JP2010094584A - Method of treating ballast water and apparatus for treating ballast water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of treating ballast water, by which performance of a filtration membrane is maintained for a long period of time and an apparatus for treating the ballast water. <P>SOLUTION: The method of treating the ballast water includes: a raw water supply step (a) of: supplying sea water taken as raw water to the filtration membrane during the anchorage of a ship; a membrane filtration step (b) of: filtering the raw water using a filtration membrane loaded on the ship by complete filtration method to separate into the ballast water and filtration residue waste water while the ship is anchored at the collection place of the sea water; and a chemical cleaning step (c) of: cleaning the filtration membrane after being used for the filtration in the membrane filtration step with a chemical during navigation of the ship. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a ballast water treatment method and a ballast water treatment apparatus using a filtration membrane.

  In ships such as cargo ships, ballast water is generally loaded to stabilize the hull when navigating with empty cargo, and the ballast water is discharged outside the hull after navigation. As ballast water, seawater is usually used, but if there are aquatic organisms in the ballast water, the ecosystem may change or the specific organism may change due to the aquatic organisms flowing into a different sea area from the original habitat when the ballast water is discharged. There is a problem that an anomaly occurs. In order to avoid this problem, as of October 2008, the International Maritime Organization (IMO) has made preparations for the entry into force of the Convention to limit the number of organisms in ballast water discharged from ships in 2009. The development of ballast water treatment equipment that meets technical standards is urgently required worldwide.

  As a method of killing and removing aquatic organisms existing in ballast water, a method of removing aquatic organisms with a filter is conventionally known. However, although relatively large organisms can be removed with a filter, microorganisms can be efficiently removed. Since it is difficult to remove, there is a problem that a combination with other means for removing microorganisms is necessary. Various other methods have been proposed. For example, the method of killing aquatic organisms by shearing force and cavitation using two plates with slits has a problem that the effect of removing microorganisms is small. The method used has a problem that the sterilization effect has low sustainability, and the method using chlorine has a problem that the effect is easily influenced by the water temperature, contact time, pH, and the like. In addition, the method of electrolyzing ballast water to generate chlorine and killing aquatic organisms through its oxidation action requires the supply of high concentrations of chlorine to remove various aquatic organisms. There is. Furthermore, methods for killing aquatic organisms by heating and ultraviolet irradiation have also been studied, but there are problems that it is difficult to make simple equipment, such as the need for securing a heat source in the method by heating. In the method, it is difficult to uniformly treat the entire ballast water, and there is a problem that the equipment cost is high.

  On the other hand, a method for treating ballast water by a membrane filtration method using a microfiltration membrane (MF membrane), an ultrafiltration membrane (UF membrane) or the like has been proposed. According to the membrane filtration method, both relatively large aquatic organisms and microorganisms can be efficiently removed. However, in the membrane filtration method, when the filtration membrane is clogged, the treatment capacity of the ballast water decreases. In addition, since seawater used for ballast water has a high ion concentration, there is a problem that scales accumulate on the surface of the filtration membrane during long-term operation, causing clogging or breakage of the filtration membrane. In addition, when the scale takes in organic substances, a strong contamination layer is formed.

  In addition, the total filtration method is advantageous in that the equipment can be simplified while maintaining the removal efficiency of underwater organisms. However, in order to prevent clogging of the filtration membrane in the total filtration method, it is necessary to wash the filtration membrane at a predetermined frequency.

  Patent Document 1 discloses a plankton removal process for removing planktons in seawater by passing seawater in a harbor area where a ship is anchored through a filtration membrane having a pore size of 2 μm or more, and seawater from which planktons have been removed has a pore size of 1. A method for producing ballast water for ships, which has a bacteria removal step of removing bacteria in seawater by passing through a bacteria filtration membrane of less than 0 μm, and uses the membrane filtrate obtained in the bacteria removal step as ballast water Is proposed to provide a backwashing step for washing the bacterial filtration membrane by backwashing. In addition, the filtration function of the bacterial filtration membrane is restored by performing the backwashing process, and when the backwashing process is completed, the process moves to the bacteria removal process again, and it is possible to perform filtration over a long period of time by repeating this process. Is described.

  In Patent Document 2, in a film treatment method for ballast water provided with a membrane treatment device for separating microorganisms having a predetermined size or more on a ship body or on a ship body, a cleaning liquid containing a surfactant is used as a membrane surface and the membrane surface. The membrane surface is washed with a cleaning solution containing an enzyme that decomposes the fouling substance after a soaking treatment that permeates between fouling substances containing at least one of protein, lipid, carbohydrate, and plant fiber attached to the surface. A treatment method for ballast water is proposed, and microfiltration membranes are used as membranes. Surfactant immersion treatment and enzyme washing treatment are usually performed after stopping the passage of seawater into the membrane device body. It is described that there is.

