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Measures for the Safe Removal, Collection and Disposal of

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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


1
Measures for the Safe Removal, Collection and
Disposal of Harmful Anti-fouling Systems
Edward Kleverlaan IMO-Technical Officer
2
Introduction
  • Issues - general
  • Article 5 of the AFSC
  • Look at
  • Removal techniques
  • Collection techniques
  • Disposal / Treatment methods
  • Summary

3
Shipyard facilities
4
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

5
Shipyard facilitiespotential sources of
contaminants
  • Underground and above ground storage tanks
  • Chemical storage
  • Spills and leaks
  • Solid waste
  • Older facilities through which seepage can occur
  • Non-maintained facilities

6
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

7
Types of coatings
  • Pesticide based
  • TBT
  • Copper
  • Arsenic
  • Mercury
  • PCBs
  • Pesticide free
  • Silicone
  • Epoxy
  • Ablative
  • Self-polishing
  • Non-ablative

8
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

9
Main AFSC Issues
  • Increased paint removals/overcoats by AFSC ban
    of use of TBT by September 2008
  • Worker Health issues Increased (gases, dust,
    aerosols)
  • Problems with removal of fouling organisms, paint
    residues, paint chips, and grit increase
  • Handling and long term disposal of hazardous
    substances

10
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

11
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

12
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

13
Examples of poor collection and treatment
  • Lack of proper containment during antifouling
    paint removal can result in deleterious
    substances being released into the aquatic
    environment.

14
1.4 Aerosols, dust and grit
  • Environmental health issues
  • Contact, breathing
  • Safety of Workers
  • Spray, grit

15
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.

16
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)

17
2.1 Main Techniques
  • Removal techniques
  • Scraping
  • Blasting
  • Grit
  • Water
  • Collection Techniques
  • Sumps
  • Berms

18
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

19
2.1.2 Hull Biofoulant Removal Pressure Washing
  • Low-Pressure (lt1,000 psi) Water Washing useful
    in removing slime and other low adhesion
    biofoulants
  • 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

20
2.1.3 Management of Biofouling Waste
  • Removed fouling organisms should be collected for
    disposal
  • 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

21
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

22
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.

23
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)

24
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

25
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.

26
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.

27
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.

28
2.4 Waste Water
  • Water management is probably the largest waste
    stream
  • 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)

29
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.

30
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.

31
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
    solids.
  • An engineered holding settling tank system is an
    important component of the treatment system. The
    settling tank is designed to remove most of the
    solids.
  • 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.

32
Waste Water Treatment
33
Travel Lift System
34
Marine Railway System
35
Drydock
36
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

37
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
    streams

38
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.

39
2.7 Treatment with activated sludge
  • TBT will attach to organic material and bind
    loosely.
  • 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,
    1984)

40
2.8 Floating Treatment Plant
  • System developed in 1999
  • Waste separation and carbon treatment
  • TBT lt 50 ng/l

41
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

42
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.

43
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

44
4 Summary
  • REMEMBER
  • 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
  • THANK YOU
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