阅读说明：本技术 利用土壤剖面表层重金属累积比例解析重金属污染来源的方法 (Method for analyzing heavy metal pollution source by using soil profile surface layer heavy metal accumulation proportion ) 是由 马杰 翁莉萍 陈雅丽 李永涛 于 2020-06-05 设计创作，主要内容包括：本发明涉及一种利用土壤剖面表层重金属累积比例解析重金属污染来源的方法,所述方法包括：对土壤进行剖面样品采样,测定剖面中Cd、Cu、Pb和Zn重金属含量,用表层土壤重金属含量减去深层土壤重金属确定重金属累积量,扣除重金属地质背景,进而计算不同重金属累积之间的比值。基于与不同污染源(大气沉降、有机肥、灌溉水和矿渣)重金属比值的对比,初步定性确定点位最有可能的重金属污染来源。利用主成分分析确定每个点位可能的多重污染来源。采用逐步线性回归的方法确定不同污染源对点位污染的贡献比例。该方法克服了传统受体模型重金属源解析数据量需求大的缺点,也不需要重金属同位素源解析方法复杂的实验操作。提供了一种对单一或较少田块的,流程简单,易于操作的土壤重金属源解析,具有广泛的应用前景。(The invention relates to a method for analyzing a heavy metal pollution source by utilizing the accumulation proportion of heavy metals on the surface layer of a soil profile, which comprises the following steps: sampling a profile sample of the soil, measuring the contents of Cd, Cu, Pb and Zn in the profile, subtracting the heavy metal in the deep soil from the heavy metal in the surface soil to determine the heavy metal accumulation amount, deducting the geological background of the heavy metal, and further calculating the ratio of different heavy metal accumulations. Based on the comparison with the heavy metal ratio of different pollution sources (atmospheric sedimentation, organic fertilizer, irrigation water and slag), the most probable heavy metal pollution source of the point location is preliminarily determined qualitatively. And determining possible multiple pollution sources of each point by utilizing principal component analysis. And determining the contribution ratio of different pollution sources to point pollution by adopting a stepwise linear regression method. The method overcomes the defect that the requirement of the traditional receptor model for heavy metal source analysis data volume is large, and complex experimental operation of the heavy metal isotope source analysis method is not needed. Provides a soil heavy metal source analysis method which is simple in process and easy to operate for single or few fields and has wide application prospect.)

1. A method for analyzing a heavy metal pollution source by utilizing a soil profile surface layer heavy metal accumulation ratio is characterized by comprising the following steps of: the method comprises the following steps:

s1: sampling a soil profile sample, and obtaining a layered profile soil sample, wherein the number of layers is at least two, namely a surface layer and a deep layer;

s2: digesting a profile soil sample to obtain the concentrations of Cd, Cu, Pb and Zn;

s3: subtracting the concentration values of heavy metals Cd, Cu, Pb and Zn in the surface soil from the corresponding concentration values of heavy metals in the bottom soil to obtain the concentration of the accumulated heavy metals in the surface of the sampling point;

s4: collecting and obtaining content data of heavy metals Cd, Cu, Pb and Zn in the pollution sources in the source analysis area, and respectively calculating average values of different heavy metals to serve as characteristic values of the heavy metals in different pollution sources in the area;

s5: calculating the ratio between the accumulated heavy metals on different surface layers obtained in the step S3 and the ratio between different heavy metals S4, including Pb/Cd, Pb/Cu, Zn/Pb, Cu/Cd, Zn/Cd and Zn/Cu, and making a radar map according to the ratios;

s6: classifying according to the similarity degree of the radar map of the sampling point location and the radar map of the pollution source point location, and judging the heavy metal pollution source of the point location through data information;

s7: by establishing a linear regression equation of the element ratio of the point location to the pollution source, the contribution proportion of different pollution sources to the point location pollution is determined by the normalization coefficient of the linear regression equation, and the purpose of analyzing the heavy metal pollution source is achieved.

2. The method for analyzing the heavy metal pollution source by utilizing the accumulation proportion of the heavy metals on the surface layer of the soil profile according to claim 1, wherein the method comprises the following steps: the soil profile collection depth is as follows: 0-20cm, 20-40cm, 40-60cm, 60-100cm, 0-20cm being the surface layer, 60-100cm being the deep layer.

3. The method for analyzing the heavy metal pollution source by utilizing the accumulation proportion of the heavy metals on the surface layer of the soil profile according to claim 1, wherein the method comprises the following steps: after the section soil sample is air-dried, grinding the sample to make the particle size of the sample less than 100 meshes, weighing the sample, and adopting HNO₃-H₂O₂The method comprises the steps of digesting, fixing the volume after digestion liquid is cooled after digestion is completed, and obtaining the concentrations of Cd, Cu, Pb and Zn by adopting inductively coupled plasma mass spectrometry for one-time sample injection.

4. The method for analyzing the heavy metal pollution source by utilizing the accumulation proportion of the heavy metals on the surface layer of the soil profile according to claim 1, wherein the method comprises the following steps: the pollution sources in the source resolving area comprise atmospheric sedimentation, organic fertilizer, irrigation water and slag.

