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Measures for the Safe Removal, Collection and Disposal of


Measures for the Safe Removal, Collection and Disposal of Harmful Anti-fouling Systems Edward Kleverlaan IMO-Technical Officer Introduction Issues - general Article 5 ... – PowerPoint PPT presentation

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Title: Measures for the Safe Removal, Collection and Disposal of

Measures for the Safe Removal, Collection and
Disposal of Harmful Anti-fouling Systems
Edward Kleverlaan IMO-Technical Officer
  • Issues - general
  • Article 5 of the AFSC
  • Look at
  • Removal techniques
  • Collection techniques
  • Disposal / Treatment methods
  • Summary

Shipyard facilities
Shipyard facilitiesActivities of concern
  • Vessel repair and maintenance
  • Fueling
  • Painting
  • Paint stripping
  • Public access and recreation
  • Building/grounds maintenance
  • Chemical storage and handling
  • Ship liquid discharges
  • Ship breaking
  • Cargo handling

Shipyard facilitiespotential sources of
  • Underground and above ground storage tanks
  • Chemical storage
  • Spills and leaks
  • Solid waste
  • Older facilities through which seepage can occur
  • Non-maintained facilities

Shipyard facilities potential discharges
  • Hazardous waste
  • Anti-fouling systems
  • Biocides
  • Solid Waste
  • Dry and liquid bulk
  • Bilge Water
  • Ballast Water
  • Cleaning agents
  • Nutrients
  • Liquid waste
  • Hydro blast streams
  • Anti-fouling outwash
  • Storm water discharge
  • Fuel and hydraulic leaks
  • Oil
  • Sewage
  • Particulate matter

Types of coatings
  • Pesticide based
  • TBT
  • Copper
  • Arsenic
  • Mercury
  • PCBs
  • Pesticide free
  • Silicone
  • Epoxy
  • Ablative
  • Self-polishing
  • Non-ablative

ARTICLE 5 - Waste Materials
  • .a Party shall take appropriate measures in its
    territory to require that wastes from the
    application or removal of anti-fouling system
    controlled in Annex 1 be collected, handled,
    treated, and disposed of in a safe and
    environmentally sound manner to protect human
    health and the environment

Main AFSC Issues
  • Increased paint removals/overcoats by AFSC ban
    of use of TBT by September 2008
  • Worker Health issues Increased (gases, dust,
  • Problems with removal of fouling organisms, paint
    residues, paint chips, and grit increase
  • Handling and long term disposal of hazardous

1.1 Bio-fouling
  • Biofoulants The actual biofoulant organisms can
    pose a threat of pollution from
  • TBT or other pesticide contamination
  • Increased Biological Oxygen Demand (BOD) if
    dumped in the sea
  • Non-Indigenous Species

1.2 Contaminated dust and particles
  • Cleaning of vessel bottoms creates dust and paint
    particles whatever the coating
  • Need to contain the dust
  • Need to treat the wastes produced

1.3 Contaminated water
  • Contaminated water must be contained
  • Sumps
  • Berms
  • Contaminated water must be treated
  • Treatment systems can be expensive and complex
  • But basic solids control is not expensive

Examples of poor collection and treatment
  • Lack of proper containment during antifouling
    paint removal can result in deleterious
    substances being released into the aquatic

1.4 Aerosols, dust and grit
  • Environmental health issues
  • Contact, breathing
  • Safety of Workers
  • Spray, grit

2 Best Management Practice
  • Definition Good Housekeeping
  • conduct everyday activities in a more
    ecologically-sound and safe manner keeping
    pollutants out of surface waters and ground
    waters, and, recognizing that total containment
    and recovery is not always practical.

