JP2002273434A - Treating device and treating method for ionic substance- containing water using activated carbon electrode and regenerating method of activated carbon electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of treating an ionic substance-containing water using an activated carbon electrode which efficiently adsorbs ions which are included in water to be treated, conveniently and surely removes the ions which are adsorbed on electrodes and can regenerate the electrode, a regenerating method of the activated carbon electrode and a treating device for the ionic substance-containing water. SOLUTION: Solid activated carbon electrodes 1, 2 are disposed in a treating water vessel 6 and releasing electrodes 3, 4 for having no ionic adsorbability are disposed on both outer sides of the solid activated carbon electrodes and, in the electric double layer adsorption treatment, a direct current power source 7 is connected with the solid activated carbon electrode. In the regeneration of the solid activated carbon electrodes which adsorb an ionic substance, the ionic substance is released by short- circuiting between the solid activated carbon electrodes (8c-8d), thereafter, a direct current power source is connected with the releasing electrodes so as to invert the polarity, furthermore, the ionic substance is moved from the solid activated carbon electrodes and the solid activated carbon electrodes are thus surely regenerated with a simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for electrically purifying ionic substance-containing water. More particularly, the present invention relates to a method for converting ionic substances from water to be treated containing ions to a solid activated carbon electrode having a high surface area. The present invention relates to a method for purifying by double-layer adsorption, a method for regenerating the solid activated carbon electrode, and an apparatus for treating ionic substance-containing water.

[0002]

2. Description of the Related Art Conventionally, as a method for purifying ionic substances in a liquid, 1) a method of pressure filtration using a reverse osmosis membrane, 2) a large number of ion exchange membranes disposed between electrodes, There are known an electrodialysis method in which ions are separated by electrophoresis, 3) a method of adsorbing on an ion exchange resin, and 4) a method of heating and distilling.

[0003] However, these methods consume a large amount of energy, are expensive in membranes and resins, complicate washing and regeneration steps, and require chemicals. There is a problem that the material is vulnerable to clogging or the like caused by the substance.

As a method for solving the above problem, ion adsorption by an electric double layer has been proposed. For example, in Japanese Patent Application Laid-Open No. H5-258992, a large number of high surface area conductive layers,
A method using a flow-through capacitor in which a non-conductive layer is spirally wound is shown. Also, Japanese Patent Application Laid-Open No. 6-32598
In JP-A No. 3 (1999) -1995, there is disclosed a plate-shaped liquid-flow type electric double-layer capacitor having a configuration in which an activated carbon layer is disposed with a non-conductive liquid-permeable sheet interposed therebetween and a collector electrode is disposed outside the activated carbon layer.

[0005]

However, these methods have practical problems in any case. That is, in the method described in Japanese Patent Application Laid-Open No. H5-258992, there is a problem in that since the device has a complicated spiral structure, drift is likely to occur when the liquid is passed and the ability is not stable. Also,
In the method described in JP-A-6-325983, the drift is improved, but in both cases, when the activated carbon is regenerated, the liquid is passed while the circuit including the capacitor is short-circuited. In the method, ions adsorbed on the activated carbon cannot be forcibly discharged, and there is a problem that ions remain.

As a method of more completely releasing the ions in the activated carbon, it is conceivable to invert the polarity of the circuit at the time of adsorption and reversely charge the capacitor to release the ions by electric repulsion. Immediately after the start of the reverse charging, the ions start to move to the activated carbon of the pair after the polarity inversion, and are adsorbed again. Therefore, there is a problem that the residual ratio of the ions adsorbed to the activated carbon becomes larger than that of the method by the circuit short circuit. In both cases, measures such as increasing the volume of the activated carbon part in order to increase the amount of ion adsorption or using a configuration including a plurality of unit capacitors are conceivable. Becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its main object to efficiently and efficiently adsorb ions contained in water to be treated and to easily and reliably adsorb ions adsorbed on an electrode. An object of the present invention is to provide a method for treating ionic substance-containing water using an activated carbon electrode capable of removing and regenerating an electrode, a method for regenerating the activated carbon electrode, and a treatment apparatus for treating ionic substance-containing water.

