JP2007137260A - Ballast water tank structure, ballast water manufacturing device, and manufacturing method of ballast water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of ballast water capable of manufacturing the ballast water by removing microorganism in sea water by a filtration film and preventing introduction of the microorganism not originally living in a specified sea territory by a large amount of the ballast water discharged from a vessel, a ballast water tank structure and a ballast water manufacturing device. <P>SOLUTION: An undefined form bag type container is arranged in a ballast water tank of the vessel, the inside of the ballast water tank is partitioned into the inside and the outside of the bag type container, either one of the inside and the outside of the bag type container is made into a reservoir tank of the sea water pumped up and the other is made into a reservoir tank of treated water treating the microorganism in the reserved sea water in these ballast water tank structure and ballast water manufacturing device and this manufacturing method of the ballast water. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ballast water tank structure, a ballast water production apparatus, and a ballast water production method that store ballast water that does not adversely affect the marine environment that is loaded to stabilize the center of gravity during navigation of a ship.

  Crude oil tankers, ore carriers, car carriers, etc. may sail with low or no cargo. At that time, the hull is lifted by buoyancy, and the screw and rudder are not submerged under the surface of the water, or the hull on the surface of the water is greatly affected by the wind and the maneuverability is impaired, making it extremely dangerous for navigation. For this reason, in order to adjust the buoyancy at the time of navigation, a normal ship carries a ballast water of 30 to 40% by weight of the normal load.

  For example, transportation by crude oil tankers is a round trip between oil-producing countries and consuming countries, and there is no cargo when navigating from consuming countries to oil-producing countries. . On the other hand, a ship loaded with ballast water discharges the ballast water in the sea near the oil-producing country or at a port and reloads with crude oil.

  In recent years, the ballast water discharged from ships has brought in microorganisms that do not inherently live in specific waters, which has resulted in the destruction of marine ecosystems, not only causing serious damage to the lives of those waters, The destruction of the global marine environment has occurred and has become a serious international problem. For this reason, various methods have been studied on an international scale for the purpose of preventing contamination by microorganisms in the ballast water.

  As a method for preventing marine pollution by removing microorganisms in seawater pumped as ballast water, for example, a method of killing microorganisms by heating seawater (Japanese Patent Laid-Open No. 2003-181443), irradiating seawater with ultraviolet rays A method of inactivating microorganisms (Japanese translations of PCT publication No. 2000-515803, JP-A-11-265684), a method of killing seawater through an electrolyzer (JP-A-2003-334563), and treatment with iodine A method (Japanese Patent Publication No. 2002-504851) and a method of treating with hypochlorous acid (Japanese Patent Laid-Open No. 04-322788) have been proposed.

On the other hand, when pumping ballast water to the ship in the port area where the ship is anchored, the ship's anchorage period is limited, so after pumping seawater into the ballast tank, It has also been studied to perform a pollution prevention treatment with microorganisms in the ballast water as described above.
JP 2003-181443 A (Claims) JP 2000-515803 A (Claims) JP 11-265684 A (Claims) JP 2003-334563 A (Claims) Japanese translation of PCT publication No. 2002-504851 (Claims) JP 04-322788 A (Claims)

  However, when the seawater is pumped directly into the ballast tank, and then the seawater in the ballast tank is sequentially removed, for example, by filtration to remove microorganisms in the seawater, the filtered water is returned to the ballast tank, resulting in infinite dilution. As a result, there is a problem that the remaining amount of microorganisms in the ballast water cannot be reduced to a specified value or less even during a relatively long voyage. As a solution to this problem, when pumping seawater into a ballast aquarium partitioned into a plurality of chambers, an empty chamber is provided, and microorganism removal water is sequentially transferred to the empty chamber. However, this method is difficult to implement in that the balance of the ship is lost, and there is a problem that the adjustment of piping and valves becomes complicated. Moreover, when seawater is directly pumped into the ballast water tank, slime is generated on the inner wall of the ballast water tank, and there is a problem that the ballast water tank cannot be used as a storage tank for treated water that has been subjected to microorganism removal processing.

