KR101991991B1 - Dual-chamber type bioelectrochemical apparatus for removing arsenic and nitrogen compounds and the method - Google Patents

Abstract

The present invention relates to a dual chamber-type bio-electrochemical device capable of simultaneous removal of nitrogen and arsenic, and more particularly, to a method and apparatus for removing toxic ternary arsenic The present invention relates to a biodegradable biochemical electrochemical device for oxidizing nitric acid ions in groundwater in the form of pentavalent arsenic which is weak and easily removable by adsorption. The biodegradable bio-electrochemical device according to the present invention can generally perform oxidation of trivalent arsenic and reduction of nitrate nitrogen without permeation of nitrate nitrogen by using a bipolar membrane as a separator instead of a hydrogen ion exchange membrane used as a separator It is economical and eco-friendly compared to other technologies because it utilizes the spontaneous reaction of electron transfer microorganisms due to low external potential supply. It supplies electric potential to the oxidized electrode in the potential supply method, The use of the mixed strains has the advantage that oxidation of trivalent arsenic and reduction of nitrate nitrogen can be performed simultaneously with higher efficiency than the conventional method.

Description

TECHNICAL FIELD [0001] The present invention relates to a biosynthetic bioelectrochemical device for removing arsenic and nitrogen, and a method thereof. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a dual chamber-type bioelectrochemical device capable of removing nitrogen and arsenic, and more particularly, to a method and apparatus for removing toxic trivalent arsenic from groundwater, The present invention relates to a biodegradable biochemical electrochemical device for oxidizing nitric acid ions in groundwater in a form of pentavalent arsenic which is weak and easily removable by adsorption.

Due to urbanization and industrialization, contamination by various oxidized forms of toxic chemicals (nitrate nitrogen, heavy metals, etc.) is increasing. According to the Ministry of Environment 's operation of the groundwater quality monitoring network in 2013, 8,4% of 6,073 groundwater samples exceeded the water quality standards. Groundwater contamination is mostly caused by general pollutants such as nitrate nitrogen (84.8%), but contamination by specific hazardous substances (15.2%), especially arsenic contamination (6.3%) is serious. Accordingly, it is in urgent need to develop a treatment technique capable of eliminating it more efficiently and stably.

Various techniques such as physical / chemical, electrodialysis, ion exchange, and biological methods have been used for restoration of groundwater. However, in the case of physical / chemical and electrodialysis, secondary treatment is required or a large amount of sludge There is a problem. In the case of biological methods, various organic substances such as methanol, lactate, and acetate can be used as electron donors, so that competition with other heterotrophic bacteria using organic substances may occur, and various fermentation products may be secondary pollutants , Which is known to interfere with groundwater flow.

On the other hand, bioelectrochemical devices can support the anaerobic respiration of organisms by reducing the redox substances by the electrons generated from the electrodes and using them as artificial electron donors or using the reduction electrodes as electron donors. Bioelectrochemical devices are technologies that can remove pollutants from groundwater at relatively low cost. Compared with conventional groundwater purification methods, which have various problems such as maintenance difficulties, secondary pollution problems, expensive treatment costs, and difficulties in maintaining microorganisms, the use of a compact facility and a low energy input (low cost) Removal is possible.

Conventionally, Korean Patent Publication No. 2012-0045372 discloses a bio-electrochemical contaminant removal apparatus for removing nitrate nitrogen and organic chlorine compounds as a conventional method for removing contaminants using bioelectrochemical devices. Korean Patent No. 1176437 The present invention relates to a biological electrochemical wastewater treatment apparatus for simultaneous removal of ammonia and organic matter and a wastewater treatment method using the same, Korean Patent Registration No. 1267541 discloses a biological electrochemical wastewater treatment apparatus for simultaneous removal of organic nitrogen and organic matter, Method is disclosed.

However, the existing bioelectrochemical devices applied to the groundwater environment focus mostly on the removal of nitrate nitrogen and organic chlorine compounds, and devices for removing heavy metal contaminants such as arsenic are extremely rare, especially nitrate nitrogen and arsenic There is no biochemical device to remove at the same time.

