A heavy metal contaminated soil chemical leaching remediation device and leaching remediation method

Abstract

The application relates to the technical field of soil remediation, and particularly discloses a heavy metal contaminated soil chemical leaching remediation device and a leaching remediation method. The heavy metal contaminated soil chemical leaching remediation device comprises a reaction tank provided with a containing cavity on the top side and a plurality of disturbance assemblies. A baffle plate is arranged in the containing cavity of the reaction tank, and the baffle plate forms a spiral flow channel in the containing cavity of the reaction tank. The disturbance assembly comprises a pipe body arranged in the spiral flow channel. A liquid driving assembly is arranged on the pipe body. A power assembly for driving the pipe body to move in the spiral flow channel is arranged on the baffle plate or the reaction tank. The heavy metal contaminated soil chemical leaching remediation device reduces energy consumption, reduces the input ratio of remediation reagents, and saves the cost of remediation reagents. The heavy metal contaminated soil chemical leaching remediation method forms multidimensional disturbance in the spiral flow channel, effectively breaks the laminar flow state of the mud, promotes the mixing of the reagents and the mud, and improves the uniformity and efficiency of the remediation reaction.

Description

Technical Field

[0001] This invention relates to the manufacture of special environmental protection equipment for the prevention and control of heavy metal pollution, and particularly to the field of soil remediation technology, specifically a chemical leaching remediation device and leaching remediation method for heavy metal contaminated soil. Background Technology

[0002] Ex-situ leaching of contaminated soil is commonly used to remediate soil contaminated with one or more heavy metals such as arsenic, lead, cadmium, mercury, nickel, and copper. This technology uses remediation agents to complex or dissolve the heavy metal pollutants, causing them to transfer from the solid phase of the soil to the liquid phase, thus purifying the soil. An ex-situ leaching system for contaminated soil includes a mud-rock separation and slurry preparation system, a particle size classification system, a chemical leaching system, a mud-water separation system, a wastewater treatment system, and a control system.

[0003] Existing chemical leaching systems typically use mechanically stirred reaction tanks as the core processing unit. The mud and remediation agents are added to the reaction tank in proportion, and then the motor drives the stirring blades to rotate, causing the mud to flow and allowing the remediation agents and heavy metals to react in contact. In order to overcome the tendency of soil particles to settle, a high-power motor is often required to keep the soil particles in the mud suspended. When facing reaction tanks with a large aspect ratio, the energy consumption required to maintain the required shear force is large, which increases the cost of soil remediation. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the existing defects and provide a chemical leaching remediation device and method for heavy metal contaminated soil. The chemical leaching remediation device for heavy metal contaminated soil reduces energy consumption, and while ensuring the precipitation effect of heavy metals, it reduces the input ratio of remediation agents, saves the cost of remediation agents, and also reduces the load on subsequent wastewater treatment. The chemical leaching remediation method for heavy metal contaminated soil forms multi-dimensional disturbances in the spiral flow channel, effectively breaking the laminar flow state of the mud, promoting the mixing of agents and mud, and improving the uniformity and efficiency of the remediation reaction.

[0005] The technical solution adopted by this invention to solve its technical problem includes: On the one hand, a chemical leaching remediation device for heavy metal contaminated soil is provided, including a reaction tank with a accommodating cavity on the top side and several disturbance components. The accommodating cavity of the reaction tank is provided with a spirally arranged baffle plate, which forms a spiral flow channel in the accommodating cavity of the reaction tank.

[0006] The disturbance component includes a tube located within the spiral flow channel, a liquid drive component mounted on the tube, and a power component that drives the tube to move within the spiral flow channel, mounted on the baffle plate or the reaction vessel.

[0007] The reaction vessel contains slurry in its accommodating cavity. Slurry flows into the pipe body, and the liquid drive component is located in the slurry. The power component drives the pipe body and the liquid drive component to move back and forth in the spiral flow channel, and the liquid drive component causes the slurry in the pipe body to flow upward or downward.

