CN115201448B - Method and device for analyzing release and migration characteristics of polybrominated diphenyl ethers in polluted site - Google Patents
Method and device for analyzing release and migration characteristics of polybrominated diphenyl ethers in polluted site Download PDFInfo
- Publication number
- CN115201448B CN115201448B CN202210601039.3A CN202210601039A CN115201448B CN 115201448 B CN115201448 B CN 115201448B CN 202210601039 A CN202210601039 A CN 202210601039A CN 115201448 B CN115201448 B CN 115201448B
- Authority
- CN
- China
- Prior art keywords
- leaching
- water outlet
- release
- outlet port
- solution
- 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
Images
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
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/62—Detectors specially adapted therefor
- G01N30/72—Mass spectrometers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
- G01N2013/003—Diffusion; diffusivity between liquids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N2030/022—Column chromatography characterised by the kind of separation mechanism
- G01N2030/025—Gas chromatography
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Immunology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Remote Sensing (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The invention discloses a method for analyzing release and migration characteristics of polybrominated diphenyl ethers in a polluted site, which comprises the following steps: step 1, sampling in situ in a polluted site to obtain an undisturbed soil column; preparing a simulated rainwater solution or collecting rainwater in a polluted site; step 2, filling the undisturbed soil column into a rock core holder; step 3, pre-washing the undisturbed soil column; and 4, carrying out a leaching experiment: pumping the simulated rainwater solution or rainwater collected in a polluted site into the core holder for leaching at constant pressure and constant flow through the water inlet, and respectively collecting the leaching solution flowing out of each water outlet port; and 5, measuring the water flux of each water outlet port, measuring the concentration of PBDEs in the leaching solution flowing out of each water outlet port, and analyzing the release and migration characteristics of the polybrominated diphenyl ethers in the polluted site according to the detection result. The invention can accurately reflect the release characteristics of the PBDEs in the soil of the polluted site and characterize the influence of the preferential flow path on the PBDEs release.
Description
Technical Field
The invention relates to the technical field of environment, in particular to a method and a device for analyzing release and migration characteristics of polybrominated diphenyl ethers in a polluted site based on an undisturbed soil column leaching experiment.
Background
Under the background of shortage of land resources and urban land in China, restoration, development and reuse of polluted fields are important national requirements which are important for people to gain great interest. Polybrominated diphenyl ethers (PBDEs) are Persistent Organic Pollutants (POPs) widely existing in the environment, and due to the characteristics of environmental persistence, long-distance transmission, bioaccumulation, toxic effect on organisms and human bodies and the like, research on the environmental problems becomes a hot spot of the current environmental science. PBDEs are produced in 80 th of the 20 th century in China, and become one of the main producing countries of decabromodiphenyl ether (BDE-209) in 2000. PBDEs are widely added into plastic products and the like as brominated flame retardants, but the PBDEs are easy to escape from products and enter the environment, so that the environmental pollution is caused; researches have found that the content of PBDEs in the environment such as soil is increased year by year after 80 years in the 20 th century. Only for electronic products, PBDEs exist in circuit boards, electronic components, cables, plastic housings, keyboards and displays, and with the disposal of a large number of electronic products as electronic waste after use, PBDEs pollution to the environment can be caused, especially PBDEs pollution in soil is serious in the field of electronic waste disassembly and distribution. PBDEs in surface soils may be released into the soil interstitial water and migrate down to underground aquifers, causing groundwater contamination.
Currently, batch experiments (batch test) and packed column experiments performed in laboratories, lysimeter experiments performed in the field, and other methods are mostly adopted for research on the release and migration behaviors of PBDEs in soil. The batch experiment is to add soil into water to prepare soil suspension, then to stir or oscillate for a certain time, and to sample and determine the release of pollutants released into water phase or colloid. The method destroys the soil structure, and can not simulate the water flow condition in the soil medium, and the measured pollutant release capacity is generally far higher than that of the actual soil. Compared with batch experiments, pollutant release and migration experiments performed by using the filled homogeneous soil column are closer to actual soil conditions, and hydrodynamic conditions of underground aquifers can be simulated to a certain extent, but the filled column generally has no prior flow path common in soil, and the pollutant release and migration capability in the soil can not be accurately evaluated. The lysimeter experiment is carried out on site, can accurately predict the pollutant release characteristics under actual conditions, but has long experimental period and high cost. Therefore, a new experimental method must be developed to reveal the release and migration characteristics of POPs such as PBDEs in complex underground porous media.
Aiming at the problems, the invention develops an undisturbed soil column leaching experimental method which is used for researching the release and migration characteristics of PBDEs in actual soil. The method selects typical PBDEs in the polluted site as a research object, collects the undisturbed soil column, inspects the influence of the water chemistry conditions (such as pH and ionic strength) on the PBDEs released by the undisturbed soil column through the leaching experiment carried out in the core holder, researches the influence of soil heterogeneity and complex water chemistry conditions on the migration characteristics of the PBDEs, and has great significance for researching the problem of how the interaction of complex water chemistry factors influences the migration capability of organic pollutants and the like.
Disclosure of Invention
The invention aims to provide a method for analyzing release and migration characteristics of polybrominated diphenyl ethers in a polluted site based on an undisturbed soil column leaching experiment aiming at the technical defects of PBDEs release and migration behavior analysis in soil in the prior art.
