Chemical remediation treatment process and device for soil heavy metal pollution

Abstract

The invention relates to the technical field of soil remediation, in particular to a chemical remediation treatment process and device for soil heavy metal pollution, the device comprises a pickling tank, a pickling progress monitoring device, a solid-liquid separation device, a catalytic reaction tank and a stirring catalysis device, the pickling progress monitoring device is connected with the pickling tank and used for monitoring the soil pickling progress in real time, an inlet of the solid-liquid separation device is connected with the pickling tank and used for conducting solid-liquid separation on mixed liquid obtained through soil pickling, and the catalytic reaction tank is connected with a liquid phase outlet of the solid-liquid separation device. And the stirring catalysis device is arranged in the catalytic reaction tank and is used for driving a catalyst and the solution to reversely rotate in the electrochemical oxidation tank. By adopting the chemical remediation treatment process and device for soil heavy metal pollution, the soil remediation efficiency and remediation effect can be effectively improved, and resource utilization of heavy metal in soil is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation, and more specifically, to a chemical remediation treatment process and device for heavy metal pollution in soil. Background Art

[0002] After heavy metal pollutants enter the soil, due to their characteristics of being easy to accumulate, having strong concealment, being difficult to eradicate, and being easy to enter the food chain, which endanger human health and the safety of the ecosystem, they will cause serious harm to the farmland ecological environment and the living space of soil microorganisms. Some heavy metals can also be transformed into compounds with stronger toxicity. Therefore, the remediation of soil heavy metal pollution has become a highly concerned issue for governments at all levels and scientists.

[0003] Soil pickling technology is a remediation technology for polluted soil. By mixing the soil with a chemical solvent, the pollutants are dissolved, separated from the soil and treated, and finally soil purification and resource utilization are achieved. However, it should be noted that the current soil pickling technology still relies on experience accumulation to judge the pickling end point. Some equipment separates the solid and liquid by extracting the sample solution and then conducts various heavy metal tests on the pickling solution. It is time-consuming and laborious and requires multiple tests to determine, with extremely low efficiency. Moreover, the types and contents of heavy metals in different soils are also different. Therefore, the error of extracting the sample solution for testing is large, resulting in low efficiency of soil pickling.

[0004] In addition, after pickling and solid-liquid separation of some soils polluted by heavy metals, the pickling solution contains a relatively high concentration of hexavalent chromium. The heavy metal ion pollution in the pickling solution needs to be fully reacted to be removed. Adding a corresponding catalyst can effectively improve the reaction efficiency. For example, hexavalent chromium has strong toxicity, with strong teratogenic, carcinogenic and mutagenic toxicity, and seriously pollutes the environment. Trivalent chromium is an essential trace element for the human body. Both are the most common stable valence states, and the current common removal of chromium is to reduce hexavalent chromium to trivalent chromium, and then form Cr(OH) 3 precipitate for recycling by increasing the pH value. The commonly used chromium reduction method is electrochemical catalytic oxidation method. In this reaction, iron and carbon are mixed to make a microelectrolysis catalyst, and the primary battery effect formed between iron and carbon is used to reduce hexavalent chromium in the liquid. Specifically, iron loses electrons at the anode and is oxidized to ferrous ions (Fe2+), and hexavalent chromium gains electrons at the cathode and is reduced to trivalent chromium. However, in practical applications, the reaction is prone to be incomplete, and the reduction of hexavalent chromium in the solution is not thorough, seriously affecting the elimination of heavy metal ion pollution and the resource recycling of heavy metals.

[0005] In summary, due to the problem that the progress of soil heavy metal acid washing is difficult to monitor and the low efficiency of eliminating heavy metal pollution ions, the effect of soil remediation in the existing technology is not good, and there is an urgent need to improve the chemical remediation process and equipment for soil heavy metal pollution. Summary of the invention

[0006] In order to overcome the problem of poor soil remediation effect in the above-mentioned prior art, the present invention provides a chemical remediation treatment process and device for soil heavy metal pollution.

[0007] In order to solve the above technical problems, a first aspect of the present invention provides a chemical remediation treatment device for soil heavy metal pollution.

[0008] A second aspect of the present invention provides a chemical remediation process for heavy metal contamination in soil.

[0009] A chemical remediation treatment device for heavy metal pollution in soil comprises: a pickling tank, a pickling progress monitoring device, a solid-liquid separation device, a catalytic reaction tank and a stirring catalytic device. The pickling tank is used for soil pickling. The pickling progress monitoring device is connected to the pickling tank and is used to monitor the progress of soil pickling in real time. The inlet of the solid-liquid separation device is connected to the pickling tank and is used to perform solid-liquid separation on the mixed liquid obtained by soil pickling. The catalytic reaction tank is connected to the liquid phase outlet of the solid-liquid separation device and is used to receive the solution obtained after solid-liquid separation and react to reduce the valence state of chromium ions and reduce heavy metal pollution in the solution. The stirring catalytic device is arranged in the catalytic reaction tank and is used to drive the catalyst and the solution to rotate in the opposite direction in the electrochemical oxidation tank.

[0010] In the technical solution of the present invention, the progress of soil pickling can be monitored in real time by the pickling progress monitoring device, without repeated sampling for experimental measurement, thereby improving the monitoring efficiency of soil pickling; the stirring catalytic device can drive the solution and the catalyst to rotate in the opposite direction, so that the catalyst and the solution are fully in contact, thereby improving the chemical reaction efficiency. The chemical remediation treatment device for soil heavy metal pollution of the present invention can effectively improve the soil remediation effect.

[0011] Furthermore, the pickling progress monitoring device includes a float assembly, a linkage assembly and an observation assembly. The float assembly is floated in the pickling tank, one end of the linkage assembly is transmission-connected to the float assembly, and the other end of the linkage assembly is connected to the observation assembly to drive the observation assembly to change.

[0012] In this solution, as the pickling process progresses, heavy metal ions in the soil enter the solution, causing the density of the solution to gradually increase. The float assembly will gradually rise as the solution density increases. The rising of the float assembly will drive the linkage assembly to move, thereby driving the observation assembly to change. By observing the changes in the observation assembly, the pickling progress can be intuitively judged. When the observation assembly tends to be stable, it indicates that the density of the solution has become stable, that is, the end point of soil heavy metal pickling has been reached.

[0013] Furthermore, the pickling progress monitoring device further includes a filtering assembly and a sludge scraping mechanism. The filtering assembly is connected to the pickling tank and forms a filtering space in the pickling tank. The float assembly is placed in the filtering space. The sludge scraping mechanism is connected to the pickling tank and is in moving contact with the outer surface of the filtering assembly.

[0014] In this solution, by forming a filtering space in the pickling tank through the filtering assembly, on the one hand, it can filter out the soil in the mixed liquid and obtain a relatively pure mixed liquid environment in the filtering space. On the other hand, it can reduce the disturbance generated by the stirring of the mixed liquid and ensure the relative stability of the float assembly in the filtering space. The sludge scraping mechanism can scrape off the sediment adhering to the outer surface of the filtering assembly, thereby continuously ensuring the filtering effect of the filtering assembly.

[0015] Furthermore, the observation assembly includes a U-shaped tube, a piston tube, and a translational piston. The U-shaped tube is fixedly connected to the outer side wall of the pickling tank and contains liquid. One end of the U-shaped tube is connected to the piston tube. The translational piston is fixedly connected to the linkage assembly and is slidably connected in the piston tube.

[0016] In this solution, the translational piston is pushed to move in the piston tube through the linkage assembly, causing the liquid level height at one end in the U-shaped tube to change, thereby intuitively observing the pickling progress of the soil.

[0017] Furthermore, the stirring and catalyzing device includes a rotating mechanism, a driving mechanism, a stirring assembly, and a suspension tank assembly. The rotating mechanism is arranged in the catalytic reaction tank. The stirring assembly and the suspension tank assembly are respectively connected to the rotating mechanism. The suspension tank assembly is used to carry the catalyst. The driving mechanism is connected to the rotating mechanism to drive the stirring assembly and the suspension tank assembly to rotate in opposite directions simultaneously.

[0018] In this solution, the driving mechanism drives the rotating mechanism to move, thereby driving the stirring assembly and the suspension tank assembly to rotate in opposite directions simultaneously, promoting the full contact between the catalyst in the suspension tank assembly and the solution in the catalytic reaction tank to improve the reaction conversion rate.

