Method for in-situ treatment of uranium-polluted water body and application

Abstract

The invention relates to a method for in-situ treatment of a uranium-polluted water body and application. A method for in-situ treatment of a uranium-polluted water body comprises the following steps that a bacterial suspension is prepared, one or more of brucella, geobacterium, clostridium or shewanella is selected as a strain, the bacterial suspension is cultured to the logarithmic phase and resuspended and trained, the bacterial suspension is obtained, and the final concentration of the bacterial suspension is 1 * 10 < 6 >-1 * 10 < 9 > CFU / mL; clay minerals are selected from one or more of kaolinite, montmorillonite, illite, smectite, chlorite, sepiolite, glauconite or talc, and the concentration of the clay turbid liquid is 0.01-10 g / L; and synchronously adding the bacterial suspension and the clay suspension into the uranium-polluted water body. Through clay mineral-microorganism interaction, uranium elements are promoted to be embedded between clay layers and then reduced, uranium pollution is fixed between the clay layers and isolated from the external environment, and uranium pollution solidification is truly achieved.

Description

Technical Field

[0001] The present application belongs to the technical field of heavy metal contaminated water restoration, and specifically relates to a method and application of in-situ treatment of uranium contaminated water. Background Art

[0002] With the increasing demand for nuclear fuel, the development and utilization of uranium resources are increasingly promoted, and the green and low-carbon transformation of energy is accelerated, and the demand for natural uranium supply has increased significantly. Therefore, it is particularly important to solve the problems of uranium mining and smelting, nuclear fuel processing and manufacturing, etc., which often cause soil and various water pollution and pose potential threats to the health and ecological security of surrounding residents. In addition, after years of development, a large number of uranium mining areas have been retired or are about to be retired. The environmental problems of groundwater in mines will become more prominent, and the ecological security of groundwater in mining areas will face new challenges. The remediation technology and methods for groundwater pollution in retired mines urgently need to be studied and developed in depth.

[0003] At present, the in-situ remediation technologies for uranium-contaminated water bodies mainly include physical, chemical and biological methods. The physical method mainly removes uranium from water bodies by means of adsorption and ion exchange. Its main disadvantages are that the materials are expensive, the ion exchangers are difficult to regenerate and dispose, and they are easy to desorb when the geochemical conditions change, resulting in secondary pollution. The chemical method reduces uranium ions to insoluble solids by adding chemical reagents to achieve the purpose of removal. Its main disadvantage is that the treatment effect of low-concentration pollution is poor and it is easy to cause serious secondary chemical pollution. The biological method uses the metabolic activities of microorganisms to adsorb, transform or degrade uranium in wastewater. It is widely studied and applied because of its low cost, low investment, simple operation and environmental friendliness. However, the physiological activity of microorganisms is often inhibited by the toxicity of uranium, the reduction rate is low, the remediation cycle is long, and the remediation effect is not ideal. In addition, the latest post-remediation monitoring study found that the crystal form of the bioremediation reduction product is poor and it is easily oxidized by iron and manganese oxides, dissolved oxygen, nitrates and other substances in the environmental medium, resulting in secondary migration of pollution.

[0004] In summary, the key to uranium contaminated water remediation technology is to (1) achieve uranium contamination reduction and solidification in an environmentally friendly, efficient, and low-cost manner, and (2) ensure the long-term stability of the remediation product. However, there is currently no technology that can achieve the above goals at the same time. Therefore, it is particularly important to develop new environmentally friendly, long-lasting and efficient uranium contamination remediation technologies. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a method for in situ treatment of uranium-contaminated water bodies, which utilizes clay mineral-microorganism interaction to efficiently treat uranium-contaminated water bodies in situ, reduces the mobile heavy metal pollutant U(VI) to difficult-to-migrate U(IV) in situ, and fixes it between clay structure layers or in the complex, isolating it from external environmental interference and preventing secondary pollution.

[0006] The present application provides a method for in-situ treatment of uranium-contaminated water, comprising the following steps: Prepare bacterial suspension, and use Brucella Brucella sp. )、Geobacterium( Geobacter sp. )、Clostridium( Clostridium sp. ) or Shewanella ( Shewanella sp. ) to the logarithmic phase, and then resuspended in sterilized uranium-contaminated water or oligotrophic OM (Oligotrophic Medium) medium for 8 to 12 hours, wherein the concentration of glucose in the oligotrophic OM medium is 0.1 to 5 g / L, and the concentration of NH4Cl is 0.01 to 2 g / L, to obtain the bacterial suspension, and the final concentration of the bacterial suspension is 1×10 6 ~1×10 9 CFU / mL; Preparing a clay suspension, wherein the clay mineral is selected from one or more of kaolinite, montmorillonite, illite, smectite, chlorite, sepiolite, glauconite or talc, and the clay mineral is mixed with water to obtain the clay suspension, wherein the concentration of the clay suspension is 0.01-10 g / L; The bacterial suspension and the clay suspension are added simultaneously to treat the uranium-contaminated water body.

