General Dispersant Theory

Abstract Chemical dispersants have a role in the cleanup of oil spills. However, neither dispersion nor any other current technique is a panacea for this purpose. There are situations where dispersants can be used for the benefit of our natural resources; but there are also instances where they should not be used. Similarly, there are conditions under which they are effective, as well as limits where they become ineffective. These aspects of the subject, as well as the mechanism of and basis for dispersing oil slicks, will be discussed. An understanding of the mechanism of dispersency is of prime importance in order to appreciate the behavior and variation in effectiveness of various generic types of surface active agents in promoting oil-in-water dispersions. In this regard, the presence of naturally occurring surfactants in crude oil and their properties are discussed. Even for the same chemical agent, its efficiency can vary due to the influence of many factors such as method of application, degree of mixing, type of oil, temperature of water, amount of circulation in the body of water, etc. Some chemicals can be more sensitive to a specific factor than others. Therefore, an appreciation of mechanism and the effect of environmental and application factors is necessary in order to assess the appropriate scope of application for dispersants as a tool for the handling of oil spills.