WO2011065434A1

WO2011065434A1 - Process for treatment of ship ballast water

Info

Publication number: WO2011065434A1
Application number: PCT/JP2010/071039
Authority: WO
Inventors: 健司林
Original assignee: 鶴見曹達株式会社; 東亞合成株式会社
Priority date: 2009-11-27
Filing date: 2010-11-25
Publication date: 2011-06-03
Also published as: JPWO2011065434A1; TW201144235A

Abstract

A method for treating ship ballast water, characterized in that the ballast water is mixed with ammonia or an ammonium salt and a hypochlorous acid salt to eradicate or kill aquatic organisms in the ballast water and suppress the generation of any trihalomethane compound; and an agent for treating ballast water, which can be used for the method.

Description

Ship ballast water treatment method

The present invention relates to a method for treating ballast water of a ship so that it can be safely discharged, and a treatment agent for ballast water used in the treatment method.

In recent years, cases in which aquatic organisms have been artificially transported and settled in waters beyond their natural distribution and disturbed the ecosystems of new waters have been reported and problematic in various countries. Such organisms are called alien invading organisms, most of which are bivalves, starfish, barnacles, or benthic and attached organisms such as seaweed. Possible causes of migration and settlement are via ship such as sticking to the hull or mixing with ballast water, or due to fisheries such as import for aquaculture or release or movement mixed with imported marine products. ing. With the progress of research such as oceanographic surveys, planktons such as dinoflagellates, copepods, and jellyfishes are carried by ballast water as alien invasive organisms, and benthic and attached organisms are also affected by ballast water during larval plankton. It is recognized that it is carried in large quantities, and this is considered to be one of the major causes of ecosphere disturbance. In view of such circumstances, it is pointed out that it is important to prevent the movement of aquatic organisms by ballast water, and ballast water exchange is required in a water area 200 nautical miles or more away from land.
The International Maritime Organization has taken up this issue since the late 1980s. In February 2004, “International Convention for the Control and Management of Ships' Ballast Water and the International Convention for the Control and Management of Ship Ballast Water and Precipitates” SEDIMENTS) ”and is trying to regulate ballast water management. This treaty clarifies the future direction that ships that are engaged in international voyages, such as requiring the installation of an approved ballast water management system (such as a ballast water treatment system). Further, as described above, there is an accident that the ship being exchanged capsizes due to the ballast water exchange in a water area that is 200 nautical miles or more away from the land, and the direction of strengthening the regulation management of the ballast water is accelerated.

In recent years, there has been an increasing interest in the presence of chemical substances that are generated or by-produced during ballast water treatment. When these chemical substances are not treated at all and ballast water is discharged in the target sea area, etc., as in the case of the alien invaders described above, there is a concern that the marine environment may be polluted and eventually adversely affect the ecosystem. Yes. Contamination with chemical substances, for example, chemical substances such as bactericides mixed for the purpose of killing and sterilizing alien invaders in ballast water remain in ballast water even after killing and sterilization, and do not treat them. It can also occur by draining the wastewater. Therefore, there is a demand for the construction of a system that can remove ballast water in a safe state without adversely affecting the ecosystem by removing both alien invaders and chemical substances that are generated or by-produced even in trace amounts during discharge. Has been.

Commonly used ballast water treatment methods often generate some harmful substances. For example, when chlorinating ballast water using hypochlorite, bromoform is produced as a minor by-product. To do. In addition to bromoform, trihalomethanes substituted with halogen such as chloride and bromide contained in seawater may be generated.
Regarding the reduction of trihalomethanes, various attempts have been made to reduce trihalomethanes, especially chloroform, produced when chlorinating drinking water. In tap water, sodium hypochlorite, a hypochlorite, is widely used for sterilization and disinfection, but this sodium hypochlorite and humic substances present in neutral raw water of about pH 7 React to produce trihalomethanes such as chloroform as a by-product. In order to suppress by-products such as chloroform, by adding a substance that generates ammonium ions such as ammonia to basic sodium hypochlorite, chloramine is generated in advance, and this is used for sterilization and disinfection. It is known that the generation of chloroform and the like is suppressed. Further, a method has been proposed in which trihalomethane precursors (humic substances, etc.) are removed from raw water for use in drinking water and the like, and the generation of trihalomethanes is suppressed (for example, Japanese Patent Publication No. 3-15516, (See JP-A-8-155493 and JP-A-10-202297).
However, seawater and brackish water usually used for ballast water are significantly different in nature from neutral drinking water such as having a pH of about 8 and containing abundant bromide ions. In these seawater and brackish water, trihalomethane such as bromoform is used. No investigation has been made yet on the suppression of the occurrence of mosquitoes.

The present invention relates to a ballast water treatment method capable of killing and sterilizing aquatic organisms such as alien invaders in ship's ballast water and suppressing the generation of trihalomethanes including bromoform, and a ballast used in the treatment method. It is an object to provide a treatment agent for water.

