JP6332599B2 - Water treatment system - Google Patents

Description

  The present invention relates to a water treatment system that normalizes the water by removing the organic substance from the water containing the organic substance, and in particular, the industrial wastewater discharged from various factories and research facilities, and the final disposal site. The present invention relates to a water treatment system for purifying water by efficiently removing organic substances from leachate, groundwater and the like.

  Conventionally, a water treatment device that can remove organic substances from water efficiently and stably by alternately removing organic substances by adsorption (adsorption process) and regenerating adsorbents (desorption process) using adsorbents. It has been known. (For example, patent document 1). This water treatment apparatus realizes continuous purification of water, basically does not require replacement of the adsorbent, and can stably remove organic substances with high efficiency.

  When activated carbon fiber is used as an adsorbent, it is generally known that activated carbon fiber has a property of removing organic substances with high efficiency, especially in wastewater treatment containing low concentrations of organic substances, because the adsorption rate is fast. Yes. In the water treatment apparatus, the adsorbed and removed organic substance is desorbed from the adsorbent during regeneration, and is discharged as a gas (desorption gas) containing the organic substance, and is discharged by a secondary treatment apparatus such as a combustion apparatus. By performing the next treatment, the organic substance is decomposed and detoxified, and the waste water treatment is completed (for example, Patent Document 2).

  FIG. 1 shows an example of the relationship between the concentration of organic substances in the water to be treated and the amount of adsorption. As shown in FIG. 1, it is known that the adsorption amount tends to increase depending on the organic substance concentration. That is, the lower the concentration, the larger the amount of adsorbent necessary to obtain the predetermined removal efficiency, so the enlargement of the secondary processing apparatus has been a problem.

JP 2006-55712 A JP 2006-55713 A

  The present invention has been made against the background of the above-described technical problems, and in water treatment containing a low concentration organic substance, water can be stably removed at low cost with high efficiency, and the secondary treatment apparatus can be downsized. It is an object to provide a processing system.

As a result of intensive studies in order to solve the above problems, the present inventors have finally completed the present invention. That is, the present invention is as follows.
(1) The organic substance is adsorbed and removed by bringing the water to be treated containing the organic substance into contact with the adsorption element, the adsorbed organic substance is desorbed by bringing the water vapor into contact, and the desorbed gas is liquefied and condensed to be treated. A water treatment system comprising two or more water treatment devices that continuously perform adsorption, desorption, and condensation to obtain concentrated water containing organic substances having a higher concentration than water,
Concentrated water discharged by treating the water to be treated with the water treatment device at the preceding stage is supplied to the at least one other water treatment device installed at the subsequent stage of the water treatment device and treated. In the water treatment system, the concentrated water discharged from the subsequent water treatment device has a higher concentration than the concentrated water discharged from the previous water treatment device.
(2) The water treatment system according to (1), wherein excess water attached to the adsorption element is removed and discharged as removed water.
(3) The water treatment system according to (2), wherein water vapor is used to remove excess water adhering to the adsorption element.
(4) The water treatment system according to (2) or (3), wherein the removed water is returned to the water to be treated.
(5) The water treatment system according to any one of (1) to (4), wherein the adsorption element includes at least one member selected from the group consisting of activated carbon, activated carbon fiber, and zeolite.
(6) The water treatment system according to any one of (1) to (5), wherein the treated water discharged from the water treatment device that treats the concentrated water is returned to the treated water. .
(7) The water according to any one of (1) to (6), wherein the water to be treated is heat-exchanged and the desorption gas discharged from the water treatment device is liquefied and condensed to obtain concentrated water. Processing system.
(8) The water treatment system according to any one of (1) to (7), wherein the adsorption element is different for each water treatment apparatus.
(9) An aeration apparatus that volatilizes and removes the organic substance by bringing water into contact with the gas and a gas that decomposes the organic substance by heating the gas after the water treatment system according to any one of (1) to (8) A water treatment system comprising a combustion device and configured to decompose organic substances in concentrated water discharged from the water treatment system and discharge clean gas.
(10) The water treatment system according to (9), wherein the aeration treated water discharged from the aeration apparatus is configured to be returned to the water treatment apparatus.
(11) A waste liquid combustion apparatus that heats the liquid and decomposes the organic substance is provided at a subsequent stage of the water treatment system according to any one of (1) to (8), and the concentrated water discharged from the water treatment system A water treatment system configured to decompose organic substances and discharge clean gases.
(12) The water treatment system according to any one of (9) to (11), wherein the concentrated water supplied to the aeration apparatus or the waste liquid combustion apparatus is supplied without performing liquefaction condensation.
(13) Any one of (9) to (12) configured to heat-exchange clean gas discharged from the combustion device or the waste liquid combustion device and raise a temperature of water vapor supplied to the water treatment device Water treatment system as described in.
(14) The water treatment system according to any one of (9) to (13), wherein the clean gas discharged from the combustion device is subjected to heat exchange, and the temperature of the gas supplied to the aeration device is increased. .

