Soil pollution source analysis method and related equipment

Abstract

The invention provides a soil pollution source analysis method and related equipment, and is applied to the technical field of data processing. The method comprises the following steps: acquiring soil profile sample information, environment end member sample information and a preset fractionation model; the environmental end member sample information is preprocessed, and the ratio information of the initial cadmium isotope is generated and comprises the ratio information of the cadmium isotope in the surface water body, the ratio information of the cadmium isotope in the atmospheric total sedimentation sample and the ratio information of the cadmium isotope in the soil forming parent material sample; performing correction processing on the ratio information of the initial isotope based on a preset fractionation model to generate ratio information of the target cadmium isotope; performing correction processing on the soil profile sample information to generate an isotope source analysis result; processing the isotope source analysis result to generate isotope source verification information; and processing the isotope source verification information to generate soil pollution source information.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular to a soil pollution source analysis method and related equipment. Background Art

[0002] Cadmium (Cd) is the most prominent heavy metal element with an abnormal geological background in my country's soil. The weathering of cadmium-rich sedimentary rocks (such as clastic sedimentary rocks and carbonate rocks) or Quaternary sediments causes a high geological background of Cd in the soil. In addition, human activities such as the application of agricultural fertilizers and irrigation further cause the enrichment of Cd in the soil.

[0003] Source control is an important means to achieve soil Cd pollution prevention and control. By identifying the input pathways and fluxes of soil Cd and suppressing the input of anthropogenic sources in a targeted manner, the accumulation of Cd in the soil can be gradually reduced. Quantitative source analysis of the sources of soil Cd pollution is the key to source control. Currently, the commonly used source analysis methods include methods based on mathematical statistics such as PCA, PMF, and cluster analysis, source inventory methods based on historical pollution long-term monitoring data, and isotope source analysis methods based on stable isotope signals. Among the three methods, the isotope source analysis method has the characteristics of high sensitivity and does not need to rely on a large amount of historical data. It is considered to be a relatively reliable source analysis technology. However, in the process of source analysis for Cd, it should be noted that the differences in Cd isotope signals in different environmental media in nature are mainly derived from the fractionation process, which occurs frequently in the processes of adsorption-analysis, precipitation-dissolution, etc., and will cause certain difficulties for isotope source analysis. People usually ignore the impact of this low-temperature fractionation process in nature on the source analysis of Cd pollution.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] The purpose of this application is to provide a soil pollution source analysis method and related equipment, which at least overcomes the problems existing in the prior art to a certain extent, and realizes soil Cd pollution source analysis through a series of treatments by obtaining soil profile, environmental end member sample information and preset fractionation model. First, pre-treat the environmental end member sample to obtain the initial cadmium isotope ratio information, then use the fractionation model to correct the target ratio information, correct the soil profile sample information to generate the isotope source analysis result, process the analysis result to obtain the isotope source verification information, and finally obtain the soil pollution source information. It comprehensively considers various factors and uses a variety of models to provide a scientific and effective method and approach for accurately analyzing the soil Cd pollution source.

[0006] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present invention.

[0007] According to one aspect of the present application, a method for analyzing soil pollution sources is provided, comprising: obtaining soil profile sample information, environmental end member sample information, and a preset fractionation model, wherein the environmental end member sample information includes surface water body information, total atmospheric deposition sample information, and soil parent material sample information, and the preset fractionation model includes a non-equilibrium fractionation model and an equilibrium fractionation model; pre-processing the environmental end member sample information to generate initial cadmium isotope ratio information, wherein the initial cadmium isotope ratio information includes cadmium isotope ratio information in surface water bodies, cadmium isotope ratio information in total atmospheric deposition samples, and cadmium isotope ratio information in soil parent material samples; correcting the initial isotope ratio information based on the preset fractionation model to generate target cadmium isotope ratio information; correcting the soil profile sample information to generate an isotope source analysis result; processing the isotope source analysis result to generate isotope source verification information; processing the isotope source verification information to generate soil pollution source information.

[0008] Another aspect of the present application is a soil pollution source analysis device, characterized in that the device includes: an acquisition module for acquiring soil profile sample information, environmental end member sample information, and a preset fractionation model, wherein the environmental end member sample information includes surface water body information, total atmospheric deposition sample information, and soil parent material sample information, and the preset fractionation model includes a non-equilibrium fractionation model and an equilibrium fractionation model; a processing module for preprocessing the environmental end member sample information to generate initial cadmium isotope ratio information, wherein the initial cadmium isotope The ratio information of cadmium isotopes includes the ratio information of cadmium isotopes in surface water, the ratio information of cadmium isotopes in total atmospheric deposition samples and the ratio information of cadmium isotopes in soil parent material samples; the initial isotope ratio information is corrected based on a preset fractionation model to generate the ratio information of target cadmium isotopes; the soil profile sample information is corrected to generate the isotope source analysis result; the isotope source analysis result is processed to generate the isotope source verification information; the isotope source verification information is processed to generate the soil pollution source information.

[0009] According to another aspect of the present application, an electronic device is characterized in that it includes: a first processor; and a memory for storing executable instructions of the first processor; wherein the first processor is configured to implement the above-mentioned soil pollution source analysis method by executing the executable instructions.

[0010] According to another aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a second processor, the above-mentioned soil pollution source analysis method is implemented.

[0011] The present application provides a method and related equipment for analyzing soil pollution sources. The server obtains soil profile, environmental end member sample information and a preset fractionation model, and realizes soil Cd pollution source analysis through a series of processing. First, the environmental end member sample is pre-processed to obtain the initial cadmium isotope ratio information, and then the target ratio information is corrected using the fractionation model. The soil profile sample information is corrected to generate the isotope source analysis result, and the analysis result is processed to obtain the isotope source verification information, and finally the soil pollution source information is obtained. It comprehensively considers various factors and uses a variety of models to provide a scientific and effective method and approach for accurately analyzing the soil Cd pollution source.

[0012] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A flow chart showing a method for analyzing soil pollution sources provided by an embodiment of the present application is shown;

[0014] Figure 2 A schematic structural diagram of a soil pollution source analysis device provided in one embodiment of the present application is shown. DETAILED DESCRIPTION

[0015] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0016] Combine the following Figure 1 To describe the soil pollution source analysis method according to the exemplary embodiment of the present application. It should be noted that the following application scenarios are only shown to facilitate understanding of the spirit and principle of the present application, and the embodiments of the present application are not limited in this regard. On the contrary, the embodiments of the present application can be applied to any applicable scenario.

[0017] In one embodiment, the present application also proposes a method for analyzing soil pollution sources and related equipment. Figure 1 The following schematically shows a flow chart of a method for analyzing soil pollution sources according to an embodiment of the present application. Figure 1 As shown, the method is applied to a server, comprising:

[0018] S101, obtaining soil profile sample information, environmental end member sample information, and a preset fractionation model.

[0019] In one embodiment, the environmental end member sample information includes surface water information, total atmospheric deposition sample information and soil parent material sample information, and the preset fractionation model includes a non-equilibrium fractionation model and an equilibrium fractionation model. In the study area, according to factors such as topography (such as setting sampling points in different topographic areas such as mountains, plains, and river valleys), land use types (such as setting sampling points in different utilization types such as farmland, forest land, industrial areas, and residential areas), and soil types (such as setting sampling points in different texture soil distribution areas such as loam, sand, and clay), soil profile sampling points are selected at representative locations. Each sampling point needs to be a certain distance (such as 50-100 meters) away from obvious pollution sources (such as landfills, sewage outlets, etc.) to avoid interference with soil profile samples by local pollution sources and ensure that the samples can reflect the overall characteristics of regional soil.

