A method, system, equipment and medium for rapid microbial remediation of multi-media contaminated uranium mines

Abstract

The present invention discloses a method, system, equipment and medium for rapid remediation of multi-media contaminated uranium mines by microorganisms, and relates to the technical field of pollution remediation. The method comprises: screening microorganism remediation according to target parameters and corresponding set thresholds to obtain an adapted remediation scheme for the site to be remediated; the target parameters include source item characteristics and the comprehensive relative abundance of functional bacteria; the source item characteristics include pH value, U concentration and porosity; microbial remediation includes chemical-microorganism combined remediation, microbial agent enhanced remediation and microbial in-situ stimulation remediation; remediation reagents are prepared according to the adapted remediation scheme, and the remediation reagents are used to remediate multi-media contamination in uranium mines. The present invention can utilize the main characteristics of multi-media contamination in uranium mines to quickly screen different multi-media remediation adaptation technologies for uranium mines, and improve the efficiency of microbial remediation of multi-media contamination in uranium mines through chemical-microorganism combined remediation, microbial agent enhanced remediation or microbial in-situ stimulation remediation.

Description

Technical Field

[0001] The present invention relates to the technical field of pollution remediation, and in particular to a method, system, equipment and medium for rapid remediation of uranium mine multi-media contaminated microorganisms. Background Art

[0002] Uranium tailings (slag) and uranium waste rock generated after mining and smelting in hard rock uranium mines are generally stored in open-air piles. During the long-term contact with the natural environment, a multi-media site environment with the coexistence of liquid-solid-bio phases such as leachate-uranium tailings (slag) / waste rock-microorganisms is formed. At the same time, with the widespread application of the fourth-generation sandstone-type uranium mining and smelting technology in recent years, in-situ leaching is carried out in the mineral-bearing aquifers of uranium mines by pumping. When the mines are decommissioned at the end of production, there are also groundwater-sandstone-microorganism multi-media sites to be repaired from the perspective of hydrogeological characteristics. The current environmental protection technology is mostly focused on the repair and management of a single medium, and there is no better technical method for multi-media pollutants in uranium mines.

[0003] Since the 1960s, research on the interaction between microorganisms and uranium has been widely carried out. First, in the liquid phase system, microorganisms can provide reducing electrons during the growth and metabolism process, converting U from a mobile hexavalent to a stable tetravalent precipitate, thereby repairing uranium pollution. In recent studies, it has also been found that in solid phase systems such as uranium tailings (slag), waste rock, and soil, there are microbial strains that can be artificially separated, screened, and cultivated, and have the function of reducing and mineralizing uranium. The in-situ remediation of uranium pollution is solved through the coupling of multiple biological effects such as biosorption, bioreduction, and biomineralization. Especially in uranium mines mined by acid, the coordinated control of sulfate and pH is achieved during the transformation of functional microorganisms, thereby providing environmental support for the long-term stability of remediation and management.

[0004] However, the natural environment in which uranium mines are located often contains more than just a single medium. When conducting remediation and treatment on a large spatial scale, it is more about solving pollution control in a solid-liquid-biosystem environment. Among them, the migration and transformation of the solid-liquid interface in different pore conditions, the adsorption and mineralization of the solid-biosystem interface, and the nutrient competition of the microbial community at the solid-liquid interface are all difficulties in the engineering application of microbial remediation and treatment, especially the slow mass transfer rate of microbial agents in low porosity. These problems have caused the overall cycle of microbial remediation technology to be relatively long. Due to the differences in geographical location, geological conditions and regional environment of different uranium mines, when conducting rapid microbial remediation, it is necessary to monitor dozens of ecological indicators of pollution sources, and when conducting engineering experiments, there are no relevant key control indicators for sources with different pollution levels, resulting in a long initial operation start-up cycle when actually carrying out microbial remediation projects, and poor volatility of results during the implementation process, which has become the main problem of rapid microbial remediation of multi-media contaminated uranium mines. Summary of the invention

[0005] The purpose of the present invention is to provide a method, system, equipment and medium for rapid remediation of uranium mine multi-media contaminated microorganisms, which can quickly screen different uranium mine multi-media remediation adaptation technologies and improve the efficiency of uranium mine multi-media contaminated microorganism remediation.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A method for rapid microbial remediation of multi-media contaminated uranium mines, comprising:

[0008] Obtaining target parameters of the site to be remediated in the uranium mine contaminated area; the target parameters include source item characteristics and comprehensive relative abundance of functional bacteria; the source item characteristics include pH value, U concentration and porosity;

[0009] Performing microbial remediation screening according to the target parameters and the corresponding set thresholds to obtain an adapted remediation plan for the site to be remediated; the microbial remediation includes chemical-microbial combined remediation, microbial agent enhanced remediation and microbial in situ stimulation remediation;

[0010] A repair reagent is prepared according to the adapted repair scheme, and the repair reagent is used to repair multi-media pollution in uranium mines.

