CN115015522B - Method for predicting VOCs vapor invasion attenuation coefficient of deep soil by radon concentration - Google Patents
Method for predicting VOCs vapor invasion attenuation coefficient of deep soil by radon concentration Download PDFInfo
- Publication number
- CN115015522B CN115015522B CN202210756470.5A CN202210756470A CN115015522B CN 115015522 B CN115015522 B CN 115015522B CN 202210756470 A CN202210756470 A CN 202210756470A CN 115015522 B CN115015522 B CN 115015522B
- Authority
- CN
- China
- Prior art keywords
- vocs
- radon
- radon concentration
- concentration
- attenuation coefficient
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 229910052704 radon Inorganic materials 0.000 title claims abstract description 119
- SYUHGPGVQRZVTB-UHFFFAOYSA-N radon atom Chemical compound [Rn] SYUHGPGVQRZVTB-UHFFFAOYSA-N 0.000 title claims abstract description 119
- 239000012855 volatile organic compound Substances 0.000 title claims abstract description 76
- 238000000034 method Methods 0.000 title claims abstract description 40
- 239000002689 soil Substances 0.000 title claims abstract description 35
- 230000009545 invasion Effects 0.000 title claims abstract description 10
- 238000012544 monitoring process Methods 0.000 claims abstract description 20
- 238000004364 calculation method Methods 0.000 claims abstract description 11
- 239000000700 radioactive tracer Substances 0.000 claims abstract description 7
- 239000003570 air Substances 0.000 claims description 60
- 239000002680 soil gas Substances 0.000 claims description 49
- 238000005070 sampling Methods 0.000 claims description 42
- 238000001179 sorption measurement Methods 0.000 claims description 18
- 238000005553 drilling Methods 0.000 claims description 14
- 238000001514 detection method Methods 0.000 claims description 10
- 238000007789 sealing Methods 0.000 claims description 10
- 238000012360 testing method Methods 0.000 claims description 10
- 239000004033 plastic Substances 0.000 claims description 9
- 239000003344 environmental pollutant Substances 0.000 claims description 7
- 231100000719 pollutant Toxicity 0.000 claims description 7
- 239000004568 cement Substances 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims description 4
- 239000002002 slurry Substances 0.000 claims description 4
- 239000012080 ambient air Substances 0.000 claims description 3
- 238000012216 screening Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 9
- 238000005259 measurement Methods 0.000 abstract description 6
- 230000006399 behavior Effects 0.000 abstract description 4
- 239000003795 chemical substances by application Substances 0.000 abstract description 3
- 238000012937 correction Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- -1 and meanwhile Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000005315 distribution function Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000011895 specific detection Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/24—Earth materials
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Medicinal Chemistry (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Pathology (AREA)
- Food Science & Technology (AREA)
- Immunology (AREA)
- Combustion & Propulsion (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Remote Sensing (AREA)
- Measurement Of Radiation (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The invention discloses a method for predicting a vapor intrusion attenuation coefficient of VOCs in deep soil by utilizing radon gas concentration, belonging to the technical field of vapor intrusion risk prediction; the method for predicting the vapor invasion attenuation coefficient of the VOCs in the deep soil by utilizing the radon concentration completely records the working flow of the method, and can rapidly predict the vapor invasion risk of the underground space and obtain the attenuation coefficient of the underground space; the radon concentration is monitored by distribution points in the indoor and outdoor and under the foundation, so that the effect of rapidly predicting the steam invasion risk of the building can be achieved; the attenuation coefficient can be obtained more accurately by a field monitoring method, and the uncertainty of the result is reduced; according to the invention, radon is used as the tracer agent by utilizing the excellent characteristics that radon has almost no indoor source and has similar behaviors with VOCs underground, so that the attenuation coefficient can be obtained more quickly and accurately; and the indoor source and the outdoor source are brought into a calculation model, data are acquired through actual measurement, the risk of the building being invaded by steam is more intuitively known, and the steam invasion attenuation coefficient is more accurately acquired.