[0007] Preferably, the concentration of glucose in the oligotrophic OM medium is 0.6 g / L, and the concentration of NH4Cl is 0.1 g / L.

[0008] Preferably, the final concentration of the bacterial suspension is 5×10 7 CFU / mL.

[0009] Preferably, the clay mineral is montmorillonite.

[0010] Preferably, the particle size of the clay mineral is 75-1700 μm.

[0011] Preferably, the particle size of the clay mineral is 150 μm.

[0012] Preferably, the concentration of the clay suspension is 0.5 g / L.

[0013] Preferably, the bacterial suspension and the clay suspension are added in the following manners: Directly and synchronously adding the bacterial suspension and the clay suspension into the uranium-contaminated water body, wherein the volume ratio of the bacterial suspension, the clay suspension and the uranium-contaminated water body is 1:1:1000; Alternatively, the bacterial suspension and the clay suspension are stirred for 2 to 12 hours to obtain a mixed solution, wherein the volume ratio of the bacterial suspension to the clay suspension is 1:1, and then added to the uranium-contaminated water body, wherein the volume ratio of the mixed solution to the uranium-contaminated water body is 1:500.

[0014] Preferably, the above method further comprises treating the uranium-contaminated water at a pH value of 5 to 7.

[0015] The present application also provides the application of any of the above-mentioned methods for in-situ treatment of uranium-contaminated water bodies in the remediation of heavy metal-contaminated water bodies.

[0016] Clay minerals are green, cheap, and easy to obtain. Because of their large specific surface area and strong adsorption capacity, they are often used as adsorption materials for uranium pollutants U(VI), but their unique hydrophobicity and self-sealing properties are ignored. By combining clay minerals and microorganisms, clay minerals can protect microorganisms from (reduce) the toxic effects of uranium contamination. Because clay minerals can adsorb U(VI) and reduce the concentration (i.e., toxicity) of free U(VI); in addition, clay minerals encapsulate microorganisms, providing them with a barrier protection effect to avoid / reduce radiotoxicity. On the other hand, the microorganisms used in this application can secrete a higher content of hydroxamate-type iron carriers, strongly chelate uranium pollutants U(VI), and promote U(VI) to insert into clay interlayers to form a stable U(VI)-iron carrier-clay structure iron ternary complex. The U(VI) inserted into the interlayer is then reduced to a larger U(IV) and locked in the interlayer. In addition, the clay treatment system can form a dense, hydrophobic and self-sealing clay layer on the periphery of the reduction product, which can isolate the influence of changes in the external environment on the inner layer U(IV).

[0017] Compared with the prior art, the advantages of this application are: (1) The variable-valence metal elements in the clay mineral structure of the present application will be reduced at this time (such as the structural Fe(III) will be reduced to Fe(II)), creating a reducing atmosphere. In this reducing atmosphere, microorganisms and reduced clay minerals simultaneously fix the U(VI) pollutants in situ. Because most of the U(VI) has been adsorbed onto the surface of the clay and microorganisms, the reduction rate is significantly faster than that of simple biological reduction. The reduced product U(IV) formed can be inserted into the clay layers and is wrapped in a layer of impermeable clay mineral aggregate on the outside, isolating it from the external environment, and greatly improving its stability. Clay minerals have strong hydrophobicity and self-sealing properties, and the reduced clay aggregate wrapped on the outside makes the uranium contamination remediation obtain long-term stability and is not easily affected by changes in later environmental conditions.

[0018] (2) By adjusting the pH value between 5 and 7, the electron transfer direction of clay minerals can be regulated, the intercalation ratio of the reduction product U(IV) can be significantly increased, and the long-term stability of the U(VI) pollution control effect can be ensured.

[0019] (3) The bacterial strains and clay minerals used in this application are widely available, environmentally friendly, safe, non-toxic and harmless. Clay minerals protect the physiological and biochemical activities of microorganisms from the chemical toxicity and radioactive hazards of uranium pollution, and can provide trace elements and nutrients for microorganisms.

