Novel ex-situ remediation equipment for Cr (VI) polluted site

Abstract

The utility model discloses novel Cr (VI) contaminated site ex-situ remediation equipment, which comprises a soil crushing and screening module, a dosing module and a radio frequency module, contaminated soil is crushed and screened by the soil crushing and screening module and then is conveyed to the dosing module for adding a soil remediation agent; and finally, the soil is conveyed to the radio frequency module for radio frequency remediation of the soil. According to the device, a chemical reduction technology and a radio frequency technology are coupled, and the remediation effect on a Cr (VI) polluted site is further improved through the dissolution promoting effect of the radio frequency effect on the heavy metal Cr (VI); the integrated automatic equipment is designed, the integration level is high, low consumption and high efficiency are achieved, and the market competitiveness and innovativeness are high.

Description

Technical Field

[0001] The utility model relates to a novel ex situ repair device for Cr(VI) contaminated sites, belonging to the technical field of environmental protection equipment. Background Art

[0002] Chromium is a common heavy metal contaminant in soil, primarily existing in two forms: Cr(III) and Cr(VI). Cr(VI) is more toxic and poses a greater risk to humans. Currently, the main remediation methods for Cr(VI)-contaminated sites in China include chemical reduction, solidification and stabilization, and leaching. Chemical reduction is widely used due to its simplicity and low cost. However, in actual engineering applications, chemical reduction has drawbacks such as long remediation times and the side effects of chemicals on the soil. Utility Model Content

[0003] The technical problem to be solved by the present invention is to provide a novel ex situ remediation device for Cr(VI) contaminated sites, so as to solve the technical problems existing in the above-mentioned prior art.

[0004] The technical solution adopted by the present invention is: a new type of ex situ remediation equipment for Cr(VI) contaminated sites, including a soil crushing and screening module, a dosing module and a radio frequency module. The contaminated soil is crushed and screened by the soil crushing and screening module and then transported to the dosing module for adding soil remediation agents, and finally transported to the radio frequency module for soil radio frequency remediation.

[0005] Preferably, the soil crushing and screening module is an ALLU screening bucket.

[0006] Preferably, the dosing module includes a conveyor belt located below the discharge port of the soil crushing and screening module, a spraying pipe is arranged above the conveyor belt along the conveying direction of the conveyor belt, and one or more nozzles are arranged at the lower end of the spraying pipe, and the end of the spraying pipe is connected to a medicine box and a medicine pump.

[0007] Preferably, protective covers are provided on the periphery of the conveyor belt and the spray pipe.

[0008] Preferably, the RF module includes a stirring drum, the feed port of the stirring drum is located below the discharge port of the dosing module, the axis of the stirring drum is arranged in the horizontal direction, a spiral stirrer is coaxially arranged inside the stirring drum, and the spiral stirrer is driven by a motor fixed on the stirring drum. The inner top and inner bottom of the stirring drum are respectively equipped with an RF electrode anode and an RF electrode cathode, and the RF electrode anode and the RF electrode cathode are electrically connected to an RF power supply; a temperature sensor is provided inside the stirring drum; and a discharge valve is provided at the bottom of the stirring drum.

[0009] Preferably, a lower hopper is provided at the inlet end of the mixing drum.

[0010] Beneficial effects of the utility model:

[0011] 1. Compared with the existing technology, the utility model couples chemical reduction technology with radio frequency technology, and further improves the remediation effect of Cr(VI) contaminated sites by promoting the dissolution of heavy metal Cr(VI) through radio frequency.

[0012] 2. Compared with traditional chemical reduction technology, the utility model can greatly shorten the remediation time and can remediate a large amount of contaminated soil in a short time.

[0013] 3. The repair agent used in the present invention is green and environmentally friendly, has little impact on the soil, and is conducive to the later utilization of the soil.

[0014] 4. The utility model designs an integrated automation equipment with high integration, low consumption and high efficiency, and has strong market competitiveness and innovation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0016] Figure 2 This is a comparison diagram of the use effect of this utility model.

[0017] The figure marks in the drawings of the specification include: screening crusher 10, conveyor belt 20, spray pipe 21, nozzle 22, protective cover 23, mixing drum 30, lower hopper 31, spiral stirrer 32, motor 33, RF electrode anode 34, RF electrode cathode 35, discharge valve 36, temperature sensor 37. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1:

[0020] A new type of ex situ remediation equipment for Cr(VI) contaminated sites, such as Figure 1 As shown, it includes soil crushing and screening module, dosing module and radio frequency module.

[0021] The soil crushing and screening module is a screening crusher 10. In this embodiment, an ALLU screening bucket is used. The soil crushing and screening module crushes and screens the contaminated soil. The particle size of the crushed soil is 25-30 mm.

[0022] like Figure 1As shown, the dosing module includes a conveyor belt 20 located below the discharge port of the soil crushing and screening module. A spraying pipe 21 is provided above the conveyor belt 20 along the conveying direction of the conveyor belt 20. Seven nozzles 22 are evenly spaced at the lower end of the spraying pipe 21. The end of the spraying pipe 21 is connected to a medicine box and a medicine pump. The chemicals are sprayed onto the soil through the nozzles 22 to ensure uniform spraying and save on chemical dosage. The chemical in this embodiment is an organic acid remediation chemical, which is green and environmentally friendly, has little impact on the soil, and is conducive to the later utilization of the soil.

