Root protection and chromium enrichment strengthening device and method for plant growing in chromium contaminated soil

Abstract

The application relates to the technical field of planting, and discloses a root protection and chromium enrichment strengthening device and method for plant planting in chromium-polluted soil, which comprises a planting fixing device, a root isolation device and a chromium enrichment device. The three functions of physical planting fixation, root isolation protection and repair strengthening of plants are integrated in one body, the survival rate of chromium enrichment plant planting is improved, and with the help of a coarse filtration layer, an adsorption conversion layer and a slow-release layer with selective barrier function, a protective barrier can be established between the plant roots and the chromium-polluted soil, so that the initial chromium exposure concentration of the roots is reduced, the survival rate of seedlings and the early growth speed are significantly improved, and a lower expansion ring is arranged on the planting fixing device, the angle of the lower expansion ring on the universal ball can be adjusted through the angle rotation of the clamping seat, and the planting fixation of plants with different root sizes can be realized.

Description

Technical Field

[0001] This invention belongs to the field of planting, specifically relating to a device and method for root protection and chromium enrichment enhancement in chromium-contaminated soil. Background Technology

[0002] The remediation and safe utilization of chromium-contaminated soil is an important issue in the current environmental protection field. Chromium (Cr) is a common heavy metal pollutant in soil. It is highly toxic to plant roots, can inhibit plant growth, and reduce the efficiency of phytoremediation.

[0003] Currently, the remediation of chromium-contaminated soil mostly involves using chromium-accumulating plants, which are planted on the soil to absorb chromium ions. However, when using existing technologies for phytoremediation of chromium-contaminated soil, the roots of the plant seedlings come into direct contact with the high concentration of chromium in the soil, which can lead to root poisoning, low survival rates, and slow growth. Furthermore, relying solely on the accumulation capacity of the phytoaccumulating plants results in a long remediation cycle, and the remediation effect is not ideal for moderately to severely contaminated soil.

[0004] This application proposes a root protection and chromium enrichment enhancement device and method for planting plants in chromium-contaminated soil, which improves upon the aforementioned deficiencies. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a root protection and chromium enrichment enhancement device and method for planting plants in chromium-contaminated soil, which has the function of protecting the roots of planted plants and enhancing the chromium enrichment effect.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A root protection and chromium enrichment enhancement device and method for planting plants in chromium-contaminated soil, the structure of which includes a planting fixing device, a root isolation device and a chromium enrichment device. The planting fixing device is installed at the inner bottom of the root isolation device and is on the same center line as the root isolation device. A chromium enrichment device that can promote chromium enrichment efficiency is installed on the outer wall of the root isolation device.

[0008] In one specific implementation scheme, the planting fixing device includes an upper fixing ring, a lower expansion ring, a strap, perforated holes, and a receiving mechanism. The lower expansion ring is located directly below the upper fixing ring and is centered on the same location. The upper fixing ring and the lower expansion ring are connected by several sets of receiving mechanisms, which are arranged in a circular array. The inner sidewalls of the upper fixing ring and the lower expansion ring are connected to the strap, and the sidewall of the strap has several perforated holes.

[0009] In one specific implementation scheme, the upper fixing ring includes a locking block, a pin, and a mounting groove. The top of the upper fixing ring has a plurality of locking blocks arranged symmetrically in pairs, and a pin is installed between each pair of symmetrical locking blocks. The top of the upper fixing ring has a mounting groove that can be installed and fixed with the receiving mechanism.

[0010] In one specific implementation scheme, the lower expansion ring includes a left arc plate, a right arc plate, bolts, and a sliding groove. The right arc plate is spliced ​​to one side of the left arc plate to form the lower expansion ring. The two ends connecting the left and right arc plates are threadedly fixed by bolts. Sliding grooves are provided on both the left and right arc plates, and the sliding grooves are fixed to the bottom of the receiving mechanism by screws.

