A method for soil remediation using plants and microorganisms

Abstract

This invention discloses a method for soil remediation using plants and microorganisms, belonging to the field of soil remediation. The method includes the following steps: a composite remediation carrier is sequentially mixed with a suspension of *Pseudomonas* bacteria and a suspension of *Aspergillus niger* spores and subjected to shaking treatment to obtain particles carrying both bacteria; the particles carrying both bacteria are impregnated with calcium dihydrogen phosphate solution and then dried to obtain a composite material containing both bacteria; after tilling the soil, the composite material containing both bacteria and Indian mustard seeds are sequentially applied, maintaining the soil moisture content at 60-70% of field capacity; on the 60th day after sowing, the entire Indian mustard plant is harvested, completing the soil remediation. This invention solves the problem of the difficulty of microbial survival in soil by constructing a composite carrier integrating adsorption, passivation, and slow nutrient release; when immobilizing functional microbial agents, the composite remediation carrier both activates heavy metals in the rhizosphere to promote plant absorption and immobilizes them in the non-rhizosphere to prevent migration, while simultaneously providing nutrients, achieving a combined microbial-plant remediation of contaminated soil.

Description

Technical Field

[0001] This invention relates to the field of soil remediation, and more specifically to a method for remediating soil using plants and microorganisms. Background Technology

[0002] Lead-contaminated soil remediation is a key and challenging area in environmental governance. Traditional remediation methods mainly include physical / chemical remediation, microbial remediation, and phytoremediation. Physical / chemical remediation techniques such as leaching and solidification / stabilization are effective but costly, require complex equipment, are prone to secondary pollution, and cause significant damage to soil structure and ecological functions. Microbial remediation, while environmentally friendly, has limited effectiveness in treating high-concentration lead-contaminated soils, and requires stringent conditions for strain selection and cultivation. Phytoremediation, which utilizes hyperaccumulating plants to absorb heavy metals, is low-cost and easy to operate, but has a long remediation cycle, and improper treatment of lead accumulated in plants can easily cause secondary pollution.

[0003] Patent application CN 109821893A discloses a method for remediating lead-contaminated soil and recovering lead using castor beans. This method enriches the soil with lead by continuously planting castor beans, and then recovers lead compounds through steps such as straw burning, ash formation, and water bath extraction. Although it achieves the resource utilization of lead, it still has problems such as long remediation cycle, complex lead recovery process, and limited remediation efficiency for high-concentration contaminated soil.

[0004] Patent application CN 115651665A discloses a remediation method combining chemical leaching and stabilization. It uses a specific ratio of remediation liquid and powder to perform multiple leaching and stabilization treatments on lead-contaminated soil. Although it has a significant effect on the remediation of high-concentration lead-contaminated soil, this method relies on chemical agents, is costly, and improper treatment of leaching waste liquid may cause secondary pollution. It also lacks the ecological sustainability of bioremediation.

[0005] In the practice of plant-microbe co-remediation of lead-contaminated soil, simply applying laboratory-propagated functional microbial agents directly to contaminated soil often fails to achieve the desired results. This is because exogenous microorganisms face fierce competition from the native soil flora. Furthermore, the soil may lack available carbon and nitrogen nutrients, and the combined effects of environmental stressors such as pH imbalance, high salinity, and drought can lead to rapid inactivation and mass mortality of exogenous strains, preventing them from successfully colonizing the soil and fulfilling their core function of transforming and fixing lead ions. On the other hand, simply mixing microbial agents with remediation plants makes it difficult for microorganisms to accurately accumulate in the rhizosphere region of the plants. The lack of an effective signal transduction and material exchange "bridge" between the two results in a weak and unstable synergistic effect between plant lead absorption and microbial lead transformation, severely limiting remediation efficiency and reliability.

[0006] Therefore, providing a method for remediating lead-contaminated soil that can effectively solve the problem of easy inactivation of microorganisms is an important issue that urgently needs to be addressed in this field. Summary of the Invention

[0007] To address the problems in existing technologies, this invention constructs a multifunctional composite carrier integrating adsorption, passivation, and microbial nutrition, solving the survival problem of microbial agents in combined microbial-plant applications. In this invention, the composite remediation carrier immobilizes functional microbial communities, synergistically activating pollutants in the rhizosphere and promoting plant absorption, while permanently immobilizing heavy metals in the non-rhizosphere zone, achieving efficient and stable soil remediation. Specifically, the technical solution of this invention includes the following:

[0008] A method for soil remediation using plants and microorganisms, the method comprising the following steps:

[0009] The composite repair carrier was sequentially mixed with a suspension of Pseudomonas aeruginosa and a suspension of Aspergillus niger spores and subjected to shaking treatment to obtain particles carrying two bacteria.

[0010] The two-bacterial-loaded particles were impregnated with calcium dihydrogen phosphate solution and then dried to obtain a two-bacterial composite material;

[0011] After tilling the soil, apply the double-bacterial composite material and Indian mustard seeds in sequence, maintaining the soil moisture content at 60-70% of field capacity;

[0012] On the 60th day after sowing, the entire Indian mustard plant was harvested, and soil remediation was completed.

[0013] Furthermore, the preparation method of the composite repair carrier includes the following steps:

[0014] Humic acid was pretreated and activated to obtain pretreated humic acid. The pretreated humic acid and zirconium oxychloride were mixed and stirred to obtain a zirconium-humic acid solution. The zirconium-humic acid solution was mixed with 85wt% phosphoric acid solution, and the pH was adjusted to 2.8~3.2 before stirring to obtain a humic acid-zirconium phosphate complex.

[0015] Soy protein isolate and humic acid-zirconium phosphate complex were mixed and reacted by oscillation to obtain humic acid complex.

[0016] A humic acid complex, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), 4-dimethylaminopyridine (DMAP), and hydroxyapatite were mixed and stirred to obtain an apatite complex.

[0017] A quinone-containing complex was obtained by mixing and stirring apatite complex, dopamine hydrochloride, and copper sulfate.

[0018] After calcination, porous diatomaceous earth is mixed and stirred with 3-aminopropyltriethoxysilane to obtain aminated diatomaceous earth.

[0019] The composite remediation carrier was prepared by mixing and stirring a quinone-containing complex with amino-modified diatomaceous earth.

[0020] Furthermore, the weight ratio of the pretreated humic acid, zirconium oxychloride, and 85wt% phosphoric acid solution is 5~7:10~20:13~14.

[0021] Furthermore, the conditions for the stirring reaction of the pretreated humic acid, zirconium oxychloride, and 85wt% phosphoric acid solution include a reaction temperature of 60-70℃ and a reaction time of 8-12h.