  The water treatment system according to the present invention basically eliminates the need for replacement of the adsorbent, continuously removes organic substances in the water with high efficiency, and reduces the volume of treated water and the concentration of organic substances at a high magnification. By collecting the concentrated water as a concentrated solution and subjecting the concentrated water to secondary treatment, the secondary treatment apparatus can be downsized, and water treatment can be efficiently performed at low cost.

It is an example of the relationship figure of the organic substance density | concentration in to-be-processed water, and the adsorption amount of an organic substance. It is an example of the system block diagram of the water treatment system in embodiment of this invention. It is an example of the block diagram of the water treatment apparatus which can be used for implementation of this invention. It is an example of the system block diagram of the water treatment system in embodiment of this invention. It is an example of the system block diagram of the water treatment system in embodiment of this invention. It is an example of the block diagram of the aeration apparatus which can be used for implementation of this invention. It is an example of the block diagram of the combustion apparatus which can be used for implementation of this invention. It is an example of the system block diagram of the water treatment system in embodiment of this invention. It is an example of the block diagram of the waste liquid combustion apparatus which can be used for implementation of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments shown in the drawings, the same or corresponding parts are omitted as appropriate, and the description thereof will not be repeated.

  FIG. 2 is one of the system configuration diagrams of the water treatment system in the embodiment of the present invention. As shown in FIG. 2, the water treatment system according to the present embodiment mainly includes a front-stage water treatment apparatus 100 and a rear-stage water treatment apparatus 200.

  The water treatment apparatus 100 includes a first treatment tank 110 and a second treatment tank 120 in which adsorbents 111 and 121 as adsorption elements are accommodated, respectively. The adsorbents 111 and 121 adsorb organic substances contained in the water to be treated by contacting the water to be treated. Therefore, in the water treatment apparatus 100, by supplying the water to be treated to the adsorbents 111 and 121, the organic substance is adsorbed by the adsorbents 111 and 121, thereby cleaning the water to be treated and discharging it as the treated water 1. Will be. The adsorbents 111 and 121 are desorbed of the organic substances adsorbed by contacting a smaller amount of water vapor than the water to be treated. The water vapor discharged from the first treatment layer 110 and the second treatment tank 120 as the desorption gas and the desorbed organic substance are liquefied and condensed by the condenser 130 and discharged as the concentrated water 1 to the outside of the water treatment apparatus.

  The first treatment tank 110 and the second treatment tank 120 are connected with piping of a treated water supply line, a treated water discharge line, a water vapor supply line, and a desorption gas discharge line, and each line has a valve. Etc., the flow path switching means that is switched to the connected / disconnected state is connected to each processing tank. The 1st processing tank 110 and the 2nd processing tank 120 function as an adsorption tank and a desorption tank alternately by operating opening and closing of the valve mentioned above. When the 1st processing tank 110 is functioning as an adsorption tank, the 2nd processing tank 120 functions as a desorption tank. Specifically, when the water to be treated is supplied to the first treatment tank 110 and a flow path is secured so that the treated water 1 is discharged from the first treatment tank 110, the second treatment tank 120 has water vapor. The flow path configuration is such that the supplied and desorbed gas is discharged from the second processing tank 120. The water treatment apparatus 100 in the present embodiment is configured such that the adsorption tank and the desorption tank are alternately switched over time.

