4 Shipboard Ballast Operations How is it handled?Loading condition is assessed and ballast allocated to remain within safe operational limitsBallast movements coordinated with cargo operationsImpact on CrewProvides for vessel safetyControls vessel motion for better comfortRequires daily management of ballast and maintenance of systems and tanks
11 Ballast System – Design Considerations Total ballast volume – 6,000 to >100,000 m3Flow rates – 200 to 5000 m3/hrHead requirements – up to 30mIn service flexibility (# tks, pipe, valves, …)Ballast Exchange OptionsPartial Ballast ConditionsControl systems
12 What are AIS?Aquatic Invasive Species (AIS) are organisms transported by human activities to a region where they did not occur historically and have established reproducing populations in the wild.(Ref. Dobroski, ‘Aquatic Invasive Species and Ballast Water Management’)
13 How do we manage AIS?Prevention – Best line of defense, vector managementEradication – Costly and often impossible, over $6 million to eradicate Caulerpa (algae) from two small southern CA embaymentsSpecies management once established – restrict local movement, control populations in sensitive habitats if possible(Ref. Dobroski, ‘Aquatic Invasive Species and Ballast Water Management’)
14 How do they get here?Many mechanisms (vectors) capable of transporting AIS around the worldAquaculture, live seafood shipments, bait, pet store trade, intentional releaseCommercial ships responsible for up to 80% of introductions in coastal habitatsIncludes ballast water and vessel fouling(Ref. Dobroski, ‘Aquatic Invasive Species and Ballast Water Management’)
15 Ballast Water and AISSpecies are introduced upon ballast water discharge in recipient regions(Ref. Dobroski, ‘Aquatic Invasive Species and Ballast Water Management’)
16 Ballast Water Management Options in California Retain all ballast on board the vesselBallast water exchangeDischarge to an approved shoreside treatment facility (currently no such facilities in CA)Use of alternative, environmentally sound CSLC or USCG approved method of treatment(Ref. Dobroski, ‘Aquatic Invasive Species and Ballast Water Management’)
17 Ballast Water Treatment Standards Organism Size ClassCalifornia1,2IMO Regulation D-21WashingtonOrganisms greater than 50 µm in minimum dimensionNo detectable living organisms< 10 viable organisms per cubic meterTechnology to inactivate or remove:95% zooplankton99% bacteria and phytoplanktonOrganisms 10 – 50 µm in minimum dimension< 0.01 living organisms per ml< 10 viable organisms per mlOrganisms less than 10 µm in minimum dimensionEscherichia coliIntestinal enterococciToxicogenic Vibrio cholerae (01 & 0139)< 103 bacteria/100 ml< 104 viruses/100 ml< 126 cfu3/100 ml< 33 cfu/100 ml< 1cfu/100 ml or< 1cfu/gram wet weight zoological samples< 250 cfu/100 ml< 100 cfu/100 ml< 1 cfu/100 ml or< 1 cfu/gram wet weight zooplankton samples See Implementation Schedule (below) for dates by which vessels must meet California Interim Performance Standards and IMO Ballast Water Performance Standard Final discharge standard for California, beginning January 1, 2020, is zero detectable living organisms for all organism size classes Colony-forming-unitImplementation Schedule for Performance Standards(Ref. Dobroski, ‘Aquatic Invasive Species and Ballast Water Management’)Ballast Water Capacity of VesselStandards apply to new vessels in this size class constructed on or afterStandards apply to all other vessels in this size class beginning in< 1500 metric tons20092016< 1500 – 5000 metric tons2014> 5000 metric tons2012
18 Treatment Technology Challenge Achieve desired kill rateWork at high flow rates and with large volumesWork with water of varying salinity, temperature, nutrients, clarityDo not introduce other personnel/environmental hazardsProvide mechanism/process for testing/monitoringDo not disrupt ship operations/scheduleFit in limited space and survive ship conditions (vibration, pitch/roll motions,...)Use available powerDo not add to ship maintenanceBe economical to buy, install, use and maintain
19 Treatment Technology Solutions Chemical Biocides (“Active Substances”)Chlorine (Generated on Board)Ozone (Generated on Board)Proprietary Chemicals (some delivered pre-mixed)Mechanical Separation - FiltersPhysical Change to Ballast Water EnvironmentIrradiate (UV light)DeoxygenateHeat
20 Chlorine NaCl + H2O + 2e NaOCl + H2 Generate Chlorine / Sodium Hypochlorate (bleach) with electrolytic cells on boardAdd solution when taking on ballast, maintain levels during voyageLethal in hours>80% chance can meet IMO criteriaSystems designed but limited testing to dateHigh dosage levels can promote steel corrosionConcern about chemical residuals
