KR101914027B1 - Method for electrochemical water treatment using carbon electrodes and system thereof - Google Patents

Abstract

The present invention relates to a method and system for electrochemical water treatment using a carbon electrode. (A) adsorbing and concentrating a nitrogen compound in water on the surface of the pair of carbon electrodes by applying a direct current power of 1.4 V or less to the pair of carbon electrodes; And (b) reversing the polarity of the DC power source to the carbon electrode pair and raising the DC power source to 1.4 V or more to convert the nitrogen compound adsorbed and concentrated on the electrode to nitrogen gas form .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an electrochemical water treatment method and system using a carbon electrode,

The present invention relates to a method and system for electrochemical water treatment using a carbon electrode. More particularly, the present invention relates to a process for producing a carbon electrode which can be carried out in the same reaction tank by using a carbon electrode, a pretreatment process for adsorbing and concentrating a nitrogen compound, and an electrochemical oxidation and reduction process for converting a nitrogen compound into a nitrogen gas, And an electrochemical water treatment method and system using the same.

Nitrogen compounds present in water such as wastewater and drinking water not only cause various environmental problems such as eutrophication but also have a bad influence on human health such as cyanosis when drinking water containing a large amount of nitrogen compounds.

Various treatment methods have been studied and developed in order to eliminate them. General techniques that are currently used for the removal of nitrogen compounds in the water include biological treatment techniques, physical treatment techniques such as ammonia removal, chemical treatment techniques such as catalytic wet air oxidation, treatment using ion exchange processes, RO membranes And various electrochemical treatment techniques such as electrolysis using an electrolytic electrode are known.

In the case of biological treatment technology, it is affected by external environment such as temperature and presence of toxic substances in water. In case of treatment system, it takes up a lot of installation site and requires considerable skill in operation. The ammonia removal method has a disadvantage that it is difficult to meet the required water quality standards because the treatment cost is low but the treatment effect is small. In the case of the treatment method using the ion exchange process, there is a problem that the treatment method and operation are simple, but harmful chemicals for regeneration of the ion exchange resin are used and a regenerated waste liquid containing a high concentration of nitrogen compounds is generated. Membrane treatment requires considerable skill in the management and operation of membranes. In addition, there is a problem of discharging concentrated water containing a high concentration of nitrogen compounds as in the case of ion exchange processes, and disadvantages of using chemicals in order to prevent scaling and fouling of membranes And the operation cost is high due to a large power ratio in the pump operation. In order to overcome the disadvantages of such a treatment method, recently, many treatment methods using an electrochemical reaction have been developed. Electrochemical treatments are characterized by high removal rate and short treatment time regardless of biodegradation of pollutants and are known to be an effective method for the treatment of industrial wastewater. A general electrochemical treatment method is a method of treating ammonia nitrogen through an anodic oxidation reaction and simultaneously treating nitrate nitrogen through a cathodic reduction reaction. The mechanism of elimination reaction through the electrochemical oxidation-reduction reaction of ammonia nitrogen and nitrate nitrogen is as follows.

- Anodic oxidation reaction

- Cathodic reduction reaction

The electrochemical treatment technology using the conventional electrolytic electrode based on the principle of this reaction is a technology for electrochemically converting nitrogen compounds in water into nitrogen gas or the like by electrolysis using an electrolytic electrode continuously or intermittently, There is a disadvantage in that a high-cost electrolytic electrode is used and the energy consumption is very large and the operation cost is very high.

Accordingly, the present invention has been made to solve the above-mentioned problems and it is an object of the present invention to provide an economical underwater nitrogen compound which can reduce removal efficiency of nitrogen compounds contained in wastewater, drinking water and the like, And a method and system for electrochemical water treatment using a carbon electrode as a treatment method.

An object of the present invention is to provide an electrochemical water treatment method using a carbon electrode capable of efficiently and economically removing nitrogen compounds in water.

Another object of the present invention is to provide an electrochemical water treatment method using a carbon electrode with a small installation area of the treatment system and a greatly reduced energy consumption.

