Soil remediation improver and soil remediation improvement method

Abstract

The present application relates to the technical field of soil remediation, and in particular to a soil remediation modifier and a soil remediation modification method.The soil remediation modifier is crosslinked by intercalation modified bentonite, vinyl grafted nanocellulose and N,N'-methylene bisacrylamide, wherein the intercalation modified bentonite is modified by synergistic modification of white horehound betaine and dimethyl allyl amine chloride; the vinyl grafted nanocellulose is prepared by acyl chloride alkylation reaction, and forms a chemical crosslinking network with the intercalation bentonite.The present application realizes multifunctional integrated repair of water retention, sand fixation, heavy metal passivation and plant promotion through the synergistic effect of multiple components, has the advantages of environmental friendliness, long-term stability, strong adaptability and the like, and is suitable for desertification control and ecological restoration of contaminated soil.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil remediation, in particular to a soil remediation modifier and a soil remediation modification method. BACKGROUND

[0002] With the increasingly serious global soil degradation problem, salinization and heavy metal pollution have become key factors restricting the sustainable development of agriculture. Traditional soil improvement techniques have bottlenecks such as single function, short duration, and poor environmental compatibility. In the field of saline-alkali soil treatment, existing modifiers mostly use gypsum, organic fertilizer and other materials, which can adjust soil pH value in the short term, but cannot solve the problem of fast water evaporation and surface crust leading to plant root hypoxia. Conventional sand fixation agents (such as polyacrylamide) are easily degraded under high temperature and high salt conditions, and lack ecological coordination. For heavy metal pollution, the current mainstream technologies include chemical stabilization (such as phosphate passivation) and microbial remediation, but the former easily causes secondary pollution due to phosphorus enrichment, and the latter is difficult to be applied on a large scale due to environmental adaptability.

[0003] Patent technology document CN111040769B discloses a soil remediation modifier and a soil remediation modification method. The soil remediation modifier of the application has low cost, good heavy metal solidification and stabilization effect, and is suitable for large-scale application. The soil remediation modification method of the application is simple to operate and has good remediation effect. Patent technology document CN115537206A discloses a saline-alkali soil remediation modifier and a preparation method thereof. The application method of the soil remediation modifier is to spray it on the ground before ploughing or watering or before a heavy rain, or to apply it to the soil through drip irrigation, which can effectively improve soil salinization.

[0004] However, the above-mentioned modifier is too single and one-sided, therefore, it is urgent to develop a new type of soil remediation modifier to improve and repair the land with both salinization and heavy metal pollution SUMMARY

[0005] Therefore, the present application aims to provide a soil remediation modifier and a soil remediation modification method to improve and repair the land with both salinization and heavy metal pollution.

[0006] To achieve the above purpose, the present application provides a soil remediation modifier, which is obtained by intercalation modification bentonite, vinyl grafted nanocellulose and N,N'-methylene bisacrylamide crosslinking; the weight ratio of the intercalation modification bentonite, the vinyl grafted nanocellulose and the N,N'-methylene bisacrylamide is 0.5-1:0.3-0.5:3-5.

[0007] Preferably, the intercalation modified bentonite is obtained by intercalation modification of bentonite by resveratrol betaine and dimethyl diallyl amine based ammonium chloride; the weight ratio of the resveratrol betaine, dimethyl diallyl amine based ammonium chloride and bentonite is 2-4:3-5:10-12.

[0008] The size of the bentonite is 0.5-1mm.

[0009] Preferably, the resveratrol betaine is obtained by reaction of the hydroxyl group of resveratrol and the acyl chloride group of chlorobetaine acyl chloride; the weight ratio of resveratrol and chlorobetaine acyl chloride is 2-3:3.5-5.

[0010] Preferably, the preparation method of the vinyl grafted nanocellulose is as follows:

[0011] (1) the nanocellulose is acyl chlorinated by thionyl chloride to obtain acyl chlorinated cellulose;

[0012] (2) the acyl chloride group of the acyl chlorinated cellulose reacts with the amino group of allyl amine to obtain the vinyl grafted nanocellulose.

