CN108817076A - The method and system of microorganism electrochemical respirator reinforcing remedying oil-polluted soils - Google Patents

Abstract

The invention discloses a method and system for strengthening and repairing petroleum-contaminated soil with a microbial electrochemical respirator. The chemical respirator system includes a microbial electrochemical respirator. The anode of the respirator is set in the anaerobic reaction system, and the cathode is set in the aerobic reaction system. The aerobic reaction system is equipped with biopile ventilation equipment and biological nutrient dripping filter equipment. ; The anaerobic reaction system is equipped with material and nutrient dosing ports, sewage discharge ports, agitators, gas export, and activated sludge treatment equipment. The restoration is carried out by coupling the anaerobic reaction system and the aerobic reaction system of the microbial electrochemical respirator. The invention can simultaneously restore petroleum-contaminated soils with different water contents, can remove petroleum hydrocarbons with maximum efficiency, has short treatment period, good restoration effect, no secondary pollution, and sustainable operation.

Description

Microbial electrochemical respirator strengthens method and system for repairing oil-contaminated soil

technical field

The invention relates to the technical field of remediation of polluted soil, in particular to a method and a system for strengthening remediation of petroleum-contaminated soil by a microbial electrochemical respirator.

Background technique

With the prosperity and development of our country's social economy, petroleum resources have been deeply utilized, thus promoting the development of petroleum exploration. However, due to management and technical defects in the utilization of petroleum, a large amount of crude oil flows directly or briefly into the soil, resulting in serious pollution of large areas of soil. The voids filled with oil not only affect the permeability of the soil, but also severely damage the three-phase structure of soil water, gas, and solid in crude oil, affecting the growth of soil microorganisms and the respiration of plant roots in the soil and the absorption of nutrients and water , causing plant root rot and necrosis, seriously endangering the growth of plants. At the same time, the oil in the soil moves and diffuses along with the moisture in the soil, causing groundwater to be polluted.

At present, the techniques of contaminated soil remediation can be roughly divided into three categories, namely physical methods, chemical methods and biological methods. Among them, the first two types of methods have limited repair effects, high costs, and are likely to cause secondary pollution, while the third type of methods will not produce similar problems. Heat treatment is a common physical method used to treat oil-contaminated soil. Since there are many types of oil-contaminated soil, the water content of the excavated oil-contaminated soil is also different. There are oil-contaminated soils with extremely high water content. If heat treatment is used to treat the oil-contaminated soil with extremely high water content, then The process of removing water from oil-contaminated soil will generate a lot of energy consumption, resulting in extremely high treatment costs and low treatment efficiency. However, chemical treatment can easily cause secondary pollution, and biological treatment is only suitable for remediation of low-concentration oil-contaminated soil and the remediation period is long.

The natural remediation process of oil-contaminated soil has a long cycle and low efficiency. In order to reduce the harm of oil-contaminated soil, developed countries have formulated relevant soil remediation plans to explore effective remediation technologies. How to remediate oil-contaminated soil efficiently, safely and at low cost has become an environmental issue. One of the important topics in the field.

Compared with other remediation technologies, microbial fuel cells (MFCs) is a technology that uses electrogenic microorganisms to directly convert chemical energy into electrical energy. It does not consume external energy and has no secondary pollution during operation. It has great potential in electricity, contaminated soil remediation, greenhouse gas emission reduction and pollution toxicity detection. At present, the research progress on the power generation performance of MFCs at home and abroad is relatively slow. Compared with the power generation capacity, it is easier to realize the pollutant treatment application by using its ability to degrade organic matter. The performance of MFCs is characterized by a power/current curve obtained by varying the resistance of the external circuit. Very high resistance or open circuit, the voltage is the highest, but the current is zero resulting in zero power. Decreasing the resistance results in a decrease in voltage, then an increase in current results in a bell curve. When the resistance is small, or the cells are in a short circuit, MFCs deliver maximum current because there is no voltage to reduce the power to zero. In terms of energy generation, the optimal power point for MFCs is the point where they are at their maximum power. For the purpose of optimizing pollutant control, the optimal operating point is when short-circuited, and the short-circuited MFC provides the maximum current, which means that the highest oxidation rate of organic matter is guaranteed. Microbial electrochemical snorkel (MES) is a new type of short-circuited MFCs. MES cannot provide current, but uses the current generated by the degradation of organic pollutants in situ to optimize the treatment of pollutants, which can maximize the oxidation of organic matter, and the system does not need to contain membranes or any other types of separators. During the treatment of pollutants, MES will not produce secondary pollution and will not produce bad odor. It is a clean energy technology and a green technology for remediating pollutants. Therefore, the application of MES to remediation of oil-contaminated soil can speed up the remediation process and improve the remediation effect.

