A soil heavy metal separation device and a separation method

Abstract

This application relates to a soil heavy metal separation device and method. The soil heavy metal separation device includes: a crushing and dissolving tank, comprising a first opening, a stirring mechanism, and a water injection hole; the first opening faces a first direction; the water injection hole is located at one end of the crushing and dissolving tank along the first direction; the stirring mechanism is located inside the crushing and dissolving tank; a pretreatment water tank, connected to the crushing and dissolving tank, including a filter assembly and a sediment opening; the filter assembly is rotatably arranged around a first axis and is located at the sediment opening; the filter assembly has at least three filter surfaces and sealing ridges, at least two sealing ridges are in sealing contact with the inner wall of the pretreatment water tank, and at least one filter surface is located at the sediment opening; an electroadsorption water tank, connected to the pretreatment water tank, including a recovery opening, at least two electrodes, and at least two scraper mechanisms; the scraper mechanisms are extendable along the first direction to the recovery opening, and the scraper mechanisms abut against the electrode surfaces. This application can efficiently treat soil with a high degree of heavy metal pollution.

Description

Technical Field

[0001] This application relates to the field of heavy metal soil pollution treatment technology, and in particular to a soil heavy metal separation device and separation method. Background Technology

[0002] Through continuous exploration and development in recent years, the main remediation technologies for treating heavy metal pollution in soil include physical remediation, chemical remediation, and bioremediation. Each method has its own advantages, but also limitations. For example, bioremediation is not thorough and takes a long time. For small amounts of heavily polluted soil, existing remediation technologies are not ideal, and problems such as heavy metal reactivation and spillover exist. Summary of the Invention

[0003] Based on the above analysis, this application aims to provide a soil heavy metal separation device and separation method that can treat soil with a high degree of heavy metal pollution.

[0004] The purpose of this application is mainly achieved through the following technical solutions:

[0005] In a first aspect, embodiments of this application provide a soil heavy metal separation device, comprising: a crushing and dissolving tank, including a first opening, a stirring mechanism, and a water injection hole; the first opening faces a first direction; the water injection hole is located at one end of the crushing and dissolving tank along the first direction; the stirring mechanism is located inside the crushing and dissolving tank; a pretreatment water tank, connected to the crushing and dissolving tank, including a filter assembly and a sediment opening; the filter assembly is rotatably disposed around a first axis and disposed at the sediment opening; the filter assembly has at least three filter surfaces and sealing ridges, at least two sealing ridges are in sealing contact with the inner wall of the pretreatment water tank, and at least one filter surface is located at the sediment opening; an electroadsorption water tank, connected to the pretreatment water tank, including a recovery opening, at least two electrodes, and at least two scraper mechanisms; the scraper mechanisms are extendable and retractable along the first direction to the recovery opening, and the scraper mechanisms abut against the electrode surfaces.

[0006] According to an embodiment of the first aspect of this application, along a first direction, a crushing and dissolving tank, a pretreatment water tank, and an electro-adsorption water tank are arranged sequentially at intervals; the crushing and dissolving tank includes a first outlet, the pretreatment water tank includes a second inlet and a second outlet, and the electro-adsorption water tank includes a third inlet and a third outlet, with the first outlet connected to the second inlet and the second outlet connected to the third inlet.

[0007] According to an embodiment of the first aspect of this application, the stirring mechanism includes: a stirring shaft extending along a first direction, the stirring shaft being retractable along the first direction; a plurality of first stirring rods extending radially along the stirring shaft and evenly distributed circumferentially along the stirring shaft; a plurality of second stirring rods evenly distributed circumferentially along the stirring shaft, the second stirring rods being located on the side of the first stirring rods away from the first opening; the second stirring rods include a main rod and a plurality of auxiliary rods, the main rod extending radially along the stirring shaft, the plurality of auxiliary rods being evenly distributed circumferentially along the main rod, and the plurality of auxiliary rods being located on the same conical surface coaxial with the main rod.

[0008] According to an embodiment of the first aspect of this application, the filter assembly includes: a roller hinged to the inner wall of a pretreatment tank; a drum coaxially arranged with the roller; the drum being a prism with a regular polygonal cross-section; each side of the drum having an opening and communicating with a second outlet; a plurality of filter screens located on each side of the drum to form a plurality of filter surfaces; and a plurality of sealing strips located on each side edge of the drum to form a plurality of sealing edges.

[0009] According to an embodiment of the first aspect of this application, each side of the roller is a concave curved surface, and the axis of each curved surface is parallel to the first axis; the sealing strip protrudes relative to the filter screen.