  Therefore, an object of the present invention is to produce ballast water by efficiently removing microorganisms in seawater with a filter membrane without complicating adjustment of piping and valves, and a large amount of ballast water discharged from a ship. It is an object of the present invention to provide an efficient method for producing ballast water, a ballast water tank structure, and a ballast water production apparatus that does not bring in microorganisms that do not originally inhabit a specific sea area and that does not destroy the marine environment.

  In such a situation, the present inventors have conducted intensive investigations. As a result, an indefinite bag-shaped container is arranged in the ballast water tank of the ship, and the inside of the ball-shaped container is divided into the inside and the outside of the ball-shaped container. The seawater pumped and stored either inside or outside the bag-like container is subjected to microorganism removal treatment, and the resulting treated water is supplied to either the inside or outside of the bag-like container and stored. For example, even with a large amount of seawater, microorganisms can be efficiently removed with a simple device during a relatively long voyage. In addition, a large amount of ballast water discharged from a ship brings in microorganisms that do not naturally inhabit a specific sea area. It has been found that the marine environment is not destroyed, and the present invention has been completed.

  That is, the present invention (1) arranges a bag-shaped container of indefinite shape in a ballast water tank of a ship, partitions the inside of the ball-shaped water tank into an inside and an outside of the bag-shaped container, A ballast water tank structure is provided, in which one of the water and the outside is used as a storage tank for pumped seawater, and the other is used as a storage tank for treated water obtained by removing microorganisms from the stored seawater. .

  The present invention (2) provides the ballast water tank structure, wherein the treated water is filtered treated water.

  Moreover, this invention (3) provides the said ballast water tank structure characterized by the said filtered treated water being filtered water processed with the microorganisms filtration membrane.

  Moreover, this invention (4) connects the said ballast water tank structure, the microorganism removal apparatus which removes the microorganisms in the seawater stored by this one storage tank, and this one storage tank and this microorganism removal apparatus. The present invention provides a ballast water production apparatus comprising a seawater supply pipe, a microorganism removal treated water supply pipe connecting the microorganism removal apparatus and the other storage tank.

  Moreover, this invention (5) provides the said ballast water manufacturing apparatus characterized by the said microorganisms removal apparatus being an immersion type hollow fiber membrane apparatus or a pressurization type hollow fiber membrane apparatus.

  Moreover, this invention (6) arrange | positions the bag-shaped container of indefinite shape in the ballast water tank of a ship, partitions the inside of this ball-shaped water tank into the inside and outside of this bag-shaped container, The ballast water is characterized in that the seawater pumped up and stored in either the outside or the outside is subjected to microorganism removal treatment, and the resulting treated water is supplied to and stored in the inside or outside of the bag-like container The manufacturing method of this is provided.

  Moreover, this invention (7) provides the said ballast water manufacturing method characterized by the said microorganisms removal process being the process by a hollow fiber membrane.

  According to the present invention, microorganisms in seawater can be removed during a relatively long voyage. Further, since the bag-like container is disposed in the ballast water tank to form a variable volume double tank, the installation of complicated piping and valves can be omitted, and the apparatus can be made compact. In addition, as the microorganism removal progresses, for example, the amount of seawater inside the bag-like container decreases, the amount of membrane filtrate water outside the bag-like container increases, and the balance between the inside and outside of the bag-like container changes, The water level of seawater existing inside the ballast tank does not change. For this reason, there is no adverse effect on navigation such as the unstable center of gravity of the hull. Moreover, in the case of a filtration process, since filtered water does not return to the ballast water tank in which original seawater was stored, it does not become infinite dilution, but an efficient filtration process can be performed. In addition, in the case of treatment with a microbial membrane, the remaining amount of seawater remaining in the bottom of the bag-like container after removal of microorganisms is relatively small, so even if a sterilizing agent or heat treatment is performed, the sterilizing agent is used. The amount may be small, and the energy consumption accompanying heating may be small. Further, the ballast water discharged from the ship does not bring in microorganisms that do not originally live in the specific sea area, and further does not destroy the marine environment. Even seawater containing a relatively large amount of oil is removed in advance before being treated with the microbial filtration membrane, so that the microbial filtration membrane is not contaminated and can be treated stably for a long period of time. .

