KR20120028771A - Waste water treatment apparatus and method - Google Patents

Abstract

PURPOSE: An apparatus for treating wastewater and a method for treating wastewater are provided to effectively eliminate organic materials from wastewater and to uniformly purify the entire wastewater. CONSTITUTION: An apparatus for treating wastewater includes a bubble generating part(200) and a plasma treating part(300). The bubble generating part supplies gas to wastewater and forms bubbles in the wastewater. The plasma treating part supplies a wastewater storing space. The plasma treating part applies electric field to the wastewater to be plasma-treated. Gas in the bubble of the wastewater is ionized based on the electric filed such that the wastewater is purified. The gas is one of air, oxygen, nitrogen, or argon.

Description

Wastewater Treatment System and Wastewater Treatment Method {WASTE WATER TREATMENT APPARATUS AND METHOD}

The present invention relates to a wastewater treatment apparatus and a wastewater treatment method. More specifically, the present invention relates to a wastewater treatment apparatus and a wastewater treatment method capable of uniformly purifying the entire wastewater.

Wastewater treatment aims at the removal of contaminants contained in the wastewater, and can be classified into primary treatment, secondary treatment and tertiary treatment depending on the treatment method.

Here, the primary treatment means a method for physically removing the suspended matter in the wastewater, which is usually the process from the sewage treatment plant to the initial settling basin. Secondary treatment is intended to remove organic matter dissolved in wastewater and organic matter not treated in the first treatment, and biological treatment is mainly used. Tertiary treatment refers to a combination of physical, chemical, and biological treatments to remove highly biodegradable organic matter and nutrients such as nitrogen and phosphorus that could not be removed in the secondary treatment.

Typically, the wastewater discharged from the sewage treatment plant refers to the secondary treatment. However, there is not yet a high rate of reuse of secondary treated wastewater discharged from sewage treatment plants. When wastewater is reused, efforts are being made to purify and reuse wastewater because it can drastically improve environmental problems caused by water depletion.

As part of this effort, there have been attempts to purify wastewater by directly decomposing wastewater using plasma discharge. However, according to this conventional method, since plasma discharge is generally biased, there is a problem that the entire wastewater cannot be uniformly purified by simple plasma discharge.

Therefore, a technique for purifying wastewater by introducing plasma gas from the outside and injecting the plasma gas into the wastewater has been introduced. However, according to this method, there is a problem that the purification effect of the wastewater is weakened because only a small amount of plasma gas can be dissolved in the wastewater.

The object of the present invention is to solve all the problems of the prior art described above.

Another object of the present invention is to provide a wastewater treatment apparatus and a wastewater treatment method capable of uniformly purifying the entire wastewater.

In addition, another object of the present invention is to provide a wastewater treatment apparatus and a wastewater treatment method capable of effectively removing organic matter in the wastewater.

In order to achieve the above object, a wastewater treatment apparatus according to an embodiment of the present invention comprises a bubble generator for supplying gas to the wastewater to form bubbles in the wastewater; And a plasma processing unit that provides a space for storing the wastewater and applies an electric field to the wastewater to plasma treat the wastewater, wherein the gas in the bubble in the wastewater is ionized by the electric field to purify the wastewater. It features.

The gas may be any one of air, oxygen, nitrogen, and argon.

The bubble generator may include a pump for pressurizing and transporting the waste water.

The voltage applied to the plasma processing unit may be 1 to 15 kV.

The frequency of the voltage applied to the plasma processing unit may be 5 to 40 kHz.

The plasma processing unit may plasma-process the wastewater using a dielectric barrier discharge.

The plasma processing unit includes: a cylindrical dielectric barrier tube for providing a space for storing the wastewater and for forming a dielectric barrier discharge; A cylindrical external electrode disposed outside the dielectric barrier tube and to which a positive voltage is applied; And a cylindrical internal electrode disposed in the dielectric barrier tube at a predetermined distance from the dielectric barrier tube and to which a ground voltage is applied.

The plasma processing unit may be configured to include a plurality of plasma generating unit for plasma processing the wastewater independently.