[0011] Optionally, microbial remediation screening is performed according to the target parameters and the corresponding set thresholds to obtain an adapted remediation plan for the site to be remediated, specifically including:

[0012] When the U concentration in the liquid phase of the site to be repaired is greater than 5 mg / L and / or the pH value is less than 3, the adapted repair scheme is selected as chemical-microbial combined repair;

[0013] When the liquid phase of the site to be remediated satisfies the U concentration ≤ 5 mg / L and / or the pH value ≥ 3, further determining whether the porosity ≤ 0.3 and / or the relative abundance of functional microorganisms ≥ 1% is satisfied;

[0014] If the conditions are met, the adaptive repair scheme is selected as microbial in situ stimulation repair;

[0015] If it is not satisfied, the adapted repair scheme is selected as microbial agent enhanced repair.

[0016] Optionally, the specific process of each adaptation and repair solution is:

[0017] When the U concentration in the liquid phase of the site to be remediated is greater than 5 mg / L and / or the pH value is less than 3, the pollution level is determined to be high, and the pollution level is reduced by using a chemical reduction remediation agent, sodium sulfide, wherein the amount of sodium sulfide is 0.2 to 1 g / kg, until the U concentration in the multi-media liquid phase is ≤5 mg / L and / or the pH value is ≥3, and then microbial remediation is performed;

[0018] When the U concentration in the liquid phase of the site to be repaired meets the condition of ≤5 mg / L and / or the pH value ≥3, it is further determined whether the porosity ≤0.3 and / or the relative abundance of functional microorganisms ≥1% are met. If so, carbon source reagents are screened to enhance the indigenous functional microorganisms for in situ biostimulation. If not, indigenous functional microorganisms are screened, tolerance acclimation is carried out, and a repair system is constructed through outdoor large-scale cultivation, and then microbial enhanced repair is carried out.

[0019] Optionally, a method for determining a setting threshold corresponding to the target parameter is:

[0020] In the uranium mine multi-media system with different factors, the microorganisms are cultured under set parameters in a single microbial growth cycle. When the number of microbial growth decreases by 60% to 80% compared with conventional culture, it is determined that the set parameters have a significant inhibitory effect on microbial growth and subsequent remediation. Different microbial remediation methods are further applied according to the set parameters until the number of functional microorganisms growing in a single microbial growth cycle reaches 10 6 ~10 8 CFU / mL, then the set parameter is determined to be the set threshold value corresponding to the target parameter.

[0021] Optionally, the repair reagent uses a carbon source reagent that is a fast-acting carbon source or a slow-acting carbon source according to the adapted repair scheme.

[0022] The present invention also provides a uranium mine multi-media contaminated microbial rapid remediation system, comprising:

[0023] A parameter acquisition module is used to obtain target parameters of the site to be remediated in the uranium mine contaminated area; the target parameters include source item characteristics and comprehensive relative abundance of functional bacteria; the source item characteristics include pH value, U concentration and porosity;

[0024] A microbial remediation method screening module is used to screen microbial remediation according to the target parameters and the corresponding set thresholds to obtain an adapted remediation plan for the site to be remediated; the microbial remediation includes chemical-microbial combined remediation, microbial agent enhanced remediation and microbial in situ stimulation remediation;

[0025] The uranium mine multi-media pollution remediation module is used to prepare remediation reagents according to the adapted remediation scheme, and use the remediation reagents to remediate the uranium mine multi-media pollution.

[0026] The present invention also provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the above-mentioned method for rapid remediation of uranium mine multimedia contamination by microorganisms.

[0027] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method for rapid microbial remediation of multimedia contaminated uranium mines as described above.

