Heavy metal soil pollution treatment method based on multi-technology joint repair

Abstract

The application relates to the technical field of contaminated soil regeneration, in particular to a heavy metal soil pollution treatment method based on multi-technology joint repair, which comprises the following steps: collecting the chromium metal concentration of heavy metal contaminated soil and the soil moisture content; clustering the initial concentration of chromium metal, and screening the main reference round; analyzing the difference distribution characteristics of the chromium metal concentration change, and determining the first reference value of the chromium metal concentration at the current time of the current round; determining the reference value of the chromium metal concentration at the current time based on the change distribution characteristics and trend characteristics of the chromium metal concentration; obtaining the influence degree of the soil moisture content at the current time on the measurement result of the chromium metal concentration through experiments; correcting the collected chromium metal concentration based on the numerical value of the influence degree and in combination with the reference value of the chromium metal concentration; and treating the heavy metal contaminated soil according to the corrected chromium metal concentration data. The application aims to improve the soil environment and enhance the effect of biological repair.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of contaminated soil remediation, in particular to a heavy metal soil pollution treatment method based on multi-technology joint remediation. BACKGROUND

[0002] Traditional soil heavy metal pollution remediation technologies, such as physical methods, can effectively remove pollutants, but their high cost and damage to the ecosystem limit their widespread application; chemical remediation methods can have a faster effect, but may cause secondary pollution or only "sequester" pollutants in the soil, without fundamentally reducing environmental risks. Single plant remediation or microbial remediation is environmentally friendly, but generally has problems such as long remediation period, low efficiency, and poor tolerance to high concentration pollution. Therefore, developing efficient, economical and environmentally friendly multi-technology joint remediation strategies has become a research hotspot and future development trend in the field of soil pollution remediation.

[0003] When monitoring soil heavy metals using spectral equipment, environmental factors such as soil moisture content can affect the accuracy of the monitoring results, thereby affecting the accuracy of adjusting the biological release density based on chromium metal concentration. If the release is excessive, it may lead to increased competition between species, thereby affecting the supply of resources such as food and space, and inhibiting the activity and overall function of individuals; conversely, if the release is insufficient, it may limit the effective improvement of the soil microenvironment by the organisms. SUMMARY

[0004] To solve the above technical problems, the present application provides a heavy metal soil pollution treatment method based on multi-technology joint remediation to solve the existing problems.

[0005] The heavy metal soil pollution treatment method based on multi-technology joint remediation of the present application adopts the following technical solutions:

[0006] Collecting the chromium metal concentration and soil moisture content at each time point of each round at the preset monitoring point of the heavy metal contaminated soil;

[0007] Based on the data correlation of the initial concentration of chromium metal in the current and all previous rounds, screening the main reference rounds; analyzing the difference distribution characteristics of the chromium metal concentration changes between the current round and each main reference round to determine the concentration similarity between the current round and each main reference round; based on the numerical value of the concentration similarity, determining the first reference value of the chromium metal concentration at the current time point of the current round;

[0008] Obtaining the change distribution characteristics and trend characteristics of the chromium metal concentration at the adjacent time point, and combining the first reference value of the chromium metal concentration to determine the reference value of the chromium metal concentration at the current time point;

[0009] The influence degree of the soil water content at the current time on the measurement result of the chromium metal concentration is obtained through experiments; the collected chromium metal concentration is corrected based on the numerical size of the influence degree and the chromium metal concentration reference value; and the heavy metal contaminated soil is treated according to the chromium metal concentration data after correction.

[0010] The screening mainly refers to a main reference round, specifically: clustering the initial concentrations of chromium metal of all rounds of the current and history, and taking all the history rounds in the same cluster as the main reference round of the initial concentration of chromium metal of the current round.

[0011] The concentration similarity between the current round and each main reference round is determined, specifically:

[0012] The chromium metal concentration content curve of each round is obtained.

