KR20150102399A - Wastewater treatment method utilizing microbial fuel cell and microbial fuel cell using the same - Google Patents

Abstract

The present invention relates to a method for treating waste water by utilizing a microbial fuel cell, and a microbial fuel cell using the same. The method according to the present invention treats waste water by utilizing a microbial fuel cell, wherein an organic material and a nitrogen compound are treated, and at the same time, even ethanol amine may be decomposed and treated. Thus, when waste water is recycled by utilizing a microbial fuel cell, the waste water can be treated to have a better water quality. Moreover, by using a microbial fuel cell using the method, a large quantity of waste water can be recycled in various places, and a large quantity of environmentally-friendly energy can be generated.

Description

TECHNICAL FIELD The present invention relates to a method for treating wastewater using a microbial fuel cell and a microbial fuel cell using the microbial fuel cell,

The present invention relates to a method for treating wastewater using a microbial fuel cell and a microbial fuel cell using the same.

Due to recent increases in energy costs, studies on the development of alternative energy and energy-efficient processes have been intensified. A microbial fuel cell (MFC) is a device that uses an electrochemically active microorganism to decompose organic matter and convert it into electrical energy. Such a microbial fuel cell is an epoch-making process that can replace the existing wastewater treatment process as an energy-consuming process into an energy production process because it can produce energy while simultaneously treating organic pollutants present in the wastewater. Studies are underway.

These microbial fuel cells are composed of an anode, a cathode and a cation exchange membrane. The basic principle is that the organic matter is oxidized by microorganisms in the anode reactor under anaerobic conditions, And the electrons are moved to the cathode through an external lead. The hydrogen ions move to the cathode through the cation exchange membrane and react with electrons and oxygen to produce water. At this time, current is produced by the electrons flowing through the external conductor. These microbial fuel cells are considered to be a very innovative technology in that they do not generate additional secondary contaminants by producing electricity while treating pollutants.

On the other hand, in the operation of such a microbial fuel cell, the present research is insufficient for a microbial fuel cell which decomposes nitrogen compounds even more reliably while decomposing organic matters in wastewater. Since contaminated wastewater contains not only organic matter but also a large amount of nitrogen compounds, it is important to develop a microbial fuel cell that can more reliably treat them.

In addition, ethanolamine (ETA) is widely used as a pH adjuster such as contaminated wastewater or an acidic component absorbent of flue gas. Therefore, a large amount of ethanolamine is often present in the wastewater. Although it is urgent to develop a microbial fuel cell that can be used, there is still a lot of researches on it. Specifically, ethanolamine is decomposed into acetic acid and ammonium, and ammonium is oxidized and decomposed by microorganisms under aerobic conditions. Since the oxidation electrode portion of a general microbial fuel cell is composed of anaerobic conditions, But it is difficult to simultaneously decompose the organic material and ammonia. In addition, a treatment method using an ion exchange resin to treat ethanolamine is mainly studied, and a study on a biological decomposition method and an oxidative decomposition method is actively carried out. However, these methods require additional treatment techniques because of the disadvantages of additional chemicals and excessive energy consumption, disadvantages such as byproducts after processing, and very slow processing speed. In the case of conventional biological treatment, there is a disadvantage that the facilities are complicated and the treatment area is widened due to the necessity of an aerobic reaction tank for nitrification of ammonium and an anaerobic or anoxic tank for converting nitrate nitrogen or nitrite nitrogen converted from ammonium into nitrogen gas have.

Although a microbial fuel cell capable of simultaneously treating organic matters, nitrogen compounds, and ethanol amines is required to be developed, there is a problem in that a lot of researches on it are lacking.

Japanese Patent Application Laid-Open No. 10-2014-0018728 (Patent Document 1) discloses a prior art document related to the present invention. More specifically, the Patent Document 1 discloses a method for improving the electrode material and morphology of a microbial fuel cell, And the use of carbon fiber yarn to improve the efficiency.

Patent Document 1. Korean Patent Publication No. 10-2014-0018728

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide a wastewater treatment method using a microbial fuel cell capable of simultaneously treating various organic substances, nitrogen compounds and ethanolamine present in wastewater, And to provide a microbial fuel cell using the same.

