Method for determining heavy metal content of solid waste powder

Abstract

The application discloses a solid waste powder heavy metal content determination method, relates to the technical field of heavy metal content analysis, and comprises the following steps: S1, pretreatment is carried out on the solid waste powder, chemical reagents are added to a mother liquor preparation reaction tank to perform heavy metal element leaching; specific element color reagents are added, and specific metal complexes of each heavy metal element subjected to fluorescent labeling are obtained; S2, an electrophoresis tank fluorescence detection composite system is used to perform electrophoretic separation on the heavy metal complexes, fluorescence detection is performed, and test index data are acquired; and S3, a specific evaluation method is used to divide a danger grade according to the test index data, and subsequent solid waste powder disposal is guided. The application can quantitatively evaluate the heavy metal content of the solid waste powder and perform visual processing, and simultaneously provides relevant scientific basis and technical support for improving the processing rapid decision-making efficiency and processing rationality of the solid waste powder material on a construction site.

Description

Technical Field

[0001] This invention relates to the field of heavy metal content analysis technology, and in particular to a method for determining the heavy metal content of solid waste powder. Background Technology

[0002] With the acceleration of industrialization and urbanization, the amount of solid waste generated continues to increase, and the heavy metals it contains pose a significant threat to environmental quality and human health. Specifically, heavy metals such as lead, cadmium, copper, and chromium are of great concern due to their high toxicity, persistence, and bioaccumulation. Once these heavy metals enter the soil, water, or atmosphere, they are difficult to degrade naturally and may persist for a long time, leading to potential risks to ecosystem imbalance and human health. Therefore, accurately measuring the heavy metal content in solid waste and developing effective disposal strategies have become important issues in the fields of environmental protection and resource recycling.

[0003] Currently, the determination of heavy metal content in solid waste mainly relies on laboratory analytical methods, such as atomic absorption spectrometry (AAS) and inductively coupled plasma mass spectrometry (ICP-MS). However, existing evaluation methods still have certain problems or shortcomings. First, the current determination methods are too time-consuming, as samples need to be collected and sent to the laboratory for processing and analysis, which cannot meet the needs of rapid decision-making at construction sites. Second, the laboratory equipment relied upon by existing testing methods is expensive and complex to operate, requiring professional technicians, increasing the manpower and technical threshold, and making it difficult to promote in widespread practical applications. Third, existing traditional testing methods for heavy metal content in solid waste powder usually only provide numerical data, making it difficult to intuitively show the distribution of heavy metals, which brings difficulties to the understanding and application of non-professionals, and also cannot meet the needs of rapid decision-making at construction sites. Therefore, there is an urgent need to propose a reasonable and effective method for visual classification and engineering application determination of solid waste, to provide relevant scientific basis and technical support for improving the efficiency and rationality of solid waste powder material treatment decisions at construction sites. Summary of the Invention

[0004] In view of the problems existing in the methods for determining the engineering applications of heavy metals in solid waste, this invention is proposed.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A method for determining the heavy metal content of solid waste powder includes the following steps:

[0007] S1. Pre-treat the solid waste powder, add chemical reagents to the mother liquor preparation reaction tank to leach heavy metal elements; add specific element colorimetric reagents to obtain specific metal complexes of each heavy metal element after fluorescent labeling.

[0008] S2. Electrophoretic separation of heavy metal complexes is performed using an electrophoretic pool fluorescence detection composite system, and fluorescence detection is used to obtain test index data.

[0009] S3. Classify the hazard level based on specific evaluation methods according to test index data to guide the subsequent disposal of solid waste powder;

[0010] As a preferred technical solution of the present invention, in step S1, the electrophoresis pool fluorescence detection composite system includes an electrophoresis device, a fluorescence detection system disposed at the bottom of the electrophoresis pool, and a numerical control unit disposed below the fluorescence detection system.

