JP4351594B2 - Method and apparatus for separating volatile organic compounds from wastewater - Google Patents

Description

  The present invention separates the volatile organic compound from the waste water in which the volatile organic compound is dissolved when the volatile organic compound such as trichlorethylene or tetrachloroethylene is dissolved in the groundwater or industrial wastewater. And a device for the same.

  The Soil Contamination Countermeasures Law enacted on May 22, 2002 lists 11 types of volatile organic compounds including the above-mentioned trichlorethylene and tetrachlorethylene as harmful volatile organic compounds contained in groundwater.

  Conventionally, when separating these volatile organic compounds from the wastewater in which they are dissolved, a method of bubbling (aeration) in which air is blown into the wastewater has been adopted. In addition to having to blow a large amount of air, the amount of exhausted gas also increases, so the size of the device increases, and the increase in the size of the blower that compresses air leads to an increase in noise and power consumption. There was a problem such as.

  Therefore, Patent Document 1 as prior art discloses that the waste water is stored at a predetermined depth by introducing the waste water into a sealed container having a reduced pressure from the bottom and discharging it from a higher part. A method of separating volatile organic compounds by boiling and evaporating the waste water at a portion where the liquid depth from the water surface in the waste water is deep is provided.

Further, Patent Document 2 as another prior art discloses that the waste water is introduced from the bottom into a sealed container that has been decompressed in a state where gas such as air is absorbed and dissolved therein. By discharging, the volatile organic compound is separated by degassing the accumulated wastewater so that it is foamed in the portion where the liquid depth from the surface of the wastewater is deep. Provides a way to do.
JP 2002-282844 A JP 2003-164860 A

  These methods in Patent Documents 1 and 2 have an advantage that the apparatus can be greatly reduced in size compared to the conventional method.

  However, in the former method disclosed in Patent Document 1, separation is performed by boiling and evaporating wastewater. Therefore, among the 11 kinds of volatile organic compounds established by the above-mentioned law, in particular, for example, trichlorethylene, cis Although effective for separation of volatile organic compounds with low boiling points such as -1,2-dichloroethylene or 1,1-dichloroethylene, the waste water is boiled and evaporated in the part where the liquid depth from the water surface is deep. Therefore, it is necessary to increase the temperature of the wastewater, and as a result, there is a problem that the heat energy added to the wastewater must be greatly increased.

  Further, although the latter method in Patent Document 2 can eliminate or reduce the heat energy applied to the wastewater, it can reduce the degree of pressure reduction in the sealed container by foaming at a portion where the liquid depth from the water surface is deep in the wastewater. It must be quite high, and thus requires a large amount of energy to depressurize the sealed container, and in this method, among the 11 kinds of volatile organic compounds, 1,2-dichloroethane, In the case of a volatile organic compound having high solubility in water such as 1,1,2-trichloroethane or 1,3-dichloropropene, the separation rate is tetrachloroethylene, carbon tetrachloride among the 11 kinds of volatile organic compounds. Or greater than the separation rate in the case of volatile organic compounds with low water solubility such as trichlorethylene There is a problem that is low in.

  An object of the present invention is to provide a method and an apparatus for solving these problems.

In order to achieve this technical problem, the method of the present invention is, firstly, as described in claim 1, “while the carbon dioxide gas is dissolved in the waste water containing the volatile organic compound dissolved, the sealed container The inside of the container is decompressed by exhausting the vacuum generation source from the lower side of the packed bed provided therein, and the carbon dioxide gas is dissolved in the upper part of the packed bed inside the sealed container. The waste water is ejected at a temperature higher than the saturated steam temperature inside the sealed container . "
It is characterized by that.

Next, the device of the present invention, first, as described in claim 2 ,
“ A gas-liquid mixer that dissolves carbon dioxide gas in wastewater containing dissolved volatile organic compounds, a sealed container having a packed bed inside, and the inside of the sealed container from below the packed bed A vacuum generator for reducing the pressure by exhausting the gas, means for jetting waste water from the gas-liquid mixer to an upper part of the packed bed inside the sealed container, and jetted to the upper side of the packed bed And means for increasing the temperature of the waste water to be higher than the saturated steam temperature in the closed container . "
It is characterized by that.

