Anaerobic microbiological treatment system and method for underground water polluted by chlorinated organic compounds

Abstract

The invention discloses an anaerobic microbiological treatment system and method for underground water polluted by chlorinated organic compounds. The system comprises a fermentation tank, an adjusting tank, an air supply system, a material supply system, an output system and a monitoring system, wherein the air supply system, the material supply system, the output system and the monitoring system are connected with the fermentation tank and the adjusting tank. The method comprises the following steps: S1, adjusting polluted underground water; s2, constructing an anaerobic environment; s3, adding microorganisms; s4, balancing the pressure; s5, bacterial liquid detection; s6, dynamically treating the polluted underground water; and S7, detecting and reinjecting the treated underground water. According to the invention, the polluted underground water can be stably, continuously and efficiently treated by using the anaerobic dechlorination microbial liquid, in the use process, a 0.22 [mu] m filter membrane is used for removing particles at each gas inlet end, bacteria and microorganisms are interfered to prevent cross contamination, and the whole system is kept sealed in the whole fermentation and treatment process, so that the pollution of the underground water is avoided. And on the premise that strict sealing is kept, accurate liquid supplementing, stirring, sampling detection and collection reinjection can be achieved, the high integrated automation function is achieved, and application and popularization are facilitated.

Description

Technical Field

[0001] The present invention relates to the field of microorganisms and environmental protection technology, and in particular to an anaerobic microbial treatment system and method for groundwater contaminated by chlorinated organic matter. Background Art

[0002] Continuous flow fermentation of anaerobic dechlorinating microorganisms is a biotechnology that uses anaerobic microorganisms to degrade chlorinated organic pollutants under conditions of continuous feeding and discharging. Anaerobic dechlorinating microorganisms (such as Dehalococcoides, Dehalobacter, etc.) use chlorinated organic matter as electron acceptors through respiration, gradually dechlorinating to produce low-toxic or non-toxic products (such as ethylene and ethane). In general culture systems, the long-term and stable metabolic activity of microorganisms is maintained by continuously inputting substrates (pollutants, nutrient solution) and outputting fermentation liquid. However, in order to achieve continuous sterile, closed, and continuous fermentation, many technical difficulties need to be overcome.

[0003] Groundwater treatment is an important part of ensuring the safety and sustainable use of water resources. Its purpose is to remove pollutants (such as heavy metals, organic matter, microorganisms, salts, etc.) in groundwater so that it meets the standards for domestic water, industrial water or recharge.

[0004] Anaerobic dechlorinating microbial continuous flow fermentation treatment technology is an environmental biotechnology that utilizes the metabolic activities of microorganisms (such as dechlorinating respiration) under anaerobic conditions to remove chlorine-containing pollutants (such as chlorinated hydrocarbons and pesticide residues) from groundwater. This technology achieves efficient microbial enrichment and continuous degradation of pollutants through a continuous flow reactor, making it suitable for remediation of groundwater contaminated by chlorinated organic compounds.

[0005] Current microbial groundwater treatment technology has made significant progress. Patent publication number CN116375269B discloses a method for remediating groundwater containing organic pollutants, comprising the following steps: 1) extracting groundwater containing organic pollutants using multiple extraction pumps, adding a divalent iron salt at a solid-to-liquid ratio of 1:50-200, mixing, and adjusting the pH of the system to 6-8 to obtain an intermediate treatment solution (I); 2) adding a remediation agent to the resulting intermediate treatment solution (I), stirring and reacting for 3-6 hours to obtain an intermediate treatment solution (II); 3) sequentially passing the resulting intermediate treatment solution (II) through an anaerobic reactor and an aerobic tank for treatment, and discharging after meeting standards. The anaerobic reactor's filler contains microorganisms comprising at least two of the following: denitrifying bacteria, Bacillus coagulans, Bacillus subtilis, Bacillus clausii, Bacillus indica, and Serratia marcescens. The organic matter removal rate can reach over 98%. However, this method does not allow for continuous dynamic microbial cultivation and continuous treatment. Summary of the Invention

[0006] In response to the above problems, the present invention provides a system and method for treating groundwater contaminated by chlorinated organic compounds using anaerobic microorganisms.

[0007] The technical solution of the present invention is:

[0008] An anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds comprises a fully sealed fermentation tank and a regulating tank, an air supply system, a feed supply system, an output system, and a monitoring system connected to the fermentation tank and the regulating tank, a first sealing cover being provided on the top of the fermentation tank, a first stirring motor being provided in the middle of the upper surface of the first sealing cover, a first stirring rod being provided after the output end of the first stirring motor passes through the first sealing cover, and a temperature controller being provided on the outside of the fermentation tank;

[0009] The fermentation tank is connected to the regulating tank through an injection pipe. A second sealing cover is provided on the top of the regulating tank, and a sewage pipe is provided on one side of the regulating tank.

[0010] Furthermore, a second stirring motor is provided in the middle of the upper surface of the regulating tank, and a second stirring rod is provided after the output end of the second stirring motor passes through the second sealing cover.

[0011] Description: Facilitates the conditioning and treatment of groundwater through agitation.

[0012] Furthermore, the air supply system includes an N2 tube and an H2 tube, each of which is provided with a numerically controlled valve. The N2 tube and the H2 tube are commonly connected to an air intake pipe, on which a deaerator and a mass flow meter are provided. A branch at the end of the air intake pipe passes through the first sealing cover and is connected to the interior of the fermentation tank. A numerically controlled valve is provided on the branch at the end of the air intake pipe.

[0013] Note: Oxygen in the injected gas is removed by a deaerator, and the injected amount is recorded by a mass flow meter.

[0014] Furthermore, the feeding system includes an acid feeding tank, an alkali feeding tank, a culture medium feeding tank and a reducing agent feeding tank, another branch at the end of the air inlet pipe is connected to the culture medium feeding tank, and a numerical control valve is provided on the branch at the end of the air inlet pipe. The interior of the culture medium feeding tank is connected to the interior of the fermentation tank through a first feeding pipe passing through the first sealing cover, and the first feeding pipe is provided with a first diversion pump. The interiors of the acid feeding tank, the alkali feeding tank and the reducing agent feeding tank are connected to the interior of the fermentation tank through a second feeding pipe passing through the first sealing cover, and the interiors of the acid feeding tank, the alkali feeding tank and the reducing agent feeding tank are connected to the interior of the regulating tank through a second feeding pipe passing through the second sealing cover, and each of the second feeding pipes is provided with a second diversion pump, and filter membranes are provided on both branches of the air inlet pipe, and air pressure balance pipes are provided between the acid feeding tank, the alkali feeding tank, the culture medium feeding tank and the reducing agent feeding tank and the fermentation tank and the regulating tank, and the air pressure balance pipes are provided with filter membranes.