[0020] Use a special soil sampling drill for sampling. For shallow soil at a depth of 5-10cm, insert the sampling drill vertically into the soil, gently rotate and press down, take out the soil core, collect the 5-10cm part of the surface as a shallow soil sample, put it into a clean polyethylene bag, and mark the sampling point number, depth (5-10cm), sampling date and other information. For the middle soil at a depth of 30-50cm, continue to use the sampling drill to go deep into the corresponding depth, use the same operation to take out the soil core, select the 30-50cm part as the middle soil sample, put it into a new polyethylene bag, and mark the relevant information. For the deep soil at a depth of 70-100cm, operate the sampling drill again to the target depth, obtain the soil sample at a depth of 70-100cm, put it into a polyethylene bag and mark it. For a soil profile, collect ≥3 repeated samples according to the above method to ensure the reliability and representativeness of the data. Record the geographic coordinates of each sampling point on site (use GPS to obtain longitude, latitude and altitude), surrounding environmental characteristics (such as vegetation coverage, whether there are irrigation facilities, nearby traffic conditions, etc.), soil profile color, texture (such as sand, loam, clay, etc.), humidity and other basic information. Transport the collected soil profile samples back to the laboratory as soon as possible, and avoid squeezing, vibration and high temperature during transportation. After arriving at the laboratory, let the samples dry naturally in a cool and ventilated place before subsequent processing and analysis.

[0021] Surface water information is obtained, and sampling points are set up in different types of surface water bodies such as rivers, lakes, and ponds in the study area. For rivers, sampling points are set up at the upstream, middle, downstream, and entrances of major tributaries of the river according to the length and basin area of ​​the river; for lakes and ponds, sampling points are set up in the central area and at different locations near the shore, such as the center of the lake, the shallow water area near the shore, the water inlet, and the water outlet. Use a water sampler (such as a plexiglass water sampler or a stainless steel water sampler) to collect water samples. At each sampling point, sink the water sampler 0.5-1 meter below the water surface (for deeper water bodies, different depth layers can be collected, such as 0.5 meters, 1 meter, 2 meters, etc.) to collect water samples, and the collection volume is not less than 1 liter. Put the collected water samples into polyethylene buckets or glass bottles that have been pre-cleaned and rinsed with the sampled water to avoid contamination of the water samples. Record the type of water body (river, lake, pond, etc.), water environment characteristics (water temperature, water depth, transparency, water flow speed, surrounding land use type, etc.), sampling time (accurate to the minute), weather conditions and other information at the sampling point. The collected water samples should be protected from light and stored at low temperatures during transportation, and sent back to the laboratory for analysis as soon as possible. In the laboratory, if it cannot be analyzed immediately, the water samples can be refrigerated and stored below 4°C, but the storage time should not be too long (generally not more than 48 hours) to prevent changes in the composition of the water samples.

[0022] To obtain the information of total atmospheric deposition samples, select an open, unobstructed location (such as the roof, open grassland, etc.) in the study area to install a total atmospheric deposition sampler. The air inlet of the sampler should be 1.5-2 meters from the ground to avoid interference from factors such as ground dust. Use glass fiber filter membrane or quartz fiber filter membrane to collect atmospheric deposition. Determine the sampling time according to research needs, generally ranging from one week to one month. During the sampling period, regularly check the operation of the sampler to ensure its normal operation, such as checking whether the filter membrane is damaged and whether the sampling flow is stable. Record the installation location of the sampler (detailed address, geographic coordinates), sampling start and end time (accurate to minutes), and weather conditions during sampling (such as daily temperature, air pressure, relative humidity, rainfall, wind speed, wind direction, etc.). After sampling, carefully remove the filter membrane, fold the filter membrane in half with clean tweezers, and put it in a pre-marked sealed bag. Desiccant should be placed in the sealed bag to prevent the filter membrane from getting wet. Store the sealed filter membrane at low temperature and away from light, and send it to the laboratory for processing as soon as possible. In the laboratory, the filters can be stored frozen at below -20°C until analysis.

[0023] To obtain information on soil parent material samples, look for soil parent material outcrops that have not been significantly disturbed by human activities in the study area, such as fresh rock outcrops and uncultivated deep soil. For rock outcrops, select outcrops of different lithologies (such as granite, limestone, sandstone, etc.) for sampling; for deep soil, select samples collected in nature reserves, undeveloped mountains and other areas to ensure that the samples can represent the local soil parent material characteristics. For rock samples, use a geological hammer to collect an appropriate amount of rock blocks on the fresh surface of the rock outcrop, and avoid collecting severely weathered or contaminated parts. Put the collected rock blocks into a clean cloth bag and mark the sampling point number, rock type, geological characteristics (such as stratigraphic age, rock structure, etc.), sampling date and other information. For deep soil samples, use a shovel or sampling drill to collect soil samples at a depth of less than 1-2 meters, with a collection volume of no less than 500 grams, put them in a plastic bag, and also mark the relevant information. Store the collected soil parent material samples in a cool and dry place to prevent the samples from being weathered, eroded or contaminated. During transportation, avoid collision and squeezing of samples. After arriving at the laboratory, rock samples can be directly processed and analyzed, while soil samples need to be naturally air-dried before subsequent operations.

[0024] The preset fractionation model includes non-equilibrium fractionation model and equilibrium fractionation model. The non-equilibrium fractionation model contains two main variables, namely, the δ 114 / 110 Cd solid and the δ of the liquid phase after the reaction 114 / 110 Cd solution , which respectively represent the changes in the cadmium (Cd) isotope ratios in the solid and liquid phases after the solid-liquid distribution process is completed, and are the objects to be described and predicted by the model.

[0025] The parameters in the model are δ 114 / 110 Cd initial (Cd isotope ratio of the liquid phase before the reaction), f (the mass fraction of the Cd remaining in the liquid phase after adsorption to the total Cd in the original reaction system) and α (fractionation coefficient). 114 / 110 Cd initial is the initial condition parameter, which provides starting information for subsequent calculations; f reflects the residual proportion of Cd in the liquid phase during the solid-liquid adsorption process, and its value range determines the boundary conditions of the model calculation; α is the key parameter describing the degree of fractionation, which determines the degree of difference in the distribution of Cd isotopes between the solid and liquid phases.

[0026] In the solid phase formula middle, The part represents the contribution of the initial liquid phase isotope ratio to the solid phase isotope ratio after a series of complex fractionation processes, taking into account the fractionation coefficient α and the liquid phase residual ratio f. αThis reflects the effect of the fractionation process on the residual Cd in the liquid phase. With the increase of the fractionation degree (α) and the change of the residual ratio (f) in the liquid phase, the effect of this term on the isotope ratio of the solid phase is nonlinear. The term (1-f) in the numerator and denominator plays a normalization role, making the calculated result within a reasonable range. The final subtraction of 1000 is to adjust the calculated result to a form consistent with the definition of the δ value.

[0027] Liquid phase formula δ 114 / 110 Cd solution =f α-1 (δ 114 / 110 Cd initial +1000)-1000 describes the effect of the initial liquid phase isotope ratio on the final liquid phase isotope ratio based on the fractionation coefficient α and the liquid phase residual ratio f during the solid-liquid partition process. α-1 The term also shows a nonlinear relationship, reflecting the change of Cd isotope ratio in the liquid phase during fractionation. Subtracting 1000 is also to meet the calculation specifications of δ value. α and f α-1 Such exponential terms make the model have obvious nonlinear characteristics. This means that in practical applications, slight changes in model parameters may lead to large differences in calculation results, requiring more complex mathematical methods to solve and analyze, such as numerical iteration methods. The two parameters f and α are interrelated and jointly affect the calculation of isotope ratios of solid and liquid phases. In the actual experimental data fitting process, it is necessary to consider the values ​​of these two parameters at the same time to find the parameter combination that best describes the experimental data. This correlation increases the difficulty of determining the model parameters, but it also more comprehensively reflects the complex physical and chemical relationship in the solid-liquid distribution process.