[0023] In this embodiment, Figure 1 As shown, a protective cover 23 is provided on the periphery of the conveyor belt 20 and the spray pipe 21 to prevent the organic agent from volatilizing.

[0024] like Figure 1 As shown, the RF module includes a mixing drum 30, and a lower hopper 31 is provided at the inlet end of the mixing drum 30. The lower hopper 31 is located below the discharge port of the dosing module. The axis of the mixing drum 30 is arranged in the horizontal direction. A spiral stirrer 32 is coaxially provided inside the mixing drum 30. The spiral stirrer 32 is driven by a motor 33 fixed to the mixing drum 30. An RF electrode anode 34 and an RF electrode cathode 35 are respectively installed at the inner top and inner bottom of the mixing drum 30. The RF electrode anode 34 and the RF electrode cathode 35 are electrically connected to an RF power supply; a temperature sensor 37 is provided inside the mixing drum 30; and a discharge valve 36 is provided at the bottom of the mixing drum 30.

[0025] The ALLU screening bucket crushes and screens the contaminated soil, and then conveys the soil via the conveyor belt 20. During the soil conveyance process, an organic acid remediation agent is sprayed into the contaminated soil via the nozzle 22. After spraying, the soil is transported to the mixing drum 30 via the conveyor belt 20. The spiral stirrer 32 fully mixes the remediation agent with the contaminated soil and ensures that the soil is evenly heated inside the drum to improve the remediation efficiency. The soil undergoes radio frequency remediation inside the mixing drum 30, and the temperature sensor 37 ensures that the temperature inside the mixing drum 30 remains within the required range.

[0026] Comparative experiment:

[0027] The experiment used chromium-contaminated soil from an alloy factory in Hunan. A certain amount of chromium-contaminated soil was added to the radio frequency device, with a moisture content controlled at 30%-40%. Reducing agents such as ferrous sulfate, calcium polysulfide, and organic acids were added in proportion to the chromium content of the soil. After mixing, the radio frequency device was activated, with a power of 50W. The reaction time was adjusted to maximize chromium removal efficiency. A control group experiment without the radio frequency device was also conducted to compare the effectiveness of radio frequency-enhanced removal of chromium-contaminated soil.

[0028] The experimental results show that the effect of radio frequency enhancement and CaSx in treating chromium contaminated soil is the best among the above experiments. Figure 2 .Depend on Figure 2 It can be seen that in the CaSx system alone, the leaching concentration of Cr(VI) decreases with increasing CaSx dosage, and the reduction efficiency increases with increasing reaction time. However, when the CaSx dosage is 8 times the Cr(VI) content in the soil and the curing reaction time is increased to 60 days, the leaching concentration of Cr(VI) still does not reach the leaching requirement of 0.05 mg / L, and the removal rate at this time is approximately 75%. In the system with RF and CaSx co-treatment, the Cr(VI) treatment efficiency is related to the RF time. Under the experimental conditions, the RF treatment time of 25 minutes is the best. When the stoichiometric ratio is 4:1, the removal rate after RF treatment increases from 30% to 75%. When the stoichiometric ratio is 8:1, the removal rate after RF treatment increases from 75% to approximately 100%. Therefore, the RF-CaSx system promotes the removal of Cr(VI), significantly improving the treatment efficiency and greatly shortening the reaction time.

[0029] The above is only a specific implementation method of the present invention, but the scope of protection of the present invention is not limited to this. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A novel ex situ remediation device for Cr(VI) contaminated sites, characterized by: It includes a soil crushing and screening module, a dosing module and a radio frequency module. The contaminated soil is crushed and screened by the soil crushing and screening module and then transported to the dosing module for adding soil remediation agents, and finally transported to the radio frequency module for soil radio frequency remediation.

2. The novel ex situ remediation equipment for Cr(VI) contaminated sites according to claim 1, characterized in that: The soil crushing and screening module is an ALLU screening bucket.

3. The novel ex situ remediation equipment for Cr(VI) contaminated sites according to claim 1, characterized in that: The dosing module includes a conveyor belt located below the discharge port of the soil crushing and screening module. A spraying pipe is arranged above the conveyor belt along the conveying direction of the conveyor belt. One or more nozzles are arranged at the lower end of the spraying pipe. The end of the spraying pipe is connected to a medicine box and a medicine pump.

4. The novel ex situ remediation equipment for Cr(VI) contaminated sites according to claim 3, characterized in that: Protective covers are provided on the peripheries of the conveyor belt and the spraying pipe.

5. The novel ex situ remediation equipment for Cr(VI) contaminated sites according to claim 1, characterized in that: The RF module includes a stirring drum, the feed port of the stirring drum is located below the discharge port of the dosing module, the axis of the stirring drum is arranged in the horizontal direction, a spiral stirrer is coaxially arranged inside the stirring drum, and the spiral stirrer is driven by a motor fixed on the stirring drum. The top and bottom of the stirring drum are respectively installed with a RF electrode anode and a RF electrode cathode, and the RF electrode anode and the RF electrode cathode are electrically connected to a RF power supply; a temperature sensor is provided inside the stirring drum; and a discharge valve is provided at the bottom of the stirring drum.

6. The novel ex situ remediation equipment for Cr(VI) contaminated sites according to claim 5, characterized in that: The inlet end of the mixing drum is provided with a lower hopper.

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