[0015] Note: The acid, alkali, culture medium and reducing agent required in the fermentation tank are replenished in time through the feeding system, and a 0.22μm filter membrane is used to prevent cross contamination.

[0016] Furthermore, the output system includes a reinjection tank and a liquid-sealed tank. The reinjection tank is connected to the interior of the fermentation tank through a reinjection pipe passing through the first sealing cover. The reinjection pipe is provided with a third diversion pump. The liquid-sealed tank is connected to the interior of the fermentation tank through an air outlet pipe passing through the first sealing cover and the second sealing cover. The liquid-sealed tank is also provided with an exhaust pipe. The liquid-sealed tank is filled with water accounting for 50 to 60% of its total volume. The end of the exhaust pipe is connected to an activated carbon adsorber.

[0017] Note: The tail gas generated during the fermentation process is collected and purified by the liquid seal tank of the output system, and the liquid seal tank is used to liquid seal the fermentation tank.

[0018] Furthermore, the monitoring system includes a pressure sensor, a temperature sensor, a pH sensor and an Eh sensor that penetrate the first sealing cover and the second sealing cover and extend deep into the fermentation tank and the regulating tank, and the temperature sensor, pH sensor and Eh sensor are all connected to an external controller.

[0019] Description: Real-time monitoring of the fermentation status inside the fermentation tank through various sensors.

[0020] The present invention also provides a method for treating groundwater contaminated by chlorinated organic compounds with anaerobic microorganisms, which is based on any one of the above-mentioned systems for treating groundwater contaminated by chlorinated organic compounds with anaerobic microorganisms, comprising the following steps:

[0021] S1. Contaminated groundwater regulation: The contaminated groundwater is pumped into the regulating tank and continuously stirred. The monitoring system monitors the pH and redox potential Eh in the regulating tank in real time. N2 is injected through the gas supply system to maintain an anaerobic environment inside the regulating tank. A reducing agent is injected through the feeding system to maintain the redox potential Eh inside the regulating tank ≤ -400±10mV. Acid or alkali solution is injected through the feeding system to maintain the pH of the contaminated groundwater in the regulating tank at 7 to 7.5;

[0022] S2. Establishing an anaerobic environment: injecting a sterile culture medium into the fermentor, monitoring the pH and redox potential Eh in the fermentor in real time through the monitoring system, then introducing nitrogen at 5-10% of the total volume of the fermentor for 0.5-1 hour to reduce the dissolved oxygen in the culture medium inside the fermentor, then injecting a reducing agent through the feeding system to maintain the redox potential Eh inside the fermentor ≤-400±10 mV, and injecting acid or alkali solution through the feeding system to maintain the pH inside the fermentor at 7-7.5;

[0023] S3, adding microorganisms: injecting anaerobic dechlorination microbial mother liquor into the fermentation tank, setting the temperature to 20-30°C, stirring speed to 100-200 rpm, and starting cultivation;

[0024] S4. Pressure balance: During initial use, 5-10% of the total volume of the fermenter is introduced with H2. Then, 5-10% of the headspace volume of the fermenter is introduced with a mixed gas at intervals of 1 hydraulic retention time. The internal pressure of the fermenter is then monitored in real time by a pressure sensor. When the monitored pressure falls below the set value of 101 ± 1 kPa, the mixed gas is replenished through the gas replenishment system. The mixed gas is a mixture of N2 and H2 at a volume ratio of 9:1.

[0025] S5. Bacterial liquid detection: The production system is turned on and bacterial liquid is collected regularly, once every 1-2 hours, with a collection volume of 1-2 mL. The OD600 of the collected bacterial liquid is measured by a spectrophotometer, and the collected bacterial liquid is counted by a microscope to monitor the bacterial liquid concentration and establish a bacterial liquid growth curve;

[0026] S6. Dynamic treatment of contaminated groundwater: When the bacterial solution concentration reaches the maximum value, that is, when the bacterial solution reaches the logarithmic growth phase, the regulated contaminated groundwater is injected into the fermentation tank through the injection pipe, ensuring that the volume ratio of contaminated groundwater to bacterial solution in the fermentation tank is 0.5-1.5:9. Then, the mixture is stirred and mixed. The dynamic hydraulic retention time in the fermentation tank is t, which is calculated as follows:

[0027]

[0028] Where n is the maximum bacterial concentration; n1 is the bacterial concentration of the first test; n2 is the bacterial concentration of the second test; n m is the bacterial solution concentration detected for the mth time, and the value of t at this time is less than the interval between the two bacterial solution collections; v is the detection interval of the bacterial solution concentration; the meaning and calculation method of t1 are as follows: before starting S6, sampling and treating the groundwater sample, taking 1-2 mL of the contaminated groundwater sample, mixing it with the bacterial solution in the fermentation tank according to the ratio in S6, and then conducting water quality testing, and the time required for the measured pollutant concentration in the groundwater sample to be lower than the Class IV water quality standard limit;

[0029] Output the treated groundwater to the reinjection tank of the production system to wait for reinjection, while keeping steps S1 to S4 running synchronously;

[0030] S7. Testing and reinjection of treated groundwater: Take 1 mL of treated groundwater for testing every 1 to 2 hours to test the concentration of chlorinated organic pollutants in the treated groundwater. If it meets the limit of Class IV water quality standards, reinjection will be carried out. If it does not meet the limit of Class IV water quality standards, the treatment in S6 will be carried out again.

[0031] Furthermore, in S2, the initial amount of sterile culture medium added to the fermenter is 60%±5% of the volume of the fermenter. When the Eh sensor detects that the Eh value inside the fermenter is higher than -400mV, the reducing agent is added. The reducing agent contains: L-cysteine ​​with a molar concentration of 2mol / L and Na2S with a molar concentration of 1mmol / L. The injection amount per minute is 1 / 1000 of the volume of the fermenter until the standard is met. When the pH sensor detects that the pH value inside the fermenter is out of range, acid or alkali is added. The acid is HCl with a molar concentration of 1mol / L, and the alkali is NaOH with a molar concentration of 1mol / L. The injection amount per minute is 1 / 1000 of the volume of the fermenter until the standard is met.

[0032] Description: By optimizing and adjusting the internal detailed parameters of the fermentation tank, the fermentation process is ensured to proceed steadily and efficiently.