Yet another object of the present invention is to provide a system for an electrochemical water treatment method using the carbon electrode capable of performing a process of adsorption and concentration of a nitrogen compound in the same reaction tank and a process of electrochemical oxidation and reduction of a nitrogen compound .

One aspect of the present invention relates to a method of electrochemical water treatment using a carbon electrode. (A) adsorbing and concentrating a nitrogen compound in water on the surface of the pair of carbon electrodes by applying a direct current power of 1.4 V or less to the pair of carbon electrodes; And (b) reversing the polarity of the DC power source to the carbon electrode pair and raising the DC power source to 1.4 V or more to convert the nitrogen compound adsorbed and concentrated on the electrode to nitrogen gas form .

In the electrochemical water treatment method, raw water containing a nitrogen compound is introduced into a first reaction tank in which a direct current power of 1.4 V or less is applied to a pair of carbon electrodes, the nitrogen compound is adsorbed and concentrated on the carbon electrode pair, The treated water is discharged; If the concentration of the nitrogen compound in the treated water exceeds a set value, stopping the introduction and discharge of the raw water containing the nitrogen compound into the first reaction tank; Raw water containing a nitrogen compound is introduced into a second reaction tank to which a direct current power of 1.4 V or less is applied to the carbon electrode pair and the nitrogen compound is adsorbed and concentrated on the carbon electrode pair of the second reaction tank, / RTI > The DC power applied to the carbon electrode pair of the first reaction tank is increased to 1.4 V or higher while the carbon electrode pair of the second reaction tank is adsorbed and concentrated to adsorb and concentrate the nitrogen compound in the carbon electrode pair of the first reaction tank And converting into a form of nitrogen gas.

Another aspect of the present invention relates to an electrochemical water treatment system using a carbon electrode. The electrochemical water treatment system includes a raw water inflow portion into which raw water flows and a treated water discharge portion that discharges treated water to the outside, and is configured to adsorb, concentrate, and remove nitrogen compounds in the raw raw water, A first reaction tank; A DC power supply connected to the pair of carbon electrodes to apply DC power; And a control unit for measuring and controlling a DC power supply value and a current value applied to the pair of carbon electrodes, wherein DC power of 1.4 V or less is applied to the carbon electrode pair from the DC power supply unit.

And the electrolyte supply tank is connected to the first reaction tank to maintain the electrolyte concentration.

And an ion selective electrode sensor for measuring a nitrogen compound concentration in the treated water discharge portion of the first reaction tank.

Wherein the carbon electrode is selected from the group consisting of carbon cloth, activated carbon, carbon aerosol, carbon nanotube, and mixtures thereof.

And the anode and the cathode of the carbon electrode are symmetrical or asymmetric.

Wherein the carbon electrode is impregnated with at least one selected from the group consisting of palladium, zinc, tin, iron and metal oxides.

The electrochemical water treatment system further includes a second reaction tank in which raw water is inputted to the first reaction tank or the second reaction tank alternately and the second reaction tank includes a raw water inflow portion into which raw water flows, Wherein the carbon electrode pair of the second reaction tank is connected to a DC power supply unit to apply a DC power thereto, The DC power supply value and the current value applied to the carbon electrode pair of the second reaction tank are measured and controlled by the control unit and the carbon electrode pair of the second reaction tank is supplied with DC power of 1.4 V or less from the DC power supply unit .

In the electrochemical water treatment system, raw water containing a nitrogen compound is introduced into a first reaction tank in which a direct current power of 1.4 V or less is applied to a pair of carbon electrodes, and the nitrogen compound is adsorbed and concentrated on a pair of carbon electrodes, Water is discharged; If the concentration of the nitrogen compound in the treated water exceeds a set value, stopping the introduction and discharge of the raw water containing the nitrogen compound into the first reaction tank; Raw water containing a nitrogen compound is introduced into a second reaction tank to which a direct current power of 1.4 V or less is applied to the carbon electrode pair and the nitrogen compound is adsorbed and concentrated on the carbon electrode pair of the second reaction tank, / RTI > The DC power applied to the carbon electrode pair of the first reaction tank is increased to 1.4 V or higher while the carbon electrode pair of the second reaction tank is adsorbed and concentrated to adsorb and concentrate the nitrogen compound in the carbon electrode pair of the first reaction tank And converting into a form of nitrogen gas.

