An Analysis on Various Ballast Water Treatment Techniques for ORV Sagar Nidhi

Transcription

1 Indian Journal of Geo-Marine Sciences Vol. 43(11), November 2014, pp An Analysis on Various Ballast Water Treatment Techniques for ORV Sagar Nidhi D. Rajasekhar*, P.S. Deepaksankar, Ananthakrishna Rao, D. Narendrakumar, K. Ramasundaram & S. Siva Chidambaram National Institute of Ocean Technology, Ministry of Earth Sciences, Govt. of India, Chennai *[ Received 07 March 2014; revised 04 September 2014 Discharge of ballast water from ship is a major source of introduction of non-indigenous species to marine, estuarine, and freshwater ecosystems. Ships carry ballast water to have stability and maneuverability during voyage.transport of ballast water across the globe playsa majorrole in ecological imbalance as it carries organisms from oceanic to shallow areas, where they may start a new invasion. In 2004, the International Maritime Organization (IMO) initiated regulatory measures to minimize the species shift by adopting the International convention for the control and management of ship s ballast water and sediments. Since then, vessels have been increasingly practicing ballast water exchanges. To keep up with IMO requirements and also the stricter requirements stipulated by few ports around the world, ships need to have effective ballast water treatment system. An analysis is carried-out to optimize the selection of ballast treatment system for ORV Sagar Nidhi among the number of existing systems based on their compatibility and suitability.sagar Nidhi is a state of art ice class ocean research vessel (ORV) of the National Institute of Ocean Technology (NIOT), carrying research at both Indian and Antarctic waters. Such vessels have limited options for treating ballast water, since a few treatment systems are designed specifically for their needs. Efficacy, residual toxicity, size, weight, electrical load requirement, and safety were the parameters considered while evaluating a ballast water system for Sager Nidhi. As a result of optimization, a ballast water treatment system with filtration and ultra violet treatment was chosen. [Keywords: Ballast water treatment, Invasive, Chemical disinfection, Filtration, Efficacy, Residual toxicity] Introduction Ballast water inside a ship can be seen as an onboard aquarium full of microscopic life forms, since the sea-water containing small living organisms is pumped into the ballast tanks along with coastal sediments. Water from one port area is taken inside the ship and this wateralong with all the surviving organismsmay be discharged at the next port of call, depending on ballast requirement. Introduction of foreign living species, called as exotic species, to a new area devoid of natural predators, can result in their populations growing very quickly. Such species sometimes turn invasive when they outcompete the native species in the new habitat. Only a few species are successful invaders, since most species are not able to survive in new surroundings due to the difference in conditions such as temperature, salinity and availability of food 4. These are very hardy species that have the potential to cause major harm to ecology, economy or human health. The consequences of bio-invasion could be infections to humans, extinction of species, ecological imbalance and damages to port structures. In such cases, the solution lies in preventing them from invading in the first place or in eliminating the invaded exotic species 4. Getting rid of the established exotic species is practically impossible or very expensive. Prevention of invasion is the more practical and economical solution. Though no ballast water treatment method can completely eliminate the risk, there are a few methods available to minimize the risk viz., UV radiation, Water exchange method, Sodium Hydroxide, Cavitation and so on 1,14. The objectives of this analysis were to identify and optimize the ballast water treatment technique best suited for ORV Sagar Nidhi, to meet IMO requirements and to maintain ecological balance and to minimize the cost, time and work involvement 2. Figure-1 and Figure-2 shows ORV Sagar Nidhi and Ballast water exchange respectively.

