Model for Investigating Relationships between Surfactant Micropollutant Properties and Their Separation from Liquid in a Bubble Column

Abstract

The removal of surfactant micropollutants, such as dyes, pharmaceuticals, and proteins, through foam is very important in biotechnology and wastewater treatment. The literature shows that previous models consider mass balances within the foam but not the adsorption dynamics of micropollutant surfactants on bubble surfaces in the liquid solution. Thus, the main objective of this work is to examine the removal of surfactant micropollutants in a bubble column considering both mass balance and adsorption dynamics to calculate surfactant transport from the liquid bulk to the bubble surface. This allows investigation of the relationships between surfactant hydrophobicity and surfactant separation efficiency from the liquid. It was found that the removal of the surfactant strongly depends on the dynamic adsorption behavior of surfactant on bubble surfaces, and the highest foam fractionation performance was achieved when the surfactant molecule was highly hydrophobic. This work demonstrates that the adsorption dynamics rather than adsorption thermodynamics on bubble surfaces is critical when modeling the removal of surfactant micropollutants from water solutions.

Evaluation of an external foam column for in situ product removal in aerated surfactin production processes

“…For example, a quasistatic model for foam fractionation was developed by Grassia (2023) to better understand the influences of operating conditions on the fractionation process and performance. In addition, García-Figueroa et al (2023) worked on a model to also consider the biochemical properties and adsorption of the product as an influence on the separation. Another recent attempt was made by Keshavarzi et al (2022), modeling BSA recovery by froth flotation with an emphasis on bubble size distribution as well as foam stability.…”