[0022] Furthermore, the weight ratio of the soy protein isolate to the humic acid-zirconium phosphate complex is 90~110:20~30.

[0023] Furthermore, the conditions for the oscillating reaction of the soy protein isolate and the humic acid-zirconium phosphate complex include a reaction temperature of 35-45°C and a reaction time of 1.5-3 hours.

[0024] Further, the weight ratio of the humic acid complex, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, dimethylaminopyridine and hydroxyapatite is 10:0.3~0.5:0.05~0.1:1.1~1.5.

[0025] Furthermore, the conditions for the stirring reaction of the humic acid complex, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, dimethylaminopyridine and hydroxyapatite include a reaction temperature of 25-28°C, a reaction pH of 5.8-3.2 and a reaction time of 3-5 h.

[0026] Furthermore, the weight ratio of the apatite complex, dopamine hydrochloride, and copper sulfate is 100:4~6:0.4~0.6.

[0027] Furthermore, the conditions for the stirring reaction of the apatite complex, dopamine hydrochloride, and copper sulfate include a reaction temperature of 25-28°C and a reaction time of 6-8 hours.

[0028] Furthermore, the weight ratio of the porous diatomaceous earth to 3-aminopropyltriethoxysilane is 80:2.5~3.5.

[0029] Furthermore, the conditions for the stirring reaction of the porous diatomaceous earth and 3-aminopropyltriethoxysilane include a reaction temperature of 25-28°C and a reaction time of 4-6 hours.

[0030] Furthermore, the weight ratio of the quinone-containing complex to the aminated diatomaceous earth is 50-60:35-40.

[0031] Furthermore, the conditions for the stirring reaction of the quinone-containing complex and the aminated diatomaceous earth include a reaction temperature of 25-28°C and a reaction time of 10-14 h.

[0032] Furthermore, the weight ratio of the composite repair carrier, Pseudomonas bacterial suspension, and Aspergillus niger spore suspension is 10:100~150:100~150.

[0033] Furthermore, the concentration of the Pseudomonas bacterial suspension is 10. 10 CFU / mL.

[0034] Furthermore, the concentration of the Aspergillus niger spore suspension is 10. 10 per mL.

[0035] Furthermore, the conditions for the oscillation treatment of the composite repair carrier and the Pseudomonas bacterial suspension include an oscillation speed of 150-200 r / min and an oscillation time of 1-2 h.

[0036] Furthermore, the conditions for the oscillation treatment of the composite remediation carrier and Aspergillus niger spore suspension include an oscillation speed of 150-200 r / min and an oscillation time of 1-2 h.

[0037] Furthermore, the concentration of the calcium dihydrogen phosphate solution is 1~3wt%.

[0038] Furthermore, the impregnation conditions include a vacuum pressure of -0.05 MPa and an impregnation time of 5 to 10 minutes.

[0039] Furthermore, the drying conditions include a drying temperature of 40°C and a drying time of 4 to 6 hours.

[0040] Furthermore, the dosage of the dual-bacterial composite material is 75~85 g / m³. 2 .

[0041] Furthermore, the dosage of the Indian mustard is 4 g / m³. 2 .

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] (1) In this invention, humic acid is first pretreated by alkali dissolution and acid precipitation. This method removes impurities from the humic acid and simultaneously exposes its active functional groups to obtain pretreated humic acid. The pretreated humic acid first undergoes a coordination reaction with zirconium oxychloride to form a zirconium-humic acid complex. This complex then reacts further with phosphoric acid to finally generate a humic acid-zirconium phosphate complex. The humic acid-zirconium phosphate complex is combined with soy protein isolate through hydrogen bonding and other interactions, introducing bio-derived organic matter and functional groups to obtain a humic acid complex. Under the action of EDC and DMAP, the above humic acid complex is covalently linked with hydroxyapatite, which not only enhances the structural stability of the material but also provides passivation sites for heavy metal fixation to obtain an apatite complex. A polydopamine coating was constructed on the surface of an apatite composite through the oxidative self-polymerization reaction of dopamine, resulting in a quinone-containing composite. Porous diatomaceous earth was first purified by calcination, then modified by silanization, and finally grafted with amino groups to obtain aminated diatomaceous earth. The quinone-containing composite was covalently anchored on the surface of the aminated diatomaceous earth using the Schiff base reaction between quinone and amino groups, thus constructing a composite remediation carrier with both adsorption and passivation functions and microbial loading capacity. This composite remediation carrier loaded Pseudomonas and Aspergillus niger through adsorption to form an immobilized microbial system, resulting in dual-bacterial particles. The dual-bacterial particles were vacuum impregnated with calcium dihydrogen phosphate, which not only provided nutrients for the microorganisms but also further enhanced the passivation function of the material to obtain a dual-bacterial composite material.

[0044] (2) In this invention, the composite remediation carrier achieves good synergistic effect through a sophisticated multi-level design. Diatomaceous earth serves as the framework, ensuring the porosity and permeability of the carrier. The loaded humic acid-zirconium phosphate-hydroxyapatite nanocomposite provides a huge specific surface area and abundant active sites, achieving synergy between structure and function. On this basis, the functions of each component complement each other: humic acid and zirconium phosphate rapidly adsorb and enrich lead ions through ion exchange and coordination, and then hydroxyapatite converts them into lead phosphate, completing the synergy from adsorption to passivation, improving immobilization efficiency and long-term stability. Soy protein isolate and calcium dihydrogen phosphate provide nitrogen and phosphorus sources for the loaded microorganisms, while the polydopamine coating and diatomaceous earth framework provide a good habitat for microorganisms, achieving synergy between the carrier and the organism, which is conducive to enhancing the survival and colonization ability of the microbial agent. The composite remediation carrier combines adsorption materials, passivation, microbial nutrient sources and porous framework into one, providing a platform for microbial-plant co-remediation by reducing the risk of pollutant migration and promoting absorption by plant roots.

[0045] (3) In this invention, after applying the dual-bacterial composite material and Indian mustard seeds to contaminated soil, the microorganisms inside the plant secrete organic acids in the rhizosphere, which can activate the lead element in the soil and effectively enhance the absorption efficiency of Indian mustard for lead. The root secretions of Indian mustard in turn feed the growth of microorganisms, forming an efficient "plant-microorganism" interaction cycle. The nitrogen and phosphorus sources provided by the soybean protein isolate in the carrier continuously supply "ammunition" for this biological complex, ensuring the long-term stability of the remediation activity and achieving effective remediation of lead-contaminated soil. Detailed Implementation

[0046] The technical solution of the present invention will be clearly and completely described below through embodiments. 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 are within the scope of protection of the present invention.