  However, when supplying ballast water using a membrane filtration method and a total filtration method capable of simplifying and downsizing the equipment, the ballast water treatment method and ballast that can maintain the performance of the filtration membrane well over a long period of time A water treatment device has not yet been proposed.

JP 2006-239530 A JP 2007-268379 A

  The present invention solves the above-mentioned problems and improves the performance of the filtration membrane over a long period of time when the ballast water is supplied by the membrane filtration method and the total filtration method capable of simplifying and downsizing the equipment. An object is to provide a ballast water treatment method and a ballast water treatment apparatus that can be maintained.

  The present invention has the following configuration.

[1] The following steps:
(A) Raw water supply process for supplying seawater collected during berthing to the membrane as raw water
(B) A membrane filtration step of separating raw water into ballast water and filtration residue waste water by filtering by a total filtration method using a filtration membrane mounted on the vessel while the vessel is anchored at the seawater collection site And (c) A ballast water treatment method including a chemical washing step of washing the filtration membrane after being used for filtration in the membrane filtration step with a chemical during ship navigation.

  [2] The ballast water treatment method according to [1], wherein the filtration membrane is a microfiltration membrane.

  [3] In the above [1] or [2], the raw water supplied in the raw water supply step (a) is a pretreatment for removing foreign matters in seawater using a foreign matter removing device. The ballast water treatment method as described.

  [4] The ballast water treatment method according to [3], wherein the foreign matter removing apparatus is sterilized and washed after the pretreatment.

  [5] The above [3] or [4], wherein the foreign matter removing apparatus after the sterilization cleaning and the filtration membrane after the chemical cleaning step (c) are performed using fresh water containing or not containing the chemical. ] The ballast water treatment method of description.

  [6] The ballast water treatment method according to any one of [1] to [5], wherein the membrane filtration step (b) is performed by pressure filtration.

[7] The ballast water produced in the membrane filtration step (b) above is
The number of living organisms with a minimum diameter of 50 μm or more is less than 10 per 1 m ^{3 of} ballast water,
The number of living organisms having a minimum diameter of 10 μm or more and less than 50 μm is less than 10 per 1 ml of ballast water,
The number of colonizations of Vibrio cholerae O-1 and O-139 is less than 1 per 100 ml of ballast water or less than 1 per 1 g of zooplankton,
The ballast water treatment method according to any one of the above [1] to [6], wherein the number of colonies formed of E. coli is less than 250 per 100 ml of ballast water and the number of colonies of enterococci is less than 100 per 100 ml of ballast water.

  [8] The above-described [1] to [1], further including a water washing step of discharging the filtration residue waste water outside the hull and washing the filtration membrane with raw water while the vessel is anchored after the membrane filtration step of (b) above. [7] The ballast water treatment method according to any one of [7].

  [9] The ballast water treatment method according to [8], wherein the membrane filtration step and the water washing step are alternately repeated a plurality of times.

  [10] The ballast water treatment method according to any one of [1] to [9], wherein the cleaning in the chemical cleaning step (c) is performed by immersing a filtration membrane in the chemical.

  [11] The ballast water treatment method according to any one of [1] to [10], wherein the cleaning waste liquid generated in the chemical cleaning step (c) is detoxified.

  [12] The ballast water treatment method according to [11], wherein the agent is an acid, an alkali, an oxidizing agent, or a mixture thereof, and the detoxification treatment is a neutralization treatment.

  [13] The ballast water treatment method according to any one of [1] to [12], wherein after the chemical cleaning step (c), the ship is navigated with the filtration membrane immersed in fresh water.

  [14] The method according to any one of [1] to [13], further including a refiltration step of filtering the ballast water again through a filtration membrane and discharging it outside the hull after the chemical cleaning step of (c). Ballast water treatment method.

[15] A ballast water treatment apparatus for producing ballast water using seawater as raw water,
A raw water supply system, a membrane filtration system, a chemical supply system and a piping system for connecting them,
The raw water supply system has a water intake for collecting seawater;
A filtration membrane device in which the membrane filtration system contains a filtration membrane for filtering raw water to separate it into ballast water and filtration residue waste water; a pipe for supplying raw water and chemicals to the filtration membrane device; and A pipe for feeding ballast water from the filtration membrane device and a pipe for discharging filtration residue waste water;
Ballast water treatment in which the medicine supply system includes a medicine tank that contains a medicine for washing the filtration membrane after being used for filtration, and a pipe for supplying the medicine from the medicine tank to at least the filtration membrane device. apparatus.