  The water treatment apparatus 100 has the apparatus configuration shown in FIG. 3, and when the adsorption tank is switched to the desorption tank, the water adhering to the adsorbents 111 and 121 is removed (dehydrated) and discharged as removed water. An apparatus that initiates desorption by water vapor supply is preferred. This is because the amount of concentrated water can be reduced and the concentration rate can be increased by removing water adhering to the adsorbents 111 and 121 in advance and then performing water vapor desorption. As the means for removing adhering water, means such as self-weight removal, high-speed purge with a high-pressure gas such as compressed air, nitrogen, and water vapor, and suction using a vacuum pump can be used, but high-speed purge with water vapor is preferred. This is because there is no need to separately add a means for removing the adhering water, the adhering water can be removed with high efficiency, and the treatment tank is heated, so that the desorption efficiency is increased. The water vapor used for dehydration is liquefied and condensed when it comes into contact with the adhering water and becomes part of the removed water.

  It is preferable that the removed water is returned to the water to be treated and treated again. This is because it is not necessary to separately process the removed water with another water treatment apparatus.

  The adsorbents 111 and 121 preferably include at least one member selected from the group consisting of activated carbon, activated carbon fiber, and zeolite. As the adsorbents 111 and 121, activated carbon, activated carbon fiber, or zeolite in the form of particles, granules or honeycombs is used, and it is more preferable to use activated carbon fiber. Since the activated carbon fiber has a fibrous structure with micropores on the surface, the contact efficiency with water is high, and the adsorption rate of organic substances in water is particularly high, which is extremely high compared to other adsorbents. It is a member that can realize adsorption efficiency.

The physical properties of the activated carbon fibers that can be used as the adsorbents 111 and 121 are not particularly limited, but the BET specific surface area is 700 to 2000 m ² / g, and the total pore volume is 0.4 to 0.9 cm ³ /. g, and those having an average pore diameter of 17 to 18 mm are preferred. 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 17 mm, the adsorption amount of the organic substance becomes low, and the BET ratio When the surface area exceeds 2000 m ² / g, the total pore volume exceeds 0.9 m ³ / g, and the average pore diameter exceeds 18 mm, the adsorption capacity for substances having a low 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 vapor pressure, temperature, and the like of water vapor that is a desorption medium of the water treatment apparatus are not particularly limited, but may be set as appropriate according to the heat-resistant temperature and physical properties of the adsorbent used. However, it is necessary to desorb with water vapor having a mass smaller than that of the water to be treated supplied to the water treatment apparatus. When the mass of water vapor is larger, the organic substance is not concentrated, and concentrated water containing an organic substance having a higher concentration than the organic substance concentration in the water to be treated cannot be obtained.

  The condenser 130 is generally known as a device that indirectly contacts a desorption gas with a cooling medium such as cooling water, industrial water, cold water, or brine, and liquefies and condenses the desorption gas by heat exchange. The water to be treated may be used as the cooling medium. This is because the cooling medium is not supplied separately. In this case, the water to be treated has a flow path configuration that is treated by the water treatment apparatus 100 after heat exchange in the condenser 130.

  The water treatment device 200 is a water treatment device having the same device configuration as the water treatment device 100. However, the concentrated water 1 discharged from the water treatment apparatus 100 is connected to be treated as treated water, and the amount of adsorbent filled in the water treatment apparatus 200 is the amount of adsorbent filled in the water treatment apparatus 100. Less is preferred. As described above with reference to FIG. 1, the higher the concentration of the organic substance in the water to be treated, the more the adsorption amount increases. The same processing performance can be obtained with an amount smaller than the amount. This is because the concentrated water 1 discharged from the water treatment apparatus 100 is concentrated again by the water treatment apparatus 200, and therefore the concentration ratio can be further improved. For the same reason, if there is an adsorbent whose removal performance and concentration ratio are improved according to the concentration of organic substances in water, the water treatment apparatus 100 and the water treatment apparatus 200 may be filled with adsorbents of different types and physical properties. good.