  In the present invention, the microorganism removal treatment is not particularly limited. For example, heat treatment for heating the seawater to kill the microorganisms, ultraviolet irradiation treatment for irradiating the seawater with ultraviolet rays to inactivate the microorganisms, and seawater as an electrolytic device. Electrical treatment that kills through, iodine treatment, hypochlorous acid treatment, sand filtration treatment, filtration treatment using biological filter, filtration treatment using granular anthracite filter material, filtration membrane treatment using microbial filtration membrane, etc. Among these, a filtration membrane treatment using a microorganism filtration membrane is preferable in that a microorganism can be highly removed. Further, the remaining amount of microorganisms in the treated water subjected to the microorganism removal treatment may be anything that prevents pollution of the ocean when the treated water is discarded into the ocean. For example, the International Maritime Organization (IMO) in February 2004 However, those that clear the “ballast water and sediment discharge standards” adopted in the discussion of the “Ballast Water Management Convention”.

  An example of the ballast water tank structure, the ballast water production apparatus, and the ballast water production method in the embodiment of the present invention will be described with reference to FIGS. 1 and 2. 1 and 2 are schematic cross-sectional views of the ship of this example. FIG. 1 shows a state in which seawater is pumped up and stored in a bag-like container, and FIG. 2 shows the seawater stored in the bag-like container with a microbial filtration membrane. It is a figure which shows the state which processed and obtained the membrane filtered water was stored outside the bag-shaped container. The ballast water tank structure 10 includes an indefinite bag-shaped container 3 disposed in a ballast water tank 2 of a ship 1, and partitions the ballast water tank 2 into an interior 31 and an exterior 32 of the bag-shaped container 3. 2 is used as a storage tank for the pumped seawater (FIG. 1), and the seawater 41 stored in the outside 32 of the bag-like container 2 is used as a storage tank for the membrane filtrate treated by the microorganism filtration membrane device 5 (FIG. 1). 2)

  The structure of the ballast water tank 2 of the ship 1 is not particularly limited, and for example, a double hull structure in which a cargo chamber 11 for loading a load such as crude oil and the ballast water tank 2 is partitioned is preferable. As the double hull structure, various forms other than the one shown in FIG. 1 can be applied. 1 is provided with a water pipe connection port 34 through which membrane filtrate flows in or out.

  The bag-shaped container 3 having an indefinite shape is, for example, an impermeable and hollow flexible bag, and has a water pipe connection port 33 through which seawater flows in or out. In addition, the capacity of the bag-like container 3 is not particularly limited, and the bag-shaped container 3 swells in the ballast water tank 1 to 80% by volume or more, preferably 90% by volume or more, more preferably in the ballast water tank 1. Thereby, the load capacity of the ballast water is not limited, and the usability is improved. The material of the bag-like container 3 is not particularly limited, and examples thereof include polyisoprene, chloroprene rubber, acrylic rubber, ethylene-propylene rubber, ABS resin, polypropylene, polyvinyl chloride, polyamide, polyethylene, and polyester.

  The form of installation of the bag-like container 3 in the ballast water tank 2 is not particularly limited, and the load of the bag-like container in a state (stored state) in which membrane filtrate is stored outside the bag-like container as shown in FIG. It is preferable that the bag on the chamber 11 side and the inner wall of the ballast water tank 2 are fixed at a plurality of locations 12 because the bag is smoothly expanded and contracted and the bag is not damaged. The ballast water tank structure of the present invention is substantially only required to install a bag-like container with respect to the ballast water tank of an existing ship, and can reduce the manufacturing cost.

  In the present invention, the seawater that is pumped and stored inside the bag-like container 3 is not particularly limited, but is usually seawater in a harbor area where a ship is anchored, and the seawater contains normal oil in addition to microorganisms. 0.05 to 1.0% is contained, and turbidity is 1 to 100 degrees. In addition, among the microorganisms in seawater, microorganisms of particular international concern include coliforms, cholera, enterococci, daphnia larvae, North Pacific starfish larvae, Asian kelp larvae, zebra larvae larvae and Toxic algae and the like can be mentioned, and the size of these microorganisms is mostly several μm, and the smallest is 0.3 to 0.5 μm.