Using the electrochemical water treatment method using the carbon electrode according to the present invention, an adsorption and concentration process of a nitrogen compound and an electrochemical oxidation and reduction process of converting a nitrogen compound into a nitrogen gas form can be performed in the same reaction tank It is possible to remove nitrogen compounds in the water by using a carbon electrode which has a high efficiency of removal of nitrogen compounds in the water than the conventional method and has a relatively low cost and a semi-permanent lifetime instead of an expensive consumable electrolytic electrode, It is economical and can greatly reduce the installation area of the treatment system and energy consumption during treatment.

1 illustrates an electrochemical water treatment system using a carbon electrode according to one embodiment of the present invention.
2 illustrates an electrochemical water treatment system using a carbon electrode according to another embodiment of the present invention.
3 illustrates the structure of a pair of carbon electrodes according to one embodiment of the present invention.

One aspect of the present invention relates to an electrochemical water treatment system 200 using a carbon electrode.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a configuration diagram of an electrochemical water treatment system 200 using a carbon electrode according to one embodiment of the present invention. Referring to FIG. 1, an electrochemical water treatment system 200 using a carbon electrode according to the present invention includes a raw water inflow portion 10 into which raw water flows and a treated water discharge portion 70a that discharges treated water to the outside A first reaction tank 40a that adsorbs, concentrates, and removes nitrogen compounds in the raw water, and includes at least one pair of carbon electrodes 100a; A DC power supply unit 80 connected to the pair of carbon electrodes 100a to apply DC power; And a control unit 90 for measuring and controlling a DC power supply value and a current value applied to the carbon electrode pair 100a and the carbon electrode pair 100a is connected to the DC power supply unit 80 at a voltage of 1.4 V Or less can be applied.

In the raw water inflow section 10, raw water containing a nitrogen compound flows. The nitrogen compound may include ammonia (NH4 +) ions or nitric acid (NO3-) ions in water.

The first reaction tank 40a may include at least one pair of carbon electrodes 100a, and may perform an adsorption and concentration process of a nitrogen compound and an electrochemical removal process of a nitrogen compound.

3 shows the structure of the carbon electrode pair 100 constituting the first reaction tank 40a according to one embodiment of the present invention. Referring to FIG. 3, the pair of carbon electrodes 100 may include at least one pair of carbon electrodes 101 of an anode and a cathode. The carbon electrode 101 may include a current collector 102. As the material of the carbon electrode 101, carbon cloth, activated carbon, carbon aerosol, carbon nanotube, or the like can be used, but it is not necessarily limited thereto. These may be used alone or in combination of two or more.

The current collector 102 has excellent conductivity and may be used conventionally. For example, titanium, graphite foil, stainless steel, or the like can be used. The anode and the cathode of the carbon electrode 101 may be symmetrical or asymmetric. The carbon electrode 101 may be impregnated with at least one selected from palladium, zinc, tin, iron, and metal oxides. 3, the materials may be impregnated into both the pair of carbon electrodes 101 of the positive electrode and the negative electrode, or may be impregnated on the surface of the pair of the carbon electrodes 101 of the pair of the positive electrode and the negative electrode. . If the carbon electrode 101 is impregnated with the above-mentioned material, the electrochemical oxidation-reduction reaction of the nitrogen compound in water can be further promoted, and the object of the present invention can be easily achieved.

A direct current power of 1.4 V or less can be applied to the surface of the carbon electrode 100. When the direct current power of the above range is applied to the surface of the carbon electrode 100 in the above range, the ions constituting the nitrogen compound in the water can be adsorbed and concentrated on the surface of the electrode using the principle of the electric double layer. When a direct current power of more than 1.4 V is applied, an adsorption reaction does not occur and an electrochemical oxidation-reduction reaction occurs, so that the adsorption does not proceed on the carbon electrode 100, The surface of the carbon electrode 100 is covered with the surface of the carbon electrode 100, thereby remarkably lowering the adsorption efficiency and accelerating the deterioration of the carbon electrode 100.

