KR101466113B1 - High efficiency ballast water treatment system using co2 and treatment method thereof - Google Patents

Abstract

In the present invention, provided are a highly efficient electrolysis ballast water treatment device using carbon dioxide and a treatment method where carbon dioxide is dissolved in sea water, thereby decreasing the pH of sea water and turning into fine bubbles, which, thus, increases HOCI rate with excellent oxidizing power among total oxidation substances generated by the electrolysis when the pH of seawater is decreased. Therefore the treatment device of the present invention can increase the efficiency of sterilization in the same concentration condition of TRO compared with a ballast water treatment device of an existing electrolytic water process method.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-efficiency electrolytic ship ballast water treatment apparatus and a treatment method using carbon dioxide,

More particularly, the present invention relates to an apparatus and a method for treating a high-efficiency electrolyzed vessel ballast water using carbon dioxide, and more particularly, to a system and a method for treating a ballast water containing carbon dioxide generated by electrolysis when the pH of seawater is lowered by dissolving carbon dioxide in seawater, Since the presence of highly oxidizing HOCl in oxidizing substances increases, it is possible to increase the sterilization efficiency compared to the existing electrolytic water treatment type ballast water treatment apparatus under the same TRO concentration condition. Therefore, the high efficiency electrolytic vessel ballast water treatment apparatus And a method of processing the same.

In general, when there is no load on the ship and the propeller on the back of the ship floats on the surface of the water, the vessel is not steered properly. Therefore, in order to maintain the stability of the vessel, the center of gravity of the vessel must be lowered during operation.

However, since the gross weight of a ship is limited for safety, the vessel should be submerged under water by injecting ship equilibrium material in parallel to the center of the ship in accordance with the total weight of the cargo or passenger do. In addition, the ship equilibrium material is to be such that it can be easily discharged from the ship if necessary.

As a method for lowering the center of gravity of such a vessel, there has been traditionally a method of loading a solid material such as sand or lead as a ship equilibrium material under the vessel. However, such a solid material has a problem that it is not easy to discharge a solid material from a ship, and recently, water which is easy to inject and discharge into a ship is used as a parallel material. The water (seawater) used as such a ballast water balance material is called ballast water.

Injection and discharge of such ballast water are mostly carried out in ports or in the sea area where cargo or passengers ride.

Meanwhile, the ballast water is injected into or discharged from the ship by using a pump of the ship. At this time, the aquatic creatures included in the seawater are also injected or discharged into the ship. Therefore, seawater and aquatic organisms injected into the ship can be discharged to other places than the first place by moving long distance according to the operating distance of the ship.

Most of these aquatic organisms are unable to adapt to the new environment and die, but some of them may survive and disturb existing ecosystems or even destroy ecosystems in their area.

Therefore, the problem of disposal of ballast water has been highlighted by many countries, for example, by limiting the exchange of ballast water within the port through their own legal system or by forcing them to exchange in advance in places where water depth is high.

On the other hand, in the conventional electrolyzed vessel equilibrium water treatment method, when the water source to be electrolyzed is fresh water, the electrolytic substance necessary for electrolysis is generally lower than that of seawater, and thus the efficiency of generating sterilizing material is low.

The following Patent Document 1 discloses an apparatus and method for treating a ballast water, but does not disclose a method for lowering the pH of seawater by using carbon dioxide.

Korean Patent Registration No. 0883444

There is a need in the art for a new method for processing equipments and processing methods for ship equilibrium water that can increase sterilization efficiency under the same TRO (total residual oxidants) concentration condition.