[0013] The absolute value of the difference between the chromium metal concentration at the corresponding time of the chromium metal concentration content curve of the current round and each main reference round is calculated, the sum of all the absolute values of the difference between the current round and each main reference round is obtained, and the negative correlation mapping result of the sum is taken as the concentration similarity between the current round and each main reference round.

[0014] The first reference value of the chromium metal concentration of the current round at the current time is determined, including:

[0015] The chromium metal concentration content curve of the main reference round with the concentration similarity greater than the preset similarity threshold value is taken as the reference curve of the current round.

[0016] The average value of the chromium metal concentration at the corresponding time of all reference curves at the current time is taken as the first reference value of the chromium metal concentration at the current time.

[0017] The reference value of the chromium metal concentration at the current time is determined, specifically:

[0018] The change amount of the chromium metal concentration at each time is calculated, the threshold segmentation of the change amount of the chromium metal concentration at all historical times is performed, and the concentration change stability is obtained based on the overall distribution characteristics of the segmentation result.

[0019] The second reference value of the chromium metal concentration at each time is obtained based on the chromium metal concentration value at the previous time and the change amount of the chromium metal concentration at each time.

[0020] The concentration change stability is taken as the weight of the second reference value, the difference between the natural number 1 and the concentration change stability is taken as the weight of the first reference value, and the chromium metal concentration reference value at the current time is obtained by weighted summation.

[0021] The chromium metal concentration change amount is determined by the difference between the chromium metal concentration at the previous moment and the chromium metal concentration at the current moment.

[0022] The concentration change stability is obtained, and specifically:

[0023] The average of all chromium metal concentration change amounts greater than the chromium metal concentration change threshold in the historical moments is taken as a first average value, and the average of all chromium metal concentration change amounts less than the chromium metal concentration change threshold is taken as a second average value.

[0024] The difference between the chromium metal concentration change amount at the previous moment and the first average value is calculated and recorded as a first difference, and the difference between the chromium metal concentration change amount at the previous moment and the second average value is calculated and recorded as a second difference; the normalized value of the positive fusion result of the second difference and the negative fusion result of the first difference is taken as the concentration change stability at the previous moment.

[0025] The second reference value of the chromium metal concentration at each moment is specifically the difference between the chromium metal concentration value at the previous moment and the chromium metal concentration change amount.

[0026] The influence degree of the soil moisture content on the chromium metal concentration measurement result at the current moment is obtained, and specifically:

[0027] The average of the absolute values of the differences between the detected chromium metal concentration and the actual concentration of all soil reference samples at the current moment is calculated, and the average is normalized to obtain the influence degree of the soil moisture content at the current moment on the chromium metal concentration measurement result.

[0028] The chromium metal concentration reference value is combined to correct the collected chromium metal concentration, and specifically:

[0029] All influence degrees are threshold segmented to obtain an influence degree threshold, and the label value P of the influence degree less than the threshold is set to 0; otherwise, the label value P is set to 1.

[0030] The specific formula for correction is:

[0031]

[0032] wherein, represents the corrected chromium metal concentration at the current moment, represents the chromium metal concentration reference value at the current moment, represents the influence degree of the soil moisture content on the chromium metal concentration measurement result, represents the chromium metal concentration monitored at the current moment using the spectral equipment.

[0033] The application has at least the following beneficial effects:

