KR20150055929A - Electrolysis Type Ballast Water Treatment System usable in fresh Water Area - Google Patents

Abstract

The present invention relates to an electrolysis-type ballast water treatment system usable in a freshwater area, which can kill underwater creatures in ballast water by generating strong oxidizers through electrolysis under the condition of fresh water having less charge carriers. The ballast water treatment system comprises: a housing (10) having an inlet (11) into which non-treated ballast water is introduced and an outlet (12) from which treated ballast water is discharged; and at least one BDD electrode module (20) which is installed in the housing to kill underwater creatures in ballast water flowing into the housing (10) by generating ozone and hydroxyl radicals through the electrolysis of ballast water consisting of fresh water. Therefore, the present invention is capable of preventing disturbance of the ecosystem in surrounding sea areas due to ballast water of a ship sailing ports having a low salt concentration like Shanghai, the ocean and inland areas at the same time and extending the ballast water treatment to freshwater areas of the world.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrolysis type ballast water treatment system usable in freshwater areas,

The present invention relates to a ship ballast water treatment apparatus for preventing marine pollution by killing aquatic organisms contained in ship ballast water, and more particularly, to a ship ballast water treatment apparatus capable of generating a strong oxidant (O 3, OH radical) To an electrolysis type ship ballast water treatment apparatus which can be used in a fresh water area where the aquatic organisms in the ballast water can be killed.

In general, ballast water refers to water that is injected into a tank in a ship to maintain the balance of the ship, such as a cargo ship. A cargo ship is designed to carry cargo and has sufficient buoyancy to prevent sinking when the cargo is loaded. Therefore, if the freight is not loaded on the cargo ship, the buoyancy causes the ship to rise excessively above the water surface, thus increasing the risk of rollover accidents. In addition, if the ship is not properly immersed in water, a part of the propeller is exposed on the water, which causes a problem that propulsion is deteriorated.

Therefore, it is necessary to inject a certain amount of water instead of cargo to the center of gravity of the vessel where the cargo is not loaded. In this case, the water to be injected is the ballast water. Ordinary cargo ships carry 30 to 40% of the cargo load as ship equilibrium.

However, the ballast water described above includes aquatic organisms such as plankton and bacteria in seawater. If these ship equilibria are loaded on ships and they are discharged to other countries across borders, marine pollution will occur due to disturbance of indigenous ecosystems in the surrounding waters due to various aquatic organisms contained in the discharged ballast water.

Accordingly, the International Maritime Organization (IMO) adopted the Convention on Ballast Water Management in 2004 in order to regulate ship ballast water, which is the main cause of marine pollution. The Convention on Ballast Water Management requires vessels newly built to comply with IMO to be obligated to install ballast water treatment facilities approved by IMO from 2012 to 2020 depending on their size.

As the Convention on Ballast Water Management, enacted by the International Maritime Organization (IMO), is expected to become effective in the near future, Korea has also enacted the Rules for the Implementation of the Ballast Water Management Law (Law No. 8788, Dec. 21, 2007). Among them, the treatment standard that can discharge the ballast water from the port is to accept the international convention standard, and when the number of aquatic organisms having a size of 50 μm or more is less than 10 per 1 m 3, If less than 10, the ballast water can be discharged from the port.

Ship water ballast water treatment facilities use various methods such as electrolysis method (straight tube type, side stream method), ultraviolet ray sterilization method (UV method), filter method and sterilization method using ozone to satisfy these processing standards. Among them, the electrolysis method is a method of treating ballast water through disinfection using direct disinfection method using hypochlorous acid (HClO, NaClO), hydroxyl radical (OH Radical) generated by electrolysis of seawater or electric potential difference.

As such, the electrolysis method uses an electrolytic process in which oxygen or chlorine is generated, such as a seawater decomposition process. As the electrode, metal titanium is used as a substrate and a platinum group metal such as iridium (Ir) or ruthenium Oxide coating is used.