[0008]

In order to achieve the above object, a method for treating ionic substance-containing water according to the present invention is directed to a method for purifying an ionic substance contained in water to be treated by electric double layer adsorption. A treatment tank, comprising one or more pairs of solid activated carbon electrodes and a pair of discharge electrodes having no ion-adsorbing ability, and when treating the water to be treated, supplying a DC power supply to the pair of solid activated carbon electrodes. To connect the ionic substance to the electric double layer, and to regenerate the solid activated carbon electrode to which the ionic substance is adsorbed, after short-circuiting the pair of solid activated carbon electrodes, discharge the DC power supply. The ionic substance is released from the solid activated carbon electrode by connecting to an electrode for use.

In the present invention, it is preferable that the solid activated carbon electrode contains an activated carbon / carbon composite material, the activated carbon contains activated carbon powder or activated carbon fiber, and the carbon composite material contains a phenolic carbide composite material.

In the present invention, when the solid activated carbon electrode is regenerated, the water to be treated having the ionic substance adsorbed thereon is discharged, and water for regeneration is injected into the treatment tank from a water tank for regeneration provided in advance. Then, the solid activated carbon electrode is regenerated, and when the regeneration is completed, the regenerating water is transferred to the regenerating water tank again.

In the present invention, the pair of discharge electrodes are disposed on both outer sides of the pair of solid activated carbon electrodes, and the polarities of the electrodes are reversed between the discharge electrode and the solid activated carbon electrodes. It can be configured to be set so that

Further, in the present invention, a plurality of pairs of the solid activated carbon electrodes may be provided, and each pair may be sequentially selected and connected to the DC power supply to perform an adsorption process.

[0013] The treatment apparatus for ionic substance-containing water of the present invention is a treatment apparatus for purifying ionic substances in water to be treated by adsorbing an electric double layer, wherein the treatment tank and one or more pairs of solid activated carbon are formed. An electrode, a pair of discharge electrodes having no ion-adsorbing ability, a DC power supply, a switching unit for selecting an electrode connected to the DC power supply, and a circuit for short-circuiting the pair of solid activated carbon electrodes to each other. At least, when treating the water to be treated, the DC power source and the solid activated carbon electrode forming the pair are connected, the ionic substance is adsorbed by the electric double layer, and the solid activated carbon adsorbed by the ionic substance is When the electrodes are regenerated, the pair of solid activated carbon electrodes is short-circuited by the short circuit, and the switching means connects the DC power supply and the discharge electrode to form the solid active carbon electrode. The ionic material from the electrode is intended to be released.

That is, in order to solve the above-mentioned problems, the present invention provides an electric double layer adsorption of ions in the water to be treated by a treatment apparatus using solid activated carbon for both electrodes, and when the activated carbon adsorption is saturated, the solid activated carbon electrode is used. Short circuit including
Thereafter, by applying a current to the discharge electrodes arranged on both outer sides of the solid activated carbon electrode, the adsorbed ions are released with high efficiency to regenerate the solid activated carbon at both electrodes.

By using the above-described solid activated carbon, it is possible to form a thin plate-shaped solid activated carbon electrode having an adsorption performance per volume equal to or higher than that of powdered activated carbon. Can be generated. Therefore, ions in water can be adsorbed without using an ion-exchange membrane or the like which is expensive and may be blocked due to salt precipitation or the like.

Further, when a plurality of unit capacitors are provided in order to increase the amount of ion adsorption, the unit capacitors are divided and not energized at the same time, so that the amount of ion adsorption can be increased without enlarging the power supply. Can be.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In a preferred embodiment of the method for treating water containing ionic substances according to the present invention, a solid activated carbon electrode and a discharge electrode having no ion-adsorbing ability on both outer sides thereof are provided in a treatment water tank. An electrode is provided.In the electric double layer adsorption treatment, a DC power supply is connected to the solid activated carbon electrode by a changeover switch, and in the regeneration of the solid activated carbon electrode having adsorbed an ionic substance, the solid activated carbon electrode is short-circuited to ionize. After releasing the ionic substance, a DC power supply is connected to the discharge electrode by a changeover switch to further move the ionic substance from the solid activated carbon electrode,
The solid activated carbon electrode can be reliably regenerated with a simple structure, and the adsorption capacity of the solid activated carbon electrode can be maintained high by repeating this adsorption / regeneration.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

Embodiment 1 First, a method for treating ionic substance-containing water using a solid activated carbon electrode, a method for regenerating a solid activated carbon electrode, and an apparatus for treating ionic substance-containing water according to a first embodiment of the present invention. Will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically showing the structure of the ionic substance-containing water treatment apparatus according to the present embodiment. In FIG. 1, 1-2 are solid activated carbon electrodes, 3-4 are discharge electrodes,
Is the water to be treated, 6 is a treatment tank, 7 is a DC power supply, and 8a to 8a.
f is a switch contact for switching the state of the circuit of the DC power supply. In addition, the to-be-processed water 5 contains ions, the to-be-processed water 5 is injected into the treatment water tank 6, and the electric double layer adsorption and desalination treatment of the ionic substance is performed. This procedure will be described below.

