duct an independent international calibration of environment by mankind’ Goldberg, keynote adavailable alternative non-TBT marine coatings.

and 3 the cost benefits from the use of these waters, see papers published in the Proceedings coatings was estimated to be from $100 to $130 of the International Organotin Symposium of the million annually in fuel avoidance savings costs.

Paint Control Act of 1988′ OAPCA which was signed into United States law by President Reagan on 16 June 1988.

These new regulations, introduced in Jan-The first regulatory action in the UK to reduce uary 1987, reduced the maximum allowable tin the environmental impact of organotin comcontent of copolymer paints from 7.5 to 5.5% pounds from antifouling paint was announced by the Environment Minister in Parliament on 24 1986, which amended the Control of Pollution trol of Pollution anti-fouling paints Regulations.

These prohibited the retail sale and the supply for retail sale of antifouling paints containing a triorganotin compound as well as the wholesale and retail sale of anti-fouling treatments containing such a compound.

above interim measures were insufficient and that ‘a total ban on the use of TBT antifouling paints on all vessels including vessels engaged in international voyages should be introduced as soon as possible as an international agreement’.

MEPC agreed to request the IMO by the industry; but that the international traffic Council meeting in November 1999, for approval of large ships in Japanese waters is their main of ‘the holding of a 1-week diplomatic conference source of TBT pollution today.

[download id="2"]

With an oil and water interface, there is some mixing of fuel and water so that free oil and emulsified oil are part of the ballast water.

However, most shipyards that occasionally deal with compensated-fuel-tank ships are also faced with numerous other waste water processing needs and opportunities, both within the yard and in the surrounding port areas.

The basic approach to the economic analysis was to identify the capable systems and perform a cost / benefit analysis on some of the most promising types.

The basic cost for the storage tank ranges from $100,000 for a storage tank or a used barge to $250,000 for a new barge.

The sensitivity analysis in Table VI shows a decided sensitivity to working on fewer than one ship per year.

To effectively complete this task, the subject of waste water and its treatment was first researched through a literature survey.

After removing the free oil, Bath cannot discharge to the local public water works because the water works uses bacteria to purify the water.

From the above tables it can be seen that for membranes and oily water separators to compete with coalescing tanks at the preferred flow rates, multiple units must be operated in parallel.

The former process is not recommended for it could potentially lend itself to establishing an anaerobic population since an oil layer will always be developing for skimming.

[download id="3"]

Coagulation studies have concentrated on evaluating the performance of two metal-salt coagulants and their ability to remove copper and zinc with the large amount of the particulate material that is typically present in shipyard wash waters.

The primary variables that control particulate material removal, and also the adsorption of adsorption-amenable organic compounds, are coagulation, pH and coagulant dose.

As an example, Figure 1 and 2 below show the typical effect of increasing coagulant dose and increasing pH, respectively, on the percent reduction of copper from Sample CV6.

The maximum percent removals observed were generally a function of the coagulation pH related to copper and zinc solubility.

In this series of tests the sample wash water (influent) was first treated by batch coagulation, the resultant flocculent removed, and the clarified supernatant (coagulated influent) fed into the process train.

Sample 1 was removed after the sample had passed through the sand filter, and Samples 2 and 3 were taken after the sample had passed through the respective activated carbon columns.

The purpose of the sand filter was to determine if additional removal of fine particulates from the sample could significantly reduce the copper and zinc levels.

A review of Table 4 indicates that on average, coagulation treatment was most effective, reducing copper and zinc levels to 86% and 72% their initial concentration, respectively.

[download id="69"]

Storm water discharges into adjacent receiving waters are facing increasing regulatory compliance requirements which include not only additional BMPs, but chemical monitoring programs.

In addition to material selection, placement of the porous adsorber within the storm water system must be given careful consideration.

The engineering literature provides no details on the specific configurations of storm water collection systems typically encountered at a large commercial or Naval shipyard, however, a mix of combined sewers, sanitary sewers and separate storm water sewers would be expected.