[0010] According to an embodiment of the first aspect of this application, a third inlet and a third outlet are arranged along a second direction, and the first direction and the second direction are perpendicular to each other; a water outlet filter is provided at the third outlet; at least two electrodes are parallel to each other, both parallel to the first direction and both parallel to the second direction.

[0011] According to an embodiment of the first aspect of this application, the scraper mechanism includes: a first drive assembly having a first telescopic end along a third direction; the third direction, the first direction, and the second direction are mutually perpendicular; a second drive assembly connected to the first telescopic end and having a second telescopic end along the first direction; and a scraper assembly connected to the second telescopic end.

[0012] According to an embodiment of the first aspect of this application, the scraper assembly includes: a blade body extending along a second direction and inclined relative to the electrode surface toward the direction away from the outlet; a slag collection tank extending along the second direction; one end of the slag collection tank along a third direction is connected to the blade body, and the other end is connected to a second telescopic end.

[0013] Secondly, embodiments of this application provide a method for separating heavy metals in soil, using the soil heavy metal separation equipment of the first aspect of this application. The method includes: excavating soil contaminated with heavy metals, breaking the soil and pouring it into the first opening of a crushing and dissolving tank; adding water through a water injection hole, while simultaneously mixing the soil and water through a stirring mechanism to form a mixture; passing the mixture into a pretreatment water tank, filtering the mixture to obtain a filtrate and a filtrate; rotating the filter assembly so that the filtrate and the filter surface rotate together to a sediment opening to recover sediment; passing the filtrate into an electro-adsorption water tank, electrolyzing the filtrate to obtain a residual liquid and a heavy metal mixture; scraping off and collecting the heavy metal mixture on the electrodes through a scraper mechanism and recovering it.

[0014] An embodiment of the second aspect of this application involves passing the filtrate into an electro-adsorption water tank, electrolyzing the filtrate to obtain a mixture of residual liquid and heavy metals, including: recovering the residual liquid, filtering and removing impurities from the residual liquid, and adding it to a crushing and dissolving tank.

[0015] Compared with the prior art, the technical solution of this application can achieve at least one of the following effects:

[0016] 1. In the soil heavy metal separation equipment provided in this application, the crushing and dissolving tank can crush and mix the soil contaminated with heavy metals into a mixed liquid; the pretreatment tank can pretreat the mixed liquid, filter and recover the silt in the wastewater; and the electroadsorption tank can electrolyze the heavy metal pollutants in the filtrate, causing them to precipitate and be recovered. Therefore, the soil heavy metal separation equipment of this application embodiment can realize the separation of heavy metals in soil.

[0017] 2. In the pretreatment water tank of this application embodiment, the filter assembly is located at the second outlet and can rotate, so that the mixed liquid must pass through the filter assembly for filtration; at the same time, the filter assembly can rotate, and when the sediment on one of the filter surfaces accumulates to a certain extent, the filter assembly can be rotated so that the other filter surface can continue to filter, while the first filter surface will rotate away the accumulated sediment, so as to facilitate the real-time recovery of sediment.

[0018] 3. The electro-adsorption water tank in this application embodiment realizes the electrolysis of heavy metal pollutants through the electric field formed between the electrodes, so that the heavy metal mixture is precipitated on the electrodes. At the same time, the scraper assembly can directly scrape the heavy metal mixture off the electrodes to facilitate the real-time recovery of the heavy metal mixture.

[0019] In this application, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this application will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing this application. The objectives and other advantages of this application can be realized and obtained from the specific points highlighted in the description and accompanying drawings. Attached Figure Description

[0020] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Throughout the drawings, the same reference numerals denote the same parts.

[0021] Figure 1 This is a schematic diagram of a soil heavy metal separation device according to an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the internal structure of a soil heavy metal separation device according to an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the stirring mechanism according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the structure of a filtering component according to an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the scraper mechanism according to an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of a scraper assembly according to an embodiment of this application;

[0027] Figure 7 This is a flowchart of a soil heavy metal separation method according to an embodiment of this application;

[0028] Figure label:

[0029] 1. Crushing and dissolving tank; 11. First opening; 12. Stirring mechanism; 121. First stirring rod; 122. Second stirring rod; 122a. Main rod; 122b. Secondary rod; 123. Stirring shaft; 13. Water injection hole; 14. First outlet;

[0030] 2. Pretreatment water tank; 21. Second inlet; 22. Second outlet; 23. Filter assembly; 23a. Filter surface; 23b. Sealing ridge; 231. Roller; 232. Drum; 233. Filter screen; 234. Sealing strip; 24. Cleaning port; 25. Divider plate;

[0031] 3. Electro-adsorption water tank; 31. Electrode; 32. Scraper mechanism; 321. First drive assembly; 322. Second drive assembly; 323. Scraper assembly; 323a. Scraper body; 323b. Sludge collection tank; 33. Third inlet; 34. Third outlet; 35. Water outlet filter screen;

[0032] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0033] The preferred embodiments of this application are described in detail below with reference to the accompanying drawings, which constitute a part of this application and are used together with the embodiments of this application to illustrate the principles of this application, but are not intended to limit the scope of this application.