The ionized gas may decompose water molecules of the wastewater to generate hydrated radicals.

The hydrated radicals may react with the organic matter contained in the wastewater to purify the wastewater.

The gas may be supplied to the bubble generator with a constant flow rate.

The wastewater supply unit may further include a wastewater supply unit supplying the wastewater to the bubble generator, and the wastewater may be supplied to the bubble generator while having a constant flow rate.

In order to achieve the above object, the wastewater treatment method according to an embodiment of the present invention is to supply a gas to the wastewater to form bubbles in the wastewater, applying an electric field to the wastewater plasma treatment of the wastewater, The gas in the bubble in the wastewater is ionized by an electric field, and the wastewater is purified.

According to the present invention, there is an effect capable of uniformly treating the entire wastewater.

Moreover, according to this invention, there exists an effect which can remove the organic substance which exists in waste water effectively.

1 is a view showing the configuration of a wastewater treatment apparatus according to an embodiment of the present invention.
2 is a flowchart illustrating a process of forming a bubble in a wastewater by a bubble generator in accordance with an embodiment of the present invention.
3 is a cross-sectional view illustrating an arrangement state of a dielectric barrier tube, an external electrode, and an internal electrode of a plasma processing unit according to an exemplary embodiment of the present invention.
4 is an enlarged view illustrating a configuration of a bubble generator in the wastewater treatment apparatus of FIG. 1.
FIG. 5 is an enlarged view of a configuration of a bubble generator in a wastewater treatment apparatus including a wastewater separator.
6 is a view showing the configuration of a wastewater treatment apparatus according to another embodiment of the present invention.
7 is a view showing the configuration of a wastewater treatment apparatus according to another embodiment of the present invention.

DETAILED DESCRIPTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein may be implemented with changes from one embodiment to another without departing from the spirit and scope of the invention. In addition, it is to be understood that the location or arrangement of individual components within each embodiment may be changed without departing from the spirit and scope of the invention. Accordingly, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention should be taken as encompassing the scope of the claims of the claims and all equivalents thereto. Like reference numerals in the drawings indicate the same or similar elements throughout the several aspects.

Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

1 is a view showing the overall configuration of the wastewater treatment apparatus 10 according to an embodiment of the present invention.

1, the wastewater treatment apparatus 10 according to an embodiment of the present invention includes a wastewater supply unit 100, a bubble generator 200, a plasma treatment unit 300, and a treated water storage unit 400. It can be seen that it can be configured.

First, the wastewater supply unit 100 of the present invention may perform a function of supplying the stored wastewater to the bubble generator 200. The wastewater supply unit 100 may be configured to have a constant volume to temporarily store a predetermined amount of wastewater for a long time. Here, the wastewater is a generic term for liquid wastes that have not been used, and may include all of household wastewater, industrial wastewater, and livestock wastewater.

A wastewater supply pipe 110 may be installed at one side of the wastewater supply unit 100 so that the wastewater may be supplied to the bubble generator 200. The wastewater is preferably supplied to the bubble generator 200 through the wastewater supply pipe 110 while having a constant flow rate. In this case, it can help to uniformly distribute the bubbles inside the waste water. In a similar sense, the wastewater is preferably supplied to the bubble generator 200 at a constant temperature and at a constant pressure.

Next, the bubble generator 200 of the present invention may perform a function of forming bubbles in the wastewater by supplying gas to the wastewater. Here, the type of gas may be any one of air, oxygen, nitrogen, and argon present in the atmosphere, and in some cases, may be a gas in which oxygen, nitrogen, and argon are additionally mixed with air present in the atmosphere. In addition, the bubble formed in the waste water may be a micro bubble having a diameter of 10 to 100um or a nano bubble having a diameter of 10 to 1000nm, in some cases may be a general bubble having a diameter of 100um or more.

The gas may be supplied to the bubble generator 200 through the gas introduction pipe 210 installed at one side of the bubble generator 200. The gas is preferably supplied to the bubble generator 200 while having a constant flow rate. In this case, the bubbles may have a uniform size and may help to uniformly distribute the bubbles in the waste water. In a similar sense, the gas is preferably supplied to the bubble generator 200 at a constant temperature and at a constant pressure.