Under the NPDES program a permit would be issued to a facility specifying effluent limits, actions to be taken to meet the limits, and monitoring and self reporting requirements for those limits.

The final sections of this report focus on the evaluation and testing of adsorbent materials for the removal of heavy metals from a synthetic saline storm water.

where M is the metal sorbate, S is the solid sorbent and MS is the metal-solid sorbent complex.

For the sorption of metals to the carbonaceous adsorbents we tested, physical entrapment of the metal into internal pores was probably the dominant sorption mechanism (i.e., physisorption).

This capacity is determined by generating an equilibrium sorption isotherm, which is a plot of the equilibrium aqueous concentration (Ceq – mass sorbate/volume of solution) versus the corresponding sorbed concentration (Csorb – mass sorbate/mass sorbent).

Batch adsorption isotherms were determined for Cu2+ with both adsorbents in a synthetic storm water solution of 100 mM NaCl adjusted to pH 6.3± 0.2 with 100 mM Na(HCO3)2.

[download id="71"]

Procedures for treating wastewater at the Livermore facility start with the addition of iron (II) chloride to remove sulfides and to promote settling.

In one sewage plant in Switzerland, TBT levels in water were reduced from 181 ppt to 9 ppt mainly by sedimentation in the primary classifier and subsequent treatment steps (Fent 1996).

Residual concent rat ions of mo n obut y lt in at t h e ug/L lev el in t h e effluen t will p ro bably n o t p o se a h azard t o aquat ic o rgan isms since t he effluent will event ually be great ly dilut ed and t oxicit y of monobut ylt in t o aquat ic organisms has only been observed at much higher concentrations (mg/L).

Another portion of the TBT removed from the water column was transported to sediments.

Sources and Rate of Degradation of Tri(n-butyl)tin in Marine Sediments Near Auckland, New Zealand.

T h ere is n o ev iden ce o r m en tio n o f h o w t o co n tro l t h e co n cen t rat io n s disch arged in t o t h e waters, only that reduced concentrations seem to be effective.

Chemosphere (1996) 32:12, Tap water from residential areas where PVC pipe had been recently installed as well as raw and treated water from water treatment plants was collected and analyzed for several organotins.

[download id="70"]

There are numerous reports available, summarizing and comparing various “clean technologies”, which have potential application in the shipyard environment.

Biological treatment capabilities include activated sludge, nitrification and denitrification, anaerobic and aerobic digestion, and wetlands.

Internet Address: http://terrassa.pnl.gov:2080 Pacific Northwest National Laboratory works in all phases of the technology development cycle from Research and Development to industrial implementation.

They are studying carbon dioxide (CO2) pellet blasting, FLASHJETTM coating removal, laser paint stripping, plastic media blasting, sodium bicarbonate wet stripping, water blasting and wheat starch blasting.

The final product contains approximately 20% alumina (attributes to the abrasives hardness of 6-7 Mohs) and 54% silica (provides fracture characteristics) and other components including calcia and soda.

Carbon dioxide pellet blasting is a paint removal and/or cleaning technology that turns liquid carbon dioxide into pellets and blasts them through a nozzle or centrifugally towards the surface being cleaned.

As the dry ice pellets strike the surface, they induce an extreme temperature difference between the coating and the underlying substrate, weakening the chemical and physical bonds between the surface materials and the substrate.

- difficult to focus and control laser beam to allow stripping of curved or complex parts [1] – coating removal efficiency is affected by coating color and gloss [1] – requires use of Class 1 laser enclosure to ensure worker protection [1] – see the contact points in the the Bibliography cooresponding to the references below for more information [1] U.S. EPA.

Plastic media blasting (PMB) is a dry stripping process that projects plastic media at a surface through either low-pressure air (10 to 60 psi) or centrifugal wheels.

[download id="68"]