However, there is no relevant report on the combination of microbial electrochemical respirator with oil-contaminated soil anaerobic reaction system and oil-contaminated soil aerobic reaction system to strengthen the remediation of oil-contaminated soil.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method and system for the enhanced restoration of petroleum-contaminated soil by a microbial electrochemical respirator. The high oxygen effectively reduces energy consumption, does not produce secondary pollution, is green, clean and sustainable.

The present invention solves the above technical problems with the following technical solutions:

Microbial electrochemical respirator of the present invention strengthens the method for repairing petroleum-contaminated soil, and it comprises following operation steps:

1) Construct a reaction system, which includes an anaerobic reaction system for oil-contaminated soil, an aerobic reaction system for oil-contaminated soil, and a microbial electrochemical respirator system. The anaerobic reaction system for oil-contaminated soil is adjacent to the aerobic reaction system for oil-contaminated soil Setup, the microbial electrochemical respirator system includes a microbial electrochemical respirator, the anode of the microbial electrochemical respirator is set in the anaerobic reaction system of oil-contaminated soil, and the cathode of the microbial electrochemical respirator is set in the oil-contaminated soil aerobic reaction system , the oil-contaminated soil aerobic reaction system is equipped with bio-pillar ventilation equipment and biological nutrient trickling filter equipment; the oil-contaminated soil anaerobic reaction system is provided with material and nutrient addition ports, sewage discharge outlets, agitators and Gas export, activated sludge treatment equipment;

2) Pretreat the oil-contaminated soil, adjust the pH value of the oil-contaminated soil with low water content and high water content to neutral, and adjust the ratio of C, N, P, and K in the soil to 90-100:9- 12:1:1;

3) Pile the pretreated contaminated soil with low moisture content in the oil-contaminated soil aerobic reaction system of step 1, and place the pretreated contaminated soil with high moisture content in the anaerobic reaction system of oil-contaminated soil in step 1 In the reaction system; start the microbial electrochemical respirator in the microbial electrochemical respirator system, and use the microbial electrochemical respirator to couple the oil-contaminated soil anaerobic reaction system for repair, and ensure that the petroleum hydrocarbon degrading bacteria are at 6.5×10 ⁸ cfu/kg ～7.5×10 ⁸ cfu/kg, at the same time, through the microbial electrochemical respirator coupled with the aerobic reaction system of oil-contaminated soil, the oxygen content in the soil is controlled at 25% to 30%, and the petroleum hydrocarbon-degrading bacteria are guaranteed to be at 8.5×10 ⁸ cfu/kg～9.5×10 ⁸ cfu/kg;

4) Monitor the results of soil remediation:

The activated sludge at different positions in the anaerobic reaction system of oil-contaminated soil is randomly inspected every 5 days. When the activated sludge reaches the standard, the activated sludge is separated from gas and liquid, the soil is backfilled, and the generated biogas slurry is stored for organic use. fertilizer production;

Samples were taken at different positions of the biopile in the oil-contaminated soil aerobic reaction system every 5 days. The sampling position was the same each time, and the petroleum hydrocarbon content was measured. After the test was qualified, the soil pile was cleared and backfilled.

In the step 2), the moisture content of the oil-contaminated soil with low moisture content is less than 35%, and it is processed by a crusher and a sieving machine to crush the bulk soil to a particle size of less than 2.5cm, and remove the stones and other sundries are screened out, and the sieved soil is mixed with the crop straw to make the porosity reach 50% to 60%, and the soil moisture is adjusted so that the soil moisture content is at 20% %~35% range;

The oil-contaminated soil with a high water content has a water content of more than 60%. After removing stones and other sundries, the water content is adjusted to make the contaminated soil a fluid state that can be stirred.

In step 2), the C, N, P, and K ratios in the soil are adjusted to 90-100:9-12 by adding urea, superphosphate, monoammonium phosphate and potassium chloride to the petroleum-contaminated soil with low moisture content: 1:1; adjust the ratio of C, N, P, and K in the soil to 90-100:9-12:1 by adding peanut cake, superphosphate, monoammonium phosphate, and potassium chloride to oil-contaminated soil with high moisture content :1.

The microbial electrochemical respirator of the present invention strengthens the system for repairing oil-contaminated soil, which is mainly composed of an anaerobic reaction system for oil-contaminated soil, an aerobic reaction system for oil-contaminated soil and a microbial electrochemical respirator system. The anaerobic reaction system for oil-contaminated soil and The oil-contaminated soil aerobic reaction system is respectively provided with reaction pools, which are adjacently arranged, and a partition wall is provided between the two reaction pools. The above reaction pools of the oil-contaminated soil anaerobic reaction system are provided with materials and nutrients. There are multiple sets of agitators in the reaction tank, and the reaction tank is connected with gas export and activated sludge treatment equipment. The anaerobic reaction system of oil-contaminated soil is equipped with online monitoring equipment for pressure, temperature and gas. The aerobic reaction system of the oil-contaminated soil comprises biological nutrient trickling filter equipment, biological pile ventilation equipment, gas and temperature and humidity online monitoring equipment, and the biological pile ventilation equipment is provided with a circulation pipeline, and the biological nutrient trickling filter equipment and The circulation lines of the bio-pillar ventilation are connected; the microbial electrochemical respirator system comprises a microbial electrochemical respirator, and the anode of the microbial electrochemical respirator is arranged in the reaction pool of the oil-contaminated soil anaerobic reaction system, and the microbial electrochemical respirator The cathode is set in the reaction pool of the oil-contaminated soil aerobic reaction system;

