Device and method for groundwater microbial remediation

Abstract

The invention discloses a device and a method for groundwater microbial remediation. The device comprises an ultra-fine bubble generator, a bubble conveying pipe, a bacterial liquid storage device, a bacterial liquid conveying pipe, an adapter and a bubble and bacterial liquid uniform distribution integrated device, the bubble and bacterial liquid uniform distribution integrated device comprises a gas area and a bacterial liquid area which are not communicated with each other, the gas area is communicated with a bubble conveying pipe, and the bacterial liquid area is communicated with a bacterial liquid conveying pipe; the bubble and bacterial liquid uniform distribution integrated device is of a cylinder structure, aeration heads are uniformly distributed on the side surface corresponding to the gas area, and bacterial liquid conveying ports are uniformly distributed on the side surface corresponding to the bacterial liquid area; the air outlet direction of the aeration head is perpendicular to the diameter direction of the cylinder, and when the aeration head sprays air, the bubble and bacterial liquid uniform distribution integrated device can rotate; the ultra-fine bubble generator is connected to the adapter through a bubble conveying pipe, the bacterial liquid storage device is connected to the adapter through a bacterial liquid conveying pipe, and the lower portion of the adapter is connected to the bubble and bacterial liquid uniform distribution integrated device.

Description

Technical Field

[0001] The present invention relates to the technical field of groundwater pollution remediation, and in particular to a device and method for groundwater microbial remediation. Background Art

[0002] In the field of environmental engineering, microbial remediation technology is an important remediation method, especially in groundwater pollution control. This technology utilizes the metabolic effects of microorganisms to degrade and transform pollutants in groundwater, thereby achieving the purpose of pollution remediation.

[0003] In the field of water treatment technology, aeration is a common technical means. By injecting air into the water, the oxygen concentration in the water can be increased, promoting the growth and reproduction of aerobic microorganisms, thereby improving the self-purification ability of the water body.

[0004] The existing groundwater microbial remediation technology mainly adopts the static dosing method, that is, the microbial agent is directly added to the groundwater, relying on natural diffusion and mixing to achieve contact between the microbial agent and the pollutant. Among them, the aerobic microbial remediation technology injects air into the groundwater by setting up an aeration device to promote the growth and reproduction of aerobic microorganisms.

[0005] However, existing groundwater microbial remediation technologies have some problems in practical applications. First, the static addition of bacterial agents limits the scope of action of the agents, making it difficult to ensure uniform dispersion of the agents, and easily leading to excessive or low concentrations of the agents in local areas, affecting the remediation effect. Secondly, existing aeration devices are difficult to adapt to complex underground environments, and the aeration range is limited, the gas retention time is short, and it is difficult to maintain an aerobic state for a long time, making it difficult to achieve comprehensive remediation of groundwater. In addition, when injecting air into groundwater, existing technologies often ignore the uniform mixing of air and bacterial agents, resulting in a mismatch between oxygen and microbial agents in the action area and action time, affecting the growth of microorganisms and the remediation effect.

[0006] The patent specification with publication number CN113290033A discloses a method for in-situ injection and enhanced soil and groundwater remediation using a microbubble generating device, which is carried out by a microbubble generating device. The method comprises: step 1, adding clean water and / or a medicine into a dissolving tank, and turning on the agitator to prepare a remediation agent; step 2, using a microbubble generating device, inhaling gas and a prepared medicine at the same time, and pressurizing the pump to produce microbubbles; step 3, injecting the microbubble dissolved gas medicine into the contaminated soil and groundwater environment through a pipeline through an injection well group; step 4, after the microbubbles in step 3 enter the ground, wait for the microbubbles to be slowly released and gradually float up; step 5, repeat step 3 until all areas with designed injection points have completed the injection of the agent. In step 1, the prepared remediation agent includes any one or more combinations of oxidants, reductants, activators, regulators, microbial nutrients or microbial strains according to the different soil and groundwater pollutants. Although this patented technology introduces microbubbles, it is essentially still a static method of adding bacterial agents through natural diffusion, in which the effect of microbubbles on the diffusion of bacterial agents is still very limited. Summary of the invention

[0007] In view of the above-mentioned technical problems and the shortcomings in the art, the present invention provides a device and method for groundwater microbial remediation.