[0011] In one specific implementation scheme, the receiving mechanism includes a U-shaped seat, a universal ball joint, a clamping seat, an adjusting bolt, a steering seat, and a slider. The top two ends of the U-shaped seat are connected and fixed to the bottom of the locking block on the upper fixing ring. A universal ball joint is installed on the U-shaped seat. The clamping seat is rotatably engaged on the universal ball joint through a slot. An adjusting bolt is installed on the clamping seat. The bottom of the clamping seat is rotatably engaged with the steering seat through a bearing pin. A slider is installed on the bottom of the steering seat and is engaged inside a groove.

[0012] In one specific implementation, the adjusting bolt passes through the opening of the clamping seat and is secured by a nut.

[0013] In one specific implementation scheme, the root isolation device includes a flowerpot base, exchange holes, slots, a coarse filter layer, trapezoidal blocks, an adsorption conversion layer, and a slow-release layer. The flowerpot base has exchange holes on its side walls and bottom. The inner wall of the flowerpot base has several slots, on which the coarse filter layer is slidably engaged. The outer wall of the coarse filter layer has several trapezoidal blocks that engage with the slots. The inner wall of the coarse filter layer has an adsorption conversion layer and a slow-release layer arranged sequentially. The coarse filter layer, the adsorption conversion layer, and the slow-release layer form a multi-layer composite structure.

[0014] In one specific implementation, the coarse filter layer is made of non-woven fabric with relatively large pore size and high mechanical strength, which can prevent large particles, gravel, etc. in the contaminated soil from entering the interior of the planting fixing device.

[0015] In one specific implementation, the adsorption conversion layer is composed of a porous polymer matrix loaded with active components and the active components, wherein the porous polymer matrix provides the contact area, and the active components include zero-valent iron nanoparticles, modified layered double hydroxides, and sulfide-modified materials.

[0016] In one specific implementation, the sustained-release layer is composed of a dense, hydrophilic, and biocompatible porous membrane made from a blend of polylactic acid (PLA) and starch.

[0017] In one specific implementation, the chromium enrichment device includes a sealing cap, conduits, a storage chamber, a placement chamber, a control unit, a diversion pipe, and a micro pump. The chromium enrichment device has a storage chamber and a placement chamber inside. The top of the chromium enrichment device is threadedly connected to the sealing cap. A diversion pipe is installed inside the storage chamber. One end of the diversion pipe is connected to the outlet of the micro pump. Several drain outlets at the bottom of the diversion pipe pass through the chromium enrichment device and are connected to several conduits. Several of the conduits are installed at the bottom of the chromium enrichment device. A control unit is installed inside the placement chamber.

[0018] In one specific implementation, the control unit includes a power module and a signal processing module, which are electrically connected to the micropump and can drive the micropump to operate.

[0019] In one specific implementation, the conduit includes permeation holes and a humidity sensor. The conduit corresponds to several exchange holes on the flowerpot base and, with the aid of an L-shaped structure, can pass through the exchange holes and the straps to extend into the interior of the planting fixing device. Several permeation holes are provided on the side wall of the end of the conduit that extends into the planting fixing device, and a humidity sensor is installed on the tail end of the conduit.

[0020] In one specific implementation, filters are installed on several of the permeation holes to prevent particles or matrix from clogging the permeation holes.

[0021] According to the above-mentioned technical solution, the root protection and chromium enrichment enhancement device and method for planting plants in chromium-contaminated soil of the present invention have the following beneficial effects:

[0022] (1) This invention integrates three major functions: physical planting fixation, root isolation and protection, and repair and strengthening of plants, thereby improving the survival rate of chromium-rich plants.

[0023] (2) The present invention provides a lower expansion ring on the planting fixing device. By means of the angle rotation of the clamping seat on the universal ball, the diameter of the lower expansion ring can be adjusted, which is suitable for planting and fixing plants with different root sizes.

[0024] (3) By adding a root isolation device, the present invention can establish a protective barrier between plant roots and chromium-contaminated soil by means of a coarse filter layer, an adsorption conversion layer and a slow release layer with selective blocking function, thereby reducing the initial chromium exposure concentration of the roots and significantly improving the survival rate and early growth rate of seedlings.

