JP5861547B2 - Wastewater treatment system - Google Patents

Description

  The present invention relates to a wastewater treatment system that normalizes the wastewater by removing the organic compound from the wastewater containing the organic compound, and in particular, the organic wastewater from the industrial wastewater containing the organic compound discharged from various factories and research facilities. The present invention relates to a wastewater treatment system that purifies industrial wastewater by efficiently removing compounds.

  Conventionally, aeration treatment is widely known as a method for removing volatile organic compounds from wastewater. This treatment method is a system that introduces gas such as outside air into the waste water, causes it to bubble, and further heats the inside of the aeration tank as necessary, thereby volatilizing volatile organic compounds in the waste water and removing them from the waste water. It is.

  However, in aeration treatment, the removal efficiency of organic compounds with low volatility from wastewater is low. In such a case, the efficiency may be increased by increasing the heating temperature and residence time. And the increase in running cost was a problem.

  On the other hand, an exchangeable adsorption device is generally known as a final treatment method for wastewater treatment. The exchangeable adsorption device referred to here is a simple system that allows the organic compound-containing water to flow through a tank filled with an adsorbent such as activated carbon and efficiently removes harmful organic compounds in the water using the adsorbent. It is a processing device.

  However, the exchangeable adsorption device continues to adsorb organic compounds for a certain period of time, and if the adsorption capacity of the adsorbent reaches saturation, it can be replaced with a new one or once the adsorbent is taken out from the device and regenerated, allowing continuous purification. Furthermore, the purification of water, unlike the purification of air, is unavoidable for the growth of microorganisms, and the life of the adsorbent may be shortened.

  In order to solve such a problem, it is conceivable to extend the replacement cycle by using a large amount of adsorbent, but it is inevitable to enlarge the apparatus and invest in the equipment. In addition, the conventional purification device has a problem that the toxic substance adsorption performance changes at the start of use of the adsorbent and before the end of use (immediately before the replacement of the adsorbent), and the purification process cannot be stably performed. .

  In order to overcome such problems, water treatment systems that can be removed efficiently and stably by alternately performing an adsorption process and a desorption process have been studied (for example, Patent Documents 1, 2, and 3). These water treatment systems realize continuous purification of water, and basically do not require replacement of the adsorbent, and can remove a large amount of organic compounds with high efficiency and stability.

  The water treatment system of Patent Document 2 is configured as a complete water treatment system by treating a desorption gas containing an organic compound discharged in the dehydration process and the desorption process by oxidizing and decomposing it with a combustion device. ing. In addition, the water treatment system of Patent Document 3 introduces an aeration apparatus to efficiently and stably remove a large amount of a large amount of organic compounds in water, and discharges from the aeration gas and water treatment apparatus discharged from the aeration apparatus. The organic compound concentration in the mixed exhaust gas of the desorbed gas can be stably supplied to the combustion apparatus, and can be oxidatively decomposed with high efficiency.

  In the water treatment system of Patent Document 3, the temperature of the combustion apparatus is increased to 300 ° C. or higher to oxidatively decompose the organic compound. Since the heat of combustion is obtained at this time, the temperature of the cracked gas rises. By recovering the heat, it is possible to preheat the combustion apparatus itself and to preheat the heated gas of the water treatment apparatus, thereby reducing the amount of heating energy.

JP 2006-55712 A JP 2008-188492 A JP2012-40479A

In a combustion device using heat recovery, the concentration of organic compounds in the exhaust gas introduced into the combustion device is concentrated to a high concentration, so that the decomposition gas temperature becomes higher and the treatment air volume itself can be reduced. A water treatment system can be provided.
That is, the mixed exhaust gas in Patent Document 3 is composed of exhaust gas from two lines of aeration gas and desorption gas. If one or both of the air volumes can be reduced, the above-described economic effect can be obtained. can get.
From this point of view, the present invention realizes continuous purification of water, basically does not require replacement of the adsorbent, removes organic compounds with high efficiency and stability, and discharges from the aeration apparatus and water treatment apparatus. Another object of the present invention is to provide a water treatment system capable of concentrating organic compounds in exhaust gas supplied to a combustion apparatus and efficiently decomposing and recovering heat.

As a result of intensive studies, the present inventors have finally completed the present invention. That is, the present invention is as follows.
1. A wastewater treatment system for purifying wastewater by removing organic compounds from wastewater containing organic compounds,
An aeration tank that volatilizes and removes organic compounds from the wastewater by discharging wastewater containing organic compounds with gas supplied from an aeration apparatus, and discharges aeration gas containing organic compounds;
Connected to the aeration apparatus, includes an adsorbing element that adsorbs an organic compound by contacting wastewater containing the organic compound, and desorbs the adsorbed organic compound by contacting heated gas, and supplies the wastewater to the adsorbing element Then, the organic compound is adsorbed on the adsorption element and discharged as treated water. By supplying a heating gas to the adsorption element, the organic compound is desorbed from the adsorption element and discharged as a desorption gas containing the organic compound. Waste water treatment equipment,
A combustion apparatus connected to the aeration tank and the waste water treatment apparatus, and oxidizing and decomposing a mixed gas of an aeration gas and a desorption gas containing an organic compound discharged from the aeration tank and the waste water treatment apparatus to discharge a decomposition gas. ,
The gas supplied from the aeration device of the aeration tank uses the desorption gas discharged from the waste water treatment device as a supply source,
The waste water treatment apparatus continuously moves a portion where the adsorption element has been desorbed to a portion where adsorption processing is performed and moves a portion where the adsorption element is completed to a portion where desorption processing is performed. It can treat treated water.
Wastewater treatment system.
2. 2. The waste water treatment system according to claim 1, wherein the waste water treatment apparatus blows off excess waste water adhering to the adsorption element by blowing gas to the adsorption element and discharges it as removed waste water.
3. 3. The waste water treatment system according to 2 above, wherein the removed waste water discharged from the waste water treatment device is again supplied to the waste water treatment device as waste water.
4). The waste water treatment system according to any one of 1 to 3, wherein the adsorption element includes at least one member selected from the group consisting of activated carbon, activated carbon fiber, and zeolite.
5. 5. The wastewater treatment system according to any one of 1 to 4, wherein the cracked gas discharged from the combustion device is heat-exchanged, and the heated gas of the wastewater treatment device is preheated.

