WO2005110928A1

WO2005110928A1 - Production method of ballast water for vessel, production system of ballast water for vessel and use

Info

Publication number: WO2005110928A1
Application number: PCT/JP2005/003125
Authority: WO
Inventors: Makio Tamura; Sumiyuki Fusiki
Original assignee: Organo Corporation
Priority date: 2004-05-19
Filing date: 2005-02-25
Publication date: 2005-11-24
Also published as: JP2005329300A

Abstract

A production method of ballast water for vessel in which membrane treated water is produced by passing fresh water through a microfilteration membrane, an ultrafiltration membrane or a reverse osmosis membrane thereby removing microorganisms in the fresh water, or membrane treated fresh water is produced by passing sea water through the reverse osmosis membrane thereby removing microorganisms in the sea water. Fresh water can be prevented from being decomposed during transportation by removing microorganisms in fresh water or sea water using a method other than an annihilation method and by producing fresh water from sea water simultaneously.

Description

Specification

TECHNICAL FIELD The present invention relates to a method for producing ballast water for ships, an apparatus for producing ballast water for ships, and uses thereof.

[0001] The present invention relates to a method for producing ballast water for ships from which microorganisms have been removed (hereinafter, also simply referred to as "ballast water") loaded for stabilizing the center of gravity during navigation of a ship, and for producing ballast water for ships. Equipment and use.

Background art

[0002] Crude oil power, ore carriers, car carriers, and the like sometimes travel with a small amount of empty or loaded cargo. At this time, the hull rises due to the buoyancy, and the rudder of the screw is not submerged below the water surface. Therefore, normal ship loading order was to adjust the buoyancy of cruising, the normal loading weight of 30- 40 weight ^_0/0 of the ballast water.

[0003] For example, transportation using oil-tank power is a round trip between an oil-producing country and a consuming country. 《Last water. On the other hand, ships loaded with ballast water discharge ballast water near the oil-producing countries or in ports and reload crude oil.

[0004] Ship power The discharged ballast water introduces microorganisms that do not naturally inhabit specific sea areas, resulting in the destruction of marine ecosystems and not only seriously damaging the lives of the people in the water area. The destruction of the global marine environment is occurring and is a serious international problem. For this reason, various methods have been studied on an international scale for the purpose of removing microorganisms from ballast water (JP-A-2003-181443, JP-A-2000-515803, JP-A-11-265684). JP-A-2003- „, JP-T-2002-504851, JP-A-04-322788).

[0005] Conventionally, seawater has been used as ballast water for ships. However, in recent years, examples have been reported in which tap water is used as ballast water for ships for the purpose of supporting and supplying water to remote islands. In oil-producing countries, there is a shortage of fresh water such as drinking water and industrial water.There is a possibility of using tap water as ballast water for ships and bringing it to oil-producing countries for effective use. The

Disclosure of the invention

[0006] However, fresh water such as tap water is usually left standing for several days, even if it is tap water, since the free chlorine added thereto disappears, so that it becomes putrid odor and cannot be drunk. For example, it takes about 10 days for Japanese power to travel to oil-producing countries, so the freshwater onboard the vessel will rot and become unusable. Since freshwater spoils due to microorganisms in freshwater, the microorganisms may be killed by a known method. However, for example, the method of heating fresh water is not economical depending on the means of procuring heating energy, and it is difficult to completely kill microorganisms. In addition, the method of irradiating freshwater with ultraviolet light requires a huge amount of power to kill or inactivate all microorganisms, and a large number of UV devices are installed in parallel to treat high-flow freshwater. The cost of installation of the device will increase. The method of treating fresh water with chemicals such as iodine and hypochlorous acid requires a high concentration of chemicals to kill some types of bacteria. You have to use The method of killing microorganisms in freshwater is, as described above, difficult to completely kill microorganisms, and the small amount of microorganisms remaining without killing grows during transportation. The development of a method for removal is eagerly desired.

[0007] The present invention provides a method for removing microorganisms in freshwater or seawater by a method other than killing, and simultaneously desalinating seawater to prevent decay of freshwater during transportation and to reduce freshwater utilization value. A method and apparatus for producing ballast water for ships to be maintained, wherein the membrane-treated water obtained by the method for producing ballast water for ships is used as ballast water for ships.

