Method for biological pretreatment of rare earth ore mining wastewater by using organisms

Abstract

The application provides a biological pretreatment method of rare earth ore mining wastewater. The pretreatment method uses a mixed bacterial flora meeting the requirements of bacteria genus obtained through domestication to activate and gradually expand culture; then the mixed bacterial flora is domesticated in different concentrations of wastewater to be treated to adapt to the treatment environment, and finally added into the wastewater to perform deamination treatment. The application uses the mixed bacterial flora to realize rapid denitrification of the rare earth ore mining wastewater through an anaerobic ammonia oxidation process, expands the conventional treatment method, and reduces the load and operation cost of the wastewater treatment system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a method for biological pretreatment of rare earth mine mining wastewater by using biology. BACKGROUND

[0002] At present, the in-situ leaching mining process is generally used in rare earth mines, and ammonium sulfate solution has strong displacement capacity for rare earth in different leaching agents, so it is used in large quantities in mining. Therefore, the wastewater generated in mining contains a large amount of sulfate ions and ammonium ions, and the rare earth mine wastewater has the characteristics of high ammonia nitrogen and low COD. Direct discharge of such wastewater will not only affect the environment but also pose a threat to human health.

[0003] At present, the methods for treating high ammonia nitrogen wastewater in rare earth mine mining mainly include chemical method, electrochemical method, degassing membrane method and electrolytic chlorine method. The chemical method usually needs to add a large amount of reagent, the treatment cost is high and secondary pollution is easy to occur, the electrochemical method has the characteristics of easy corrosion of electrode and poor stability, the degassing membrane method has high pretreatment requirements and large investment cost, and the electrolytic chlorine method is also a kind of electrochemistry, which has the disadvantages of easy corrosion and poor stability. Biological method is also a common method for treating high ammonia nitrogen wastewater. For example, A / O process, i.e. nitrification-denitrification biological denitrification process, refers to that ammonia nitrogen in wastewater is removed through a series of reactions such as nitrification and denitrification under the action of various microorganisms, so as to achieve the purpose of removing ammonia nitrogen. However, the traditional biological nitrification-denitrification process has been more and more unable to meet the denitrification requirements of low C / N and high ammonia nitrogen content wastewater. Under such wastewater, the growth of microorganisms is poor and the treatment efficiency is low. Therefore, it is necessary to screen mixed bacteria groups suitable for survival in low C / N and high ammonia nitrogen content wastewater and significantly improve the treatment efficiency. SUMMARY

[0004] In order to solve the above technical problems, the present application provides a biological pretreatment method for rare earth mine mining wastewater. The method is used for biological pretreatment of high ammonia nitrogen wastewater in rare earth mine mining by using mixed bacteria groups with strong specificity and good effect.

[0005] In order to achieve the above technical purpose, the present application provides a method for biological pretreatment of rare earth mine mining wastewater by using biology, characterized in that the specific steps are as follows:

[0006] (1) selecting a mixed bacteria group composed of the following microorganisms: Candidatus Brocadia genus, Candidatus Kuenenia genus, Klebsiella genus, Pseudomonas genus, Candidatus Jettenia genus, Candidatus Anammoxoglobus genus and other genera <5%;

[0007] (2) Activating the mixed bacteria colony in the basic medium and gradually expanding the culture to form a mixed bacteria colony liquid;

[0008] (3) Taking part of the wastewater to be treated and diluting it in different concentrations to acclimate and culture the mixed bacteria colony liquid in step (2) until the mixed bacteria colony can completely adapt to the undiluted wastewater, and acclimating and culturing in the undiluted wastewater until OD600 nm is 1.0-1.5;

[0009] (4) Adding the mixed bacteria colony with OD600 nm of 1.0-1.5 obtained by acclimation and culture in step (3) into the wastewater at a proportion of 5-10% by volume for deamination treatment; the molar ratio of N:P in the reactor should be controlled to be (4-6):1 during the treatment process, the oxygen concentration in the reactor should be controlled to be below 0.5%, and the pH should be controlled to be 7.5-8.

