A method for determining the landfill age of stockpiled waste based on humus composition

Abstract

The present invention discloses a method for determining the landfill age of stockpiled waste based on humus composition, which relates to the technical field of environmental protection. The method for determining the landfill age of stockpiled waste based on humus composition disclosed by the present invention includes the following steps: drilling and sampling the stockpiled waste; performing pre-treatments such as air-drying, screening, and impurity removal on the samples; measuring the humus composition and its content to obtain the carbon content of humic acid; measuring the three-dimensional fluorescence of the leaching solution of humic acid extracted from humus soil and performing parallel factor analysis to obtain the total fluorescence intensity of humic acid-like substances therein; fitting the unit fluorescence index F<subgt;u< / subgt; with the landfill age in the form of an exponential function; and then performing statistical analysis on the unit fluorescence index F<subgt;u< / subgt> and the landfill age. The method for determining the landfill age of stockpiled waste based on humus composition and its three-dimensional fluorescence intensity provided by the present invention is fast and simple, and can intuitively determine the stabilization degree and landfill age of the stockpiled waste in the landfill.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection, especially the determination of the stability degree and exploitation conditions of stockpiled waste, and particularly relates to a method for determining the landfill age of stockpiled waste based on the humus composition. Background Art

[0002] At present, China has stored nearly 8 billion tons of stockpiled waste, with great potential for resource utilization. However, since the stockpiled waste consists of waste with different landfill ages, there are significant differences in its stability degree, and most of the landfill ages are unclear, making it difficult to intuitively determine the degree of stabilization, thus hindering its resource utilization. Therefore, studying the transformation law of substances in the stockpiled waste in landfills and seeking effective fitting indicators to represent the landfill age of landfills and stockpiled waste is of crucial significance for judging the stability degree of stockpiled waste and further resource utilization.

[0003] Regarding the characterization of the stabilization process of landfills, many related studies have been done by scholars, but there is still no unified set of analysis and evaluation indicators. Some studies analyze the content indicators of four components, namely organic matter, total sugar, crude fiber, and biodegradable substances, in waste with different landfill ages in large landfills to evaluate the stabilization process of landfills. There are also studies that analyze the humus composition and molecular weight changes of landfilled waste with different landfill ages in landfills, and use the extractability, HA / FA, and molecular weight dispersion degree of the humus in landfilled waste to characterize the stability degree of landfilled waste. It can be seen that the change of biodegradable organic components in landfilled waste during the landfill process is an important way to represent the stabilization process of landfills.

[0004] Currently, there are no relevant patents on the determination models and methods for landfill age, and the literature is only limited to the research on the stabilization process of landfills and the characterization of the stability degree of landfilled waste. The present invention is the first to create a quantitative model for determining the landfill age of stockpiled waste in landfills. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for determining the landfill age of stockpiled waste based on the humus composition, which is fast, simple, and can intuitively determine the stabilization degree and landfill age of the stockpiled waste in landfills.

[0006] To achieve the purpose of the present invention, the present invention provides a method for determining the landfill age of stockpiled waste based on the humus composition, including the following specific steps:

[0007] S1. Drill samples from the stockpiled waste;

[0008] S2. Air-dry, screen, and remove impurities from the obtained samples to obtain humus soil, then grind the humus soil and pass it through a 10-mesh sieve, a 50-mesh sieve, and a 100-mesh sieve in sequence;

[0009] S3. Measure the humus composition and its content of the sieved humus soil above to obtain the carbon content of humic acid in the humus soil;

[0010] S4. Extract humic acid from the sieved humus soil above to obtain a humic acid leaching solution, then measure the three-dimensional fluorescence data of the humic acid leaching solution and perform parallel factor analysis to obtain the total fluorescence intensity of humic acid-like substances;

[0011] S5. Fit the unit fluorescence index F u with the landfill age in the form of an exponential function;

[0012] S6. Perform statistical analysis on the above unit fluorescence index F u and the landfill age.

[0013] Further, the landfill age of the stockpiled waste is 7 to 30 years.

[0014] Further, the method for drilling and sampling is as follows: For stockpiled waste with different landfill ages, drill 3 times respectively at a depth of 5 m to obtain the required samples.

[0015] Further, in step S3, the humus composition is fulvic acid, humic acid, and humin, and the method for measuring the humus composition and its content is the sodium pyrophosphate extraction - potassium dichromate oxidation - external heating method.

[0016] Further, in step S3, the carbon content of the humic acid refers to the total carbon content of fulvic acid and humic acid.

[0017] Further, the unit fluorescence index F u is the unit fluorescence intensity in the humus soil of different landfill years, with the unit of R.U. / mg.