2 RAJASEKHAR et al.: BALLAST WATER TREATMENT TECHNIQUES FOR ORV SAGAR NIDHI 2043 Figure 1: ORV Sagar Nidhi Figure 2: Ballast water exchange IMO Convention In 2004, IMO adopted the International convention for the control and management of ship s Ballast water and sediments, in order to reduce the risk of introductions of exotic species 4,15. Annex Section B Management and Control Requirements for Ships states that: Ships must implement and have on board a ballast water management plan approved by the administration (Regulation B-1) Ships must maintain a ballast water logbook (Regulation B-2) to record ballast water movements viz., uptake, treatment, exchange, circulation, discharge so on 5. Under the BWM convention, the ships should adopt measures for ballast water management, as stated in Regulation B-3 Ballast Water Management for Ships.Table-1 shows the timeline set by IMO for existing and newly built vessels 15. Newly Built Vessels Existing Vessel Table-1: Timeline for vessels equipment Year of Construction Ballast Water Capacity (m 3 ) In or after 2009 < 5000 After 2009 but before In or after Before Before 2009 < 1500 or > 5000 D2 D1 or D2 D2 D2 D1 or D2 D2 D1 or D2 D1 Regulation D-1 Ballast Water Exchange Standard requires an efficiency of 95% volumetric exchange of Ballast water with marine water (at least 200 nautical miles from the nearest land and in water at least 200 meters in depth). Regulation D-2 Ballast Water Performance Standard concerns water quality for discharge, related to specified maximum concentrations of micro-organisms. Annex-Section E Survey and Certification Requirements for Ballast Water Management stipulates requirements for initial certification and renewal surveys, including examples of Ballast Water Management Certificate and Form of Ballast Water Record Book. Ballast Water Management (BWM) The following criteria are selected while considering a ballast water treatment method/plant.figure-3 shows schematic representation of BWM system. It should bereliable, inexpensive and less time consuming. It is effective at removing organisms and ease in installation. It should be environmental friendly, less hazardous and safe for crew and scientist 4. It should comply with statutory bodies and should be easy to operate. Water Exchange method (BWM-D1) Though water exchange is a simple procedure, sediments remain in the ballast water tanks and efficiencies for organism removal from sediments

3 2044 INDIAN J. MAR. SCI., VOL 43, NO.11 NOVEMBER 2014 have been reported to be low. This is a timeconsuming process with repeated filling and removal of sea water. Toachieve the exchange criteria laid down by IMO, which is at least 95% water exchange, the ballast tanks need to be emptied and filled about thrice their full volume. Further, a 95% exchange does not necessarily assure 95% organism removal as homogeneous distribution might not be present, but at times it could exceed 95% also. Propeller emergence, extra working hours for the crew, higher stresses, damage risk due to sloshing etc., arethelimitations of water exchange method. Ships which are used to exchange ballast water en route, need minimum time, less capital and it is a simple process to implement. Following three ballast water exchange methods have been evaluated and determined to be acceptable to IMO. Fig 3: Ballast water treatment methods Figure 4: Ballast water treatment methods 1. Sequential method: A process by which a ballast tank intended for the carriage of water ballast is first emptied and then refilled with replacement ballast water to achieve at least a 95% volumetric exchange. 2. Flow through method: A process by which replacement ballast water is pumped into ballast tank intended for the carriage of water ballast, allowing water to flow through overflow or other arrangements. At least three times the tank volume is to be pumped through the tank and 3. Dilution method: A process by which replacement ballast water is filled through the top of the ballast tank intended for the carriage of water ballast with simultaneous discharge from the bottom at the same flow rate and maintaining a constant level in the tank throughout the ballast exchange operation. At least three times the tank volume is to be pumped through the tank. The flow through method and the dilution method are often referred to as pump through methods. However, only effective treatment of ballast water can bring down the species to innocuous levels 6. Ballast water treatment methods (BWM-D2) Type approved technologies based on various concepts are discussed below.figure-4 shows different treatment technologies that extirpate various sizes of organisms. Size of the organisms varies from viruses to small fish. Combination of different treatment technologies have shown the capability to treat the ballast water to the level required by the D-2 standard 7. Most of the systems apply treatment at the uptake of ballast water, and some systems treat the ballast water both at uptake and discharge. Out of 67 pre-treatment systems, 51systemsuse filtration method 2 ; rest of the 16 systems use different methods or with a combination of two or more pre-treatment steps 8. Most (60systems) make use of an active substance with the most frequently used technique being electrolysis/electro chlorination (25 systems). The second most commonly used technology is UV