[0028] The equilibrium fractionation model is similar to the non-equilibrium fractionation model. The equilibrium fractionation model also focuses on the δ 114 / 110 Cd' solid and the δ of the liquid phase after the reaction 114 / 110 Cd' solution These two variables are used to describe the Cd isotope ratio in the solid and liquid phases under equilibrium conditions. The model parameters also include δ 114 / 110 Cd initial , f and α. Their meanings in the equilibrium fractionation model are basically the same as those in the nonequilibrium fractionation model, but their roles in the model calculation are different.

[0029] In the solid phase formula In the molecule αδ 114 / 110 Cd initial+1000f(α-1) reflects the comprehensive contribution of the initial liquid phase isotope ratio to the solid phase isotope ratio after adjustment by the fractionation coefficient α and considering the adsorption ratio f under equilibrium conditions. 114 / 110 Cd initial It is the direct contribution of the isotope ratio of the initial liquid phase to the solid phase after distillation, and 1000f(α-1) considers the effect of isotope fractionation on the solid phase during adsorption. The denominator f+(1-f)α represents the comprehensive weight of the solid and liquid phases at equilibrium, reflecting the comprehensive influence of the solid-liquid ratio and the degree of distillation on the calculation of the solid-to-solid isotope ratio.

[0030] Liquid phase formula In the molecule δ 114 / 110 Cd initial +1000(1-f)(1-α) describes the comprehensive change of the isotope ratio of the initial liquid phase after adsorption and fractionation during the equilibrium fractionation process. 114 / 110 Cd initial is the initial value, 1000(1-f)(1-α) reflects the effect of adsorption and fractionation on the isotope ratio of the liquid phase. The denominator is the same as the solid phase formula, which plays a role in balancing the relationship between the solid and liquid phases.

[0031] Reflection of nonlinearity and equilibrium relationship: The model is also nonlinear, because both the numerator and denominator contain the product term of variables f and α. This nonlinear structure reflects the complex interaction between the solid and liquid phases in the equilibrium fractionation process. At the same time, the model structure accurately reflects the dynamic equilibrium relationship between the solid and liquid in the equilibrium state in the form of the numerator and denominator, that is, the isotope ratio of the solid and liquid phases is an equilibrium state achieved by considering the interaction of multiple factors such as the initial state, fractionation degree and solid-liquid ratio. Any change in any parameter will affect the isotope ratio of the solid and liquid phases until equilibrium is reached again. This is different from the non-equilibrium and dynamically changing process described in the non-equilibrium fractionation model. The equilibrium fractionation model emphasizes the stable isotope distribution relationship between the solid and liquid phases under specific conditions.

[0032] In another embodiment, soil profile samples were collected from a mining area in southwest my country, with profile sampling depths of 10 cm, 40 cm, and 90 cm. In addition, 3 surface water samples and 3 soil parent material (rock) samples were collected. The stable isotope ratios of the above samples were analyzed, and the results were as follows:

[0033] sample <![CDATA[δ 114 / 110 Cd]]> 10cm soil -1.09 40cm soil -1.53 90cm soil -2.17 Surface water -0.60±0.05 rock -2.69±0.07

[0034] In the laboratory, quartz with a particle size range of 0.15-0.25 μm was used, and 10, 30, 50, 70, 100 μg / L Cd2+ solutions were selected, and HCl and NaOH were used to adjust the pH to 6. 1 g of quartz was mixed with 500 ml of solution, and shaken at 300 rpm for 48 hours, and then a 0.22 μm filter membrane was used for solid-liquid separation. The isotope ratios in the solid phase and the residual liquid phase were measured respectively, and the following experimental data were obtained:

[0035]

[0036] Non-equilibrium model fitting R 2 =0.92, equilibrium model fitting R 2 =0.97, it can be seen that the solid-liquid fractionation process conforms to the equilibrium fractionation mechanism and the next step can be carried out.

[0037] Use Δ 114 / 110 Cd solid-solution The mean of -0.32 is corrected:

[0038] parameter value <![CDATA[δ POL ]]> -0.60 <![CDATA[δ POL ′]]> -0.92 <![CDATA[δ PM ]]> -2.69 <![CDATA[f POL (10cm)]]> 90％ <![CDATA[f POL (40cm)]]> 65％ <h2 style=";text-align:left;direction:ltr"><![CDATA[f <h2 style=";text-align:left;direction:ltr"> POL <h2 style=";text-align:left;direction:ltr"> (70cm)]]><h2 style=";text-align:left;direction:ltr"> 29％

[0039] S102, preprocessing the environmental end member sample information to generate initial cadmium isotope ratio information.

[0040] In one embodiment, the environmental end member sample information is processed to generate surface water sample solution information, total atmospheric deposition sample solution information and soil parent material sample solution information. The surface water sample is processed to generate solution information, and the collected surface water sample is transferred to the laboratory as soon as possible. In the laboratory, the water sample is first shaken thoroughly, and then an appropriate amount (such as 500 ml) of the water sample is filtered through a 0.22-0.45 micron filter membrane to remove suspended particles. The filtered water sample is transferred to a clean polytetrafluoroethylene container to prevent the water sample from chemically reacting with the container wall and affecting subsequent analysis. Take a certain amount (such as 50 ml) of the filtered water sample, slowly add an appropriate amount of nitric acid (superior grade pure), and acidify the water sample to a pH value of less than 2. The acidification process should be carried out in a fume hood, and nitric acid should be slowly added while stirring the water sample continuously to prevent local over-acidification from causing certain components to volatilize or other chemical reactions. The acidified water sample can be refrigerated below 4°C and wait for further processing to generate surface water sample solution information. If the concentration of target elements such as cadmium in the water sample is too high and exceeds the detection range of the subsequent analytical instrument, dilution treatment is required. For example, the water sample is diluted with deionized water at a certain ratio (such as 1:10 or 1:100, etc., determined according to the actual concentration), and then transferred to a volumetric flask and fixed to a certain volume (such as 100 ml or 500 ml, etc.) to obtain a surface water sample solution, and the volume of the solution, dilution multiple and other information are recorded. This information is part of the surface water sample solution information.

[0041] The total atmospheric deposition sample is processed to generate solution information. After the sealed bag containing the total atmospheric deposition filter membrane is brought back to the laboratory from the sampling site, it is carefully opened in the clean bench. Use clean scissors to cut the filter membrane into small pieces and put it into a polytetrafluoroethylene digestion tank, trying to ensure that the filter membrane fragments are evenly distributed at the bottom of the digestion tank so that the subsequent digestion reaction can be fully carried out. Add an appropriate amount of mixed acid (such as nitric acid-hydrochloric acid-hydrofluoric acid mixed acid, the ratio can be determined according to the actual situation, but it must be ensured that the filter membrane and the sediment therein can be completely digested) to the digestion tank, seal the digestion tank and put it into a microwave digestion instrument for digestion. The digestion procedure is optimized according to the model and sample amount of the digestion instrument, and generally includes heating, temperature maintenance and cooling stages. For example, the heating stage is heated to 150°C at a rate of 10°C per minute and maintained for 5 minutes; then the temperature is raised to 180°C at a rate of 5°C per minute and maintained for 10 minutes; finally, it is naturally cooled to room temperature. During the digestion process, ensure that the digestion tank is well sealed to prevent acid mist leakage. After digestion is completed, take out the digestion tank and cool it to room temperature in a fume hood. Then transfer the digestion solution to a clean polytetrafluoroethylene volumetric flask, rinse the inner wall of the digestion tank with deionized water several times, transfer the rinse solution to the volumetric flask, and dilute to a certain volume (such as 50 ml or 100 ml, etc.) to obtain the total atmospheric deposition sample solution. Record the solution volume, dilution process and other related information as the total atmospheric deposition sample solution information.

