Presentation on theme: "Exchange of Ballast Water at Sea and Onboard Treatment"— Presentation transcript:
1 Exchange of Ballast Water at Sea and Onboard Treatment
2 Contents The environmental problem Ballast water exchange The transition to ballast water treatment onboardSystems’ installation criteriaCurrent technologies
3 Ballast water is important for a vessel’s stability and her structural integrity in the ballasted condition
4 The scale of the problem The problem of marine invasive species is nothing new. For hundreds of years, species have traveled around the world through international shipping via ballast water and bio-fouling and in other ways having the same effect such as aquaculture and canals.Source: UNEP/GRID-Arendal Maps and Graphics Library
5 The scale of the problem Round GobyDinoflagellate Gymnodium catenatumDreissena PolymorphaAsterias AmurensisVibrio CholeraeMnemiopsis leidyi
6 Zebra Mussel was introduced in lake St Zebra Mussel was introduced in lake St. Claire in 1991 and within 10 years has been expanded to all Great Lakes of the United States.Source: ISSG
7 In February 2004, the International Maritime Organization adopted the International Convention for the Control and Management of Ships Ballast Water and Sediments aiming to prevent and minimize the risks to the environment, to human health, property and resources caused by the transfer of marine invasive species
8 BWM Standards Exchange Standard: D-1 Sequential method with at least 95% volumetric exchangeFlow-through method with at least three times volumetric exchangePerformance Standard: D-2Number of viable organisms of a certain size …Less than 10 viable organisms per 1 m³ greater than 50mLess than 10 viable organisms per 1 ml smaller than 50m and greater than 10mLimited number of indicator microbes1 CFU Vibrio cholera per 100 ml250 CFU eschericia coli per 100 ml100 CFU enterocci per 100 mlThe current recommended method for controlling the introduction of non-indigenous species is ballast water exchange known as standard D-1 according to the Convention. The standard D-2 is a ballast water performance standard and refers to regulation D-2 of the Convention which has to do with the treatment technologies. All vessels that use ballast water treatment systems must comply with the specifice disharge limits not only for the living organisms but also for some microbes in order to prevent any risk of sea pollution, as you can see . For example, the treated ballast water discharged into the sea must not contain more than... (και λέω τα επιτρεπτά όρια)Το D-2 προσδιορίζει την απαιτούμενη ποσότητα έρματος ποπυ απορρίπτεται στη θάλασσα μετά την επεξεργασία του στο πλοίο. Οι παράμετροι που προσδιορίζει είναι η συγκέντρωση και το μέγεθος των ζωντανών οργανισμών στο απορριπτόμενο έρμα. Ως ζωντανοί οργανισμοί θεωρούνται εκείνοι που μετά την επεξεργασία μπορούν να ολοκληρώσουν τον κύκλο της ζωής και να αναπαραχθούν.Επεξήγηση του πίνακα=1.Ζωοπλαγκτόν2.Φυτοπλαγκτόν3.Δείκτες μικροβιακής μόλυνσης (παθογόνος μικροοργανισμός και μικρόβια που αποβάλλονται από το παχύ έντερο) με σκοπό να ελαχιστοποιηθεί ο κίνδυνος απόρριψής τους όταν το έρμα έχει αντληθεί από λιμάνια με μολυσμένα νερά.