  The water treatment system according to the present invention can remove organic compounds continuously with high efficiency, basically does not require the replacement of the adsorbent, and is stable at a high concentration of organic compounds in the desorption gas. Therefore, there is an advantage that the organic compound can be removed from the water and the exhaust gas discharged from the water treatment apparatus can be treated stably and with high capacity at low cost.

1 is a system configuration diagram of a wastewater treatment system according to Embodiment 1 of the present invention. It is a schematic diagram which shows the example of the other waste water treatment equipment which can be utilized in the waste water treatment system in Embodiment 1 of this invention. It is a schematic diagram which shows the example of the further another waste water treatment apparatus which can be utilized in the waste water treatment system in Embodiment 1 of this invention. It is a system block diagram of the waste water treatment system in Embodiment 2 of this invention. It is a system block diagram of the waste water treatment system in Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the same or corresponding parts are denoted by the same reference numerals in the drawings, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a system configuration diagram of a wastewater treatment system according to Embodiment 1 of the present invention. Below, with reference to this FIG. 1, the structure of the waste water treatment system 1A in this Embodiment is demonstrated.

  As shown in FIG. 1, the wastewater treatment system 1 </ b> A according to the present embodiment mainly includes an aeration tank 100, a wastewater treatment device 200, and a combustion device 300.

  The aeration tank 100 includes an aeration apparatus 111 that generates bubbles, and the aeration tank 100 is configured such that by supplying wastewater from the piping line L1, organic compounds in the wastewater are volatilized and discharged from the piping line L2. The organic compound is removed from the wastewater, and the piping line L3 introduces gas into the aeration device 111 to volatilize and remove the organic compound from the wastewater. The piping line L4 removes the aerated gas containing the organic compound. It is a piping line for discharging. Here, the gas introduced into the aeration apparatus 111 from the piping line L3 uses desorption gas discharged from the piping line L7 of the wastewater treatment apparatus 200 described later. With such a configuration, since the aeration treatment is performed using the desorption gas, the air volume of the mixed exhaust gas is reduced as compared with the case where the aeration treatment is performed using the outside air. Therefore, the organic compound concentration in the mixed exhaust gas of the combustion apparatus 300 is reduced. This is because it can be concentrated. Although not shown in the drawings, an adjustment valve is provided between the piping lines L3 and L7, or a piping line and an adjustment valve for the purpose of taking outside air into the aeration apparatus 111 are provided, and then the piping lines L10 and L11 of the combustion apparatus 300 are provided. Further, means for detecting the decomposition gas temperature in L14 and the organic compound concentration in the piping line L8 may be provided so that the intake amount of outside air and desorption gas can be adjusted according to the set temperature and concentration.

  The wastewater treatment apparatus 200 has a first treatment tank 210 and a second treatment tank 220 in which adsorbents 211 and 221 as adsorption elements are accommodated, respectively. The adsorbents 211 and 221 adsorb organic compounds contained in the primary treated water by bringing wastewater into contact therewith. Therefore, in the wastewater treatment apparatus 200, the organic compound is adsorbed by the adsorbents 211 and 221 by supplying the wastewater to the adsorbents 211 and 221. As a result, the wastewater is cleaned and discharged as primary treated water. Become. Moreover, the adsorbents 211 and 221 desorb the adsorbed organic compound by contacting the heated gas. Therefore, in the wastewater treatment apparatus 200, the organic compound is desorbed from the adsorbents 211 and 221 by supplying the heating gas to the adsorbents 211 and 221. Thereby, the heated gas is discharged as a desorption gas containing the organic compound. It will be.

  Piping lines L2, L5, L6, and L7 are connected to the first processing tank 210 and the second processing tank 220, respectively. The piping line L2 is a piping line for supplying the primary treatment water discharged from the aeration tank 100 to the first treatment tank 210 and the second treatment tank 220, and the first treatment tank 210 and the second treatment line are connected by valves V201 and V202. The connection / disconnection state with respect to the processing tank 220 is switched. The piping line L6 is a piping line for supplying heated gas to the first processing tank 210 and the second processing tank 220, and is connected / disconnected to the first processing tank 210 and the second processing tank 220 by valves V203 and V204. The state is switched. The pipe line L5 is a pipe for discharging secondary treated water from the first treatment tank 210 and the second treatment tank 220, and is connected / not connected to the first treatment tank 210 and the second treatment tank 220 by valves V205 and V206. The connection status is switched. The piping line L7 is a piping line for discharging the desorption gas from the first processing tank 210 and the second processing tank 220, and is connected / disconnected to the first processing tank 210 and the second processing tank 220 by valves V207 and V208. The state is switched.