2.1 Best Management Practices
  • BMPs fall into two general groups
  • Source-control (e.g., vessel shrouding,
    sweeping, covering waste piles, and bermed
    storage for wastes and paints) and
  • Collection, filtration and treatment (e.g., hull
    washwater settling tanks and filters)

2.1 Main Techniques
  • Removal techniques
  • Scraping
  • Blasting
  • Grit
  • Water
  • Collection Techniques
  • Sumps
  • Berms

2.1.1 Hull Biofoulant Removal
  • The primary processes for removal of hull
    biofoulants are scraping and pressure washing.
  • Hand Scraping using large flat-bladed scrapers,
    generally has a slow production rate, and is only
    suited for working on small areas
  • Mechanical Scraping Many types of mechanical
    scrapers have been developed that clean the hull
    down to the surface of the coating

2.1.2 Hull Biofoulant Removal Pressure Washing
  • Low-Pressure (lt1,000 psi) Water Washing useful
    in removing slime and other low adhesion
  • High-Pressure (1,000 5,000 psi) Water Washing
    is very effective in removing low and high
    adhesion biofoulants
  • Pressure Washing with Chemical Additives
    increases the effectiveness of biofoulant removal

2.1.3 Management of Biofouling Waste
  • Removed fouling organisms should be collected for
  • Sweep, vacuum , biofouling organisms and deposit
    in containers for disposal
  • Do not allow biofouling organisms to sit around
    the yard in containers it could cause heath
    problems and attract pests

2.2.1 Paint Removal Dry Abrasive Blasting
  • Sand abrasives are generally considered to have
    the highest emission rates of particulate matter
  • Slag abrasives
  • Furnace Slag (possible PAH Contamination)
  • Smelter Slag (possible Metal Contamination)
  • Mineral abrasives, such as garnet, are mined and
    processed into abrasives
  • Metallic abrasives include iron and steel shot
    and grit
  • Alternative types of abrasives
  • glass abrasive
  • dry-ice

2.2.2 Blasting Grit media choice
  • Some rules-of-thumb for media selection
  • Choose the least aggressive media. This will
    result in less wear and lower equipment
    maintenance expense.
  • Use the smallest media particle size - more
    effective. More impacts per second will yield a
    faster process.
  • Find the lowest blast pressure. This offers the
    benefits of energy savings in reduced compressed
    air requirements, as well as less wear and lower
    maintenance costs.

2.2.3 Blasting Types - 1
  • Compressed Air Dry Abrasive Blasting process has
    highest pollutant emission rates, particulate
    released directly to the air, and the abrasive is
    not reused
  • Slurry Blasting uses water instead of air as
    the medium to accelerate the abrasive. air
    emissions greatly reduced due to the
    water-curtain effect, the pollutants not
    eliminated, but transferred from one media (air)
    to another (water)

2.2.3 Blasting Types - 2
  • Open-Loop Dry Abrasive Blasting processes -
    abrasive is reused outside loop.
  • Depending upon type of abrasive being used and
    the use of an abrasive cleaning process prior to
    reuse, the particulate emission rates can be
    significantly decreased or increased.
  • Closed-Loop Dry Abrasive Blasting processes
    continuously contain both the abrasive and the
    particulate emissions with the blasting system.
  • Lowest emission rates of dry abrasive systems and
    prevents contamination of the dry-dock floor with
    spent abrasive

2.2.4 Management of spent grit
  • Avoid spent abrasive and dust to re-suspend in
    the air by wind, or transport by runoff to the
    surface waters.
  • Reduce the amount of pollutants that reach the
    environmental media of concern by increasing the
    cleaning frequency to remove accumulated abrasive
    and dust prior to exposure to rainfall and/or
    other sources of runoff.
  • Covered Dumpsters/Bins Covering dumpsters and
    bins being used to store spent abrasive prior to
    transport to a storage or containment area
    prevents the re-suspension of dust.

2.2.5 Reduce and recycle spent grit
  • Clean all deck surfaces of spent grit (by
    sweeping, brushing, shovelling and vacuuming)
    prior to submersion.
  • Clean and collect spent grit from yard areas at
    the end of the work shift
  • Filter or provide collectors around yard drains
    to prevent flushing of spent grit into the storm
    water runoff or sewer system
  • Recycling of spent abrasive for use as an
    aggregate material in the production of asphalt
    and cement clinker.

2.3.1 Management of Paint Chips (TBT)
  • Difficult to separate grit from paint chips
  • Continuous cleaning of the yard surface and
    containment of the waste paint will help reduce
    contamination of the water.