Description
Technical Field
The invention relates to the technical field of vapor intrusion risk prediction, in particular to a method for predicting a vapor intrusion attenuation coefficient of VOCs in deep soil by utilizing radon concentration.
Background
With the development of age and technology, there is an increasing concern about the potential hazard of vapor intrusion, i.e., the penetration of Volatile Organic Compounds (VOCs) from contaminated soil and groundwater through the floors of buildings into indoor air. Monitoring the risk of vapor intrusion often requires the detection of the concentration of VOCs within the building. In practice, however, for certain evaluations of buildings where there is a potential for vapor intrusion, particularly those involving the detection of indoor air VOCs levels, existing sources of indoor VOCs within the building will have a significant impact on the results. Therefore, for VOCs present in the room, direct detection of the concentration of VOCs in the room air is not effective in identifying vapor intrusion. Measuring the concentration of VOCs in the underfloor soil gas is currently the preferred method of identifying the effects of vapor intrusion, but the actual rate of transmission of the soil gas into the building varies from building structure to building material, thus there is uncertainty in the concentration that can actually threaten the indoor air quality; radon is a naturally occurring compound in the soil gas, migration behavior is very similar to VOCs, there is usually no indoor source, and vapor intrusion is the main source of radon in indoor air. Therefore, the detection of radon concentration in soil gas and indoor air can effectively evaluate the potential steam invasion risk of a building.
To evaluate the risk of potential vapor intrusion into a building using radon as a tracer for VOCs entering the building, the radon concentration under, inside and outside the building must be detected to calculate the attenuation factor for the given building, which characterizes the dilution of radon from soil gas to indoor air; the attenuation coefficient at home and abroad at present is calculated by a JEM model, the calculated result is generally conservative, and the attenuation coefficient calculated by the method has the following defects: 1. the problem of indoor source is not considered in the model, and the heterogeneity of soil is ignored, so that the result is conservative; 2. the actual situation is very complex, and the model cannot adapt to all situations; 3. there is no workflow to form a system and there is some uncertainty in the results. Aiming at the defects, the invention provides a method for predicting the vapor intrusion attenuation coefficient of the VOCs in the deep soil by utilizing radon concentration.
Disclosure of Invention
The invention aims to provide a method for predicting the vapor intrusion attenuation coefficient of the deep soil VOCs by utilizing radon gas concentration, which is characterized in that the working procedure is standardized, and the uncertainty of a calculation result is reduced; the problem of indoor sources is considered in the calculation model, the attenuation coefficient is calculated through the actual measurement result, and the result is more practical and reliable.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
the method for predicting the vapor intrusion attenuation coefficient of the deep soil VOCs by utilizing the radon concentration specifically comprises the following steps:
s1, selecting a building as a test area, installing radon measuring instruments and VOCs sampling and adsorbing devices in the indoor and indoor clean areas and the outdoor of the building, constructing a soil gas sampling port of the building, and monitoring soil gas under the foundation of the building;
s2, detecting air of each monitoring point and soil gas of each soil gas sampling port in the S1 by using a radon measuring instrument, and recording radon concentration data;
s3, collecting VOCs in the air of each monitoring point by using a VOCs sampling adsorption device, sealing an adsorption pipe, transferring the adsorption pipe to a laboratory for detection, and measuring the concentration of the VOCs;
s4, comparing the radon concentration Cind_R of the indoor air with the radon concentration Cout_R of the outdoor air based on the data obtained in the S2;
s5, if Cind_R is less than Cout_R, indicating that no steam invasion risk exists indoors; if Cind_R > Cout_R, then enter S6, carry on the further screening work;
s6, combining the data obtained in the S2 and the S3, and respectively comparing the radon concentration cind_R of the indoor air with the radon concentration csg_R of the soil gas, and the concentration cind_V of the VOCs in the indoor air with the VOCs concentration csg_V of the soil gas;
s7, if Cind_R is larger than Csg_R, indicating that radon source exists in the building room, wherein radon is not suitable to be used as a tracer; if Cind_V > Csg_V, then this indicates that the cell source is the primary source of VOCs; if Cind_R < Csg_R and Cind_V < Csg_V, then S8 is entered for further determination
S8, based on the data obtained in the step S2, recording radon concentration in the air in the clean area in the room as Cindc_R;
and S9, processing the data obtained in the S2-S8 comprehensively, and calculating to obtain the indoor attenuation coefficient SAF of the volatile pollutants of the test building.
