JP6221437B2 - Ballast water treatment system and ballast water treatment method - Google Patents

Description

  The present invention relates to a ballast water treatment system and a ballast water treatment method for removing an active substance in ballast water before draining ballast water.

  In general, since ships, especially cargo ships, are designed to include the weight of cargo, etc., ships that are unloaded or lightly loaded must be able to ensure proper submersion depth and safe navigation during unloaded conditions. Because of necessity, seawater is taken at the port before leaving the port to balance the ship. The water used as this ballast is called ballast water. When this ballast water leaves the port without loading, the seawater of the port is loaded into the ballast tank at the port of departure, while the ballast water is drained when loading in the port.

  By the way, when ballast water is poured and discharged by a ship that reciprocates between a loading port and an unloading port, which have different environments, the coastal due to the difference in microorganisms contained in the ballast water at the loading port and the unloading port. There are concerns about adverse effects on ecosystems. Therefore, at the international conference on ship ballast water management, an international convention (ballast water management treaty) for the regulation and management of ship ballast water and sediment was adopted in February 2004, and treatment of ballast water is required. It became.

The standard (D-2 standard) established by the International Maritime Organization (IMO) as a standard for the treatment of ballast water is that the number of organisms (mainly zooplankton) of 50 μm or more contained in ballast water discharged from ships is 1 m ³ The number of organisms (mainly phytoplankton) of less than 10, 10 μm or more and less than 50 μm is less than 10 in 1 ml, the number of Vibrio cholerae is less than 1 cfu in 100 ml, the number of E. coli is less than 250 cfu in 100 ml, enterococci The number is less than 100 cfu in 100 ml.

  In the Ballast Water Management Convention, when active substances such as chlorine, chlorine-based disinfectants, hydrogen peroxide, and ozone are used for ballast water treatment, standards are also set for the active substance concentration during ballast water drainage. In order to satisfy such ballast water treatment standards, as a ballast water treatment system, a chlorine-based disinfectant, a storage device for active substances (disinfectants) such as hydrogen peroxide and ozone, or their onboard generators, and these In many cases, a system in which an apparatus for adding an active substance to ballast water is combined with an active substance removing means as a means for removing the active substance remaining in the ballast water when discharging the ballast water is employed. For example, Patent Document 1 discloses that a sterilizing microorganism is sterilized by adding a chlorine-based disinfectant such as sodium hypochlorite or calcium hypochlorite to ballast water to ensure residence time, and sodium sulfite. And a ballast water treatment system in which a chlorine reducing agent such as sodium thiosulfate is added.

  In such a ballast water treatment system, it is necessary to leave the active substance at an appropriate concentration in the ballast tank during the voyage so that microorganisms and the like do not grow again. On the other hand, before the ballast water drainage at the loading port, it is necessary to remove the active substance from the ballast water as described above. It was often removed. For example, Patent Document 2 discloses that electrolyzed water containing hypochlorous acid is generated by electrolyzing a part of seawater with an electrolyzed water generator, and sterilizing microorganisms and the like by injecting the water into ballast water. There has been disclosed a ballast water treatment apparatus provided with a neutralizing agent charging device for charging a ballast water drainage channel for removal.

JP 2009-297610 A JP 2011-173058 A

  However, some ships have a ballast water drainage mechanism that drains water without using a ballast water injection / drainage pipe, such as gravity drainage or eductor drainage. For example, in gravity drainage, a part of ballast water is discharged through a ballast water pipe, but the remaining ballast water is discharged directly out of the ship using water pressure from a discharge port provided in the hull. . In the conventional ballast water treatment device, the neutralizing agent is introduced into the ballast water in the ballast water pipe, so that the necessary neutralization treatment is practically performed when draining without the ballast water pipe as described above. There is a problem that it cannot be implemented. In addition, since the amount of ballast water can reach tens of thousands of tons depending on the ship, even if a neutralizing agent is added directly to the ballast tank, it is practically impossible to react with the entire ballast water and remove residual chlorine. is there.

  The present invention solves such a problem and is applicable to a ship having a ballast water drainage mechanism that drains ballast water without using a ballast water pipe, and removes the active substance in the ballast water before draining the ballast water. It is an object of the present invention to provide a water treatment system and a ballast water treatment method.