The microbial electrochemical respirator is a plurality of groups of stainless steel nets, the stainless steel nets are fixed around by PVC plates, and the bottom is supported by a tripod; the partition wall is provided with a microbial electrochemical respirator connection port, and the stainless steel nets pass through the microbial electrochemical respirator. The chemical respirator connection port is connected with the oil-contaminated soil aerobic reaction system and the microbial electrochemical respirator system.

The biopile ventilation equipment includes a ventilation main pipe, a ventilation branch pipe and a blower, and the ventilation main pipe is evenly laid on the top of the biopile in the oil-contaminated soil aerobic reaction system in a serpentine shape and is connected with the blower to form a circulation pipeline; the ventilation The branch pipes are arranged vertically to the ventilation main pipe, and are connected to the ventilation main pipe by flower-shaped connecting pipes, and a plurality of air holes are arranged on the ventilation branch pipes.

The agitator of the oil-contaminated soil anaerobic reaction system is a double-helix agitator, which is connected to a peripheral engine; the pressure, temperature and gas online monitoring equipment includes a pressure probe, a temperature probe and a gas probe, and the three probes are embedded In the activated sludge in the reaction tank, and a common induction line is connected to the external detector; the agitator of the oil-contaminated soil anaerobic reaction system is a double-helix agitator, which is connected to an external engine; the pressure, The temperature and gas online monitoring equipment includes pressure probe, temperature probe and gas probe. The three probes are buried in the activated sludge in the reaction tank, and share a sensing line connected to the external detector; the gas export, activated sludge The processing equipment includes a gas outlet pipe, a gas-liquid separator, an activated carbon adsorbent storage tank and a biogas slurry storage tank. The gas outlet of the liquid separator is connected to the activated carbon adsorbent storage tank, and the liquid outlet of the gas-liquid separator is connected to the biogas slurry storage tank; the material and nutrient dosing port is connected to the anaerobic reaction nutrient solution storage tank through the dosing pump.

The gas, temperature and humidity on-line monitoring equipment of the aerobic reaction system for petroleum-contaminated soil includes a plurality of probes evenly laid in the sludge, and the probes are connected to external detectors.

The biological nutrient trickle filtration equipment of the petroleum-contaminated soil aerobic reaction system includes an aerobic reaction nutrient solution storage tank and a dosing pump, the input port of the dosing pump is connected to the aerobic reaction nutrient solution storage tank, and the output port of the dosing pump is Connect the circulation pipeline of the biopile ventilation equipment to form a circulation delivery.

Compared with prior art, the present invention has following advantage:

(1) The present invention can use the microbial respirator to couple the biological ventilation and aerobic treatment of oil-contaminated soil with anaerobic treatment for optimal combination, and can simultaneously treat oil-contaminated soil with extremely high water content and oil with relatively low water content Pollution of soil, full use of energy, can save costs.

(2) In the process of biological ventilation treatment of oil-contaminated soil with relatively low moisture content, the oxygen that cannot be fully utilized by microorganisms during the ventilation process can be provided to the cathode of the microbial respirator (MES) as an electrode receptor, which can not only save Energy, and the use of microbial electrochemical rebreathers (MES) to enhance bioremediation of oil-contaminated soils.

(3) Microbial electrochemical rebreather (MES) is a new type of short-circuit microbial fuel cells (MFCs). The anode is placed in the anaerobic reaction treatment system of oil-contaminated soil with extremely high water content, which has the maximum oxidation of organic matter. Advantages, it can efficiently remove petroleum hydrocarbons.

(4) The system of the present invention has short treatment cycle, good repair effect, no secondary pollution, and the liquid separated from the treated petroleum hydrocarbon activated sludge can be further used in the production of organic fertilizer, which is green, clean and sustainable.

Description of drawings

Fig. 1 is a structural schematic diagram of a system for strengthening and remediating petroleum-contaminated soil by a microbial electrochemical respirator of the present invention.

Fig. 2 is a schematic diagram of the installation structure of the microbial electrochemical respirator system in Fig. 1 .

Fig. 3 is a schematic structural diagram of the anaerobic reaction system for oil-contaminated soil in Fig. 1 .