In another aspect of the present invention, an apparatus for analyzing the release and migration characteristics of polybrominated diphenyl ethers in contaminated sites is provided.
The technical scheme adopted for realizing the purpose of the invention is as follows:
a method for analyzing release and migration characteristics of polybrominated diphenyl ethers in a contaminated site, comprising the steps of:
preparing a simulated rainwater solution or collecting rainwater in a polluted site;
and 4, carrying out a leaching experiment: pumping the simulated rainwater solution or rainwater collected in a polluted site into the core holder for leaching at constant pressure and constant flow through the water inlet, and respectively collecting the leaching solution flowing out of each water outlet port;
and 5, measuring the water flux of each water outlet port, measuring the concentration of PBDEs in the leaching solution flowing out of each water outlet port, and analyzing the release and migration characteristics of the polybrominated diphenyl ethers in the polluted site according to the detection result.
In the above technical solution, in the step 1, the undisturbed soil column to be detected is obtained by the following method: removing vegetation on the surface layer of the soil, then collecting an undisturbed soil column at the depth of 0-10 cm on the surface layer by using a pulse sampler, sealing the bottom of the pulse sampler by using a sealing film after the undisturbed soil column is collected, sleeving a protective sleeve on the pulse sampler, and transporting the pulse sampler back to a laboratory for storage in a refrigerator.
In the above technical solution, in the step 1, when preparing the simulated rainwater solution, two groups of simulated rainwater solutions are prepared, one group of simulated rainwater solutions with the same pH and different ionic strengths, and the other group of simulated rainwater solutions with the same ionic strength and different pH;
preferably, one of the two sets of simulated rainwater solutions has a pH of 5.6 and ionic strengths of 10, 5, 1, 0.1 and 0.01mM, and the other set of simulated rainwater solutions has an ionic strength of 1mM and pH values of 4.0, 6.0, 8.0 and 10.0, respectively.
In the above technical solution, in the step 2, the undisturbed soil column and the pulse sampler are placed together in the core holder.
In the above technical scheme, in the step 3, the pre-washing time is 24-48h, and the drainage time of the undisturbed soil column under the action of gravity is 16-20h.
In the above technical scheme, in the step 4, the leaching time is 4-8h in each leaching experiment, and the drainage time of the undisturbed soil column under the action of gravity is 16-20h after each leaching experiment;
when analyzing the influence of rainwater with different ionic strengths on the release characteristics of polybrominated diphenyl ethers in a polluted site, sequentially using simulated rainwater solutions with pH of 5.6 and ionic strengths of 10, 5, 1, 0.1 and 0.01mM to carry out a leaching experiment, and collecting the leaching solution flowing out of each water outlet port at intervals of 20-40min during each leaching experiment;
when analyzing the influence of rainwater with different ionic pH values on the release characteristics of polybrominated diphenyl ethers in a polluted site, carrying out a leaching experiment by sequentially using simulated rainwater solutions with the ionic strength of 1mM and the pH values of 4.0, 6.0, 8.0 and 10.0, and collecting the leaching solution flowing out of each water outlet port at intervals of 20-40min during each leaching experiment.
In the above technical solution, in the step 5, the water flux = the volume of the collected leaching solution per unit time of each water outlet port divided by the port area.
In the above technical solution, in the step 5, the determination of PBDEs comprises the following steps:
step s1, extracting PBDEs in the leaching solution, transferring the leaching solution into a brown bottle, adding BDE-77 as a recovery rate indicator, then adding n-hexane and oscillating for liquid-liquid extraction for multiple times, mixing the extraction solutions obtained by multiple operations, blowing nitrogen, fixing the volume to 1mL by using the n-hexane, carrying out vortex oscillation, absorbing the extraction solution, filtering the extraction solution by using a 0.22-micron organic phase nylon filter, transferring the extraction solution into a gas phase sample bottle, adding BDE-118 as an internal standard, and storing the internal standard in a refrigerator to serve as a liquid to be detected;
and step s2, using a gas chromatography-mass spectrometer to measure the types and the concentrations of the PBDEs in the solution to be measured.
In the above technical solution, in the step s2, the gas chromatograph-mass spectrometer chromatographic column is an Rtx-1614 capillary column (15 m × 0.25mm × 0.10 μm). The carrier gas is helium, the flow rate is 2mL/min, the sample injection is not divided, and the sample injection amount is 1 mu L.
The temperature-raising program is: keeping the temperature at 110 ℃ for 3min, heating to 200 ℃ at the speed of 25 ℃/min, heating to 280 ℃ at the speed of 15 ℃/min, then heating to 305 ℃ at the speed of 20 ℃/min, keeping the temperature for 5min, and keeping the temperature for 18.183min in total.
The mass spectrum conditions are as follows: negative Chemical Ion (NCI) source, selected Ion Monitoring (SIM) mode, ion source temperature 250 ℃ and transmission line temperature 280 ℃. The BDE-209 quantitative ions are fragment ions with mass-to-charge ratios (m/z) of 466 and 468, and the other PBDEs quantitative ions are bromide ions (m/z of 79 and 81).