[0034] The application first collects the chromium metal concentration and soil moisture content of each round and each time of the heavy metal contaminated soil monitoring point. The collection of chromium metal concentration data can accurately track the soil pollution level, and the monitoring of soil moisture content can help understand the influence of environmental factors on heavy metals and provide comprehensive soil condition information. Cluster analysis of chromium metal concentration and selection of main reference rounds can find the regularity of concentration change, so as to select the reference round most similar to the current round and improve the accuracy of prediction. Then, by analyzing the difference of concentration change, the rules of pollution diffusion, accumulation or decline can be revealed, which provides basic data support for subsequent remediation work and helps to more accurately assess the pollution level. By referring to the similarity of historical concentration to determine the reference value of the current concentration, accidental errors can be effectively eliminated, and stable and reliable remediation reference basis can be provided. The trend and distribution characteristics of chromium metal concentration are obtained, which helps to predict future pollution and adjust remediation strategies. The influence of soil moisture content on chromium metal concentration measurement results is analyzed to help adjust the detection method and correct the data, so that the monitoring results are more accurate and the error interference on decision-making is reduced. Finally, the density of earthworms is adjusted according to the corrected chromium metal concentration. Accurate adjustment of the density of earthworms can avoid waste of biological resources and ensure that the activity of earthworms can effectively improve the soil environment and enhance the effect of biological remediation. If the density is too high, resource shortage may be caused by species competition; if it is too low, the remediation effect may be insufficient. Reasonable density can improve the remediation efficiency and reduce resource waste. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0036] Figure 1 The flowchart of the heavy metal soil pollution treatment method based on multi-technology joint remediation provided by the application is shown in the following figure:

[0037] Figure 2 The flowchart of the acquisition of the reference value of the chromium metal concentration at the current time provided by the application is shown in the following figure: DETAILED DESCRIPTION

[0038] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined object of the application, the specific implementation, structure, features and effects of the heavy metal soil pollution treatment method based on multi-technology joint repair according to the present application are described in detail below in combination with the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0040] The specific scheme of the heavy metal soil pollution treatment method based on multi-technology joint repair provided by the present application is described below in combination with the drawings.

[0041] The heavy metal soil pollution treatment method based on multi-technology joint repair provided by one embodiment of the present application.

[0042] Specifically, the heavy metal soil pollution treatment method based on multi-technology joint repair is provided as follows, please refer to Figure 1 The method comprises the following steps:

[0043] S1: Collecting the chromium metal concentration and soil moisture content at each time point of each round at the preset monitoring point of the heavy metal contaminated soil.

[0044] The present application uses X-ray fluorescence spectrometry (XRF) to monitor the chromium metal content in the soil. In order to better obtain the earthworm release density in the soil, it is necessary to continuously monitor the chromium metal content in the soil, so as to facilitate subsequent changes in earthworm release density under different conditions according to the change of chromium metal content.

[0045] In the process of repairing the chromium metal contaminated soil, multiple rounds of earthworms need to be released, so it is necessary to monitor the chromium metal concentration in the contaminated soil before each round of release. In this embodiment, each round in the present application includes M preset time points, M is 30, and the time length between adjacent time points is 1 day. The implementer can adjust it according to the actual situation, and the present application does not limit it.

[0046] The present application divides the soil to be repaired into grid, wherein the grid center point is the monitoring point of the soil chromium content, and the soil at the grid center point is selected as the soil sample of the corresponding grid. According to the chromium concentration monitoring result of the soil sample at the grid center point, the biological release density in the grid is adjusted.

[0047] Since the water content in the soil will affect the determination of the content of chromium metal, the soil water content at the monitoring point position is also collected in the present application, wherein the time-domain reflectometry (TDR) is used to monitor the soil water content in the present embodiment.

[0048] S2: Based on the data correlation of the initial concentration of chromium metal in the current and all historical rounds, the main reference rounds are screened; the difference distribution characteristics of the concentration change of chromium metal in the current round and each main reference round are analyzed to determine the concentration similarity of the current round and each main reference round; and based on the numerical size of the concentration similarity, the first reference value of the chromium metal concentration at the current time of the current round is determined.

[0049] The chromium metal concentration of each round is curve-fitted to obtain a chromium metal concentration curve; in the present application, the initial chromium metal concentration of the current round and the initial chromium metal concentration of all historical rounds are taken as inputs, the absolute value of the difference of the chromium metal concentration is taken as the clustering distance, and the DBSCAN clustering algorithm is used to select all historical rounds in the same clustering cluster as the main reference rounds.