  The first treatment tank 210 and the second treatment tank 220 function alternately as an adsorption tank and a desorption tank by operating the above-described opening and closing of the valves V201 to V208. Specifically, the first treatment tank 210 is adsorbed. When functioning as a tank, the second processing tank 220 functions as a desorption tank, and when the first processing tank 210 functions as a desorption tank, the second processing tank 220 functions as an adsorption tank. . That is, the waste water treatment apparatus 200 in the present embodiment is configured such that the adsorption tank and the desorption tank are alternately switched over time. The piping line L2 is connected to a tank functioning as an adsorption tank among the first processing tank 210 and the second processing tank 220 and supplies drainage to the adsorption tank, and the piping line L6 is a first processing tank. Of the tank 210 and the second treatment tank 220, the heated gas is supplied to the desorption tank connected to the tank functioning as the desorption tank. The piping line L5 is connected to a tank functioning as an adsorption tank among the first treatment tank 210 and the second treatment tank 220, and discharges primary treated water from the adsorption tank. Of the 1 treatment tank 210 and the 2nd treatment tank 220, it connects with the tank which is functioning as a desorption tank, and discharge | releases desorption gas.

  The adsorbents 211 and 221 are configured by members including at least one of activated carbon, activated carbon fiber, and zeolite. Preferably, as the adsorbents 211 and 221, activated carbon or zeolite having a granular shape, a granular shape, or a honeycomb shape is used, and more preferably activated carbon fiber is used. Since the activated carbon fiber has a fibrous structure having micropores on the surface, the contact efficiency with water is high, and the adsorption rate of organic compounds in water is particularly high, which is extremely high compared to other adsorption elements. It is a member that can realize adsorption efficiency.

The physical properties of the activated carbon fibers that can be used as the adsorbents 211 and 221 are not particularly limited, but the BET specific surface area is 700 to 2000 m ² / g, and the pore volume is 0.4 to 0.9 cm ³ / g. The average pore diameter is preferably 14 to 18 mm. This is because when the BET specific surface area is less than 700 m ² / g, the pore volume is less than 0.4 m ³ / g, and the average pore diameter is less than 14 mm, the adsorption amount of the organic compound becomes low, and the BET ratio When the surface area exceeds 2000 m ² / g, the pore volume exceeds 0.9 m ³ / g, and the average pore diameter exceeds 18 mm, the adsorption capacity for substances with small molecular weight decreases due to the large pore diameter. This is because the strength becomes weak, the cost of the material becomes high, and it becomes economically disadvantageous.

  The combustion apparatus 300 is an apparatus for combusting and oxidizing and decomposing mixed gas of aeration gas discharged from the aeration tank 100 and desorption gas discharged from the waste water treatment apparatus 200, and piping lines L8, L9, L10, L11. It is connected to the. The combustion apparatus 300 includes a heat exchanger 310 and a heating furnace 320. The heat exchanger 310 is for preheating a mixed exhaust gas of aeration gas and desorption gas introduced into the heating furnace 320 in advance. The heating furnace 320 is for burning the desorption gas introduced using the electric heater 321. The piping line L8 is for mixing the aerated gas discharged from the piping line L4 of the aeration tank 100 and the desorption gas discharged from the piping line L7 of the waste water treatment apparatus 200, and supplying the mixed gas to the heat exchanger 310. The piping line L <b> 9 is a piping line for introducing the desorption gas preheated by the heat exchanger 310 into the heating furnace 320. The piping lines L10 and L11 are piping lines for discharging cracked gas generated when the desorption gas burns in the heating furnace 320 to the outside via the heat exchanger 310.

  The type of the combustion apparatus 300 is not particularly limited. For example, a direct combustion apparatus that directly oxidatively decomposes mixed exhaust gas at a high temperature of 650 to 800 ° C. or a mixed exhaust gas using a platinum catalyst or the like is used. A catalytic combustion device that oxidatively decomposes by catalytic oxidation reaction, a heat storage direct combustion device that performs direct oxidative decomposition economically while performing heat recovery using a heat storage body, and a combination of a platinum catalyst and a heat storage body efficiently It is possible to use a regenerative catalytic combustion apparatus that oxidizes and decomposes the mixed exhaust gas through a catalytic oxidation reaction. By decomposing the desorption gas using the combustion apparatus 300, the organic compound is completely removed.

  Next, with reference to FIG. 1, the details of the waste water cleaning process performed in the waste water treatment system 1A in the present embodiment will be described. The following description is based on the state where the first treatment tank 210 of the waste water treatment apparatus 200 functions as an adsorption tank and the second treatment tank 220 functions as a desorption tank. The same process is performed when the desorption tank is replaced.

  As shown in FIG. 1, the waste water is introduced into the aeration tank 100 via a piping line L1. The introduced wastewater is aerated, and the organic compound is removed from the wastewater by volatilizing from the wastewater, and the water after the organic compound is removed is introduced into the piping line L2 as an aeration tank as primary treated water Discharged from. It is introduced into the waste water treatment apparatus 200.

  The primary treated water discharged from the aeration tank 100 is sent to the first treatment tank 210 to contact the adsorbent 211 and the organic compound contained in the primary treated water is adsorbed by the adsorbent 211. Is done. The water after the organic compound is adsorbed by the adsorbent 211 is introduced into the piping line L5 and discharged from the waste water treatment apparatus 200 as secondary treated water.