The bubble generator 200 may include a pump (not shown) to form bubbles in the wastewater. Such a pump may serve to pressurize the wastewater so that bubbles may form in the wastewater.

2 is a flowchart illustrating a process of forming a bubble in the waste water by the bubble generator 200 according to an embodiment of the present invention.

First, referring to FIG. 2, wastewater and gas may be introduced into the bubble generator 200.

Next, referring further to FIG. 2, waste water and gas may be mixed in the pump of the bubble generator 200. At this time, the wastewater may be pressurized by a pump.

Next, referring further to FIG. 2, wastewater and gas may be further mixed along a constant line connected to the pump. At this time, since the pressure of the line is lowered as the waste water is pressurized by the pump, the gas and the waste water are easily mixed so that the gas is supplied in the form of a bubble into the waste water.

Finally, referring to FIG. 2, wastewater supplied with gas in a bubble form is discharged.

Next, the plasma processing unit 300 of the present invention may perform a function of providing a space for storing the wastewater supplied through the wastewater discharge pipe 220. To this end, the plasma processing unit 300 may be configured to include a three-dimensional space having a predetermined volume so that the waste water flows through. Such a three-dimensional space may mean a space in the dielectric barrier tube 310, which will be described later, or may mean a space in the sealed reactor 360, which will be described later.

On the other hand, as described above, since the waste water is supplied to the plasma processing unit 300 via the bubble generating unit 200, the wastewater supplied to the plasma processing unit 300 may be in a state containing a bubble.

In addition, the plasma processing unit 300 of the present invention may perform a function of plasma treatment of the wastewater by applying an electric field to the wastewater. The gas in the bubble is ionized during the plasma treatment process, and thus the wastewater can be purified, which will be described in more detail as follows.

When a voltage having a constant frequency is applied to the plasma processing unit 300 to generate an electric field inside the plasma processing unit 300, the gas existing in the waste water in a bubble state may be converted into a plasma state. Particles constituting such a plasma may react directly or indirectly with the organic matter contained in the wastewater, and the reaction may purify the wastewater.

For example, the ions and free electrons that make up the plasma can decompose water molecules in the wastewater to produce hydrated radicals. Here, the hydration radical is OH ?, OH ₂ ? O? And the like. Such hydrated radicals may react with organic matter contained in the wastewater. For example, hydrated radicals OH ?, O? And the like can react with NH ₄ , one of the organics, to produce N ₂ and H ₂ O. The reaction of the hydrated radicals as described above can be extended to all organic matter contained in the wastewater, the waste water can be purified by the reaction of the hydration radical and the organic matter.

The gas bubbles are relatively uniformly distributed inside the liquid liquid. Therefore, in the present invention in which the waste water is purified by ionizing the gas in the uniformly distributed bubbles, it is possible to realize the effect of uniformly treating the whole waste water.

In order to purify the whole waste water more uniformly, it is necessary to adjust the size and distribution of bubbles more uniformly. To this end, the method described above (how to keep the feed rate, feed pressure, feed temperature of waste water and gas constant) may be further used.

On the other hand, the voltage applied to the plasma processing unit 300 needs to be appropriately adjusted. If the voltage is too high, water molecules can be directly decomposed by the electric field, and if the voltage is too low, the gas in the bubble may not be ionized. In view of the above, the voltage applied to the plasma processing unit 300 is preferably 1 to 15 kV.

In addition, the frequency of the voltage applied to the plasma processing unit 300 also needs to be appropriately adjusted. Similar to the case of voltage, if the frequency is too high, not only gaseous gas but also liquid water molecules can be decomposed together by the electric field, and if the frequency is too low, the gas in the bubble may not be ionized. In view of such a point, the frequency of the voltage applied to the plasma processing unit 300 is preferably 5 to 40 kHz.

