TRIBUTYL TIN REMEDIATION AND STABILISATION

Key Researchers: Brett Turner

PROBLEM DESCRIPTION

Organotins including tributyl tin (TBT) are an effective biocide that were widely used historically to prevent or inhibit the growth of algae, barnacles, shellfish and other marine invertebrates on the hulls of a ships. TBT antifouling paints were used successfully for over 40 years, however about 20 years after their introduction (late 1970’s) it was shown that TBT was linked to oyster deformities in the Pacific oyster Crassostrea gigas in Arcachon Bay, France [2] and caused serious adverse effects in marine organisms including imposex, the development of male sex characteristics in female organisms [3]. Consequently in 1990 the International Maritime Organisation (IMO) adopted a resolution to ban the use of organotin paints on vessels less than 25m with prohibition eventually coming into effect under the AFS convention on 17 September 2008 [4].  By 2004 it was estimated that more than 80% of the world’s fleet was protected by TBT-[5]. The widespread use of these organotin however has created a lasting legacy of TBT contaminated sediments with the majority, if not all, shipping ports, and repair docks affected the world over

SCIENTIFIC AND ENGINEERING APPROACHES

  • Determine the potential of plants for phytoremediation of dredged harbour sediments.
  • Evaluate the possibility of mass stabilisation using various binders such as cement, fly-ash, kiln slag.
  • This has potential for reuse as engineering geomaterial to expand shipping ports.
  • Systematic evaluation of the kinetics of TBT and heavy metal leaching from stabilised TBT contaminated sediment.
  • Examine the thermal breakdown of the TBT contaminated sediment as a possible method applying thermal destructive methods.
  • Examine the suitability of plant based materials outlined in topic 1 for the removal of TBT contamination from sediment and solution.

APPLICATIONS

  • Remediation of contaminated dredge material
  • Design of optimal stabilisation matrix
  • Determination of contaminant flux as a precursor for changing current Australian water quality guidelines PRB decrease impact on airport infrastructure
  • Design of phytoremediation method for contaminated dredged spoil
  • Design of thermal destruction methods.