As a result, the inventors of the present invention have conducted extensive research on a method for effectively removing nitrate nitrogen and arsenic in ground water. As a result, it has been found that the use of a bipolar membrane as a separator in a disposable bioelectrochemical device When arsenic is highly toxic and highly toxic, it is oxidized to pentavalent arsenic, which is low in toxicity, and the nitrate nitrogen is high in the reducing electrode part. Denitrification efficiency, and it is confirmed that nitrate nitrogen and arsenic can be removed at the same time, thereby completing the present invention.

Japanese Patent 2009-241049

Accordingly, an object of the present invention is to provide a discrete bioelectrochemical device capable of simultaneously removing arsenic and nitrogen.

It is also an object of the present invention to provide a method for simultaneous removal of arsenic and nitrogen in treated water using the above-mentioned biotic electrochemical device.

In order to achieve the above object,

The oxidized electrode part includes an oxidized electrode and is supplied with the treated water. The electrolyzed arsenic-oxidizing microorganism treats the oxidized electrode part and the reduced electrode part by the bipolar membrane located at the center, And the reducing electrode unit includes a reference electrode and a reducing electrode. The reducing electrode unit is a dual chamber-type unit which is supplied with treated water and denitrifies nitrate nitrogen into nitrogen gas by an electroactive denitrifying microorganism, ) Reactor; And

A potential control unit comprising a power supply unit and a lead to control a constant potential between the reference electrode and the oxidation electrode or the reduction electrode;

Which can remove arsenic and nitrogen in the treatment water simultaneously.

More preferably, the electroactive arsenic oxidation-related microorganism may be a mixed strain comprising Alphaproteobacteria and Betaproteobacteria as the right firing bacteria.

More preferably, the potential control unit supplies a potential to the oxidizing electrode, and maintains the potential difference between the reference electrode and the oxidizing electrode at +0.5 V can do.

In addition, the present invention provides a method for simultaneous removal of arsenic and nitrogen in treated water using an apparatus for removing biotic electrochemical contaminants.

More preferably, the method comprises: a first step of injecting treatment water into the inlet of the reactor and supplying a potential to the reactor; The trivalent arsenic in the treated water injected in the first step is oxidized to the pentavalent arsenic by the electroactive arsenic oxidation-related microorganisms in the oxidation electrode portion of the reactor, and the generated electrons and hydrogen ions are reduced And a second step in which the nitrate is reduced by the electroactive denitrifying microorganism in the reducing electrode unit to nitrogen gas to remove nitrogen.

More preferably, the method may further comprise the step of adsorbing and removing the oxidized pentavalent arsenic using an adsorbent in the second step.

More preferably, the electroactive arsenic oxidation-related microorganism may be a mixed strain comprising Alphaproteobacteria and Betaproteobacteria as the right firing bacteria.

More preferably, the supply of the potential can supply a potential to the oxidized electrode, while maintaining the potential difference between the reference electrode and the oxidized electrode at +0.5 V.