[0019] Further, the suspension bin assembly includes a catalyst bin, a buoyant member, a retaining rod, and a suspension middle cylinder. The retaining rod is fixedly connected to the suspension middle cylinder and extends circumferentially. Both the catalyst bin and the buoyant member are annular and surround the outside of the suspension middle cylinder and are respectively fixedly connected to the retaining rod. The suspension bin assembly is movably connected to the rotating mechanism in the vertical direction and rotates with the rotating mechanism.

[0020] In this solution, buoyancy is provided by the buoyant member, and the catalyst bin and the buoyant member are connected to the suspension middle cylinder through the retaining rod. Since the suspension bin assembly is movably connected to the rotating mechanism in the vertical direction, it can always be suspended in the solution as the liquid level changes, so that the catalyst in the suspension bin assembly can always be in contact with the solution. At the same time, the suspension bin assembly can rotate with the rotating mechanism, promoting further contact between the solution and the catalyst and effectively carrying out the catalytic reaction.

[0021] Further, the catalyst bin has an inner cavity for accommodating the catalyst. The side wall of the catalyst bin is provided with a liquid inlet hole communicating with the inner cavity. There are multiple catalyst bins and multiple buoyant members, and each catalyst bin and each buoyant member are arranged at intervals in the circumferential direction of the suspension middle cylinder.

[0022] In this solution, the solution can react with the catalyst through the liquid inlet hole. The multiple catalyst bins arranged at intervals can promote the contact between the catalyst and the solution, and the buoyant members arranged at intervals can provide stable buoyancy.

[0023] Further, the rotating mechanism includes a plurality of shafts arranged vertically. Each shaft rotates around the same vertical axis. The suspension bin assembly is provided with a plurality of through holes in the vertical direction, and each shaft respectively passes through each through hole and is movably connected.

[0024] In this solution, the suspension bin assembly is movably connected to the rotating mechanism by a plurality of shafts respectively passing through a plurality of through holes, and at the same time each shaft rotates around the same vertical axis, so that the suspension bin assembly can rotate with the rotating mechanism and can also float as the liquid level of the solution changes, ensuring that the catalyst is always in contact with the solution.

[0025] Further, a soil feed port is provided on the side wall of the pickling tank. A feed bin is connected to the outside of the soil feed port, and a rinsing screen is connected to the inside of the soil feed port.

[0026] In this solution, the soil to be pickled is placed in the feed bin, and the mixed liquid in the pickling tank continuously contacts and rinses the soil through the rinsing screen, so that the soil is evenly diffused in the pickling solution, improving the pickling effect of the soil.

[0027] The present invention provides a chemical remediation treatment process for soil heavy metal pollution, which is used in combination with the above device and includes the following steps:

[0028] S1: Acidify the heavy metal - contaminated soil in an acid - washing tank.

[0029] S2: Observe the acid - washing progress of the soil in the acid - washing tank in real - time through an acid - washing progress monitoring device until the soil acid - washing is completed.

[0030] S3: Perform solid - liquid separation on the mixed liquid obtained after acid - washing through a solid - liquid separation device.

[0031] S4: Feed the solution obtained after solid - liquid separation into a catalytic reaction tank, and make the solution and the catalyst rotate in opposite directions through a stirring and catalyzing device to promote the chemical reaction of heavy metal ions and reduce heavy metal pollution.

[0032] In the treatment process of this solution, through the acid - washing progress monitoring device, the process of sampling and experimentation is not required, thus effectively improving the efficiency of monitoring the acid - washing progress of the soil and determining the acid - washing end - point. Through the suspended catalytic stirring reaction device, the conversion rate of hexavalent chromium ions into trivalent chromium ions can be increased, the soil remediation effect can be improved, and it is beneficial to the subsequent resource utilization of soil heavy metals.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] First, based on the acid - washing characteristics of soil heavy metals and the accumulation of experimental results of the research group, the present invention is a set of chemical remediation treatment devices for soil heavy metal pollution designed specifically. Soil screening and acid - liquid swirling acid - washing are carried out in the acid - washing tank. After solid - liquid separation, the heavy metal - contaminated ions are reacted in the catalytic reaction tank. For example, hexavalent chromium is reduced to trivalent chromium. By using the chemical remediation treatment device for soil heavy metal pollution of the present invention, on the one hand, all heavy metals in the soil can be acid - washed into the acid - washing solution, thus removing heavy metals from the soil; on the other hand, after solid - liquid separation, the solution containing soil heavy metal ions is fully reacted to reduce heavy metal pollution, which is beneficial to the subsequent recovery and utilization of heavy metals, and enables the heavy metals in the soil to be resource - utilized.

[0035] Second, for the chemical remediation treatment device for soil heavy metal pollution of the present invention, by designing a float assembly, a linkage assembly, and an observation assembly in the acid - washing tank, the density change of the mixed liquid containing heavy metal ions in the acid - washing tank is reflected as the change of the liquid level in a U - shaped tube that can be directly observed, thereby visually monitoring the acid - washing progress. Compared with sampling and experimental analysis, the efficiency is significantly improved, thus greatly improving the efficiency of soil acid - washing.

[0036] III. For the chemical remediation treatment device for soil heavy metal pollution of the present invention, by arranging a filtering component and a mud scraping component outside the floating component, the filtering component can filter out the soil in the mixed liquid, obtain a relatively pure mixed liquid environment in the filtering space, and at the same time can reduce the disturbance generated by the stirring of the mixed liquid, ensuring the relative stability of the floating component in the filtering space. The mud scraping mechanism can scrape off the sediment adhering to the outer surface of the filtering component, thereby ensuring the filtering effect of the filtering component.

[0037] IV. For the chemical remediation treatment device for soil heavy metal pollution of the present invention, a stirring and catalyzing device is arranged in the catalytic reaction pool, realizing the rotation of the catalyst and the solution in opposite directions, enabling the catalyst to be in full contact with the solution, thereby improving the reaction efficiency of the conversion of hexavalent chromium ions to trivalent chromium ions.

[0038] V. For the chemical remediation treatment device for soil heavy metal pollution of the present invention, a suspension bin component is arranged on the stirring and catalyzing device, which can carry the catalyst and always suspend at a certain depth in the solution, ensuring that the catalyst is completely immersed in the solution. At the same time, by designing a multi-layer catalyst bin and floating component structure, the coverage area of the catalyst in the catalytic reaction pool is increased, and the suspension bin component can rotate horizontally in the solution smoothly.

[0039] VI. The chemical remediation treatment process for soil heavy metal pollution of the present invention, when used in combination with the above device, can efficiently repair heavy metal-polluted soil, reduce heavy metal ion pollution, and is also conducive to the subsequent resource recycling of heavy metals in the soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is the overall structural schematic diagram of the chemical remediation treatment device for soil heavy metal pollution of the present invention;

[0041] Figure 2 is the structural schematic diagram of the pickling pool and the pickling progress monitoring device;

[0042] Figure 3 is Figure 2 the front view of

[0043] Figure 4 is Figure 2 the top view of

[0044] Figure 5 is the structural schematic diagram of the floating component;

[0045] Figure 6 is Figure 5 the enlarged view at A of

[0046] Figure 7 is Figure 2 the enlarged view at B of

[0047] Figure 8 is Figure 2 an enlarged view of part C of

[0048] Figure 9 a partial structural schematic diagram of the second rack;

[0049] Figure 10 a structural schematic diagram of the filtration component and the sludge scraping mechanism;

[0050] Figure 11 is Figure 10 a structural schematic diagram from another angle;

[0051] Figure 12 is Figure 11 an enlarged view of part D of

[0052] Figure 13 is Figure 11 an enlarged view of part E of

[0053] Figure 14 a structural schematic diagram of the sludge scraping plate and the sludge scraping connecting piece;

[0054] Figure 15 a structural schematic diagram of the catalytic reaction tank and the stirring catalytic device;

[0055] Figure 16 is Figure 15 a structural schematic diagram of each mechanism at the inner bottom of the catalytic reaction tank in

[0056] Figure 17 a structural schematic diagram of the rotating mechanism and the driving mechanism;

[0057] Figure 18 is Figure 17 a structural schematic diagram from a lower side view;

[0058] Figure 19 is Figure 17 a structural schematic diagram from an upper side view;

[0059] Figure 20 a structural schematic diagram of the suspension bin assembly;

[0060] Figure 21 is Figure 20 a partial schematic diagram of the catalyst bin and the float parts in

[0061] Figure 22 a connection schematic diagram of the suspension middle cylinder and the through shaft after removing the outer cylinder structure;

[0062] Figure 23 a connection structural schematic diagram of the cross beam at the top of the catalytic reaction tank and the through shaft;

[0063] Figure 24 a structural schematic diagram of the measurement component.