[0033] Furthermore, the injection amount of the anaerobic dechlorination microbial mother liquor in S3 is 2-10% of the volume of the fermentation tank, and the anaerobic dechlorination microbial mother liquor includes the same sterile culture medium and bacterial strain as in S2, and the bacterial strain is one or more of Dehalococcoides, Dehalogenimonas, Desulfitobacterium, Pseudomonas, Rhodococcus, and Methanogens, and the bacterial strain concentration is 1-5×10 7 cells / mL.

[0034] Description: By optimizing and screening the anaerobic dechlorination microbial mother liquor strains, the strain most suitable for the fermentation system of the present invention is finally obtained.

[0035] Furthermore, in S7, the amount of treated groundwater injected each time does not exceed 10% of the total volume of the injection tank. If it does not meet the limit of Class IV water quality standards, the amount of groundwater treated again in S6 shall not exceed 10% of the total volume of the injection tank. After the fermentation tank outputs the treated groundwater, the culture medium is added at the same time as the next input of the regulated contaminated groundwater. The ratio of the volume of the culture medium to the volume of the regulated contaminated groundwater is 0.5 to 1.5:9. Each time the treated groundwater is output, the current concentration of the bacterial solution in the fermentation tank is detected. m , when n m When / n is less than 50%, S6 is suspended and culture medium and H2 are added to the fermenter. The amount of culture medium added is 1-2% of the total volume of the fermenter, the supplement rate is 0.1% / h, and the amount of H2 added is to reach the pressure setting value of 101±1kPa.

[0036] Note: By optimizing the parameters for groundwater reinjection after S7 treatment, it is ensured that the reinjected groundwater meets the standards and the entire system remains stable.

[0037] The beneficial effects of the present invention are:

[0038] (1) The anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds of the present invention can stably, continuously and efficiently treat contaminated groundwater using anaerobic dechlorinating microbial liquid. During use, a 0.22 μm filter membrane is used to remove particles, interfering bacteria and microorganisms at each air inlet end to prevent cross contamination. The entire system remains sealed during fermentation and treatment, and under the premise of maintaining a strict seal, accurate liquid replenishment, stirring, sampling and testing, and collection and reinjection can be achieved. It has a strong integrated automation function and is easy to promote and use.

[0039] (2) The anaerobic microbial treatment method for groundwater contaminated by chlorinated organic matter of the present invention is to initially establish an anaerobic environment by passing nitrogen, use a redox electrode to detect the redox potential of the solution in the fermentation tank in real time, and supplement a reducing agent according to the detection result until the redox potential reaches a set value and stabilizes; at the same time, use a pH electrode to detect the pH of the solution in the fermentation tank in real time, and supplement acid / base according to the detection result to ensure that the pH reaches a set value and stabilizes; inoculate the anaerobic dechlorination microbial mother liquor, set a suitable culture temperature and stirring rate, and formally start the culture; after starting the culture, reasonably arrange the hydraulic retention time according to the groundwater treatment requirements, reasonably control the addition of auxiliary materials and the groundwater output, ensure the liquid level balance in the fermentation tank, and supplement nitrogen or hydrogen as needed; if tail gas is generated during the fermentation process, the tail gas can be treated by a tail gas absorption device and then discharged; if no gas is generated, the tail gas bottle can be liquid-sealed to ensure the anaerobic environment.

[0040] (3) The anaerobic microbial treatment method for groundwater contaminated by chlorinated organic compounds of the present invention focuses on optimizing the dynamic hydraulic retention time of the contaminated groundwater and provides a highly targeted calculation formula. The calculation formula is based on the time required for the measured pollutant concentration in the groundwater sample to be lower than the Class IV water quality standard limit. At the same time, the concentration of the bacterial solution at each stage is used as a basis to ultimately obtain a scientific and reasonable calculation formula for dynamic balance, which can ensure that the treated groundwater meets the standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the overall structure of an anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds according to the present invention;

[0042] Figure 2 This is a schematic diagram of the treatment of 1,2-dichloroethane-contaminated groundwater in Experimental Example 3 of the present invention.

[0043] Among them, 1-fermentation tank, 11-first sealing cover, 12-stirring motor, 13-injection pipe, 2-air supply system, 21-N2 pipe, 22-H2 pipe, 23-intake pipe, 24-deaerator, 25-mass flow meter, 3-feeding system, 31-acid feeding tank, 32-alkali solution feeding tank, 33-culture medium feeding tank, 34-reducing agent feeding tank, 35-first feeding pipe, 36-first diversion pump, 37-second feeding pipe , 38-second diversion pump, 39-air pressure balance pipe, 4-output system, 41-reinjection tank, 42-liquid seal tank, 43-reinjection pipe, 44-third diversion pump, 45-air outlet pipe, 46-exhaust pipe, 47-activated carbon adsorber, 5-monitoring system, 6-first stirring rod, 7-temperature controller, 8-regulating tank, 81-second sealing cover, 82-sewage pipe, 83-second stirring motor, 84-second stirring rod. DETAILED DESCRIPTION

[0044] Example 1

[0045] like Figure 1 As shown, an anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds includes a fully sealed fermentation tank 1 and a regulating tank 8, an air supply system 2, a feeding system 3, an output system 4, and a monitoring system 5 connected to the fermentation tank 1 and the regulating tank 8. A first sealing cover 11 is provided on the top of the fermentation tank 1, and a first stirring motor 12 is provided in the middle of the upper surface of the first sealing cover 11. The output end of the first stirring motor 12 passes through the first sealing cover 11 and is provided with a first stirring rod 6. A temperature controller 7 is provided on the outside of the fermentation tank 1, and the temperature controller 7 is a commercially available electric heater.

[0046] The fermentation tank 1 is connected to the regulating tank 8 through an injection pipe 13. A second sealing cover 81 is provided on the top of the regulating tank 8. A sewage pipe 82 is provided on one side of the regulating tank 8. A second stirring motor 83 is provided in the middle of the upper surface of the regulating tank 8. The output end of the second stirring motor 83 passes through the second sealing cover 81 and is provided with a second stirring rod 84.

[0047] The air supply system 2 includes an N2 pipe 21 and an H2 pipe 22, each of which is provided with a digitally controlled valve. The N2 pipe 21 and the H2 pipe 22 are connected to an air inlet pipe 23, which is provided with a deaerator 24 and a mass flow meter 25. A branch at the end of the air inlet pipe 23 passes through the first sealing cover 11 and is connected to the interior of the fermentation tank 1. The branch at the end of the air inlet pipe 23 is provided with a digitally controlled valve, which is a commercially available digitally controlled valve.

