Purification method of contaminated soil and system

Abstract

The present invention relates to a method and system for purifying contaminated soil. By performing primary purification of contaminated soil through the effective supply and activation of microbial strains within the contaminated soil and improving the heavy metal removal efficiency through a plasma purification process, the stability of the soil after purification can be enhanced, the purification efficiency of the contaminated soil can be maximized, and the method is environmentally friendly.

Description

Technology Field

[0001] The present invention relates to a method and system for purifying contaminated soil, and more specifically, to an environmentally friendly method and system for purifying contaminated soil that can enhance soil stability after purification and maximize purification efficiency by performing primary purification of contaminated soil through the effective supply and activation of microbial strains within the contaminated soil and improving heavy metal removal efficiency through a plasma purification process. Background Technology

[0002] Generally, various types of garbage and industrial waste, which account for the largest portion of environmental pollution sources, are ultimately buried and abandoned in landfills. Thereafter, they continue to undergo changes and transformations as they move through various mediums such as water, soil, and air, causing soil and groundwater contamination and foul odors, thereby affecting the natural ecosystem, including humans.

[0003] However, compared to damage caused by pollution through soil, the exposure rate is relatively slower and the transmission pathways are complex, so treatment technologies regarding this have not yet been established.

[0004] Soil remediation technology is an important field for solving environmental pollution problems, and the remediation of soil contaminated by industrialization and urbanization is particularly urgent.

[0005] Conventional soil remediation technologies are classified into physicochemical treatment technologies, thermal treatment technologies, and biological treatment technologies.

[0006] When classifying contaminated soil treatment methods in detail, in-situ physical / chemical treatment technologies include air injection (soil vapor extraction, air sparking), steam / hot air injection, electrical thermal injection, and soil flushing; in-situ bio-remediation technologies include bioventing, biopiling, bioaugermentation, and biostimulation; and ex-situ treatment technologies include bioreactor and soil washing methods.

[0007] The physicochemical treatment technology used is Soil Vapor Extraction (SVE), the principle of which involves artificially inducing airflow within the contaminated site to promote the evaporation of harmful compounds remaining in the soil pores. It utilizes injection and extraction boreholes; through this process, pollutants are transferred from the soil to the air, and the contaminated air undergoes a post-treatment process before being released into the atmosphere.

[0008] Thermal treatment technology is a physical treatment method that physically separates contaminants from one phase to another by injecting the contaminated medium, mainly VOCs, SVOCs, PCBs, and pesticides, into a thermal desorption device (rotary dryers, heated screws, fluidized bed dryers) and heating it above a temperature at which the contaminants can volatilize.

[0009] Biological treatment technologies include bioremediation, which involves installing multiple injection holes at the contaminated site and locally introducing microorganisms and nutrients into the holes to decompose organic pollutants.

[0010] Physical methods are simple and fast but often fail to completely remove pollutants; chemical methods are effective but can place an additional burden on the environment due to the use of toxic chemicals; and biological methods, which utilize microorganisms to decompose pollutants, are environmentally friendly but have slow purification speeds and limited effectiveness against specific pollutants.

[0011] Recently, a new purification method combining microorganisms and plasma technology has been attracting attention. Microorganisms possess the ability to effectively decompose specific pollutants, while plasma technology is effective in removing trace heavy metals by utilizing high temperatures. The convergence of these technologies holds the potential to enhance the purification efficiency of contaminated soil and expand the possibilities for treating various pollutants.

[0012] In particular, methods to increase the survival rate of microorganisms and enhance stability after plasma treatment are being researched, presenting a new paradigm for contaminated soil remediation.

[0013] In addition, Korean registered patent No. 10-1206925 discloses a continuous batch contaminated soil washing system comprising at least two continuous batch contaminated soil washing devices that wash contaminated soil and wash water injectors / high-pressure aeration mixers / sedimentation devices / wash wastewater dischargers / washed soil dischargers in one cycle, a flow rate adjustment tank connected to the continuous batch contaminated soil washing devices into which the wash wastewater of each continuous batch contaminated soil washing device flows, a water treatment device connected to the flow rate adjustment tank for purifying the wash wastewater, and a control device that controls each continuous batch contaminated soil washing device to operate sequentially by controlling the operating times of each continuous batch contaminated soil washing device differently in order to use the flow rate adjustment tank and the water treatment device in a temporal order. However, the system has a problem in that it is merely a device for treating wash wastewater, rather than a device for selectively washing contaminated soil by particle.

[0014] Conventional technologies suffer from reduced washing efficiency due to excessive washing time and costs resulting from the fact that contaminated soil is washed and fed in without being dry-sorted by particle size beforehand. In particular, although Korean Registered Patent No. 10-0475431 proposes a soil washing device capable of separating and discharging soil in multiple stages by particle size and separating fine soil separately, it suffers from reduced washing treatment efficiency due to the batch-type operation rather than continuous processing.

[0015] In addition, conventional technologies produce fine soil and floating soil generated during the washing process into contaminated waste sludge for disposal, which not only incurs excessive waste treatment costs but also causes secondary environmental pollution. Furthermore, in the case of fine soil, it is difficult for the washing agent to penetrate, so there is a problem in that contaminants adsorbed on the fine soil cannot be effectively removed.