When the adsorbed and concentrated nitrogen compound in the water is saturated, the voltage of the carbon electrode 100 is reversely applied to reverse the polarity, and a voltage of 1.4 V or more is applied to the saturated nitrogen compound in the form of nitrogen gas And can be removed. At this time, when the DC power source of less than 1.4 V is applied, the conditions for causing an electrochemical oxidation and reduction reaction in which the nitrogen compound in the water is converted into the nitrogen gas are not enough and the object of the present invention can not be achieved.

The treated water discharging portion 70a of the first reaction tank 40a may be provided with an ion selective electrode sensor 50a for measuring the nitrogen compound concentration. The ion selective electrode sensor 50a may be connected to the controller 90 to measure the concentration of nitrogen compounds in the treated water from which nitrogen compounds released from the first reaction tank 40a have been removed. In addition, the ion selective electrode sensor 50a can measure the nitrogen compound concentration at predetermined time intervals.

The DC power supply unit 80 is provided outside the first reaction tank 40a to supply DC power to the pair of carbon electrodes 100a and reverses the polarity of the DC power supply to the pair of carbon electrodes 100a Can supply.

The control unit 90 may be connected to the DC power supply unit 80. The control unit 90 can measure and control the voltage and current value applied to the carbon electrode pair 100a. The controller 90 controls the three-way valve 30 on the inflow side and the two-way valve 60a Can be controlled.

Referring to FIG. 1, the electrolyte supply tank 120 may be installed outside the first reaction tank 40a and may be connected to the first reaction tank 40a to supply the electrolyte to the first reaction tank 40a. In addition, an electric conductivity sensor 110a may be installed in the first reaction tank 40a to measure an electric conductivity of the electrolyte in the first reaction tank 40a.

In the present invention, a conventional electrolyte may be used. For example, KOH or NaCl may be used, but is not limited thereto. When the electric conductivity of the electrolyte measured by the electric conductivity sensor 110a is lower than 2 mS / cm, the electrolyte is supplied to the first reaction tank 40a from the electrolyte supply tank 120, The concentration can be maintained.

When the electrolyte supply vessel 120 is included as described above, the electrochemical oxidation-reduction reaction of the nitrogen compound adsorbed and concentrated in the pair of carbon electrodes 100a in the first reaction vessel 40a is maintained smoothly while the electrolyte concentration is maintained constant So that the object of the present invention can be easily achieved.

The water treatment system 200 of the present invention may further include a second reaction tank 40b so that raw water may be alternately introduced into the first reaction tank 40a or the second reaction tank 40b.

The second reaction tank is provided with a raw water inflow portion 10 for introducing raw water and a treated water discharge portion 70b for discharging treated water to the outside, and adsorbs, concentrates, and removes nitrogen compounds in the raw raw water, And the carbon electrode pair 100b of the second reaction tank is connected to the DC power supply unit 80 so that the DC power is applied to the pair of carbon electrodes 100b of the second reaction tank, The direct current power supply and the current value are measured and controlled by the controller 90. The carbon electrode pair 100b of the second reactor is supplied with DC power of 1.4 V or less from the DC power supply unit 80, And the electrochemical removal process of the nitrogen compound can be performed.

The current value applied to the carbon electrode pair 100a of the first reaction tank 40a becomes, for example, 0 to 0.05 A and the nitrogen compound concentration of the treated water measured by the ion selective electrode sensor 50a The 3-way valve 30 on the raw water inflow water 10 side and the 2-way valve 60a on the process water discharge portion 70a side are operated by the control of the controller 90 The raw water including the nitrogen compound may be introduced into the second reaction tank 40b to which the raw water has not previously been introduced so that the adsorption and concentration process of the nitrogen compound in the water alternately with the first reaction tank 40a can be advanced.

When the second reaction tank 40b is installed, the nitrogen compound in the water can be treated more efficiently, and the object of the present invention can be achieved easily.