9 Ballast Water Exchange Ballast Water Exchange should be undertaken:at least 200 nm from the nearest land and in water at least 200 m in depth, or if not possibleat 50 nm and 200 m depth, or if not possiblein areas designated by the Port StateNeither deviation nor delay of the ship shall be required and exchange should only be undertaken when safety of the ship is guaranteedsuch locations are not always “available” on a specific routenor deviation from it’s rout shall be required from a shipexchange shall only be carried out when the safety of the vessel in not impairedDesignation of area where BW exchange shall be carried out is possibleShips can be required to deviate from her route to sail to a designated area
10 Plans & Documents on Board Each ship shall have on board a:Ballast Water Management Plan (approved)Ballast Water Record BookBallast Water Management Plan:detailed safety proceduresdetailed descriptions to be taken to implement Ballast Water Managementprocedures for disposalprocedures for coordinating Ballast Water Managementdesignate officer in chargeBallast Water Record Booklet may be in electronically forminspections possible of the on-board documentsadditional samplings possibletime for analysing the sampling shall not be used for unduly delaying the vesselwhen ships is regarded as threat to the environment (sampling, missing documents, equipment out of order …) discharge of BW in port can be prohibited
11 BW Exchange Methods Sequential method Flow-through method Initial quantity of ballastEmpty tankInsert new ballastFlow-through methodBallast water exchange involves replacing coastal water with open ocean water during a voyage either by emptying and refilling ballast tanks or by flow-through process (a process by which replacement ballast water is pumped into a ballast tank or hold allowing water to overflow through openings on open deck). Both methods are considered to be a success only when when we have achieved at least 95% of ballast tank volumetric exchange.Although, during ballast exchange the vessel is en route and there is no delays in the trip and it's an easy process to implement, it is important to underline that that ocean exchange is not always biologically effective and possible to perform due to ship safety and operational issues involved. For example, a vessel that carries out sequential exchange while is exposed to wave loads might experience bending moments and shear stresses, an actual threat to her structural integrity.All these condiderations indicate that a portion of the ballast water transported annually will have to be treated by other methods, or discharged as untreated ballast water.Ballast water exchange, you are actually exchange coastal waters with mid-ocean sea water because it has been scientifically proven that marine organisms taken on in coastal waters are less likely to survive when discharged in open sea due to changes in the water’s temperature and salinity.This method works differently. During this process, ballast water is pumped into a ballast tank, allowing water to flow through, overflow.In order this method to succeed and achieve an exchange of 95%, the tank volume should be pumped through the tank three times.In this case you should note that1. A direct overflow via the airpipe head is not permitted as it could put at risk the watertight integrity of the vessel.2. After each ballast water exchange under flow-through process, a thorough check of each airpipe head for the functionality should be carried out.3. It is not implemented in low temperature weather conditions that would result in icing.4. The inlet and oulet piping should be as remotely from each other as practicable.Initial quantity of ballast1st exchange2nd exchange3rd exchange
12 How effective is ballast water exchange? The need for prompt action and control of the introduction of unwanted marine species, required the maritime industry to adopt Ballast water exchange methods without any previous efficiency tests.Studies of exchange method’s efficiency with the help of pigments has shown that, a small percentage of these organisms remain at ballast tanks, which under certain circumstances may survive.The need for prompt action and control of the introduction of the marine unwanted species, has made maritime industry to adopt Ballast water exchange method without any previous efficiency tests.Studies followed years later for method’s efficiency even with the help of pigments has shown that, exchange is not 100% effective as a small percentage of these organisms remain at ballast tanks, which under certain circumstances may survive.
13 How effective is ballast water exchange? Some vessels accumulate tonnes of sediments that contain their own living organisms.Great concern is the transfer of phytoplankton cysts in sediments from ships: 65% out of 343 ships inspected in Australia were found with these sediments.BWE may provide additional oxygen and food to organisms that remain in the ballast tank.It is considered to be more effective when there is a big difference in salinity.MEPC 46/3 2000: ΙΜΟ characterize BW Exchange as a temporary measure and brings forward ballast water treatment as an alternative solution to the problem, a solution possibly more effective and safe.Furthemore, It is clear that in some cases the process of exchange may present an even worse scenario than discharging the residual originally ballasted organisms.For example, some vessels accumulate tens of tonnes of sediments that contain their own biota. The transport of viable toxic dinoflagellate cysts in ballast sediments is of great concern: 65% of 343 cargo vessels surveyed in Australia carried sediments in their ballast tanks of which half as many contained dinoflagellate cysts. Cysts has also been recorded in ballast tank sediments of vessels arriving in Canada, New Zealand, U.K., and USA.A part of this biota that avoids dilution during Bwexchange remains in the residual water and sediment and may be provided during exchange with fresh supplies of oxygen and food.Sediment accumulation in a double botton tank
14 How effective is ballast water exchange? In the period of 1996 – 1997 surveys have been conducted on container ships that travelled from Oakland, California, Kobe and Yokohama in Japan, with final destination in Hong Kong, a trip that lasted 16 days.On average, the abundance of harmful plant organisms measured on board at the port of destination after ballast exchange was reduced by 87% compared with the ships that arrived with the original ballast (from 4235 to 550 organisms per liter ballast).One of the first and most completed studies on ocean exchange effectiveness in controlling the abundance of harmful plant organisms released in Hong Kong has been conducted the period of on container ships followed the same route each time they travelled from Oakland with final destination Hong Kong.3 container ships made 20 trips without any ocean exchange after the ballasting in Oakland waters and 2 vessels made 14 trips proceeding to ocean exchange in Pacific ocean, 24 hours after their departing.On average... original ballast.In general, all the studies has shown that the volumetric exchange effectiveness is affected from many factors such as the vessel's age, the season of the year and the method used for the exchange. In fact, in newbuildings ballast pump suction systems are designed in a way that helps flow better.