[0042] The soil parent material sample is processed to generate solution information. After the soil parent material sample is naturally air-dried in the laboratory, impurities such as stones and plant roots are removed. Then use a mortar or ball mill to grind the sample to a fine powder state, and pass it through a 200-mesh sieve to make the sample particles uniform. Weigh a certain amount (such as 0.5-1 gram) of the sieved sample and put it into a polytetrafluoroethylene crucible for digestion treatment. Add an appropriate amount of mixed acid (such as hydrofluoric acid-nitric acid-perchloric acid mixed acid) to the crucible, and place the crucible on a hot plate for heating and digestion. During the heating process, pay attention to controlling the temperature to prevent the sample from splashing, and stir continuously. For example, first heat at a low temperature (100-150℃) until the sample no longer produces a large number of bubbles, then gradually heat to 200-250℃, and continue to heat until the solution is clear and transparent, ensuring that the sample is completely digested into a clear solution. After the digestion is completed, remove the crucible from the hot plate and cool to room temperature. Rinse the crucible wall with a small amount of deionized water, transfer the solution to a clean polytetrafluoroethylene volumetric flask, dilute to a certain volume (such as 50-100 ml), obtain the soil parent material sample solution, and record the dilute volume and other information as the soil parent material sample solution information.

[0043] The surface water sample solution information is processed to generate the cadmium isotope ratio information in the surface water, the atmospheric total deposition sample information is processed to generate the cadmium isotope ratio information in the atmospheric total deposition sample, and the soil parent material sample solution information is processed to generate the cadmium isotope ratio information in the soil parent material sample. Specifically, the cadmium isotope ratio information in the surface water is generated, the multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) is turned on, and the instrument operating procedures are followed to preheat and debug to ensure the stability of the instrument performance. Use NIST 3108 as a standard and report the Cd isotope ratio to ensure accurate determination of the cadmium isotope ratio. Before testing, the sample needs to be purified by ion exchange resin to remove other elements except Cd. Then, take an appropriate amount (such as 1-5 ml, determined according to the instrument sensitivity and sample concentration) of the treated surface water sample solution and dilute it with a diluent (generally ultrapure water or dilute nitric acid solution) to a suitable concentration range to meet the detection requirements of the instrument and avoid the influence of too high or too low concentration on the measurement results. The diluted sample solution is introduced into MC-ICP-MS for measurement. During the measurement process, each sample is measured repeatedly multiple times (such as 3-5 times) to improve the accuracy and precision of the measurement results.

[0044] The instrument measures 114 Cd and 110 Cd The ion intensity signal is automatically calculated according to a specific calculation formula to calculate the cadmium isotope ratio (δ 114 / 110 Cd,‰). For example, the calculation formula is δ 114 / 110 Cd=[(114 Cd / 110 Cd ) 样品 -(114 Cd / 110 Cd ) 标准 ] / (114 Cd / 110 Cd ) 标准 ×1000‰, where (114 Cd / 110 Cd ) 样品 The sample measured was 114 Cd The isotope ratio of (114 Cd / 110 Cd ) 标准 It is a standard product 114 Cd The isotope ratio of cadmium and Cd is recorded, and the statistical parameters such as the mean value and standard deviation are calculated to finally obtain the ratio information of cadmium isotopes in surface water.

[0045] The cadmium isotope ratio information in the total atmospheric deposition sample is generated by first preparing and calibrating the instrument. The operation steps are the same as those for the surface water sample measurement. Take an appropriate amount (e.g., 1-5 ml) of the treated total atmospheric deposition sample solution, dilute it to a suitable concentration range with a diluent, and then introduce it into the MC-ICP-MS for measurement. Repeat the measurement multiple times (3-5 times). Calculate the δ 114 / 110 Cd value, record the results and calculate statistical parameters such as the mean value and standard deviation, so as to obtain the ratio information of cadmium isotopes in the total atmospheric deposition samples.

[0046] The cadmium isotope ratio information in the soil parent material sample is generated, and the instrument preparation and calibration steps remain unchanged. Take an appropriate amount (such as 1-5 ml) of the treated soil parent material sample solution, dilute it, and perform MC-ICP-MS determination. Repeat the determination 3-5 times, and calculate δ 114 / 110 The Cd value is recorded and processed, and finally the cadmium isotope ratio information in the soil parent material samples is obtained. This cadmium isotope ratio information will be used for subsequent isotope adsorption-desorption fractionation correction, isotope source analysis, and analysis and judgment of soil cadmium pollution sources.

[0047] S103, correcting the initial isotope ratio information based on a preset fractionation model to generate target cadmium isotope ratio information.

[0048] In one embodiment, the ratio information of the initial cadmium isotope is processed to generate water samples and solid phase samples. It is assumed that the ratio information of the initial cadmium isotope is obtained by collecting, processing and analyzing environmental end member samples (such as surface water, total atmospheric precipitation, soil parent material, etc.). For example, after the surface water sample is collected, it is filtered, acidified, digested and other processing steps in the laboratory, and then measured using a multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS) to obtain the ratio data of cadmium isotopes in the surface water, such as values. Similarly, the total atmospheric precipitation and soil parent material are processed and analyzed, and the corresponding cadmium isotope ratio data are also obtained. According to these initial cadmium isotope ratio information, the sample is divided into a water sample and a solid phase sample by a physical or chemical method. For example, for a soil sample, the pore water (water sample) and the soil particles (solid phase sample) in the soil are separated by a centrifugal separation method. During the centrifugation process, appropriate centrifugal speed and time are set, such as centrifuging at 3000 rpm for 30 minutes, so that the pore water is separated from the soil particles, and the water sample and the solid phase sample are collected separately.

[0049] The water sample is processed based on the non-equilibrium fractionation model to generate the first liquid phase cadmium isotope ratio. The method also includes a calculation formula for obtaining the first liquid phase cadmium isotope ratio, which is:

[0050] δ 114 / 110 Cd solution =f α-1 (δ 114 / 110 Cd initial +1000)-1000;

[0051] Among them, δ 114 / 110 Cd solution , δ 114 / 110 Cd initial are the cadmium isotope ratio of the solid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, respectively; f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system; and α is the fractionation coefficient.

[0052] The non-equilibrium fractionation model is used to describe the fractionation behavior of cadmium isotopes between solid and liquid phases under non-equilibrium conditions. For water samples, the formula of the model is assumed to be δ 114 / 110 Cd solution =f α-1 (δ 114 / 110 Cd initial +1000)-1000(here δ 114 / 110 Cd solution is the isotope ratio of the treated liquid phase, δ 114 / 110 Cd initial is the initial liquid phase isotope ratio, f is the mass fraction of the remaining Cd in the liquid phase after adsorption to the total Cd in the original reaction system, and α is the fractionation coefficient).