  [16] The ballast water treatment apparatus according to [15], wherein the filtration membrane is a microfiltration membrane.

[17] A foreign matter removing system is further provided.
The foreign matter removing system removes foreign matter in seawater, a pipe for supplying the seawater from the raw water supply system to the foreign matter removing device, and the seawater after removing foreign matter as raw water. The ballast water treatment apparatus according to [15] or [16], wherein

  [18] A desalination treatment unit containing a reverse osmosis membrane is further provided, and the desalination treatment unit removes the fresh water obtained by desalinating the filtered ballast water from the foreign matter removing device and the membrane filtration device. The ballast water treatment device according to any one of [15] to [17], wherein the ballast water treatment device is configured to be supplied to at least one of them.

[19] A detoxification treatment agent supply system is further provided,
The detoxification treatment agent supply system includes a detoxification treatment agent tank containing a detoxification treatment agent for detoxifying the washed chemical, and at least harmless from the detoxification treatment agent tank into the washed chemical. The ballast water treatment apparatus according to any one of [15] to [18], further comprising a pipe for injecting the chemical treatment agent.

  ADVANTAGE OF THE INVENTION According to this invention, when supplying ballast water by a membrane filtration method and a total filtration system, the ballast water treatment method and ballast water treatment apparatus which can maintain the performance of a filtration membrane favorably over a long period of time are provided. . Moreover, since the ballast water treatment apparatus of this invention can be set as a simple and small structure, it can be used conveniently also for a small ship, for example.

<Ballast water treatment method>
The ballast water treatment method of the present invention includes the following steps:
(A) Raw water supply process for supplying seawater collected during berthing to the membrane as raw water
(B) A membrane filtration step of separating raw water into ballast water and filtration residue waste water by filtering by a total filtration method using a filtration membrane mounted on the vessel while the vessel is anchored at the seawater collection site And (c) a chemical washing step of washing the filtration membrane after being used for filtration in the membrane filtration step with a chemical during ship navigation. Hereinafter, an example of the ballast water treatment method of the present invention will be described with reference to FIG.

(A) Raw water supply step (a) In the raw water supply step, seawater is collected with a ballast pump while the ship is anchored and supplied to a membrane filtration device having a filtration membrane.

  The raw water supplied to the membrane filtration device may be pre-treated to remove foreign matters such as turbid matter and relatively large underwater organisms by passing the foreign matter removal device before the membrane filtration device. Good. By using the foreign matter removing device, the risk of damage to the filtration membrane can be reduced. Foreign matter removal by the foreign matter removing device can be performed by, for example, an auto strainer, a rotating screen, a hydrocyclone, a sand filter, or the like. The raw water after removing the foreign matter is supplied to the membrane filtration device as it is or through an auxiliary pump.

  When using a foreign matter removing device, it is preferable to sterilize and clean the foreign matter removing device after pretreatment. As the disinfectant, for example, halogen compounds, peroxides, amphoteric surfactants, and the like are used. As the disinfectant, when the agent used for washing the filtration membrane in the (c) agent washing step of the present invention is a disinfectant, the same one is preferable, and a disinfectant solution using fresh water is preferable. A preferred specific example is the use of sodium hypochlorite at a mass concentration of 1 to 5 mg / l.

  Furthermore, it is preferable that the foreign matter removing apparatus after sterilization washing is further washed with fresh water. As fresh water, for example, fresh water obtained using a reverse osmosis membrane may be used, or fresh water loaded on a ship may be used. In the present specification, the reverse osmosis membrane (RO membrane) refers to a membrane that can move an object in a direction opposite to the osmotic pressure difference by pressurization.

  Although a well-known thing can be used as a reverse osmosis membrane in this invention, For example, a cellulose type asymmetric membrane, a polyamide-type composite membrane etc. are mentioned, for example. Moreover, as a shape of a reverse osmosis membrane element, a spiral type and a hollow fiber type are used, for example.

(B) Membrane filtration step (b) In the membrane filtration step, the raw water is ballasted by filtering the whole water using a filtration membrane mounted on the vessel while the vessel is anchored at the seawater collection site. And filtration residue wastewater. The total filtration system simplifies the device configuration. In addition, the filtration membrane is mounted on the ship, whereby a chemical cleaning step described later can be performed during the navigation of the ship.

  In the present invention, since the ballast water is treated with the filter membrane at the time of seawater collection (that is, while the ship is anchored at the sampling place), the ship is navigated, so that the equipment can be simplified. For example, when performing ballast water treatment during ship navigation or ballast water drainage, a problem arises that mud sediment called mud is taken into the ballast tank and the ballast tank is contaminated. When mud accumulates in the ballast tank, it becomes a hotbed of bacteria, causing the problem that the quality of the ballast water deteriorates by the time of drainage. In the present invention, by treating the ballast water during seawater collection, the sediment is not taken into the ballast tank, and the ballast tank can be kept clean. That is, the present invention has an advantage that it is easy to maintain the quality of the ballast water during navigation.