First, a switch for selecting an electrode to be energized is connected to the DC power source 7. The switch is adjusted to connect the circuit contacts 8a and 8c, 8b and 8d, and the solid activated carbon electrode 1 is used as an anode. Electric double layer adsorption is performed using the solid activated carbon electrode 2 as a cathode. Then, most of the anions contained in the water 5 to be treated are attracted to the anode (solid activated carbon electrode 1), and the cations are attracted to the cathode (solid activated carbon electrode 2). Cations are adsorbed on the surface of solid activated carbon. Then, after the ions contained in the water 5 to be treated are adsorbed until the activated carbon is saturated, the solid activated carbon electrode is regenerated by releasing the ions.

Upon release of the ions, the treated water 9 having been subjected to the adsorption treatment is discharged through a discharge line 10, and instead, the concentrated water 11 is injected from a concentrated water tank 13 through a concentrated water transfer line 12. Next, the switch contacts 8c and 8d are connected, the circuit is short-circuited, ions are released from the electric double layer capacitor, and the solid activated carbon electrodes 1, 2 are made electrically neutral. Thereafter, the switch contacts 8a and 8e, 8b and 8
By connecting f, anions remaining on the anode (solid activated carbon electrode 1) and cations remaining on the cathode (solid activated carbon electrode 2) move toward the discharge electrodes 3, 4.

Since the discharge electrodes 3 and 4 are formed of a material having no ion-adsorbing ability, for example, a metal or the like, the ions discharged from the solid activated carbon electrodes 1 and 2 float in water, and the concentrated water 11 The ion concentration inside increases, and the amount of ions adsorbed on the solid activated carbon electrodes 1 and 2 decreases. After the regeneration of the solid activated carbon electrodes 1 and 2 by the release of ions, the concentrated water 11 having the increased ion concentration is transferred again to the concentrated water tank 13 through the concentrated water transfer line 12. Thereafter, the same procedure is repeated until the salt concentration of the concentrated water 11 becomes close to supersaturation. When the salt concentration of the concentrated water 11 becomes close to supersaturation, the concentrated water 11 is discharged through the concentrated water discharge line 14.

As described above, according to the method for treating ionic substance-containing water, the method for regenerating a solid activated carbon electrode, and the apparatus for treating ionic substance-containing water according to the present embodiment, the solid activated carbon electrode 1 until the adsorbed ions are saturated. 2, the anion and the cation are adsorbed in the electric double layer, and when saturated, the condensed water 11 is introduced into the treatment tank 6 to short-circuit the solid activated carbon electrodes 1 and 2 to release the adsorbed ions and to release the solid activated carbon. Electricity is supplied to the discharge electrodes 3 and 4 having no ion-adsorbing ability provided on both outer sides of the electrodes 1 and 2 so that the solid activated carbon electrodes 1 and
By further moving ions from 2, the solid activated carbon electrode can be regenerated with high efficiency.

The arrangement of the solid activated carbon electrodes 1 and 2 and the discharge electrodes 3 and 4 is not limited to the configuration shown in FIG.
The polarity of the electrodes may be reversed, and between the solid activated carbon electrodes or in a direction orthogonal to the pair of solid activated carbon electrodes (for example, in a case where the solid activated carbon electrodes are opposed to the left and right directions in the drawing, the direction orthogonal to the paper surface). May be arranged. Further, the voltages supplied during adsorption and release may be the same or different.

Further, the short-circuiting of the solid activated carbon electrodes 1 and 2 and the switching of the connection of the DC power source 7 may be performed manually, but a sensor for detecting the ion concentration of the condensed water 11 is installed in the water tank 6 for treatment. It is also possible to adopt a configuration in which the connection is automatically switched in conjunction with the output from the server.

Embodiment 2 Next, a method and an apparatus for treating ionic substance-containing water using a solid activated carbon electrode according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a structure in which a plurality of capacitors are provided in the device in order to enhance the ability to adsorb ions in the ionic substance adsorption method using solid activated carbon.