[0025] (4) By adding a chromium enrichment device, the present invention uses a humidity sensor to detect the humidity of the root environment in real time, thereby intelligently controlling the speed of the micro pump to achieve precise slow release of the chromium enrichment promoter, avoiding the situation where the plant roots rot due to excessive supply, or the chromium enrichment effect is affected by insufficient supply. Attached Figure Description

[0026] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0027] Figure 1 This is a schematic diagram of the root protection and chromium enrichment enhancement device and method for planting plants in chromium-contaminated soil, as described in the embodiments of this application.

[0028] Figure 2 This is a schematic diagram of the planting fixation device in the embodiments of this application;

[0029] Figure 3 This is a schematic diagram of the structure of the upper fixing ring and the lower expanding ring in the embodiments of this application;

[0030] Figure 4 This is a schematic diagram of the receiving mechanism in the embodiments of this application;

[0031] Figure 5 This is a schematic diagram illustrating the expansion process of the receiving mechanism in an embodiment of this application;

[0032] Figure 6 This is a schematic diagram of the root isolation device in the embodiments of this application;

[0033] Figure 7 This is a schematic diagram of the chromium enrichment device in the embodiments of this application;

[0034] Figure 8 This is a schematic diagram showing the internal cross-section of the chromium enrichment device in the embodiments of this application;

[0035] Figure 9 This is a schematic diagram of the catheter structure in an embodiment of this application;

[0036] Figure 10 This is a schematic diagram of the cooperation between the catheter and the implantation fixation device in the embodiments of this application.

[0037] In the diagram: Planting fixing device-1, root isolation device-2, chromium enrichment device-3, upper fixing ring-11, lower expansion ring-12, strap-13, perforated hole-14, receiving mechanism-15, locking block-111, pin-112, mounting groove-113, left arc plate-121, right arc plate-122, bolt-123, sliding groove-124, U-shaped seat-151, universal ball-shaped bracket-152, clamping seat-15 3. Adjusting bolt - 154, Steering seat - 155, Slider - 156, Flower pot base - 21, Exchange hole - 22, Slot - 23, Coarse filter layer - 24, Trapezoidal block - 25, Adsorption conversion layer - 26, Slow release layer - 27, Sealing cap - 31, Conduit - 32, Liquid storage chamber - 33, Placement chamber - 34, Control unit - 35, Diverter pipe - 36, Micro pump - 37, Permeation hole - 321, Humidity sensor - 322. Detailed Implementation

[0038] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0039] Example 1: Please refer to Figures 1-5 The specific embodiments of the present invention are as follows:

[0040] A root protection and chromium enrichment enhancement device and method for planting plants in chromium-contaminated soil, the structure of which includes a planting fixing device 1, a root isolation device 2 and a chromium enrichment device 3. The planting fixing device 1 is installed at the inner bottom of the root isolation device 2 and is on the same center line as the root isolation device 2. The chromium enrichment device 3, which can promote the chromium enrichment efficiency, is installed on the outer wall of the root isolation device 2.

[0041] Please see Figures 2-3 The planting fixing device 1 includes an upper fixing ring 11, a lower expansion ring 12, a strap 13, a hollow hole 14, and a receiving mechanism 15. The lower expansion ring 12 is located directly below the upper fixing ring 11 and is in the same center. The upper fixing ring 11 and the lower expansion ring 12 are connected by several sets of receiving mechanisms 15. The several receiving mechanisms 15 are arranged in a circular array. The inner sidewalls of the upper fixing ring 11 and the lower expansion ring 12 are connected to the strap 13. Several hollow holes 14 are opened on the sidewall of the strap 13.

[0042] Several perforations 14 allow the roots of the planted plants to come into contact with the external soil, facilitating the exchange of gases and water.

[0043] Please see Figures 2-3The upper fixing ring 11 includes a locking block 111, a pin 112, and a mounting groove 113. The top of the upper fixing ring 11 has a plurality of locking blocks 111 arranged in pairs symmetrically, and a pin 112 is installed between each pair of symmetrical locking blocks 111. The top of the upper fixing ring 11 has a mounting groove 113, which can be installed and fixed with the receiving mechanism 15.

[0044] After several pins 112 are installed, they form a "well" shaped structure, which can support the planted seedlings and prevent the plants from tilting.