[0048] The feeding system 3 includes an acid feeding tank 31, an alkali feeding tank 32, a culture medium feeding tank 33 and a reducing agent feeding tank 34. Another branch at the end of the air inlet pipe 23 is connected to the culture medium feeding tank 33. A numerical control valve is provided on the branch at the end of the air inlet pipe 23. The interior of the culture medium feeding tank 33 is connected to the interior of the fermentation tank 1 after passing through the first feeding pipe 35 through the first sealing cover 11. The first feeding pipe 35 is provided with a first diversion pump 36. The interiors of the acid feeding tank 31, the alkali feeding tank 32 and the reducing agent feeding tank 34 are all connected to the fermentation tank 1 after passing through the second feeding pipe 37 through the first sealing cover 11. Internally connected, the interiors of the acid feeding tank 31, the alkali feeding tank 32, and the reducing agent feeding tank 34 are all connected to the interior of the regulating tank 8 through the second feeding pipe 37 passing through the second sealing cover 81. Each second feeding pipe 37 is provided with a second diversion pump 38. The two branches of the air inlet pipe 23 are provided with a filter membrane with a thickness of 0.22 μm. An air pressure balance pipe 39 is provided between the acid feeding tank 31, the alkali feeding tank 32, the culture medium feeding tank 33, and the reducing agent feeding tank 34 and the fermentation tank 1 and the regulating tank 8. The air pressure balance pipe 39 is provided with a filter membrane with a thickness of 0.22 μm;

[0049] The output system 4 includes a reinjection tank 41 and a liquid seal tank 42. The reinjection tank 41 is connected to the interior of the fermentation tank 1 through a reinjection pipe 43 that passes through the first sealing cover 11. A third diversion pump 44 is provided on the reinjection pipe 43. The liquid seal tank 42 is connected to the interior of the fermentation tank 1 through an outlet pipe 45 that passes through the first sealing cover 11 and the second sealing cover 81. An exhaust pipe 46 is also provided on the liquid seal tank 42. The liquid seal tank 42 is filled with water that accounts for 50-60% of its total volume. An activated carbon adsorber 47 is connected to the end of the exhaust pipe 46. The first diversion pump 36, the second diversion pump 38, and the third diversion pump 44 are all commercially available diversion pumps. The activated carbon adsorber 47 is a commercially available PP polypropylene material 3000 air volume small activated carbon adsorption box;

[0050] The monitoring system 5 includes a pressure sensor, a temperature sensor, a pH sensor and an Eh sensor which penetrate through the first sealing cover 11 and the second sealing cover 81 and extend into the fermentation tank 1 and the regulating tank 8. The temperature sensor, pH sensor and Eh sensor are all connected to an external controller.

[0051] Example 2

[0052] A method for treating groundwater contaminated by chlorinated organic compounds with anaerobic microorganisms, based on a system for treating groundwater contaminated by chlorinated organic compounds in Example 1, comprises the following steps:

[0053] S1. Contaminated groundwater regulation: The contaminated groundwater is pumped into the regulating tank 8 and continuously stirred. The monitoring system 5 monitors the pH and redox potential Eh in the regulating tank 8 in real time. N2 is injected through the air supply system 2 to maintain an anaerobic environment inside the regulating tank 8. A reducing agent is injected through the feeding system 3 to maintain the redox potential Eh inside the regulating tank 8 ≤ -400±10mV. Acid or alkali solution is injected through the feeding system 3 to maintain the pH of the contaminated groundwater in the regulating tank 8 at 7.2;

[0054] S2. Construction of anaerobic environment: sterile culture medium is injected into the fermenter 1, and the pH and redox potential Eh in the fermenter 1 are monitored in real time by the monitoring system 5. Then, 7% of the total volume of the fermenter 1 is introduced into the nitrogen dioxide, and the dissolved oxygen in the culture medium of the fermenter 1 is reduced for 0.75h. Then, a reducing agent is injected through the feeding system 3 to maintain the redox potential Eh of the fermenter 1 ≤ -400mV. Acid or alkali solution is injected through the feeding system 3 to maintain the pH of the fermenter 1 at 7.2. The initial amount of sterile culture medium added to the fermenter 1 is 60% of the volume of the fermenter 1. When the Eh sensor monitors that the fermenter 1 is If the internal Eh value is higher than -400mV, the reducing agent is added. The reducing agent contains: L-cysteine ​​with a molar concentration of 2mol / L and Na2S with a molar concentration of 1mmol / L. The injection rate is 1 / 1000 of the volume of the fermenter 1 per minute until the standard is met. When the pH sensor detects that the pH value inside the fermenter 1 is out of range, acid or alkali is added. The acid is HCl with a molar concentration of 1mol / L, and the alkali is NaOH with a molar concentration of 1mol / L. The injection rate is 1 / 1000 of the volume of the fermenter 1 per minute until the standard is met.

[0055] S3. Adding microorganisms: inject anaerobic dechlorination microbial mother liquor into the fermenter 1, set the temperature to 30°C, stir at 150 rpm, and start culturing. The injection amount of anaerobic dechlorination microbial mother liquor is 5% of the volume of the fermenter 1. The anaerobic dechlorination microbial mother liquor includes the same sterile culture medium and bacterial strain as in S2. The bacterial strain is the commercially available KB-1 bacterial agent produced by Major Company in the United States, containing Dehalococcoides, Dehalogenimonas, and Desulfitobacterium bacteria. The bacterial strain concentration is 1 to 5×10 7 cells / mL, ensure that the bacterial concentration is >1×10 7 cells / mL;

[0056] S4. Pressure balance: During initial use, 7% of the total volume of fermenter 1 is introduced with H2. Then, 7% of the headspace volume of fermenter 1 is introduced with a mixed gas at intervals of one hydraulic retention time. The internal pressure of fermenter 1 is then monitored in real time by a pressure sensor. When the monitored pressure is lower than the set value of 101 kPa, the mixed gas is replenished through gas replenishment system 2. The mixed gas is a mixture of N2 and H2 at a volume ratio of 9:1.

[0057] S5. Bacterial liquid detection: Turn on the output system 4 and collect bacterial liquid at regular intervals, once every 1.5 hours. The amount collected each time is 1.5 mL. The OD600 of the collected bacterial liquid is detected by a spectrophotometer. At the same time, the collected bacterial liquid is counted under a microscope to monitor the bacterial liquid concentration and establish a bacterial liquid growth curve.