Fig. 4 is a schematic structural diagram of the aerobic reaction system of oil-contaminated soil in Fig. 1 .

In the figure: 1. Oil-contaminated soil anaerobic reaction system; 2. Petroleum-contaminated soil aerobic reaction system; 3. Microbial electrochemical respirator system; 4. Scaffold; 5. Microbial electrochemical respirator connection port; 6. Cut-off Valve; 7. Dosing pump; 8. Exhaust fan; 9. Centrifugal pump; 10. Flow meter; 11. Blower; 12. Gas-liquid separator; 13. Activated carbon adsorbent storage tank; 14. Biogas slurry storage tank; 15 1. Anaerobic reaction nutrient solution storage tank; 16. Aerobic reaction nutrient solution storage tank; 17. Pressure, temperature, gas online monitoring equipment; 18. Material and nutrient substance feeding port; 19. Probe; 20. Double helix agitator ;21. Engine; 22. Flower-shaped connection; 23. Gas and temperature and humidity monitoring equipment; 24. Probe; 25. Ventilation branch pipe; 26. Air hole; 27. Partition wall; 28. Gas outlet pipe; 30. Ventilation supervisor; 31. Sludge discharge port; 32. Microbial electrochemical respirator.

Detailed ways

Below in conjunction with accompanying drawing, technical scheme of the present invention is described further:

As shown in Figure 1, the system of microbial electrochemical respirator of the present invention strengthens and repairs oil-contaminated soil mainly consists of microbial electrochemical respirator system 3, petroleum-contaminated soil anaerobic reaction system 1 and petroleum-contaminated soil aerobic reaction system 2. The oil-contaminated soil anaerobic reaction system 1 and the oil-contaminated soil aerobic reaction system 2 are respectively equipped with reaction pools, and are arranged adjacently. A partition wall 27 is provided between the two reaction pools, and a microbial electrochemical reactor is provided on the partition wall 27. Respirator connection port 5.

As shown in Figure 2, microbial electrochemical respirator system 3 comprises microbial electrochemical respirator 32, and the anode of microbial electrochemical respirator 32 is arranged in the reaction pool of oil polluted soil anaerobic reaction system 1, and microbial electrochemical respirator 32 The cathode is arranged in the reaction tank of the oil-contaminated soil aerobic reaction system 2; the microbial electrochemical respirator 32 is a plurality of groups of stainless steel mesh, and the surroundings of the stainless steel mesh are fixed by PVC plates, and the bottom is supported by a tripod 4; the stainless steel mesh 32 wears The microbial electrochemical respirator connecting port 5 is connected to the petroleum contaminated soil aerobic reaction system and the microbial electrochemical respirator system.

As shown in Figure 3, above the reaction tank of the petroleum-contaminated soil anaerobic reaction system 1, there are material and nutrient addition ports 18 and sludge discharge ports 31, and multiple groups of double-helical agitators 20 are arranged in the reaction tank. The twin-helix agitator 20 is connected to an external engine 21, and the reaction tank of the petroleum-contaminated soil anaerobic reaction system 1 is connected with gas export and activated sludge treatment equipment, and the gas export and activated sludge treatment equipment include a gas export pipe 28 , gas-liquid separator 12, activated carbon adsorbent storage tank 13 and biogas slurry storage tank 14, the gas outlet pipe 28 is connected with the activated carbon adsorbent storage tank 13, and the gas outlet pipe 28 is equipped with a purge valve 29 and a shut-off valve 6 With the flowmeter 10, the inlet of the gas-liquid separator 12 is connected to the sludge discharge port 31 through a pipeline, and a shut-off valve 6 is arranged on the pipeline, and the gas outlet of the gas-liquid separator 12 is connected to the activated carbon adsorbent storage tank 13 through a pipeline. , and the pipeline is equipped with an exhaust fan 8, a shut-off valve 6 and a flow meter 10, the liquid outlet of the gas-liquid separator 12 is connected to the biogas slurry storage tank 14 through the pipeline, and a centrifugal pump 9, a shut-off valve 6 and a centrifugal pump 9 are installed on the pipeline. A flowmeter 10, a material and nutrient addition port 18 are connected to an anaerobic reaction nutrient solution storage tank 15 through a pipeline, and a flowmeter 10, a shut-off valve 6 and a dosing pump 7 are installed on the pipeline; The reaction tank of reaction system 1 is connected with pressure, temperature and gas online monitoring equipment 17, and the monitoring equipment 17 includes a plurality of probes 19, wherein there are pressure probes, temperature probes and gas probes, and these probes are all buried in the activated sludge in the reaction tank , and share a sensing line connected to the external detector.