[0045] Please see Figure 3 The lower expansion ring 12 includes a left arc plate 121, a right arc plate 122, a bolt 123, and a groove 124. The right arc plate 122 is spliced ​​to one side of the left arc plate 121 to form the lower expansion ring 12. The two ends of the connection between the left arc plate 121 and the right arc plate 122 are fixed by bolts 123. The left arc plate 121 and the right arc plate 122 are both provided with grooves 124. The grooves 124 are fixed to the bottom of the receiving mechanism 15 by screws.

[0046] Please see Figures 3-4 The receiving mechanism 15 includes a U-shaped seat 151, a universal ball 152, a clamping seat 153, an adjusting bolt 154, a steering seat 155, and a slider 156. The top two ends of the U-shaped seat 151 are connected and fixed to the bottom of the locking block 111 on the upper fixing ring 11. The universal ball 152 is installed on the U-shaped seat 151. The clamping seat 153 is rotatably engaged on the universal ball 152 through a slot. The adjusting bolt 154 is installed on the clamping seat 153. The bottom of the clamping seat 153 is rotatably engaged with the steering seat 155 through a bearing pin. The bottom of the steering seat 155 is equipped with a slider 156. The slider 156 is engaged inside the slide groove 124 and can slide and adjust its position on the slide groove 124.

[0047] Please see Figures 4-5 The adjusting bolt 154 passes through the opening of the clamping seat 153 and is fixed by a nut. When it is necessary to adjust the position and angle of the clamping seat 153, the fixing of the adjusting bolt 154 can be loosened by rotating the nut. This can simultaneously loosen the clamping force of the clamping seat 153 on the universal ball 152, so that the clamping seat 153 can be rotated on the universal ball 152 to the required angle. Then, the adjusting bolt 154 can be used to re-clamp and fix the position of the clamping seat 153.

[0048] Please see Figures 4-5 The steering seat 155 is designed so that when the angle of the clamping seat 153 is adjusted, the steering seat 155 can rotate synchronously, so that the bottom slider 156 always remains horizontal and vertical with the lower extension ring 12, so that the slider 156 can be installed with the slide groove 124 and slide.

[0049] Please see Figures 3-5 When it is necessary to adjust the diameter of the lower expansion ring 12, the left arc plate 121 and the right arc plate 122 on the lower expansion ring 12 are fixed by loosening the bolt 123, as well as the position between the slider 156 and the slide groove 124. Then, the angle of the clamping seat 153 on the universal ball 152 is rotated outward. As the clamping seat 153 rotates, the bottom slider 156 slides synchronously on the slide groove 124, always maintaining the connection with the lower expansion ring 12. After the adjustment is completed, the clamping seat 153 is clamped and fixed again by adjusting the bolt 154. The diameter of the lower expansion ring 12 can be adjusted, which is suitable for planting and fixing plants with different root sizes.

[0050] Please see Figures 2-5 The strap 13 is made of silicone, which has high strength, breathability and flexibility. When the expansion ring 12 expands outward, the strap 13 can elastically stretch and contract as it expands outward.

[0051] Example 2: Please refer to Figure 6 The specific embodiments of the present invention are as follows:

[0052] Please see Figure 6 The root isolation device 2 includes a flowerpot base 21, an exchange hole 22, a slot 23, a coarse filter layer 24, a trapezoidal block 25, an adsorption conversion layer 26, and a slow-release layer 27. The flowerpot base 21 has exchange holes 22 on its side walls and bottom, which can contact the external soil. The inner wall of the flowerpot base 21 has several slots 23, on which the coarse filter layer 24 is slidably engaged. The outer wall of the coarse filter layer 24 is fixed with several trapezoidal blocks 25 that engage with the slots 23 for easy replacement. The inner wall of the coarse filter layer 24 is provided with the adsorption conversion layer 26 and the slow-release layer 27 in sequence. The coarse filter layer 24, the adsorption conversion layer 26, and the slow-release layer 27 form a multi-layer composite structure.