[0008] [1] A device for groundwater microbial remediation, comprising an ultrafine bubble generator, a bubble delivery pipe, a bacterial liquid storage device, a bacterial liquid delivery pipe, an adapter, and an integrated device for uniformly distributing bubbles and bacterial liquid;

[0009] The integrated device for uniformly distributing air bubbles and bacterial liquid comprises a gas zone and a bacterial liquid zone which are not connected to each other, wherein the gas zone is connected to a bubble delivery pipe, and the bacterial liquid zone is connected to a bacterial liquid delivery pipe; the integrated device for uniformly distributing air bubbles and bacterial liquid is a cylindrical structure, and an aeration head is uniformly distributed on the side of the gas zone, and a bacterial liquid delivery port is uniformly distributed on the side of the bacterial liquid zone; the gas outlet direction of the aeration head is perpendicular to the diameter direction of the cylinder, and the integrated device for uniformly distributing air bubbles and bacterial liquid can rotate when the aeration head sprays gas;

[0010] The ultrafine bubble generator is connected to the adapter through the bubble delivery tube, the bacterial liquid storage device is connected to the adapter through the bacterial liquid delivery tube, and the adapter is connected to the integrated device for uniform distribution of bubbles and bacterial liquid below. The adapter is connected to the bubble delivery tube and the bacterial liquid delivery tube above, and to the integrated device for uniform distribution of bubbles and bacterial liquid below, which plays a supporting and fixing role.

[0011] The air outlet direction of the aeration head of the present invention is perpendicular to the diameter direction of the cylinder of the bubble and bacteria liquid uniform distribution integrated device. This layout can generate asymmetric force during aeration, causing the bubble and bacteria liquid uniform distribution integrated device to rotate clockwise or counterclockwise.

[0012] The device for groundwater microbial remediation of the present invention is based on the asymmetric force generated when ultrafine bubbles are ejected from the aeration head, so that the bubble and bacterial liquid uniformly distributed integrated device rotates itself, significantly expanding the scope of action of the bacterial liquid in the groundwater and ensuring the uniform dispersion of the bacterial liquid. At the same time, ultrafine bubbles are used to create a long-term retained and fully uniform aerobic environment, so that the bacterial liquid and ultrafine bubbles are fully mixed, achieving a good matching effect in terms of both the scope of action and the action time, forming an efficient aerobic microbial remediation micro-domain environment, which is beneficial to groundwater microbial remediation.

[0013] The device for groundwater microbial restoration, the ultrafine bubble generator and the bacterial liquid storage device can be placed on the ground of the area to be restored.

[0014] The ultrafine bubble generator of the device for groundwater microbial remediation can be made of metal and / or corrosion-resistant materials.

[0015] The device for groundwater microbial remediation, the bubble diameter generated by the ultrafine bubble generator is less than 1000nm, the bubble internal pressure is 3-10bar, the floating time of 1m is more than 21 days, the retention time is more than 90 days, and the bubble density is more than 10 8 Pieces / mL.

[0016] The device for groundwater microbial remediation, the air bubble and bacterial liquid uniformly distributed integrated device can be made of plastic composite materials and / or corrosion-resistant materials.

[0017] In the device for groundwater microbial remediation, the ratio of the height to diameter of the cylinder of the integrated device for uniformly distributing air bubbles and bacterial liquid can be 1 to 4:1, such as 2.5:1.