[0064] In the attached drawings: 1. pickling tank; 11. soil feed port; 12. feed bin; 13. rinse net; 14. pickling propeller; 15. stirring motor; 16. pickling liquid inlet; 17. pickling liquid outlet; 18. first crossbeam; 181. annular portion; 182. limit ring; 19; guide assembly; 191. rolling support; 192. rolling element; 2. pickling progress monitoring device; 21. float assembly; 211. float body; 212. first rack; 213. limit rod; 214. limit boss; 22. linkage assembly; 221. first rotating shaft; 222. first gear; 223. second gear; 22 4. Second rack; 2241. Guide groove; 23. Observation assembly; 231. U-shaped tube; 2311. First tube section; 2312. Second tube section; 232. Piston tube; 233. Translation piston; 24. Filter assembly; 241. Filter frame; 242. Filter membrane; 243. Filter space; 244. L-shaped fixed column; 25. Scraping mechanism; 251. Scraping plate; 252. Scraping transmission assembly; 2521. Third gear; 2522. Fourth gear; 2523. Scraping rotating bearing; 2524. Scraping ring; 253. Scraping connection assembly; 2531. Receiver ring; 2532. Receiver column ; 254, scraper drive; 3, catalytic reaction tank; 31, solution inlet; 32, solution outlet; 33, bearing ring; 34, bearing bearing; 35, first mounting shaft; 36, second mounting shaft; 37, support member; 38, second crossbeam; 381, positioning column; 382, ​​positioning bearing; 4, stirring catalytic device; 41, rotating mechanism; 411, stirring sleeve; 412, through shaft; 4121, shaft body; 4122, arc step; 413, gear transmission assembly; 4131, first bearing; 4132, first external gear; 4133, second external gear; 4134, first internal gear; 41 35. Second inner gear; 4136. Rotating ring; 4137. Positioning outer ring; 42. Driving mechanism; 421. Driving motor; 422. First driving gear; 423. Second driving gear; 43. Stirring assembly; 44. Suspension chamber assembly; 441. Catalyst chamber; 4411. Inner cavity; 4412. Liquid inlet hole; 442. Float; 4421. Float tip; 443. Retaining rod; 444. Suspension middle tube; 4441. Outer tube; 4442. Inner disk; 4443. Through hole; 5. Measuring assembly; 51. Measuring tube; 52. Measuring cell; 53. Measuring valve; 6. Solid-liquid separation device. DETAILED DESCRIPTION

[0065] The accompanying drawings are only for illustrative purposes and should not be construed as limiting the patent; for better illustration of this embodiment, some components in the drawings may be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationships described in the drawings are only for illustrative purposes and should not be construed as limiting the patent.

[0066] The technical solution of the present invention will be further specifically described below through specific embodiments in conjunction with the accompanying drawings:

[0067] Embodiment 1

[0068] Reference Figure 1 , this embodiment discloses a chemical remediation treatment device for soil heavy metal pollution, including a pickling tank 1, a pickling progress monitoring device 2, a solid-liquid separation device 6, a catalytic reaction tank 3 and a stirring and catalyzing device 4.

[0069] Among them, the pickling tank 1 is used for soil pickling. The soil and the pickling solution are subjected to swirling pickling in the pickling tank 1, and all the heavy metals in the soil are pickled into the acidic mixed solution, thereby removing the heavy metal pollution in the soil.

[0070] The pickling progress monitoring device 2 is connected to the pickling tank 1 and is used for real-time monitoring of the soil pickling progress. By observing the pickling progress monitoring device 2, information on the arrival of the soil pickling end point can be obtained. Compared with the prior art in which repeated sampling experiments are used to monitor the pickling progress, this embodiment can effectively improve the soil pickling efficiency.

[0071] The inlet of the solid-liquid separation device 6 is connected to the pickling tank and is used for solid-liquid separation of the mixed solution obtained by soil pickling. The liquid phase outlet of the solid-liquid separation device 6 is connected to the catalytic reaction tank 3. The catalytic reaction tank 3 is used to receive the solution obtained after solid-liquid separation and carry out relevant reactions to reduce the heavy metal pollution in the solution. The solid-liquid separation device 6 can adopt a solid-liquid separation compressor, and the catalytic reaction tank 3 and the pickling tank 1 are connected through the solid-liquid separation compressor and pipelines. When the soil pickling is completed, the solid-liquid separation compressor is started for solid-liquid separation, so that the separated solution enters the catalytic reaction tank 3.

[0072] The stirring and catalyzing device 4 is arranged in the catalytic reaction tank 3 and is used to drive the catalyst and the solution to rotate in the opposite direction in the electrochemical oxidation tank, thereby promoting the full contact between the catalyst and the solution for reaction and improving the reaction efficiency.

[0073] In this embodiment, the pickling progress monitoring device 2 can monitor the progress of soil pickling in real time, eliminating the need for repeated sampling for experimental determination, thus improving the monitoring efficiency of soil pickling. The stirring and catalyzing device 4 can drive the solution and the catalyst to rotate in opposite directions, enabling the catalyst and the solution to come into full contact and thereby improving the reaction efficiency. The chemical remediation treatment device for soil heavy metal pollution using this solution can effectively improve the soil remediation effect and promote the resource utilization of soil heavy metals.

[0074] The structure of each part of this embodiment will be further described in detail below.

[0075] Refer to Figures 2 to 4 , the upper end of the pickling tank 1 is generally cylindrical, and the bottom of the pickling tank 1 is funnel-shaped with a cross-section gradually decreasing downward. Three pickling propellers 14 are installed on the inner side wall of the pickling tank 1, and each pickling propeller 14 is respectively connected to a stirring motor 15 for driving. The rotational central axis direction of each pickling propeller 14 can be horizontal and does not pass through the vertical central axis of the pickling tank 1, that is, each pickling propeller 14 is horizontally and laterally arranged. From a top view, the rotational central axes of each pickling propeller 14 can form an equilateral triangle in the pickling tank 1, which can better push the water flow to rotate in the tank, perform swirl pickling of the soil with the pickling solution, and allow the soil to be fully mixed with the pickling solution. An acid pickling solution inlet 16 is provided on the side wall of the pickling tank 1, and the pickling solution is put into the pickling tank 1 through the acid pickling solution inlet 16. An acid pickling solution outlet 17 is opened at the bottom of the pickling tank 1 for discharging the mixed solution after pickling.

[0076] Refer to Figures 2 to 4 , a soil feed inlet 11 is opened on the side wall of the pickling tank 1. The outside of the soil feed inlet 11 is connected to a feed bin 12, and the inside of the soil feed inlet 11 is connected to a rinsing screen 13. The feed bin 12 can have a cross-sectional shape that gradually narrows from top to bottom. The top of the feed bin 12 is open, and the upper part of the bottom of the feed bin 12 is connected to the soil feed inlet 11 on the side wall of the pickling tank 1. The rinsing screen 13 protrudes towards the inside of the pickling tank 1 to facilitate the contact between the pickling solution and the soil. The lowermost part of the feed bin 12 can accommodate other sundries in the soil.

[0077] During use, the heavy metal-polluted soil is placed in the feed bin 12. The acid solution in the pickling tank 1 continuously contacts and rinses the soil through the holes in the rinsing screen 13, causing the soil to be evenly dispersed in the pickling solution. The heavy metal elements in the soil dissolve into the pickling solution in an ionic state. The rinsing screen 13 can screen the soil, and larger soil clods will be broken and dissolved under the flushing of the pickling solution. If there are hard stones, glass, and other sundries in the soil, they will be isolated at the bottom of the feed bin 12, and the sundries at the bottom of the feed bin 12 can be cleaned out after the soil pickling is completed.

[0078] Only when the soil is fully pickled can the heavy metal pollution in the soil be removed as much as possible, thus achieving the purpose of soil remediation. In the related art, there is a method of testing the composition of the pickling solution through experiments to monitor the progress of pickling, but this requires repeated sampling and experiments, and there are many types of heavy metal elements involved, and there are also many corresponding experiments to be conducted, resulting in low efficiency. However, the inventors have found that during the process of heavy metal pickling in soil, the density of the pickling solution will increase as the heavy metals enter in the ionic state. For example, at a concentration of 10% by mass, the density of sulfuric acid solution is about 1.06g / cm 3 , and the density of copper sulfate solution is about 1.08g / cm 3 , the density of cadmium sulfate solution is about 1.15g / cm 3 、The density of chromium sulfate solution is about 1.2g / cm 3 Therefore, the progress of soil pickling can be judged by the change in the density of the pickling solution.