According to an aspect of the present invention,

A method for treating wastewater utilizing microbial fuel cells,

And injecting trivalent iron (Fe (III)) into the microbial fuel cell.

A microbial fuel cell according to another aspect of the present invention includes:

In a microbial fuel cell,

And decomposing at least one selected from the group consisting of organic substances, nitrogen compounds, and ethanol amines contained in the wastewater into which trivalent iron is injected.

In the wastewater treatment method according to the present invention, in treating wastewater using a microbial fuel cell, it is possible to treat organic substances and nitrogen compounds, and at the same time decompose ethanolamine. Thus, in recycling wastewater by utilizing a microbial fuel cell, there is an effect of improving wastewater to better water quality. In addition, the microbial fuel cell using the wastewater treatment method can treat more wastewater in various places and produce a greater amount of environmentally friendly energy.

1 is a structural view of a reactor used in Example 1. Fig.
2 is a graph showing the amounts of voltage generation in Examples 1 and 2 and Comparative Example 1;
3 is a graph comparing COD removal rates of the microbial fuel cells according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2. FIG.
4 is a graph comparing ammonia removal rates of the microbial fuel cells according to Example 1, Example 2, Comparative Example 1, and Comparative Example 2. FIG.
5 is a graph showing the ammonia removal rate and coulon efficiency of the microbial fuel cells according to Example 3, Example 4, Comparative Example 1, and Comparative Example 2. FIG.

Accordingly, the present inventors have made extensive efforts to develop a wastewater treatment method and a microbial fuel cell capable of simultaneously treating an organic matter, a nitrogen compound, and an ethanolamine. As a result, they have found that a method for treating wastewater using a microbial fuel cell according to the present invention, Batteries.

Specifically, the method for treating wastewater according to the present invention utilizes a microbial fuel cell, and includes the step of injecting trivalent iron (Fe (III)) into the microbial fuel cell.

Thus, the fuel cell is capable of simultaneously decomposing organic matter, nitrogen compounds, and ethanolamine present in wastewater by injecting trivalent iron. There is a large amount of organic matter and nitrogen compounds in the wastewater, and since ethanolamine is frequently used as a pH adjusting agent and an acidic component absorbent in recent years, a method of simultaneously treating such organic matter, nitrogen compounds and ethanolamine The development was urgent. Accordingly, the present invention has been developed as a waste water treatment method capable of simultaneously treating the organic matter, the nitrogen compound, and the ethanolamine.

On the other hand, the trivalent iron is not particularly limited, but may preferably be hematite or goethite, more preferably goethite. When the hematite or goethite is injected into the microbial fuel cell as trivalent iron, the effect of decomposing and treating the organic substances, the nitrogen compounds and the ethanolamine is excellent, and the COD, the ammonia removal rate and the ethanolamine removal rate are finally achieved.

Also, ammonia (NH ₃ ) is present in a large amount in the nitrogen compound present in the wastewater. According to the method for treating wastewater according to the present invention, the trivalent iron acts as an electron acceptor, and the electron donor to it is ammonium (NH ₄ ⁺ ) produced from the ammonia, and the trivalent iron receives electrons from the ammonium Organic compounds, nitrogen compounds and ethanolamine can be decomposed. The decomposition and treatment of organic matter, nitrogen compounds and ethanolamine by the wastewater treatment method according to the present invention can be represented by the following reaction formula 1.

[Reaction Scheme 1]

The microbial fuel cell according to another aspect of the present invention is characterized in that the microbial fuel cell decomposes at least one selected from the group consisting of organic matter, nitrogen compounds, and ethanolamine present in the wastewater by injecting trivalent iron.

The trivalent iron is not particularly limited, but may preferably be hematite or goethite, more preferably goethite.

