A device and treatment method for remediating contaminated soil by temperature-controlled electric combined leaching method

Abstract

The present invention relates to a device and a treatment method for remediating contaminated soil by a temperature-controlled electric combined leaching method, comprising: a leaching device, a pressurizing device, a soil treatment device, a circuit device, a connecting device, a supporting device, a waste liquid collecting device and a temperature-controlled circulation device. The beneficial effects of the present invention are as follows: the present invention is provided with a temperature-controlled circulation device and a leaching device, and by adjusting the temperature of the device during the remediation process, part of the bound water in the soil is converted into free water, the viscosity coefficient of the water is reduced, and the structure of the soil is damaged to a certain extent, thereby improving the permeability of the soil, promoting the desorption of heavy metal elements in the soil from the soil, and increasing the percentage of free heavy metal elements in the soil to the total elements, thereby accelerating the migration of pore water and heavy metal ions in the soil, and at the same time controlling the pH of the electrolyte in the leaching device and the waste liquid collecting device through water circulation.

Description

Technical Field

[0001] The invention relates to a heavy metal contaminated soil repair device, and in particular to a temperature-controlled electric combined elution method for repairing contaminated soil and a treatment method. Background Art

[0002] In recent years, the problem of heavy metal pollution in my country's soil has become increasingly serious. On the one hand, due to the advancement of urbanization, the construction and relocation of environmentally polluting enterprises such as electroplating plants, and the weak environmental awareness of some entrepreneurs, the phenomenon of indiscriminate dumping of pollutants and illegal discharge of industrial wastewater has become more and more serious. Farmland in some areas has even become an ideal place to discard heavy metal pollutants. Heavy metal pollutants enter the soil and rivers through precipitation, seepage and other channels, causing large-scale soil pollution. According to research, one ton of chromium slag is enough to pollute more than 10 hectares of farmland; on the other hand, the current heavy metal contaminated soil remediation technology is not mature enough. Traditional treatment methods such as soil replacement and isolation cannot migrate heavy metal pollutants out of the soil. A large number of pollutants in the soil still have the possibility of entering the human body through migration, food chain and other channels, causing serious troubles to people's lives and safety. In the long run, the problem of heavy metal pollution in soil has many disadvantages for my country's environmental protection and economic development.

[0003] Using appropriate technical means to migrate heavy metal pollutants out of the soil and reduce the concentration of pollutants in the soil to an appropriate range has become a current research hotspot. The elution method uses water pressure to inject elution liquid containing complexing agents, chelating agents and other ingredients into the soil, so that the heavy metal pollutants in the soil undergo complexation reactions, desorb from the soil particles, and leach out of the soil with the elution liquid, thereby achieving the purpose of purifying the contaminated soil; the electric remediation method applies an electric field at both ends of the soil, so that the charged heavy metal elements in the heavy metal contaminated soil are migrated out of the soil through electromigration, electroosmosis and other means, thereby reducing the heavy metal content in the soil. Both of the above methods have the advantages of simple operation and low cost, but the removal rate for heavy metal contaminated soil, especially silty contaminated soil, is low. The low permeability of silty contaminated soil restricts the effect of elution, and the single electric remediation technology is also restricted by the strong adsorption force between heavy metal elements and soil particles, resulting in unsatisfactory remediation effects.

[0004] In summary, it is particularly important to propose a device and treatment method for remediating contaminated soil by temperature-controlled electric combined leaching. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem of low efficiency in existing electric repair devices and repair methods, and to provide a temperature-controlled electric combined elution method for repairing contaminated soil and a treatment method, which improves the efficiency of heavy metal contaminated soil repair by improving the permeability of the soil, the adsorption relationship between heavy metal elements and the soil, and the pH value in the soil.