[0079] refer to Figure 2 and Figure 3 The pickling progress monitoring device 2 of this embodiment is used to monitor the soil pickling progress in the pickling tank 1 in real time, and includes a float component 21, a linkage component 22 and an observation component 23. The float component 21 is floated in the pickling tank 1, one end of the linkage component 22 is transmission-connected to the float component 21, and the other end of the linkage component 22 is connected to the observation component 23 to drive the observation component 23 to change.

[0080] In this embodiment, as the pickling process continues, heavy metal ions in the soil enter the mixed solution, causing the density of the mixed solution to gradually increase. The float component 21 will gradually rise as the density of the mixed solution increases. The rise of the float component 21 will drive the linkage component 22 to move, thereby driving the observation component 23 to change. By observing the changes in the observation component 23, the progress of the pickling can be intuitively judged. When the liquid level of the observation component 23 tends to be stable, it means that the density of the mixed solution has tended to be stable, that is, the end point of the soil heavy metal pickling has been reached.

[0081] More specifically refer to Figure 5 and Figure 6 The float assembly 21 includes a float body 211. A first crossbeam 18 is provided on the top of the pickling tank 1. The float body 211 is movably connected to the first crossbeam 18 in the vertical direction. The float body 211 is fixedly connected to a first rack 212 in the vertical direction for transmission connection with the linkage assembly 22. The float body 211 is movably connected to the first crossbeam 18 in the vertical direction, so that the float body 211 can stably float in the pickling tank 1, and then the height change of the float body 211 is stably transmitted to the linkage assembly 22 for output through the first rack 212 arranged vertically.

[0082] Reference Figure 5 and Figure 6 ,The first crossbeam 18 spans above the pickling tank 1, and both ends of the first crossbeam 18 are fixedly connected to the pickling tank 1. An annular portion 181 is provided in the middle of the first crossbeam 18 to facilitate the installation of the float body 211. The float body 211 can be generally conical, hollow inside, with its tip facing downward, and the float body 211 is located below the annular portion 181 in the middle of the first crossbeam 18. The taper of the float body 211 can be set smaller, so that it can float up and down a longer distance when the density of the mixed liquid changes, in order to drive the observation assembly 23 to change and be easier to observe. A first rack 212 is fixedly connected to the middle position at the top of the float body 211, and the first rack 212 is arranged in the vertical direction. The first rack 212 can move up and down with the float body 211, and thus output to the linkage assembly 22.

[0083] In order to limit the position of the float body 211 in the horizontal direction and prevent the float assembly 21 from detaching from the first crossbeam 18, the float assembly 21 further includes a limiting rod 213, and the first crossbeam 18 is provided with a limiting ring 182. A plurality of limiting rings 182 are arranged along the inner circle of the annular portion 181 of the first crossbeam 18. A plurality of limiting rods 213 are fixedly connected to the top of the float body 211 in the vertical direction and pass through the limiting ring 182. A limiting boss 214 is provided at the top of the limiting rod 213, and the outer diameter of the limiting boss 214 is larger than the inner diameter of the limiting ring 182. The movable connection is realized by the limiting rod 213 passing through the limiting ring 182, so that the float assembly 21 floats horizontally at a certain range of position heights. When the mixed liquid in the pickling tank 1 is drained, the float assembly 21 can be supported by the limiting boss 214 to prevent the float assembly 21 from detaching from the bottom when the pickling solution is insufficient. Among them, a plurality of limiting rods 213 are arranged circumferentially at the top of the float body 211, which can not only prevent the float body 211 from shifting in the horizontal direction, but also avoid the float body 211 rotating around the vertical axis.

[0084] Reference Figures 5 to 7 ,The linkage assembly 22 includes a first rotating shaft 221, a first gear 222, a second gear 223 and a second rack 224. The first rotating shaft 221 is rotatably connected to the first crossbeam 18. One end of the first rotating shaft 221 is coaxially fixedly connected to the first gear 222, and the other end of the first rotating shaft 221 is coaxially fixedly connected to the second gear 223. The first gear 222 meshes with the first rack 212, the second gear 223 meshes with the second rack 224, the second rack 224 is slidably connected to the first crossbeam 18, and one end of the second rack 224 is connected to the observation assembly 23. A bearing seat is provided on the first crossbeam 18, and the first rotating shaft 221 is rotatably connected to the bearing seat through a bearing.

[0085] During the entire transmission process, the rise of the float body 211 drives the first rack 212 to move in the vertical direction. The first rack 212 drives the first gear 222 to rotate, thereby driving the first rotating shaft 221 to rotate. The first rotating shaft 221 drives the second gear 223 to rotate, and the second gear 223 drives the second rack 224 to move. The second rack 224 drives the observation assembly 23 to change, so as to display the progress of soil pickling.

[0086] Specifically, referring to Figure 2 the XYZ coordinate system shown, the first rack 212 is arranged along the Z-axis direction, the first rotating shaft 221 is arranged along the X-axis direction, and the second rack 224 is arranged along the Y-axis direction. Through the meshing transmission of the first gear 222 and the first rack 212, the translational motion of the float body 211 along the Z-axis direction is converted into the rotational motion of the first rotating shaft 221 around the axis in the X-axis direction. Then, through the meshing of the second gear 223 and the second rack 224, the rotation of the first rotation around the X direction is converted into the translational motion of the second rack 224 along the Y-axis direction.

[0087] Therefore, in this embodiment, through the linkage assembly 22, the height change of the float body 211 in the Z direction is converted into the displacement change of the second rack 224 in the Y direction, so as to facilitate connecting the external observation assembly 23. Of course, what is provided in this embodiment is only a specific form of the linkage assembly 22, and those skilled in the art can also implement it through other transmission structures, which will not be elaborated here.

[0088] In order to more obviously display the height change of the float body 211, the diameter of the second gear 223 can be set to be larger than the diameter of the first gear 222. For example, the diameter of the second gear 223 is six times that of the first gear 222. When rotating the same angle, the linear velocity of the second gear 223 is also six times that of the first gear 222, which can magnify the floating distance of the float body 211, so as to drive the change of the observation assembly 23 and make it easier to observe.

[0089] Referring to Figures 7 to 9 , a guiding assembly 19 is fixedly connected to the first cross beam 18. The guiding assembly 19 includes a rolling support 191 and a rolling member 192. The rolling member 192 is rotatably connected to the rolling support 191 and can rotate along the length direction of the second rack 224. A guiding groove 2241 is formed at the bottom of the second rack 224, and the second rack 224 abuts against the rolling member 192 through the guiding groove 2241. In this embodiment, by providing the guiding assembly 19, the second rack 224 can move on the rolling member 192, and at the same time, the guiding groove 2241 at the bottom of the second rack 224 plays a limiting role to prevent the second rack 224 from deviating.

[0090] Specifically, the rolling support 191 is arranged along the length direction of the second rack 224. The rolling element 192 can be formed by connecting the mounting shaft through bearings. The inner ring of the bearing is fixedly connected to the mounting shaft, and both ends of the mounting shaft are fixedly connected to the rolling support 191. The outer ring of the bearing is exposed upward to contact the bottom of the second rack 224, so that the bottom of the second rack 224 can be supported, and at the same time, the resistance during the movement of the second rack 224 is reduced. A guide groove 2241 is also formed along the length direction at the bottom of the second rack 224. The width of the guide groove 2241 is slightly larger than the width of the bearing. Through the guide groove 2241, the second rack 224 can be limited, so that it moves along the rolling direction of the bearing and will not break away along the side.

[0091] Of course, the rolling support 191 and the rolling element 192 shown in this embodiment are only a specific way to guide the second rack 224. Those skilled in the art can also design other guiding structures to achieve this. For example, it can be achieved through a guide rail-slider structure. When using the guide rail-slider structure, the guide rail is fixedly connected to the first cross beam 18 along the length direction of the second rack 224, and a slider is slidably connected to the guide rail. Multiple sliders can be provided. The top of the slider is fixedly connected to the bottom of the second rack 224, and the second rack 224 is guided and limited through the guide rail-slider.

