In-situ repair material for river basin bottom mud sediment as well as preparation method and application of in-situ repair material

Abstract

The invention belongs to the technical field of river basin bottom mud sediment remediation, and particularly relates to an in-situ remediation material for river basin bottom mud sediment as well as a preparation method and application thereof, the in-situ remediation material comprises a framework material as well as an exogenous functional microbial flora and a local microbial complex flora which are loaded on the framework material; the framework material is prepared from coal gangue waste; the exogenous functional microbial flora is an anaerobic microbial flora; wherein the anaerobic microbial flora has the function of degrading aromatic compounds, and the aromatic compounds comprise polycyclic aromatic hydrocarbon, benzene series or phenolic substances; the native microorganism composite flora is obtained by screening sediment of river basin bottom mud; according to the method, the degradation capacity of the functional microbial flora is remarkably improved, meanwhile, harmonious symbiosis of the introduced exogenous functional microorganisms and the local microbial complex flora is effectively promoted, the continuous stability and high efficiency of the river basin bottom mud sediment remediation process are ensured, and the overall remediation effect of the river basin bottom mud sediment is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of watershed sediment remediation technology, and specifically relates to an in-situ remediation material for watershed sediments, its preparation method, and its application. Background Technology

[0002] With the incomplete combustion of fossil fuels, crop straw, and tobacco, large amounts of aromatic compounds such as polycyclic aromatic hydrocarbons (PAHs), benzene compounds, and phenols are often dispersed into the air via dust, then settle into rivers and soil, and finally accumulate in the sediments of watersheds. PAHs and other organic pollutants not only possess strong toxicity and harmfulness, significantly inhibiting aquatic ecosystems and plant growth, but also exhibit high resistance to conventional microbial degradation, increasing the difficulty of effective remediation. Long-term accumulation will severely pollute the aquatic environment and pose a potential threat to human health and safety. Therefore, taking effective sediment remediation measures has become particularly urgent and necessary.

[0003] Currently, remediation methods for riverbed sediments are mainly divided into two categories: in-situ remediation and ex-situ remediation. Among them, in-situ remediation has become the most widely used remediation method due to its simplicity and low cost. Immobilized microbial technology is a commonly used method in in-situ remediation, which has high operability and can fix specific microorganisms on carrier materials, avoiding the loss problem of direct application of biological agents. However, conventional immobilized microbial technology has problems such as poor environmental adaptability, expensive framework materials, and low microbial immobilization strength, making it difficult to achieve continuous and efficient degradation of pollutants in the sediment. In addition, current research mostly focuses on the remediation of riverbed sediments with ordinary pollution and mostly uses aerobic microbial immobilization technology. However, the remediation process of sediments is often carried out in an anaerobic environment, in which aerobic microorganisms cannot play an efficient degradation role. Therefore, it is not suitable for the remediation of sediments in large river basins. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides an in-situ remediation material for watershed sediments, its preparation method, and its application, in order to solve the technical problems of conventional immobilized microbial technology, such as poor environmental adaptability, expensive skeleton materials, and low microbial immobilization strength, which make it difficult to achieve continuous and efficient degradation of pollutants in sediments.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides an in-situ remediation material for watershed sediments, comprising a framework material and an exogenous functional microbial community and a native microbial complex loaded on the framework material; The skeleton material is obtained from coal gangue waste; The exogenous functional microbial community is an anaerobic microbial community; wherein, the anaerobic microbial community has the function of degrading aromatic compounds, the aromatic compounds including polycyclic aromatic hydrocarbons, benzene series compounds or phenolic substances; The indigenous microbial complex was obtained by screening sediments from the bottom of the watershed.

[0006] Furthermore, the preparation process of the skeleton material includes: Coal gangue waste is crushed, ground, and sieved to obtain coal gangue powder; Coal gangue powder is calcined to obtain calcined coal gangue; Surface-modified coal gangue was obtained by using surfactants to modify the surface of calcined coal gangue. The surface-modified coal gangue is mixed with a binder, shaped, and reacted to obtain the skeleton material.

[0007] Furthermore, the process of calcining coal gangue powder to obtain calcined coal gangue includes: Coal gangue powder and sodium hydroxide are mixed in a mass ratio of 1:(0.01-0.03), and then calcined at 500-1000℃ to obtain calcined coal gangue.

[0008] Furthermore, the surfactant is one of a cationic surfactant, anionic surfactant, and nonionic surfactant; wherein the cationic surfactant is hexadecyltrimethylammonium bromide, the anionic surfactant is sodium dodecylbenzenesulfonate, and the nonionic surfactant is polyvinyl alcohol.

[0009] Furthermore, the mass ratio of the surface-modified coal gangue to the binder is 1:1 to 1:3; wherein the binder is one or both of silica sol and alumina sol.

[0010] Furthermore, the preparation process of the exogenous functional microbial community includes: Activated sludge was obtained from the anaerobic tank of the biochemical treatment system of a coal chemical wastewater treatment plant. Activated sludge was inoculated into a culture medium with a preset first concentration of polycyclic aromatic hydrocarbons as substrates and cultured under anaerobic conditions to obtain a mixed microbial community with polycyclic aromatic hydrocarbon degradation efficiency. A mixed bacterial community with enhanced degradation efficiency was inoculated into a culture medium with a preset second concentration of polycyclic aromatic hydrocarbons as substrates and cultured under anaerobic conditions to obtain a mixed bacterial community with enhanced polycyclic aromatic hydrocarbon degradation efficiency. A mixed bacterial community with enhanced polycyclic aromatic hydrocarbon (PAH) degradation efficiency was inoculated into a culture medium with a preset third concentration of PAHs as the substrate, and enriched under an anaerobic environment to obtain a dominant bacterial community with PAH degradation efficiency, which was then used as an exogenous functional microbial community.

[0011] Furthermore, the preset first concentration is 1-3 mg / L, the preset second concentration is 5-10 mg / L, and the preset third concentration is 5-10 mg / L; the exogenous functional microbial community includes Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0012] Furthermore, the preparation process of the indigenous microbial complex includes: Obtain bottom sediments from a predetermined watershed and pre-treat them to obtain bottom sediment samples; Sediment samples were inoculated into conventional culture medium and cultured statically under simulated river sediment conditions. After purification, the purified dominant bacterial population was obtained. The purified dominant bacterial population was inoculated into a conventional culture medium for enrichment culture to obtain a local microbial complex.