[0008] As a preferred embodiment of the present invention, the liquid drive assembly includes a motor mounted on the pipe body, and a plurality of blades are mounted on the power output shaft of the motor.

[0009] As a preferred embodiment of the present invention, the outer periphery of the tube body is provided with a plurality of openings connecting the inside and outside of the tube body, and the ratio of the sum of the cross-sectional areas of all the openings to the cross-sectional area of ​​the inner cavity of the tube body is 1.0:5.0-20.0.

[0010] All the openings are located above the blades, and the top of the tube is above the surface of the mud.

[0011] As a preferred embodiment of the present invention, an elastic base plate is provided between the bottom of the baffle plate and the bottom side of the reaction vessel accommodating cavity.

[0012] The distance between the bottom of the pipe and the base plate is 5.0mm-20.0mm, and the liquid drive component causes the mud inside the pipe to flow upward.

[0013] As a preferred embodiment of the present invention, an elastic tube is installed at the bottom of the tube body.

[0014] As a preferred embodiment of the present invention, the power assembly includes a mounting base, on which a rotating limiting roller and a driving roller are mounted, and the tube body is mounted on the mounting base via a fixing frame.

[0015] As a preferred embodiment of the present invention, the drive roller is replaced by a hub motor, and a conductive ring is installed on the mounting base.

[0016] As a preferred embodiment of the present invention, a retaining ring is fixed on the limiting roller, and the bottom side of the retaining ring abuts against the top of the baffle plate.

[0017] As a preferred embodiment of the present invention, it further includes a spray pipe and a mud conveying pipe, wherein a plurality of nozzles are installed on the spray pipe.

[0018] On the other hand, a method for chemical leaching remediation of heavy metal contaminated soil is also provided, which is applied to any of the aforementioned chemical leaching remediation devices for heavy metal contaminated soil, and includes the following steps: The external mud enters one end of the spiral channel at a set flow rate, while the repair agent is sprayed onto the mud flowing into the spiral channel, so that the repair agent and mud come into contact and mix in real time.

[0019] After the slurry in the reaction vessel cavity rises to the predetermined level, the pipe body and the liquid drive assembly are both located inside the slurry, with the top of the baffle plate above the slurry surface.

[0020] The power unit and the liquid drive unit are activated. The power unit drives the pipe and the liquid drive unit to move back and forth in the spiral flow channel, and the liquid drive unit causes the mud in the pipe to flow upward or downward.

[0021] By extracting or using gravity flow, the slurry at the end furthest from the slurry feed point in the spiral channel is drawn out, maintaining a continuous flow of slurry from one end to the other within the spiral channel.

[0022] Compared with the prior art, the beneficial effects of the present invention are: 1. The chemical leaching remediation device for heavy metal contaminated soil of the present invention lifts the heavy soil particles in the lower layer to the upper layer or presses the light soil particles in the upper layer and the remediation agent into the lower layer, eliminating the stratification of soil particles in the reaction tank, reducing the mixing blind zone in the reaction tank, ensuring full contact between the remediation agent and soil particles, reducing energy consumption, and reducing the input ratio of remediation agent while ensuring the heavy metal leaching effect, saving the cost of remediation agent, and also reducing the load on subsequent wastewater treatment.

[0023] 2. The chemical leaching remediation device for heavy metal contaminated soil of the present invention has several openings on the outer periphery of the pipe body that connect the inside and outside of the pipe body along the axial direction of the pipe body. When the mud in the pipe body flows downward, the mud in each vertical part of the reaction tank is forced to the bottom of the reaction tank cavity, and the heavy soil particles in the lower layer are dispersed by jet, reducing the sedimentation and caking of the mud at the bottom of the cavity.

[0024] 3. In the heavy metal contaminated soil chemical leaching remediation device of the present invention, the mud in the tube flows upward and the deformation of the bottom plate causes the mud that has settled and hardened on the bottom plate to detach from the bottom plate, which solves the problem that the settled and hardened mud and the remediation agent cannot effectively contact each other and improves the reaction rate of the remediation agent.