[0028] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0029] The present invention discloses a method, system, equipment and medium for rapid microbial remediation of multi-media contamination in uranium mines. The method includes screening microbial remediation according to target parameters and corresponding set thresholds to obtain an adapted remediation scheme for the site to be remediated; the target parameters include source item characteristics and comprehensive relative abundance of functional bacteria; the source item characteristics include pH value, U concentration and porosity; microbial remediation includes chemical-microbial combined remediation, microbial agent enhanced remediation and microbial in-situ stimulation remediation; remediation reagents are prepared according to the adapted remediation scheme, and the remediation reagents are used to remediate multi-media contamination in uranium mines. The present invention can utilize the main characteristics of multi-media contamination in uranium mines to quickly screen different multi-media remediation adaptation technologies for uranium mines, and improve the efficiency of microbial remediation of multi-media contamination in uranium mines through chemical-microbial combined remediation, microbial agent enhanced remediation or microbial in-situ stimulation remediation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 The figure is a schematic diagram of the process of the multi-media contaminated microbial rapid remediation method for uranium mines according to the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The purpose of the present invention is to provide a method, system, equipment and medium for rapid remediation of uranium mine multi-media contaminated microorganisms, which can quickly screen different uranium mine multi-media remediation adaptation technologies and improve the efficiency of uranium mine multi-media contaminated microorganism remediation.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] like Figure 1 As shown, the present invention provides a method for rapid microbial remediation of uranium mine multi-media contamination, comprising the following specific steps:

[0036] Step (1) conduct a source survey of the contaminated area to be remediated in the uranium mine, master the key source characteristics of the multi-media pollution in the uranium mine, and select the suitable remediation method for the site to be remediated from chemical-microbial combined remediation, microbial agent enhanced remediation or microbial in situ stimulation remediation according to the growth quantity of functional microorganisms under different conditions, with the source characteristics of pH value, U concentration and effective porosity and the relative abundance of functional microorganisms as screening nodes;

[0037] Step (2) is to carry out relevant carbon source material screening, microbial strain screening and domestication, and multi-technique coupling experimental research to master the material preparation characteristics and microbial domestication methods;

[0038] Step (3), using the materials screened in step (2) and the microbial strains to perform rapid remediation of multi-media pollution in uranium mines.

[0039] In step (1), the uranium mine multi-media contaminated area refers to a uranium contaminated site in the uranium mine and its surrounding areas where liquid, solid and biological phases coexist, generally referring to uranium tailings (slag) reservoirs, uranium mine waste rock dumps, and sandstone uranium mine underground leaching aquifers.

[0040] In step (1), the source survey of the contaminated area to be remediated in the uranium mine needs to collect the migration, transformation and diffusion characteristics of pollutants in uranium tailings (slag), soil and groundwater, and understand the uranium concentration, pH value, porosity and relative abundance characteristics of key functional microorganisms in the microbial community that mainly affect the migration and transformation of pollutants.

[0041] Among them, the porosity should be determined with reference to the liquid saturation porosity determination method in GB-T 34533-2023; the relative abundance of key functional microorganisms is determined by high-throughput sequencing technology to carry out microbial community sequencing of relevant samples for the 16S bacterial kingdom.

[0042] According to our company's research on microbial in situ remediation technology in most mines across the country, microbial remediation technology can be applied to a wide range of pollution control sites. However, there are different utilization scenarios for chemical-microbial combined remediation, microbial agent remediation and carbon source in situ stimulation remediation. By studying the adaptation environment of different technologies, we can effectively identify the effective utilization environment to shorten the remediation cycle and improve the remediation efficiency.

[0043] In an environment with high uranium concentration and low pH value, the growth number of functional microorganisms will be significantly reduced. When the liquid phase environment in the multi-media meets the U concentration ≤ 5 mg / L and / or pH value ≥ 3, the functional microorganisms can grow normally and the microbial remediation is faster. If the liquid phase conditions in the multi-media are not met, chemical remediation is required for pretreatment, preferably 0.2-1g sodium sulfide / kg soil. When the above conditions are met, further judge the solid phase environment when the porosity is ≤ 0.3 and / or the relative abundance of functional microorganisms is ≥ 1%, screen cheap and efficient carbon source reagents / materials to strengthen the indigenous functional microorganisms for in-situ biostimulation, directly grow and culture the original indigenous functional microorganisms in situ, do not set up outdoor culture equipment, and further reduce the cost of microbial remediation technology. When this condition is not met, it is necessary to screen the indigenous functional microorganisms in the solid medium, carry out tolerance acclimatization, and build a remediation system through outdoor large-scale cultivation to carry out microbial enhanced remediation.