[0020] (4) This application can be widely used in the remediation of heavy metal pollution, has high environmental adaptability and good treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a monitoring diagram of dissolved uranium concentration in water in Example 1.

[0022] Figure 2 This is the monitoring diagram of dissolved uranium concentration in water in Example 2.

[0023] Figure 3 This is a diagram for detecting dissolved uranium concentration in water in Example 3.

[0024] Figure 4 This is a graph showing the detection of hexavalent uranium concentration in water in Example 4.

[0025] Figure 5 This is an electron microscope scanning image of Example 5.

[0026] Figure 6 This is a high-resolution transmission electron microscope scanning image of Example 6.

[0027] Figure 7 This is the result of detecting the amount of microorganisms in the water body in Example 7.

[0028] Figure 8 This is the detection result of uranium concentration in water in Example 8.

[0029] Fig. 9 This is a graph showing the detection of dissolved uranium concentration in water in Example 9.

[0030] Fig.10 This is a graph showing the detection of hexavalent uranium concentration in water in Example 10. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in conjunction with specific embodiments. The examples given are only for illustrating the present application, not for limiting the scope of the present application. The materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources.

[0032] A method for in-situ treatment of uranium-contaminated water bodies comprises the following steps: (1) Prepare bacterial suspension, using Brucella Brucella intermedia LMG 3301), Geobacter ( Geobacter sulfurreducensATCC 51573), Clostridium ( Clostridium intestinale DSM 6191) or Shewanella ( Shewanella putrefaciens ATCC 51753) in a common culture medium, such as LB, TB medium, etc., cultured to the logarithmic phase, resuspended in sterilized uranium-contaminated water or oligotrophic OM medium for 8-12 hours to obtain a bacterial suspension with a final concentration of 1×10 6 ~1×10 9 CFU / mL, preferably 5×10 7 CFU / mL. The concentration of glucose in oligotrophic OM medium is 0.1~5g / L, and the concentration of NH4Cl is 0.01~2g / L.

[0033] (2) preparing a clay suspension, wherein the clay mineral is selected from one or more of kaolinite, montmorillonite, illite, smectite, chlorite, sepiolite, glauconite or talc, preferably montmorillonite. The clay mineral is mixed with water to obtain a clay suspension, wherein the concentration of the clay suspension is 0.01 to 10 g / L, preferably 0.5 g / L.

[0034] (3) Adding the bacterial suspension and the clay suspension simultaneously into the uranium-contaminated water body, wherein the adding method includes: The bacterial suspension and the clay suspension are directly and synchronously added into the uranium-contaminated water body, and the volume ratio of the bacterial suspension, the clay suspension and the uranium-contaminated water body is 1:1:1000; Alternatively, the bacterial suspension and the clay suspension are mixed and stirred for 2 to 12 hours to obtain a mixed solution, wherein the volume ratio of the bacterial suspension to the clay suspension is 1:1, and then the mixed solution is added to the uranium contaminated water body, wherein the volume ratio of the mixed solution to the uranium contaminated water body is 1:500.

[0035] (4) The uranium-contaminated water body is treated at a pH value of 5 to 7. The pH value can be adjusted by adding organic acids produced by microbial fermentation or alkali-producing microorganisms (such as sulfate-reducing bacteria SRB).

[0036] Example 1 A method for in-situ treatment of uranium-contaminated water bodies comprises the following steps: (1) Prepare bacterial suspension, and select Geobacter ( Geobacter sulfurreducens ATCC 51573, purchased from American Type Culture Collection, was cultured in LB medium to the logarithmic phase and resuspended in sterilized uranium-contaminated water (U(VI) concentration 400 μM) for 12 h to obtain a bacterial suspension with a final concentration of 5 × 10 7 CFU / mL.

[0037] (2) Prepare a clay suspension, wherein the clay mineral is montmorillonite. Add 0.5 g of montmorillonite with a particle size of 150 μm into 1 L of water and mix and stir to obtain a clay suspension.

[0038] (3) Add 1 mL of bacterial suspension and 1 mL of clay suspension directly into 1 L of uranium-contaminated water.

[0039] (4) Set up a montmorillonite control group: add 0.5 g of montmorillonite with a particle size of 150 μm to 1 L of water and mix and stir to obtain a clay suspension. Geobacter control group: logarithmic phase Geobacter suspension, with a final concentration of 5×10 7 CFU / mL). The dosage of each control group was the same as that of the experimental group.

