Device and method for treating petroleum-polluted wastewater by using clay mineral-microorganism composite system

Abstract

The invention discloses a device and a method for treating petroleum-polluted wastewater by using a clay mineral-microorganism composite system, and belongs to the technical field of environmental microorganism remediation. The device comprises a plurality of clay mineral filler adsorption units which are sequentially connected in series; an inlet end filter and an inlet end water quality monitor are arranged at the inlet end of the clay mineral filler adsorption unit at the head end, and the inlet end filter is connected with the inlet end water quality monitor; an outlet end filter and an outlet end water quality monitor are arranged at the outlet end of the clay mineral filler adsorption unit at the tail end; the outlet end water quality monitor is connected with the outlet end filter; the plurality of microbial fermentation chambers are arranged in one-to-one correspondence with the plurality of clay mineral filler adsorption units; and the continuous degradation cabin is used for providing a suitable environment for continuously degrading petroleum hydrocarbon pollutants by microorganisms. The clay minerals are utilized to stimulate microorganisms to degrade crude oil, and the degradation efficiency of a microbiological method is improved in combination with the characteristic that the clay minerals can efficiently adsorb petroleum hydrocarbons.

Description

Technical Field

[0001] This invention belongs to the field of environmental microbial remediation technology, and more specifically relates to an apparatus and method for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system. Background Technology

[0002] Treatment technologies for petroleum hydrocarbon-containing wastewater include physical methods, chemical methods, and microbial methods.

[0003] Physical and chemical methods are energy-intensive, costly, and prone to causing secondary pollution. While biological methods are green, sustainable, and low-cost, they are time-consuming, inefficient, and difficult to handle large volumes of petroleum hydrocarbon wastewater in a short period. Any combined technology with biotechnology inevitably increases costs. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] An apparatus for treating petroleum-contaminated wastewater using a clay mineral-microorganism composite system, comprising:

[0006] Multiple clay mineral packing adsorption units are connected in series. These units are used to adsorb petroleum hydrocarbons. The inlet end of the first clay mineral packing adsorption unit is equipped with an inlet filter and an inlet water quality monitor, which are connected together. The outlet end of the last clay mineral packing adsorption unit is equipped with an outlet filter and an outlet water quality monitor, which are connected together.

[0007] Multiple microbial fermentation chambers are provided, and each of the multiple microbial fermentation chambers is correspondingly set with a clay mineral packing adsorption unit. The microbial fermentation chambers provide microbial liquid to the corresponding clay mineral packing adsorption units.

[0008] The continuous degradation chamber provides a suitable environment for the continuous degradation of petroleum hydrocarbon pollutants by microorganisms in the failed clay mineral packing adsorption unit.

[0009] The pressurized petroleum hydrocarbon-containing wastewater is filtered through the inlet filter and then sequentially enters the clay mineral packing adsorption unit containing a high concentration of bacterial solution. The clay minerals in the clay mineral packing adsorption unit stimulate microorganisms to efficiently degrade petroleum hydrocarbons. If the petroleum hydrocarbon degradation rate is not up to standard as detected by the outlet water quality monitor, the wastewater will re-enter the clay mineral packing adsorption unit located at the head end for secondary treatment.

[0010] Furthermore, the clay mineral filler adsorption unit includes:

[0011] A clay mineral packing column having a hollow cavity;

[0012] The clay mineral core is disposed within the hollow cavity of the clay mineral packing column, and there is a certain gap between the clay mineral core and the clay mineral packing column to form an annular space, which serves as a channel for injecting bacterial solution into the clay mineral core.

[0013] Furthermore, a one-way valve is provided between the clay mineral core and the annular space to ensure that the bacterial solution can enter the clay mineral core through the annular space, while the liquid in the clay mineral core cannot enter the annular space.

[0014] Furthermore, it also includes a pressure pump, which pressurizes the petroleum hydrocarbon-containing wastewater and then introduces it into the clay mineral filler through the inlet filter.

[0015] Furthermore, the clay mineral core is detachably disposed at the center of the clay mineral packing column; the type and number of clay minerals in the clay mineral core, as well as the type and cell concentration of microorganisms used, are determined based on the composition and content of petroleum hydrocarbons in the petroleum-polluted wastewater.

[0016] Furthermore, the clay minerals in the clay mineral core include conventional clay minerals and / or modified clay minerals; the conventional clay minerals include one or more of kaolinite, montmorillonite, illite, soapstone, palygorskite, vermiculite, and chlorite; the modification methods of the modified clay minerals include thermal modification, acid modification, alkali modification, organic modification, or metal cation modification; the metal cations modified by the metal cations include one or more of sodium, potassium, calcium, iron-manganese, zinc, aluminum, and chromium.