[0034] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the term "connected" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] Throughout the text, the terms “top,” “bottom,” “above,” “below,” and “on top” refer to the relative positions of components of the device, such as the relative positions of the top and bottom substrates within the device. It is understood that the device is multifunctional and independent of its spatial orientation.

[0036] The applicant discovered that when treating soil contaminated with heavy metals, the degree of contamination often exceeds the capacity of heavy metal separation equipment, resulting in the continued presence of heavy metal contamination after treatment. To more effectively separate heavy metals from the soil, multiple treatments are typically performed, essentially repeating a single treatment process, which is complex. Therefore, treating soil with a high degree of heavy metal contamination often results in low efficiency and low quality.

[0037] Based on the above analysis, the applicant proposes a soil heavy metal separation device, including a crushing and dissolving tank, a pretreatment water tank, and an electro-adsorption water tank. The crushing and dissolving tank crushes and mixes the heavy metal-contaminated soil into a liquid mixture, facilitating subsequent treatment. The pretreatment water tank filters sediment from the liquid mixture. The filter assembly has at least three filter surfaces. When sediment accumulates on one filter surface to a certain extent, the filter assembly can be rotated so that a new filter assembly can still be used for filtration. The filter surface with accumulated sediment can be recycled, thus continuously filtering the liquid mixture. Simultaneously, the electro-adsorption water tank electrolyzes the filtrate. A scraper mechanism scrapes off the heavy metal mixture deposited on the electrodes, thus continuously electrolyzing the filtrate. Because it can continuously treat heavy metal-contaminated soil, the soil heavy metal separation device of this application can improve the efficiency and quality of heavy metal separation in soil.

[0038] Figure 1 This is a schematic diagram of a soil heavy metal separation device according to an embodiment of this application. Figure 2 This is a schematic diagram of the internal structure of a soil heavy metal separation device according to an embodiment of this application.

[0039] Please see Figure 1and Figure 2 This application provides a soil heavy metal separation device, including: a crushing and dissolving tank 1, including a first opening 11, a stirring mechanism 12, and a water injection hole 13; the first opening 11 faces a first direction X; the water injection hole 13 is located at one end of the crushing and dissolving tank 1 along the first direction X; the stirring mechanism 12 is located inside the crushing and dissolving tank 1; a pretreatment water tank 2, connected to the crushing and dissolving tank 1, including a filter assembly 23 and a sediment opening; the filter assembly 23 is rotatably arranged around a first axis and is located at the sediment opening; the filter assembly 23 has at least three filter surfaces 23a and sealing ridges 23b, at least two sealing ridges 23b are in sealed contact with the inner wall of the pretreatment water tank 2, and at least one filter surface 23a is located at the sediment opening; an electroadsorption water tank 3, connected to the pretreatment water tank 2, including a recovery opening, at least two electrodes 31, and at least two scraper mechanisms 32; the scraper mechanisms 32 are extendable and retractable along the first direction X to the recovery opening, and the scraper mechanisms 32 abut against the surface of the electrodes 31.

[0040] In this embodiment, the pretreatment water tank 2 is further provided with a partition plate 25, which divides the internal space of the pretreatment water tank 2 into an upper space and a lower space. The inner wall of the upper space includes the inner surface of the partition plate 25 and the inner wall of the pretreatment water tank 2 above the partition plate 25. The filter assembly 23 is disposed in the upper space, and at least two sealing edges 23b are in sealing contact with the inner wall of the upper space. For example, the partition plate 25 includes an integral arc plate and a connecting plate. The radial section of the arc plate is an arc, and the connecting plate is obliquely and sealingly connected to the inner wall of the upper space. The filter assembly 23 is rotatably disposed in the space formed by the arc plate, and the top opening of the space formed by the arc plate is a mud and sand opening.

[0041] When the soil heavy metal separation device of this application embodiment is set on a horizontal plane, the first direction X can be a vertical direction, and the second direction Y and the third direction Z can be two mutually perpendicular horizontal directions.

