JP2001149918A - Treating apparatus of wastewater including volatile organic substance and treating method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treating apparatus of wastewater which allows a volatile organic substance in the wastewater to be subjected to the treatment economically and efficiently. SOLUTION: This treating apparatus of wastewater is constituted in such a manner that the wastewater which is supplied from a wastewater supplying means 1 and includes the volatile organic substance is treated in an aeration treatment chamber 10, the wastewater is, thereby, subjected to the gas-liquid separation and separated into the gas including the volatile organic substance and the water gotten rid of the volatile organic substance, the gas including the volatile organic substance is transferred into a normal pressure low temperature micro wave plasma device 20 and subjected to a plasma decomposition treatment, the gas after treated is subjected to an adsorption treatment on an activated carbon treating column 31, after a constant period, the volatile organic substance which is adsorbed on the activated carbon material 32 is liberated by steam supplied from a steam supplying means 41, the generated gas is condensed by a cooler 42 and the condensed water is transferred into the waste supplying means 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for treating wastewater containing volatile organic substances, and more particularly, to an apparatus and a method using a normal-pressure low-temperature plasma apparatus.

[0002]

2. Description of the Related Art In recent years, with the increase in the concentration of organic substances in river water, a large amount of chlorine for sterilization or purification has tended to be used, and carcinogenic substances or mutagens generated by the reaction of these organic substances with chlorine. There is a problem that the concentration of trihalomethane, which is a toxic substance, is increased, and the trihalomethane is slightly dissolved in tap water.

In various industries such as the machinery industry, the electronics industry, and the cleaning industry, trichloroethylene, 1,1,1-trichloroethane, tetrachloroethylene, carbon tetrachloride, 1,1,1,1-trichloroethane used for the purpose of degreasing and cleaning.
It is also a problem that factory effluents containing organic halogenated substances such as 2-trichloroethane and 1,2-dichloroethane and volatile organic substances such as benzene permeate underground and contaminate groundwater. Groundwater has special characteristics such as extremely slow flow velocity and no dilution / diffusion.It is difficult to recover once it is contaminated. The demand is great. Further, a technique for purifying not only groundwater but also river water, lake water and the like contaminated by volatile organic substances including these organic halogenated substances is desired. In addition, it is very dangerous that even small amounts of these volatile organic substances are present in industrial water for food and pharmaceuticals, and the industry in this field removes small amounts of volatile organic substances dissolved in water. Technology is long-awaited.

Conventionally, as a method of treating a volatile organic substance dissolved in water, wastewater containing the volatile organic substance is treated in an aeration tank or the like to transfer the volatile organic substance to a gaseous phase, and to obtain the obtained volatile substance. Passing a gas containing a volatile organic substance through activated carbon,
2. Description of the Related Art A method for adsorbing volatile organic substances is known. For example, Japanese Patent Application Laid-Open No. 6-47370 discloses that the surface of a hollow fiber membrane is evacuated by draining wastewater containing a volatile organic substance in the hollow portion of the hollow fiber membrane, or the volatile organic substance is dissolved on the outer surface of the hollow fiber membrane. Disclosed is an apparatus for performing an adsorption process by flowing volatile wastewater into a gas phase by exhausting a hollow portion of a hollow fiber membrane to make a volatile organic substance shift to a gas phase, and adsorbing a gas containing the volatile organic substance to activated carbon. . The method of adsorption treatment of volatile organic substances with activated carbon does not decompose the volatile organic substances contained in the exhaust gas but simply separates them from the exhaust gas. In order to do so, a method of removing volatile organic substances adsorbed on activated carbon by steam and treating wastewater containing volatile organic substances obtained after cooling has been performed.