[0011] The electrophoresis device has a buffer addition and discharge port on the front side wall of its outer wall and an electrophoresis sample cell replacement port on its right side wall. The electrophoresis device includes an electrophoresis sample cell, and positive and negative electrophoresis sample cell electrodes are provided at both ends of the sample cell. The lead wires of the electrophoresis sample cell electrodes are connected to the power supply of the electrophoresis device.

[0012] The fluorescence detection system includes a fluorescently labeled excitation layer and a high-precision fluorescence detection system; the fluorescently labeled excitation layer is disposed at the bottom of the electrophoresis sample cell, and the electrophoresis sample cell and the fluorescently labeled excitation layer are separated by a high-transmittance, water-impermeable layer; the fluorescently labeled excitation layer is connected and disposed above the high-precision fluorescence detection system, which includes multiple high-precision fluorescence detection cameras.

[0013] The numerical control unit is located below the power supply of the fluorescence detection system and the electrophoresis device, and the numerical control unit and the fluorescence detection system are connected by a data transmission conduit.

[0014] As a preferred embodiment of the present invention, the method for pretreating solid waste powder in step S1 includes: sampling solid waste powder using a quartering method; placing a batch of solid waste powder into a vibrating screen and vibrating to mix it evenly; spreading the mixed solid waste powder into a uniformly thick square layer; dividing it into four equal parts using a cross-shaped cutting method; taking two parts from the diagonal and mixing them again; repeating this process until the sample weight is 500-600g.

[0015] The collected solid waste powder was ground. The sample was added to a ball mill, and alumina ceramic balls were selected as the grinding medium. The ball size was 1-5 mm, the ball-to-material ratio was 10:1, the rotation speed was 300-500 rpm / min, and the grinding time was 30-40 min.

[0016] Heavy metal leaching was performed on the ground solid waste powder sample. The leaching reagent was a 3-5 mol / L hydrochloric acid solution, and the leaching time was set to 24 h. After the predetermined leaching time was reached, the leachate was filtered through a 0.45 μm microporous membrane to obtain a high leaching amount solution of heavy metals from the solid waste powder.

[0017] To perform colorimetric treatment on heavy metals in solid waste powder, fluorescently labeled heavy metal complex ligands were added to a high-leaching solution of heavy metals from the solid waste powder. The specific reagents used were as follows:

[0018] Cu was specifically complexed and labeled using 5 mmol / L 1,10-phenanthroline reagent at an excitation wavelength of 370 nm and an emission wavelength of 520 nm.

[0019] Pb was specifically complexed and labeled using 1 μmol / L Leadmium Green reagent at an excitation wavelength of 490 nm and an emission wavelength of 520 nm.

[0020] Cd was specifically complexed and labeled using 5 μmol / L Cadmium-specific fluorophore at an excitation wavelength of 488 nm and an emission wavelength of 520 nm.

[0021] Cr was specifically complexed and labeled using 1 mmol / L Alizarin Red S at an excitation wavelength of 430 nm and an emission wavelength of 560 nm.

[0022] After mixing the ligand reagents, add the solid waste powder heavy metal high leaching solution and incubate for 40-60 min to ensure complete complexation of heavy metal elements; after the complexation is completed, the sample solution is subjected to SPE solid phase extraction to separate the excess ligands from the heavy metal complex.

[0023] The specific technical parameters for solid-phase extraction were selected as follows: cation exchange resin was selected as the adsorbent, methanol was selected as the activation pretreatment reagent, and 2% HCl solution was used as the elution solvent; the sample loading flow rate was limited to 1~2 ml / min during solid-phase extraction; the eluent was collected and then concentrated by heating to obtain the solid waste powder heavy metal electrophoresis sample solution.

