A soil heavy metal adsorption repair agent based on waste biomass

Abstract

The application provides a soil heavy metal adsorption repair agent based on waste biomass and belongs to the technical field of soil heavy metal repair.The soil heavy metal adsorption repair agent comprises, by weight fraction, 50-80 parts of biomass electric field ash, 10-25 parts of vermiculite powder, 8-16 parts of amino acid, 0.2-0.8 parts of ferrous sulfide, 10-20 parts of sodium alginate, 2-5 parts of a binder and 300-500 parts of water.The soil heavy metal adsorption repair agent prepared from the biomass electric field ash as the main component has a remarkable adsorption effect on heavy metal elements such as lead, chromium, mercury and arsenic in the soil, can increase the pH of the soil, improve the content of elements such as calcium, magnesium, potassium and sodium in the soil, promote the growth and development of crops, and has the advantages of simple preparation method, easy operation, and suitability for large-scale popularization and application.

Description

Technical Field

[0001] This invention belongs to the field of soil heavy metal remediation technology, and particularly relates to a soil heavy metal adsorption and remediation agent based on waste biomass. Background Technology

[0002] Soil is a precious natural resource; without it, humans cannot survive. Excessive heavy metal content alters the soil environment and structure, leading to decreased crop yield and quality. Furthermore, heavy metals can migrate through the soil and crops and be absorbed by humans, seriously threatening human health.

[0003] Due to human activities, soil pollution problems in agricultural, industrial, and urban areas have become increasingly serious in recent decades. Soil heavy metal remediation mainly involves two mechanisms: (1) removing harmful substances from the soil and reducing the total concentration of heavy metals; and (2) altering the migration rate and bioavailability of heavy metals in the soil to reduce the degree of pollution. According to the soil remediation mechanism, the remediation process can be divided into physical remediation, chemical remediation, and bioremediation. Physical remediation involves covering highly polluted soil with clean, unpolluted soil to reduce the heavy metal content per unit volume. Bioremediation mainly refers to using plants and their root microorganisms to remove, degrade, or fix pollutants in the soil. The principles mainly include plant stabilization, extraction, transformation, volatilization, and root filtration. Although the above two remediation technologies are simple and easy to operate, they cannot fundamentally purify the soil and remove heavy metals.

[0004] Compared to physical and bioremediation, chemical remediation is widely used due to its higher efficiency and faster processing speed. Chemical remediation often involves adding heavy metal adsorbents to the soil. Currently, the adsorption properties of materials such as wood ash, fly ash, biochar, sepiolite, and red mud have been studied and applied to the preparation of adsorbents. Studies have shown that fly ash has good adsorption performance for heavy metals such as copper, cadmium, and lead in soil. However, wood ash has a higher potassium and calcium content, and compared to fly ash, it has stronger alkalinity and heavy metal adsorption capacity, making it more suitable for preparing heavy metal adsorbents. However, both fly ash and wood ash still contain high levels of heavy metals, and improper use may exacerbate the heavy metal pollution level in the soil. Therefore, it is essential to develop a new type of soil heavy metal adsorbent that is safe, does not cause secondary pollution to the soil, has strong adsorption capacity, and is simple to prepare. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a soil heavy metal adsorption and remediation agent based on waste biomass.

[0006] One of the technical solutions of the present invention:

[0007] A soil heavy metal adsorption and remediation agent based on waste biomass, comprising the following raw materials by weight: 50-80 parts of biomass electric field ash, 10-25 parts of vermiculite powder, 8-16 parts of amino acids, 0.2-0.8 parts of ferrous sulfide, 10-20 parts of sodium alginate, 2-5 parts of binder, and 300-500 parts of water.

[0008] Further, by weight, it includes the following raw materials: 66 parts biomass electric field ash, 18 parts vermiculite powder, 9 parts amino acids, 0.4 parts ferrous sulfide, 13 parts sodium alginate, 4 parts binder, and 352 parts water.

