Laser cleaning: an alternative method for removing oil-spill fuel residues

Cleaning methods employed in last oil spills usually require direct contact or the intervention of external agents that can lead to additional contamination and damage of treated surfaces. As an alternative, a laser-based methodology is proposed in this work for controlled removal of fuel residues caused by the accident of Prestige tanker from rocks, as well as tools and equipment employed in fuel retaining and elimination procedures. Ablation thresholds of fuel crust and underlying material have been investigated with the aim to establish operational parameters that preserve the structural integrity and identity of the latter. The clean-up process was controlled by the selflimiting nature of the process or by laser-induced plasma spectroscopy. Contaminated, no contaminated and cleaned areas of the samples have been characterized by complementary microscopy techniques to help in the task of optimizing the laser cleaning procedure and checking the effectiveness of the removal process.