In view of the above problems, the present inventors have killed and sterilized aquatic organisms in ballast water to prevent migration and fixation of alien invading organisms and the like such as bromoform which may be harmful when produced in large quantities. We have intensively studied how to suppress the occurrence. As a result, by mixing ammonia or ammonium salt and hypochlorite in ballast water, the generation of trihalomethanes such as bromoform in ballast water is suppressed even under seawater conditions, and bromoform in ballast water to be drained, etc. It has been found that the concentration of water can be greatly reduced and aquatic organisms in ballast water can be effectively killed and sterilized. The present invention has been made based on these findings.

According to the present invention, the following means are provided:
(1) A ballast water treatment method comprising mixing ballast water with ammonia or an ammonium salt and hypochlorite to kill and sterilize aquatic organisms in the ballast water and suppress generation of trihalomethanes .
(2) The method for treating ballast water as described in (1) above, wherein the concentration of bromoform in the ballast water at the time of discharge is 300 μg / L or less.
(3) The method for treating ballast water as described in (2) above, wherein the bromoform concentration is 150 μg / L or less.

(4) The residual chlorine concentration in the ballast water is adjusted to 1 mg / L or more and 100 mg / L or less by mixing the ammonia or ammonium salt and hypochlorite to kill and sterilize aquatic organisms. The method for treating ballast water according to any one of (1) to (3) above.
(5) The method for treating ballast water according to (4) above, wherein the residual chlorine concentration in the ballast water is adjusted to 2 mg / L or more and 20 mg / L or less to kill and sterilize aquatic organisms.
(6) The method for treating ballast water according to (4) above, wherein the residual chlorine concentration in the ballast water is adjusted to 2 mg / L or more and 10 mg / L or less to kill and sterilize aquatic organisms.
(7) After killing and sterilizing aquatic organisms in ballast water by mixing ammonia or ammonium salt and hypochlorite, reducing and neutralizing residual chlorine in the ballast water with sulfite The method for treating ballast water according to any one of items (1) to (6), wherein:

(8) When mixing ammonia or ammonium salt and hypochlorite in ballast water, after mixing ammonia or ammonium salt with ballast water, hypochlorite is mixed with ballast water. The method for treating ballast water according to any one of (1) to (7).
(9) In mixing the ammonia or ammonium salt and hypochlorite with the ballast water, the ammonia or ammonium salt and hypochlorite are mixed in advance and added to the ballast water (1) The method for treating ballast water according to any one of items (7) to (7).
(10) When mixing ammonia or ammonium salt and hypochlorite into ballast water, after mixing hypochlorite with ballast water, ammonia or ammonium salt is mixed with ballast water. The method for treating ballast water according to any one of (1) to (7).
(11) In mixing ammonia or ammonium salt and hypochlorite into ballast water, after adding ammonia or ammonium salt to the ballast tank in advance, the ballast water mixed with hypochlorite is added to the ballast tank. The method for treating ballast water according to any one of (1) to (7), wherein the ballast water is injected.

(12) The ballast according to any one of (1) to (11) above, wherein the ammonia or ammonium salt is a compound capable of reacting with hypochlorite to produce chloramine. Water treatment method.
(13) A ballast water treating agent for use in the method for treating ballast water described in any one of (1) to (12) above, comprising a combination of ammonia or ammonium salt and hypochlorite.
(14) The treatment agent for ballast water as described in (13) above, wherein the ammonia or ammonium salt is a compound capable of reacting with hypochlorite to produce chloramine.

According to the present invention, aquatic organisms that can be alien invaders in the ballast water of ships are sterilized and sterilized, and the generation of trihalomethanes such as bromoform in the ballast water is effectively and continuously suppressed and discharged. A method for treating ballast water that can reduce the concentration of trihalomethanes such as bromoform in the ballast water can be provided. Moreover, according to this invention, the processing agent of the ballast water used for the said processing method can be provided.
According to the treatment method of the present invention, a low-cost component that is easily available as a treatment agent is used, and it is safe without contaminating the environment / ecosystem of the discharged water area by alien invading organisms or chemical substances that may be harmful. It becomes possible to discharge ballast water.

The above and other features and advantages of the present invention will become more apparent from the following description.

The ballast water treatment method of the present invention is a method for effectively killing and sterilizing aquatic organisms in ballast water, and can suppress the generation of bromoform and the like when performing the killing and sterilization treatment. More specifically, by mixing ammonia or ammonium salt and hypochlorite in the ballast water, aquatic organisms in the ballast water are sterilized and sterilized between intake and drainage, and in the meantime, It is characterized by suppressing the generation of trihalomethanes such as bromoform (hereinafter referred to as bromoform) and suppressing the concentration of bromoform and the like in the ballast water to a low level. According to the method of the present invention, it is possible to discharge ballast water out of the ship without bringing aquatic organisms in the intake water area into the drainage water area and in a state where the concentration of bromoform is sufficiently reduced, The negative impact on the marine environment and marine ecosystem of the drainage can be avoided.
In the present invention, “killing / sterilizing” includes not only the death of living organisms but also the state in which they cannot reproduce even if they are alive, for example, the generation or generation of microorganisms or bacteria in ballast water while navigating to the destination. It also includes preventing proliferation. “Aquatic organisms in ballast water” refers to bacteria, microorganisms and organisms that can be contained in ballast water, as well as organisms contained in sediments deposited at the bottom of ballast tanks as well as aquatic organisms contained in ballast water. Eggs are also included. These aquatic organisms include alien invaders that are concerned about disturbing the ecosystem of the destination water area by moving and establishing beyond the distribution area of the main body.
Hereinafter, the present invention will be described in detail.