[0006] This temperature-controlled electric combined leaching method contaminated soil remediation device includes a leaching device, a pressurizing device, a soil treatment device, a circuit device, a connecting device, a supporting device, a waste liquid collection device and a temperature-controlled circulation device;

[0007] The elution device comprises an upper stainless steel plate, an interface, a first reserved hole and a stainless steel pipe; the upper stainless steel plate is made by cutting the stainless steel plate, a hole is opened on the upper stainless steel plate and a pressure device connection port is welded for connecting the pressure device; the stainless steel plate and the stainless steel pipe are welded to form the main body of the elution device, a first temperature control circulation device interface and a second temperature control circulation device interface are welded on the stainless steel pipe for connecting the temperature control circulation device; a stainless steel ring is welded at the bottom of the stainless steel pipe, and 18 first reserved holes are evenly punched on the stainless steel ring for insertion and connection of bolts; during the electric repair process, the elution liquid is placed in the elution device to achieve the purpose of increasing the removal rate of heavy metal pollutants through elution;

[0008] The pressurizing device includes a conduit and an air pump, and the air pump is connected to the pressurizing device connection port of the leaching device through the conduit; during the repair process, the leaching device is pressurized by the air pump, so as to achieve the purpose of improving the ability of the leaching liquid to penetrate the soil;

[0009] The soil treatment device includes a third reserved hole, a stainless steel hollow circular plate and a stainless steel circular tube; the stainless steel hollow circular plate and the bottom of the stainless steel circular tube are welded to form the main body of the soil treatment device; a stainless steel circular ring is welded on the upper part of the stainless steel circular tube, and 18 third reserved holes are evenly punched on the stainless steel circular ring for the insertion and connection of bolts; during the remediation process, the soil treatment device is used to place the contaminated soil to be treated;

[0010] The circuit device comprises a stainless steel electrode sheet, a fourth reserved hole, an electrode sheet placement device, a graphite electrode rod, a graphite electrode rod placement device, a digital display adjustable DC power supply and an ammeter; the stainless steel electrode sheet is made of a stainless steel plate, and a fourth reserved hole is punched on the stainless steel electrode sheet for connecting a wire; the stainless steel electrode sheet is placed on the electrode sheet placement device; the graphite electrode rod is placed on the graphite electrode rod placement device; the stainless steel electrode sheet, the ammeter, the digital display adjustable DC power supply and the graphite electrode rod are sequentially connected through a wire; during the repair process, the circuit device is used to provide voltage;

[0011] The connecting device includes bolts, second reserved holes, a circular hollow PVC liner plate and nuts; the circular hollow PVC liner plate is made by cutting the PVC plate, 18 second reserved holes are evenly opened around the circular hollow PVC liner plate, and 18 bolts and 18 nuts are prepared for the connection and sealing of the soil treatment device and the leaching device in the later stage. The bolts are connected and fixed with the nuts through the first reserved holes, the second reserved holes and the third reserved holes to connect the soil treatment device and the leaching device;

[0012] The support device is welded by a stainless steel bar and a first stainless steel column leg, and is painted with anti-skid paint; the support device is used to support and fix the structure located above it;

[0013] The waste liquid collection device includes a plastic cover and a waste liquid collection chamber. The waste liquid collection chamber is cast by concrete. A plastic cover with holes is arranged above the waste liquid collection chamber to reduce the evaporation of the solution and the influence of external conditions on the repair during the repair.

[0014] The temperature control circulation device includes a water level controller, a water level sensor, a temperature sensor, a temperature control device, a junction box, a heating tube and a stainless steel water tank; water covers are arranged above the two stainless steel water tanks, and the stainless steel water tanks contain electrolytes used for heating and water circulation; the heating tubes and the junction box are welded to the bottom of the stainless steel water tanks, and the junction box, the temperature control device and the temperature sensor are connected in sequence through wires to control the temperature of the electrolyte in the stainless steel water tanks; the stainless steel water tanks are connected to the elution device and the waste liquid collection device through a water pump, a water outlet pipe and a water inlet pipe to realize water circulation between the stainless steel water tanks and the elution device and the waste liquid collection device; the water level sensor and the temperature sensor are both located in the stainless steel water tanks, the water level sensor is connected to the water level controller, and the water level controller is connected to the water pump; the water level in the stainless steel water tank is monitored by the water level controller and the water level sensor to prevent the heating tube from dry burning.

[0015] Preferably, a first handle is welded on the stainless steel pipe to facilitate the transportation of the rinsing device.

[0016] As a preference: a second handle is welded on the stainless steel round tube.

[0017] As a preference, the inner and outer sides of the first steel material of the leaching device and the soil treatment device are coated with epoxy resin to ensure the insulation of the device, and the outer side of the outer layer of epoxy resin is coated with a first thermal insulation material to reduce heat dissipation.

[0018] Preferably, the electrode sheet placement device is composed of a first stainless steel ring, a second stainless steel ring and a second stainless steel column leg, the first stainless steel ring is connected to the second stainless steel ring by welding, and the second stainless steel column leg is arranged at the bottom of the first stainless steel ring.