The biodegradable bio-electrochemical device according to the present invention can generally perform oxidation of trivalent arsenic and reduction of nitrate nitrogen without permeation of nitrate nitrogen by using a bipolar membrane as a separator instead of a hydrogen ion exchange membrane used as a separator It is economical and eco-friendly compared to other technologies because it utilizes the spontaneous reaction of electron transfer microorganisms due to low external potential supply. It supplies electric potential to the oxidized electrode in the potential supply method, The use of the mixed strains has the advantage that oxidation of trivalent arsenic and reduction of nitrate nitrogen can be performed simultaneously with higher efficiency than the conventional method.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a discrete bioelectrochemical device according to an embodiment of the present invention; FIG.
FIG. 2 is a schematic diagram of oxidation of trivalent arsenic and reduction of nitrate nitrogen occurring in the discrete biochemical apparatus of the present invention. FIG.
FIG. 3A is a graph showing a change in trivalent arsenic concentration under a condition that a potential of +0.5 V is supplied to an oxidized electrode portion using a constant electric field in a discrete bioelectrochemical device according to an experimental example of the present invention. FIG.
FIG. 3B is a graph showing a change in nitrate nitrogen concentration under a condition that a potential of +0.5 V is supplied to the oxidized electrode portion using a constant electric field in a discrete bioelectrochemical device according to an experimental example of the present invention. FIG.
FIG. 3c is a graph showing changes in the potentials of the oxidizing electrode and the reducing electrode under the condition that a potential of +0.5 V is supplied to the oxidizing electrode portion using a constant electric field in a disposable bioelectrochemical device according to an experimental example of the present invention Graph.
FIG. 4A is a graph showing a change in trivalent arsenic concentration under a condition of supplying a potential of 1.0 V using a power supply in a disposable bioelectrochemical device according to an experimental example of the present invention. FIG.
FIG. 4B is a graph showing changes in nitrate nitrogen concentration under a condition of supplying a potential of 1.0 V using a power supply in a disposable bioelectrochemical device according to an experimental example of the present invention. FIG.
FIG. 4C is a graph showing the potential change of the oxidizing electrode and the reducing electrode under the condition of supplying a potential of 1.0 V using a power supply in a disposable bioelectrochemical apparatus according to an experimental example of the present invention. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a discrete bioelectrochemical device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The present invention provides a discrete biochemical electrochemical device capable of simultaneous removal of nitrogen and arsenic.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a discrete bioelectrochemical device according to an embodiment of the present invention; FIG.

The apparatus for removing contaminants according to the present invention is divided into an oxidation electrode unit 40 and a reduction electrode unit 50 by a bipolar membrane 30 located at the center, (41), and is supplied with treated water to oxidize trivalent arsenic in the treated water by the electroactive arsenic oxidation-related microorganisms into pentavalent arsenic, and the reduction electrode unit includes a reference electrode (42) and a reduction electrode A dual chamber-type reactor for supplying treated water and denitrifying nitrate nitrogen into nitrogen gas by an electroactive denitrifying microorganism; And a potential control unit comprising a power supply unit 10 and a lead 20 for controlling a constant potential between the reference electrode and the oxidation electrode or the reduction electrode.

The apparatus may further include a magnetic bar 60 for inducing a smooth reaction in the reactor and a sampling port 70 for sampling.

The arsenic and nitrogen removal mechanism in the discrete biochemical apparatus of the present invention is as follows.

FIG. 2 is a schematic view of the phenomenon of arsenic oxidation and nitrogen reduction occurring in a discrete bioelectrochemical device according to the present invention.

2, the treated water is injected through an inlet (not shown) of the oxidized electrode unit 10 and attached to the oxidized electrode 41 provided in the oxidized electrode unit 40, The treated trivalent arsenic is effectively oxidized to pentavalent arsenic by the growing electroactive arsenic oxidation-related microorganisms, and the treated water is discharged through an outlet (not shown) The electrons and the hydrogen ions move to the reduction electrode portion along the external lead wire 20 and the bipolar membrane 30, respectively. Oxidized pentavalent arsenic has relatively low toxicity and mobility compared to trivalent arsenic and can be easily removed by adsorption.

At this time, it is preferable that the electroactive arsenic oxidation-related microorganism is a mixed strain having Alphaproteobacteria and Betaproteobacteria as the right firing bacteria. When using the above-mentioned mixed strains, the arsenic oxidation rate can be about 1.4 to 60 times higher than that in the case of using a pure single strain ( Klebsiella sp. JHW3) or other right-sided fungus (see Experimental Example 5 and Tables 3 and 4) .

On the other hand, the treated water containing nitrate nitrogen is injected through the inlet (not shown) of the reducing electrode unit 50, and the nitrate nitrogen adheres to the reducing electrode 51 in the reducing electrode unit 50 or floats The treated water is reduced and treated as a final electron acceptor of the electroactive denitrifying microorganism, and the treated water is discharged through an outlet (not shown).

Here, in order for the hydrogen ions migrating to the reduction electrode portion to be used as the electron donor of the denitrifying microorganisms in the reduction electrode portion, it is necessary to reduce the hydrogen to 1 mole of hydrogen ions, A power supply is required, which is equivalent to one eighth of the amount of electricity supplied to a conventional bioelectrochemical system, thereby reducing energy consumption. In addition, it is possible to provide a method of reducing energy consumption which can simultaneously treat arsenic and nitrogen using microorganisms in waste sludge, which have been regarded as objects of treatment. Therefore, using the bioelectrochemical device according to the present invention, arsenic and nitrate nitrogen can be simultaneously removed.