[0013] Preferably, the amount ratio of the nanocellulose and thionyl chloride in step (1) is 10-12g:20-30mL.

[0014] Preferably, the amount ratio of the acyl chlorinated cellulose and allyl amine in step (2) is 8-10g:15-20mL.

[0015] Preferably, the size of the nanocellulose in step (1) is 50-200nm.

[0016] Further, the application also provides a soil improvement and remediation method, comprising the following steps: mixing the soil improvement and remediation agent with deionized water according to a weight ratio of 1:50, and spraying 3-4L / m 2 to the soil to be improved, and curing for 10-30d.

[0017] The beneficial effects of the application are:

[0018] The soil improvement and remediation agent of the application realizes the organic unity of multiple functions such as water conservation and sand fixation, heavy metal passivation and plant growth promotion, and exhibits significant technical advantages in the field of saline-alkalized and heavy metal composite contaminated soil remediation.

[0019] The present application constructs a complex interlayer structure with rigid skeleton and flexible segment by combining natural active ingredients with intercalation modification of bentonite, and the introduction of active ingredients provides dual action sites of coordination and electrostatic adsorption for heavy metal ions, which significantly improves the fixation efficiency of heavy metals. In addition, the synergistic effect of this structure and nanocellulose further strengthens the formation of three-dimensional network, making the repair agent show persistent stability in sand fixation and water retention performance.

[0020] The present application solves the agglomeration problem of bentonite and cellulose in traditional repair agents due to interface incompatibility by intercalation modification of bentonite and alkenylation treatment of nanocellulose. The modified bentonite and nanocellulose form a homogeneous dispersion system through chemical bonding and physical adsorption. This uniform dispersion structure not only enhances the mechanical strength of the repair agent, but also constructs a dynamic hydrogen bond network, thereby significantly improving the water retention capacity and wind erosion resistance.

[0021] The present application uses naturally derived resveratrol and nanocellulose as core components, avoiding the potential toxicity of traditional chemical repair agents to soil microorganisms and plants, and not causing harmful effects on the natural growth of plants. The synergistic effect between components reduces the bioavailability of heavy metals, and at the same time provides a suitable microenvironment for plant roots, thereby significantly improving the germination rate and growth vigor of plants. DETAILED DESCRIPTION

[0022] To make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below with specific examples.

[0023] Example 1: A soil improvement repair agent, the specific preparation steps are as follows:

[0024] (1) Mix 2g resveratrol, 2.1g triethylamine, 20mL tetrahydrofuran and 20mL N,N-dimethylformamide, stir uniformly to obtain a mixed solution; then disperse 3.5g chlorobenzyl chloride in 20mL tetrahydrofuran, disperse uniformly, then slowly add to the mixed solution, keep at room temperature for 4h, after the reaction is completed, rotary evaporation to obtain resveratrol betaine;

[0025] (2) Disperse 10g bentonite in 400mL deionized water, ultrasonic treatment for 30min, then add 50mL NaCl solution, stir at 60℃ for 12h, centrifuge, wash to obtain activated bentonite; dissolve 2g resveratrol betaine and 3g dimethyl diallyl amine chloride in deionized water, add activated bentonite, stir at 70℃ under nitrogen atmosphere for 6h, centrifuge the obtained product, wash the precipitate with ethanol / water (1:1) for 3 times, finally vacuum freeze-dry to obtain intercalation modified bentonite;

[0026] (3) Under the atmosphere of nitrogen, 10 g of nanocellulose was placed in a dry reaction kettle, 100 mL of anhydrous N,N-dimethylformamide, 20 mL of thionyl chloride were added, mixed and stirred for 30 min, then warmed to 40°C for 12 h, the reaction liquid was poured into ice ether for precipitation, suction filtration, and washed with tetrahydrofuran, and vacuum dried at 40°C for 6 h to obtain acyl chloride cellulose;

[0027] (4) Under the light-free environment, 8 g of acyl chloride cellulose was dispersed in 200 mL of anhydrous N,N-dimethylformamide, then 15 mL of allylamine and 1 g of triethylamine were added dropwise into the reaction system, and reacted at room temperature for 40 h. The reaction liquid was centrifuged, and the obtained precipitate was washed with tetrahydrofuran and methanol in turn, and finally vacuum dried at 35°C for 24 h to obtain vinyl grafted nanocellulose.