On the other hand, the nitrogen compound may be ammonia (NH ₃ ), and the trivalent iron serves as an electron acceptor, and the electron donor to it is ammonium (NH ₄ ⁺ ) produced from the ammonia, The nitrogen compound and the ethanolamine decomposes at least one selected from the group consisting of an organic substance, a nitrogen compound and an ethanolamine, and the decomposition of any one or more selected from the group consisting of the organic substance, the nitrogen compound and the ethanolamine is represented by the following reaction formula 1 . ≪ / RTI >

[Reaction Scheme 1]

Meanwhile, the COD removal rate of the microbial fuel cell may be 85.0-99.9% after 3 cycles, and the ammonia removal rate may be 65.0-99.0% even after 3 cycles, and the ammonia removal rate after ethanolamine injection may be 55.0-99.9%.

A wastewater treatment apparatus according to another aspect of the present invention may employ the wastewater treatment method according to the present invention or may include a microbial fuel cell.

An apparatus for recovering electricity according to another aspect of the present invention is a system for recovering electricity produced by the microbial fuel cell after treating wastewater by a wastewater treatment method according to the present invention or by means of a microbial fuel cell according to the present invention The generated electricity can be recovered.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Example

Example  One

An air-reducing electrode made of acrylic material was used, and a single chamber MFC (see FIG. 1) was used. Three reactors of the same size and material were operated simultaneously in fed-batch mode. 0.2 g of goethite (FeOOH) was injected into the microbial fuel cell as trivalent iron. Using a prepared microbial fuel cell, 0.08 kg of artificial wastewater containing acetate (1 g / L) and ammonium (0.3 g / L) was treated to obtain electricity.

Example  2

Electricity was obtained after treating wastewater using the same method as in Example 1 except that hematite (Fe ₂ O ₃ ) was used instead of goethite.

Example  3

The same method as in Example 1 was used, except that wastewater containing 0.5 g / L of ethanolamine (ETA) was used before treating the wastewater using the microbial fuel cell according to Example 1 The wastewater was treated and electricity was obtained.

Example  4

The wastewater was treated in the same manner as in Example 2, except that wastewater containing 0.5 g / L of ethanolamine was used before treating the wastewater using the microbial fuel cell according to Example 2 After that, electricity was obtained.

Comparative Example

Comparative Example  One

Unlike the above example, the wastewater was treated with a microbial fuel cell which did not use any rail, and electricity was obtained.

Comparative Example  2

Electricity was obtained after treating wastewater using the same method as in Example 1, except that waste water was treated with a microbial fuel cell into which ferric chloride (FeCl ₃ ) was injected.

Initially, acetate was injected into the substrate to induce microbial growth and electrode adhesion. The voltage generation graph of the start-up step in Example 1, Example 2 and Comparative Example 1 is shown in Fig. 2 (a: Comparative Example 1, b: Example 1, and c: Example 2). After the third cycle in all the reactors, the voltage was stable at about 0.49 ~ 0.5 V, and it was judged that the electroactive bacteria were sufficiently attached to the electrodes, and the experiment was performed by injecting ETA.

Experimental Example

Experimental Example  One: COD  Measurement of removal rate

Experiments were conducted to compare the COD removal rates with the cases of Example 1, Example 2, and Comparative Examples 1 to 5. The experiments were carried out using microbial biodegradation of the pollutants through the metabolic process in the microbial fuel cell. The results are shown in FIG. As can be seen from FIG. 3, it can be seen that Examples 1 and 2 have far superior COD removal rates as compared with Comparative Examples 1 to 2. Specifically, in the case of Examples 1 and 2, the COD removal rate continues to increase after the third cycle, reaching a removal rate of 90% or more. On the other hand, in Comparative Example 1 to Comparative Example 2, the COD removal rate is less than 80% Respectively. In particular, it was confirmed that Comparative Example 2 barely maintained the removal rate of 60% after the 3rd cycle. In addition, it can be confirmed that the case of Example 1 is superior to the case of Example 2 in COD removal rate.