[0010] The further technical solution of the present application is that the mixed bacteria in step (1) are obtained by acclimation after being collected from the sea, mining areas or salt fields with high salt content, and the specific process is as follows:

[0011] a. Randomly selecting sediment samples and water samples from the sea, mining areas or salt fields with high salt content, mixing them, and then loading them into sterile sampling bags and storing them under low temperature conditions;

[0012] b. After the samples collected in step a are transported back to the laboratory, they are mixed, shaken and suspended, and the upper suspension after suspension is taken as the mixed bacteria for later acclimation;

[0013] c. The mixed bacteria in step b are acclimated using liquid culture media with different ammonium sulfate concentrations to obtain a mixed bacteria colony suitable for high ammonia nitrogen wastewater, and the formula of the basic culture medium is: sodium chloride 10 g / L, potassium dihydrogen phosphate 1 g / L, magnesium sulfate 0.03 g / L, calcium chloride 1.15 g / L, ferrous sulfate 0.03 g / L, and distilled water 1 L; the ammonium sulfate concentration in the culture medium at the beginning of acclimation is 0.5 g / L, and then gradually increased to 10 g / L in the final stage culture medium, and the culture time of each stage is 4-5 days;

[0014] d. After the acclimation and culture of the mixed bacteria are completed, 20% of glycerol is added according to the volume ratio, and then the mixed bacteria are placed in a cryopreservation tube and stored at -80℃.

[0015] The preferred technical scheme of the present application: the activation and expansion process of the mixed bacteria in step (2) is to activate the mixed bacteria in 500 mL of base medium and gradually expand to 10 L of culture medium; the medium formula is sodium chloride 10 g / L, potassium dihydrogen phosphate 1 g / L, magnesium sulfate 0.03 g / L, calcium chloride 1.15 g / L, ferrous sulfate 0.03 g / L, and ammonium sulfate 5 g / L.

[0016] The preferred technical scheme of the present application: the ammonia nitrogen value in the wastewater to be treated in steps (3) and (4) is 1000-3000 mg / L, the sulfate content is 1000-4000 mg / L, the organic matter concentration is low, COD < 50 mg / L, and low phosphorus P < 5 mg / L.

[0017] The preferred technical scheme of the present application: the acclimation process of the wastewater to be treated in step (3) is as follows: first, take part of the wastewater to be treated and dilute it to 10-20% of the original wastewater concentration, and add 5-10% of the mixed bacteria liquid in step (2) by volume ratio for acclimation culture one or more times until the OD600 nm of the mixed bacteria reaches 0.7-1.0; then take part of the wastewater to be treated and dilute it to 50-100% of the original wastewater concentration, and add 5-10% of the mixed bacteria liquid with OD600 nm of 0.7-1.0 by volume ratio for acclimation culture one or more times until the OD600 nm of the mixed bacteria reaches 1.0-1.5; the conditions and time of each acclimation culture are the same, and the wastewater dilution concentration is different; the conditions of each acclimation culture are as follows: the molar ratio of N:P is (4-6):1, the oxygen concentration in the reactor should be controlled below 0.5%, the pH is controlled at 7.5-8, the temperature is 28-32°C, and the culture time is 14-16 days.

[0018] The preferred technical scheme of the present application: in step (3), the molar ratio of N:P is detected by alkaline potassium persulfate digestion UV spectrophotometry or potassium persulfate digestion ammonium molybdate spectrophotometry; when the molar ratio of N:P is less than 4, phosphates are added to control the molar ratio of N:P in the range of (4-6):1.

[0019] The preferred technical scheme of the present application: in step (3), the growth of microorganisms is detected every 12 hours during the operation of the reactor using a spectrophotometer, and the OD600 nmWhen the ratio of N:P is 1.0-1.5, the DNA of the mixed microbial flora in the extraction reactor is sequenced in the v3-v4 region of 16S rRNA to determine the microbial flora genus and the dominant genus >10% in the reactor; during the operation of the reactor, when the OD600 nm When the OD600 of the mixed microbial flora decreases, the number of microorganisms under a microscope is small, or the ammonia nitrogen chemical index does not decrease, the mixed microbial flora liquid is added again in a proportion of 5-10% by volume to continue treatment, and the molar ratio of N:P in the reactor is adjusted to (4-6):1, the oxygen concentration in the reactor should be controlled to be below 0.5%, and the pH is controlled to be 7.5-8.