[0050] It is considered that even if the initial concentrations of chromium metal in all rounds in the same clustering cluster are similar, the activity of the organism absorbing chromium metal is affected by other environmental factors such as weather conditions and temperature, resulting in inconsistent trends of the final chromium metal concentration. Therefore, the similarity analysis of the chromium metal concentration curve at the current time and the chromium metal concentration curve of each main reference round is performed in the clustering cluster where the initial concentration of chromium metal in the current round is located, and the reference curve with greater similarity is selected to correct the current monitoring result. It should be noted that since each monitoring period in the present application is M days, the data obtained are also corresponding. For example, the monitoring data t of the day represents the tth day of the current round, which can be compared and analyzed with the data of the first t days in the historical monitoring period.

[0051] Therefore, the present application obtains the sum of all absolute values of the differences of the chromium metal concentrations corresponding to the time of the chromium metal concentration content curves of the current round and each main reference round by calculating the absolute value of the difference of the chromium metal concentration corresponding to the time of the chromium metal concentration content curves of the current round and each main reference round, and takes the negative correlation mapping result of the sum as the concentration similarity of the current round and each main reference round. In the present embodiment, the negative correlation mapping result of the sum is specifically: the difference between 1 and the normalized result obtained by normalizing the sum, and in the present embodiment, the normalization method adopts the arctangent transformation method.

[0052] It should be understood that the smaller the difference between the chromium concentrations obtained at each monitoring time in the two chromium metal concentration content curves, the stronger the similarity of the two chromium concentration monitoring curves.

[0053] According to the above method, the concentration similarity of the current round and all main reference rounds can be obtained, and the embodiment sets the similarity threshold T=0.9, and the main reference round whose concentration similarity with the current round is greater than the similarity threshold T is taken as the reference curve.

[0054] Further, the average value of the chromium metal concentration at the corresponding time of all reference curves at the current time is taken as the first reference value of the chromium metal concentration at the current time.

[0055] S3: Obtain the change distribution feature and the trend feature of the chromium metal concentration at the adjacent time, and determine the reference value of the chromium metal concentration at the current time in combination with the first reference value of the chromium metal concentration.

[0056] The chromium metal concentration content curve is analyzed, and it is considered that in the soil, the chromium metal concentration is relatively easy to be enriched and absorbed by earthworms-plant in the initial stage of high concentration, and as the chromium metal concentration in the soil decreases, the difficulty of enrichment and absorption of earthworms-plant increases, so the speed of decrease of the chromium metal concentration in the soil will decrease, so the chromium metal concentration content curve can be analyzed according to this feature, the difference between the chromium metal concentration at the previous time and the chromium metal concentration at the current time is calculated, and the change amount of the chromium metal concentration at the previous time of the current time is obtained, then the change of the change amount of the chromium metal concentration is analyzed, and the chromium metal concentration at the current time is obtained based on the chromium metal concentration collected at the previous time. If the monitoring time is in the early stage of each round, that is, in the period when the speed of decrease of the chromium metal concentration in the soil is relatively fast, the reliability of the chromium metal concentration result obtained by this method is relatively low, on the contrary, in the later stage of the treatment round, the change of the chromium metal concentration is small, and the chromium metal concentration with high reliability can be obtained.

[0057] The trend of the chromium metal concentration change curve is analyzed, the initial concentration of chromium metal is different in different rounds, and the corresponding change trend of chromium metal is also different, so the reliability of using this method needs to be calculated in combination with the chromium metal concentration change curve of the corresponding round. Specifically, for the chromium metal concentration content curve of the current round, the application obtains the change value of the chromium metal concentration at all historical times at the current time, processes all the obtained chromium metal concentration change values using the Otsu threshold algorithm to obtain a chromium metal concentration change threshold, and takes the average value of all the chromium metal concentration change values greater than the chromium metal concentration change threshold in the historical times as a first average value. The average value of all the chromium metal concentration change values less than the chromium metal concentration change threshold is taken as a second average value. It should be understood that if the chromium metal concentration change value at the historical time is less than the chromium metal concentration change threshold, it means that the time is in the change stage of the small change trend of the chromium metal concentration, otherwise, it is in the large change trend.