[0028] (5) 90 mL of deionized water, 0.5 g of intercalation modified bentonite, 3 g of N,N'-methylene bisacrylamide, 0.3 g of vinyl grafted nanocellulose and 0.5 g of ammonium persulfate were mixed, and after reaction at 70°C for 4 h, a soil remediation modifier was obtained.

[0029] Example 2: A soil improvement and remediation agent, the specific preparation steps are as follows:

[0030] (1) 2.5 g of oridonin, 2.3 g of triethylamine, 23 mL of tetrahydrofuran and 23 mL of N,N-dimethylformamide were mixed to obtain a mixed solution; then 4 g of choline chloride acyl chloride was dispersed in 25 mL of tetrahydrofuran, and slowly added to the mixed solution after uniform dispersion, kept at room temperature for 5 h, and after the reaction was completed, oridonin choline was obtained by rotary evaporation.

[0031] (2) 11 g of bentonite was dispersed in 430 mL of deionized water, ultrasonic treated for 30 min, then 50 mL of NaCl solution was added, stirred at 60°C for 12 h, centrifuged and washed to obtain activated bentonite; 3 g of oridonin choline and 4 g of dimethyl diallyl amine chloride were dissolved in deionized water, and the activated bentonite was added, stirred at 70°C under the atmosphere of nitrogen for 6 h, the obtained product was centrifuged, the precipitate was washed with ethanol / water (1:1) for 3 times, and finally vacuum freeze-dried to obtain intercalation modified bentonite.

[0032] (3) Under the atmosphere of nitrogen, 11 g of nanocellulose was placed in a dry reaction kettle, 110 mL of anhydrous N,N-dimethylformamide, 25 mL of thionyl chloride were added, mixed and stirred for 30 min, then warmed to 43°C for 12 h, the reaction liquid was poured into ice ether for precipitation, suction filtration, and washed with tetrahydrofuran, and vacuum dried at 40°C for 6 h to obtain acyl chloride cellulose.

[0033] (4) In the dark environment, 9 g of acyl chloride cellulose was dispersed in 200 mL of anhydrous N,N-dimethylformamide, then 18 mL of allylamine and 1.1 g of triethylamine were added dropwise into the reaction system, and reacted at room temperature for 45 h. The reaction solution was centrifuged, and the obtained precipitate was washed with tetrahydrofuran and methanol in turn, and finally dried at 35°C under vacuum for 24 h to obtain the vinyl grafted nanocellulose;

[0034] (5) 95 mL of deionized water, 0.8 g of intercalation modified bentonite, 4 g of N,N'-methylene bisacrylamide, 0.4 g of vinyl grafted nanocellulose and 1 g of ammonium persulfate were mixed, and after reacting at 70°C for 4 h, a soil remediation modifier was obtained.

[0035] Example 3: A soil improvement and remediation agent, the specific preparation steps are as follows:

[0036] (1) 3 g of oridonin, 2.5 g of triethylamine, 25 mL of tetrahydrofuran and 25 mL of N,N-dimethylformamide were mixed to obtain a mixed solution; then 5 g of choline chloride acyl chloride was dispersed in 30 mL of tetrahydrofuran, and then slowly added into the mixed solution, and kept at room temperature for 5 h. After the reaction was completed, oridonin choline was obtained by rotary evaporation;

[0037] (2) 12 g of bentonite was dispersed in 450 mL of deionized water, and ultrasonic treatment was carried out for 30 min, then 50 mL of NaCl solution was added, and stirred at 60°C for 12 h. After centrifugation and washing, the activated bentonite was obtained. 4 g of oridonin choline and 5 g of dimethyl diallyl amine chloride were dissolved in deionized water, and the activated bentonite was added. Stirring was carried out at 70°C under nitrogen atmosphere for 6 h. The obtained product was centrifuged, the precipitate was washed with ethanol / water (1:1) for 3 times, and finally vacuum freeze-dried to obtain the intercalation modified bentonite;