[0020] The preferred technical solution of the present application is that in step (3), as the operation time of the reactor increases, the OD600 of the mixed microbial flora decreases, and the number of microorganisms under a microscope is small or the ammonia nitrogen chemical index does not decrease, so the mixed microbial flora needs to be supplemented. nm

[0021] The preferred technical solution of the present application is that in step d, after the domestication and cultivation of the mixed microbial flora are completed, the v3-v4 region of 16S rRNA is high-throughput sequenced to determine the microbial flora genus in the reactor.

[0022] The sequencing process to determine the microbial flora genus in the reactor in steps (3) and d is the same, and the primers used are:

[0023] 341F: 5'-CCTACGGGNGGCWGCAG-3',

[0024] 805R: 5'-GACTACHVGGGTATCTAATCC-3';

[0025] The Illumina NovaSeq 6000 platform is used for sequencing to obtain more than 50,000 raw sequences, and after quality detection and annotation by using qiime2 software, the mixed microbial flora satisfies the following microbial composition: Candidatus Brocadia genus, Candidatus Kuenenia genus, Klebsiella genus, Pseudomonas genus, Candidatus Jettenia genus, Candidatus Anammoxoglobus genus and other genera <5%;

[0026] After the above microbial composition is obtained in step (3), 20% of glycerol is added in a proportion and placed in a cryopreservation tube for storage at-80℃.

[0027] ​The preferred technical scheme of the present application: the concentration of ammonium sulfate in the mixed bacteria domestication process in step c is 0.5 g / L, 1 g / L, 1.5 g / L, 2 g / L, 2.5 g / L, 3 g / L, 5 g / L, and 10 g / L.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] The mixed bacteria provided by the present application are obtained through continuous screening and domestication under laboratory conditions, and can be applied to rare earth mine wastewater with low C / N, high ammonia nitrogen, high sulfate and high heavy metal concentration. Ammonia nitrogen and nitrate nitrogen are removed and N2 is generated through anaerobic ammonia oxidation of microorganisms. Compared with the traditional microbial nitrification and denitrification process, the process based on anaerobic ammonia oxidation can effectively reduce the aeration cost and treatment time. Compared with other biological treatment methods such as microalgae and other eukaryotes, the mixed bacteria provided by the present application have the advantages of high cultivation efficiency, reduced sludge production and reduced organic carbon demand. The biological gene resources of the mixed bacteria are beneficial to the development of downstream products, and a more efficient and affordable wastewater treatment method is expected to be further developed. Through the treatment of the mixed bacteria, the ammonia nitrogen and total nitrogen content of the rare earth mine wastewater can be reduced by 95.5% and 96.2%. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the overall flow chart of the laboratory domestication and wastewater treatment of the mixed bacteria in the example;

[0031] Figure 2 is the COD change in the nearly one week before and after wastewater treatment in Example 1;

[0032] Figure 3 is the ammonia nitrogen change in the nearly two weeks before and after wastewater treatment in Example 1;

[0033] Figure 4 is the nitrate nitrogen change in the nearly two weeks before and after wastewater treatment in Example 1;

[0034] Figure 5 is the proportion of bacteria genera after stable operation of the system in Example 1. DETAILED DESCRIPTION

[0035] The present application will be further described below in conjunction with examples. The accompanying drawings are reference drawings of the examples, and the specific schemes of the following examples are not intended to limit the scope of the claimed present application. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without creative labor are within the scope of the present application. Figures 1 to 5 The accompanying drawings are reference drawings of the examples, and the specific schemes of the following examples are not intended to limit the scope of the claimed present application. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without creative labor are within the scope of the present application.

