Review of foam fractionation as a water treatment technology

Foam fractionation is a well-developed technology used to separate surface-active compounds from solution by exploiting their affinity for the air-water interface. The technology was founded in the 1940s and has since evolved into a key technology for treatment of many different pollutants from a variety of different industries such as textiles and dyes, heavy metals, proteins in food processing waste and even per- and poly-fluoroalkyl substances (PFAS). The technology has even progressed from a standard batch process to a continuous process with an applied reflux to being presently used as an in-situ groundwater remediation and soil remediation process. This review provides a snapshot of the historical evolution of foam fractionation, a discussion of the mechanism behind foam fractionation, the effect of key operating variables on the performance parameters, identification of the key transport processes that take place within a foam fractionation system, a review of the modeling of foam fractionation as a water treatment technology and a review of the applications of foam fractionation as a water treatment technology.