[0047] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0048] Preparation Example 1:

[0049] The preparation method of the composite repair carrier includes the following steps:

[0050] Eight parts by weight of humic acid were dispersed in 200 parts by weight of deionized water. The pH was adjusted to 10.0 with 1 mol / L sodium hydroxide solution. The mixture was stirred at 200 r / min for 1 h at 40 °C. After stirring, the pH was adjusted to 2.0 with 1 mol / L hydrochloric acid solution. After standing for 12 h, the mixture was centrifuged at 400 r / min for 10 min. The precipitate was collected, washed with deionized water until neutral, and then freeze-dried to obtain pretreated humic acid.

[0051] Five parts by weight of pretreated humic acid were dispersed in 200 parts by weight of deionized water. Ten parts by weight of zirconium oxychloride were added, and the mixture was heated to 60°C and stirred at 300 r / min for 1 h to obtain a zirconium-humic acid solution. Thirteen parts by weight of 85 wt% phosphoric acid solution were dispersed in 50 parts by weight of deionized water to obtain a phosphoric acid solution. The phosphoric acid solution was slowly added dropwise to the zirconium-humic acid solution to obtain a mixed system. The pH of the mixed system was adjusted to 2.8, and the reaction was continued to be stirred at 60°C for 8 h. After the reaction was completed, the mixture was cooled to 25°C and centrifuged at 8000 r / min for 15 min to collect the precipitate. The precipitate was washed three times each with deionized water and anhydrous ethanol. The washed precipitate was placed in a vacuum drying oven at 60°C and dried for 24 h. The precipitate was then ground into powder and passed through a 200-mesh sieve to obtain a humic acid-zirconium phosphate composite.

[0052] 90 parts by weight of soy protein isolate were dispersed in 500 parts by weight of phosphate buffer at pH 7.4. After stirring at 200 r / min for 30 min at 25 °C, 20 parts by weight of humic acid-zirconium phosphate complex were added. The temperature was raised to 35 °C and the mixture was shaken at 150 r / min for 1.5 h. After the reaction was completed, the mixture was centrifuged at 8000 r / min for 15 min, the precipitate was collected and freeze-dried to obtain the humic acid complex.

[0053] Ten parts by weight of humic acid complex were dispersed in 100 parts by weight of deionized water. 0.3 parts by weight of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.05 parts by weight of 4-dimethylaminopyridine, and 1.1 parts by weight of hydroxyapatite were added. The mixture was stirred at 300 r / min for 3 h at pH 5.8 and 25 °C. After the reaction was completed, 10 parts by weight of 0.1 mol / L glycine solution was added to terminate the reaction. The mixture was dialyzed in phosphate buffer at pH 7.4 for 48 h to obtain the apatite complex.

[0054] 100 parts by weight of the apatite complex were dispersed in 500 parts by weight of Tris-HCl buffer at pH 8.5. 4 parts by weight of dopamine hydrochloride and 0.4 parts by weight of copper sulfate were added. The mixture was stirred at 200 r / min for 6 h in a dark environment at 25 °C. After the reaction was completed, the mixture was centrifuged at 12000 r / min for 20 min and washed three times with deionized water to obtain the quinone-containing complex.

[0055] 80 parts by weight of porous diatomaceous earth were calcined at 450°C for 2 hours, then cooled to 25°C and dispersed in a mixed solvent (V 乙醇 V 去离子水 In a mixture of 1:1, the pH was adjusted to 4.5 with glacial acetic acid, and then 2.5 parts by weight of 3-aminopropyltriethoxysilane were added. The mixture was stirred at 150 r / min at 25 °C for 4 h. After the reaction was completed, the mixture was washed three times alternately with ethanol and deionized water, and then dried under vacuum at 40 °C to obtain aminated diatomaceous earth.

[0056] 50 parts by weight of a quinone-containing complex and 35 parts by weight of aminated diatomaceous earth were dispersed in 500 parts by weight of a phosphate buffer solution at pH 7.5. The mixture was stirred at 200 r / min for 10 h at 25 °C. After the reaction was completed, the precipitate was collected by centrifugation and washed three times with deionized water to obtain the composite repair carrier.

[0057] Preparation Example 2:

[0058] The preparation method of the composite repair carrier includes the following steps:

[0059] Nine parts by weight of humic acid were dispersed in 200 parts by weight of deionized water. The pH was adjusted to 10.0 with 1 mol / L sodium hydroxide solution. The mixture was stirred at 200 r / min at 42℃ for 1.2 h. After stirring, the pH was adjusted to 2.2 with 1 mol / L hydrochloric acid solution. After standing for 12 h, the mixture was centrifuged at 400 r / min for 10 min. The precipitate was collected, washed with deionized water until neutral, and then freeze-dried to obtain pretreated humic acid.

[0060] 5.5 parts by weight of pretreated humic acid were dispersed in 200 parts by weight of deionized water, and 12 parts by weight of zirconium oxychloride were added. The mixture was heated to 62°C and stirred at 300 r / min for 1.2 h to obtain a zirconium-humic acid solution. 13.2 parts by weight of 85 wt% phosphoric acid solution were dispersed in 50 parts by weight of deionized water to obtain a phosphoric acid solution. The phosphoric acid solution was slowly added dropwise to the zirconium-humic acid solution to obtain a mixed system. The pH of the mixed system was adjusted to 2.9, and the reaction was continued to be stirred at 62°C for 9 h. After the reaction was completed, the mixture was cooled to 25°C and centrifuged at 8000 r / min for 15 min to collect the precipitate. The precipitate was washed three times each with deionized water and anhydrous ethanol. The washed precipitate was placed in a vacuum drying oven at 60°C and dried for 24 h. The precipitate was then ground into powder and passed through a 200-mesh sieve to obtain the humic acid-zirconium phosphate composite.

[0061] 95 parts by weight of soy protein isolate were dispersed in 500 parts by weight of phosphate buffer at pH 7.4. After stirring at 200 r / min for 30 min at 25 °C, 22 parts by weight of humic acid-zirconium phosphate complex were added. The temperature was raised to 37 °C and the reaction was shaken at 150 r / min for 1.7 h. After the reaction was completed, the mixture was centrifuged at 8000 r / min for 15 min, the precipitate was collected and freeze-dried to obtain the humic acid complex.