The electroactive denitrifying microorganisms used in the present invention are well known to those skilled in the art because they are microorganisms used in the field of a non-mediated microbial fuel cell (or biofuel cell) and bioelectrochemical system. It is not a feature of the invention.

In the present invention, the treated water flowing into the oxidation electrode unit 40 is treated water such as wastewater or ground water containing trivalent arsenic, and the treated water flowing into the reducing electrode unit 50 contains nitrate nitrogen Wastewater, ground water, or the like.

In the present invention, the oxidizing electrode 41 and the reducing electrode 51 may be carbon paper or graphite rod, but the present invention is not limited thereto.

In the present invention, the bipolar membrane is used as a separator and prevents permeation of nitrate nitrogen from the reducing electrode portion to the oxidizing electrode portion, thereby increasing the overall nitrate nitrogen removal rate.

In the present invention, it is preferable that the supply of the potential supplies a potential to the oxidizing electrode. In the case of supplying the potential to the oxidizing electrode, the nitrate nitrogen removal rate is higher than that in the case of supplying the oxidizing electrode to the reducing electrode (see Experimental Example 4 and Table 2), and the arsenic oxidation rate may also increase. At this time, it is preferable to maintain the potential difference between the reference electrode and the oxidation electrode at +0.5 V, which may inhibit the bioelectrochemical oxidation reaction of trivalent arsenic.

At this time, the power supply apparatus 10 may use a potentiostat or a power supply, but the present invention is not limited thereto.

In addition, the present invention provides a method for simultaneous removal of arsenic and nitrogen in treated water using the above-mentioned two-dimensional bioelectrochemical device.

Specifically, a method for simultaneous removal of arsenic and nitrogen in treated water using a discrete bioelectrochemical device according to the present invention,

A first step of injecting treatment water into an inlet of the reactor and supplying a potential to the reactor; The trivalent arsenic in the treated water injected in the first step is oxidized to the pentavalent arsenic by the electroactive arsenic oxidation-related microorganisms in the oxidation electrode portion of the reactor, and the generated electrons and hydrogen ions are reduced And a second step in which the nitrate is reduced by the electroactive denitrifying microorganism in the reducing electrode unit to nitrogen gas to remove nitrogen.

In this case, the pentavalent arsenic oxidized in the second step is relatively less toxic and mobile than the trivalent arsenic and can be easily removed by adsorption. Accordingly, the method according to the present invention may further comprise a step of adsorbing and removing the oxidized pentavalent arsenic using an adsorbent in the second step. At this time, the adsorbent can be used without limitation as long as it is an adsorbent capable of adsorbing the pentavalent arsenic. For example, an adsorbent known in the art can be used.

In the method according to the present invention, it is preferable that the electro-active arsenic oxidation-related microorganism uses a mixed strain comprising the alphaproteobacteria and the betaproteobacteria as the right-burner, When used, it can exhibit an arsenic oxidation rate of about 1.4 to 60 times higher than when using a pure single strain ( Klebsiella sp. JHW3) or other right fungus.

In the method according to the present invention, it is preferable that the supply of the potential supplies a potential to the oxidizing electrode. When the potential is supplied to the oxidizing electrode, the nitrate nitrogen removal rate is higher than that in the case of supplying it to the reducing electrode, and the arsenic oxidation rate may also increase. At this time, it is preferable to maintain the potential difference between the reference electrode and the oxidizing electrode at +0.5 V, and if it is outside the above range, the bioelectrochemical oxidation reaction of trivalent arsenic may be inhibited.

In the method according to the present invention, the treated water flowing into the oxidizing electrode portion is treated water such as wastewater or ground water containing trivalent arsenic, and the treated water flowing into the reducing electrode portion is wastewater containing nitrate nitrogen Or treated water such as ground water.