Another aspect of the present invention relates to a water treatment method using the above-described electrochemical water treatment system 200 using a carbon electrode. (A) adsorbing and concentrating a nitrogen compound in the water on the surface of the carbon electrode pair 100a by applying a direct current power of 1.4 V or less to the carbon electrode pair 100a; And (b) reversing the polarity of the DC power source to the carbon electrode pair 100a and increasing the DC power source to 1.4V or more to convert the nitrogen compound adsorbed and concentrated to the electrode into a form of nitrogen gas .

1, the direct current power supply unit 80 is connected to the pair of carbon electrodes 100a to apply a direct current power of 1.4 V or less to the pair of carbon electrodes 100a, Raw water including nitrogen compounds such as NH4 + ions and nitric acid (NO3-) ions flows into the first reaction tank 40a through the operation of the 3-way valve 30 by operating the raw water inflow pump 20 do. The nitrogen compound of the introduced raw water is adsorbed and concentrated on the surface of the carbon electrode pair 100a to which the direct current power of 1.4 V or less is applied in the first reaction tank 40a, (70a).

The current value applied to the carbon electrode pair 100a of the first reaction vessel 40a measured by the control unit 90 becomes 0 to 0.05 A and the current value applied to the carbon electrode pair 100a measured by the ion selective electrode sensor 50a is, Way valve 30 to the first reaction tank 40a when the measured value of the nitrogen compound concentration of the treated water discharged from the first reaction tank 40a becomes equal to or greater than a preset value, Way valve 60a on the side of the process water discharging portion 70a of the process water supply port 60a to stop the introduction and discharge of the raw water. Next, the polarity of the DC power source applied to the carbon electrode pair 100a of the first reaction tank 40a is reversed, and the applied DC power is raised to 1.4V or higher, The nitrogen compound is converted into a nitrogen gas form by an electrochemical redox reaction to treat the nitrogen compound in the water.

When the water treatment system 200 of the present invention further includes a second reaction tank 40b, the first reaction tank 40a is connected to the carbon electrode Is adsorbed and concentrated on the surface of the pair (100a), and the drain water is discharged through the treated water discharge portion (70a).

The current value applied to the carbon electrode pair 100a of the first reaction vessel 40a measured by the control unit 90 becomes 0 to 0.05 A and the current value applied to the carbon electrode pair 100a measured by the ion selective electrode sensor 50a is, When the measured value of the nitrogen compound concentration of the treated water discharged from the one reaction tank 40a becomes equal to or greater than the set value, the control unit 90 controls the 3-way valve 30 to operate the first reaction tank 40a, Way valve 60a on the side of the process water outlet 70a of the first reaction tank 40a to stop the introduction and discharge of the raw water 40a into the first reaction tank. Then, raw water including a nitrogen compound is injected into the second reaction tank 40b to which the direct current power of 1.4 V or less is applied to the carbon electrode pair 100b, and the nitrogen compound is injected into the second reaction tank 40b The treated water having the nitrogen compound removed while being adsorbed and concentrated on the electrode pair 100b is discharged to the treated water discharge portion 70b of the second reaction tank 40b.

The DC power applied to the carbon electrode pair 100a of the first reaction tank 40a is increased to 1.4V or higher while being adsorbed and concentrated in the carbon electrode pair 100b of the second reaction tank 40b, The nitrogen compound adsorbed and concentrated in the carbon electrode pair 100a of the electrode 40a is converted into a nitrogen gas form by an electrochemical redox reaction to treat the nitrogen compound in the water.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples. The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

Example  One

The electrochemical system 200 of the present invention as shown in Fig. 2 was manufactured.

At this time, the carbon electrode 101 was produced by using activated carbon (highly porous activated carbon) and impregnating the surface with palladium, and graphite foil was used as the current collector. The pair of carbon electrodes 101 of the positive electrode and the pair of the negative electrode were provided in pairs so that four pairs of carbon electrodes 100a and 100b were provided in the first reaction chamber 40a and the second reaction chamber 40b, respectively.

The electrolyte used was NaCl, and the electrolyte conductivity of the electrolyte was maintained at 2 mS / cm from the electrolyte supply tank 120. A DC power source of 1.4 V was applied to the carbon electrode pair 110a of the first reaction tank 40a by the DC power supply unit 80 connected to the control unit 90. [

At this time, the nitrogen compound values of the treated water of the ion selective electrode sensors 50a and 50b were set to 5 mg / L, respectively.