[0038] (3) Under the nitrogen atmosphere, 12 g of nanocellulose was placed in a dry reaction kettle, 110 mL of anhydrous N,N-dimethylformamide and 30 mL of thionyl chloride were added, mixed and stirred for 30 min, then the temperature was raised to 45°C and reacted for 12 h. The reaction solution was poured into ice ether for precipitation, suction filtration, washed with tetrahydrofuran, and dried at 40°C under vacuum for 6 h to obtain acyl chloride cellulose;

[0039] (4) In the dark environment, 10 g of acyl chloride cellulose was dispersed in 200 mL of anhydrous N,N-dimethylformamide, then 20 mL of allylamine and 1.2 g of triethylamine were added dropwise into the reaction system, and reacted at room temperature for 50 h. The reaction solution was centrifuged, and the obtained precipitate was washed with tetrahydrofuran and methanol in turn, and finally dried at 35°C under vacuum for 24 h to obtain the vinyl grafted nanocellulose;

[0040] (5) 100 mL of deionized water, 1 g of intercalated modified bentonite, 5 g of N,N'-methylene bisacrylamide, 0.5 g of vinyl grafted nanocellulose, and 1.5 g of ammonium persulfate were mixed, and after reaction at 70°C for 4 h, a soil remediation modifier was obtained.

[0041] Comparative Example 1: The difference from Example 2 is that resveratrol is replaced by phenol, and the remaining steps are the same as Example 2. The specific preparation steps are as follows:

[0042] (1) 2.5 g of phenol, 2.3 g of triethylamine, 23 mL of tetrahydrofuran, and 23 mL of N,N-dimethylformamide were mixed to obtain a mixed solution; then 4 g of betaine chloride was dispersed in 25 mL of tetrahydrofuran, and after uniform dispersion, it was slowly added to the mixed solution, and kept at room temperature for 5 h. After the reaction was completed, the benzobetaine was obtained by rotary evaporation.

[0043] (2) 11 g of bentonite was dispersed in 430 mL of deionized water and ultrasonically treated for 30 min, then 50 mL of NaCl solution was added, and stirred at 60°C for 12 h. After centrifugation and washing, the activated bentonite was obtained. 3 g of benzobetaine and 4 g of dimethyl diallyl amine chloride were dissolved in deionized water, and the activated bentonite was added. Stirring was carried out at 70°C for 6 h under nitrogen atmosphere. The product was centrifuged, the precipitate was washed with ethanol / water (1:1) for 3 times, and finally vacuum freeze-dried to obtain the intercalated modified bentonite.

[0044] (3) Under a nitrogen atmosphere, 11 g of nanocellulose was placed in a dry reaction kettle, 110 mL of anhydrous N,N-dimethylformamide and 25 mL of thionyl chloride were added, mixed and stirred for 30 min, then the temperature was raised to 43°C and reacted for 12 h. The reaction liquid was poured into ice ether for precipitation, suction filtration, washed with tetrahydrofuran, and vacuum dried at 40°C for 6 h to obtain acyl chloride cellulose.

[0045] (4) In a dark environment, 9 g of acyl chloride cellulose was dispersed in 200 mL of anhydrous N,N-dimethylformamide, then 18 mL of allylamine and 1.1 g of triethylamine were added dropwise to the reaction system, and the reaction was carried out at room temperature for 45 h. The reaction liquid was centrifuged, the precipitate was washed with tetrahydrofuran and methanol in turn, and finally vacuum dried at 35°C for 24 h to obtain the vinyl grafted nanocellulose.

[0046] (5) 95 mL of deionized water, 0.8 g of intercalated modified bentonite, 4 g of N,N'-methylene bisacrylamide, 0.4 g of vinyl grafted nanocellulose, and 1 g of ammonium persulfate were mixed, and after reaction at 70°C for 4 h, a soil remediation modifier was obtained.