In the above technical scheme, in the step 5, the water outlet port with the largest water flux is used as a main water outlet port, the total release rate of polybrominated diphenyl ethers in the leaching solution of each water outlet port is calculated, the capability of releasing and vertically migrating polybrominated diphenyl ethers in the surface soil of the contaminated site under specific conditions is predicted, and the heterogeneity of the polybrominated diphenyl ethers is analyzed by comparing the flow rate of the leaching solution of the main water outlet port and other water outlet ports with the content difference of the polybrominated diphenyl ethers.
In another aspect of the present invention, a device for analyzing release and migration characteristics of polybrominated diphenyl ethers in a contaminated site comprises a double-cylinder constant-pressure constant-flow pump, a piston container, a core holder and a water collection funnel, wherein: the water inlet of the double-cylinder constant-pressure constant-flow pump is connected with ultrapure water, the water outlet of the double-cylinder constant-pressure constant-flow pump is connected to the inlet of the piston container through a pipeline, a simulated rainwater solution is filled in the piston container, the outlet of the piston container is connected to the water inlet of the core holder through a water supply pipeline, an inlet pressure gauge is arranged on the water supply pipeline, an undisturbed soil column is filled in the core holder, a screen is arranged below the undisturbed soil column to prevent soil particles from flowing out, the bottom of the core holder is provided with N water outlet ports, one water outlet port is arranged at the central position and is a central water outlet port, the other water outlet ports are symmetrically arranged by taking the central water outlet port as the center, each water outlet port is connected with a water collecting funnel, and a leaching solution flowing out of the water outlet port is collected into a sample receiving pipe at the lower part through the water collecting funnel;
the prepared simulated rainwater solution is stored in the piston container, the simulated rainwater solution is pumped into the original-state soil column by the double-cylinder constant-pressure constant-flow pump at constant pressure and constant flow rate, and the leaching solution flows out through the water outlet port after the original-state soil column is leached.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention adopts the undisturbed soil column to carry out leaching experiment, and can accurately reflect the release characteristics of PBDEs in the soil of the polluted site.
2. The invention monitors the release of PBDEs through a plurality of water outlet ports, and can characterize the influence of the priority flow path on the PBDEs release.
Drawings
FIG. 1 is a field diagram of collecting undisturbed soil columns of a polluted site, wherein (a) is a pulse sampler and a connecting rod, and (b) is the collected undisturbed soil columns.
FIG. 2 is a diagram of an experimental apparatus for leaching undisturbed soil column.
Fig. 3 is a schematic diagram of an undisturbed soil column leaching experimental device. Wherein (a) is a schematic view of the whole device, and (b) is a schematic view of the position of the water outlet port.
FIG. 4 is a graph showing the variation of the flux of the effluent from four outlet ports in different ion intensity eluviation experiments.
Fig. 5 is a water flux change diagram of outflow liquid from four water outlet ports in the process of simulating the leaching of rainwater solution into an undisturbed soil column at different pH values.
In the figure: 1-ultrapure water, 2-double-cylinder constant-pressure constant-flow pump, 3-piston container, 4-simulated rainwater solution, 5-inlet pressure gauge, 6-core holder, 7-water collecting funnel, 8-sample receiving pipe, 9-test tube rack, 10-undisturbed soil column and 11-water outlet port.
Detailed Description
The present invention will be described in further detail with reference to specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
Example 1
1.1 collecting undisturbed soil column
And (3) selecting a Z1 point position of a certain polluted site to collect an undisturbed soil column (shown in figure 1). Before collecting the soil column, removing surface vegetation, and then collecting the undisturbed soil column on the surface at the depth of 0-10 cm by using a stainless steel pulse sampler with the diameter of 7.5cm (inner diameter) and the depth of 10 cm. After the undisturbed soil column is collected, the bottom of the pulse sampler is sealed by a sealing film and sleeved with a protective sleeve (fixed by a rubber band), and the pulse sampler is transported back to a laboratory and stored in a refrigerator at 4 ℃.
1.2 preparation of simulated rainwater solution
Preparing simulated rainwater solutions with different ionic strengths and pH values according to the pH value, the conductivity, the ionic composition and the content of rainwater in Tianjin city as leaching solutions. First, ca (NO) is used 3 ) 2 ·4H 2 O、(NH 4 ) 2 SO 4 、CaCl 2 、KNO 3 、MgSO 4 ·7H 2 O、Na 2 SO 4 The equivalent analysis pure-grade medicine is prepared into simulated rainwater with the ionic strength of 60mM according to the content in the table 1And (4) reserving liquid.
Table 1 simulation of rainwater stock pH and ionic molarity
The leaching solutions with different ionic strengths are prepared by the following method: the stock solutions were diluted 6, 12, 60, 600 and 6000 times respectively to obtain eluates with ionic strength: 10. 5, 1, 0.1 and 0.01mM. All leachates were adjusted to pH 5.6 using NaOH and HCl at a concentration of 0.01M.
The leaching solutions with different pH values are prepared by the following method: the stock solution was diluted 60-fold to give a shower solution having an ionic strength of 1mM, and the pH was adjusted to 4.0, 6.0, 8.0 and 10.0 using NaOH and HCl at a concentration of 0.1M, respectively.