[0053] The solid phase sample is processed based on the non-equilibrium fractionation model to generate a first solid phase cadmium isotope ratio. The method also includes a calculation formula for obtaining the first solid phase cadmium isotope ratio, which is:

[0054] Among them, δ 114 / 110 Cd solid , δ 114 / 110 Cd initial are the cadmium isotope ratio of the solid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, respectively; f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system; and α is the fractionation coefficient. Substitute the corresponding parameters obtained from the solid phase sample (such as the initial cadmium isotope ratio, adsorption ratio, fractionation coefficient, etc.) into the above formula for calculation. For example, using the same initial liquid phase isotope ratio δ as before 114 / 110 Cd initial =0.2‰, the mass fraction of Cd remaining in the liquid phase after adsorption to the total Cd in the original reaction system is f=0.3, and the fractionation coefficient α=0.9998 (according to the relevant theory of isotope geochemistry, this value is usually between 0.9995 and 1). Substituting it into the formula, the first solid phase isotope ratio δ is calculated. 114 / 110 Cdsolid The value of .

[0055] The first liquid phase cadmium isotope ratio and the first solid phase cadmium isotope ratio are processed to generate first solid-liquid partition information. It is assumed that the solid-liquid partition information is generated by calculating the difference or ratio between the first liquid phase isotope ratio and the first solid phase isotope ratio. For example, the solid-liquid partition information can be defined as (Here D is the solid-liquid distribution information).

[0056] Substitute the calculated first liquid phase isotope ratio and the first solid phase isotope ratio into the above formula for calculation. 114 / 110 Cd liquid and δ 114 / 110 Cd solid Substituting the value of into the formula, we can get the value of the first solid-liquid distribution information D, which can reflect the distribution of cadmium isotopes between the solid and liquid phases, and help to further study the migration and transformation laws of cadmium in the environment.

[0057] The water sample is processed based on the equilibrium fractionation model to generate a second liquid phase cadmium isotope ratio. The method also includes a calculation formula for obtaining the second solid phase cadmium isotope ratio, which is: Among them, δ 114 / 110 Cd′ solid , δ 114 / 110 Cd initial are the cadmium isotope ratio of the solid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system, and α is the fractionation coefficient. Assume that we have the following data: δ 114 / 110 Cd initial =-0.5‰, f = 0.6, α = 0.9998. Substituting these data into the above formula:

[0058] The solid phase sample is processed based on the equilibrium fractionation model to generate a second solid phase cadmium isotope ratio. The method also includes a calculation formula for obtaining the second solid phase cadmium isotope ratio, which is: Among them, δ 114 / 110 Cd′ solid , δ 114 / 110 Cd initial are the cadmium isotope ratio of the solid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, respectively; f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system; and α is the fractionation coefficient.

[0059] The second liquid phase cadmium isotope ratio and the second solid phase cadmium isotope ratio are processed to generate second solid-liquid distribution information. The method also includes a calculation formula for obtaining the second liquid phase cadmium isotope ratio, which is: Among them, δ 114 / 110 Cd′ solution ,δ 114 / 110 Cd initial are the cadmium isotope ratio of the liquid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, respectively; f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system; and α is the fractionation coefficient. Assume that we have the following data: δ 114 / 110 Cd initial =-0.5‰, f=0.6, α=0.9998.

[0060] The first solid-liquid distribution information and the second solid-liquid distribution information are processed to generate target solid-liquid distribution information, and the target solid-liquid distribution information is processed to obtain target cadmium isotope ratio information. The method also includes a calculation formula for obtaining the target cadmium isotope ratio, and the calculation formula is:

[0061] Δ 114 / 110 Cd solid-solution =δ 114 / 110 Cd′ solid -δ 114 / 110 Cd′ solution ; Among them, δ 114 / 110 Cd′ solid is the second solid phase cadmium isotope ratio, δ 114 / 110 Cd′ solution is the cadmium isotope ratio of the second liquid phase. Assuming δ 114 / 110 Cd′ solid =-0.65‰, δ 114 / 110 Cd′ solution =-0.35‰, substitute into the formula to calculate: Δ 114 / 110 Cd solid-solution =-0.65‰-(-0.35‰)=-0.3‰.

[0062] S104, correcting the soil profile sample information to generate isotope source analysis results.

[0063] In one embodiment, the soil profile sample information is processed to generate the isotope measured value of the environmental end member sample input by anthropogenic pollution, the isotope correction value of the anthropogenic pollution input corrected by isotope fractionation, the isotope ratio of the soil parent material, the contribution rate of anthropogenic pollution to soil cadmium accumulation and the contribution rate of soil parent material to soil cadmium accumulation. First, soil profile samples are collected by selecting multiple representative locations in the study area. For example, in areas of different land use types such as farmland, industrial area, forest, etc., soil samples are collected at certain depth intervals (such as 0-10cm, 10-20cm, 20-30cm, etc.). The collected soil samples are pre-treated, including removing impurities such as stones and plant roots, and then the soil samples are air-dried, ground and sieved (such as through a 200 mesh sieve) to make them into uniform powdered samples for subsequent analysis. Assume that surface water from farmland areas (as one of the environmental end-member samples of anthropogenic pollution input) is collected, and after processing, the ratio of cadmium (Cd) isotopes in it is measured using a high-precision mass spectrometer to obtain δ POL For example, the cadmium isotope δ 114 / 110 The measured value of Cd is -0.5‰, where δ POL =-0.5‰.

[0064] Taking into account the fractionation process of cadmium isotopes in environmental media (such as the fractionation that occurs during the adsorption-desorption process at the water-soil interface), the measured values ​​are corrected by a specific fractionation model (such as the equilibrium fractionation model or non-equilibrium fractionation model mentioned above). Assume that after the fractionation correction calculation, the corrected anthropogenic pollution input isotope correction value δ POL ' is -0.8‰.

[0065] The soil parent material samples that are not obviously polluted by human activities are collected in the study area. After being processed similarly to the soil profile samples, the cadmium isotope ratios are measured. 114 / 110 The ratio of Cd is -2.2‰, that is, δ PM =-2.2‰.

[0066] The isotope measured values ​​of environmental end-member samples of anthropogenic pollution input, isotope correction values ​​of anthropogenic pollution input corrected by isotope fractionation, isotope ratios of soil parent materials, contribution rates of anthropogenic pollution to soil cadmium accumulation, and contribution rates of soil parent materials to soil cadmium accumulation are processed to generate isotope source analysis results; the method also includes a calculation formula for obtaining the isotope source analysis results, which is: δ POL '=δ POL +Δ 114 / 110 Cd solid-solution ; Among them, δ POLThe measured isotope value of the environmental end member sample representing the input of anthropogenic pollution, δ POL ' represents the input isotope correction value for anthropogenic contamination due to isotope fractionation correction, δ PM represents the isotope ratio of the parent material, δ soil Characteristic values ​​of cadmium isotopes in soil, f POL represents the contribution rate of anthropogenic pollution to soil cadmium accumulation, f PM Represents the contribution rate of parent material to soil cadmium accumulation.

[0067] The cadmium isotope analysis of the collected soil profile samples was performed to obtain the average characteristic value of cadmium isotopes in the entire soil. Assuming that a soil profile is within the depth range of 0-30cm, the cadmium isotope δ 114 / 110 The characteristic value of Cd is -1.0‰, that is, δ soil =-1.0‰.

[0068] Contribution rate of anthropogenic pollution to soil cadmium accumulation (f POL ) and the contribution rate of parent materials to soil cadmium accumulation (f PM ): Contribution rate of anthropogenic pollution to soil cadmium accumulation f POL , the formula is Substituting the above assumed values, That is, the contribution rate of anthropogenic pollution to the cadmium accumulation in this soil profile is 86%. PM , the formula is Substituting the values ​​into That is, the contribution rate of soil parent material to cadmium accumulation in this soil profile is 14‰. Through the above parameters, isotope source analysis results are further generated. For example, isotope source analysis results may include information such as a comprehensive assessment of the relative importance of anthropogenic pollution and soil parent material to soil cadmium accumulation. In this example, it can be concluded that in this soil profile in the study area, anthropogenic pollution plays a more important role in soil cadmium accumulation.