[0018] Further, the calculation formula of the unit fluorescence index F u is as follows:

[0019]

[0020] where FI HS represents the total three-dimensional fluorescence intensity of humic acid-like substances in the humic acid extraction solution, with the unit of R.U.; n represents the dilution factor when measuring the three-dimensional fluorescence of the humic acid extraction solution; C HS represents the carbon content of humic acid in the humus soil, with the unit of g / kg; m represents the mass of the pretreated humus soil added when preparing the humic acid extraction solution, with the unit of g.

[0021] Further, in step S5, the fitting of the unit fluorescence index F uThe method of fitting with the landfill age includes the following steps:

[0022] P1. Taking 18 years of landfill age as the demarcation point, perform piecewise fitting;

[0023] P2. When the landfill age is less than or equal to 18 years, the value of the unit fluorescence index F u increases exponentially with the increase of the landfill years. The fitting exponential function is y = 1325e 0.0996x , and R 2 is 0.9822;

[0024] P3. When the landfill age is greater than or equal to 18 years, the value of the unit fluorescence index F u decreases exponentially with the increase of the landfill years. The fitting exponential function is y = 60350e -0.106x , and R 2 is 0.9316.

[0025] Furthermore, in the step S6, the statistical analysis is Pearson correlation analysis, that is: when the landfill age is less than or equal to 18 years, the two are significantly positively correlated; when the landfill age is greater than or equal to 18 years, the two are significantly negatively correlated.

[0026] The present invention has achieved the following beneficial effects:

[0027] 1. The present invention defines a new index, namely the unit fluorescence index F u , and establishes a set of landfill years fitting models, which can effectively fit the quantitative relationship between the humus soil in the stockpiled waste and the landfill age.

[0028] 2. The determination method of the present invention is fast, simple, and can intuitively determine the stabilization degree of the stockpiled waste in the landfill and the landfill years, which is of crucial significance for subsequent mining and further resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a fitting model diagram of the quantitative relationship between the unit fluorescence F u and the landfill age in an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The following describes the specific embodiments of the present invention in detail. All the features disclosed in this specification, or all the steps in any method or process disclosed, except for mutually exclusive features and / or steps, can be combined in any manner. Specific Embodiment

[0032] A method for determining the landfill years of stockpiled waste based on the humus composition and its three-dimensional fluorescence intensity includes the following steps:

[0033] S1. Drill and sample the stockpiled waste with a landfill age of 7 to 30 years, specifically including the stockpiled waste with landfill ages of 7, 13, 16, 18, 22, 27, and 30 years. To ensure the representativeness of samples with different landfill ages and the comparability between samples, three samples are taken at the same depth of 5 m for each age.

[0034] S2. Sample pretreatment: Air-dry, screen, and remove impurities from the samples. The humus soil after screening and impurity removal is ground and passed through 10-mesh, 50-mesh, and 100-mesh sieves in sequence.

[0035] S3. Use the sodium pyrophosphate extraction - potassium dichromate oxidation - external heating method to determine the composition and content of humus in the pretreated humus soil, that is: determine the composition and content of fulvic acid, humic acid, and humin, and then obtain the carbon content of humic acid in the humus soil, that is: the total carbon content of fulvic acid and humic acid.

[0036] S4. Extract humic acid from the sieved humus soil (that is, during the process of using the sodium pyrophosphate extraction - potassium dichromate oxidation - external heating method to determine the composition and content of humus, humic acid has been extracted), obtain the humic acid leaching solution, then measure the three-dimensional fluorescence data of the humic acid leaching solution and perform parallel factor analysis to obtain three effective fluorescence components (C1, C2, and C3, where C1 is fulvic acid-like substance, C2 is humic acid-like substance, and C3 is protein-like), and obtain the total fluorescence intensity of the humic acid-like substance, that is, the sum of the fluorescence intensities of C1 and C2.

[0037] S5. Define a unit fluorescence index F u , with the unit of R.U. / mg, to characterize the unit fluorescence intensity in humus soil with different landfill ages.

[0038] The calculation formula for the unit fluorescence index F u is as follows:

[0039]

[0040] where FI HS represents the total three-dimensional fluorescence intensity of humic acid-like substances in the humic acid extraction solution, with the unit of R.U.; n represents the dilution factor when measuring the three-dimensional fluorescence of the humic acid extraction solution; C HS represents the carbon content of humic acid in the humus soil, with the unit of g / kg; m represents the mass of the pretreated humus soil added when preparing the humic acid extraction solution, with the unit of g.

[0041] S6. Fit the unit fluorescence index F u with the landfill age in the form of an exponential function.

[0042] The fitting method includes the following steps:

[0043] P1. By analyzing the fluorescence intensity distribution of each fluorescence component of humic acid in humic soil samples with different landfill ages, it is found that the fluorescence intensity values of the three components C1, C2, and C3 all show a trend of first increasing and then decreasing with the increase of landfill age, and all reach their peaks when the landfill age is about 18 years. At the same time, through the analysis of the humification index (HIX) in the three-dimensional fluorescence parameters, it is found that it has the same variation characteristics as the fluorescence intensity of the above-mentioned components. Therefore, taking 18 years of landfill age as the demarcation point, the unit fluorescence index F u is segmented and fitted with the landfill age in the form of an exponential function.