Example 2
The original-state soil column leaching experimental device is built:
as shown in fig. 3, the undisturbed soil column leaching experimental device comprises a double-cylinder constant-pressure constant-flow pump 2, a piston container 3, a rock core holder 6 and a water collection funnel 7, wherein: ultrapure water 1 is connected to the water inlet of double-cylinder constant voltage constant current pump 2, the delivery port of double-cylinder constant voltage constant current pump passes through the pipe connection to the import of piston container 3, simulation rainwater solution 4 is equipped with in the piston container 3, the export of piston container 3 is connected to the water inlet of core holder 6 through the supply line, be equipped with import manometer 5 on the supply line, original state earth pillar 10 is packed in the core holder 6, the screen cloth is equipped with to original state earth pillar below prevents that soil particles from flowing out, the bottom of core holder is equipped with a N water outlet 11, and one of them water outlet sets up at central point as central water outlet, and all the other water outlet with central water outlet sets up as central symmetry, connects a collection funnel 7 on each water outlet, the drenching solution that the water outlet flows out collects to the sample pipe 8 of lower part through collection funnel 7.
More specifically, the prepared simulated rainwater solution 4 is stored in the piston container 3, and the simulated rainwater solution 4 is pumped into the double-cylinder constant-pressure constant-flow pump 2 at a constant flow rateIn the undisturbed soil column 10, a pulse sampler provided with the undisturbed soil column 10 is arranged in the rock core holder 6, and a screen with the aperture of 200 meshes is arranged below the soil column to prevent large-size soil particles from flowing out. The lower end of the core holder 6 has 7 water outlet ports (each water outlet port has a diameter of 1.6 cm), and the arrangement is shown in fig. 3 (b): wherein 1 water outlet port (numbered as "7 #") is located at the center as a central port, and the other 6 water outlet ports (numbered as "1#" to "6 #") are arranged in a regular hexagon around the central port. Each water outlet port captures 2cm of flow area 2 Leaching solution; the total collection area was 14cm 2 . The eluviation flows out from the water outlet port at the bottom of the core holder 6, and is collected to a sample receiving tube 8 through a water collecting funnel 7 (made of polytetrafluoroethylene), wherein the sample receiving tube 8 is a glass test tube, and the glass test tube is arranged on a test tube rack 9.
Example 3
Utilize the original state earth pillar eluviation experimental apparatus of embodiment 2 building, carry out original state earth pillar eluviation experiment under the different ionic strength condition, including steps such as experiment post preflushing, eluviation experiment and the analysis of drenching solution sample:
(1) Experimental original state soil column pre-washing
Continuously leaching the undisturbed soil column for 48h by using a simulated rainwater solution with the ionic strength of 0.01mM and the pH of 5.6 at the flow speed of 15mM/h to remove soluble impurities in the undisturbed soil column and balance the moisture content in the undisturbed soil column, then stopping leaching, and draining the undisturbed soil column for 18.7h under the action of gravity.
(2) Leaching experiment
Simulated rain water solution (pH = 5.6) with ionic strength of 10mM was eluviated to undisturbed soil column for 5.3h, then eluviation was stopped and undisturbed soil column was drained by gravity for 18.7h. And sampling once at 7 water outlet ports at the lower end of the undisturbed soil column every 20min during leaching, and detecting.
The above experimental operation was repeated, and leaching experiments were sequentially performed with the same undisturbed soil column and 5 simulated rainwater solutions of different ionic strengths (pH = 5.6) in the following order: 10mM, 5mM, 1mM, 0.1mM and 0.01mM. The original-state soil column is leached for 5.3 hours each time, leaching is stopped, and the original-state soil column is drained for 18.7 hours under the action of gravity.
(3) Determination of water flux of eluviation solution and concentration of PBDEs
And (3) measuring the water flux: the volume of the collected leaching solution per outlet port per unit time was measured, divided by the port area (2 cm) 2 ) The flux (in cm/h) was obtained.
The extraction method of PBDEs in the leaching solution comprises the following steps: the drench solution was transferred to a 20mL brown bottle and 2. Mu.L of 5. Mu.g/mL BDE-77 was added as an indicator of recovery. Then adding 2mL of normal hexane, oscillating for 30min for liquid-liquid extraction, repeatedly extracting the original leaching solution twice, mixing the three extraction solutions, blowing nitrogen, slowly blowing to below 1mL, fixing the volume to 1mL by using the normal hexane, carrying out vortex oscillation for 30s, sucking the extraction solution, filtering by using a 0.22 mu m organic phase nylon filter, transferring to a gas phase sample bottle, adding 2 mu L of 5 mu g/mL BDE-118 serving as an internal standard, and storing in a refrigerator at the temperature of-20 ℃ to be detected.
Determination of PBDEs in the extracts: the type and concentration of PBDEs in the extract were determined by gas chromatography-mass spectrometry (GC-MS) using a gas chromatography-mass spectrometer model 7890A-5975C (Agilent, USA).
The gas chromatography-mass spectrometer chromatographic column is an Rtx-1614 capillary column (15 m × 0.25mm × 0.10 μm). The carrier gas is helium, the flow rate is 2mL/min, the sample injection is not divided, and the sample injection amount is 1 mu L.
The temperature rising procedure is as follows: keeping the temperature at 110 ℃ for 3min, heating to 200 ℃ at the speed of 25 ℃/min, heating to 280 ℃ at the speed of 15 ℃/min, then heating to 305 ℃ at the speed of 20 ℃/min, keeping the temperature for 5min, and keeping the temperature for 18.183min in total.