[0092] Reference Figure 5 、 Figures 10 to 14 Refer to

[0093] Reference Figure 5 The pickling progress monitoring device 2 further includes a filtering component 24 and a sludge scraping mechanism 25. The filtering component 24 is connected to the pickling tank 1 and forms a filtering space 243 in the pickling tank 1. The float component 21 is placed in the filtering space 243. The sludge scraping mechanism 25 is connected to the pickling tank 1 and is in moving contact with the outer surface of the filtering component 24. By forming the filtering space 243 in the pickling tank 1 through the filtering component 24, on the one hand, the soil in the mixed liquid can be filtered out to obtain a relatively pure mixed liquid environment in the filtering space 243, and on the other hand, the disturbance generated by the stirring of the mixed liquid can be reduced to ensure the relative stability of the float component 21 in the filtering space 243. The sludge scraping mechanism 25 can scrape off the sediment adhering to the outer surface of the filtering component 24, thereby ensuring the filtering effect of the filtering component 24.

[0094] Specifically, an opening is provided at the top of the filtering space 243 so that the float assembly 21 can be placed in the filtering space 243 from the top. The circumferential and bottom parts of the filtering space 243 are both sealed and isolated by the filtering membrane 242 to prevent sediment in the mixed liquid from entering. The internal size of the filtering space 243 is larger than that of the float assembly 21, so the float assembly 21 will not come into direct contact with the filtering component 24, avoiding affecting the floating of the float main body 211. The filtering space 243 formed inside the filtering component 24 can be a conical shape approximately similar to that of the float main body 211, but with a larger size. This can not only ensure the effective floating of the float main body 211 but also reduce the volume of the mixed liquid to be filtered.

[0095] Reference Figures 10 to 14 , the mud scraping mechanism 25 includes a mud scraping plate 251, a mud scraping transmission assembly 252, a mud scraping connection assembly 253, and a mud scraping driving member 254. The fixed end of the mud scraping driving member 254 is fixedly connected to the first cross beam 18. The output end of the mud scraping driving member 254 is connected to the mud scraping transmission assembly 252. The mud scraping transmission assembly 252 is connected to the mud scraping connection assembly 253 to drive the mud scraping connection assembly 253 to rotate around the filtering component 24. The mud scraping connection assembly 253 is fixedly connected to the mud scraping plate 251, and the mud scraping plate 251 is in contact with the filtering membrane 242. The mud scraping mechanism 25 can scrape the sediment adhering to the outer surface of the filtering membrane 242, thereby ensuring the filtering effect of the filtering component 24.

[0096] Specifically, the mud scraping connection assembly 253 can be in a substantially frame shape surrounding the outside of the filtering component 24. For example, the mud scraping connection assembly 253 includes a plurality of receiving rings 2531 and receiving columns 2532. Each individual receiving ring 2531 is arranged horizontally around the outside of the filtering component 24, and different receiving rings 2531 are arranged in sequence along the vertical direction. The receiving columns 2532 are used for fixed connection between the receiving rings 2531 to form the frame structure of the mud scraping connection assembly 253. A plurality of mud scraping plates 251 can be provided and are respectively fixedly connected to the receiving rings 2531. For example, two mud scraping plates 251 are oppositely arranged on both sides of the filtering component 24. The length direction of the mud scraping plate 251 is inclined vertically, so that one side of the mud scraping plate 251 fits against the outside of the filtering component 24. The mud scraping driving member 254 can be a mud scraping motor, and the fixed end of the mud scraping motor is fixedly connected to the first cross beam 18.

[0097] Reference Figures 10 to 14, the sludge scraping transmission assembly 252 includes a third gear 2521, a fourth gear 2522, a sludge scraping rotating bearing 2523 and a sludge scraping ring 2524. The sludge scraping rotating bearing 2523 is coaxially arranged with the filtering assembly 24. The third gear 2521 is coaxially and fixedly connected to the output end of the sludge scraping driving member 254. The fourth gear 2522 is coaxially and fixedly connected to the outer ring of the sludge scraping rotating bearing 2523. The inner ring of the sludge scraping rotating bearing 2523 is fixedly connected to the first cross beam 18. The sludge scraping ring 2524 is sleeved on the outer ring of the bearing, and the bottom of the sludge scraping ring 2524 is fixedly connected to the sludge scraping connection assembly 253. The third gear 2521 is driven to rotate by the sludge scraping driving member 254. The third gear 2521 drives the fourth gear 2522 to rotate through meshing. The fourth gear 2522 drives the outer ring of the bearing to rotate, so that the sludge scraping ring 2524 drives the sludge scraping assembly to rotate around the filtering assembly 24 to scrape the sediment adhering to the outer surface of the filter membrane 242.

[0098] In some other embodiments, the sludge scraping transmission assembly 252 can also be connected by other transmission structures, as long as the output power of the sludge scraping driving assembly can be transmitted to the sludge scraping plate 251, which will not be elaborated here.

[0099] Reference Figure 12 and Figure 13 , the upper end of the receiving column 2532 at the top is fixedly connected to the lower end of the sludge scraping ring 2524 on the outer ring of the sludge scraping rotating bearing 2523. The top of the filtering frame 241 is fixedly connected to the bottom of the first cross beam 18 through an L-shaped fixing column 244. The L-shaped fixing column 244 extends outward in the horizontal direction to form a supporting part, so that the inner ring of the sludge scraping rotating bearing 2523 can be carried and fixed on the supporting part of the L-shaped fixing column 244.

[0100] Reference Figure 7 and Figure 8 , the observation assembly 23 includes a U-shaped tube 231, a piston tube 232 and a translational piston 233. The U-shaped tube 231 is fixedly connected to the outer side wall of the pickling tank 1 and contains liquid. One end of the U-shaped tube 231 is communicated with the piston tube 232. The translational piston 233 is fixedly connected to the linkage assembly 22 and slidably connected in the piston tube 232. By pushing the translational piston 233 to move in the piston tube 232 through the linkage assembly 22, the liquid level height at one end in the U-shaped tube 231 changes, so as to visually observe the progress of soil pickling.

[0101] Specifically, the U-shaped tube 231 and the piston tube 232 can be integrally formed or connected through an intermediate pipeline, as long as the piston tube 232 is hermetically connected to one end of the U-shaped tube 231. Among them, the piston tube 232 at least includes a tube section that is collinear with the second rack 224, so that the second rack 224 can push the translational piston 233 to move in the piston tube 232. The U-shaped tube 231 is fixedly connected to the outer side of the side wall of the pickling tank 1 through a pipe clamp. A colored and non-volatile liquid is contained in the U-shaped tube 231, and a scale is provided on the side wall of the U-shaped tube 231 for easy observation.

[0102] In order to make the change in the liquid level height in the U-shaped tube 231 more obvious, the side of the U-shaped tube 231 connected to the piston tube 232 can be the first tube section 2311, and the other side of the U-shaped tube 231 can be the second tube section 2312. The diameter of the first tube section 2311 is larger than that of the second tube section 2312. For example, if the diameter of the first tube section 2311 is twice that of the second tube section 2312, then the cross-sectional area of the first tube section 2311 is four times that of the second tube section 2312, and the change in the liquid level height can be magnified four times for easy observation.

[0103] In some other embodiments, the observation assembly 23 can be displayed in other ways. For example, the observation assembly 23 is realized by connecting an object block through a traction rope at the end of the second rack 224. The traction rope can change the movement direction through a pulley block, and the change in the height of the object block is used for display.

[0104] It can be understood that the pickling progress and the change of the observation assembly 23 do not necessarily have to be linear, as long as there is a positive correlation trend between the two, and thus the pickling progress can be judged. When the observation assembly 23 tends to be stable and the pickling solution is sufficient, it can be judged that the soil pickling reaches the end point.

[0105] After the soil pickling is completed, the mixed liquid in the pickling tank 1 is subjected to solid-liquid separation to obtain the repaired soil and the solution polluted by heavy metal ions. The solution polluted by heavy metal ions needs to be reacted to reduce the heavy metal ion pollution in the solution, and the reaction is carried out in the catalytic reaction tank 3.

[0106] Reference Figure 15 , the catalytic reaction tank 3 is generally cylindrical, and a solution inlet 31 and a solution outlet 32 are respectively arranged on both sides of its bottom. Through the solution inlet 31, the solution obtained by pickling and solid-liquid separation can be put into the reaction to reduce the heavy metal ion pollution in the solution, and through the solution outlet 32, the fully reacted solution can be discharged. The soil in the pickling tank 1 is pickled to obtain a mixed liquid, and after solid-liquid separation, the solution containing heavy metal ions is put into the catalytic reaction tank 3 from the solution inlet 31.