[0053] Please see Figure 6 The coarse filter layer 24 is made of non-woven fabric with relatively large pore size and high mechanical strength, which can prevent large particles and gravel in the polluted soil from entering the interior of the planting fixing device 1, while slowing down the intrusion of fine soil particles, thereby keeping the internal matrix clean, providing protection for the inner adsorption conversion layer 26 and slow release layer 27, extending their service life, and through the connection between the trapezoidal block 25 and the flower pot base 21, it can provide structural strength for the entire protective layer.

[0054] Please see Figure 6 The adsorption conversion layer 26 is composed of a porous polymer matrix loaded with active components and the active components. The porous polymer matrix provides the contact area, and the active components include zero-valent iron nanoparticles (Fe). 0It consists of modified layered double hydroxide (LDH) and sulfide-modified material (FeS), and zero-valent iron nanoparticles (Fe). 0 Cr(VI) reacts with dissolved oxygen in the permeate water, forming a microscopic galvanic cell environment on the material surface. Through redox reactions, Cr(VI) is reduced to Cr(III), which is less toxic and less mobile. The Cr³⁺ and Fe³⁺ generated by the reaction Cr₂O₇²⁻ + 6Fe²⁺ + 14H⁺ → 2Cr³⁺ + 6Fe³⁺ + 7H₂O readily form insoluble (Cr)₂O in the near-neutral rhizosphere microenvironment. x Fe1 - x The )(OH)3 mixed hydroxide precipitate is permanently fixed inside the protective layer matrix, achieving detoxification and fixation of the most harmful chromium forms;

[0055] Modified layered double hydroxides (LDHs) can efficiently capture chromium in anionic form, such as chromate (CrO4²⁻), through interlayer ion exchange and surface adsorption. Finally, a reducing sulfur source is provided by a sulfide-modified material (FeS), which promotes the reduction of Cr(VI) and the formation of a stable chromium-iron hydroxide precipitate.

[0056] Please see Figure 6 When the adsorption and conversion layer 26 is in use, when the water in the polluted soil contains Cr(VI) and attempts to penetrate into the planting device, the active components will undergo rapid adsorption and redox reactions with it, trapping and converting chromium ions in the layer, thereby achieving selective blocking of chromium.

[0057] Please see Figure 6 The slow-release layer 27 is composed of a dense, hydrophilic and biocompatible polylactic acid (PLA) blended with starch. By further controlling the permeation rate of water and nutrients, a stable rhizosphere microenvironment is formed, and it can serve as a short-term slow-release carrier for the chromium enrichment device (3), allowing it to slowly release into the interior.

[0058] Example 3: Please refer to Figures 7-10 The specific embodiments of the present invention are as follows:

[0059] Please see Figures 1-8The chromium enrichment device 3 includes a sealing cap 31, a conduit 32, a liquid storage chamber 33, a placement chamber 34, a control unit 35, a diversion pipe 36, and a micro pump 37. The chromium enrichment device 3 has a liquid storage chamber 33 and a placement chamber 34 inside. The top of the chromium enrichment device 3 is threadedly connected to the sealing cap 31. The sealing cap 31 allows chromium enrichment promoters to be added into the liquid storage chamber 33. The liquid storage chamber 33 is equipped with a diversion pipe 36. One end of the diversion pipe 36 is connected to the outlet of the micro pump 37. Several drain outlets at the bottom of the diversion pipe 36 pass through the chromium enrichment device 3 and are connected to several conduits 32. Several conduits 32 are installed at the bottom of the chromium enrichment device 3. The placement chamber 34 is equipped with a control unit 35.

[0060] Please see Figure 8 The control unit 35 contains a power module and a signal processing module, and is electrically connected to the micro pump 37, which can drive the micro pump 37 to operate.

[0061] Please see Figures 7-10 The conduit 32 includes a permeation hole 321 and a humidity sensor 322. The conduit 32 corresponds to several exchange holes 22 on the flowerpot base 21. With the help of the L-shaped structure, it can pass through the exchange holes 22 and the strap 13 and extend into the interior of the planting fixing device 1. Several permeation holes 321 are opened on the side wall of the end of the conduit 32 that extends into the planting fixing device 1. A humidity sensor 322 is installed on the tail end of the conduit 32. The humidity sensor 322 can collect environmental humidity data of root growth in real time and convert the collected data into electrical signals and transmit them to the signal processing module of the control unit 35.

