Device and method for repairing organic contaminated soil through in-situ resistance heating desorption

Abstract

The invention discloses a device and method for repairing organic contaminated soil through in-situ resistance heating desorption, and belongs to the technical field of soil regeneration treatment.The device comprises a plurality of waste gas collecting devices, a movable purification vehicle and a waste gas purification device arranged on the movable purification vehicle; the waste gas collecting device comprises an in-situ heating cover, a plurality of heating rods arranged in the in-situ heating cover and a collector arranged at the top of the in-situ heating cover and communicated with the interior of the in-situ heating cover, the in-situ heating cover comprises a side wall, and a fixing frame is connected to the inner wall of the side wall; the heating rods are uniformly dispersed and fixedly connected to the fixing frame, a solar power generation cover plate is arranged at the top of the side wall, and the collector is connected with the waste gas purification device through a waste gas pipe. The device is convenient to install, clean energy is provided through solar power generation, polluted soil can be treated for a long time, the treatment cost is low, and the environment is protected. And the soil transportation cost of ex-situ treatment is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of soil regeneration and treatment, and in particular to a device and method for in-situ resistance heating desorption and restoration of organic contaminated soil. Background Art

[0002] Remediation technologies for organically contaminated soil include physical and chemical methods, bioremediation and pyrolysis. Physical and chemical methods include soil leaching, thermal desorption and chemical oxidation, which directly remove or transform pollutants through physical or chemical means. Bioremediation uses the natural degradation ability of microorganisms or plants to reduce the content of organic pollutants in the soil. Pyrolysis decomposes organic pollutants in the soil at high temperatures and is suitable for treating pollutants that are difficult to biodegrade.

[0003] Thermal desorption technology is a non-combustion environmental remediation technology. It heats the organic pollutants in the soil to a sufficient temperature through direct or indirect heat exchange under vacuum conditions or when a carrier gas is introduced, so that the organic pollutants can be volatilized or separated from the contaminated medium and enter the gas treatment system. During the thermal desorption process, the physical separation process of pollutants from one phase to another is usually not accompanied by the destruction of organic pollutants. By controlling the temperature of the thermal desorption system and the residence time of the contaminated soil, the pollutants can be selectively volatilized without chemical reactions such as oxidation and decomposition.

[0004] Most of the existing thermal desorption methods use ex situ soil remediation, that is, the contaminated soil is transported to the thermal desorption equipment for soil remediation. Such soil remediation increases the transportation cost and labor cost of the soil. The existing in situ remediation is also carried out through vehicle-mounted thermal desorption equipment, which transfers the soil to the thermal desorption equipment on the vehicle for soil remediation. The transportation and transfer of soil will increase the cost of soil remediation. Therefore, a low-cost in situ thermal desorption device for remediating organic contaminated soil is needed. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a device and method for in-situ resistance heating desorption and remediation of organic contaminated soil.

[0006] The technical solution of the present invention is: an in-situ resistance heating desorption and remediation device for organic contaminated soil, comprising several exhaust gas collection devices, a mobile purification vehicle, and an exhaust gas purification device arranged on the mobile purification vehicle, the exhaust gas collection device comprising an in-situ heating hood, a plurality of heating rods arranged inside the in-situ heating hood, and a collector arranged on the top of the in-situ heating hood and connected to the inside of the in-situ heating hood, the in-situ heating hood comprising a side enclosure, the inner wall of the side enclosure is connected to a fixing frame, the heating rods are evenly dispersed and fixedly connected to the fixing frame, a solar power generation cover is provided on the top of the side enclosure, the collector is connected to the exhaust gas purification device through an exhaust gas pipe, the exhaust gas purification device comprises an air filter device and an oxidative pyrolysis device connected to the air filter device, and the solar power generation cover is electrically connected to the electric heating rod and the exhaust gas purification device, respectively.

[0007] Furthermore, the heating rod comprises a heating shell, a heating core is fixedly connected to the interior of the heating shell, and a heating coil is wound around the outer wall of the heating core.

[0008] Description: The soil is heated by the heating rod. After the heating coil is energized, the heat is transferred to the heating shell. The heating shell can not only protect the internal heating coil, but also transfer heat to the soil.

[0009] Furthermore, the collector includes a condenser, the lower end of which passes through the solar power generation cover and is connected to the interior of the in-situ heating cover, the middle of the condenser is connected to a collection tank, and the upper end of the condenser is fixedly connected to the exhaust pipe.

[0010] Note: The height of the mobile purification vehicle is higher than the ground surface. The gas condensed in the condenser tube will flow back. Collecting the condensate in the collection tank can prevent the condensate from flowing back into the soil.