Meanwhile, the plasma processing unit 300 of the present invention may use various methods to generate an electric field. For example, the plasma processing unit 300 of the present invention may include a DBD plasma source, an inductively coupled plasma (ICP) plasma source, a capacitively coupled plasma (CCP) plasma source, a transformer coupled plasma (TCP) plasma source, and an ECR (ECR). An electron cyclotron resonance (SCP) plasma source, a surface wave plasma (SWP) plasma source, or the like can be employed.

1 illustrates a case in which the plasma processing unit 300 of the present invention employs a DBD plasma source among the various plasma sources as described above. Hereinafter, the configuration of the plasma processing unit 300 employing the DBD plasma source will be described with reference to FIGS. 1 and 3.

Referring to FIG. 1, it can be seen that the plasma processing unit 300 includes the dielectric barrier tube 310, the external electrode 320, and the internal electrode 330.

In order to facilitate understanding of the arrangement of the above components, the arrangement state of the dielectric barrier tube 310, the outer electrode 320 and the inner electrode 330 is shown at an angle different from that of FIG.

First, the dielectric barrier tube 310 may be configured in a cylindrical shape to provide a space for temporarily storing wastewater. To this end, the internal electrode 330 disposed inside the dielectric barrier tube 310 may be disposed at a predetermined distance from the dielectric barrier tube 310. Wastewater may flow into the space formed between the dielectric barrier tube 310 and the internal electrode 330.

In addition, the dielectric barrier tube 310 may perform a function of forming a dielectric barrier discharge. More specifically, the dielectric barrier tube 310 may limit the amount of charge delivered by one micro discharge and allow the micro discharge to spread throughout the electrode. For this purpose, the dielectric barrier tube 310 is preferably made of a material having a high dielectric constant (eg, a material such as glass, quartz, ceramic, etc.). Meanwhile, the thickness of the outer wall of the dielectric barrier tube 310 (ie, the difference between the outer diameter and the inner diameter of the dielectric barrier tube 310) is preferably about 1 to 3 mm.

Next, the external electrode 320 may be formed in a cylindrical shape and disposed outside the dielectric barrier tube 310. As illustrated in FIG. 1, the external electrode 320 may be connected to the high frequency power source 340, and a positive voltage may be applied to the external electrode 320 through the high frequency power source 340. The material of the external electrode 320 is not particularly limited but may be preferably aluminum or SUS.

Next, the internal electrode 330 may be formed in a cylindrical shape and disposed inside the dielectric barrier tube 310. In this case, as described above, the internal electrode 330 may be disposed at a predetermined distance from the dielectric barrier tube 310. As shown in FIG. 1, a ground voltage 350 may be applied to the internal electrode 330. The material of the internal electrode 330 is not particularly limited but may be preferably aluminum or SUS.

As a positive voltage is applied to the external electrode 320, an electric field is generated in the space between the dielectric barrier tube 310 and the internal electrode 330, and further, the gas inside the bubble of the wastewater flowing into the space may be ionized. Will be. The wastewater can be purified by ionization of gas as described above.

Next, the treatment water storage unit 400 of the present invention may be configured to have a predetermined volume to perform a function of storing the purified waste water (hereinafter, treated water). One side of the treated water storage unit 400 may be provided with a treated water introduction pipe 410, through which the treated water may be introduced into the treated water storage unit 400. The treated water stored in the treated water storage unit 400 may be used in general industrial water through an additional treatment process, since all organic matters are removed.

On the other hand, although not shown in Figure 1, the wastewater treatment apparatus 10 of the present invention may be configured to further include a temperature control means (not shown) for adjusting the temperature of the wastewater. Such temperature control means may adjust the temperature of the wastewater to change the amount of gas that may be contained in the wastewater. In addition, the temperature regulating means may adjust the temperature of the wastewater to favor ionization of the gas in the wastewater.

Meanwhile, according to one embodiment of the present invention, bubbles may be formed by supplying gas to all waste water or part of waste water supplied to the plasma processing unit 300.

4 is a diagram illustrating a configuration for supplying gas to all wastewater supplied to the plasma processing unit 300.