[0058] S6. Dynamic treatment of contaminated groundwater: When the bacterial solution concentration reaches the maximum value, that is, when the bacterial solution reaches the logarithmic growth phase, the regulated contaminated groundwater is injected into the fermentation tank 1 through the injection pipe 13, ensuring that the volume ratio of the contaminated groundwater to the bacterial solution in the fermentation tank 1 is 1:9. The mixture is then stirred and mixed. The dynamic hydraulic retention time in the fermentation tank 1 is t, which is calculated as follows:

[0059]

[0060] Where n is the maximum bacterial concentration; n1 is the bacterial concentration of the first test; n2 is the bacterial concentration of the second test; n m is the bacterial solution concentration detected for the mth time, and the value of t at this time is less than the interval between the two bacterial solution collections; v is the detection interval of the bacterial solution concentration; the meaning and calculation method of t1 are as follows: before starting S6, sampling and treating the groundwater sample, taking 1.5 mL of the contaminated groundwater sample, mixing it with the bacterial solution in fermenter 1 according to the ratio in S6, and then performing water quality testing, the time required for the measured pollutant concentration in the groundwater sample to be lower than the Class IV water quality standard limit;

[0061] Output the treated groundwater to the reinjection tank 41 of the production system 4 to wait for reinjection, while keeping steps S1 to S4 being carried out synchronously;

[0062] S7. Testing and reinjection of treated groundwater: Take 1 mL of treated groundwater for testing every 1-2 hours to test the concentration of chlorinated organic pollutants in the treated groundwater. If it meets the Class IV water quality standard limit, reinjection is carried out. If it does not meet the Class IV water quality standard limit, S6 treatment is carried out again. The Class IV water quality standard limit is the Class IV water quality limit in GB / T14848-2017 "Groundwater Quality Standard", including but not limited to: 1,2-dichloroethane ≤ 40.0 μg / L, tetrachloroethylene ≤ 300 μg / L;

[0063] The amount of treated groundwater injected each time is 8% of the total volume of the reinjection tank 41. If it does not meet the limit of Class IV water quality standards, it will be treated again in S6. The amount of groundwater to be treated again is 8% of the total volume of the reinjection tank 41. After the fermentation tank 1 outputs the treated groundwater, the culture medium is added at the same time as the next input of the regulated contaminated groundwater. The volume ratio of the culture medium to the volume of the regulated contaminated groundwater is 1:9. Each time the treated groundwater is output, the current concentration of the bacterial solution in the fermentation tank 1 is detected. m , when n m When / n is less than 50%, S6 is suspended and culture medium and H2 are added to the fermentation tank 1. The amount of culture medium added is 1.5% of the total volume of the fermentation tank 1, the supplement rate is 0.1% / h, and the amount of H2 added is to reach the pressure setting value of 101 kPa.

[0064] The specific components of the sterile culture medium are shown in Table 1;

[0065] Table 1 Composition and content of sterile culture medium

[0066]

[0067] Note: The above substances are dissolved in deionized water at the appropriate concentrations and sterilized to prepare the culture medium. Chlorinated organic compounds include, but are not limited to, 1,2-dichloroethane, tetrachloroethylene, trichloroethylene, chlorobenzene, polychlorinated biphenyls, and other chlorinated organic pollutants. Their concentration is determined by culture requirements. Some substances are heat-labile and cannot be sterilized by high temperature or autoclaving, requiring sterilization through a 0.22 μm filter.

[0068] Example 3

[0069] This embodiment differs from embodiment 2 in that:

[0070] S1. Contaminated groundwater regulation: inject a reducing agent through the feeding system 3 to maintain the redox potential Eh ≤ -400 ± 10 mV in the regulating tank 8, and inject acid or alkali solution through the feeding system 3 to maintain the pH of the contaminated groundwater in the regulating tank 8 at 7;

[0071] S2. Construction of an anaerobic environment: Sterile culture medium is injected into the fermenter 1, and the pH and redox potential Eh in the fermenter 1 are monitored in real time by the monitoring system 5. Subsequently, 5% of the total volume of the fermenter 1 is introduced into the nitrogen gas, and the dissolved oxygen in the culture medium in the fermenter 1 is reduced for 0.5 h. Then, the redox potential Eh in the fermenter 1 is maintained at ≤-390 mV by injecting a reducing agent. Acid or alkali solution is injected through the feeding system 3 to maintain the pH in the fermenter 1 at 7. The initial amount of sterile culture medium added to the fermenter 1 is 55% of the volume of the fermenter 1.

[0072] Example 4

[0073] This embodiment differs from embodiment 2 in that:

[0074] S1. Regulating contaminated groundwater: injecting a reducing agent through the feeding system 3 to maintain the redox potential Eh ≤ -410 mV in the regulating tank 8, and injecting acid or alkali solution through the feeding system 3 to maintain the pH of the contaminated groundwater in the regulating tank 8 at 7.5;

[0075] S2. Construction of an anaerobic environment: Sterile culture medium is injected into the fermenter 1, and the pH and redox potential Eh in the fermenter 1 are monitored in real time by the monitoring system 5. Subsequently, 10% of the total volume of the fermenter 1 is introduced into the nitrogen dioxide for 1 hour to reduce the dissolved oxygen in the culture medium in the fermenter 1. Then, a reducing agent is injected to maintain the redox potential Eh ≤ -410 mV in the fermenter 1. Acid or alkali solution is injected through the feeding system 3 to maintain the pH in the fermenter 1 at 7.5. The initial amount of sterile culture medium added to the fermenter 1 is 65% of the volume of the fermenter 1.

[0076] Example 5

[0077] This embodiment differs from embodiment 2 in that:

[0078] S3. Adding microorganisms: Injecting anaerobic dechlorination microbial mother liquor into fermenter 1, setting the temperature to 29.9° C. and the stirring speed to 100 rpm, and starting the culture. The injection amount of anaerobic dechlorination microbial mother liquor is 2% of the volume of fermenter 1. The bacterial strain is BS-1, a commercially available bacterial agent produced by Beijing Sanju Environmental Protection, containing Pseudomonas and Rhodococcus bacteria;

[0079] Example 6

[0080] This embodiment differs from embodiment 2 in that:

[0081] S3. Adding microorganisms: Inject anaerobic dechlorination microbial mother liquor into the fermenter 1, set the temperature to 30.1°C, stir at 200 rpm, and start culturing. The injection volume of anaerobic dechlorination microbial mother liquor is 10% of the volume of the fermenter 1. The bacterial strain is the commercially available Bio-Dechlor INOCULUM agent produced by Shanghai Aojiang Ecology, which contains Desulfitobacterium bacteria.