[0107] ReferenceFigure 24 , a measuring assembly 5 is connected to the outer side wall of the catalytic reaction tank 3. The measuring assembly 5 includes a measuring tube 51, a measuring cell 52 and a measuring valve 53. The measuring tube 51 is located at the lower side wall of the catalytic reaction tank 3 and is in communication with the inside of the catalytic reaction tank 3. The other end of the measuring tube 51 is provided with a measuring cell 52, and the measuring cell 52 is fixedly connected to the side wall of the catalytic reaction tank 3. A measuring valve 53 is connected to the measuring tube 51. By opening the measuring valve 53, the liquid in the catalytic reaction tank 3 can be put into the measuring cell 52, and the liquid in the catalytic reaction tank 3 can be sampled to facilitate monitoring of the reaction progress in the catalytic reaction tank 3.

[0108] Reference Figure 15 , a stirring and catalyzing device 4 is arranged in the catalytic reaction tank 3 to promote the full contact between the solution and the catalyst, thereby promoting the reaction in the catalytic reaction tank 3. The stirring and catalyzing device 4 includes a rotating mechanism 41, a driving mechanism 42, a stirring assembly 43 and a suspension bin assembly 44. The rotating mechanism 41 is arranged in the catalytic reaction tank 3. The stirring assembly 43 and the suspension bin assembly 44 are respectively connected to the rotating mechanism 41. The driving mechanism 42 is connected to the rotating mechanism 41 to drive the stirring assembly 43 and the suspension bin assembly 44 to rotate in opposite directions simultaneously.

[0109] The following is a specific description of the suspension reaction device.

[0110] Reference Figure 15 , the suspension reaction device is arranged in the catalytic reaction tank 3. Taking the illustrated direction as an example, the rotating mechanism 41 is distributed in the height space of the entire catalytic reaction tank 3 along the vertical direction. The driving mechanism 42 is connected to the outer side of the bottom of the catalytic reaction tank 3 and passes through the bottom of the catalytic reaction tank 3 to be in transmission connection with the rotating mechanism 41. The lower end of the rotating mechanism 41 is connected to the stirring assembly 43, and the solution in the catalytic reaction tank 3 can be stirred by the stirring assembly 43 to form a swirl. Above the stirring assembly 43 and vertically movably connected to the rotating mechanism 41 is the suspension bin assembly 44. The suspension bin assembly 44 can carry the catalyst required for the reaction and float with the change of the liquid level height in the catalytic reaction tank 3 to ensure that the catalyst can always be in contact with the solution to promote the reaction. The rotating mechanism 41 can make the suspension bin assembly 44 and the stirring assembly 43 rotate in opposite directions, thereby promoting the contact between the catalyst and the solution and enabling the heavy metal ions to fully react and transform. The following is a further description of the specific structure of the rotating mechanism 41.

[0111] Reference Figures 15 to 19 , the rotating mechanism 41 includes a stirring collar 411, a through shaft 412 and a gear transmission assembly 413. The stirring collar 411 and the through shaft 412 are respectively in transmission connection with the gear transmission assembly 413. Among them, the gear transmission assembly 413 realizes the opposite rotation directions of the stirring collar 411 and the through shaft 412 through a series of gear transmissions.

[0112] Specifically, the stirring collar 411 is in the shape of a hollow column and is rotatably connected to the bottom of the catalytic reaction tank 3. A bearing ring 33 extends upward from the bottom of the catalytic reaction tank 3. An outer bearing 34 is fixedly sleeved on the outside of the bearing ring 33, and the stirring collar 411 is fixedly sleeved on the outer ring of the bearing 34, thereby realizing the rotational connection between the stirring collar 411 and the bottom of the catalytic reaction tank 3.

[0113] Reference Figures 17 to 19 , the gear transmission assembly 413 includes a first bearing 4131, a first external gear 4132, a second external gear 4133, a first internal gear 4134 and a second internal gear 4135. The first external gear 4132 and the second external gear 4133 are both rotatably connected to the catalytic reaction tank 3 respectively. The inner side of the upper end of the stirring collar 411 is coaxially and fixedly connected to the first internal gear 4134. The first external gear 4132 is located in the stirring collar 411 and meshes with the first internal gear 4134. The second external gear 4133 meshes with the first external gear 4132. The outer ring of the first bearing 4131 is fixedly connected to the catalytic reaction tank 3. The inner ring of the first bearing 4131 is coaxially and fixedly connected to the second internal gear 4135. The second internal gear 4135 meshes with the second external gear 4133. The bottom end of the through shaft 412 is fixedly connected to the second internal gear 4135.

[0114] Reference Figure 17 and Figure 18 , a first mounting shaft 35, a second mounting shaft 36 and a support member 37 are provided on the top of the bearing ring 33. The first external gear 4132 is rotatably connected to the first mounting shaft 35, the second external gear 4133 is rotatably mounted on the second mounting shaft 36. An outer positioning ring 4137 is sleeved on the outer ring of the first bearing 4131. The top end of the support member 37 is fixedly connected to the outer positioning ring 4137. The first mounting shaft 35 and the second mounting shaft 36 are both arranged in the vertical direction. The first mounting shaft 35 is fixedly connected to the top end face of the bearing ring 33. The projection of the second mounting shaft 36 on the horizontal plane is located inside the bearing ring 33 and is fixedly connected to the bottom wall of the catalytic reaction tank 3. The first external gear 4132 and the second external gear 4133 can be rotatably connected to the upper ends of the first mounting shaft 35 and the second mounting shaft 36 respectively through bearings. The first mounting shaft 35 and the second mounting shaft 36 provide axial support for the first external gear 4132 and the second external gear 4133. Among them, the first mounting shaft 35 and the second mounting shaft 36 are both located in the stirring collar 411, making the structure more compact.

[0115] It can be understood that when a pair of external gears mesh, the rotating shafts of the respective external gears rotate in opposite directions; when a pair of internal gears mesh, the rotating shafts of the respective internal gears rotate in the same direction. In this embodiment, the transmission from the stirring collar 411 to the through shaft 412, the meshing relationship of each gear is as follows: the first internal gear 4134 meshes with the first external gear 4132, the first external gear 4132 meshes with the second external gear 4133, and the second external gear 4133 meshes with the second internal gear 4135. Therefore, in the entire transmission path, there is a pair of external gears meshing and two pairs of internal and external gears meshing. Since the meshing of internal and external gears does not change the rotation direction of the shaft, and the meshing of external gears changes the rotation direction of the shaft, the above transmission relationship can make the stirring collar 411 and the through shaft 412 have opposite rotation directions.

[0116] By selecting an appropriate transmission ratio, different rotational speeds can be generated between the stirring collar 411 and the through shaft 412. For example, in this embodiment, since the linear velocity of the gears at each meshing point is the same, but the diameter of the second internal gear 4135 is larger than that of the first internal gear 4134, the angular velocity of the second internal gear 4135 is less than that of the first internal gear 4134. That is, if the second internal gear 4135 rotates one week, the number of rotations of the first internal gear 4134 will be greater than one week, making the rotational speed of the stirring assembly 43 greater than the rotational speed of the catalyst chamber 441, promoting the contact between the catalyst and the liquid, and improving the efficiency of converting hexavalent chromium ions into trivalent chromium ions.

[0117] Reference Figures 17 to 19 , the first internal gear 4134 is fixedly connected to the inner side of the upper end of the stirring collar 411. The projection of the first external gear 4132 on the horizontal plane is located within the stirring collar 411, so it can mesh with the first internal gear 4134. The height of the first external gear 4132 in the vertical direction is higher than that of the first internal gear 4134, so that the lower end of the first external gear 4132 meshes with the first internal gear 4134, and the upper end of the first external gear 4132 extends above the stirring collar 411. The projection of the axis of the second external gear 4133 on the horizontal plane is located within the stirring collar 411, making the structure compact, and the second external gear 4133 meshes with the upper end of the first external gear 4132. The second internal gear 4135 meshes with the second external gear 4133, so the second external gear 4133 can drive the second internal gear 4135 to rotate. The second internal gear 4135 is fixedly connected to the inner ring of the first bearing 4131, thereby driving the inner ring of the first bearing 4131 to rotate. The outer ring of the first bearing 4131 is fixedly connected to the top of the bearing ring 33 at the bottom of the catalytic reaction tank 3, which can be connected through an intermediate connecting part, so that the first bearing 4131 can be supported above the stirring collar 411.