4 RAJASEKHAR et al.: BALLAST WATER TREATMENT TECHNIQUES FOR ORV SAGAR NIDHI 2045 Table-2: IMO D-2 Standard for Discharge Ballast Water Microorganism category IMO Regulation Plankton, size > 50 μm < 10 viable cells / m 3 Plankton, size μm < 10 viable cells / ml Toxicogenic Vibrio Cholerae < 10 Colony Forming Unit / 100 ml Escherichia Coli < 250 Colony Forming Unit / 100 ml Intestinal Enterococci < 100 Colony Forming Unit / 100 ml radiation (24 systems) 10. The treatment capacities of most systems range from 60m 3 /h to more than 10,000m 3 /h. Table-2 shows IMO D-2 standard for discharge Ballast water and Table-3 shows comparison of various types of ballast water treatment methods. From the above comparison, it is clear that most of the ballast water treatment systems use 2-3 disinfectant methods together, divided into different stages. A general ballast water treatment plant comprises of two stages with one stage using physical separation and the second stage employing some disinfectant technology 16. The choice of treatment system used in combination depends on a variety of factors such as type of ship, space available on the ship, flow rate required and cost limitations 17. Table-3: Comparison of various Ballast water methods Process Benefits Consideration Solid-liquid separation Filtration: Using disc or Fixed screen with automatic backwashing Hydrocyclone: High velocity centrifugal rotation of water to separate particles Coagulation: Optional pre-treatment prior to separation to aggregate particles to increase their size Chemical disinfection (oxidizing biocides) 3 Chlorination: An oxidizing biocide that, when diluted in water, destroys cell walls of microorganisms Electro-chlorination: Creates oxidizing solution by employing direct current into water which creates electrolytic reaction Ozonation: Ozone gas (1-2 mg/i) is bubbled into the water decomposes and reacts with other chemicals to kill micro-organisms Chemical disinfection (non-oxidizing biocides) 3 Menadione/Vitamin K: Menadione is toxic to invertebrates Physical disinfection Ultraviolet irradiation: Amalgam lamps surrounded by quartz sleeves produce UV light, which denatures the DNA of the microorganism and therefore prevents it from reproducing De-oxygenation: Reduces pressure of oxygen in space above the water with inert gas injection or by means of a vacuum to asphyxiate the micro-organisms Cavitation: Induced by ultrasonic energy or gas injection. Disrupts the cell wall of organisms Effective for larger particles and organisms More effective than filtration More efficient for large size particle Well established and used in municipal and industrial water disinfection applications Same as chlorination Especially effective at killing micro-organisms Natural synthetic products are available Effective against microorganisms, extensively used in municipal and industrial water treatment applications Removal of oxygen may result in a decrease in corrosion propensity. Useful as pre-treatment to aid in overall treatment process Maintaining flow with minimum pressure drop requires backwashing Effective only for larger particles Additional tank to store water which has been treated due to long residence time for process to be effective Ineffective against cysts unless concentration of at least 2 mg/i used. May lead to by-products viz., chlorinated hydrocarbons/trihalomethanes As chlorination, Brine is needed to produce the chlorine, can be stored onboard the vessel as feedstock for the system Not as effective for larger organisms. Produces bromate as a by-product. Ozonate generators are required in order to treat large volumes of ballast water. Treated water will typically require neutralizing before discharge Relies on good UV transmission through the water and hence needs clear water and unfouled quartz sleeves to be effective. Enhanced by combining with ozone, hydrogen peroxide or titanium dioxide The time required for organisms to be asphyxiated is between 1 and 4 days Must be used in conjunction with additional treatment process downstream in order to kill all micro-organisms Evaluations The main criterion for treatment system evaluation was compatibility with the vessel ORV Sagar Nidhi. Sagar Nidhihas a versatile ocean observing platform equipped with technologically advanced scientific equipments and related facilities utilized for deep sea mining, launching and recovery of Remotely Operable Vehicle (ROV), Autonomous