[0013] This invention also provides a method for preparing an in-situ remediation material for watershed sediments, comprising: The exogenous functional microbial community is mixed with the native microbial complex community to obtain a mixed microbial community solution; wherein, the volume ratio of the exogenous functional microbial community to the native microbial complex community in the mixed microbial community solution is 1:0.2-1:0.5. The scaffold material was completely immersed in the mixed bacterial solution and grown under anaerobic conditions to obtain primary growth material; Primary growth material is added to the bottom sediments of the watershed, adapted to grow in the actual environment of the watershed, and the adapted primary growth material is recovered. The primary growth material, after adapting to growth, is immersed in a mixed microbial solution and then undergoes secondary growth under anaerobic conditions to obtain in-situ remediation material for watershed sediment sediments.

[0014] The present invention also provides an application of an in-situ remediation material for watershed sediment deposits, wherein the in-situ remediation material is used in the remediation and treatment process of watershed sediment deposits.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The in-situ remediation material for watershed sediments provided by this invention loads exogenous functional microbial communities and native microbial composite communities onto a framework material prepared using coal gangue waste. By introducing exogenous functional microbial communities and native microbial composite communities, the degradation capacity of the functional microbial communities is significantly enhanced, while the harmonious symbiosis between the introduced exogenous functional microorganisms and the native microbial composite communities is effectively promoted. This ensures the continuous stability and high efficiency of the watershed sediment remediation process, significantly improving the overall remediation effect of watershed sediments. Specifically, the framework material prepared using coal gangue waste has a good pore structure, abundant active sites, and a significant specific surface area, providing more attachment points for the adsorption and growth of microbial communities. At the same time, its porous nature facilitates the interaction between microorganisms and the framework material. The interaction between the microorganisms promotes their immobilization and reproduction; their porous structure also facilitates the diffusion of oxygen and nutrients, thereby enhancing their activity; furthermore, the porosity and large specific surface area are conducive to the coexistence and synergistic effect of multiple microorganisms on their surface, enhancing the overall degradation capacity of the microbial community. Different types of microorganisms can work together to decompose complex pollutants or improve biotransformation efficiency through synergistic effects; the exogenous functional microbial community has a highly efficient degradation capacity for aromatic organic compounds, and the synergistic effect of the composite microbial community is even better for the degradation of other types of organic compounds; the native microbial composite community is screened from the sediment of this watershed, which can further promote the adaptability of the exogenous functional microbial community to the environment; the in-situ remediation material prepared by this invention can more effectively promote the comprehensive degradation of pollutants and the deep remediation of sediment.

[0016] Furthermore, using coal gangue waste as a skeleton material helps with resource recycling, reduces environmental pollution, and improves ecological benefits. In addition, using industrial waste coal gangue as a skeleton material is more economically attractive compared to other commercially available skeleton materials. Modification with surfactants significantly enhances the hydrophilicity and surface functional group diversity of the skeleton material, making it more suitable for the attachment and growth of specific microorganisms. Secondly, surfactant modification enhances the interaction forces with microorganisms, including hydrogen bonds, van der Waals forces, and electrostatic interactions, thereby improving the adhesion ability and strength of microorganisms. The skeleton material itself has a certain adsorption capacity, which can help adsorb harmful substances in the environment, reduce pollution, and exert a dual effect of environmental governance. Solidification and granulation of the skeleton material facilitates its application in actual operations. Furthermore, the solidified particles gradually disperse over time, achieving a slow-release effect.

[0017] Furthermore, co-doping with sodium hydroxide during calcination significantly increases the diversity of the pore structure and crystal morphology of the framework material, which is beneficial to improving the diffusion rate and adsorption capacity of the substance, making it suitable for adsorbing pollutants of different molecular sizes.

[0018] Furthermore, exogenous functional microbial communities are screened and enriched in an anaerobic environment and then cultured in an anaerobic environment, making them more suitable for the remediation of sediment pollutants.

[0019] Furthermore, in the preparation of in-situ remediation materials, the skeleton material is completely immersed in a mixed bacterial solution and grown in an anaerobic environment. After adapting to the actual environment, it is then grown again in an anaerobic environment, which can significantly improve the environmental adaptability and continuous and stable degradation of the material. Attached Figure Description

[0020] Figure 1 A flowchart illustrating the preparation method of the in-situ remediation material for watershed sediments provided by this invention. Detailed Implementation

[0021] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0022] This invention provides an in-situ remediation material for watershed sediments, comprising a framework material, exogenous functional microbial communities, and a native microbial complex; both the exogenous functional microbial communities and the native microbial complex are loaded onto the framework material.

[0023] The skeleton material is made from coal gangue waste.

[0024] The exogenous functional microbial community is an anaerobic microbial community; wherein, the anaerobic microbial community has the function of degrading aromatic compounds, the aromatic compounds including polycyclic aromatic hydrocarbons, benzene series compounds or phenolic substances.

[0025] The indigenous microbial complex was obtained by screening sediments from the bottom of the watershed.

[0026] Optionally, the preparation process of the skeleton material is as follows: Step 101: Crush, grind and sieve the coal gangue waste to obtain crushed coal gangue.

[0027] Step 102: Mix the crushed coal gangue with solid sodium hydroxide at a mass ratio of 1:0.01-1:0.03, then place the mixture in a muffle furnace and calcine it at 500-1000℃ for 4 hours to obtain calcined coal gangue.

[0028] Step 103: Surface modification treatment of calcined coal gangue using surfactants to obtain surface-modified coal gangue; specifically, calcined coal gangue is mixed with surfactants to obtain a mixed solution; the mixed solution is stirred and reacted at room temperature for 24 hours, and solid-liquid separation is performed after the reaction to obtain separated solid coal gangue; the separated solid coal gangue is placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue.

[0029] The surfactant is one of a cationic surfactant, anionic surfactant, and nonionic surfactant; preferably, the cationic surfactant is hexadecyltrimethylammonium bromide, the anionic surfactant is sodium dodecylbenzenesulfonate, and the nonionic surfactant is polyvinyl alcohol; in the mixed solution, the mass fraction of the calcined coal gangue is 5%-10%, and the mass fraction of the surfactant is 1%-5%.

[0030] Step 104: Mix the modified coal gangue with the binder to obtain a mixed coal gangue; place the mixed coal gangue in a pre-selected spherical mold for shaping, then place it in an oven and react at 100-140℃ for 24 hours to obtain the skeleton material; wherein, the mass ratio of the surface-modified coal gangue to the binder is 1:1-1:3; preferably, the binder is one or both of silica sol and alumina sol.