[0044] Traditional studies have shown that in high initial uranium concentrations, due to radioactive exposure and biological toxicity, functional microbial cells will be inhibited and undergo apoptosis, thus affecting the microbial repair cycle and repair efficiency. 2+ with SO 4 2- The acid radical ions have strong binding energy and weak ability to accept reduced electrons. They can maintain strong stability and are not easily reduced and repaired. Therefore, the present invention uses the growth number of functional microorganisms under different conditions as the judgment condition, and screens uranium concentration of 5 mg / L and pH value = 3 as the preliminary judgment basis for chemical-microbial combined remediation and other remediation methods in multi-media contaminated microbial rapid remediation.

[0045] Since the 1990s, the study of microbial remediation has generally used 16S high-throughput sequencing technology to analyze the diversity of bacterial microorganisms. It is generally believed that the microbial population with a relative abundance of ≥1% is the dominant population in the ecological environment and can use the energy in the environment to maintain stable genetics to a certain extent. However, after mining and smelting, most of the microorganisms in the uranium mine multi-media have formed a stable oxidative bacterial community, and the activity of various bacterial communities with uranium reduction and repair functions such as uranium-reducing bacteria, sulfate-reducing bacteria, and iron-reducing bacteria is inhibited. Therefore, the present invention uses the relative abundance of available indigenous functional microorganisms as one of the bases for distinguishing between microbial agent remediation and carbon source in situ stimulation methods. When the relative abundance of indigenous functional microorganisms meets the standard, carbon source in situ stimulation is used.

[0046] The diameter of microbial cells is generally 1 to 10 μm. In order to ensure the stable growth of microbial inoculants, the number of microorganisms in the inoculants usually needs to reach 10 6CFU / mL or more. However, in a multi-media environment, the porosity of the solid medium will affect the mass transfer rate of the microbial agent, and the mass transfer rate affects the uniform distribution of the microbial agent on a large spatial scale on the one hand, and affects the stable growth of microbial cells in the solid medium on the other hand. In different media such as tailings, soil, sandstone, etc., indicators such as porosity, permeability, and particle size distribution will synergistically affect the growth rate of functional microorganisms. Considering that the long-term growth of microbial cells in solid media mainly depends on adsorption in pores, the porosity test method is simple and supported by relevant national standards. Therefore, the present invention uses porosity as one of the bases for distinguishing between microbial agent remediation and carbon source in situ stimulation methods.

[0047] The carbon source reagents in step (2) mainly include two categories: fast-acting carbon sources and slow-acting carbon sources. Among them, fast-acting carbon sources refer to organic reagents with strong solubility such as ethanol, sodium lactate, sodium acetate, etc. Fast-acting carbon sources are suitable for relatively poor porosity, which is not conducive to the rapid microbial remediation when the microbial agent is transferred in a solid-liquid multi-media environment. In addition, due to the short residence time of soluble substances, they are suitable for short-term biological stimulation with a relatively high initial functional microbial abundance but a low organic carbon content. Slow-acting carbon sources are usually materials with a relatively stable carbon skeleton structure that can slowly degrade in the natural environment to release organic carbon sources. In this method, it refers to the use of slow-acting carbon sources such as micron- or nano-scale biochar, alginate gel, polyvinyl alcohol gel, etc. for long-term microbial in situ remediation. Due to their difficult to dissolve characteristics, even if micron- or nano-scale materials are mixed and injected, they require good permeability and high porosity in the multi-media system to be evenly dispersed in the multi-media system to achieve rapid remediation of pollutants by indigenous microorganisms. In general, the repair cycle of slow-release carbon sources is longer, but the repair effect is stable and the final repair effect is better than that of fast-acting carbon sources. The type of carbon source selected can be comprehensively judged based on the repair target value.

[0048] Among them, the preparation of biochar is to grind cheap waste such as straw, rice husk, sawdust, etc., and then calcine them at a high temperature of 300-500°C in an air atmosphere. After removing impurities, the carbon content is guaranteed to be above 80% to meet the biochar requirement in this method; alginate gel is obtained by adding a 1.5%-2.5% sodium alginate solution drop by drop in a 1.5%-2.5% calcium lactate solution through a micro syringe, washing the formed transparent small balls with distilled water for 2-3 times, and placing them in a 1.5%-2.5% calcium chloride solution for 24 hours to solidify; polyvinyl alcohol gel is obtained by adding a 1.5%-2.5% sodium alginate solution drop by drop in a 1.5%-2.5% calcium chloride solution through a micro syringe, and washing the formed transparent small balls with distilled water for 2-3 times.