[0005] As the wastewater treatment method, there is a biological treatment method in which volatile organic substances in water are decomposed by microorganisms. For example, while supplying oxygen in an aeration tank, microorganisms having a purification function with volatile organic substances are provided. There is an activated sludge method in which a volatile organic substance is oxidatively decomposed by microorganisms in activated sludge in the presence of dissolved oxygen by man-made operation so that the ratio is always constant. In addition, there is a submerged combustion method in which organic substances are chemically decomposed into carbon dioxide and water by air oxidation under high temperature and high pressure in which wastewater retains a liquid phase.

[0006]

However, the above-mentioned conventional method has a problem that a large-sized activated carbon treatment apparatus is required to adsorb volatile organic substances. In addition, a separate water treatment device is required to treat wastewater containing volatile organic substances after desorption from activated carbon. The activated sludge method is
Since only low-concentration volatile organic substances can be treated, if the concentration of volatile organic substances in the obtained wastewater is high, the wastewater must be diluted as necessary, and furthermore, the activity of microorganisms such as temperature There is a problem in operation and maintenance, such as difficulty in stable operation because it is susceptible to external influences.

In addition, in the submerged combustion method, a reaction apparatus is required, and the required reaction conditions are a temperature of 300 ° C.
Since the temperature is strict at 350 ° C. and the pressure is 80 to 200 kg / cm ^2, and the material of the device must have corrosion resistance, the device is expensive and the operating cost for maintaining high temperature and high pressure is high. In recent years, a catalytic wet oxidation method using a solid catalyst has been developed, and although the reaction conditions have been relaxed, depending on the type of compound to be decomposed, high temperature and high pressure may still be required, and the above problems have not been solved. .

[0008] The present invention has been made in view of such circumstances, and the invention according to claim 1 is to decompose a volatile organic substance contained in exhaust gas in advance, thereby providing an activated carbon treatment apparatus. It is an object of the present invention to provide a wastewater treatment apparatus that can reduce volatile organic substances in wastewater economically and efficiently by reducing the size and further eliminating the need for a separate water treatment apparatus by returning generated wastewater. The object of the present invention is to provide a wastewater treatment apparatus capable of more efficiently and efficiently treating a volatile organic substance in wastewater. Further, the wastewater treatment apparatus containing volatile organic substances according to the third aspect of the present invention provides a wastewater treatment apparatus capable of detoxifying volatile organic substances in wastewater even more economically and efficiently. An object of the present invention is to. Further, the method for treating wastewater containing volatile organic substances according to the invention according to claim 4 reduces the size of the activated carbon treatment apparatus by previously decomposing volatile organic substances contained in exhaust gas,
Further, it is an object of the present invention to provide a wastewater treatment device that can economically and efficiently treat volatile organic substances in wastewater by eliminating the need for providing a separate water treatment device by returning generated wastewater, and The object of the present invention is to provide a method for treating wastewater that can more efficiently and detoxify volatile organic substances in wastewater more economically and efficiently. Further, the method for treating wastewater containing volatile organic substances according to the invention according to claim 6 aims to provide a method for treating wastewater that can detoxify volatile organic substances in wastewater even more economically and efficiently. And

[0009]