The ballast water treatment method of the present invention uses ammonia or ammonium salt together with hypochlorite as a killing / sterilizing component.
Ballast water is water loaded in a ship's hold or ballast tank in order to maintain the stability of the ship. Generally, brackish water mixed with seawater or seawater and fresh water is often used. The aspirated ballast water contains many aquatic organisms, bacteria, and the like, and a bactericidal agent is used to kill and sterilize these. Chlorine and hypochlorous acid, which are powerful disinfectants, can be suitably used for the removal of organisms in ballast water, while chlorine and hypochlorous acid added for killing and disinfecting purposes are There is concern that bromoform and the like are generated by reacting with organic substances (for example, humic substances) dissolved in seawater and brackish water used as ballast water.
In view of such circumstances, the present invention is characterized in that an ammonia component or an ammonium salt component is contained in the ballast water in addition to the hypochlorite component. By using ammonia or ammonium salt in combination with chlorform, etc. in ballast water while maintaining the ability to kill and sterilize aquatic organisms in ballast water compared to when hypochlorite is used alone. Generation | occurrence | production can be suppressed or prevented effectively and continuously. In the ballast water treated by the method of the present invention, the generation of bromoform and the like is suppressed to a low level during the period from intake to drainage, and it can be safely performed without further reduction treatment of bromoform or the like during drainage. Can be discharged or reused.

Examples of the trihalomethanes in the present invention include bromoform (tribromomethane), chloroform (trichloromethane) substituted with chloride or bromide in seawater, bromodichloromethane, dibromochloromethane, and the like. Among these, the treatment method of the present invention can suitably suppress the generation of bromoform. As mentioned above, seawater and brackish water are often used as ballast water, and bromoform is likely to be generated because bromide ion concentrations in seawater and brackish water are generally higher than in fresh water. Therefore, among the trihalomethanes generated by hypochlorite and the like, it is particularly important from the viewpoint of environmental and ecosystem protection to suppress the generation of bromoform. The treatment method of the present invention can effectively and continuously suppress the generation of bromoform or the like even when seawater or brackish water is used as ballast water.

Regarding the bromoform concentration in ballast water, individual standards may be set in some countries, and regulations are expected to be tightened in the future. Regarding the chemical substances contained in ballast water at the time of discharge, the international maritime organization established in February 2004 “International Convention for the Regulation and Management of Ship Ballast Water and Sediment”. toxicity (P ersistent, B ioaccumulative and T oxic (PBT)), and PEC / PNEC (PEC: P redicted E nvironmental C oncentration / PNEC: P redicted N o E ffect C oncentration) environmental impact assessment that is provided. Moreover, even if the above evaluation is satisfied, it tends to be desired to be more environmentally friendly. Usually, the bromoform concentration in the ballast water at the time of discharge is often around 500 μg / L. If the processing method of this invention is used, the bromoform density | concentration of the ballast water at the time of drainage can be 500 microgram / L or less so that it may demonstrate also in the below-mentioned Example. Further, in the present invention, the treatment is preferably performed so that the bromoform concentration is 300 μg / L or less, more preferably 150 μg / L or less, and particularly preferably 130 μg / L or less. .

In order to effectively kill and sterilize aquatic organisms contained in ballast water, it is important how much residual chlorine is contained in the ballast water that can effectively act on killing, sterilization and oxidation reactions. Can be expressed as residual chlorine concentration. Residual chlorine is also called effective chlorine, and is a concept that includes free chlorine such as hypochlorous acid and bound chlorine such as chloramine and bromoamine. Residual chlorine concentration is also called effective chlorine concentration, and represents the oxidation ability of free chlorine and combined chlorine in terms of chlorine.
In the present invention, by mixing ammonia or ammonium salt and hypochlorite in ballast water, free chlorine such as hypochlorous acid and bound chlorine such as chloramine and brolamin are generated as residual chlorine. These residual chlorines exert sterilizing and killing effects on living organisms. Chloramine is a substance produced by reaction of hypochlorite with ammonia or ammonium salt. In addition, bromamine is produced by the reaction of hypochlorite added to seawater with hypochlorite produced by substitution of bromine in seawater with ammonia or ammonium salt. Similarly, it is a kind of bonded chlorine.