[0069] S105, processing the isotope source analysis result to generate isotope source verification information.

[0070] In one implementation, it is assumed that we have obtained the isotope source analysis results through the previous method, including the following data:

[0071] Contribution rate of anthropogenic pollution to soil cadmium accumulation (f POL ):

[0072] Assume that the contribution rate of anthropogenic pollution to soil cadmium accumulation is f POL =0.6 (i.e. 60‰), which means that in this soil sample, 60‰ of the cadmium accumulation comes from human pollution.

[0073] Contribution rate of soil parent material to soil cadmium accumulation (f PM ):

[0074] Correspondingly, the contribution rate of parent material to soil cadmium accumulation is PM =0.4 (i.e. 40‰), indicating that 40‰ of the cadmium accumulation comes from the parent material.

[0075] Input isotope correction value (δ POL ') and isotope ratios of parent materials (δ PM )

[0076] Assume δ POL '=-0.2‰,δ PM =-1.5‰. These values ​​are key data obtained in the process of isotope source analysis, reflecting the isotopic characteristics of cadmium from different sources.

[0077] Processing of isotope source analysis results:

[0078] Verification method 1: Data rationality check:

[0079] Range Check:

[0080] First check whether the contribution rate is within a reasonable range. In this example, f POL and f PM The values ​​are all between 0 and 1, which is consistent with the physical meaning. If the contribution rate is greater than 1 or less than 0, it means that the data may be wrong.

[0081] Sum check:

[0082] Check f POL +f PM Is it equal to 1. In our example, 0.6+0.4=1, which means that from the perspective of contribution rate, the data is reasonable and no other possible sources of cadmium are omitted.

[0083] Verification method 2: Compare with known data:

[0084] It is assumed that there are historical data or other reliable studies in the same study area showing that the contribution rate of anthropogenic pollution to soil cadmium accumulation in the area is generally between 0.5 and 0.7.

[0085] We calculated f POL =0.6 is within this range, which provides certain verification support for our isotope source analysis results.

[0086] Similarly, if other studies have given the approximate range of cadmium isotope ratios of the soil parent materials in this area, we can compare δ PMIs the value within a reasonable range?

[0087] Verification method three: model verification:

[0088] If a specific fractionation model (such as equilibrium fractionation model or non-equilibrium fractionation model) is used in the isotope source analysis process, reverse verification can be performed by substituting the analysis results into the model.

[0089] For example, suppose we use the equilibrium fractionation model, which is formulated as δ POL '=δ POL +Δ 114 / 110 Cd solid-solution We can use the calculated δ POL ', known δ POL (Assume that δ is known in the previous step POL =0.0‰) and Δ obtained by other experiments or theoretical estimates 114 / 110 Cd solid-solution (Assume it is -0.2‰) Substitute it into the formula for verification.

[0090] Calculation: (0.0‰)+(-0.2)‰=-0.2‰, which is consistent with the δ we obtained before. POL '=-0.2‰, indicating that the model calculation and analytical results are consistent in this aspect.

[0091] The isotope verification information includes the following:

[0092] Data Reasonableness Report: Generate a report stating that the contribution rate and isotope ratio data in the isotope source analysis results are reasonable in terms of range and sum checks. For example: "The contribution rate of anthropogenic pollution f POL =0.6, soil parent material contribution rate f PM =0.4, the sum of the two is 1, the data is reasonable. "

[0093] Comparative analysis report: Write a comparative analysis report to indicate the consistency between our analysis results and known data or research. For example: "The contribution rate of human pollution is f POL =0.6, which is consistent with the range of human pollution contribution rate in historical data of the region (0.5-0.7), verifying the reliability of the results. ”

[0094] Model verification report: records the results of model verification, indicating the consistency between the model calculation and the analytical results. For example: "Through the reverse verification of the equilibrium fractionation model, the calculated δ POL 'It is consistent with the analytical results and the model verification has passed. ' These report contents together constitute the isotope source verification information, which is used to evaluate the accuracy and reliability of the isotope source analysis results.

[0095] S106: Process the isotope source verification information to generate soil pollution source information.

[0096] In one embodiment, the isotope source analysis results are processed to generate the fractionation coefficient of the soil formation process, the concentration of zirconium in the soil parent material, the concentration of zirconium in the soil, the concentration of cadmium in the soil parent material, and the concentration of cadmium in the soil. Assuming that the concentration of cadmium in the soil parent material is C cd，PM =8.07mg / kg, the concentration of cadmium in soil C cd，soil =49.6 mg / kg. Assuming that the fractionation coefficient of the soil formation process can be obtained by experimental determination or theoretical calculation, it is assumed here that ε=0.2 (only for example). According to the method described in the article, these parameters are obtained by processing the isotope source analysis results. For example, by analyzing the cadmium isotope ratios in soil profile samples and environmental end member samples, the cadmium concentration in the soil parent material and soil, as well as the fractionation coefficient in the soil formation process, are calculated in combination with relevant models.

[0097] The zirconium concentration in the soil parent material, the zirconium concentration in the soil, the cadmium concentration in the soil parent material and the cadmium concentration in the soil are processed to generate the cadmium concentration value of the residual phase after soil formation.

[0098] Assume that the concentration of zirconium in the parent material is C zr，PM =485mg / kg, the concentration of zirconium in soil C zr，soil =411mg / kg.

[0099] According to the formula Calculate the cadmium concentration value f of the residual phase after soil formation PED .

[0100] Substitute the hypothetical data:

[0101] The fractionation coefficient of the soil formation process and the cadmium concentration value of the residual phase after soil formation are processed to generate the difference value of the isotope signal between the weathered soil and the parent material before weathering. The method includes a calculation formula for obtaining the difference value of the isotope signal between the weathered soil and the parent material before weathering, and the calculation formula is:

[0102] Δ 114 / 110 Cd soil-PM =δ soil -δ PM =εlnf PED ;

[0103] Among them, Δ 114 / 110 Cd soil-PM is the difference in isotopic signals between the weathered soil and the parent material before weathering, ε is the fractionation coefficient of the soil formation process, and f PED is the cadmium concentration of the residual phase after soil formation. PED Calculated according to the following formula:

[0104]

[0105] c Zr，PM 、c Zr，soil are the concentration of zirconium in the parent material and in the soil, respectively, c Cd，PM 、c Cd，soil They are the concentration of cadmium in parent material and the concentration of cadmium in soil, respectively.

[0106] Assume δ soil =1.5‰,δ PM =1.0‰. Given that ε=0.2, fP ED =1.33.

[0107] First calculate εlnf PED :0.2×ln(1.33)≈0.2×0.287=0.0574.

[0108] Recalculate Δ 114 / 110 Cd soil-PM :Δ 114 / 110 Cd soil-PM =δ soil -δ PM =1.5‰-1.0‰=0.5‰.

[0109] Verify whether they are equal (there may be errors in actual situations). They are not equal here. This is due to the arbitrariness of the assumed data. In actual research, these data will be obtained through precise experimental measurement and calculation.

[0110] The difference in isotope signals between weathered soil and parent material before weathering, the cadmium concentration of the residual phase after soil formation, the isotope ratio of the parent material of soil formation, the characteristic values ​​of cadmium isotopes in soil and the isotope correction values ​​of anthropogenic pollution input by isotope fractionation correction are processed to generate isotope source verification information.