According to the present invention, there is provided a gas phase transfer means for transferring a volatile organic substance from a waste water containing a volatile organic substance supplied through a waste water supply means to a gas phase. A normal-pressure low-temperature plasma device for decomposing volatile organic substances in the gas obtained by the means, and activated carbon treatment means for adsorbing volatile organic substances remaining in the gas generated by the normal-pressure low-temperature plasma device to activated carbon, A water vapor supply means for passing water vapor through the activated carbon to which the volatile organic substance is adsorbed to transfer the volatile organic substance to a gas phase; a cooling device for cooling the gas to make a condensate; A treatment unit for treating wastewater containing volatile organic substances, comprising: a supply unit or a unit for returning the wastewater to the vapor-phase transfer unit. According to a second aspect of the present invention, there is provided the wastewater treatment apparatus according to the first aspect, wherein the vapor phase transfer means is an apparatus provided with aeration means or membrane deaeration means. A processing device is provided. According to a third aspect of the present invention, there is provided the wastewater treatment apparatus according to the first or second aspect, wherein the normal-pressure low-temperature plasma apparatus is a normal-pressure low-temperature microwave plasma apparatus or a normal-pressure low-temperature discharge plasma apparatus. An apparatus for treating wastewater containing volatile organic substances is provided. In addition, the present invention provides a fourth aspect of the present invention, wherein the volatile organic substance is discharged from the wastewater containing the volatile organic substance supplied from the wastewater supply means into the gaseous phase by the vapor phase transfer means for transferring the volatile organic substance from the wastewater to the gas phase. To a gaseous phase, and decomposes volatile organic substances in the gas by a normal-pressure low-temperature plasma apparatus, and supplies the gas generated by the processing to an activated carbon processing apparatus to remove the volatile organic substances remaining in the gas into activated carbon. After being adsorbed to the activated carbon treatment device, a vapor containing volatile organic substances and water vapor generated by passing steam through the activated carbon treatment device is cooled by a cooling device to obtain a condensed liquid, and the condensed liquid is discharged to a drainage supply means or a gas phase transfer means. The present invention provides a method for treating wastewater containing volatile organic substances, characterized in that the wastewater is supplied to a wastewater. According to a fifth aspect of the present invention, there is provided the method for treating wastewater according to the fourth aspect, wherein the means for transferring the volatile organic substance from the wastewater to the gas phase is provided with an aeration means or a membrane deaeration means. Provided is a method for treating wastewater containing a volatile organic substance. According to a sixth aspect of the present invention, there is provided the wastewater treatment method according to the fourth or fifth aspect, wherein the normal-pressure low-temperature plasma apparatus is a normal-pressure low-temperature microwave plasma apparatus or a normal-pressure low-temperature discharge plasma apparatus. Provided is a method for treating wastewater containing volatile organic substances.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The volatile organic substances to be treated in the present invention include, for example, organic halogenated substances,
The following include, but are not limited to, odorants: (Hydrocarbons) benzene, toluene, xylene, methane, ethane, butane, hexane, cyclohexane, hexene; (alcohols) isopropyl alcohol, methanol; (ketones) acetone, methyl ethyl ketone; (organic acids) formic acid, acetic acid; (aldehyde (Formers) formaldehyde, acetaldehyde; (esters) ethyl acetate, butyl acetate; (organic halogenated substances) trichloroethylene, 1,
1,1-trichloroethane, tetrachloroethylene, carbon tetrachloride, 1,1,2-trichloroethane, 1,2-dichloroethane, Freon-12 (CFC-12), Freon-113 (CFC-113), methyl bromide; Substances) dimethyl sulfide, mercaptan, ammonia;

The wastewater in the present invention may be water of any origin, for example, tap water, industrial water, groundwater,
Well water, river water, lake water, sewage, industrial wastewater, and the like are included, but are not limited thereto.

Next, FIG. 1 shows a flow sheet of an apparatus for treating wastewater containing volatile organic substances according to an embodiment of the present invention, which will be described below. Reference numeral 1 shown in FIG. 1 denotes a wastewater supply means, which may be any means as long as the wastewater containing the volatile organic substance introduced from the pipe 2 can be transferred to the gas phase transfer means. In the embodiment of FIG. 1, the condensed water condensed by the cooling device 42 described later is returned to the drainage supply means 1 via the pipe 3, and the condensed water is also transferred from the pipe 4 to the gas phase transfer means together with the wastewater introduced from the pipe 2. Be transported. In the embodiment shown in FIG. 1, an aeration tank 10 is used as a gas phase transfer means for transferring volatile organic substances in water to a gas phase.