In addition, the device of the present invention secondly , as described in claim 3 ,
“ A plurality of sealed containers with a packed bed inside, a vacuum generator for maintaining the inside of each sealed container at a reduced pressure by exhausting from the lower side of the packed bed, and dissolving volatile organic compounds Means for injecting the waste water contained in the state into the upper part of the packed bed inside the first stage sealed container located in the first stage among the respective sealed containers through a gas-liquid mixer; Means for injecting waste water discharged from the lower part of the preceding closed container out of the containers to the upper part of the packed bed in the latter closed container adjacent to the preceding sealed container through the gas-liquid mixer; The at least one sealed container located in an intermediate stage among the respective sealed containers is filled with waste water ejected therein with heat energy in the vacuum generator in the at least one sealed container. Comprising a means for heating to a temperature higher than the steam temperature, further, the gas-liquid mixer in at least one of the sealed container, this includes a means for supplying air, at least one closed container out of the respective sealed container The gas-liquid mixer in the other closed containers other than the above is provided with means for supplying carbon dioxide gas thereto .
It is characterized by that.

As described in the embodiments described later, according to the invention described in claim 1 and claim 2 , the separation efficiency when separating the volatile organic compound dissolved in the wastewater from the wastewater is the case of the prior art. In particular, in the case of a volatile organic compound having solubility in water, it can be separated with high separation efficiency.

In particular, according to the invention described in claim 3, when the separation of the volatile organic compound is performed in multiple stages by a plurality of sealed containers, the amount of carbon dioxide used can be reduced, and the running cost can be reduced. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an apparatus according to a first embodiment.

  This apparatus includes a sealed container 1 in which a packed bed 2 made of a filler such as Raschig ring is provided. The inside of the sealed container 1 is connected to a vacuum generator 3 such as a vacuum pump from the lower side of the packed bed 2. Is maintained at a reduced pressure lower than the atmospheric pressure.

  A spray nozzle 4 is provided in the sealed container 1 above the packed bed 2, and waste water containing a volatile organic compound such as trichlorethylene, such as ground water or industrial waste water, is provided in the spray nozzle 4. The waste water is supplied through the waste water supply pipe 5 so that the waste water is jetted downward, while the treated water collected at the bottom of the sealed container 1 is discharged from the discharge pipe 6 to the outside. It is configured to discharge.

In the middle of the waste water supply line 5, the waste water is heated to an appropriate temperature, or the heating means 7 not to be heated and the carbon dioxide gas supplied from the gas supply line 9 are mixed with the waste water. And a gas-liquid mixer 8 which is dissolved.

The waste water sent through the waste water supply pipe 5 is controlled so as to have an appropriate temperature in the heating means 7, and then the carbon dioxide gas is dissolved in the gas- liquid mixer 8, and then the vacuum is previously applied. It is ejected from the spray nozzle 4 into the sealed container 1 which is kept in a reduced pressure state by the generator 3.

  In this way, the waste water ejected from the spray nozzle 4 into the sealed container 1 flows down so as to pass through the packed bed 2 in the sealed container 1 and then accumulates at the bottom of the sealed container 1.

In this case, the temperature T1 when the wastewater is ejected from the spray nozzle 4 (hereinafter simply referred to as the temperature of the wastewater) is made equal to the saturated steam temperature T2 in the sealed container 1 or the saturated steam temperature. When lower than T2, the waste water ejected from the spray nozzle 4 into the sealed container 1 is dissolved in the waste water when ejected and when flowing down so as to pass through the packed bed 2. The degassing that carbon dioxide gas in the form of bubbles escapes is performed. By this degassing, the volatile organic compound dissolved in the wastewater can be vaporized and separated from the wastewater. At the bottom of 1, treated water that has been degassed is collected, and this treated water is discharged from the discharge pipe 6 to the outside.

  On the other hand, when the temperature T1 of the waste water is set higher than the saturated steam temperature T2 in the sealed container 1, the waste water ejected into the sealed container 1 from the spray nozzle 4 is ejected and the packed bed 2 is When flowing down to pass, flash evaporation and deaeration are performed at the same time. By this flash evaporation and deaeration, volatile organic compounds dissolved in the waste water are vaporized and separated from the waste water. The treated water after the deaeration process is collected at the bottom of the sealed container 1, and the treated water is discharged from the discharge pipe 6 to the outside.