  In order to solve the above problems, firstly, the present invention is a ballast water treatment system for sterilizing ballast water using an active substance, and a circulating flow for circulating ballast water poured into a ballast tank. There is provided a ballast water treatment system comprising a path and an active substance removing means for removing the active substance in the ballast water circulating through the circulation channel (Invention 1).

  According to the above invention (Invention 1), since the active substance in the ballast water can be removed while circulating the ballast water using the circulation channel, the ballast water drainage that drains the ballast water without using the ballast water pipe. Even a ship having a mechanism may discharge ballast water from which the active substance in the ballast water has been removed so as to satisfy the standard of active substance concentration at the time of ballast water drainage directly out of the ship from the ballast water drainage mechanism. it can.

  In the above invention (Invention 1), the active substance removal means is a neutralization treatment means for neutralizing the active substance, a decomposition treatment means for decomposing the active substance, or an adsorption process for adsorbing the active substance. It is preferable to use a means (Invention 2).

  In the said invention (invention 1 and 2), it is preferable that the said active substance is chlorine (invention 3).

  Secondly, the present invention is a ballast water treatment method for sterilizing ballast water using an active substance, wherein the active substance in the ballast water is removed while circulating the ballast water poured into the ballast tank. A method for treating ballast water is provided (Invention 4).

  According to the above invention (Invention 4), since the active substance in the ballast water can be removed while circulating the ballast water, the ship has a ballast water drainage mechanism that drains the ballast water without going through the ballast water pipe. However, the ballast water from which the active substance in the ballast water is removed so as to satisfy the standard of the active substance concentration at the time of ballast water drainage can be directly discharged out of the ship from the ballast water drainage mechanism (invention 4).

  In the said invention (invention 4), it is preferable to remove the said active substance by the neutralization process, a decomposition process, or an adsorption process (invention 5).

  In the said invention (invention 4 and 5), it is preferable that the said active substance is chlorine (invention 6).

  According to the ballast water treatment system and the ballast water treatment method of the present invention, the active substance in the ballast water can be removed while circulating the ballast water, so that the ballast water is discharged without using the ballast water pipe. Even a ship with a water drainage mechanism discharges ballast water from which the active substances in the ballast water have been removed so as to satisfy the criteria for the concentration of active substances during ballast water drainage directly from the ballast water drainage mechanism to the outside of the ship. be able to.

1 is a flowchart schematically showing a ballast water treatment system according to a first embodiment of the present invention. It is a flowchart which shows roughly the processing system of the ballast water based on the 2nd Embodiment of this invention.

[First Embodiment]
Hereinafter, the ballast water treatment system according to the first embodiment of the present invention will be described with reference to FIG.

  In FIG. 1, a ship ballast water treatment system 100 takes in raw water as ballast water at an unloading port, and also draws and discharges the ballast water at a loading port, and the intake and discharge portion. 1 includes a main line 2 for feeding ballast water connected to 1 and a ballast tank 3 provided at the end of the main line 2, and a ballast pump (not shown) as a water supply means is provided in the middle of the main line 2. Is provided.

  Further, at a position near the ballast tank 3 in the middle of the main line 2, a sterilizing agent supply device 4 for supplying a sterilizing agent as an active substance is connected via a sterilizing agent supply line 4a. Further, a neutralizing agent supply device 5 for supplying a neutralizing agent for neutralizing the active substance in the ballast water is connected via a neutralizing agent supply line 5a at a position near the intake / drainage part 1 in the middle of the main line 2. ing. In addition, a circulation line 6 connected from the ballast tank 3 to a position between the water intake / drainage unit 1 and the neutralizing agent supply device 5 in the middle of the main line 2 is provided.

  An open / close valve 7 is provided in the vicinity of the connection portion of the main line 2 with the intake / drainage portion 1. The position where the on-off valve 7 is provided is closer to the intake / drainage part 1 than the position where the circulation line 6 is connected to the main line 2. A circulation line inlet valve 8 is provided in the vicinity of the connection portion of the circulation line 6 with the ballast tank 3, and a circulation line outlet valve 9 is provided in the vicinity of the connection portion of the circulation line 6 with the main line 2.

  Next, using the ship ballast water treatment system 100 shown in FIG. 1, the ballast water is used to kill bacteria and plankton when the ballast water is loaded, and to remove the active substance when the ballast water is drained. The processing method will be described below.