[0011] Furthermore, the fixing frame comprises a connecting net, and a clamping piece for clamping with the heating rod is movably connected to the connecting net.

[0012] Note: Fix the heating rod by connecting the clips on the net to facilitate installation and removal of the heating rod.

[0013] Furthermore, the solar power generation cover plate includes a cover plate, a battery is fixedly connected to the top of the cover plate, a protection plate is fixedly connected to the top of the battery, a photovoltaic power generation panel is fixedly connected to the top of the protection plate, and the photovoltaic power generation panel is electrically connected to the battery.

[0014] Description: Photovoltaic panels generate electricity and then store it in batteries. The protective plate can effectively prevent the solar power cover from bumping into the battery during transportation, and can also provide support for the photovoltaic panels.

[0015] Furthermore, the air filtering device includes an air filter cartridge, in which a plurality of adsorption racks for placing bagged adsorbents are clamped, a cartridge cover is hingedly connected to the top of the air filter cartridge, the bottom of the air filter cartridge is connected to the exhaust gas pipe, the cartridge cover is fixedly connected to an exhaust pipe, and the other end of the exhaust pipe is connected to the oxidative pyrolysis device.

[0016] Description: Volatile gases are adsorbed by the gas filtering device, thereby rendering the volatile gases in the soil harmless.

[0017] Furthermore, the bagged adsorbent is composed of the following components in percentage by mass: 30-45% blast furnace carbon slag, 20-30% activated carbon powder, 10-12% activated alumina particles, and the remainder is molecular sieve.

[0018] Note: The above-mentioned bagged adsorbent has a strong adsorption capacity for volatile gases, and the bagged adsorbent is also easy to replace.

[0019] Furthermore, the oxidative pyrolysis device includes an oxidation bin, the bottom of which is connected to the exhaust pipe, a heating mesh slot is fixedly connected to the oxidation bin, an electric heating wire is provided in the heating mesh slot, a catalyst box containing a catalyst is placed above the heating mesh slot, and an exhaust port is provided at the top of the oxidation bin.

[0020] Description: The volatile gas is heated, oxidized and decomposed under the action of a catalyst, which can further decompose the volatile gas.

[0021] Furthermore, the catalyst is composed of spherical Co y Cu 3-y -MOF-74, granular Mn-MOF, and powdered Co-MOF are mixed in a mass ratio of 1:1:1.

[0022] Description: The above catalyst has a good catalytic effect on the oxidative pyrolysis of volatile gases and can improve the oxidative pyrolysis efficiency of volatile gases.

[0023] Furthermore, a method for in-situ resistance heating desorption repair of organic contaminated soil is provided. Based on the above-mentioned in-situ resistance heating desorption repair of organic contaminated soil device, the method comprises the following steps: S1. Move the exhaust gas collection device to the plot that needs to be treated, and then press 1 / 30cm in the soil. 2 Insert the electric heating rod into the ground according to the standard, the insertion depth is 40~50cm, fix the top of the electric heating rod with a fixing frame, then fix the fixing frame with the inner wall of the side enclosure with bolts, and fix the solar power generation cover with the top of the side enclosure with bolts; S2. The solar power generation cover is used to power the electric heating rod, which heats the soil to volatilize and decompose the organic matter in the soil. The heating temperature of the electric heating rod is 280~300℃, and the volatile gas is passed into the exhaust pipe through the collector. The collector simultaneously collects the condensed liquid in the exhaust pipe. The exhaust pipe passes the exhaust gas into the air filter device to adsorb the volatile organic matter in the exhaust gas, and then the exhaust gas enters the oxidative pyrolysis device. The organic matter is oxidized and pyrolyzed by the oxidative pyrolysis device. The pyrolysis temperature is 250~260℃, and the pyrolysis time is consistent with the heating time of the electrolytic hot rod, which is 1~2h.

[0024] Description: The above-mentioned method of in-situ resistance heating desorption to repair organic contaminated soil can effectively remove volatile organic pollutants in the soil.

[0025] The beneficial effects of the present invention are as follows: the present invention seals the soil in different areas through an in-situ heating cover, and then heats the soil in the sealed area through a heating rod, so that the volatile organic gas in the soil evaporates, gathers in a collector, and then is introduced into a mobile purification vehicle through an exhaust pipe for exhaust gas purification. The device of the present invention is easy to install, provides clean energy through solar power generation, can carry out long-term treatment of contaminated soil, has low treatment cost, and saves the transportation cost of soil treated in situ. The device of the present invention treats volatile organic gas by adsorption and pyrolysis oxidation, and has double purification and good purification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0027] Figure 2 It is a schematic structural diagram of the exhaust gas purification device of the present invention.