  Therefore, the present inventors supply air to the gas-liquid mixer 8 in the above-described apparatus, in other words, dissolve the air into the waste water, and then pass through the waste water supply line 5. Implementation of determining the separation efficiency of the volatile organic compound by measuring the concentration of the volatile organic compound in the wastewater being sent and the concentration of the volatile organic compound in the treated water discharged from the discharge pipe The results obtained for the case where the volatile organic compound is tetrachloroethylene having low solubility in water and 1,1,2-trichloroethane having high solubility in water are as shown in FIG.

  That is, the implementation shown in FIG. 2 is performed by appropriately adjusting either one or both of the temperature T1 of the wastewater and the degree of decompression in the sealed container 1, and the temperature T1 of the wastewater and the sealed container. The temperature difference ΔT with the saturated steam temperature T2 in 1 is changed in various ways.

  In FIG. 2, when the temperature difference ΔT is in a positive temperature range higher than zero, that is, when the temperature T1 of the wastewater is higher than the saturated steam temperature T2 in the sealed container 1, the wastewater is contained in the sealed container 1. When the temperature difference ΔT is zero and in the negative temperature range lower than zero, that is, when the waste water is discharged, the flash evaporation and the deaeration are performed. When the temperature T1 is equal to the saturated steam temperature T2 in the sealed container A or lower than the saturated steam temperature T2 in the sealed container 1, wastewater flows down into the sealed container 1 and down the packed bed 2. Sometimes only degassing takes place without flash evaporation.

  In FIG. 2, the curve A indicated by the solid line indicates that the volatile organic compound dissolved in the wastewater is 1,1,2-trichloroethane, and the dotted curve B indicates the volatilization dissolved in the wastewater. This is a case where the organic organic compound is tetrachloroethylene.

  As is apparent from FIG. 2, when both flash evaporation and degassing are performed simultaneously in the closed vessel 1, the separation efficiency is considerably high for both tetrachloroethylene and 1,1,2-trichloroethane. When only deaeration is performed in the sealed container 1, the separation efficiency in 1,1,2-trichloroethane having high water solubility is significantly lower than that in tetrachloroethylene having low water solubility.

  Therefore, in the present invention, carbon dioxide gas is supplied instead of supplying air to the gas-liquid mixer 8.

  Then, carbon dioxide gas is dissolved in the gas-liquid mixer 8 with respect to waste water containing 1,1,2-trichloroethane having high solubility in the water, and this waste water is stored in the sealed container 1 at a temperature T1 of the waste water. When the temperature difference ΔT between the steam and the saturated steam temperature T2 is set to −2 ° C. to perform degassing only, carbon dioxide is dissolved in the gas-liquid mixer 8 with respect to the wastewater, and the wastewater is supplied to the sealed container. Table 1 shows the results of both the case where only the deaeration is performed by setting the temperature difference ΔT between the waste water temperature T1 and the saturated steam temperature T2 to -2 ° C.

  As is clear from this implementation, by using carbon dioxide instead of air as the gas body dissolved in the wastewater, the separation efficiency in 1,1,2-trichloroethane having a high solubility in water is reduced, and the tetrachloroethylene having a low solubility in water is obtained. About 30% higher than the separation efficiency.

  Further, the waste water in which carbon dioxide gas is dissolved is jetted into the sealed container 1 with the temperature difference ΔT between the waste water temperature T1 and the saturated steam temperature T2 being + 1 ° C., and flash evaporation and deaeration are performed simultaneously. In this case, the separation efficiency in the 1,1,2-trichloroethane can be improved to about 92%.

These reasons are recognized as described below.
That is, the solubility in water in the carbon dioxide gas is remarkably high, such as about 45 times the solubility in air in water at a temperature of 25 ° C., and a much larger amount of carbon dioxide than in the case of mixing and dissolving air in wastewater. Gas can be dissolved by mixing.
The carbon dioxide dissolved in the waste water does not immediately become bubbles at the location of the gas-liquid mixer 8 for carbon dioxide with respect to the waste water, and is separated from the waste water. When the pressure drops greatly to a low decompression state, it becomes bubbles and separates from the wastewater.
On the other hand, the carbon dioxide gas becomes acidic when it is dissolved in the wastewater, and the pH value of the wastewater is lowered to the acidic side, and as a result, the solubility of the carbon dioxide gas in the wastewater is lowered by the shift to the acidic side. Become.
As a result, the amount of carbon dioxide gas generated as bubbles due to the pressure drop to the reduced pressure state in the sealed container 1, that is, the amount of carbon dioxide degassed, can be dissolved in the gas-liquid mixer 8. Since the gas has a value obtained by adding the carbon dioxide gas corresponding to the decrease in the solubility in the wastewater as described above , the degassing amount of the carbon dioxide gas from the wastewater can be greatly increased.