[0040] (5) Uranium-contaminated water was treated at pH = 4 and pH = 7. 400 μM sodium lactate was added to the system as an electron donor, and the system was anaerobically co-cultured at room temperature for 7 days. Centrifugal sampling was performed every day to monitor the dissolved uranium in the water. The results are as follows: Figure 1 shown.

[0041] pass Figure 1 It can be seen that under the same pH conditions, the adsorption efficiency and adsorption capacity of the clay mineral-microorganism interaction system are the highest, and the adsorption effect of montmorillonite is significantly stronger than that of Geobacter. For the same experimental system, the adsorption capacity is stronger under pH=7.

[0042] Example 2 A method for in-situ treatment of uranium-contaminated water bodies comprises the following steps: Steps (1) to (4) are the same as those in Example 1.

[0043] (5) Treatment of uranium-contaminated water at pH = 7. 400 μM sodium lactate was added to the system as an electron donor, and 1 mM AlCl3 was added. The system was anaerobically cultured at room temperature for 7 days, and centrifuged and sampled every day to monitor the concentration of dissolved uranium in the water (i.e., desorption). The results are as follows: Figure 2 shown.

[0044] pass Figure 2 It can be seen that Al 3+ It has a strong competitive adsorption ability, which causes the U(VI) originally adsorbed on the surface of montmorillonite and Geobacter to desorb, and the concentration of dissolved uranium rises. Because in the clay mineral-microorganism interaction system, most of the uranium (>90%) has been locked in the clay layers, and is wrapped in a layer of clay isolation layer on the outside, it is difficult to dissociate, so the concentration of dissolved uranium has not increased significantly. The concentration of dissolved uranium subsequently decreases in the presence of Geobacter in the system, mainly due to biological reduction. The treatment efficiency of the embodiment is high, the structure is stable, it is not easy to desorb, and the effect is significantly better than that of the control group.

[0045] Example 3 A method for in-situ treatment of uranium-contaminated water, steps (1) to (5) are the same as those in Example 2, except that instead of using AlCl3, HCl, NH4Cl and MgCl2 are added respectively, and a blank control is set. The results are as follows Figure 3 shown.

[0046] pass Figure 3 It can be seen that in the control system without desorbent, the concentration of dissolved uranium is low, indicating that most of the uranium is adsorbed on the surface of montmorillonite and / or Geobacter. Different desorbents have different abilities to compete with uranium for adsorption, that is, different desorption strengths for uranium. + Weaker than H + and Mg 2+ No matter which desorbent is used, it is impossible to significantly desorb the uranium element in the clay mineral-microorganism interaction system.

[0047] Example 4 A method for in-situ treatment of uranium-contaminated water bodies comprises the following steps: Steps (1) to (5) are the same as those in Example 1, except that the uranium-contaminated water is treated only under the condition of pH = 7.

[0048] Arsenic azo colorimetry was used to quantify U(VI) in the system before and after the reaction. The results are as follows: Figure 4 shown.

[0049] pass Figure 4 It can be seen that the montmorillonite system can only adsorb U(VI) but cannot reduce it. The degree of reduction and fixation of U(VI) in the pure Geobacter system is relatively low, which may be due to the toxicity of high-concentration uranium pollutants inhibiting the reduction activity of Geobacter. In the clay mineral-microorganism interaction system, montmorillonite adsorbs most of the U(VI), the concentration of free U(VI) is greatly reduced, and the biological toxicity is also reduced; and montmorillonite can also shield the radioactive toxicity of uranium pollution and ensure the reduction activity of microorganisms. The strong adsorption characteristics of the clay mineral-microorganism system increase the contact opportunities between Geobacter and U(VI) and accelerate the reduction and fixation process of U(VI).

[0050] Example 5 A method for in-situ treatment of uranium-contaminated water, wherein steps (1) to (5) are the same as those of Example 4, except that the montmorillonite control group is not selected. Scanning electron microscopy (SEM) reveals the spatial contact relationship between clay minerals, microorganisms and uranium minerals, such as Figure 5 shown.

[0051] pass Figure 5It can be seen that the bright part in the backscattered BSE spectrum is the heavy element enrichment area and U(IV) product. The U(IV) product generated by the reduction of the pure microbial system Geobacter is exposed to the external environment and is easily affected by the changes in geochemical conditions in the later period; the reduction product U(IV) generated in the clay mineral-microorganism interaction system is encapsulated in the clay mineral aggregate and isolated from the external environment.