15 Ballast water management timetable Res. A.1005 (25)Ballast Convention is not yet into force. So far, 33 states representing 26,46% of world tonnage have ratified the Convention. As you can see yourselves, we have covered the 1st parametre and the second one is still in progress. As soon as the second parametre is covered the Convention will enter into force 12 months.According to this timetable, all vessels must have from 2016 and after a ballast water treatment system. The following examples are instructive in how to interpret the above tableFor example: a ship with a ballast water capacity less than m3 constructed in 2009 will not be required to comply D2 standard until its second annual survey but not later than 31 December For example: a ship with a ballast water capacity of less than m3 constructed after 2009 must have a ballast water treatment system upon delivery or when the convention enters into force, whichever occurs first.Of course all the above under the condition that BWM Convention has already entered into force.Τα πλοία που πρέπει πρώτα να βάλουν αυτό σύστημα είναι αυτά που κατασκευάστηκαν μετά την 1η Ιανουαρίου 2009 και έχουν χωρητικότητα δεξαμενών έρματος μικρότερη από κυβικά μέτρα. Με την απόφαση Α.1005(25) δίνεται η δυνατότητα στα κράτη που έχουν ήδη ή πρόκειται να κυρώσουν τη Σύμβαση να μην απαιτούν από τα πλοία που κατασκευάστηκαν μέσα στο 2009 να εγκαταστήσουν σύστημα μέχρι την δεύτερη ετήσια επιθεώρηση τους αλλά όχι αργότερα από τη 31 Δεκεμβρίου 2011.Ratification status: 33 countries and 26,46% of world tonnage (per March Requested: 30/35)
16 Onboard ballast water treatment An example of a process cycle with a) treatment upon ballasting and b) neutralization of treated ballast water upon de- ballasting
17 Installation criteria of a ballast water treatment system In order these systems to be installed into a vessel, must have some specific criteria.1. must be cost-effective for their construction and their maintenance2. must be efficient and kill all the living organisms and pathogens3. must be practical. Systems are being designed in a way that you and your colleages not be involved in its use.4. must be environmentally acceptable for the marine environment as it's possible the treatment ballast discharged could be toxic and pollute the sea.5. must be safe for the health's crew.
18 Current Technologies Filtration Environmentally friendly treatment technique of ballast water.1st phase of many treatment systems in order to retain the larger organisms and solid particles.Here I'll show you some of the current technologies used. First of all, I have to mention that no single ballast water technology has been able to remove all organisms or all types of organisms from ballast tanks. A conbination of different technologies has been proven to be more effective than one technology alone.Filtration, is considered to be the most environmentally friendly treated technique of ballast water. Ballast water can be filtered before it enters into the tanks or while it is being discharged.The advantage to filtering as water is pumped into the tanks is that organisms that are filtered out may be retained in their native habitat. One of its main drawbacks is that it requires specialized equipment which may be expensive to purchase and install. Filtration is the only technology that you can see it almost to every system as the 1st phase of treatment and it's usually combined with other technologies.Γίνεται φιλτράρισμα του νερού που μπαίνει παράλληλα με την απόρριψη του φιλτραρισμένου νερού στο σημείο όπου έγινε η άντληση. Απομακρύνονται ιζήματα και σωματίδια. Συνήθως καθαρίζονται αυτόματα με τη βοήθεια αντίστροφης πίεσης νερού ή αέρα. Επομένως, η εξουδετέρωση γίνεται κατά την επεξεργασία.
