KR20010088986A - waste water treating method and apparatus by microwave plasma - Google Patents

Abstract

PURPOSE: A wastewater treatment method using micro wave plasma and an equipment thereof are provided, which can treat effectively wastewater under by oxidizing BOD and COD, sterilizing microorganism, cutting pigment ring and oxidizing volatile organic matter. CONSTITUTION: The system comprises the followings: (i) a cylindrical vertical wastewater treatment vessel (12); (ii) a micro wave pipe (10) that is vertically installed in the vessel (12), to the top of which oxygen and hydrogen peroxide are fed through an oxygen supplier (4) and a hydrogen peroxide supplier (5) respectively and to the bottom end of which a membrane (11) is installed; (iii) a magnetron (2) which is set around a wave guide (1) that is set at the top of the micro wave pipe (10) for keeping oxygen atoms and OH radicals which are generated from internal reaction as plasma ; (iv) a tuner (7) and circulator (8) which are set beneath the magnetron (2); and (v) a membrane (11) that is set at the end of the micro wave pipe (10), at the outer film of which hydrogen is formed and oxygen atoms that is generated inside the pipe (10) react with hydrogen to form OH radical.

Description

Wastewater treatment method by microwave plasma and apparatus therefor {waste water treating method and apparatus by microwave plasma}

The present invention relates to a wastewater treatment method using a microwave plasma and an apparatus thereby.

In general, the treatment of wastewater is the removal of various types of contaminants remaining in water by physical, chemical, and biological treatment methods, and coagulation by flocculants, sedimentation, flotation, digestion by anaerobic and aerobic microorganisms. The process, the filtration process through a filtration membrane, the sterilization, disinfection, etc. using the oxidizing power of chlorine have been mainly performed.

However, due to poorly degradable components that were not treated well with this process, the quality of the effluent could no longer be improved.

These hardly degradable factors include organic compounds with high binding strength between macromolecules such as humus and molecular rings, and toxic substances that microorganisms cannot eat.

Therefore, there is a need for highly oxidizing materials that can break the bonding strength of these hardly degradable materials.

In recent years, 1.77 volts of hydrogen peroxide and 2.07 volts of ozone, which are higher than chlorine having an oxidation potential of 1.36 volts, have been used. There are also other unknown oxygen atoms with high oxidation potentials.

However, as the oxidation potential of the OH radical (2.8 volts), which is an intermediate in the conversion process in water, is higher than the oxidizing power of the preceding, researches to generate this effectively and use it for water treatment continue. That is, research on advanced oxidation processing (AOP) technique for water treatment is actively being conducted.

These methods include a mixture of ozone, hydrogen peroxide, and ultraviolet light, a method of irradiating ultraviolet light to photocatalysts such as titanium dioxide, a method of accelerating electron beams to irradiate the wastewater, an X-ray irradiation method, and bubble breakdown by ultrasonic cavitation. And advanced oxidation treatment techniques such as a method using a low temperature plasma and a method using a low temperature plasma.

The method of irradiating the target wastewater by accelerating the electron beam and the X-ray irradiation method, the irradiation of the electron beam or X-rays, there is a disadvantage that can not be effective water treatment due to the low depth of penetration into the water.

The method using hydrogen peroxide or ozone and other media is indirectly generating OH radicals in the course of their reactions, which requires a lot of equipment, which requires complicated and increased installation costs and expensive raw materials. It has the disadvantage of low efficiency.

In addition, ozone (2.07 volts of oxidation potential) generated by flowing air or oxygen between insulators composed of dielectrics has a half life in water of about 20-30 minutes, whereas an oxidation potential is maintained. High OH radicals and ionizing gases (O-, O atoms) have a very short time from their formation to extinction, so even if they are produced by a direct method, they are almost impossible to transport into water, making it almost impossible to come into contact with wastewater.

Therefore, the utilization of OH radicals in the water treatment process was only an indirect method in which ozone, ultraviolet rays, hydrogen peroxide, etc. were generated by the mutual reaction process in water.

In order to solve this problem, U.S. Patent No. 5,630,915 installed an electrode in a gas transfer path installed in water and caused high pressure discharge in the gas to generate an ionizing gas, attempting to contact liquid, and from an electrode placed on the water surface. Attempts have been made to discharge the high voltage toward the surface to bring the ionizing gas into contact with the surface.

The present invention is a vapor of water or hydrogen peroxide, which is a substance combined with hydrogen, in a state in which one or a plurality of magnetrons (microwaves) are excited and dissociated in a reactor without mutual interference beyond the conventional technical limitations described above. Is injected in a constant ratio to generate OH radicals or to dissociate oxygen atoms into water in an atomized state with water, and the electrolytic membrane is a negative electrode for electrolysis and the outer container is a positive electrode for electrolysis of water. By connecting the hydrogen gas generated by the action to the gas permeable membrane, the oxygen atom coming out through the membrane toward the liquid is combined with the hydrogen atom produced by electrolysis to generate OH radicals, and also generates ultrasonic vibration or mechanical vortex Increase the catalytic oxidation efficiency It relates to a water treatment apparatus and method

1 shows an apparatus according to an embodiment of the present invention.