A pipe 4 for introducing waste water is installed in the upper part of the aeration treatment tank 10, and waste water containing volatile organic substances transferred from the waste water supply means 1 is aerated through the pipe 4. It is put into the upper part of the processing tank 10. The aeration tank 10 is filled with a filler 11 such as Raschig ring or teralet packing, and a drain pipe 12 of treated water and a blower 13 for intake are connected to a lower part of the aeration tank.
The wastewater is aerated to transfer volatile organic substances to the gas phase,
It is configured to perform gas-liquid separation into a gas containing a volatile organic substance and wastewater from which the volatile organic substance has been removed. The treated water after the volatile organic substances are separated by aeration treatment is discharged from the drain pipe 12 and used for industrial water such as cooling water, washing water or agricultural water, and disinfected and sterilized into drinking water. Is also used.

Means for transferring volatile organic substances in water to the gas phase include aeration means such as an aeration tank 10;
A membrane degassing means or a boiling means can be applied, but an aeration means or a membrane degassing means is preferred from the viewpoint that treatment such as heating is unnecessary and simple. Here, an apparatus provided with a membrane deaerator is shown in FIG.

The container 51 of the membrane degassing means 50 shown in FIG. 2 is a container having an air inlet 52 for sucking outside air and an outlet 53 for a gas containing volatile organic substances and water vapor.
A large number of hollow fiber membranes 54 are arranged in the inside 1 at predetermined intervals so that both ends thereof are supported and fixed by the potting agent 15. Further, at one end of the container 51, the hollow fiber membrane 5 supported and fixed by the potting agent 55 is provided.
There is provided an inlet 56 for water containing a volatile organic substance, which communicates with a space formed by the inner wall 4 and the inner wall of the container 51, and at the other end, a discharge port for discharging treated water from which the volatile organic substance has been removed. An outlet 57 is provided. By the potting agent 15, a partition wall that blocks a space formed between the multiple hollow fiber membranes 54, 54,..., And the inlet 56 and the outlet 57 of the water containing the volatile organic substance is formed. It is formed. Further, an exhaust port 53 is provided on a part of the peripheral surface of the container 51, and a decompressor (intake blower) 5 is provided in the middle of the exhaust port 53.
8 are installed. When the gas in the container 51 is sucked by the decompressor 58, external air is taken into the container 51 from an intake port 52 provided in the container 51, and further, volatile organic substances flowing inside the hollow fiber membrane 54. The volatile organic substance is transferred from the water containing to the gas phase through the hollow fiber membrane 54. With this configuration, the exhaust gas containing the volatile organic substance is discharged from the exhaust port 53 provided in the container 51.

The hollow fiber membrane 54 has a pore diameter of 0.05 μm.
m or less can be used, but if used for a long time, water vapor leaks, and as a result, water may leak from the porous membrane.
A multilayer composite hollow fiber membrane comprising a homogeneous membrane having the following film thickness and a porous membrane having a reinforcing function, wherein a homogeneous membrane and a porous membrane are alternately laminated, and a side of the multilayer composite hollow fiber membrane which comes into contact with an aqueous solution. Is a homogeneous membrane or a porous membrane, the layer not in contact with the aqueous solution is a porous membrane, and the composite hollow fiber membrane has a chloroform permeation rate of 1 × 10 ⁻³ (c
It is preferable that the hollow fiber membrane has a permeability of at least m ³ (STP) / cm ² / sec / cmHg. Chloroform transmission rate is 1 × 10 ⁻³ (cm ³ (STP) / c
If the pressure is less than m ² / sec / cmHg), the permeation rate of the volatile organic substance contained in water through the composite membrane is low, and the volatile organic substance cannot be efficiently transferred to the gas phase.

Materials for forming the porous layer of such a composite membrane include polyethylene, polypropylene, poly-3-
Polyolefins such as methylbutene-1, poly-4-methylpentene-1 and the like, vinylidene fluoride, fluorinated polymers such as polytetrafluoroethylene, and polymers such as polysulfone, polyetherketone, and polyetheretherketone can be used. Is preferably a polyolefin which is a crystalline polymer capable of easily forming a porous material. Materials used for the homogeneous layer of the composite film include segmented polyurethane, silicon-based polymer, low-density polyethylene, and poly-4-methylpentene-1.
And polyacrylamide, etc., and a polymer having high affinity for volatile organic substances is preferable.

