Water molecules are made of two hydrogen atoms and one oxygen atom. The hydrogen and oxygen have different electronegativities, and because this difference is between 0.5 and 1.6--and because water molecules are asymmetrical--water is polar. This means that water molecules have a strong attraction to each other due to hydrogen bonding. Oil molecules, on the other hand. are non polar and held together by the relatively weak London dispersion force. These differences in polarity and intermolecular forces keep the oil and water from mixing, and cause oil slicks on the water surface. These oil slicks can be very harmful to the ecosystems in which they occur.
Because of this, chemical dispersants are often considered as options to help clear oil spills. Dispersants break up oil spills by containing molecules that have both polar and non-polar ends, attracting both the water and the oil molecules, breaking up the slick and forming the oil into small droplets, allowing it to both spread out easier and get broken down easier by bacteria in the water.
However, the chemical dispersants that we are currently using can have negative effects on human health and underwater ecosystems. In this article from the CBC, John Davis from No More Rigs suggests that Bill C-22 would streamline the process of using chemicals to break up oil spills. The article also stated that, while oil and dispersant were equally toxic while separate, their toxicity increased by a factor of 52 when combined. It also raised that Environment Canada says both that Corexit 9500A is 27 times safer than dish soap, but also poses a "high and immediate human health risk," seemingly contradicting itself.
There are, however, other ways to clean up oil spills. If caught early the surface of the water can be skimmed, and the surface oil removed. Also, if left for long enough, the wind and waves will naturally disperse the oil. Another common method of cleaning up oil spills is adding bacteria to the water that eat the oil, speeding up the natural biodegration.
There are, however, other ways to clean up oil spills. If caught early the surface of the water can be skimmed, and the surface oil removed. Also, if left for long enough, the wind and waves will naturally disperse the oil. Another common method of cleaning up oil spills is adding bacteria to the water that eat the oil, speeding up the natural biodegration.
So, are chemical dispersants a good choice for cleaning up oil spills?