Preferably, the construction of the building soil gas sampling port mentioned in S1 specifically includes the following steps:
a1, drilling through a building bottom plate by using a drilling tool, continuing to drill downwards to form a drilling hole, and placing a PVC pipe with a hole on the side wall in the drilling hole;
a2, sealing the upper part of the PVC pipe by using a rubber plug with the top connected with a plastic pipe, wherein the lower part of the rubber pipe stretches into the PVC pipe for 5-10cm, and the tail end of the plastic pipe, which is far away from the PVC pipe, is connected with a three-way valve;
a3, respectively connecting an inlet end of the radon measuring instrument and an inlet end of the VOCs adsorption tube through a communicating pipe on the three-way valve, and simultaneously connecting an outlet end of the VOCs adsorption tube with the VOCs sampling pump;
a4, backfilling soil between the PVC pipe and the inner wall of the borehole, and sealing the top with cement slurry, so that the soil gas is prevented from invading the room along a sampling channel due to sampling, and the monitoring result is prevented from being influenced by the mixing of ambient air and the soil gas;
a5, setting sampling flow and sampling time of a sampling pump, completing collection of the soil gas VOCs sample, and recording the measured radon concentration data after the reading of the radon instrument to be measured is stable.
Preferably, the depth of the drilled hole mentioned in A1 is more than or equal to 6m, and the open hole part on the PVC pipe is positioned in soil 1.5-6.0 m below the building floor and ensures that the open hole is not blocked.
Preferably, the radon concentration measurement in the air and soil gas mentioned in S2 is performed by an electrostatic collection method or a pulse ionization chamber method.
Preferably, the indoor attenuation coefficient SAF of the volatile pollutant in the test building mentioned in S9 is calculated by dividing the radon concentration in the corrected indoor air by the radon concentration in the soil gas, and the calculation formula is as follows:
C correction of ＝Cind_R-Cout_R-Cindc_R (2)
In the formula (1), csg_R represents radon concentration in soil gas;
in formula (2), cind_r represents radon concentration in indoor air; cout_r represents radon concentration in the outdoor air; cindc_r represents radon concentration in the air in the clean room.
Compared with the prior art, the method for predicting the vapor intrusion attenuation coefficient of the VOCs in the deep soil by utilizing the radon concentration has the following beneficial effects:
(1) The invention provides a method for predicting the vapor intrusion attenuation coefficient of the deep soil VOCs by utilizing radon concentration, which completely records the working flow of the method, and can rapidly predict the vapor intrusion risk of the underground space and obtain the attenuation coefficient of the underground space;
(2) The method for predicting the radon concentration of the deep soil vapor intrusion has the advantages that the radon concentration is not monitored at present, the radon concentration is monitored at points in the indoor and outdoor places and under the foundation, the effect of rapidly predicting the risk of building vapor intrusion can be achieved, and the uncertainty of the result is reduced;
(3) The existing attenuation coefficient is often obtained through experience or a numerical model, but factors influencing the attenuation coefficient are many, such as atmospheric pressure, soil texture and the like, and the effect of obtaining the attenuation coefficient more accurately can be achieved through a field monitoring method;
(4) The JEM model used in the prior art calculates the attenuation coefficient of vapor intrusion through the concentration of VOCs, but because the number of indoor sources of the VOCs is large, the method has the advantages that radon hardly has indoor sources and has similar behavior with the VOCs underground, and radon is selected as a tracer agent, so that the effect of more accurately acquiring the attenuation coefficient can be achieved;
(5) In the prior art, only the concentration of VOCs in a room and under a foundation is often considered, but the consideration of indoor sources and outdoor sources is insufficient, the indoor sources and the outdoor sources are taken into a calculation model, data are acquired through actual measurement, the risk of vapor intrusion of a building is more intuitively known, and the vapor intrusion attenuation coefficient is more accurately acquired.