Referring to FIG. 4, it can be seen that all wastewater supplied to the plasma processing unit 300 flows into the plasma processing unit 300 through the gas processing unit. In this configuration, gas may be supplied to all wastewater supplied to the plasma processing unit 300 to form bubbles.

FIG. 5 is a diagram illustrating a configuration for supplying gas only to some wastewater supplied to the plasma processing unit 300.

Referring to FIG. 5, some of the wastewater A of the wastewater supplied to the plasma processing unit 300 flows into the plasma processing unit 300 via the bubble generating unit 200, but is partially supplied to the plasma processing unit 300. Wastewater (B) can be seen that the direct flow into the plasma processing unit 300 through the wastewater separation pipe 120 without passing through the bubble generating unit (200).

In the case of employing such a configuration, since some of the wastewater in which bubbles are formed may be treated by mixing the remaining wastewater in which bubbles are not formed, there is an advantage in that a large amount of wastewater can be effectively treated.

6 is a view showing the overall configuration of the wastewater treatment apparatus 20 according to another embodiment of the present invention.

Since the wastewater treatment apparatus 20 of FIG. 6 is the same as the wastewater treatment apparatus 10 of FIG. 1 except for the configuration of the plasma treatment unit 300, the following description is the same as the wastewater treatment apparatus 10 of FIG. The description will be omitted.

Referring to FIG. 6, the plasma processor 300 according to another embodiment of the present invention may include a reactor 360 and a plurality of plasma generators 370.

First, the reactor 360 may perform a function of providing a space in which wastewater is temporarily stored. To this end, the reactor 360 may be installed so that the internal space is sealed.

Next, the plasma generating unit 370 may mean a unit for plasma treatment of wastewater by generating plasma independently. In FIG. 6, three plasma generating units 370 are illustrated in the reactor 360, but are not necessarily limited thereto.

Referring further to FIG. 6, each of the plasma generators 370 is a dielectric tube 372. It can be seen that the first electrode 374, the second electrode 376 and the power generator 378 is included.

Dielectric tube 372, first electrode 374. The dielectric barrier discharge described above may be used for the second electrode 376 and the power generator 378 to plasma treat the wastewater. More specifically, when a power source having a constant frequency is applied to the first electrode 374 and the second electrode 376 by the power generation unit 378, the space between the second electrode 376 and the dielectric tube 372. A discharge is generated in the wastewater, and the wastewater may be plasma-treated by the discharge.

7 is a view showing the overall configuration of the wastewater treatment apparatus 30 according to another embodiment of the present invention.

Since the wastewater treatment apparatus 30 of FIG. 7 is the same as the wastewater treatment apparatus 10 of FIG. 1 except that the plasma treatment unit 300 employs an ICP plasma source, the wastewater treatment of FIG. The same configuration as that of the device 10 will be omitted.

Referring to FIG. 7, it can be seen that the induction coil 380 is wound around the outer surface of the dielectric barrier tube 310.

The induction coil 380 may perform a function of generating an induction magnetic field to generate an electromagnetic field inside the dielectric barrier tube 310. To this end, RF power may be applied from the high frequency power supply 382 at both ends of the induction coil 380.

As the electromagnetic field is generated in the dielectric barrier tube 310, since the gas in the bubble in the wastewater is ionized and the wastewater may be purified, the detailed description thereof will be omitted.

Example

The wastewater was purified by using the wastewater treatment apparatus 10 shown in FIG. 1. The gas supplied to the wastewater was air, and a voltage of 10 kV at a frequency of 40 kHz was applied to the external electrode 320. The purified water was collected to measure the change in suspended solids concentration (SS), biological oxygen demand (BOD), and chemical oxygen demand (COD). Table 1 below is a table showing measured values.

TABLE 1

Referring to Table 1, it can be seen that the suspended solids concentration, biological oxygen demand, chemical oxygen demand is significantly reduced. From these results, it was confirmed that the wastewater treatment apparatus 10 of the present invention can effectively purify the wastewater.