[0031] Optionally, the preparation process of the exogenous functional microbial community is as follows: Step 201: Obtain activated sludge from the anaerobic tank of the biochemical treatment system of the coal chemical wastewater treatment plant.

[0032] Step 202: Inoculate the activated sludge into a culture medium with a preset first concentration of polycyclic aromatic hydrocarbons as substrates, and culture it under anaerobic conditions to obtain a mixed microbial community with polycyclic aromatic hydrocarbon degradation efficiency; wherein, the preset first concentration is 1-3 mg / L.

[0033] Step 203: Inoculate the mixed bacterial community with degradation efficiency into a culture medium with a preset second concentration of polycyclic aromatic hydrocarbons as substrates, and culture it under anaerobic conditions to obtain a mixed bacterial community with enhanced polycyclic aromatic hydrocarbon degradation efficiency; wherein, the preset second concentration is 5-10 mg / L.

[0034] Step 204: Inoculate the mixed bacterial community with enhanced polycyclic aromatic hydrocarbon (PAH) degradation efficiency into a culture medium with a preset third concentration of PAHs as the substrate, and carry out enrichment culture under anaerobic conditions to obtain a dominant bacterial community with PAH degradation efficiency as an exogenous functional microbial community; wherein, the preset third concentration is 5-10 mg / L; it should be noted that the exogenous functional microbial community contains at least 10 species; among them, the main species include Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0035] Optionally, the preparation process of the indigenous microbial complex is as follows: Step 301: Obtain bottom sediments from the predetermined watershed and pre-treat them to obtain bottom sediment samples.

[0036] Step 302: Inoculate the sediment sample into a conventional culture medium and allow it to stand in a simulated river sediment environment. Then, purify the sample to obtain the purified dominant bacterial population. The simulated river sediment environment is 2-8℃.

[0037] Step 303: Inoculate the purified dominant bacterial group into a conventional culture medium for enrichment culture to obtain a local microbial complex. It should be noted that the local microbial complex contains at least 10 species, mainly including Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0038] As attached Figure 1 As shown, the present invention also provides a method for preparing an in-situ remediation material for watershed sediments, comprising the following steps: Step 100: Mix the exogenous functional microbial community with the native microbial complex community to obtain a mixed microbial community solution A; completely immerse the skeleton material in the mixed microbial community solution A and grow it under anaerobic conditions to obtain primary growth material. The volume ratio of the exogenous functional microbial community to the native microbial complex community in the mixed microbial community solution A is 1:0.2-1:0.5.

[0039] Step 200: Add the primary growth material to the bottom sediment of the watershed, allow it to adapt and grow in the actual environment of the watershed, and recover the primary growth material after adaptation.

[0040] Step 300: Mix the exogenous functional microbial community with the native microbial composite community to obtain a mixed microbial community solution B; immerse the primary growth material after adaptation in the mixed microbial community solution B and perform secondary growth under anaerobic conditions to obtain an in-situ remediation material for watershed sediment sediments. The volume ratio of the exogenous functional microbial community to the native microbial composite community in the mixed microbial community solution B is 1:0.2-1:0.5.

[0041] The in-situ remediation material for watershed sediments described in this invention can be used for the efficient remediation of watershed sediments. The preparation of the in-situ remediation material uses coal gangue, surfactants, and microbial culture media as raw materials. These raw materials are not only widely available in the market and easy to purchase, but also economical, greatly reducing the complexity and overall cost of production. The entire preparation process is green and environmentally friendly, and the resulting product is not only safe and harmless but also recyclable, fundamentally avoiding the risk of secondary pollution. During the preparation process, the modified coal gangue is used as a framework material for microbial growth and attachment, which not only achieves effective utilization of waste but also significantly enhances the structural stability and performance of the composite material. The prepared in-situ remediation material exhibits excellent remediation efficacy against polycyclic aromatic hydrocarbon pollutants in sediments, with remarkable high-efficiency removal capabilities.

[0042] This invention modifies the surface of coal gangue by introducing specific functional groups, such as amino, carboxyl, and hydroxyl groups, which greatly promotes the interaction between microorganisms, provides a wider and more stable attachment space for microorganisms, and significantly improves the attachment strength of microorganisms. It not only optimizes the growth environment of microorganisms, but also enhances the material's ability to biodegrade pollutants, ensuring the long-term stability and high efficiency of its remediation performance.

[0043] The following specific embodiments further illustrate the in-situ remediation material for watershed sediments provided by the present invention: Example 1 This embodiment 1 provides a method for preparing an in-situ remediation material for watershed sediments, including the following steps: Step 1: Crush, grind, and pass the coal gangue waste through a 200-mesh sieve to obtain coal gangue powder.

[0044] Step 2: Mix 1g of coal gangue powder with 0.01g of sodium hydroxide, then place the mixture in a muffle furnace and calcine at 500℃ for 4 hours to obtain calcined coal gangue.

[0045] Step 3: Add 5g of calcined coal gangue to 100mL of a 1% (w / w) hexadecyltrimethylammonium bromide solution to obtain mixed solution A; stir mixed solution A at room temperature for 24h, and then separate the solid and liquid components to obtain the separated solid coal gangue A; place the separated solid coal gangue A in an oven and react at 100℃ for 24h to obtain surface-modified coal gangue A; separately add 5g of calcined coal gangue to 100mL of a 1% (w / w) sodium dodecylbenzenesulfonate solution to obtain mixed solution B; stir mixed solution B at room temperature for 24h, and then separate the solid and liquid components to obtain the separated solid... Coal gangue B; the separated solid coal gangue B was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue B; then 5g of calcined coal gangue was added to 100mL of polyvinyl alcohol solution with a mass percentage of 1% to obtain mixed solution C; mixed solution C was stirred and reacted at room temperature for 24 hours, and then the solid and liquid were separated to obtain separated solid coal gangue C; the separated solid coal gangue C was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue C; surface-modified coal gangue A, surface-modified coal gangue B and surface-modified coal gangue C were mixed to obtain surface-modified coal gangue.

[0046] Step 4: Take 1g of surface-modified coal gangue and mix it with 1g of silica sol to obtain a mixed coal gangue; place the mixed coal gangue in a pre-selected spherical mold for shaping, and then place it in an oven and react at 100℃ for 24h to obtain the skeleton material.