  First, when pouring raw water (ballast water) at the time of departure from the port, the ballast water is drawn from the drainage section 1 by opening the intake / drainage section 1 and driving the ballast pump with the on-off valve 7 opened. And is injected into the ballast tank 3. At this time, the bactericide solution is supplied from the bactericide supply device 4 and merged into the main line 2. By supplying the bactericide solution to the ballast tank 3 in this way, plankton and bacteria in the ballast water can be killed by the effective chlorine generated from the bactericide.

  As the sterilizing agent, ozone, halogen compounds, peroxides such as hydrogen peroxide, peracetic acid, and the like can be used. Among these, halogen compounds are preferable. As the halogen compound, hypochlorite such as sodium hypochlorite and calcium hypochlorite, isocyanuric acid such as dichloroisocyanuric acid and trichloroisocyanuric acid, chlorine dioxide and the like can be used. In particular, sodium hypochlorite, calcium hypochlorite and dichloroisocyanuric acid are preferably used.

  Next, the time of ballast water discharge at the time of arrival or departure at a port will be described. When discharging the ballast water from the ballast tank 3, the on-off valve 7 is first closed and the ballast pump is driven with the circulation line inlet valve 8 and the circulation line outlet valve 9 opened. As a result, a circulation passage is formed in the system in which the ballast water in the ballast tank 3 circulates from the circulation line 6 to the ballast tank 3 via the main line 2. In such a state where the ballast water is circulating, the neutralizing agent is supplied from the neutralizing agent supply device 5 to the main line 2 in accordance with the residual chlorine concentration in the ballast water, so that the ballast water is in an environmentally safe state. The residual chlorine concentration in the ballast water can be reduced to a level that can be drained with water.

  The neutralizing agent may be appropriately selected according to the active substance. For example, when the active substance is chlorine, sodium sulfite, sodium bisulfite (sodium hydrogen sulfite), sodium thiosulfate, or the like can be used. It is particularly preferable to use sodium sulfite.

  After reducing the residual chlorine concentration in the ballast water to a level at which the ballast water can be drained, the ballast water in the ballast tank 3 is driven by opening the intake / drainage unit 1 and driving the ballast pump with the open / close valve 7 open. Is discharged from the intake / drainage section 1 through the main line 2. Moreover, even if a ballast water drainage mechanism that drains water without passing through the main line 2 is provided, such as gravity drainage or eductor drainage, the residual chlorine concentration in the ballast water is already in a state where the ballast water is safe for the environment. Therefore, there is no problem even if the ballast water is discharged directly from the ballast water drainage mechanism to the outside of the ship without passing through the main line 2.

[Second Embodiment]
Next, a ballast water treatment system according to a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, the same constituent elements as those in the first embodiment are described using the same reference numerals.

  As shown in FIG. 2, the ballast water treatment system 200 according to the second embodiment of the present invention replaces the bactericide supply device 4 and the bactericide supply line 4a in the ballast water treatment system 100 according to the first embodiment. In the middle of the main line 2 and a circulation line instead of the neutralizing agent supply device 5 and the neutralizing agent supply line 5a in the ballast water treatment system 100 of the first embodiment. 6 is composed of the same components as the ballast water treatment system 100 of the first embodiment except that an adsorption tower 11 filled with activated carbon as an adsorbent is provided in the middle of 6.

  The ballast water treatment system 200 performs killing of bacteria and plankton when loading ballast water, and removing active substances when draining ballast water, using the ship ballast water treatment system 200 shown in FIG. Is described below.

  First, when pouring raw water (ballast water) at the time of departure from the port, the ballast water is drawn from the drainage section 1 by opening the intake / drainage section 1 and driving the ballast pump with the on-off valve 7 opened. And is injected into the ballast tank 3. At this time, the electrolysis apparatus 10 in the middle of the main line 2 partially electrolyzes the ballast water that is seawater to generate electrolytic chlorine. Plankton and bacteria in the ballast water can be killed by the electrolytic chlorine generated in this way.