[0042] In this embodiment, the crushing and dissolving tank 1 is used to crush soil contaminated with heavy metals and simultaneously mix it with water to dissolve the heavy metals in the mixture. The soil contaminated with heavy metals is introduced into the crushing and dissolving tank 1 through the first opening 11, while water is injected through the water injection hole 13. The stirring mechanism 12 thoroughly mixes the soil and water, ensuring that all heavy metal pollutants in the soil dissolve in the water. Components in the soil such as silica and calcium carbonate, which are insoluble in water, are mixed into the mixture as insoluble substances. It is important to emphasize that the amount of water injected should be significantly greater than the amount of soil, so that the mixture primarily exhibits liquid characteristics. Furthermore, the injected water can be pure water, water containing impurities, or the water ultimately recovered by the soil heavy metal separation device in this embodiment.

[0043] The pretreatment tank 2 is used to filter the mixed liquor, removing insoluble substances and forming sludge that accumulates on the filter assembly 23. The pretreatment tank 2 also has a cleaning port 24 for cleaning the sludge from the filter screen 233. The filter assembly 23 has at least three filter surfaces 23a, each capable of filtering the mixed liquor independently. For example, if the filter assembly 23 has six filter surfaces 23a, each with a central angle of 60°, the corresponding central angle of the arc plate of the partition plate 25 is 240°. When sludge accumulates to a certain level on the filter surfaces 23a used for filtering the mixed liquor, it can be considered that the accumulation will affect the normal use of the filter surfaces 23a. At this point, the filter assembly 23 can be rotated by a certain angle, such as 60°, allowing the rotated filter surfaces 23a without accumulated sludge to continue filtering the mixed liquor. Simultaneously, considering the viscous flow characteristics of the sludge, it will be rotated along with the filter assembly 23 to the cleaning port 24 for easy recovery. The sediment on filter screen 233 can be cleaned and recycled manually or automatically. For example, considering the viscous flow characteristics of sediment, it can be removed from filter screen 233 using a suction device. The recycled sediment, after being treated with organic matter, pH levels, and mineral salts, can be used as backfill soil.

[0044] In the filter assembly 23, at least two sealing ridges 23b are in sealed contact with the inner wall of the pretreatment water tank 2, which can ensure that the mixture will not leak out from the gap between the filter assembly 23 and the inner wall of the pretreatment water tank 2 when the filter assembly 23 rotates, thereby giving the soil heavy metal separation device of this application embodiment good filtration capability.

[0045] The filtrate, after being filtered by the pretreatment tank 2, enters the electro-adsorption tank 3 through the second outlet 22 for electrolysis. The electro-adsorption tank 3 implements the electrolysis process via electrodes 31, with at least two electrodes 31 connected to the positive and negative electrodes respectively and immersed in the mixed solution. The heavy metal solubles in the mixed solution undergo an electrolytic reaction and precipitate on the electrodes 31, forming a heavy metal mixture, thus achieving the purpose of removing heavy metals. When the heavy metal mixture on the electrodes 31 accumulates to a certain extent, it can be considered that the heavy metal mixture will affect the electrolysis process. At this time, the scraper mechanism 32 scrapes away the heavy metal mixture on the electrodes 31 along the first direction X, allowing the electrodes 31 to perform continuous electrolysis. Simultaneously, a stirring mechanism extends from the recovery opening to facilitate the recovery of the heavy metal mixture, for example, to further refine the heavy metal elemental form.

[0046] By continuously injecting water into the crushing and dissolving tank 1 to dissolve heavy metal pollutants, and through the rotatable filter assembly 23 in the pretreatment tank 2 and the movable scraper mechanism 32 in the electro-adsorption tank 3, the soil heavy metal separation device of this application embodiment can clean and separately recover the silt on the filter assembly 23 and the heavy metal mixture on the electrode 31 while maintaining continuous treatment of heavy metal wastewater, thereby improving the treatment efficiency of heavy metal contaminated soil.

[0047] It should be noted that the residual liquid after electrolysis will still contain a certain amount of other pollutants, such as organic pollutants. Subsequent organic wastewater treatment should be carried out. After treatment, it can be injected back into the crushing and dissolving tank 1 to make full use of the water, which is beneficial to environmental protection.

[0048] Further reading Figure 1 and Figure 2 Along the first direction X, the crushing and dissolving tank 1, the pretreatment water tank 2, and the electro-adsorption water tank 3 are arranged in sequence; the crushing and dissolving tank 1 includes a first outlet 14, the pretreatment water tank 2 includes a second inlet 21 and a second outlet 22, and the electro-adsorption water tank 3 includes a third inlet 33 and a third outlet 34. The first outlet 14 is connected to the second inlet 21, and the second outlet 22 is connected to the third inlet 33; a water filter screen 35 is provided at the third outlet 34.