  In the present invention, in order to prevent the growth of microorganisms in the ballast water during navigation and maintain the water quality better, for example, after the membrane filtration step, the ballast water is further subjected to antibacterial treatment during the navigation of the ship. Also good. Since the amount of microorganisms in the ballast water is almost completely removed by membrane filtration, the antibacterial agent used for the antibacterial treatment can be at a low concentration. When the chemical | medical agent used in order to wash | clean a filtration membrane in the (c) chemical | medical agent washing | cleaning process of this invention is a bactericidal agent, the same thing as this is preferable. Preferable specific examples include use of sodium hypochlorite at a mass concentration of 1 to 5 mg / l.

  (B) As the filtration membrane used in the membrane filtration step, for example, a microfiltration membrane (MF membrane), an ultrafiltration membrane (UF membrane), a nanofiltration membrane (NF membrane) or the like can be used. In the present specification, a microfiltration membrane (MF membrane) is a membrane that can prevent permeation of an object larger than 0.1 μm, and an ultrafiltration membrane (UF membrane) is an object of 2 nm to 0.1 μm. A membrane capable of preventing permeation and a nanofiltration membrane refer to a membrane capable of preventing permeation of an object smaller than 2 nm. As main aquatic organisms in seawater, plankton having a size of about 10 μm or more, bacteria having a size of about 0.5 to 5.0 μm, bacteria having a size of about 0.3 to 5.0 μm (for example, Escherichia coli, Vibrio cholerae, Enterococci and the like). The filtration membrane is preferably a microfiltration membrane. In this case, the removal effect of aquatic organisms is high and the treatment capacity per membrane area is high.

  Examples of the shape of the filtration membrane include a hollow fiber type, a flat membrane type, a tubular type, and a spiral type, but the hollow fiber type is preferable in that the membrane area per unit volume can be maximized.

  Examples of the material of the filtration membrane include cellulose acetate, aromatic polyamide, polyvinyl alcohol, polysulfone, polyvinylidene fluoride, polyethylene, polyacrylonitrile, ceramic, polypropylene, polycarbonate, polytetrafluoroethylene, etc., which have high mechanical strength and high resistance. A film made of polyvinylidene fluoride is preferable because it is excellent in chemical durability such as chemical properties.

  As a more specific preferred structure of the filtration membrane, it has a dense blocking layer of 0.1 to 0.2 μm and a porous strength support layer, and the cross-sectional pore diameter of the strength support layer is at least twice that of the blocking layer. One composite membrane is mentioned. The module structure is preferably a cylindrical type having a large membrane area per unit volume. Typically, the filtration membrane modules as described above can be arranged in parallel to form a filtration membrane device.

  (B) In the membrane filtration step, both pressure filtration and suction filtration are possible, but pressure filtration is preferred in that good filtration efficiency can be obtained by increasing the filtration differential pressure with simple equipment. In particular, it is preferable to perform pressure filtration using a membrane filtration device in which an immersion type filtration membrane module is disposed in a pressure vessel. The immersion type module does not require piping for connecting the modules, and is advantageous in that the installation area of the apparatus is remarkably small.

(B) The filtration speed in the membrane filtration step is typically controlled by quantitative filtration (that is, a method of keeping the filtration speed constant by changing the filtration pressure), for example, 50 to 150 L · m ² · hr. More preferably, it is 100 to 120 L · m ² · hr. When the filtration speed is slower than 50 L · m ² · hr, the processing time tends to be longer and the anchorage time of the ship tends to be longer. When the filtration speed is faster than 150 L · m ² · hr, the treatment time is shortened but the filtration time is reduced. There is a tendency that the clogging of the film easily proceeds and the cleaning recovery property by the drug is lowered.