[0062] Ten parts by weight of humic acid complex were dispersed in 100 parts by weight of deionized water, along with 0.35 parts by weight of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.07 parts by weight of 4-dimethylaminopyridine, and 1.3 parts by weight of hydroxyapatite. The mixture was stirred at 300 r / min for 3.5 h at pH 5.9 and 26 °C. After the reaction was completed, 10 parts by weight of 0.1 mol / L glycine solution was added to terminate the reaction. The mixture was then dialyzed in phosphate buffer at pH 7.4 for 54 h to obtain the apatite complex.

[0063] 100 parts by weight of the apatite complex were dispersed in 500 parts by weight of Tris-HCl buffer at pH 8.5. 4.5 parts by weight of dopamine hydrochloride and 0.45 parts by weight of copper sulfate were added. The mixture was stirred at 200 r / min for 6.5 h in a dark environment at 26 °C. After the reaction was completed, the mixture was centrifuged at 12000 r / min for 20 min and washed three times with deionized water to obtain the quinone-containing complex.

[0064] 80 parts by weight of porous diatomaceous earth were calcined at 470℃ for 2.5 h, cooled to 25℃, and dispersed in a mixed solvent (V 乙醇 V 去离子水 In a mixture of 1:1, the pH was adjusted to 4.7 with glacial acetic acid, and then 2.7 parts by weight of 3-aminopropyltriethoxysilane were added. The mixture was stirred at 150 r / min at 26 °C for 4.5 h. After the reaction was completed, the mixture was washed three times alternately with ethanol and deionized water, and then dried under vacuum at 40 °C to obtain aminated diatomaceous earth.

[0065] 52 parts by weight of a quinone-containing complex and 36 parts by weight of aminated diatomaceous earth were dispersed in 500 parts by weight of a phosphate buffer solution at pH 7.6. The mixture was stirred at 200 r / min for 11 h at 26 °C. After the reaction was completed, the precipitate was collected by centrifugation and washed three times with deionized water to obtain the composite repair carrier.

[0066] Preparation Example 3:

[0067] The preparation method of the composite repair carrier includes the following steps:

[0068] Ten parts by weight of humic acid were dispersed in 200 parts by weight of deionized water. The pH was adjusted to 10.0 with 1 mol / L sodium hydroxide solution. The mixture was stirred at 200 r / min at 45℃ for 1.5 h. After stirring, the pH was adjusted to 2.5 with 1 mol / L hydrochloric acid solution. After standing for 12 h, the mixture was centrifuged at 400 r / min for 10 min. The precipitate was collected, washed with deionized water until neutral, and then freeze-dried to obtain pretreated humic acid.

[0069] Six parts by weight of pretreated humic acid were dispersed in 200 parts by weight of deionized water, and 15 parts by weight of zirconium oxychloride were added. The mixture was heated to 65°C and stirred at 300 r / min for 1.5 h to obtain a zirconium-humic acid solution. 13.5 parts by weight of 85 wt% phosphoric acid solution were dispersed in 50 parts by weight of deionized water to obtain a phosphoric acid solution. The phosphoric acid solution was slowly added dropwise to the zirconium-humic acid solution to obtain a mixed system. The pH of the mixed system was adjusted to 3.0, and the reaction was continued to be stirred at 65°C for 10 h. After the reaction was completed, the mixture was cooled to 25°C and centrifuged at 8000 r / min for 15 min to collect the precipitate. The precipitate was washed three times each with deionized water and anhydrous ethanol. The washed precipitate was placed in a vacuum drying oven at 60°C and dried for 24 h. The precipitate was then ground into powder and passed through a 200-mesh sieve to obtain the humic acid-zirconium phosphate composite.

[0070] 100 parts by weight of soy protein isolate were dispersed in 500 parts by weight of phosphate buffer at pH 7.4. After stirring at 200 r / min for 30 min at 25 °C, 25 parts by weight of humic acid-zirconium phosphate complex were added. The temperature was raised to 40 °C and the reaction was shaken at 150 r / min for 2 h. After the reaction was completed, the mixture was centrifuged at 8000 r / min for 15 min, the precipitate was collected and freeze-dried to obtain humic acid complex.

[0071] Ten parts by weight of humic acid complex were dispersed in 100 parts by weight of deionized water. 0.4 parts by weight of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.09 parts by weight of 4-dimethylaminopyridine, and 1.4 parts by weight of hydroxyapatite were added. The mixture was stirred at 300 r / min for 4 h at pH 6.0 and 27 °C. After the reaction was completed, 10 parts by weight of 0.1 mol / L glycine solution was added to terminate the reaction. The mixture was dialyzed in phosphate buffer at pH 7.4 for 60 h to obtain the apatite complex.

[0072] 100 parts by weight of the apatite complex were dispersed in 500 parts by weight of Tris-HCl buffer at pH 8.5. 5 parts by weight of dopamine hydrochloride and 0.5 parts by weight of copper sulfate were added. The mixture was stirred at 200 r / min for 7 h in a dark environment at 27 °C. After the reaction was completed, the mixture was centrifuged at 12000 r / min for 20 min and washed three times with deionized water to obtain the quinone-containing complex.

[0073] 80 parts by weight of porous diatomaceous earth were calcined at 500°C for 3 hours, then cooled to 25°C and dispersed in a mixed solvent (V 乙醇 V 去离子水 In a mixture of 1:1, the pH was adjusted to 5 with glacial acetic acid, and then 3 parts by weight of 3-aminopropyltriethoxysilane were added. The mixture was stirred at 150 r / min at 27 °C for 5 h. After the reaction was completed, the mixture was washed three times alternately with ethanol and deionized water, and then dried under vacuum at 40 °C to obtain aminated diatomaceous earth.

[0074] 55 parts by weight of the quinone-containing complex and 38 parts by weight of the aminated diatomaceous earth were dispersed in 500 parts by weight of pH 7.7 phosphate buffer and stirred at 200 r / min for 12 h at 27 °C. After the reaction was completed, the precipitate was collected by centrifugation and washed three times with deionized water to obtain the composite repair carrier.

[0075] Preparation Example 4:

[0076] The preparation method of the composite repair carrier includes the following steps:

[0077] 12 parts by weight of humic acid were dispersed in 200 parts by weight of deionized water. The pH was adjusted to 10.0 with 1 mol / L sodium hydroxide solution. The mixture was stirred at 200 r / min for 2 h at 50 °C. After stirring, the pH was adjusted to 3.0 with 1 mol / L hydrochloric acid solution. After standing for 12 h, the mixture was centrifuged at 400 r / min for 10 min. The precipitate was collected, washed with deionized water until neutral, and then freeze-dried to obtain pretreated humic acid.