[0049] During the separation of heavy metals in the soil, the liquid flows sequentially through the crushing and dissolving tank 1, the pretreatment water tank 2, and the electro-adsorption water tank 3. The crushing and dissolving tank 1, the pretreatment water tank 2, and the electro-adsorption water tank 3 are arranged sequentially along the first direction X, which can utilize gravity to make the liquid flow more smoothly.

[0050] Figure 3 This is a schematic diagram of a stirring mechanism according to an embodiment of this application.

[0051] Further, please refer to Figure 3 and combined Figure 1 and Figure 2 The stirring mechanism 12 includes: a stirring shaft 123 extending along a first direction X, the stirring shaft 123 being telescopic along the first direction X; a plurality of first stirring rods 121 extending radially along the stirring shaft 123 and evenly distributed circumferentially along the stirring shaft 123; a plurality of second stirring rods 122 evenly distributed circumferentially along the stirring shaft 123, the second stirring rods 122 being located on the side of the first stirring rods 121 away from the first opening 11; the second stirring rods 122 include a main rod 122a and a plurality of auxiliary rods 122b, the main rod 122a extending radially along the stirring shaft 123, the plurality of auxiliary rods 122b being evenly distributed circumferentially along the main rod 122a, and the plurality of auxiliary rods 122b being located on the same conical surface coaxial with the main rod 122a.

[0052] The mixing mechanism 12 can move along the first direction X via the extension and retraction of the mixing shaft 123, that is, it can move up and down as a whole. At the same time, the mixing mechanism 12 can rotate as a whole via the rotation of the mixing shaft 123. Through axial movement and circumferential rotation, the mixing mechanism 12 can fully mix the soil contaminated with heavy metals with water to form a mixed liquid, so that the heavy metal pollutants are fully dissolved in the mixed liquid in the form of ions, which facilitates the subsequent separation of silt and heavy metals.

[0053] The first stirring rod 121 is located near the first opening 11, which can break up the heavy metal contaminated soil that has just been poured into the crushing and dissolving tank 1, facilitating the mixing of the heavy metal contaminated soil with water. The second stirring rod 122 is located away from the first opening 11, which can thoroughly mix the broken-up heavy metal contaminated soil with water. The main rod 122a can mix the heavy metal contaminated soil and water in a circumferential direction, while the conically arranged secondary rods 122b can further mix the heavy metal contaminated soil and water in an axial direction on the basis of circumferential mixing, so that the heavy metal pollutants in the heavy metal contaminated soil can be fully dissolved into the mixture. In addition, the first stirring rod 121 does not adopt the form of a main rod 122a and a secondary rod 122b, which makes the gaps between the multiple first stirring rods 121 larger, preventing large pieces of soil from getting stuck between the multiple first stirring rods 121.

[0054] Considering that the heavy metal mixture may be washed off the electrode 31 by the water flow of the filtrate, a water filter 35 can be installed at the third outlet 34 to ensure that the water flowing out of the third outlet 34 contains almost no insoluble matter. The remaining liquid obtained at this time may still contain organic pollutants, which need to be further purified for recycling.

[0055] Figure 4 This is a schematic diagram of a filtering component according to an embodiment of this application.

[0056] Further, please refer to Figure 4 and combined Figure 1 and Figure 2 The filter assembly 23 includes: a roller 231, hinged to the inner wall of the pretreatment water tank 2; a roller 232, coaxially arranged with the roller 231; the roller 232 is a prism with a regular polygonal cross section; each side of the roller 232 is provided with an opening and communicates with the second outlet 22; a plurality of filter screens 233 are located on each side of the roller 232 to form a plurality of filter surfaces 23a; and a plurality of sealing strips 234 are located on each side edge of the roller 232 to form a plurality of sealing edges 23b.

[0057] Roller 231 and drum 232 are coaxially arranged and can rotate synchronously. Drum 232 is a prism with a regular polygonal interface, and each side is provided with a filter screen 233 to form a filter surface 23a. During the filtration of the mixed liquid on the filter surface 23a corresponding to one side, if there is too much sediment on the filter screen 233, the drum 232 is rotated, and the filter surface 23a corresponding to that side will be opened, allowing the filter surface 23a corresponding to the next side to filter the mixed liquid. While the filter surface 23a corresponding to the next side is filtering the mixed liquid, the filter screen 233 with accumulated sediment can be cleaned and the sediment can be recovered. It should be noted that after the drum 232 rotates, the filter screen 233 with accumulated sediment is exposed at the cleaning operation port 24 to facilitate cleaning and recovery of sediment. The sealing strip 234 is located at the side edge of the drum 232 and is used to seal between the side edge of the drum 232 and the inner wall of the pretreatment water tank 2. When the drum 232 rotates, the sealing strip 234 can prevent the mixture from leaking out between the side edge and the inner wall of the pretreatment tank 2, so that the filter screen 233 with accumulated mud and sand can be cleaned and recycled smoothly.