[0049] In step (2), indigenous functional microorganisms refer to microorganisms with uranium reduction and restoration functions that can exist for a long time in the multi-media environment of uranium mine tailings (slag), soil, and groundwater to be repaired. They generally refer to uranium-reducing bacteria, sulfate-reducing bacteria, iron-reducing bacteria, and other microorganisms that have the ability to reduce and mineralize uranium. Due to differences in living environments, there are very few indigenous functional microorganisms in the multi-media systems of some uranium mines, and it is impossible to use the method of injecting carbon sources for in-situ stimulation. In this case, it is necessary to use a microbial agent injection method. Before use, it is necessary to separate indigenous functional microorganisms from uranium mine tailings (slag), soil, and groundwater, and carry out environmental adaptability acclimation to 5-10 mg / L uranium concentration, pH 3-5, and temperature 20-25°C. After laboratory acclimation and cultivation, the functional microorganisms need to reach a growth number of 10 in the multi-media environment. 6 Only when the content is above CFU / mL can it be directly used in the remediation of multi-media pollution in uranium mines.

[0050] Since the multi-media contaminated area of ​​uranium mines is usually characterized by sulfate content of 2-5 g / L and total iron content of 0.2-0.5 g / L, the culture system needs to be adjusted to the corresponding concentration during the acclimatization culture process. The indigenous microbial culture system given in this method is: K 2 HPO 4 0.2~0.5g, Na 2 SO 4 1-2.5 g, MgSO 4 7H 2 O 0.2~0.5g, NH 4 Cl 0.5~1.0g, FeSO 4 0.1~0.2g, FeCl 3 0.1-0.2g, ethanol / sodium lactate / sodium acetate 0.2-0.5%, distilled water 1000mL, and add 1-5% mass ratio of multi-media sample to the culture system. During the acclimation culture process, gradually increase the content of 1-5% multi-media sample until the multi-media sample reaches 50% and the number of functional microorganisms growing is also 10 6 CFU / mL or above, completing the domestication and cultivation process of functional microorganisms.

[0051] In particular, since the microbial agent contains a liquid environment in which microbial metabolic components and microbial cells coexist, it has certain viscosity characteristics and is blocked by the pore structure during the injection process, making it impossible to continuously carry out the multi-media system injection. Therefore, this method believes that the cultured microbial agent can be diluted at a dilution ratio of 1 to 5%. The diluted microbial agent can ensure that it is evenly injected into the multi-media system to be repaired during the repair period.

[0052] In step (3), according to the suitable remediation method for the site to be remediated screened in step (1), combined with chemical pretreatment, the multi-media system is subjected to the carbon source reagents / materials obtained by screening, and the functional microorganisms obtained by culturing are domesticated to carry out multi-media pollution rapid remediation, wherein, according to the pollution level of the polluted area to be remediated, the dosage of ethanol, sodium lactate, sodium acetate and other fast-acting carbon source reagents is 2-5 g / kg of the solid to be remediated, and the fast-acting carbon source can be directly dissolved and injected; the dosage of biochar, alginate gel, polyvinyl alcohol gel and other slow-release carbon sources is 1-2 g / kg of solid, and the addition needs to be done by slurry injection; the inoculation amount of the functional microbial agent is 1-5% liquid-to-solid ratio, and the cultured functional microbial agent needs to be diluted at a dilution ratio of 1-5% and then added by slurry injection.

[0053] Through the identification of the main control characteristics, this method can simply and quickly adapt different microbial rapid remediation technologies to different multi-media pollution in uranium mines, and provides remediation technologies for three different scenarios: chemical-microbial combination, microbial agent enhanced remediation, and carbon source reagent in situ stimulation, to solve the problems of long microbial remediation cycle and slow remediation effect of microbial agents in multi-media systems of uranium mines.

[0054] The following embodiments are provided according to the above specific scheme.