Drawings
FIG. 1 is a flow chart of a method for predicting the vapor intrusion attenuation coefficient of VOCs in deep soil by utilizing radon concentration;
fig. 2 is a schematic diagram of the arrangement of air sampling ports of underground soil of a building according to the method for predicting the vapor intrusion attenuation coefficient of VOCs in deep soil by utilizing radon concentration.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.
Example 1:
referring to fig. 1-2, the method for predicting the vapor intrusion attenuation coefficient of the deep soil VOCs by using radon concentration specifically comprises the following steps:
s1, selecting a building as a test area, installing radon measuring instruments and VOCs sampling and adsorbing devices in the indoor and indoor clean areas and the outdoor of the building, constructing a soil gas sampling port of the building, and monitoring soil gas under the foundation of the building;
s1, constructing a building soil gas sampling port, which specifically comprises the following steps:
a1, drilling through a building bottom plate by using a drilling tool, continuing to drill downwards to form a drilling hole, and placing a PVC pipe with a hole on the side wall in the drilling hole;
the depth of the drilling hole mentioned in A1 is more than or equal to 6m, the open pore part on the PVC pipe is positioned in the soil 1.5-6.0 m below the building bottom plate and ensures that the open pore is not blocked;
a2, sealing the upper part of the PVC pipe by using a rubber plug with the top connected with a plastic pipe, wherein the lower part of the rubber pipe stretches into the PVC pipe for 5-10cm, and the tail end of the plastic pipe, which is far away from the PVC pipe, is connected with a three-way valve;
a3, respectively connecting an inlet end of the radon measuring instrument and an inlet end of the VOCs adsorption tube through a communicating pipe on the three-way valve, and simultaneously connecting an outlet end of the VOCs adsorption tube with the VOCs sampling pump;
a4, backfilling soil between the PVC pipe and the inner wall of the borehole, and sealing the top with cement slurry, so that the soil gas is prevented from invading the room along a sampling channel due to sampling, and the monitoring result is prevented from being influenced by the mixing of ambient air and the soil gas;
a5, setting sampling flow and sampling time of a sampling pump, completing collection of a soil gas VOCs sample, and recording the measured radon concentration data after the reading of the radon instrument to be measured is stable;
s2, detecting air of each monitoring point and soil gas of each soil gas sampling port in the S1 by using a radon measuring instrument, and recording radon concentration data;
s2, measuring radon concentration in the air and the soil gas by an electrostatic collection method or a pulse ionization chamber method;
s3, collecting VOCs in the air of each monitoring point by using a VOCs sampling adsorption device, sealing an adsorption pipe, transferring the adsorption pipe to a laboratory for detection, and measuring the concentration of the VOCs;
s4, comparing the radon concentration Cind_R of the indoor air with the radon concentration Cout_R of the outdoor air based on the data obtained in the S2;
s5, if Cind_R is less than Cout_R, indicating that no steam invasion risk exists indoors; if Cind_R > Cout_R, then enter S6, carry on the further screening work;
s6, combining the data obtained in the S2 and the S3, and respectively comparing the radon concentration cind_R of the indoor air with the radon concentration csg_R of the soil gas, and the concentration cind_V of the VOCs in the indoor air with the VOCs concentration csg_V of the soil gas;
s7, if Cind_R is larger than Csg_R, indicating that radon source exists in the building room, wherein radon is not suitable to be used as a tracer; if Cind_V > Csg_V, then this indicates that the cell source is the primary source of VOCs; if Cind_R < Csg_R and Cind_V < Csg_V, then S8 is entered for further determination
S8, based on the data obtained in the step S2, recording radon concentration in the air in the clean area in the room as Cindc_R;
s9, processing the data obtained in the S2-S8 comprehensively, and calculating to obtain the indoor attenuation coefficient SAF of the volatile pollutants of the test building;
the indoor attenuation coefficient SAF of the volatile pollutants of the test building mentioned in S9 is calculated by dividing the radon concentration in the corrected indoor air by the radon concentration in the soil gas, and the calculation formula is as follows:
C correction of ＝Cind_R-Cout_R-Cindc_R (2)
In the formula (1), csg_R represents radon concentration in soil gas;
in formula (2), cind_r represents radon concentration in indoor air; cout_r represents radon concentration in the outdoor air; cindc_r represents radon concentration in the air in the clean room.