[0036] The microbial mixed bacteria used in the following examples are obtained through domestication in the laboratory according to the process in the following table: Figure 1 The specific steps are as follows:

[0037] a. Randomly select sediment samples and water samples from high-salt-content marine, mining or salt field areas, mix them and put them into sterile sampling bags, and store them under low temperature conditions; after being taken back to the laboratory, mix, shake and suspend the collected samples, and take the upper suspension as a mixed bacterial strain for subsequent operations;

[0038] b. The sample collected in step a is inoculated into a basic culture medium, and the culture medium formula is as follows: sodium chloride 10 g / L, potassium dihydrogen phosphate 1 g / L, magnesium sulfate 0.03 g / L, calcium chloride 1.15 g / L, ferrous sulfate 0.03 g / L, ammonium sulfate 0.5 g / L, distilled water 1 L; after being cultured at 30°C, 140 rpm / min and anaerobic conditions for 3-4 days, the concentration of ammonium sulfate is gradually increased, and the concentration gradient of ammonium sulfate is: 0.5 g / L, 1 g / L, 1.5 g / L, 2 g / L, 2.5 g / L, 3 g / L, 5 g / L, 10 g / L; after being cultured under the same conditions for 3-4 days at each gradient, the microorganisms under the concentration of 10 g / L of ammonium sulfate are taken as a mixed bacterial community; the v3-v4 region in the 16S rRNA is subjected to high-throughput sequencing.

[0039] The above sequencing process is as follows:

[0040] The primers are as follows:

[0041] 341F: 5'-CCTACGGGNGGCWGCAG-3',

[0042] 805R: 5'-GACTACHVGGGTATCTAATCC-3';

[0043] Sequencing is performed using the Illumina NovaSeq 6000 platform to obtain more than 50,000 raw sequences, and the qiime2 software is used for quality detection and annotation to determine the genera of the bacterial community and the dominant genera: Candidatus Brocadia genus, Candidatus Kuenenia genus, Klebsiella genus, Pseudomonas genus, Candidatus Jettenia genus, Candidatus Anammoxoglobus genus and other genera <5%, and then 20% of glycerol is added in proportion and placed in a cryotube at -80°C.

[0044] The process of high-throughput sequencing of the v3-v4 region in the 16S rRNA in the following examples is the same as the above sequencing process, and the genera of the bacterial community and the dominant genera are determined after sequencing.

[0045] Example one: rare earth mine wastewater in Pingyuan County, Meizhou City, Guangdong Province is treated, taking 2L rare earth mine wastewater in Pingyuan County, Meizhou City, Guangdong Province, and analyzing the wastewater quality. The wastewater quality analysis results are as follows:

[0046] Water quality index COD NH3-N TN TP Content 100 mg / L 2500 mg / L 3000 mg / L 3 mg / L

[0047] The above wastewater is treated, and the treatment process is as follows:

[0048] (1) The above mixed strain cryopreservation tube is activated in 500mL of basal medium and gradually expanded to 10L of culture medium. The culture medium formula is sodium chloride 10g / L, potassium dihydrogen phosphate 1g / L, magnesium sulfate 0.03g / L, calcium chloride 1.15g / L, ferrous sulfate 0.03g / L, and ammonium sulfate 5g / L.

[0049] (2) After adjusting the N:P ratio of the wastewater to 5:1 using potassium phosphate dibasic, take 100mL of wastewater and dilute it 10 times, and inoculate the above mixed strain. Under anaerobic conditions at 30℃, the culture is cultured, enriched, and acclimated for 15 days. After obtaining the primary acclimated strain, it is inoculated into 5 times diluted wastewater and cultured, enriched, and acclimated for 15 days under the same conditions. When the growth of the strain is poor, the growth factors required for microbial growth such as vitamins or trace elements are supplemented in time. After obtaining the second acclimated strain, it is inoculated into undiluted wastewater. During the acclimation process, if the growth of the strain is slow, the wastewater is appropriately diluted by 1-3 times. When the strain can fully adapt, it is introduced into undiluted wastewater for acclimation. After acclimation, the mixed strain liquid meets OD600 nm 1.0-1.5. After obtaining the final acclimated strain, the strain DNA is extracted, and the v3-v4 region in its 16S rRNA is high-throughput sequenced to determine the strain genus and dominant strain genus that meet the above requirements.