According to the present invention, there is provided a high-efficiency electrolytic ship ballast water treatment apparatus using carbon dioxide, comprising: a seawater inflow pipe for introducing seawater; PH adjusting means for injecting carbon dioxide into a part of the seawater flowing through the seawater inlet pipe to lower the pH of the seawater; Fine bubble generating means for atomizing the carbon dioxide bubbles contained in the seawater whose pH has been lowered and converting the carbon dioxide bubbles into carbon dioxide fine bubbles; (HOCl) in the total oxidizing substances contained in the electrolyzed seawater by electrolyzing the seawater whose pH is lowered by dissolving the carbon dioxide microbubbles in the downstream of the microbubble generating means, An electrolytic treatment means for sterilizing the sea water in which the carbon dioxide microbubbles are dissolved by an excessive amount of hypochlorous acid and injecting the treated sea water into the ballast tank; And a ballast tank positioned at a rear end of the electrolytic processing means; / RTI >
The electrolytic processing means includes a rectifier; And at least one electrolytic module including a positive electrode and a negative electrode terminal connected to the rectifier and a comb-type electrolytic unit formed to be alternately disposed on the positive and negative terminals and scaled by the carbon dioxide microbubbles, An electrolysis reactor; And a control panel for controlling an electrolysis driving time of the electrolytic reactor by controlling the DC rectification of the rectifier and the electrolytic driving time of the comb-type electrolytic unit; And a control unit.

According to another preferred aspect of the present invention, the pH adjusting means comprises: a venturi injector; A concentrated carbon dioxide tank for injecting carbon dioxide into seawater introduced into the venturi injector; A regulator for adjusting the amount of carbon dioxide injected into the concentrated carbon dioxide tank according to the pH and the flow rate of seawater flowing into the venturi injector; And a mixing tank for dissolving concentrated carbon dioxide and seawater to produce carbon dioxide bubbles; / RTI >
The fine bubble generating means includes a fine bubble nozzle for atomizing carbon dioxide bubbles introduced from the mixing tank into a carbon dioxide fine bubbler and injecting the carbon dioxide bubbles into the main seawater inflow pipe.

According to another preferred aspect of the present invention, the mixing tank is characterized in that a partition wall is formed to increase the contact time between concentrated carbon dioxide and seawater.

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A method for treating a high-efficiency electrolyzed vessel ballast water using carbon dioxide includes the steps of: injecting carbon dioxide into a part of seawater flowing through a seawater inlet pipe to lower the pH of the seawater; Atomizing the carbon dioxide bubbles contained in the seawater into a carbon dioxide microcapsule; The present invention relates to an electrolytic apparatus for electrolyzing seawater in which carbon dioxide microbubbles are dissolved to lower the pH of the seawater, thereby increasing the ratio of the presence of hypochlorous acid (HOCl) among the total oxidizing substances contained in the electrolyzed seawater, Disinfecting the seawater in which the bubbles are dissolved with an excessive amount of hypochlorous acid and removing the scale generated in the electrolysis using the carbon dioxide microbubbles; And injecting the sterilized seawater into a ballast tank; And a control unit.

According to another preferred feature of the present invention, the carbon dioxide can be separated and concentrated from the exhaust gas generated during the operation of the ship.

According to one embodiment of the present invention, by dissolving carbon dioxide in seawater to lower the pH of seawater and converting seawater having a low pH to carbon dioxide microcapsules, the ratio of the presence of highly oxidative HOCl in total oxidizing substances contained in seawater is increased In the case of sea water, the ratio of HOCl is higher than that of conventional electrolytic ship equilibrium water treatment method under the same TRO concentration condition, so that the sterilization efficiency can be increased and the equipment size can be reduced and the driving cost can be lowered have.

Further, even when using fresh water as ballast water, it is possible to artificially set the pH lower than the pH of the fresh water condition by carbon dioxide microbubbles to further increase the amount of generated HOCl, thereby securing a sterilizing efficiency higher than a certain level at a low TRO concentration It is effective.

In addition, the pH of seawater can be controlled by artificially controlling the reaction of HOCl ^- & gt ^; H ⁺ + OCl ^- , thereby reducing the amount of hydrogen gas generated and improving the safety of electrolysis.