  On the other hand, the heated gas is introduced into the waste water treatment apparatus 200 via the piping line L6 in parallel with the introduction of the waste water. The introduced heated gas is sent to the second treatment tank 220 and comes into contact with the adsorbent 221 to desorb the organic compound adsorbed on the adsorbent 221. The heated gas containing the organic compound desorbed from the adsorbent 221 is introduced into the piping line L7 and discharged from the waste water treatment apparatus 200 as a desorbed gas.

  The aerated gas discharged from the aeration tank 100 and the desorbed gas discharged from the waste water treatment device 200 are sent to the combustion device 300 as mixed exhaust gas in the piping line L8 and are oxidatively decomposed by burning in the heating furnace 320. . The cracked gas generated in the heating furnace 320 is introduced into the piping line L9 and discharged from the combustion device 300. This cracked gas is harmless to the human body mainly containing carbon dioxide and water vapor.

  By using the wastewater treatment system 1A as described above, the aeration tank 100 functions as a pretreatment device for the wastewater treatment device 200. Specifically, the organic compound having a particularly low boiling point in the wastewater can be largely removed in the aeration tank to reduce the load of the organic compound on the wastewater treatment device, so that the wastewater treatment device 200 is increased in size. In addition, it is possible to provide a wastewater treatment system that can efficiently and stably treat wastewater while preventing an increase in running cost.

  Moreover, depending on the physical properties of the organic compound in the wastewater, the desorption gas discharged from the wastewater treatment apparatus 200 may have a large concentration fluctuation, but the aeration gas discharged from the aeration tank 100 has a high concentration and a constant concentration. Therefore, by mixing the aeration gas and the desorption gas, the concentration fluctuation of the desorption gas is suppressed, and the organic compound gas concentration of the exhaust gas supplied to the combustion device 300 can be stabilized. A wastewater treatment system capable of treating exhaust gas discharged from the aeration tank 100 and the wastewater treatment device 200 with high efficiency and stability while preventing an increase in running cost can be provided.

  Further, by using the wastewater treatment system 1A as described above, the adsorbent is basically not exchanged, so that the wastewater can be continuously cleaned without stopping the system. In other words, compared to the case where an exchangeable wastewater treatment apparatus equipped with a cartridge-type adsorbent is used as a post-treatment wastewater treatment apparatus for the aeration tank 100, replacement work for a cartridge-type adsorbent to a new one or regeneration treatment work after removal. Is not required, and the labor and running costs are not increased.

  Moreover, by using the wastewater treatment system 1A as described above, the adsorption treatment and the desorption treatment are alternately and continuously repeated in the first treatment tank 210 and the second treatment tank 220 of the wastewater treatment apparatus 200. Thus, by comprising so that adsorption | suction processing and desorption processing may be repeated alternately and continuously, the organic compound contained in waste_water | drain can be removed stably with high capability at low cost. Therefore, by adopting the above configuration, it is possible to provide a wastewater treatment system capable of cleaning wastewater with high efficiency and stability.

  Moreover, in the waste water treatment system 1A in the above-described embodiment, the case where the waste water treatment apparatus 200 having a configuration in which the first treatment tank 210 and the second treatment tank 220 are alternately replaced with the adsorption tank and the desorption tank is illustrated. However, a waste water treatment apparatus having a different configuration may be employed. Hereinafter, an example thereof will be described with reference to FIGS.

  2 and 3 are schematic views showing examples of other waste water treatment apparatuses that can be used in the waste water treatment system according to the present embodiment. 2 and 3, only the adsorbent provided in the waste water treatment apparatus and the components arranged in the vicinity of the adsorbent are shown, and the other components are not shown.

  FIG. 2 shows a case where an adsorbent 250 having a cylindrical outer shape is used. As shown in FIG. 2, when using an adsorbent 250 having a cylindrical outer shape, a rotation shaft 261 is provided at the axial center of the adsorbent 250 configured to allow fluid to flow in the axial direction. The rotary shaft 261 is rotationally driven by an actuator or the like. Then, piping lines L2, L5, L6, and L7 (see FIG. 1) not shown in FIG. 2 are connected close to both end surfaces of the adsorbent 250 in the axial direction, and a part of the adsorbent 250 is subjected to an adsorption process. 2 is used as a portion (indicated by reference numeral 251 in FIG. 2), and another part of the adsorbent 250 is used as a portion for performing desorption processing (indicated by reference numeral 252 in FIG. 2). That is, primary treated water is introduced from one side in the axial direction into the portion indicated by reference numeral 251 of the adsorbent 250 and primary treated water is derived from the other side in the axial direction, and is indicated by reference numeral 252 of the adsorbent 250. The heated gas is introduced into the portion from one side in the axial direction, and the desorption gas is led out from the other side in the axial direction.

  Here, in the waste water treatment apparatus shown in FIG. 2, the adsorbent 250 rotates at a predetermined speed in the direction of arrow A in the figure with the rotation shaft 261 as the center of rotation. As a result, the portion where the adsorption process of the adsorbent 250 is completed moves to the zone where the desorption process is performed, and the portion where the desorption process of the adsorbent 250 is completed moves to the zone where the adsorption process is performed. Therefore, in the waste water treatment apparatus, the adsorption process and the desorption process are simultaneously performed, and the cleaning process can be continuously performed.