[0008] Under such circumstances, the present inventors have conducted intensive studies, and as a result, a membrane treatment in which microorganisms in fresh water were removed by passing fresh water through a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane. Water, and using the membrane-treated water as ballast water, or passing seawater through a reverse osmosis membrane to remove microorganisms in the seawater and obtain desalinated membrane-treated water. When used as water, microorganisms in seawater or freshwater can be effectively removed by a microbial filtration membrane, and in the case of seawater, freshwater is also simultaneously desalinated. And that if the membrane-treated water is stored in, for example, a ballast water storage tank, it can be pumped to ships as ballast water when needed. The invention has been completed.

[0009] That is, the present invention provides a method for passing freshwater through a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane, thereby obtaining a membrane-treated water from which microorganisms in the freshwater have been removed. It is a manufacturing method.

[0010] Further, the present invention is a method for producing ballast water for ships, which includes a step of removing microorganisms in seawater by passing seawater through a reverse osmosis membrane and obtaining desalinated membrane-treated water.

[0011] Further, in the method for producing ballast water for a ship, the fresh water is preferably at least one of industrial water, tap water, river water, lake water, groundwater, and sewage treatment water.

[0012] In the method for producing ballast water for a ship, it is preferable that the oil component in the seawater is adsorbed and removed by a hydrophobic adsorbent.

[0013] In the method for producing ballast water for ships, it is preferable that a bactericide is added to the membrane-treated water.

[0014] Further, the present invention provides a precision filtration membrane device, an ultrafiltration membrane device or a reverse osmosis membrane device for removing microorganisms in the supplied freshwater, and a ballast water storage tank for storing the treated water. And a ballast water producing apparatus for a ship, comprising:

[0015] The present invention also provides a ballast water for ships, comprising: a reverse osmosis membrane device that removes microorganisms from seawater supplied from seawater supply means and desalinates the water; and a ballast water storage tank that stores membrane-treated water. Manufacturing equipment.

[0016] Further, it is preferable that the marine ballast water producing apparatus further includes a chemical adding means for adding a germicide to the membrane-treated water.

[0017] In the marine ballast water producing apparatus, it is preferable that the microfiltration membrane device is an immersion type hollow fiber membrane device or a pressure type hollow fiber membrane device.

Further, the present invention is the use of membrane-treated water obtained by the method for producing ballast water for ships as ballast water for ships.

According to the present invention, microorganisms in seawater or freshwater are removed by a microorganism filtration membrane, so that microorganisms in freshwater or seawater are removed by a method other than the method of killing them. At the same time, it is desalinated to prevent freshwater decay during transportation and to maintain the value of freshwater use. You can have.

Brief Description of Drawings

FIG. 1 is a flowchart of a ballast water producing apparatus used in Example 1.

FIG. 2 is a flowchart of a ballast water production apparatus used in Example 3.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described. In the method for producing marine ballast water according to the present embodiment, the fresh water is not particularly limited, and includes, for example, industrial water, tap water, river water, lake water, groundwater, or treated sewage water. Many of these freshwaters contain microorganisms and usually have a turbidity of 1-100 degrees.

[0022] Seawater is not particularly limited, and is seawater in a harbor area where ships are normally anchored. It contains 0.05-1.0% of oil, besides microorganisms, and has a turbidity of 1-100 degrees. . Among freshwater and seawater microorganisms, those that particularly affect spoilage include coliform bacteria, cholera bacteria, enterococci, larvae of daphnia, larvae of North Pacific starfish, larvae of Asian kelp, larvae of zebra mussels and Toxic algae and the like are mentioned, and the size of these microorganisms is almost several / zm, most is / J, and the size is 0.3-0.