[0050] (3) The mixed strain liquid (OD600 nmIn 1.0~1.5) according to the volume ratio of 5~10% of the wastewater for deamination treatment; the process of maintaining the molar ratio of N: P is 5:1, the oxygen concentration in the reactor should be controlled below 0.5%, pH control in 7.5-8; and in the reaction process by basic potassium persulfate digestion ultraviolet spectrophotometry and potassium persulfate digestion ammonium molybdate spectrophotometry detection N: P molar ratio, when N: P molar ratio is less than 4, add phosphate to control N: P molar ratio in 5:1. In the process of reactor operation, the growth of microorganisms is observed under microscope every 12 hours, when the biomass of microorganisms reaches the maximum value, the DNA of mixed microbial community in the reactor is extracted, and the v3-v4 region of 16S rRNA is sequenced to determine the proportion of microbial community in the reactor and the dominant genus Candidatus Brocadia genus (34.20%), Candidatus Kuenenia genus (21.96%), Klebsiella genus (16.23%), Pseudomonas genus (11.63%), Candidatus Jettenia genus (8.49%), Candidatus Anammoxoglobus genus (5.91%) and other genera (1.58%) (see Figure 5 ).

[0051] (4) In the process of reactor operation, when the treatment efficiency is low or not up to standard, that is, if the OD600 nm of mixed microbial community decreases, the number of microorganisms under the microscope is small or the chemical index of ammonia nitrogen does not decrease, add a certain genus according to the proportion of genus in step (3) to make the proportion consistent, and adjust the reactor operation conditions and add trace elements or growth factors required for microbial growth to optimize the concentration of microorganisms.

[0052] The main indicators after treatment are as follows: the overall residence time is 3-5 days. As shown in Figure 2 、 Figure 3 、 Figure 4 (Fig. the horizontal coordinate is the running days, the vertical coordinate is mg / L) shows that the removal rate of COD in wastewater is more than 80%, the removal rate of total nitrogen is more than 90%, the removal rate of ammonia nitrogen is more than 95%, and the whole biological pretreatment system runs stably, which greatly improves the treatment efficiency of the subsequent system, and makes the capacity of the whole wastewater treatment system improve by more than 40%.

[0053] Example 2. Another kind of mining wastewater is treated, and the analysis results of the wastewater are as follows:

[0054] Water quality index COD [COD] TN TP Content 80 mg / L 3000 mg / L 3500 mg / L 2.5 mg / L

[0055] The wastewater in Example 2 is treated by the same process steps as in Example 1, and during the operation of the reactor, the growth of the microorganisms is observed by microscopy every 12 hours, and when the biomass of the microorganisms reaches the maximum value, the DNA of the mixed microbial flora in the reactor is extracted, and the v3-v4 region of the 16S rRNA is sequenced to determine the proportion of the genera of the microbial community in the reactor and the dominant genera:

[0056] Candidatus Brocadia (38.26%), Candidatus Kuenenia (18.67%), Pseudomonas (14.73%), Klebsiella (13.92%), Candidatus Jettenia (6.27%), Candidatus Anammoxoglobus (5.80%), and other genera (2.35%).

[0057] After one week of treatment, the COD of the wastewater is 21 mg / L (with a removal rate of 74%), the total nitrogen is 235 mg / L (with a removal rate of 93%), and the ammonia nitrogen is 90 mg / L (with a removal rate of 97%), and the entire biological pretreatment system runs stably, greatly improving the treatment efficiency of the subsequent system, and making the capacity of the entire wastewater treatment system increase by more than 40%.

[0058] The above is only a specific embodiment of the present application, which is described in more detail and in more detail, but it cannot be understood as limiting the scope of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of the present application should be subject to the appended claims.