[0017] Furthermore, the clay mineral core has a three-dimensional mesh structure made of cotton thread or nylon material, with clay mineral particles filling the middle.

[0018] The clay mineral core is provided with dense quartz sand filter layers at both ends and in the middle to restrict the clay mineral particles from flowing out with the water flow.

[0019] Furthermore, the microbial fermentation chamber provides the clay mineral core with a bacterial solution of a concentration of bacterial cells that meets the degradation requirements, and adjusts the temperature and nutrient conditions of the microbial fermentation chamber in real time based on feedback data from the outlet water quality monitoring instrument.

[0020] The clay mineral packing column is equipped with a temperature controller, which can maintain a constant temperature of the clay mineral packing column to ensure the optimal working temperature for microorganisms and to perform high-temperature pretreatment of the clay mineral core without adding microorganisms.

[0021] Furthermore, the microorganisms include petroleum hydrocarbon-degrading bacteria, which include one or more of *Pseudomonas aeruginosa*, *Pseudomonas cetozoae*, and *Bacillus licheniformis*; the viable concentration of the microorganisms is ≥10⁻⁶. 8 cell / mL.

[0022] A method for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system, employing the apparatus described in any one of the preceding claims for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system, the method comprising the following steps:

[0023] S10. Pressurize the incoming oil-contaminated wastewater through a booster pump, and set the pressure value to ensure that the pressurized oil-contaminated wastewater can pass through all clay mineral packing columns and flow out from the outlet filter.

[0024] S20. Oil-contaminated wastewater is pressurized and passed through an inlet filter. The inlet filter is set according to the water quality characteristics of the oil-contaminated wastewater to ensure that larger particles are filtered out.

[0025] S30. The composition and content data of petroleum hydrocarbons in petroleum-polluted wastewater can be read by the inlet water quality monitoring instrument.

[0026] S40. Determine the type, length, and type and cell concentration of microorganisms in the clay mineral core according to the type and content of the petroleum contaminants to be treated; further determine the set temperature of the temperature controller in each clay mineral core column according to the selected type of microorganisms.

[0027] S50. Load the clay mineral core into the center of the clay mineral filler column and compact it;

[0028] S60. Add the selected microbial strain to the microbial fermentation chamber, and inject it into the annular space of the clay mineral packing column after the bacterial concentration meets the requirements.

[0029] S70. Set the temperature of the temperature controller in each clay mineral packing column according to step S40. After a period of stable cultivation, it can be operated stably.

[0030] S80, Connect an outlet end filter to the outlet of the last clay mineral packing column located at the end;

[0031] S90. Read the data from the water quality monitor at the outlet end. If the petroleum hydrocarbon removal rate does not meet the standard, it will re-enter the annular space of the last clay mineral packing column at the end for secondary treatment.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] This invention provides an apparatus and method for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system. Utilizing the research finding that clay minerals can significantly stimulate microbial degradation of crude oil, and combining this with the efficient adsorption of petroleum hydrocarbons by clay minerals, this invention not only increases the degradation efficiency of traditional microbial methods but also proposes for the first time a pre-enrichment followed by treatment approach. Specifically, when faced with a large volume of petroleum hydrocarbon-containing wastewater in a short period, the primary method is to use clay minerals to adsorb and enrich the petroleum hydrocarbons. Then, the clay mineral packing column is removed and transferred to a continuous degradation chamber where microorganisms degrade the petroleum hydrocarbons in the clay mineral packing. Simultaneously, inexpensive and easily replaceable new clay mineral packing columns are added to the treatment device to continuously treat the petroleum hydrocarbon-containing wastewater, ensuring low cost while meeting practical needs. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] Figure 1 This is a device for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system;

[0036] Figure 2 This is a schematic diagram of the structure of the continuous degradation chamber;

[0037] Figure 3 A schematic diagram of a clay mineral core;

[0038] The components include: 1. Pressure pump; 2. Inlet filter; 3. Inlet water quality monitor; 4. Clay mineral packing column; 5. Clay mineral packing column temperature controller; 6. First clay mineral core; 7. One-way valve; 8. First microbial fermentation chamber; 9. Second clay mineral core; 10. Second microbial fermentation chamber; 11. Third clay mineral core; 12. Third microbial fermentation chamber; 13. Outlet filter; 14. Outlet water quality monitor; 15. Continuous degradation chamber; 16. Clay mineral core placement tank; 17. Nutrient maintenance system; 18. Continuous degradation chamber temperature controller; 19. Dense quartz sand filter layer; 20. Permeable material three-dimensional grid structure. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] refer to Figure 1-3 A device for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system, comprising:

[0042] Multiple clay mineral packing adsorption units are connected in series. The clay mineral packing adsorption units are used to adsorb petroleum hydrocarbons. The inlet end of the clay mineral packing adsorption unit at the first end is equipped with an inlet filter 2 and an inlet water quality monitor 3. The inlet filter 2 is connected to the inlet water quality monitor 3. The outlet end of the clay mineral packing adsorption unit at the end is equipped with an outlet filter 13 and an outlet water quality monitor 14. The outlet water quality monitor 14 is connected to the outlet filter 13.

[0043] Multiple microbial fermentation chambers are set up one-to-one with multiple clay mineral packing adsorption units. The microbial fermentation chambers provide microbial inoculum to the corresponding clay mineral packing adsorption units.

[0044] The continuous degradation chamber 15 provides a suitable environment for the continuous degradation of petroleum hydrocarbon pollutants by microorganisms in the depleted clay mineral packing adsorption unit.

[0045] The pressurized petroleum hydrocarbon-containing wastewater is filtered through the inlet filter 2 and then sequentially enters the clay mineral packing adsorption unit containing a high concentration of bacterial solution. The clay minerals in the clay mineral packing adsorption unit stimulate microorganisms to efficiently degrade petroleum hydrocarbons. If the petroleum hydrocarbon degradation rate is not up to standard as detected by the outlet water quality monitor 14, the wastewater will re-enter the clay mineral packing adsorption unit located at the beginning for secondary treatment.

[0046] In this embodiment, the inlet water quality monitor 3 and the outlet water quality monitor 14 can monitor a series of water quality parameters such as petroleum hydrocarbons, microorganisms, and COD; the outlet of the clay mineral packing column 4 located at the end is connected to the outlet filter 13; the outlet filter 13 is connected to the outlet water quality monitor 14; after determining that the petroleum hydrocarbon content at the outlet does not meet the standard, the wastewater is sent back to the inlet to achieve secondary treatment of the wastewater.

[0047] In this embodiment, the clay mineral filler adsorption unit includes:

[0048] Clay mineral packing column 4, the clay mineral packing column 4 has a hollow cavity;

[0049] The clay mineral core is placed inside the hollow cavity of the clay mineral packing column 4. There is a certain gap between the clay mineral core and the clay mineral packing column 4 to form an annular space, which is a channel for injecting bacterial solution into the clay mineral core.

[0050] In this embodiment, a one-way valve 7 is provided between the clay mineral core and the annular space to ensure that the bacterial solution can enter the clay mineral core through the annular space, while the liquid in the clay mineral core cannot enter the annular space.

[0051] Specifically, the one-way valve 7 ensures that the bacterial solution can enter the clay mineral core through the annular space, while the liquid in the clay mineral core cannot enter the annular space. The position of the one-way valve 7 ensures the uniform distribution of the bacterial solution in the clay mineral core.

[0052] The microbial inoculum is produced by cell proliferation in a microbial fermentation chamber and then injected into a clay mineral core after reaching a specific cell concentration. The flow direction of the inoculum is opposite to that of the petroleum-polluted wastewater.

[0053] In this embodiment, the one-way valve 7 enables the bacterial solution to be evenly distributed in the clay mineral core. The one-way valve 7 allows the bacterial solution to enter the clay mineral core but does not allow the bacterial solution to enter the annular flow channel from the clay mineral core.

[0054] The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system provided in this embodiment also includes a pressurizing pump 1. The pressurizing pump 1 pressurizes the petroleum hydrocarbon-containing wastewater and then sends it through the inlet filter 2 into the clay mineral core.

[0055] Specifically, the petroleum hydrocarbon-containing wastewater is pressurized by the booster pump 1 and then passes through the inlet filter 2. The booster pump 1 can achieve electric pressurization and adjustable pressure. The pressure can be set according to the flow rate requirements and can ensure that it passes through all clay mineral packing columns and flows out stably.

[0056] The inlet filter 2 and the outlet filter 13 are selected according to the characteristics of the petroleum-polluted wastewater being treated.