[0019] Preferably, a fifth reserved hole and a sixth reserved hole are provided on the plastic cover, the fifth reserved hole matches the soil treatment device, and the sixth reserved hole matches the graphite electrode rod, and the plastic cover is divided into two parts to facilitate the subsequent closing of the cover.

[0020] Preferably, the second steel material of the stainless steel water tank is coated with a second thermal insulation material on the outside.

[0021] Preferably: during the electric repair process, corresponding electrolytes are placed in the rinsing device and the waste liquid collection device respectively; the electrolyte in the rinsing device can be selected from relevant salt solutions, organic acids, inorganic acids, surfactants and other solutions that promote the repair effect; the electrolyte in the waste liquid collection device can be selected from solutions with strong conductivity.

[0022] Preferably, during the electric repair process, a corresponding electrolyte is placed in the temperature-controlled circulation device, and the type of electrolyte should be the same as the electrolyte in the corresponding elution device or waste liquid collection device connected thereto.

[0023] The method for repairing a contaminated soil device by a temperature-controlled electric combined elution method comprises the following steps:

[0024] 1) Place the support device at the bottom of the waste liquid collection chamber, place the soil treatment device on the support device, and place a cloth bag in the soil treatment device;

[0025] 2) Load about 600kg of heavy metal contaminated soil into the bag in the soil treatment device;

[0026] 3) Place the electrode placement device and the stainless steel electrode on the top of the soil treatment device, and connect the stainless steel electrode, the ammeter and the digital adjustable DC power supply in sequence with wires;

[0027] 4) Place a circular hollow PVC liner plate between the soil treatment device and the leaching device, and connect and seal the leaching device and the soil treatment device with bolts and nuts;

[0028] 5) Place the graphite electrode rod on the graphite electric rod placement device and connect it to the digital display adjustable DC power supply with a wire;

[0029] 6) Prepare 500kg of electrolyte for the leaching device and put it into the leaching device; prepare 1000kg of electrolyte for the waste liquid collection device and put it into the waste liquid collection device;

[0030] ), connecting the pressurizing device to the elution device through a conduit;

[0031] 8) Add 2000kg of each electrolyte into two stainless steel water tanks, and connect the two stainless steel water tanks to the elution device and the waste liquid collection chamber respectively through a water pump, an inlet pipe and an outlet pipe;

[0032] 9) Place the water level sensor and temperature sensor into the stainless steel water tank, 0.3 meters from the bottom of the tank;

[0033] 10) Turn on the air pump, water pump, temperature control device and power supply to conduct the repair test, adjust the voltage to 30V-100V, adjust the temperature to 45 degrees-80 degrees, adjust the air pump to make the air pressure in the elution device reach a certain value, cover the waste liquid collection chamber with a plastic cover, and turn off the power supply after 24h-100h to end the test;

[0034] 11) Remove the leaching device and the circuit device in turn, take out the soil in the soil treatment device, and select 5-20 points to take soil samples according to requirements to detect the content of heavy metal pollutants.

[0035] During the soil remediation process, heavy metal elements in the soil migrate to the electrolyte on both sides of the soil chamber under the influence of temperature field, electric field, chemical field, gravity field, etc., among which positively charged heavy metal elements migrate to the cathode, and negatively charged heavy metal elements and compounds of other elements migrate to the anode, thereby achieving the purpose of purifying the soil.

[0036] The beneficial effects of the present invention are:

[0037] 1) The present invention complements the advantages of the electric remediation method and the elution method, enhances the ability of the elution liquid to enter the soil by means of electroosmosis and the like, and separates the heavy metal elements from the soil particles by the desorption effect of the elution liquid, so that the heavy metal elements in the soil with relatively low adsorption force can be migrated out of the soil under the action of the electric field, thereby improving the remediation efficiency.