[0009] Furthermore, the present invention uses the ash residue from the waste biomass power plant as the bottom ash produced during the combustion power generation process. It is mainly composed of elements such as Ca, Si, Al, Mg, K, and Na, and has extremely low heavy metal content, including lead content ≤0.18‰, cadmium content ≤0.05‰, arsenic content ≤0.28‰, chromium content ≤1.54‰, and mercury content = 0.

[0010] Biomass electric field ash is alkaline and features a large specific surface area, high porosity, low content of harmful substances, and strong adsorption. The soil heavy metal adsorption and remediation agent of this invention uses biomass electric field ash as the main component. After the adsorption and remediation agent is applied to soil contaminated with heavy metals, it can not only effectively adsorb heavy metals, but also increase the soil pH, increase the content of transferable elements such as K, Ca, and Mg, and increase the content of elements such as calcium, magnesium, potassium, and sodium in the soil, thereby promoting the transfer of nutrients to the roots of planted plants and promoting crop growth and development.

[0011] Furthermore, the amino acid includes one or more of serine, threonine, or tyrosine.

[0012] Furthermore, the adhesive comprises one or more of polystyrene, polyacrylate, or polyurethane.

[0013] Furthermore, the vermiculite powder has a particle size of 100-300 nm.

[0014] The second technical solution of the present invention:

[0015] A method for preparing the aforementioned soil heavy metal adsorption and remediation agent based on waste biomass includes the following steps:

[0016] (1) Dry the biomass electric field ash residue and then crush it;

[0017] (2) Weigh the raw materials according to the specified weight proportions and set aside;

[0018] (3) Take 1 / 4 part by weight of water, add sodium alginate, amino acids and ferrous sulfide in sequence, stir evenly, add potassium persulfate, and continue stirring to obtain a composite solution.

[0019] (4) Mix the biomass electric field ash and vermiculite powder evenly, add the remaining weight of water and binder to obtain a mixed solution;

[0020] (5) Add the mixed solution dropwise to the composite solution while stirring, let it stand, and take the precipitate;

[0021] (6) Wash the precipitate and dry it to obtain the soil heavy metal adsorption and remediation agent.

[0022] Further, in step (1), the biomass electric field ash is dried at 200-320℃ for 40-80 min and then pulverized to 0.2-30 μm.

[0023] Further, in step (2), the amount of potassium persulfate added is 2-5% of the mass of sodium alginate, and after adding potassium persulfate, the mixture is stirred and reacted at 30-50°C for 12-20 hours.

[0024] Furthermore, in step (6), the drying temperature is 100-150℃ and the time is 3-6h.

[0025] The biomass electric field ash residue of this invention is dried and pulverized before use, which further increases its surface porosity, forming interconnected pores and increasing its adsorption capacity for heavy metals. During the mixing process with vermiculite powder, the vermiculite powder enters the pore structure of the biomass electric field ash residue, providing support for the pores of the particles.

[0026] In this invention, sodium alginate, amino acids, and ferrous sulfide are mixed during the preparation process. Under the action of potassium persulfate, the amino and hydroxyl functional groups of the amino acids can form a cross-linked network structure with sodium alginate. Sodium alginate itself can act as an adsorbent and remediation agent to adsorb heavy metals. During the mixing of the composite solution and the mixed solution, some biomass electric field ash and vermiculite powder enter the interior of the network structure, which on the one hand increases the adsorption time of the adsorbent and remediation agent, and on the other hand, the adsorbed heavy metals are effectively fixed. At the same time, ferrous sulfide is uniformly distributed on the network structure. Utilizing its high solubility, it displaces heavy metals from the soil and, combined with the affinity of the hydroxyl and amino groups on the surface of the network structure for heavy metals, fixes the heavy metals on the interpenetrating network. Furthermore, the addition of sodium alginate in this invention not only plays a role in adsorbing heavy metals, but also plays an important role in the immobilization of the heavy metal bio-adsorbent and remediation agent prepared in this invention.

[0027] The third technical solution of the present invention:

[0028] The application of the aforementioned soil heavy metal adsorption and remediation agent in the remediation of soil heavy metal pollution.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] (1) The present invention uses the waste biomass electric field ash generated during the combustion power generation process as the main component. The raw material source is abundant, turning waste into treasure, improving the soil environment and promoting crop growth, while not causing secondary pollution to the soil.