The ballast water produced in the membrane filtration step (b) has the following criteria:
The number of living organisms with a minimum diameter of 50 μm or more is less than 10 per 1 m ^{3 of} ballast water,
The number of living organisms having a minimum diameter of 10 μm or more and less than 50 μm is less than 10 per 1 ml of ballast water,
The number of colonizations of Vibrio cholerae O-1 and O-139 is less than 1 per 100 ml of ballast water or less than 1 per gram of zooplankton,
It is preferable that the number of colonies formed of E. coli is less than 250 per 100 ml of ballast water, and the number of colonies of enterococci is less than 100 per 100 ml of ballast water. The above standards are in accordance with the ballast water purification regulation standards when discharged into regulated water areas as defined in the Ballast Water Management Convention adopted by the International Maritime Organization (IMO) in 2004. (b) Manufactured in the membrane filtration process When the ballast water to be satisfied satisfies the above criteria, it is preferable that the ballast water can be discharged out of the hull in a clean state. Note that organisms having a minimum diameter of 50 μm or more are mainly zooplankton, and organisms having a minimum diameter of 10 μm or more and less than 50 μm are mainly phytoplankton. Whether or not the ballast water satisfies the above criteria is evaluated by a known measuring method according to the above Ballast Water Management Convention.

  (B) When clogging of the filtration membrane in the membrane filtration step is concerned, the filtration membrane can be rinsed and drained (drainage) after the (b) membrane filtration step. The rinsing can be performed using, for example, the raw water after the pretreatment. More typically, a water washing step of draining (draining) part or all of the filtration residue wastewater generated in the membrane filtration step while berthing the vessel, and washing (rinsing) the filtration membrane with raw water To implement. Furthermore, it is preferable to repeat the membrane filtration step and the water washing step a plurality of times alternately. Thereby, clogging in the membrane filtration step can be prevented better, and the filtration efficiency can be kept good.

(C) Chemical cleaning step (c) In the chemical cleaning step, (b) the filtration membrane used for the filtration in the membrane filtration step is washed with the chemical during ship navigation. Typically, after completion of the (b) membrane filtration step, the raw water is drained from the membrane filtration device, and then the chemical is brought into contact with the filtration membrane for cleaning. (C) Since the cleaning time of the filtration membrane can be secured for a long time by performing the chemical cleaning process while the ship is navigating, a good cleaning effect can be obtained even with a relatively low concentration of the chemical. The amount of detoxifying agent used can be reduced.

  Cleaning is preferably performed by immersing a filter membrane in the drug from the viewpoint that the facility can be simplified. Typically, during ship navigation, a drug is introduced into a membrane filtration device that accommodates a filter membrane, the filter membrane is immersed in the drug for a predetermined time, and then the drug is discharged as a cleaning waste liquid.

  As a chemical | medical agent, although an acid, an alkali, an oxidizing agent, or these mixtures can be used preferably, it is preferable to use the oxidizing agent which has a bactericidal action, and an acid and an alkali are used as needed.

  (C) Although the cleaning waste liquid generated in the chemical cleaning step is discharged outside the hull, in order to reduce the burden on the environment due to the drainage, it is preferable to perform a detoxification process before the discharge. The detoxification treatment can be performed by bringing a detoxification treatment agent into contact with the cleaning waste liquid. The detoxification treatment agent can be selected according to the type of chemical used in (c) the drug washing step. Specifically, for example, the agent is an acid, an alkali, an oxidizing agent, or a mixture thereof, and the detoxification treatment is a neutralization treatment. For example, when the drug is an oxidizing agent, neutralization is performed with a reducing agent.

  As a preferable combination of a chemical | medical agent and a detoxification processing agent, the combination etc. of sodium hypochlorite as a chemical | medical agent and sodium sulfite and sodium bisulfite as a detoxification processing agent can be illustrated.

  The drug is typically supplied in a solution state, but it is preferable that the drug is diluted with fresh water in terms of good drug cleaning efficiency. As the fresh water, for example, fresh water obtained using a reverse osmosis membrane as shown in FIG. 1 as a small RO may be used, or fresh water loaded on a ship may be used.

  (C) It is preferable to rinse the filter membrane with fresh water after the chemical washing step. As the fresh water, for example, fresh water obtained using a reverse osmosis membrane as shown in FIG. 1 as a small RO may be used, or fresh water loaded on a ship may be used.

  (C) After the chemical cleaning step, it is preferable to navigate the ship with the filtration membrane immersed in fresh water. In this case, deterioration of the filtration membrane can be avoided better, and further, corrosion of the membrane filtration device can be prevented.

  It is preferable that the ballast water treatment method of the present invention further includes a refiltration step in which the ballast water is filtered again with a filtration membrane and discharged out of the hull after the chemical cleaning step (c). By including the refiltration step, the ballast water can be drained out of the hull in a cleaner state in the arrival water area of the ship. Specifically, ballast water from the ballast tank can be passed through the filtration membrane. In this case, the ballast water may be directly passed through the filtration membrane or, for example, may be passed through the filtration membrane after being pretreated through a foreign matter removing device.