[0062] Please see Figure 9 Each of the permeation holes 321 is equipped with a filter screen to prevent particles or substrate from clogging the permeation holes 321. The chromium enrichment promoter in the liquid storage chamber 33 can be transported to the area around the plant roots through the permeation holes 321, and the slow release is achieved through the permeation holes 321 to ensure that the promoter is in full contact with the roots.

[0063] Please see Figure 8 The micro pump 37 can control the discharge rate of the accelerator liquid inside the storage chamber 33. By presetting the humidity threshold through the control unit 35, when the humidity sensor 322 detects that the humidity of the root environment is lower than the threshold, the transmitted signal will control the micro pump 37 to increase the rotation speed and increase the accelerator supply rate; when the humidity is higher than the threshold, the rotation speed of the micro pump 37 will be reduced, thereby reducing the supply rate and realizing the precise slow release of the accelerator. This avoids the situation where the plant roots rot due to excessive supply or the chromium enrichment effect is affected by insufficient supply.

[0064] Based on the above embodiments, the root protection and chromium enrichment enhancement device for planting in chromium-contaminated soil is implemented as follows:

[0065] S1, clear the weeds in the chromium-contaminated soil area, and then adjust the diameter of the lower expansion ring 12 on the planting fixing device 1 according to the size of the root system of the plants to be planted, and add chromium enrichment promoter into the liquid storage chamber 33 of the chromium enrichment device 3.

[0066] S2, fill the pot base 21 of the planting fixing device 1 and the root isolation device 2 with a good planting and seedling substrate, and plant the chromium-rich plant seedlings to be planted into the planting fixing device 1. The seedlings can be supported by several pins 112, and the assembled planting fixing device 1 is placed at the planting point in the chromium-contaminated soil area.

[0067] S3, and sets the humidity threshold through the control unit 35, provides real-time feedback data through the humidity sensor 322, automatically adjusts the slow release rate of the promoter with the help of the micro pump 37, and checks the remaining amount of chromium enrichment promoter in the reservoir 33 every 15-20 days and replenishes it in time.

[0068] S4, and the seedling roots are isolated from the chromium-contaminated soil by the coarse filter layer 24, the adsorption and conversion layer 26 and the slow release layer 27 on the root isolation device 2, thereby improving the seedling survival rate and early growth rate.

[0069] S5. After the plants have grown to maturity, the above-ground parts of the plants are harvested for chromium recovery treatment.

[0070] In the description of this invention, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0071] The control method of the present invention is through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Therefore, the present invention will not explain the control method and circuit connection in detail.