  Next, FIG. 3 shows a second embodiment.

  In the second embodiment, the waste water sent through the waste water supply pipe 10, that is, the waste water containing a volatile organic compound such as trichlorethylene and having a temperature of 15 ° C. or less is used as the first sealed container 11, 2 is a case where the separation process is performed in five stages of the sealed container 12, the third sealed container 13, the fourth sealed container 14, and the fifth sealed container 15, and each of the sealed containers 11, 12, 13, 14, 15 is provided. Are provided with packed layers 11a, 12a, 13a, 14a, 15a of fillers such as Raschig rings for promoting deaeration and evaporation described later.

  The waste water sent from the waste water supply pipe 10 is jetted downward from the spray nozzle 11b to the upper part of the first sealed container 11, and then pumped out from the bottom of the first sealed container 11 by the pump 16. The waste water discharged from the first sealed container 11 is configured to be sent to the spray nozzle 12b provided at the upper part in the second sealed container 12 through the transfer pipe 17 and ejected downward.

  Next, the waste water pumped out from the bottom of the second sealed container 12 by the pump 18 is sent to the spray nozzle 13b provided in the upper part of the third sealed container 13 via the transfer pipe 19 so as to be ejected downward. It is configured.

  Next, the waste water pumped out from the bottom of the third sealed container 13 by the pump 20 is sent to the spray nozzle 14b provided at the upper part in the fourth sealed container 14 via the transfer pipe 21 so as to be jetted downward. It is configured.

  Next, the waste water pumped out from the bottom of the fourth sealed container 14 by the pump 22 is sent to the spray nozzle 15b provided in the upper part of the fifth sealed container 15 via the transfer pipe 23 so as to be ejected downward. It is configured.

  And the processed water in the bottom part of the said 5th airtight container 15 is pumped out by the pump 24, and is comprised through the processed water discharge conduit 25.

  The waste water supply pipe 10 and the transfer pipes 17, 19, 21, and 23 include gas-liquid mixers 26, 27, 28, 29, and 30 for mixing and dissolving the gas body with respect to the waste water. Each is provided.

  A first heat exchanger 31 is provided in the middle of the transfer line 19 from the second sealed container 12 to the third sealed container 13 at a portion upstream of the mixing means 26 in the middle of the waste water supply pipe 10. Are each provided with a second heat exchanger 32.

  By connecting the duct 33 from the lower side of the packed bed 11a, 12a, 13a, 14a, 15a in the sealed containers 11, 12, 13, 14, 15 of each stage to the first heat exchanger 31 The vapor below the packed layers 11a, 12a, 13a, 14a, and 15a in the sealed containers 11, 12, 13, 14, and 15 is introduced into the first heat exchanger 31, The waste water supply pipe 10 is configured to heat waste water, and by connecting a vacuum generator of a vacuum pump 34 to the first heat exchanger 31, the sealed containers 11, 12, 13 are connected. , 14 and 15 are held in a reduced pressure lower than the atmospheric pressure.

  By supplying the exhaust gas compressed by the vacuum pump 34 to the second heat exchanger 32, waste water sent from the second sealed container 12 to the third sealed container 13 is converted into thermal energy in the vacuum pump 34. It is comprised so that it may heat with the compressed exhaust gas which is one of these.

  One of thermal energy in the vacuum pump 34 is obtained by inserting a cooling jacket 34a in the vacuum pump 34 in the middle of the transfer pipe line 17 from the first sealed container 11 to the second sealed container 12. However, the waste water sent from the first sealed container 11 to the second sealed container 12 is heated by the heat generated by driving the vacuum pump 34.

  In FIG. 3, the code | symbol 35 shows the gas-liquid contactor which provides the filling layer 35a by fillers, such as a Raschig ring, inside.

  A part of the treated water flowing through the treated water discharge conduit 25 is extracted on the upstream side of the flow rate adjusting valve 25a provided in the middle of the treated water discharge conduit 25, and the inside of the gas-liquid contactor 35 is extracted. The processing water which is introduced into the upper part through the pipe line 36 and is accumulated in the bottom of the gas-liquid contactor 35 is discharged through the pump 37 and the pipe line 38 in the processed water discharge pipe line 25. It is configured to return to the finished water on the downstream side of the flow rate adjusting valve 25a.