[0038] 2) The present invention is provided with a temperature control circulation device and a leaching device. By adjusting the temperature of the device during the repair process, part of the bound water in the soil is converted into free water, the viscosity coefficient of the water is reduced, and the structure of the soil is damaged to a certain extent, thereby improving the soil permeability, promoting the desorption of heavy metal elements from the soil, and increasing the percentage of free heavy metal elements in the soil to the total elements, thereby accelerating the migration of pore water and heavy metal ions in the soil. At the same time, the pH of the electrolyte in the leaching device and the waste liquid collection device is controlled by water circulation;

[0039] 3) The elution device of the present invention introduces the elution liquid into the soil by means of water pressure, electroosmosis, etc., which reduces the OH - On the one hand, it increases the content of heavy metals, and on the other hand, it produces complexation with heavy metal ions, further promoting the desorption of heavy metal elements from the soil, while improving the electrical migration effect of heavy metal ions, thereby improving the electroremediation efficiency of heavy metal contaminated soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of a leaching device, a soil treatment device, a connecting device, and a supporting device of a device for remediating contaminated soil by a temperature-controlled electric combined leaching method;

[0041] Figure 2It is a schematic diagram of a circuit device for a device for remediating contaminated soil by a temperature-controlled electric combined leaching method;

[0042] Figure 3 , Figure 4 , Figure 5 It is an overall schematic diagram of the device for remediating contaminated soil using the temperature-controlled electric combined elution method.

[0043] Description of the accompanying drawings: 1-upper stainless steel plate, 2-pressurizing device connection port, 3-first temperature control circulation device interface, 4-second temperature control circulation device interface, 5-first handle, 6-first reserved hole, 7-stainless steel pipe, 8-bolt, 9-second reserved hole, 10-round hollow PVC liner plate, 11-nut, 12-third reserved hole, 13-stainless steel hollow circular plate, 14-second handle, 15-first steel, 16-epoxy resin, 17-first thermal insulation material, 18-stainless steel circular pipe, 19-stainless steel bar, 20-first stainless steel column leg, 21-anti-slip paint, 22-stainless steel electrode sheet, 23-fourth reserved hole, 24-first stainless steel ring, 25-second stainless steel ring (the hole size in the middle of the ring is the same as the first a stainless steel ring 24 is different), 26-a second stainless steel column leg, 27-an electrode sheet placement device, 28-a graphite electrode rod, 29-a graphite electrode rod placement device, 30-a conductor, 31-a digitally adjustable DC power supply, 32-an ammeter, 33-a plastic cover, 34-a fifth reserved hole (corresponding to a soil treatment device), 35-a sixth reserved hole (corresponding to a graphite electrode rod), 36-a waste liquid collection chamber, 37-a conduit, 38-an air pump, 39-a water inlet pipe, 40-a water outlet pipe, 41-a water pump, 42-a water level controller, 43-a water level sensor, 44-a temperature sensor, 45-a temperature control device, 46-a junction box, 47-a heating tube, 48-a water cover, 49-a second steel material, 50-a second thermal insulation material, 51-a stainless steel water tank. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principles of the present invention, several improvements and modifications may be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0045] The temperature-controlled electric combined leaching method for remediating contaminated soil is mainly equipped with a temperature-controlled circulation device and a leaching device, based on the traditional electric remediation method. During the electric remediation process, the soil is heated in real time to increase the temperature of the soil, so that part of the bound water in the soil becomes free water, the viscosity of the water is reduced, and the structure of the soil is damaged to a certain extent, thereby improving the permeability of the soil, promoting the desorption of heavy metal elements in the soil, and increasing the percentage of free heavy metal elements in the soil to the total elements. The migration of pore water and heavy metal ions in the soil is accelerated, and the pH of the electrolyte in the leaching device and the waste liquid collection device is controlled by water circulation. During the remediation process, the leaching liquid is introduced into the soil through the leaching device by water pressure, electroosmosis, etc., which reduces the OH in the soil on the one hand. - On the one hand, it increases the content of heavy metals, and on the other hand, it produces complexation with heavy metal ions, further promoting the desorption of heavy metal elements from the soil, while improving the electrical migration effect of heavy metal ions.

[0046] The materials and instruments used in the following examples are all commercially available.