  In addition, for example, when the raw water has properties that are difficult to filter through membranes, such as when many organic substances such as proteins and sugar components are contained, it is preferable to add an oxidizing agent to the raw water before the membrane filtration step (b). . The oxidizing agent can be added, for example, immediately before the pretreatment by the foreign substance removing apparatus or immediately before the membrane filtration. As an oxidizing agent, the same thing as the example of the oxidizing agent which can be used in (c) chemical | medical agent washing | cleaning processes can be used preferably, for example.

<Ballast water treatment equipment>
The present invention also provides a ballast water treatment apparatus for producing ballast water using seawater or fresh water obtained by desalinating the seawater as raw water. The ballast water treatment apparatus of the present invention includes a raw water supply system, a membrane filtration system, a chemical supply system, and a piping system that connects them. The raw water supply system has a water intake section for collecting seawater. The membrane filtration system includes a filtration membrane device containing a filtration membrane for filtering raw water and separating it into ballast water and filtration residue waste water, piping for supplying raw water and a chemical to the filtration membrane device, respectively, and the A pipe for supplying ballast water from the filtration membrane device to the ballast tank and a pipe for discharging the filtration residue waste water; The drug supply system includes a drug tank that stores a drug for cleaning the filtration membrane after being used for filtration, and a pipe for supplying the drug from the drug tank to at least the filtration membrane device.

  In FIG. 2, the ballast water treatment apparatus 1 which is an example of the ballast water treatment apparatus of this invention is shown. In the ballast water treatment device 1, the raw water supply system has a seawater collection pipe 101 and a ballast pump 301 as a water intake, and the membrane filtration system includes a filtration membrane device 12 in which a filtration membrane is accommodated, and the filtration membrane device. 12 includes a pipe 103 for supplying raw water and chemicals, a pipe 104 for supplying ballast water from the filtration membrane device 12, a pipe 105 for discharging filtration residue waste water, and a pipe 114 for air break. . The drug supply system includes a drug tank 13 for storing a drug for washing the filtration membrane after used for the filtration, and a pipe 110 for supplying the drug from the drug tank 13 to at least the filtration membrane device 12. .

  The ballast water treatment apparatus according to the present invention is configured to pass foreign matter removal apparatus 11 in seawater, piping for supplying the seawater or fresh water to the foreign matter removal apparatus 11 from the raw water supply system, and seawater after removing foreign substances as raw water. It is preferable to further include a foreign matter removing system having a pipe for performing the above operation. In the ballast water treatment apparatus of the present invention, it is preferable to further include a desalination treatment unit 14 containing a reverse osmosis membrane. The desalination unit 14 is preferably configured to supply fresh water obtained by desalinating the filtered ballast water to at least one of the foreign matter removing device 11 and the membrane filtration device 12. Further, the ballast water treatment apparatus of the present invention comprises a detoxification treatment tank 15 and a detoxification treatment having a pipe for injecting the detoxification treatment agent from the detoxification treatment agent tank 15 into at least the washed chemical. It is preferable to further include an agent supply system.

  An exemplary embodiment for producing ballast water using the ballast water treatment apparatus of the present invention will be described with reference to FIG. First, seawater collected using the ballast pump 301 via the pipe 101 with the valve 212 opened is sent to the foreign matter removing apparatus 11 via the pipe 102 by opening the valves 201 and 202. The foreign matter removing device 11 has a foreign matter removing mechanism such as an auto strainer, a rotating screen, a hydrocyclone, a sand filter, etc., and removes foreign matters such as turbid matters and relatively large underwater organisms to obtain raw water. In the case of sterilizing the foreign matter removing apparatus, ballast water is sent from the pipe 111 to the desalination treatment unit 14, and after the desalination treatment is performed, the valve 208 is opened to remove the obtained fresh water via the pipe 113. Send to device 11. The desalination unit 14 typically contains a reverse osmosis membrane. The desalination unit 14 in FIG. 2 is connected to the ballast tank B via the pipe 111 and is connected to the membrane filtration device 12 via the pipe 112. Thereby, after taking in the ballast water and performing the desalination treatment, the valve 208 is closed, the valve 209 is opened, fresh water is allowed to flow to the membrane filtration device 12 via the pipe 112, and the membrane filtration device 12 is washed with fresh water. it can. Further, the fresh water can form a drug solution by being mixed with the drug supplied from the drug tank 13 via the pipe 110 before entering the membrane filtration device 12.

  The foreign matter removing device 11 is connected to the membrane filtration device 12 by a pipe 103, and the valves 203 and 204 are opened so that the seawater after removing the foreign matter can be sent to the membrane filtration device 12 as raw water via the pipe 103. In the membrane filtration device 12, the raw water is filtered by passing the raw water through the filtration membrane by a total filtration method, and separated into ballast water and filtration residue waste water. Filtration residue wastewater is discharged outside the hull through the pipe 105 by opening the valve 210 during filtration and / or after filtration, putting air for discharge into the membrane filtration device 12 via the pipe 114, and opening the valve 205. Ballast water is fed into the ballast tank B via the pipe 104.