  Further, the treated water 2 discharged from the water treatment apparatus 200 may be mixed with the treated water 1 discharged from the water treatment apparatus 100 and discharged, but as shown in FIG. The structure processed again with the water treatment apparatus 100 is preferable. It is because it can concentrate efficiently, maintaining removal efficiency. In consideration of receiving a short path when the water to be treated is passed through the adsorbent, the higher the concentration of the organic substance in the water, the more the organic substance concentration in the treated water is affected. Therefore, in the actual design of the water treatment apparatus 200, when the organic substance concentration in the treated water 2 discharged from the water treatment apparatus 200 is removed to the same concentration as the treated water 1 discharged from the water treatment apparatus 100, There is a possibility of adopting a costly system such as increasing the filling amount rather than the amount of adsorbent or performing adsorption processing in multiple stages. On the other hand, the organic substance concentration in the treated water 2 of the water treatment apparatus 200 is set to a treatment efficiency equal to the organic substance concentration in the treated water of the water treatment apparatus 100, and the treated water 2 is supplied to the water treatment apparatus 100. Thus, the cost increase of the water treatment apparatus 200 as described above can be avoided by adopting the flow path configuration for reprocessing.

  In the embodiment of the present invention, the two water treatment devices, the water treatment device 100 and the water treatment device 200, will be described. However, two or more water treatment devices are used to increase the concentration rate of the concentrated water. Also good. For example, the concentrated water 2 discharged from the water treatment device 200 may be treated by a water treatment device 201 (not shown) having the same device configuration as the water treatment device 100 or the water treatment device 200, and the same device configuration. The concentrated water 3 discharged from the water treatment device 201 may be treated by a water treatment device 202 (not shown). As described above, the concentration of organic substances increases as a result of concentration, and the amount of adsorbent required for the latter-stage water treatment device decreases, so the later the lower the amount of steam necessary for desorption, the higher the concentration factor. Because you can.

  FIG. 5 is one of the system configuration diagrams of the water treatment system according to the embodiment of the present invention. As shown in FIG. 5, the water treatment system in the present embodiment may mainly include a water treatment device 100, a water treatment device 200, an aeration device 300, and a combustion device 400.

  The aeration apparatus 300 is an apparatus for treating the concentrated water 2 discharged from the water treatment apparatus 200. As shown in FIG. 6, an aeration tank 310 and a gas supply unit 320 for supplying bubble gas to the aeration tank 310 are provided. Have. The concentrated water 2 is supplied to the aeration tank 310, comes into contact with bubbles generated from the gas supply device 320, and the organic substance in the concentrated water is volatilized and removed by shifting to the gas, and the aerated treated water and the aeration containing the organic substance Exhaust the gas.

  Although not shown, the aerated treated water discharged from the aerated apparatus 300 may be mixed and discharged with the treated water of the water treatment apparatus, but is configured to be supplied to the water treatment apparatus 100 or the water treatment apparatus 200 again. Is preferable. This is because when the organic substance is removed with high efficiency (for example, 99% or more removal efficiency), it is more efficient to perform the adsorption treatment with the water treatment apparatus 100 than to increase the removal efficiency of the aeration apparatus 300. . The aeration treated water of the aeration apparatus 300 has a processing efficiency that can be removed to an organic substance concentration equivalent to the water to be treated supplied to the water treatment apparatus 100 or the water treatment apparatus 200, and does not need to be treated with high removal efficiency.

  Although not shown, instead of supplying the concentrated water 2 to the aeration apparatus 300, the desorption gas may be directly supplied to the aeration tank 310 without condensing the desorption gas by the condenser 230 of the water treatment apparatus 200. . This is because when the water in the aeration tank comes into contact with the desorption gas, it is liquefied and condensed, so there is no need to condense.