Claims

1. A method for biological pretreatment of rare earth ore mining wastewater by using organisms, characterized in that The specific steps are as follows: (1) selecting a mixed flora comprising the following microorganisms: Candidatus Brocadia, Candidatus Kuenenia, Klebsiella, Pseudomonas, Candidatus Jettenia, Candidatus Anammoxoglobus and other genera <5%; (2) activating and gradually expanding the mixed flora in a basic medium to form a mixed flora liquid; the activation and expansion process of the mixed flora is to activate and gradually expand the mixed flora in 500 mL of the basic medium to 10 L of the culture medium; the formula of the basic medium is sodium chloride 10 g / L, potassium dihydrogen phosphate 1 g / L, magnesium sulfate 0.03 g / L, calcium chloride 1.15 g / L, ferrous sulfate 0.03 g / L, ammonium sulfate 5 g / L; (3) Take a portion of the mining wastewater to be treated and dilute it sequentially at different concentrations to acclimate and cultivate the mixed bacterial culture solution in step (2) until the mixed bacterial culture can fully adapt to the undiluted mining wastewater, and acclimate and cultivate it in the undiluted mining wastewater until OD600. nm The N:P molar ratio was determined by alkaline potassium persulfate digestion ultraviolet spectrophotometry or potassium persulfate digestion ammonium molybdate spectrophotometry. When the N:P molar ratio was less than 4, phosphate was added to control the N:P molar ratio within the range of 4 to 6:

1. (4) The OD600 of the domesticated culture obtained in step (3) is adjusted to 0.1-0.2 nm The mixed bacteria with a volume ratio of 1.0-1.5 are added into the mining wastewater in a proportion of 5-10% for deamination treatment; during the treatment, the molar ratio of N:P in the reactor is maintained at (4-6):1, the oxygen concentration in the reactor is controlled below 0.5%, and the pH is controlled at 7.5-8; The mixed flora in step (1) is obtained by domestication after being collected from high-salt oceans, mining areas or salt fields, and the specific steps are as follows: a. Randomly select sediment samples and water samples from high-salt oceans, mining areas or salt fields, mix them, and then put them into sterile sampling bags and store them under low-temperature conditions; b. After the samples collected in step a are mixed, shaken and suspended in the laboratory, the upper suspension is taken as the mixed flora for later domestication; c. The mixed flora in step b is domesticated using liquid media with different ammonium sulfate concentrations to obtain a mixed flora suitable for high-ammonia-nitrogen wastewater, and the formula of the basic medium is: sodium chloride 10 g / L, potassium dihydrogen phosphate 1 g / L, magnesium sulfate 0.03 g / L, calcium chloride 1.15 g / L, ferrous sulfate 0.03 g / L, and distilled water 1 L; the ammonium sulfate concentration in the culture medium at the beginning of domestication is 0.5 g / L, and then gradually increases to 10 g / L in the final stage of the culture medium, and the culture time for each stage is 4-5 days; d. After the domestication and culture of the mixed flora are completed, 20% glycerol is added according to the volume ratio, and then the mixed flora is stored in a cryopreservation tube at -80°C.

2. The method for biological pretreatment of rare earth ore mining wastewater by using organisms according to claim 1, characterized in that: The ammonia nitrogen value in the mining wastewater to be treated in steps (3) and (4) is 1000-3000 mg / L, the sulfate content is 1000-4000 mg / L, the organic matter concentration is low, COD <50 mg / L, and low phosphorus P <5 mg / L.