  Next, the time of ballast water discharge at the time of arrival or departure at a port will be described. When discharging the ballast water from the ballast tank 3, the on-off valve 7 is first closed and the ballast pump is driven with the circulation line inlet valve 8 and the circulation line outlet valve 9 opened. As a result, a circulation passage is formed in the system in which the ballast water in the ballast tank 3 circulates from the circulation line 6 to the ballast tank 3 via the main line 2. An adsorption tower 11 filled with activated carbon is provided in the middle of the circulation line 6, and residual chlorine in the ballast water is adsorbed by the activated carbon, so that the ballast water is circulated and the ballast water is in an environmentally safe state. The residual chlorine concentration in the ballast water can be reduced to a level that can be drained with water.

  After reducing the residual chlorine concentration in the ballast water to a level at which the ballast water can be drained, the ballast water in the ballast tank 3 is driven by opening the intake / drainage unit 1 and driving the ballast pump with the open / close valve 7 open. Is discharged from the intake / drainage section 1 through the main line 2. Moreover, even if a ballast water drainage mechanism that drains water without passing through the main line 2 is provided, such as gravity drainage or eductor drainage, the residual chlorine concentration in the ballast water is already in a state where the ballast water is safe for the environment. Therefore, there is no problem even if the ballast water is discharged directly from the ballast water drainage mechanism to the outside of the ship without passing through the main line 2.

  As mentioned above, although this invention has been demonstrated with reference to an accompanying drawing, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible. For example, the means for removing the active substance is not limited to the neutralization treatment means such as the neutralizing agent supply device 5 or the adsorption treatment means such as the adsorption tower 11, and decomposes residual chlorine using a catalyst, for example. A decomposition treatment means such as a catalyst decomposition apparatus may be provided in the middle of the circulation line 6.

  Moreover, in the said embodiment, although the main line 2 is used as a ballast water supply line both at the time of water injection and at the time of drainage, the water injection pipe and the water discharge pipe may be provided separately. .

  The neutralizing agent, the adsorbent, and the catalyst are not limited to those described in the above embodiment, and any appropriate one may be selected according to the active substance to be removed.

  INDUSTRIAL APPLICABILITY The ballast water treatment system and treatment method of the present invention can be suitably used for the treatment of ballast water in a ship having a ballast water drainage mechanism that drains ballast water without using ballast water piping.

DESCRIPTION OF SYMBOLS 100,200 ... Ballast water treatment system 1 ... Drainage part 2 ... Main line 3 ... Ballast tank 4 ... Sterilizer supply device 5 ... Neutralizer supply device 6 ... Circulation line 7 ... Open / close valve 8 ... Circulation line inlet valve 9 ... Circulation line outlet valve 10 ... electrolysis device 11 ... adsorption tower

Claims (6)

A main line connecting the intake and drainage unit and the ballast tank to form a main flow path;
A circulation line that is connected to the main line in a switchable manner in parallel and forms a circulation flow path for circulating ballast water poured into the ballast tank together with the main line ,
Chlorine treatment means that is provided in the main flow path and sterilizes ballast water using an active substance,
An active substance removing means provided in the circulation flow path for removing the active substance in the ballast water ;
When injecting ballast water, the channel is switched to the main channel and the chlorination means is driven,
A ballast water treatment system , wherein when discharging ballast water, the flow path is switched to the circulation flow path and the active substance removing means is driven .   The active substance removing means is a neutralization treatment means for neutralizing the active substance, a decomposition treatment means for decomposing the active substance, or an adsorption treatment means for adsorbing the active substance. Item 2. The ballast water treatment system according to Item 1.   The ballast water treatment system according to claim 1 or 2, wherein the active substance is chlorine. A step of pouring ballast water into a main flow path formed by a main line connecting the intake / drainage unit and the ballast tank;
A step of the Ru to circulate mainline in parallel and switchably connected to the circulation line and the main line and the ballast water that is water injection in the ballast tank to the circulation flow path formed by,
A step of sterilizing ballast water using an active substance by a chlorination means provided in the main flow path;
A step of removing the active substance in the ballast water by an active substance removing means provided in the circulation channel ,
When injecting ballast water, the channel is switched to the main channel and the chlorination means is driven,
A ballast water treatment method characterized by switching a flow path to the circulation flow path and driving the active substance removing means when discharging ballast water .   The ballast water treatment method according to claim 4, wherein the active substance is removed by neutralization treatment, decomposition treatment, or adsorption treatment.   The method for treating ballast water according to claim 4 or 5, wherein the active substance is chlorine.

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