[0058] Further, the difference between the chromium metal concentration change amount at the time point one time ago and the first average value is calculated, denoted as a first difference; the difference between the chromium metal concentration change amount at the time point one time ago and the second average value is calculated, denoted as a second difference; and the negative correlation mapping result of the second difference and the normalized value of the positive fusion result of the first difference are taken as the concentration change stability at the time point one time ago. In this embodiment, the difference between variables is calculated by the absolute value of the difference; the negative correlation mapping result of the variable is calculated by the reciprocal of the variable. It should be noted that if the second difference is 0, a preset value needs to be added to the denominator, and the value of this embodiment is 0.01; and the positive fusion of multiple variables is calculated by multiplication.

[0059] It should be understood that, since the chromium metal content in the soil as a whole shows a downward trend, the first average value represents the high concentration change of the chromium metal content, and the second average value represents the low concentration change of the chromium metal content, so the closer the chromium metal concentration change amount at the time point one time ago to the second average value, the higher the stable trend of the concentration change, and the greater the concentration change stability obtained.

[0060] Further, the chromium metal concentration value at the time point one time ago is subtracted from the chromium metal concentration change amount to obtain a second reference value of the chromium metal concentration at the current time point; the concentration change stability is taken as the weight of the second reference value, and the difference between the natural number 1 and the concentration change stability is taken as the weight of the first reference value, and the sum is added to obtain a chromium metal concentration reference value at the current time point. Wherein, the flow chart of obtaining the chromium metal concentration reference value at the current time point is as shown in Figure 2

[0061] It should be understood that the higher the chromium metal concentration change trend stability at the time point one time ago, the higher the reliability of the chromium metal concentration obtained according to the chromium metal concentration change trend, and vice versa, so the first reference value obtained by combining the historical chromium metal concentration change curve is needed to obtain the chromium metal concentration reference value.

[0062] S4: obtaining the influence degree of the soil water content at the current time on the measurement result of the chromium metal concentration through experiments; based on the numerical value of the influence degree, combining the chromium metal concentration reference value to correct the collected chromium metal concentration; and based on the corrected chromium metal concentration data, treating the heavy metal contaminated soil.

[0063] The soil water content has different degrees of influence on the measurement result of the chromium metal concentration. When the soil water content is low, it almost has no significant influence on the measurement of chromium elements; while under high water content, the water content will have a certain influence on the measurement result. Therefore, first, the water content of the soil in the detection area needs to be monitored, and the influence degree of the water content on the measurement of chromium elements under different water contents is determined through experiments, so as to set a reasonable influence threshold.​

[0064] First of all, it needs to be pointed out that in the experiment, in order to study the influence of soil moisture content on the measurement of chromium element, different concentrations of chromium nitrate solution prepared will be added in the uncontaminated soil sample. By controlling the content and adding amount of chromium nitrate, soil reference samples with different chromium metal concentrations can be obtained. At the same time, in the same chromium concentration group, the soil moisture content is adjusted to form a moisture content gradient. That is, for each group of soil reference samples with the same chromium metal concentration, the soil moisture content changes in a gradient manner, so as to evaluate the influence of moisture content on the measurement results of chromium element. The present application uses XRF method to detect each soil reference sample with known chromium metal content, and obtains the detected chromium metal concentration. In the experiment, a plurality of groups of soil reference samples with different chromium metal contents but the same moisture content are selected, the average value of the absolute value of the difference between the detected chromium metal concentration and the actual concentration of all soil reference samples is calculated under the same moisture content, and is normalized to obtain the degree of influence of the chromium metal concentration measurement results under the soil moisture content.