1 is a schematic view showing the structure of a ship ballast water treatment apparatus according to an embodiment of the present invention.
Fig. 2 is a plan view showing the mixing tank in the pH adjusting means of Fig. 1;
Fig. 3 is an enlarged plan view of the electrolytic reactor in the electrolytic processing means of Fig. 2; Fig.
4 is a schematic view showing the internal structure of the electrolysis module in the electrolysis reactor of FIG.
5 is a graph showing the distribution of hypochlorous acid and hypochlorous acid ions according to pH.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the following embodiments.

The embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements. In the drawings, like reference numerals are used throughout the drawings.

In addition, to include an element throughout the specification does not exclude other elements unless specifically stated otherwise, but may include other elements.

1 is a schematic view showing the structure of a ship ballast water treatment apparatus according to an embodiment of the present invention.

1, the ballast water treatment apparatus according to the present embodiment includes a ballast tank 120, ballast water injection means and ballast water discharge means, pH adjusting means, fine bubble generating means, and electrolytic processing means .

The ballast tank 120 may vary depending on the size of the vessel, and in the case of a large-sized vessel, it may exceed 100,000 m 2, but the present invention is not limited thereto.

The ballast water injecting means includes a seawater inflow pump 10 and a seawater inflow pipe 21 into which seawater is introduced from the direction (I) by driving the seawater inflow pump 10.

The ballast water discharging means includes a ballast water discharge pipe 22 connected to the ballast tank 120 to discharge the ballast water in the direction (D). At this time, the ballast water discharge pipe 22 may further include a ballast water inflow pump (not shown) and a dissolving tank (not shown).

The first and second branch pipes 23 and 24 send the seawater introduced through the seawater inlet pipe 21 to the electrolytic treatment means 140 or supply a part of them to the pH adjusting means and the fine bubble generating means . The first branch pipe (23) is a main seawater inflow pipe and most of the seawater is transferred to the electrolytic treatment means through the first branch pipe (23). The second branch pipe 24 is a seawater inflow pipe for dissolving carbon dioxide, and part of the seawater flowing through the seawater inflow pipe 21 flows into the pH control means through the second branch pipe 24. At this time, the first and second branch pipes (23, 24) may be provided with valves for regulating and supplying the supply amount of seawater.

Fig. 2 is a plan view showing the mixing tank in the pH adjusting means of Fig. 1;

1 and 2, the pH adjusting means is means for lowering the pH of seawater by injecting carbon dioxide into the seawater introduced through the seawater inlet pipe 21 and the second branch pipe 24, Is a means for atomizing the carbon dioxide bubbles contained in the seawater whose pH is reduced and converting it into a carbon dioxide microcapsule.

The pH control means includes a concentration carbon dioxide tank 111 for injecting carbon dioxide into the seawater introduced into the venturi injector 113 and the venturi injector 113 and a carbon dioxide injection amount of the concentrated carbon dioxide tank 111 to the venturi injector 113 A regulator 112 for adjusting the pH and the flow rate of the incoming seawater, and a mixing tank 150 for dissolving concentrated carbon dioxide and seawater to form carbon dioxide bubbles. The micro-bubble generating means atomizes the carbon dioxide bubbles flowing through the carbon dioxide bubble discharge pipe (26) from the mixing tank (150) into a finer carbon dioxide microbubbles and then flows into the first branch pipe (23, main seawater inflow pipe) And a fine bubble nozzle 116 which is mixed with seawater to make seawater having a low pH and then injected into the electrolytic treatment means.

Here, reference numerals 28 and 29 denote supply pipes for supplying carbon dioxide of the concentrated carbon dioxide tank 111 to the venturi injector 113, respectively.

The venturi injector 113 and the mixing tank 150 are connected to the first mixing water pipe 25 and the first mixing water pipe 25 is connected to the mixing tank 150 through a valve And a pH sensor 114 for measuring the pH of the mixed seawater. At this time, the venturi injector 113 may be replaced with a perforated plate or an orifice tube if necessary, and the present invention is not limited thereto.

