Removing mineral oil residues from beaches with vegetable oils

摘要

Experiments conducted in artificial sand columns with Brent Crude Oil have demonstrated the loss of short-chain volatile n-alkanes from the surface and the chromatographic separation of the remaining compounds down core. The weathering index ranged from approx 4 in the crude oil to approx 0.3 after 14 days. Biodiesel derived from rapeseed oil was able to dissolve the remaining heavy fractions and these were carried into the sediments. Periodic washing wit hclean seawater was also able to lift more of the crude oil from the sediment than untreated sands. The effectiveness of the biodiesel in increasing the mobility of the residual crude oil fractions was dependent uponthe time of addition after a spill; the shroter the delay, the more effective the system. Previous experiments have demonstrated the rapidity in which crude oil residuals can be removed if effectively agitated in relatively small volumes of biodiesel. these results indicate that if biodiesel if left on sediments contaminated with crude oil, there is a continuing effect leading to the removal of surface oil to either the water column through tidal washing or deeper into the sediments. Due to the rapid degradability of biodiesel, leaving biodiesel in the sediments should improve beach remediation.