  The combustion apparatus 400 is an apparatus for processing the aerated gas discharged from the aeration apparatus 300, and includes a heat exchanger 410 and a heating furnace 420 as shown in FIG. The aerated gas is preheated by heat exchange in the heat exchanger 410, and the processing gas purified by oxidizing and decomposing an organic substance in the gas at a predetermined temperature in the heating furnace 420 is discharged. The processing gas passes through the heat exchanger 410 and is heat-exchanged with the aeration gas, and is then discharged out of the apparatus as a clean gas.

  The type of the combustor 400 is not particularly limited. For example, a direct combustor that directly oxidizes and decomposes gas at a high temperature of 650 to 800 ° C. or a catalyst using a platinum catalyst or the like as a catalyst. Catalytic oxidation device that oxidizes and decomposes by oxidation reaction, thermal storage direct combustion device that performs direct oxidative decomposition economically while performing heat recovery using a heat storage body, efficient aeration by combining a platinum catalyst etc. with a heat storage body It is possible to use a regenerative catalytic oxidizer or the like that oxidizes and decomposes gas by a catalytic oxidation reaction. The organic material is completely removed by oxidizing and decomposing the aerated gas using the combustion apparatus 400.

  Although not shown, the combustion apparatus 400 may have a configuration in which a heat exchanger is added after the heat exchanger 410 to exchange heat between water vapor and clean gas supplied to the water treatment apparatus. By the heat exchange, the temperature of the steam rises, the desorption efficiency in the water treatment device is improved, the volume of concentrated water is reduced, and the concentration rate is improved. Although not shown, the gas supplied to the aeration apparatus instead of water vapor may be heat exchanged by a heat exchanger. It is because aeration efficiency increases.

  FIG. 8 is one of the system configuration diagrams of the water treatment system in the embodiment of the present invention. As shown in FIG. 8, the water treatment system in the present embodiment may mainly include a water treatment device 100, a water treatment device 200, and a waste liquid combustion device 500.

  The waste liquid combustion apparatus 500 is an apparatus for processing the concentrated water 2 discharged from the water treatment apparatus 200. As shown in FIG. 9, a liquid sprayer 510, a combustion furnace 520, a burner 530, and a gas supplier 540. The concentrated water 2 is sprayed in a mist form by the liquid sprayer 510, mixed with the air supplied from the gas supply unit 540, supplied to the combustion furnace 520, and burned at a high temperature in the burner 530, whereby the organic substance is It is decomposed and released into the atmosphere as clean gas. By directly burning the concentrated water 2 using the waste liquid combustion apparatus 500, the organic substances are completely removed.

  Although not shown, in the waste liquid combustion apparatus 500, instead of supplying the concentrated water 2, the desorption gas is not condensed by the condenser 230 of the water treatment apparatus 200, and the combustion furnace 520 is directly connected without using the liquid sprayer. A desorption gas may be supplied. This is because a condenser and a liquid sprayer are not necessary.

  Although not shown, the waste liquid combustion apparatus 500 may have a configuration in which a heat exchanger is connected to the clean gas line to exchange heat between the air supplied from the gas supply unit 540 and the steam supplied to the water treatment apparatus and the clean gas. good. This is because the heat exchange increases the temperature of air and water vapor, improving the treatment efficiency of the waste liquid combustion apparatus, improving the desorption efficiency of the water treatment apparatus, and increasing the concentration ratio.

  Although it does not specifically limit as an organic substance which can be processed with the water treatment system of this invention contained in the to-be-processed water of this invention, Acetone, 1, 4- dioxane, 2-methyl- 1, 3- dioxolane, 1, 3 -Dioxolane, tetrahydrofuran, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethanol, n-propyl alcohol, isopropyl alcohol, acetic acid, phenol, acrylonitrile, dichloromethane, 1,2-dichloroethane, trichloroethylene, N-methyl-2-pyrrolidone , Dimethylacetamide, N, N-dimethylformamide and the like.

  2 to 9, the concentrated water discharged from the water treatment device (water treatment device 100 in FIG. 2) is converted into another water treatment device (water treatment device 200 in FIG. 2). By re-concentrating, it is possible to concentrate organic substances in the water to be treated with high efficiency while maintaining high removal efficiency of organic substances from the water to be treated. The increase can be prevented.