[0055] Example 1

[0056] A study was conducted on the soil and shallow aquifer of a uranium-contaminated site to be remediated at a hard rock uranium mine in southern China. Grid-based distribution, a total of 25 samples of 50 kg of soil and 25L of groundwater were obtained. Through test analysis, the pH value distribution characteristics of the soil in the contaminated site were 2.7-6.0, with an average value of 4.3, and the uranium concentration was 80-300 mg / kg, with an average value of 120 mg / kg; the pH value of groundwater was 3.0-5.0, with an average value of 4.6, and the uranium concentration was 3.2-5.6 mg / L, with an average value of 3.6 mg / L. Due to the strong acidity and high uranium concentration in the liquid phase, the soil and groundwater samples were first mixed and chemically pretreated with a mass ratio of 0.2g sodium sulfide / kg soil. During the period, stirring was performed once a day to fully mix the chemical reagents and samples. After 3-5 days of reaction, the pH value in the liquid phase was significantly increased to 6.0-6.2, and the uranium concentration was reduced to 2.5-3.0 mg / L.

[0057] The uranium-contaminated area is an old production site. The existing soil contains some tailings components. The addition of non-native soil has increased the porosity of the soil. The porosity in the area is generally 0.35-0.42. By using 16S bacterial group high-throughput sequencing technology and measuring the microbial community in the V3-V4 functional area, the total relative abundance of functional microorganisms such as uranium-reducing bacteria, sulfate-reducing bacteria, and iron-reducing bacteria that have the ability to reduce and mineralize uranium is 0.038% <1%. Therefore, the method of enhanced remediation with microbial agents is suitable for this multi-media system.

[0058] The solid soil medium is cultured with a functional microbial culture medium, and the culture medium component is selected as K 2 HPO 4 0.5g, Na 2 SO 4 2.5 g, MgSO 4 7H 2 O0.5g, NH 4 Cl0.5g, FeSO 4 0.1 g, FeCl 3 0.1g, sodium lactate 2mL, pH 6.8-7.0, distilled water 1000mL. Add 5% by mass of soil and groundwater mixture to the culture medium each time until the number of functional microorganisms reaches After that, the functional microorganisms were separated and then continued to be domesticated in a mixture of soil and groundwater with a mass ratio of 10%, and the mixture was increased by 5% each time until the number of functional microorganisms growing in the mixture of soil and groundwater with a mass ratio of 50% reached 10. 6 CFU / mL, the domestication of the functional microorganism is completed.

[0059] exist The organic glass column was filled with 4.6 kg of the mixture of soil and groundwater to be remediated. Functional microorganisms were cultured in batches. The culture medium composition was K 2 HPO 4 0.5g, Na 2 SO 4 2.5 g, MgSO 4 7H 2 O0.5g, NH 4 Cl0.5g, FeSO 4 0.1 g, FeCl 30.1g, sodium lactate 2mL, pH6.8-7.0, distilled water 1000mL. The cultured microbial agent was diluted to 1% with clean water and injected into the soil-groundwater mixture at 1mL / min through a peristaltic pump. After standing for 28 days at room temperature, the proportion of easily migrated acid-extractable uranium in the soil decreased by 20.14%, the proportion of stable residual uranium increased by 25.24%, and the uranium concentration in the liquid phase decreased from 2.6mg / L to below 0.3mg / L. Compared with the use of carbon source reagents for microbial remediation, the remediation cycle was shortened by 30 to 50 days.

[0060] Example 2

[0061] In-situ leaching uranium mining technology is one of the popular technologies for uranium mining and metallurgy. Sampling was carried out in the final production mining area of ​​a neutral uranium mining base in a sandstone-type uranium mine in northern China. By carrying out in-situ drilling operations at the well site, 10 sandstone samples and groundwater samples were obtained at the depth of the mineral-bearing aquifer in the well site. The pH value of the sandstone samples was 7.3-8.0, the uranium concentration was 60-150 mg / kg, and the average was 90 mg / kg. The pH value of the groundwater samples was 7.5-8.4, and the uranium concentration was 1.5-2.2 mg / L, with an average of 1.8 mg / L. Since the neutral in-situ leaching uranium mining technology is to extract CO 2 +O 2 Injection into mineral-bearing aquifers, CO 2 Hydrolysis to generate CO 3 - , so that the pH value rises to the weak alkaline range, in O 2 Uranium resources are dissolved under oxidizing conditions. After the uranium concentration and pH value meet the adaptation range, neutral sandstone uranium ore does not need chemical pretreatment and can be directly repaired by microorganisms for rapid repair.