As shown in Figure 4, the oil-contaminated soil aerobic reaction system 2 includes biological nutrient trickle filter equipment, bio-pile ventilation equipment, gas and temperature and humidity online monitoring equipment 23, wherein the bio-pile ventilation equipment includes a ventilation main pipe 30, a ventilation branch pipe 25 and the blower 11, the ventilation main pipe 30 is evenly laid in a serpentine shape on the top of the biopile in the reaction tank of the petroleum-contaminated soil aerobic reaction system 2 and is connected with the blower 11 to form a circulation pipeline; the ventilation branch pipe 25 is arranged perpendicular to the ventilation main pipe 30 , and connected to the ventilation main pipe 30 through the flower-shaped connecting pipe 22, and a plurality of air holes 26 are arranged on the ventilation branch pipe 25; the gas and temperature and humidity online monitoring equipment 23 includes a plurality of probes 24 evenly laid in the sludge in the reaction tank, and the probes are connected to To the external detector, the probe includes a temperature probe, a temperature probe and a gas probe; the biological nutrient trickle filtration equipment includes an aerobic reaction nutrient solution storage tank 16 and a dosing pump 7, and the input port of the dosing pump 7 is connected The oxygen reaction nutrient solution storage tank 16, the output port of the dosing pump 7 is connected with the circulation pipeline of the bio-pillar ventilation equipment through pipelines to form a circulation delivery, and a shut-off valve 6 and a flow meter 10 are installed on the pipeline.

The reaction tank of the system in this embodiment is made of red brick, crushed stone, sand and Portland cement, and a layer of anti-seepage geomembrane is laid on the bottom. The ring beam and pool cover of the anaerobic reaction tank are made of No. 200 concrete. The bottom of the anaerobic and aerobic reaction pool is made of No. 100 concrete, and the pool wall is made of No. 150 concrete. The strength of cement mortar is generally not lower than No. 75, and the strength of joint mortar is not lower than No. 100. The bottom size of the whole system is 34m long x 24m wide and 2.5m high. The anaerobic reaction pool is 17m long x 12m wide and 2.5m high; the aerobic reaction pool is 17m long x 12m wide and 2.5m high.

The microbial electrochemical respirator system 3 is equipped with 3 to 6 groups of microbial electrochemical respirator 32 with a size of 12m in length and 1.5m in height. Each microbial electrochemical respirator 3 is supported by 4-6 legs 4 and placed vertically in the system with a distance of 0.5m from the bottom. The anode of the microbial electrochemical respirator 32 is placed in the anaerobic reaction system 1 for treating oil-contaminated soil with extremely high water content, and the cathode is placed in the aerobic reaction system 2 for treating oil-contaminated soil with relatively low water content. The electrochemical respirator 32 passes through the partition wall 27, and simultaneously strengthens the anaerobic and aerobic treatment of oil-contaminated soil with different water contents through the microbial electrochemical respirator 32.

When dealing with petroleum-contaminated soil with a relatively high moisture content (water content above 60%), the material is pretreated and fed into the petroleum-contaminated soil anaerobic reaction system 1 through the material and nutrient feeding port 18, and then fed through the feeding pump 7. Add the nutrient solution in the anaerobic reaction nutrient solution storage tank 15 into the anaerobic system. The nutrient solution used is peanut cake, superphosphate, monoammonium phosphate and potassium chloride to adjust the ratio of carbon, nitrogen, phosphorus and potassium in the soil to 90-100:9-12:1:1, and adjust the pH value to neutral. The number of agitators in the anaerobic system is 3-6 groups respectively arranged between two microbial electrochemical rebreathers 32 and powered by an external engine 21 . The pressure probe, temperature probe, and gas probe of the pressure, temperature, and gas online monitoring equipment 17 are buried in the petroleum activated sludge, and a common induction line is connected to an external detector. The outlet pipe 28 is exhausted, and the released gas is purified by the activated carbon adsorption tank 13 . The treated activated sludge is extracted by the exhaust fan 8 and the centrifugal pump 9, and after being treated by the gas-liquid separator 12, the gas passes through the activated carbon adsorption tank 13 for tail gas treatment and is discharged into the atmosphere up to the standard, and the activated sludge is centrifuged by the centrifugal pump 9 The biogas slurry and soil are separated, and the biogas slurry enters the biogas slurry storage tank 14 for storage and is used to produce organic fertilizer after reaching the inspection standard, and the soil is backfilled.