  The characteristic configurations of the embodiments of the present invention described above with reference to FIGS. 2 to 9 can be combined with each other.

  Further, in the embodiments of the present invention described above, the description has been made without particularly showing the constituent elements 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 to 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.

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.
(Organic substance removal effect)
The water to be treated was 1,4-dioxane 1 mg / L. The removal effect was confirmed by measuring the 1,4-dioxane concentration of the water treatment device, the aeration device, and the combustion device after 500 hours of operation.
(Organic substance concentration evaluation)
Each water and gas was analyzed and measured by gas chromatography.

[Example 1]
As the system, the embodiment shown in FIGS. 4 and 5 was used.
The water treatment apparatus 100 is filled with activated carbon fibers having a BET specific surface area of 1650 m ² / g as an adsorbent in each treatment tank in a weight of 130 kg and treated water containing 1 mg / L of 1,4-dioxane is 100 m ³ / h. Was introduced to obtain treated water.

  Next, water at 120 ° C. was supplied to the adsorbent to remove (dehydrate) adhering water from the adsorbent, and the removed water was returned to the water to be treated of the water treatment apparatus 100. Subsequently, desorption was performed by supplying water vapor at 120 ° C. to the adsorbent. The water vapor used for desorption and 1,4-dioxane desorbed from the adsorbent were liquefied in a condenser and discharged as concentrated water. The amount of water vapor used for dehydration and desorption was 627 kg / h. The adsorption time was set to 20 min and a switching cycle was set. The 1,4-dioxane concentration in the treated water at that time could be removed to 0.005 mg / L or less. Concentrated water was 700 L / h, and was concentrated about 142 times as much as the water to be treated of the water treatment apparatus 100.

Next, activated carbon fibers having a BET specific surface area of 1650 m ² / g as an adsorbent are filled in the water treatment device 200 in a weight of 3.5 kg in each treatment tank, and the concentrated water discharged from the water treatment device 100 is treated water. As a result, treated water was obtained. The treated water discharged from the water treatment apparatus 200 was mixed with the treated water of the water treatment apparatus 100, returned to the treated water supplied to the water treatment apparatus 100, and reprocessed.

  Next, water at 120 ° C. was supplied to the adsorbent to remove (dehydrate) adhering water from the adsorbent, and the removed water was returned to the water to be treated in the water treatment apparatus 200. Next, water vapor at 120 ° C. was supplied to the adsorbent to perform desorption. The water vapor used for desorption and 1,4-dioxane desorbed from the adsorbent were liquefied in a condenser and discharged as concentrated water. The amount of water vapor used for dehydration and desorption was 17 kg / h. The adsorption time was set to 20 min and a switching cycle was set. The concentrated water was concentrated at about 37 times the water to be treated of the water treatment apparatus 200 (concentrated water of the water treatment apparatus 100) at a water amount of 19 L / h.

As shown in Table 2, the water treatment device 100 and the water treatment device 200 of this example can reduce the amount of water to be treated of 100 m ³ / h to 19 L / h, and can be concentrated at a concentration factor of 5200 times or more. It was.

  Next, the concentrated water discharged from the water treatment device 200 is supplied to the aeration device 300, and heated while supplying water vapor so that the concentration of water to be treated in the water treatment device 100 is 1,4-dioxane or less. Aeration treatment was performed. The discharged aerated treated water was returned to the treated water of the water treatment apparatus 100. The amount of water vapor at that time was 73 kg / h.

  Next, the aeration gas discharged from the aeration apparatus 300 is supplied to an electric heater type catalytic oxidation apparatus provided with a platinum catalyst as the combustion apparatus 400 to oxidize and decompose 1,4-dioxane in the aeration gas by 99% or more. Processed to let.

  As shown in Table 1, as an organic substance removal effect, the water purified by the water treatment system of this example can be treated with a 1,4-dioxane concentration of 0.005 mg / L or less in the treated water even after 500 hours. It was possible. As shown in Table 3, the total amount of water vapor used in this example was 717 kg / h, and the electric power used for the electric heater of the combustion device 400 was 8 kW.