[0018] In some embodiments, in the device for groundwater microbial remediation, the cylindrical side of the integrated device for evenly distributing bubbles and bacterial liquid is divided into two parts corresponding to the gas zone and the bacterial liquid zone respectively, the aeration head occupies half of the area of ​​the cylindrical side, and the bacterial liquid delivery port occupies half of the area of ​​the cylindrical side.

[0019] The aeration hole diameter of the device for groundwater microbial remediation can be 1 to 3 mm.

[0020] In the device for groundwater microbial remediation, the diameter of the bacterial liquid delivery port can be 1 to 5 mm, for example, 2 mm.

[0021] In the device for groundwater microbial remediation, the microbial degradation agent can be stored in the bacterial liquid storage device. The microbial degradation agent can select highly complementary degradation strains to construct a microbial degradation bacterial community, and prepare the microbial degradation bacterial liquid through the expansion culture of the bacterial agent and engineering parameter design. Further, the microbial degradation agent can include Variovorax paradoxus and Pseudomonas veronii, etc.

[0022] [2] A method for groundwater microbial remediation, using the device for groundwater microbial remediation described in [1];

[0023] The method for groundwater microbial remediation comprises:

[0024] The ultrafine bubble generator is started to deliver ultrafine bubbles to the gas zone through the bubble delivery pipe, and the bubbles are ejected through the aeration head. The asymmetric force generated when the ultrafine bubbles are ejected causes the bubble and bacterial liquid uniform distribution integrated device to rotate;

[0025] The bacterial liquid storage device is started, and the microbial bacterial liquid is transported to the bacterial liquid area through the bacterial liquid transport pipe. The microbial bacterial liquid is evenly input into the groundwater from the bacterial liquid transport port during the rotation of the integrated device for uniformly distributing air bubbles and bacterial liquid.

[0026] The present invention uses the rotation caused by ultrafine bubble aeration to effectively increase the action range of the bacterial solution in groundwater and ensure that the bacterial solution is evenly dispersed. At the same time, ultrafine bubbles are used to create a fully evenly distributed and long-lasting aerobic environment, so that the bacterial solution and the ultrafine bubbles are fully mixed to form a good aerobic microbial remediation micro-domain environment, achieving a good matching effect on both the action range and the action time, thereby improving the groundwater microbial remediation effect.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The bacterial agent is more evenly dispersed and has a wider range of action: The existing technology uses static dosing of bacterial agents, relying on natural diffusion and mixing, which leads to uneven dispersion of the bacterial agent and limited range of action. The present invention uses the asymmetric force generated by the ultra-fine bubbles ejected from the aeration head to make the bubble and bacterial liquid uniformly distributed integrated device rotate itself, significantly expanding the range of action of the bacterial liquid in the groundwater and ensuring that the bacterial liquid is evenly dispersed, avoiding the problem of excessive or low concentration of the bacterial agent in local areas, and improving the remediation effect.

[0029] 2. The aerobic state is more stable and the aeration effect is better: the aeration device in the existing aerobic microbial remediation technology is difficult to adapt to the complex underground environment, the aeration range is limited, the gas retention time is short, and it is difficult to maintain the aerobic state for a long time. The present invention uses ultra-fine bubbles to create a long-term, fully uniform aerobic state, which solves the shortcomings of the existing aeration device, is conducive to the growth and reproduction of aerobic microorganisms, thereby improving the self-purification ability of the water body and realizing the comprehensive remediation of groundwater.

[0030] 3. The microbial agent and air are mixed more fully, and the matching of the action is more accurate: When injecting air into groundwater, the prior art often ignores the uniform mixing of air and microbial agent, resulting in the mismatch between oxygen and microbial agent in the action area and action time. The present invention achieves a good matching effect in terms of action range and action time by fully mixing the bacterial liquid with ultrafine bubbles, forming an efficient aerobic microbial remediation micro-domain environment, which is conducive to the growth of microorganisms and the performance of remediation, and further improves the effect of groundwater microbial remediation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of a device used for groundwater microbial remediation in a specific implementation manner.