[0031] (2) The soil heavy metal adsorption and remediation agent prepared by the present invention can have a significant adsorption effect on heavy metal elements such as lead, chromium, mercury and arsenic in the soil. Moreover, the preparation method is simple and easy to operate, and is suitable for large-scale promotion and application. Detailed Implementation

[0032] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0033] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0034] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0035] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0036] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0037] This invention proposes a soil heavy metal adsorption and remediation agent based on waste biomass. All raw materials used are commercially available. The soil heavy metal adsorption and remediation agent comprises the following raw materials by weight: 50-80 parts of biomass electric field ash, 10-25 parts of vermiculite powder, 8-16 parts of amino acids, 0.2-0.8 parts of ferrous sulfide, 10-20 parts of sodium alginate, 2-5 parts of binder, and 300-500 parts of water.

[0038] In some preferred embodiments of the present invention, the raw materials include the following by weight: 66 parts of biomass electric field ash, 18 parts of vermiculite powder, 9 parts of amino acids, 0.4 parts of ferrous sulfide, 13 parts of sodium alginate, 4 parts of binder, and 352 parts of water.

[0039] In some preferred embodiments of the present invention, the biomass power plant ash used is sourced from a biomass power plant in Anhui Province. It is the bottom ash produced during the combustion power generation process. Tests show that it is mainly composed of elements such as Ca, Si, Al, Mg, K, and Na. Furthermore, the heavy metal content is extremely low, with lead content ≤0.18‰, cadmium content ≤0.05‰, arsenic content ≤0.28‰, chromium content ≤1.54‰, mercury content = 0, and it is alkaline (pH = 9.65) with a density of 2.2 g / mL.

[0040] In some preferred embodiments of the present invention, the amino acids used include one or more of serine, threonine or tyrosine. All of the above amino acids contain hydroxyl and amino groups and are purchased from Henan Yiduoyuan Biotechnology Co., Ltd.

[0041] In some preferred embodiments of the present invention, the adhesive used includes one or more of polystyrene, polyacrylate, or polyurethane.

[0042] In some preferred embodiments of the present invention, the particle size of the vermiculite powder used is 100-300 nm.

[0043] This invention also proposes a method for preparing the aforementioned soil heavy metal adsorption and remediation agent based on waste biomass, comprising the following steps:

[0044] (1) Dry the biomass electric field ash residue and then crush it;

[0045] (2) Weigh the raw materials according to the specified weight proportions and set aside;

[0046] (3) Take 1 / 4 part by weight of water, add sodium alginate, amino acids and ferrous sulfide in sequence, stir evenly, add potassium persulfate, and continue stirring to obtain a composite solution.

[0047] (4) Mix the biomass electric field ash and vermiculite powder evenly, add the remaining weight of water and binder to obtain a mixed solution;

[0048] (5) Add the mixed solution dropwise to the composite solution while stirring, let it stand, and take the precipitate;

[0049] (6) Wash the precipitate and dry it to obtain the soil heavy metal adsorption and remediation agent.

[0050] Before use, the biomass electric field ash residue is dried and crushed to further increase its surface porosity, form interconnected pores, and increase its adsorption capacity for heavy metals. The drying temperature, time, and particle size of the crushed residue have a direct impact on its adsorption performance. Based on the above principles, in some preferred embodiments of the present invention, step (1) involves drying the biomass electric field ash residue at 200-320℃ for 40-80 minutes and then crushing it to 0.2-30μm.

[0051] Potassium persulfate is used to initiate the formation of a cross-linked network structure between amino acids and sodium alginate. In some preferred embodiments of the present invention, the amount of potassium persulfate added in step (2) is 2-5% of the mass of sodium alginate. After adding potassium persulfate, the mixture is stirred and reacted at 30-50°C for 12-20 hours.