[0078] 7 parts by weight of pretreated humic acid were dispersed in 200 parts by weight of deionized water, and 20 parts by weight of zirconium oxychloride were added. The mixture was heated to 70°C and stirred at 300 r / min for 2 h to obtain a zirconium-humic acid solution. 14 parts by weight of 85 wt% phosphoric acid solution were dispersed in 50 parts by weight of deionized water to obtain a phosphoric acid solution. The phosphoric acid solution was slowly added dropwise to the zirconium-humic acid solution to obtain a mixed system. The pH of the mixed system was adjusted to 3.2, and the reaction was continued to be stirred at 70°C for 12 h. After the reaction was completed, the mixture was cooled to 25°C and centrifuged at 8000 r / min for 15 min to collect the precipitate. The precipitate was washed three times each with deionized water and anhydrous ethanol. The washed precipitate was placed in a vacuum drying oven at 60°C and dried for 24 h. The precipitate was then ground into powder and passed through a 200-mesh sieve to obtain the humic acid-zirconium phosphate composite.

[0079] 110 parts by weight of soy protein isolate were dispersed in 500 parts by weight of phosphate buffer at pH 7.4. After stirring at 200 r / min for 30 min at 25 °C, 30 parts by weight of humic acid-zirconium phosphate complex were added. The temperature was raised to 45 °C and the mixture was shaken at 150 r / min for 3 h. After the reaction was completed, the mixture was centrifuged at 8000 r / min for 15 min, the precipitate was collected and freeze-dried to obtain the humic acid complex.

[0080] Ten parts by weight of humic acid complex were dispersed in 100 parts by weight of deionized water. 0.5 parts by weight of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.1 parts by weight of 4-dimethylaminopyridine, and 1.5 parts by weight of hydroxyapatite were added. The mixture was stirred at 300 r / min for 5 h at pH 6.2 and 28 °C. After the reaction was completed, 10 parts by weight of 0.1 mol / L glycine solution was added to terminate the reaction. The mixture was dialyzed in phosphate buffer at pH 7.4 for 72 h to obtain the apatite complex.

[0081] 100 parts by weight of the apatite complex were dispersed in 500 parts by weight of pH 8.5 Tris-HCl buffer, 6 parts by weight of dopamine hydrochloride and 0.6 parts by weight of copper sulfate were added, and the mixture was stirred at 200 r / min for 8 h in a dark environment at 28 °C. After the reaction was completed, the mixture was centrifuged at 12000 r / min for 20 min and washed three times with deionized water to obtain the quinone-containing complex.

[0082] 80 parts by weight of porous diatomaceous earth were calcined at 550°C for 4 hours, then cooled to 25°C and dispersed in a mixed solvent (V 乙醇 V 去离子水 In a mixture of 1:1, the pH was adjusted to 5.5 with glacial acetic acid, and then 3.5 parts by weight of 3-aminopropyltriethoxysilane were added. The mixture was stirred at 150 r / min at 28 °C for 6 h. After the reaction was completed, the mixture was washed three times alternately with ethanol and deionized water, and then dried under vacuum at 40 °C to obtain aminated diatomaceous earth.

[0083] 60 parts by weight of a quinone-containing complex and 40 parts by weight of aminated diatomaceous earth were dispersed in 500 parts by weight of a phosphate buffer solution with pH 7.9. The mixture was stirred at 200 r / min at 28 °C for 14 h. After the reaction was completed, the precipitate was collected by centrifugation and washed three times with deionized water to obtain the composite repair carrier.

[0084] Preparation Example 5:

[0085] The preparation method of the composite repair carrier includes the following steps:

[0086] In Preparation Example 4, zirconium oxychloride was replaced with zirconium sulfate, and all other operations were the same as in Preparation Example 4.

[0087] Preparation Example 6:

[0088] The preparation method of the composite repair carrier includes the following steps:

[0089] The step of preparing the quinone-containing complex in Preparation Example 4 was removed. Instead, the apatite complex was directly mixed and stirred with aminated diatomaceous earth for reaction. Other operations were the same as in Preparation Example 4.

[0090] Preparation Example 7:

[0091] The preparation method of the composite repair carrier includes the following steps:

[0092] The 3-aminopropyltriethoxysilane amination modification of diatomaceous earth in Preparation Example 4 is omitted, and other operations are consistent with Preparation Example 4.

[0093] Example 1:

[0094] A method for soil remediation using plants and microorganisms includes the following steps:

[0095] Pseudomonas WCS358 was inoculated into liquid culture medium and cultured at 28°C with shaking at 180 rpm for 16 h. After culturing, the bacterial cells were collected by centrifugation at 8000 rpm for 10 min at 4°C. The cells were washed twice with sterile physiological saline and then resuspended in physiological saline to adjust the bacterial concentration to 10. 10 A Pseudomonas bacterial suspension was obtained at CFU / mL;

[0096] Aspergillus niger was inoculated onto potato dextrose agar plates and cultured at 28°C for 5 days. The spores on the plates were then rinsed with sterile physiological saline containing 0.05 wt% Tween-80, and the bacterial cells were washed twice with sterile physiological saline. The plates were then resuspended in physiological saline, and the spore suspension concentration was adjusted to 10. 10 A suspension of Aspergillus niger spores was obtained at a concentration of 1 spore per mL.

[0097] 10 parts by weight of the composite repair carrier prepared in Example 1 were mixed with 100 parts by weight of Pseudomonas bacterial suspension and treated with shaking at 150 r / min for 1 h at 25 °C to obtain the first mixture. The first mixture was centrifuged at 4000 r / min for 10 min in a sterile environment, and the wet particles loaded with Pseudomonas were collected.

[0098] The above wet granules were mixed with 100 parts by weight of Aspergillus niger spore suspension and treated with shaking at 150 r / min at 25°C for 1 h to obtain a second mixture. The second mixture was centrifuged at 4000 r / min for 10 min in a sterile environment, and the supernatant was discarded to obtain granules loaded with two bacteria.

[0099] The above-mentioned double-bacterial particles were transferred into a vacuum filtration device, impregnated with 200 parts by weight of 1wt% calcium dihydrogen phosphate solution, and a vacuum pressure of -0.05MPa was applied and maintained for 5 minutes to obtain impregnated particles. The impregnated particles were dried in a hot air drying oven at 40℃ for 4 hours to obtain the double-bacterial composite material.