[0047] Comparative Example 2: The difference from Example 2 is that resveratrol betaine is not added during intercalation, and the remaining steps are the same as Example 2. The specific preparation steps are as follows:

[0048] (1) 11 g of bentonite was dispersed in 430 mL of deionized water, ultrasonically treated for 30 min, and then 50 mL of NaCl solution was added, stirred at 60°C for 12 h, centrifuged and washed to obtain activated bentonite; 4 g of dimethyl diallyl amine chloride was dissolved in deionized water, and the activated bentonite was added, and stirred at 70°C for 6 h under nitrogen atmosphere, the obtained product was centrifuged, the precipitate was washed with ethanol / water (1:1) for 3 times, and finally vacuum freeze-dried to obtain intercalated modified bentonite;

[0049] (2) Under nitrogen atmosphere, 11 g of nanocellulose was placed in a dry reaction kettle, 110 mL of anhydrous N,N-dimethylformamide and 25 mL of thionyl chloride were added, mixed and stirred for 30 min, then the temperature was raised to 43°C and reacted for 12 h, the reaction liquid was poured into ice ether for precipitation, suction filtration, and washed with tetrahydrofuran, and vacuum dried at 40°C for 6 h to obtain acyl chloride cellulose;

[0050] (3) In the dark environment, 9 g of acyl chloride cellulose was dispersed in 200 mL of anhydrous N,N-dimethylformamide, then 18 mL of allylamine and 1.1 g of triethylamine were added dropwise to the reaction system, and reacted at room temperature for 45 h, the reaction liquid was centrifuged, and the obtained precipitate was washed with tetrahydrofuran and methanol in turn, and finally vacuum dried at 35°C for 24 h to obtain vinyl grafted nanocellulose;

[0051] (4) 95 mL of deionized water, 0.8 g of intercalated modified bentonite, 4 g of N,N'-methylene bisacrylamide, 0.4 g of vinyl grafted nanocellulose and 1 g of ammonium persulfate were mixed, and after reaction at 70°C for 4 h, a soil remediation modifier was obtained.

[0052] Comparative Example 3: The difference from Example 2 is that the nanocellulose is not alkylated, but directly mixed, and the remaining steps are the same as Example 2. The specific preparation steps are as follows:

[0053] (1) 2.5 g of resveratrol, 2.3 g of triethylamine, 23 mL of tetrahydrofuran and 23 mL of N,N-dimethylformamide were mixed to obtain a mixed solution; then 4 g of chlorobetaine acyl chloride was dispersed in 25 mL of tetrahydrofuran, and then slowly added to the mixed solution, and kept at room temperature for 5 h, after the reaction was completed, rotary evaporation was performed to obtain resveratrol betaine;

[0054] (2) 11 g of bentonite was dispersed in 430 mL of deionized water, ultrasonic treatment for 30 min, then 50 mL of NaCl solution was added, stirred at 60°C for 12 h, centrifuged, washed to obtain activated bentonite; 3 g of white resveratrol betaine and 4 g of dimethyl diallyl amine chloride were dissolved in deionized water, and the activated bentonite was added, stirred at 70°C under nitrogen atmosphere for 6 h, the obtained product was centrifuged, the precipitate was washed with ethanol / water (1:1) for 3 times, and finally vacuum freeze-dried to obtain the intercalation modified bentonite;

[0055] (3) 95 mL of deionized water, 0.8 g of intercalation modified bentonite, 4 g of N,N'-methylene bisacrylamide, 0.4 g of nanocellulose and 1 g of ammonium persulfate were mixed, and reacted at 70°C for 4 h to obtain a soil remediation modifier.

[0056] Comparative Example 4: The difference from Example 2 is that the bentonite is not intercalated, but is directly added with nanocellulose, and the rest of the steps are the same as Example 2. The specific preparation steps are as follows:

[0057] 95 mL of deionized water, 0.8 g of bentonite, 4 g of N,N'-methylene bisacrylamide, 0.4 g of nanocellulose and 1 g of ammonium persulfate were mixed, and reacted at 70°C for 4 h to obtain a soil remediation modifier.