[0047] Step 5: Obtain activated sludge from the anaerobic tank of the biochemical treatment system of the coal chemical wastewater treatment plant to obtain activated sludge; inoculate the activated sludge into a culture medium with 1 mg / L polycyclic aromatic hydrocarbons (PAHs) as the substrate and culture it under anaerobic conditions. Measure the degradation efficiency of the mixed bacterial community in the activated sludge for PAHs at different time points until the degradation efficiency of the mixed bacterial community for PAHs reaches more than 90%, thus obtaining a mixed bacterial community with PAH degradation efficiency; inoculate the mixed bacterial community with degradation efficiency into a culture medium with 5 mg / L PAHs as the substrate and culture it under anaerobic conditions to obtain a mixed bacterial community with enhanced PAH degradation efficiency; then, inoculate the mixed bacterial community with enhanced PAH degradation efficiency into a culture medium with 5 mg / L PAHs as the substrate and enrich it under anaerobic conditions to obtain a dominant bacterial community with PAH degradation efficiency, which serves as an exogenous functional microbial community.

[0048] It should be noted that the concentration and activity of the dominant bacterial community are further improved through repeated inoculation and expanded culture; the exogenous functional microbial community contains at least 10 species; among them, Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoides are the main species.

[0049] Step 6: Take sediment from the target watershed, remove impurities, grind and mix evenly to obtain sediment samples; inoculate the sediment samples into conventional culture medium and incubate them at 2-8℃ under environmental conditions simulating river sediment, and then purify them to obtain the purified dominant bacterial population.

[0050] Step 7: Inoculate the purified dominant bacterial group into a conventional culture medium for enrichment culture to obtain a local microbial complex. It should be noted that the concentration and activity of the dominant bacterial group can be further improved by repeated inoculation and expanded culture. The local microbial complex contains at least 10 species, mainly including Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0051] Step 8: Mix 100 mL of exogenous functional microbial flora with 20 mL of native microbial complex flora to obtain mixed flora solution A; add 100 g of skeleton material to mixed flora solution A and grow it in an anaerobic environment for 3 days to obtain primary growth material.

[0052] Step 9: Add the primary growth material to the bottom sediment of the target watershed, allow it to adapt and grow in the actual watershed environment for 20 days, and then recover the primary growth material after adaptation.

[0053] Step 10: Mix 100 mL of exogenous functional microbial flora with 20 mL of native microbial complex flora to obtain mixed flora solution B; add 100 g of the primary growth material after adaptation to the mixed flora solution B, and grow it in an anaerobic environment for 3 days to obtain in-situ remediation material for watershed sediment sediments.

[0054] Example 2 This embodiment 2 provides a method for preparing an in-situ remediation material for watershed sediments, including the following steps: Step 1: Crush, grind, and pass the coal gangue waste through a 200-mesh sieve to obtain coal gangue powder.

[0055] Step 2: Mix 1g of coal gangue powder with 0.03g of sodium hydroxide, and then calcine it in a muffle furnace at 800℃ for 4 hours to obtain calcined coal gangue.

[0056] Step 3: Add 8g of calcined coal gangue to 100mL of a 3% (w / w) hexadecyltrimethylammonium bromide solution to obtain mixed solution A; stir mixed solution A at room temperature for 24h, and then separate the solid and liquid components to obtain solid coal gangue A; place the separated solid coal gangue A in an oven and react at 100℃ for 24h to obtain surface-modified coal gangue A; separately add 8g of calcined coal gangue to 100mL of a 3% (w / w) sodium dodecylbenzenesulfonate solution to obtain mixed solution B; stir mixed solution B at room temperature for 24h, and then separate the solid and liquid components to obtain solid coal gangue A. Coal gangue B; the separated solid coal gangue B was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue B; then 8g of calcined coal gangue was added to 100mL of a 3% (w / w) polyvinyl alcohol solution to obtain a mixed solution C; the mixed solution C was stirred and reacted at room temperature for 24 hours, and then the solid and liquid were separated to obtain the separated solid coal gangue C; the separated solid coal gangue C was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue C; the surface-modified coal gangue A, surface-modified coal gangue B, and surface-modified coal gangue C were mixed to obtain surface-modified coal gangue.

[0057] Step 4: Take 1g of surface-modified coal gangue and mix it with 2g of aluminum sol to obtain a mixed coal gangue; place the mixed coal gangue in a pre-selected spherical mold for shaping, and then place it in an oven and react at 140℃ for 12h to obtain the skeleton material.

[0058] Step 5: Obtain activated sludge from the anaerobic tank of the biochemical treatment system of the coal chemical wastewater treatment plant to obtain activated sludge; inoculate the activated sludge into a culture medium with 1 mg / L polycyclic aromatic hydrocarbons (PAHs) as the substrate and culture it under anaerobic conditions. Measure the degradation efficiency of the mixed bacterial community in the activated sludge for PAHs at different time points until the degradation efficiency of the mixed bacterial community for PAHs reaches more than 90%, thus obtaining a mixed bacterial community with PAH degradation efficiency; inoculate the mixed bacterial community with degradation efficiency into a culture medium with 10 mg / L PAHs as the substrate and culture it under anaerobic conditions to obtain a mixed bacterial community with enhanced PAH degradation efficiency; then, inoculate the mixed bacterial community with enhanced PAH degradation efficiency into a culture medium with 10 mg / L PAHs as the substrate and enrich it under anaerobic conditions to obtain a dominant bacterial community with PAH degradation efficiency, which serves as an exogenous functional microbial community.

[0059] It should be noted that the concentration and activity of the dominant bacterial community are further improved through repeated inoculation and expanded culture; the exogenous functional microbial community contains at least 10 species; among them, Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoides are the main species.

[0060] Step 6: Take sediment from the target watershed, remove impurities, grind and mix evenly to obtain sediment samples; inoculate the sediment samples into conventional culture medium and incubate them at 2-8℃ under environmental conditions simulating river sediment, and then purify them to obtain the purified dominant bacterial population.

[0061] Step 7: Inoculate the purified dominant bacterial group into a conventional culture medium for enrichment culture to obtain a local microbial complex. It should be noted that the concentration and activity of the dominant bacterial group can be further improved by repeated inoculation and expanded culture. The local microbial complex contains at least 10 species, mainly including Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0062] Step 8: Mix 100 mL of exogenous functional microbial flora with 30 mL of native microbial complex flora to obtain mixed flora solution A; add 100 g of skeleton material to mixed flora solution A and grow it in an anaerobic environment for 4 days to obtain primary growth material.