[0072] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes 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 root protection and chromium enrichment enhancement device for planting plants in chromium-contaminated soil, comprising a planting fixing device (1), a root isolation device (2), and a chromium enrichment device (3), wherein the planting fixing device (1) is installed at the inner bottom of the root isolation device (2), and the chromium enrichment device (3) is installed on the outer wall of the root isolation device (2); characterized in that: The planting fixing device (1) includes an upper fixing ring (11), a lower expansion ring (12) located directly below the upper fixing ring (11), and a number of receiving mechanisms (15) located between the upper fixing ring (11) and the lower expansion ring (12). The number of receiving mechanisms (15) are arranged in a circular array. The inner sidewalls of the upper fixing ring (11) and the lower expansion ring (12) are connected to a strap (13). The sidewall of the strap (13) is provided with a number of hollow holes (14). The root isolation device (2) includes a flowerpot base (21), exchange holes (22) provided on the side wall and bottom of the flowerpot base (21), a number of slots (23) located on the inner wall of the flowerpot base (21), a coarse filter layer (24) for sliding engagement with the slots (23), and a number of trapezoidal blocks (25) installed on the outer wall of the coarse filter layer (24). An adsorption conversion layer (26) and a slow release layer (27) are sequentially provided on the inner wall of the coarse filter layer (24). The coarse filter layer (24) and the adsorption conversion layer (26) and the slow release layer (27) form a multi-layer composite structure. The chromium enrichment device (3) includes a liquid storage chamber (33) and a placement chamber (34) with an internal opening, a sealing cap (31) threaded to the top of the chromium enrichment device (3), a diversion pipe (36) installed inside the liquid storage chamber (33), a micro pump (37) located at one end of the diversion pipe (36), and several conduits (32) connected to the bottom of the diversion pipe (36). A control unit (35) is installed inside the placement chamber (34). The upper fixing ring (11) includes a locking block (111), a pin (112) and a mounting groove (113). The top of the upper fixing ring (11) has a plurality of locking blocks (111), which are arranged symmetrically in pairs. A pin (112) is installed between each pair of symmetrical locking blocks (111). The top of the upper fixing ring (11) has a mounting groove (113) which can be installed and fixed with the receiving mechanism (15). The lower expansion ring (12) includes a left arc plate (121), a right arc plate (122) spliced ​​on one side of the left arc plate (121), bolts (123) located at both ends of the left arc plate (121) and the right arc plate (122), and a sliding groove (124) is provided on both the left arc plate (121) and the right arc plate (122). The receiving mechanism (15) includes a U-shaped seat (151), a universal ball (152) mounted on the U-shaped seat (151), a clamping seat (153) for rotating engagement with the universal ball (152), and an adjusting bolt (154) located on the clamping seat (153). The bottom of the clamping seat (153) is rotatably fitted with a steering seat (155), and the bottom of the steering seat (155) is fitted with a slider (156), which engages inside the slide groove (124). The conduit (32) includes a permeation hole (321) and a humidity sensor (322). The conduit (32) extends into the side wall of the planting fixing device (1) and has a plurality of permeation holes (321). A humidity sensor (322) is installed on the tail end of the conduit (32).

2. The root protection and chromium enrichment enhancement device for planting in chromium-contaminated soil according to claim 1, characterized in that: The coarse filter layer (24) is made of non-woven fabric with large pore size.

3. The root protection and chromium enrichment enhancement device for planting in chromium-contaminated soil according to claim 2, characterized in that: The adsorption conversion layer (26) is composed of a porous polymer matrix loaded with active components and active components, including zero-valent iron nanoparticles, modified layered double hydroxides and sulfide-modified materials.

4. The root protection and chromium enrichment enhancement device for planting in chromium-contaminated soil according to claim 3, characterized in that: The sustained-release layer (27) is composed of a dense, hydrophilic and biocompatible porous membrane made of polylactic acid and starch.

5. The root protection and chromium enrichment enhancement device for planting in chromium-contaminated soil according to claim 4, characterized in that: A filter screen is installed on each of the permeation holes (321).

6. A method for using the root protection and chromium accumulation enhancement device for planting plants in chromium-contaminated soil, employing the root protection and chromium accumulation enhancement device for planting plants in chromium-contaminated soil as described in claim 5, wherein the method of use is as follows: S1, clear the weeds in the chromium-contaminated soil area, and then adjust the diameter of the lower expansion ring (12) on the planting fixing device (1) according to the size of the root system of the plant to be planted, and add chromium enrichment promoter into the liquid storage chamber (33) of the chromium enrichment device (3). S2, fill the pot base (21) of the planting fixing device (1) and root isolation device (2) with a good planting and seedling substrate, and plant the chromium-rich plant seedlings that need to be planted into the planting fixing device (1). The seedlings can be supported by several pins (112), and the assembled planting fixing device (1) is placed in the planting point of the chromium-contaminated soil area. S3, and set the humidity threshold through the control unit (35), provide real-time feedback data through the humidity sensor (322), and automatically adjust the slow release rate of the promoter with the help of the micro pump (37), and check the remaining amount of chromium enrichment promoter in the reservoir (33) every 15 days and replenish it in time; S4, and through the coarse filter layer (24), adsorption conversion layer (26) and slow release layer (27) on the root isolation device (2), the seedling roots are isolated from the chromium-contaminated soil, thereby improving the seedling survival rate and early growth rate; S5. After the plants have grown to maturity, the above-ground parts of the plants are harvested for chromium recovery treatment.

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