5 2046 INDIAN J. MAR. SCI., VOL 43, NO.11 NOVEMBER 2014 Underwater Vehicle, manned/unmanned submersibles and exploration of gas hydrates. The vessel is inspected annually by IRS and DNV Table-4: Vessel Particulars - Sagar Nidhi Hull form Class notations Length Beam Draft Service speed DWT GRT Mono Hull ICE class 1C and DP II m 18 m 4.20 m 15 knots 3050 T 4862 T Fig 5: Ballast water tank on-board ORV Sagar Nidhi Ballast system onboard Sagar Nidhi The ballasting scheme will vary depending on the cargo loading plan. The ballast system utilizes a centrifugal pump capable of delivering100 m 3 /hour. In general, the vessel operates with a few slack ballast tanks, thereby requiring most tanks to be either completely empty or completely full. The The best score is given to the system which occupies the smallest footprint and has the lowest weight. Electrical Load: Electrical load is another practical consideration that may challenge certain treatment systems. Electrical load required for the treatment device and any additional auxiliaries required to support its operation are considered for evaluation. Selection Criteria for Sagar Nidhi Table-5 shows the list of ballast treatment systems available. The first five systems have been chosen for evaluation based on its compatibility with Sagar Nidhi and the ability to meet the IMO D-2 performance standards with minimal hold/contact time. In some cases there are multiple systems offering the same method of treatment. In such cases, it has been chosen to identify only one classes, under the provisions and is classed by the IRS and DNV.Pertinent data shown in table-4. treatment system operating hours will vary based on the method of treatment. Due to better stability and limited loading, Sagar Nidhi need not carry ballast during each voyage. Figure-5 shows ballast water tank on-board ORV Sagar Nidhi. Evaluation categories Ballast water treatment system (BWTS) technologies are evaluated based on their characteristics in a number of categories.efficacy, residual toxicity, equipment size and weight, electrical load, lifecycle costs, and safety are the few evaluation categories. Within each category, the technologies are assigned a numerical ranking with the value one representing the highest degree of compatibility. The rankings are based on quantitative comparisons of measurable values. For instance, systems with larger space envelopes or higher costs receive diminished scores. Efficacy: This is a measure of a treatment system s effectiveness at killing or removing organisms. Evaluation in this category is based on the published results of biological efficacy tests 17. Residual Toxicity: This is a measure of potential harm that treated water may cause to the environment. It is measured by testing for acute and chronic toxicity across multiple species, and by measuring residual levels of active substances 7. Equipment Size and Weight: Equipment size and weight are significant factors for small and medium size vessels; limited space and increase in weight may have an impact on vessel payload and stability. The system with lowest electrical power demand is given the best score 9. Safety: Safety is a concern in systems which require the storage or transfer of harmful chemical agents. Evaluation in this category is based on the relative severity of the hazardous substances employed and its quantity. The best score is assigned to systems that have the smallest degree of risk. system of each type, so that a representative cross section may be evaluated. Hyde Guardian Ballast Water Treatment System It utilizes a combination of mechanical filtration and UV sterilization and the ballast water is treated during both uptake and discharge 11. Following filtration through a 50 micron disc, the ballast water is exposed to UV radiation 2. During discharge, the

6 RAJASEKHAR et al.: BALLAST WATER TREATMENT TECHNIQUES FOR ORV SAGAR NIDHI 2047 ballast water passes only through the UV treatment chamber. The maximum processing capacity of the system is 150 m 3 /hour. The Hyde Guardian BWTS is shown in Figure-6. Table-5: Ballast treatment systems Sl No Manufacturer System 1 Hyde Guardian Filtration + UV (treated in both operation) 2 Hitachi Filtration + Flocculation (treated in uptake only) 3 Pure Ballast Filtration + UV AOT reactor (treated in both operation) 4 Sodium Hydroxide Filtration + Sodium Hydroxide treatment - Under development 5 Balpure Filtration + Electrolysis (treated in both operation) 6 Siemens Filtration + Electrolysis (treated in both operation) 7 Hyundai Filtration + Electrolysis (treated in both operation) 8 Wartsila Aquarius Filtration + UV (treated in both operation) 9 Bio sea Filtration + UV (treated in both operation) 10 ERMA first Filtration + Hydrocyclone + Chlorine(treated in both operation) 