[Example 2]
As a system, a water treatment device 201 was further added to the subsequent stage of the water treatment device 200 of Example 1.
The water treatment apparatus 201 is filled with activated carbon fibers having a BET specific surface area of 2000 m ² / g as an adsorbent in each treatment tank in a weight of 0.5 kg, and the concentrated water discharged from the water treatment apparatus 200 of Example 1 is treated. Treated water was obtained by supplying as water. The treated water discharged from the water treatment device 201 was returned to the treated water supplied to the water treatment device 100, mixed and reprocessed.

  Next, water at 120 ° C. was supplied to the adsorbent to remove (dehydrate) adhering water from the adsorbent, and the removed water was returned to the water to be treated in the water treatment apparatus 200. Next, water vapor at 120 ° C. was supplied to the adsorbent to perform desorption. The water vapor used for desorption and 1,4-dioxane desorbed from the adsorbent were liquefied in a condenser and recovered as concentrated water. The amount of water vapor used for dehydration and desorption was 4 kg / h. The adsorption time was set to 20 min and a switching cycle was set. Concentrated water was 4 L / h, and was concentrated about four times as much as the water to be treated of the water treatment apparatus 201 (concentrated water of the water treatment apparatus 200).

As shown in Table 2, the water treatment apparatus 100, the water treatment apparatus 200, and the water treatment apparatus 201 of this example can reduce the volume of water to be treated of 100 m ³ / h to 4 L / h, and the concentration rate is 25000 times or more. It was possible to concentrate.

  Next, the concentrated water discharged from the water treatment apparatus 201 is supplied to the aeration apparatus 300 and heated while supplying water vapor so that the concentration of the water to be treated in the water treatment apparatus 100 is not more than 1,4-dioxane concentration. Aeration treatment was performed. The discharged aerated treated water was returned to the treated water of the water treatment apparatus 100. At that time, the amount of water vapor was 16 kg / h.

  Next, the aeration gas discharged from the aeration apparatus 300 is supplied to an electric heater type catalytic oxidation apparatus provided with a platinum catalyst as the combustion apparatus 400 to oxidize and decompose 1,4-dioxane in the aeration gas by 99% or more. Processed to let.

  As shown in Table 1, as an organic substance removal effect, the water purified by the water treatment system of this example can be treated with a 1,4-dioxane concentration of 0.005 mg / L or less in the treated water even after 500 hours. It was possible. Further, as shown in Table 3, the total amount of water vapor used in this example was 664 kg / h, and the power used for the electric heater of the combustion apparatus 400 was 2 kW.

[Reference example]
Concentrated water discharged from the water treatment apparatus 100 in Example 1 is supplied to the aeration apparatus 300, and the heated aeration process is performed while supplying water vapor so that the 1,4-dioxane concentration is 1 mg / L or less. It was. The discharged aerated treated water was returned to the treated water of the water treatment apparatus 100. The amount of water vapor at that time was 671 kg / h.

  Next, the aeration gas discharged from the aeration apparatus 300 is supplied to an electric heater type catalytic oxidation apparatus provided with a platinum catalyst as the combustion apparatus 400 to oxidize and decompose 1,4-dioxane in the aeration gas by 99% or more. Processed to let. The power at that time was 64 kW.

  The water purified by the water treatment system shown in the reference example was able to be treated at 1,5-dioxane concentration of 0.005 mg / L or less even after 500 hours, as shown in Table 3, The total amount of water vapor used was 1300 kg / h, and the power used for the electric heater of the combustion apparatus 400 was 64 kW.

  The water treatment system obtained by the present invention basically does not require replacement of the adsorbent, continuously removes organic substances in water with high efficiency, and reduces the volume of treated water and the concentration of organic substances. By collecting the concentrated water concentrated at a magnification and subjecting the concentrated water to secondary treatment, the secondary treatment equipment can be downsized and water treatment can be efficiently performed at low cost. It ’s big.