[0058] Further reference Figure 4 Each side of the roller 232 is a concave curved surface, and the axis of each curved surface is parallel to the first axis; the sealing strip 234 protrudes relative to the filter screen 233.

[0059] Sediment has certain viscosity and flow characteristics, and it may still fall off the filter screen 233 when the drum 232 rotates. The side of the drum 232 forms a concave curved surface, and the sealing strip 234 protrudes relative to the filter screen 233, making the filter surface 23a also form a concave curved surface, thereby increasing the contact area of ​​sediment and reducing the possibility of sediment falling off. In addition, the concave filter surface 23a can also accumulate more sediment, reducing the frequency of drum 232 rotation.

[0060] Further reference Figure 1 and Figure 2 The third inlet 33 and the third outlet 34 are arranged along the second direction Y; the third inlet 33 and the second outlet 22 are connected; at least two electrodes 31 are parallel to each other, both parallel to the first direction X, and both parallel to the second direction Y.

[0061] The third inlet 33 and the third outlet 34 are arranged along the second direction Y, so that the filtrate in the electroadsorption tank 3 flows along the second direction Y. The two electrodes 31 are parallel to each other, forming a parallel plate electric field, which is parallel to both the first direction X and the second direction Y. That is, the two electrodes 31 form a parallel plate electric field with respect to the third direction Z. The filtrate flowing along the second direction Y flows directly through the two electrodes 31 and undergoes electrolysis under the action of the electric field, and is deposited on the electrodes 31 to form a heavy metal mixture.

[0062] Figure 5 This is a schematic diagram of a scraper mechanism according to an embodiment of this application.

[0063] Further, please refer to Figure 5 The scraper mechanism 32 includes: a first drive assembly 321 having a first telescopic end along a third direction Z; the third direction Z, the first direction X, and the second direction Y are perpendicular to each other; a second drive assembly 322 connected to the first telescopic end and having a second telescopic end along the first direction X; and a scraper assembly 323 connected to the second telescopic end.

[0064] The first drive assembly 321 has a first telescopic end along a third direction Z, and the second drive assembly 322 is connected to the first telescopic end. The first drive assembly 321 drives the second drive assembly 322 and the scraper assembly 323 along the third direction Z, enabling the scraper assembly 323 to move closer to or further away from the electrode 31. Exemplarily, the first drive assembly 321 can be a telescopic cylinder. The scraper assembly 323 is connected to the second telescopic end. The second drive assembly 322 drives the scraper assembly 323 along a first direction X, enabling the scraper assembly 323 to perform the action of scraping away the heavy metal mixture. Exemplarily, the second drive assembly 322 can be in the form of a slide rail slider.

[0065] When scraping off the heavy metal mixture on electrode 31, the first drive assembly 321 brings the second drive assembly 322 closer to electrode 31 and causes the scraper assembly 323 to come into contact with electrode 31. The second drive assembly 322 drives the scraper assembly 323 to move along the first direction X, scraping off the heavy metal mixture on electrode 31. The scraper assembly 323 continues to move along the first direction X and moves out of the opening of the electroadsorption water tank 3 to clean up the heavy metal mixture scraped off by the scraper.

[0066] Figure 6 This is a schematic diagram of a scraper assembly according to an embodiment of this application.

[0067] Further, please refer to Figure 6 The scraper assembly 323 includes: a blade body 323a extending along the second direction Y and inclined relative to the surface of the electrode 31 toward the direction away from the outlet; a slag collection tank 323b extending along the second direction Y; one end of the slag collection tank 323b along the third direction Z is connected to the blade body 323a, and the other end is connected to the second telescopic end.

[0068] The scraper assembly 323 moves along the first direction X to scrape off the heavy metal mixture on the electrode 31. The conductor of the scraper assembly 323 extends along the second direction Y and is inclined away from the opening direction relative to the surface of the electrode 31. As the scraper assembly 323 moves, the blade 323a can scrape off the heavy metal mixture from the surface of the electrode 31, ensuring that the heavy metal mixture can be scraped off smoothly. The slag collection tank 323b is used to collect the scraped heavy metal mixture. One end of the slag collection tank 323b is connected to the blade 323a along the third direction Z, and the other end is connected to the second telescopic end. The heavy metal mixture scraped off by the conductor will slide into the slag collection tank 323b along the inclined direction of the blade 323a. When the scraper assembly 323 is removed from the opening of the electroadsorption water tank 3, it is only necessary to clean and recover the heavy metal mixture in the slag collection tank 323b.