  FIG. 3 shows a case where an adsorbent 270 having a cylindrical outer shape is used. As shown in FIG. 3, when using an adsorbent 270 having a cylindrical outer shape, for example, a unit adsorbing unit 275 surrounded by a metal frame 285 so that fluid can flow in the radial direction. Are arranged in the circumferential direction into a cylindrical shape, and this is rotationally driven around the axis by an actuator (not shown). Then, piping lines L2, L5, L6, and L7 (see FIG. 1) not shown in FIG. 3 are connected in the vicinity of the adsorbent 270, and a part of the unit adsorbing unit of the adsorbent 270 is adsorbed. It is used as a portion (a portion indicated by reference numeral 271 in FIG. 3), and another part of the unit adsorption unit is used as a portion (a portion indicated by reference numeral 272 in FIG. 3) for performing a desorption process. That is, to the unit adsorption unit indicated by reference numeral 271 of the adsorbent 270, the primary treated water is introduced from the radially outer side, the secondary treated water is led toward the radially inner side, and discharged toward one of the axial directions. Thus, a heating gas is introduced into the unit adsorption unit indicated by reference numeral 272 of the adsorbent 270 from the inside in the radial direction via the introduction pipe 281, and the desorption gas is led out toward the outside in the radial direction to lead out the extraction pipe 282. It will be discharged through.

  Here, in the wastewater treatment apparatus shown in FIG. 3, the adsorbent 270 rotates stepwise at a predetermined speed in the direction of arrow A in the figure around the axis. As a result, the unit adsorption unit for which the adsorption process of the adsorbent 270 is completed moves to the zone for performing the desorption process, and the unit adsorption unit for which the desorption process for the adsorbent 270 is completed moves to the zone for performing the adsorption process. become. Therefore, in the waste water treatment apparatus, the adsorption process and the desorption process are simultaneously performed, and the cleaning process can be continuously performed.

  When the adsorbents 250 and 270 having the shapes as shown in FIGS. 2 and 3 are used, the adsorbents 250 and 270 are configured to be filled with granular materials or filled with fibrous materials. Although it is good, it is more preferable to comprise a honeycomb structure. This is because the adsorbents 250 and 270 are made of a honeycomb-like structure, so that the pressure loss can be suppressed to an extremely low level, the processing capacity is increased, and clogging due to solids such as dust is prevented. This is because the occurrence can be suppressed relatively low.

(Embodiment 2)
FIG. 4 is a schematic diagram showing the configuration of the wastewater treatment system according to Embodiment 2 of the present invention. In FIG. 4, illustration of the same parts as the waste water treatment system 1A in the first embodiment of the present invention is omitted. Below, with reference to this FIG. 4, the structure of the waste water treatment system 1B in this Embodiment is demonstrated.

  As shown in FIG. 4, the waste water treatment system 1B in the present embodiment is different from the above-described waste water treatment system 1A in the first embodiment of the present invention in the configuration of the waste water treatment apparatus 200. In the wastewater treatment system 1B in the present embodiment, a piping line L12 for introducing gas into the wastewater treatment apparatus 200 is connected to the piping line L6 for introducing heated gas into the wastewater treatment apparatus 200. Valves V209 and V210 for switching the connection / disconnection state of the piping lines L6 and L12 to the waste water treatment apparatus 200 are provided in the piping lines L6 and L12, respectively. Further, in the wastewater treatment system 1B in the present embodiment, a piping line L13 for discharging removed wastewater from the wastewater treatment device 200 is connected to the piping line L7 for discharging desorption gas from the wastewater treatment device 200. In addition, valves V211 and V212 for switching the connection / disconnection state of the piping lines L7 and L13 to the waste water treatment apparatus 200 are provided in the piping lines L7 and L13, respectively. The other end of the piping line L13 is connected to a piping line L2 for introducing wastewater into the wastewater treatment apparatus 200.

  In the wastewater treatment apparatus 200 of the wastewater treatment system 1B in the present embodiment, a dehydration process (purge process) is performed between the adsorption process and the desorption process. Specifically, as in the case of the wastewater treatment system 1A in the first embodiment of the present invention described above, in the wastewater treatment apparatus 200, the first treatment tank 210 and the first treatment tank 210 are operated by opening and closing valves V201 to 208. The second treatment tank 220 is alternately switched to the adsorption tank and the desorption tank. When the second treatment tank 220 is switched to the desorption tank, first, the desorption tank is connected to the piping line L12 and the piping line L13, and is connected via the piping line L12. A dehydration process is performed to blow off excess wastewater adhering to the surface of the adsorbent by introducing gas into the desorption tank and sprayed onto the adsorbent, and the removed wastewater blown off passes through the piping line L13 and the piping line L2. The wastewater treatment device 200 is supplied again. Then, after performing the dehydration process for a predetermined time, the connection between the desorption tank and the piping line L12 and the piping line L13 is released, and the piping line L6 and the piping line L7 are connected to the desorption tank, and the desorption process is performed. In addition, as the gas introduced into the desorption tank during the dehydration treatment, it is preferable to use a gas having a high temperature and a lower humidity. For example, it is preferable to use dry air heated to a predetermined temperature. .