  The ballast water production apparatus 20 of the present invention includes a ballast water tank structure 10, an oil adsorption / removal device 6 that removes oil in seawater 31, and a microorganism filtration membrane device 5 that removes microorganisms in seawater 31. The seawater intake pipe 91 having an opening in the sea, the seawater supply pipe 95 connected to the water pipe connection port 33, and the treated water supply pipe 92 connected to the oil adsorption removal device 6 are connected by the three-way valve 8, and the oil adsorption removal device 6 The microbial filtration membrane device 5 is connected by a connection pipe 93, and the microbial filtration membrane device 5 and the water pipe connection port 34 of the ballast water tank 2 are connected by a membrane filtration water supply pipe 94. In addition, a turbidity device (not shown) can be installed in the subsequent stage of the oil content adsorption removal apparatus 6 and in the upstream stage of the microorganism filtration membrane apparatus 5 as necessary. Moreover, the oil component adsorption removal apparatus 6 is an arbitrary component, and can be omitted. Moreover, as related equipment of the ballast water production apparatus 20 of the present invention, a seawater pump that pumps the seawater 4 into the interior 31 of the bag-like container 3, and the seawater stored in the bag-like container 3 as an oil adsorption removal device 6 and a microorganism filtration membrane There is a liquid feed pump that supplies the apparatus 5.

  Examples of the shape of the microorganism filtration membrane used in the ballast water production apparatus 20 of the present invention include a hollow fiber membrane, a flat membrane, and a tubular membrane. Among these, the hollow fiber membrane is preferable in that the filtration area per unit volume can be maximized.

  The hollow fiber membrane has a hollow structure, and further has a plurality of pores communicating with the holes forming the hollow structure and communicating with the holes on the membrane surface, and there are an external pressure type and an internal pressure type. . In the present invention, when a microfiltration membrane is used as the microorganism filtration membrane, the pore diameter of the hollow fiber membrane is 0.01 to 0.4 μm, preferably 0.01 to 0.3 μm. Moreover, when using an ultrafiltration membrane, it is 0.002-0.01 micrometer as a diameter of the pore of a hollow fiber membrane. The size of microorganisms such as bacteria and larvae inhabiting seawater is usually several μm, and the smallest is about 0.3 to 0.5 μm. Therefore, if a hollow fiber membrane having the above pore diameter is used, These microorganisms such as bacteria and larvae can be almost completely removed. In addition, backwashing is performed to remove microorganisms adhering to the membrane surface and restore its filtration ability, but separately from this backwashing, bubbles are bubbled from the outside of the membrane surface during filtration to the membrane surface. It is preferable to use an external pressure type hollow fiber membrane in that an operation of peeling and removing attached microorganisms can be performed.

  The hollow fiber membrane is used as an immersion type hollow fiber membrane device or a pressure type hollow fiber membrane device. The method using the submerged hollow fiber membrane device is a method of removing microorganisms in the seawater by passing the inside of the hollow fiber of the device immersed in the seawater storage tank by a head difference or suction by a suction pump or the like. . In addition, as described above, both the immersion type hollow fiber membrane device and the pressure type hollow fiber membrane device generate fine bubbles from below the hollow fiber membrane, and appropriately remove the microorganisms adhering to the hollow fiber membrane. It can be filtered while washing the surface.

  Examples of the material for the microfiltration membrane used in the present invention include polyethylene, polypropylene, polysulfone, polyvinylidene chloride, polyvinylidene fluoride, chlorinated polyethylene, chlorinated polypropylene, polyacrylonitrile, and cellulose acetate.

  The method for passing seawater through the microbial filtration membrane is not particularly limited, but two or more microbial filtration membrane devices incorporating the microbial filtration membrane may be arranged in parallel. In this case, even if one microbial filtration membrane device is in the backwashing step, the other microbial filtration membrane device can perform the microbial removal step, and a large amount of membrane filtered water can be obtained continuously.

  Oils contained in trace amounts in seawater are captured by microbial filtration membranes, but unlike microorganisms and other turbid substances, oils cannot be easily removed by the bubbling or backwashing process once attached to the membrane surface, It clogs the microorganism filtration membrane and causes a reduction in filtration capacity. Therefore, the life of the microbial filtration membrane can be extended by passing seawater through the oil adsorption / removal device 6 in the previous stage of the microbial filtration membrane device 5.