  On the other hand, the non-condensable gas in the second heat exchanger 32 is extracted as exhaust gas from the conduit 39, and this exhaust gas is heated to a temperature of about 900 ° C. or higher in the heater 40, The gas-liquid contactor 35 is introduced to the lower side of the packed bed 35a and directly contacts the treated water flowing down the packed bed 35a in the gas-liquid contactor 35. Configure to release inside.

  Among the gas-liquid mixers 26, 27, 28, 29, 30, the gas-liquid mixers 26, 28, 29, 30 for the first sealed container 11, the fourth sealed container 14, and the fifth sealed container 15 are provided. Carbon dioxide gas from a carbon dioxide gas supply source 42 such as a carbon dioxide cylinder is supplied as gas bodies to be mixed / dissolved in the wastewater through gas pipelines 43, 44 and 45.

  On the other hand, among the gas-liquid mixers 26, 27, 28, 29, and 30, the gas-liquid mixers 27 and 28 for the second sealed container 12 and the third sealed container 13 are gas bodies that are mixed and dissolved in waste water. The air compressed by the compressor 46 is supplied through the gas pipes 47 and 48.

  In this configuration, the waste water sent from the waste water supply pipe 10 is mixed and dissolved with carbon dioxide gas in the gas-liquid mixer 26, and then ejected from the spray nozzle 11b into the first sealed container 11. Thus, since deaeration is performed when this jetting and when flowing down the packed bed 11a, volatile organic compounds in the wastewater are vaporized and separated from the wastewater.

  The waste water that has been degassed in the first sealed container 11 is heated to a temperature higher than the saturated vapor temperature in the second sealed container 12 by the heat energy in the vacuum pump 34, and the gas-liquid mixer 27. In this case, the air is mixed and dissolved, and then is ejected from the spray nozzle 12b into the second sealed container 12, so that the flash evaporation and the deaeration are simultaneously performed at the time of the ejection and when flowing down the packed bed 12a. Volatile organic compounds in the wastewater are vaporized and separated from the wastewater.

  The waste water that has finished flash evaporation and deaeration in the second sealed container 12 is heated to a temperature higher than the saturated vapor temperature in the third sealed container 13 by the heat energy in the vacuum pump 34 in the second heat exchanger 32. And the air is mixed and dissolved in the gas-liquid mixer 28, and then sprayed from the spray nozzle 13b into the third hermetic container 13, so that the spraying and the packed bed 13a flow down. Since flash evaporation and degassing occur simultaneously, volatile organic compounds in the wastewater are vaporized and separated from the wastewater.

  The waste water after the flash evaporation and deaeration in the third sealed container 13 is mixed and dissolved in the gas-liquid mixer 29, and then ejected from the spray nozzle 14b into the fourth sealed container 14. Thus, since deaeration is performed when this jetting and when flowing down the packed bed 14a, volatile organic compounds in the wastewater are vaporized and separated from the wastewater.

  The waste water that has been degassed in the fourth sealed container 14 is mixed and dissolved in the gas-liquid mixer 30, and then ejected from the spray nozzle 15 b into the fifth sealed container 15. Since deaeration is performed when jetting and when flowing down the packed bed 14a, volatile organic compounds in the wastewater are vaporized and separated from the wastewater.

  And the treated water which completed the separation | separation of a volatile organic compound accumulates in the bottom part in the said 5th airtight container 15, This treated water is pumped out with the pump 24, and the treated water discharge pipe 25 is collected. It is discharged through.

  On the other hand, all of the gas generated in each of the sealed containers 11, 12, 13, 14, and 15 reaches the first heat exchanger 31 through the duct 33, and is used for heating wastewater for processing purposes. , And then reaches the second heat exchanger 32 where it is used as a heat source for flash evaporation in the third sealed vessel 13 and the water vapor in the gas is removed from the condensed water. It is burned.

  Therefore, from the second heat exchanger 32, the non-condensable gas containing the volatile organic compound and air vaporized in the sealed containers 11, 12, 13, 14, and 15 is discharged as an exhaust gas. It will be.