[0024] As a preferred embodiment of the present invention, step S2, which involves electrophoretic separation of heavy metal complexes using an electrophoretic pool fluorescence detection composite system, specifically comprises:

[0025] The collected solid waste powder heavy metal electrophoresis sample solution was added to the electrophoresis pool of the composite system for gel electrophoresis. A 15% polyacrylamide gel was used as the gel; phosphate buffer (PBS) was used as the buffer; the pH was adjusted to 5.5-6.0 using 0.1% HCl; the electrophoresis voltage was set to 100-120V; and the electrophoresis time was set to 30-60 minutes. The electrophoresis pool contained two lanes. The solid waste powder heavy metal electrophoresis sample solution was injected into the first lane, and an equal volume of heavy metal standard solution was injected into the second lane. This solution was a standard solution containing the maximum heavy metal content allowed by environmental regulations, prepared by titration with a precisely known concentration. The heavy metal standard solution contained four heavy metal elements: Cu, Pb, Cd, and Cr, and was treated with the same fluorescent ligand complexation labeling as the solid waste powder heavy metal electrophoresis sample solution before electrophoretic separation began.

[0026] In step S2, obtaining the test index data specifically involves: after reaching the preset electrophoresis time, turning off the power, turning on the fluorescence imaging device of the composite system to detect the specific complexes of the metal, and obtaining the length L of each band in the electrophoretic pattern. ij After background correction to remove non-specific fluorescence signals, the fluorescence signal intensity Q of each band was recorded. ij , where i is the lane number, i=1,2; j is the color band number, j=1,2,3,4; the test index data is imported into ImageJ image analysis software, and the fluorescence intensity distribution map of the heavy metal leaching data of the first lane and the fluorescence intensity distribution map of the heavy metal standard data of the second lane are plotted with length as the x-axis and fluorescence intensity as the y-axis respectively.

[0027] As a preferred embodiment of the present invention, in step S3, classifying the hazard level based on a specific evaluation method according to the test index data specifically involves: using image processing software to integrate the fluorescence intensity distribution map of the heavy metal standard data, and defining the result as heavy metal standard data m. 标准j The integration limit is the length L of each strip. 2j Integrating is performed separately for different elements corresponding to different bands; similarly, integration is performed on the fluorescence intensity distribution map of heavy metal leaching data, and the result is defined as obtaining the heavy metal leaching data m. 1j , where j is the nth color band, j=1,2,3,4;

[0028] Define the difference M in heavy metal leaching data j The specific calculation formula is as follows:

[0029]

[0030] Where: M j The difference in heavy metal leaching data; m1j This represents the heavy metal leaching data for the j-th band in the first lane; m 标准j Here are the heavy metal standard data for the j-th band in lane 2; where j = 1, 2, 3, 4.

[0031] Define the environmental concentration difference of heavy metals C j C j With M j The specific relationship to satisfy is:

[0032] Table 1 Conversion Table for Environmental Concentration Differences of Heavy Metals

[0033]

[0034] The key feature of hazard level classification is the calculation of the comprehensive evaluation index HI, and the specific formula for its calculation is as follows:

[0035]

[0036] Where: HI is the hazard index; C j R represents the environmental difference in heavy metals. j Let R be the hazard level coefficient of the j-th element. j The hazard levels of each heavy metal element are set according to the content requirements of various elements in the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard" GB15618-2018 and the "Drinking Water Hygiene Standard" GB5749-2022. The specific values ​​are shown in Table 2, where j=1,2,3,4.

[0037] Table 2 Reference Table for Hazard Levels of Various Heavy Metal Elements

[0038]

[0039] Based on the Hazard Index (HI), guidance is provided for the subsequent treatment of solid waste powder, specifically as follows:

[0040] (1) HI<100: Suitable for resource utilization;

[0041] (2) 100≤HI<300: More suitable, but requires careful evaluation;

[0042] (3) 300≤HI<400: Not very suitable, the processing solution needs to be improved;

[0043] (4) HI≥400: Not suitable for resource utilization and requires safe treatment.

[0044] Compared with existing technologies, this invention has the following advantages: it enables more accurate and scientific quantitative evaluation and analysis of the heavy metal content classification and visualization of solid waste powder at the particle scale; it can simultaneously determine multiple different heavy metal elements in solid waste powder and visualize the heavy metal content, simplifying the analysis results; and it introduces new evaluation indicators based on traditional evaluation methods, considering various influencing factors, providing relevant scientific basis and technical support for improving the efficiency of rapid decision-making and the rationality of solid waste powder treatment at construction sites. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0046] Figure 1 Flowchart of the method for determining the heavy metal content of solid waste powder.

