Leachate purification system using plasma technology

Abstract

The present invention is a leachate treatment based on cold plasma technology. The device disclosed in this invention includes a storage tank, a plasma reactor, an inlet and an outlet, fittings, a pump and a table. During the treatment process, the storage tank initially contains the raw fluid (leaching passing through the pre-treatment) and transfers the fluid to the reactor through the inlet by means of a pump. The pre-treatment systems are directly connected to the tank of the leachate treatment device based on cold plasma technology and its output is transferred to the plasma system. The reactor of the device activates the flowing fluid by producing active species and returns it to the interface tank and after several recirculation stages, finally transfers it to the outlet duct. This cycle is repeated several times until the activation process is complete, efficient and appropriate to the target treatment. The plasma active fluid system of the present invention operates based on the electrical discharge of the dielectric barrier. In this way, the flowing fluid flow, when placed in the electric discharge path of the plasma reactor, contains active oxygen, nitrogen, and hydroxyl species, and as a result, the contaminants in the fluid are reduced and it becomes suitable for use in controlling qualitative and quantitative parameters.

Description

Description of the invention Title of the invention (as stated in the declaration) Leachate purification system using plasma technology Leachate treatment system using plasma technology Technical background of the relevant invention The present invention generally relates to the field of environment, and more specifically to the field of water and wastewater, and more specifically to an atmospheric cold plasma system for leachate treatment. Technical problem and stating the objectives of the invention In the 21st century, water scarcity and the elimination of its pollutants are one of the fundamental challenges of humanity. Therefore, recycling and treating wastewater, as well as eliminating pollutants from water resources, has become particularly important in all countries, especially in countries facing water scarcity. Along with the growth of industries and population, the production of municipal solid waste (MSW) and industrial waste is increasing day by day. So that the daily production of municipal waste in Iran exceeds 50 million tons. Therefore, various methods are used to dispose of the resulting waste, including composting, incineration, and landfilling. Composting plays a small role in the disposal of production waste due to the high volume of waste produced and the need to employ a large workforce. On the other hand, new methods of burning waste so that the amount of pollutants entering the air is at a standard level require advanced and expensive equipment, which is not economically viable. In terms of operating and investment costs, the landfill method has received more attention compared to other methods.Comparative studies conducted on municipal waste disposal methods show that landfilling, in addition to its economic advantage due to its low cost, has fewer adverse environmental effects than other municipal waste disposal methods. As a result, sanitary landfilling is one of the most common methods of municipal solid waste disposal in most countries of the world today. Landfilling has been widely accepted as the final method of solid waste disposal due to its economic advantages. Despite the many advantages of this method, the production of highly contaminated leachate with significant changes in the volume flow produced and its chemical composition has become a major problem and concern. In short, municipal solid waste management is an important environmental, social and economic issue today. Because the growth rate of municipal waste is much higher compared to the increase in population on Earth. In addition, stricter laws are applied to land and groundwater. Leachate is defined as the effluent stream resulting from rainwater infiltration into waste, biochemical processes in landfill cells, and water contained in the waste. In fact, leachate Leachates are any type of liquid that, while passing through various materials, suspended or dissolved solids or any other material, extracts and carries with it the material that has passed through it. These materials usually have the ability to enter the environment and produce a lot of pollution. Leachates contain high concentrations of organic and inorganic pollutants including humic compounds, ammonia, heavy metals and various types of mineral salts. Leachate is a major contributor to environmental pollution, so it is important to treat it before it enters groundwater, rivers, or nearby bodies of water. Considering the above explanations, the development of a device for leachate treatment using plasma, which in fact uses plasma, can be a suitable solution for removing pollutants that cannot be removed using other methods. The cost-effectiveness and the need for much less area than competing technologies due to the replacement of several purification process units in a single stage are the major advantages of this method. Plasma is the fourth state of matter in which ionized particles behave quasi-neutrally and aggregate. Plasma discharges in liquids are of increasing interest due to their potential applications in a variety of biological, environmental, and medical fields. Highly reactive chemical species, especially reactive oxygen and nitrogen species (RONs) and hydrogen peroxide, are generally responsible for COD reduction and the removal of bacteria and microbes from leachate. Transient electric fields also create flow kinetics and thermal effects that can directly influence chemical mechanisms. The device presented in the present invention can be used in all landfill leachate production sites, municipal treatment plants, hospital wastewater treatment plants, and research laboratories. A description of the state of the prior art and the history of developments related to the claimed invention. Many studies at home and abroad have addressed the treatment of landfill leachate. For example, Ghanbari, Khojastehpour, Ebrahimi Nik, and Rouhani, in a 2017 article, examined the efficiency of a two-stage anaerobic digester in treating landfill leachate. This group of researchers also proposed a combined reactor-sweeper device method in treating landfill wastewater and leachate in an invention with application number 139950140003010024. As another example, we can mention the study by researchers Hosseinzadeh, Jahanshahi, Pirou, and Najafpour in 2019 on treating landfill leachate using a polymer nanostructure membrane in a direct osmosis process of an adsorption-membrane bioreactor. There has also been international research on wastewater, especially landfill leachate. Patent number WO2023191315 is an example of this research. In another patent document, number GB2616256, a wastewater treatment system based on an aerobic bioreactor and a solid electrolysis cell has been designed and proposed. In another patent document, number EP4222116, a treatment system and method for removing nutrients and other pollutants to produce low-solid and high-quality wastewater has been registered. In 2021, Amin Mojiri et al. reviewed the article entitled "Treatment of landfill leachate with different techniques". In 2016, Anneliese Kobas et al. studied the effect of plasma technology on the inertia of sludge produced during the treatment of landfill leachate. The present invention, regardless of the various embodiments it may have, is a cold plasma-based leachate treatment device from a landfill. The present invention is a suitable tool for removing various pollutants and types of microorganisms from the leachate, and due to its unique design, it can perform the treatment process continuously and continuously; without facing the problem of equipment heating and loss of efficiency. The present invention, due to the simplicity of providing the necessary facilities, can be used in all centers under the supervision of the Ministry of Interior and municipalities and prevent the entry of hazardous substances into urban sewage, underground resources, and agricultural fields. In general, the effectiveness of advanced oxidation processes depends on the ability to produce hydroxyl radicals. The kinetic rate of advanced oxidation processes also depends on the concentration of radicals produced, the concentration of the pollutant, the temperature, and the presence of inhibitors such as bicarbonate ion (HCO3). The AOP process involves the use of ozone, hydrogen peroxide, and ultraviolet radiation, either individually or in combination: O3 / UV, H2O2 / UV, O3 / H2O2 / UV. All of these AOPs have one thing in common: the production of hydroxyl radicals, which are very reactive. In fact, the advanced oxidation method is based on the production of hydroxyl radicals by various processes. Plasma is used as one of the advanced oxidation methods for the treatment of water, wastewater, and leachate. Plasma includes all three technologies of ozone, hydrogen peroxide, and UV simultaneously, hence more hydroxyl radicals are produced in water, wastewater, and leachate under plasma treatment, resulting in a higher percentage of pollutant removal under plasma treatment than other advanced oxidation methods. Providing a solution to an existing technical problem along with an accurate, sufficient, and integrated description of the invention As mentioned, in the present invention, a leachate treatment device is provided using plasma technology. The present invention provides a system based on atmospheric cold plasma technology based on two parallel flat electrodes, at least one of which is covered by a dielectric insulator. The large irradiated surface is the main advantage of this type of production source, while the need for a flat substrate and a narrow gap between the electrodes are its limitations. In general, all sources have the ability to produce plasma in the air or in a closed chamber, in cases where air impurities interfere with the process. Usually, inert gases such as helium, argon or even nitrogen are used in the production of plasma flames. Which can produce active oxygen, nitrogen, and hydroxyl species using dielectric discharge, resulting in leachate purification. Except for the concepts specifically defined in the context of the present invention, all technical and scientific terms used shall have the same meaning as understood by those knowledgeable or skilled in this field (the fields covered by the present invention). An attempt has been made here to mention the most preferred materials and tools for describing the method, although many similar materials and tools can be used to describe the present invention and / or perform the experiments and processes of this invention. Below, one or more embodiments of the present invention are presented with respect to the form provided in the "Technical Drawing" file. It should be noted that these embodiments merely indicate one or more representatives of the present invention, so the present invention is not specifically limited to any of these cases. In one or more embodiments of the present invention, a leachate treatment device based on atmospheric cold plasma technology according to claim 1, wherein the plasma reactor includes eighteen high voltage power supplies, eighteen dimmers for voltage control, twenty-four first electrodes, twenty-four glass tubes, high voltage wires, a second electrode, an internal conduit for conveying fluid to the top of the device and spilling it between the two electrodes, six insulating plates, and a support column for the second electrode; in an embodiment of the present invention, the inlet conduit also includes an inlet valve for controlling the flow of fluid and the outlet conduit also includes an outlet valve for controlling the flow of the active fluid produced. In one embodiment of the present invention, the accumulation tank includes an inlet and an outlet. In one embodiment of the present invention, if the accumulation tank is used for storage (passive inlet and outlet), the initial raw fluid is accumulated with the active fluid in a chamber and this cycle is repeated until all the fluid reaches uniform quality parameters. In one embodiment of the present invention, the accumulation tank is made of polyethylene, polypropylene or a combination thereof. In one embodiment of the present invention, the plasma reactor includes eighteen high voltage power supplies, a protective body, twenty-four first electrodes, a dielectric glass tube, a second electrode, and conductive connecting wires; in such a way that the first electrode is installed in the center of the dielectric glass tube and the leading side of the second electrode is fixed on the connecting tank and the trailing side of the second electrode is open. The first and second electrodes are made of stainless steel (316 steel) or any stainless conductive material. The second electrode is designed in the shape of a hollow cylinder, so that the fluid passes through the empty space inside it. The first electrode is enclosed in the form of cylindrical rods with a certain distance adjacent to the outer surface of the connected second electrode. In one embodiment of the present invention, the dielectric body is made of quartz, ceramic, glass, pyrex, a combination thereof, or any similar dielectric material and is designed in the shape of a cylinder. The conductive interface wires connect the first and second electrodes to the power source and include an insulating coating.In an experiment of the present invention, another tube with a smaller diameter is inserted inside the second electrode tube to act as a holder for the upper insulating plate, a place to place the power sources, and a place to connect the first electrodes. In such a way as to prevent direct connection of the second electrode and the first electrodes. This tube is made of stainless steel (316 steel) or any other anti-rust and anti-corrosive material. In the general aspect of the present invention, the leachate treatment device operates with the help of plasma technology based on the electrical discharge of the dielectric barrier using a dielectric body, in such a way that the first electrode is connected to the positive end of the high-voltage power supply by conductive connecting wires and the second electrode is connected to the negative end of the high-voltage power supply by conductive connecting wires, in such a way that by applying a high voltage by the high-voltage power supply, the potential difference created between the first electrode and the second electrode causes an electrical discharge. The said electrical discharge causes the production of active oxygen, nitrogen and hydroxyl species, and as a result, the pollutants present in the fluid are reduced and it is suitable for use in controlling qualitative and quantitative parameters. In this way, the fluid is transferred by the active fluid reservoir pump through the active / passive inlet to the inlet duct and then enters the empty space inside the second electrode and rises from it. When the fluid reaches the end of the second electrode, it flows on the outer surface of the second electrode.In this way, the fluid is placed in the electrical discharge path between the first and second electrodes and reduces the contaminants in the fluid by producing active oxygen, nitrogen, and hydroxylated species. As the fluid flows over the outer surface of the second electrode, the fluid passes through the discharge region of the dielectric barrier, activated, and is transported through the active / passive outlet conduit. In one embodiment of the present invention, the process of activating the fluid through the passive method is repeated in several steps. The following are some examples in accordance with one or more embodiments of the present invention in full. It should be noted that these examples are merely provided for a better understanding of the technology provided and the present invention can be prepared without such details. As previously stated, these examples are described only as one or more examples of the present invention and do not limit the scope of protection of the present invention in any way, and other methods are also within the scope of the present invention. Figure 1 shows a schematic of a leachate treatment device based on cold plasma technology in accordance with one or more embodiments. According to Figure 2, the device (Figure 1) includes a storage tank (3), a pump (2), a fluid activation plasma reactor (1), a high voltage power supply (5), and a device body (4). Figure 3-a shows a schematic of the plasma reactor chamber for the active fluid. As shown in Figure 3-b, the plasma reactor is connected to an acrylonitrile butadiene styrene insulating plate (1). An insulating flange (2) is used to collect the active fluid from which it is transferred to the active / passive outlet. A gasket (3) is used to prevent fluid leakage. A steel flange (4) is used to connect a steel tube (5) to fix and position the first electrodes (10), glass tubes (8), and the upper insulating plate (11). The fluid rises and overflows from the second electrode (6), which is a steel tube. The glass tube is restrained from the end by the insulating plate (7) and from the top by the insulating plate (9). This system is designed and constructed in such a way that the accumulation tank (3) is connected to the reactor (3-a) by inlet and outlet ducts; in such a way that the plasma reactor system (Figure 3-a) is installed on the insulating plate (1). The accumulation tank (3) is connected to the fluid reservoir pump (2), in such a way that this pump (2) transfers the fluid to the other components of the plasma active fluid device. According to Figure 1, Figure 2, Figure 3-a and Figure 3-b, by applying a high voltage by the high voltage power supply (4), the potential difference created between the first electrode (10) and the second electrode (6) causes an electrical discharge. The fluid activation process is carried out in such a way that the fluid is transferred from the accumulation tank (3) to the inlet duct by the pump (2) and then enters the empty space inside the second electrode (11) and rises from it. When the fluid reaches the end of the second electrode (6), it flows on the outer surface of the second electrode (6). In this way, the fluid is placed in the electrical discharge path between the first electrode (10) and the second electrode (6) and causes the production of active oxygen, nitrogen and hydroxyl species in the plasma reactor. As the fluid flows on the outer surface of the second electrode (6), the plasma active fluid is directed towards the active / passive outlet of the device. Explanation of shapes, maps and diagrams The figures presented illustrate one or more embodiments of the present invention by way of example only. Therefore, the figures presented do not limit the scope of the present invention. Figure 1 shows a general schematic of an active fluid device based on cold plasma technology in accordance with one or more embodiments. Figure 2 shows a schematic of the components of an active fluid device based on cold plasma technology in accordance with one or more embodiments. Figure 3-a shows a general schematic of the external view of the active fluid plasma reactor. Figure 3-b shows a schematic of the components of an active fluid plasma reactor. A clear and precise statement of the advantages of the claimed invention over prior inventions. The present achievement of the leachate treatment device is based on cold plasma technology. The advantages of this product over previous knowledge are: 1. Converting air into plasma and producing active oxygen and nitrogen species without the need for oxygenated fluid or problematic compounds; 2. Maximum cross-sectional area for fluid contact with plasma so that the entire volume of the flowing fluid is processed; 3. Production of various active species such as hydroxyl radical, ozone, hydrogen peroxide, etc. by cold plasma; 4. Using green technology and being eco-friendly; 5. Low production cost and economic efficiency; 6. Beyond the minimum acceptable product, the possibility of industrial exploitation and increasing the dimensions and scale of the device if needed 7. Possibility of connecting to two active and passive paths for different applications and operating conditions Description of at least one implementation method for implementing the invention The present invention, regardless of the embodiments it may have, is a leachate treatment device based on cold plasma technology. In one example of the present invention, the dielectric used in the plasma reactor system is made of quartz, the first and second electrodes are made of stainless steel (316 steel). The second electrode is designed in the shape of a hollow cylinder, so that the fluid passes through the empty space inside it, the first electrode is connected to the positive end of the high-voltage power supply by conductive connecting wires and the second electrode is connected to the negative end of the high-voltage power supply by conductive connecting wires, so that by applying a high voltage by the high-voltage power supply, a potential difference of 12 kV to the first electrode and the second electrode causes an electric discharge. In this example, the dielectric tube and the body of the first electrode, the second electrode and the holding tube are designed in the shape of a cylinder, so that the radius of the dielectric body is about 1 mm larger than the radius of the first electrode.A hole is provided inside the connector connections in which a steel screw is placed; in such a way that the screw head is connected to the second electrode and the end of the second electrode is connected to the negative end of the high-voltage power supply by the conductive wires of the connector. When the fluid activation process starts, the fluid is transferred to the reactor from the connections by a pump. Then, the fluid enters the empty space of the second electrode and rises from the second electrode. Upon reaching the open end of the second electrode, the fluid flows on the outer surface of the second electrode, in such a way that the thickness of the fluid flowing on the outer surface of the second electrode is a maximum of 3 mm. Considering that the fluid passes through the electrical discharge between the first and second electrodes, it is affected by the plasma produced and active oxygen, nitrogen and hydroxyl species are produced in it. As the fluid flows on the outer surface of the second electrode, the plasma active fluid is collected through the insulating flange and enters the active / inactive path through the outlet duct.The activation process in the passive route is repeated several times until sufficient active species are produced and the fluid has the required qualitative and quantitative indicators. Explicit mention of the industrial application of the invention The present achievement, regardless of the fact that it can have different embodiments, is related to the field of leachate treatment based on cold plasma technology; in such a way that by applying cold plasma formed from air flow, active oxygen, nitrogen, and hydroxyl species are produced, and as a result, the pollutants present in the fluid are reduced and it becomes suitable for use in order to control qualitative and quantitative parameters. On the other hand, given the availability of the equipment required to build the device and the lack of complexity in construction, it can be industrially manufactured and mass-produced, making a significant contribution to leachate treatment and the environment. Brief description of the invention The present invention is a leachate treatment based on cold plasma technology. The device disclosed in this invention includes a storage tank, a plasma reactor, an inlet and outlet ducts, fittings, a pump, and a table. During the treatment process, the storage tank initially contains the raw fluid (leachate passing through the pre-treatment) and a pump transfers the fluid through the inlet duct to the reactor. The pre-treatment systems are directly connected to the tank of the leachate treatment device based on cold plasma technology, and its output is transferred to the plasma system. The reactor of the device activates the passing fluid by producing active species and returns it to the interface tank and, after several recirculation stages, finally transfers it to the outlet duct. This cycle is repeated several times until the activation process is complete, efficient, and appropriate to the target treatment. The plasma-activated fluid system of the present invention operates on the basis of the electrical discharge of the dielectric barrier.In this way, the flowing fluid flow, when placed in the electrical discharge path of the plasma reactor, contains active oxygen, nitrogen, and hydroxyl species, and as a result, the contaminants in the fluid are reduced and it becomes suitable for use in controlling qualitative and quantitative parameters.

Claims

Claim What is claimed: Claim 1) A leachate treatment device based on atmospheric cold plasma technology, comprising: - an accumulation tank; - a plasma reactor; in such a way that the plasma reactor operates on the basis of dielectric barrier discharge; - two inlet ducts; in such a way that one is for active feeding (when pumped from the outlet pipeline of the pretreatment system to the reactor) and the other is for passive feeding (when the fluid is pumped from the accumulation source to the reactor). - two outlet ducts; in such a way that one is for active exit (when sent from the device pipeline to the pretreatment systems) and the other is for passive exit (when the fluid is sent from the reactor to the accumulation source); - a device table Claim 2) A leachate treatment device based on atmospheric cold plasma technology according to claim 1, wherein the accumulation tank is equipped with a fluid transfer pump to provide fluid flow to other components of the device; also, said tank has an inlet duct at the top and an outlet duct at the bottom, through which the fluid enters through the inlet duct and is directed towards the pump after exiting the outlet duct.Claim 3) A leachate treatment device based on atmospheric cold plasma technology according to claim 1, wherein the plasma reactor includes twenty-four high-voltage power supplies, twenty-four dimmers for voltage control, twenty-four first electrodes, twenty-four glass tubes, a high-voltage wire, a second electrode, an internal conduit for transferring fluid to the top of the device and pouring it between the two electrodes, six insulating plates and a support column for the second electrode; wherein the outer surface of each first electrode is covered with a glass tube. wherein the second electrode is installed in the form of a tube in the middle of the system and one side is placed on the table and the other end is open. wherein the first electrodes are enclosed in the form of cylindrical rods adjacent to the outer surface of the second electrode at a certain distance. wherein the plasma reactor operates based on the electrical discharge of the dielectric barrier. In such a way that the first electrodes are connected to the positive end of the high-voltage power supply by conductive connection wires, and the second electrode is connected to the negative end of the high-voltage power supply by conductive connection wires.In a way that by applying a high voltage, the potential difference created between the first and second electrodes causes an electrical discharge. In a way that water enters through the hole created on its body, which is connected to the bottom of the second electrode, is directed upwards and finally flows through it, and after passing through the space between the two electrodes, the resulting active fluid is directed towards the outlet channels.

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