[0047] Embodiment 1: Device

[0048] In this embodiment, a stainless steel plate and a stainless steel tube are used to make the elution device. Figure 1 As shown, a stainless steel plate with a thickness of 4 mm is used to make an upper stainless steel plate 1 with a diameter of 11000 mm by cutting or the like, a hole with a diameter of 20 mm is opened at a position about 100 mm away from the edge, and a pressure device connection port 2 with a diameter of 20 mm and a height of 30 mm is welded for connecting the pressure device; the stainless steel plate 1 is welded to a stainless steel pipe 7 with an inner diameter of 1000 mm, a thickness of 4 mm, and a height of 500 mm obtained by cutting to form the main body of the elution device, and the first temperature control is welded on it at positions 100 mm and 200 mm away from the top respectively. The circulation device interface 3 and the second temperature control circulation device interface 4 (the specifications of the first temperature control circulation device interface 3 and the second temperature control circulation device interface 4 are the same as those of the pressurizing device connection port 2) are used to connect the temperature control circulation device. Two first handles 5 are symmetrically welded at a distance of 200 mm from the top to facilitate the transportation of the elution device; a stainless steel ring with a thickness of 4 mm, an inner diameter of 1000 mm, and an outer diameter of 1100 mm is welded on the bottom surface of the stainless steel pipe 7, and 18 first reserved holes 6 with a diameter of 10 mm are evenly drilled around the ring to facilitate the insertion and connection of bolts 8 to form an elution device.

[0049] In this embodiment, the pressure device is made of organic glass plates and organic glass columns, such as Figure 3 As shown, the air pump 38 is connected to the elution device by a conduit 37 with an inner diameter of 20 mm and a length of 5000 mm to form a pressurizing device.

[0050] In this embodiment, Figure 1 As shown, a soil treatment device is manufactured, a stainless steel hollow circular plate 13 with a thickness of 4 mm and a diameter of 1100 mm is prepared by welding steel bars, and the stainless steel hollow circular plate 13 is welded to the bottom surface of a stainless steel round tube 18 with a height of 500 mm, an inner diameter of 1000 mm and a thickness of 4 mm to form the main body of the soil treatment device, and two second handles 14 are symmetrically welded at a position 200 mm away from the top of the stainless steel round tube 18, and a stainless steel circular ring with a thickness of 4 mm, an inner diameter of 1000 mm and an outer diameter of 1100 mm is welded on the top of the stainless steel round tube 18, and 18 third reserved holes 12 with a diameter of 10 mm are punched at positions corresponding to the stainless steel ring of the rinsing device for insertion and connection of the bolts 8; similar to the rinsing device, an epoxy resin 16 with a thickness of 10 mm is applied on the inside and outside of the first steel material 15 of the soil treatment device to ensure the insulation of the device, and a first thermal insulation material 17 with a thickness of 20 mm is applied on the outside of the outer epoxy resin 16 to reduce heat dissipation.

[0051] In this embodiment, the circuit device is as follows Figure 2 As shown, a stainless steel electrode sheet 22 with a diameter of 800 mm and a thickness of 40 mm is made of a stainless steel plate, and a fourth reserved hole 23 with a diameter of 20 mm is punched near the edge thereof to facilitate the connection of the wire 30; a first stainless steel ring 24 with an inner diameter of 800 mm, an outer diameter of 900 mm, and a thickness of 50 mm is welded to a second stainless steel ring 25 with an inner diameter of 850 mm and an outer diameter of 900 mm to prepare an electrode sheet placement device 27 and spray paint to ensure the insulation of the electrode sheet placement device 27; a graphite electrode rod 28 with a height of 1000 mm and a diameter of 100 mm is prepared, as shown Figure 2 and Figure 3 As shown, a graphite electrode rod holder 29 with an outer diameter of 400mm, an inner diameter of 100mm and a height of 200mm is cast with concrete; and a stainless steel electrode sheet 22, an ammeter 32, a digital adjustable DC power supply 31 and a graphite electrode rod 28 are connected through a wire 30 to form a circuit device.

[0052] In this embodiment, the connecting device is as follows Figure 1 As shown, a circular hollow PVC liner plate 10 with a thickness of 50 mm, an inner diameter of 1000 mm, and an outer diameter of 1100 mm is made by cutting a PVC plate, and 18 second reserved holes 9 with a diameter of 10 mm are opened around the circular hollow PVC liner plate 10 corresponding to the positions of the leaching device and the soil treatment device. At the same time, 18 bolts 8 and 18 nuts 11 are purchased to form a connecting device.

[0053] In this embodiment, the supporting device is as follows Figure 1As shown, 10 stainless steel bars 19 with lengths of 550 mm, 1100 mm, and 1550 mm are welded with 4 first stainless steel column legs 20 with a height of 400 mm to form a supporting device, and anti-skid paint 21 is applied thereon.

