Oil spill containment by use of air bubbles

Abstract

This report summarizes the activities and results from the research project "Oil spill containment by use of air bubbles". The goal of the pro;ect has been to investigate how air bubble induced flows can be used as a barrier against oil spills in coastal and environmentally sensitive areas and to prepare for industrial development of bubble based systems. Through a series of laboratory- and field experiments it has been demonstrated that a bubble oil boom (BOB) can be designed to block surface contamination for currents higher than 1 knot. This is roughly a doubling of the capacity compared to existing commercial pneumatic systems. It seems likely that an appropriately designed BOB can withstand higher currents also. The key new element to the BOB iS the "bubble raft -idea,i.e a grating of parallel spargers to produce an area-distributed bubble source instead of a single line source. The area-distributed bubble source yields a significantly stronger plume upwelling flow with less variability /turbulence and thus thicker outwelling flow at the surface than that from a single line Source for a given air flow rate, constituting a significantly more effective barrier against a surface oil slick.