[0052] Example 6 A method for in-situ treatment of uranium-contaminated water, wherein steps (1) to (5) are the same as those in Example 4, except that the Geobacter control group is not selected. High-resolution transmission electron microscopy (TEM) shows the spacing of lattice fringes of clay minerals, such as Figure 6 shown.

[0053] pass Figure 6 It can be seen that the d(001) interlayer spacing of montmorillonite is ~1.25nm; U(VI) physically adsorbs onto the surface of montmorillonite but does not insert into the interlayers, so it does not expand the d(001) interlayer spacing of clay. Because it does not enter the interlayers, it is easily desorbed; in the clay mineral-microorganism interaction system, the small molecule U(VI) enters the (001) interlayers and is reduced to a larger reduction product U(IV), which is locked in the clay interlayers and expands the interlayer spacing to ~1.75nm.

[0054] Example 7 A method for in-situ treatment of uranium contaminated water, steps (1) to (5) are the same as in Example 5. The microbial biomass of the uranium contaminated water remediation system is measured, and the result is as follows Figure 7 In this paper, the uranium contaminated water remediation system refers to a mixed system that uses clay mineral-microorganism interaction to synergistically treat uranium contaminated water.

[0055] pass Figure 7 It can be seen that the pure Geobacter system was directly exposed to high concentrations of uranium pollutants; under the effects of chemical toxicity and radiotoxicity, the CFU of Geobacter was significantly reduced. On the contrary, in the clay mineral-microorganism interaction system, thanks to the adsorption of free U(VI) by clay minerals, the physiological activity of Geobacter was not greatly affected, and the CFU did not change significantly.

[0056] Example 8 A method for in-situ treatment of uranium-contaminated water bodies, wherein steps (1) to (5) are the same as those of Example 5, and after anaerobic co-cultivation at room temperature for 7 days, the reaction system is exposed to air and subjected to aeration and shaking for 7 days, and the concentration changes of dissolved uranium and U(VI) in the system are detected. The results are as follows: Figure 8 shown.

[0057] pass Figure 8It can be seen that after exposure to air, the U(IV) precipitate generated by the pure Geobacter reduction system is unstable and is secondary oxidized and dissolved, so the concentrations of dissolved uranium and U(VI) in the system are significantly increased; the reduction product U(IV) generated in the clay mineral-microorganism interaction system has a stable structure and is not affected by changes in environmental conditions, so the concentrations of dissolved uranium and U(VI) do not change before and after oxygen exposure.

[0058] Example 9 A method for in-situ treatment of uranium-contaminated water bodies comprises the following steps: (1) Prepare two groups of bacterial suspensions, using Brucella Brucella intermedia LMG 3301, purchased from BC / LMG Bacteria Collection, Belgium) and Shewanella ( Shewanella putrefaciens ATCC 51753, purchased from American Type Culture Collection), mixed at a ratio of 1:1, cultured in LB medium to the logarithmic phase, resuspended in oligotrophic OM medium (glucose concentration of 0.6 g / L, NH4Cl concentration of 0.1 g / L) for 8 hours to obtain a mixed bacterial suspension with a final concentration of 1×10 6 CFU / mL (low concentration) and 1×10 9 CFU / mL (high concentration).

[0059] (2) Prepare a clay suspension, where illite is selected as the clay mineral. Add 0.5 g of illite with a particle size of 150 μm into 1 L of water and mix and stir to obtain a clay suspension.

[0060] (3) 1 mL of mixed bacterial suspension of Brucella and Shewanella and 1 mL of illite clay suspension were directly added into 1 L of uranium-contaminated water (U(VI) concentration: 400 μM) simultaneously.

[0061] (4) Illite control group: 0.5 g illite with a particle size of 150 μm was added to 1 L of water and mixed and stirred to obtain a clay suspension. Brucella and Shewanella mixed bacterial suspension control group: Brucella and Shewanella mixed bacterial suspension in logarithmic phase in a ratio of 1:1, with a final concentration of 1×10 6 CFU / mL (low concentration) and 1×10 9 CFU / mL (high concentration). The dosage of each control group was the same as that of the experimental group.

[0062] (5) Uranium-contaminated water was treated at pH 7. 400 μM sodium lactate was added to the system as an electron donor and the system was anaerobic co-cultured at room temperature for 7 days. ICP-OES was used to quantify the concentration of dissolved uranium in the system before and after the reaction. The results are as follows: Fig. 9 shown.

[0063] pass Fig. 9 It can be seen that the clay mineral-mixed bacteria interaction system has the best adsorption effect, the illite adsorption effect is significantly stronger than the mixed bacteria, and the higher the concentration of the mixed bacteria, the better the adsorption effect.