  The membrane filtration device 12 is connected to the chemical tank 13 through pipes 110, 112, and 103, and is also connected to the desalination unit 14 through the pipe 112. After the filtration, the valve 209 is opened, the valve 208 is closed, the pump 303 is operated while flowing fresh water through the pipe 112, and the drug is allowed to flow from the drug tank 13 to the membrane filtration device 12 via the pipe 110. Filter device 12 can be filled with a drug solution. The cleaning waste liquid is discharged out of the hull via the pipe 105 by opening the valves 205 and 210.

  The chemical tank 13 is also connected to the foreign substance removing device 11 by pipes 109 and 113. For example, when a sterilizing agent is used for cleaning the filter membrane, the foreign substance removing apparatus 11 can be sterilized and cleaned by operating the pump 302 and supplying the drug from the drug tank 13 to the foreign substance removing apparatus 11 via the pipe 109.

  The detoxification treatment agent tank 15 stores a detoxification treatment agent for detoxifying cleaning waste liquid generated during chemical cleaning of the membrane filtration device 12 and sterilization cleaning when the foreign substance removal device 11 is sterilized and cleaned. The pipe 108 is connected to the ballast tank B via the pipe 116. The cleaning waste liquid from the membrane filtration device 12 that enters the pipe 108 via the pipe 105 can be detoxified by operating the pump 304 and flowing the detoxification treatment agent from the detoxification treatment tank 15 via the pipe 115. Similarly, when the foreign matter removing device 11 is sterilized and washed, the valves 206 and 207 are opened, and the detoxification treatment agent is passed through the piping 115 to the cleaning waste liquid that has flowed from the foreign matter removing device 11 through the piping 106, 107, and 108. Can act.

  The detoxification treatment agent can be detoxified when the pump 305 is operated and supplied into the ballast tank B through the pipe 116 to discharge the ballast water containing the antibacterial agent. In addition, when a problem occurs in the membrane filtration apparatus and urgent action is required, seawater via the ballast pump 301 is directly introduced into the ballast tank B via the pipe 117 by closing the valves 201 and 202 and opening the valve 211. You can also

  When re-filtering the ballast water in order to drain the ballast water out of the hull in a clean state, the ballast water in the ballast tank B is replaced with seawater by closing the valve 212 and opening the valve 213. Membrane filtration can be performed by the same procedure as the above-described ballast water production from seawater except that the water is pumped through the pipe 118. In this case, the pumped-up ballast water may be passed through the foreign matter removing device 11 or may be passed directly to the membrane filtration device 12 via a pipe (not shown).

  Furthermore, in the case where the raw water has a property that it is difficult to perform membrane filtration, when the oxidizing agent is added to the raw water, it is preferable to add the oxidizing agent to the raw water before being passed through the foreign matter removing device or the membrane filtering device. For example, when the chemical | medical agent accommodated in the chemical | medical agent tank 13 is an oxidizing agent, the pump 302 or the pump 303 is operated at the time of the membrane filtration while the ship is anchored, and before it is made to flow into the foreign material removal apparatus 11 or the membrane filtration apparatus 12. An oxidant can be allowed to act on the raw water via the pipe 109 or the pipe 110. Similarly, when the agent is not an oxidant, an oxidant tank (not shown) is separately provided, and the oxidant can be supplied from the oxidant tank.

  Preferable examples of the filtration membrane, reverse osmosis membrane, chemical, detoxifying agent and oxidizing agent used in the ballast water treatment apparatus of the present invention include the same as those described above in the ballast water treatment method.

  The ballast water treatment method and the ballast water treatment apparatus of the present invention can be suitably used for the production of ballast water used in various ships. Since the ballast water treatment apparatus of the present invention can have a simple and small configuration, it can be suitably used particularly for small ships.