[0065] Under the same moisture content, the greater the difference between the XRF measurement results and the actual results in the soil reference samples with different chromium metal concentrations, the greater the influence of the soil moisture content on the measurement results of the chromium metal concentration. Since the soil moisture content has no influence on the measurement of the chromium metal concentration when it is low, the degree of influence of the soil moisture content on the measurement of the chromium metal concentration is analyzed, all the degrees of influence are processed using the Otsu threshold algorithm to obtain a threshold value of the degree of influence, and the value less than the threshold value is marked as not being disturbed, and the marked value P is 0; otherwise, it is marked as being disturbed, and the marked value P is 1; wherein the Otsu threshold algorithm is a known technology, and will not be described herein.

[0066] Therefore, based on the analysis of the detected soil moisture content at the current moment, it is judged whether the degree of influence of the chromium metal concentration at the current moment on the corresponding soil moisture content is marked as P=1, if yes, it means that the measurement result of the current soil chromium metal content is influenced by the soil moisture content, then the soil moisture content and the corresponding moisture content in the experiment are clustered and analyzed to obtain the average value of the degree of influence of the moisture content on the measurement of the chromium metal concentration in the cluster corresponding to the current moisture content, and it is marked as Hc.

[0067] In summary, the obtained chromium metal concentration value is corrected as follows:

[0068]

[0069] wherein, represents the corrected chromium metal concentration at the current moment, represents the chromium metal concentration reference value at the current moment, represents the degree of influence of the moisture content on the measurement result of the chromium metal concentration, Indicates monitoring of the chromium metal concentration at the current time using a spectroscopic device.

[0070] Within each treatment batch, the chromium metal concentration in the soil is monitored, in particular at the end of each batch, according to the monitored chromium metal concentration and the previously experimentally obtained relationship curve between the earthworm release density and the chromium metal concentration, the corresponding earthworm release density is selected for release. The present application sets each treatment batch to be 30 days, and the earthworms are released once every 30 days. It should be noted that before a new round of release, the earthworms previously enriched with chromium metal must be recovered.

[0071] Through the continuous multi-round earthworm-plant combined remediation method, the chromium metal concentration in the soil is gradually reduced, and by monitoring the change of the chromium metal concentration, the earthworm release amount is real-time regulated to ensure the effectiveness and progress of the treatment process.

[0072] It should be noted that the above sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. And the above describes the specific embodiments of the present application. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0073] Each of the embodiments in the present application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments.

[0074] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; the technical solutions recorded in the above-described embodiments are modified, or some technical features are replaced, without changing the essence of the corresponding technical solutions out of the scope of the technical solutions of the embodiments of the present application, which should be included in the protection scope of the present application.

Claims

1. A method for heavy metal soil pollution treatment based on multi-technology combined repair, characterized in that, The method comprises the following steps: Collecting the chromium concentration and soil moisture content at each time point of each round at the preset monitoring point of the heavy metal contaminated soil; Based on the data correlation of the initial chromium concentration of the current and all historical rounds, screening the main reference rounds; analyzing the difference distribution characteristics of the chromium concentration change of the current round and each main reference round to determine the concentration similarity of the current round and each main reference round; based on the numerical size of the concentration similarity, determining the first reference value of the chromium concentration at the current time of the current round; Obtaining the change distribution characteristics and trend characteristics of the chromium concentration at the adjacent time, and combining the first reference value of the chromium concentration to determine the reference value of the chromium concentration at the current time; Obtaining the influence degree of the soil moisture content at the current time on the measurement result of the chromium concentration through experiments; based on the numerical size of the influence degree, combining the reference value of the chromium concentration to correct the collected chromium concentration; based on the corrected chromium concentration data, treating the heavy metal contaminated soil; The correction of the collected chromium concentration based on the reference value of the chromium concentration is specifically: Threshold segmentation processing is performed on all obtained influence degrees to obtain an influence degree threshold, and the marked value P of the influence degree less than the threshold is set to 0; otherwise, the marked value P is set to 1; The specific formula for correction is: wherein, represents the chromium metal concentration corrected at the current time point, represents the chromium metal concentration reference value at the current time point, represents the degree of influence of the soil moisture content on the chromium metal concentration measurement result, represents the monitoring of the chromium metal concentration at the current time point using the spectral device.

