the science behind foam fractionation through theory and equations. As stated earlier, continuous foam separation is closely related to foam fractionation where hydrophobic solutes attach to the surfaces of bubbles and rise to form foam. Foam fractionation is used on a smaller scale whereas continuous foam separation is implemented on a larger scale such as water treatment for a city. An article published by the Water Environment Federation in 1969, discussed the idea of using foam fractionation to treat pollution in rivers and other water resources in cities. Since then, little research has been done to further understand this process. There are still many studies that implement this process for their research, such as the separation of biomolecules in the medical field. Background Surface chemistry Continuous foam separation is dependent on the contaminant’s ability to adsorb to the surface of the solvent based on their chemical potentials. If the chemical potentials promote surface adsorption, the contaminant will move from the bulk of the solvent and form a film at the surface of the foam bubble. The resulting film is considered a monolayer. As contaminants', or surfactants', concentration in the bulk decreases, the surface concentration increases; this increases surface tension at the liquid-vapor interface. Surface tension describes how difficult it is to extend the area of a surface. If surface tension is high, there is a large free energy required to increase the surface area. The surface of the bubbles will contract due to this increased surface tension. This contraction encourages the formation of a foam. Foams Definition Foam is a type of colloidal dispersion where gas is dispersed throughout a liquid phase. The liquid phase is also called the continuous phase because it is an uninterrupted, unlike the gas phase. Structure As the foam is formed, it changes in structure. As the liquid foams up into the gas, the foam bubbles begin as packed uniform spheres. This phase is the wet phase. The farther up the column the foam travels, the air bubbles distort to form polyhedral shapes, the dry phase. The liquid that separates the flat faces between two polyhedral bubbles is called the lamellae; it is a continuous liquid phase. The areas where three lamellae meet are called plateau borders. When the bubbles in the foam are the same size the lamellae in the plateau borders meet at 120 degree angles. Since the lamella is slightly curved, the