[0057] In this embodiment, the clay mineral core is detachably disposed at the center of the clay mineral packing column 4; the type and number of clay minerals in the clay mineral core, as well as the type and cell concentration of microorganisms used, are determined based on the composition and content of petroleum hydrocarbons in the petroleum-polluted wastewater.

[0058] After the clay mineral core becomes saturated with adsorbed petroleum hydrocarbons, it can be replaced with a new clay mineral core. The replaced clay mineral core is placed in the continuous degradation chamber 15 to complete the degradation. After the degradation is completed, it can be recycled.

[0059] In this embodiment, the clay minerals in the clay mineral core include conventional clay minerals and / or modified clay minerals; the conventional clay minerals include one or more of kaolinite, montmorillonite, illite, soapstone, palygorskite, vermiculite, and chlorite; the modified clay minerals are modified by means of thermal modification, acid modification, alkali modification, organic modification, or metal cation modification; the metal cations modified by metal cations include one or more of sodium, potassium, calcium, iron-manganese, zinc, aluminum, and chromium.

[0060] The clay mineral core (type and number of clay minerals) and microbial use (type and cell concentration) in the clay mineral packing column 4 are determined based on the composition and content of petroleum hydrocarbons in the petroleum-polluted wastewater.

[0061] The treatment of different types of petroleum-contaminated wastewater involves combinations of clay minerals and microorganisms, including but not limited to the following:

[0062] Table 1. Clay mineral and microbial assemblages used in petroleum-contaminated wastewater with different major pollutants.

[0063]

[0064]

[0065] In this embodiment, the interior of the clay mineral core is a three-dimensional mesh structure 20 of permeable material made of cotton thread or nylon, with clay mineral particles filling the middle.

[0066] Dense quartz sand filter layers 19 are provided at both ends and in the middle of the clay mineral core to restrict the clay mineral particles from flowing out with the water flow.

[0067] In this embodiment, the microbial fermentation chamber provides the clay mineral core with a bacterial solution of a concentration of bacterial cells that meets the degradation requirements, and adjusts the temperature and nutrient conditions of the microbial fermentation chamber in real time based on feedback data from the outlet water quality monitor 14.

[0068] The clay mineral packing column 4 is equipped with a clay mineral packing column temperature controller 5, which can control the constant temperature of the clay mineral packing column to ensure the optimal working temperature of microorganisms and to perform high-temperature pretreatment of the clay mineral packing core without adding microorganisms.

[0069] In this embodiment, the microorganisms include petroleum hydrocarbon-degrading bacteria, which include one or more of Pseudomonas aeruginosa, Pseudomonas cetozoides, and Bacillus licheniformis; the viable concentration of the microorganisms is ≥10. 8 cell / mL.

[0070] The microbial fermentation chamber provides the clay mineral core with a bacterial solution of a concentration of bacterial cells that meets the actual degradation requirements; the temperature and nutrient conditions of the microbial fermentation chamber are adjusted in real time based on the feedback data from the outlet water quality monitoring instrument 14.

[0071] In this embodiment, when the clay mineral core fails (e.g., reaches crude oil adsorption saturation) and cannot cope with the incoming wastewater, the clay mineral core should be replaced promptly, and the microbial formula should be adjusted and the microbial cell concentration increased. Simultaneously, the failed clay mineral core is removed and placed in the continuous degradation chamber 15 for further degradation.

[0072] The continuous degradation chamber 15 includes multiple clay mineral core placement tanks 16, a nutrient maintenance system 17, and a continuous degradation chamber temperature controller 18, which can provide a suitable environment for the continuous degradation of petroleum hydrocarbon pollutants by microorganisms in the clay mineral core.

[0073] In this embodiment, there are preferably three clay mineral filler adsorption units and three microbial fermentation chambers, with each of the three microbial fermentation chambers corresponding to one of the three clay mineral filler adsorption units.

[0074] Among them, the three clay mineral cores set in the clay mineral packing column 4 of the three clay mineral packing adsorption units are respectively set as the first clay mineral core 6, the second clay mineral core 9 and the third clay mineral core 11, and the three microbial fermentation chambers are respectively the first microbial fermentation chamber 8, the second microbial fermentation chamber 10 and the third microbial fermentation chamber 12.