The mass spectrum conditions are as follows: negative Chemical Ion (NCI) source, selected Ion Monitoring (SIM) mode, ion source temperature 250 ℃, transmission line temperature 280 ℃. The BDE-209 quantitative ions are fragment ions with mass-to-charge ratios (m/z) of 466 and 468, and the other PBDEs quantitative ions are bromide ions (m/z of 79 and 81).
(4) Results of the experiment
In the process of leaching the undisturbed soil column with simulated rainwater solutions with different ionic strengths, an obvious preferential flow path is presented (only 4 ports of 7 water outlet ports below the undisturbed soil column are drained) (fig. 4).
As shown in fig. 4, the water flux of different water outlet ports also changed in the consecutive experiments: during the first time of leaching with 10mM simulated rainwater solution, water is discharged through the 4# -and 6# -outlet ports, and the 4# outlet port is the main outlet port, during the second time of leaching with 5mM simulated rainwater solution, water is discharged through the 4# "," 6# "," 7# "outlet ports, and the 7#" outlet port is the main outlet port, during the second time of leaching, the water flux through the 4# "and" 6# "ports is reduced, water samples start to be discharged from the adjacent 7#", during the third time of leaching with 1mM simulated rainwater solution, the water flux through the 3# "," 4# "," 6 "outlet port, and the 3#" outlet port is the main outlet port, during the third time of leaching, the water samples start to be discharged from the adjacent 3# ", during the third time of leaching with 0.1mM simulated rainwater solution, the 4#" and "6#" outlet ports are reduced, and the water samples start to be discharged from the adjacent 4# ", and the fifth time of leaching with 0.1mM simulated rainwater solution, the 4#", and the fifth time of leaching with the main outlet port, the 4# ", and the main outlet port, and the water flow of the fifth time of the simulated rainwater solution is 0.. According to the experimental results, when the original-state soil columns are leached by using simulated rainwater solutions with different ionic strengths, the preferential flow paths are different.
In fig. 4, (a) the ionic strength of the simulated stormwater solution is 10mM, (b) the ionic strength of the simulated stormwater solution is 5mM, (c) the ionic strength of the simulated stormwater solution is 1mM, (d) the ionic strength of the simulated stormwater solution is 0.1mM, and (e) the ionic strength of the simulated stormwater solution is 0.01mM. The flow rate was set at 15mm/h, pH =5.6. The vertical dashed line indicates that the undisturbed soil column is gravity drained for 18.7h. And analyzing the water sample flowing out of each water outlet port. The black square represents the combination of water samples for extraction treatment, and the characters above the square are the sample numbers.
Combining the collected eluates, combining the eluates in adjacent glass test tubes (under one water outlet port, combining the eluates in two or more glass test tubes with adjacent eluates in time), detecting BDE-209 in each combined water sample, detecting BDE-209 with higher concentration (0.05 to 0.75 ng/mL) in some water samples, not detecting other PBDEs (see Table 2), and not detecting BDE-209 in other water samples, wherein the BDE-209 concentration in the sample (with the eluates ionic strength of 10 mM) with the number of H1 is the highest.
TABLE 2 BDE-209 release concentration in eluviation experiments with different ionic strengths
Note: the sample numbers are shown in FIG. 4.
In the above experiment, all the BDE-209 that can be measured are from the water sample of the main apopore, which indicates that the heterogeneity of the surface soil of the field is high. The release and the migration of polybrominated diphenyl ethers are influenced by simulating rainwater outflow in the flow path, and the polybrominated diphenyl ethers in the soil are easier to release and vertically migrate from pore paths with large rainwater outflow. Comparing the release rates of BDE-209 at different ionic strengths, the highest release capacity of polybrominated diphenyl ethers was found at 10mM ionic strength.
Example 4
Utilize the original state earth pillar eluviation experimental apparatus of embodiment 2 building, carry out original state earth pillar eluviation experiment under the different pH condition, including steps such as experiment post preflushing, eluviation experiment and the analysis of drenching solution sample:
(1) Pre-washing experimental column
The procedure was the same as in example 3.
(2) Leaching experiment
And (3) leaching the undisturbed soil column for 5.3h by using a simulated rainwater solution with the pH of 4.0 and the ionic strength of 1mM, and then stopping leaching, wherein the undisturbed soil column drains for 18.7h under the action of gravity. During leaching, samples were taken every 20min at 7 water outlets of the column and analyzed immediately. The above experimental operation was repeated, and leaching experiments were sequentially performed with the same undisturbed soil column and 4 simulated rainwater solutions of different pH (all ionic strengths were 1 mM) in the following order: 4.0, 6.0, 8.0 and 10.0. The undisturbed soil column is leached for 5.3h each time, leaching is stopped, and the undisturbed soil column is drained for 18.7h under the action of gravity.
(3) Determination of water flux and PBDEs concentration of eluviation solution
The procedure was the same as in example 3.
(4) Results of the experiment
In the process of leaching the undisturbed soil column by the simulated rainwater solution with different pH values, an obvious preferential flow path is presented, and only 2 ports of '1 #' and '5 #' are provided with water to be discharged (figure 5). In successive experiments, the water flux of the 2 outlet holes also changed: during the second leaching, the water flux through port # 1 increased, becoming the main outlet and continued until the end of the experiment.
