A device for remediation of hexavalent chromium contaminated soil

Abstract

The utility model discloses a kind of repair devices of hexavalent chromium contaminated soil, more specifically relates to soil pollution remediation technical field, including mixing shell, the transmission pipe that is rotated and installed in the mixing shell inner chamber bottom surface and is penetrated downwards, mixing pipe is fixed on the transmission pipe upper end, drive motor is also fixed in the mixing shell lower end, it is connected between the drive motor with the transmission pipe by gear set, transmission pipe inner ring is provided with screening assembly.The repair device of hexavalent chromium contaminated soil of the utility model, by the double effect of " mixing pipe rotation+blocking piece impact", the caked soil is broken to small particle, cooperate the cycle processing of screening assembly, ensure that soil particle size is uniform, improve the reduction of hexavalent chromium, adopt biochar as repair agent, not only can reduce hexavalent chromium, but also can improve soil structure;Device has good adaptability to different types of soil, can meet the demand by adjusting screening aperture, facilitate the operation of device.

Description

Technical Field

[0001] This utility model relates to the field of soil pollution remediation technology, and in particular to a remediation device for hexavalent chromium contaminated soil. Background Technology

[0002] Heavy metals generally exist in nature at natural concentrations. However, activities such as mining and smelting metal ores, as well as electroplating and leather making, cause heavy metals such as chromium, lead, cadmium, and cobalt to enter the soil, resulting in environmental pollution.

[0003] Currently, the main remediation technologies for hexavalent chromium contaminated soil include: Chemical reduction method: Hexavalent chromium is reduced to trivalent chromium (Cr³⁺) by adding reducing agents (such as ferrous sulfate and sodium sulfite). However, in traditional processes, the reducing agent is not mixed evenly with the soil, which can easily lead to incomplete local remediation. Bioremediation: This method utilizes microorganisms or plants to absorb and transform hexavalent chromium, but the remediation cycle is long (usually several months to several years), making it difficult to meet the needs of rapid remediation. Physical separation method: Hexavalent chromium is separated by electrostatic remediation or soil leaching, but it is costly, energy-intensive, and prone to secondary pollution.

[0004] Existing remediation devices generally suffer from the following problems: insufficient contact of remediation agents due to incomplete breaking up of soil clumps, low mixing efficiency of remediation agents and soil, and high labor costs due to low automation of the devices. Utility Model Content

[0005] The main purpose of this invention is to provide a remediation device for hexavalent chromium contaminated soil, which can effectively solve the problems of incomplete soil clumping treatment, uneven mixing of remediation agents, and low remediation efficiency.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A remediation device for hexavalent chromium contaminated soil includes a mixing shell, a downwardly penetrating transmission pipe rotatably mounted on the bottom surface of the inner cavity of the mixing shell, a mixing pipe fixed at the upper end of the transmission pipe, a drive motor fixed at the lower end of the mixing shell, the drive motor being connected to the transmission pipe via a gear set, and a screening component being provided in the inner ring of the transmission pipe.

[0007] Preferably, the lower part of the mixing pipe is inverted conical, and multiple blocking components are fixed to the inner surface sidewall of the mixing pipe.

[0008] Preferably, the screening component includes an inverted conical mounting frame, a screw conveyor fixed on the inner surface of the mounting frame, an inclined plate fixed on the upper part of the outer surface of the screw conveyor, and multiple feed holes opened on the lower part of the outer surface of the screw conveyor.

[0009] Preferably, the mounting frame is fixedly connected to the mixing pipe, and the upper end of the mounting frame has multiple screening holes.

[0010] Compared with the prior art, the present invention has the following beneficial effects: This remediation device uses the dual action of "mixing pipe rotation + blocking component impact" to break up clumped soil into fine particles. Combined with the recycling process of the screening component (unbroken particles re-enter the crushing process), it ensures uniform soil particle size and improves the reduction rate of hexavalent chromium. This remediation device uses biochar as a remediation agent, which can not only reduce hexavalent chromium, but also improve soil structure (increase organic matter content). The device is well adaptable to different types of soil (sand, loam, clay), and the requirements can be met by adjusting the pore size of the screening holes, making the device easy to operate. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the internal structure of the mixing shell of this utility model; Figure 3 This is a cross-sectional view of the mixing pipe of this utility model; Figure 4 For the present utility model Figure 3 Enlarged view of point A in the middle.

[0012] In the diagram: 1. Mixing shell; 2. Transmission pipe; 3. Mixing pipe; 4. Blocking component; 5. Drive motor; 6. Screening component; 61. Mounting bracket; 62. Screw conveyor; 63. Inclined plate; 64. Screening hole; 65. Feed hole. Detailed Implementation

[0013] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0014] like Figure 1 and Figure 2As shown, a remediation device for hexavalent chromium contaminated soil includes a mixing shell 1. A downward-through transmission pipe 2 is rotatably installed on the bottom surface of the inner cavity of the mixing shell 1. A mixing pipe 3 is fixed at the upper end of the transmission pipe 2. A drive motor 5 is also fixed at the lower end of the mixing shell 1. The drive motor 5 is connected to the transmission pipe 2 through a gear set. At the same time, in order to prevent the soil from being thrown out under the action of centrifugal force when the mixing pipe 3 rotates, the gear at the output end of the drive motor 5 is smaller than the gear of the transmission pipe 2 to prevent the mixing pipe 3 from rotating too fast. When the device is working, the soil to be remediated is poured into the mixing pipe 3. When the drive motor 5 is working, it drives the mixing pipe 3 to rotate through the gear set. Due to the design of multiple blocking parts 4, the soil can collide with the blocking parts 4 when the mixing pipe 3 rotates, which can break up the clumps of soil and prevent the clumps of soil from not being completely mixed with the chemical solution. A screening component 6 is provided in the inner ring of the transmission pipe 2.