The invention provides a method for predicting the vapor intrusion attenuation coefficient of the deep soil VOCs by utilizing radon concentration, which completely records the working flow of the method, and can rapidly predict the vapor intrusion risk of the underground space and obtain the attenuation coefficient of the underground space; the method for predicting the radon concentration of the deep soil vapor intrusion has the advantages that the radon concentration is not monitored at present, the radon concentration is monitored at points in the indoor and outdoor places and under the foundation, the effect of rapidly predicting the risk of building vapor intrusion can be achieved, and the uncertainty of the result is reduced; in addition, the existing attenuation coefficient is often obtained through experience or a numerical model, but factors influencing the attenuation coefficient are many, such as atmospheric pressure, soil texture and the like, and the effect of obtaining the attenuation coefficient more accurately can be achieved through a field monitoring method; furthermore, the JEM model used in the prior art calculates the attenuation coefficient of vapor intrusion through the concentration of VOCs, but because the influence of more indoor sources of the VOCs on the results is larger, the invention utilizes the excellent characteristics that radon has almost no indoor sources and the behaviors of radon are similar to those of the VOCs underground, and the radon is selected as a tracer agent, so that the effect of more accurately acquiring the attenuation coefficient can be achieved; the method and the device have the advantages that the indoor source and the outdoor source are taken into a calculation model, data are acquired through actual measurement, the risk of vapor intrusion of a building is more intuitively known, and the vapor intrusion attenuation coefficient is more accurately acquired.
Example 2:
based on example 1 but with the difference that:
the method for predicting the vapor intrusion attenuation coefficient of the deep soil VOCs by utilizing the radon concentration specifically comprises the following steps:
step one, data acquisition and detection:
radon concentration and VOCs data information in underground, indoor clean areas and outdoor air of a building.
The radon concentration data in the air is directly detected by using radon measuring instruments in indoor and indoor clean areas and outdoor gas, and meanwhile, VOCs data in the air are collected by adopting VOCs adsorption tubes and are subsequently transferred to a laboratory for specific detection. The clean room is typically selected to be in the building attic. For collecting a gas sample of the soil under the building, referring to fig. 2, a drilling tool is first used to drill through the building bottom plate, a PVC pipe with a front opening is placed, the opening part of the PVC pipe is ensured to be in the soil about 5.0m below the building bottom plate, and the opening is ensured not to be blocked; the top of the PVC pipe is connected with a rubber plug, the top of the PVC pipe is sealed by a concave cap nut connected with a plastic pipe, the tail end of the plastic pipe, which is far away from the PVC pipe, is connected with a three-way valve, the three-way valve is respectively connected with a radon measuring instrument and an air inlet of a VOCs adsorption pipe through a communicating pipe, and an air outlet of the VOCs adsorption pipe is connected with a sampling pump; the cement slurry is used for sealing the opening of the bottom plate, so that soil gas is prevented from invading into a room along a sampling channel due to sampling; and finally, setting the sampling flow of the sampling pump to be 100ml/min, setting the sampling time to be 20-30 min, completing the collection of the soil gas VOCs sample, and recording the measured radon concentration data after the reading of the radon instrument to be measured is stable.
Step two, radon concentration analysis:
the radon concentration in the air of the monitoring point is measured according to an electrostatic collection method or a pulse ionization chamber method.
Both of the above measurement methods can be used for instantaneous or continuous measurement of radon concentration.
