Foam Fractionation as an Efficient Method for the Separation and Recovery of Surfactants and Surface-Inactive Agents: State of the Art.

Surface-active agents are widely used in industrial processes and products for daily use. Surfactants are essential in consumer products, although they are environmentally harmful. Consequently, new technologies are being sought to address the surfactant waste problem effectively. Foam fractionation is a multifunctional method of removing or purifying surface-active and inactive agents. This environmentally friendly technology enables foam separation of many compounds based on adsorption at the gas-liquid interface. The technology has been employed in wastewater treatment, remediation, metallurgy, biotechnology, pharmacy, and the cosmetics and food industries. This review highlights process handling and equipment design in terms of the enrichment and recovery of many proteins, surfactants, metal ions, and pollutants. Furthermore, the mode of action, basic laws, and mechanisms of the technology are explained, and relevant examples of the application of foam fractionation will be provided.