[0063] Step 9: Add the primary growth material to the bottom sediment of the target watershed, allow it to adapt and grow in the actual watershed environment for 20 days, and then recover the primary growth material after adaptation.

[0064] Step 10: Mix 100 mL of exogenous functional microbial flora with 30 mL of native microbial complex flora to obtain mixed flora solution B; add 100 g of the primary growth material after adaptation to the mixed flora solution B, and grow it in an anaerobic environment for 4 days to obtain in-situ remediation material for watershed sediment sediments.

[0065] Example 3 This embodiment 3 provides a method for preparing an in-situ remediation material for watershed sediments, including the following steps: Step 1: Crush, grind, and pass the coal gangue waste through a 200-mesh sieve to obtain coal gangue powder.

[0066] Step 2: Mix 1g of coal gangue powder with 0.03g of sodium hydroxide, and then calcine it in a muffle furnace at 1000℃ for 4 hours to obtain calcined coal gangue.

[0067] Step 3: Add 10g of calcined coal gangue to 100mL of a 5% (w / w) hexadecyltrimethylammonium bromide solution to obtain mixed solution A; stir mixed solution A at room temperature for 24h, then separate the solid and liquid components to obtain solid coal gangue A; place the separated solid coal gangue A in an oven and react at 100℃ for 24h to obtain surface-modified coal gangue A; separately add 10g of calcined coal gangue to 100mL of a 5% (w / w) sodium dodecylbenzenesulfonate solution to obtain mixed solution B; stir mixed solution B at room temperature for 24h, then separate the solid and liquid components to obtain solid coal gangue A. Solid coal gangue B was separated and placed in an oven at 100°C for 24 hours to obtain surface-modified coal gangue B. Another 10g of calcined coal gangue was added to a 100mL (5% by mass) polyvinyl alcohol solution to obtain a mixed solution C. The mixed solution C was stirred and reacted at room temperature for 24 hours. After the reaction, solid and liquid were separated to obtain the separated solid coal gangue C. The separated solid coal gangue C was placed in an oven and reacted at 100°C for 24 hours to obtain surface-modified coal gangue C. Surface-modified coal gangue A, surface-modified coal gangue B, and surface-modified coal gangue C were mixed to obtain surface-modified coal gangue.

[0068] Step 4: Take 1g of surface-modified coal gangue and mix it with 3g of aluminum sol to obtain a mixed coal gangue; place the mixed coal gangue in a pre-selected spherical mold for shaping, and then place it in an oven and react at 100℃ for 12h to obtain the skeleton material.

[0069] Step 5: Obtain activated sludge from the anaerobic tank of the biochemical treatment system of the coal chemical wastewater treatment plant to obtain activated sludge; inoculate the activated sludge into a culture medium with 2 mg / L polycyclic aromatic hydrocarbons (PAHs) as substrate and culture it under anaerobic conditions. Measure the degradation efficiency of the mixed bacterial community in the activated sludge for PAHs at different time points until the degradation efficiency of the mixed bacterial community for PAHs reaches more than 90%, thus obtaining a mixed bacterial community with PAH degradation efficiency; inoculate the mixed bacterial community with degradation efficiency into a culture medium with 8 mg / L PAHs as substrate and culture it under anaerobic conditions to obtain a mixed bacterial community with enhanced PAH degradation efficiency; then, inoculate the mixed bacterial community with enhanced PAH degradation efficiency into a culture medium with 8 mg / L PAHs as substrate and enrich it under anaerobic conditions to obtain a dominant bacterial community with PAH degradation efficiency, which serves as an exogenous functional microbial community.

[0070] It should be noted that the concentration and activity of the dominant bacterial community are further improved through repeated inoculation and expanded culture; the exogenous functional microbial community contains at least 10 species; among them, Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoides are the main species.

[0071] Step 6: Take sediment from the target watershed, remove impurities, grind and mix evenly to obtain sediment samples; inoculate the sediment samples into conventional culture medium and incubate them at 2-8℃ under environmental conditions simulating river sediment, and then purify them to obtain the purified dominant bacterial population.

[0072] Step 7: Inoculate the purified dominant bacterial group into a conventional culture medium for enrichment culture to obtain a local microbial complex. It should be noted that the concentration and activity of the dominant bacterial group can be further improved by repeated inoculation and expanded culture. The local microbial complex contains at least 10 species, mainly including Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0073] Step 8: Mix 100 mL of exogenous functional microbial flora with 50 mL of native microbial complex flora to obtain mixed flora solution A; add 100 g of skeleton material to mixed flora solution A and grow it in an anaerobic environment for 5 days to obtain primary growth material.

[0074] Step 9: Add the primary growth material to the bottom sediment of the target watershed, allow it to adapt and grow in the actual watershed environment for 30 days, and then recover the primary growth material after adaptation.

[0075] Step 10: Mix 100 mL of exogenous functional microbial flora with 50 mL of native microbial complex flora to obtain mixed flora solution B; add 100 g of the primary growth material after adaptation to the mixed flora solution B, and grow it in an anaerobic environment for 5 days to obtain in-situ remediation material for watershed sediment sediments.

[0076] Example 4 This embodiment 4 provides a method for preparing an in-situ remediation material for watershed sediments, including the following steps: Step 1: Crush, grind, and pass the coal gangue waste through a 200-mesh sieve to obtain coal gangue powder.

[0077] Step 2: Mix 1g of coal gangue powder with 0.02g of sodium hydroxide, and then calcine it in a muffle furnace at 900℃ for 4 hours to obtain calcined coal gangue.

[0078] Step 3: Add 7g of calcined coal gangue to 100mL of a 4% (w / w) hexadecyltrimethylammonium bromide solution to obtain mixed solution A; stir mixed solution A at room temperature for 24h, and then separate the solid and liquid components to obtain solid coal gangue A; place the separated solid coal gangue A in an oven and react at 100℃ for 24h to obtain surface-modified coal gangue A; separately add 7g of calcined coal gangue to 100mL of a 4% (w / w) sodium dodecylbenzenesulfonate solution to obtain mixed solution B; stir mixed solution B at room temperature for 24h, and then separate the solid and liquid components to obtain solid coal gangue A. Coal gangue B; the separated solid coal gangue B was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue B; then 7g of calcined coal gangue was added to 100mL of polyvinyl alcohol solution with a mass percentage of 4% to obtain mixed solution C; mixed solution C was stirred and reacted at room temperature for 24 hours, and then the solid and liquid were separated to obtain separated solid coal gangue C; the separated solid coal gangue C was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue C; surface-modified coal gangue A, surface-modified coal gangue B and surface-modified coal gangue C were mixed to obtain surface-modified coal gangue.

