The Effectiveness of Dispersants: Variation With Energy

Abstract

A study of the relationship of dispersant effectiveness and mixing energy was performed. Energy was varied by changing the rotational speed of a specially designed apparatus. The effects of dispersant type and oil type were also measured. The stability of the resulting emulsions was gauged by measuring the amount of oil that remained in the water column over time. The findings are that each oil-dispersant combination shows a unique threshold or onset of dispersion. The effectiveness goes up linearly with energy, expressed as flask rotational speed. Natural dispersion was also measured and shows behavior similar to that of chemical dispersion, except that the thresholds occur at a higher energy and effectiveness rises more slowly with increasing energy. Effectiveness (defined as the percentage of oil in the water column) rises rapidly to 80 to 90 percent with increasing energy for light oils treated with chemical dispersants. Heavier oils will disperse, but to lesser effectiveness values.

Oil and oil dispersant do not cause synergistic toxicity to fish embryos

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Petroleum-collecting and dispersing chemicals for cleaning sea surface from thin petroleum slicks

“…They decompose these slicks into tiny emulsions which are later subjected to biochemical destruction under the influence of microorganisms, wind, light, etc. The danger of the petroleum emulsified by dispersants does not exceed that of mechanically dispersed one, provided that their concentrations are equal [10,11].…”

Effectiveness of a new water‐based oil spill dispersant comprised of an alkyl polyglycoside

“…Oil can also have undesirable long-term environmental effects and consequently can cause economic damage near a spill. There are several methods of oil spill remediation (1)(2)(3)(4)(5)(6)(7)(8). The best method, mechanical removal of the oil, is not suitable if the seas are too rough or if the oil slick is rapidly spread over a wide area and there is not enough time to set up a complete removal apparatus.…”