11 Hycator Filtration + Hydrodynamic cavitation (under development) Table-6: Footprint and test results Hyde Guardian system Test results >50 micron <10micron micron Land based test 1.45/m 3 <10/ml <0.1/ml at NIOZ Ship base test 0/m /ml <0.1/ml Foot Print Filter size mm 2 Total size 3560 mm (L) x 1375 mm(w) x 180 mm(h) Total weight 480 kg Efficacy: The Hyde Guardian system has been tested in seawater in accordance with convention protocols and has been granted IMO type approval 11. Equipment Size and Weight: The HG150 treatment device is available as a skid mounted unit or as loose components installed separately. Table-6 shows the total footprints and weights for the loose mounted option. Residual Toxicity: The Hyde system does not generate active substances. By-products from a UV treatment process may arise either as a direct or indirect result of photochemical reactions 12. Electrical Load: An electrical power of 17.2 kw is needed for the entire system. category 3 health hazard. Handling of lamps only occurs after 3000 operating hours or every 5 years. Hitachi Clear Ballast Purification System It is a multi-stage process which relies on magnetic separation of coagulated flocs to effect treatment. During uptake, water is pumped through a mixing tank into which magnetic power and coagulants are introduced which causes sediments and organisms to floc together. When the water passes through the separator the flocs adhere to magnetic discs.figure- 7 shows Hitachi Clear Ballast Purification System. Efficacy: Hitachi system was tested in accordance with convention protocols and had been granted IMO type approval 13,15. Table-7 shows test results of efficacy levels and foot print of the system. Residual Toxicity: As this system uses neither biological toxicity nor neutralizing chemical, no harmful byproduct is generated. Equipment size and weight: Since this system enables flexible equipment layout plans, equipment can be divided into some parts and installed apart from each other. Safety: The system utilizes UV lamps, which contains mercury of 200 mg per UV lamp and it is a

7 2048 INDIAN J. MAR. SCI., VOL 43, NO.11 NOVEMBER 2014 Figure 6: Hyde Guardian BWTS Figure 7: Hitachi Clear Ballast PurificationSystem Table-7: Footprint and test results Hitachi Clear BallastPurificationSystem Efficacy Footprint and power requirement Organisms> 50 µm(per m 3 ) <1 Ballast Pump Capacity 200 (m³/h) Organisms>10µm and<50µm (per ml) <1 Coagulation Tank 1.2 m 2 Escherichia coli (cfu/100 ml) <250 Flocculation Tank (Vertical Blade) 3.3 m 2 Intestinal Enterococci (cfu/100ml) <100 Magnetic Separator 4.2 m 2 Toxicogenic Vibrio cholerae (cfu/100ml) <1 Filter separator 4.3 m 2 Additive Processing Unit * m 2 Collected Flocs Heating Equipment 1.4 m 2 Control panel 1.2 m 2 Electric Power 21 kw Table-8: Footprint and test results Alfa Laval Pure Ballast System Efficacy Footprint (mm) Organisms> 50 µm(per m 3 ) < Filter size 1800 (L) x 1020 (W) x 1250(D) Organisms>10µm and<50µm (per ml) <1.1 Reactor 1300 (L) x 700(W) x 2000(H) Escherichia coli (cfu/100 ml) <1 Total size 6000(L) x 5020(W) x 6850(D) Intestinal Enterococci (cfu/100ml) <1 Toxicogenic Vibrio cholerae (cfu/100ml) <1 Electrical load: The electrical power demand for the 200m 3 system is 21kW. Safety: It is an environmentally friendly system since no chemicals are used. Biological toxicity tests as per IMO convention has been confirmed to have no impact on organisms even if it is discharged without being diluted 11. Table-9: Test results BALPURE Sodium Hypochlorite System Description Uptake Discharge IMO standard Plankton <10 per m 3 micron/m3 Plankton 50 but <10 per ml per ml Escherichia colicfu/100ml 11 <1 <250 cfu/100ml Enterococcicfu/100ml <100 cfu/100ml Vibrio cholera cfu/100ml <1 <1 <1 cfu/100ml Alfa Laval Pure Ballast This system utilizes a combination of mechanical filtration and photo catalytic reaction to remove any organisms. During uptake, the ballast water is pumped through a filter assembly and then passed through a reactor where free radicals generated by UV light and titanium dioxide catalyst disinfect the water 2. The minimum processing capacity is 250m 3 /h. Figure-8 shows Alfa Laval Pure ballast system. Efficacy: The Pure Ballast system has been tested in accordance with convention protocols and has been granted IMO type approval.table-8 shows test results of efficacy levels and foot print of the system. Equipment Size and Weight: The Pure Ballast system is comprised of several independently mounted components which include the filter assembly, reactor vessel (or AOT unit), CIP unit, and control cabinet. Residual Toxicity: Alfa Laval system uses active substances in the form of radicals which are similar to those that occur naturally in the surface layer of seawater when exposed to the sun. Electrical Load: The total electrical load requirement is kw.