2.4 Waste Water
  • Water management is probably the largest waste
  • Recovery and reuse of water can have a
    significant reduction on pollution loadings
  • Percent recovery of liquid waste stream (volume
    of water used/volume of water disposed)

2.4.1 Collection of Hull Waste Water
  • Collect hull washwater and remove all visible
    solids before discharging to a sewer or receiving
    waters. Inspect and clean all sumps, filters
    and/or screens regularly
  • Avoid any high pressure washing of hull unless
    prior clean-up of the dock floor, lift platform,
    or yard surface is completed.
  • Various treatment systems are available to remove
    the contaminants from hull washwater.

2.4.2 Collection of Hull Waste Water
  • Option 1 - Very Low concentrations of suspended
    solids and/or organics (e.g. storm water),
  • collected wastewater can be pumped and disposed
    of directly into the sanitary sewer system.
  • Option 3- If the volume of wastewater is
    relatively small and contains a high
    concentration of solids,
  • the wastewater can be directly processed by a
    mechanical filter system.

2.4.3 Collection of Hull Waste Water
  • Option 2 - usually applicable to ship and boat
    building and repair facilities with large volumes
    of wastewater containing high concentrations of
  • An engineered holding settling tank system is an
    important component of the treatment system. The
    settling tank is designed to remove most of the
  • After treatment, the clarified effluent or
    overflow from the holding/settling tank can be
    discharged into the sewer system.
  • The settled sludge can be further processed by
    dewatering through a mechanical filter and then
    disposed of at an approved facility.

Waste Water Treatment
Travel Lift System
Marine Railway System
2.4.3 Add On Controls for drydocks
  • Drydock/ground liquid barriers
  • impervious barrier, may be temporary or
    permanent, prevents contact of the waste stream
    with the ground or floor of the drydock,
    contains the waste stream until it can be removed
  • Filter System/Barrier
  • barrier that filters the waste stream as it flows
    from the drydock

2.5 Treatment Technology
  • No off-the-shelf technology that will reduce
    TBT levels in water to below safe-levels (less
    than 30-50 parts per trillion, ie 50ng/l)
  • Unproven technology such as Dissolved Air
    Floatation, and Activated Carbon Adsorption are
    the best candidates to destroy TBT in waste

2.6 Alternates
  • Alternative processes include the use of
    oxidizers (hydrogen peroxide and ozone) and the
    use of UV light to degrade TBT in wastewaters
  • Heat agitation and organic solvents to separate
    TBT from water are also used.

2.7 Treatment with activated sludge
  • TBT will attach to organic material and bind
  • Treats up to 20 tonnes of effluent per hour.
    Concentrating the TBT into a small volume of oil
    which can be safely incinerated or re-used.
  • Industrial waste streams from shipyards have
    measured TBT levels as high as 480,000 ng/L,
    which is known to be sufficient to kill the
    bacteria in activated sludge (Argaman et al,

2.8 Floating Treatment Plant
  • System developed in 1999
  • Waste separation and carbon treatment
  • TBT lt 50 ng/l

3.1 Summary Removal Methods
  • Removal of paint and fouling organisms can be
    performed in a number of ways
  • Abrasive Grit
  • High pressure Hydroblasting
  • Ultra high pressure Hydroblasting
  • Mechanical removal (scraping)
  • What is the best way?
  • Ultra high pressure is currently recommended

3.2 Summary Treatment/Disposal
  • Waste treatment is possible at high cost
  • Treat to the level that can be achieved
    practically and economically
  • Good housekeeping is the key to waste reduction.

3.3 Summary
  • Contamination Sources
  • Fouling organisms- living and dead
  • Paint Chips
  • Grit
  • Spraying
  • Reduction of waste and treatment
  • Use Best Management Practice for source
    reduction, collection and treatment

4 Summary
  • Keep it practical and safe for workers
  • Containment primary step in waste management
  • Recycling further step in reduction of waste and
    overall cost for treatment/disposal
  • Untreated hazardous waste TBT and other biocidal
    paint chips special waste to land sites or
    treated by purpose built systems
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