaerosol generator (5) and wait for the aerosols in the box to reach dynamic balance. S3. The volatile organic compounds and microbial aerosols in dynamic equilibrium are simultaneously introduced into the co-exposure equilibrium chamber (1) through the output path of the pipeline system for dynamic equilibrium. Microbial aerosol samples are collected and enriched using a bioaerosol collection device (6). The enriched microorganisms are then subjected to gradient dilution and plate culture. The culturable number of microorganisms in the sample is calculated based on the dilution factor. The change in the culturable number of microorganisms is observed to observe the effect of volatile organic compounds on microbial aerosols. The formula for calculating the number of culturable individuals is as follows: ； wherein C 液体浓度 is the number of microorganisms cultivable diluted on the plate count.

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