When dealing with oil-contaminated soil with a low water content (water content less than 35%), the materials are piled in the oil-contaminated soil aerobic reaction system 2 . The internal diameter of the ventilation main pipe 30 in the oil-contaminated soil aerobic reaction system 2 is 10cm, and the distance from the top of the soil pile is 0.2m. It is made of PVC material, and a plurality of air holes 26 are arranged on the ventilation branch pipe 25 . The biological nutrient dripping filter equipment is connected to the circulation pipeline of the biological pile ventilation equipment to form a circular delivery of biological nutrient substances. The nutrients used in oil-contaminated soil aerobic reaction system 2 are urea, superphosphate, monoammonium phosphate and potassium chloride to adjust the ratio of carbon, nitrogen, phosphorus and potassium in the soil to 90-100:9-12:1 :1, adjust the pH to neutral. Aerobic response system 2 for oil-contaminated soil is equipped with a total of 9 gas and temperature and humidity probes, which are evenly placed in the middle of the soil pile and connected to the detector outside the soil pile through induction lines to monitor the dynamic changes of the biopile in real time so as to pass through the pile in time. The bio-nutrient trickling filter regulates the nutrients of the biopile.

The present invention is ectopic soil restoration. After clearing and excavating the polluted soil, it enters the system of the present invention for treatment after certain pretreatment. The contaminated soil to be treated can be divided into oil-contaminated soil with extremely high water content and oil-contaminated soil with relatively low water content.

The polluted soil with relatively low moisture content is processed by a crusher and a sieving machine, and the bulk soil is crushed to a particle size of less than 2.5cm, and the stones and other sundries are screened and processed separately. The sieved soil is mixed with crop stalks to make the porosity reach 50%-60%, and finally sent to the oil-contaminated soil aerobic reaction system 2 in the system of the present invention.

After the petroleum-contaminated soil with extremely high moisture content is screened, after removing sundries and stones, it is stacked in the petroleum-contaminated soil anaerobic reaction system 1 of the system of the present invention, and the moisture is adjusted to make the petroleum activated sludge Becomes a stirrable fluid.

The following are application examples of the present invention:

Step 1, build the reaction system:

The reaction pool of the system is made of red brick, gravel, sand and Portland cement, and the bottom is covered with a layer of anti-seepage geomembrane. The ring beam and pool cover of the anaerobic reaction tank are made of No. 200 concrete. The bottom of the anaerobic reaction pool and the aerobic reaction pool are made of No. 100 concrete, and the pool wall is made of No. 150 concrete. The strength of cement mortar is generally not lower than No. 75, and the strength of joint mortar is not lower than No. 100. The bottom size of the whole system is 34m long x 24m wide and 2.5m high. The oil polluted soil anaerobic reaction system is 17m long x 12m wide and 2.5m high; the oil polluted soil aerobic reaction system is 17m long x 12m wide and 2.5m high. Lay 6 sets of microbial electrochemical respirators, 5 sets of agitators, and 1 set of pressure, temperature, and gas online monitoring equipment 17 in the oil-contaminated soil anaerobic reaction system; evenly lay online detection equipment 23 in the oil-contaminated soil anaerobic reaction system And connected to the ventilation main pipe (6 x 8, the ventilation branch pipes are 2m apart) and the ventilation branch pipes, a total of 48 and the biological nutrient dripping filter equipment.

Step 2, Petroleum Hydrocarbon Contaminated Soil Pretreatment:

The polluted soil is taken from the polluted area of the oil field. For the polluted soil with relatively low moisture content, the excavator is used to clear the polluted soil, and the large stones, plant roots and other sundries in the polluted soil are removed by crushing and screening machines. During the sieving process, the pH detection and adjustment are carried out at the same time, and the soil pH is adjusted to neutral. Add crop roots and straw with a particle size of about 4mm to the polluted soil to make the porosity of the mixed soil reach 50% to 60%, and add urea, superphosphate, monoammonium phosphate and potassium chloride to adjust the C in the soil , N, P, K ratio is 100:10:1:1, and adjust the soil moisture content in the range of 20% to 35%, stir and mix evenly. The pretreated polluted soil is added into the oil polluted soil aerobic reaction system 2 in the system of the present invention.

The polluted soil is taken from the polluted area of the oil field. For the polluted soil with extremely high water content, it is excavated and screened, and the sundries and stones are removed, then the pH of the soil is adjusted to neutral, and peanut cakes and superphosphate are added at the same time. , monoamine phosphate and potassium chloride to adjust the ratio of C, N, P and K in the soil to 95:12:1:1. Then send into the middle of the oil-contaminated soil anaerobic reaction system 1 of the system of the present invention.

Step 3, petroleum hydrocarbon contaminated soil remediation:

Restore petroleum hydrocarbons by coupling the anaerobic reaction system of petroleum contaminated soil with a microbial electrochemical respirator: start the online monitoring equipment in the anaerobic reaction system, adjust the speed of the agitator to 100r/min, run for 3 hours, and stir 4 times a day to make the petroleum Hydrocarbon sludge and nutrient solution are evenly mixed so that anaerobic microorganisms can fully degrade petroleum hydrocarbon pollutants, and the number of viable microorganisms is regularly detected to ensure that the degrading bacteria degrading petroleum hydrocarbons are within 6.5×10 ⁸ cfu/kg～7.5×10 ⁸ cfu/kg .