  The oil-water separation device is not particularly limited, and for example, a device using a hydrophobic adsorbent is preferable because it exhibits a high oil content adsorption capability with a simple method. Examples of the hydrophobic adsorbent include a non-woven filter made of a material such as lipophilic polyethylene or polypropylene, a powder, and a hollow fiber membrane. Specifically, when an oil adsorbent “Diamarus (registered trademark)” is used, the oil can be removed extremely efficiently. For example, seawater having an oil content of 0.05 to 1.0% can be converted to seawater having an oil content of 0.005 to 0.02% by the oil removal process of seawater.

  Removal of oil in seawater is necessary to prevent contamination of the microbial filtration membrane, but it is preferable to remove turbidity in seawater in advance in order to reduce the load of microbial removal on the microbial filtration membrane. It does not restrict | limit especially as a method of removing the turbidity in seawater, A well-known turbidity removal apparatus can be used. Examples of the turbidity removal device include a sand filtration device, a device provided with a nonwoven fabric filter cloth made of polyethylene or polypropylene, a long fiber bundle turbidity removal device that adsorbs turbidity to a bundle of fibers erected in a filtration tank body, and the like. It is done. Use of an oil adsorbent “Diamarus (registered trademark)” is preferred in that both oil removal and turbidity can be removed.

  Next, the manufacturing method of the ballast water of this invention is demonstrated with reference to FIG.1 and FIG.2. First, the three-way valve 8 is switched so that the seawater intake pipe 91 and the seawater supply pipe 95 are connected. Next, the seawater in the harbor area where the ship is anchored is pumped into the interior 31 of the bag-like container 3 disposed in the ballast tank 2 by a seawater pump (not shown). As the seawater is pumped up, the bag-like container 3 into which the seawater flows gradually swells and eventually swells to the full extent in the ballast tank 2 (FIG. 1). A ship loaded with ballast water, for example, travels to the oil producing country after leaving the port of the consuming country. Next, the seawater stored in the bag-like container 3 is treated with the microorganism filtration membrane device 5 to remove microorganisms using a relatively long period during the voyage. That is, the three-way valve 8 is switched so that the treated water supply pipe 92 and the seawater supply pipe 95 are connected. Next, the seawater in the bag-like container 3 is pumped up by a liquid feed pump (not shown), and the membrane filtered water flows into the outside 32 of the bag-like container 3 through the oil adsorption / removal device 6 and the microorganism filtration membrane device 5. As the stored seawater is pumped up, the bag-like container 3 from which the seawater flows is gradually deflated, and finally the membrane-filtered water is filled in the outside 32 of the bag-like container in the ballast water tank 2 (FIG. 2).

  1 and 2, as the removal of microorganisms progresses during navigation, the amount of seawater in the interior 31 of the bag-like container 3 decreases, and the amount of membrane filtered water in the exterior 32 of the bag-like container 3 increases accordingly. Only the balance between the inside 32 and the outside 32 of the container 3 changes, and the water level of the seawater present in the inside 32 of the ballast tank 2 does not change. For this reason, there is no adverse effect on navigation such as the unstable center of gravity of the hull. In addition, since the remaining amount of seawater left at the bottom of the interior 32 of the bag-like container 3 after removal of the microorganisms is relatively small, even if a bactericidal agent or heat treatment is performed, the amount of bactericidal agent used is also small. The energy consumption accompanying heating is also good.

  The method for producing ballast water of the present invention may include a step of washing the microbial filtration membrane by backwashing. In the microorganism removal process, as time elapses, microorganisms or the like that cause clogging of the membrane adhere to the microorganism filtration membrane, and the membrane differential pressure rises at the inlet and outlet of the membrane. For this reason, the filtration of seawater is stopped, and the microbial filtration membrane is back-washed using the membrane filtrate as washing water. By performing the backwashing step, the filtration function of the microorganism filtration membrane is restored. And when the backwashing process is completed, it moves to a microorganism removal process again, and filtration over a long period of time is enabled by performing this repeatedly. The microbial concentrate produced by backwashing is subjected to known sterilization treatments such as addition of chemicals such as hypochlorous acid and heat treatment. Since this microbial concentrate is relatively small, the amount of the bactericide used may be small, and the energy consumed by heating is small.

  The ballast water of the present invention is manufactured on a ship during relatively long navigation. As a result, a large amount of seawater can be effectively treated with the microorganism filtration membrane, and the microorganisms that do not originally inhabit the specific sea area are not brought in by the ballast water discharged from the ship.