It is a figure explaining the example of the ballast water treatment method of this invention. It is a figure explaining the example of the ballast water treatment apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ballast water processing apparatus 11 Foreign material removal apparatus 12 Membrane filtration apparatus 13 Chemical tank 14 Desalination processing unit 15 Detoxification processing agent tank 101,102,103,104,105,106,107,108,109,110,111,112 , 113, 114, 115, 116, 117, 118 Piping 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213 Valve 301 Ballast pump 302, 303, 304, 305 Pump

Claims (19)

The following steps:
(A) Raw water supply process for supplying seawater collected during berthing to the membrane as raw water
(B) A membrane filtration step of separating raw water into ballast water and filtration residue waste water by filtering by a total filtration method using a filtration membrane mounted on the vessel while the vessel is anchored at the seawater collection site And (c) A ballast water treatment method including a chemical washing step of washing the filtration membrane after being used for filtration in the membrane filtration step with a chemical during ship navigation.   The ballast water treatment method according to claim 1, wherein the filtration membrane is a microfiltration membrane.   3. The ballast water treatment according to claim 1, wherein the raw water supplied in the raw water supply step (a) is a pretreatment for removing foreign matter in the seawater using a foreign matter removing device. Method.   The ballast water treatment method according to claim 3, wherein the foreign matter removing device is sterilized and washed after the pretreatment.   The ballast water treatment according to claim 3 or 4, wherein the foreign matter removing device after the pretreatment and the filtration membrane in the chemical cleaning step (c) are performed using fresh water containing or not containing the chemical. Method.   The ballast water treatment method according to any one of claims 1 to 5, wherein the membrane filtration step (b) is performed by pressure filtration. The ballast water produced in the membrane filtration step (b) is based on the following criteria:
The number of living organisms with a minimum diameter of 50 μm or more is less than 10 per 1 m ^{3 of} ballast water,
The number of living organisms having a minimum diameter of 10 μm or more and less than 50 μm is less than 10 per 1 ml of ballast water,
The number of colonizations of Vibrio cholerae O-1 and O-139 is less than 1 per 100 ml of ballast water or less than 1 per 1 g of zooplankton,
The ballast water treatment method according to any one of claims 1 to 6, wherein the number of colonies formed of E. coli is less than 250 per 100 ml of ballast water, and the number of colonies of enterococci satisfies less than 100 per 100 ml of ballast water.   After the membrane filtration step of (b), further comprising a water washing step of discharging the filtration residue waste water out of the hull while washing the vessel and washing the filtration membrane with the raw water. The ballast water treatment method according to any one of the above.   The ballast water treatment method according to claim 8, wherein the membrane filtration step and the water washing step are alternately repeated a plurality of times.   The ballast water treatment method according to any one of claims 1 to 9, wherein the cleaning in the chemical cleaning step (c) is performed by immersing the filtration membrane in the chemical.   The ballast water treatment method according to any one of claims 1 to 10, wherein the washing waste liquid generated in the chemical washing step (c) is detoxified.   The ballast water treatment method according to claim 11, wherein the chemical is an acid, an alkali, an oxidizing agent, or a mixture thereof, and the detoxification treatment is a neutralization treatment.   The ballast water treatment method according to any one of claims 1 to 12, wherein after the chemical cleaning step (c), the ship is navigated with the filtration membrane immersed in fresh water.   The ballast water according to any one of claims 1 to 13, further comprising a refiltration step of filtering the ballast water again through the filtration membrane and discharging it outside the hull after the chemical cleaning step of (c). Processing method. A ballast water treatment device for producing ballast water using seawater as raw water,
A raw water supply system, a membrane filtration system, a chemical supply system and a piping system for connecting them,
The raw water supply system has a water intake for collecting seawater;
A filtration membrane device in which the membrane filtration system contains a filtration membrane for filtering raw water to separate it into ballast water and filtration residue waste water; a pipe for supplying raw water and chemicals to the filtration membrane device; and A pipe for feeding ballast water from the filtration membrane device and a pipe for discharging filtration residue waste water;
Ballast water treatment in which the medicine supply system includes a medicine tank that contains a medicine for washing the filtration membrane after being used for filtration, and a pipe for supplying the medicine from the medicine tank to at least the filtration membrane device. apparatus.   The ballast water treatment apparatus according to claim 15, wherein the filtration membrane is a microfiltration membrane. A foreign matter removal system;
The foreign matter removing system removes foreign matter in seawater, a pipe for supplying the seawater from the raw water supply system to the foreign matter removing device, and passing the seawater after removing foreign matter as raw water. The ballast water treatment apparatus according to claim 15 or 16, further comprising:   The apparatus further comprises a desalination unit containing a reverse osmosis membrane, and the desalination unit removes fresh water obtained by desalinating the filtered ballast water from at least one of the foreign matter removing device and the membrane filtration device. The ballast water treatment device according to any one of claims 15 to 17, wherein the ballast water treatment device is configured to be supplied to the water. Further equipped with a detoxifying treatment agent supply system,
The detoxification treatment agent supply system has a detoxification treatment agent tank containing a detoxification treatment agent for detoxifying the washed chemical, and at least harmless from the detoxification treatment agent tank into the washed chemical. The ballast water treatment apparatus according to any one of claims 15 to 18, further comprising a pipe for injecting the chemical treatment agent.

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