[0079] Step 4: Take 1g of surface-modified coal gangue, 1g of aluminum sol and 1g of silica sol and mix them to obtain a mixed coal gangue; place the mixed coal gangue in a pre-selected spherical mold for shaping, and then place it in an oven and react at 120℃ for 18h to obtain the skeleton material.

[0080] Step 5: Obtain activated sludge from the anaerobic tank of the biochemical treatment system of the coal chemical wastewater treatment plant to obtain activated sludge; inoculate the activated sludge into a culture medium with 2 mg / L polycyclic aromatic hydrocarbons (PAHs) as substrate and culture it under anaerobic conditions. Measure the degradation efficiency of the mixed bacterial community in the activated sludge for PAHs at different time points until the degradation efficiency of the mixed bacterial community for PAHs reaches more than 90%, thus obtaining a mixed bacterial community with PAH degradation efficiency; inoculate the mixed bacterial community with degradation efficiency into a culture medium with 10 mg / L PAHs as substrate and culture it under anaerobic conditions to obtain a mixed bacterial community with enhanced PAH degradation efficiency; then, inoculate the mixed bacterial community with enhanced PAH degradation efficiency into a culture medium with 10 mg / L PAHs as substrate and enrich it under anaerobic conditions to obtain a dominant bacterial community with PAH degradation efficiency, which serves as an exogenous functional microbial community.

[0081] It should be noted that the concentration and activity of the dominant bacterial community are further improved through repeated inoculation and expanded culture; the exogenous functional microbial community contains at least 10 species; among them, Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoides are the main species.

[0082] Step 6: Take sediment from the target watershed, remove impurities, grind and mix evenly to obtain sediment samples; inoculate the sediment samples into conventional culture medium and incubate them at 2-8℃ under environmental conditions simulating river sediment, and then purify them to obtain the purified dominant bacterial population.

[0083] Step 7: Inoculate the purified dominant bacterial group into a conventional culture medium for enrichment culture to obtain a local microbial complex. It should be noted that the concentration and activity of the dominant bacterial group can be further improved by repeated inoculation and expanded culture. The local microbial complex contains at least 10 species, mainly including Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0084] Step 8: Mix 100 mL of exogenous functional microbial flora with 40 mL of native microbial complex flora to obtain mixed flora solution A; add 100 g of skeleton material to mixed flora solution A and grow it in an anaerobic environment for 4 days to obtain primary growth material.

[0085] Step 9: Add the primary growth material to the bottom sediment of the target watershed, allow it to adapt and grow in the actual watershed environment for 25 days, and then recover the primary growth material after adaptation.

[0086] Step 10: Mix 100 mL of exogenous functional microbial flora with 30 mL of native microbial complex flora to obtain mixed flora solution B; add 100 g of the primary growth material after adaptation to the mixed flora solution B, and grow it in an anaerobic environment for 4 days to obtain in-situ remediation material for watershed sediment sediments.

[0087] Example 5 This embodiment 5 provides a method for preparing an in-situ remediation material for watershed sediments, including the following steps: Step 1: Crush, grind, and pass the coal gangue waste through a 200-mesh sieve to obtain coal gangue powder.

[0088] Step 2: Mix 1g of coal gangue powder with 0.02g of sodium hydroxide, then place the mixture in a muffle furnace and calcine at 600℃ for 4 hours to obtain calcined coal gangue.

[0089] Step 3: Add 6g of calcined coal gangue to 100mL of a 2% (w / w) hexadecyltrimethylammonium bromide solution to obtain mixed solution A; stir mixed solution A at room temperature for 24h, and then separate the solid and liquid components to obtain the separated solid coal gangue A; place the separated solid coal gangue A in an oven and react at 100℃ for 24h to obtain surface-modified coal gangue A; separately add 6g of calcined coal gangue to 100mL of a 2% (w / w) sodium dodecylbenzenesulfonate solution to obtain mixed solution B; stir mixed solution B at room temperature for 24h, and then separate the solid and liquid components to obtain the separated solid... Coal gangue B; the separated solid coal gangue B was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue B; then 6g of calcined coal gangue was added to 100mL of polyvinyl alcohol solution with a mass percentage of 2% to obtain mixed solution C; mixed solution C was stirred and reacted at room temperature for 24 hours, and then the solid and liquid were separated to obtain separated solid coal gangue C; the separated solid coal gangue C was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue C; surface-modified coal gangue A, surface-modified coal gangue B and surface-modified coal gangue C were mixed to obtain surface-modified coal gangue.

[0090] Step 4: Take 1g of surface-modified coal gangue and 2g of silica sol and mix them to obtain a mixed coal gangue; place the mixed coal gangue in a pre-selected spherical mold for shaping, and then place it in an oven and react at 120℃ for 24h to obtain the skeleton material.

[0091] Step 5: Obtain activated sludge from the anaerobic tank of the biochemical treatment system of the coal chemical wastewater treatment plant to obtain activated sludge; inoculate the activated sludge into a culture medium with 3 mg / L polycyclic aromatic hydrocarbons (PAHs) as substrate and culture it under anaerobic conditions. Measure the degradation efficiency of the mixed bacterial community in the activated sludge for PAHs at different time points until the degradation efficiency of the mixed bacterial community for PAHs reaches more than 90%, thus obtaining a mixed bacterial community with PAH degradation efficiency; inoculate the mixed bacterial community with degradation efficiency into a culture medium with 5 mg / L PAHs as substrate and culture it under anaerobic conditions to obtain a mixed bacterial community with enhanced PAH degradation efficiency; then, inoculate the mixed bacterial community with enhanced PAH degradation efficiency into a culture medium with 5 mg / L PAHs as substrate and enrich it under anaerobic conditions to obtain a dominant bacterial community with PAH degradation efficiency, which serves as an exogenous functional microbial community.

[0092] It should be noted that the concentration and activity of the dominant bacterial community are further improved through repeated inoculation and expanded culture; the exogenous functional microbial community contains at least 10 species; among them, Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoides are the main species.