21 Ozone Ozone generator on board using high voltage AC current Applied at uptake or dischargeLethal in 5-15 hoursShort half life limits corrosion and makes safe at discharge<60% chance can meet IMO 2004 criteriaSystems designed but limited testing to date
22 Proprietary Chemicals Pre-Mixed proprietary chemicals introduced at metered dosage rate when taking on ballastChemicals degrade over time, designed to be safe at dischargeLethal in 24 hrs>80% chance can meet IMO 2004 criteriaFull size testing ongoingHigh dosage levels can promote steel corrosionConcern about chemical residualsExamplePeracetic AcidC2H4O3acetic acid, hydrogen peroxide with sulfuric acid catalyst.Produced on shore, delivered to ship in chemical tanks
23 Mechanical Separation Filters and Cyclones Filters for larger organismsDone at uptake and/or discharge‘Lethal’ at time of treatment<80% chance can meet IMO 2004 criteriaFull scale testing on going
24 Filtration with Backflush Ballast Water TreatmentSNAME Northern California Section MeetingFiltration with Backflush50 microns is the practical lower limitAutomatic backflush is required to allow for unattended operationBackflush process reduces the net flow rate and increases the system pressure dropsExternal backflushing pump is requiredProbably not practical for bulkers and tankers with high flow rates and volumes. The target particle size for the filter stage, as mentioned earlier, is in the 50 to 100 micron size range. Prototype testing aboard a barge indicated that 50 microns is probably the practical lower limit for shipboard use (Parsons, Harkins 2000).Testing has also demonstrated the following:a 5-10mm (3/16” to 3/8”) prescreen upstream of the filter is required to protect the finer screensautomatic backflush capability is required to allow for unattended operation – However, the backflush process can reduce the net flow rate and increase the system pressure drops. Real in-service experience has shown that the reduction in flow rate can be quite different than test-bed values.a pressure sustaining valve is required downstream of the filters to maintain the pressure differential between the discharge chamber and backflush chamberbackflush timing in service can vary greatly from system test-bed valuesfilter performance is enhanced if left in “wet lay-up” between ballast operationshandling filter screens by crew for larger units must be addressed
25 Filtration with Backflush Ballast Water TreatmentSNAME Northern California Section MeetingFiltration with BackflushCan remove most of the larger life formsA 50 micron screen will remove most or all of the zooplankton and some of the phytoplankton and dinoflagellates.Filters of a practical size are not effective against bacteria and virusesUseful in reducing turbidity (suspended solids)
26 Ballast Water Treatment SNAME Northern California Section Meeting Cyclonic Separationfigure
27 Ballast Water Treatment SNAME Northern California Section Meeting Cyclonic SeparationCan remove solids heavier than the sea water and larger than about 50 micronsAbout 5% to 10% of the total flow rate is removed in the sludge dischargePressure drop is about 0.8 bar plus backpressure valve at 1.2 to 1.5 barA few important installation notes regarding shipboard installations of hydrocyclones:They should be installed as vertical as possible with the inlet at the top. They can be inclined if overhead space limitations exist, but performance may suffer as they approach a horizontal orientation.A 3/16” to 3/8” screen mesh is recommended at the sea water in intake to remove very large organisms.Gravity filling of tanks through a hydrocyclone will not work because the gravity head can not push solids overboard.They are particularly applicable on the ballast intake cycle where the separated particles can be discharged with a small percentage of the pumped water back into the harbor of origin.They have the advantage of being scalable to even the largest ballast pumping rates found on ships. Either a single very large unit or a bank of smaller hydrocyclones in parallel can be used to achieve the desired throughput. It is also may be possible to arrange units in series and optimize each for a different particle size or density. Note, total throughput to ballast tanks is still limited by pump capacity, increased system pressure, and volume of diverted sludge.
