Magnetic characteristics of sediment grains concurrently contaminated with TBT and metals toxic heavy metals in a small marina

Abstract

Bottom sediments near shipyards are often susceptible to receiving accidental spills of TBT and metals or its degradation products from hull scraping of antifouling system paints applied prior to 2008 when the AFS Convention 2001 was not into force. We investigated TBT and metals contaminations of bottom sediments near shipyards of a small marina located in Busan, Korea and found that they were highly contaminated with TBT and Cu, Zn, and other metals. To better understand their environmental impacts and to make an optimal remediation plan, we characterized individual antifouling fragments in terms of metal and TBT contents, magnetic properties and grain size. Individual antifouling fragments exhibited simultaneously high levels of TBT and metals and high magnetic susceptibility appeared to be a major source of pollution in the bottom sediment. Therefore, the magnetic separation in combination with size-separation appears to be effective remediation method to remove the TBT and metals contaminated shipyard sediments. The operational detail on this separation scheme is currently being under examined using a bench-scale pilot in Ansan and Las Palmas.to force. We investigated TBT and metals contaminations of bottom sediments near shipyards of a small marina located in Busan, Korea and found that they were highly contaminated with TBT and Cu, Zn, and other metals. To better understand their environmental impacts and to make an optimal remediation plan, we characterized individual antifouling fragments in terms of metal and TBT contents, magnetic properties and grain size. Individual antifouling fragments exhibited simultaneously high levels of TBT and metals and high magnetic susceptibility appeared to be a major source of pollution in the bottom sediment. Therefore, the magnetic separation in combination with size-separation appears to be effective remediation method to remove the TBT and metals contaminated shipyard sediments. The operational detail on this separation scheme is currently being under examined using a bench-scale pilot in Ansan and Las Palmas.