In the present invention, the ballast water at the time of discharge by the killing / sterilizing treatment using ammonia or ammonium salt and hypochlorite is the above-mentioned “International Convention for Regulation and Management of Ship Ballast Water and Precipitate”. It is preferable that the ballast water discharge standard defined in the above is satisfied. Specific criteria, D clause of the Treaty: ballast water management standards regulations D-2: in ballast water discharge standard, the minimum size 50μm or more organisms, 1 m ³ per viable count less than 10, and the minimum size 50μm For organisms of less than 10 μm or less, the number of surviving organisms is less than 10 per mL, and (1) for virulent Vibrio cholerae (O1 and O139) as indicator microorganisms as human health standards, or less than 1 cfu / 100 mL, or Zooplankton samples less than 1 cfu / 1 g (wet weight), (2) E. coli less than 250 cfu / 100 mL, (3) Enterococci less than 100 cfu / 100 mL, killed and sterilized to meet these It is preferable to carry out. Among these, the treatment method of the present invention can be suitably used for killing and sterilizing bacteria and organisms having a size of 10 μm or more. Specific examples of organisms having a size of 10 μm or more include aquatic organisms such as zooplankton, phytoplankton, invertebrates, and algae. According to the provisions of the Convention, cfu is a colony forming unit (group unit), and the minimum size is a minimum value of height, width or depth.

The content of ammonia or ammonium salt and the content of hypochlorite to be mixed in the ballast water only need to be able to kill and sterilize aquatic organisms in the ballast water. For example, it can be set as content which can kill and sterilize aquatic organisms so that the ballast water discharge | emission standard mentioned above may be satisfied. _{LC 50} representing the acute toxicity values of chloramine are combined chlorine (half lethal concentration) was 0.012mg / L, _{LC 50} (lethal concentration representing the acute toxicity values of free chlorine from salt hypochlorite ) Is 0.005 mg / L. Generally, since the acute toxicity value for many aquatic organisms is around 0.01 to 0.1 mg / L, the acute toxic effects of chloramine and hypochlorite are high. The ability is also very high. In view of such sterilizing / killing ability, in the present invention, ammonia or ammonium salt and hypochlorite are mixed with ballast water so that the residual chlorine in the ballast water is 1 mg / L or more and 100 mg / L or less. It is more preferable to mix so that it may become 2 mg / L or more and 100 mg / L or less, It is more preferable to mix so that it may become 2 mg / L or more and 20 mg / L or less, 2 mg / L or more and 10 mg / L or less It is particularly preferable to mix so that By setting it within this range, aquatic organisms in the ballast water can be more effectively killed and sterilized, and it is practical without consuming more ammonia, ammonium salt or hypochlorite than necessary.

The content of ammonia or ammonium salt is not particularly limited as long as it can maintain the above-mentioned residual chlorine concentration, but ammonia or ammonium salt is stoichiometrically equivalent to 2 equivalents with respect to the initial effective chlorine concentration of hypochlorite. It is preferable to use an ammonium salt, more preferably equivalent to 1.5 equivalents, and still more preferably equivalent to 1.2 equivalents. The initial effective chlorine concentration of hypochlorite refers to the effective chlorine concentration obtained from the amount of ballast water and the amount of sodium hypochlorite added.

In the present invention, the mode of mixing ammonia or ammonium salt and hypochlorite with ballast water is not particularly limited. For example, ammonia or ammonium salt and hypochlorite may be mixed in the ballast water before being injected into the ballast tank (for example, mixed in piping when seawater is taken into the ballast tank) or after water intake It may be added to the ballast tank and mixed. In addition, in this specification, the ballast tank means a tank that contains water to stabilize the ship, and in addition to the dedicated ballast tank for the ship, the ballast water is added to an oil tank in a tanker or a tank installed in the hold. Including cases.

The mixing order of ammonia or ammonium salt and hypochlorite is not particularly limited. For example, ammonia or ammonium salt is first added to ballast water, and then hypochlorite is added. A method of adding chlorate and then adding ammonia or ammonium salt, a method of premixing ammonia or ammonium salt and hypochlorite, adding the mixture to ballast water, and putting ammonia or ammonium salt into the ballast tank in advance Then, a method of injecting ballast water mixed with hypochlorite into the tank can be mentioned. As demonstrated in the examples described later, in the treatment method of the present invention, ammonia or ammonium salt and sodium hypochlorite are mixed in advance to form chloramine and then added to ballast water. However, even when ammonia or ammonium salt and hypochlorite are mixed separately to produce chloramine, chloramine, etc. in ballast water, the generation of bromoform in ballast water can be effectively suppressed. it can. Among them, preferred is a method in which ammonia or ammonium salt is first added to ballast water, and then hypochlorite is added. More preferably, ammonia or ammonium salt and hypochlorite are mixed in advance, and the mixture is mixed. It is a method of adding to ballast water.