[0062] Through the determination of multiple sandstone-groundwater multi-media samples, the porosity of the samples was in the range of 0.23-0.30. The high-throughput sequencing technology was used to carry out 16S bacterial group V4-V5 zone determination of the fixable microbial flora in the sandstone. Among them, the total relative abundance of microbial communities with the ability to reduce and mineralize uranium, such as uranium-reducing bacteria, sulfate-reducing bacteria and iron-reducing bacteria, was 1.28%>1%, which belongs to the existence conditions of indigenous functional microorganisms with certain conditions, and only needs to meet the current environmental demand for carbon source concentration.

[0063] By The organic glass column was filled with 2.5 kg of sandstone and groundwater mixture. 2 mL of ethanol was added to each kg of the mixture (the mass of ethanol at room temperature was about 1.58 g). The mixture was injected from top to bottom by a peristaltic pump. The multi-media contaminated microbial rapid remediation of sandstone uranium mines was carried out by in-situ activity stimulation of indigenous functional microorganisms. Since the groundwater environment has been in a relatively cold constant temperature environment for a long time, in a simulated groundwater environment at 15 ° C, under 120 days of static conditions, the final uranium concentration reached 0.3 mg / L, the pH value and other metal ion concentrations in the solution basically reached the remediation target value, and the proportion of acid-extractable uranium content in the sandstone decreased by 16.82%, and the stable residual uranium content increased by 18.90%. Compared with the in-situ remediation using functional microbial agents, the remediation cycle was shortened by 60 to 80 days.

[0064] Example 3

[0065] In Example 2, in order to exert the functional microbial activity for a long time, the fast-acting carbon source is replaced with a slow-acting carbon source alginate hydrogel. The preparation method is as follows: 100 mL of 2% sodium alginate solution by mass is slowly injected into 50 mL of 2% calcium lactate solution by mass through a micro syringe, and the entire unformed solid is discarded, and the continuous stable solid spheres are retained. The surface suspension solution is washed with distilled water for 3 times, and then the surface is further cured in 100 mL of 1% calcium chloride solution by mass for 24 hours, and the surface suspension solution is washed with distilled water for 3 times for standby use.

[0066] By The organic glass column is filled with 2.5kg of sandstone and groundwater mixture, and an aqueous solution of 1g of alginate gel is added to each kg of the mixture, and the mixture is injected by direct addition, and the multi-media contaminated microbial rapid remediation of sandstone uranium mines is carried out by in-situ activity stimulation of indigenous functional microorganisms. Maintaining the same operating conditions as in Example 2, under 180d of static conditions, the final uranium concentration is below 0.05mg / L, and the pH value and other metal ion concentrations in the solution basically reach the remediation target value, and the proportion of mobile acid-extractable uranium content in sandstone decreases by 18.20%, and the proportion of stable residual uranium content increases by 19.33%. Compared with the in-situ remediation using functional microbial agents, the remediation cycle is shortened by 20 to 30d.

[0067] The above embodiment has the following beneficial effects:

[0068] (1) The method for rapid remediation of multi-media contaminated uranium mines by microorganisms provided by the present invention can not only control the migration and diffusion of uranium pollution from the source of the uranium mine, but also provide different adaptation technologies for multi-media systems such as uranium tailings (slag), soil, groundwater, etc. in different scenarios.

[0069] (2) According to the method for rapid remediation of uranium mine multi-media contamination by microorganisms provided by the present invention, the proportion of easily migrated acid-extractable uranium in the solid phase of the multi-media system of tailings (slag), soil, and groundwater is reduced, and the proportion of stable residual content is increased. At the same time, the concentration of uranium that can migrate and diffuse in the liquid phase is reduced to below 0.3 mg / L, achieving a multi-media synergistic treatment effect.

[0070] (3) The method for rapid microbial remediation of multi-media contamination in uranium mines provided by the present invention provides judgment conditions and preparation processes of corresponding reagents and microbial agents for three different methods: chemical-microbial combined remediation, microbial agent enhanced remediation, and carbon source reagent / material in situ stimulation, thereby providing key materials and corresponding parameters for rapid remediation of multi-media contamination in uranium mines.

[0071] (4) According to the method for rapid microbial remediation of multi-media contamination in uranium mines provided by the present invention, methods for using corresponding reagents, materials and microbial agents are provided, providing technical support for the engineering application of the method.