[0028] Figure 3 It is a schematic diagram of the heating rod structure of the present invention.

[0029] Figure 4 It is a top view of the connection between the clamping piece and the heating rod of the present invention.

[0030] Figure 5 It is a top view of the connection between the connection net and the card connector of the present invention.

[0031] Figure 6 It is a connection relationship diagram between the heating mesh slot and the catalyst box of the present invention.

[0032] Figure 7 It is a top view of the heating mesh slot of the present invention.

[0033] Among them, 1-waste gas collection device, 10-in-situ heating cover, 2-mobile purification vehicle, 11-side panel, 12-fixed frame, 13-heating rod, 14-solar power generation cover, 15-collector, 16-waste gas pipe, 3-waste gas purification device, 131-heating shell, 132-heating core, 133-heating coil, 151-condenser, 152-collection tank, 121-connecting net, 122-clip-on fittings, 141-cover, 142-battery, 143-protective plate, 144-photovoltaic power generation panel, 31-gas filter device, 311-gas filter cylinder, 312-adsorption frame, 313-cylinder cover, 314-exhaust pipe, 32-oxidation pyrolysis device, 321-oxidation bin, 322-heating mesh slot, 323-electric heating wire, 324-catalyst box, 325-exhaust port. DETAILED DESCRIPTION

[0034] Example 1: Figure 1 As shown, a device for in-situ resistance heating desorption and remediation of organic contaminated soil includes several exhaust gas collecting devices 1, a mobile purification vehicle 2, and an exhaust gas purification device 3 arranged on the mobile purification vehicle 2. The exhaust gas collecting device 1 includes an in-situ heating cover 10, a plurality of heating rods 13 arranged inside the in-situ heating cover 10, and a collector 15 arranged on the top of the in-situ heating cover 10 and connected to the inside of the in-situ heating cover 10. The in-situ heating cover 10 includes a side enclosure 11, the inner wall of the side enclosure 11 is connected to a fixing frame 12, the heating rods 13 are evenly dispersed and fixedly connected to the fixing frame 12, a solar power generation cover 14 is provided on the top of the side enclosure 11, the collector 15 is connected to the exhaust gas purification device 3 through an exhaust gas pipe 16, the exhaust gas purification device 3 includes an air filter 31 and an oxidative pyrolysis device 32 connected to the air filter 31, and the solar power generation cover 14 is electrically connected to the electric heating rods 13 and the exhaust gas purification device 3 respectively.

[0035] like Figure 3 As shown, the heating rod 13 includes a heating shell 131 , a heating core 132 is fixedly connected to the interior of the heating shell 131 , and a heating coil 133 is wound around the outer wall of the heating core 132 .

[0036] The collector 15 includes a condenser 151 , the lower end of which passes through the solar power generation cover 14 and is connected to the inside of the in-situ heating cover 10 , the middle of the condenser 151 is connected to a collecting tank 152 , and the upper end of the condenser 151 is fixedly connected to the exhaust pipe 16 .

[0037] like Figure 4 , Figure 5 As shown, the fixing frame 12 includes a connecting net 121 , and a clamping piece 122 for clamping with the heating rod 13 is movably connected to the connecting net 121 .

[0038] The solar power generation cover plate 14 includes a cover plate 141 , a battery 142 is fixedly connected to the top of the cover plate 141 , a protection plate 143 is fixedly connected to the top of the battery 142 , a photovoltaic power generation panel 144 is fixedly connected to the top of the protection plate 143 , and the photovoltaic power generation panel 144 is electrically connected to the battery 142 .

[0039] like Figure 2 As shown, the air filter device 31 includes an air filter cartridge 311, in which a plurality of adsorption racks 312 for placing bagged adsorbents are clamped, a cartridge cover 313 is hinged on the top of the air filter cartridge 311, the bottom of the air filter cartridge 311 is connected to the exhaust pipe 16, and an exhaust pipe 314 is fixedly connected to the cartridge cover 313, and the other end of the exhaust pipe 314 is connected to the oxidative pyrolysis device 32.

[0040] The bagged adsorbent is composed of the following components in percentage by mass: 30% blast furnace carbon slag, 20% activated carbon powder, 10% activated alumina particles, and the remainder is molecular sieve.

[0041] like Figure 6 , Figure 7 As shown, based on Example 1, Example 2 differs from Example 1 in that the oxidative pyrolysis device 32 includes an oxidation bin 321, the bottom of the oxidation bin 321 is connected to the exhaust pipe 314, a heating mesh slot 322 is fixedly connected to the oxidation bin 321, an electric heating wire 323 is provided in the heating mesh slot 322, a catalyst box 324 containing a catalyst is placed above the heating mesh slot 322, and an exhaust port 325 is provided on the top of the oxidation bin 321.