Although the present invention has been described by specific matters such as specific components and limited embodiments and drawings, it is provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. Those skilled in the art can make various modifications and changes from this description. Therefore, the spirit of the present invention should not be limited to the above-described embodiments, and the scope of the spirit of the present invention is defined not only in the claims below, but also in the ranges equivalent to or equivalent to the claims. Will belong to.

10, 20: wastewater treatment device
100: wastewater supply unit
110: wastewater supply pipe
120: wastewater separation pipe
200: bubble generator
210: gas introduction pipe
220: wastewater discharge pipe
300: plasma processing unit
310: dielectric barrier tube
320: external electrode
330: internal electrode
340: high frequency power
350: ground voltage
360: reactor
370: plasma generating unit
372: dielectric tube
374: first electrode
376: second electrode
378: high frequency power supply
380: induction coil
382: high frequency power supply
400: treated water storage unit
410: treatment water introduction pipe

Claims (21)

A bubble generator for supplying gas to wastewater to form bubbles in the wastewater; And
Plasma processing unit for providing a space for storing the waste water and plasma treatment of the waste water by applying an electric field to the waste water
Including,
And said gas in said bubble in said waste water is ionized by said electric field to purify said waste water. The method of claim 1,
The gas is waste water treatment apparatus, characterized in that any one of air, oxygen, nitrogen, argon. The method of claim 1,
The bubble generator is a wastewater treatment apparatus, characterized in that it comprises a pump for pressurizing and transporting the wastewater. The method of claim 1,
The voltage applied to the plasma processing unit is wastewater treatment apparatus, characterized in that 1 to 15 kV. The method of claim 1,
The frequency of the voltage applied to the plasma processing unit is wastewater treatment apparatus, characterized in that 5 to 40 kHz. The method of claim 1,
And the plasma processing unit plasma-processes the wastewater using a dielectric barrier discharge. The method of claim 6,
The plasma processing unit,
A cylindrical dielectric barrier tube for providing a space in which the wastewater is stored and for forming a dielectric barrier discharge;
A cylindrical external electrode disposed outside the dielectric barrier tube and to which a positive voltage is applied; And
A cylindrical internal electrode disposed at a predetermined distance from the dielectric barrier tube and applied with a ground voltage inside the dielectric barrier tube.
Wastewater treatment apparatus comprising a. The method of claim 1,
The plasma processing unit comprises a plurality of plasma generating unit for plasma treatment of the waste water independently. The method of claim 1,
Waste water treatment apparatus characterized in that the water molecules of the waste water are decomposed by the ionized gas to produce hydrated radicals. 10. The method of claim 9,
And said hydration radical reacts with the organic matter contained in said wastewater to purify said wastewater. The method of claim 1,
The gas is a wastewater treatment apparatus, characterized in that supplied to the bubble generating unit having a constant flow rate. The method of claim 1,
Further comprising a waste water supply for supplying the waste water to the bubble generating unit,
The waste water treatment apparatus, characterized in that the waste water is supplied to the bubble generating unit having a constant flow rate. Supplying gas to the wastewater to form bubbles in the wastewater, applying an electric field to the wastewater to plasma treat the wastewater, and ionizing the gas in the bubble in the wastewater by the electric field to purify the wastewater. A wastewater treatment method characterized by the above-mentioned. The method of claim 13,
The gas is waste water treatment method, characterized in that any one of air, oxygen, nitrogen, argon. The method of claim 13,
The plasma treatment voltage is a wastewater treatment method, characterized in that 1 to 15 kV. The method of claim 13,
The frequency of the plasma treatment voltage is 5 to 40 kHz, the wastewater treatment method. The method of claim 13,
And treating said wastewater using a dielectric barrier discharge. The method of claim 13,
Waste water treatment method characterized in that the water molecules of the waste water are decomposed by the ionized gas to produce hydrated radicals. The method of claim 18,
The waste water treatment method characterized in that the waste water is purified by the reaction of the hydration radicals with the organic matter contained in the waste water. The method of claim 13,
The gas is wastewater treatment method characterized in that it is supplied to the wastewater with a constant flow rate. The method of claim 13,
Wastewater treatment method characterized in that the wastewater has a constant flow rate while the gas is supplied to the wastewater.

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