[0052] If the drying time is too long or the temperature is too high, it will damage the structure of the adsorption repair agent. If the time is too short or the temperature is too low, it will reduce the degree of curing of the adsorption repair agent. Based on the above principles, in the preferred embodiment of the present invention, the drying temperature in step (6) is 100-150℃ and the time is 3-6h.

[0053] In this embodiment of the invention, room temperature refers to 25±2℃.

[0054] The technical solution of the present invention will be further illustrated by the following embodiments.

[0055] Example 1

[0056] (1) The biomass electric field ash residue was dried at 280℃ for 60 min and then pulverized to 22 μm;

[0057] (2) Weigh the raw materials according to the following weight proportions: 66 parts of biomass electric field ash, 18 parts of vermiculite powder (particle size of 220nm), 9 parts of amino acid (tyrosine), 0.4 parts of ferrous sulfide, 13 parts of sodium alginate, 4 parts of binder (polystyrene) and 352 parts of water.

[0058] (3) Take 1 / 4 part by weight of water and put it into a mixing tank. Add sodium alginate, amino acids and ferrous sulfide in sequence. Stir at room temperature and 1000 r / min for 10 min. After stirring evenly, add 4% by weight of potassium persulfate of sodium alginate and continue stirring for 10 min to obtain a composite solution.

[0059] (4) Mix the biomass electric field ash and vermiculite powder evenly, add the remaining weight of water and binder, and stir for 5 minutes to obtain a mixed solution;

[0060] (5) Add the mixed solution dropwise to the composite solution at a rate of 5 mL / min while stirring. Let it stand for 20 min and then collect the precipitate.

[0061] (6) Wash the precipitate with water and dry it at 130℃ for 4 hours to obtain the soil heavy metal adsorption and remediation agent.

[0062] Example 2

[0063] (1) The biomass electric field ash residue was dried at 320℃ for 40 min and then pulverized to 30 μm;

[0064] (2) Weigh the raw materials according to the following weight proportions: 80 parts of biomass electric field ash, 10 parts of vermiculite powder (particle size of 300nm), 8 parts of amino acid (serine), 0.8 parts of ferrous sulfide, 20 parts of sodium alginate, 2 parts of binder (polystyrene) and 500 parts of water.

[0065] (3) Take 1 / 4 part by weight of water and put it into a mixing tank. Add sodium alginate, amino acids and ferrous sulfide in sequence. Stir at room temperature and 1000 r / min for 10 min. After stirring evenly, add 5% by weight of potassium persulfate of sodium alginate and continue stirring for 10 min to obtain a composite solution.

[0066] (4) Mix the biomass electric field ash and vermiculite powder evenly, add the remaining weight of water and binder, and stir for 5 minutes to obtain a mixed solution;

[0067] (5) Add the mixed solution dropwise to the composite solution at a rate of 5 mL / min while stirring. Let it stand for 20 min and then collect the precipitate.

[0068] (6) Wash the precipitate with water and dry it at 150℃ for 3 hours to obtain the soil heavy metal adsorption and remediation agent.

[0069] Example 3

[0070] (1) The biomass electric field ash residue was dried at 200℃ for 80 min and then pulverized to 0.2 μm;

[0071] (2) Weigh the raw materials according to the following weight proportions: 50 parts of biomass electric field ash, 25 parts of vermiculite powder (particle size of 100nm), 16 parts of amino acid (threonine), 0.2 parts of ferrous sulfide, 10 parts of sodium alginate, 5 parts of binder (polyacrylate) and 300 parts of water.

[0072] (3) Take 1 / 4 part by weight of water and put it into a mixing tank. Add sodium alginate, amino acids and ferrous sulfide in sequence. Stir at room temperature and 1000 r / min for 10 min. After stirring evenly, add 2% by weight of potassium persulfate of sodium alginate and continue stirring for 10 min to obtain a composite solution.

[0073] (4) Mix the biomass electric field ash and vermiculite powder evenly, add the remaining weight of water and binder, and stir for 5 minutes to obtain a mixed solution;

[0074] (5) Add the mixed solution dropwise to the composite solution at a rate of 5 mL / min while stirring. Let it stand for 20 min and then collect the precipitate.