2 is another embodiment of FIG.

3 is an exemplary view showing a state in which the present invention is applied and applied

The main configuration of the apparatus according to the present invention includes a waveguide, a magnetron installed around the waveguide, an oxygen supplier 4 and a hydrogen peroxide supply 5 installed to supply oxygen gas and hydrogen peroxide liquid into the waveguide, and the magnetron A tuner and a circulator connected to each other, a microwave tube extending from the waveguide and having an oxygen atom and OH radicals generated by a reaction therein in a plasma state, and a membrane installed at a lower portion of the microwave tube (11). And hydrogen generated by electrolysis between the vessel 12 and the membrane 11 are formed on the outer membrane of the membrane 11, including the vessel 12 containing the wastewater to be treated, (10) When an oxygen atom and an OH radical formed therein come out, the oxygen atom combines with hydrogen to form OH radicals, and the method Inject the gas and hydrogen peroxide liquid, but the liquid hydrogen peroxide is sprayed by ultrasonic injection nozzle to produce hydrogen peroxide vapor, oxygen atom and OH radical are generated by magnetron and tuner, and then plasma is sent to the membrane 11, The OH radical is discharged into the water through the membrane and the oxygen atom is treated with the hydrogen gas generated on the outer surface of the membrane 11 by electrolysis to treat the wastewater by generating OH radicals in the water. .

Hereinafter, the present invention will be described in detail with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view of main parts for explaining the main configuration of the apparatus according to the present invention.

As shown, first in the figure, a waveguide 1 is provided on the top and a magnetron 2 is installed on the side thereof. One or more magnetrons 2 are installed around the waveguide 1.

An ultrasonic spray nozzle 3 is installed at the center between the waveguides 1 and the spray nozzle 3 is connected to the hydrogen peroxide supply 5.

The hydrogen peroxide supply 5 may be a hydrogen peroxide generator or a hydrogen peroxide storage tank. The hydrogen peroxide here is atomized while being supplied with pressure to the ultrasonic jet nozzle 3 in the liquefied state.

On the other hand, an oxygen inlet 6 is formed at one side of the injection nozzle 3.

The oxygen gas injection into the oxygen inlet 6 is made by the oxygen supply 4. The oxygen supplier 4 may be an oxygen generator or an oxygen storage tank.

A tuner 7 is installed below the magnetron 2 and a circulator 8 is installed below it.

Circulators are useful for diverting microwaves in different directions. The circulator 8 is opened in two directions, one of which is opened downwardly so as to communicate with the upper side of the microwave tube 10 and the other through the waveguide 9 which is lowered downwardly of the microwave tube 10. Make it communicate with the lower side.

The microwave tube 10 is made of quartz, that is, quartz or ceramic material, which allows microwaves to be transmitted without loss.

The membrane 11 is connected to the bottom of the microwave tube 10. Membrane 11 is used to have a gas-permeable property and the material is an alloy of Ag: Zr is 95: 5.

The periphery of the membrane 11 is filled with waste water to be treated, and the outer circumference is surrounded by the container 12.

In other words, the arrangements of the above-mentioned devices are contained in the container 12.

When the vessel 12 is positive and the membrane 11 is negatively electrolyzed, the wastewater between the vessel 12 and the membrane 11 is electrolyzed and oxygen is added to the plus side of the vessel 12. Hydrogen is generated on the periphery of the membrane 11.

On the other hand, a flange 13 is installed on the upper side of the container 12 so that the device according to the present invention can be attached and detached at a predetermined position.

The operation according to the above configuration will be described below.

In the present invention, the components of the plasma gas generated by the microwave are formed at the gas inlet so that the components of atomized oxygen (2.42 volts), OH radicals, and the like are formed.

First, a liquid hydrogen peroxide is supplied from the hydrogen peroxide supply 1, and is sprayed while atomizing through an ultrasonic spray nozzle. At the same time, oxygen gas is supplied from the oxygen supplier 4, and the inside of the waveguide 1 is in a state where oxygen gas and hydrogen peroxide gas are mixed.

At this time, oxygen gas (that is, oxygen molecule: oxidation potential 1.20 volts) is excited and atomized oxygen by the configuration of the microwave and tuner 7 and the microwave tube 10 communicating with the magnetron 2 installed therein. And dissociate into oxygen atom (oxidation potential 2.42 volts) having high oxidizing power. For reference, the oxidation potential of the atomized oxygen atom is in the middle range between the OH radical and ozone, and also occurs in the production and disappearance of ozone.