When ammonia or ammonium salt and hypochlorite are mixed separately into ballast water, the mixing interval may be any as long as the residual chlorine can be maintained at a predetermined concentration. For example, this interval is 1 second or more and 1 hour. Can be within. In addition, a space between the two may be simply connected by a pipe, a mixer may be inserted, or a tank may be inserted. In this case, the problem of odor or heat generated by mixing ammonia or ammonium salt with hypochlorite can be solved.
In addition, when seawater or the like is taken into the ship as ballast water, it is first returned to the habitat after removing large organisms and plankton using a filter, and then added to the filtered ballast water as described above. Further, ammonia or ammonium salt and hypochlorite may be mixed in the order of addition.

In the present invention, the treatment time with ammonia or ammonium salt and hypochlorite is not particularly limited as long as it can kill and sterilize aquatic organisms in ballast water. Further, the upper limit of the processing time may be determined based on the voyage time of the ship. For example, it can be set to a time obtained by loading ballast water and arriving at the port of call and draining the ballast water, excluding sulfite treatment time described later. Such a treatment time is preferable because aquatic organisms in the ballast water can be effectively killed and sterilized, and can be discharged without hindrance.

Examples of hypochlorite used in the present invention include alkali metal salts such as sodium and potassium, and alkaline earth metal salts such as calcium. Of these, potassium and the like are plant-based nutrient components, and barium and the like are toxic. Therefore, sodium hypochlorite, which is a sodium salt that is a seawater component and is easy to handle, is preferable. Hypochlorite is preferably used as an aqueous solution.
The ammonia or ammonium salt used in the present invention may be any substance that can react with hypochlorite to produce chloramine. Specifically, ammonia or aqueous ammonia can be used as ammonia. Specific examples of the ammonium salt include inorganic ammonium salts such as ammonium chloride, ammonium sulfate, and ammonium nitrate, and ammonium acetate. These ammonium salts may be added in solid form or handled in the form of an aqueous solution diluted with water or seawater, but an aqueous solution is preferred from the viewpoint of handling.
Among these, in the present invention, from the viewpoint of low cost and easy handling, ammonia water, ammonium chloride, and ammonium sulfate are preferable, and it is more preferable to use ammonia water or an inorganic ammonium salt of chloride which is a seawater component. More preferably, it is used.

In the present invention, residual chlorine in ballast water is measured by a method of measuring residual chlorine concentration by amperometric method, DPD (diethyl-p-phenylenediamine) method, oxidation-reduction potential (hereinafter also abbreviated as ORP), etc. Controlling the concentration is also a preferred embodiment. Generally, when hypochlorite or the like is added to water containing a large amount of impurities such as seawater, hypochlorite may be decomposed and consumed. Therefore, in order to ensure the killing and sterilizing effects of aquatic organisms regardless of the water quality used as ballast water, a mixed amount management system for hypochlorite and ammonium ions is used. In addition, it is preferable to have a system that can measure and control the residual chlorine concentration. By using a current titration method, a DPD method, or a method using an oxidation-reduction potential, the residual chlorine concentration can be measured with high accuracy and controlled within a desired range.

In the present invention, after killing and sterilizing the aquatic organisms in the ballast water using the above-described ammonia or ammonium salt and hypochlorite, the residual chlorine in the ballast water is reduced and neutralized with sulfite. It is preferable to do. Residual chlorine may cause adverse effects on organisms even in trace amounts, so when discharging ballast water, it is necessary to reduce and neutralize it before treating it so that it does not affect aquatic organisms. There is. Therefore, in the present invention, it is preferable to provide a step of containing sulfite in the ballast water after killing and sterilizing the aquatic organisms in the ballast water, thereby reducing and neutralizing residual chlorine in the ballast water. It can be in a safe state that does not affect living organisms.
In the present invention, the amount of sulfite contained in the ballast water may be an amount that can reduce residual chlorine contained in the ballast water to a range that does not affect aquatic organisms. Specifically, to reduce the residual chlorine to a range that does not affect aquatic organisms, the residual chlorine concentration in the ballast water may be 0.06 mg / L or less.

Examples of the sulfite used in the present invention include alkali metal salts such as sodium and potassium, and sodium salt which is the main component of seawater is particularly preferable. The sulfite is preferably used as an aqueous solution.
About the aspect of a process by a sulfite, it does not specifically limit, A sulfite may be added in a ballast tank, and when draining ballast water, you may contain a sulfite. In the ballast water treatment method of the present invention, sulfite is preferably added to the ballast water during drainage.

When discharging ballast water out of the ship, it is preferable not to drain ballast water in a low oxygen state. That is, it is preferable that the low-oxygen state wastewater does not damage the aquatic organisms around the ship. In the case of a normal ocean, 7 to 8.5 mg / L of dissolved oxygen is contained, but it is preferable to ensure that the dissolved oxygen is in a state of 6 mg / L or more, which is a standard for oxygen deficiency concentration in aquaculture. . Excess sulfite is oxidized to become a sulfate that exists in nature, but dissolved oxygen is also consumed in addition to oxygen in the air. In this case, aeration may be performed in the ballast tank or air may be blown into the drain pipe, but this may cause an increase in the berthing fee. Therefore, it is preferable to adjust the amount of sulfite added to an appropriate amount. In this method, as in the case of the treatment with ammonia or ammonium salt and hypochlorite described above, an amperometric method, a DPD method, and a method utilizing an oxidation-reduction potential are effective. In the ballast water treatment method of the present invention, when ballast water containing residual chlorine is drained, the residual chlorine in the ballast water is completely reduced and neutralized by adjusting the redox potential of the drainage to less than 500 mV with sulfite. be able to.