[0075] Specifically, the first microbial fermentation chamber 8, the second microbial fermentation chamber 10, and the third microbial fermentation chamber 12 provide the first clay mineral core 6 with a bacterial solution of a concentration of bacterial cells that meets the actual degradation requirements; the second microbial fermentation chamber 10 provides the second clay mineral core 9 with a bacterial solution of a concentration of bacterial cells that meets the actual degradation requirements; and the third microbial fermentation chamber 12 provides the third clay mineral core 11 with a bacterial solution of a concentration of bacterial cells that meets the actual degradation requirements.

[0076] This embodiment provides an apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system. Utilizing the research finding that clay minerals can significantly stimulate microbial degradation of crude oil, and combining this with the characteristic of clay minerals efficiently adsorbing petroleum hydrocarbons, it not only increases the degradation efficiency of traditional microbial methods but also proposes for the first time a pre-enrichment followed by treatment approach. Specifically, when faced with a large volume of petroleum hydrocarbon-containing wastewater in a short period, the apparatus primarily uses clay minerals to adsorb and enrich the petroleum hydrocarbons. Then, the clay mineral packing column 4 is removed and transferred to the continuous degradation chamber 15, where microorganisms degrade the petroleum hydrocarbons in the clay mineral packing. Simultaneously, inexpensive and easily replaceable new clay mineral packing columns 4 are added to the treatment device to continuously treat the petroleum hydrocarbon-containing wastewater, meeting practical needs while ensuring low cost.

[0077] Example 2

[0078] A method for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system, employing the apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system provided in Example 1, includes the following steps:

[0079] S10. Pressurize the incoming oil-contaminated wastewater through a booster pump, and set the pressure value to ensure that the pressurized oil-contaminated wastewater can pass through all clay mineral packing columns and flow out from the outlet filter.

[0080] S20. Oil-contaminated wastewater is pressurized and passed through an inlet filter. The inlet filter is set according to the water quality characteristics of the oil-contaminated wastewater to ensure that larger particles are filtered out.

[0081] S30. The composition and content data of petroleum hydrocarbons in petroleum-polluted wastewater can be read by the inlet water quality monitoring instrument.

[0082] S40. Determine the type, length, and type and cell concentration of clay mineral cores based on the type and content of the petroleum contaminants to be treated. If the petroleum contaminants are complex in composition and high in content, multiple combinations of different types of clay mineral-microorganisms can be selected. Further determine the set temperature of the temperature controller in each clay mineral core column based on the selected type of microorganisms.

[0083] S50. Load the clay mineral core into the center of the clay mineral filler column and compact it;

[0084] S60. Add the selected microbial strain to the microbial fermentation chamber, and inject it into the annular space of the clay mineral packing column after the bacterial concentration meets the requirements.

[0085] S70. Set the temperature of the temperature controller in each clay mineral packing column according to step S40. After a period of stable cultivation, it can be operated stably.

[0086] S80, Connect an outlet end filter to the outlet of the last clay mineral packing column located at the end;

[0087] S90. Read the data from the water quality monitor at the outlet end. If the petroleum hydrocarbon removal rate does not meet the standard, it will re-enter the annular space of the last clay mineral packing column at the end for secondary treatment.

[0088] The technical solutions of the present invention have been fully described above. It should be noted that the specific embodiments of the present invention are not limited to the above description. All technical solutions formed by those skilled in the art based on the spirit and essence of the present invention by adopting equivalent transformations or equivalent transformations in terms of structure, method or function fall within the protection scope of the present invention.

Claims

1. A device for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system, characterized in that, include: Multiple clay mineral packing adsorption units are connected in series. These units are used to adsorb petroleum hydrocarbons. The inlet end of the first clay mineral packing adsorption unit is equipped with an inlet filter and an inlet water quality monitor, which are connected together. The outlet end of the last clay mineral packing adsorption unit is equipped with an outlet filter and an outlet water quality monitor, which are connected together. Multiple microbial fermentation chambers are provided, and each of the multiple microbial fermentation chambers is correspondingly set with a clay mineral packing adsorption unit. The microbial fermentation chambers provide microbial liquid to the corresponding clay mineral packing adsorption units. The continuous degradation chamber provides a suitable environment for the continuous degradation of petroleum hydrocarbon pollutants by microorganisms in the failed clay mineral packing adsorption unit. The pressurized petroleum hydrocarbon-containing wastewater is filtered through the inlet filter and then sequentially enters the clay mineral packing adsorption unit containing a high concentration of bacterial solution. The clay minerals in the clay mineral packing adsorption unit stimulate microorganisms to efficiently degrade petroleum hydrocarbons. If the petroleum hydrocarbon degradation rate is not up to standard as detected by the outlet water quality monitor, the wastewater will re-enter the clay mineral packing adsorption unit located at the head end for secondary treatment.