[0018] A gas-phase transfer means for transferring volatile organic substances in water to a gas phase is connected to a normal-pressure low-temperature plasma device.
In the embodiment of FIG. 1, the gas containing the volatile organic substance discharged from the pipe 14 provided on the upper part of the aeration tank 10 is transferred to the normal-pressure low-temperature plasma apparatus. In a normal-pressure low-temperature plasma device, volatile organic substances in a transferred gas are decomposed by reacting with plasma generated by the device,
The gas after the decomposition reaction is discharged from the low-pressure plasma apparatus at normal pressure. The normal-pressure low-temperature plasma device is a plasma device that generates plasma in which only the electron temperature is extremely high under normal pressure, as long as it can decompose volatile organic substances, and is preferably An ordinary-pressure low-temperature microwave plasma apparatus or an ordinary-pressure low-temperature discharge plasma apparatus can be used, and FIG. 1 shows an ordinary-pressure low-temperature microwave plasma apparatus 20.

Normal pressure low-temperature microwave plasma apparatus 2 shown in FIG.
0 has a microwave source 21 which is connected by a waveguide 22 to a microwave cavity 23 in which a container 24 is placed. When the microwave source 21 is turned on, a microwave field is generated in the microwave cavity 23, and a microwave field is also generated in the container 24 installed therein. The container 24 is provided with a gas inlet 27, and a gas containing a volatile organic substance is introduced from the aeration tank 10 through the pipe 14 into the container 24 through the gas inlet 27 and becomes a fuel for the plasma 26. The microwave power typically required to generate the plasma 26 is 0.3-5 kW. In view of the high temperature of the plasma 26 in the container 24, the container wall is made of a heat-resistant material such as quartz.

The container 24 is also provided with an ignition port 28, and an electrode 29 is inserted through the ignition port 28 when generating plasma. The presence of the electrode 29 in the container 24 increases the intensity of the microwave field at a portion adjacent to the tip of the electrode 29, and discharge starts when the intensity of the microwave field in this region becomes sufficiently large. As a result, the gas around the electrode 29 is ionized, and the plasma 26 is formed and floats on the upper part in the container 24. After the plasma 26 is generated in the container 24, the electrode 29 is pulled out of the container 24. The electrode 29 is an elongated member having a pointed tip, and may be made of a conductive material. From the viewpoint of not affecting the microwave field, the electrode material is preferably carbon fiber. The size of the plasma 26 in the container 24 is adjusted by changing the output level of the microwave source 21. An exhaust port 25 is provided at a lower portion of the container 24, and a gas after the volatile organic substance has reacted with the plasma is exhausted from the exhaust port 25.

FIG. 3 shows another embodiment of a normal-pressure low-temperature plasma apparatus that can be used in the water treatment apparatus of the present invention.
It is a longitudinal cross-sectional view of a normal-pressure low-temperature discharge plasma device. The cylindrical normal-pressure low-temperature discharge plasma apparatus shown in FIG. 3 is of a packed-bed discharge type and has an internal electrode 71 and an external electrode 72. The porous adsorbent 73 and the granular ferroelectric substance 74 are physically mixed and filled. Internal electrode 71 and external electrode 7
Between the two, a high voltage is applied by the power supply 75. At both ends of the plasma processing chamber 79, a Teflon cap 76 and a holding plate 77 are provided. The device also has a gas inlet 78 through which gas containing volatile organic substances is introduced. The introduced gas containing the volatile organic substance is mixed with the porous adsorbent 73 into the ferroelectric substance 74 through the through hole of the Teflon holding plate 77 at one end in the flow path indicated by the arrow a to fill the plasma. After being introduced into the processing chamber 79 and the volatile organic substance is decomposed by the plasma, the gas after the processing is discharged from the through hole of the holding plate 77 on the other end side as a flow indicated by an arrow b from the exhaust port 80. .