[0042] The catalyst consists of spherical Co y Cu 3-y -MOF-74, granular Mn-MOF, and powdered Co-MOF are mixed in a mass ratio of 1:1:1.

[0043] Embodiment 2: This embodiment is different from Embodiment 1 in that there are four exhaust gas collecting devices 1 .

[0044] Embodiment 3: This embodiment is different from Embodiment 1 in that there are 8 exhaust gas collecting devices 1 .

[0045] Embodiment 4: This embodiment provides a method for in-situ resistance heating desorption repair of organic contaminated soil, based on the in-situ resistance heating desorption repair of organic contaminated soil device in the above embodiment 3, comprising the following steps: S1. Move the exhaust gas collection device 1 to the land to be treated, and then press 1 / 30cm in the soil. 2The electric heating rod 13 is inserted into the ground according to the standard, the insertion depth is 40 cm, the top of the electric heating rod 13 is fixed by the fixing frame 12, and then the fixing frame 12 is fixedly connected to the inner wall of the side enclosure 11 by bolts, and the solar power generation cover plate 14 is fixedly connected to the top of the side enclosure 11 by bolts; S2. The solar power generation cover plate 14 is used to supply power to the electric heating rod 13. The heating rod 13 heats the soil to volatilize and decompose the organic matter in the soil. The heating temperature of the electric heating rod is 300°C. The volatilized gas passes through the collector 15 into the exhaust pipe 16. The collector 15 simultaneously collects the condensed liquid in the exhaust pipe 16. The exhaust pipe 16 passes the exhaust gas into the air filter device 31 to adsorb the volatile organic matter in the exhaust gas. Then the exhaust gas enters the oxidative pyrolysis device 32. The organic matter is oxidatively pyrolyzed by the oxidative pyrolysis device 32. The pyrolysis temperature is 250°C. The pyrolysis time is consistent with the heating time of the electrolytic heating rod, which is 1 hour.

[0046] Example 5: This example is different from Example 4 in that the bagged adsorbent is composed of the following components in percentage by mass: 40% blast furnace carbon slag, 25% activated carbon powder, 11% activated alumina particles, and the remainder is molecular sieve.

[0047] Example 6: This example is different from Example 4 in that the bagged adsorbent is composed of the following components in percentage by mass: 45% blast furnace carbon slag, 30% activated carbon powder, 12% activated alumina particles, and the remainder is molecular sieve.

[0048] Embodiment 7: This embodiment differs from Embodiment 4 in that: In S1, the insertion depth of the electric heating rod is 50 cm; In S2, the heating temperature of the electric heating rod is 280°C, the pyrolysis temperature is 260°C, and the pyrolysis time is consistent with the heating time of the electrolytic heating rod, which is 2h.

[0049] Embodiment 8: This embodiment differs from Embodiment 4 in that: In S1, the insertion depth of the electric heating rod is 45 cm; In S2, the heating temperature of the electric heating rod is 290°C, the pyrolysis temperature is 255°C, and the pyrolysis time is consistent with the heating time of the electrolytic heating rod, which is 2h.

[0050] The heating coil 133, photovoltaic panel 144 and electric heating wire 323 used in the above embodiments are all commercially available products. As long as they can achieve the functions of the present invention, those skilled in the art can choose to use them according to common sense, and no special limitation is made here.

Claims

1. A device for in-situ resistance heating desorption and remediation of organic contaminated soil, characterized in that: The invention comprises a plurality of waste gas collection devices (1), a mobile purification vehicle (2), and a waste gas purification device (3) arranged on the mobile purification vehicle (2), wherein the waste gas collection device (1) comprises an in-situ heating cover (10), a plurality of heating rods (13) arranged inside the in-situ heating cover (10), and a collector (15) arranged on the top of the in-situ heating cover (10) and connected to the inside of the in-situ heating cover (10), wherein the in-situ heating cover (10) comprises a side enclosure (11), and the inner wall of the side enclosure (11) is connected to a fixing frame (12). ), the heating rods (13) are evenly dispersed and fixedly connected to the fixing frame (12), a solar power generation cover plate (14) is provided on the top of the side enclosure (11), the collector (15) is connected to the exhaust gas purification device (3) through an exhaust gas pipe (16), the exhaust gas purification device (3) comprises an air filter device (31) and an oxidative pyrolysis device (32) connected to the air filter device (31), and the solar power generation cover plate (14) is electrically connected to the electric heating rods (13) and the exhaust gas purification device (3), respectively.