8 RAJASEKHAR et al.: BALLAST WATER TREATMENT TECHNIQUES FOR ORV SAGAR NIDHI 2049 Safety: The Alfa Laval system utilizes UV lamps which contain small amounts of mercury. Use of protective clothing and safe clean-up procedures minimizes the risk of damage. BALPURE Sodium Hypochlorite Dosing Post filtering, a small stream of main ballast line is directed to the system, which undergoes increase in pressure and then it passes through an orifice and flow transmitter. The electrolyzer generates oxidants and the oxidants are injected back to the main stream on the discharge side of pump. During de-ballasting, controlled addition of sodium sulphite to the suction side of the ballast pump neutralizes the residual oxidants 14. BALPURE- Sodium Hypochlorite Dosing system is shown in figure-9. Fig 8: Alfa Laval Pure ballast system Efficacy: The Balpure Ballast system has been tested in accordance with convention protocols and has been granted IMO type approval 13.Table-9 shows efficacy test results of BALPURE system. Residual Toxicity: Bench scale testing revealed that water treated with 3.0 mg/l chlorine and neutralized with 9.0 mg/l of ascorbic acid had residual levels below the detection limit of mg/l immediately after neutralization. Equipment Size and Weight: The Sodium Hypochlorite system is comprised of several independently mounted components, which occupy a minimal amount of space within the vessel 14. A summary of the total footprint and weight is shown in table-10. Table-10: Footprint of BALPURE system Ballast Water Flow rate Max (m 3 /h) 500 1%Slip Stream Seawater Feed to BALPURE 6 (m 3 /h) Nominal Power for 12 ppm (kw) 26 Nominal Power for 8 ppm (kw) 17 Nominal Power for 6 ppm (kw) 13 Nominal Power for 4 ppm (kw) 9 System Footprint (m 2 ) 7.9 Filter Footprint (m 2 ) 0.3 Nominal Pressure Drop (Bar) <0.3 Maximum Pressure Drop (Bar) 0.5 SodiumBisulfite(Liters/h) 3.8 ***De-ballastOnly Electrical Load: Under normal conditions of operation, the dosing rate will be 6 8 ppm. Hence the electrical load under normal operation would be Fig. 9: BALPURE- Sodium Hypochlorite Dosing around 15kW. Safety: This system utilizes sodium hypochlorite and sodium sulfite solutions, which are moderate health hazards and can cause irritation of the skin, eyes, and respiratory tract. NaOH The system utilizes an added dosage of sodium hydroxide solution which is stored in a tank at 50% concentration to increase ballast water ph to levels that are toxic to aquatic organisms. Neutralization is accomplished by the injection of carbon dioxide gas to the ballast water that forms carbonic acid. At the dosing levels described above, the system will consume 0.34kg per minute of caustic soda during uptake and 0.4kg per minute of CO 2 during neutralization.figure-10 shows scheme of NaOH Ballast water system 14. Efficacy: To date, the only published test results available are from bench-scale testing performed at the GSI facility which is shown in table 11. Residual Toxicity: The residual toxicity tests did not achieve neutralization with carbonic acid. Instead, the ph of the treated water was returned to normal levels through dilution. Equipment Size and Weight: The system comprises of several independently mounted components. Most significant component is chemical agent s storage tank. Electrical Load: The electrical load requirement is being minimal, as it required only running the ph instrumentation and controller.