[0075] (6) Wash the precipitate with water and dry it at 100℃ for 6 hours to obtain the soil heavy metal adsorption and remediation agent.

[0076] Example 4

[0077] (1) The biomass electric field ash residue was dried at 220℃ for 50 min and then pulverized to 0.5 μm;

[0078] (2) Weigh the raw materials according to the following weight proportions: 66 parts of biomass electric field ash, 18 parts of vermiculite powder (particle size of 180nm), 10 parts of amino acid (tyrosine), 0.6 parts of ferrous sulfide, 11 parts of sodium alginate, 4 parts of binder (polyurethane) and 360 parts of water.

[0079] (3) Take 1 / 4 part by weight of water and put it into a mixing tank. Add sodium alginate, amino acids and ferrous sulfide in sequence. Stir at room temperature and 1000 r / min for 10 min. After stirring evenly, add 3% by weight of potassium persulfate of sodium alginate and continue stirring for 10 min to obtain a composite solution.

[0080] (4) Mix the biomass electric field ash and vermiculite powder evenly, add the remaining weight of water and binder, and stir for 5 minutes to obtain a mixed solution;

[0081] (5) Add the mixed solution dropwise to the composite solution at a rate of 5 mL / min while stirring. Let it stand for 20 min and then collect the precipitate.

[0082] (6) Wash the precipitate with water and dry it at 130℃ for 5 hours to obtain the soil heavy metal adsorption and remediation agent.

[0083] Comparative Example 1

[0084] Same as Example 1, except that step (1) is omitted.

[0085] Comparative Example 2

[0086] Same as Example 1, except that the biomass electric field ash residue is replaced by the same weight of plant ash (commercially available, pH=8.12).

[0087] Comparative Example 3

[0088] Same as Example 1, except that the biomass electric field ash was dried at 100°C for 50 minutes and then pulverized to 22μm.

[0089] Comparative Example 4

[0090] Same as Example 1, except that in step (6), the product is dried at 200°C for 7 hours.

[0091] Comparative Example 5

[0092] Same as Example 1, except that the addition of vermiculite powder is omitted.

[0093] Comparative Example 6

[0094] Same as Example 1, except that the raw materials are weighed in the following proportions by weight: 40 parts of biomass electric field ash, 35 parts of vermiculite powder (particle size 220nm), 6 parts of amino acid (tyrosine), 1 part of ferrous sulfide, 8 parts of sodium alginate, 3 parts of binder (polystyrene) and 300 parts of water.

[0095] Performance testing

[0096] I. Effects of Adsorption Remediation Agents on the Content of Available Heavy Metals and pH in Soil

[0097] Land near an industrial park that is contaminated with heavy metals was selected and divided into 10 equal plots, each 25m². 2 In September, the adsorption remediation agents prepared in Examples 1-4 and Comparative Examples 1-6 were uniformly applied to the soil surface at an application rate of 80 kg / mu. The soil was then tilled to ensure uniform mixing of the adsorption remediation agents with the soil. After 30 days of equilibrium adsorption, the available content of heavy metals and pH in each soil plot were determined according to DB61 / T 1162-2018. The results are shown in Table 1.

[0098] Table 1. Available heavy metal content and pH of each soil sample

[0099]

[0100]

[0101] As shown in Table 1, the adsorption remediation agent prepared in the embodiments of the present invention can improve the acidic environment of the soil and reduce the content of available heavy metals in the soil. The results of the comparative examples show that changing the dosage and preparation parameters all reduce the adsorption performance, indicating that the performance of the adsorption remediation agent of the present invention is closely related to the preparation process, and that the raw materials used have complementary and synergistic effects.

[0102] II. Planting Experiment

[0103] In testing the effects of the adsorption remediation agent on the heavy metal content and pH of the soil, after uniformly applying the adsorption remediation agents prepared in Examples 1-4 and Comparative Examples 1-6 to the soil surface in September, 10 plots were plowed and leveled, and alfalfa was planted. The sowing rate was 7 kg per hectare, with a row spacing of 16 cm. The alfalfa was harvested 45 days after sowing, leaving a stubble of no less than 5 cm. A blank control was set up, and alfalfa was planted in completely uncontaminated soil. The planting process was the same as above. The yield of the first crop of alfalfa was statistically analyzed, and the results are shown in Table 2.