Comparative Example  One

The electrochemical system 200 was fabricated in the same manner as in Example 1, except that the direct current power source was applied at 2.5V.

Experimental Example : (Experimental Study on the Treatment of Synthetic Wastewater Containing Nitrogen)

Total Nitrogen (T-N) is the sum of organic nitrogen (protein, peptide urine and fault wastewater) and inorganic nitrogen (ammonia nitrogen, nitrite nitrogen and nitrate nitrogen).

In order to test the TN removal efficiency of the electrochemical water treatment system 200 according to the present invention, the synthetic wastewater having the TN concentration of 100 mg / L was circulated, and the electrochemical water treatment system 200 of Example 1 and Comparative Example 1 Respectively.

The current value of the first reaction tank 40a of Example 1 and Comparative Example 1 measured by the control unit 90 becomes 0 A and the treated water discharged from the first reaction tank 40a to which the DC voltage is applied is discharged When the concentration of the nitrogen compound is measured to be not less than 5 mg / L as measured by the ion selective electrode sensor 50a, the 3-way valve 30 on the raw water inflow water 10 side and the treatment The 2-way valve 60a on the water discharging portion 70a side is operated to stop the introduction of the raw water containing the nitrogen compound into the first reaction tank 40a and to stop the flow of the raw water containing the nitrogen compound into the second reaction tank 40b to sequentially carry out the adsorption and concentration process of the nitrogen compound in the wastewater. At this time, the DC power applied to the carbon electrode pair 100a of the first reaction tank 40a is raised to 10 V while the adsorption and concentration of the carbon electrode pair 100b of the second reaction tank 40b proceeds, Nitrogen compounds adsorbed and concentrated in the carbon electrode pair 100a of the reaction tank 40a were converted into nitrogen gas form by an electrochemical oxidation-reduction reaction and treated with nitrogen in the water.

In Example 1 and Comparative Example 1, the T-N concentrations of the final treated water obtained from the two treated water discharge portions 70a and 70b were respectively measured and averaged, and the T-N removal efficiency was calculated therefrom. The above experiment was repeated 30 times and the average value thereof was calculated.

Further, experiments were also conducted on synthetic wastewater having TN concentrations of 200 mg / L and 300 mg / L in the same manner as described above. However, the nitrogen compound values of the treated water of the ion selective electrode sensors 50a and 50b were set to 10 mg / L and 15 mg / L, respectively. The average value of the treated water TN of the synthetic wastewater thus measured and the TN removal efficiency were calculated and are shown in Table 1 below.

Experiment Influent TN
(mg / L) Treated TN
(mg / L) T-N Removal Efficiency (%) One Example 1 100 3.9 96.1 Comparative Example 1 100 67.3 32.7 2 Example 1 200 6.3 96.9 Comparative Example 1 200 139.9 30.1 3 Example 1 300 12.7 95.8 Comparative Example 1 300 204.5 31.9

Referring to Table 1, the TN removal efficiency of Example 1 was significantly higher than that of Comparative Example 1. From the results, the electrochemical water treatment system 200 of the present invention was applied with DC power exceeding 1.4 V Is applied to the pair of carbon electrodes 100a and 100b, the adsorption efficiency of the nitrogen compound is greatly reduced.

10: raw water inflow part 20: raw water inflow pump
30: 3-way valve 40a: first reaction tank
40b: second reaction tank 50a, 50b: ion selective electrode sensor
60a, 60b: two-way valves 70a, 70b:
80: DC power supply unit 90:
100, 100a, 100b: carbon electrode pair 101: carbon electrode
102: current collector 110a, 110b: electric conductivity sensor
120: Electrolyte supply tank 200: Water treatment system

Claims (10)