  By adopting the configuration as in the wastewater treatment system 1B in the present embodiment described above, the effect obtained when the configuration as in the wastewater treatment system 1A in the first embodiment of the present invention described above is employed. In addition, since the desorption efficiency of the organic compound from the adsorbents 211 and 221 is greatly increased, an effect of being able to provide a wastewater treatment system capable of cleaning wastewater with higher efficiency and stability can be obtained. In addition, in this Embodiment mentioned above, although demonstrated, the case where it comprised so that the removal waste_water | drain discharged | emitted from the waste water treatment apparatus 200 might be supplied to the said waste water treatment apparatus 200 again was demonstrated, the said removal waste_water | drain May be configured to be cleaned by separately using a wastewater treatment apparatus or the like equipped with an exchangeable adsorption element.

(Embodiment 3)
FIG. 5 is a schematic diagram showing the configuration of the waste water treatment system according to Embodiment 3 of the present invention. In FIG. 5, illustration of the same parts as the waste water treatment system 1A in the first embodiment of the present invention and the waste water treatment system 1B in the second embodiment is omitted. Below, with reference to this FIG. 5, the structure of the waste water treatment system 1C in this Embodiment is demonstrated.

  As shown in FIG. 5, the wastewater treatment system 1C in the present embodiment is different in the configuration of the wastewater treatment system 1A in the first embodiment of the present invention described above, the wastewater treatment system 1B in the second embodiment, and the combustion apparatus 300. doing. In the wastewater treatment system 1C according to the present embodiment, one more heat exchange 311 is connected to the combustion device 300, and heat exchange is performed between the cracked gas discharged from the heat exchanger 310 and the gas in the combustion device 300. This is for preheating the heating gas necessary for the desorption process of the waste water treatment apparatus 200. The piping line L14 is a piping line for supplying gas to the heat exchanger 311, and the piping line L6 is a piping line for introducing the heated gas preheated by the heat exchanger 311 to the waste water treatment apparatus 200. . The piping lines L14 and L11 are piping lines for discharging the cracked gas discharged from the heat exchanger 310 to the outside via the heat exchanger 311.

  In the combustion apparatus 300 of the wastewater treatment system 1C in the present embodiment, preheating of the heated gas of the wastewater treatment apparatus 200 is performed in the heat exchanger 311 using the cracked gas discharged from the combustion apparatus 300.

  By adopting the configuration like the wastewater treatment system 1C in the present embodiment described above, the configuration like the wastewater treatment system 1A and the wastewater treatment system 1B in the first embodiment of the present invention described above is adopted. In addition to the effects obtained, the amount of heat necessary for raising the temperature of the heating gas required for the waste water treatment apparatus 200 can be reduced, so that the effect of achieving a waste water treatment system capable of purifying waste water more efficiently can be obtained. In the present embodiment described above, heating means such as a heater may be added as necessary.

  The characteristic configurations of the wastewater treatment systems 1A, 1B, and 1C according to the first to third embodiments of the present invention described above can be combined with each other. For example, a wastewater treatment apparatus including the adsorbents 250 and 270 configured as shown in FIGS. 2 and 3 may be applied to the wastewater treatment apparatus 200 of the wastewater treatment system 1B according to Embodiment 2 of the present invention. In this case, a zone for performing dehydration processing is provided in a zone for performing desorption processing of the adsorption elements 250 and 270, and portions of the adsorption elements 250 and 270 located in the zone for performing the dehydration processing are provided. The above-described piping lines L12 and L13 are connected in proximity to each other, and the waste water treatment apparatus 200 is configured so that the dehydration process is performed between the adsorption process and the desorption process.

  In the first to third embodiments of the present invention described above, the description has been made without particularly showing the components such as the fluid conveying means such as the pump and the fan and the fluid storing means such as the storage tank. What is necessary is just to arrange | position a component in an appropriate position as needed.

  Thus, the above-described embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Hereinafter, the present invention will be described in more detail with reference to Examples of Embodiment 3, but the present invention is not limited to these Examples.
The evaluation was performed by the following method.
(BET specific surface area)
The BET specific surface area was measured by measuring the amount of nitrogen adsorbed on the sample when the relative pressure was raised in the range of 0.0 to 0.15 in the atmosphere of the boiling point of liquid nitrogen (-195.8 ° C), and a BET plot. Was used to determine the surface area (m ² / g) per unit mass of the sample.
(Pore volume)
The pore volume was measured by a nitrogen gas adsorption method at a relative pressure of 0.95.
(Average pore diameter)
The average pore diameter was determined by the following formula.
dp = 40000 Vp / S (where dp: average pore diameter (径))
Vp: pore volume (cc / g)
S: BET specific surface area (m ² / g)
(Organic compound removal effect)
The raw water was water containing 1000 mg / L of 1,4-dioxane and 14000 mg / L of acetaldehyde. The 1,4-dioxane and acetaldehyde concentrations in and out of the aeration tank, waste water treatment device and combustion device after 500 hours of operation were measured, and the removal effect was confirmed by calculating the discharge amount of each organic compound.
(Organic compound concentration evaluation)
The water concentration and gas at the inlet and outlet were analyzed and measured by gas chromatography.

[Example 1]
In an aeration tank having an effective aeration capacity of 20 L, an aeration temperature of 60 ° C., an aeration intensity of 2.5 min ⁻¹ , an aeration air volume of 50 L / min, a residence time of 2 hr, a treated water volume of 10 L / hr of 1,4-dioxane 1000 mg / L, and acetaldehyde 10000 mg Raw water containing / L was introduced to obtain primary treated water. In addition, the aeration air volume used the desorption gas of the waste water treatment equipment as the supply source. The outlet concentration at that time was 1,4-dioxane 500 mg / L or less and acetaldehyde 5 mg / L or less, and 1,4-dioxane was removed from raw water by 50% or more and acetaldehyde by 99.9% or more. . Moreover, the organic compound density | concentration of the aeration gas discharged | emitted from an aeration tank became 1, 4- dioxane 500ppm and acetaldehyde 17000ppm.