[0111] Reasonableness of cadmium concentration: Check the cadmium concentration of the residual phase after soil formation PED Is it within a reasonable range? Generally speaking, the cadmium concentration should be within the range that meets the local soil background value and relevant environmental standards. Assuming that the local soil cadmium background concentration ranges from 0.1 to 1.5 mg / kg, then PED =1.2mg / kg is within this range, indicating that the value is feasible in terms of concentration rationality.

[0112] Reasonableness of isotope ratio differences: Check the difference in isotope signals between weathered soil and parent material before weathering Δ 114 / 110 Cd soil-PMThis difference reflects the isotope fractionation during soil formation. Usually, this difference should be within the expected range based on known physical and chemical processes and local geological conditions. For example, if the isotope difference is generally between 0-0.5‰ based on studies of similar local soils, then Δ 114 / 110 Cd soil-PM =0.3‰ is reasonable.

[0113] Comparison with regional average values: The characteristic values ​​of cadmium isotopes in soil soil =1.5‰ and compared with the average value of soil cadmium isotope characteristic value in the region. Assuming that the average range of soil cadmium isotope characteristic value in the region is 1.2-1.8‰, then δ soil Within this range, this indicates that the cadmium isotope characteristics of the soil sample are consistent with the regional characteristics, which indirectly verifies the reliability of the data.

[0114] Comparison with soil parent materials: Comparison of characteristic values ​​of cadmium isotopes in soils soil The isotope ratio δ PM Calculate the difference δ soil -δ PM =1.5‰-1.0‰=0.5‰. This difference can reflect the external influences on the soil during its formation (such as pollution from human sources, etc.). If there is relevant research showing the range of differences in the region under similar conditions, it can be used to determine whether the difference is reasonable. For example, if research shows that the difference in the region is usually between 0.3-0.7‰, then 0.5‰ is reasonable.

[0115] Assume that there is a model that describes the fractionation behavior of cadmium isotopes during soil formation and contamination, such as: δ POL ′=δ POL +Δ 114 / 110 Cd solid-solution (where δ POL is the measured isotope value of the environmental end-member sample input by anthropogenic pollution, Δ 114 / 110 Cd solid-solution is the difference in cadmium isotope fractionation between solid and liquid). POL ′=2.0‰, assuming δ POL =1.8‰ (obtained through other measurements), which can be obtained through model calculation or experimental measurement. Assuming that Δ 114 / 110 Cd solid-solution =0.2‰. Verification: δ POL +Δ 114 / 110 Cd solid-solution =1.8‰+0.2‰=2.0‰=δ POL ′, which indicates that the isotope correction value is consistent with the model expectations and verifies the reliability of the data under the model framework.

[0116] Generate isotope source verification information, the information report includes the following: Reasonable report: "Cadmium concentration in the residual phase after soil formation f PED =1.2mg / kg Within the local soil cadmium background concentration range (0.1-1.5mg / kg), the difference in isotopic signals between the weathered soil and the parent material before weathering Δ 114 / 110 Cd soil-PM =0.3‰ is within the expected range of 0-0.5‰, and the data are reasonable in terms of concentration and isotope fractionation. "Comparison report: "The characteristic values ​​of cadmium isotopes in soil δ soil =1.5‰ is within the average range of soil cadmium isotope characteristic values ​​in the region (1.2-1.8‰), and δ soil -δ PM =0.5‰ is within the difference range (0.3-0.7‰) under similar conditions in the region, indicating that the soil cadmium isotope characteristics are consistent with regional characteristics and are reasonably affected by external factors. "Model verification report: "Verified by the relevant fractionation model, δ POL ′=2.0‰ and δ POL =1.8‰ and Δ 114 / 110 Cd solid-solution =0.2‰ conforms to the model relationship δ POL ′=δ POL +Δ 114 / 110 Cd solid-solution , verifying the reliability of the isotope correction values." These reports constitute the isotope source verification information, which is used to comprehensively evaluate and verify the accuracy and reliability of relevant data.

[0117] In another embodiment, the isotope source analysis results are verified. In this case, for soil at a depth of 10 cm and 40 cm, f PM <50%,δ POL ′>δ PM ; For soil at a depth of 90 cm, f PM >50%,δ POL ′>δ PM .

[0118] It can be obtained that at three soil depths, Δ 114 / 110 Cd soil-PM >0. The Cd concentration and Zr concentration at three soil depths were analyzed and f PED as follows:

[0119]

[0120]

[0121]

[0122] It can be seen that the source analysis results of soil at depths of 10cm, 40cm, and 90cm using this method are reliable.

[0123] In this application, the server obtains soil profile, environmental end member sample information and preset fractionation model, and realizes soil Cd pollution source analysis through a series of processing. First, the environmental end member sample is pre-processed to obtain the initial cadmium isotope ratio information, and then the target ratio information is corrected by the fractionation model. The soil profile sample information is corrected to generate the isotope source analysis result, and the analysis result is processed to obtain the isotope source verification information, and finally the soil pollution source information is obtained. It comprehensively considers various factors and uses multiple models to provide a scientific and effective method and approach for accurately analyzing the soil Cd pollution source.

[0124] In one embodiment, if Figure 2 As shown, the present application also provides a soil pollution source analysis device, comprising:

[0125] An acquisition module 201 is used to acquire soil profile sample information, environmental end member sample information, and a preset fractionation model, wherein the environmental end member sample information includes surface water information, total atmospheric deposition sample information, and soil parent material sample information, and the preset fractionation model includes a non-equilibrium fractionation model and an equilibrium fractionation model;

[0126] The processing module 202 is used to pre-process the environmental end member sample information to generate initial cadmium isotope ratio information, wherein the initial cadmium isotope ratio information includes cadmium isotope ratio information in surface water, cadmium isotope ratio information in total atmospheric deposition samples and cadmium isotope ratio information in soil parent material samples; correct the initial isotope ratio information based on a preset fractionation model to generate target cadmium isotope ratio information; correct the soil profile sample information to generate isotope source analysis results; process the isotope source analysis results to generate isotope source verification information; process the isotope source verification information to generate soil pollution source information.

[0127] Each embodiment in this application is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the analytical method, electronic device, electronic device, and readable storage medium embodiment for evaluating soil pollution sources, since they are basically similar to the above-mentioned analytical method embodiment for soil pollution sources, the description is relatively simple, and the relevant parts can be referred to the partial description of the above-mentioned analytical method embodiment for soil pollution sources.

Claims

1. A method for analyzing soil pollution sources, characterized in that: include: Acquire soil profile sample information, environmental end member sample information, and a preset fractionation model, wherein the environmental end member sample information includes surface water information, total atmospheric deposition sample information, and soil parent material sample information, and the preset fractionation model includes a non-equilibrium fractionation model and an equilibrium fractionation model; Preprocessing the environmental end member sample information to generate initial cadmium isotope ratio information, wherein the initial cadmium isotope ratio information includes cadmium isotope ratio information in surface water, cadmium isotope ratio information in total atmospheric deposition samples, and cadmium isotope ratio information in soil parent material samples; Correcting the initial isotope ratio information based on a preset fractionation model to generate target cadmium isotope ratio information; Correcting the soil profile sample information to generate isotope source analysis results; Processing the isotope source analysis result to generate isotope source verification information; The isotope source verification information is processed to generate soil pollution source information.

2. The method according to claim 1, characterized in that Preprocessing the environmental end member sample information to generate initial cadmium isotope ratio information includes: Processing the environmental end member sample information to generate surface water sample solution information, total atmospheric deposition sample solution information and soil parent material sample solution information; Processing the surface water sample solution information to generate cadmium isotope ratio information in the surface water; Processing the total atmospheric deposition sample information to generate cadmium isotope ratio information in the total atmospheric deposition sample; The soil parent material sample solution information is processed to generate cadmium isotope ratio information in the soil parent material sample.