In fig. 5, (a) a simulated stormwater solution having a pH of 4.0, (b) a simulated stormwater solution having a pH of 6.0, (c) a simulated stormwater solution having a pH of 8.0, and (d) a simulated stormwater solution having a pH of 10.0. The flow rate was set at 15mM/h, ionic strength =1mM. The vertical dashed lines indicate that the column was gravity drained for 18.7h. The black square represents the combination of water samples for extraction treatment, and the characters above the square are the sample numbers.
(3) In the leaching solutions collected from the water outlet ends in leaching experiments with different pH values, combining the collected leaching solutions in adjacent glass test tubes (under one water outlet port, the leaching solutions in two or more glass test tubes adjacent to each other in leaching time are combined), detecting BDE-209 in each combined water sample, detecting BDE-209 with higher concentration (0.06-1.00 ng/mL) in part of the water samples, not detecting other PBDEs (see Table 3), and not detecting BDE-209 in other water samples; wherein, the BDE-209 concentration in the sample h3 obtained under the condition that the pH of the leaching solution is 10 is the highest and reaches 1.00ng/mL.
TABLE 3 release concentration of BDE-209 in different pH eluviation experiments
Note: sample numbers are shown in FIG. 5.
Compared with the embodiment 3, in the process of dissolving the undisturbed soil column by the simulated rainwater solution with different pH values, all the BDE-209 capable of being measured are also from the water sample of the main water outlet. The influence of the pH of the rainwater on the release and migration of the polybrominated diphenyl ethers is also shown, and the polybrominated diphenyl ethers are easier to release and migrate from the paths with large rainwater outflow quantity. Comparing the release rates of BDE-209 at different pH, it was found that the polybrominated diphenyl ethers were more highly releasable at a pH of 10 in the leacheate.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (11)
1. A method for analyzing release and migration characteristics of polybrominated diphenyl ethers in a contaminated site is characterized by comprising the following steps:
step 1, sampling in situ in a polluted site to obtain an undisturbed soil column to be detected;
preparing a simulated rainwater solution or collecting rainwater in a polluted site;
step 2, filling the undisturbed soil column into a core holder, wherein the top of the core holder is provided with a water inlet, the bottom of the core holder is provided with N water outlet ports, one water outlet port is arranged at the central position and is a central water outlet port, and the other water outlet ports are symmetrically arranged by taking the central water outlet port as a center;
step 3, pre-washing the undisturbed soil column: pumping the simulated rainwater solution or rainwater collected in a polluted site into the core holder for pre-washing through the water inlet under the conditions of constant pressure and constant current, removing soluble impurities in the undisturbed soil column and balancing the moisture content in the undisturbed soil column, and then stopping leaching, wherein the undisturbed soil column is drained under the action of gravity;
and 4, carrying out a leaching experiment: pumping the simulated rainwater solution or rainwater collected in a polluted site into the core holder for leaching through the water inlet at constant pressure and constant flow, and respectively collecting the leaching solution flowing out of each water outlet port;
and 5, measuring the water flux of each water outlet port, measuring the concentration of PBDEs in the leaching solution flowing out of each water outlet port, and analyzing the release and migration characteristics of the polybrominated diphenyl ethers in the polluted site according to the detection result.
2. The method for analyzing release and migration characteristics of polybrominated diphenyl ethers in a polluted site according to claim 1, wherein in the step 1, the undisturbed soil column to be detected is obtained by the following method: removing vegetation on the surface layer of the soil, collecting an original soil column at the depth of 0-10 cm in the surface layer by using a pulse sampler, sealing the bottom of the pulse sampler by using a sealing film after the original soil column is collected, sleeving a protective sleeve on the pulse sampler, and transporting the pulse sampler back to a laboratory for storage in a refrigerator.
3. The method for analyzing release and migration characteristics of polybrominated diphenyl ethers in a contaminated site according to claim 1, wherein in the step 1, when preparing the simulated rainwater solutions, two sets of the simulated rainwater solutions are prepared, one set being the simulated rainwater solutions having the same pH and different ionic strengths, and the other set being the simulated rainwater solutions having the same ionic strength and different phs.
4. The method of analyzing the release and migration characteristics of polybrominated diphenyl ethers in a contaminated site according to claim 3, wherein one of the two sets of simulated rainwater solutions is a simulated rainwater solution having a pH of 5.6 and ionic strengths of 10, 5, 1, 0.1 and 0.01mM, and the other is a simulated rainwater solution having an ionic strength of 1mM and a pH of 4.0, 6.0, 8.0 and 10.0, respectively.
5. The method for analyzing the release and migration characteristics of polybrominated diphenyl ethers in a contaminated site according to claim 2, wherein in step 2, an undisturbed soil column is placed in the core holder along with a pulse sampler.
6. The method for analyzing the release and migration characteristics of polybrominated diphenyl ethers in a polluted site as claimed in claim 1, wherein in the step 3, the pre-washing time is 24-48h, and the drainage time of the undisturbed soil column under the action of gravity is 16-20h.