[0025] 4. The chemical leaching remediation method for heavy metal contaminated soil exemplified in this invention creates multi-dimensional disturbances within the spiral channel, effectively breaking the laminar flow state of the mud, promoting the mixing of the agent and the mud, and improving the uniformity and efficiency of the remediation reaction. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an embodiment of the present invention; Figure 2 for Figure 1 Enlarged schematic diagram of the structure at point A; Figure 3 This is a schematic diagram of the exploded structure of the present invention; Figure 4 This is a top view of the structure of the present invention; Figure 5 This is a schematic diagram of the disturbance component structure of the present invention.

[0027] In the diagram: 1. Reaction tank, 2. Baffle plate, 3. Disturbance assembly, 301. Limiting roller, 302. Drive roller, 303. Mounting base, 304. Pipe body, 305. Conductive ring, 306. Snap ring, 307. Opening, 4. Spray pipe, 5. Nozzle, 6. Slurry conveying pipe, 7. Base plate, 8. Liquid drive assembly, 801. Motor, 802. Blade, 9. Elastic tube. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Example 1: Please refer to Figures 1-5 This embodiment discloses a chemical leaching remediation device for heavy metal contaminated soil, including a reaction tank 1 with a accommodating cavity on the top side and several disturbance components 3. The accommodating cavity of the reaction tank 1 is provided with a spirally arranged baffle 2. The bottom of the baffle 2 abuts against the bottom side of the accommodating cavity of the reaction tank 1, and the baffle 2 forms a spiral flow channel in the accommodating cavity of the reaction tank 1.

[0030] The disturbance component 3 includes a tube 304 located in the spiral flow channel, a liquid drive component 8 installed on the tube 304, and a power component that drives the tube 304 to move in the spiral flow channel is installed on the baffle 2 or the reaction vessel 1.

[0031] The reaction vessel 1 contains mud in its accommodating cavity. The pipe 304 is vertically arranged, and both the pipe 304 and the liquid driving component 8 are located in the mud. The liquid driving component 8 causes the mud in the pipe 304 to flow upward or downward.

[0032] This embodiment also includes a spray pipe 4 and a mud conveying pipe 6. Several nozzles 5 are installed on the spray pipe 4. External mud flows into the containment cavity of the reaction tank 1 through the mud conveying pipe 6. External repair agent is sprayed into the reaction tank 1 through the spray pipe 4 and the nozzles 5. The position of the repair agent spraying coincides with the position of the mud flowing into the containment cavity of the reaction tank 1.

[0033] Furthermore, the projection of the baffle 2 onto the horizontal plane is an equidistant spiral shape.

[0034] The working process and principle of this embodiment are as follows: The operator directs external mud into one end of the spiral channel at a set flow rate through the mud conveying pipe 6. The operator then sprays external repair agent onto one end of the spiral channel through the spray pipe 4 and nozzle 5. The spraying position of the repair agent coincides with the position where the mud flows into the spiral channel. After the mud in the containment chamber of the reaction tank 1 rises to the predetermined liquid level, mud flows into the pipe body 304. Both the pipe body 304 and the liquid drive component 8 are located inside the mud, and the top of the baffle plate 2 is higher than the liquid surface of the mud.

[0035] The operator activates both the power unit and the liquid drive unit 8. The power unit drives the pipe 304 and the liquid drive unit 8 to move back and forth within the spiral flow channel. The liquid drive unit 8 causes the slurry in the pipe 304 to flow upwards or downwards. The upper and lower layers of slurry mix within the spiral flow channel, lifting the heavier soil particles from the lower layer to the upper layer or pressing the lighter soil particles and remediation agent from the upper layer into the lower layer. This eliminates the stratification of soil particles within the reaction tank 1, reduces the mixing blind zone within the reaction tank 1, and ensures that the large-diameter soil particles and remediation agent in the slurry are evenly mixed. The remediation agent and soil particles are in full contact, and the remediation agent penetrates into the internal pore structure of the soil particles. This results in more complete and thorough precipitation of heavy metals from the soil particles, reducing energy consumption. While ensuring the effectiveness of heavy metal precipitation, the input ratio of remediation agent is reduced, saving remediation agent costs and also reducing the load on subsequent wastewater treatment.