The biodegradable bio-electrochemical device according to the present invention can generally perform oxidation of trivalent arsenic and reduction of nitrate nitrogen without permeation of nitrate nitrogen by using a bipolar membrane as a separator instead of a hydrogen ion exchange membrane used as a separator It is economical and eco-friendly compared to other technologies because it utilizes the spontaneous reaction of electron transfer microorganisms due to low external potential supply. It supplies electric potential to the oxidized electrode in the potential supply method, It is possible to oxidize trivalent arsenic at an efficiency of about 60 times or more as compared with the conventional method by using a mixed strain and at the same time to reduce nitrate nitrogen, Can be used.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are only the preferred embodiments of the present invention, and the present invention is not limited by the following Examples.

< Example  1> A real type  Manufacture of bioelectrochemical devices

As shown in FIG. 1, a discrete bioelectrochemical device in which an oxidized electrode portion and a reduced electrode portion were separated was prepared. The volumes of the oxidized electrode and the reduced electrode were 350 mL respectively, and the oxidized electrode and the reduced electrode were fabricated to have a size of 2.5 × 5.0 cm using a carbon cloth. The lead wire was a copper wire and the reference electrode was an Ag / AgCl electrode. The bipolar membrane was used as the separation membrane, the arsenic - contaminated soil as the oxidation electrode, and the activated sludge as the reduction electrode. The concentration of trivalent arsenic introduced was 80 mg / L and the concentration of nitrate nitrogen was 50 mg / L. All experiments were carried out batchwise. Here, during the 8th batch reaction of the oxidized electrode portion, only one batch reaction of the reducing electrode portion proceeded, because the reduction rate of nitrate nitrogen is slower than the oxidation rate of trivalent arsenic.

< Example  2>

The procedure of Example 1 was repeated except that no nitrate nitrogen was added to the reducing electrode portion.

< Experimental Example  1> Changes in arsenic concentration and nitrate nitrogen concentration during dislocation supply

In the discrete bioelectrochemical device of the present invention, a potential of +0.5 V was constantly applied between the oxidizing electrode and the reference electrode of the oxidizing electrode portion using a constant electric field, and the change of the trivalent arsenic concentration and the nitrate nitrogen concentration Are observed and shown in Figs. 3A and 3B, respectively.

As shown in Figure 3A, trivalent arsenic was oxidized to pentavalent arsenic within 3 days during the 8 batch reactions. Specifically, the trivalent arsenic oxidation efficiency to the 6th batch reaction was> 95%, the 7th batch reaction was 88%, and the 8th batch reaction was 78%.

Also, as shown in FIG. 3B, one batch reaction occurred in the reducing electrode portion during 8 batch reactions in the oxidation electrode portion. The nitrate nitrogen decreased uniformly without accumulation of nitrite nitrogen, and finally, Gt; 99%. &Lt; / RTI &gt;

Therefore, the discrete bioelectrochemical device according to the present invention can oxidize trivalent arsenic, which is highly toxic even with a low potential supply, in the form of pentavalent arsenic which is relatively less toxic and can be easily removed by adsorption, Nitrogen can be removed with a removal efficiency of 99% or more.

Further, in the discrete bioelectrochemical device according to the present invention, the potential change of the oxidizing electrode and the reducing electrode was observed under the condition that +0.5 V potential was constantly supplied to the oxidizing electrode portion using a constant electric field, Respectively.

As shown in FIG. 3c, the oxidized electrode potential maintained +0.5 V due to the constant potential supply, but the reduced electrode potential showed a deviation of -0.5 to -0.7 V from the second batch reaction.

< Experimental Example  2> Power supply  Changes in arsenic concentration and nitrate nitrogen concentration during the use of dislocation supply

In the discrete bioelectrochemical device of the present invention, a potential of 1.0 V was applied between the oxidizing electrode and the reducing electrode using a power supply, and the change of the trivalent arsenic concentration and the nitrate nitrogen concentration were observed, 4b.

As to arsenic concentration, trivalent arsenic was oxidized to pentavalent arsenic within 3 days during 8 batches of reactions. The efficiency of trivalent arsenic oxidation in the first batch was 88%, and from the 2nd to the 6th The batch reaction was> 95%, the 7th batch reaction was 90%, and the 8th batch reaction was 88%.