[0044] P2. When the landfill age ≤ 18 years, the value of the unit fluorescence index F u increases exponentially with the increase of landfill age, and the fitted exponential function is y = 1325e 0.0996x , where R 2 is 0.9822. Among them, y is the unit fluorescence index F u , x is the landfill age, as shown in Figure 1 .

[0045] P3. When the landfill age ≥ 18 years, the value of the unit fluorescence index F u decreases exponentially with the increase of landfill age, and the fitted exponential function is y = 60350e -0.106x , where R 2 is 0.9316. Among them, y is the unit fluorescence index F u , x is the landfill age, as shown in Figure 1 .

[0046] S7. Statistical analysis is carried out on the unit fluorescence index F u and the landfill age.

[0047] This statistical analysis uses Pearson correlation analysis, that is: when the landfill age ≤ 18 years, R = 0.96, p < 0.05 (where R is the correlation coefficient and p is the probability. In statistics, according to the significance test method, the p-value obtained is generally considered significant when p < 0.05 and very significant when p < 0.01), indicating that there is a significant positive correlation between the two (the unit fluorescence index F u and the landfill age) within this range; when the landfill age ≥ 18 years, R = -0.97, p < 0.05, indicating that there is a significant negative correlation between the two (the unit fluorescence index F u and the landfill age) within this range.

[0048] The above-described embodiments only represent the specific implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for determining the landfill age of stockpiled waste based on the humus composition, characterized in that, It includes the following specific steps: S1. Drill samples from the stockpiled waste; S2. Air-dry, screen, and remove impurities from the obtained samples to obtain humus soil, then grind the humus soil and pass it through a 10-mesh sieve, a 50-mesh sieve, and a 100-mesh sieve in sequence; S3. Determine the composition and content of humus in the sieved humus soil to obtain the carbon content of humic acid in the humus soil; S4. Extract humic acid from the sieved humus soil to obtain a humic acid leaching solution, then measure the three-dimensional fluorescence data of the humic acid leaching solution and perform parallel factor analysis to obtain the total fluorescence intensity of humic acid-like substances; S5. Fit the unit fluorescence index F in the form of an exponential function to the landfill age, where the unit fluorescence index F u is the unit fluorescence intensity in humus soil with different landfill years, with the unit of R.U. / mg, and its calculation formula is: u Among them, FI represents the total three-dimensional fluorescence intensity of humic acid-like substances in the humic acid extract, with the unit of R.U.; n represents the dilution factor when measuring the three-dimensional fluorescence of the humic acid extract; C HS represents the carbon content of humic acid in humus soil, with the unit of g / kg; m represents the mass of pretreated humus soil added when preparing the humic acid extract, with the unit of g; HS ​ S6. Statistically analyze the above-mentioned unit fluorescence index F u and the landfill age.

2. The method for determining the landfill age of stockpiled waste based on the humus composition according to claim 1, wherein The landfill age of the stockpiled waste is 7 to 30 years.

3. The method for determining the landfill age of stockpiled waste based on the humus composition according to claim 1, characterized in that The method for drilling samples is as follows: For stockpiled waste with different landfill ages, drill 3 times at a depth of 5 m respectively to obtain the required samples.

4. The method for determining the landfill age of stockpiled waste based on the humus composition according to claim 1, wherein In step S3, the humus composition is fulvic acid, humic acid, and humin, and the method for determining the humus composition and its content is the sodium pyrophosphate extraction - potassium dichromate oxidation - external heating method.

5. The method for determining the landfill age of stockpiled waste based on the humus composition according to claim 1, characterized in that, In step S3, the carbon content of the humic acid refers to the total carbon content of fulvic acid and humic acid.

6. The method for determining the landfill age of stockpiled waste based on the humus composition according to claim 1, wherein In the step S5, the method of fitting the unit fluorescence index F u with the landfill age in the form of an exponential function includes the following steps: P1. Take 18 years of landfill age as the demarcation point for piecewise fitting; P2. When the landfill age is less than or equal to 18 years, the value of the unit fluorescence index F u increases exponentially with the increase of landfill years, and the fitted exponential function is y = 1325e 0.0996x , and R 2 is 0.9822; P3. When the landfill age is greater than or equal to 18 years, the value of the unit fluorescence index F u decreases exponentially with the increase of landfill years, and the fitted exponential function is y = 60350e -0.106x , and R 2 is 0.9316.

7. The method for determining the landfill age of stockpiled waste based on the humus composition according to claim 1, characterized in that In step S6, the statistical analysis is Pearson correlation analysis, that is: when the landfill age is less than or equal to 18 years, the two are significantly positively correlated; when the landfill age is greater than or equal to 18 years, the two are significantly negatively correlated.

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