Step three, data processing:
the effect of the chemicals in the soil gas on the indoor air quality is generally expressed as an attenuation factor, SAF, defined as the detected concentration Cind of the volatile chemical of interest in the indoor air (corrected by subtracting the outdoor air concentration Cout and the indoor clean zone air concentration Cinc) divided by the measured concentration Cinu of the chemical in the soil gas, and its calculation formula is:
the indoor attenuation coefficient SAF of the volatile pollutant of the test building is calculated by dividing the radon concentration in the corrected indoor air by the radon concentration in the soil gas, and the calculation formula is as follows:
C correction of ＝Cind_R-Cout_R-Cindc_R (2)
In the formula (1), csg_R represents radon concentration in soil air;
in formula (2), cind_r represents radon concentration in indoor air; cout_r represents radon concentration in the outdoor air; cindc_r represents radon concentration in the air in the clean room.
For each sampling event, samples were taken at 4 different locations outdoors, indoors clean room and below the foundation, the standard deviation of the samples below the foundation was typically higher, reflecting the higher spatial variability within the medium. As shown in table 1, each sampling event was monitored at least 8 times, and the detection was maintained in normal use. For the indoor radon concentration level, 32 monitoring results from 4 different positions are summarized, if the 32 monitoring results are uniformly distributed and normally distributed, the upper limit of the 95% confidence level is adopted as the indoor radon concentration level, and otherwise, the maximum value is adopted as the indoor radon concentration level. The radon concentration level outdoors and under the foundation is calculated according to the indoor radon concentration level calculation method.
Table 1 example data
* And (5) indicating that the monitoring result distribution does not accord with the normal distribution, and selecting the maximum value as the air radon concentration level of the cleaning area.
The overall normal mean, i.e. the upper confidence limit for the true evaluation value μ of radon concentration in different media at a confidence level of 1-a, can be calculated by the following formula:
wherein:
-sample average;
t a (n-1) -t distribution function, and can check the t distribution score table in the statistical manual;
n-sample volume;
a, the probability that the overall mean value is larger than the confidence upper limit, and when the confidence level is 95%, a is 0.05;
s-sample standard deviation.
The sample standard deviation s can be calculated by:
wherein:
x-sample detection value.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.
Claims (4)
1. The method for predicting the vapor intrusion attenuation coefficient of the deep soil VOCs by utilizing the radon concentration is characterized by comprising the following steps of:
s1, selecting a building as a test area, installing radon measuring instruments and VOCs sampling and adsorbing devices in the indoor and indoor clean areas and the outdoor of the building, constructing a soil gas sampling port of the building, and monitoring soil gas under the foundation of the building;
s2, detecting air of each monitoring point and soil gas of each soil gas sampling port in the S1 by using a radon measuring instrument, and recording radon concentration data;
s3, collecting VOCs in the air of each monitoring point by using a VOCs sampling adsorption device, sealing an adsorption pipe, transferring the adsorption pipe to a laboratory for detection, and measuring the concentration of the VOCs;
s4, comparing the radon concentration Cind_R of the indoor air with the radon concentration Cout_R of the outdoor air based on the data obtained in the S2;
s5, if Cind_R is less than Cout_R, indicating that no steam invasion risk exists indoors; if Cind_R > Cout_R, then enter S6, carry on the further screening work;
s6, combining the data obtained in the S2 and the S3, and respectively comparing the radon concentration cind_R of the indoor air with the radon concentration csg_R of the soil gas, and the concentration cind_V of the VOCs in the indoor air with the VOCs concentration csg_V of the soil gas;
s7, if Cind_R is larger than Csg_R, indicating that radon source exists in the building room, wherein radon is not suitable to be used as a tracer; if Cind_V > Csg_V, then this indicates that the cell source is the primary source of VOCs; if Cind_R < Csg_R and Cind_V < Csg_V, then S8 is entered for further determination
S8, based on the data obtained in the step S2, recording radon concentration in the air in the clean area in the room as Cindc_R;
s9, processing the data obtained in S2-S8 comprehensively, and calculating to obtain the indoor attenuation coefficient SAF of the volatile pollutants of the test building, wherein the indoor attenuation coefficient SAF of the volatile pollutants of the test building is calculated by dividing the radon concentration in the corrected indoor air by the radon concentration in the soil gas, and the calculation formula is as follows:
in the formula (1), csg_R represents radon concentration in soil gas;
in formula (2), cind_r represents radon concentration in indoor air; cout_r represents radon concentration in the outdoor air; cindc_r represents radon concentration in the air in the clean room.