[0016] Therefore, there is an urgent need for a more effective contaminated soil remediation solution that overcomes the limitations of existing technologies by providing a method and device that efficiently separates waste vinyl from contaminated soil and effectively removes pollutants by combining microorganisms and plasma technology. Prior art literature

[0017] Domestic Patent Registration No. 10-1658523 Domestic Patent Registration No. 10-2061828 The problem to be solved

[0018] The present invention was developed to improve upon the aforementioned problems. The first objective of the present invention is to provide an environmentally friendly method and system for contaminated soil remediation, which involves performing primary remediation of contaminated soil through the effective supply and activation of microbial strains within the contaminated soil, and enhancing the efficiency of heavy metal removal through a plasma remediation process, thereby increasing the stability of the soil after remediation and maximizing the efficiency of contaminated soil remediation.

[0019] The second problem that the present invention aims to solve is to provide a method and system for purifying contaminated soil by biologically treating selected contaminated soil to purify it to a recyclable level in a short period of time in order to fundamentally eliminate soil and groundwater contamination caused by leachate continuously flowing from unsanitary landfills, and ultimately to enable the remediated and restored landfill to be recycled into useful land (residential land, flower complex, livestock barn, park, sports facility, parking lot, etc.).

[0021] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0022] To achieve the above objective, the contaminated soil purification method according to the present invention has the following technical features: a step of separating waste vinyl materials within the contaminated soil; a step of inserting a plurality of microbial strain inlet pipes into the contaminated soil; a step of introducing microbial strains into the contaminated soil using the microbial strain inlet pipes; a first purification step of purifying the contaminated soil through a microbial reaction process; a step of transporting the contaminated soil that has undergone the first purification step by a belt conveyor; and a second purification step in which the contaminated soil transported by the belt conveyor passes through a plasma purification device, wherein fine heavy metals within the contaminated soil are removed by thermal decomposition or oxidation using the heat of a plasma arc.

[0024] After the step of separating waste vinyl materials within the contaminated soil, recycled petroleum and hydrogen gas can be produced by undergoing a recycling process for the separated waste vinyl materials.

[0026] The above microbial strain inlet tube has an inner diameter between 100 mm and 200 mm, and has numerous fine holes formed on its outer surface at intervals of 5 mm to 10 mm, allowing the microbial strain to be evenly dispersed into the contaminated soil.

[0028] In the step of sorting and separating the waste vinyl materials mentioned above, the contaminated soil is crushed to a size of 10 mm or less, ferrous metals are removed using a magnetic separator, and then the waste vinyl materials can be sorted and separated manually.

[0030] In the above first purification step, the process is maintained for 72 hours under conditions of a temperature of 25°C and a humidity of 60%, and the microbial strain introduced can produce phenol oxidase capable of decomposing phenol.

[0032] In the above second purification step, the temperature of the plasma arc is controlled to 5,000℃ to set optimal thermal decomposition and oxidation conditions according to the types of heavy metals, such as lead, mercury, and cadmium, in the contaminated soil.

[0034] In the above second purification stage, in addition to the heat of the plasma arc, electromagnetic waves with a frequency of 2.45 GHz are additionally utilized to increase the decomposition efficiency of heavy metals by more than 20%.

[0036] In the step of sorting and separating the waste vinyl materials, a silicone coating may be applied to the surface of the belt conveyor to increase the survival rate of microorganisms by more than 10% and to prevent re-contamination of residues after plasma purification.

[0038] After the above second purification step, a cooling device for cooling the contaminated soil to 25°C or lower can be additionally included to increase the soil stability after plasma treatment by more than 15%.

[0040] In the step of sorting and separating the waste vinyl materials mentioned above, the waste vinyl materials can be efficiently separated with an accuracy of over 95% through an automated separation system using optical sensors.

[0042] Prior to the first purification step mentioned above, a pH adjuster may be added to the contaminated soil to adjust the acidity of the contaminated soil to between pH 6.5 and 7.5, thereby creating a pH environment suitable for microbial activity.

[0044] In the above second purification stage, the temperature of the plasma arc can be monitored and controlled in real time between 1000℃ and 1500℃ using a PID control device.

[0046] The above belt conveyor includes an inverter speed control device capable of adjusting the transport speed of contaminated soil to between 0.5 m / min and 2 m / min, which can increase the efficiency of the purification process by more than 10%.

[0048] The contaminated soil purification method according to the present invention has a technical feature comprising: a step of removing odors and sterilizing by using plasma generated by a discharge process to decompose and remove odor substances and contaminants remaining in the soil, while simultaneously decomposing the covalent bonds of nitrogen gas (N2) and oxygen gas (O2) molecules in the air to generate nitrogen oxide gas (NO), and performing a powerful sterilization treatment by active molecules.

[0049] The contaminated soil purification method according to the present invention removes harmful substances by generating ozone (O3) and OH radicals, and by applying a magnetic field of a permanent magnet to excited air to sustain an electrochemical reaction through extending the contact time with active molecules, the amount of nitrogen oxide gas (NO) generated can be further increased, and the removal efficiency of pollutants and odor substances and the sterilization efficiency can be significantly improved.

[0051] Meanwhile, the contaminated soil purification system according to the present invention has technical features comprising: a plurality of microbial strain inlet pipes installed in the contaminated soil to introduce microbial strains into the contaminated soil and purify the contaminated soil through a microbial reaction process; a belt conveyor for transporting the contaminated soil that has undergone the microbial reaction process; and a plasma purification device that removes fine heavy metals within the contaminated soil by applying heat from a plasma arc to the contaminated soil transported by the belt conveyor to thermally decompose or oxidize them.

[0053] The contaminated soil purification system according to the present invention has a technical feature comprising a waste vinyl recycling device that separates and recycles waste vinyl within the contaminated soil.

[0054] The above waste vinyl recycling device can produce recycled petroleum and hydrogen gas.

[0056] In order to evenly disperse the microbial strains within the contaminated soil, numerous fine holes are formed on the outer surface of the microbial strain injector at intervals of 5 mm to 10 mm.