The microfiltration membrane (MF) used for the treatment of fresh water includes a hollow fiber membrane, a flat membrane, a snail membrane, and a tubular membrane. Among them, the hollow fiber membrane is preferable because the filtration area per unit volume can be maximized. The hollow fiber membrane uses a large number of hollow fibers arranged in parallel, has a hollow structure, and further has a large number of pores communicating with the holes forming the hollow structure and communicating with the holes on the membrane surface. It is an external pressure type and an internal pressure type. In the present embodiment, when a microfiltration membrane is used, the diameter of the pores of the hollow fiber membrane is 0.01-0.4 μm, preferably 0.01-0.3 m. In the case of an ultrafiltration membrane used for the treatment of fresh water, the diameter of the pores of the hollow fiber membrane is 0.002 to 0.011 m. The size of microorganisms such as bacteria and larvae that inhabit freshwater is usually several m, and the smallest one is about 0.3-0.5 μm. In addition, microorganisms such as these bacteria and larvae in fresh water can be almost completely removed. In addition, it is preferable to perform backwashing to remove microbes attached to the membrane surface and restore its filtration ability.However, apart from main backwash, bubbles are generated by the external force of the membrane surface during filtration. To remove microorganisms attached to the membrane surface. It is preferable to use an external pressure type hollow fiber membrane in that the separation and removal operation can be performed.

[0024] 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 an immersion type hollow fiber membrane device is a method of removing microorganisms in fresh water by sucking a hole side of the hollow fiber of the device crushed in a fresh water storage tank with a suction pump. In addition, as described above, both the immersion type hollow fiber membrane device and the pressure type hollow fiber membrane device generate fine bubbles in the downward direction of the hollow fiber membrane, and while appropriately removing microorganisms attached to the hollow fiber membrane, Filtration can be continued while washing the surface of the membrane.

[0025] Materials for the microfiltration membrane used in the present embodiment include polyethylene, polypropylene, polysulfone, hydrophilized polysulfone, polychloridized biylidene, polyvinylidene fluoride, chlorinated polyethylene, chlorinated polypropylene, polyacrylonitrile, Examples thereof include polyether sulfone and cellulose acetate.

A reverse osmosis membrane used for the treatment of fresh water or seawater is usually used as a reverse osmosis membrane device incorporating a reverse osmosis membrane module. As the reverse osmosis membrane module, for example, a module having a structure in which a bag-shaped reverse osmosis membrane is spirally wound around a permeated water collecting pipe, and the upper part thereof is covered with an outer package. Seawater or freshwater is injected into the reverse osmosis membrane module by a pump. Thereby, salts and organic substances in seawater or freshwater can be removed, and microorganisms such as bacteria and larvae can be almost completely removed. Therefore, when the raw water is seawater, the permeated water of the reverse osmosis membrane is desalinated.

[0027] The method of passing fresh water through a microfiltration membrane, ultrafiltration membrane, or reverse osmosis membrane, or the method of passing seawater through a reverse osmosis membrane is not particularly limited. It is preferable to arrange more than one group in parallel. In this case, even if one membrane device is a backwashing process or a regeneration process, the other membrane device can perform a microorganism removing step, and a large amount of membrane-treated water can be continuously obtained. Further, the membrane-treated water obtained in the microbial removal step can be stored in a ballast water storage tank, so that ballast water can be sent at a high flow rate to a ship anchored in the ballast water storage tank. The advantage is that the berthing period of the ship will not be extended to pump ballast water.

When using a microfiltration membrane or an ultrafiltration membrane, a backwashing step of washing the filtration membrane by backwashing is performed. As the time elapses in the microorganism removal process, the cause of membrane clogging The quality of microorganisms and the like adhere to the filtration membrane, and the membrane differential pressure increases at the inlet and the outlet of the membrane. Therefore, the filtration of fresh water is stopped, and the filtration membrane is backwashed using the membrane-treated water as washing water. By performing the backwashing step, the filtration function of the filtration membrane is restored. Then, after the backwashing step is completed, the process proceeds to the microorganism removing step again, and by repeating this step, filtration for a long period of time is enabled.

[0029] In the method for producing ballast water according to the present embodiment, if the raw water is seawater, the oil content in the seawater is removed in advance before the treatment with the reverse osmosis membrane, thereby preventing clogging of the reverse osmosis membrane surface. However, it is preferable in that a decrease in transmission ability can be prevented. In other words, unlike microorganisms and other turbid substances, oil cannot be easily removed when it adheres to the membrane surface, causing clogging of the filtration membrane and causing a reduction in filtration performance.

