Title: Measures for the Safe Removal, Collection and Disposal of Harmful Anti-fouling Systems
1Measures for the Safe Removal, Collection and
Disposal of Harmful Anti-fouling Systems
Edward Kleverlaan IMO-Technical Officer
2Introduction
- Issues - general
- Article 5 of the AFSC
- Look at
- Removal techniques
- Collection techniques
- Disposal / Treatment methods
- Summary
3Shipyard facilities
4Shipyard 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
5Shipyard 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
6Shipyard 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
7Types of coatings
- Pesticide based
- TBT
- Copper
- Arsenic
- Mercury
- PCBs
- Pesticide free
- Silicone
- Epoxy
- Ablative
- Self-polishing
- Non-ablative
8ARTICLE 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
9Main 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
101.1 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
111.2 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
121.3 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
13Examples of poor collection and treatment
- Lack of proper containment during antifouling
paint removal can result in deleterious
substances being released into the aquatic
environment.
141.4 Aerosols, dust and grit
- Environmental health issues
- Contact, breathing
- Safety of Workers
- Spray, grit
152 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.
162.1 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)
172.1 Main Techniques
- Removal techniques
- Scraping
- Blasting
- Grit
- Water
- Collection Techniques
- Sumps
- Berms
182.1.1 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
192.1.2 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
202.1.3 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
212.2.1 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
222.2.2 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.
232.2.3 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)
242.2.3 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
252.2.4 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.
262.2.5 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.
272.3.1 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.
282.4 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)
292.4.1 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.
302.4.2 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. -
312.4.3 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. -
32Waste Water Treatment
33Travel Lift System
34Marine Railway System
35Drydock
362.4.3 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
372.5 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
382.6 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.
392.7 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)
402.8 Floating Treatment Plant
- System developed in 1999
- Waste separation and carbon treatment
- TBT lt 50 ng/l
413.1 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
423.2 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.
433.3 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
444 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