[0100] The target contaminated area was tilled to a depth of 20cm, using a fertilizer concentration of 75g / m³. 2 Apply the appropriate amount of the dual-bacterial composite material evenly to the soil surface. Immediately after application, use a rotary tiller to perform a second shallow mixing operation to fully mix the dual-bacterial composite material with the top 0-5cm of soil.

[0101] According to 4g / m 2 The seeds of Indian mustard are sown evenly. After sowing, the seeds are covered with 1-2 cm of soil and lightly compacted. Sprinkler irrigation is carried out after sowing to keep the soil moisture content at 60-70% of field capacity. This humidity is then monitored and maintained daily.

[0102] Sixty days after sowing, the Indian mustard plants are harvested in their entirety to complete the soil remediation process. The harvested Indian mustard plants are then placed in a 120°C high-temperature drying oven for complete dehydration, and then transferred to a professional hazardous waste incinerator equipped with a heavy metal flue gas treatment system for safe incineration. Lead compounds enriched in the fly ash are collected for resource recovery.

[0103] Example 2:

[0104] A method for soil remediation using plants and microorganisms includes the following steps:

[0105] Pseudomonas WCS358 was inoculated into liquid culture medium and cultured at 28°C with shaking at 180 rpm for 16.5 h. After culturing, the bacterial cells were collected by centrifugation at 8000 rpm for 10 min at 4°C. The cells were washed twice with sterile physiological saline and then resuspended in physiological saline to adjust the bacterial concentration to 10. 10 A Pseudomonas bacterial suspension was obtained at CFU / mL;

[0106] Aspergillus niger was inoculated onto potato dextrose agar plates and incubated at 28°C for 5.5 days. The spores on the plates were then rinsed with sterile physiological saline containing 0.05 wt% Tween-80, and the bacterial cells were washed twice with sterile physiological saline. The plates were then resuspended in physiological saline, and the spore suspension concentration was adjusted to 10. 10 A suspension of Aspergillus niger spores was obtained at a concentration of 1 spore per mL.

[0107] 10 parts by weight of the composite repair carrier prepared in Example 2 were mixed with 120 parts by weight of Pseudomonas bacterial suspension and treated with shaking at 150 r / min at 25°C for 1.3 h to obtain the first mixture. The first mixture was centrifuged at 4000 r / min for 10 min in a sterile environment, and the wet particles loaded with Pseudomonas were collected.

[0108] The above wet granules were mixed with 120 parts by weight of Aspergillus niger spore suspension and treated with shaking at 150 r / min at 25°C for 1.3 h to obtain a second mixture. The second mixture was centrifuged at 4000 r / min for 10 min in a sterile environment, and the supernatant was discarded to obtain granules loaded with two bacteria.

[0109] The above-mentioned double-bacterial particles were transferred into a vacuum filtration device, impregnated with 200 parts by weight of 1.5wt% calcium dihydrogen phosphate solution, and a vacuum pressure of -0.05MPa was applied and maintained for 5 minutes to obtain impregnated particles. The impregnated particles were dried in a hot air drying oven at 40℃ for 4.5 hours to obtain the double-bacterial composite material.

[0110] The target contaminated area was tilled to a depth of 20cm, using a fertilizer concentration of 79g / m³. 2 Apply the appropriate amount of the dual-bacterial composite material evenly to the soil surface. Immediately after application, use a rotary tiller to perform a second shallow mixing operation to fully mix the dual-bacterial composite material with the top 0-5cm of soil.

[0111] According to 4g / m 2 The seeds of Indian mustard are sown evenly. After sowing, the seeds are covered with 1-2 cm of soil and lightly compacted. Sprinkler irrigation is carried out after sowing to keep the soil moisture content at 60-70% of field capacity. This humidity is then monitored and maintained daily.

[0112] Sixty days after sowing, the Indian mustard plants are harvested in their entirety to complete the soil remediation process. The harvested Indian mustard plants are then placed in a 120°C high-temperature drying oven for complete dehydration, and then transferred to a professional hazardous waste incinerator equipped with a heavy metal flue gas treatment system for safe incineration. Lead compounds enriched in the fly ash are collected for resource recovery.

[0113] Example 3:

[0114] A method for soil remediation using plants and microorganisms includes the following steps:

[0115] Pseudomonas WCS358 was inoculated into liquid culture medium and cultured at 28°C with shaking at 180 rpm for 17 h. After culturing, the bacterial cells were collected by centrifugation at 8000 rpm for 10 min at 4°C. The cells were washed twice with sterile physiological saline and then resuspended in physiological saline to adjust the bacterial concentration to 10. 10 A Pseudomonas bacterial suspension was obtained at CFU / mL;

[0116] Aspergillus niger was inoculated onto potato dextrose agar plates and cultured at 28°C for 6 days. The spores on the plates were then rinsed with sterile physiological saline containing 0.05 wt% Tween-80, and the bacterial cells were washed twice with sterile physiological saline. The plates were then resuspended in physiological saline, and the spore suspension concentration was adjusted to 10. 10 A suspension of Aspergillus niger spores was obtained at a concentration of 1 spore per mL.

[0117] 10 parts by weight of the composite repair carrier prepared in Example 3 were mixed with 140 parts by weight of Pseudomonas bacterial suspension and treated with shaking at 150 r / min at 25°C for 1.8 h to obtain the first mixture. The first mixture was centrifuged at 4000 r / min for 10 min in a sterile environment, and the wet particles loaded with Pseudomonas were collected.

[0118] The above wet granules were mixed with 140 parts by weight of Aspergillus niger spore suspension and treated with shaking at 150 r / min at 25°C for 1.8 h to obtain a second mixture. The second mixture was centrifuged at 4000 r / min for 10 min in a sterile environment, and the supernatant was discarded to obtain granules loaded with two bacteria.

[0119] The above-mentioned double-bacterial particles were transferred into a vacuum filtration device, impregnated with 200 parts by weight of 2wt% calcium dihydrogen phosphate solution, and a vacuum pressure of -0.05MPa was applied and maintained for 5 minutes to obtain impregnated particles. The impregnated particles were dried in a hot air drying oven at 40℃ for 5 hours to obtain the double-bacterial composite material.

[0120] The target contaminated area was tilled to a depth of 20cm, using 82g / m³ of soil. 2Apply the appropriate amount of the dual-bacterial composite material evenly to the soil surface. Immediately after application, use a rotary tiller to perform a second shallow mixing operation to fully mix the dual-bacterial composite material with the top 0-5cm of soil.

[0121] According to 4g / m 2 The seeds of Indian mustard are sown evenly. After sowing, the seeds are covered with 1-2 cm of soil and lightly compacted. Sprinkler irrigation is carried out after sowing to keep the soil moisture content at 60-70% of field capacity. This humidity is then monitored and maintained daily.