3. The method according to claim 1, characterized in that The initial cadmium isotope ratio information is corrected based on a preset fractionation model to generate target cadmium isotope ratio information, including: Processing the initial cadmium isotope ratio information to generate a water sample and a solid phase sample; Processing the water sample based on a non-equilibrium fractionation model to generate a first liquid phase cadmium isotope ratio; Processing the solid phase sample based on a non-equilibrium fractionation model to generate a first solid phase cadmium isotope ratio; Processing the first liquid phase cadmium isotope ratio and the first solid phase cadmium isotope ratio to generate first solid-liquid distribution information; The method also includes a calculation formula for obtaining the first solid phase cadmium isotope ratio, the calculation formula being: Among them, δ 114 / 110 Cd solid , δ 114 / 110 Cd initial are the cadmium isotope ratio of the solid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system, and α is the fractionation coefficient; The method also includes a calculation formula for obtaining the cadmium isotope ratio of the first liquid phase, and the calculation formula is: δ 114 / 110 Contd solution =f α-1 (δ 114 / 110 Contd initial +1000)-1000; Among them, δ 114 / 110 Cd solution , δ 114 / 110 Cd initial are the cadmium isotope ratio of the liquid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, respectively; f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system; α is the fractionation coefficient.

4. The method of claim 3, further comprising: performing correction processing on the target cadmium isotope ratio information based on a preset fractionation model to generate the target cadmium isotope ratio information; Processing the water sample based on an equilibrium fractionation model to generate a second liquid phase cadmium isotope ratio; Processing the solid phase sample based on an equilibrium fractionation model to generate a second solid phase cadmium isotope ratio; Processing the second liquid phase cadmium isotope ratio and the second solid phase cadmium isotope ratio to generate second solid-liquid distribution information; Processing the first solid-liquid distribution information and the second solid-liquid distribution information to generate target solid-liquid distribution information; Processing the target solid-liquid distribution information to obtain target cadmium isotope ratio information; The method also includes a calculation formula for obtaining the second solid phase cadmium isotope ratio, and the calculation formula is: Among them, δ 114 / 110 Cd' solid , δ 114 / 110 Cd initial are the cadmium isotope ratio of the solid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system, and α is the fractionation coefficient; The method also includes a calculation formula for obtaining the cadmium isotope ratio of the second liquid phase, and the calculation formula is: Among them, δ 114 / 110 Cd' solution , δ 114 / 110 Cd initial are the cadmium isotope ratio of the liquid phase after the reaction and the cadmium isotope ratio of the liquid phase before the reaction, respectively; f is the mass fraction of the cadmium remaining in the liquid phase after adsorption to the total cadmium in the original reaction system; α is the fractionation coefficient.

5. The method according to claim 4, characterized in that The method further comprises: performing correction processing on the ratio information of the target cadmium isotope based on a preset fractionation model to generate the ratio information of the target cadmium isotope; The method also includes a calculation formula for obtaining a target cadmium isotope ratio, wherein the calculation formula is: D 114 / 110 CD solid-solution =d 114 / 110 CD' solid -d 114 / 110 CD' solution ; Among them, δ 114 / 110 Cd' solid is the second solid phase cadmium isotope ratio, δ 114 / 110 Cd' solution is the cadmium isotope ratio of the second liquid phase.

6. The method according to claim 4, characterized in that Correcting the soil profile sample information to generate isotope source analysis results, including: Processing the soil profile sample information to generate isotope measured values ​​of environmental end-member samples input by anthropogenic pollution, isotope correction values ​​of anthropogenic pollution input corrected by isotope fractionation, isotope ratios of soil parent materials, contribution rates of anthropogenic pollution to soil cadmium accumulation, and contribution rates of soil parent materials to soil cadmium accumulation; Processing the measured isotope values ​​of the environmental end-member samples of the anthropogenic pollution input, the isotope correction values ​​of the anthropogenic pollution input corrected by the isotope fractionation, the isotope ratios of the soil parent material, the contribution rate of the anthropogenic pollution to the soil cadmium accumulation, and the contribution rate of the soil parent material to the soil cadmium accumulation, to generate isotope source apportionment results; The method also includes a calculation formula for obtaining an isotope source analysis result, and the calculation formula is: Among them, δ POL The measured isotope value of the environmental end member sample representing the input of anthropogenic pollution, δ POL ' represents the input isotope correction value for anthropogenic contamination due to isotope fractionation correction, δ PM represents the isotope ratio of the parent material, δ soil Characteristic values ​​of cadmium isotopes in soil, f POL represents the contribution rate of anthropogenic pollution to soil cadmium accumulation, f PM Represents the contribution rate of parent material to soil cadmium accumulation.

7. The method of claim 6, wherein the isotope source analysis result is processed to generate isotope source verification information, comprising: Processing the isotope source analysis results to generate a fractionation coefficient of the soil formation process, a zirconium concentration in the soil parent material, a zirconium concentration in the soil, a cadmium concentration in the soil parent material, and a cadmium concentration in the soil; Processing the zirconium concentration in the soil parent material, the zirconium concentration in the soil, the cadmium concentration in the soil parent material, and the cadmium concentration in the soil to generate a cadmium concentration value of the residual phase after soil formation; Processing the fractionation coefficient of the soil formation process and the cadmium concentration value of the residual phase after the soil formation to generate a difference value of the isotope signal between the weathered soil and the parent material before weathering; Processing the difference value of the isotope signal between the weathered soil and the parent material before weathering, the cadmium concentration of the residual phase after soil formation, the isotope ratio of the parent material for soil formation, the characteristic value of the cadmium isotope in the soil, and the isotope correction value of the artificial source pollution input for the isotope fractionation correction to generate isotope source verification information; The method includes a calculation formula for obtaining the difference value of the isotope signal between the weathered soil and the parent material before weathering, and the calculation formula is: D 114 / 110 CD soil-PM =d soil -d PM =εlnf PED ; Among them, Δ 114 / 110 Cd soil-PM is the difference in isotopic signals between the weathered soil and the parent material before weathering, ε is the fractionation coefficient of the soil formation process, and f PED is the cadmium concentration of the residual phase after soil formation, f PED Calculated according to the following formula: Among them, c Zr,PM 、c Zr,soil are the concentration of zirconium in the parent material and in the soil, respectively, c Cd,PM 、c Cd,soil They are the concentration of cadmium in parent material and the concentration of cadmium in soil, respectively.

8. A soil pollution source analysis device, characterized in that: The device includes: An acquisition module, used to acquire soil profile sample information, environmental end member sample information, and a preset fractionation model, wherein the environmental end member sample information includes surface water information, total atmospheric deposition sample information, and soil parent material sample information, and the preset fractionation model includes a non-equilibrium fractionation model and an equilibrium fractionation model; A processing module is used to pre-process the environmental end member sample information to generate initial cadmium isotope ratio information, wherein the initial cadmium isotope ratio information includes cadmium isotope ratio information in surface water, cadmium isotope ratio information in total atmospheric deposition samples and cadmium isotope ratio information in soil parent material samples; correct the initial isotope ratio information based on a preset fractionation model to generate target cadmium isotope ratio information; correct the soil profile sample information to generate isotope source analysis results; process the isotope source analysis results to generate isotope source verification information; process the isotope source verification information to generate soil pollution source information.

9. An electronic device, characterized in that: include: a first processor; and a memory for storing executable instructions for the first processor; The first processor is configured to execute the soil pollution source analysis method of any one of claims 1 to 7 by executing executable instructions.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the second processor, the soil pollution source analysis method according to any one of claims 1 to 7 is implemented.

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