7. The method for analyzing the release and migration characteristics of polybrominated diphenyl ethers in the polluted site as claimed in claim 3, wherein in the step 4, the leaching time is 4-8h in each leaching experiment, and the drainage time of an undisturbed soil column under the action of gravity is 16-20h after each leaching experiment;
when analyzing the influence of rainwater with different ionic strengths on the release characteristics of polybrominated diphenyl ethers in a polluted site, carrying out a leaching experiment by sequentially using simulated rainwater solutions with pH of 5.6 and ionic strengths of 10, 5, 1, 0.1 and 0.01mM respectively, and collecting the leaching solution flowing out of each water outlet port at intervals of 20-40min during each leaching experiment;
when analyzing the influence of rainwater with different ion pH values on the release characteristics of polybrominated diphenyl ethers in a polluted site, carrying out leaching experiments in sequence by using simulated rainwater solutions with the ionic strength of 1mM and the pH values of 4.0, 6.0, 8.0 and 10.0 respectively, and collecting the leaching solution flowing out of each water outlet port at intervals of 20-40min during each leaching experiment.
8. The method for analyzing the release and migration characteristics of polybrominated diphenyl ethers in a contaminated site according to claim 1, characterized in that in said step 5, the water flux = the volume of the collected leaching solution per outlet port per unit time divided by the port area;
in the step 5, the determination of PBDEs comprises the following steps:
step s1, extracting PBDEs in the leaching solution, transferring the leaching solution into a brown bottle, adding BDE-77 as a recovery rate indicator, then adding n-hexane and oscillating for liquid-liquid extraction for multiple times, mixing the extraction solutions obtained by multiple operations, blowing nitrogen, fixing the volume to 1mL by using the n-hexane, carrying out vortex oscillation, absorbing the extraction solution, filtering the extraction solution by using a 0.22-micron organic phase nylon filter, transferring the extraction solution into a gas phase sample bottle, adding BDE-118 as an internal standard, and storing the internal standard in a refrigerator to serve as a liquid to be detected;
and step s2, using a gas chromatography-mass spectrometer to measure the types and the concentrations of the PBDEs in the solution to be measured.
9. The method for analyzing release and migration characteristics of polybrominated diphenyl ethers in a contaminated site according to claim 8, wherein in step s2, the gas chromatography-mass spectrometer chromatographic column is a Rtx-1614 capillary column of 15m x 0.25mm x 0.10 μm, the carrier gas is helium, the flow rate is 2mL/min, split-flow sample injection is not performed, and the sample injection amount is 1 μ L;
the temperature rising procedure is as follows: keeping the temperature at 110 ℃ for 3min, heating to 200 ℃ at the speed of 25 ℃/min, heating to 280 ℃ at the speed of 15 ℃/min, then heating to 305 ℃ at the speed of 20 ℃/min, keeping the temperature for 5min, and keeping the temperature for 18.183min in total;
the mass spectrum conditions are as follows: and selecting an ion monitoring mode for the negative chemical ion source, wherein the temperature of the ion source is 250 ℃, the temperature of the transmission line is 280 ℃, the BDE-209 quantitative ions are fragment ions with mass-to-charge ratios of 466 and 468, and the other PBDEs quantitative ions are bromide ions.
10. The method for analyzing the release and migration characteristics of polybrominated diphenyl ethers in the polluted site as claimed in claim 1, wherein in step 5, the outlet port with the largest water flux is taken as a main outlet port, the total release rate of the polybrominated diphenyl ethers in the eluents of all the outlet ports is calculated to predict the release and vertical migration capability of the polybrominated diphenyl ethers in the surface soil of the polluted site under specific conditions, and the release heterogeneity of the polybrominated diphenyl ethers is analyzed by comparing the flow rate of the eluents of the main outlet port and other outlet ports with the content of the polybrominated diphenyl ethers.
11. The utility model provides a polybrominated diphenyl ether releases and device of migration characteristic in analysis contaminated site which characterized in that, includes double-cylinder constant voltage constant current pump, piston container, rock core holder and catchment funnel and constitutes, wherein: the water inlet of the double-cylinder constant-pressure constant-flow pump is connected with ultrapure water, the water outlet of the double-cylinder constant-pressure constant-flow pump is connected to the inlet of the piston container through a pipeline, a simulated rainwater solution is filled in the piston container, the outlet of the piston container is connected to the water inlet of the core holder through a water supply pipeline, an inlet pressure gauge is arranged on the water supply pipeline, an undisturbed soil column is filled in the core holder, a screen is arranged below the undisturbed soil column to prevent soil particles from flowing out, the bottom of the core holder is provided with N water outlet ports, one water outlet port is arranged at the central position and is a central water outlet port, the other water outlet ports are symmetrically arranged by taking the central water outlet port as the center, each water outlet port is connected with a water collecting funnel, and a leaching solution flowing out of the water outlet port is collected into a sample receiving pipe at the lower part through the water collecting funnel;