These platinum group metal complex oxide electrodes have relatively low overvoltage for oxygen generation and are known to oxidize the electrode toxic organic substances on the electrode surface and to maintain the integrity for a long time in an oxygen or chlorine solution atmosphere. Such an electrode is called a DSA (Dimensionally Stable Anode) electrode.

These DSA electrodes are not difficult to use in seawater and brackish water with high salt concentration, but it is difficult to use hypochlorite (HClO, NaClO) in freshwater area with low salt concentration. . That is, in the freshwater region, there are fewer charge carriers such as salinity, which leads to an increase in resistance, which results in a decrease in durability between the substrate and the platinum group metal complex oxide layer, resulting in a decrease in electrode efficiency.

For reference, the nose refers to water mixed with seawater and fresh water appearing in the coastal habitat or the inlet, and refers to the middle of seawater and freshwater in terms of salt concentration. Nodule and fresh water are generally classified based on the concentration of 500 mg / l of salt, but they may be classified based on 1,000 mg / l. The United States Geological Survey has found that freshwater, fresh water, brackish water, brackish water, saltwater if it has a water content of 100,000 to 100,000, (Brine).

On the other hand, the salt concentration of seawater may be expressed as PSU (Practical Salinity Unit) indicating g mass of dissolved substance dissolved in 1 kg of seawater. The concentration of salt in Baltic Sea with increasing trade volume and trade volume is 0.25PSU It is remarkably lower than the salt concentration of sea water (33 PSU), which is close to fresh water.

In order to solve the problem of the DSA electrode described above, methods of using an additional device such as a filter and UV or plasma in an electrolysis method have been studied, but it is necessary to use an expensive filter, UV and plasma methods are also expensive and are not easy to apply.

On the other hand, boron doped diamond electrodes (hereinafter, referred to as "BDD electrodes") are capable of generating ozone and OH radicals, which are strong oxidizing agents, through electrolysis even under fresh water conditions, and are applied to wastewater treatment apparatuses. Therefore, it is necessary to develop a BDD electrode with high durability and strong oxidizing agent, such as ozone and OH radical, capable of withstanding high voltage due to the increase of resistance in a fresh water area such as an injury, and it is also used in fresh water It is necessary to develop a ship ballast water treatment system.

The prior art relating to a ship ballast water treatment facility using electrolysis will be described below.

Patent Document 1 discloses an electrolytic-type ship ballast water treatment apparatus which discharges ballast water using electrolytic water as well as discharges hydrogen gas generated during production of electrolytic water safely into seawater outside the hull.

Patent Document 2 discloses a marine fresh water generator that is used for fresh water production on a ship and uses concentrated brine of an abandoned fresh water generator to optimally maintain the electrical conductivity of the electrolytic raw water flowing into the electrolytic reactor inlet side And an electrolysis type ship ballast water treatment apparatus using the same.

Patent Document 3 discloses that the inside of the chlorine injection pipe installed between the electrolytic device and the ballast tank is always maintained in a positive pressure to prevent the leakage of the leaking water from the explosion dangerous area to the safety zone and minimize the length of the chlorine injection pipe And a chlorine injection into the ballast tank can be performed quickly. The electrolytic ballast water treatment apparatus and the explosion prevention control method using the electrolytic ballast water treatment apparatus are disclosed.

The prior art related to the BDD electrode for the electrolysis of fresh water is as follows.

Patent Document 4 discloses an ozone generator capable of improving stability and permanence of an electrode (anode) when ozone gas is generated by electrolysis of water by using boron-doped conductive diamond as an electrode.

Patent Document 5 discloses an electrochemical wastewater treatment method using a boron-doped diamond electrode so as to economically and effectively remove nitrate nitrogen and microorganisms in wastewater by electrolyzing contaminated wastewater by using a boron-doped diamond electrode .

