Abstract
The rate at which an oil spill spreads will determine the extent of contamination and toxic effects that affect the environment. When spilled at sea, oil first forms a slick that is then broken into smaller oil droplets due to physical dispersion caused by a combination of wind, currents and wave action. A series of laboratory experiments were conducted to determine how oil partitions into the aqueous phase when subjected to mixing energies common to estuaries. In the experiment, an oil/water system was mixed in a reactor and sampled after 48 h. Three experimental runs were performed for eight increasing mixing energies: 0 s⁻¹, 2.6 s⁻¹, 7.4 s⁻¹, 10.8 s⁻¹, 13.4 s⁻¹, 14.6 s⁻¹, 15.6 s⁻¹ and 20.4 s⁻¹. GC-MS was used to analyze the samples for the presence and concentration of several PAH parent compounds and their constituents, while a Coulter Counter was used to determine size and volume distributions of the entrained petroleum colloids in the water column. The volume of entrained petroleum colloids increased significantly between 0 s⁻¹ and 2.6 s⁻¹; further increases in energy showed no correlation to volume of entrained petroleum colloids. A liquid-liquid partition coefficient (K[d]) was estimated for several of the PAHs analyzed. The estimated K[d] values were at least one order of magnitude higher than K[ow] values reported for the same PAHs suggesting that the mixing energy did contribute to a colloidal phenomenon. Although no correlation was found between the increased mixing energies and oil entrainment, the formation of colloids did play a significant role in determining the concentration of PAHs in the aqueous phase. Further studies are needed to determine at what point a correlation develops between the mixing energy and the volume of entrained petroleum colloids.
Rogers, Ellen Tiffany (2001). The effects of mixing energy on water column oil. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2001 -THESIS -R6447.