[0058] Performance test

[0059] Water retention capacity: The sand and NaCl were mixed uniformly according to the ratio of 100:3, and a proper amount of sand sample was placed in a culture dish, 1L·m -2 of soil remediation modifier was sprayed on the surface of the sand sample, and after the emulsion formed a shell on the surface of the sand sample, a certain amount of water was sprayed on the surface of the sand sample, and the wet sand sample was placed in an oven at a constant temperature of 50°C, then the sand sample was weighed every 1 h, repeated 3 times, and the water retention was determined according to the weight loss of the sand sample. The test results are shown in Table 1;

[0060] Sand fixation capacity: The sand fixation capacity was evaluated by measuring the wind erosion modulus. The sand sample was dried at a temperature of 50°C and a humidity of 30% for 24 h, and the soil remediation modifier solution was sprayed on the surface of the sand cone model, and the spraying amount was 1L·m -2 . The wind erosion resistance test was carried out, and the test results are shown in Table 1.

[0061] Pot experiment: 1 kg of mixed Inner Mongolia sand soil sample containing 3 wt.% NaCl was placed in a flowerpot (height 13 cm, surface diameter 12 cm), and the soil remediation modifier was added and mixed uniformly, then the pot experiment was carried out at room temperature of 20°C, a certain amount of water was added to the soil every day, 15 seeds of purple alfalfa were sown in each flowerpot, and the germination rate was recorded after 15 days of sowing, each group was repeated three times, and the test results are shown in Table 1.

[0062] Heavy metal content: 8 kg of soil was taken and divided into 8 parts, seven of which were added to the soil remediation modifier obtained by the implementation and the comparative example for curing, and the remaining one group was the control group, the TCLP toxicity leaching method was used to determine the heavy metal content in the soil, and the control group Cd 2+ content was 7.6 mg / kg, and the test results are shown in Table 1.

[0063] Table 1 Performance test results

[0064]

[0065] Data analysis: From the test data of examples 1-3 in Table 1, it can be seen that the soil improvement and remediation agent prepared by the present application has significant comprehensive performance advantages in practical application. The 12h water retention rate is not less than 65.9%, which indicates that the formula can effectively reduce water loss and significantly improve the water retention of saline-alkali sandy soil; in the wind erosion test, the wind erosion modulus of the implementation can reach (0.15g / (m 2 ·min) at the lowest, showing excellent wind resistance and sand fixation capacity; at the same time, it also has excellent heavy metal adsorption performance, and the germination rate of alfalfa in the pot experiment is as high as 88.2%, which indicates that the formula does not have a negative impact on plant growth, and the present application realizes the synergistic improvement of multiple functions such as water retention, sand fixation, growth promotion and heavy metal remediation, providing an efficient solution for the treatment of saline-alkali and heavy metal compound contaminated soil.

[0066] From the comparison of the test data of examples 2 and comparative examples 1 and 2 in Table 1, it can be seen that the use of resveratrol betaine instead of phenol as a modified component can systematically improve the comprehensive performance of the soil remediation modifier. On the one hand, the large steric hindrance effect of the rigid aromatic ring structure of resveratrol helps to maintain the stability of the interlayer channel, and on the other hand, its double bond can be grafted with nanocellulose and crosslinked to form a network, which may be the structural basis for the improvement of the water retention performance and sand fixation effect of the modifier. At the same time, it may form weak π-π interaction with nanocellulose, so that nanocellulose can be crosslinked during subsequent polymerization; in terms of heavy metal passivation, the phenolic hydroxyl group of resveratrol derivative and the betaine group can be coordinated and electrostatically interacted with Cd 2+The stable complex is formed, and the macromolecular size advantage of the stable complex relative to phenol makes the action have higher spatial selectivity, so that the adsorption complexing capacity of the stable complex for heavy metal ions is stronger; and for the plant growth promoting effect, resveratrol betaine has a more moderate biological activity than traditional phenolic compounds, which can reduce the inhibition of microorganisms, so that it does not have a greater impact on the natural growth of plants. The multifunctional synergistic effect shows that the introduction of resveratrol betaine optimizes the overall performance of the soil remediation modifier.