[0054] In this embodiment, the waste liquid collection device is as follows: Figure 3 As shown, a waste liquid collection chamber 36 with a height of 800 mm, a length of 2000 mm, a width of 2000 mm and a thickness of 200 mm is cast with concrete, and a plastic cover plate 33 with a length of 2200 mm and a width of 2200 mm is made by cutting and trimming, a fifth reserved hole 34 with a diameter of 1150 mm is opened in the middle of the plastic cover plate 33, a sixth reserved hole 35 with a diameter of 110 mm is opened at the position opposite to the placement of the graphite electrode rod, and the plastic cover plate 33 is evenly divided into two parts to facilitate the subsequent closing of the cover.

[0055] In this embodiment, the temperature control circulation device is as follows Figure 3 As shown, two stainless steel water tanks 51 with a diameter of 1000 mm, a height of 1000 mm, and a thickness of 4 mm and a water cover 48 with a diameter of 1050 mm and a thickness of 4 mm are made of stainless steel material to hold the electrolyte for heating and water circulation; the second heat-insulating material 50 with a thickness of 10 mm is applied to the outside of the second steel material 49 of the stainless steel water tank 51; the heating tube 47 with a length of 600 mm and the junction box 46 are welded to the bottom of the stainless steel water tank 51, and the junction box 46 is connected to the temperature control device 45 and the temperature sensor 44 in sequence with a wire to control the temperature of the electrolyte in the stainless steel water tank 51; the water circulation between the stainless steel water tank 51 and the elution device and the waste liquid collection device is realized by the water pump 41 and the water outlet pipe 40 and the water inlet pipe 39 with a diameter of 20 mm; the water level controller 42 and the water level sensor 43 are connected by wires to monitor the water level in the stainless steel water tank 51 to prevent the heating tube 47 from drying out.

[0056] In this embodiment, the overall effect diagram of the temperature-controlled electric combined elution method for remediating contaminated soil is as follows: Figure 3 , 4 , as shown in Figure 5.

[0057] In this embodiment, the stainless steel plate used is stainless steel 304, the power supply used is an adjustable ordinary digital display DC power supply (0-360V), the ammeter used is a mechanical ammeter (0-100a), and the wires, PVC lining plates, graphite electrode rods, bolts, nuts, air pumps, conduits, water pipes, water pumps, water level controllers, water level sensors, temperature sensors, and temperature control devices used are all common products on the market.

[0058] The specific implementation manner does not limit the technical solution of the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation shall fall within the protection scope of the present invention.

[0059] Embodiment 2, operation method

[0060] In this embodiment, a support device is placed at the bottom of the waste liquid collection chamber 36, and a soil treatment device is placed on the support device, and a cloth bag is placed in the soil treatment device; about 600 kg of heavy metal contaminated soil is loaded into the cloth bag of the soil treatment device; an electrode sheet placement device 27 and a stainless steel electrode sheet 22 are placed on the upper part of the soil treatment device, and the stainless steel electrode sheet 22 is connected to an ammeter 32 and a digital adjustable DC power supply 31 in sequence with a wire 30; a circular hollow PVC gasket 10 is placed between the soil treatment device and the leaching device, and the leaching device and the soil treatment device are connected and sealed with bolts 8 and nuts 11; a graphite electrode rod 28 is placed on a graphite electrode rod placement device 29 and connected to a digital adjustable DC power supply 31; 500 kg of electrolyte for the leaching device is prepared and placed in the leaching device; a waste liquid is prepared Collect 1000kg of electrolyte in the device and put it into the waste liquid collection device; connect the pressurizing device to the rinsing device through the conduit 37; add 2000kg of electrolyte in each configuration into two stainless steel water tanks 51, and connect the two stainless steel water tanks 51 to the rinsing device and the waste liquid collection chamber 36 respectively through the water pump 41 and the water pipe; put the water level sensor 43 and the temperature sensor 44 into the stainless steel water tank 51, and the sensor is placed 300mm away from the bottom of the water tank; turn on the air pump 38, the water pump 41, the temperature control device 45, and the power supply to carry out the repair test, adjust the voltage to 30V-100V, adjust the temperature to 45 degrees-80 degrees, adjust the air pump 38 so that the air pressure in the rinsing device is about 1.3 times the atmospheric pressure, cover the plastic cover 33 on the waste liquid collection chamber 36, and turn off the power supply after 24h-100h to end the test;

[0061] After the soil remediation is completed, remove the leaching device and the circuit device in turn, take out the soil in the soil treatment device, and select 5-20 points to take soil samples according to requirements to detect the content of heavy metal pollutants.