[0082] Example 7

[0083] This embodiment differs from embodiment 2 in that:

[0084] S4. Pressure balance: During initial use, 5% of the total volume of fermenter 1 is introduced with H2. Then, 5% of the headspace volume of fermenter 1 is introduced with a mixed gas at intervals of one hydraulic retention time. The internal pressure of fermenter 1 is then monitored in real time by a pressure sensor. When the monitored pressure is lower than the set value of 100 kPa, the mixed gas is replenished through gas replenishment system 2. The mixed gas is a mixture of N2 and H2 at a volume ratio of 9:1.

[0085] S5. Bacterial liquid detection: Turn on the output system 4 and collect the bacterial liquid regularly, once every 1 hour, with a collection volume of 1 mL. Detect the OD600 of the collected bacterial liquid using a spectrophotometer. Count the collected bacterial liquid using a microscope, monitor the bacterial liquid concentration, and establish a bacterial liquid growth curve.

[0086] Example 8

[0087] This embodiment differs from embodiment 2 in that:

[0088] S4. Pressure balance: During initial use, 10% of the total volume of fermenter 1 is introduced with H2. Then, 10% of the headspace volume of fermenter 1 is introduced with a mixed gas at intervals of one hydraulic retention time. The internal pressure of fermenter 1 is then monitored in real time by a pressure sensor. When the monitored pressure is lower than the set value of 102 kPa, the mixed gas is replenished through gas replenishment system 2. The mixed gas is a mixture of N2 and H2 at a volume ratio of 9:1.

[0089] S5. Bacterial liquid detection: Turn on the output system 4 and collect bacterial liquid at regular intervals, once every 2 hours, with a collection volume of 2 mL. Detect the OD600 of the collected bacterial liquid using a spectrophotometer. Count the collected bacterial liquid using a microscope, monitor the bacterial liquid concentration, and establish a bacterial liquid growth curve.

[0090] Example 9

[0091] This embodiment differs from embodiment 2 in that:

[0092] S6. Dynamic treatment of contaminated groundwater: ensure that the volume ratio of contaminated groundwater to the bacterial solution in fermentation tank 1 is 0.5:9;

[0093] The meaning and calculation method of t1 are as follows: sampling and treating the groundwater sample before starting S6, taking 1 mL of the contaminated groundwater sample and mixing it with the bacterial solution in fermenter 1 according to the ratio in S6, and then conducting water quality testing, and the time required for the measured pollutant concentration in the groundwater sample to be lower than the Class IV water quality standard limit;

[0094] S7. Inspection and reinjection of treated groundwater: The amount of treated groundwater reinjected each time is 5% of the total volume of the reinjection tank 41. If it does not meet the limit of Class IV water quality standards, S6 treatment is carried out again. The amount of re-treated groundwater is 5% of the total volume of the reinjection tank 41. After the fermentation tank 1 outputs the treated groundwater, the culture medium is added at the same time as the next input of the regulated contaminated groundwater. The culture medium and H2 are replenished into the fermentation tank 1. The amount of culture medium added is 1% of the total volume of the fermentation tank 1, and the replenishment rate is 0.1% / h. The amount of H2 added is to reach the pressure setting value of 100kPa.

[0095] Example 10

[0096] This embodiment differs from embodiment 2 in that:

[0097] S6. Dynamic treatment of contaminated groundwater: ensure that the volume ratio of contaminated groundwater to the bacterial solution in fermentation tank 1 is 1.5:9;

[0098] The meaning and calculation method of t1 are as follows: sampling and treating the groundwater sample before starting S6, taking 2 mL of the contaminated groundwater sample and mixing it with the bacterial solution in fermenter 1 according to the ratio in S6, and then conducting water quality testing. The time required for the measured pollutant concentration in the groundwater sample to be lower than the Class IV water quality standard limit;

[0099] S7. Reinjection of treated groundwater: The amount of treated groundwater reinjected each time is 9% of the total volume of the reinjection tank 41. If it does not meet the limit of Class IV water quality standards, S6 treatment is carried out again. The amount of re-treated groundwater is 9% of the total volume of the reinjection tank 41. After the fermentation tank 1 outputs the treated groundwater, the culture medium is added at the same time as the next input of the regulated contaminated groundwater. The culture medium and H2 are replenished into the fermentation tank 1. The amount of culture medium added is 2% of the total volume of the fermentation tank 1, and the replenishment rate is 0.1% / h. The amount of H2 added is to reach the pressure setting value of 102kPa.

[0100] Experimental Example 1

[0101] We carried out anaerobic microbial treatment of groundwater contaminated by chlorinated organic matter according to the method of Example 2, wherein the dynamic hydraulic retention time in the fermentation tank 1 is t, and the calculation formula is as follows:

[0102]

[0103] Where n is the maximum bacterial concentration; n1 is the bacterial concentration of the first test; n2 is the bacterial concentration of the second test; n mis the bacterial solution concentration detected for the mth time, and the value of t at this time is less than the interval between the two bacterial solution collections; v is the detection interval of the bacterial solution concentration; the meaning and calculation method of t1 are as follows: before starting S6, sampling and treating the groundwater sample, taking 1.5 mL of the contaminated groundwater sample, mixing it with the bacterial solution in fermenter 1 according to the ratio in S6, and then performing water quality testing, the time required for the measured pollutant concentration in the groundwater sample to be lower than the Class IV water quality standard limit;

[0104] After testing, the value of t1 is 2.5h. The current concentration of the bacterial solution collected for the first time is the maximum value. The ratio of the maximum bacterial solution concentration to the current concentration of the bacterial solution collected for the second time is 1.02. The calculation formula is as follows:

[0105] t={{{2.5×1}-1.5}×1.02}

[0106] The above calculation formula means: from the start of S6 until the first bacterial liquid concentration collection, a hydraulic retention time of 2.5 hours is used. When the process reaches 1.5 hours, the bacterial liquid is collected for concentration measurement, and then the hydraulic retention time is corrected. The hydraulic retention time obtained at this time is 1.02 hours. If no correction is made, the original remaining hydraulic retention time is 1 hour. Then the process continues. If 1.02 hours is less than the next bacterial liquid collection time of 1.5 hours, the process can be terminated directly according to the remaining hydraulic retention time of 1.02 hours.

[0107] The purpose of setting the dynamic hydraulic retention time is: because the concentration of the bacterial solution decreases, we need to ensure that the treated groundwater meets the requirements. Therefore, the modified method of the calculation formula is used to obtain a more scientific and reasonable dynamic hydraulic retention time.