[0058] In order to separate the above waste vinyl, the contaminated soil can be crushed to a size of 10 mm or less using a crusher, then the ferrous metals can be removed using a magnetic separator, and then the waste vinyl can be separated by manual sorting.

[0060] In the plasma purification process using the above-mentioned plasma purification device, in addition to the heat of the plasma arc, electromagnetic waves of a frequency of 2.45 GHz are additionally utilized using an electromagnetic wave generator to increase the decomposition efficiency of heavy metals by more than 20%.

[0062] In order to increase the survival rate of microorganisms in contaminated soil by more than 10% and prevent re-contamination of residues after plasma purification, it is desirable to apply a silicone coating to the surface of the belt conveyor.

[0064] After the plasma purification process by the above-mentioned plasma purification device, a cooling device for cooling the contaminated soil to 25°C or lower may be additionally included to improve soil stability after plasma treatment.

[0066] In the sorting and separation process of the waste vinyl mentioned above, an automated separation device using an optical sensor may be used to increase the separation efficiency of the waste vinyl.

[0068] In the plasma purification process using the above-mentioned plasma purification device, the system may be configured to include a PID control device capable of monitoring and controlling the temperature of the plasma arc in real time between 1000℃ and 1500℃.

[0070] In order to improve the purification process of contaminated soil, the belt conveyor may be configured to include an inverter speed control device capable of adjusting the transport speed of contaminated soil to between 0.5 m / min and 2 m / min.

[0072] The contaminated soil purification system according to the present invention further comprises an odor removal and sterilization device that uses plasma generated by a discharge process to decompose and remove odorous substances and pollutants remaining in the soil, while simultaneously decomposing the covalent bonds of nitrogen gas (N2) and oxygen gas (O2) molecules in the air to generate nitrogen oxide gas (NO) and performing powerful sterilization treatment by active molecules.

[0074] The contaminated soil purification system according to the present invention removes harmful substances by generating ozone (O3) and OH radicals, and by applying a magnetic field of a permanent magnet to excited air to sustain an electrochemical reaction through extending the contact time with active molecules, it can further increase the amount of nitrogen oxide gas (NO) generated and significantly improve the removal efficiency of pollutants and odor substances and the sterilization efficiency. Effects of the invention

[0075] As explained above, the present invention has the following effects.

[0076] First, in the step of sorting and separating waste vinyl in contaminated soil, waste vinyl can be efficiently separated with an accuracy of over 95% through an automated separation system using optical sensors.

[0077] Second, in the step of driving multiple microbial strain inlet pipes into the contaminated soil, the microbial strain inlet pipes are formed with an inner diameter between 100 mm and 200 mm, and multiple fine holes are formed on the outside at intervals of 5 mm to 10 mm to evenly disperse the microbial strains.

[0078] Third, in the step of supplying microbial strains into the contaminated soil through a microbial strain input pipe, a microbial reaction process is carried out, and during this process, the temperature of the contaminated soil is maintained between 30°C and 35°C and the humidity is controlled between 60% and 70%, making it possible to create an environment that maximizes the activity of microorganisms by more than 50%.

[0079] Fourth, in the first purification stage, specific microbial strains are selectively used to remove more than 90% of phenol, thereby allowing for more effective removal of specific pollutants in contaminated soil.

[0080] Fifth, contaminated soil that has undergone the first purification stage is transported by a belt conveyor, and the belt conveyor can be coated with silicone to increase the survival rate of microorganisms by more than 10% and prevent re-contamination of residues after plasma purification. The belt conveyor includes an inverter speed control device that can adjust the transport speed of contaminated soil between 0.5 m / min and 2 m / min, thereby increasing the efficiency of the purification process by more than 10%.

[0081] Sixth, by including a second purification stage in which the contaminated soil passes through a first plasma purification device to remove fine heavy metals in the contaminated soil by thermally decomposing or oxidizing them with the heat of the plasma arc, it is possible to apply a PID control system that can monitor and adjust the temperature of the plasma arc in real time between 1000℃ and 1500℃, and additionally utilize electromagnetic waves of 2.45GHz frequency to increase the decomposition efficiency of heavy metals by more than 20%.

[0082] Seventh, the soil stability after plasma treatment can be increased by more than 15% by additionally including a cooling device to cool the contaminated soil to 25°C after the second purification stage, and a pH adjuster can be added to the contaminated soil before the first purification stage to adjust the pH to between 6.5 and 7.5 to create a pH environment suitable for microbial activity.

[0084] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0085] FIG. 1 is a flowchart illustrating a method for purifying contaminated soil according to the present invention. FIG. 2 is a drawing illustrating an additional process in the waste vinyl sorting and classification step in the contaminated soil purification method according to the present invention. FIG. 3 is a drawing illustrating a PID control device and a cooling device in the secondary purification stage of the contaminated soil purification method according to the present invention. FIG. 4 is a conceptual diagram illustrating a contaminated soil purification system according to the present invention. FIG. 5 is an enlarged view of a microbial strain input pipe in a contaminated soil purification system according to the present invention. Specific details for implementing the invention

[0086] Hereinafter, a method and system for purifying contaminated soil according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0087] FIG. 1 is a flowchart illustrating a contaminated soil purification method according to the present invention, FIG. 2 is a diagram explaining an additional process in the waste vinyl sorting and classification step in the contaminated soil purification method according to the present invention, FIG. 3 is a diagram illustrating a PID control device and a cooling device in the secondary purification step in the contaminated soil purification method according to the present invention, FIG. 4 is a conceptual diagram illustrating a contaminated soil purification system according to the present invention, and FIG. 5 is an enlarged view of a microbial strain input pipe in the contaminated soil purification system according to the present invention.