[0118] Reference Figure 18, the inner ring of the first bearing 4131 and the second internal gear 4135 can be connected through an intermediate part, for example, through a rotating ring 4136. The bottom end of the through shaft 412 can also be indirectly fixedly connected to the second internal gear 4135 through the rotating ring 4136.

[0119] Another advantage of the gear transmission assembly 413 used in this embodiment is that the central axes of the through shaft 412 and the stirring collar 411 are the same, that is, the rotation centers of the through shaft 412 and the stirring collar 411 are the same. Therefore, the rotation center of the stirring assembly 43 can be made the same as the rotation center of the suspension tank assembly 44. Both can be located at the center of the cylindrical catalytic reaction tank 3, which can cover the catalytic reaction tank 3 more fully than an eccentric setting, promoting the contact reaction between the solution stirring and the catalyst. At the same time, only one driving mechanism 42 is required in this embodiment to drive two opposite rotational motions, while two driving mechanisms 42 are usually required in the prior art. For each bearing used in this embodiment, if it needs to bear an axial load, a bearing type that can bear the axial load can be selected, such as a cylindrical roller bearing, which can provide support in the axial direction.

[0120] Reference Figure 15 , Figure 17 and Figure 22 , the through shaft 412 includes a plurality of shaft bodies 4121 circumferentially distributed along the second internal gear 4135. The bottoms of the shaft bodies 4121 are respectively fixedly connected to the second internal gear 4135. The suspension tank assembly 44 is provided with a plurality of through holes 4443 in the vertical direction. The shaft bodies 4121 respectively pass through the through holes 4443 and are movably connected to the suspension tank assembly 44.

[0121] In this embodiment, the shaft body 4121 can be bent from bottom to top. For example, the bottom of the shaft body 4121 is fixedly connected to the second internal gear 4135 through a rotating ring 4136. Each shaft body 4121 forms a bent structure that converges inward from the bottom end upward. After the shaft bodies 4121 converge, they extend vertically upward, making the structure more compact. When ensuring that the suspension bin assembly 44 has the functions of rotation and floating, the number of shaft bodies 4121 can be selected according to actual needs. For example, three shaft bodies 4121 are used in this embodiment. Three or more shaft bodies 4121 can ensure to a certain extent that the suspension bin assembly 44 always remains horizontally stable during the vertical floating process, thereby ensuring to a certain extent that the chemical reaction of converting hexavalent chromium ions into trivalent chromium ions proceeds continuously and stably. The suspension bin assembly 44 is connected through a plurality of shaft bodies 4121 passing through the through holes 4443, so that the suspension bin assembly 44 can not only float stably in the vertical direction but also rotate together with the through shaft 412. Since the suspension bin assembly 44 is movably connected in the vertical direction and can always float in the liquid along with the change of the liquid level height in the catalytic reaction tank 3, the catalyst in the suspension bin assembly 44 can always be in contact with the liquid, effectively carrying out the catalytic reaction.

[0122] Reference Figure 15 and Figure 23 , a second cross beam 38 is fixedly connected to the top of the catalytic reaction tank 3. A positioning column 381 extends downward from the bottom of the second cross beam 38. A positioning bearing 382 is sleeved on the positioning column 381. The outer ring of the positioning bearing 382 is fixedly connected to the top of each shaft body 4121. The positioning bearing 382 positions each shaft body 4121 to form a stable through shaft 412 structure. The top of each shaft body 4121 has an arc-shaped step 4122 that can match the outer ring of the positioning bearing 382 for fixed connection with the outer ring of the positioning bearing 382.

[0123] Reference Figures 20 to 22 , the suspension bin assembly 44 will be specifically described below. The suspension bin assembly 44 can carry a catalyst to contact with the solution, thereby promoting the reaction. The suspension bin assembly 44 includes a catalyst bin 441, a float piece 442, a retaining rod 443, and a suspension middle cylinder 444. The retaining rod 443 is fixedly connected to the suspension middle cylinder 444 and extends circumferentially. Both the catalyst bin 441 and the float piece 442 are annular and surround the outside of the suspension middle cylinder 444 and are respectively fixedly connected to the retaining rod 443. The suspension bin assembly 44 is movably connected to the rotating mechanism 41 in the vertical direction and rotates with the rotating mechanism 41. The rotating mechanism 41 has a plurality of shaft bodies 4121 arranged vertically. Each shaft body 4121 rotates around the same vertical axis. The suspension bin assembly 44 is provided with a plurality of through holes 4443 in the vertical direction. Each shaft body 4121 respectively passes through each through hole 4443 for movable connection.

[0124] In this embodiment, buoyancy is provided by the float member 442, and the catalyst chamber 441 and the float member 442 are connected to the suspension middle cylinder 444 through the retaining rod 443. Since the suspension chamber assembly 44 is movably connected to the rotating mechanism 41 in the vertical direction, it can always be suspended in the solution as the liquid level changes, so that the catalyst in the suspension chamber assembly 44 can always be in contact with the solution. At the same time, the suspension chamber assembly 44 can rotate with the rotating mechanism 41 to promote further contact between the solution and the catalyst, and effectively carry out the catalytic reaction.

[0125] Specifically, the catalyst chamber 441 can be generally circular ring-shaped and has an inner cavity 4411 for accommodating the catalyst. The catalyst can be made by mixing iron and carbon to form a micro-electrolysis catalyst, and the primary battery effect formed between iron and carbon is used to reduce hexavalent chromium. A liquid inlet hole 4412 communicating with the inner cavity 4411 is provided on the side wall of the catalyst chamber 441, so that the liquid can enter the inner cavity 4411 to contact the catalyst. The float member 442 can also be generally circular ring-shaped, or formed by combining multiple arcs to form a circular ring. A plurality of catalyst chambers 441 and float members 442 can be provided, and the diameters of the catalyst chambers 441 and the float members 442 can be different and are alternately sleeved in the radial direction, so that the catalyst chambers 441 and the float members 442 are spaced apart in the circumferential direction of the suspension middle cylinder 444 to provide buoyancy for the suspension chamber assembly 44 better and more balanced. When the float member 442 is set as a ring, float tips 4421 can be provided at both ends of the ring to reduce the liquid resistance during rotation. The catalyst in the suspension chamber assembly 44 can always be in contact with the liquid, thereby effectively promoting the chemical reaction of converting hexavalent chromium into trivalent chromium.

[0126] Embodiment 2

[0127] Reference Figure 20 , this embodiment is similar to Embodiment 1, the difference is that in this embodiment, the float member 442 includes an inner float and an outer float, and the catalyst chamber 441 includes a first chamber body, a second chamber body and a third chamber body. They are arranged in sequence from the inside to the outside as: the first chamber body, the inner float, the second chamber body, the third chamber body and the outer float. By setting an appropriate buoyancy size, the suspension chamber assembly 44 can always be in the liquid, so that the suspension chamber assembly 44 can be in full contact with the liquid in the catalytic reaction tank 3 and carry out a chemical reaction.

[0128] Reference Figure 20 and Figure 22 , the floating middle cylinder includes an outer cylinder 4441 and an inner disk 4442. Among them, the outer cylinder 4441 is vertically penetrated, and the inner disk 4442 is provided with a plurality of through holes 4443 in the vertical direction and is fixedly connected to the outer cylinder 4441. Each retaining rod 443 is fixedly connected to the outside of the outer cylinder 4441, and each shaft body 4121 passes through the through hole 4443 of the inner disk 4442 for movable connection.

[0129] ReferenceFigure 22 On one side surface of the retaining rod 443, it is fixedly connected to the catalyst chamber 441 and the float member 442. The other side surface of the retaining rod 443 is streamlined, and through this streamlined design, the resistance in contact with the liquid can be reduced. For example, retaining rods 443 are fixedly connected to both the upper side and the lower side of the catalyst chamber 441 and the float member 442 respectively. The bottom of the retaining rod 443 located on the upper side is fixedly connected to the catalyst chamber 441 and the float member 442, and the top is streamlined. The top of the retaining rod 443 located on the lower side is fixedly connected to the catalyst chamber 441 and the float member 442, and the bottom is streamlined.

[0130] Example 3

[0131] This embodiment provides a chemical remediation treatment process for soil heavy metal pollution, which is used in combination with the device as shown in Figures 1 to 24 and includes the following steps:

[0132] S1: Perform soil pickling on the heavy metal - contaminated soil in the pickling tank 1;

[0133] S2: Observe the soil pickling progress in the pickling tank 1 in real - time through the pickling progress monitoring device 2 until the soil pickling is completed;

[0134] S3: Perform solid - liquid separation on the mixed liquid obtained after pickling through the solid - liquid separation device 6;

[0135] S4: Feed the solution obtained after solid - liquid separation into the catalytic reaction tank 3, and make the solution and the catalyst rotate in opposite directions through the stirring and catalyzing device 4 to promote the reaction and reduce heavy metal pollution.