5. The method for analyzing the heavy metal pollution source by utilizing the accumulation proportion of the heavy metals on the surface layer of the soil profile according to claim 1, wherein the method comprises the following steps: and (3) performing principal component analysis on the element proportion of the pollution source and the sampling point location, determining the relationship between different pollution sources and pollution points, and screening the pollution source which can possibly generate pollution to the point location.

6. The method for analyzing the heavy metal pollution source by utilizing the accumulation proportion of the heavy metals on the surface layer of the soil profile according to claim 1, wherein the method comprises the following steps: the linear regression equation is as follows:

wherein the content of the first and second substances,

Technical Field

The invention belongs to the field of environmental geology, relates to a soil heavy metal pollution source analysis technology, and particularly relates to a method for analyzing a heavy metal pollution source by utilizing a soil profile surface layer heavy metal accumulation proportion.

Background

Soil is an essential natural resource for human survival, but with the growth of population and the development of economy, the soil environment problem of China is increasingly highlighted, wherein heavy metals are main pollutants of farmland soil. The national soil pollution survey shows that the standard exceeding rate of heavy metal point positions of soil in cultivated lands in China is 19.4%. Understanding the pollution sources of the heavy metals in the soil is an important premise for monitoring and evaluating the ecological environment of a research area, and is also a fundamental measure for formulating and taking corresponding source reduction and resistance control measures so as to protect the soil quality of farmlands and the safety of agricultural products. However, due to the complex sources of heavy metals in soil, the migration and accumulation processes of heavy metals in soil are influenced by various factors, and the source composition and the soil characteristics have strong spatial variability. Therefore, in the case of contaminated soil with multiple pollution sources, how to accurately identify and analyze the main heavy metal pollution sources in a specific research area is the key to effectively treat the heavy metal pollution of the soil.

With the increasing importance of heavy metal pollution, the application and development of soil heavy metal source analysis technology are rapid, and common methods include statistical numerical methods such as principal component analysis, cluster analysis and multivariate statistical analysis, an input product list method, an isotope fingerprint method and the like. The statistical numerical method relies on a large amount of soil analysis data and other related data to obtain an empirical conclusion; the list rule of the input products is to calculate the contribution of various sources to the total input of the soil heavy metal by investigating the content and the usage amount of the heavy metal in various input products, and the default of the contribution of the sources to the total input of the soil heavy metal is equal to the contribution to the accumulated heavy metal in the soil. Isotope fingerprinting is less used due to the higher requirements on the detection technology, which at the same time requires significant differences in the composition of the isotopes from different sources. Most simple methods only qualitatively presume potential pollution sources of the soil heavy metals, and do not analyze the pollution sources quantitatively. Methods that can be quantified suffer from the disadvantage of relying on large amounts of data or complex experiments. The method is simple, convenient and easy to operate, can quantitatively analyze the soil heavy metal source, and has important research significance for controlling and treating the soil heavy metal pollution source.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides a soil heavy metal source analysis method which is simple, convenient and easy to operate and based on the section heavy metal accumulation proportion, carries out quantitative analysis on a soil heavy metal source and the contribution thereof, and provides an effective theoretical basis for controlling and treating the soil heavy metal source.

The technical problem to be solved by the invention is realized by adopting the following technical scheme:

a method for analyzing a heavy metal pollution source by utilizing a soil profile surface layer heavy metal accumulation ratio comprises the following steps:

s1: sampling soil profile samples in a field needing heavy metal source analysis, and collecting samples in four depth ranges of 0-20cm, 20-40cm, 40-60cm and 60-100cm by using a soil profile sampler to obtain layered profile soil samples;

s2: after the section soil sample is air-dried, grinding the sample to make the grain diameter of the sample less than 100 meshes, weighing a certain amount of sample, and adopting HNO₃-H₂O₂The method comprises the steps of digesting, after digestion is completed, determining the volume after the digestion solution is cooled, and obtaining the concentrations of Cd, Cu, Pb and Zn by adopting inductively coupled plasma mass spectrometry for one-time sample injection;

s3: subtracting the concentration values of heavy metals Cd, Cu, Pb and Zn in the surface soil (0-20cm) from the concentration values of heavy metals corresponding to the bottom soil (60-100cm) to obtain the concentration of the heavy metals accumulated on the surface of the sampling point so as to deduct the geological background of the heavy metals;

s4: collecting and acquiring data of contents of heavy metals Cd, Cu, Pb and Zn in atmospheric sedimentation of pollution sources in a source analysis area, organic fertilizers, irrigation water and slag from literature reports, and respectively calculating average values of different heavy metals to serve as characteristic values of the heavy metals in different pollution sources in the area;

s5: calculating the ratio between the accumulated heavy metals on different surface layers obtained in the step S3 and the ratio between different heavy metals S4, including Pb/Cd, Pb/Cu, Zn/Pb, Cu/Cd, Zn/Cd and Zn/Cu, and making a radar map according to the ratios;

s6: classifying according to the similarity degree of the radar map of the sampling point location and the radar map of the pollution source point location, and primarily judging the most probable heavy metal pollution source of the point location through visual data information;

s7: further, performing principal component analysis on element proportions of the pollution source and the sampling point location to determine the relationship between different pollution sources and pollution points, and screening out the pollution source which may pollute the point location;

s8: by establishing a linear regression equation of the element ratio of the point location to the pollution source, determining the contribution proportion of different pollution sources to the point location pollution by the normalization coefficient of the linear regression equation, and achieving the purpose of analyzing the heavy metal pollution source;

if no more criteria for contamination source selection are required in the linear regression operation, step 7 can be omitted, further simplifying the source resolution operation.