Experimental Example  2: Ammonia removal rate measurement

Experiments were carried out to compare the ammonia removal rates in the case of Examples 1, 2 and Comparative Examples 1 to 2. [ The experiments were carried out using microbial biodegradation of the pollutants through the metabolic process in the microbial fuel cell. The results are shown in FIG. As can be seen from FIG. 4, it was confirmed that the ammonia removal rate of Examples 1 and 2 was much higher than that of Comparative Examples 1 to 2. As shown in FIG. Specifically, in Examples 1 and 2, the ammonia removal rate was 75% or more even after 3 cycles, whereas Comparative Example 1 was less than 65%, and Comparative Example 2 was only 25% or less Respectively. In addition, it was confirmed that the ammonia removal ratio of Example 1 was higher than that of Example 2. [

Experimental Example  3: Ethanolamine  Measurement of removal rate

Experiments were conducted to compare the ethanolamine removal ratios in the case of Example 3, Example 4, and Comparative Example 1 to Comparative Example 2 adapted to the acetate and ammonium treatment. This experiment was carried out using the same method as Experimental Example 1 and Experimental Example 2, and the result is shown in FIG. As can be seen from FIG. 5, it was confirmed that the ethanolamine removal rate of Example 3 and Example 4 was much superior to that of Comparative Examples 1 to 2. Specifically, in the case of Example 3 and Example 4, it was confirmed that the ammonia removal rate was 60% or more in spite of the ETA injection, whereas the ammonia removal ratio in Comparative Examples 1 to 2 was only 40% or less. From these results, it was confirmed that the ethanolamine removal efficiency of Example 3 and Example 4 was superior to that of Comparative Examples 1 to 2. [ In addition, it was confirmed that the ethanolamine removal rate of Example 3 was higher than that of Example 4.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. It is natural.

Claims (18)

A method for treating wastewater utilizing microbial fuel cells,
And injecting trivalent iron (Fe (III)) into the microbial fuel cell.
The method according to claim 1,
Wherein the microbial fuel cell decomposes at least one selected from the group consisting of organic matter, nitrogen compounds, and ethanolamine present in the wastewater by injecting trivalent iron.
3. The method of claim 2,
Wherein the nitrogen compound is ammonia (NH ₃ ).
The method of claim 3,
Wherein the trivalent iron is acting as an electron acceptor, and thus for the electron donor is an ammonium (NH ₄ ⁺⁾ generated from the ammonia, wherein the 3 accepts the electron from the iron ammonium organic substance, from the group consisting of nitrogen compounds, and ethanolamine Wherein the decomposition of any one or more selected from the group consisting of organic compounds, nitrogen compounds, and ethanol amines is performed through the following reaction formula (1).
[Reaction Scheme 1]

The method according to claim 1,
Characterized in that the trivalent iron is hematite or goethite.
The method according to claim 1,
Characterized in that the trivalent iron is goethite.
In a microbial fuel cell,
Wherein at least one selected from the group consisting of organic matter, nitrogen compounds, and ethanol amines contained in the wastewater is injected into the microbial fuel cell.
8. The method of claim 7,
Wherein the nitrogen compound is ammonia (NH ₃ ).
9. The method of claim 8,
Wherein the trivalent iron is acting as an electron acceptor, and thus for the electron donor is an ammonium (NH ₄ ⁺⁾ generated from the ammonia, wherein the 3 accepts the electron from the iron ammonium organic substance, from the group consisting of nitrogen compounds, and ethanolamine Wherein the decomposition of any one or more selected from the group consisting of organic compounds, nitrogen compounds, and ethanol amines is performed through the following reaction formula (1).
[Reaction Scheme 1]

8. The method of claim 7,
Wherein the trivalent iron is hematite or goethite.
8. The method of claim 7,
Wherein the trivalent iron is goethite.
8. The method of claim 7,
Wherein the COD removal rate of the microbial fuel cell is 85.0-99.9% after 3 cycles.
8. The method of claim 7,
Wherein the microbial fuel cell has an ammonia removal rate of 65.0-99.0% after 3 cycles.
8. The method of claim 7,
Wherein the microbial fuel cell has an ammonia removal rate of 55.0-99.9% after ethanolamine injection.
A wastewater treatment apparatus using the wastewater treatment method according to any one of claims 1 to 6.
15. A wastewater treatment apparatus comprising the microbial fuel cell according to any one of claims 7 to 14.
An apparatus for recovering electricity produced by a microbial fuel cell after treating wastewater by a wastewater treatment method according to any one of claims 1 to 6.
An apparatus for recovering electricity produced by a microbial fuel cell according to any one of claims 7 to 14.

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