DESCRIPTION OF SYMBOLS 100: Water treatment apparatus 110: 1st process tank 111: Adsorbent 120: 2nd process tank 121: Adsorbent 130: Condenser 200: Water treatment apparatus 210: 1st process tank 211: Adsorbent 220: 2nd process tank 221: Adsorbent 230: Condenser 300: Aeration device 310: Aeration tank 320: Gas supply device 400: Combustion device 410: Heat exchanger 420: Heating furnace 500: Waste liquid combustion device 510: Liquid sprayer 520: Combustion furnace 530: Burner 540: Gas supply

Claims (12)

Organic substances are adsorbed and removed by bringing the water to be treated containing organic substances into contact with the adsorption element, and the adsorbed organic substances are desorbed by bringing water vapor into contact with the adsorption element, and this desorbed gas is liquefied and condensed to be higher than the treated water. A water treatment system comprising two or more water treatment devices that continuously perform adsorption, desorption, and condensation to obtain concentrated water containing a concentration of organic substances,
Concentrated water discharged by treating the water to be treated with the water treatment device at the preceding stage is supplied to the at least one other water treatment device installed at the subsequent stage of the water treatment device and treated. The concentrated water discharged from the subsequent water treatment device is higher in concentration than the concentrated water discharged from the previous water treatment device .
The water treatment device is configured to remove excess water adhering to the adsorption element using water vapor between the adsorption and the desorption, and to discharge the water as removed water, and using the water vapor It is configured to shift to the desorption after heating of the adsorption element,
The water treatment device arranged at the last stage of the water treatment device is a water treatment system that discharges the desorption gas with concentrated water or as the desorption gas . The water treatment system according to claim 1 , wherein the removed water is returned to the treated water.   The water treatment system according to claim 1 or 2, wherein the adsorption element includes at least one member selected from the group consisting of activated carbon, activated carbon fiber, and zeolite. The treated water discharged from the water processing apparatus for processing a concentrated water, the water treatment system according configured to claim 1, any one of 3 to be returned the to the water to be treated. The water to be treated was heat exchange, water treatment system according to claim 1 configured to obtain a liquefied condensed into concentrated water desorption gas discharged in any one of 4 from the water treatment system. The suction device, water treatment system according to any one of 5 different claims 1 to each of the water treatment system. Downstream of the water treatment system according to any one of claims 1 to 6, and aeration device for volatilization removal of organic matter and water is contacted with a gas, a combustion apparatus for decomposing organic matter by heating the gas wherein the concentrated water or decompose the organic material in the desorption gas, configured water treatment systems so as to discharge the cleaned gas is discharged from the water treatment system. The water treatment system of claim 7, wherein configured to aeration treatment water discharged from the aeration device is returned to the pre Kisui processor. The water treatment system according to claim 7 or 8 , wherein the clean gas discharged from the combustion device is heat-exchanged to increase the temperature of water vapor supplied to the water treatment device. The water treatment system according to any one of claims 7 to 9 , wherein heat treatment is performed on clean gas discharged from the combustion device, and the temperature of the gas supplied to the aeration device is increased. Organic substances are adsorbed and removed by bringing the water to be treated containing organic substances into contact with the adsorption element, and the adsorbed organic substances are desorbed by bringing water vapor into contact with the adsorption element, and this desorbed gas is liquefied and condensed to be higher than the treated water. A water treatment system comprising two or more water treatment devices that continuously perform adsorption, desorption, and condensation to obtain concentrated water containing a concentration of organic substances,
Concentrated water discharged by treating the water to be treated with the water treatment device at the preceding stage is supplied to the at least one other water treatment device installed at the subsequent stage of the water treatment device and treated. The concentrated water discharged from the subsequent water treatment device is higher in concentration than the concentrated water discharged from the previous water treatment device.
The water treatment device arranged at the last stage of the water treatment device is configured to discharge the desorption gas with concentrated water or as a desorption gas,
A waste liquid combustion apparatus that heats the concentrated water or desorption gas discharged from the water treatment device arranged at the last stage to decompose organic substances in the concentrated water or the desorption gas and discharge clean gas , Water treatment system.   The water treatment system according to claim 11, wherein the clean gas discharged from the waste liquid combustion apparatus is heat-exchanged to raise the temperature of water vapor supplied to the water treatment apparatus.