9 2050 INDIAN J. MAR. SCI., VOL 43, NO.11 NOVEMBER 2014 Safety: This system utilizes caustic soda solution and liquid CO 2, both of which are category-3 (moderate) health hazards. Short termexposure to liquid CO 2 can cause tissue damage, dizziness or asphyxiation. Approximately 550 kg of NaOH and 300kg of CO 2 are stored. Table-11: Test results for NaOHSystem Efficacy Organisms> 50 µm(per m 3 ) >178 Organisms>10µm and<50µm (per ml) <2-6 Escherichia coli (cfu/100 ml) <1 Intestinal Enterococci (cfu/100ml) <1 Toxicogenic Vibrio cholerae (cfu/100ml) <1 Fig. 10: Scheme of NaOH Ballast water system Results and Discussion: Ranking based on Efficacy: The systems are ranked based on full scale test results, which is based on a system s type approval status, known compatibility with sea water salinity and achievement of efficacy in less time. Table-12: Ballast water systems ranking based on Efficacy Parameter Alfa Laval Hyde Marine Hitachi Balpure NaOH >50 micron/m 3 < < <50 &>10 micron /ml <1.1 <10 < <2-6 Escherichia coli (cfu/100ml) <1 < 0.1 <250 <1 <1 Intestinal Enterococci (cfu/100 <1 3.4 <100 <0.5-1 <1 ml) Toxicogenic Vibrio cfu/ml <1 0 <1 <1 <1 IMO Type approval IMO Approved IMO Approved IMO Approved IMO Approved Not approved Required residence No Minimum Period No Minimum Period No Minimum Period No Minimum Period Variable based on concentration Ranking Not ranked Table-13: Ballast water systems ranking based on residual toxicity Description Alfa Laval Hyde Marine Hitachi Balpure NaOH Residual oxidant None None None 0.002mg/L n/a Ranking Table-14: Ballast water systems ranking based on Electrical Load Description Alfa Laval Hyde Marine Hitachi Balpure NaOH Electrical load 42kW 17kW kW Ranking Table-15: Ballast water systems ranking based on Equipment size and weight Description Alfa Laval Hyde Marine Hitachi Balpure NaOH Foot print m NA Weight kg NA NA NA Ranking Not ranked Residual Toxicity: Ranking of residual toxicity shown in table-13 is based on whether active substances are used and if so whether residual levels are within limits imposed by laws. Electrical Load: Ranking is strictly assigned based on the electrical load needed to operate the system and any supporting auxiliaries that are additional to the vessel in its current configuration 12. The analysis shows that electrical loads may be categorized in the following groups: negligible loads, loads between 1 and 10 kw, loads between 10 and 20 kw and loads greater than 20 kw. Equipment Size and Weight: Footprint and weight were considered together to receive a combined score. This score is assigned based on the product of square footage and weight. The analysis shows that the composite values may be categorized in the following groups: Values < 10,000, values between 10,000 and 40,000, and values greater than 40,000. Safety: Safety is ranked based on the use of active

10 RAJASEKHAR et al.: BALLAST WATER TREATMENT TECHNIQUES FOR ORV SAGAR NIDHI 2051 substances, whether handling of such substances is required, and the risk of environmental pollution or injury 12. Remarks: Alfa Laval Pure Ballast: The technology shows promise in saline water but is ineligible for consideration due to removal from the fresh water market. Hyde Guardian: It is an IMO type approved treatment process which requires no minimum residence time after treatment. The size and weight characteristics are among the best of the commercially marketed technologies evaluated. The electrical load is moderate but still manageable for a small vessel. There is minimal need for vessel system modifications and minimal safety risks 11. ease, which suits all types of vessels, and can be sized for all flow rates, however, it is seen by the vendor as most cost competitive for ships requiring large flow rates. Conclusion: Evaluation of the five technologies revealed both major and minor factors which influenced their respective compatibilities with Sagar Nidhi. Based on this evaluation it is concluded that Hyde Guardian system suits best among the available technology. The system is IMO type approved, occupies less space, less toxic, higher safety and requires less modification for