[0032] Figure 2 It is a schematic diagram of the device transfer structure for groundwater microbial remediation in a specific implementation method.

[0033] Figure 3 It is a schematic diagram of the cross-sectional structure of an integrated device for uniformly distributing bubbles and bacterial liquid in a device for groundwater microbial remediation in a specific implementation manner. The arrow indicates the direction of the aeration head, which is perpendicular to the diameter direction of the cylinder. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention. The operating methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0035] See also Figures 1 to 3A device for groundwater microbial remediation includes an ultrafine bubble generator 1, a bubble delivery pipe 2, a bacterial liquid storage device 3, a bacterial liquid delivery pipe 4, an adapter 5, and a bubble and bacterial liquid uniformly distributed integrated device 6. The bubble and bacterial liquid uniformly distributed integrated device 6 is divided into a gas zone and a bacterial liquid zone that are not connected to each other, wherein the gas zone is connected to the bubble delivery pipe 2, and the bacterial liquid zone is connected to the bacterial liquid delivery pipe 4. The bubble and bacterial liquid uniformly distributed integrated device 6 is a cylindrical structure, and the cylindrical side of the bubble and bacterial liquid uniformly distributed integrated device 6 is divided into two parts corresponding to the gas zone and the bacterial liquid zone respectively, and the aeration head 7 is uniformly distributed on the side corresponding to the gas zone and the aeration head 7 occupies half of the area of ​​the cylindrical side, and the bacterial liquid delivery port 8 is uniformly distributed on the side corresponding to the bacterial liquid zone and the bacterial liquid delivery port 8 occupies half of the area of ​​the cylindrical side. The gas outlet direction of the aeration head 7 is perpendicular to the diameter direction of the cylinder, and the bubble and bacterial liquid uniformly distributed integrated device 6 can rotate when the aeration head 7 sprays gas. The ultrafine bubble generator 1 is connected to the adapter 5 through the bubble delivery pipe 2, the bacterial liquid storage device 3 is connected to the adapter 5 through the bacterial liquid delivery pipe 4, and the adapter 5 is connected to the bubble and bacterial liquid uniform distribution integrated device 6 below. The ultrafine bubble generator 1 is made of metal and / or corrosion-resistant materials. The bubble diameter generated by the ultrafine bubble generator 1 is less than 1000nm, the bubble internal pressure is 3-10bar, the floating time of 1m is more than 21 days, the retention time is more than 90 days, and the bubble density generated is more than 10 8 The bacterial liquid storage device 3 stores aerobic microbial agents. The bubble and bacterial liquid uniform distribution integrated device 6 is made of plastic composite material and / or corrosion-resistant material.

[0036] A method for groundwater microbial remediation, using the above-mentioned device for groundwater microbial remediation, comprising:

[0037] Step 1: Prepare the ultrafine bubble generator 1, bubble delivery tube 2, bacterial liquid storage device 3, bacterial liquid delivery tube 4, adapter 5 and bubble and bacterial liquid uniform distribution integrated device 6. The ultrafine bubble generator 1 uses high-speed gyroscopic cutting and Venturi mixing technology to generate ultrafine bubbles with a diameter of less than 1000nm. Compared with ordinary bubbles, ultrafine bubbles have unique physical and chemical properties, high bubble density, long floating time, long retention time, and can homogenize and increase dissolved oxygen. The ultrafine bubble generator 1 is made of metal, and the bubble density generated exceeds 10 8 The bacterial solution storage device 3 uses a 50L stainless steel tank to store the microbial degradation agent. The microbial degradation agent uses Variovorax paradoxus bacteria and Pseudomonas veronii bacteria in a 1:1 bacterial solution volume ratio (bacterial solution OD 600=1.0) and the same volume was taken for the degradation of benzene in groundwater. The effective live bacteria count of the bacterial solution used was ≥100 million / L, and the number of mold and miscellaneous bacteria was ≤3.0×10 6 / mL, the rate of foreign bacteria is ≤10%, and under laboratory evaluation conditions, the degradation rate of benzene series is more than 50% within 1 month. The ultrafine bubble generator 1 and the bacterial liquid storage device 3 are placed on the ground of the benzene series contaminated area of ​​the medical and chemical park.