[0088] Referring to FIGS. 1 to 5, a contaminated soil purification method according to a preferred embodiment of the present invention effectively removes trace heavy metals and specific pollutants through efficient sorting and recycling of waste vinyl, effective input and dispersion of microbial strains, and a plasma purification process, while increasing the survival rate of microorganisms, improving soil stability after plasma treatment, and maximizing the activity of microorganisms through pH control and the creation of an optimal environment, thereby maximizing the purification efficiency of contaminated soil, increasing the overall efficiency of the purification process, and preventing re-contamination, thus making an innovative contribution to the field of contaminated soil purification.

[0089] In the contaminated soil remediation method according to a preferred embodiment of the present invention, an efficient sorting and recycling process for waste vinyl materials may be optionally included. For example, a sorting process for waste vinyl materials is required only when waste vinyl materials (including synthetic resins) are included in the contaminated soil, and a recycling process is performed only when the sorted waste vinyl materials can be recycled.

[0091] In the method for purifying contaminated soil according to a preferred embodiment of the present invention, the types of contaminants in the contaminated soil are as follows. For example, ① Organic matter: petroleum hydrocarbons (TPH), PAHs (polycyclic aromatic hydrocarbons), PCBs (polychlorinated biphenyls) ② Inorganic matter: heavy metals (lead, cadmium, arsenic), cyanides, nitrates ③ Radioactive materials: uranium, cesium-137

[0092] Furthermore, soil contaminants include petroleum contaminants including benzene, toluene, xylene, ethylbenzene, total petroleum hydrocarbons (TPH), trichloroethylene (TCE), tetrachloroethylene (PCE), organophosphorus compounds, benzopyrene, PCBs, cyanide, and phenol; and heavy metal contaminants including arsenic, lead, cadmium, hexavalent chromium, copper, mercury, zinc, nickel, and fluorine.

[0094] In the method for purifying contaminated soil according to a preferred embodiment of the present invention, considerations regarding soil characteristics are as follows.

[0095] ① Physical characteristics: Particle size, permeability, porosity ② Chemical characteristics: pH, organic matter content, ion exchange capacity ③ Biological characteristics: Microbial diversity

[0097] A method for purifying contaminated soil according to a preferred embodiment of the present invention has the following technical features: a step of separating waste vinyl (including synthetic resin) within the contaminated soil (S110); a step of inserting a plurality of microbial strain inlet pipes (110) into the contaminated soil (S120); a step of introducing microbial strains into the contaminated soil using the microbial strain inlet pipes (110) (S130); a first purification step (S140) of purifying the contaminated soil through a microbial reaction process; a step (S150) of transporting the contaminated soil that has undergone the first purification step (S140) by a belt conveyor (120); and a second purification step (S160) in which the contaminated soil transported by the belt conveyor (120) passes through a plasma purification device (130), thereby removing fine heavy metals within the contaminated soil by thermal decomposition or oxidation using the heat of a plasma arc.

[0098] After the step (S110) of separating waste vinyl materials within the contaminated soil, recycled petroleum and hydrogen gas can be produced by undergoing the step (S111) of recycling the separated waste vinyl materials (including synthetic resin). That is, the separated waste vinyl materials (including synthetic resin) can be converted into recycled petroleum and hydrogen gas through a pyrolysis process.

[0099] The above-mentioned microbial strain inlet tube (110) has a large number of fine holes (111) formed therein, which can evenly disperse the microbial strain into the contaminated soil.

[0100] In the step (S110) of sorting and separating the waste vinyl, the contaminated soil is crushed to a size of 10 mm or less, then the ferrous metals are removed using a magnetic separator (14), and then the waste vinyl can be sorted and separated manually.

[0101] In the step (S110) of sorting and separating the waste vinyl, it is preferable to apply a silicone coating to the surface of the belt conveyor (120) to increase the survival rate of microorganisms by more than 10% and to prevent re-contamination of residues after plasma purification.

[0102] Furthermore, in the step (S110) of sorting and separating the waste vinyl, the waste vinyl can be efficiently separated with an accuracy of 95% or more through an automated separation device (19) using an optical sensor.

[0104] In addition, in the first purification step (S120), the microbial strain introduced is maintained for 72 hours under conditions of a temperature of 25°C and a humidity of 60%, and can produce phenol oxidase capable of decomposing phenol.

[0105] Microorganisms that can be used in the present invention include Bacillus subtilis, Bacillus polymyxa, Rhodopseudomonas, Autotrophic bacter, Pseudomonas, Nitrobacter, Trichoderma viride, Cellulomonas sp., Actinomyces, and filamentous fungi; two or more of these may also be used in combination, and in particular, the novel strain Bacillius sp. khr-10-mx (Korea Institute of Science and Technology Microorganism Accession No. KCTC8533P) and Cellulomonas sp. It is preferable to use khr-15-mx (Korea Institute of Science and Technology Microbiology Accession No. KCTC 8534P) and the complex strain khr5-mx (Korea Institute of Science and Technology Microbiology Accession No. KCTC 0078BP) alone or in combination.

[0106] Furthermore, microorganisms that can be used in the present invention may further include Pseudomonas (petroleum decomposition) and Geobacter (metal reduction).

[0108] Before the first purification step (S140) above, a pH adjuster (e.g., sulfuric acid / sodium hydroxide) may be added to the contaminated soil to adjust the acidity of the contaminated soil to between pH 6.5 and 7.5 in order to create a pH environment suitable for microbial activity.

[0110] In the above second purification step (S160), the temperature of the plasma arc is controlled to 5,000℃ to set optimal thermal decomposition and oxidation conditions according to the types of heavy metals such as lead, mercury, and cadmium in the contaminated soil.

[0111] In the above second purification step (S160), in addition to the heat of the plasma arc, electromagnetic waves of a frequency of 2.45 GHz are additionally utilized to increase the decomposition efficiency of heavy metals by more than 20%.

[0112] After the above second purification step (S160), a cooling device (190) for cooling the contaminated soil to 25°C or lower can be additionally included to increase the soil stability after plasma treatment by more than 15%.

[0113] In the above second purification step (S160), the temperature of the plasma arc can be monitored and controlled in real time between 1000℃ and 1500℃ using a PID control device (20).

[0114] In a method for purifying contaminated soil according to a preferred embodiment of the present invention, plasma is a fourth state of matter composed of ions, electrons, and neutral particles, and has excellent performance in decomposing organic matter and oxidizing / reducing heavy metals through high-energy reactions. The principle of plasma generation can be to perform gas ionization using high voltage (1 to 50 kV), high frequency (1 kHz to 10 MHz), or microwave (2.45 GHz).

[0116] In addition, the contaminated soil purification method according to a preferred embodiment of the present invention has a technical feature comprising a step (S170) of decomposing and removing odorous substances and contaminants remaining in the soil using plasma generated by a discharge process, while simultaneously decomposing the covalent bonds of nitrogen gas (N2) and oxygen gas (O2) molecules in the air to generate nitrogen oxide gas (NO), and performing a strong sterilization treatment by active molecules to remove odors and sterilize.

[0117] A method for purifying contaminated soil according to a preferred embodiment of the present invention removes harmful substances by generating ozone (O3) and OH radicals, and by applying a magnetic field of a permanent magnet to excited air to sustain an electrochemical reaction through extending the contact time with active molecules, the amount of nitrogen oxide gas (NO) generated can be further increased, and the removal efficiency of pollutants and odor substances and the sterilization efficiency can be significantly improved.

[0119] Meanwhile, the contaminated soil purification system (100) according to a preferred embodiment of the present invention has technical features comprising: a plurality of microbial strain inlet pipes (110) installed in the contaminated soil to purify the contaminated soil through a microbial reaction process by introducing microbial strains into the contaminated soil; a belt conveyor (120) for transporting the contaminated soil that has undergone the microbial reaction process; and a plasma purification device (130) that removes fine heavy metals in the contaminated soil by applying heat from a plasma arc to the contaminated soil transported by the belt conveyor (120) to thermally decompose or oxidize them.

[0121] Furthermore, the contaminated soil purification system (100) according to a preferred embodiment of the present invention has a technical feature comprising: a sensor unit (140) connected to a microbial strain input pipe (110) for measuring the contamination level of a contaminant, a pH sensor, a temperature sensor, a water level sensor, a pumping volume sensor, and a precipitation volume sensor; and a server unit (150) for collecting each sensor data transmitted from the sensor unit (140) according to the type of sensor data.

[0122] In a contaminated soil purification system (100) according to a preferred embodiment of the present invention, a sensor unit (140) including a contamination sensor, a pH sensor, a temperature sensor, a water level sensor, a pumping amount sensor, and a precipitation amount sensor operates to measure the contamination level of the contaminated soil, and the server unit (150) collects each sensor data transmitted from the sensor unit (140) according to the type of sensor data. A microbial strain can be selected according to the type of data collected by the server unit (150).

[0124] A contaminated soil purification system (100) according to a preferred embodiment of the present invention can dynamically adjust plasma parameters (e.g., voltage, frequency) according to the concentration of contaminants through AI-based real-time control, and can drive the plasma system with a solar panel (efficiency improved by 22%) through green energy linkage.

[0126] The microbial strain inlet tube (110) of the present invention is formed with an inner diameter of, for example, between 100 mm and 200 mm, and has a plurality of fine holes (111) formed on the outer surface at intervals of, for example, between 5 mm and 10 mm, so that the microbial strain can be evenly dispersed into the contaminated soil.

[0127] The belt conveyor (120) of the present invention includes an inverter speed control device (121) capable of adjusting the conveying speed of contaminated soil to between 0.5 m / min and 2 m / min, thereby increasing the efficiency of the purification process by more than 10%.

[0129] Furthermore, the contaminated soil purification system (100) according to a preferred embodiment of the present invention may further comprise a waste vinyl recycling device (180) that separates and recycles waste vinyl within the contaminated soil. The waste vinyl recycling device (180) can produce recycled petroleum and hydrogen gas.

[0131] In order to separate the waste vinyl materials, the contaminated soil can be crushed to a size of 10 mm or less using a crusher (15), then the ferrous metals can be removed using a magnetic separator (14), and then the waste vinyl materials can be separated by manual sorting.

[0133] In the sorting and separation process of the waste vinyl above, an automated separation device (19) using an optical sensor may be used to increase the separation efficiency of the waste vinyl.

[0135] Regarding the physical properties of plasma, 1) the types are as follows.

[0136] ① Thermal Plasma: Arc discharge, generation of high temperatures of 5,000–20,000°C (e.g., DC / AC plasma torch).

[0137] ② Non-Thermal Plasma: A state in which only electrons maintain a high-energy state at low temperatures (room temperature to 200°C), such as dielectric discharge and corona discharge.

[0138] 2) The core reaction mechanism is as follows.

[0139] ① Generation of active species: OH, O3, H2, O2, UV photons, etc., decompose organic bonds

[0140] ② Heavy metal treatment: Fe 2+ / Fe 3+ Precipitation reaction through a reduction system, for example, Cr(VI) → Cr(III)

[0142] In the above plasma purification device (130), the plasma generation principle implements gas ionization using high voltage (1 to 50 kV), high frequency (1 kHz to 10 MHz), or microwave (2.45 GHz). In addition to the heat of the plasma arc, the decomposition efficiency of heavy metals can be increased by more than 20% by utilizing electromagnetic waves of 2.45 GHz frequency using an electromagnetic wave generator (13).

[0144] In addition, it is desirable to apply a silicone coating to the surface of the belt conveyor (120) to increase the survival rate of microorganisms in contaminated soil by more than 10% and to prevent re-contamination of residues after plasma purification.

[0146] After the plasma purification process by the above-mentioned plasma purification device (130), a cooling device (190) for cooling the contaminated soil to 25°C or lower can be additionally included to increase soil stability after plasma treatment.

[0148] In the plasma purification process by the above plasma purification device (130), a PID control device (20) capable of monitoring and adjusting the temperature of the plasma arc in real time between 1000℃ and 1500℃ may be further included.

[0150] In order to increase the purification process of the contaminated soil according to a preferred embodiment of the present invention, the belt conveyor (120) may be configured to include an inverter speed control device (121) capable of adjusting the transport speed of the contaminated soil to between 0.5 m / min and 2 m / min.

[0152] A contaminated soil purification system according to a preferred embodiment of the present invention may further comprise an odor removal and sterilization device (22) that uses plasma generated by a discharge process to decompose and remove odorous substances and contaminants remaining in the soil, and simultaneously decomposes the covalent bonds of nitrogen gas (N2) and oxygen gas (O2) molecules in the air to generate nitrogen oxide gas (NO), and performs a powerful sterilization treatment by active molecules.

[0153] A contaminated soil purification system according to a preferred embodiment of the present invention removes harmful substances by generating ozone (O3) and OH radicals, and by applying a magnetic field of a permanent magnet to excited air to sustain an electrochemical reaction through extending the contact time with active molecules, it can further increase the amount of nitrogen oxide gas (NO) generated and significantly improve the removal efficiency of pollutants and odor substances and the sterilization efficiency.

[0155] Compared to existing contaminated soil remediation technologies, the present invention offers significantly improved treatment efficiency and, in particular, has the advantage of enabling the treatment of various pollutants through the combination of microbial treatment and plasma purification.

[0156] In the first purification step (S120), which is the core of the present invention, a microbial strain inlet tube (110) with an inner diameter of 100 to 200 mm is used, and micro-holes are formed on the outer surface at intervals of 5 to 10 mm to promote uniform dispersion of the strain.

[0157] The following microorganisms can be utilized in the present invention.

[0158] ① Bacillus subtilis

[0159] ② Bacillus polymyxa

[0160] ③ Rhodopseudomonas

[0161] ④ New strain Bacillus sp. khr-10-mx(KCTC8533P)

[0162] ⑤ Cellulomonas sp. khr-15-mx(KCTC 8534P)

[0163] ⑥ Mixed strain khr5-mx(KCTC 0078BP)

[0164] In addition, in the second purification step (S130), which is the core of the present invention, a high-temperature plasma arc of 5,000°C and electromagnetic waves of 2.45 GHz frequency can be applied in combination. In particular, the newly developed dual plasma system has the following characteristics.

[0165] 1) Main plasma torch

[0166] ① Temperature: 5,000 ℃

[0167] ② Power: 50-100 kW

[0168] ③ Gas: Argon / Nitrogen mixture

[0169] 2) Auxiliary plasma torch

[0170] ① Temperature: 1,000∼1,500 ℃

[0171] ② Power: 20–30kW

[0172] ③ Gas: Oxygen / Hydrogen mixture

[0173] Through this dual system, the decomposition efficiency of heavy metals can be improved by 40% compared to existing systems, and energy consumption can be reduced by 25%.

[0175] In the plasma purification process of the present invention, complex contamination treatment can be performed, and by including a first step as a plasma-biological complex system; a second step of decomposing organic matter with plasma; and a third step of reducing residual heavy metals with Geobacter, the purification treatment time can be shortened by more than 60% compared to conventional methods.

[0176] The plasma purification device of the present invention may, for example, use a centrifugal plasma reactor.

[0177] In the plasma purification device of the present invention, the heavy metal stabilization technology is as follows: 1) Plasma melting and immobilization process: Soil melted with a 1,500 ℃ plasma arc → heavy metals are captured in a silicate matrix, and performance: lead leaching amount 50 mg / L → 0.1 mg / L (less than EPA standard).

[0178] 2) Looking at the reduction plasma treatment, hydrogen plasma application: As(V) is reduced to As(0) to produce an insoluble precipitate.

[0179] 3) When examining the plasma-soil interaction mechanism, surface reaction amplification technology can be used, such as: ① Microdischarge: improving the accessibility of pollutants to the surface by forming localized plasma within soil pores, and ② Catalytic coupling system: introducing TiO₂ or zeolite into the soil can increase the plasma reaction efficiency by 200%.

[0180] 4) Looking at the electrochemical coupling effect, electrodynamic movement: By applying an electric field (1~5V / cm), heavy metal ions can be moved toward the electrode side to concentrate the plasma decomposition area.

[0182] In addition, in the odor removal and sterilization step (S170), odor substances are removed by utilizing ozone and OH radicals generated by plasma discharge, and the sterilization effect is enhanced through an electrochemical reaction using the magnetic field of a permanent magnet. In particular, the newly introduced nanocatalyst system has the following characteristics.

[0183] 1) Catalyst composition

[0184] ① Main catalyst: TiO2 / WO3 nanocomposite

[0185] ② Co-catalyst: AgPt nanoparticles

[0186] ③ Carrier: Porous ceramic

[0187] 2) Mechanism of Action

[0188] ① Increased generation of OH radicals through photocatalytic reactions

[0189] ② Decomposition of odor-causing substances through selective oxidation

[0190] ③ Enhancement of sterilization effect through the release of antimicrobial metal ions

[0192] Furthermore, in the cooling and stabilization process, the soil can be cooled to below 25°C after plasma treatment, and a newly developed hybrid cooling system can be applied.

[0193] The hybrid cooling system combines water cooling and air cooling, and can reduce cooling costs by 50% through the reuse of cooling water and the maximization of heat exchange efficiency.

[0195] By purifying contaminated soil from landfills and other sources using this method, contaminated unsanitary landfills can be repurposed into useful land (residential sites, flower complexes, farmlands, livestock barns, parks, sports facilities, parking lots, etc.), and environmental pollution can be effectively prevented.

[0197] The present invention provides the following technical effects.

[0198] ① Maximizing Contaminated Soil Remediation Efficiency: The remediation efficiency of contaminated soil can be maximized through the efficient sorting and incineration of waste vinyl, the effective input and dispersion of microbial strains, and the plasma purification process.

[0199] ② Improvement of microbial survival rate: By controlling pH and creating an optimal environment, the survival rate of microorganisms can be increased, and soil stability after plasma treatment can be improved.

[0200] ③ Prevention of re-contamination: Re-contamination can be prevented by cooling and sterilization treatment after the plasma purification process.

[0201] ④ Heavy metal removal: Heavy metals can be effectively removed using plasma.

[0202] ⑤ Odor removal and sterilization: Residual pollutants in the soil can be effectively removed through odor removal and sterilization treatment using nanocatalysts.

[0204] Meanwhile, the present specification and drawings disclose preferred embodiments of the present invention. Although specific terms have been used, they are used merely in a general sense to facilitate the explanation of the technical content of the invention and to aid in understanding the invention, and are not intended to limit the scope of the invention.

[0205] It is obvious to those skilled in the art that, in addition to the embodiments disclosed herein, other variations based on the technical concept of the present invention are possible. Explanation of the symbols

[0206] 13: Electromagnetic wave generator 14: Magnetic separator 15: Grinder 17: PID controller 19: Automated separation device using optical sensors 20: PID controller 22: Odor removal and sterilization device 100: Contaminated Soil Remediation System 110: Microbial strain inlet tube 111: Fine hole 120: Belt conveyor 121: Inverter speed controller 130: Plasma purification device 140: Sensor unit 150: Server unit 180: Waste vinyl recycling device 190: Cooling device