2. The method for predicting the vapor intrusion attenuation coefficient of deep soil VOCs according to claim 1, wherein said constructing a building soil gas sampling port mentioned in S1 specifically comprises the steps of:
a1, drilling through a building bottom plate by using a drilling tool, continuing to drill downwards to form a drilling hole, and placing a PVC pipe with a hole on the side wall in the drilling hole;
a2, sealing the upper part of the PVC pipe by using a rubber plug with the top connected with a plastic pipe, wherein the lower part of the plastic pipe stretches into the PVC pipe for 5-10cm, and the tail end of the plastic pipe, which is far away from the PVC pipe, is connected with a three-way valve;
a3, respectively connecting an inlet end of the radon measuring instrument and an inlet end of the VOCs adsorption tube through a communicating pipe on the three-way valve, and simultaneously connecting an outlet end of the VOCs adsorption tube with the VOCs sampling pump;
a4, backfilling soil between the PVC pipe and the inner wall of the borehole, and sealing the top with cement slurry, so that the soil gas is prevented from invading the room along a sampling channel due to sampling, and the monitoring result is prevented from being influenced by the mixing of ambient air and the soil gas;
a5, setting sampling flow and sampling time of a sampling pump, completing collection of the soil gas VOCs sample, and recording the measured radon concentration data after the reading of the radon instrument to be measured is stable.
3. The method for predicting the vapor intrusion attenuation coefficient of deep soil VOCs according to claim 2, wherein the depth of the drilled hole mentioned in A1 is equal to or more than 6m, and the open hole part on the PVC pipe is located in the soil 1.5-6.0 m below the floor of the building and ensures that the open hole is not blocked.
4. The method for predicting the vapor intrusion attenuation coefficient of VOCs in deep soil by using radon concentration according to claim 1, wherein said measuring radon concentration in air and soil gas mentioned in S2 is accomplished by an electrostatic collection method or a pulse ionization chamber method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210756470.5A CN115015522B (en) | 2022-06-30 | 2022-06-30 | Method for predicting VOCs vapor invasion attenuation coefficient of deep soil by radon concentration |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210756470.5A CN115015522B (en) | 2022-06-30 | 2022-06-30 | Method for predicting VOCs vapor invasion attenuation coefficient of deep soil by radon concentration |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115015522A CN115015522A (en) | 2022-09-06 |
| CN115015522B true CN115015522B (en) | 2024-03-26 |
Family
ID=83078669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210756470.5A Active CN115015522B (en) | 2022-06-30 | 2022-06-30 | Method for predicting VOCs vapor invasion attenuation coefficient of deep soil by radon concentration |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115015522B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101607831B1 (en) * | 2015-07-31 | 2016-03-31 | (주)Ehs기술연구소 | Method for predicting indoor ventilatiory volume based on radon radiation amount of construction material and apparatus for reducing radon automatically using the same method |
| CN112859141A (en) * | 2021-01-07 | 2021-05-28 | 深圳市奇信集团股份有限公司 | Indoor radon concentration prediction and control method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101922211B1 (en) * | 2018-04-30 | 2018-11-26 | 주식회사 베터라이프 | System for predicting indoor radon and method thereof |
-
2022