The mixing tank 150 may have partition walls 152a and 152b formed therein so that the contact time between concentrated carbon dioxide and seawater is increased to facilitate dissolution. In this embodiment, two such partition walls are formed However, the present invention is not limited thereto, and only one barrier rib may be formed, or three or more barrier ribs may be formed at predetermined intervals.

In addition, the mixing tank 150 may be provided with a carbon dioxide discharging unit 115 that mixes carbon dioxide and seawater into carbon dioxide bubbles, and then discharges the remaining untreated carbon dioxide gas or large-sized large bubbles into the atmosphere.

The fine bubble nozzles 116 serve to atomize the carbon dioxide bubbles introduced from the mixing tank 150 to form more minute carbon dioxide fine bubbles.

Herein, it means that the carbon dioxide bubbles of about 30 탆 of the micropores are shrunk to about 10 탆 at a pressure of about 1.5 atm, and then compressed to about 0.1 to 10.0 탆 by shrinking to about 15 atm.

The electrolytic treatment means includes an electrolytic treatment means for sterilizing the electrolytically generated sodium hypochlorite in which the carbon dioxide microbubbles flowing through the fine bubble nozzle 116 are dissolved and injecting the electrolyzed sea water into the ballast tank 120, line processing type ballast water processing means.

The electrolytic processing means includes a control panel (not shown) for controlling the DC rectification of the rectifier 130, the rectifier 130, and the electrolytic drive time of the comb-shaped electrolytic unit to be described later, and at least one electrolytic module 141). ≪ / RTI > The electrolytic treatment means also includes an electrolytic water inlet (30) for injecting sterilized seawater by electrolysis into the ballast tank (120).

At this time, a TRO sensor 41 may be provided in the electrolytic water inlet 30 to detect the TRO concentration of the sterilized sea water and the flow meter 42 when necessary.

FIG. 3 is an enlarged plan view showing an electrolysis reactor in the electrolysis processing means of FIG. 2, and FIG. 4 is a schematic view showing an internal structure of an electrolysis module in the electrolysis reactor of FIG.

3, four electrolysis modules 141 are illustrated as one set for processing 300 tons per hour. However, the present invention is not limited to this, and the number of electrolysis modules is not limited to that of the ballast The capacity may be increased or decreased to 3 or less or 5 or more depending on the need.

4, the electrolysis module 141 includes a body 141a having a substantially square shape, a cathode terminal 142 and a cathode terminal 142 to receive DC rectification from the rectifier 130 into the body 141a, (143) are connected and arranged. At this time, the negative terminal 142 and the positive terminal 143 have support portions 142a and 143a facing each other inside the body 141a. In addition, the voltage of the rectifier 130 varies depending on the amount of applied current, and a voltage of 10 V or less for seawater or 15 V or less for fresh water can be applied, and the present invention is not limited thereto.

The comb-shaped electrolytic parts 144 and 145 are connected to the support parts 142a and 143a of the anode terminal 142 and the anode terminal 143, respectively, so as to be alternately arranged inside the body 141. [ At this time, the comb-shaped electrolytic units 144 and 145 may be formed by coating ruthenium on a titanium base so as to have good corrosion resistance even in seawater and fresh water, but the present invention is not limited thereto.

When the incoming seawater passes through the comb-type electrolysis units 144 and 145 of the electrode disassembling module 141, the electrolysis processing unit constructed as described above is electrolyzed through a potential difference according to the following reaction formula (1).

[Reaction Scheme 1]

<Chlorination>

NaCl → Na ⁺ + Cl ^-

2Cl ^- ? Cl ₂ + 2e ^-

Cl ₂ + H ₂ O → HCl + HOCl

HOCl -> H ⁺ + OCl ^-

H ₂ O → H ⁺ + OH ^-

Na ⁺ + OH ^- &gt; NaOH

Cl ₂ + ₂ NaOH → NaOCl + NaCl + H ₂ O

<Bromination>

HOCl + Br- &gt; HOBr + Cl-

HOBr → H + + OBr-

Among the chemical species generated by the above reaction formula 1, oxidation substances such as HOCl, OCl ^- , OH ^- , NaOCl, HOBr and OBr ^- are collectively referred to as total residual oxidants (TRO) and TRO is a disinfectant for various microorganisms. In particular, free available chlorine with high efficiency of disinfection with high oxidation resistance is HOCl and OCl ^- .