KR 10-2011-0023484 A KR 10-2011-0109299 A KR 10-2012-0122383 A KR 10-2003-0054255 A KR 10-2006-0046358 A

Disclosure of the Invention The present invention has been conceived to solve the above problems of the prior art, and it is an object of the present invention to provide a BDD electrode capable of generating ozone and OH radicals, which are strong oxidizing agents, The present invention is directed to an electrolytic ship ballast water treatment apparatus that can be used in a ship.

To achieve the above object, according to the present invention, there is provided a water treatment system comprising: a housing having an inlet portion into which a ballast water before treatment is introduced and an outlet portion through which processed ballast water is discharged; And one or more BDD electrode modules installed in the housing to generate ozone and hydroxyl radicals through electrolysis of ship ballast water composed of fresh water and to kill aquatic organisms in the ballast water flowing into the inside of the housing .

According to the electrolytic ship ballast water treatment apparatus of the present invention, several BDD electrode modules are connected in series. For a variety of applications depending on capacity, a flange can be used as shown in Fig.

According to the electrolytic ship ballast water treatment apparatus of the present invention, the BDD electrode of the BBD electrode module is formed by cleaning a valve metal (Ru, Ir, Sn, Ti, Nb, Ta, And a diamond doped with boron is formed by a CVD (chemical vapor deposition) method.

According to the electrolytic ship ballast water treatment apparatus of the present invention, the coating thickness of diamond doped with boron in the BDD electrode is 1 to 10 탆.

According to the electrolytic ship ballast water treatment apparatus of the present invention, the size, shape and shape of the BDD electrode are determined according to the capacity of the processing apparatus.

According to the electrolytic ship ballast water treatment apparatus of the present invention, the BDD electrode has a plate shape or a mesh shape.

According to the electrolytic ship ballast water treatment apparatus of the present invention, the housing is provided on at least one of the inlet port through which the ballast water flows into the tank of the ship or the discharge port through which the ballast water is discharged from the tank of the ship do,.

The electrolytic vessel ballast water treatment apparatus of the present invention generates ozone and OH radicals through electrolysis reaction at the BBD electrode in seawater and ballast water as well as seawater ballast water to kill microbes in the ballast water, It is possible to treat the ballast water in the freshwater area.

Accordingly, ecosystem disturbance in the surrounding waters due to ship equilibrium of vessels operating at low salt concentrations and ships operating in the ocean and inland at the same time, is prevented, and ship equilibrium water treatment is extended to the entire desalination regions of the world.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing an electrolytic ship ballast water treatment apparatus usable in a fresh water area according to the present invention; FIG.
2 is a sectional view showing a BDD electrode module which is a main part of the present invention.
3 is an electron microscope image showing the surface of a BDD electrode which is a main part of the present invention.
Figure 4 is a partial enlarged view of Figure 3;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electrolytic ship ballast water treatment apparatus of the present invention will be described with reference to the accompanying drawings.

1 and 2, an electrolytic ship ballast water treatment apparatus according to the present invention includes an inlet 11 for introducing the ballast water before treatment and an outlet 12 for discharging the treated ballast water (10); (10) for generating ozone and hydroxyl radical through electrolysis of ship equilibrium water composed of fresh water to kill the aquatic organisms in the ballast water flowing into the inside of the housing (10) And a plurality of BDD electrode modules 20 connected in series.

The BDD electrode 25 of the BBD electrode module 20 is formed by cleaning a valve metal (Ru, Ir, Sn, Ti, Nb, Ta, etc.) substrate or a Si substrate and then performing a chemical vapor deposition (CVD) The surface of the BBD electrode 25 doped with boron can be confirmed through FIGS. 3 and 4. FIG. Here, the coating thickness of the doped boron in the BDD electrode 25 is preferably 1 to 10 탆.

The size, shape and shape of the BDD electrode 25 are determined according to the capacity of the processing apparatus. Specifically, although the BBD electrode 25 of the embodiment is shown in the form of a circular mesh, it may be formed in various shapes such as a plate shape as required.