[0108] Experimental Example 2

[0109] Similarly, we carried out anaerobic microbial treatment of groundwater contaminated by chlorinated organic matter according to the method of Example 7. After testing, the value of t1 was 2.75h. At this time, the current concentration of the bacterial solution collected for the first time was not the maximum value because several treatments had been carried out before. The value of is 1.09, The value of is 1.13, The value of is 1.2, The value is 1.28, so the calculation formula is as follows:

[0110] t={{{2.75×1.09}-1}×1.13}-1}×1.2

[0111] The above calculation formula means that from the start of S6 until the first bacterial solution concentration is collected, since the bacterial solution concentration is not at its maximum at this time, the initial ideal hydraulic retention time of 2.75 hours needs to be corrected to obtain an initial hydraulic retention time of 2.99, taking into account factors such as experimental errors. When the treatment reaches 1 hour, the bacterial solution is collected for concentration measurement, and then the hydraulic retention time is corrected. The hydraulic retention time obtained at this time is 1.99*1.13=2.24 hours. If no correction is made, the original remaining hydraulic retention time is 2.99-1=1.99 hours.

[0112] Continue the treatment, collect the bacterial solution after 1 hour for concentration measurement, and then perform hydraulic retention time correction. The hydraulic retention time obtained at this time is 1.24*1.2=1.48h. If no correction is performed, the original remaining hydraulic retention time is 2.24-1=1.24h;

[0113] Continue the treatment, collect the bacterial solution after 1 hour for concentration measurement, and then perform hydraulic retention time correction. The hydraulic retention time obtained at this time is 0.48*1.28=0.61h. If no correction is performed, the original remaining hydraulic retention time is 1.48-1=0.48h;

[0114] Then continue the treatment. If 0.61h is less than the next bacterial liquid collection time of 1h, the process can be terminated directly according to the remaining hydraulic retention time of 0.61h.

[0115] Experimental Example 3

[0116] The anaerobic microbial treatment of groundwater contaminated by chlorinated organic matter was carried out according to the method of Example 2. The concentration of 1,2-dichloroethane in the contaminated groundwater was monitored during each treatment. The results were as follows: Figure 2 As shown, it can be seen that the device and method of the present application can effectively remove 1,2-dichloroethane in contaminated groundwater, and the 1,2-dichloroethane in the treated groundwater meets the Class IV water quality limit in GB / T14848-2017 "Groundwater Quality Standard".

Claims

1. An anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds, characterized in that: The invention comprises a fully sealed fermentation tank (1) and a regulating tank (8), an air supply system (2), a feeding system (3), an output system (4) and a monitoring system (5) connected to the fermentation tank (1) and the regulating tank (8); a first sealing cover (11) is provided on the top of the fermentation tank (1); a first stirring motor (12) is provided in the middle of the upper surface of the first sealing cover (11); an output end of the first stirring motor (12) passes through the first sealing cover (11) and is provided with a first stirring rod (6); and a temperature controller (7) is provided on the outside of the fermentation tank (1); The fermentation tank (1) is connected to the regulating tank (8) through an injection pipe (13). A second sealing cover (81) is provided on the top of the regulating tank (8), and a sewage pipe (82) is provided on one side of the regulating tank (8).

2. The anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds according to claim 1, characterized in that: A second stirring motor (83) is provided in the middle of the upper surface of the regulating tank (8), and a second stirring rod (84) is provided after the output end of the second stirring motor (83) passes through the second sealing cover (81).

3. The anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds according to claim 1, characterized in that: The air supply system (2) includes an N2 tube (21) and an H2 tube (22), each of which is provided with a numerical control valve. The N2 tube (21) and the H2 tube (22) are commonly connected to an air intake pipe (23), and the air intake pipe (23) is provided with a deaerator (24) and a mass flow meter (25). A branch at the end of the air intake pipe (23) passes through the first sealing cover (11) and is connected to the interior of the fermentation tank (1). The branch at the end of the air intake pipe (23) is provided with a numerical control valve.

4. The anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds according to claim 1, characterized in that: The feeding system (3) includes an acid feeding tank (31), an alkali feeding tank (32), a culture medium feeding tank (33) and a reducing agent feeding tank (34); another branch at the end of the air inlet pipe (23) is connected to the culture medium feeding tank (33); a numerical control valve is provided on the end branch of the air inlet pipe (23); the interior of the culture medium feeding tank (33) is connected to the interior of the fermentation tank (1) after passing through the first sealing cover (11) through a first feeding pipe (35); a first diversion pump (36) is provided on the first feeding pipe (35); the interiors of the acid feeding tank (31), the alkali feeding tank (32) and the reducing agent feeding tank (34) are all passed through a second feeding pipe (37) The first sealing cover (11) is connected to the interior of the fermentation tank (1), and the interiors of the acid feeding tank (31), the alkali feeding tank (32) and the reducing agent feeding tank (34) are connected to the interior of the regulating tank (8) through the second feeding pipe (37) passing through the second sealing cover (81). Each of the second feeding pipes (37) is provided with a second diversion pump (38), and the two branches of the air inlet pipe (23) are provided with a filter membrane. An air pressure balance pipe (39) is provided between the acid feeding tank (31), the alkali feeding tank (32), the culture medium feeding tank (33) and the reducing agent feeding tank (34) and the fermentation tank (1) and the regulating tank (8), and the air pressure balance pipe (39) is provided with a filter membrane.

5. The anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds according to claim 1, characterized in that: The output system (4) includes a reinjection tank (41) and a liquid seal tank (42). The reinjection tank (41) is connected to the interior of the fermentation tank (1) through a reinjection pipe (43) penetrating the first sealing cover (11). A third diversion pump (44) is provided on the reinjection pipe (43). The liquid seal tank (42) is connected to the interior of the fermentation tank (1) through an air outlet pipe (45) penetrating the first sealing cover (11) and the second sealing cover (81). An exhaust pipe (46) is also provided on the liquid seal tank (42). The interior of the liquid seal tank (42) is filled with water accounting for 50 to 60% of its total volume. The end of the exhaust pipe (46) is connected to an activated carbon adsorber (47).

6. The anaerobic microbial treatment system for groundwater contaminated by chlorinated organic compounds according to claim 1, characterized in that: The monitoring system (5) includes a pressure sensor, a temperature sensor, a pH sensor, and an Eh sensor that penetrate through the first sealing cover (11) and the second sealing cover (81) and extend into the interior of the fermentation tank (1) and the regulating tank (8), and the temperature sensor, pH sensor, and Eh sensor are all connected to an external controller.