2. The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system according to claim 1, characterized in that, The clay mineral filler adsorption unit includes: A clay mineral packing column having a hollow cavity; The clay mineral core is disposed within the hollow cavity of the clay mineral packing column, and there is a certain gap between the clay mineral core and the clay mineral packing column to form an annular space, which serves as a channel for injecting bacterial solution into the clay mineral core.

3. The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system according to claim 2, characterized in that, A one-way valve is provided between the clay mineral core and the annular space to ensure that the bacterial solution can enter the clay mineral core through the annular space, while the liquid in the clay mineral core cannot enter the annular space.

4. The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system according to claim 2, characterized in that, It also includes a pressure pump, which pressurizes the petroleum hydrocarbon-containing wastewater and then sends it through the inlet filter into the clay mineral filler.

5. The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system according to claim 2, characterized in that, The clay mineral core is detachably installed at the center of the clay mineral packing column; the type and number of clay minerals in the clay mineral core, as well as the type and cell concentration of microorganisms used, are determined based on the composition and content of petroleum hydrocarbons in the petroleum-polluted wastewater.

6. The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system according to claim 2, characterized in that, The clay minerals in the clay mineral core include conventional clay minerals and / or modified clay minerals; the conventional clay minerals include one or more of kaolinite, montmorillonite, illite, soapstone, palygorskite, vermiculite, and chlorite; the modification methods of the modified clay minerals include thermal modification, acid modification, alkali modification, organic modification, or metal cation modification; the metal cations modified by the metal cations include one or more of sodium, potassium, calcium, iron-manganese, zinc, aluminum, and chromium.

7. The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system according to claim 2, characterized in that, The clay mineral core has a three-dimensional mesh structure made of cotton thread or nylon material, and is filled with clay mineral particles in the middle. The clay mineral core is provided with dense quartz sand filter layers at both ends and in the middle to restrict the clay mineral particles from flowing out with the water flow.

8. The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system according to claim 2, characterized in that, The microbial fermentation chamber provides the clay mineral core with a bacterial solution of a concentration of bacterial cells that meets the degradation requirements, and adjusts the temperature and nutrient conditions of the microbial fermentation chamber in real time based on feedback data from the water quality monitoring instrument at the outlet end. The clay mineral packing column is equipped with a temperature controller, which can maintain a constant temperature of the clay mineral packing column to ensure the optimal working temperature for microorganisms and to perform high-temperature pretreatment of the clay mineral core without adding microorganisms.

9. The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system according to claim 1, characterized in that, The microorganisms include petroleum hydrocarbon-degrading bacteria, which include one or more of *Pseudomonas aeruginosa*, *Pseudomonas cetozoae*, and *Bacillus licheniformis*; the viable concentration of the microorganisms is ≥10⁻⁶. 8 cell / mL.

10. A method for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system, characterized in that, The apparatus for treating petroleum-polluted wastewater using a clay mineral-microorganism composite system as described in any one of claims 1 to 9, the method comprising the following steps: S10. Pressurize the incoming oil-contaminated wastewater through a booster pump, and set the pressure value to ensure that the pressurized oil-contaminated wastewater can pass through all clay mineral packing columns and flow out from the outlet filter. S20. Oil-contaminated wastewater is pressurized and passed through an inlet filter. The inlet filter is set according to the water quality characteristics of the oil-contaminated wastewater to ensure that larger particles are filtered out. S30. The composition and content data of petroleum hydrocarbons in petroleum-polluted wastewater can be read by the inlet water quality monitoring instrument. S40. Determine the type, length, and type and cell concentration of microorganisms in the clay mineral core according to the type and content of the petroleum contaminants to be treated; further determine the set temperature of the temperature controller in each clay mineral core column according to the selected type of microorganisms. S50. Load the clay mineral core into the center of the clay mineral filler column and compact it; S60. Add the selected microbial strain to the microbial fermentation chamber, and inject it into the annular space of the clay mineral packing column after the bacterial concentration meets the requirements. S70. Set the temperature of the temperature controller in each clay mineral packing column according to step S40. After a period of stable cultivation, it can be operated stably. S80, Connect an outlet end filter to the outlet of the last clay mineral packing column located at the end; S90. Read the data from the water quality monitor at the outlet end. If the petroleum hydrocarbon removal rate does not meet the standard, it will re-enter the annular space of the last clay mineral packing column at the end for secondary treatment.

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