  In the ballast water tank structure 10 and the ballast water production apparatus 20 of this example, the inside 31 of the bag-like container 3 is used as a storage tank for storing the seawater pumped up in the ballast water tank 2, and the outside 32 of the bag-like container 3. However, the present invention is not limited to this, and as shown in FIGS. 3 and 4, as a storage tank for storing seawater pumped up outside 32 of the bag-like container 3, The interior 31 of the container 3 may be a membrane filtration water storage tank. In this case, the membrane filtered water flows into or out of the water pipe connection port 33, and seawater flows into or out of the water pipe connection port 34.

  A method of using such a ballast water production apparatus 20a to treat seawater pumped to the outside 32 of the bag-like container 3 with a microorganism filtration membrane and filling the bag-like container 3 with the membrane filtrate is shown in FIGS. The description will be given with reference. First, the three-way valve 8 is switched so that the seawater intake pipe 91 and the seawater supply pipe 95 are connected. Next, the seawater in the harbor area where the ship is anchored is pumped to the outside 32 of the bag-like container 3 arranged in the ballast water tank 2 by a seawater pump (not shown). As the seawater is pumped up, the ballast tank 2 is filled with seawater (Fig. 3). A ship loaded with ballast water, for example, travels to the oil producing country after leaving the port of the consuming country. Next, using a relatively long period during the voyage, seawater stored in the outside 32 of the bag-like container 3 in the ballast tank 2 is treated by the microorganism filtration membrane device 5 to remove microorganisms. That is, the three-way valve 8 is switched so that the treated water supply pipe 92 and the seawater supply pipe 95 are connected. Next, the seawater filled in the outside 32 of the bag-like container 3 is pumped up by a liquid feed pump (not shown), and the membrane filtrate is passed through the oil adsorption / removal device 6 and the microorganism filtration membrane device 5 to the inside 31 of the bag-like container 3. Let it flow. As the stored seawater is pumped up, the bag-like container 3 into which the seawater flows gradually swells and eventually swells to the full extent in the ballast water tank 2 (FIG. 4). Also in the ballast water manufacturing method using the ballast water manufacturing apparatus 20a of FIG.3 and FIG.4, there exists an effect similar to the ballast water manufacturing method using the ballast water manufacturing apparatus 20 of FIG.1 and FIG.2. In addition, in the case of the ballast water manufacturing method using the ballast water manufacturing apparatus 20a of FIG.3 and FIG.4, although slime may generate | occur | produce on the inner wall of the ballast water tank 2, the inside of the bag-shaped container 3 is made into membrane filtered water. As long as the membrane filtered water is not contaminated.

  EXAMPLES Next, although an Example is given and this invention is demonstrated more concretely, this is only an illustration and does not restrict | limit this invention.

  The actual ballast water production apparatus installed on land shown in FIG. 5 was used without using an actual ship. That is, seawater (hereinafter referred to as “raw seawater”) in port A in Japan where the ship is anchored was filled in a bag-like container of an experimental ballast water production apparatus, and this seawater was treated under the following operating conditions. The coliforms of raw seawater and treated water (membrane filtered water) were measured by the following measuring method. The oil content of the raw seawater was 8 mg / l as an n-hexane extract, and the turbidity of the raw seawater was 5 degrees.

(Experimental ballast water production system)
The apparatus shown in FIG. 5 was used. The experimental ballast water production apparatus 30 includes a raw seawater tank 51 containing a bag-like container 52 made of polyvinyl chloride, a hollow fiber membrane type microorganism filtration device 5a, and a backwash tank 53, and is a hollow fiber membrane type. The microbial filtration device 5a used was obtained by immersing a hollow fiber membrane module 57 “STELLAPORE SUR31534” (manufactured by Mitsubishi Rayon) made of a microfiltration membrane having a treatment capacity of 3 m ³ / hour in a treatment tank 58. The bag-like container 52 and the hollow fiber membrane type microorganism filtration device 5a are connected by a pipe 47, and the hollow fiber membrane type microorganism filtration device 5a and the backwash tank 53 are connected by a treated water pipe 42, and the backwash tank 53 and The raw seawater tanks 51 were connected by a return pipe (overflow pipe) 48. A suction pump 44 was installed in the treated water pipe 42. Further, a backwash pump 45 was installed so that the filtered water in the backwash tank 53 could be backwashed by the backwash pipe 43. The maximum volume of the bag-like container 52 was almost the same as the internal volume of the raw seawater tank.