[0062] In this embodiment, the voltage during soil remediation is set by a circuit device; the required eluent is added by a elution device; the water pressure in the elution device is regulated by a pressurizing device to enhance the elution effect; the temperature in the elution device and the waste liquid collection device is set and regulated by a temperature control circulation device, and the electrolyte circulation between the stainless steel water tank and the waste liquid collection device and the elution device is controlled, and the pH of the electrolyte in the above two devices is adjusted; the waste water generated during the remediation process is collected by the waste liquid collection device; the stability of the device is ensured by a supporting device; through the above means, the heavy metal elements in the soil are migrated out of the soil under the joint action of the electric field, chemical field, etc., thereby remediating the contaminated soil, and the influence of temperature, voltage, type of eluent, and eluent hydraulic pressure on the remediation effect is studied.

Claims

1. A device for remediating contaminated soil by temperature-controlled electric combined elution method, characterized in that: It includes a leaching device, a pressurizing device, a soil processing device, a circuit device, a connecting device, a supporting device, a waste liquid collecting device and a temperature control circulation device; The elution device comprises an upper stainless steel plate (1), an interface, a first reserved hole (6) and a stainless steel pipe (7); a hole is opened on the upper stainless steel plate (1) and a pressurizing device connection port (2) is welded; the upper stainless steel plate (1) and the stainless steel pipe (7) are welded to form a main body of the elution device, and a first temperature control circulation device interface (3) and a second temperature control circulation device interface (4) are welded to the stainless steel pipe (7); a stainless steel ring is welded to the lower part of the stainless steel pipe (7), and the first reserved holes (6) are evenly punched on the stainless steel ring; The pressurizing device comprises a conduit (37) and an air pump (38), and the air pump (38) is connected to the pressurizing device connection port (2) of the elution device via the conduit (37); The soil processing device comprises a third reserved hole (12), a stainless steel hollow circular plate (13) and a stainless steel circular tube (18); the stainless steel hollow circular plate (13) and the bottom of the stainless steel circular tube (18) are welded to form a main body of the soil processing device; a stainless steel circular ring is welded to the upper part of the stainless steel circular tube (18), and the third reserved holes (12) are evenly punched on the stainless steel circular ring; The circuit device comprises a stainless steel electrode sheet (22), a fourth reserved hole (23), an electrode sheet placement device (27), a graphite electrode rod (28), a graphite electrode rod placement device (29), a digitally adjustable DC power supply (31) and an ammeter (32); the fourth reserved hole (23) is punched on the stainless steel electrode sheet (22) for connecting a wire (30); the stainless steel electrode sheet (22) is placed on the electrode sheet placement device (27); the graphite electrode rod (28) is placed on the graphite electrode rod placement device (29); the stainless steel electrode sheet (22), the ammeter (32), the digitally adjustable DC power supply (31) and the graphite electrode rod (28) are sequentially connected via the wire (30); The connecting device comprises a bolt (8), a second reserved hole (9), a circular hollow PVC liner plate (10) and a nut (11); the second reserved holes (9) are evenly arranged around the circular hollow PVC liner plate (10); the bolt (8) is connected and fixed to the nut (11) through the first reserved hole (6), the second reserved hole (9) and the third reserved hole (12) to connect the soil treatment device and the leaching device; The support device is formed by welding a stainless steel bar (19) and a first stainless steel column leg (20), and an anti-slip paint (21) is applied on the support device; The waste liquid collection device comprises a plastic cover plate (33) and a waste liquid collection chamber (36); the waste liquid collection chamber (36) is cast from concrete, and a plastic cover plate (33) with holes is arranged above the waste liquid collection chamber (36); The temperature control circulation device comprises a water level controller (42), a water level sensor (43), a temperature sensor (44), a temperature control device (45), a junction box (46), a heating tube (47) and a stainless steel water tank (51); a water cover (48) is provided above the two stainless steel water tanks (51); the heating tube (47) and the junction box (46) are welded to the bottom of the stainless steel water tank (51); the junction box (46), the temperature control device (45) and the temperature sensor (44) are connected in sequence via wires; the stainless steel water tank (51) is connected to the leaching device and the waste liquid collection device via a water pump (41), a water outlet pipe (40) and a water inlet pipe (39); the water level sensor (43) and the temperature sensor (44) are both located in the stainless steel water tank (51); the water level sensor (43) is connected to the water level controller (42); and the water level controller (42) is connected to the water pump (41); A first handle (5) is welded on the stainless steel tube (7); and a second handle (14) is welded on the stainless steel round tube (18).