[0047] Figure 2 Overall diagram of a visual classification test device for heavy metal content in solid waste powder.

[0048] Figure 3 Cross-sectional view of a visual classification test device for heavy metal content in solid waste powder.

[0049] Figure 4 This is a fluorescence intensity distribution map of heavy metal leaching data.

[0050] Figure 5 This is a fluorescence intensity distribution map of heavy metal standard data.

[0051] In the diagram: 1. Electrophoresis apparatus; 2. Fluorescence detection system; 3. Electrophoresis sample cell; 4. Electrophoresis sample cell electrode; 5. Electrophoresis apparatus power supply; 6. Fluorescent labeling excitation layer; 7. High-precision fluorescence detection system; 8. High-transmittance waterproof layer; 9. High-precision fluorescence detection camera; 10. Data transmission conduit; 11. Electrophoresis sample cell replacement port; 12. Buffer solution addition and discharge port; 13. Numerical control unit. Detailed Implementation

[0052] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0053] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0054] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0055] This invention is described in detail with reference to the schematic diagrams. When describing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0056] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0058] A method for determining the heavy metal content of solid waste powder is disclosed. The powder sample used is fly ash from the grate furnace of a waste incineration plant in Zhongshan City. The main combustible material is municipal solid waste, with a particle size range of 4-45 μm and a density range of 1.0-3.0 g / cm³. 3 .

[0059] Reference Figures 1-5 This is the first embodiment of the present invention, which provides a method for determining the heavy metal content of solid waste powder, including the following steps:

[0060] S1. Solid waste powder is sampled using the quartering method. A batch of solid waste powder is placed in a vibrating screen and mixed evenly. The mixed solid waste powder is spread into a square thin layer of uniform thickness and divided into four equal parts using a cross-shaped cutting method. Two parts from the diagonal are taken and mixed again. This process is repeated until the sample weight is 600g.

[0061] The collected solid waste powder was ground. The sample was added to a ball mill, and alumina ceramic balls were selected as the grinding medium. The ball size was 5 mm, the ball-to-material ratio was 10:1, the rotation speed was 400 rpm / min, and the grinding time was 40 min.

[0062] Heavy metal leaching was performed on the ground solid waste powder sample. The leaching reagent was a 3-5 mol / L hydrochloric acid solution, and the leaching time was set to 24 h. After the predetermined leaching time was reached, the leachate was filtered through a 0.45 μm microporous membrane to obtain a high leaching amount solution of heavy metals from the solid waste powder.

[0063] To perform colorimetric treatment on heavy metals in solid waste powder, fluorescently labeled heavy metal complex ligands were added to a high-leaching solution of heavy metals from the solid waste powder. The specific reagents used were as follows:

[0064] Cu was specifically labeled using 5 mmol / L 1,10-phenanthroline reagent; Pb was specifically labeled using 1 μmol / L Leadmium Green reagent; Cd was specifically labeled using 5 μmol / L Cadmium-specific fluorophore; and Cr was specifically labeled using 1 mmol / L Alizarin Red S.

[0065] After mixing the ligand reagents, a high leaching solution of heavy metals from solid waste powder was added and incubated for 60 min to ensure complete complexation of the heavy metal elements. After the complex was incubated, the sample solution was subjected to SPE solid-phase extraction to separate the excess ligands from the heavy metal complex.

[0066] The specific technical parameters for solid-phase extraction were as follows: cation exchange resin was selected as the adsorbent, methanol was selected as the activation pretreatment reagent, and 2% HCl solution was used as the elution solvent; the sample loading flow rate was limited to 1 ml / min during solid-phase extraction; the collected eluent was then heated and concentrated to finally obtain 10 ml of solid waste powder heavy metal electrophoresis sample solution.