(how to drive)
The simulated one-pass processing method was used. That is, the raw seawater in the bag-like container 52 is supplied to the hollow fiber membrane type microbial filtration device 5a at a processing amount of 3 m ³ / hour, and the membrane filtrate is in the seawater tank 51 and outside the bag-like container 52. Let it flow. In the microorganism removal step, air from the blower 46 is bubbled as fine bubbles from the distributor 41 installed at the lower part of the hollow fiber membrane module 57, and filtration is performed while peeling microorganisms and the like adhering to the hollow fiber membrane surface. It was. Moreover, it was set as 1 minute of backwashing processes with respect to 15 minutes of microorganism removal processes, and this was repeated. Moreover, the waste liquid in which the microorganisms were concentrated was appropriately drained from the lower part of the treatment tank 58 of the hollow fiber membrane type microorganism filtration device 5a.

(Method for measuring microorganisms)
The coliform group was added to a BGLB medium (Brilliant Green Lactose Bile Broch) and cultured at 35 ° C. for 24 hours, and then the coliform group was counted.

(Processing result)
Although the number of coliforms in the raw seawater was 3500/100 ml, no coliforms were detected in the treated water filled in the raw seawater tank 51 and outside the bag-like container 52. Moreover, the n-hexane extract of the treated water was not detected, and the turbidity was 2 degrees or less. However, the differential pressure at a predetermined flow rate immediately after backwashing at the initial stage of the filtration operation was 0.01 MPa or less, but the differential pressure immediately after backwashing after 170 hours of filtration operation was 0.045 MPa.

  The test was performed in the same manner as in Experimental Example 1 except that the treatment was performed under the following experimental ballast water production apparatus and the following operating conditions.

(Experimental ballast water production system)
An oil / water separator “Diamarus RH-03” (manufactured by Mitsubishi Rayon Engineering Co., Ltd.) (not shown) having a processing capacity of 3 m ³ / hour is disposed between the bag-like container 52 and the hollow fiber membrane type microorganism filtration device 5a. The same apparatus as in Example 1 was used.

(how to drive)
The simulated one-pass processing method was used. That is, the raw seawater in the bag-like container 52 is supplied to the hollow fiber membrane type microbial filtration device 5a at a treatment rate of 3 m ³ / hour, and the membrane filtrate is in the seawater tank 51 and outside the bag-like container 52 Let it flow. In the microorganism removal step, air was blown as fine bubbles from the distributor 41 installed in the lower part of the hollow fiber membrane module 7 and filtration was continued while peeling microorganisms and the like adhering to the surface of the hollow fiber membrane. . Moreover, it was set as the back washing process 1 minute with respect to the microorganism removal process 15 minutes, and this was repeated. Moreover, the waste liquid in which the microorganisms were concentrated was appropriately drained from the lower part of the treatment tank 8 of the hollow fiber membrane type microorganism filtration device 4a.

(Processing result)
Although the number of coliforms in the raw seawater was 3500/100 ml, no coliforms were detected in the treated water filled in the raw seawater tank 51 and outside the bag-like container 52. Moreover, the n-hexane extract of the treated water was not detected, and the turbidity was 2 degrees or less. The differential pressure at a predetermined flow rate immediately after backwashing at the initial stage of the filtration operation is 0.01 MPa or less, and the differential pressure immediately after backwashing after 170 hours of filtration operation is similarly 0.01 MPa or less. The oil content in the microfiltration membrane was effectively prevented by removing the oil content in the oil-water separator in advance.