As the porous adsorbent 73, a non-conductive substance is used from the viewpoint of generating plasma, and an inorganic porous substance is preferable. For example, Al ₂ O ₃ , Si
O ₂ , zeolite (A type, X type, Y type, etc.), TiO ₂
And the like. The ferroelectric substance 74 and the porous adsorbent 73 are preferably granular so that a gas passage can be formed in the packed bed. As for the size of the granule, the diameter of the bottom surface of the cylindrical body, the ellipse or the spherical body is 1 to 3 mm, and more preferably 1 to 2 mm. The voltage applied between the internal electrode 71 and the external electrode 72 by the power supply 75 changes depending on the concentration of the volatile organic substance in the gas to be processed,
Usually 1 to 10 kV / cm, preferably 1 to 5 kV / cm
It is.

FIG. 3 shows an ordinary-pressure low-temperature discharge plasma apparatus.
In addition to those shown in, for example, surface discharge, barrier discharge,
Examples include, but are not limited to, a plasma device using a discharge method such as pulse discharge or capillary tube discharge.

The gas after the treatment with the normal-pressure low-temperature plasma apparatus may contain an unreacted volatile organic substance and / or a volatile organic substance by-produced. After being introduced into the apparatus, in the adsorption process in the apparatus, these remaining volatile organic substances are adsorbed on activated carbon. In the embodiment of FIG. 1, an activated carbon processing tower 31 is used as an activated carbon processing apparatus, and an exhaust port 25 of a normal-pressure low-temperature microwave plasma apparatus 20 is connected to a gas inlet 33 of the activated carbon processing tower 31 by piping. In the process, the gas reacted in the normal-pressure low-temperature microwave plasma device 20 is introduced into the activated carbon treatment tower 31 from the gas inlet 33. The activated carbon treatment tower 31 is filled with an activated carbon material 32 in a cylindrical shape, and has a gas inlet 33 provided with an on-off valve 34 and a steam outlet 3 provided with an on-off valve 40.
9 is arranged so as to connect to the space outside the cylinder of the activated carbon material 32, and a gas outlet 35 having an on-off valve 36 and a steam inlet 37 having an on-off valve 38 are connected to the activated carbon material 3.
It is arranged to connect to the inside of the two cylinders. In the adsorption process, the on-off valve 34 on the gas inlet 33 and the on-off valve 36 on the gas outlet 35 are opened, and the on-off valve 38 on the steam inlet 37 and the on-off valve 40 on the steam outlet 39 are closed. The exhaust gas containing the volatile organic material passes through the activated carbon material 32, the volatile organic material in the gas is adsorbed by the activated carbon material 32, and the treated gas after the adsorption treatment is discharged from the gas outlet 35.

The activated carbon material 32 may be any activated carbon material capable of adsorbing volatile organic substances, such as granular activated carbon such as crushed charcoal or beaded charcoal, pitch-based, polyacrylonitrile-based, phenol-based, and cellulose-based. , But is not limited thereto.
Further, these activated carbon materials 32 may be configured to be detachable from the activated carbon adsorption tower 31 in a cartridge type.

At any time after the adsorption treatment process has been performed for a certain period of time, the volatile organic substance is desorbed by steam to regenerate the activated carbon, for example, at a crossing point at which the volatile organic substance starts to leak. In this desorption process, the on-off valve 34 on the gas inlet 33 and the on-off valve 36 on the gas outlet 35 are closed, and the on-off valve 38 on the steam inlet 37 and the on-off valve 40 on the steam outlet 39 are opened. The steam inlet 37 is connected to the steam supply means 41, and steam is supplied from the steam supply means 41 to the activated carbon treatment tower 31. When the supplied water vapor passes through the activated carbon material 32, the volatile organic substance adsorbed on the activated carbon is desorbed and transferred to the gas phase. The gas containing the volatile organic substance and the steam is discharged from the steam outlet 39 and transferred to the cooling device 42.