  This exhaust gas is led to the heater 40 and heated to a temperature of about 900 ° C. or more, so that the volatile organic compound is decomposed into hydrogen chloride, hydrochloric acid, etc., and then led to the gas-liquid contactor 35. Here, it is in direct contact with the treated water.

  As a result, hydrogen chloride, hydrochloric acid and the like decomposed from the volatile organic compound in the exhaust gas are separated so as to be absorbed and dissolved in the treated water, so that the discharge pipe 41 in the gas-liquid contactor 35 It is possible to reliably reduce the release of hydrogen chloride and hydrochloric acid from the atmosphere.

  In the second embodiment, a part of the treated water is supplied to the gas-liquid contactor 35 by opening the flow rate adjusting valve 25a in the treated water discharge pipe 25. However, the present invention is not limited to this, and all the treated water may be supplied to the gas-liquid contactor 35 by closing the flow rate adjusting valve 25a.

  In the second embodiment, the separation of volatile organic compounds from waste water is performed by the first sealed container 11, the second sealed container 12, the third sealed container 13, the fourth sealed container 14, and the fifth sealed container 15. When performing over five stages, the first sealed container 11, the fourth sealed container 14 and the fifth sealed container 15 among the sealed containers are degassed by dissolving carbon dioxide gas in advance, so that high separation efficiency is achieved. Can be maintained.

  On the other hand, in the other closed containers among the respective closed containers, that is, the second closed container 12 and the third closed container 13, separation is performed by both flash evaporation and degassing. High separation efficiency can be maintained by using air as the dissolved gas body without using carbon dioxide gas.

  Therefore, in the second embodiment, air can be used for some of the plurality of sealed containers that perform flash evaporation and deaeration. Since the amount of carbon dioxide used can be reduced by the amount of air used for some of the sealed containers, the running cost can be reduced as compared with the case where carbon dioxide is used for all of the sealed containers.

It is a figure which shows the apparatus by the 1st Embodiment in this invention. In the apparatus of FIG. 1, it is a figure which shows the relationship between the temperature difference of the waste water supplied to an airtight container, the saturated vapor temperature in an airtight container, and the separation efficiency of a volatile organic compound. It is a figure which shows the apparatus by the 1st Embodiment in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Packing layer 3 Vacuum generator 4 Spray nozzle 5 Waste water supply line 6 Drain line 7 Heating means 8 Gas-liquid mixer 9 Gas supply line

Claims (3)

Carbon dioxide gas is dissolved in waste water containing dissolved volatile organic compounds, while the inside of the sealed container is depressurized by exhausting it to a vacuum generation source from below the packed bed provided inside. The waste water in which the carbon dioxide gas is dissolved is jetted into the upper part of the packed bed in the inside of the sealed container with its temperature being higher than the saturated vapor temperature in the inside of the sealed container. A method for separating volatile organic compounds from wastewater. A gas-liquid mixer that dissolves carbon dioxide in wastewater containing dissolved volatile organic compounds;
An airtight container having a packed bed inside;
A vacuum generator for reducing the pressure inside the sealed container by exhausting from below the packed bed;
Means for ejecting the waste water from the gas-liquid mixer to the upper part of the packed bed in the inside of the sealed container;
Means for increasing the temperature of the waste water ejected on the upper side of the packed bed to be higher than the saturated steam temperature inside the sealed container;
An apparatus for separating volatile organic compounds from wastewater. A plurality of sealed containers each provided with a packed bed;
A vacuum generator for maintaining the inside of each sealed container in a reduced pressure state by exhausting from the lower side of the packed bed;
Waste water containing dissolved volatile organic compounds is ejected to the upper part of the packed bed in the first stage sealed container located in the first stage among the sealed containers through a gas-liquid mixer. Means,
Waste water discharged from the lower part of the preceding sealed container out of each of the sealed containers is jetted to the upper part of the packed bed in the latter sealed container adjacent to the preceding sealed container through the gas-liquid mixer. And means for
At least one sealed container located in an intermediate stage among the respective sealed containers has a waste water sprayed inside thereof, based on a thermal energy in the vacuum generator, from a saturated vapor temperature in the at least one sealed container. Equipped with a means of heating to a higher temperature,
Furthermore, the gas-liquid mixer in the at least one sealed container includes means for supplying air thereto,
The gas-liquid mixer in the remaining other closed containers excluding the at least one closed container among the closed containers includes a means for supplying carbon dioxide gas thereto.
An apparatus for separating volatile organic compounds from wastewater.

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