Meanwhile, the housing 10 may be installed at either one of the inlet port through which the ballast water flows into the tank of the ship or the outlet port through which the ship ballast water is discharged from the tank of the ship, or both the inlet port and the outlet port.

The electrolytic ship ballast water treatment apparatus of the present invention configured as described above can prevent contamination of the surrounding sea area by discharging the aquatic organisms contained in the ballast water including seawater and nautical water as well as fresh water.

The ballast water flows in through the inlet 11 of the housing 10 and is connected in series to the ozone and OH radicals generated through the electrolysis reaction in the BDD electrode module 20 installed in the housing 10 The microbes of ship equilibrium water are killed. The BDD electrode 25 provided in the BDD electrode module 20 can generate ozone and OH radicals through electrolysis even when the component of the ballast water is seawater or radial water as well as fresh water.

Specifically, the BDD electrode 25 generates ozone, OH radicals, and various oxidizing agents at the anode during the electrolysis. Ozone is a substance with a high potential difference (2.07 V) next to the OH radical, which is then removed by oxidizing microorganisms and organic substances in the ballast water. In addition, since it does not leave any chemical substance after oxidation, it has an advantage of not causing secondary pollution, and is also used for water treatment and sewage treatment.

The OH radical has the highest potential difference (2.80 V) among the major oxidants. The OH radicals generated during electrolysis are present only for a few seconds or less, but they are excellent in sterilization and disinfection of almost all pollutants. In addition, the OH radical has a strong oxidizing power, and thus has a powerful effect of decomposing and removing pollutants. It is a natural substance harmless to human body which is not toxic. By ion exchange with cell membrane, And sterilization is performed.

The sterilized ship ballast water is discharged through the outlet 12 of the housing 10 so that only the ballast water number of the microbes destroyed is discharged to the outside of the ship to prevent ecosystem disturbance in the surrounding sea area.

In addition, when the housing 10 is installed at an inlet of a tank installed on a ship, microbial propagation in the tank can be prevented by sterilizing ship ballast water flowing into the tank, It is possible to sterilize the ballast water discharged from the tank so that only the ballast water with microorganisms killed can be discharged.

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, It will be appreciated by those skilled in the art that numerous changes and modifications can be made to the invention without departing from the spirit and scope of the invention. And all such modifications and changes as fall within the scope of the present invention are therefore to be regarded as being within the scope of the present invention.

10 ... housing
11 ... inlet portion
12 ... outlet
20 ... BDD electrode module
25 ... BDD electrode

Claims (7)

A housing (10) having an inlet (11) through which the ballast water before processing is introduced and an outlet (12) through which the processed ballast water is discharged;
(10) installed in the housing (10) so as to generate ozone and hydroxyl radicals through electrolysis of ship ballast water composed of fresh water to kill the aquatic organisms in the ballast water flowing into the inside of the housing (10) And an electrode module (20). The method according to claim 1,
Wherein the BDD electrode module (20) is connected in series, and the electrolytic vessel ballast water treatment apparatus is connectable in various flanges according to the treatment capacity. The method according to claim 1,
The BDD electrode 25 of the BBD electrode module 20 is formed by cleaning a valve metal (Ru, Ir, Sn, Ti, Nb, Ta or the like) substrate or a Si substrate and then performing a chemical vapor deposition (CVD) And a diamond is produced. The method of claim 3,
Wherein the coating thickness of the boron doped in the BDD electrode (25) is 1 to 10 占 퐉. The method of claim 3,
The size, shape and shape of the BDD electrode (25) are determined according to the capacity of the processing apparatus. The method of claim 3,
Wherein the BDD electrode (25) has a plate shape or a mesh shape. 7. The method according to any one of claims 1 to 6,
Wherein the housing (10) is installed at at least one of an inlet where the ballast water flows into the tank of the ship or an outlet through which the ballast water is discharged from the tank of the ship.

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