2. The device for remediating contaminated soil by temperature-controlled electric combined elution method according to claim 1 is characterized in that: The inner and outer sides of the first steel material (15) of the leaching device and the soil treatment device are both coated with epoxy resin (16), and the outer side of the outer layer of epoxy resin (16) is coated with a first thermal insulation material (17).

3. The device for remediating contaminated soil by temperature-controlled electric combined elution method according to claim 1 is characterized in that: The electrode sheet placement device (27) is composed of a first stainless steel circular ring (24), a second stainless steel circular ring (25) and a second stainless steel column leg (26); the first stainless steel circular ring (24) and the second stainless steel circular ring (25) are connected by welding, and the second stainless steel column leg (26) is arranged at the bottom of the first stainless steel circular ring (24).

4. The device for remediating contaminated soil by temperature-controlled electric combined elution method according to claim 1 is characterized in that: A fifth reserved hole (34) and a sixth reserved hole (35) are provided on the plastic cover plate (33); the fifth reserved hole (34) matches the soil treatment device, and the sixth reserved hole (35) matches the graphite electrode rod (28); the plastic cover plate (33) is divided into two parts.

5. The device for remediating contaminated soil by temperature-controlled electric combined elution method according to claim 1 is characterized in that: The second steel material (49) of the stainless steel water tank (51) is coated with a second thermal insulation material (50) on the outside.

6. The device for remediating contaminated soil by temperature-controlled electric combined elution method according to claim 1 is characterized in that: Corresponding electrolytes are placed in the rinsing device and the waste liquid collection device respectively; the electrolyte in the rinsing device adopts relevant salt solutions, organic acids, inorganic acids or surfactants that promote the repair effect; the electrolyte in the waste liquid collection device adopts a solution with strong conductivity.

7. The device for remediating contaminated soil by temperature-controlled electric combined elution method according to claim 1 is characterized in that: The corresponding electrolyte is placed in the temperature control circulation device, and the type of the electrolyte is the same as the electrolyte in the corresponding elution device or waste liquid collection device connected to it.

8. A method for remediating contaminated soil by a temperature-controlled electric combined elution method as claimed in claim 1, characterized in that: The following steps are involved: 1) Place the support device at the bottom of the waste liquid collection chamber (36), place the soil treatment device on the support device, and place a cloth bag in the soil treatment device; 2) Put the heavy metal contaminated soil into the cloth bag in the soil treatment device; 3) placing an electrode placement device (27) and a stainless steel electrode (22) on the upper part of the soil treatment device, and connecting the stainless steel electrode (22), an ammeter (32) and a digital display adjustable DC power supply (31) in sequence with a wire (30); 4) placing a circular hollow PVC liner plate (10) between the soil treatment device and the leaching device, and connecting and sealing the leaching device and the soil treatment device with bolts (8) and nuts (11); 5) placing the graphite electrode rod (28) on the graphite electrode rod placement device (29) and connecting it to the digital display adjustable DC power supply (31) via a wire (30); 6) Prepare electrolyte for the elution device and place it in the elution device; prepare electrolyte for the waste liquid collection device and place it in the waste liquid collection device; 7) Connecting the pressurizing device to the elution device via the conduit (37); 8) preparing an electrolyte and adding it to two stainless steel water tanks (51), and connecting the two stainless steel water tanks (51) to the elution device and the waste liquid collection chamber (36) respectively through a water pump (41), a water inlet pipe (39) and a water outlet pipe (40); 9) Place the water level sensor (43) and the temperature sensor (44) into the stainless steel water tank (51); 10) Turn on the air pump (38), water pump (41), temperature control device (45) and power supply to conduct a repair test, adjust the voltage to 30V-100V, adjust the temperature to 45°C-80°C, adjust the air pump to make the air pressure in the elution device reach a certain value, cover the waste liquid collection chamber (36) with a plastic cover (33), and turn off the power supply after 24h-100h to end the test; 11) Remove the leaching device and the circuit device in turn, take out the soil in the soil treatment device, and select 5-20 points to take soil samples to detect the content of heavy metal pollutants.

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