2. The heavy metal soil pollution treatment method based on multi-technology combined repair according to claim 1, characterized in that, The screening of the main reference rounds is specifically: clustering the initial chromium concentration of the current and all historical rounds, and taking all historical rounds with the same clustering cluster as the initial chromium concentration of the current round as the main reference rounds.

3. The heavy metal soil pollution treatment method based on multi-technology combined repair according to claim 1, characterized in that, The determination of the concentration similarity of the current round and each main reference round is specifically: Obtaining the chromium concentration content curve of each round; Calculating the absolute value of the difference of the chromium concentration at the corresponding time of the chromium concentration content curve of the current round and each main reference round, obtaining the cumulative sum of all absolute difference values obtained by the current round and each main reference round, and taking the negative correlation mapping result of the cumulative sum as the concentration similarity of the current round and each main reference round.

4. The heavy metal soil pollution treatment method based on multi-technology combined repair according to claim 3, characterized in that, The determination of the first reference value of the chromium concentration at the current time of the current round includes: Taking the chromium concentration content curve of the main reference round with the concentration similarity greater than the preset similarity threshold as the reference curve; Taking the average value of the chromium concentration at the corresponding time of all reference curves at the current time as the first reference value of the chromium concentration at the current time.

5. The heavy metal soil pollution treatment method based on multi-technology combined repair according to claim 1, characterized in that, The determination of the reference value of the chromium concentration at the current time is specifically: Calculating the chromium concentration change amount at each time, threshold segmenting the chromium concentration change amount at all historical times, obtaining the concentration change stability based on the overall distribution characteristics of the segmentation result; Based on the chromium concentration value and the chromium concentration change amount at each time, obtaining the second reference value of the chromium concentration at each time; Taking the concentration change stability as the weight of the second reference value, taking the difference between the natural number 1 and the concentration change stability as the weight of the first reference value, and weightedly summing to obtain the reference value of the chromium concentration at the current time.

6. The heavy metal soil pollution treatment method based on multi-technology combined repair according to claim 5, characterized in that, The chromium metal concentration change amount is determined by a difference between a chromium metal concentration at a previous moment of each moment and a chromium metal concentration at a current moment.

7. The heavy metal soil pollution treatment method based on multi-technology combined repair according to claim 5, characterized in that, The concentration change stability is obtained by: An average of all chromium metal concentration change amounts greater than a chromium metal concentration change threshold in historical moments is taken as a first average, and an average of all chromium metal concentration change amounts less than the chromium metal concentration change threshold is taken as a second average. A difference between the chromium metal concentration change amount at the previous moment of the current moment and the first average is taken as a first difference, and a difference between the chromium metal concentration change amount at the previous moment of the current moment and the second average is taken as a second difference, and a normalized value of a negative mapping result of the second difference and a positive fusion result of the first difference is taken as the concentration change stability at the previous moment of the current moment.

8. The heavy metal soil pollution treatment method based on multi-technology combined repair according to claim 5, characterized in that, The second reference value of the chromium metal concentration at each moment is specifically a difference between a chromium metal concentration at a previous moment of each moment and a chromium metal concentration change amount.

9. The heavy metal soil pollution treatment method based on multi-technology combined repair according to claim 1, characterized in that, The influence degree of the soil water content at the current moment on the chromium metal concentration measurement result is obtained by: The soil water content at the current moment is used to calculate an average of absolute value differences between detected chromium metal concentrations and actual concentrations of all soil reference samples, and normalization is performed to obtain the influence degree of the soil water content at the current moment on the chromium metal concentration measurement result.

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