[0067] S2. The electrophoretic separation of heavy metal complexes using an electrophoretic pool fluorescence detection composite system is as follows: The collected solid waste powder heavy metal electrophoresis sample solution is added to the electrophoretic pool of the composite system for gel electrophoresis. The gel used is 15% polyacrylamide gel; the buffer is phosphate buffered saline (PBS); the pH is adjusted using 0.1% HCl to the range of [5.5, 6.0]; the electrophoresis voltage is set to 120V; the electrophoresis time is set to 40min; the electrophoresis pool contains two lanes. 10ml of solid waste powder heavy metal electrophoresis sample solution is injected into the first lane, and an equal amount of 10ml of heavy metal standard content solution is injected into the second lane. This solution is the standard solution with the maximum heavy metal content allowed by environmental regulations, prepared by titration with a precisely known concentration. The heavy metal standard content solution contains four heavy metal elements: Cu, Pb, Cd, and Cr, and is treated with the same fluorescent ligand complexation labeling as the solid waste powder heavy metal electrophoresis sample solution, and then electrophoretic separation begins.

[0068] After the preset electrophoresis time is reached, the power is turned off, and the fluorescence imaging device of the composite system is turned on to detect the specific metal complexes and obtain the length L of each band in the electrophoretic pattern. ij After background correction to remove non-specific fluorescence signals, the fluorescence signal intensity Q of each band was recorded. ij Where i is the lane number, i=1,2; j is the color band number, j=1,2,3,4; the test index data is imported into ImageJ image analysis software, and fluorescence intensity distribution maps of heavy metal leaching data in the first lane and heavy metal standard data in the second lane are plotted with length as the x-axis and fluorescence intensity as the y-axis respectively.

[0069] S3. Based on the test index data, a specific evaluation method is used to classify the hazard level. The fluorescence intensity distribution map of the heavy metal standard data is integrated to obtain the result of the heavy metal standard data m. 标准j As shown in Table 5, the fluorescence intensity distribution map of the heavy metal leaching data was integrated to obtain the heavy metal leaching data m. 1j As shown in Table 6, where j represents the nth color band, j=1,2,3,4:

[0070] Table 5: Heavy Metal Standard Data

[0071]

[0072] Table 6: Heavy Metal Leaching Data

[0073]

[0074] Calculate the difference M in heavy metal leaching data j The environmental concentration difference of heavy metals, C, was obtained through conversion. j The specific results are shown in Table 7:

[0075] Table 7: Conversion Results of Heavy Metal Environmental Concentration Difference

[0076]

[0077] Taking all parameters into account, the hazard index HI is calculated, and the specific calculation results are shown in Table 8:

[0078] Table 8: Calculation Results of Hazard Index

[0079]

[0080] In this embodiment, based on the hazard index calculation results, the hazard index of this batch of solid waste powder is 372.05, which falls within the range of 300≤HI<400. Therefore, it is classified as not very suitable for engineering use and requires improved treatment methods, based on the heavy metal environmental concentration difference C. j It is known that the concentration of Pb and Cd elements in this batch of solid waste powder materials needs to be reduced.

[0081] In summary, this method enables more accurate and scientific quantitative evaluation and analysis of heavy metal content classification in solid waste powder at the particle scale. Furthermore, it can simultaneously determine multiple heavy metal elements in solid waste powder and visualize their content, simplifying the analysis results. Moreover, it introduces new evaluation indicators based on traditional methods, considering various influencing factors, providing relevant scientific basis and technical support for improving the efficiency and rationality of on-site treatment of solid waste powder materials.