[0030] The method of removing oil from seawater is not particularly limited, and a known oil / water separator can be used. The oil / water separator using a hydrophobic adsorbent is preferable because it exhibits a high oil adsorption capacity by a simple method. Examples of the hydrophobic adsorbent include a nonwoven fabric filter, a powder material, and a hollow fiber membrane made of a material such as lipophilic polyethylene or polypropylene. Specifically, the use of the oil adsorbent “Diamarus (registered trademark)” enables the oil to be removed very efficiently. By the process of removing oil from seawater, for example, seawater with an oil content of 0.05 to 1.0% can be converted to seawater with an oil content of 0.005 to 0.02%.

[0031] Further, in order to reduce the load of removing microorganisms on the filtration membrane or the reverse osmosis membrane, it is preferable to remove turbid matter in seawater or freshwater in advance. The method for removing turbid matter in seawater or freshwater is not particularly limited, and a known clarifier can be used. Examples of the turbidity removing device include a sand filtration device, a device equipped with a nonwoven fabric filter cloth made of polyethylene or polypropylene, and a long fiber bundle clarifying device that adsorbs turbid matter to a bundle of polyester fibers filled in a filter tank. Is mentioned. The use of the oil adsorbent "Diamarus (registered trademark)" is preferred because both oil removal and turbidity can be removed.

[0032] Further, it is preferable to add a bactericide to the membrane-treated water, since the decay of fresh water as the membrane-treated water is further prevented. Examples of the disinfectant include hypochlorous acid. The location where the disinfectant is added to the membrane treated water is not particularly limited, and is a pipe connecting the membrane device to the ballast water storage tank, a pipe connecting the ballast water storage tank or the ballast water storage tank to the ballast water tank of the ship. And the like.

[0033] The apparatus for producing ballast water according to the present embodiment includes a microfiltration membrane device, an ultrafiltration membrane device, or a reverse osmosis membrane device that removes microorganisms in freshwater supplied from the freshwater supply means; Or a ballast water storage tank (first device) that accumulates seawater, or a reverse osmosis membrane device that removes microorganisms from the supplied seawater and desalinates the seawater, and a ballast that accumulates membrane-treated water And a water storage tank (second device). In addition, both the first device and the second device may further include a drug adding means for adding a bactericide to the membrane-treated water. The medicine adding means is usually constituted by a medicine tank, a pump, piping, and the like. Further, it is preferable that the second device is provided with an oil component adsorption / removal device for removing the oil component in seawater, in front of the reverse osmosis membrane device. In addition, in the first apparatus, a turbidity removing apparatus is installed before the membrane apparatus, and in the second apparatus, before the membrane apparatus and after the oil adsorption and removal apparatus, as necessary. The fresh water supply means is a means for supplying fresh water to the filtration membrane device, and includes a fresh water pump and a fresh water intake pipe having an opening at one end in a fresh water source and the other end connected to the fresh water pump. The seawater supply means is a means for supplying seawater to the reverse osmosis membrane device, and includes a seawater pump and a seawater intake pipe having one end opening in seawater and the other end connected to the seawater pump. In both the first device and the second device, the piping from the membrane device to the ballast water storage tank and the ballast water storage tank are preferably sterilized. The number of ballast water storage tanks and the type of tanks are not particularly limited. Further, as related facilities of the manufacturing apparatus of the present embodiment, there are a liquid feed pump for drawing ballast water in a ballast water storage tank, and a liquid feed pipe connecting the liquid feed pump and a ballast water tank of a ship anchored. The ballast water producing apparatus according to the present embodiment may be installed on land or on a ship. In the case of installation on a ship, the ballast water tank will be a reservoir for freshwater or seawater that is raw water, and will also be a ballast water storage tank.

[0034] According to the present embodiment, microorganisms in seawater or freshwater can be effectively removed by the microbial filtration membrane. In the case of seawater, freshwater is simultaneously desalinated. The value of freshwater can be maintained. Also, if membrane-treated water is stored in, for example, a ballast water storage tank, it can be pumped as ballast water to ships and ships when necessary.

Example Next, the ability to explain the present invention more specifically with reference to examples is merely an example and does not limit the present invention.