[0122] Sixty days after sowing, the Indian mustard plants are harvested in their entirety to complete the soil remediation process. The harvested Indian mustard plants are then placed in a 120°C high-temperature drying oven for complete dehydration, and then transferred to a professional hazardous waste incinerator equipped with a heavy metal flue gas treatment system for safe incineration. Lead compounds enriched in the fly ash are collected for resource recovery.

[0123] Example 4:

[0124] A method for soil remediation using plants and microorganisms includes the following steps:

[0125] Pseudomonas WCS358 was inoculated into liquid culture medium and cultured at 28°C with shaking at 180 rpm for 118 h. After culturing, the bacterial cells were collected by centrifugation at 8000 rpm for 10 min at 4°C. The cells were washed twice with sterile physiological saline and then resuspended in physiological saline to adjust the bacterial concentration to 10. 10 A Pseudomonas bacterial suspension was obtained at CFU / mL;

[0126] Aspergillus niger was inoculated onto potato dextrose agar plates and cultured at 28°C for 7 days. The spores on the plates were then rinsed with sterile physiological saline containing 0.05 wt% Tween-80, and the bacterial cells were washed twice with sterile physiological saline. The plates were then resuspended in physiological saline, and the spore suspension concentration was adjusted to 10. 10 A suspension of Aspergillus niger spores was obtained at a concentration of 1 spore per mL.

[0127] 10 parts by weight of the composite repair carrier prepared in Example 4 were mixed with 150 parts by weight of Pseudomonas bacterial suspension and treated with shaking at 150 r / min at 25°C for 2 h to obtain the first mixture. The first mixture was centrifuged at 4000 r / min for 10 min in a sterile environment, and the wet particles loaded with Pseudomonas were collected.

[0128] The above wet granules were mixed with 150 parts by weight of Aspergillus niger spore suspension and treated with shaking at 150 r / min at 25°C for 2 h to obtain a second mixture. The second mixture was centrifuged at 4000 r / min for 10 min in a sterile environment, and the supernatant was discarded to obtain granules loaded with two bacteria.

[0129] The above-mentioned double-bacterial particles were transferred into a vacuum filtration device, impregnated with 200 parts by weight of 3wt% calcium dihydrogen phosphate solution, and a vacuum pressure of -0.05MPa was applied and maintained for 5 minutes to obtain impregnated particles. The impregnated particles were dried in a hot air drying oven at 40℃ for 6 hours to obtain the double-bacterial composite material.

[0130] The target contaminated area was tilled to a depth of 20cm, using 85g / m³ of soil. 2 Apply the appropriate amount of the dual-bacterial composite material evenly to the soil surface. Immediately after application, use a rotary tiller to perform a second shallow mixing operation to fully mix the dual-bacterial composite material with the top 0-5cm of soil.

[0131] According to 4g / m 2 The seeds of Indian mustard are sown evenly. After sowing, the seeds are covered with 1-2 cm of soil and lightly compacted. Sprinkler irrigation is carried out after sowing to keep the soil moisture content at 60-70% of field capacity. This humidity is then monitored and maintained daily.

[0132] Sixty days after sowing, the Indian mustard plants are harvested in their entirety to complete the soil remediation process. The harvested Indian mustard plants are then placed in a 120°C high-temperature drying oven for complete dehydration, and then transferred to a professional hazardous waste incinerator equipped with a heavy metal flue gas treatment system for safe incineration. Lead compounds enriched in the fly ash are collected for resource recovery.

[0133] Comparative Example 1:

[0134] A method for soil remediation using plants and microorganisms includes the following steps:

[0135] The composite repair carrier prepared in Example 4 was replaced with the composite repair carrier prepared in Example 5, and all other operations were the same as in Example 4.

[0136] Comparative Example 2:

[0137] A method for soil remediation using plants and microorganisms includes the following steps:

[0138] The composite repair carrier prepared in Example 4 was replaced with the composite repair carrier prepared in Example 6, and all other operations were the same as in Example 4.

[0139] Comparative Example 3:

[0140] A method for soil remediation using plants and microorganisms includes the following steps:

[0141] The composite repair carrier prepared in Example 4 was replaced with the composite repair carrier prepared in Example 7, and all other operations were the same as in Example 4.

[0142] Comparative Example 4:

[0143] A method for soil remediation using plants and microorganisms includes the following steps:

[0144] The step of loading Aspergillus niger in Example 4 is removed, and other operations are the same as in Example 4.

[0145] Comparative Example 5:

[0146] A method for soil remediation using plants and microorganisms includes the following steps:

[0147] The composite repair carrier in Example 4 was removed, and the Pseudomonas bacterial suspension and Aspergillus niger spore suspension were directly mixed with calcium dihydrogen phosphate solution to obtain the dual-bacterial composite material. Other operations were the same as in Example 4.

[0148] Effect test:

[0149] The lead concentration in the soil was adjusted to 800 mg / kg to obtain the lead-contaminated soil required for the experiment. This soil was used to test the remediation effect of lead-contaminated soil in Examples 1-4 and Comparative Examples 1-5.

[0150] Soil lead removal rate test: After the remediation experiment, soil samples with a depth of 0-20 cm were collected from the experimental areas of Examples 1-4 and Comparative Examples 1-5, respectively. The collected soil samples were air-dried, ground, and sieved in sequence, and then digested using the aqua regia-perchloric acid digestion method. After digestion, the total lead content in the soil was measured, and the soil lead removal rate was calculated.

[0151] ;

[0152] C0 represents the lead content of the soil before remediation;

[0153] C1 represents the lead content in the remediated soil.

[0154] Plant lead accumulation test: After harvesting Indian mustard plants on day 60, the collected plant samples were washed, dried, and dried to constant weight. The dried samples were then ground using a plant pulverizer, and 0.5 g of the dried powder was weighed and digested using aqua regia-perchloric acid digestion. After digestion, the lead concentration in the solution was measured, and the lead accumulation in the plant samples of Examples 1-4 and Comparative Examples 1-5 was calculated.

[0155] ;

[0156] c represents the concentration of lead in the test solution;

[0157] V is the volume of the test solution;

[0158] m is the dry weight of the plant;

[0159] Plant biomass test: All Indian mustard plants harvested per square meter were washed, dried, and dried to constant weight. The dry weight of plants in Examples 1-4 and Comparative Examples 1-5 was recorded and expressed in grams per square meter (g / m²). The test results are shown in Table 1.