Remediation of petroleum hydrocarbons by coupling the aerobic reaction system of the petroleum-contaminated soil with a microbial electrochemical respirator: Ventilate 6 times a day, each time for 2.5 hours, through online monitoring equipment, determine the changes in the microbial growth environment, and continuously adjust the growth environment factors , maintain the microbial growth and metabolic environment, and regularly detect the number of viable microorganisms to ensure that the petroleum hydrocarbon degrading bacteria are at 8.5×10 ⁸ cfu/kg~9.5×10 ⁸ cfu/kg, and control the soil oxygen content at 25%~30% .

Step 4: Detect the remediation results of petroleum hydrocarbon contaminated soil:

The activated sludge at different positions in the anaerobic reaction system of petroleum-contaminated soil is randomly inspected every 5 days. After 45 days of reaction, the removal rate of petroleum hydrocarbons reaches more than 90%, and the activated sludge is up to the standard. Activated sludge treatment, soil backfill, biogas Liquid storage is used for the production of organic fertilizers.

Sampling was carried out at different positions of the bio-pile in the aerobic reaction system of oil-contaminated soil every 5 days. The position of each sampling was the same, and the content of petroleum hydrocarbons was measured. After 40 days of bio-pile reaction, the removal rate of petroleum hydrocarbons reached more than 91%. After the disposal, the soil pile will be cleared and backfilled after passing the inspection.

Claims (9)