[0072] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0073] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for rapid microbial remediation of multi-media contaminated uranium mines, characterized in that: include: Obtain target parameters for the site to be remediated in the uranium mine contaminated area; The target parameters include source item characteristics and comprehensive relative abundance of functional bacteria; the source item characteristics include pH value, U concentration and porosity; Performing microbial remediation screening according to the target parameters and the corresponding set thresholds to obtain an adapted remediation plan for the site to be remediated; the microbial remediation includes chemical-microbial combined remediation, microbial agent enhanced remediation and microbial in situ stimulation remediation; Preparing a repair reagent according to the adapted repair scheme, and using the repair reagent to repair uranium mine multi-media contamination; Microbial remediation screening is performed according to the target parameters and the corresponding set thresholds to obtain an adapted remediation plan for the site to be remediated, specifically including: When the U concentration in the liquid phase of the site to be repaired is greater than 5 mg / L and / or the pH value is less than 3, the adapted repair scheme is selected as chemical-microbial combined repair; When the liquid phase of the site to be remediated satisfies the U concentration ≤ 5 mg / L and / or the pH value ≥ 3, further determining whether the porosity ≤ 0.3 and / or the relative abundance of functional microorganisms ≥ 1% is satisfied; If the conditions are met, the adaptive repair scheme is selected as microbial in situ stimulation repair; If it is not satisfied, the adapted repair scheme is selected as microbial agent enhanced repair.

2. The method for rapid remediation of uranium mine multi-media contaminated microorganisms according to claim 1 is characterized in that: The specific process of each adaptation and repair solution is as follows: When the U concentration in the liquid phase of the site to be remediated is greater than 5 mg / L and / or the pH value is less than 3, the pollution level is determined to be high, and the pollution level is reduced by using a chemical reduction remediation agent, sodium sulfide, wherein the amount of sodium sulfide is 0.2 to 1 g / kg, until the U concentration in the multi-media liquid phase is ≤5 mg / L and / or the pH value is ≥3, and then microbial remediation is performed; When the U concentration in the liquid phase of the site to be repaired meets the condition of ≤5 mg / L and / or the pH value ≥3, it is further determined whether the porosity ≤0.3 and / or the relative abundance of functional microorganisms ≥1% are met. If so, carbon source reagents are screened to enhance the indigenous functional microorganisms for in situ biostimulation. If not, indigenous functional microorganisms are screened, tolerance acclimation is carried out, and a repair system is constructed through outdoor large-scale cultivation, and then microbial enhanced repair is carried out.

3. The method for rapid remediation of uranium mine multi-media contaminated microorganisms according to claim 1 is characterized in that: The method for determining the setting threshold value corresponding to the target parameter is: In the uranium mine multi-media system with different factors, the microorganisms are cultured under set parameters in a single microbial growth cycle. When the number of microbial growth decreases by 60% to 80% compared with conventional culture, it is determined that the set parameters have a significant inhibitory effect on microbial growth and subsequent remediation. Different microbial remediation methods are further applied according to the set parameters until the number of functional microorganisms growing in a single microbial growth cycle reaches 10 6 ~10 8 CFU / mL, then the set parameter is determined to be the set threshold value corresponding to the target parameter.

4. The method for rapid remediation of uranium mine multi-media contaminated microorganisms according to claim 1 is characterized in that: The repair reagent adopts a carbon source reagent of a fast-acting carbon source or a slow-acting carbon source according to the adapted repair scheme.

5. A uranium mine multi-media contaminated microbial rapid remediation system, using the method described in any one of claims 1 to 4, characterized in that: include: A parameter acquisition module is used to obtain target parameters of the site to be remediated in the uranium mine contaminated area; The target parameters include source item characteristics and comprehensive relative abundance of functional bacteria; the source item characteristics include pH value, U concentration and porosity; A microbial remediation method screening module is used to screen microbial remediation according to the target parameters and the corresponding set thresholds to obtain an adapted remediation plan for the site to be remediated; the microbial remediation includes chemical-microbial combined remediation, microbial agent enhanced remediation and microbial in situ stimulation remediation; The uranium mine multi-media pollution remediation module is used to prepare remediation reagents according to the adapted remediation scheme, and use the remediation reagents to remediate the uranium mine multi-media pollution.

6. An electronic device, characterized in that: The electronic device comprises a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the method for rapid remediation of uranium mine multi-media contaminated microorganisms according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that: The device stores a computer program, which, when executed by a processor, implements the method for rapid remediation of uranium mine multi-media contaminated microorganisms as described in any one of claims 1 to 4.

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