In addition, as shown in FIG. 4B, at the nitrate nitrogen concentration, the nitrite nitrogen accumulation phenomenon was found initially, but finally the removal efficiency was> 99% without the accumulation of nitrite nitrogen.

Further, in the discrete bioelectrochemical device according to the present invention, the potential change of the oxidizing electrode and the reducing electrode is observed under the condition that the potential is supplied using the power supply, and is shown in FIG. 4C.

Compared with Experimental Example 1, relatively unstable dislocations were found in both the oxidizing electrode and the reducing electrode, and the dislocation tended to decrease as the trivalent arsenic of the oxidizing electrode portion became depleted.

Therefore, the discrete bioelectrochemical device of the present invention achieves simultaneously the oxidation of trivalent arsenic and the reduction reaction of nitrate nitrogen, even when other potential supply devices are applied, so that the toxic trivalent arsenic and nitrate nitrogen It can be removed at the same time.

< Comparative Example  1 > Single group  Manufacture of bio-electrochemical devices

A single-chamber bioelectrochemical device according to Journal of Hazardous Materials 283 (2015) 617-622 was prepared.

The volume of a single bath was 250 mL. A silver electrode (graphite rod (5 cm ² )) was used as the oxidizing electrode and the reducing electrode, and an Ag / AgCl electrode was used as the reference electrode. The concentration of trivalent arsenic introduced into the oxidation electrode was 15 mg / L.

< Experimental Example  3> Triglyceride according to reactor structure Oxidation rate  Measure

In the bioelectrochemical device according to the present invention, the following experiment was conducted to examine the effect of the reactor structure on contaminant removal.

Specifically, trivalent arsenic was injected into the discrete bioelectrochemical devices of Example 1 and Example 2 and the single-cell bioelectrochemical device of Comparative Example 1, and then, using a potentiostat, The oxidation rate of trivalent arsenic with time was measured while applying a potential of +0.5 V.

The experimental results are shown in Table 1 below.

division Example 1 Example 2 Comparative Example 1 Reactor structure Available (350 mL each) Available (350 mL each) Single-chambered (250 mL) Oxidation electrode and reduction electrode material Carbon paper
(12.5 cm ² ) Carbon paper
(12.5 cm ² ) Graphite rod
(5 cm ² ) Membrane Material Bipolar membrane Bipolar membrane none Reference electrode Ag / AgCl Ag / AgCl Ag / AgCl Power supply Schedule crisis Schedule crisis Schedule crisis Potential supply amount +0.5 V +0.5 V +0.5 V The electron donor Trivalent arsenic
(80 mg / L) Trivalent arsenic
(80 mg / L) Trivalent arsenic
(15 mg / L) The electron donor Nitrate nitrogen none none Trivalent arsenic oxidation rate 27 g / m ³ / d 27 g / m ³ / d 0.42 g / m ³ / d

As shown in Table 1, the oxidation rate of trivalent arsenic was found to be 0.42 g / m ³ / d in the case of the single-chamber (single chamber) reactor without the separation membrane of Comparative Example 1, The device showed that the oxidation rate of trivalent arsenic was 27 g / m ³ / d regardless of the presence or absence of an electron acceptor in the reducing electrode. As described above, the discrete bioelectrochemical apparatus according to the present invention exhibits a trivalent arsenic oxidation rate which is about 64 times higher than that of the single-tank reactor, and thus can treat highly toxic trivalent arsenic with high efficiency.

< Experimental Example  4> Measurement of denitration efficiency according to membrane type and potential supply method

The following experiment was conducted to investigate the effect of the type of separation membrane and the potential supply method on the removal of contaminants in the bioelectrochemical device according to the present invention.

Specifically, in a discrete bioelectrochemical device of Example 1, a separation membrane was used as a proton exchange membrane (PEM) instead of a bipolar membrane, and a reduction electrode of -0.4 V was applied to the reduction electrode using a potentiostat Lt; / RTI &gt; In addition, nitrate nitrogen removal rate with time was measured by injecting only nitrate nitrogen without the presence of an electron donor in the oxidized electrode part.