Next, as an adsorbent for the wastewater treatment apparatus, an activated carbon fiber having an average pore diameter of 14 mm, a BET specific surface area of 1650 m ² / g, and a total pore volume of 0.6 m ³ / g is used. Two elements were prepared and installed in the waste water treatment device of the damper switching type in FIG. 4, and the primary treated water after the aeration treatment was introduced so that the treated water amount became 10 L / hr, and secondary treated water was obtained. .

  Next, air was used as a gas during the dehydration process of the wastewater treatment apparatus, the dehydration wind speed was 40 cm / sec, and the air volume was 300 L / min. 130 ° C. air was used as a heating gas in the desorption process, the desorption wind speed was 40 cm / sec, and the air volume was 300 L / min. The adsorption cycle in the adsorption step was 60 min, the dehydration time in the dehydration step was 5 min, the desorption time in the desorption step was 55 min, and a switching cycle was set. The 1,4-dioxane concentration in the secondary treated water at that time is less than 10 mg / L, the acetaldehyde concentration is less than 1 mg / L, and the removal rate of 1,4-dioxane is 98% or more as shown in Table 1, and acetaldehyde The removal rate of 80% or more was possible. The average concentration of each organic compound in the desorption gas was 70 ppm 1,4-dioxane and 3 ppm acetaldehyde.

  The water purified by the water treatment system of this example was able to treat 1,4-dioxane and acetaldehyde with an efficiency of 99.5% or more even after 500 hours. Since each organic compound is volatilized and removed in the aeration tank and then subjected to advanced treatment by continuously performing adsorption and desorption in a wastewater treatment device, the treatment can be performed stably and with high efficiency without deterioration in performance.

  Next, when the concentration of the mixed exhaust gas was measured by connecting the duct of the aeration gas discharged from the aeration tank and the duct of the desorption gas discharged from the waste water treatment apparatus, 1,4-dioxane 140 ppm, acetaldehyde 2900 ppm became.

  Next, 0.5 L of platinum catalyst is installed in the combustion apparatus of FIG. 1 as a catalyst of the combustion apparatus, and the above-mentioned mixed exhaust gas is supplied at an air volume of 300 L / min, heated to 300 ° C., and then brought into contact with the catalyst. The organic compound in the mixed exhaust gas was oxidatively decomposed to obtain a decomposition gas. Table 2 shows the concentration of each organic compound in the cracked gas 500 hours after the start of operation. The 1,4-dioxane and acetaldehyde in the cracked gas were each less than 0.1 ppm and could be treated well. Moreover, when the exit temperature of a combustion apparatus was measured, the exit average temperature was 470 degreeC.

[Example 2]
In an aeration tank with an effective aeration capacity of 20 L, an aeration temperature of 60 ° C., an aeration intensity of 5.0 min ⁻¹ , an aeration air volume of 100 L / min, a residence time of 2 hr, a treated water volume of 10 L / hr of 1,4-dioxane 1000 mg / L, and acetaldehyde 10000 mg Raw water containing / L was introduced to obtain primary treated water. In addition, the aeration air volume used the desorption gas of the waste water treatment equipment as the supply source. The outlet concentration at that time was 1,4-dioxane 150 mg / L or less, acetaldehyde 5 mg / L or less, and 1,4-dioxane was 70% or more and acetaldehyde 99.9% or more could be removed from the raw water. . Moreover, the organic compound density | concentration of the aeration gas discharged | emitted from an aeration tank became 1, 4- dioxane 400ppm and acetaldehyde 8500ppm.

Next, as an adsorbent for the wastewater treatment apparatus, an adsorption of 90 mmφ using an activated carbon fiber having an average pore diameter of 14 mm, a BET specific surface area of 1650 m ² / g and a total pore volume of 0.6 m ³ / g and a thickness of 150 mm and a weight of 100 g. Two elements were prepared and installed in the waste water treatment device of the damper switching type in FIG. 4, and the primary treated water after the aeration treatment was introduced so that the treated water amount became 10 L / hr, and secondary treated water was obtained. .

  Next, air was used as a gas during the dehydration process of the wastewater treatment apparatus, the dehydration wind speed was 40 cm / sec, and the air volume was 200 L / min. 130 ° C. air was used as a heating gas in the desorption process, the desorption wind speed was 40 cm / sec, and the air volume was 200 L / min. The adsorption cycle in the adsorption step was 60 min, the dehydration time in the dehydration step was 5 min, the desorption time in the desorption step was 55 min, and a switching cycle was set. The 1,4-dioxane concentration in the secondary treated water at that time is less than 10 mg / L, the acetaldehyde concentration is less than 1 mg / L, and the removal rate of 1,4-dioxane is 98% or more as shown in Table 1, and acetaldehyde The removal rate of 80% or more was possible. The average concentration of each organic compound in the desorption gas was 35 ppm 1,4-dioxane and 2 ppm acetaldehyde.