In FIG. 2, 15 is a solid activated carbon electrode capacitor unit, 16 is a DC power supply, 17 is a power-switch contact (a is for an anode, and b is for a cathode). Rotate. Reference numeral 18 denotes a switch panel (a is for an anode, b is for a cathode), 19 is a switch (a is for an anode, b is for a cathode), 20a to 20d are solid activated carbon electrode capacitor unit-switch contacts, and the end of the broken line Is connected to the solid activated carbon electrode capacitor unit 15. 21 is a treated water tank and 22 is water to be treated.

The to-be-treated water 22 is poured into the treated water tank 21,
The electric double layer adsorption and desalination treatment of the ionic substance is performed. At this time, the switches 19a and 19b are connected to the solid activated carbon electrode formed adjacently in pairs and connected to the solid activated carbon electrode capacitor unit-switch contact 20a, 20b
Power supply-switch contacts 17a, 17b
Are rotated on the switch boards 18a and 18b.

When one solid activated carbon electrode capacitor unit 15 is saturated, the switches 19a and 19b are sequentially switched so as to be connected to the other solid activated carbon electrode capacitor unit-switch contacts 20c and 20d. At this time, the solid activated carbon electrode capacitor unit 15 connected to the solid activated carbon electrode capacitor unit-switch contacts 20a and 20b released from the DC power supply 16 keeps adsorbing ions on the electric double layer. The same operation is repeated until all the solid activated carbon electrode capacitor units 15 are saturated.

As described above, when a plurality of pairs of solid activated carbon electrode capacitor units are provided in order to enhance the ion adsorption capacity, a switch panel for selecting a capacitor unit pair is used instead of operating these capacitor units at once. 19a and 19b are sequentially rotated so that the DC power
, It is possible to increase the ion adsorption capacity without increasing the size of the DC power supply 16.

In this embodiment, the regeneration of the solid activated carbon electrode is not described. However, a discharge electrode is provided on both outer sides of the solid activated carbon electrode capacitor unit or between adjacent capacitor unit pairs, and the concentrated water is supplied. After introduction,
By short-circuiting each capacitor unit pair and supplying current to the discharge electrode, the solid activated carbon electrode can be regenerated in the same manner as in the first embodiment.

Further, when adsorbing ions or regenerating a solid activated carbon electrode, the water to be treated and the water for concentration may be stirred to increase the reaction efficiency.

[0033]

As described above, according to the method for treating ionic substance-containing water using the activated carbon electrode, the method for regenerating the activated carbon electrode, and the apparatus for treating ionic substance-containing water according to the present invention, solid activated carbon can be used. The treatment equipment used for both electrodes adsorbs ionic substances in the electric double layer, and when the activated carbon adsorption is saturated, shorts the circuit including the solid activated carbon electrode, and then reduces the ion adsorption capacity arranged on both sides of the solid activated carbon electrode. By energizing the discharge electrode that does not have the electrode, the adsorbed ions can be released with high efficiency to regenerate the solid activated carbon.

Further, when a plurality of solid activated carbon electrodes are included, they are not divided at the same time, but are divided and energized, so that it is possible to maintain the miniaturization of the power supply and increase the adsorption capacity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a structure of an apparatus for treating ionic substance-containing water according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing a structure of an apparatus for treating ionic substance-containing water according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Solid activated carbon electrode (anode) 2 Solid activated carbon electrode (cathode) 3 Emission electrode (anode) 4 Emission electrode (anode) 5 Water to be treated 6 Treatment tank 7 DC power supply 8a to 8f Switch for switching circuit state Contact 9 Treated water 10 Release line 11 Concentration water 12 Concentration water transfer line 13 Concentration water tank 14 Concentration water discharge line 15 Solid activated carbon electrode capacitor unit 16 DC power supply 17a Power supply-switch contact (for anode) 17b Power supply-switch contact (for cathode) 18a Switch board (for anode) 18b Switch board (for cathode) 19a Switch (for anode) 19b Switch (for anode) 20a-20d Solid activated carbon electrode capacitor unit
Switch contact 21 Treated water tank 22 Treated water

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takayuki Saito 5-7-1 Shiba, Minato-ku, Tokyo Within NEC Corporation (72) Inventor Masaru Masawa 1933-1033 Shimonumabe, Nakahara-ku, Kawasaki-shi, Kanagawa NEC Environmental Engineering Co., Ltd. (72) Inventor Toru Suganuma 1933-10 Shimonumabe, Nakahara-ku, Kawasaki-shi, Kanagawa F-term within NEC Environmental Engineering Co., Ltd. 4D024 AA01 AB15 BA02 BB05 BC01 DA04 DA07 DB09 4D061 DA01 DB13 EA10 EB04 EB14 EB19 EB29 EB37 FA06 GA06