[0036] Workers use an external liquid pump to draw mud from the end of the spiral channel away from the mud feed, or workers allow the mud from the end of the spiral channel away from the mud feed to flow out under gravity.

[0037] The power unit drives the pipe body 304 and the liquid drive component 8 to move back and forth in the spiral flow channel, so that the vertical circulation circulation area can act on every position of the container cavity of the reaction tank 1, ensuring that every part of the mud in the entire reaction tank 1 can participate in the circulation mixing.

[0038] Example 2: Figure 5 As shown, this embodiment discloses a chemical leaching remediation device for heavy metal contaminated soil. Its structure is roughly the same as that of Embodiment 1. The difference is that the liquid drive component 8 in this embodiment includes a motor 801 installed on the pipe body 304, and a number of blades 802 are installed on the power output shaft of the motor 801.

[0039] Furthermore, the motor 801 is a waterproof motor, and a conductive ring 305 is installed on the mounting base 303. The motor 801 is electrically connected to an external control switch through the conductive ring 305.

[0040] The working process and principle of this embodiment are as follows: Motor 801 drives blade 802 to rotate, causing the mud in pipe 304 to flow upward or downward.

[0041] Furthermore, the liquid drive assembly 8 is replaced with a pump-jet propulsion unit.

[0042] Example 3: Figure 3 and Figure 5 As shown, this embodiment discloses a chemical leaching remediation device for heavy metal contaminated soil. Its structure is roughly the same as that of Embodiment 2. The difference is that in this embodiment, a number of openings 307 connected to the inside and outside of the tube body 304 are provided on the outer periphery of the tube body 304 along the axial direction of the tube body 304. The ratio of the sum of the cross-sectional areas of all the openings 307 to the cross-sectional area of ​​the inner cavity of the tube body 304 is 1.0:5.0-20.0.

[0043] All the openings 307 are located higher than the blades 802, and the top of the tube 304 is located above the mud surface.

[0044] The working process and principle of this embodiment are as follows: As the slurry in the pipe 304 flows upward, it flows through the opening 307 to different vertical positions in the reaction tank 1, causing the lower layer of heavy soil particles to mix with the slurry in various vertical positions of the reaction tank 1, forming an axial circulation.

[0045] As the mud in the pipe 304 flows downward, the mud in each vertical part of the reaction tank 1 is forced to the bottom of the container cavity of the reaction tank 1, and the heavy soil particles in the lower layer are dispersed by the jet, reducing the sedimentation and caking of the mud at the bottom of the container cavity.

[0046] Example 4: Figure 3 As shown, this embodiment discloses a chemical leaching remediation device for heavy metal contaminated soil. Based on any of the embodiments from Embodiment 1 to Embodiment 3, this embodiment has an elastic bottom plate 7 between the bottom of the baffle plate 2 and the bottom side of the accommodating cavity of the reaction tank 1.

[0047] The distance between the bottom of the pipe body 304 and the base plate 7 is 5.0mm-20.0mm, and the liquid drive component 8 causes the mud in the pipe body 304 to flow upward.

[0048] The working process and principle of this embodiment are as follows: The slurry inside the pipe 304 flows upward. The slurry flow rate between the pipe 304 and the base plate 7 is fast, which reduces the hydraulic pressure at the position of the base plate 7 corresponding to the pipe 304. This causes the position of the base plate 7 corresponding to the pipe 304 to bulge outward. The deformation of the base plate 7 facilitates the detachment of the slurry that has settled and hardened on the base plate 7. The slurry that has settled and hardened collides and breaks with the inner wall of the base plate 7, and the liquid drive component 8 breaks up the slurry that has settled and hardened slurry. This solves the problem that the slurry that has settled and hardened slurry and the repair agent cannot effectively contact each other, and improves the reaction rate of the repair agent.