7. A method for treating groundwater contaminated by chlorinated organic compounds with anaerobic microorganisms, based on the system for treating groundwater contaminated by chlorinated organic compounds according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Regulating contaminated groundwater: pumping the contaminated groundwater into the regulating tank (8) and continuously stirring the contaminated groundwater; the monitoring system (5) monitors the pH and redox potential Eh in the regulating tank (8) in real time; injecting N2 through the air supply system (2) to maintain an anaerobic environment inside the regulating tank (8); injecting a reducing agent through the feeding system (3) to maintain the redox potential Eh inside the regulating tank (8) ≤ -400 ± 10 mV; and injecting acid or alkali solution through the feeding system (3) to maintain the pH of the contaminated groundwater inside the regulating tank (8) at 7 to 7.5; S2. Construction of anaerobic environment: injecting sterile culture medium into the fermenter (1), monitoring the pH and redox potential Eh in the fermenter (1) in real time through the monitoring system (5), then introducing 5-10% of the total volume of N2 into the fermenter (1) to reduce the dissolved oxygen in the culture medium inside the fermenter (1) for 0.5-1h, then injecting a reducing agent through the feeding system (3) to maintain the redox potential Eh inside the fermenter (1) ≤ -400±10mV, and injecting acid or alkali solution through the feeding system (3) to maintain the pH inside the fermenter (1) at 7-7.5; S3, adding microorganisms: injecting anaerobic dechlorination microbial mother liquor into the fermentation tank (1), setting the temperature to 20-30°C, stirring speed to 100-200 rpm, and starting cultivation; S4. Pressure balance: When used for the first time, 5-10% of the total volume of the fermentation tank (1) is introduced with H2, and then 5-10% of the headspace volume of the fermentation tank (1) is introduced once every hydraulic retention time. Thereafter, the internal pressure of the fermentation tank (1) is monitored in real time by a pressure sensor. When the monitored pressure is lower than the set value of 101±1 kPa, the mixed gas is supplemented through the gas supplement system (2). The mixed gas is a mixture of N2 and H2 at a volume ratio of 9:1; S5. Bacterial liquid detection: The output system (4) is turned on, and the bacterial liquid is collected regularly, once every 1 to 2 hours, and the amount collected each time is 1 to 2 mL. The OD600 of the collected bacterial liquid is detected by a spectrophotometer, and the collected bacterial liquid is counted by a microscope, the bacterial liquid concentration is monitored, and a bacterial liquid growth curve is established; S6. Dynamic treatment of contaminated groundwater: When the bacterial solution concentration reaches the maximum value, that is, when the bacterial solution reaches the logarithmic growth phase, the regulated contaminated groundwater is injected into the fermentation tank (1) through the injection pipe (13), ensuring that the volume ratio of the contaminated groundwater to the bacterial solution inside the fermentation tank (1) is 0.5 to 1.5:9, and then stirred and mixed. The dynamic hydraulic retention time in the fermentation tank (1) is t, and the calculation formula is as follows: Where n is the maximum bacterial concentration; n1 is the bacterial concentration of the first test; n2 is the bacterial concentration of the second test; n m is the bacterial solution concentration detected for the mth time, and the value of t at this time is less than the interval between the two bacterial solution collections; v is the detection interval of the bacterial solution concentration; the meaning of t1 and its calculation method are as follows: before starting S6, sampling and treating the groundwater sample, taking 1 to 2 mL of contaminated groundwater sample and mixing it with the bacterial solution inside the fermentation tank (1) according to the ratio in S6, and then conducting water quality testing, the time required for the measured pollutant concentration in the groundwater sample to be lower than the Class IV water quality standard limit; Output the treated groundwater to the reinjection tank (41) of the output system (4) to wait for reinjection, while keeping steps S1 to S4 being carried out synchronously; S7. Testing and reinjection of treated groundwater: Take 1 mL of treated groundwater for testing, once every 1 to 2 hours, to test the concentration of chlorinated organic pollutants in the treated groundwater. If it meets the limit of Class IV water quality standards, reinjection will be carried out. If it does not meet the limit of Class IV water quality standards, S6 treatment will be carried out again.

8. The automated continuous flow anaerobic dechlorination microbial fermentation method according to claim 7, characterized in that: In S2, the initial amount of sterile culture medium added to the fermenter (1) is 60%±5% of the volume of the fermenter (1). When the Eh sensor detects that the Eh value inside the fermenter (1) is higher than -400mV, the reducing agent is added, and the reducing agent contains: L-cysteine ​​with a molar concentration of 2mol / L and Na2S with a molar concentration of 1mmol / L. The injection amount per minute is 1 / 1000 of the volume of the fermenter (1) until the standard is met. When the pH sensor detects that the pH value inside the fermenter (1) is out of range, the acid or alkali solution is added, and the acid is HCl with a molar concentration of 1mol / L, and the alkali solution is NaOH with a molar concentration of 1mol / L. The injection amount per minute is 1 / 1000 of the volume of the fermenter (1) until the standard is met.

9. The automated continuous flow anaerobic dechlorination microbial fermentation method according to claim 7, characterized in that: The injection amount of the anaerobic dechlorination microbial mother liquor in S3 is 2-10% of the volume of the fermentation tank (1). The anaerobic dechlorination microbial mother liquor includes the same sterile culture medium and bacterial strains as those in S2. The bacterial strains are one or more of Dehalococcoides, Dehalogenimonas, Desulfitobacterium, Pseudomonas, Rhodococcus, and Methanogens. The bacterial strain concentration is 1-5×10 7 cells / mL.

10. The automated continuous flow anaerobic dechlorination microbial fermentation method according to claim 7, characterized in that: In S7, the amount of treated groundwater injected each time shall not exceed 10% of the total volume of the injection tank (41). If it does not meet the limit of Class IV water quality standard, the amount of groundwater treated again shall not exceed 10% of the total volume of the injection tank (41). After the fermentation tank (1) outputs the treated groundwater, the culture medium shall be added at the same time as the next input of the regulated contaminated groundwater. The volume ratio of the added culture medium to the volume of the regulated contaminated groundwater is 0.5 to 1.5:

9. Each time the treated groundwater is output, the current concentration of the bacterial solution in the fermentation tank (1) is detected. m , when n m When / n is less than 50%, S6 is suspended and culture medium and H2 are added to the fermentation tank (1). The amount of culture medium added is 1 to 2% of the total volume of the fermentation tank (1) at a rate of 0.1% / h. The amount of H2 added is to reach the pressure setting value of 101±1 kPa.

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