The experimental results are shown in Table 2 below.

division Example 1 Comparative Example 3 Reactor structure A real type A real type Oxidation electrode and reduction electrode material Carbon paper Carbon paper Membrane Material Bipolar membrane PEM Reference electrode Ag / AgCl Ag / AgCl Power supply Schedule crisis Schedule crisis Potential supply amount +0.5 V to the oxidation electrode
(Based on arsenic oxidation) -0.4 V to the reducing electrode
(Based on denitration) The electron donor Trivalent arsenic none The electron acceptor Nitrate nitrogen Nitrate nitrogen Nitrate Removal Rate (Reduced Electrode) 2.8 g / m ³ / d 1.8 g / m ³ / d Nitrate nitrogen permeation phenomenon
(Reduction electrode part -> oxidation electrode part) none has exist Overall nitrate removal rate 2.8 g / m ³ / d 1.3 g / m ³ / d

As shown in Table 2, when the separator was used as the PEM, the nitrate nitrogen of the reducing electrode portion was transmitted through the oxidized electrode portion. On the other hand, when the membrane was used as a bipolar membrane, no nitrate nitrogen permeation phenomenon was found and the nitrate nitrogen removal rate was also 2.8 g / m ³ / d. Thus, when using the PEM membrane (1.3 g / m ³ / Which is more than twice as high.

In addition, in the dislocation supplying method, it was found that an electron donor (arsenic) exists in the oxidized electrode portion and exhibits a higher nitrate removal rate when the potential is supplied to the oxidized electrode, rather than supplying the potential to the reducing electrode .

Therefore, the discrete bioelectrochemical device of the present invention uses a bipolar membrane as a separation membrane material, and when a potential is supplied to an oxidizing electrode in the presence of arsenic as an electron donor in an oxidizing electrode portion, nitrogen is removed at a high nitrogen removing rate, Arsenic can be oxidized.

< Experimental Example  5> Tertiary arsenic Oxidation rate  Measure

<5-1> Right  Differential arsenic Oxidation rate  change

In the biochemical electrochemical device of Example 2 according to the present invention, the right-firing bacteria in the mixed strains in the arsenic-contaminated soil used as the seed source for the oxidation of trivalent arsenic at the oxidized electrode portion were analyzed by the pattern of DGGE (Denaturing Gradient Gel Electrophoresis) The mixed strains used in the oxidation of trivalent arsenic in the device of Comparative Example 1 were analyzed using the CARD-FISH technique, and the bacteria of the proteobacteria system were subjected to the right- Respectively.

The experimental results are shown in Table 3 below.

division Example 2 Comparative Example 1 Reactor structure Available (350 mL each) Single-chambered (250 mL) Oxidation electrode and reduction electrode material Carbon paper (12.5 cm ² ) Graphite rod (5 cm ² ) Membrane Material Bipolar membrane none Reference electrode Ag / AgCl Ag / AgCl Power supply Schedule crisis Schedule crisis Potential supply amount +0.5 V +0.5 V Target substance for electron donors Trivalent arsenic (80 mg / L) Trivalent arsenic (15 mg / L) Target substance for electron acceptor none none Trivalent arsenic oxidation rate 27 g / m ³ / d 0.42 g / m ³ / d Expression center Mixed strain Mixed strain Right-burner Alphaproteobacteria
Betaproteobacteria Gammaproteobacteria
Deltaproteobacteria

As shown in Table 3, among the mixed strains in the bioelectrochemical device according to the present invention, the right-sided fungus was Alphaproteobacteria and Betaproteobacteria, but in the case of the mixed strains in the device of Comparative Example 1 Ignition bacteria were Gammaproteobacteria and Deltaproteobacteria.

Therefore, in the bioelectrochemical device according to the present invention, in order to increase the oxidation rate of trivalent arsenic, mixed strains including Alphaproteobacteria and Betaproteobacteria are used as the seed sources It is thought that it is desirable to do.