[0064] Example 10 A method for in-situ treatment of uranium-contaminated water bodies, steps (1) to (5) are the same as those in Example 9, and azoarsenic colorimetry is used to quantify U(VI) in the system before and after the reaction. The results are as follows: Fig.10 shown.

[0065] pass Fig.10 It can be seen that the illite system can only adsorb U(VI) but cannot reduce it. The degree of reduction and fixation of U(VI) in the mixed bacteria system is relatively low, which may be due to the toxicity of high-concentration uranium pollutants inhibiting the reduction activity of the mixed bacteria. In the clay mineral-mixed bacteria interaction system, the illite adsorbs most of the U(VI), the concentration of free U(VI) is greatly reduced, and the biological toxicity is also reduced; and the illite can also shield the radioactive toxicity of uranium pollution and ensure the reduction activity of microorganisms. The strong adsorption characteristics of the clay mineral-mixed bacteria system increase the contact opportunities between the mixed bacteria and U(VI), accelerating the reduction and fixation process of U(VI). The higher the concentration of the mixed bacteria, the better the reduction and fixation effect of U(VI).

[0066] In addition, it should be understood that the above-mentioned advantageous methods can be freely combined and superimposed without conflict. The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in the field of the present application, several improvements and modifications can be made without departing from the principles of the present application, and these improvements and modifications should also be regarded as the protection scope of the present application.

Claims

1. A method for in-situ treatment of uranium-contaminated water, characterized in that: The following steps are involved: A bacterial suspension is prepared, wherein the bacterial species is selected from one or more of Brucella, Geobacter, Clostridium or Shewanella, cultured to the logarithmic phase, and resuspended in sterilized uranium-contaminated water or oligotrophic OM medium for training for 8 to 12 hours, wherein the concentration of glucose in the oligotrophic OM medium is 0.1 to 5 g / L, and the concentration of NH4Cl is 0.01 to 2 g / L, to obtain the bacterial suspension, and the final concentration of the bacterial suspension is 1×10 6 ~1×10 9 CFU / mL; Preparing a clay suspension, wherein the clay mineral is selected from one or more of kaolinite, montmorillonite, illite, smectite, chlorite, sepiolite, glauconite or talc, and the clay mineral is mixed with water to obtain the clay suspension, wherein the concentration of the clay suspension is 0.01-10 g / L; The bacterial suspension and the clay suspension are added simultaneously to treat the uranium-contaminated water body.

2. The method for in-situ treatment of uranium-contaminated water according to claim 1, characterized in that: The concentration of glucose in the oligotrophic OM medium is 0.6 g / L, and the concentration of NH4Cl is 0.1 g / L.

3. The method for in-situ treatment of uranium-contaminated water according to claim 1, characterized in that: The final concentration of the bacterial suspension was 5×10 7 CFU / mL.

4. The method for in-situ treatment of uranium-contaminated water according to claim 1, characterized in that: The clay mineral is selected as montmorillonite.

5. The method for in-situ treatment of uranium-contaminated water according to claim 1, characterized in that: The particle size of the clay mineral is 75-1700 μm.

6. The method for in-situ treatment of uranium-contaminated water according to claim 5, characterized in that: The particle size of the clay mineral is 150 μm.

7. The method for in-situ treatment of uranium-contaminated water according to claim 1, characterized in that: The concentration of the clay suspension is 0.5 g / L.

8. The method for in-situ treatment of uranium-contaminated water according to claim 1, characterized in that: The method of adding the bacterial suspension and the clay suspension includes: Directly and synchronously adding the bacterial suspension and the clay suspension into the uranium-contaminated water body, wherein the volume ratio of the bacterial suspension, the clay suspension and the uranium-contaminated water body is 1:1:1000; Alternatively, the bacterial suspension and the clay suspension are mixed and stirred for 2 to 12 hours to obtain a mixed solution, wherein the volume ratio of the bacterial suspension to the clay suspension is 1:1, and then added to the uranium-contaminated water body, wherein the volume ratio of the mixed solution to the uranium-contaminated water body is 1:

500.

9. The method for in-situ treatment of uranium-contaminated water according to claim 1, characterized in that: The method also includes treating the uranium-contaminated water body under the condition of a pH value of 5 to 7.

10. Use of the method for in-situ treatment of uranium-contaminated water according to any one of claims 1 to 9 in the remediation of heavy metal-contaminated water.

Images