[0038] Step 2: Connect the ultrafine bubble generator 1 to the adapter 5 through the bubble delivery tube 2, and the bacterial liquid storage device 3 is connected to the adapter 5 through the bacterial liquid delivery tube 4. The adapter 5 is connected to the integrated device 6 for uniformly distributing bubbles and bacterial liquid. The integrated device 6 for uniformly distributing bubbles and bacterial liquid is made of a plastic composite material. The device is a cylindrical structure with a diameter of 20 cm and a height of 50 cm. The side of the cylinder is divided into two parts, one part is uniformly distributed with aeration heads 7, and the other part is uniformly distributed with bacterial liquid delivery ports 8. The aperture of the aeration head 7 is 1 mm, the spacing is 1 cm, and the direction of the aeration head 7 is perpendicular to the diameter direction of the cylinder. The aperture of the bacterial liquid delivery port 8 is 2 mm and is evenly distributed on the side of the cylinder.

[0039] Step 3: Start the ultrafine bubble generator 1 and deliver ultrafine bubbles to the adapter 5 through the bubble delivery pipe 2. The diameter of the ultrafine bubbles is less than 1000nm, the internal pressure of the bubbles is 3-10bar, the floating time of 1m is more than 21 days, and the existence time is more than 90 days. The ultrafine bubbles enter the bubble and bacterial liquid uniform distribution integrated device 6 through the adapter 5 and are ejected through the aeration head 7. Based on the asymmetric force generated when the ultrafine bubbles are ejected, the bubble and bacterial liquid uniform distribution integrated device 6 rotates itself.

[0040] Step 4: At the same time, the bacterial liquid storage device 3 is started, and the microbial agent is delivered to the adapter 5 through the bacterial liquid delivery pipe 4. The microbial agent enters the air bubble and bacterial liquid uniform distribution integrated device 6 through the adapter 5, and is delivered to the groundwater from the bacterial liquid delivery port 8.

[0041] Step 5: By controlling the flow of the ultrafine bubble generator 1 and the bacterial liquid storage device 3, adjusting the aeration volume and the amount of bacterial agent added, ensuring that the ultrafine bubble retention time matches the microbial agent remediation cycle, ensuring that the ultrafine bubble action area matches the microbial agent action range, and ensuring the microbial remediation effect of groundwater. Oxygen supply is a factor that limits the degradation of benzene series in groundwater at contaminated sites. Ultrafine bubbles have a high specific surface area and a long retention time, which can significantly increase the dissolved oxygen concentration. Ordinary bubbles float 1m in water for less than ten minutes and exist for several hours. In contrast, ultrafine bubbles float 1m for more than 21 days and exist for more than 90 days, which can homogenously increase dissolved oxygen. The research results show that when the dissolved oxygen concentration is increased by 2-3 mg / L, the degradation rate of benzene series by microorganisms is increased, among which the biodegradation rate of benzene is increased by more than 60%. The remediation of contaminated groundwater at the site meets the standards within the 90-day remediation period.

[0042] Through the above steps, the bubble and bacterial liquid uniform distribution integrated device 6 of this embodiment can significantly expand the scope of action of the bacterial liquid, achieve uniform dispersion of the bacterial liquid in groundwater, and improve the microbial remediation effect of groundwater through the long-term action of ultrafine bubbles and the full and uniform mixing of bubbles and bacterial liquid.