Claims (10)

[Claims] 1. A treatment method for purifying an ionic substance contained in water to be treated by electric double layer adsorption, wherein one or more pairs of a solid activated carbon electrode and a pair of non-ion-adsorbing electrodes are provided in a treatment tank. A discharge electrode, and when treating the water to be treated, a DC power supply is connected to the solid activated carbon electrode forming the pair to adsorb the ionic substance in the electric double layer, and the solid adsorbing the ionic substance is provided. When regenerating the activated carbon electrode, after short-circuiting the pair of solid activated carbon electrodes, the DC power supply is connected to the discharge electrode to release the ionic substance from the solid activated carbon electrode. Of water containing a toxic substance. 2. The solid activated carbon electrode comprises an activated carbon / carbon composite material, the activated carbon comprises activated carbon powder or activated carbon fiber, and the carbon composite material comprises a phenolic carbide composite material. The method for treating ionic substance-containing water according to claim 1. 3. When the solid activated carbon electrode is regenerated, the water to be treated to which the ionic substance is adsorbed is discharged, and water for regeneration is injected into the treatment tank from a water tank for regeneration provided in advance. The method for treating ionic substance-containing water according to claim 1, wherein the regeneration of the electrode is performed, and after the regeneration is completed, the regeneration water is transferred to the regeneration water tank again. 4. The pair of discharge electrodes are disposed on both outer sides of the pair of solid activated carbon electrodes, and the polarities of the electrodes are set to be opposite between the discharge electrode and the solid activated carbon electrode. The method for treating ionic substance-containing water according to any one of claims 1 to 3, wherein the ionic substance-containing water is treated. 5. The method according to claim 1, wherein a plurality of pairs of the solid activated carbon electrodes are provided, and each of the pairs is sequentially selected and connected to the DC power supply to perform an adsorption process. A method for treating ionic substance-containing water according to the above. 6. A treatment apparatus for purifying ionic substances in water to be treated by electric double layer adsorption, comprising: a treatment tank, one or more pairs of solid activated carbon electrodes, and a pair of dischargers having no ion adsorption ability. An electrode, a DC power supply, and switching means for selecting an electrode connected to the DC power supply;
At least a circuit for short-circuiting the pair of solid activated carbon electrodes with each other, and when treating the water to be treated, the DC power supply and the solid activated carbon electrode forming the pair are connected, and the ionic substance is electrically charged. Upon regeneration of the solid activated carbon electrode adsorbed with the double layer and adsorbing the ionic substance, the short-circuit circuit short-circuits the paired solid activated carbon electrodes, and the switching means causes the DC power supply and the discharge electrode to be short-circuited. The apparatus for treating ionic substance-containing water, wherein the ionic substance is discharged from the solid activated carbon electrode when connected. 7. The solid activated carbon electrode includes an activated carbon / carbon composite material, the activated carbon includes activated carbon powder or activated carbon fiber, and the carbon composite material includes a phenolic carbide composite material. 7. An apparatus for treating ionic substance-containing water according to 6. 8. The treatment tank is provided with a discharge path for releasing the treated water to be treated and a regeneration water transfer path connected to a regeneration water tank for storing regeneration water used for regeneration of the solid activated carbon electrode. Upon regeneration of the solid activated carbon electrode,
The water to be treated, to which the ionic substance is adsorbed, is discharged from the release path, regeneration water is injected from the regeneration water tank into the treatment tank, and the solid activated carbon electrode is regenerated. The apparatus for treating ionic substance-containing water according to claim 6 or 7, wherein the regeneration water is transferred to the regeneration water tank again. 9. The pair of discharge electrodes are arranged on both outer sides of the pair of solid activated carbon electrodes, and the polarity of the electrodes is set to be opposite between the discharge electrodes and the solid activated carbon electrodes. The ionic substance-containing water treatment apparatus according to claim 6, wherein the ionic substance-containing water is treated. 10. The method according to claim 6, wherein a plurality of said pairs of solid activated carbon electrodes are provided, and said switching means selects said pair of solid activated carbon electrodes sequentially to perform ion adsorption. An apparatus for treating ionic substance-containing water according to claim 1.