[0093] Step 6: Take sediment from the target watershed, remove impurities, grind and mix evenly to obtain sediment samples; inoculate the sediment samples into conventional culture medium and incubate them at 2-8℃ under environmental conditions simulating river sediment, and then purify them to obtain the purified dominant bacterial population.

[0094] Step 7: Inoculate the purified dominant bacterial group into a conventional culture medium for enrichment culture to obtain a local microbial complex. It should be noted that the concentration and activity of the dominant bacterial group can be further improved by repeated inoculation and expanded culture. The local microbial complex contains at least 10 species, mainly including Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0095] Step 8: Mix 100 mL of exogenous functional microbial flora with 20 mL of native microbial complex flora to obtain mixed flora solution A; add 100 g of skeleton material to mixed flora solution A and grow it in an anaerobic environment for 3 days to obtain primary growth material.

[0096] Step 9: Add the primary growth material to the bottom sediment of the target watershed, allow it to adapt and grow in the actual watershed environment for 28 days, and then recover the primary growth material after adaptation.

[0097] Step 10: Mix 100 mL of exogenous functional microbial flora with 20 mL of native microbial complex flora to obtain mixed flora solution B; add 100 g of the primary growth material after adaptation to the mixed flora solution B, and grow it in an anaerobic environment for 4 days to obtain in-situ remediation material for watershed sediment.

[0098] Example 6 This embodiment 6 provides a method for preparing an in-situ remediation material for watershed sediments, including the following steps: Step 1: Crush, grind, and pass the coal gangue waste through a 200-mesh sieve to obtain coal gangue powder.

[0099] Step 2: Mix 1g of coal gangue powder with 0.01g of sodium hydroxide, and then calcine it in a muffle furnace at 1000℃ for 4 hours to obtain calcined coal gangue.

[0100] Step 3: Add 9g of calcined coal gangue to 100mL of a 9% (w / w) hexadecyltrimethylammonium bromide solution to obtain mixed solution A; stir mixed solution A at room temperature for 24h, and then separate the solid and liquid components to obtain solid coal gangue A; place the separated solid coal gangue A in an oven and react at 100℃ for 24h to obtain surface-modified coal gangue A; separately add 9g of calcined coal gangue to 100mL of a 9% (w / w) sodium dodecylbenzenesulfonate solution to obtain mixed solution B; stir mixed solution B at room temperature for 24h, and then separate the solid and liquid components to obtain solid coal gangue A. Coal gangue B; the separated solid coal gangue B was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue B; then 9g of calcined coal gangue was added to 100mL of polyvinyl alcohol solution with a mass percentage of 9% to obtain mixed solution C; mixed solution C was stirred and reacted at room temperature for 24 hours, and then the solid and liquid were separated to obtain separated solid coal gangue C; the separated solid coal gangue C was placed in an oven and reacted at 100℃ for 24 hours to obtain surface-modified coal gangue C; surface-modified coal gangue A, surface-modified coal gangue B and surface-modified coal gangue C were mixed to obtain surface-modified coal gangue.

[0101] Step 4: Take 1g of surface-modified coal gangue, 1.5g of aluminum sol and 1.5g of silica sol and mix them to obtain a mixed coal gangue; place the mixed coal gangue in a pre-selected spherical mold for shaping, and then place it in an oven and react at 140℃ for 18h to obtain the skeleton material.

[0102] Step 5: Obtain activated sludge from the anaerobic tank of the biochemical treatment system of the coal chemical wastewater treatment plant to obtain activated sludge; inoculate the activated sludge into a culture medium with 3 mg / L polycyclic aromatic hydrocarbons (PAHs) as substrate and culture it under anaerobic conditions. Measure the degradation efficiency of the mixed bacterial community in the activated sludge for PAHs at different time points until the degradation efficiency of the mixed bacterial community for PAHs reaches more than 90%, thus obtaining a mixed bacterial community with PAH degradation efficiency; inoculate the mixed bacterial community with degradation efficiency into a culture medium with 8 mg / L PAHs as substrate and culture it under anaerobic conditions to obtain a mixed bacterial community with enhanced PAH degradation efficiency; then, inoculate the mixed bacterial community with enhanced PAH degradation efficiency into a culture medium with 8 mg / L PAHs as substrate and enrich it under anaerobic conditions to obtain a dominant bacterial community with PAH degradation efficiency, which serves as an exogenous functional microbial community.

[0103] It should be noted that the concentration and activity of the dominant bacterial community are further improved through repeated inoculation and expanded culture; the exogenous functional microbial community contains at least 10 species; among them, Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoides are the main species.

[0104] Step 6: Take sediment from the target watershed, remove impurities, grind and mix evenly to obtain sediment samples; inoculate the sediment samples into conventional culture medium and incubate them at 2-8℃ under environmental conditions simulating river sediment, and then purify them to obtain the purified dominant bacterial population.

[0105] Step 7: Inoculate the purified dominant bacterial group into a conventional culture medium for enrichment culture to obtain a local microbial complex. It should be noted that the concentration and activity of the dominant bacterial group can be further improved by repeated inoculation and expanded culture. The local microbial complex contains at least 10 species, mainly including Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

[0106] Step 8: Mix 100 mL of exogenous functional microbial flora with 50 mL of native microbial complex flora to obtain mixed flora solution A; add 100 g of skeleton material to mixed flora solution A and grow it in an anaerobic environment for 5 days to obtain primary growth material.

[0107] Step 9: Add the primary growth material to the bottom sediment of the target watershed, allow it to adapt and grow in the actual watershed environment for 22 days, and then recover the primary growth material after adaptation.

[0108] Step 10: Mix 100 mL of exogenous functional microbial flora with 20 mL of native microbial complex flora to obtain mixed flora solution B; add 100 g of the primary growth material after adaptation to the mixed flora solution B, and grow it in an anaerobic environment for 5 days to obtain in-situ remediation material for watershed sediment sediments.

[0109] Performance testing: Sediment from the middle and lower reaches of a watershed was selected as the target sediment for the watershed. The in-situ remediation materials for watershed sediment prepared in Examples 1-6 above were used to remediate and degrade organic pollutants such as polycyclic aromatic hydrocarbons in the sediment of the target watershed. The specific process is as follows: In-situ remediation materials for bottom sediments were applied to the surface, middle, and bottom layers of the sediments in the target watershed. After a predetermined time, the remediation status of the sediments was measured and analyzed. The area of ​​the treated sediment remediation zone was 10 m². 2 The amount of repair material applied was 0.05 kg / m³. 2The restoration effect of the bottom sediment is shown in Table 1.