[0082] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for determining the heavy metal content of solid waste powder, characterized in that: Includes the following steps, S1. Pre-treat the solid waste powder, add chemical reagents to the mother liquor preparation reaction tank to leach heavy metal elements; add specific element colorimetric reagents, specifically: use 1,10-phenanthroline reagent to label Cu, use Leadmium Green reagent to label Pb, use Cadmium-specific fluorophore to label Cd, and use Alizarin Red S to label Cr, thereby obtaining fluorescently labeled specific metal complexes of each heavy metal element; S2. Electrophoretic separation of heavy metal complexes is performed using an electrophoretic pool fluorescence detection composite system, and fluorescence detection is used to obtain test index data. S3. Classify the hazard level based on specific evaluation methods according to test index data to guide the subsequent disposal of solid waste powder; The electrophoresis pool fluorescence detection composite system described in S2 includes an electrophoresis device (1), a fluorescence detection system (2) installed at the bottom of the electrophoresis pool, and a numerical control unit (13) installed below the fluorescence detection system. The electrophoresis device (1) has a buffer addition and discharge port (12) on the front side wall of its outer wall and an electrophoresis sample cell replacement port (11) on its right side wall. The electrophoresis device (1) includes an electrophoresis sample cell (3). Positive and negative electrophoresis sample cell electrodes (4) are provided at both ends of the sample cell. The electrophoresis sample cell electrodes (4) are connected to the power supply (5) of the electrophoresis device by lead wires. The fluorescence detection system (2) includes a fluorescent labeling excitation layer (6) and a high-precision fluorescence detection system (7); the fluorescent labeling excitation layer (6) is disposed at the bottom of the electrophoresis sample cell (3), and the electrophoresis sample cell (3) and the fluorescent labeling excitation layer (6) are separated by a high-transmittance waterproof layer (8); the fluorescent labeling excitation layer (6) is connected and disposed above the high-precision fluorescence detection system (7), and the high-precision fluorescence detection system (7) includes multiple high-precision fluorescence detection cameras (9); The numerical control unit (13) is located below the power supply (5) of the fluorescence detection system (2) and the electrophoresis device. The numerical control unit (13) and the fluorescence detection system (2) are connected by a data transmission conduit (10).

2. The method for determining the heavy metal content of solid waste powder according to claim 1, characterized in that: In step S1, the method for pretreating solid waste powder includes: sampling solid waste powder using the quartering method; placing a batch of solid waste powder into a vibrating screen and vibrating to mix it evenly; spreading the mixed solid waste powder into a uniform square thin layer; dividing it into four equal parts using a cross-cutting method; taking two parts from the diagonal and mixing them again; repeating this process until the sample weight is 500~600g. The collected solid waste powder was ground. The sample was added to a ball mill, and alumina ceramic balls were selected as the grinding medium. The ball size was 1-5 mm, the ball-to-material ratio was 10:1, the rotation speed was 300-500 rpm / min, and the grinding time was 30-40 min. Heavy metal leaching was performed on the ground solid waste powder sample. The leaching reagent was a 3-5 mol / L hydrochloric acid solution, and the leaching time was set to 24 h. After the predetermined leaching time was reached, the leachate was filtered through a 0.45 μm microporous membrane to obtain a high leaching amount solution of heavy metals from the solid waste powder. To perform colorimetric treatment on heavy metals in solid waste powder, fluorescently labeled heavy metal complex ligands were added to a high-leaching solution of heavy metals from the solid waste powder. The specific reagents used were as follows: Cu was specifically complexed and labeled using 5 mmol / L 1,10-phenanthroline reagent at an excitation wavelength of 370 nm and an emission wavelength of 520 nm. Pb was specifically complexed and labeled using 1 μmol / L Leadmium Green reagent at an excitation wavelength of 490 nm and an emission wavelength of 520 nm. Cd was specifically complexed and labeled using 5 μmol / L Cadmium-specific fluorophore at an excitation wavelength of 488 nm and an emission wavelength of 520 nm. Cr was specifically complexed and labeled using 1 mmol / L Alizarin Red S at an excitation wavelength of 430 nm and an emission wavelength of 560 nm. After mixing the ligand reagents, add the solid waste powder heavy metal high leaching solution and incubate for 40-60 min to ensure complete complexation of heavy metal elements; after the complexation is completed, the sample solution is subjected to SPE solid phase extraction to separate the excess ligands from the heavy metal complex. The specific technical parameters for solid-phase extraction were selected as follows: cation exchange resin was selected as the adsorbent, methanol was selected as the activation pretreatment reagent, and 2% HCl solution was used as the elution solvent; the sample loading flow rate was limited to 1~2 ml / min during solid-phase extraction; the collected eluent was then heated and concentrated to obtain the solid waste powder heavy metal electrophoresis sample solution.