According to the ballast water treatment method of the present invention, aquatic organisms and the like in the ballast water can be killed and sterilized, and generation of by-product bromoform and the like can be suppressed. Therefore, ballast water can be discharged safely without adversely affecting the ecosystem and environment of the drainage area.

Moreover, this invention provides the processing agent of the ballast water used for the processing method of the ballast water mentioned above. The treatment agent of the present invention is a combination of ammonia or ammonium salt and hypochlorite. Combining ammonia or ammonium salt and hypochlorite means that ammonia or ammonium salt and hypochlorite may be mixed in advance as a treatment agent, or ammonia or ammonium salt and hypochlorite. It is good also as a processing agent by packaging salt etc. separately.
As the ammonia or ammonium salt used for the treating agent, a substance capable of producing chloramine by reacting with hypochlorite is preferable. Specific examples of ammonia or ammonium salts include ammonia or ammonium salts used in the above-described method for treating ballast water, and the preferred ranges are also the same. Moreover, as a hypochlorite used for the processing agent of this invention, the hypochlorite used for the processing method of the ballast water mentioned above can be mentioned, A preferable range is also the same.
The form of ammonia or ammonium salt and hypochlorite used for the treating agent may be a solid such as a powder or a liquid such as a concentrated liquid. The use mode of the treating agent, the amount mixed with the ballast water, and the like are the same as in the treatment method using ammonia or ammonium salt and hypochlorite in the above-described method for treating ballast water.
The treatment agent for ballast water of the present invention is inexpensive, easily available and easy to handle, and by using this, foreign invaders existing in the ballast water can be killed and sterilized, and the ballast water Therefore, it can be suitably used for ballast water treatment from the viewpoint of environment and safety.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

The following reagents and analyzers were used in the examples.
1. Reagents, etc. (1) Ballast water Seawater (pH 7.75, 26.6 ° C.) collected in Suehiro-cho, Tsurumi-ku, Yokohama was filtered through a filter and used as simulated ballast water. The filter used was a 95 mm diameter glass filter paper (Advantech GC-90) made of borosilicate glass fiber.
(2) Ammonia or ammonium salt As a supply source of ammonia or ammonium salt, 1 mol / L ammonia water and ammonium chloride as a reagent were used. As ammonium chloride, a reagent primary ammonium chloride dissolved in ion-exchanged water to make a 1 mol / L ammonium chloride aqueous solution was used.
(3) Standard solution of trihalomethanes Trihalomethane standard solution B (hexane solution) manufactured by Wako Pure Chemical Industries was used as a standard solution of trihalomethanes. This trihalomethane standard solution B contains chloroform 10 mg / L, bromodichloromethane 2.5 mg / L, chlorodibromomethane 4 mg / L, and bromoform 20 mg / L.
(4) Bromoform standard solution Collect exactly 1 mL of the standard solution of trihalomethanes, add it to 100 mL of n-hexane collected in advance, and add the primary diluted bromoform standard hexane solution (hereinafter referred to as the bromoform standard hexane solution simply as the bromoform standard solution). Was made. Exactly 1 mL of the primary diluted bromoform standard solution was collected and added to 50 mL of n-hexane collected in advance to prepare a secondary diluted bromoform standard solution. Accurately 1 mL of the secondary diluted bromoform standard solution was sampled and added to 50 mL of n-hexane collected in advance to prepare a bromoform standard solution. This bromoform standard solution contains 76.1 μg / L of bromoform.

(5) Sodium hypochlorite Sodium hypochlorite aqueous solution (TG ballast cleaner (trade name)) having an effective chlorine concentration of about 13% by mass was used as sodium hypochlorite.
(6) Sodium sulfite Sodium sulfite was dissolved in ion-exchanged water to obtain a 0.25 mol / L sodium sulfite aqueous solution (TG Environmental Guard (trade name)).

2. Analyzer The measurement of the analysis sample was performed using a gas chromatograph with an electron capture detector (G-5000, manufactured by Hitachi, Ltd.). The column was a capillary column made of fused silica having an inner diameter of 0.32 mm and a length of 25 m, and the inner surface was coated with a liquid phase of 5% diphenylpolysiloxane-95% dimethylpolysiloxane with a thickness of 1.20 μm. The measurement conditions were a column temperature of 120 ° C., an injection temperature of 210 ° C., and a detector temperature of 220 ° C.