installation. Acknowledgement: The Authors would like to acknowledge Hyde Marine, Hitachi, Balpure, and Alpha Laval for the support in providing valuable information about their products and also would like to thank IMO for Table 16: Ballast water systems ranking based on safety Description Alfa Laval Hyde Marine Hitachi Balpure NaOH Harmful Mercury Mercury Coagulant Powder Sodium Sulphite Caustic soda substance Rating as per 3 3 NA 2 3 NFPA Onboard <200mg Details not NA Approximately 4 Approximately 92 gallons quantity available gallons each Handling Lamp Lamp Coagulant Refilling Refilling chemical tanks required replacement replacement refilling Chemical tanks Handling frequency Every 3000 hrs Every 5 years Weekly Weekly Weekly Hazards of Minor injury due Minor injury due Minor injury due Minor injury due Major injuries, vessel damage handling to low volume to low volume to low volume to low volume due to high volume Pipe leak Not applicable Not applicable Chemical agent Chemical agent Chemical agent leak hazards leak leak Pipe rupture Not applicable Not applicable Small volume of release Small volume of release Chance of large volume release Ranking Hitachi Clear Ballast: The technology shows promise in fresh water but is ruled out due to its removal from the market. Sodium Hydroxide Dosing: The only published results available at this time are bench scale testing in fresh water. Lifecycle costs and the electrical load are low, but the size and weight are moderate. The risk is large volumes of chemical agents. However, adherence to safety procedures can mitigate these risks. Balpure: It is an IMO approved system which can treat brackish water and sea water with sharing the land / ship based test results. References: 1 Rajoo B., and Omar B.Y.,Emerging Ballast Water Treatment Technologies: A Review, J. Sustainability Sci and Manage, 6-1(2011) Zhijian T., Michael A.B., Yuefeng F.X., Crumb rubber filtration: A potential technology for ballast water treatment, Mar Environ Res, 61 (2006) Gregg, M. D., Hallegraeff, G. M., Efficacy of three commercially available ballast water biocides against vegetative microalgae, dinoflagellate cysts and bacteria. Harmful Algae6-4 (2007) David P., Rodolfo Z., Doug M., Update on the environmental and economic costs associated with alien-

11 2052 INDIAN J. MAR. SCI., VOL 43, NO.11 NOVEMBER 2014 invasive species in the United States, Ecological Economics (2004). 5 Magnus B.,Guidelines for Selection of a Ship Ballast Water Treatment System, Master thesis, Norwegian University of Science and Technology (2010). 6 Steve R., GloBallast Monograph Series No. 5, Proceedings of 1 st International Ballast Water Treatment R&D Symposium, IMO London: March Dobroski, N., Scianni, C., Takata, L., Falkner, M., Update: Ballast Water Treatment Technologies for use in California waters, Prepared by the California State lands Commission, Marine Invasive Species Program, (2009) 3. 8 Jose M., Steve R., GloBallast Monograph Series No. 15, Proceedings of 2 nd International Ballast Water Treatment R&D Symposium, IMO London: July Endersen O., Behrens, H. L., Brynestad, S., Andersen, A. B., Skong, R.., Challenges in global ballast water management, Marine Pollution Bulletin, (2004) Kuzirian, A. M., Terry, E. C. S., Bechtel, D. L., James, P. L., Hydrogen Peroxide: An Effective Treatment for Ballast Water, Biol Bulletin, (2001) Shipboard Trials of Hyde Guardian System in Caribbean Sea and Western Pacific Ocean. University of Maryland Center for Environmental Science, Environmental Acceptability Evaluation of the Hyde Guardian Ballast Water Treatment System as Part of the Type Approval Process. NIOZ, GESAMP Review of Proposals for Approval of Ballast Water Management Systems that Make Use of Active Substances - Resource Ballast Technologies System. 14 Sodium Hydroxide (NaOH) Practicality Study. The Glosten Associates, IMO Ballast Water Management Convention: Implications for shipbuilders and shipyards: Singapore Forum Talks. 16 Guidelines for Application of Ballast Water Treatment Systems in Ships Korean Register of shipping. 17 Ballast water treatment technologies and current system availability Lloyd s Register.