Toda 巿 industrial water (raw water) in Saitama Prefecture was treated using the following ballast water production equipment A under the following operating conditions. Immediately after the treatment of raw water and treated water (membrane filtered water), after storage for 1 day, and after storage for 7 days, odor measurement, bacterial count, etc. were measured. Further, the sample after storage for 7 days was subjected to a sand filtration treatment to be carried out when producing ordinary industrial water or deionized water, and the odor of the treated sample was measured. The storage was performed at room temperature and in an air atmosphere. Measurements of general bacteria were performed only on the samples immediately after treatment and after storage for 7 days. The results are shown in Table 1.

(Ballast water production equipment A)

The apparatus shown in FIG. 1 was used. The ballast water production system A is mainly composed of a hollow fiber membrane type microbial filtration device 3 and a hollow fiber membrane module consisting of a microfiltration membrane with a processing capacity of 3 m ³ Z in a treatment tank 4 “Stellapore SUR31534” (Mitsubishi Rayon ) Was used. Further, the hollow fiber membrane type microbial filtration device 3 and the treated water storage tank 6 were connected by a treated water pipe 7, and a suction pump 8 was installed in the treated water pipe 7. In addition, a backwashing pump 9 was installed so that the microfiltration membrane could be backwashed by the backwashing pipe 10 for the filtered water in the treated water storage tank 6.

[0038] (Driving method)

Raw water was supplied to ballast water production equipment A at a throughput of 3 m ³ Z. In the microorganism removing step, air from the blower 11 is bubbled as fine bubbles from a distributor 12 installed below the hollow fiber membrane module 5, and filtered while removing microorganisms and the like adhering to the surface of the hollow fiber membrane. Was done. This was repeated, except that the backwashing step was 1 minute with respect to the microorganism removing step of 15 minutes. Further, the waste liquid in which the microorganisms were concentrated was appropriately drained from the lower part of the treatment tank 4 of the hollow fiber membrane type microorganism filtration device 3.

[0039] (Odor measurement)

In accordance with the method described in JIS K0101, a sensory test is conducted by five people, and the average value is shown. The unit of the odor intensity was TON, and the results were displayed as "Odorless", 1 to 3 were "very slightly odorous", and 4 or more were "odorous". [0040] (Method for measuring general bacteria)

As for general bacteria, a sample was added to BGLB (Brilliant Green Lactose Bile Broth), cultured at 35 ° C. for 24 hours, and then measured for general bacteria. The counts were expressed in CFU per 100 mL.

(Method of measuring total plankton number)

The samples were observed under a microscope and counted. The indication was expressed in the number per 1 mL.

The procedure was performed in the same manner as in Example 1 except that the ballast water production apparatus B was used instead of the nost water production apparatus A. In Example 2, measurement of general bacteria and total plankton number was not performed. The results are shown in Table 1.

(Ballast Water Production Apparatus B and Operation Method)

An apparatus similar to ballast water production apparatus A was used except that an ultrafiltration membrane apparatus LOV membrane (manufactured by Asahi Kasei Corporation) was used instead of the hollow fiber membrane type microbial filtration apparatus. The operating pressure of the ultrafiltration membrane device LOV membrane is 0. IMPa. The operation method is the same as the operation method of ballast water production system A.

The procedure was performed in the same manner as in Example 1 except that the ballast water production apparatus C was used instead of the nost water production apparatus A. In Example 3, measurement of general bacteria and total plankton count was not performed. The results are shown in Table 1.

(Ballast water production equipment C)

The apparatus shown in FIG. 2 was used. The ballast water production device C includes a fresh water supply pump 22, a reverse osmosis membrane device 21, and a treated water storage tank 6. The reverse osmosis membrane device 21 has a reverse osmosis membrane module ES-10 (not shown) (manufactured by Nitto Denko Corporation). Is loaded. The operation of the reverse osmosis membrane module is performed by a known method, and the operating pressure is 0.6 MPa.

The process was performed in the same manner as in Example 1 except that the treatment using the nost water producing apparatus was not performed, and the raw water was used as a measurement sample (untreated). The results are shown in Table 1.

After the raw water was boiled at 100 ° C for 5 minutes instead of using the nost water production equipment Other than the above, the procedure was the same as in Example 1. The results are shown in Table 1.

In place of the treatment using the ballast water production equipment, except that the raw water was subjected to ultrasonic treatment at a frequency of 28 kHz and irradiation time of 10 minutes as mechanical crushing and cooled to prevent temperature rise,

Performed similarly to 1. The results are shown in Table 1.