[0049] Example 5: Figure 3 and Figure 5 As shown, this embodiment discloses a chemical leaching remediation device for heavy metal contaminated soil. Its structure is roughly the same as that of Embodiment 4. The difference is that in this embodiment, an elastic tube 9 is installed at the bottom of the tube body 304, and the distance between the bottom of the elastic tube 9 and the bottom plate 7 is 3.0mm-10.0mm.

[0050] The working process and principle of this embodiment are as follows: When the sludge that has settled on the bottom plate 7 cannot be removed, the elastic tube 9 deforms when it passes through the sludge, thus preventing damage to the tube body 304.

[0051] Example 6: Figure 1 and Figure 2 As shown, this embodiment discloses a chemical leaching remediation device for heavy metal contaminated soil. Its structure is roughly the same as that of Embodiment 1. The difference is that the power component of this embodiment includes a mounting base 303, on which a rotating limiting roller 301 and a drive roller 302 are mounted. The tube body 304 is mounted on the mounting base 303 through a fixing frame.

[0052] The working process and principle of this embodiment are as follows: The limiting roller 301 and the driving roller 302 clamp the baffle plate 2, so that the tube body 304 can move back and forth along the baffle plate 2.

[0053] Preferably, the drive roller 302 is replaced by a hub motor, and a conductive ring 305 is installed on the mounting base 303. The hub motor is electrically connected to an external control switch through the conductive ring 305. The hub motor and the limit roller 301 cooperate to drive the tube body 304 to move along the baffle plate 2; or the mounting base 303 is equipped with a drive device that drives the drive roller 302 to rotate. The drive device is an electric motor, a pneumatic motor or a hydraulic motor.

[0054] Furthermore, both ends of the top of the baffle 2 are provided with limiting components to prevent the power assembly from detaching from the baffle 2, or a limit switch is installed on the mounting base 303.

[0055] Example 7: Figure 2 As shown, this embodiment discloses a chemical leaching remediation device for heavy metal contaminated soil. Its structure is roughly the same as that of Embodiment Six. The difference is that in this embodiment, a retaining ring 306 is fixed on the limiting roller 301. The bottom side of the retaining ring 306 abuts against the top of the baffle plate 2. The retaining ring 306 fixes the height of the tube body 304 in the spiral flow channel, thereby improving the reliability of this chemical leaching remediation device for heavy metal contaminated soil.

[0056] Example 8: This example discloses a chemical leaching remediation method for heavy metal contaminated soil, applied to the chemical leaching remediation device for heavy metal contaminated soil in any one of Examples 1 to 7, including the following steps: The external mud enters one end of the spiral channel at a set flow rate, while the repair agent is sprayed onto the mud flowing into the spiral channel, so that the repair agent and mud come into contact and mix in real time.

[0057] After the slurry in the containment chamber of reaction vessel 1 rises to the predetermined liquid level, both pipe body 304 and liquid drive assembly 8 are located inside the slurry, and the top of baffle plate 2 is higher than the liquid surface of the slurry.

[0058] Start the power unit and the liquid drive unit 8. The power unit drives the pipe body 304 and the liquid drive unit 8 to move back and forth in the spiral flow channel. The liquid drive unit 8 causes the mud in the pipe body 304 to flow upward or downward.

[0059] By extracting or using gravity flow, the slurry at the end furthest from the slurry feed point in the spiral channel is drawn out, maintaining a continuous flow of slurry from one end to the other within the spiral channel.