(a) applying a direct current power of 1.4 V or less to a pair of carbon electrodes to adsorb and concentrate a nitrogen compound in the water on the surface of the pair of carbon electrodes; And
(b) reversing the polarity of the DC power source to the carbon electrode pair and raising the DC power source to 1.4 V or more to convert the nitrogen compound adsorbed and concentrated into the carbon electrode pair into a form of nitrogen gas An electrochemical water treatment method comprising:
In the electrochemical water treatment method,
The raw water containing a nitrogen compound is introduced into a first reaction tank in which a direct current power of 1.4 V or less is applied to a pair of carbon electrodes to adsorb and concentrate the nitrogen compound on the pair of carbon electrodes to discharge the treated water from which the nitrogen compound has been removed;
If the concentration of the nitrogen compound in the treated water exceeds a set value, stopping the introduction and discharge of the raw water containing the nitrogen compound into the first reaction tank;
Raw water containing a nitrogen compound is introduced into a second reaction tank to which a direct current power of 1.4 V or less is applied to the carbon electrode pair and the nitrogen compound is adsorbed and concentrated on the carbon electrode pair of the second reaction tank, / RTI > And
The DC power applied to the carbon electrode pair of the first reaction tank is increased to 1.4 V or higher while the carbon electrode pair of the second reaction tank is adsorbed and concentrated to adsorb and concentrate the nitrogen compound in the carbon electrode pair of the first reaction tank To convert into the form of nitrogen gas; ≪ / RTI >
An ion selective electrode sensor provided in the first reaction tank for measuring the concentration of the nitrogen compound is provided in the treated water discharge portion for discharging the treated water to the outside,
Wherein the first reaction tank is connected to an electrolyte supply tank to maintain an electrolyte concentration.
delete A first reaction tank having a raw water inflow portion into which raw water flows and a process water discharge portion that discharges treated water to the outside, and which adsorbs, concentrates, and removes nitrogen compounds in the raw water, and includes at least one pair of carbon electrodes;
A second reaction tank having a raw water inflow portion into which raw water flows and a process water discharge portion that discharges treated water to the outside, and which adsorbs, concentrates, and removes nitrogen compounds in the raw raw water, and includes at least one pair of carbon electrodes;
A DC power supply connected to the pair of carbon electrodes of the first reaction tank and the second reaction tank to apply DC power; And
And a control unit for measuring and controlling a DC power value and a current value applied to the carbon electrodes of the first reaction tank and the second reaction tank,
An ion selective electrode sensor for measuring a nitrogen compound concentration in the treated water discharge portion of the first reaction tank is provided,
The electrolyte supply tank is connected to the first reaction tank to maintain the electrolyte concentration,
The raw water is put into the first reaction tank or the second reaction tank alternately,
The carbon electrodes of the first reaction tank and the second reaction tank are each supplied with DC power of 1.4 V or less from the DC power supply unit,
The raw water containing a nitrogen compound is injected into the first reaction tank to which a direct current power of 1.4 V or less is applied to the carbon electrode pair to adsorb and concentrate the nitrogen compound on the carbon electrode pair to discharge the treated water from which the nitrogen compound has been removed;
If the concentration of the nitrogen compound in the treated water exceeds a set value, stopping the introduction and discharge of the raw water containing the nitrogen compound into the first reaction tank;
Raw water containing a nitrogen compound is introduced into a second reaction tank to which a direct current power of 1.4 V or less is applied to the carbon electrode pair and the nitrogen compound is adsorbed and concentrated on the carbon electrode pair of the second reaction tank, / RTI >
The DC power applied to the carbon electrode pair of the first reaction tank is increased to 1.4 V or higher while the carbon electrode pair of the second reaction tank is adsorbed and concentrated to adsorb and concentrate the nitrogen compound in the carbon electrode pair of the first reaction tank And converting the carbon nanotubes into a nitrogen gas.
delete delete The method of claim 3,
Wherein the carbon electrode is selected from the group consisting of carbon cloth, activated carbon, carbon aerosol, carbon nanotube, and mixtures thereof.
The method of claim 3,
Wherein the anode and the cathode of the carbon electrode are symmetrical or asymmetric.
The method of claim 3,
Wherein the carbon electrode is impregnated with at least one selected from the group consisting of palladium, zinc, tin, iron, and metal oxides.
delete delete

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