During electrolysis, HOCl and OCl ^- are irreversibly generated, and the ratio of the presence of HOCl and OCl ^- varies depending on the pH in the water as shown in FIG.

Referring to FIG. 5, it can be seen that the lower the pH is, the higher the ratio of the presence of HOCl, and the higher the pH, the higher the ratio of OCl ^- .

In general, in the case of seawater, the pH is between 8 and 9, so the HOCl generated through the electrolysis reaction is decomposed and mostly exists as (HOCl → H ⁺ + OCl ^- ) OCl ^- form.

In general, HOCl has a higher oxidizing power than OCl ^- and its sterilization efficiency is about 80 times higher.

In this embodiment, the concentrated carbon dioxide is injected into the seawater flowing through the seawater inflow pipe to make fine carbon dioxide, the pH of the seawater is lowered by dissolving the carbon dioxide micropores and the seawater, the seawater having the low pH is introduced, It can be sterilized with hypochlorous acid and then injected into a ballast tank to increase the sterilization efficiency of the ballast water.

Here, the purpose of saturating the carbon dioxide in the micro-scale is to increase the dissolution efficiency so that the dissolution of the carbon dioxide can be performed more easily.

That is, as in the present embodiment, if the pH of the seawater is artificially adjusted by lowering the pH of the seawater by the saturation of the microcrystals of the carbon dioxide, the presence ratio of HOCl increases, thereby increasing the sterilizing effect.

Table 1 below shows the amount of change in the pH of seawater due to the dissolution of CO2 in the ballast water treatment method. As shown in Table 1, when the dissolved amount of carbon dioxide microbubbles increased, the pH was gradually lowered, and the pH was measured as low at a maximum of 1,500 ppm.

CO ₂ solubility (concentration) pH 0 ppm 8.2 50 ppm 7.8 100 ppm 7.1 500 ppm 6.0 1,000 ppm 4.3 1,500 ppm 3.7

Table 2 below shows the rate of bio-degradation with changes in pH. As shown in Table 2, as the pH was lowered by carbon dioxide, the biological killing efficiency at the same TRO concentration was lowered from 8.2 to 3.7, and thus the bio-killing efficiency was 70% for the zooplankton, 50% for phytoplankton and 60% for other bacteria (E. coli).

pH TRO Biodegradation rate Zooplankton Phytoplankton E.Coli 8.2 5.0 mg / L 30% 50% 40% 7.8 5.0 mg / L 40% 60% 50% 7.1 5.0 mg / L 40% 60% 50% 6.0 5.0 mg / L 80% 90% 90% 4.3 5.0 mg / L 100% 100% 100% 3.7 5.0 mg / L 100% 100% 100%

On the other hand, the condensed carbon dioxide can be separated and concentrated from the exhaust gas generated during the operation of the ship.

At present, the International Maritime Organization (IMO) regulates the warming gas among the exhaust gas emitted from the ship, such as the ballast water regulation, so that if the regulations become effective in the future, the carbon dioxide enrichment technology of the ship's exhaust gas will be applied to the ship. It may be easier to receive the necessary carbon dioxide.

Further, when the supply of carbon dioxide from the exhaust gas of the ship is not smooth, commercially available concentrated carbon dioxide can be stored in the concentrated carbon dioxide tank 111 and utilized.

In addition, in the conventional electrolysis, a scale including MgCO ₃ and CaCO ₃ in the electrode may be generated due to a problem other than the reduction of the treatment efficiency in the generation of the hydrogen gas and the fresh water in the electrolysis, so that the electrolysis efficiency may be reduced.