The activated carbon treatment means may be of any mode as long as it is a means for adsorbing a volatile organic substance on activated carbon and then desorbing it with steam. For example, the activated carbon adsorption tower shown in FIG. The honeycomb rotor suction device 60 is not limited to the one shown in FIG. In the embodiment shown in FIG. 2, the honeycomb rotor adsorbing device 60 filled with the cylindrical activated carbon material 66 is rotating around a rotating shaft 65. The honeycomb rotor adsorption device 60 is provided with an exhaust gas introduction pipe 61 and an exhaust gas extraction pipe 63 above the rotating shaft 65, and the exhaust gas containing volatile organic substances discharged from the normal-pressure low-temperature plasma processing apparatus is introduced into the exhaust gas introduction pipe. The process gas is introduced from the pipe 61, passes through the activated carbon material 66 in the adsorption device 60, and the treated gas after the treatment is discharged from the exhaust gas discharge pipe 63. Further, a steam supply pipe 6 is provided below the rotation shaft 65.
The steam supply pipe 62 is connected to the steam supply means 41. With this configuration, steam is supplied to the honeycomb rotor adsorption device 60, and steam containing volatile organic substances desorbed from the activated carbon material 66 is discharged from the steam discharge pipe 64. Since the honeycomb rotor adsorption device 60 having the above-described configuration rotates around the rotation shaft 65, the adsorption process is performed above the rotation shaft and the desorption process is performed below the rotation shaft. Can be performed.

The steam supply means 41 may be of any form as long as it supplies steam for desorbing the volatile organic substances adsorbed on the activated carbon. The activated carbon material 66 may be any activated carbon material capable of adsorbing volatile organic substances. For example, granular activated carbon such as crushed charcoal or beaded charcoal, pitch-based, polyacrylonitrile-based, phenol-based, cellulose-based, etc. Activated carbon fibers include, but are not limited to. Further, these activated carbon materials 66 may be configured to be detachable in a cartridge type.

The cooling device 42 may be any device that cools a gas containing volatile organic substances and water vapor generated by the desorption process in the activated carbon treatment apparatus, and converts it into condensed water containing volatile organic substances. For example, a condenser for cooling the gas by circulating water may be used. 1 and 2, the condensed water containing the volatile organic substances generated by the cooling device 42 is transferred to the wastewater supply means 1 via the pipe 3 and is again processed by the device according to the present invention. In other words, the pipe 3 may be connected to gas-phase transfer means such as the aeration tank 10 and the membrane deaerator 50, and condensed water may be directly transferred to the gas-phase transfer means for processing. With this configuration, in the apparatus according to the present invention, since the apparatus has an ordinary-pressure low-temperature plasma apparatus capable of decomposing volatile organic substances, the apparatus can be obtained by desorbing volatile organic substances adsorbed on activated carbon with water vapor. The condensed water containing the volatile organic substance can be recirculated, so that there is no need to provide a separate wastewater treatment device unlike the conventional method, the device can be simplified, and the cost is advantageous.

[0030]

As described above, according to the apparatus and method for treating wastewater containing a volatile organic substance of the present invention, a normal-pressure low-temperature plasma apparatus is provided before the activated carbon treatment means, and the volatile organic substance is preliminarily prepared. By treating with activated carbon treatment means after the decomposition treatment, the activated carbon adsorption device can be downsized. In addition, the condensed water containing the volatile organic substance obtained by desorbing the volatile organic substance adsorbed on the activated carbon with water vapor is recirculated to the apparatus according to the present invention to be treated, thereby eliminating the need for a separate water treatment apparatus. Become. Furthermore, this apparatus does not have the instability of the treatment system which is a problem in the conventional biological treatment method, and does not require high temperature and high pressure unlike the submerged combustion method. is there.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing one embodiment of a wastewater treatment apparatus according to the present invention.