- 2022-06-30 CN CN202210756470.5A patent/CN115015522B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101607831B1 (en) * | 2015-07-31 | 2016-03-31 | (주)Ehs기술연구소 | Method for predicting indoor ventilatiory volume based on radon radiation amount of construction material and apparatus for reducing radon automatically using the same method |
| CN112859141A (en) * | 2021-01-07 | 2021-05-28 | 深圳市奇信集团股份有限公司 | Indoor radon concentration prediction and control method |
Non-Patent Citations (6)
| Title |
|---|
| Use of Radon Measurements for Evaluation of Volatile Organic Compound (VOC) Vapor Intrusion;Thomas E. McHugh 等;environment forensic;20080318;第107-113页 * |
| 地下建筑物辐射环境问题初探;潘英杰;薛建新;高尚雄;李玉成;环境Rn/Tn的测量与评价国际学术研讨会;20020501;第13-20页 * |
| 基于J&E/AAM模型的污染场地VOCs风险防控;逯雨;李义连;杨森;朱艳;李泉;唐志;;环境科学研究;20180105(第05期);第88-97页 * |
| 污染地块中高密度非水相液体(DNAPLs)迁移特征及判定调查技术研究进展;高尚;王磊;龙涛;曹少华;陈樯;;生态与农村环境学报;20180418(第04期);第4-14页 * |
| 箱体实验验证Johnson & Ettinger蒸气入侵模型;芦伟;李忠元;杨洁;刘勇弟;李辉;;华东理工大学学报(自然科学版);20180615(第03期);第104-111页 * |
| 高尚;王磊;龙涛;曹少华;陈樯.污染地块中高密度非水相液体(DNAPLs)迁移特征及判定调查技术研究进展.生态与农村环境学报.2018,(第04期),第4-14页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115015522A (en) | 2022-09-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Nazaroff et al. | Radon transport into a detached one-story house with a basement | |
| AU2008278247B2 (en) | In situ determination of critical desorption pressures | |
| Hodgson et al. | Soil-gas contamination and entry of volatile organic compounds into a house near a landfill | |
| CN110717693B (en) | Method for determining permeability coefficient of soil anti-seepage engineering barrier under action of pollutants | |
| Li et al. | Shrink-swell index database for Melbourne | |
| CN115015522B (en) | Method for predicting VOCs vapor invasion attenuation coefficient of deep soil by radon concentration | |
| KR102338915B1 (en) | System for detecting soil/underground water pollution | |
| Bieranowski et al. | Non-invasive tests of precast cantilever balcony in OWT-67 system | |
| Eklund et al. | Concentration of tetrachloroethylene in indoor air at a former dry cleaner facility as a function of subsurface contamination: a case study | |
| Nazaroff et al. | Radon transport into a single-family house with a basement | |
| KR101981650B1 (en) | Real-Time Radon Monitoring System for Underground Watershed | |
| Turk et al. | Radon and Remedial Action in Spokane River Valley Homes. Volume I: Experimental Design and Data Analysis | |
| CN116026284B (en) | Multifunctional layered mark measuring method | |
| Crump et al. | Reducing ingress of organic vapours into homes situated on contaminated land | |
| Turk et al. | Developing soil gas and 222Rn entry potentials for substructure surfaces and assessing 222Rn control diagnostic techniques | |
| Turk | Interim report on diagnostic procedures for radon control | |
| Tondeur et al. | Indoor radon in the region of Brussels | |
| McGrath et al. | Air infiltration from basements and sub-floors to the living space | |
| Fugler et al. | Indoor infiltration of volatile organic contaminants: Measured soil gas entry rates and other research results for Canadian houses | |
| Hughes et al. | Karst geology, radon fluctuations, and implications for measurement and mitigation | |
| De Meijer et al. | Contribution of radon flows and radon sources to the radon concentration in a dwelling | |
| Bell et al. | The Role of Ventilation 15th AlVC Conference, Buxton, Great Britain 27-30 September 1994 | |
| McAlary | Subsurface vapour intrusion into indoor air: a case study. | |
| Piersol | Final Report P-5340/FG Development and Evaluation of Soil Gas Sampling Techniques for The Research Division | |
| CN115436992A (en) | Device for evaluating performance of soil emanometer by simulating soil environment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |