A water treatment device and method based on plasma

Abstract

The present invention provides a plasma-based water treatment device and method, which relate to the technical field of water treatment. To solve the problem that a large area of ​​stable jet plasma cannot be supplied, resulting in low treatment efficiency, multiple outlet ends are arranged to be connected to a gas discharge channel, and active particles in the gas discharge channel are effectively led out by using a grounding electrode surrounding the outlet end, thereby increasing the effective area of ​​the active particles after output. The multiple outlet end design effectively improves the treatment efficiency of the plasma jet.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a plasma-based water treatment device and method. Background Art

[0002] Plasma discharge, as a water treatment technology that combines rapid treatment and green treatment, can produce different forms of physical and chemical effects, and can produce some oxidizing particles, including active free radicals (hydrogen free radicals, oxygen free radicals, hydroxyl free radicals, etc.), oxidizing molecules (hydrogen peroxide, ozone, etc.), microwaves and ultraviolet light, etc. The process of plasma technology to treat water includes various types of oxidation in advanced oxidation, such as ozone oxidation, ultraviolet light synergistic catalytic oxidation and pyrolysis, etc. It is a comprehensive and highly applicable environmentally friendly water treatment technology.

[0003] Dielectric barrier discharge (DBD) is a discharge form in which at least one of the two discharge electrodes is covered by a non-conductive insulating medium or the insulating medium is directly inserted into the discharge space. Based on DBD discharge, the atmospheric pressure discharge low-temperature plasma jet can use the airflow to blow the plasma generated in the discharge space out of the ionization area, thereby improving the flexibility of the plasma treatment process. A Chinese patent (publication number: CN110844975) discloses a plasma-based water treatment method, which combines aeration and plasma with two catalyst technologies for water treatment. However, the area where the plasma is output is limited by the specifications of the aeration pipe, resulting in the inability to supply a large area of ​​stable jet plasma, making it difficult to meet the needs of rapid and large-area sewage treatment. Summary of the invention

[0004] The purpose of the present invention is to address the defects of the prior art and provide a plasma-based water treatment device and method. By arranging multiple outlet ports to connect to a gas discharge channel, active particles in the gas discharge channel are effectively led out using a grounding electrode surrounding the outlet ports, thereby increasing the effective area after the active particles are output. The multiple outlet port design effectively improves the treatment efficiency of the plasma jet.

[0005] The first object of the present invention is to provide a plasma-based water treatment device, which adopts the following scheme: it includes a discharge electrode and a grounding electrode, the discharge electrode is wrapped with a first insulating layer and a second insulating layer in sequence, a gas discharge channel is formed between the first insulating layer and the second insulating layer, the gas discharge channel is provided with an air inlet for connecting to a gas source, the gas discharge channel is connected with multiple outlet ends, and the grounding electrode surrounds the outlet end of each gas discharge channel to lead the plasma in the gas discharge channel out from the outlet end.

[0006] Furthermore, the discharge electrode comprises a first electrode plate in a plate shape, all the outlet ends are located on the same side of the plane where the first electrode plate is located, and the outlet ends are arranged at intervals.

[0007] Furthermore, the discharge electrode also includes a rod-shaped second electrode plate, the end of the second electrode plate is connected to a side of the first electrode plate away from the outlet end, and the air inlet is located on one side of the axis of the second electrode plate.

[0008] Furthermore, all the outlet ends are arranged along a plane, which is parallel to the plane where the first electrode plate is located and arranged at intervals.

[0009] Furthermore, it also includes a container, the container is provided with a cover, the discharge electrode is mounted on the cover, and the discharge electrode terminal passes through the cover and is led out of the container.

[0010] Furthermore, the outlet end is butt-jointed with an outlet pipe, and a ground electrode surrounds the outlet pipe to guide the plasma in the gas discharge channel to form a jet input.

[0011] Furthermore, the air inlet is connected to an external air source through an air pipe, and the air inlet is equipped with a gas flow meter.

[0012] Furthermore, each of the outlet ends is connected to a bubbler.

[0013] A second object of the present invention is to provide a water treatment method using a plasma-based water treatment device, comprising:

[0014] The discharge electrode is connected to a power source, the ground electrode is grounded, and the gas inlet is connected to an external gas source to supply raw gas into the gas discharge channel;

[0015] The discharge electrode acts on the gas in the gas discharge channel to form plasma. The active particles in the plasma are output through the outlet under the guidance of the ground electrode and act on the water to be treated.

[0016] Furthermore, the outlet end is connected to a bubbler, which outputs bubbles that wrap the active particles, and the bubbles diffuse and dissolve in the water to be treated to act;

[0017] or,

[0018] The outlet end is arranged at a distance from the liquid surface of the water body to be treated, and the active particles generated by the discharge are sprayed to the liquid surface under the guidance of the outlet end to act on the water body to be treated.

[0019] Compared with the prior art, the present invention has the following advantages and positive effects:

[0020] (1) In order to solve the problem of low processing efficiency caused by the inability to supply a large area of ​​stable jet plasma, multiple outlet ends are arranged to connect to the gas discharge channel, and the active particles in the gas discharge channel are effectively led out by using the grounding electrode surrounding the outlet end, thereby increasing the effective area after the active particles are output. The multiple outlet end design effectively improves the processing efficiency of the plasma jet.

[0021] (2) The bubbling is combined with the DBD structure to increase the gas-liquid mass transfer efficiency of the plasma active particles and enhance the active oxidation effect of the plasma water treatment.

[0022] (3) Combining the advantages of plasma jet in effectively extracting ions and dielectric barrier discharge in uniform water treatment, a disk-shaped first electrode is designed to increase the discharge area, and multiple jet outlet ends are designed to effectively solve the problem of low efficiency of plasma jet.

[0023] (4) By configuring a bubbler at the outlet or arranging the outlet at a distance from the liquid surface, it is suitable for a treatment mode above the liquid surface and deep in the liquid, has a wider application scenario, and the generated plasma-activated water has a higher activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 Schematic diagram of the structure of the plasma-based water treatment device in Examples 1 and 2 of the present invention.

[0026] Figure 2 Schematic diagram of the bubbler in Examples 1 and 2 of the present invention.

[0027] Figure 3 Schematic diagram of the operation of the plasma-based water treatment device in Examples 1 and 2 of the present invention.

[0028] Figure 4 This is a schematic diagram of the outlet end being located above the liquid surface of the water body to be treated in Examples 1 and 2 of the present invention.

[0029] Among them, 1-discharge electrode, 2-second electrode plate, 3-cover body, 4-container, 5-outlet end, 6-ground electrode, 7-bubbler, 8-first electrode plate, 9-air inlet. DETAILED DESCRIPTION

[0030] Example 1

[0031] In a typical embodiment of the present invention, Figure 1-Figure 4 As shown, a plasma-based water treatment device is provided.

[0032] Atmospheric pressure discharge low temperature plasma jet can use airflow to blow the plasma generated in the discharge space out of the ionization area based on DBD discharge, so it improves the flexibility of the plasma treatment process and has a wide range of applications. At present, there is a demand to increase the concentration of active particles in the jet plasma and to produce a large area of ​​stable jet plasma under atmospheric pressure conditions to meet various treatment needs. The focus is on how to obtain rapid and large-area treatment capabilities. The plasma-based water treatment method in the prior art combines aeration and plasma and two catalyst technologies for water treatment, but the area where the plasma is output is limited by the specifications of the aeration pipe, resulting in the inability to supply a large area of ​​stable jet plasma, making it difficult to meet the needs of rapid and large-area treatment of sewage.

[0033] Based on this, a plasma-based water treatment device is provided in this embodiment, which arranges multiple outlet ports 5 to connect to the gas discharge channel, and uses the grounding electrode 6 surrounding the outlet port 5 to effectively lead out the active particles in the gas discharge channel, thereby increasing the effective area after the active particles are output. The design of multiple outlet ports 5 effectively improves the treatment efficiency of the plasma jet.

[0034] The plasma-based water treatment device in this embodiment is described below with reference to the accompanying drawings.

[0035] See also Figure 1 The plasma-based water treatment device mainly includes three parts, namely a DBD reactor, a bubbler 7 and a reaction vessel 4.

[0036] The DBD reactor is composed of electrodes and an insulating medium. The electrodes are divided into a discharge electrode 1 and a ground electrode 6. The insulating medium includes a first insulating layer and a second insulating layer. The insulating medium can be made of quartz glass, and the first quartz glass layer and the second quartz glass layer are formed accordingly. In other embodiments, the materials of the first insulating layer and the second insulating layer can be adjusted according to the needs, and other insulating media that can meet the needs can be used.

[0037] Combination Figure 1 , Figure 4 The discharge electrode 1 is wrapped with a first insulating layer and a second insulating layer in sequence, forming a structure of the discharge electrode 1, the first quartz glass layer, and the second quartz glass layer from the inside to the outside. The first quartz glass is located in the inner layer, which can fix the discharge electrode 1 and maintain the position of the discharge electrode 1. The second quartz glass layer is located in the outermost layer and is arranged at intervals with the first quartz glass layer. A cavity is formed between the first insulating layer and the second insulating layer after the interval arrangement, where the discharge occurs. The cavity serves as a gas discharge channel. The gas discharge channel is provided with an air inlet 9 for connecting to a gas source. The gas discharge channel is connected with multiple outlets 5, and the grounding electrode 6 is arranged at the outlet 5.

[0038] In order to enable the plasma in the gas discharge channel to be smoothly output to the outside of the DBD reactor and guide it to act on the water to be treated, the grounding electrode 6 is arranged around the outlet end 5, and each outlet end 5 is surrounded by a grounding electrode 6 to form a guiding effect on the position of each outlet end 5, so as to lead the plasma in the gas discharge channel out from the outlet end 5.

[0039] It should be noted that in this embodiment, see Figure 4 A tubular structure is formed at the outlet end 5, and the outlet pipe can be connected at the outlet end 5. The ground electrode 6 surrounds the outlet pipe to guide the plasma in the gas discharge channel to form a jet input.

[0040] In order to meet the demand for supplying a large area of ​​stable jet plasma, the structure of the discharge electrode 1 and the distribution of the outlet end 5 are designed. The discharge electrode 1 of the DBD reactor in this embodiment is designed as a structure combining rod and plate to increase the range of discharge.

[0041] See also Figure 1 , Figure 4 The discharge electrode 1 includes a first electrode plate 8 and a second electrode plate 2. The first electrode plate 8 is a plate-like structure, such as a circular plate or a disc, and all the outlet ends 5 are located on the same side of the plane where the first electrode plate 8 is located, and the outlet ends 5 are arranged at intervals. The second electrode plate 2 is a rod-like structure, and the end of the second electrode plate 2 is connected to the side of the first electrode plate 8 away from the outlet end 5, and the air inlet 9 is located on the side of the axis of the second electrode plate 2.

[0042] All the outlet ends 5 are arranged along a plane, which is parallel to the plane where the first electrode plate 8 is located and arranged at intervals. The outlet ends 5 are designed as jet ports to improve the output efficiency of the plasma.

[0043] See also Figure 3 ,by Figure 3 The posture shown in is used as an example for description, the axis of the second electrode plate 2 is the vertical direction, the plane where the first electrode plate 8 is located is the horizontal direction, the plane where the first electrode plate 8 is located is perpendicular to the axis of the second electrode plate 2, and at the same time, when the first electrode plate 8 is a disc-shaped structure, the first electrode plate 8 is coaxially arranged with the second substrate. A plurality of outlet ports 5 are arranged at the bottom of the second insulating layer located at the outer layer of the DBD reactor, and outlet pipes are respectively configured at the outlet ports 5 to promote jet formation.

[0044] The annular electrodes located outside the outlet 5 are connected in series to serve as the ground electrode 6, the purpose of which is to lead the plasma generated by the gas discharge out of the gas discharge channel. The plasma contains various active particles. After the active particles are output from the gas discharge channel through the outlet 5, they can be directly sprayed on the surface of the liquid to be treated or enter the liquid in the form of bubbles through the bubbler 7. The bubbler 7 is as shown in FIG. Figure 2 shown.

[0045] like Figure 1, Figure 3 , Figure 4 As shown, the DBD reactor can be directly mounted on a container 4 , the container 4 is provided with a cover 3 , the discharge electrode 1 is mounted on the cover 3 , and the connection terminal of the discharge electrode 1 passes through the cover 3 and is led out of the container 4 .

[0046] It can be understood that the second electrode plate 2 of the discharge electrode 1 in the DBD reactor is a high-voltage electrode rod, the second electrode plate 2 is connected to the power supply system, and the air inlet 9 is connected to the external gas source through the air pipe. At the same time, the gas source can be configured with a gas control system, and the gas source can be a gas cylinder, etc., and a gas flow meter is installed on the air pipe to control the flow rate of the gas.

[0047] During operation, a high-voltage AC source is used as a power source, connected to a discharge electrode 1, and gases such as argon, helium, and air are used as gas raw materials. Plasma is generated by discharging through a DBD reactor, and active particles such as hydrogen peroxide, hydroxyl radicals, ozone, and nitrate ions with oxidative properties contained therein act on the treatment solution to form plasma-activated water, which oxidatively degrades the solution.

[0048] Example 2

[0049] In another typical embodiment of the present invention, Figure 1-Figure 4 As shown, a water treatment method based on a plasma water treatment device is provided.

[0050] The water treatment method based on the plasma water treatment device comprises:

[0051] The discharge electrode 1 is connected to a power source, the ground electrode 6 is grounded, and the gas inlet 9 is connected to an external gas source to supply raw gas into the gas discharge channel;

[0052] The discharge electrode 1 acts on the gas in the gas discharge channel to form plasma, and the active particles in the plasma are output through the outlet end 5 under the guidance of the ground electrode 6 and act on the water body to be treated.

[0053] For different treatment requirements, the plasma output from the outlet 5 can be directly sprayed onto the surface of the water body to be treated, or the outlet 5 can be connected to the bubbler 7 to enter the water body to be treated in the form of bubbles and gradually diffuse.

[0054] like Figure 3 As shown, the outlet port 5 is connected to the bubbler 7, and the bubbler 7 outputs bubbles that wrap the active particles, and the bubbles diffuse and dissolve in the water to be treated to act; Figure 4 As shown, the outlet end 5 is spaced apart from the liquid surface of the water body to be treated, and the active particles generated by the discharge are sprayed to the liquid surface under the guidance of the outlet end 5 to act on the water body to be treated.

[0055] In conjunction with Example 1, the water treatment method is described in detail.

[0056] Step 1: Assemble and connect the bubbler 7 and the outlet end 5 of the DBD reactor through a rubber ring, and then assemble the DBD reactor and the cover 3 of the reaction container 4, and connect the grounding electrode 6 outside the outlet end 5 in series and ground it;

[0057] Step 2: connect the gas pipe to the gas inlet 9 of the DBD reactor and connect the gas to ensure the entry of the raw gas;

[0058] Step 3: The target treatment solution is loaded into the container 4, and the assembled reactor is inserted into the solution and covered with the cover 3;

[0059] Step 4: The discharge electrode 1 is connected to a high-voltage power supply, the power is turned on, and the voltage is applied. The gas starts to discharge between the first insulating layer and the second insulating layer. At the same time, the discharge generates plasma which is introduced into the liquid in the form of bubbles through the bubbler 7 at the jet branch pipe mouth to treat the target treatment solution.

[0060] See also Figure 3 , place the target treatment solution in the reaction vessel 4, assemble the bubbler 7, DBD reactor, cover 3, gas control system and power supply. Place the outlet 5 and bubbler 7 deep into the solution, introduce a mixed gas of argon and oxygen into the DBD reactor, and apply a 6kV AC voltage;

[0061] Discharge occurs between the first insulating layer and the second insulating layer of the DBD reactor. Active particles generated by the discharge flow into the bubbler 7 along with the gas flow. Bubbles containing plasma active particles bulge out of the pores of the bubbler 7. The bubbles continuously diffuse and dissolve in the solution to form plasma-activated water with strong oxidizing properties, thereby treating the solution.

[0062] See also Figure 4 , place the target treatment solution in the reaction container 4, assemble the DBD reactor, the cover 3, the gas control system and the power supply. After assembly, keep the outlet end 5 2mm above the liquid surface, introduce a mixed gas of argon and oxygen into the DBD reactor, and apply a 6kV AC voltage;

[0063] Discharge occurs in the gap between the first insulating layer and the second insulating layer of the DBD reactor, and the active particles generated by the discharge are sprayed to the liquid surface in the form of a jet at the outlet pipe along with the air flow, thereby treating the solution.

[0064] By configuring the bubbler 7 at the outlet end 5 or arranging the outlet end 5 at a distance from the liquid surface, it is suitable for a mode of processing above the liquid surface and deep into the liquid, has a wider application scenario, and the generated plasma-activated water has a higher activity.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A plasma-based water treatment device, characterized in that: It comprises a discharge electrode and a grounding electrode, wherein the discharge electrode is wrapped with a first insulating layer and a second insulating layer in sequence, a gas discharge channel is formed between the first insulating layer and the second insulating layer, the gas discharge channel is provided with a gas inlet for connecting to a gas source, the gas discharge channel is connected with a plurality of outlet ends, and the grounding electrode surrounds the outlet end of each gas discharge channel to lead the plasma in the gas discharge channel out from the outlet end; The discharge electrode comprises a first electrode plate in the shape of a circular plate, all outlet ends are located on the same side of the plane where the first electrode plate is located, and the outlet ends are arranged at intervals; The discharge electrode further comprises a rod-shaped second electrode plate, the end of the second electrode plate is connected to the side of the first electrode plate away from the outlet end, and the air inlet is located on the side of the axis of the second electrode plate; the axis of the second electrode plate is the vertical direction, the plane where the first electrode plate is located is the horizontal direction, and the plane where the first electrode plate is located is perpendicular to the axis of the second electrode plate; All outlet ends are arranged along a plane which is parallel to the plane where the first electrode plate is located and arranged at intervals; The container is also provided with a cover body, the discharge electrode is mounted on the cover body, and the discharge electrode terminal is led out of the container through the cover body; the outlet end is connected to an outlet pipe, and the grounding electrode surrounds the outlet pipe to guide the plasma in the gas discharge channel to form a jet input; Each of the outlet ends is connected to a bubbler.

2. The plasma-based water treatment device according to claim 1, characterized in that The air inlet is connected to an external air source through an air pipe, and the air inlet is equipped with a gas flow meter.

3. A water treatment method according to any one of claims 1 to 2, characterized in that: include: The discharge electrode is connected to a power source, the ground electrode is grounded, and the gas inlet is connected to an external gas source to supply raw gas into the gas discharge channel; The discharge electrode acts on the gas in the gas discharge channel to form plasma. The active particles in the plasma are output through the outlet under the guidance of the ground electrode and act on the water to be treated.

4. The water treatment method according to claim 3, characterized in that: The outlet end is connected to a bubbler, which outputs bubbles that wrap the active particles. The bubbles diffuse and dissolve in the water to be treated to act.

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