The following examples and comparative examples were carried out at room temperature under conditions of a maximum temperature of 30.1 ° C. (average value during the test period) and a minimum temperature of 24.2 ° C. (average value). In order to clarify the effect of the combined use of ammonia or ammonium chloride and hypochlorite, verification was performed under conditions where bromoform and the like are more likely to be generated than conditions under which ballast water is actually taken or discharged.

Example 1
After adding ammonia water to the above ballast water so as to be 22 mg / L, after adding sodium hypochlorite aqueous solution so as to have an initial effective chlorine concentration of 20 mg / L, it is sealed and covered with aluminum foil for light shielding And left at room temperature for 17 days. Thereafter, a ballast water sample 1 was obtained by adding and reducing and neutralizing an aqueous sodium sulfite solution to 30 mg / L. In Example 1 and Example 2 below, samples were prepared in duplicate.
In addition, as a blank sample, only the above ballast water was sealed in the same manner, covered with aluminum foil and shielded from light, and allowed to stand at room temperature for 17 days, and then an aqueous sodium sulfite solution was added in the same amount as sample 1 above. Was prepared as a blank sample.

Example 2
After adding an aqueous ammonium chloride solution to the above ballast water to a concentration of 22 mg / L, and then adding an aqueous sodium hypochlorite solution to an initial effective chlorine concentration of 20 mg / L, it is sealed and covered with aluminum foil for light shielding. And left at room temperature for 17 days. Then, the ballast water sample 2 was reduced and neutralized with the same amount of sodium sulfite aqueous solution as in Example 1.

Example 3
A solution in which the same amount of ammonia water (22 mg / L) and sodium hypochlorite aqueous solution (initial effective chlorine concentration 20 mg / L) as that added in Example 1 was mixed in advance was prepared and added to the above ballast water. . The ballast water sample 3 was sealed and sealed and light-shielded for 17 days at room temperature, then reduced and neutralized with the same amount of sodium sulfite aqueous solution as in Example 1.

Example 4
Prepare a solution in which the same amount of ammonia chloride aqueous solution (22 mg / L) and sodium hypochlorite aqueous solution (initial effective chlorine concentration 20 mg / L) as those added in Example 2 were mixed in advance and added to the above ballast water did. A ballast water sample 4 was obtained by sealing and sealing the whole with an aluminum foil and allowing it to stand at room temperature for 17 days, followed by reduction and neutralization with the same amount of sodium sulfite aqueous solution as in Example 1.

Comparative Example 1
An aqueous sodium hypochlorite solution was added to the above ballast water so as to have an initial effective chlorine concentration of 20 mg / L, which was then sealed and allowed to stand at room temperature for 1 day with the whole covered with an aluminum foil and shielded from light. Thereafter, the same amount of sodium sulfite aqueous solution as in Example 1 was added for reduction and neutralization. The sample was sealed and sealed for 16 days at room temperature in a state where the whole was covered with aluminum foil and shielded from light, and used as Comparative Sample 1.

Comparative Example 2
A sodium hypochlorite aqueous solution was added to the above ballast water so as to have an initial effective chlorine concentration of 20 mg / L, and then sealed, covered with an aluminum foil and shielded from light, and allowed to stand at room temperature for 17 days. Thereafter, a comparative sample 2 was prepared by adding and reducing and neutralizing the same amount of sodium sulfite aqueous solution as in Example 1.

Comparative Example 3
An aqueous sodium hypochlorite solution was added to the above ballast water so as to have an initial effective chlorine concentration of 20 mg / L, which was then sealed and allowed to stand at room temperature for 1 day with the whole covered with an aluminum foil and shielded from light. Thereafter, an aqueous sodium sulfite solution corresponding to an initial effective chlorine concentration of 10 mg / L was added for reduction and neutralization. The sample was sealed and sealed for 16 days at room temperature in a state where the whole was covered with an aluminum foil and shielded from light.

Measurement of Bromoform Concentration The amount of bromoform produced was measured for the ballast water samples obtained in Examples 1 to 4 and Comparative Examples 1 to 3. Using a whole pipette, 5 mL of each ballast water sample was collected, added to a colorimetric tube containing exactly 50 mL of n-hexane in advance, and shaken for 15 seconds to extract bromoform in the n-hexane layer. For the blank sample, sample 3 and sample 4, the bromoform concentration of the extraction layer was directly measured with an analyzer. For Samples 1 and 2 and Comparative Samples 1 to 3, since the bromoform concentration of this extraction layer is high, each of the analytical samples diluted as described below was prepared and the bromoform concentration was measured. Converted to bromoform concentration. For Sample 1 and Sample 2, 1 mL of this extraction layer was accurately collected, added to a colorimetric tube containing exactly 10 mL of n-hexane in advance, diluted 11 times, and used as an analysis sample. For Comparative Samples 1 to 3, 1 mL of this extraction layer was accurately collected, added to a colorimetric tube containing exactly 10 mL of n-hexane, and diluted 11 times. Further, exactly 1 mL of the 11-fold diluted solution was sampled, added to a colorimetric tube containing exactly 10 mL of n-hexane in advance, and finally diluted 121-fold was used as an analysis sample.
Table 1 shows the bromoform concentration of each sample.