Claims

Claim 1 A method for purifying contaminated soil comprising: a step of separating waste vinyl materials within contaminated soil (S110); a step of driving a plurality of microbial strain inlet pipes (110) into the contaminated soil (S120); a step of introducing microbial strains into the contaminated soil using the microbial strain inlet pipes (110) (S130); a first purification step (S140) for purifying the contaminated soil underground through a microbial reaction process; a step (S150) of transporting the contaminated soil that has undergone the first purification step (S140) by a belt conveyor (120); and a second purification step (S160) in which the contaminated soil transported by the belt conveyor (120) passes through a plasma purification device (130), thereby removing fine heavy metals within the contaminated soil by thermal decomposition or oxidation using the heat of a plasma arc. Claim 2 A method for purifying contaminated soil according to claim 1, characterized in that after the step (S110) of separating waste vinyl materials within the contaminated soil, the separated waste vinyl materials are recycled through a step (S111) to produce recycled petroleum and hydrogen gas. Claim 3 A method for purifying contaminated soil according to claim 1, wherein the microbial strain inlet tube (110) is formed with an inner diameter between 100 mm and 200 mm and has a plurality of fine holes (111) formed on the outer surface at intervals of 5 mm to 10 mm to evenly disperse the microbial strain into the contaminated soil. Claim 4 A method for purifying contaminated soil according to claim 1, wherein in the step (S110) of sorting and separating the waste vinyl, the contaminated soil is crushed to a size of 10 mm or less, then iron metals are removed using a magnetic separator (14), and then the waste vinyl is sorted and separated manually. Claim 5 A method for purifying contaminated soil according to claim 1, characterized in that, in step (S110), a silicone coating is applied to the surface of the belt conveyor (120) to increase the survival rate of microorganisms by more than 10% and prevent re-contamination of residue after plasma purification. Claim 6 A method for purifying contaminated soil according to claim 1, characterized in that in step (S110), waste vinyl is efficiently separated with an accuracy of 95% or more through an automated separation device (19) using an optical sensor. Claim 7 A method for purifying contaminated soil according to claim 1, characterized by introducing a pH regulator into the contaminated soil to adjust the acidity of the contaminated soil to between pH 6.5 and 7.5 prior to the first purification step (S120) to create a pH environment suitable for microbial activity. Claim 8 A method for purifying contaminated soil according to claim 1, wherein in the first purification step (S120), the first purification step is maintained for 72 hours under conditions of a temperature of 25°C and a humidity of 60%, and the microbial strain introduced produces phenol oxidase capable of decomposing phenol. Claim 9 A method for purifying contaminated soil according to claim 1, wherein in the second purification step (S160), the temperature of the plasma arc is controlled to 5,000℃ to set optimal thermal decomposition and oxidation conditions according to the types of heavy metals, such as lead, mercury, and cadmium, in the contaminated soil. Claim 10 A method for purifying contaminated soil according to claim 1, characterized in that in the second purification step (S160), in addition to the heat of the plasma arc, electromagnetic waves of a frequency of 2.45 GHz are additionally utilized to increase the decomposition efficiency of heavy metals by more than 20%. Claim 11 A method for purifying contaminated soil according to claim 1, characterized in that, in the second purification step (S160), the temperature of the plasma arc can be monitored and controlled in real time between 1000℃ and 1500℃ using a PID control device (20). Claim 12 A method for purifying contaminated soil according to claim 1, wherein the belt conveyor (120) includes an inverter speed control device (21) capable of adjusting the conveying speed of contaminated soil to between 0.5 m / min and 2 m / min, thereby increasing the efficiency of the purification process by more than 10%. Claim 13 A method for purifying contaminated soil according to claim 1, characterized by additionally including a cooling device (190) for cooling the contaminated soil to 25°C or lower after the second purification step (S160), thereby increasing the soil stability after plasma treatment by 15% or more. Claim 14 A method for purifying contaminated soil according to claim 1, further comprising the step (S170) of decomposing and removing odorous substances and pollutants remaining in the soil using plasma generated by a discharge process, while simultaneously decomposing the covalent bonds of nitrogen gas (N2) and oxygen gas (O2) molecules in the air to generate nitrogen oxide gas (NO), and performing a strong sterilization treatment by active molecules. Claim 15 A method for purifying contaminated soil according to claim 14, characterized by generating ozone (O3) and OH radicals to remove harmful substances, and applying a magnetic field of a permanent magnet to excited air to sustain an electrochemical reaction by extending the contact time with active molecules, thereby further increasing the amount of nitrogen oxide gas (NO) generated and improving the removal efficiency of pollutants and odor substances and the sterilization efficiency. Claim 16 A contaminated soil purification system comprising: a plurality of microbial strain inlet pipes (110) installed in the contaminated soil to inject microbial strains into the contaminated soil and purify the contaminated soil through a microbial reaction process; a belt conveyor (120) for transporting the contaminated soil that has undergone the microbial reaction process; and a plasma purification device (130) for removing fine heavy metals in the contaminated soil by applying heat from a plasma arc to the contaminated soil transported by the belt conveyor (120) to thermally decompose or oxidize them. Claim 17 In claim 16, a contaminated soil purification system further comprising: a sensor unit (140) connected to and installed in the microbial strain input pipe (110) and including a contamination level sensor, a pH sensor, a temperature sensor, a water level sensor, a pumping volume sensor, and a precipitation volume sensor for measuring the contamination level of a contaminant; and a server unit (150) for collecting each sensor data transmitted from the sensor unit according to the type of sensor data. Claim 18 A contaminated soil purification system according to claim 16 or 17, further comprising a waste vinyl recycling device (180) that separates and recycles waste vinyl in contaminated soil. Claim 19 In claim 18, the above waste vinyl recycling device (180) is characterized by producing recycled petroleum and hydrogen gas, in a contaminated soil purification system. Claim 20 A contaminated soil purification system according to claim 16, characterized in that a plurality of fine holes (111) are formed at intervals of 5 mm to 10 mm on the outer surface of the microbial strain input pipe (110) so as to evenly disperse the microbial strain within the contaminated soil. Claim 21 A contaminated soil purification system according to claim 16, characterized in that, in order to separate the waste vinyl, the contaminated soil is crushed to a size of 10 mm or less using a crusher (15), then iron metals are removed using a magnetic separator (14), and then the waste vinyl is separated by manual sorting. Claim 22 A contaminated soil purification system according to claim 16, characterized in that, in the plasma purification process by the plasma purification device (130) above, in addition to the heat of the plasma arc, an electromagnetic wave generator (13) is used to additionally utilize electromagnetic waves of a frequency of 2.45 GHz to increase the decomposition efficiency of heavy metals by more than 20%. Claim 23 A contaminated soil purification system according to claim 16, characterized in that a silicone coating is applied to the surface of the belt conveyor (120) to increase the survival rate of microorganisms in the contaminated soil by more than 10% and to prevent re-contamination of residues after plasma purification. Claim 24 A contaminated soil purification system according to claim 16, characterized by further including a cooling device (190) for cooling the contaminated soil to 25°C or lower after the plasma purification process by the plasma purification device (130) to increase soil stability after plasma treatment. Claim 25 A contaminated soil purification system characterized by using an automated separation device (19) utilizing an optical sensor to increase the separation efficiency of waste vinyl in the sorting and separation process of the waste vinyl in claim 16. Claim 26 In claim 16, the contaminated soil purification system further comprises a PID control device (20) capable of monitoring and controlling the temperature of the plasma arc in real time between 1000℃ and 1500℃ during the plasma purification process by the plasma purification device (130). Claim 27 In claim 16, the contaminated soil purification system includes an inverter speed control device (21) that can adjust the conveying speed of the contaminated soil to between 0.5 m / min and 2 m / min in order to increase the purification process of the contaminated soil. Claim 28 In claim 16, an odor removal and sterilization device (22) that uses plasma generated by a discharge process to decompose and remove odorous substances and pollutants remaining in the soil, while simultaneously decomposing the covalent bonds of nitrogen gas (N2) and oxygen gas (O2) molecules in the air to generate nitrogen oxide gas (NO) and performing powerful sterilization treatment by active molecules; further comprising a contaminated soil purification system. Claim 29 A contaminated soil purification system according to claim 28, characterized by generating ozone (O3) and OH radicals to remove harmful substances, and applying a magnetic field of a permanent magnet to excited air to sustain an electrochemical reaction by extending the contact time with active molecules, thereby further increasing the amount of nitrogen oxide gas (NO) generated and improving the removal efficiency of pollutants and odor substances and the sterilization efficiency.

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