2. The device for in-situ resistance heating desorption and remediation of organic contaminated soil according to claim 1, characterized in that: The heating rod (13) comprises a heating shell (131), a heating core (132) is fixedly connected to the interior of the heating shell (131), and a heating coil (133) is wound around the outer wall of the heating core (132).

3. The device for in-situ resistance heating desorption and remediation of organic contaminated soil according to claim 1, characterized in that: The collector (15) comprises a condenser (151), the lower end of the condenser (151) passes through the solar power generation cover plate (14) and is connected to the inside of the in-situ heating cover (10), the middle of the condenser (151) is connected to a collection tank (152), and the upper end of the condenser (151) is fixedly connected to the exhaust pipe (16).

4. The device for in-situ resistance heating desorption and remediation of organic contaminated soil according to claim 1, characterized in that: The fixing frame (12) comprises a connecting net (121), and a clamping piece (122) is movably connected to the connecting net (121) for clamping with the heating rod (13).

5. The device for in-situ resistance heating desorption and remediation of organic contaminated soil according to claim 1, characterized in that: The solar power generation cover plate (14) comprises a cover plate (141), a storage battery (142) is fixedly connected to the top of the cover plate (141), a protection plate (143) is fixedly connected to the top of the storage battery (142), a photovoltaic power generation panel (144) is fixedly connected to the top of the protection plate (143), and the photovoltaic power generation panel (144) is electrically connected to the storage battery (142).

6. The device for in-situ resistance heating desorption and remediation of organic contaminated soil according to claim 1, characterized in that: The gas filter device (31) comprises a gas filter cartridge (311), a plurality of adsorption racks (312) for placing bagged adsorbents being clamped inside the gas filter cartridge (311), a cartridge cover (313) being hingedly connected to the top of the gas filter cartridge (311), the bottom of the gas filter cartridge (311) being connected to the exhaust gas pipe (16), an exhaust pipe (314) being fixedly connected to the cartridge cover (313), and the other end of the exhaust pipe (314) being connected to the oxidative pyrolysis device (32).

7. The device for in-situ resistance heating desorption and remediation of organic contaminated soil according to claim 6, characterized in that: The bagged adsorbent is composed of the following components in percentage by mass: 30-45% blast furnace carbon slag, 20-30% activated carbon powder, 10-12% activated alumina particles, and the remainder is molecular sieve.

8. The device for in-situ resistance heating desorption and remediation of organic contaminated soil according to claim 6, characterized in that: The oxidation pyrolysis device (32) comprises an oxidation bin (321), the bottom of the oxidation bin (321) being connected to the exhaust pipe (314), a heating mesh slot (322) being fixedly connected inside the oxidation bin (321), an electric heating wire (323) being provided inside the heating mesh slot (322), a catalyst box (324) containing a catalyst being placed above the heating mesh slot (322), and an exhaust port (325) being provided at the top of the oxidation bin (321).

9. The device for in-situ resistance heating desorption and remediation of organic contaminated soil according to claim 8, characterized in that: The catalyst is composed of spherical Co y Cu 3-y -MOF-74, granular Mn-MOF, and powdered Co-MOF are mixed in a mass ratio of 1:1:

1.

10. A method for in-situ resistance heating desorption remediation of organic contaminated soil, based on the in-situ resistance heating desorption remediation of organic contaminated soil device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Move the exhaust gas collection device (1) to the land to be treated, and then press 1 / 30cm in the soil. 2 The electric heating rod (13) is inserted into the ground according to the standard, the insertion depth is 40 to 50 cm, the top of the electric heating rod (13) is fixed by a fixing frame (12), and then the fixing frame (12) is fixedly connected to the inner wall of the side enclosure (11) by bolts, and the solar power generation cover plate (14) is fixedly connected to the top of the side enclosure (11) by bolts; S2. The electric heating rod (13) is powered by the solar power generation cover plate (14). The heating rod (13) heats the soil to volatilize and decompose organic matter in the soil. The heating temperature of the electric heating rod is 280-300° C. The volatilized gas is passed into the exhaust pipe (16) through the collector (15). The collector (15) simultaneously collects the condensed liquid in the exhaust pipe (16). The exhaust pipe (16) passes the exhaust gas into the inside of the air filter device (31) to adsorb the volatile organic matter in the exhaust gas. The exhaust gas then enters the oxidation pyrolysis device (32). The organic matter is oxidized and pyrolyzed by the oxidation pyrolysis device (32). The pyrolysis temperature is 250-260° C. The pyrolysis time is consistent with the heating time of the electric heating rod, which is 1-2 hours.

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