19 Current Technologies Hydrocyclones Separate solid particles from water using centrifugal forces. Effective for organisms > 50 micrometers.Solid particles are separated from the water due to centrifungal forces. Only those particles (like τσούχτρες, σκουλήκια, ιοί) with a specifi gravity greater than that of water can be separated.
20 Ultraviolet radiation Current TechnologiesUltraviolet radiationAffixed to the outer membrane of organisms and destroys the cell structure. The effectiveness of this method depends on the turbidity of the ballast and the arrangement of UV radiation tubes.This method is most effective on microorganisms, so it is combined with another method to effectively remove all potential bioinvaders from ballast water. One of the main drawbacks is that UV light is ineffective in water containing suspended matter, so ballast water may need to be filtered before treatment. UV is used during ballasting and deballasting.Sediment and particles are removed with screen filters during ballast intake. They are often self-cleaning with a back-flushing cycle.Χρησ/ται για να επιτίθεται και να σπάει τη δομή των κυττάρων των οργανισμών και να καταστρέφει την αναπαραγωγική τους ικανότητα. Η αποτελεσματικότητας της τεχνολογίας αυτής εξαρτάται σε μεγάλο βαθμό από τη θολότητα του νερού καθώς αυτή θα μπορούσε να μειώσει τη δουλειά της υπεριώδους ακτινοβολίας.Πολλά συστήματα χρησ/ούν φιλτράρισμα με UV. Κατά την άντληση χρησ/νται και οι δύο ενώ κατά την απόρριψη δίδεται μία δεύτερη δόση UV πάλι.
21 Addition of stored chemicals Current TechnologiesAddition of stored chemicalsThey are dosed to ballast water to kill organisms (chlorine gas, chlorine dioxide, sodium hypochlorite and ozone).A major concern with the use of biocides is the safety of the crew who handle the chemicals. Chemicals are usually shipped and stored onboard a ship. This method needs at least 24 hours in order to be effective and kill all the organisms.
22 Current Technologies Deoxygenation Remove the dissolved oxygen in the ballast and replaces it with inert gas, usually nitrogen. Eliminates the aerobic bacteria and helps prevent corrosion of the tanks.Deoxygenation is considered to be the most simple and easy process to conduct. Inart gases are used to remove the oxygen in the ballast water and replace it, usually nitrogen. Removing the oxygen not only kills the aerobic organisms but it can also have benefits for corrosion prevention provided that the oxygen content is maintained at the correct levels.This method is being used only in systems for vessels of long term voyages as inert gases must retained inside the tanks at least 4-5 days.
23 Current Technologies Cavitation With the help of hydrodynamic forces or ultrasonic waves the cell walls are effectively destroyed.Disrupts the cell walls of organisms effectively and kill them.
24 Current Technologies Electrolytic Chlorination Electric current is applied directly to the ballast in electrolytic cells, producing chlorine as the major active substance and other chemical compounds.Electrical current is applied directly to the ballast water flow in an electrolytic chamber, generating free chlorine and other chemical compounds. This method is limited in effectiveness to seawater having a certain level of dissolved salt and could also create unwanted residuals.Πρέπει να περάσουν αρκετές ώρες για να είναι αποτελεσματική. Κατά την απόρριψη του έρματος πρέπει να γίνει ουδετεροποίηση των χημικών ουσιών ώστε το έρμα να μην είναι τοξικό.
25 Number of approved ballast water treatment systems About 2/3 of all technologies make use of active substancesAround. 20 type approved systems are currently available (forecast end of 2012: > 30)
26 Estimated number of vessels which need to be fitted with BW treatment systems in the near future Removing organisms from ballast water is a promising way to prevent the introduction of marine invasive species that cause ecological and economic harm. So far, no one method hasn't been proven that remove all organisms from ballast water, so more research must be conducted into improving existing treatment methods, developing new ones and determing the effectiveness of combining ballast water treatment methods.