[0136] In step S1, the heavy metal - contaminated soil is put into the feed bin 12 of the pickling tank 1. The mixed liquid in the pickling tank 1 contacts and rinses the soil through the holes on the rinsing mesh 13, so that the soil is evenly diffused in the pickling solution. The heavy metal elements in the soil are dissolved into the pickling solution in an ionic state, and hard debris such as stones and glass are isolated at the bottom of the feed bin 12.

[0137] In step S1, the pickling propeller 14 on the inner side wall of the pickling tank 1 is used to push the pickling solution to rotate and generate a swirl, improving the rinsing of the pickling solution on the soil and the uniform diffusion effect of the soil in the pickling solution.

[0138] In step S2, the float assembly 21 of the pickling progress monitoring device 2 floats up and down as the density of the mixed liquid in the pickling tank 1 changes. The float assembly 21 drives the observation assembly 23 to change through the linkage assembly 22, so that the pickling end point can be visually judged without sampling and experimenting on the mixed liquid.

[0139] In step S3, the pickling mixed solution and the soil are separated by the solid-liquid separation device 6, so that the repaired soil and the solution contaminated with heavy metal ions are obtained. The solution contaminated with heavy metal ions is sent into the electro-chemical oxidation cell for catalytic reaction.

[0140] In step S4, the stirring and catalytic device 4 has a stirring component 43 and a suspension bin component 44 with opposite rotation directions. The solution in the catalytic reaction cell 3 can be agitated by the stirring component 43 to form a swirling flow. The catalyst is carried by the suspension bin component 44, so that the solution and the catalyst rotate in opposite directions to promote the reaction and reduce the heavy metal pollution in the soil.

[0141] In step S4, the suspension bin component 44 of the stirring and catalytic device 4 is suspended in the solution. During the process of adding the solution into the catalytic reaction cell 3, the suspension bin component 44 can float up as the liquid level in the catalytic reaction cell 3 rises, so that the catalyst and the solution can always be in full contact.

[0142] After step S4, the recyclable heavy metal resources in the solution are recycled. For example, hexavalent chromium is reduced to trivalent chromium, and then by increasing the pH value, Cr(OH) 3 precipitate is recycled.

[0143] In the chemical remediation treatment process of soil heavy metal pollution in this embodiment, since the pickling end point can be judged without sampling and experimenting on the pickling mixed solution, the soil pickling efficiency can be effectively improved. The suspension catalytic stirring reaction device can promote the full contact between the solution and the catalyst, so the conversion rate of heavy metal ions can be increased, which is beneficial to the resource utilization of soil heavy metals. For example, hexavalent chromium is reduced to trivalent chromium, the heavy metal pollution of hexavalent chromium ions is reduced, and the metal resources of trivalent chromium are recycled.

[0144] The above embodiments are only for illustration. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A chemical remediation treatment device for heavy metal pollution in soil, characterized by: include A pickling tank (1), wherein the pickling tank (1) is used for soil pickling; A pickling progress monitoring device (2), the pickling progress monitoring device (2) is connected to the pickling tank (1) and is used to monitor the soil pickling progress in real time; A solid-liquid separation device (6), the inlet of which is connected to the pickling tank (1), and is used for performing solid-liquid separation on the mixed liquid obtained by soil pickling; A catalytic reaction pool (3), the catalytic reaction pool (3) being connected to the liquid phase outlet of the solid-liquid separation device (6), and being used to receive the solution obtained after solid-liquid separation and to react to reduce heavy metal pollution in the solution; A stirring catalytic device (4), wherein the stirring catalytic device (4) is arranged in the catalytic reaction tank (3) and is used to drive the catalyst and the solution to rotate in the opposite direction in the electrochemical oxidation tank.

2. The chemical remediation treatment device for soil heavy metal pollution according to claim 1 is characterized in that: The pickling progress monitoring device (2) comprises a float assembly (21), a linkage assembly (22) and an observation assembly (23); the float assembly (21) is arranged to float in the pickling tank (1); one end of the linkage assembly (22) is connected to the float assembly (21) in a transmission manner; and the other end of the linkage assembly (22) is connected to the observation assembly (23) to drive the observation assembly (23) to change.

3. The chemical remediation treatment device for soil heavy metal pollution according to claim 2 is characterized in that: The pickling progress monitoring device (2) further comprises a filter assembly (24) and a scraper mechanism (25); the filter assembly (24) is connected to the pickling tank (1) and forms a filter space (243) in the pickling tank (1); the float assembly (21) is disposed in the filter space (243); and the scraper mechanism (25) is connected to the pickling tank (1) and is in movable contact with the outer surface of the filter assembly (24).

4. The chemical remediation treatment device for soil heavy metal pollution according to claim 2 is characterized by: The observation assembly (23) comprises a U-shaped tube (231), a piston tube (232) and a translation piston (233); the U-shaped tube (231) is fixedly connected to the outer wall of the pickling tank (1) and contains liquid; one end of the U-shaped tube (231) is connected to the piston tube (232); the translation piston (233) is fixedly connected to the linkage assembly (22) and is slidably connected in the piston tube (232).

5. The chemical remediation treatment device for soil heavy metal pollution according to claim 1 is characterized in that: The stirring catalytic device (4) comprises a rotating mechanism (41), a driving mechanism (42), a stirring component (43) and a suspension bin component (44); the rotating mechanism (41) is arranged in the catalytic reaction pool (3); the stirring component (43) and the suspension bin component (44) are respectively connected to the rotating mechanism (41); the suspension bin component (44) is used to carry a catalyst; and the driving mechanism (42) is connected to the rotating mechanism (41) to drive the stirring component (43) and the suspension bin component (44) to rotate in opposite directions simultaneously.

6. The chemical remediation treatment device for heavy metal pollution in soil according to claim 5, characterized in that: The suspension bin assembly (44) comprises a catalyst bin (441), a floating member (442), a retaining rod (443) and a suspension middle tube (444); the retaining rod (443) is fixedly connected to the suspension middle tube (444) and extends out in a circumferential direction; the catalyst bin (441) and the floating member (442) are both annular and surround the outside of the suspension middle tube (444) and are respectively fixedly connected to the retaining rod (443); the suspension bin assembly (44) is movably connected to the rotating mechanism (41) in a vertical direction and rotates with the rotating mechanism (41).

7. The chemical remediation treatment device for soil heavy metal pollution according to claim 6 is characterized by: The catalyst bin (441) has an inner cavity (4411) for accommodating a catalyst, and a liquid inlet (4412) connected to the inner cavity (4411) is provided on a side wall of the catalyst bin (441). A plurality of catalyst bins (441) and a plurality of floats (442) are provided, and each catalyst bin (441) and each float (442) are spaced apart in the circumferential direction of the suspension center tube (444).

8. The chemical remediation treatment device for heavy metal pollution in soil according to claim 5, characterized in that: The rotating mechanism (41) includes a plurality of shaft bodies (4121) arranged vertically, each of the shaft bodies (4121) rotates around the same vertical axis, and the suspension chamber assembly (44) is provided with a plurality of through holes (4443) in the vertical direction, and each of the shaft bodies (4121) passes through each of the through holes (4443) for active connection.

9. The chemical remediation treatment device for soil heavy metal pollution according to any one of claims 1 to 8, characterized in that: A soil feed port (11) is provided on the side wall of the pickling tank (1), the outer side of the soil feed port (11) is connected to a feed bin (12), and the inner side of the soil feed port (11) is connected to a rinse net (13).

10. A chemical remediation process for heavy metal pollution in soil, using the device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: The soil contaminated by heavy metals is subjected to soil acid washing in an acid washing tank (1); S2: using the pickling progress monitoring device (2) to observe the pickling progress of the soil in the pickling tank (1) in real time until the pickling of the soil is completed; S3: performing solid-liquid separation on the mixed liquid obtained after pickling by a solid-liquid separation device (6); S4: The solution obtained after solid-liquid separation is sent to the catalytic reaction pool (3), and the solution and the catalyst are rotated in the opposite direction by the stirring catalytic device (4) to promote the chemical reaction of heavy metal ions and reduce heavy metal pollution.

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