[Table 1] Raw water; Toda City Stored immediately after treatment Saved for 1 day Saved after 7 Sand treatment Industrial water

Example 1

Odor to Fu, Chofu to Nao

General bacteria 0-0-Total number of alkantons 0 0-Example 2 Breath M Fu Example 3 tea

Odor 2 5 5 General bacteria 1 0 0-1 0 ⁴ or more-Total: r Rank tonnage 2 0 1 0 0 or more-Comparative example 2

Odor: ¾ tefu Odorless 5 5 General bacteria 0 ― 10 ⁴ or more

Total Frankton number 0-0-Comparative example 3

Odor 5¾ M. 4 7 7 General bacteria 7 0 ― 10 ⁴ or more ― Total alankton number 0 ― 0 ― Note) The odor result of 14 days storage in Example 1 2 was “2” and 14 in Example 3 The odor result for day storage is “1”.

Bacteria; CFU / 100mL Total plankton number / piece / mL

The procedure was the same as in Example 1 except that the raw water used was Arakawa river water instead of Toda II industrial water. The measurement of general bacteria and the like was omitted. The results are shown in Table 2.

The procedure was the same as in Example 2 except that the raw water used was Arakawa River water instead of Toda II industrial water. The measurement of general bacteria and the like was omitted. The results are shown in Table 2.

The procedure was the same as in Example 3, except that Arakawa River water was used as raw water instead of Toda II industrial water. The measurement of general bacteria and the like was omitted. The results are shown in Table 2.

The same procedure as in Example 4 was carried out except that the treatment using the nost water producing apparatus was not performed, and the raw water was used as a measurement sample as is (untreated). The results are shown in Table 2.

Example 4 was carried out in the same manner as in Example 4 except that the raw water was boiled at 100 ° C for 5 minutes instead of using the nost water producing apparatus. The results are shown in Table 2.

In place of the treatment using the ballast water production equipment, the same operation as in Example 4 was carried out except that the raw water was subjected to ultrasonic treatment at a frequency of 28 kHz and an irradiation time of 10 minutes as mechanical crushing and cooled to prevent a temperature rise. . The results are shown in Table 2.

[Table 2]

Raw water; Immediately after treatment 1 day storage 7 days storage Sand treatment Arakawa river water

Example 4 rtn breathless odor Example 5 ut breathless te a.

Example 6 lur—self Jifc Comparative Example 4 5 8 8 Comparative Example 5 Odorless 1 5 5 Comparative Example 6 Odorless 8 9 8

Hypochlorous acid was further added to the treated water and 2. Omg / L was added, and the measurement was carried out in the same manner as in Example 1 except that the measurement was performed after 14 days of storage. In Example 7, measurement of the number of general bacteria and total plankton was not performed. The results are shown in Table 3.

Hypochlorous acid was further added to the treated water, 2. Omg / L was added, and the measurement was carried out in the same manner as in Example 2 except that the measurement was performed after storage for 14 days. In Example 8, measurement of the number of general bacteria and total plankton was not performed. The results are shown in Table 3.

Hypochlorous acid was further added to the treated water, and 2.Omg / L was added. The measurement was carried out in the same manner as in Example 3 except that the measurement was performed after storage for 14 days. In Example 9, measurement of the number of general bacteria and the total plankton was not performed. The results are shown in Table 3.

Comparative Examples 7-9 were stored for 14 days from Comparative Examples 13 and 14, respectively. Comparative Example 10 did not perform treatment using a ballast water producing apparatus, and further added hypochlorous acid to raw water. This was performed in the same manner as in Example 1 except that the measurement was performed after adding / L and storing for 14 days. In Comparative Examples 7-9, measurement of general bacteria and total plankton count was not performed. The results are shown in Table 3.

[Table 3] Raw water; Toda city Store immediately after treatment Save for 7 days 1 Save for 4 days Sand treatment

Example 7

Example 8 Smelt with smell of breath M B.

i te Fu Comparative Example 7 Calcium odor 5 6 6 Comparative Example 8 Calcium odor 5 6 6 Comparative Example 9 Calcium odor 7 7 7 Comparative Example 10 0 Calcium odor 3 6 6

The same method as in Example 1 was adopted except that ballast water production equipment D was used instead of nost water production equipment A, and seawater from Odaiba, Tokyo, was used instead of industrial water for Toda 巿. I went. In Example 10, the measurement of the general bacteria and the total plankton number was not performed. The results are shown in Table 4.