The invention has the advantages and positive effects that:

the invention provides a method for analyzing heavy metal pollution sources in soil, which utilizes the characteristics that heavy metal input into the soil is preferentially accumulated on the surface layer of the soil and the characteristics that the ratio characteristics of the heavy metal of different pollution sources are different, and finally judges the contribution of different pollution sources to point position pollution by the normalization coefficient of a linear regression equation through the visual comparison, the principal component analysis and the stepwise linear regression of the ratio of the heavy metal accumulated on the surface layer of the polluted soil to the ratio of the heavy metal of different pollution sources. The method utilizes the general rule of pollutant occurrence, uses the principle of heavy metal isotope source analysis method and main component analysis in the traditional receptor model for reference, and organically combines the heavy metal isotope source analysis method and the main component analysis method to analyze the heavy metal pollution source. The method overcomes the defects that the traditional receptor model has large requirement on heavy metal source analysis data volume and the pollution source is analyzed in a larger area range, and replaces the complex experimental operation in the heavy metal isotope source analysis method by simple analysis of the total amount of the heavy metal. The source analysis data quantity demand is greatly reduced, the source tracing process is simpler, heavy metal source analysis can be carried out on a single or less field, and the method has important significance in prevention and control and pollution remediation of the heavy metal pollution source of the soil with the field scale.

Drawings

FIG. 1 is a schematic flow chart of a soil heavy metal source analysis method based on profile heavy metal accumulation ratio provided in the example;

FIG. 2 shows the concentrations of Cd, Cu, Pb and Zn in soils of different profiles;

FIG. 3 is a radar chart of the ratio of heavy metals in different pollution sources and the sum of the ratios of surface layer accumulated heavy metals in different point locations in the example;

FIG. 4 is a diagram of principal component analysis in the examples;

FIG. 5 is a graph of the contribution ratio of the contamination source in the example.

Detailed Description

The present invention is further illustrated by the following specific examples, which are intended to be illustrative, not limiting and are not intended to limit the scope of the invention.

Fig. 1 is a schematic flow chart of the method of the present invention, which is a method for analyzing a heavy metal source in soil based on a profile heavy metal accumulation ratio, and the method includes the steps of:

s1: sampling soil profile samples in a field needing heavy metal source analysis, and collecting samples in four depth ranges of 0-20cm, 20-40cm, 40-60cm and 60-100cm by using a soil profile sampler to obtain layered profile soil samples;

s2: after the section soil sample is air-dried, grinding the sample to make the grain diameter of the sample less than 100 meshes, weighing a certain amount of sample, and adopting HNO₃-H₂O₂The method comprises the steps of digesting, after digestion is completed, determining the volume after the digestion solution is cooled, and obtaining the concentrations of Cd, Cu, Pb and Zn by adopting inductively coupled plasma mass spectrometry for one-time sample injection;

s3: subtracting the concentration values of heavy metals Cd, Cu, Pb and Zn in the surface soil (0-20cm) from the concentration values of heavy metals corresponding to the bottom soil (60-100cm) to obtain the concentration of the heavy metals accumulated on the surface of the sampling point so as to deduct the geological background of the heavy metals;

s4: collecting and acquiring data of contents of heavy metals Cd, Cu, Pb and Zn in atmospheric sedimentation of pollution sources in a source analysis area, organic fertilizers, irrigation water and slag from literature reports, and respectively calculating average values of different heavy metals to serve as characteristic values of the heavy metals in different pollution sources in the area;

s5: calculating the ratio of the accumulated heavy metals on the surface layers of different points obtained in the step S3 and the ratio of different heavy metals S4, including Pb/Cd, Pb/Cu, Zn/Pb, Cu/Cd, Zn/Cd and Zn/Cu, and making a radar map according to the ratios;

s6: classifying according to the similarity degree of the radar map of the sampling point location and the radar map of the pollution source point location, and primarily judging the most probable heavy metal pollution source of the point location;

s7: further, performing principal component analysis on element proportions of the pollution source and the sampling point location to determine the relationship between different pollution sources and pollution points, and screening out the pollution source which may pollute the point location;

s8: by establishing a linear regression equation of the element ratio of the point location to the pollution source, the contribution proportion of different pollution sources to the point location pollution is determined by the normalization coefficient of the linear regression equation, and the purpose of analyzing the heavy metal pollution source is achieved.