[0104] Table 2 Production Statistics Results

[0105] Alfalfa yield (kg / mu) Blank control 663 Example 1 650 Example 2 632 Example 3 601 Example 4 624 Comparative Example 1 445 Comparative Example 2 406 Comparative Example 3 398 Comparative Example 4 325 Comparative Example 5 433 Comparative Example 6 457

[0106] As shown in Table 2, applying the heavy metal adsorbent and remediation agent prepared in this embodiment of the invention to heavy metal-contaminated soil can significantly increase the first-crop yield of alfalfa, basically on par with the blank control. This is because this invention uses biomass power plant ash as the main component, which not only effectively adsorbs heavy metals but also raises the soil pH to alkalinity, increasing the content of available phosphorus and potassium in the soil. Furthermore, it utilizes the cross-linked network structure formed by amino acids and sodium alginate to fix heavy metals on the interpenetrating network, achieving effective removal of heavy metals from the soil, improving the soil environment, and promoting crop growth. In contrast, comparative examples 1-6, by omitting the use of biomass power plant ash and changing the drying temperature during the preparation process, damage the structure of the adsorbent material, thereby reducing its heavy metal adsorption performance and hindering plant growth.

[0107] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A soil heavy metal adsorption and remediation agent based on waste biomass, characterized in that, By weight, it consists of the following raw materials: 50-80 parts of biomass electric field ash, 10-25 parts of vermiculite powder, 8-16 parts of amino acids, 0.2-0.8 parts of ferrous sulfide, 10-20 parts of sodium alginate, 2-5 parts of binder, and 300-500 parts of water. The vermiculite powder has a particle size of 100-300 nm; The amino acid includes one or more of serine, threonine, or tyrosine. The biomass electric field ash residue contains ≤0.18‰ lead, ≤0.05‰ cadmium, ≤0.28‰ arsenic, ≤1.54‰ chromium, and 0% mercury. The preparation method of the soil heavy metal adsorption and remediation agent based on waste biomass includes the following steps: (1) Dry the biomass electric field ash residue and then crush it; (2) Weigh the raw materials according to the specified weight proportions and set aside; (3) Take 1 / 4 part by weight of water, add sodium alginate, amino acids and ferrous sulfide in sequence, stir evenly, add potassium persulfate, and continue stirring to obtain a composite solution. (4) Mix the biomass electric field ash and vermiculite powder evenly, add the remaining weight of water and binder to obtain a mixed solution; (5) Add the mixed solution dropwise to the composite solution while stirring, let it stand, and take the precipitate; (6) Wash the precipitate and dry it to obtain the soil heavy metal adsorption and remediation agent; In step (1), the biomass electric field ash is dried at 200-320℃ for 40-80 min and then pulverized to 0.2-30 μm; In step (6), the drying temperature is 100-150℃ and the time is 3-6h.

2. The soil heavy metal adsorption and remediation agent based on waste biomass according to claim 1, characterized in that, By weight, it includes the following raw materials: 66 parts biomass electric field ash, 18 parts vermiculite powder, 9 parts amino acids, 0.4 parts ferrous sulfide, 13 parts sodium alginate, 4 parts binder, and 352 parts water.

3. The soil heavy metal adsorption and remediation agent based on waste biomass according to claim 1, characterized in that, The adhesive includes one or more of polystyrene, polyacrylate, or polyurethane.

4. The soil heavy metal adsorption and remediation agent based on waste biomass according to claim 1, characterized in that, In step (2), the amount of potassium persulfate added is 2-5% of the mass of sodium alginate. After adding potassium persulfate, the mixture is stirred and reacted at 30-50℃ for 12-20 hours.

5. The application of the soil heavy metal adsorption and remediation agent according to any one of claims 1-4 in the remediation of soil heavy metal pollution.

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