(Ballast Water Production Equipment D and Operation Method)

The raw water is seawater from Odaiba instead of freshwater, a seawater supply pump is used instead of the freshwater supply pump 22, and the seawater desalination reverse osmosis module SU-810 (manufactured by Toray) is used instead of the reverse osmosis membrane module ES-10. ) And the operation pressure was changed to 6. OMPa instead of 0.6 MPa.

The procedure was the same as in Comparative Example 1, except that seawater from Odaiba was used instead of Toda II industrial water. The results are shown in Table 4.

The procedure was the same as in Comparative Example 2, except that seawater from Odaiba was used instead of Toda II industrial water. The results are shown in Table 4.

The procedure was the same as in Comparative Example 3, except that seawater from Odaiba was used instead of Toda II industrial water. The results are shown in Table 4. [Table 4] Raw water; preserved for 1 day immediately after treatment Saved for 7 days and then treated with sand Example 1 0 1 1 1 ίκ breath Comparative example 1 1 1 4 5 5

Comparative Example 1 2 2 3 7 7

Comparative Example 1 3 2 5 8 8

[0068] As shown in each example, treated water obtained by treating fresh water with an MF membrane, a UF membrane, or an RO membrane has no odor even after being stored for one week, and general bacteria and plankton are also detected. Nakata. In addition, the treated water obtained by treating seawater with the RO membrane was fresh water, and even after being stored for one week, it did not feel odor and did not detect general bacteria or plankton. As described above, since the bacterium-plankton is not mixed in the membrane-treated water, it is possible to prevent freshwater from being putrefactive during voyage and maintain the value of freshwater. In addition, the treated water obtained by adding hypochlorous acid to the treated water of these examples did not have an odor even after being stored for a further one week (total of two weeks), so that it could be used for a longer voyage. it can. On the other hand, in the boiling treatment of the comparative example, both plantaton and general bacteria are killed, but since the storage container is not sterilized, it is presumed that bacteria are generated from the dead body of planktonic bacteria during storage. . The same applies to ultrasonic treatment, but the method of killing mechanical plankton and microorganisms represented by ultrasonic waves is that relatively large objects such as plankton are destroyed and their contents are exposed to the outside. It can be seen that there are various problems, such as being easy to become a nutrient source and small microorganisms and the like having insufficient bactericidal effect.

Claims

The scope of the claims

[1] A method for producing marine ballast water, comprising the step of passing fresh water through a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane to obtain a membrane-treated water from which microorganisms in the freshwater have been removed. .

[2] A method for producing ballast water for ships, comprising a step of removing microorganisms in seawater by passing seawater through a reverse osmosis membrane and obtaining desalinated membrane-treated water.

3. The method for producing ballast water for ships according to claim 1, wherein the fresh water is at least one of industrial water, tap water, river water, lake water, groundwater, or sewage treatment water.

[4] The method for producing ballast water for ships according to claim 2, wherein the oil content in the seawater is adsorbed and removed by a hydrophobic adsorbent.

[5] The method for producing ballast water for ships according to any one of [14] to [14], wherein a bactericide is added to the membrane-treated water.

[6] a microfiltration membrane device, an ultrafiltration membrane device or a reverse osmosis membrane device for removing microorganisms in the freshwater supplied from the freshwater supply means,

A ballast water storage tank for storing membrane treatment water,

An apparatus for producing ballast water for ships, comprising:

[7] Seawater supply means power A reverse osmosis membrane device that removes microorganisms in the supplied seawater and desalinates it,

A ballast water storage tank for storing membrane treatment water,

An apparatus for producing ballast water for ships, comprising:

8. The marine ballast water producing apparatus according to claim 6, further comprising a chemical adding means for adding a bactericide to the membrane-treated water.

9. The marine ballast water production apparatus according to claim 6, wherein the microfiltration membrane device is a immersion type hollow fiber membrane device or a pressure type hollow fiber membrane device.

[10] Use of the membrane-treated water obtained by the method for producing ballast water for a ship according to claim 15 as nolast water for a ship.