[0043] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A device for groundwater microbial remediation, characterized in that: It comprises an ultrafine bubble generator (1), a bubble delivery pipe (2), a bacterial liquid storage device (3), a bacterial liquid delivery pipe (4), an adapter (5), and an integrated device for evenly distributing bubbles and bacterial liquid (6); The integrated device (6) for uniformly distributing air bubbles and bacterial liquid comprises a gas zone and a bacterial liquid zone which are not connected to each other, wherein the gas zone is connected to a bubble delivery pipe (2), and the bacterial liquid zone is connected to a bacterial liquid delivery pipe (4); the integrated device (6) for uniformly distributing air bubbles and bacterial liquid is a cylindrical structure, and an aeration head (7) is uniformly distributed on the side of the gas zone, and a bacterial liquid delivery port (8) is uniformly distributed on the side of the bacterial liquid zone; the air outlet direction of the aeration head (7) is perpendicular to the diameter direction of the cylinder, and the integrated device (6) for uniformly distributing air bubbles and bacterial liquid can rotate when the aeration head (7) sprays gas; The ultrafine bubble generator (1) is connected to the adapter (5) via a bubble delivery pipe (2), the bacterial liquid storage device (3) is connected to the adapter (5) via a bacterial liquid delivery pipe (4), and the adapter (5) is connected to an integrated device (6) for uniformly distributing bubbles and bacterial liquid at the bottom.

2. The device for groundwater microbial remediation according to claim 1, characterized in that: The ultrafine bubble generator (1) and the bacterial liquid storage device (3) are placed on the ground of the area where groundwater is to be restored.

3. The device for groundwater microbial remediation according to claim 1, characterized in that: The ultrafine bubble generator (1) is made of metal and / or corrosion-resistant material; The diameter of the bubbles generated by the ultrafine bubble generator (1) is less than 1000nm, the internal pressure of the bubbles is 3-10bar, the floating time of 1m is more than 21 days, the retention time is more than 90 days, and the bubble density is more than 10 8 Pieces / mL.

4. The device for groundwater microbial remediation according to claim 1, characterized in that: The air bubble and bacterial liquid uniform distribution integrated device (6) is made of plastic composite material and / or corrosion-resistant material; The ratio of the height to diameter of the cylinder of the integrated device (6) for uniformly distributing air bubbles and bacterial liquid is 1 to 4:

1.

5. The device for groundwater microbial remediation according to claim 1, characterized in that: The cylindrical side surface of the integrated device (6) for uniformly distributing air bubbles and bacterial liquid is divided into two parts corresponding to the gas area and the bacterial liquid area respectively; the aeration head (7) occupies half of the area of ​​the cylindrical side surface; and the bacterial liquid delivery port (8) occupies half of the area of ​​the cylindrical side surface.

6. The device for groundwater microbial remediation according to claim 1, characterized in that: The diameter of the aeration hole (7) is 1 to 3 mm.

7. The device for groundwater microbial remediation according to claim 1, characterized in that: The diameter of the bacterial liquid delivery port (8) is 1 to 5 mm.

8. The device for groundwater microbial remediation according to claim 1, characterized in that: The bacterial liquid storage device (3) stores the microbial degradation agent; The microbial degradation agents include Bacillus subtilis and Pseudomonas vermifuge.

9. A method for groundwater microbial remediation, characterized in that: A device for groundwater microbial remediation according to any one of claims 1 to 8; The method for groundwater microbial remediation comprises: The ultrafine bubble generator (1) is started, and ultrafine bubbles are transported to the gas zone through the bubble transport pipe (2), and the bubbles are ejected through the aeration head (7). The asymmetric force generated when the ultrafine bubbles are ejected causes the bubble and bacterial liquid uniform distribution integrated device (6) to rotate; The bacterial liquid storage device (3) is started, and the microbial bacterial liquid is transported to the bacterial liquid area through the bacterial liquid transport pipe (4). The microbial bacterial liquid is evenly input into the groundwater from the bacterial liquid transport port (8) during the rotation of the air bubble and bacterial liquid uniform distribution integrated device (6).

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