3. The method for determining the heavy metal content of solid waste powder according to claim 1, characterized in that: In step S2, the electrophoretic separation of heavy metal complexes using an electrophoretic pool fluorescence detection composite system specifically involves: The collected solid waste powder heavy metal electrophoresis sample solution was added to the electrophoresis pool of the composite system for gel electrophoresis. A 15% polyacrylamide gel was used as the gel; phosphate buffer (PBS) was used as the buffer; the pH was adjusted to 5.5-6.0 using 0.1% HCl; the electrophoresis voltage was set to 100-120V; and the electrophoresis time was set to 30-60 minutes. The electrophoresis pool contained two lanes. The solid waste powder heavy metal electrophoresis sample solution was injected into the first lane, and an equal volume of heavy metal standard solution was injected into the second lane. This solution was a standard solution containing the maximum heavy metal content allowed by environmental regulations, prepared by titration with a precisely known concentration. The heavy metal standard solution contained four heavy metal elements: Cu, Pb, Cd, and Cr, and was treated with the same fluorescent ligand complexation labeling as the solid waste powder heavy metal electrophoresis sample solution before electrophoretic separation began. In step S2, obtaining the test index data specifically involves: after reaching the preset electrophoresis time, turning off the power, turning on the fluorescence imaging device of the composite system to detect the specific complexes of the metal, and obtaining the length L of each band in the electrophoretic pattern. ij After background correction to remove non-specific fluorescence signals, the fluorescence signal intensity Q of each band was recorded. ij Where i is the lane number, i=1,2; j is the color band number, j=1,2,3,4; the test index data is imported into ImageJ image analysis software, and fluorescence intensity distribution maps of heavy metal leaching data in the first lane and heavy metal standard data in the second lane are plotted with length as the x-axis and fluorescence intensity as the y-axis respectively.

4. The method for determining the heavy metal content of solid waste powder according to claim 1, characterized in that: In step S3, classifying the hazard level based on a specific evaluation method using test index data specifically involves: using image processing software to integrate the fluorescence intensity distribution map of heavy metal standard data, and defining the result as heavy metal standard data m. 标准j The integration limit is the length L of each strip. 2j Integrating is performed separately for different elements corresponding to different bands; similarly, integration is performed on the fluorescence intensity distribution map of heavy metal leaching data, and the result is defined as obtaining the heavy metal leaching data m. 1j , where j is the nth color band, j=1,2,3,4; Define the difference M in heavy metal leaching data j The specific calculation formula is as follows: ； Where: M j The difference in heavy metal leaching data; m 1j This represents the heavy metal leaching data for the j-th band in the first lane; m 标准j Here are the heavy metal standard data for the j-th band in lane 2; where j = 1, 2, 3, 4. Define the environmental concentration difference of heavy metals C j C j With M j The specific relationship to satisfy is: Table 1. Conversion Table for Heavy Metal Environmental Concentration Differences: ； The key feature of hazard level classification is the calculation of the comprehensive evaluation index HI, and the specific formula for its calculation is as follows: ； Where: HI is the hazard index; C j R represents the environmental difference in heavy metals. j R is the hazard level coefficient of the j-th element. j The hazard levels of each heavy metal element are set according to the content requirements of various elements in the "Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard" GB15618-2018 and the "Drinking Water Hygiene Standard" GB5749-2022. The specific values ​​are shown in Table 2, where j=1,2,3,4. Table 2. Reference Table for Hazard Levels of Various Heavy Metal Elements: ； Based on the Hazard Index (HI), guidance is provided for the subsequent treatment of solid waste powder, specifically as follows: (1) HI<100: Suitable for resource utilization; (2) 100≤HI<300: More suitable, but requires careful evaluation; (3) 300≤HI<400: Not very suitable, the processing solution needs to be improved; (4) HI≥400: Not suitable for resource utilization and requires safe treatment.

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