However, according to this embodiment, it is possible to effectively remove scale attached to the electrode due to the physical force and the adsorption effect of carbon dioxide microbubbles in the electrolysis shear stage, thereby effectively reducing the electrolysis efficiency.

The present invention is not limited by the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims.

It will be apparent to 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. something to do.

21; A seawater inlet pipe 22; Ballast water discharge pipe
23, 24; First and second branch pipes 111; Carbon dioxide tank
112; A regulator 113; Venturi injector
114; pH sensor 116; Fine bubble nozzle
130; Rectifier 140; The electrolytic processing means
141; An electrolysis module 150; Mixing tank
151; Bodies 152a, 152b; septum

Claims (6)

A seawater inlet pipe for introducing seawater;
PH adjusting means for injecting carbon dioxide into a part of the seawater flowing through the seawater inlet pipe to lower the pH of the seawater;
Fine bubble generating means for atomizing the carbon dioxide bubbles contained in the seawater whose pH has been lowered and converting the carbon dioxide bubbles into carbon dioxide fine bubbles;
(HOCl) in the total oxidizing substances contained in the electrolyzed seawater by electrolyzing the seawater whose pH is lowered by dissolving the carbon dioxide microbubbles in the downstream of the microbubble generating means, An electrolytic treatment means for sterilizing the sea water in which the carbon dioxide microbubbles are dissolved by an excessive amount of hypochlorous acid and injecting the treated sea water into the ballast tank; And
And a ballast tank positioned at a rear end of the electrolytic processing means,
The electrolytic processing means includes a rectifier; And at least one electrolytic module including a positive electrode and a negative electrode terminal connected to the rectifier, and a comb-type electrolytic unit arranged alternately to the positive and negative terminals and scaled by the carbon dioxide microbubbles, An electrolysis reactor; And a control panel for controlling an electrolysis driving time of the electrolytic reactor by controlling the DC rectification of the rectifier and the electrolytic driving time of the comb-type electrolytic unit; And a high-efficiency electrolyzed vessel ballast water treatment apparatus using carbon dioxide. 2. The apparatus according to claim 1,
Venturi injectors;
A concentrated carbon dioxide tank for injecting carbon dioxide into seawater introduced into the venturi injector;
A regulator for adjusting the amount of carbon dioxide injected into the concentrated carbon dioxide tank according to the pH and the flow rate of seawater flowing into the venturi injector; And
A mixing tank for dissolving concentrated carbon dioxide and sea water to form carbon dioxide bubbles; / RTI &gt;
Wherein the fine bubble generating means includes fine bubble nozzles for atomizing the carbon dioxide bubbles introduced from the mixing tank into fine particles of carbon dioxide and injecting the fine bubbles into the main seawater inflow pipe. Device. [3] The apparatus of claim 2, wherein the mixing tank is provided with a partition wall for increasing contact time between concentrated carbon dioxide and seawater. delete Injecting carbon dioxide into a portion of the seawater flowing through the seawater inlet pipe to lower the pH of the seawater;
Atomizing the carbon dioxide bubbles contained in the seawater into a carbon dioxide microcapsule;
The present invention relates to an electrolytic apparatus for electrolyzing seawater in which carbon dioxide microbubbles are dissolved to lower the pH of the seawater, thereby increasing the ratio of the presence of hypochlorous acid (HOCl) among the total oxidizing substances contained in the electrolyzed seawater, Disinfecting the seawater in which the bubbles are dissolved with an excessive amount of hypochlorous acid and removing the scale generated in the electrolysis using the carbon dioxide microbubbles; And
Injecting the sterilized seawater into a ballast tank; A method for treating a high-efficiency electrolytic ship ballast water using carbon dioxide, comprising: [6] The method of claim 5, wherein the carbon dioxide is separated and concentrated from exhaust gas generated when the vessel is operated.

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