White spill: Life cycle assessment approach to managing marine EPS litter from flood-released pontoons.

Expanded polystyrene (EPS) pollution in the marine environment is a pressing issue in Queensland, Australia due to a recent flood that scattered hundreds of EPS-containing pontoons along the coastline, causing severe ecological damage. To assist in the clean-up effort and provide crucial data for developing management guidelines, this study investigates the environmental performance of different end-of-life (EoL) disposal/recycling methods, including (i) landfill; (ii) on-site mechanical re-processing using a thermal densifier (MR); and (iii) on-site dissolution/precipitation using d -limonene (DP). Applying the life cycle assessment framework, the results showed that DP was the most environmentally favourable option. Its impacts in climate change (GWP), acidification (TAP), and fossil fuel depletion (FFD) were 612 kg CO 2 eq, 4.3 kg SO 2 eq, and 184.7 kg oil eq, respectively. For comparison, the impacts of landfilling EPS in these categories were found to be 700 kg CO 2 eq, 3.5 kg SO 2 eq, and 282 kg oil eq, respectively. Landfill also contributed considerably to eutrophication potential (MEP), at 3.77 kg N eq. Impacts from MR were most significant due to the need to transport the densifier unit to the site. The analysis also revealed that the transportation of personnel and heavy machinery to the site, was the biggest contributor to impacts in the EoL stage. Its impacts in GWP, TAP, MEP, and FFD were 1369.8 kg CO 2 eq, 6.5 kg SO 2 eq, 0.2189 kg N eq, and 497.7 kg oil eq, respectively. Monte Carlo analysis showed that the conclusions made from these results were stable and reliable. Limitations of this model and recommendations for future investigations were also discussed in this work. [Display omitted] • Transportation imposed the highest impacts during disposal of missing pontoons. • Mechanical re-processing had highest impacts. • d -limonene dissolution showed the best environmental performance. • Further research is needed to optimise d -limonene dissolution process. • Recovery of PS is desirable, but not feasible. [ABSTRACT FROM AUTHOR]