Instead of the immersion type hollow fiber membrane type microbial filtration device 5a, a pressure type hollow fiber membrane type microbial filtration device (not shown) is used, and in the same manner as in Experimental Example 1, cleaning with bubbles and periodic backwashing steps are performed. went. However, cleaning with bubbles was performed by bubbling with bubbles obtained by interrupting water flow to the membrane treatment apparatus and injecting air from the lower part of the membrane for about 5 minutes. The hollow fiber membrane module used in the pressurization type hollow fiber membrane type microbial filtration apparatus is made of ^three “Stelapore G type UMF-2024WFA” (manufactured by Mitsubishi Rayon Co., Ltd.), which is a microfiltration membrane with a processing capacity of 3 m ³ / hour. Using. In addition, an oil / water separator “Diamarus RH-03” having a processing capacity of 3 m ³ / hour was disposed in the front stage of the hollow fiber membrane type microorganism filtration device.

(Processing result)
Although the number of coliforms in the raw seawater was 3500/100 ml, no coliforms were detected in the treated water filled in the raw seawater tank 51 and outside the bag-like container 52. Moreover, the n-hexane extract of the treated water was not detected, and the turbidity was 2 degrees or less. The differential pressure data of the microfiltration membrane was the same as in Experimental Example 2.

  As shown in each Example, by treating the raw seawater stored in the bag-like container accommodated in the raw seawater tank with the ballast water production apparatus, the coliforms in the raw seawater were removed to the extent that they were not detected. . In addition, by installing an oil-water separator in front of the hollow fiber membrane type microorganism filtration device, it was possible to effectively prevent contamination of the microfiltration membrane due to oil. Moreover, there was almost no change in the water level of the raw seawater in the raw seawater tank during the microorganism removal process.

It is a typical cross-sectional view of a ship, Comprising: Seawater is drawn up and stored in the bag-shaped container. It is a typical cross-sectional view of a ship, Comprising: Seawater is processed with a microbial filtration membrane, The state which stored the obtained membrane filtrate in the exterior of a bag-shaped container is shown. It is other typical cross-sectional views of a ship, Comprising: Seawater is pumped out of the bag-like container and stored in the ballast water tank. It is other typical cross-sectional views of a ship, Comprising: Seawater is processed with a microbial filtration membrane, The state which stored the obtained membrane filtration water inside the bag-like container is shown. It is a flowchart of the experimental ballast water manufacturing apparatus used in the experiment example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ship 2 Ballast water tank 3 Bag-shaped container 4 Underwater 5 Microbial filtration membrane apparatus 5a Hollow fiber membrane type microorganism filtration apparatus 6 Oil content adsorption removal apparatus 7 Hollow fiber membrane module 8 Three-way valve 10, 10a Ballast water tank structure 11 Loading chamber 12 Bonding point 20, 20a Ballast water production apparatus 30 Experimental ballast water production apparatus 31 Inside of bag-like container 32 Outside of bag-like container 33, 34 Water pipe connection port 41 Distributor 43 Backwash pipe 44 Suction pump 45 Backwash pump 46 Blower 61 Pumped up Seawater 62 Membrane filtered water

Claims (7)

  An indefinitely shaped bag-like container is placed in a ship's ballast water tank, and the ballast water tank is partitioned into an inside and an outside of the bag-like container, and either the inside or the outside of the bag-like container can be pumped up. A ballast water tank structure characterized in that the seawater storage tank is used, and the other is used as a storage tank for treated water obtained by removing microorganisms from the stored seawater.   The ballast water tank structure according to claim 1, wherein the treated water is filtered treated water.   The ballast water tank structure according to claim 2, wherein the treated water subjected to the filtration is filtered water treated with a microorganism filtration membrane.   The ballast water tank structure according to claim 1, a microorganism removing device for removing microorganisms in seawater stored in the one storage tank, a seawater supply pipe connecting the one storage tank and the microorganism removing device, A ballast water production apparatus comprising a microorganism removal treatment water supply pipe connecting the microorganism removal apparatus and the other storage tank.   The ballast water production apparatus according to claim 4, wherein the microorganism removing device is an immersion type hollow fiber membrane device or a pressure type hollow fiber membrane device.   An irregularly shaped bag-like container is placed in the ballast water tank of the ship, the ballast water tank is partitioned into the inside and outside of the bag-like container, and pumped to either the inside or outside of the bag-like container. A method for producing ballast water, wherein the stored seawater is subjected to microorganism removal treatment, and the obtained treated water is supplied to and stored in either the inside or the outside of the bag-like container.   The method for producing ballast water according to claim 6, wherein the microorganism removal treatment is treatment with a hollow fiber membrane.

Images