<5-2> Mixed strains Pure strain  Arsenic Oxidation rate  change

In the bioelectrochemical device of Example 1 according to the present invention, the following experiment was carried out to examine the change of the arsenic oxidation rate in the case of using mixed seeds as a mixed strain and pure strains.

Specifically, instead of the mixed strain as an arsenic seed, a pure strain Klebsiella sp. The trivalent arsenic oxidation rate in the bioelectrochemical device (Comparative Example 2) performed in the same manner as in Example 1 was measured, except that JHW3 was used.

division Example 2 Comparative Example 2 Reactor structure Available (350 mL each) Available (350 mL each) Oxidation electrode and reduction electrode material Carbon paper (12.5 cm ² ) Carbon paper (12.5 cm ² ) Membrane Material Bipolar membrane Bipolar membrane Reference electrode Ag / AgCl Ag / AgCl Power supply Schedule crisis Schedule crisis Potential supply amount +0.5 V +0.5 V Target substance for electron donors Trivalent arsenic (80 mg / L) Trivalent arsenic (150 mg / L) Target substance for electron acceptor none none Trivalent arsenic oxidation rate 27 g / m ³ / d 19 g / m ³ / d Expression center Mixed strain Pure strain
( Klebsiella sp. JHW3)

As shown in Table 4, in the case of using pure strains as a seed source in the bioelectrochemical device according to the present invention, the oxidation rate of trivalent arsenic is 19 g / m ³ / d . However, when the mixed strains were used as the seed source, the oxidation rate of trivalent arsenic was 27 g / m ³ / d, which was about 1.4 times higher than that of pure strains.

Therefore, in the bioelectrochemical device according to the present invention, in order to increase the oxidation rate of trivalent arsenic, a mixed strain containing Alphaproteobacteria and Betaproteobacteria as the right- It is preferable to use it as a seed source.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

10: Power supply
20: Lead wire
30: bipolar membrane
40: oxidation electrode part
41: oxidized electrode
42: reference electrode
50: reduction electrode portion
51: reduction electrode
60: magnetic bar
70: Sampling port

Claims (8)

The oxidized electrode part includes an oxidized electrode and is supplied with the treated water. The electrolyzed arsenic-oxidizing microorganism treats the oxidized electrode part and the reduced electrode part by the bipolar membrane located at the center, And the reducing electrode unit includes a reference electrode and a reducing electrode. The reducing electrode unit is a dual chamber-type unit which is supplied with treated water and denitrifies nitrate nitrogen into nitrogen gas by an electroactive denitrifying microorganism, ) Reactor; And
A potential control unit comprising a power supply unit and a lead to control a constant potential between the reference electrode and the oxidation electrode or the reduction electrode;
Lt; / RTI &gt;
Wherein the electro-active arsenic oxidation-related microorganism is a mixed strain comprising, as a fungus, Alphaproteobacteria and Betaproteobacteria which use arsenic-contaminated soil as a seed source. A biosynthetic biochemical contaminant removal device capable of simultaneously removing nitrogen. delete The method according to claim 1,
Wherein the potential control unit supplies a potential to the oxidizing electrode and maintains a potential difference between the reference electrode and the oxidizing electrode at +0.5 V. A method for simultaneous removal of arsenic and nitrogen in treated water using the apparatus for removing odorous bio-electrochemical contaminants of claim 1. 5. The method of claim 4,
The method includes: a first step of injecting treatment water into an inlet of a reactor and supplying a potential to the reactor; And
The trivalent arsenic in the treated water injected in the first step is oxidized to the pentavalent arsenic by the electroactive arsenic oxidation-related microorganisms in the oxidation electrode portion of the reactor, and the generated electrons and hydrogen ions are reduced And a second step in which the nitrate is removed by the electroactive denitrifying microorganism in the reducing electrode part to reduce the nitrate nitrogen to nitrogen gas. Simultaneous removal method. 6. The method of claim 5,
Further comprising the step of adsorbing and removing the oxidized pentavalent arsenic using an adsorbent in the second step. delete 5. The method of claim 4,
Wherein the supply of the electric potential supplies the electric potential to the oxidizing electrode while maintaining the potential difference between the reference electrode and the oxidizing electrode at +0.5 V.

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