[0069] This application also provides a method for separating heavy metals in soil, using the soil heavy metal separation equipment described in the foregoing embodiments of this application.

[0070] Figure 7 This is a flowchart of a soil heavy metal separation method according to an embodiment of this application.

[0071] Please see Figure 7 The soil heavy metal separation method of this application includes:

[0072] S1. Excavate the soil contaminated with heavy metals, break the soil and pour it into the first opening 11 of the crushing and dissolving tank 1.

[0073] The soil contaminated with heavy metals can be excavated manually or automatically and then poured into the crushing and dissolving tank 1 through the first opening 11. Before pouring it into the crushing and dissolving tank 1, any visible stones in the soil contaminated with heavy metals should be removed to avoid damaging the separation of heavy metals from the soil.

[0074] S2. Water is added through the water injection hole 13, and the soil and water are mixed by the mixing mechanism 12 to form a mixture.

[0075] After water is added, the mixing mechanism 12 agitates the heavy metal-contaminated soil and water to form a mixture. This allows the heavy metal pollutants to dissolve in the mixture in ionic form, while conventional components in the soil, such as silica and carbonates, are incorporated into the mixture as insoluble substances. Sufficient water must be added during the water addition process to ensure that the heavy metal pollutants are fully dissolved in the mixture.

[0076] S3. Pass the mixture into the pretreatment water tank 2, filter the mixture, and obtain the filtrate and the filtrate.

[0077] The mixture entering the pretreatment tank 2 will be filtered by the filter assembly 23. Insoluble matter in the mixture will accumulate as silt on the filter surface 23a of the filter assembly 23, and the mixture will be filtered to form filtrate.

[0078] S4. Rotate the filter assembly 23 so that the filtered material and the filter surface 23a rotate together to the sediment opening to recover the sediment.

[0079] After rotating the filter assembly 23, the filter surface 23a, carrying the accumulated silt, is rotated to the silt opening. The silt can be cleaned off and recycled manually or automatically. The recycled silt, after adding organic matter and adjusting its pH and mineral salts, can be used as backfill soil.

[0080] S5. Pass the filtrate into the electro-adsorption water tank 3, electrolyze the filtrate, and obtain the residual liquid and heavy metal mixture.

[0081] After filtration, heavy metal pollutants dissolve in the filtrate in the form of ions. The filtrate is then electrolyzed in the electroadsorption tank 3, causing heavy metal ions to precipitate on the electrode 31, forming a heavy metal mixture. The remaining liquid after electrolysis contains almost no heavy metal pollutants.

[0082] S6. The heavy metal mixture on the electrode 31 is scraped off and collected by the scraper mechanism 32 and recycled.

[0083] The heavy metal mixture on electrode 31 is scraped off by scraper mechanism 32 and collected on scraper mechanism 32. When scraper mechanism 32 extends from the recovery opening, the heavy metal mixture on scraper mechanism 32 can be collected and recovered. The recovered heavy metal mixture can be used to prepare heavy metal elements.

[0084] Furthermore, step S5 also includes: recovering the remaining liquid, filtering and removing impurities from the remaining liquid, and adding it to the crushing and dissolving tank 1.

[0085] Considering that the remaining liquid contains almost no heavy metal pollutants, it can be recycled and added back into the crushing and dissolving tank 1 to achieve reuse, which is beneficial to saving resources and protecting the environment.

[0086] In summary, this application provides a soil heavy metal separation device and method. The crushing and dissolving tank can crush and mix soil contaminated with heavy metals into a mixed liquid; the pretreatment tank can pretreat the mixed liquid, filtering and recovering the silt in the wastewater; and the electro-adsorption tank can electrolyze the heavy metal pollutants in the filtrate, causing them to precipitate and be recovered. Therefore, the soil heavy metal separation device and method of this application can achieve the separation of heavy metals in soil. In the pretreatment tank of this application, the filter assembly is located at the second outlet and can rotate, ensuring that the mixed liquid inevitably passes through the filter assembly. Simultaneously, the filter assembly can rotate, allowing the other filter surface to continue filtering when silt accumulates to a certain extent on one filter surface, while the first filter surface removes the accumulated silt, facilitating real-time silt recovery. In the electro-adsorption tank of this application, the electrolysis of heavy metal pollutants is achieved through the electric field formed between the electrodes, causing the heavy metal mixture to precipitate on the electrodes. Simultaneously, the scraper assembly can directly scrape the heavy metal mixture off the electrodes, facilitating real-time recovery of the heavy metal mixture.