3. The method for biological pretreatment of rare earth ore mining wastewater by using organisms according to claim 1, characterized in that The process of acclimatization using the mining wastewater to be treated in step (3) is as follows: first, take part of the mining wastewater to be treated and dilute it to 10-20% of the original wastewater concentration, and add the mixed bacteria liquid in step (2) in a proportion of 5-10% by volume to acclimatize and cultivate once or more times until the OD600 of the mixed bacteria is 0.7-1.0; then take part of the wastewater to be treated and dilute it to 50-100% of the original wastewater concentration, and add the acclimatized mixed bacteria liquid with OD600 of 0.7-1.0 in a proportion of 5-10% by volume to acclimatize and cultivate once or more times until the OD600 of the mixed bacteria is 1.0-1.5; the conditions and time of each acclimatization cultivation are the same, and the wastewater dilution concentration is different; the conditions of each acclimatization cultivation are as follows: the molar ratio of N:P is (4-6):1, the oxygen concentration in the reactor should be controlled below 0.5%, the pH is controlled at 7.5-8, the temperature is 28-32℃, and the cultivation time is 14-16 days. nm nm nm The process of acclimatization using the mining wastewater to be treated in step (3) is as follows: first, take part of the mining wastewater to be treated and dilute it to 10-20% of the original wastewater concentration, and add the mixed bacteria liquid in step (2) in a proportion of 5-10% by volume to acclimatize and cultivate once or more times until the OD600 of the mixed bacteria is 0.7-1.0; then take part of the wastewater to be treated and dilute it to 50-100% of the original wastewater concentration, and add the acclimatized mixed bacteria liquid with OD600 of 0.7-1.0 in a proportion of 5-10% by volume to acclimatize and cultivate once or more times until the OD600 of the mixed bacteria is 1.0-1.5; the conditions and time of each acclimatization cultivation are the same, and the wastewater dilution concentration is different; the conditions of each acclimatization cultivation are as follows: the molar ratio of N:P is (4-6):1, the oxygen concentration in the reactor should be controlled below 0.5%, the pH is controlled at 7.5-8, the temperature is 28-32℃, and the cultivation time is 14-16 days.​​ 4. The method for biological pretreatment of rare earth ore mining wastewater by using organisms according to claim 1, characterized in that: The step (3) in the reactor operation process, every 12 hours using spectrophotometer to detect the growth of microorganisms, when the biomass of microorganisms reaches OD600 nm 1.0-1.5, extract the DNA of the mixed microbial flora in the extraction reactor, and sequence the v3-v4 region in the 16S rRNA to determine the genus of the microbial flora in the reactor and the dominant genus >10%; during the operation of the reactor, when the OD600 nm of the mixed microbial flora decreases, or the number of microorganisms under the microscope is small or the ammonia nitrogen chemical index does not decrease, add the mixed microbial flora liquid again in a proportion of 5-10% by volume to continue the treatment, and adjust the molar ratio of N:P in the reactor to (4-6):1, the oxygen concentration in the reactor should be controlled below 0.5%, and the pH is controlled at 7.5-8.

5. The method for biological pretreatment of rare earth ore mining wastewater by using organisms according to claim 1, characterized in that: The OD600 of the mixed bacteria population in step (3) decreases with the increase of the reactor running time nm When the number of microorganisms under microscope or the ammonia nitrogen chemical index does not decrease, the mixed bacteria population needs to be supplemented.

6. The method for biological pretreatment of rare earth ore mining wastewater by using organisms according to claim 4, characterized in that: After the domestication and culture of the mixed flora in step d are completed, the v3-v4 region in the 16S rRNA of the mixed flora is subjected to high-throughput sequencing to determine the microbial flora genera in the reactor; The process of determining the microbial flora genera in the reactor in steps (3) and d is the same, and the primers used are: 341F: 5'-CCTACGGGNGGCWGCAG-3', 805R: 5'-GACTACHVGGGTATCTAATCC-3'; Sequencing is performed using the Illumina NovaSeq 6000 platform to obtain more than 50000 raw sequences, and after quality detection and annotation using qiime2 software, the mixed flora meets the following microbial composition: Candidatus Brocadia, Candidatus Kuenenia, Klebsiella, Pseudomonas, Candidatus Jettenia, Candidatus Anammoxoglobus and other genera <5%; After obtaining the above microbial composition in step (3), 20% glycerol is added in proportion, and then placed in a cryopreservation tube and stored at-80℃.

7. The method for biological pretreatment of rare earth ore mining wastewater by using organisms according to claim 1, characterized in that: The concentration of ammonium sulfate in the mixed flora domestication process in step c is 0.5 g / L, 1 g / L, 1.5 g / L, 2 g / L, 2.5 g / L, 3 g / L, 5 g / L, 10 g / L, respectively.

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