On the other hand, the propagation by the magnetron (2) acts on the upper portion of the microwave tube 10 via the tuner (7) and the circulator (8), but a part of the reflected wave is necessarily generated. According to the present invention, the reflected wave is introduced into the lower portion of the microwave tube 10 through the wave guide 9 and recycled through the circulator 8.

Oxygen atoms and OH radicals in the plasma state exit the water 13 through the membrane 11 below. The membrane 11 passes through the gas but does not pass through the liquid, so external wastewater does not flow into the membrane 11.

Here, the OH radicals generated by the plasma are just introduced through the membrane 11 into the wastewater 13 of the wastewater, and oxygen atoms penetrate through the membrane 11, and hydrogen generated on the outer circumference of the membrane 11 by electrolysis. React with to produce OH radicals. Eventually a large amount of OH radicals can be supplied to the water.

The large amount of OH radicals thus produced can quickly treat large amounts of organic and inorganic wastewater.

The reason for installing the plurality of magnetrons 2 in the apparatus is as follows.

Plasma generation under atmospheric pressure requires high magnetrons with a high critical energy of 3 KW or more, and is about 20 times more expensive than the output of household goods such as microwave ovens, and reduces production costs by using multiple magnetrons in parallel. It is for.

2 is another embodiment of the present invention.

In this embodiment, instead of the magnetrons 2 installed around the waveguide 1 in FIG. 1, only one magnetron 20 having a strong output is installed.

The circulator 28 and the tuner 27 are provided at one side of the magnetron 20, and are connected to the cylindrical body 29 at the other side.

The inside of the cylindrical body 29 is the microwave tube 21 is formed.

Thus, R.F generated in the magnetron 20 enters into the microwave tube 21 via the cavity (cavity) 31 in the hollow cylinder 29.

On the other hand, the upper side of the microwave tube 21, the oxygen supply and hydrogen peroxide supply as in the previous embodiment of FIG. 1 is installed to supply oxygen gas and hydrogen peroxide, and the oxygen atoms and OH radicals are formed in the same operation as in the previous embodiment.

Electrolysis by the configuration of the membrane 11, the container 12, and the like under the microwave tube 21 and the operation thereof is the same as in the previous embodiment, so a detailed description thereof will be omitted.

3 is another embodiment of an apparatus according to the invention.

That is, this embodiment is one embodiment in which the apparatus for generating OH radicals is applied to the actual water treatment, in particular, on the principle of the structure as shown in FIG.

In this embodiment, by installing a plurality of OH radical generating device 50 for generating OH radicals according to the principle of the structure described above, waste water is injected through the waste water inlet 41, which is installed in several paths OH radical generating device After the wastewater was treated via (50), it was configured to be discharged to the treatment outlet (42).

According to the apparatus according to the present invention as described above, by the gas-liquid contact of the ionizing gas oxidizes the BOD, COD components in the wastewater, microbial sterilization, blocking of the pigment ring, oxidizing volatile organic compounds (VOC) components are good and effective Can be treated with water

Claims (5)

Waveguide, With magnetron installed around the waveguide, An oxygen supplier 4 and a hydrogen peroxide supply 5, which are installed to supply oxygen gas and hydrogen peroxide liquid into the waveguide, A tuner and a circulator connected to the magnetron, A microwave tube installed extending from the waveguide and having an oxygen atom and an OH radical generated in a reaction state in a plasma state; Mebrane 11 is installed on the lower portion of the microwave tube, Including a container 12 containing wastewater to be treated, Hydrogen generated by electrolysis between the vessel 12 and the membrane 11 is formed on the outer membrane of the membrane 11, and when oxygen atoms and OH radicals formed inside the microwave tube 10 come out, the oxygen atoms become hydrogen. Combined with the waste water treatment apparatus by the microwave plasma, characterized in that the formation of OH radicals The method of claim 1, The magnetron (2) is a wastewater treatment apparatus using a microwave plasma, characterized in that a plurality of the outer periphery of the waveguide (1) is installed The method of claim 1, The circulator 28 and the tuner 27 are provided at the side of the magnetron 20, and the dummy rod 30 is installed at the side of the circulator 28. Device The method of claim 1, The OH radical generator 50 includes a plurality of wastewater inlets 41 and a treatment outlet 42 in a zigzag container having a plurality of wastewater treatment apparatuses. Oxygen gas and hydrogen peroxide liquid is injected, but the liquid hydrogen peroxide is sprayed by ultrasonic injection nozzles to produce hydrogen peroxide vapor, oxygen atoms and OH radicals are generated by magnetron and tuner, and then plasma is sent to the membrane 11, The OH radicals are discharged into the water through the membrane and the oxygen atom is treated with the hydrogen gas generated on the outer surface of the membrane 11 by electrolysis to treat the wastewater by producing OH radicals in the water. Wastewater Treatment Method by Microwave Plasma