[0087] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A soil heavy metal separation device, characterized in that, include: A crushing and dissolving tank includes a first opening, a stirring mechanism, and a water injection hole; the first opening faces a first direction; the water injection hole is located at one end of the crushing and dissolving tank along the first direction; the stirring mechanism is located inside the crushing and dissolving tank; A pretreatment water tank, connected to the crushing and dissolving tank, includes a filter assembly, a sediment opening, and a second outlet. The filter assembly is rotatably arranged around a first axis and is located at the sediment opening. The filter assembly has at least three filter surfaces and sealing ridges, at least two of the sealing ridges are in sealing contact with the inner wall of the pretreatment water tank, and at least one filter surface is located at the sediment opening. The filter assembly includes: a roller hinged to the inner wall of the pretreatment water tank; a drum coaxially arranged with the roller; the drum is a prism with a regular polygonal cross-section; each side of the drum has an opening and communicates with the second outlet; multiple filter screens are located on each side of the drum, forming multiple filter surfaces; multiple sealing strips are located on each side edge of the drum, forming multiple sealing ridges; each side of the drum is a concave curved surface, and the axis of each curved surface is parallel to the first axis; the sealing strips protrude relative to the filter screens. An electro-adsorption water tank, connected to the pretreatment water tank, includes a recovery opening, at least two electrodes, and at least two scraper mechanisms; the scraper mechanisms are extendable and retractable along the first direction to the recovery opening, and the scraper mechanisms abut against the surface of the electrodes.

2. The soil heavy metal separation equipment according to claim 1, characterized in that, Along the first direction, the crushing and dissolving tank, the pretreatment water tank, and the electro-adsorption water tank are arranged at intervals in sequence; The crushing and dissolving tank includes a first outlet, the pretreatment water tank includes a second inlet, and the electro-adsorption water tank includes a third inlet and a third outlet. The first outlet is connected to the second inlet, and the second outlet is connected to the third inlet.

3. The soil heavy metal separation equipment according to claim 2, characterized in that, The stirring mechanism includes: A stirring shaft extending along the first direction, the stirring shaft being retractable along the first direction; Multiple first stirring rods extend radially along the stirring shaft and are evenly distributed circumferentially along the stirring shaft; Multiple second stirring rods are evenly distributed around the stirring shaft, and the second stirring rods are located on the side of the first stirring rod away from the first opening; the second stirring rod includes a main rod and multiple auxiliary rods, the main rod extends radially along the stirring shaft, the multiple auxiliary rods are evenly distributed around the main rod, and the multiple auxiliary rods are located on the same conical surface coaxial with the main rod.

4. The soil heavy metal separation equipment according to claim 2, characterized in that, The third inlet and the third outlet are arranged along the second direction, and the first direction and the second direction are perpendicular to each other; a water outlet filter screen is provided at the third outlet; At least two of the electrodes are parallel to each other, both parallel to the first direction, and both parallel to the second direction.

5. The soil heavy metal separation device according to claim 4, characterized in that, The scraper mechanism includes: A first drive assembly has a first telescopic end along a third direction; the third direction, the first direction, and the second direction are perpendicular to each other. The second drive assembly is connected to the first telescopic end and has a second telescopic end along the first direction; The scraper assembly is connected to the second telescopic end.

6. The soil heavy metal separation device according to claim 5, characterized in that, The scraper assembly includes: The blade extends along the second direction; A slag collection trough extends along the second direction; one end of the slag collection trough along the third direction is connected to the cutter body, and the other end is connected to the second telescopic end.

7. A method for separating heavy metals from soil, characterized in that, Using the soil heavy metal separation device according to any one of claims 1 to 6, the soil heavy metal separation method comprises: Excavate soil contaminated with heavy metals, break it up, and pour it into the first opening of the crushing and dissolving tank; Water is added through the water injection hole, and the soil and water are mixed together by the stirring mechanism to form a mixture. The mixture is passed into the pretreatment tank and filtered to obtain the filtrate and the filtrate. Rotate the filter assembly so that the filtered material and the filter surface rotate together to the sediment opening to recover the sediment; The filtrate is passed into the electro-adsorption water tank, and the filtrate is electrolyzed to obtain a residual liquid and a mixture of heavy metals. The heavy metal mixture on the electrode is scraped off and collected by a scraper mechanism and then recycled.

8. The method for separating heavy metals in soil according to claim 7, characterized in that, The filtrate is passed into the electro-adsorption water tank, and the filtrate is electrolyzed to obtain a residual liquid and a mixture of heavy metals, including: The remaining liquid is recovered, filtered to remove impurities, and then added to the crushing and dissolving tank.

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