A biological agent for uranium pollution control in alkaline environment and its application

Abstract

The present invention belongs to the field of bioengineering, and specifically relates to a biological agent and application for uranium pollution control in an alkaline environment. The present invention provides a biological agent composed of Burkholderia and Pseudomonas. The microorganisms provided by the present invention can significantly reduce the cost of remediation, while restoring the activity of microbial communities, and providing long-term environmental stability and environmental resistance.

Description

Technical Field

[0001] The invention belongs to the field of bioengineering, and in particular relates to a biological agent for treating uranium pollution in an alkaline environment and its application. Background Art

[0002] At present, uranium mining and smelting mainly adopt three production processes: acid leaching, neutral leaching and alkaline leaching. Microbial remediation technology is used to carry out in-situ remediation of the mobile and diffusible uranium in the seepage water / groundwater of the natural radioactive waste generated by different production processes. Recent studies have confirmed that there is a close interaction between microorganisms and uranium. Through the adsorption of surface groups of microbial cells, the release of electrons from intracellular and extracellular polymers, and the mineralization of biological metabolites, various complex microbial remediation functions can make uranium from mobile U 6+ Converted to stable U 4+ , thus achieving in-situ remediation of uranium. However, for the seepage water / groundwater in the natural radioactive waste generated by uranium mines, due to the complex ion environment and exposure to radionuclides, traditional microbial agents may not be able to survive directly in the current system, resulting in the microbial remediation effect failing to meet expectations. Summary of the invention

[0003] To solve the above problems, the present invention provides a biological agent, which consists of Burkholderia and Pseudomonas.

[0004] Furthermore, the Burkholderia is a strain with a deposit number of CGMCC NO.29789.

[0005] Furthermore, the Pseudomonas is a strain with a deposit number of CGMCC NO.29788.

[0006] The present invention also provides application of the above biological agent in uranium mine pollution control.

[0007] On the other hand, the present invention also provides a method for uranium mine pollution control, wherein the above-mentioned biological agent is injected into the uranium mine seepage water or groundwater to be repaired at an inoculation rate of 1 to 10%, and a corresponding microbial culture system is constructed at the same time. After the injection process is completed, the corresponding repair effect can be achieved under static conditions.

[0008] The present invention has the following beneficial effects:

[0009] The existing lime neutralization technology is easily corroded and dissolved under the long-term natural environment, and the repair effect is unstable. Although the repair effect of reverse osmosis and other technologies is good, the cost is high. The microbial remediation technology provided by the present invention can significantly reduce the repair cost while providing environmental remediation effects such as alkaline seepage water / groundwater, while restoring the activity of microbial communities and providing long-term environmental stability and environmental resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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 work.

[0011] Figure 1 Growth of Burkholderia 15d.

[0012] Figure 2 Pseudomonas growth at 15 days.

[0013] Figure 3 15d microbial agent restoration effect. DETAILED DESCRIPTION

[0014] Now, various exemplary embodiments of the present invention are described in detail. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional commercially available reagents or reagents prepared by conventional methods unless otherwise specified. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features and embodiments of the present invention.

[0015] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0016] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0017] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0018] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0019] Example 1 Microbial screening and culture system

[0020] The components of the screening culture system of the biological agent in the present invention are: 3-3.5g of ferric citrate, 0.5-1g of ammonium chloride, 0.02-0.05g of calcium chloride, 0.3-0.5g of magnesium sulfate, 3-5g of tricalcium phosphate, 5-10g of glucose, pH 7.0-7.4, and 1000mL of distilled water.

[0021] When the biological agent of the present invention is cultured in this culture system, the microorganisms can grow stably at a temperature of 20 to 35° C. and under static conditions, and the preparation of the microbial agent can be completed after 3 to 5 days of culture.

[0022] Example 2 Bacteria domestication and cultivation

[0023] According to the main characteristic indicators of seepage water / groundwater in different uranium mines, especially in weakly alkaline environments, pH value and U concentration were selected as the initial acclimation conditions. Taking the groundwater of a uranium mine in the north as an example, according to the main water quality characteristics of the groundwater, the pH value was 7.5-9.5 and the U concentration was 0.5-2.0 mg / L. The functional microbial strains obtained by separation and screening were gradually acclimated to pH value and U concentration. For the pH value, the pH value was set to 7.5 in the culture system. Under the condition of pH value of 7.5, the number of viable cells of the microorganism reached 10 7 CFU / mL, take 1% of the bacterial agent and inoculate it into the next system. After the pH value is increased by 0.5 to 8.0, it is judged again that the number of viable cells of the microorganism reaches 10 7 CFU / mL, until the acclimation is completed in a pH 9.5 environment. At the same time, the U concentration also adopts this gradient acclimation method, with the initial uranium concentration of 0.5 mg / L increasing step by step from 0.5 mg / L to 2.0 mg / L. Finally, a microbial agent with tolerance to mine groundwater was obtained.

[0024] Example 3 Microbial Agent Compounding Process

[0025] Due to the differences in the growth environment of different microbial strains, when a single strain repair condition cannot be used, it is necessary to carry out a co-culture strain compounding process for different microbial strains. The original strains of Burkholderia and Pseudomonas in the present invention are mainly added to the culture system of the present invention in a 1:1 ratio until the two functional microorganisms show iron reduction and phosphorus solubilization functions, and then 10% of the microbial agent is inoculated into a new culture system, re-cultured, and repeated passage 3 to 5 times to obtain a stable co-culture compound microbial agent.

[0026] Example 4 In-situ repair

[0027] According to the pollution level, different microbial agents developed are injected into the uranium mine seepage water / groundwater to be repaired at an inoculation rate of 1-10%, and a corresponding microbial culture system is constructed at the same time. After the injection process is completed, the corresponding repair effect can be achieved under static conditions.

[0028] For the groundwater of a sandstone uranium mine in northern my country, its water quality characteristics are pH value of 9.20 and uranium concentration of 1.2 mg / L, which belong to the general pollution level. Based on the water quality characteristics, when the microbial agent described in the present invention is used for in-situ remediation, the microbial agent obtained after domestication is inoculated into 10L of seepage water at a 1% inoculation amount, and the room temperature static remediation method is adopted. After 5 days of remediation at room temperature of 25-30°C, the number of microorganisms growing in the seepage water is significantly increased, the pH shows an upward trend, and the uranium concentration is reduced to the expected level. The results show that the microbial agent described in the present invention has significant tolerance and remediation ability for uranium mine groundwater.

[0029] Example 5 Results Analysis

[0030] 15d growth status and corresponding repair effect Figure 1 , Figure 2 and Figure 3 As shown in the figure, it can be seen that the bacteria provided by the present invention have produced relatively significant results in the uranium pollution control method.

[0031] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A biological agent, characterized in that: The reagent consists of Burkholderia and Pseudomonas; the Burkholderia is a strain with a preservation number of CGMCC NO.29789; and the Pseudomonas is a strain with a preservation number of CGMCC NO.29788.

2. Use of the biological agent as claimed in claim 1 in uranium mine pollution control.

3. A method for controlling uranium mine pollution, characterized in that: The biological agent as claimed in claim 1 is injected into the uranium mine seepage water or groundwater to be repaired at an inoculation rate of 1-10%, and a corresponding microbial culture system is constructed at the same time. After the injection process is completed, the corresponding repair effect can be achieved under static conditions.

Images