  The water purified by the water treatment system of this example was able to treat 1,4-dioxane and acetaldehyde with an efficiency of 99.5% or more even after 500 hours. Since each organic compound is volatilized and removed in the aeration tank and then subjected to advanced treatment by continuously performing adsorption and desorption in a wastewater treatment device, the treatment can be performed stably and with high efficiency without deterioration in performance.

  Next, when the concentration of the mixed exhaust gas was measured by connecting the duct of the aeration gas discharged from the aeration tank and the duct of the desorption gas discharged from the waste water treatment device, 215 ppm of 1,4-dioxane, 4250 ppm of acetaldehyde and became.

  Next, 0.5 L of platinum catalyst is installed in the combustion apparatus of FIG. 1 as a catalyst of the combustion apparatus, and the above-mentioned mixed exhaust gas is supplied at an air volume of 300 L / min, heated to 300 ° C., and then brought into contact with the catalyst. The organic compound in the mixed exhaust gas was oxidatively decomposed to obtain a decomposition gas. Table 2 shows the concentration of each organic compound in the cracked gas 500 hours after the start of operation. The 1,4-dioxane and acetaldehyde in the cracked gas were each less than 0.1 ppm and could be treated well. Moreover, when the exit temperature of a combustion apparatus was measured, the exit average temperature was 530 degreeC.

[Comparative Example 1]
The operating conditions except that the supply source of the aeration gas was outside air were the same as those in Example 1, and the performance evaluation was performed by operating the aeration tank, the waste water treatment device, and the combustion device. As a result, the removal rate of 1,4-dioxane and acetaldehyde in the wastewater was the same as that of Example 1 for both the primary treated water and the secondary treated water as shown in Table 1. On the other hand, the concentration of each organic compound in the mixed exhaust gas was 130 ppm for 1,4-dioxane and 2500 ppm for acetaldehyde. 1,4-Dioxane and acetaldehyde in the cracked gas were each less than 0.1 ppm and could be treated well, but when the outlet temperature of the combustion apparatus was measured, the average outlet temperature was 450 ° C. In comparison, the temperature was as low as 20 ° C.

[Comparative Example 2]
The operating conditions except that the supply source of the aeration gas was outside air were the same as in Example 2, and the performance evaluation was performed by operating the aeration tank, the wastewater treatment device, and the combustion device. As a result, the removal rate of 1,4-dioxane and acetaldehyde in the wastewater was the same as that of Example 1 for both the primary treated water and the secondary treated water as shown in Table 1. On the other hand, the concentration of each organic compound in the mixed exhaust gas was 140 ppm for 1,4-dioxane and 2900 ppm for acetaldehyde. 1,4-Dioxane and acetaldehyde in the cracked gas were each less than 0.1 ppm and could be treated well, but when the outlet temperature of the combustion apparatus was measured, the average outlet temperature was 470 ° C. In comparison, the temperature was as low as 60 ° C.

  1A, 1B, 1C Wastewater treatment system, 100 Aeration tank, 200 Wastewater treatment device, 210 First treatment tank, 211 Adsorbent, 220 Second treatment tank, 221 Adsorbent, 250 Adsorbent, 261 Rotating shaft, 270 Adsorbent, 275 unit adsorption unit, 281 inlet pipe, 282 lead pipe, 285 frame, 300 combustion device, 310 heat exchanger, 311 heat exchanger, 320 combustion furnace, L1-L14 piping line, V201-V212 valve.

Claims (5)

A wastewater treatment system for purifying wastewater by removing organic compounds from wastewater containing organic compounds,
An aeration tank that volatilizes and removes organic compounds from the wastewater by discharging wastewater containing organic compounds with gas supplied from an aeration apparatus, and discharges aeration gas containing organic compounds;
Connected to the aeration apparatus, includes an adsorbing element that adsorbs an organic compound by contacting wastewater containing the organic compound, and desorbs the adsorbed organic compound by contacting heated gas, and supplies the wastewater to the adsorbing element Then, the organic compound is adsorbed on the adsorption element and discharged as treated water. By supplying a heating gas to the adsorption element, the organic compound is desorbed from the adsorption element and discharged as a desorption gas containing the organic compound. Waste water treatment equipment,
A combustion apparatus connected to the aeration tank and the waste water treatment apparatus, and oxidizing and decomposing a mixed gas of an aeration gas and a desorption gas containing an organic compound discharged from the aeration tank and the waste water treatment apparatus to discharge a decomposition gas. ,
The gas supplied from the aeration device of the aeration tank uses the desorption gas discharged from the waste water treatment device as a supply source,
The waste water treatment apparatus continuously moves a portion where the adsorption element has been desorbed to a portion where adsorption processing is performed and moves a portion where the adsorption element is completed to a portion where desorption processing is performed. It can treat treated water.
Wastewater treatment system.   The wastewater treatment system according to claim 1, wherein the wastewater treatment device blows off excess wastewater adhering to the adsorption element by blowing gas onto the adsorption element and discharges it as removed wastewater.   The wastewater treatment system according to claim 2, wherein the removed wastewater discharged from the wastewater treatment device is again supplied to the wastewater treatment device as wastewater.   The wastewater treatment system according to any one of claims 1 to 3, wherein the adsorption element includes at least one member selected from the group consisting of activated carbon, activated carbon fiber, and zeolite.   The wastewater treatment system according to any one of claims 1 to 4, wherein the waste gas treatment system is configured to exchange heat with the cracked gas discharged from the combustion device and to preheat the heated gas of the wastewater treatment device.