28 Ballast Water Treatment SNAME Northern California Section Meeting Cyclonic SeparationEffectively remove the large vertebrates and invertebratesNot effective in reducing zooplankton density, but it does reduce live densitiesNot that effective in reducing bacteria, viruses, or phytoplankton
29 Physical Change to Environment Ultraviolet (UV) Light Ballast Water TreatmentSNAME Northern California Section MeetingPhysical Change to Environment Ultraviolet (UV) LightInactivates living organisms by causing DNA mutationsProven effective against zooplankton, phytoplankton, bacteria and viruses.Need pretreatment to reduce size of organisms and exposure timeCan be used on intake and dischargeUltra violet light in wavelengths from 200 to 280 nm can effectively inactivate bacteria, viruses, and other living organisms. The inactivation is caused by DNA mutations induced through absorption of UV light by DNA molecules. For disinfection of water (removal of human pathogens and viruses) the US FDA requires that all parts (each volume element) of the product receive a UV radiant exposure of at least 400 J/m2 (40 mWsec/cm2) at a wavelength of 254 nm. (USFDA 2000). UV irradiation has been the subject of laboratory testing on a range of marine organisms as well and found to be most effective in the wavelengths from 250 to 260 nm.Used on intake and discharge in case of organism regrowth
30 Ultraviolet (UV) Light Ballast Water TreatmentSNAME Northern California Section MeetingUltraviolet (UV) LightCan be automatically controlled and monitoredLong history in the marine industry and demonstrated low maintenance requirementsBasic technology is readily available on the marketTurbid materials in the ballast flow attenuate and scatter the UV radiationPre-filtration used to reduce attenuation/scatter of UV radiation and therefore improve efficiency of UV
31 Physical Change to Environment Deoxygenate Inert gas generated on boardWhen mixed with water, lowers Oxygen and pHLethal in 4 to 6 days>80% chance can meet IMO 2004 criteriaFull scale testing on going, some systems approved by IMOReduces corrosion, but can require closed tank vent system to maintain low oxygen atmosphere.
32 Physical Change to Environment Heat Treatment Heat water to threshold temperature (42 degC)Lethal in hours to daysRequires large amount of energy and can be difficult to generate heat in port when ME not running<60% chance can meet IMO 2004 CriteriaFull scale testing on goingHeat promotes corrosion
33 Combined Systems Cyclonic + UV System (courtesy Optimar/Hyde Marine) Ballast Water TreatmentSNAME Northern California Section MeetingCombined Systems Cyclonic + UV System (courtesy Optimar/Hyde Marine)
35 3 - Stage Treatment Filter + UV + Chemical 50 micron filtrationremove large particlesremove sedimentsUV lightinactivate living organismsreduced efficacy with cloudy waterCatalystsactivated by UV energy producing oxidizing chemicalsincreases efficacy of UV in cloudy water
36 Life Cycle Costs Acquisition Installation Operating Maintenance $ ? 250 m3/hr m3/hr$100k to $400k $400k to $1800kInstallation$50k to $125k $200k to $800kOperating$0.02/m3 to $0.45/m37000 m $ $3,15070,000 m $1, $31,500Maintenance $ ?
37 Safety IssuesHandling and storage of chemicals, radiation and other equipment meant to kill living organismsNew risks to personnel and the environmentIMO G9 Procedures considering eco-toxicology, human health and ship and crew safety (MEPC.126(53))Local, State, National water quality regulations
38 Regulatory Compliance and Testing Organism Size ClassCalifornia1,2Organisms greater than 50 µm in minimum dimensionNo detectable living organismsOrganisms 10 – 50 µm in minimum dimension< 0.01 living organisms per mlOrganisms less than 10 µm in minimum dimensionEscherichia coliIntestinal enterococciToxicogenic Vibrio cholerae (01 & 0139)< 103 bacteria/100 ml< 104 viruses/100 ml< 126 cfu3/100 ml< 33 cfu/100 ml< 1cfu/100 ml or< 1cfu/gram wet weight zoological samplesStricter standardsTesting is time consumingLab results may not scale well to full sizeFunctional testing and equipment certification “Type Approval”, orIn service testing (“end of pipe”) for continuous monitoring
39 Need for Engineered Solutions Develop treatment technologies (Entrepreneur stage)Design testing methods and process for type approval or continuous monitoringAutomatic ballast water analyzers (bug counters)Ship design adjustments and system integrationRegulatory development/evaluation
40 Ballast Water Management Engineering Technologies and Opportunities Spencer SchillingPresidentHerbert Engineering Corp.