FIG. 1 is a flow sheet showing one embodiment of a wastewater treatment apparatus according to the present invention.

FIG. 3 is an embodiment of a normal-pressure low-temperature plasma apparatus that can be used in the wastewater treatment apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drainage supply means 3 Circulation pipe 10 Aeration treatment tank 20 Normal pressure low temperature microwave plasma apparatus 31 Activated carbon treatment tower 41 Steam supply means 42 Cooling device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B01D 53/72 B01J 20/20 B 53/70 B01D 53/34 120D B01J 20/20 134E F-term (Reference) 4D002 AA05 AA06 AA13 AA21 AA22 AA24 AA32 AA33 AA40 AB02 AB03 AC07 AC10 BA04 BA07 BA13 CA05 CA07 CA13 CA20 DA41 EA02 EA08 HA01 4D011 AA15 AA17 AB03 4D012 BA03 CA12 CC05 CD02 CH06 CH08 CH10 4D013 AB01 AB01 AB01 CA03 4G066 AA05B AC02A AC17A AC25A BA07 BA09 BA16 CA02 CA25 CA29 CA31 CA32 CA33 CA51 CA52 DA02 GA01 GA06

Claims (6)

[Claims] 1. A vapor phase transfer means for transferring a volatile organic substance from a waste water containing a volatile organic substance supplied via a waste water supply means to a gas phase, and a volatile organic substance in a gas obtained by the means. An atmospheric pressure low-temperature plasma apparatus for decomposing the organic solvent, activated carbon treatment means for adsorbing volatile organic substances remaining in the gas generated by the atmospheric pressure low-temperature plasma apparatus to activated carbon, and water vapor to the activated carbon adsorbing the volatile organic substances. A water vapor supply means for passing the volatile organic substance into a gaseous phase to pass through, a cooling device for cooling the gas to a condensate, and a means for returning the condensate to the wastewater supply means or the gaseous phase transfer means And a wastewater treatment apparatus containing volatile organic substances. 2. The wastewater treatment apparatus according to claim 1, wherein the vapor phase transfer means is an apparatus provided with an aeration means or a membrane deaeration means. 3. The wastewater treatment apparatus according to claim 1, wherein the normal-pressure low-temperature plasma apparatus is a normal-pressure low-temperature microwave plasma apparatus or a normal-pressure low-temperature discharge plasma apparatus. Including wastewater treatment equipment. 4. A method for transferring volatile organic substances from wastewater to gaseous phase by means of a vapor phase transfer means for transferring volatile organic substances from wastewater containing volatile organic substances supplied from wastewater supply means to a gaseous phase from the wastewater. Then, the volatile organic substance in the gas is decomposed by a normal-pressure low-temperature plasma apparatus, and the gas generated by the processing is supplied to an activated carbon processing apparatus to adsorb the volatile organic substance remaining in the gas to the activated carbon. Cooling a gas containing volatile organic substances and water vapor generated by passing water vapor through the activated carbon treatment device by a cooling device to obtain a condensed liquid, and supplying the condensed liquid to a wastewater supply means or a gas phase transfer means. A method for treating wastewater containing volatile organic substances. 5. The method for treating wastewater according to claim 4, wherein the means for transferring the volatile organic substance from the wastewater to the gaseous phase is an apparatus provided with aeration means or membrane deaeration means. Wastewater treatment method including. 6. The method for treating wastewater according to claim 4, wherein the low-temperature plasma apparatus is a normal-pressure low-temperature microwave plasma apparatus or a low-pressure discharge plasma apparatus. Wastewater treatment methods including.