[0015] In addition, the lower part of the mixing pipe 3 is inverted cone-shaped. When the soil to be repaired is poured into the mixing pipe 3, the soil needs to be poured onto the outer ring of the mixing pipe 3 so that the soil can rotate when the mixing pipe 3 rotates, providing power for subsequent crushing and mixing. Multiple blocking parts 4 are fixed on the inner surface sidewall of the mixing pipe 3. The blocking parts 4 are used to prevent the normal rotation of the soil. When the mixing pipe 3 rotates, the soil can hit the sidewall of the blocking parts 4, and the impact force will break the clumps of soil into small particles to ensure that the soil and the repair agent are in full contact.

[0016] like Figure 3 and Figure 4 As shown, the screening component 6 includes an inverted conical mounting frame 61 made of high-strength plastic with a smooth surface to reduce soil retention. A screw conveyor 62 is fixed to the inner surface of the mounting frame 61 for conveying unbroken clumps of soil. An inclined plate 63 is fixed to the upper part of the outer surface of the screw conveyor 62, which allows the soil conveyed by the screw conveyor 62 to be poured back onto the outer ring of the mixing pipe 3. The mounting frame 61 is fixedly connected to the mixing pipe 3. Multiple screening holes 64 are provided at the upper end of the mounting frame 61, through which soil falling down the mixing pipe 3 accumulates on the surface of the mounting frame 61. Meanwhile, when the mixing pipe 3 rotates, it can drive the mounting frame 61 to rotate. Then, the powdered soil will fall down from the screening hole 64. Since the mounting frame 61 is designed with an inverted cone shape, the clumped soil will slide to the lowest point of the mounting frame 61. The lower part of the outer surface of the screw conveyor 62 is also provided with multiple feed holes 65. The feed holes 65 can allow the clumped soil to enter the screw conveyor 62. When the screw conveyor 62 is working, it can transport the clumped soil to the upper part. The clumped soil falls down the inclined plate 63 again into the mixing pipe 3. The mixing pipe 3 crushes the clumped soil again to facilitate the binding of the drug.

[0017] The specific implementation method of this embodiment is as follows: I. Preparatory Work The device utilizes biochar powder to remediate hexavalent chromium-contaminated soil. The hexavalent chromium reacts chemically with the biochar, reducing it to trivalent chromium, which is less toxic and more stable, accompanied by the oxidation of functional groups on the biochar surface. These products have low toxicity and weak migration, enabling the remediation of chromium-contaminated soil. 6 Biochar is widely used for the stabilization and remediation of hexavalent chromium-contaminated soils. At the same time, biochar powder has the advantages of low cost and long-term soil improvement. The soil that needs to be repaired is continuously poured into the mixing pipe 3, and biochar powder is poured in at the same time as the soil is poured in. Start the drive motor 5 and the screw conveyor 62.

[0018] II. Mixing Soil and biochar powder are poured onto the upper surface of the inclined plate 63, and then the soil and biochar powder fall down the side wall of the inclined plate 63 into the mixing pipe 3. When the mixing pipe 3 rotates, the material slides down the side wall. During the sliding process, the material will collide with the blocking part 4, breaking up the clumps of soil and biochar powder. The mixed material will gradually slide down to the side wall of the mounting frame 61, and the powdered material will fall out through the screening hole 64, thus completing the mixing of soil and biochar powder.

[0019] III. Discharge and Testing The remediated soil was collected from the bottom outlet of the mixing shell 1, and the hexavalent chromium content was tested using the "Determination of Hexavalent Chromium in Soil and Sediments by Alkali Extraction-Flame Atomic Absorption Spectrophotometry" (HJ1082-2019) until it met the standard.

[0020] It should be noted that the specific installation methods, circuit connection methods, and control methods of the drive motor 5, screw conveyor 62, and screening hole 64 in this utility model are all conventional designs, and will not be described in detail in this utility model.

Claims

1. A device for remediation of hexavalent chromium contaminated soil comprising a mixing enclosure (1), characterised in that: The mixing shell (1) has a downward-through transmission pipe (2) rotatably installed on the bottom surface of the inner cavity. The upper end of the transmission pipe (2) is fixed with a mixing pipe (3). The lower end of the mixing shell (1) is also fixed with a drive motor (5). The drive motor (5) is connected to the transmission pipe (2) through a gear set. The inner ring of the transmission pipe (2) is provided with a screening component (6).

2. A device for remediation of chromium (VI) contaminated soil according to claim 1, characterized in that: The lower part of the mixing pipe (3) is inverted cone-shaped, and multiple blocking components (4) are fixed on the inner surface sidewall of the mixing pipe (3).

3. The apparatus for remediation of Cr(VI) contaminated soil as claimed in claim 1 wherein: The screening component (6) includes an inverted conical mounting frame (61), a screw conveyor (62) is fixed on the inner surface of the mounting frame (61), an inclined plate (63) is fixed on the upper part of the outer surface of the screw conveyor (62), and a plurality of feed holes (65) are also provided on the lower part of the outer surface of the screw conveyor (62).

4. The apparatus for remediation of Cr(VI) contaminated soil according to claim 3, wherein: The mounting bracket (61) is fixedly connected to the mixing pipe (3), and the upper end of the mounting bracket (61) is provided with a plurality of screening holes (64).

Images