[0060] This chemical leaching remediation method for heavy metal contaminated soil mixes the slurry and reagents in real time at the inlet, avoiding reagent lag or uneven distribution. Utilizing the reciprocating movement of the pipe and the vertical circulation of the slurry, multi-dimensional disturbances are created within the spiral flow channel, effectively breaking the laminar flow state of the slurry, promoting the mixing of reagents and slurry, and improving the uniformity and efficiency of the remediation reaction. At the same time, the liquid level control and continuous discharge design prevent slurry sedimentation and blockage, achieving efficient and controllable slurry remediation.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A chemical leaching remediation device for heavy metal contaminated soil, characterized in that: The reaction vessel (1) includes a accommodating cavity on its top side and several disturbance components (3). The accommodating cavity of the reaction vessel (1) is provided with a spirally arranged baffle (2), which causes a spiral flow channel to be formed in the accommodating cavity of the reaction vessel (1). The disturbance component (3) includes a tube (304) located in the spiral channel, a liquid drive component (8) is installed on the tube (304), and a power component that drives the tube (304) to move in the spiral channel is installed on the baffle (2) or the reaction vessel (1). The reaction vessel (1) contains slurry in its accommodating cavity. Slurry flows into the pipe (304). The liquid drive assembly (8) is located in the slurry. The power assembly drives the pipe (304) and the liquid drive assembly (8) to move back and forth in the spiral channel. The liquid drive assembly (8) causes the slurry in the pipe (304) to flow upward or downward.

2. The chemical leaching remediation device for heavy metal contaminated soil according to claim 1, characterized in that: The liquid drive assembly (8) includes a motor (801) mounted on a tube (304), and a plurality of blades (802) are mounted on the power output shaft of the motor (801).

3. The chemical leaching remediation device for heavy metal contaminated soil according to claim 2, characterized in that: The outer periphery of the tube (304) is provided with a number of openings (307) that connect the inside and outside of it. The ratio of the sum of the cross-sectional areas of all the openings (307) to the cross-sectional area of ​​the inner cavity of the tube (304) is 1.0:5.0-20.

0. All the openings (307) are located above the blades (802), and the top of the tube (304) is located above the surface of the mud.

4. The chemical leaching remediation device for heavy metal contaminated soil according to any one of claims 1-3, characterized in that: An elastic bottom plate (7) is provided between the bottom of the baffle (2) and the bottom side of the cavity of the reaction vessel (1). The distance between the bottom of the pipe body (304) and the base plate (7) is 5.0mm-20.0mm, and the liquid drive component (8) causes the mud in the pipe body (304) to flow upward.

5. The chemical leaching remediation device for heavy metal contaminated soil according to claim 4, characterized in that: An elastic tube (9) is installed at the bottom of the tube body (304).

6. The chemical leaching remediation device for heavy metal contaminated soil according to claim 1, characterized in that: The power assembly includes a mounting base (303), on which a rotating limiting roller (301) and a drive roller (302) are mounted, and the tube body (304) is mounted on the mounting base (303) by a fixing frame.

7. The chemical leaching remediation device for heavy metal contaminated soil according to claim 6, characterized in that: The drive roller (302) is replaced by a hub motor, and a conductive ring (305) is installed on the mounting base (303).

8. The chemical leaching remediation device for heavy metal contaminated soil according to claim 6, characterized in that: A retaining ring (306) is fixed on the limiting roller (301), and the bottom side of the retaining ring (306) abuts against the top of the baffle plate (2).

9. The chemical leaching remediation device for heavy metal contaminated soil according to claim 1, characterized in that: It also includes a spray pipe (4) and a mud conveying pipe (6), on which a plurality of nozzles (5) are installed.

10. A method for chemical leaching remediation of heavy metal contaminated soil, applied to the chemical leaching remediation apparatus for heavy metal contaminated soil as described in any one of claims 1-9, characterized in that, Includes the following steps: The external mud enters one end of the spiral channel at a set flow rate, while the repair agent is sprayed onto the mud flowing into the spiral channel, so that the repair agent and mud come into contact and mix in real time. After the mud in the container of the reaction vessel (1) rises to the predetermined liquid level, the pipe body (304) and the liquid drive assembly (8) are both located in the mud, and the top of the baffle (2) is higher than the liquid surface of the mud. Start the power assembly and the liquid drive assembly (8). The power assembly drives the pipe body (304) and the liquid drive assembly (8) to move back and forth in the spiral flow channel. The liquid drive assembly (8) causes the mud in the pipe body (304) to flow upward or downward. By extracting or using gravity flow, the slurry at the end furthest from the slurry feed point in the spiral channel is drawn out, maintaining a continuous flow of slurry from one end to the other within the spiral channel.

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