1. The method for strengthening and repairing oil-contaminated soil by microbial electrochemical respirator is characterized in that: it comprises the following steps: 1) Construct a reaction system, which includes an anaerobic reaction system for oil-contaminated soil, an aerobic reaction system for oil-contaminated soil, and a microbial electrochemical respirator system. The anaerobic reaction system for oil-contaminated soil is adjacent to the aerobic reaction system for oil-contaminated soil Setup, the microbial electrochemical respirator system includes a microbial electrochemical respirator, the anode of the microbial electrochemical respirator is set in the anaerobic reaction system of oil-contaminated soil, and the cathode of the microbial electrochemical respirator is set in the oil-contaminated soil aerobic reaction system , the oil-contaminated soil aerobic reaction system is equipped with bio-pillar ventilation equipment and biological nutrient trickling filter equipment; the oil-contaminated soil anaerobic reaction system is provided with material and nutrient addition ports, sewage discharge outlets, agitators and Gas export, activated sludge treatment equipment; 2) Pretreat the oil-contaminated soil, adjust the pH value of the oil-contaminated soil with low water content and high water content to neutral, and adjust the ratio of C, N, P, and K in the soil to 90-100:9- 12:1:1; 3) Pile the pretreated contaminated soil with low moisture content in the oil-contaminated soil aerobic reaction system of step 1, and place the pretreated contaminated soil with high moisture content in the anaerobic reaction system of oil-contaminated soil in step 1 In the reaction system; start the microbial electrochemical respirator in the microbial electrochemical respirator system, and use the microbial electrochemical respirator to couple the oil-contaminated soil anaerobic reaction system for repair, and ensure that the petroleum hydrocarbon degrading bacteria are at 6.5×10 ⁸ cfu/kg ～7.5×10 ⁸ cfu/kg, at the same time, through the microbial electrochemical respirator coupled with the aerobic reaction system of oil-contaminated soil, the oxygen content in the soil is controlled at 25% to 30%, and the petroleum hydrocarbon-degrading bacteria are guaranteed to be at 8.5×10 ⁸ cfu/kg～9.5×10 ⁸ cfu/kg; 4) Monitor the results of soil remediation: The activated sludge at different positions in the anaerobic reaction system of oil-contaminated soil is randomly inspected every 5 days. When the activated sludge reaches the standard, the activated sludge is separated from gas and liquid, the soil is backfilled, and the generated biogas slurry is stored for organic use. fertilizer production; Samples were taken at different positions of the biopile in the oil-contaminated soil aerobic reaction system every 5 days. The sampling position was the same each time, and the petroleum hydrocarbon content was measured. After the test was qualified, the soil pile was cleared and backfilled. 2. according to the method for the said microbial electrochemical respirator intensified restoration of petroleum-contaminated soil according to claim 1, it is characterized in that: in said step 2), the moisture content of the petroleum-contaminated soil with low moisture content is less than 35%, and it passes Crusher and screening machine processing, crushing large pieces of soil to a particle size of less than 2.5cm, and screening out stones and other sundries, and mixing the screened soil with crop straw to make the porosity reach 50%~ 60%, and adjust the soil moisture to make the soil moisture content in the range of 20% to 35%; The oil-contaminated soil with a high water content has a water content of more than 60%. After removing stones and other sundries, the water content is adjusted to make the contaminated soil a fluid state that can be stirred. 3. according to the method for claim 1 or 2 described microbial electrochemical respirator strengthening repairing petroleum-contaminated soil, it is characterized in that: in step 2), the petroleum-contaminated soil with low moisture content is added urea, superphosphate, phosphoric acid Monoamine and potassium chloride adjust the ratio of C, N, P, and K in the soil to 90-100:9-12:1:1; the oil-contaminated soil with high moisture content can be added peanut cake, superphosphate, monophosphate Amine and potassium chloride adjust the ratio of C, N, P, and K in the soil to 90-100:9-12:1:1. 4. Microbial electrochemical respirator strengthens the system for repairing oil-contaminated soil, which is characterized in that it is mainly composed of oil-contaminated soil anaerobic reaction system, oil-contaminated soil aerobic reaction system and microbial electrochemical respirator system. The oxygen reaction system and the oil-contaminated soil aerobic reaction system are provided with reaction pools respectively, and are adjacently arranged, and a partition wall is provided between the two reaction pools. Above the reaction pool of the oil-contaminated soil anaerobic reaction system, materials and Nutrients dosing port and sludge discharge port, the reaction tank is equipped with multiple sets of agitators, and the reaction tank is connected with gas export and activated sludge treatment equipment. The oil-contaminated soil anaerobic reaction system is equipped with pressure, temperature and Gas online monitoring equipment; the oil-contaminated soil aerobic reaction system includes biological nutrient dripping filter equipment, bio-pile ventilation equipment, gas and temperature and humidity online monitoring equipment, the bio-pile ventilation equipment is provided with circulation pipelines, biological nutrient The trickling filter equipment is connected with the circulation pipeline of the bio-pile ventilation; the microbial electrochemical respirator system includes a microbial electrochemical respirator, and the anode of the microbial electrochemical respirator is arranged in the reaction tank of the oil-contaminated soil anaerobic reaction system, and the microorganisms The cathode of the electrochemical respirator is set in the reaction pool of the oil polluted soil aerobic reaction system. 5. according to the system that the described microbial electrochemical respirator of claim 4 strengthens and repairs the oil-contaminated soil, it is characterized in that: the described microbial electrochemical respirator is a plurality of groups of stainless steel nets, and the surroundings of the stainless steel nets are fixed by PVC plates, and the bottom is made of Scaffold support; the partition wall is provided with a microbial electrochemical respirator connection port, and the stainless steel mesh passes through the microbial electrochemical respirator connection port to connect the oil-contaminated soil aerobic reaction system and the microbial electrochemical respirator system. 6. according to the system of claim 4 or 5 described microbial electrochemical respirator strengthens the restoration of petroleum-contaminated soil, it is characterized in that: the bio-pile ventilation equipment includes a ventilation main pipe, a ventilation branch pipe and a blower, and the ventilation main pipe is serpentine and uniform It is laid on the upper part of the biological pile in the aerobic reaction system of oil-contaminated soil and connected with the blower to form a circulation pipeline; the ventilation branch pipe is arranged perpendicular to the ventilation main pipe, and is connected to the ventilation main pipe through a flower-shaped connecting pipe. Multiple air holes. 7. according to the system of claim 4 or 5 described microbial electrochemical respirator intensified restoration of petroleum-contaminated soil, it is characterized in that: the agitator of described petroleum-contaminated soil anaerobic reaction system is a double-helix agitator, which is connected to the Engine; the pressure, temperature and gas on-line monitoring equipment includes a pressure probe, a temperature probe and a gas probe, the three probes are buried in the activated sludge in the reaction tank, and a common induction line is connected to an external detector; the Gas export and activated sludge treatment equipment includes gas export pipe, gas-liquid separator, activated carbon adsorbent storage tank and biogas slurry storage tank, the gas export pipe is connected with activated carbon adsorbent storage tank, the inlet of gas-liquid separator is connected with the sludge The discharge ports are connected, the gas outlet of the gas-liquid separator is connected to the activated carbon adsorbent storage tank, and the liquid outlet of the gas-liquid separator is connected to the biogas slurry storage tank; Liquid storage tanks are connected. 8. According to claim 4 or 5, the system for strengthening the restoration of petroleum-contaminated soil by microbial electrochemical respirator is characterized in that: the gas and temperature and humidity online monitoring equipment of the petroleum-contaminated soil aerobic reaction system includes a plurality of evenly laid The probe is located inside the sludge, and the probe is connected to an external detector. 9. According to the system of claim 4 or 5, the microbial electrochemical respirator strengthens the repair of oil-contaminated soil, wherein the biological nutrient dripping device of the oil-contaminated soil aerobic reaction system includes an aerobic reaction nutrient solution storage The tank and the dosing pump, the input port of the dosing pump is connected to the aerobic reaction nutrient solution storage tank, and the output port of the dosing pump is connected to the circulation pipeline of the ventilation equipment of the bio-stack to form a circular transportation.