[0160]

[0161] Based on the test results in Table 1, the following conclusions can be drawn:

[0162] (1) The methods in Examples 1 to 4 of the present invention have good lead removal rate and plant enrichment, and their performance is better than that of Comparative Examples 1 to 5;

[0163] (2) The reason for the performance reduction of Comparative Example 1 may be that zirconium sulfate replaced zirconium oxychloride. Sulfuric acid has a stronger coordination ability and may compete with the binding sites of zirconium ions, resulting in disordered zirconium phosphate layered structure, poor crystallinity and small specific surface area. Its adsorption capacity and rate are significantly lower than the regular structure of Example 4, which greatly reduces the "initial immobilization capacity" of the entire carrier and reduces the total amount of Pb available for subsequent activation and absorption. Although the microbial and plant links are still working, the "raw materials" are insufficient, resulting in a decrease in final efficiency.

[0164] (3) The reason for the performance degradation of Comparative Example 2 may be that the dopamine modification was omitted and the bridging of polydopamine was lacking. The apatite complex and the aminated diatomite could not form a strong covalent bond and relied only on fragile physical adsorption. After being applied to the soil, under the action of water and machinery, the "quinone-containing complex" with adsorption and microbial loading functions fell off the porous framework "diatomite", resulting in the effective colonization and protection of microorganisms, which were easily lost and died. The physical framework support and pore buffering effect of diatomite failed, and it could not form an effective microenvironment for remediation of lead pollution. The entire synergistic remediation system collapsed, resulting in a performance degradation.

[0165] (4) The reason for the performance reduction of Comparative Example 3 may be that the amination of diatomite was omitted. The surface of unaminated diatomite lacks reactive sites and cannot be stably bound to the quinone-containing complex. The functional composite material will gradually separate from the skeleton in the soil, resulting in the loss of functional components and a decrease in the durability and stability of the repair effect. It may have a certain effect in the early stage, but it cannot play a continuous and stable role throughout the repair cycle like Example 4, thereby destroying the structural integrity and long-term effectiveness of the carrier.

[0166] (5) The reason for the reduced performance of Comparative Example 4 may be that only Pseudomonas was loaded, and the functional synergy of the microbial community was disrupted; Aspergillus niger dissolves and chelates fixed lead in the soil that is difficult for plants to absorb by secreting organic acids, and converts it into available lead that can be used by plants and bacteria; without Aspergillus niger, Pseudomonas and Indian mustard can only use the part of lead that is already available in the soil, and are powerless to deal with the large amount of lead "locked" in soil minerals; the plant biomass may be slightly higher, possibly because there are no fungi competing with plants for nutrient space;

[0167] (6) The reason for the performance degradation of Comparative Example 5 may be that the microbial agent was applied directly without a carrier. The microorganisms were directly exposed to the soil environment and suffered from stresses such as drought, nutrient competition and predation by protozoa, and could not colonize and perform their functions. Without a carrier, calcium dihydrogen phosphate was also easily lost or fixed, and could not be effectively deactivated and provide nutrients. The whole system degenerated into ordinary phytoremediation, with the same effect as natural decay.

[0168] (7) This invention solves the problem of low field survival rate of microbial agents in soil lead remediation. By constructing a “adsorption-microorganism-plant” synergistic system, the composite remediation carrier achieves a lead removal rate of more than 85% and the plant enrichment can reach more than 1000 mg / kg. In this invention, the carrier effectively protects and promotes the activity of functional microorganisms. Through the “passivation-activation-absorption” closed-loop synergistic mechanism, it ensures plant growth while efficiently removing lead. Finally, it achieves safe disposal and resource utilization of pollutants through plant incineration and recycling, and eliminates secondary pollution.

[0169] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for soil remediation using plants and microorganisms, characterized in that, The method includes the following steps: The composite repair carrier was sequentially mixed with a suspension of Pseudomonas aeruginosa and a suspension of Aspergillus niger spores and subjected to shaking treatment to obtain particles carrying two bacteria. The two-bacterial composite material was obtained by impregnating the two-bacterial particles with calcium dihydrogen phosphate solution and then drying them. After tilling the soil, apply the double-bacterial composite material and Indian mustard seeds in sequence, maintaining the soil moisture content at 60-70% of field capacity; On the 60th day after sowing, the entire Indian mustard plant was harvested, and soil remediation was completed. The preparation method of the composite repair carrier includes the following steps: Humic acid was pretreated and activated to obtain pretreated humic acid. The pretreated humic acid and zirconium oxychloride were mixed and stirred to obtain a zirconium-humic acid solution. The zirconium-humic acid solution was mixed with 85wt% phosphoric acid solution, and the pH was adjusted to 2.8~3.2 before stirring to obtain a humic acid-zirconium phosphate complex. Soy protein isolate and humic acid-zirconium phosphate complex were mixed and reacted by oscillation to obtain humic acid complex. A humic acid complex, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 4-dimethylaminopyridine and hydroxyapatite were mixed and stirred to obtain an apatite complex. A quinone-containing complex was obtained by mixing and stirring apatite complex, dopamine hydrochloride, and copper sulfate. After calcination, porous diatomaceous earth is mixed and stirred with 3-aminopropyltriethoxysilane to obtain aminated diatomaceous earth. The composite remediation carrier was prepared by mixing and stirring a quinone-containing complex with amino-modified diatomaceous earth. The weight ratio of the pretreated humic acid, zirconium oxychloride and 85wt% phosphoric acid solution is 5~7:10~20:13~14; The weight ratio of soy protein isolate to humic acid-zirconium phosphate complex is 90~110:20~30; The weight ratio of the humic acid complex, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, dimethylaminopyridine, and hydroxyapatite is 10:0.3~0.5:0.05~0.1:1.1~1.5; The weight ratio of the apatite complex, dopamine hydrochloride, and copper sulfate is 100:4~6:0.4~0.

6.

2. The method for soil remediation using plants and microorganisms as described in claim 1, characterized in that, The concentration of the Pseudomonas bacterial suspension was 10. 10 The concentration of the Aspergillus niger spore suspension was 10 CFU / mL. 10 per mL.

3. The method for soil remediation using plants and microorganisms as described in claim 1, characterized in that, The concentration of the calcium dihydrogen phosphate solution is 1~3wt%.

4. The method for soil remediation using plants and microorganisms as described in claim 1, characterized in that, The dosage of the dual-bacterial composite material is 75~85g / m³. 2 .

5. The method for soil remediation using plants and microorganisms as described in claim 1, characterized in that, The dosage of Indian mustard seeds is 4 g / m³. 2 .

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