the prepared simulated rainwater solution is stored in the piston container, the simulated rainwater solution is pumped into the original-state soil column by the double-cylinder constant-pressure constant-flow pump at constant pressure and constant flow rate, and the leaching solution flows out through the water outlet port after the original-state soil column is leached.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210601039.3A CN115201448B (en) | 2022-05-30 | 2022-05-30 | Method and device for analyzing release and migration characteristics of polybrominated diphenyl ethers in polluted site |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210601039.3A CN115201448B (en) | 2022-05-30 | 2022-05-30 | Method and device for analyzing release and migration characteristics of polybrominated diphenyl ethers in polluted site |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115201448A CN115201448A (en) | 2022-10-18 |
| CN115201448B true CN115201448B (en) | 2023-01-31 |
Family
ID=83575680
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210601039.3A Active CN115201448B (en) | 2022-05-30 | 2022-05-30 | Method and device for analyzing release and migration characteristics of polybrominated diphenyl ethers in polluted site |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115201448B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020103601A1 (en) * | 2000-12-04 | 2002-08-01 | Hayes Thomas D. | Method for identifying sources of rapidly released contaminants at contaminated sites |
| CN105891358A (en) * | 2016-04-05 | 2016-08-24 | 中国科学院生态环境研究中心 | Method for simultaneously detecting 21 hydroxyl polybrominated diphenyl ethers (OH-PBDEs) in soil |
| CN208568767U (en) * | 2018-06-28 | 2019-03-01 | 陕西省土地工程建设集团有限责任公司 | A kind of experimental rig of monitoring soil inner element migration |
| CN209542605U (en) * | 2019-01-11 | 2019-10-25 | 云南农业大学 | A kind of soil-column test device of research heavy metal in soil leaching migration |
| CN110927021A (en) * | 2020-01-02 | 2020-03-27 | 中冶南方都市环保工程技术股份有限公司 | Underground water pollutant reaction migration simulation device and use method thereof |
| CN113075329A (en) * | 2021-04-02 | 2021-07-06 | 南开大学 | Method for detecting polybrominated diphenyl ethers in contaminated site soil |
-
2022
- 2022-05-30 CN CN202210601039.3A patent/CN115201448B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020103601A1 (en) * | 2000-12-04 | 2002-08-01 | Hayes Thomas D. | Method for identifying sources of rapidly released contaminants at contaminated sites |
| CN105891358A (en) * | 2016-04-05 | 2016-08-24 | 中国科学院生态环境研究中心 | Method for simultaneously detecting 21 hydroxyl polybrominated diphenyl ethers (OH-PBDEs) in soil |
| CN208568767U (en) * | 2018-06-28 | 2019-03-01 | 陕西省土地工程建设集团有限责任公司 | A kind of experimental rig of monitoring soil inner element migration |
| CN209542605U (en) * | 2019-01-11 | 2019-10-25 | 云南农业大学 | A kind of soil-column test device of research heavy metal in soil leaching migration |
| CN110927021A (en) * | 2020-01-02 | 2020-03-27 | 中冶南方都市环保工程技术股份有限公司 | Underground water pollutant reaction migration simulation device and use method thereof |
| CN113075329A (en) * | 2021-04-02 | 2021-07-06 | 南开大学 | Method for detecting polybrominated diphenyl ethers in contaminated site soil |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115201448A (en) | 2022-10-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jardine et al. | Quantifying diffusive mass transfer in fractured shale bedrock | |
| Zand et al. | Determination of leaching behaviour of polycyclic aromatic hydrocarbons from contaminated soil by column leaching test | |
| CN109470790B (en) | Method for synchronously measuring benzopyrene in soil through rapid solvent extraction and purification | |
| US6232598B1 (en) | Process and devices for characterizing ground water measurement points by distinguishing ground water from subterranean water accumulation | |
| CN113866355B (en) | Simulation experiment method for water rock action and nuclide migration in multiple barriers of treatment library | |
| CN115201448B (en) | Method and device for analyzing release and migration characteristics of polybrominated diphenyl ethers in polluted site | |
| RU131872U1 (en) | DEVICE FOR TAKING GAS OR LIQUID SAMPLES FROM SOIL | |
| Han et al. | Measuring seasonal variations of moisture in a landfill with the partitioning gas tracer test | |
| KR20150053439A (en) | Vertical Infiltro Lysimeter | |
| CN208596054U (en) | A kind of soil solution original-position collecting device | |
| CN207472845U (en) | The experimental provision of saturated aqueous layer chlorinated hydrocarbon DNAPL pollution sources is repaired based on Zero-valent Iron-PRB reduction | |
| Smith et al. | Sampling unsaturated‐zone water for trichloroethene at Picatinny Arsenal, New Jersey | |
| CN105651563A (en) | Method for collecting atmospheric aldehyde ketone pollutants by use of self-made DNPH silica gel adsorption tube | |
| CN216377642U (en) | Denitrification test device | |
| Bishop et al. | Investigation of a solvent polluted industrial site on a deep sandstone-mudstone sequence in the UK. Part 2. Contaminant sources, distributions, transport and retardation | |
| JP2017173316A (en) | Dynamic monitoring device for radioactive cesium and method thereof | |
| Leake | Lysimeter studies | |
| Hornby et al. | Factors Which Affect Soil‐Pore Liquid: A Comparison of Currently Available Samplers with Two New Desians | |
| CN102426158B (en) | Novel method for directly measuring oil quantity in water adsorbed by oil absorption material | |
| Christiansen et al. | Direct-push delivery of dye tracers for direct documentation of solute distribution in clay till | |
| Tunks et al. | Diffusion sampler evaluation of chlorinated VOCs in groundwater | |
| Reeves et al. | Flow separation in undisturbed soils using multiple anionic tracers. Part 1. Analytical methods and unsteady rainfall and return flow experiments | |
| CN218995365U (en) | Risk assessment test device for reuse of heavy metal contaminated soil after restoration | |
| Young et al. | Injection mode effects on tracer experiments in columns | |
| CN221056265U (en) | Device for measuring subsurface mercury infiltration rate |
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 |