As is clear from the results in Table 1, when only the sodium hypochlorite aqueous solution was mixed with the ballast water, the bromoform concentration showed a high value (Comparative Samples 1 to 3). On the other hand, when adding aqueous ammonia or ammonium chloride to ballast water followed by addition of aqueous sodium hypochlorite (samples 1 and 2), mixing only aqueous sodium hypochlorite (comparative samples 1 to 3) ), The bromoform concentration could be reduced to about 1/6 to 1/7. In addition, when a premixed solution of ammonia water or ammonium chloride aqueous solution and sodium hypochlorite aqueous solution is added to the ballast water (samples 3 to 4), only sodium hypochlorite aqueous solution is mixed (comparative sample) Compared with 1-3), the bromoform concentration could be suppressed to 1/30 or less. From the above, the combined use of ammonia or ammonium salt and hypochlorite can greatly reduce the amount of bromoform generated even after long-term retention compared to when hypochlorite is added alone. I understood.
In addition, unlike neutral drinking water, the pH is high, and even when seawater containing a large amount of bromide ions is used as ballast water, ammonia or ammonium salt and hypochlorite can be used in combination. It was found that the generation of bromoform in ballast water can be greatly suppressed. That is, a method of mixing ammonia or ammonium salt and sodium hypochlorite in advance to produce chloramine and then mixing with ballast water, and first mixing ammonia or ammonium salt with ballast water, and then sodium hypochlorite It was found that bromoform formation under seawater conditions can be remarkably suppressed by both methods of mixing bromide and producing bromamine, chloramine, etc. in ballast water.

The ballast water treatment method of the present invention and the ballast water treatment agent used in the method are capable of effectively killing and sterilizing harmful aquatic organisms contained in the ballast water, and trihalomethanes such as bromoform during the killing and sterilization treatment. Generation can be suppressed. Therefore, by using the treatment method and the treatment agent of the present invention, it becomes possible to safely discharge the ballast water of the ship without polluting the environment / ecosystem of the discharge water area.

While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

This application claims priority based on Japanese Patent Application No. 2009-270655 filed in Japan on November 27, 2009, which is hereby incorporated herein by reference. Capture as part.

Claims

Ballast water treatment method characterized by mixing ammonia or ammonium salt and hypochlorite in ballast water to kill and sterilize aquatic organisms in the ballast water and suppress generation of trihalomethanes.
The method for treating ballast water according to claim 1, wherein the concentration of bromoform in the ballast water during discharge is 300 µg / L or less.
The method for treating ballast water according to claim 2, wherein the bromoform concentration is 150 µg / L or less.
The aquatic organisms are killed and sterilized by adjusting the residual chlorine concentration in the ballast water to 1 mg / L or more and 100 mg / L or less by mixing the ammonia or ammonium salt and hypochlorite. 4. The method for treating ballast water according to any one of 1 to 3.
The method for treating ballast water according to claim 4, wherein the residual chlorine concentration in the ballast water is adjusted to 2 mg / L or more and 20 mg / L or less to kill and sterilize aquatic organisms.
The method for treating ballast water according to claim 4, wherein the residual chlorine concentration in the ballast water is adjusted to 2 mg / L or more and 10 mg / L or less to kill and sterilize aquatic organisms.
After killing and sterilizing aquatic organisms in ballast water by mixing ammonia or ammonium salt and hypochlorite, the residual chlorine in the ballast water is reduced and neutralized with sulfite. The method for treating ballast water according to any one of claims 1 to 6.
2. In mixing ammonia or ammonium salt and hypochlorite with ballast water, after mixing ammonia or ammonium salt with ballast water, hypochlorite is mixed with ballast water. 8. The ballast water treatment method according to any one of 1 to 7.
The ammonia or ammonium salt and hypochlorite are mixed in advance and added to the ballast water when the ammonia or ammonium salt and hypochlorite are mixed in the ballast water. The method for treating ballast water according to claim 1.
2. In mixing ammonia or ammonium salt and hypochlorite with ballast water, after mixing hypochlorite with ballast water, ammonia or ammonium salt is mixed with ballast water. 8. The ballast water treatment method according to any one of 1 to 7.
In mixing ammonia or ammonium salt and hypochlorite in ballast water, after adding ammonia or ammonium salt to the ballast tank in advance, the ballast water mixed with hypochlorite is injected into the ballast tank. The method for treating ballast water according to any one of claims 1 to 7, wherein:
The method for treating ballast water according to any one of claims 1 to 11, wherein the ammonia or ammonium salt is a compound capable of reacting with hypochlorite to produce chloramine.
The ballast water treatment agent used in the ballast water treatment method according to any one of claims 1 to 12, wherein ammonia or an ammonium salt and a hypochlorite are combined.
The treatment agent for ballast water according to claim 13, wherein the ammonia or ammonium salt is a compound capable of reacting with hypochlorite to produce chloramine.