[0110] Table 1. Substrate remediation effects of the in-situ remediation materials prepared in Examples 1-6

[0111] As can be seen from Table 1 above, the in-situ remediation materials for watershed sediments prepared in Examples 1-6 have high removal rates of polycyclic aromatic hydrocarbons (PAHs), benzene compounds, and COD, and the effects are stable. Therefore, the in-situ remediation materials for watershed sediments can be applied stably and effectively in the remediation of PAH-contaminated sediments, especially in the remediation of sediments with severe PAH pollution. This is of great significance for environmental protection, water quality improvement, sustainable industrial development, and economic and social benefits.

[0112] The in-situ remediation material for watershed sediments described in this invention utilizes coal gangue waste to prepare a framework material that serves as an attachment platform for exogenous functional microbial communities and native microbial complex communities. The exogenous functional microbial communities enable efficient degradation of organic compounds such as polycyclic aromatic hydrocarbons (PAHs). The native microbial complex communities enhance the environmental adaptability of the exogenous functional microbial communities. The framework material is prepared through pretreatment and modification of coal gangue waste. The exogenous functional microbial communities are obtained through screening, purification, and enrichment in anaerobic ponds used for treating coal chemical wastewater. The native microbial complex communities are obtained from polluted sediments. The exogenous functional microbial communities are anaerobic, fulfilling the function of degrading PAHs, benzene compounds, and phenolic substances in the sediments, and can efficiently exert their degradation effect, more effectively promoting the comprehensive degradation of pollutants and the deep remediation of sediments.

[0113] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. An in-situ remediation material for watershed sediment deposits, characterized in that, It includes a framework material and exogenous functional microbial communities and native microbial complex communities loaded on the framework material; The skeleton material is obtained from coal gangue waste; The exogenous functional microbial community is an anaerobic microbial community; wherein, the anaerobic microbial community has the function of degrading aromatic compounds, the aromatic compounds including polycyclic aromatic hydrocarbons, benzene series compounds or phenolic substances; The indigenous microbial complex was obtained by screening sediments from the bottom of the watershed.

2. The in-situ remediation material for watershed sediments according to claim 1, characterized in that, The preparation process of the skeleton material includes: Coal gangue waste is crushed, ground, and sieved to obtain coal gangue powder; Coal gangue powder is calcined to obtain calcined coal gangue; Surface-modified coal gangue was obtained by using surfactants to modify the surface of calcined coal gangue. The surface-modified coal gangue is mixed with a binder, shaped, and reacted to obtain the skeleton material.

3. The in-situ remediation material for watershed sediments according to claim 2, characterized in that, The process of calcining coal gangue powder to obtain calcined coal gangue includes: Coal gangue powder and sodium hydroxide are mixed in a mass ratio of 1:(0.01-0.03), and then calcined at 500-1000℃ to obtain calcined coal gangue.

4. The in-situ remediation material for watershed sediments according to claim 2, characterized in that, The surfactant is one of a cationic surfactant, anionic surfactant, and nonionic surfactant; wherein the cationic surfactant is hexadecyltrimethylammonium bromide, the anionic surfactant is sodium dodecylbenzenesulfonate, and the nonionic surfactant is polyvinyl alcohol.

5. The in-situ remediation material for watershed sediments according to claim 2, characterized in that, The mass ratio of the surface-modified coal gangue to the binder is 1:1 to 1:3; wherein the binder is one or both of silica sol and alumina sol.

6. The in-situ remediation material for watershed sediments according to claim 1, characterized in that, The preparation process of the exogenous functional microbial community includes: Activated sludge was obtained from the anaerobic tank of the biochemical treatment system of a coal chemical wastewater treatment plant. Activated sludge was inoculated into a culture medium with a preset first concentration of polycyclic aromatic hydrocarbons as substrates and cultured under anaerobic conditions to obtain a mixed microbial community with polycyclic aromatic hydrocarbon degradation efficiency. A mixed bacterial community with enhanced degradation efficiency was inoculated into a culture medium with a preset second concentration of polycyclic aromatic hydrocarbons as substrates and cultured under anaerobic conditions to obtain a mixed bacterial community with enhanced polycyclic aromatic hydrocarbon degradation efficiency. A mixed bacterial community with enhanced polycyclic aromatic hydrocarbon (PAH) degradation efficiency was inoculated into a culture medium with a preset third concentration of PAHs as the substrate, and enriched under an anaerobic environment to obtain a dominant bacterial community with PAH degradation efficiency, which was then used as an exogenous functional microbial community.

7. The in-situ remediation material for watershed sediments according to claim 6, characterized in that, The preset first concentration is 1-3 mg / L, the preset second concentration is 5-10 mg / L, and the preset third concentration is 5-10 mg / L; the exogenous functional microbial community includes Burkholderia, Rhodococcus biphenyle, and Pseudomonas nitroreductoids.

8. The in-situ remediation material for watershed sediments according to claim 1, characterized in that, The preparation process of the indigenous microbial complex includes: Obtain bottom sediments from a predetermined watershed and pre-treat them to obtain bottom sediment samples; Sediment samples were inoculated into conventional culture medium and cultured statically under simulated river sediment conditions. After purification, the purified dominant bacterial population was obtained. The purified dominant bacterial population was inoculated into a conventional culture medium for enrichment culture to obtain a local microbial complex.

9. A method for preparing an in-situ remediation material for watershed sediments as described in any one of claims 1-8, characterized in that, include: The exogenous functional microbial community is mixed with the native microbial complex community to obtain a mixed microbial community solution; wherein, the volume ratio of the exogenous functional microbial community to the native microbial complex community in the mixed microbial community solution is 1:0.2-1:0.

5. The scaffold material was completely immersed in the mixed bacterial solution and grown under anaerobic conditions to obtain primary growth material; Primary growth material is added to the bottom sediments of the watershed, adapted to grow in the actual environment of the watershed, and the adapted primary growth material is recovered. The primary growth material, after adaptation, is immersed in a mixed microbial solution and then undergoes secondary growth under anaerobic conditions to obtain in-situ remediation material for watershed sediment sediments.

10. The application of a material for in-situ remediation of sediments in watersheds as described in any one of claims 1-8, characterized in that, The application of the in-situ remediation material in the remediation and treatment of sediments in watersheds.

Images