[0067] As can be seen from the comparison of the test data of Example 2 and Comparative Example 3 in Table 1, the alkenyl modification treatment of nanocellulose has a key role in improving the overall performance of the soil remediation modifier. On the one hand, the vinyl grafted nanocellulose can intercalate and modify the bentonite to form a stable three-dimensional interpenetrating network structure, and the introduction of high-density chemical crosslinking points enhances the bonding strength between the sand particles; at the same time, the active groups on the surface of the nanocellulose and the interlayer region of the bentonite provide more binding sites, enhancing the adsorption of heavy metal ions; on the other hand, the vinyl grafted nanocellulose has a certain synergistic effect with the intercalated modified bentonite, the linear molecular chains of the vinyl nanocellulose form "molecular bridges" between the interlayers of the bentonite, which not only enhances the mechanical strength of the three-dimensional network structure, but also optimizes the pore distribution, and at the same time, the hydrophilic groups of the nanocellulose form a hydrogen bond network with the interlayer water of the bentonite, constructing a multi-level water storage structure; and for heavy metal passivation, the active groups on the surface of the nanocellulose form multiple coordination sites with the resveratrol betaine in the interlayer of the bentonite, significantly improving the fixation efficiency of Cd 2+ This structural synergy achieved through molecular design enables the modifier to maintain environmental friendliness while achieving significantly improved functional durability and environmental adaptability.

[0068] As can be seen from the comparison of the performance test data of Example 2 and Comparative Example 4, the use of resveratrol betaine intercalated modified bentonite combined with alkenylated nanocellulose composite process makes the soil remediation modifier have significant advantages in water retention, sand fixation, plant growth promotion and heavy metal passivation. The improved dispersibility of the intercalated bentonite avoids the interface defects caused by particle agglomeration, and also avoids the intensification of agglomeration between bentonite and nanocellulose due to weak π-π interaction. Comparative Example 4 omits the intercalation modification step, resulting in a deterioration of the interfacial compatibility between bentonite and nanocellulose, forming a heterogeneous structure, which results in a systematic decline in all performance indicators.

[0069] Those skilled in the art should understand that the above discussion of any embodiment is only intended to be exemplary in nature and is not intended to suggest that the present application is limited to these examples; under the concept of the present application, the above embodiments or technical features among different embodiments can be combined, steps can be implemented in any order, and there are many other variations of different aspects of the present application as described above, which are not provided in details for the sake of brevity.

Claims

1. A soil remediation and amendment agent, characterized in that, It is obtained by crosslinking intercalated modified bentonite, vinyl-grafted nanocellulose and N,N'-methylenebisacrylamide; the weight ratio of intercalated modified bentonite, vinyl-grafted nanocellulose and N,N'-methylenebisacrylamide is 0.5-1:0.3-0.5:3-5; The intercalated modified bentonite is obtained by intercalating bentonite with resveratrol betaine and dimethylallylaminoammonium chloride; the weight ratio of resveratrol betaine, dimethylallylaminoammonium chloride and bentonite is 2-4:3-5:10-12. The resveratrol betaine is obtained by reacting the hydroxyl group of resveratrol with the acyl chloride group of betaine chloride; The weight ratio of resveratrol to betaine chloride is 2-3:3.5-5.

2. The soil remediation and amendment agent according to claim 1, characterized in that, The bentonite has a size of 0.5-1 mm.

3. The soil remediation and amendment agent according to claim 1, characterized in that, The vinyl-grafted nanocellulose was obtained by reacting acyl cellulose chloride and allylamine.

4. The soil remediation and amendment agent according to claim 3, characterized in that, The ratio of cellulose chloride to allylamine is 8-10g:15-20mL.

5. The soil remediation and amendment agent according to claim 3, characterized in that, The acyl cellulose chloride is obtained by acyl chlorination of nanocellulose with thionyl chloride, and the ratio of nanocellulose to thionyl chloride is 10-12g:20-30mL.

6. A method for soil improvement and remediation, characterized in that, The process includes the following steps: mixing the soil remediation amendment according to any one of claims 1-5 with deionized water at a weight ratio of 1:50, and dispensing at a concentration of 3-4 L / m³. 2 Spray it onto the soil to be improved and allow it to cure for 10-30 days.

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