Interactions between surfactants and biomass during liquid-liquid extraction

Area of Science:

• Chemical Engineering
• Biochemical Engineering
• Separation Processes

Background:

• Fermentation processes generate compounds that can hinder downstream separation.
• Surface-active compounds (surfactants) can significantly impact mass transfer in extraction systems.
• Understanding these interactions is crucial for optimizing bioprocesses.

Purpose of the Study:

• To investigate the influence of surfactants on solute mass transfer in liquid-liquid extraction.
• To elucidate the mechanisms behind surfactant-induced mass transfer enhancement.
• To examine the combined effects of surfactants, biomass, and antifoaming agents.

Main Methods:

• Liquid-liquid extraction experiments were conducted using chloramphenicol as the solute.
• Surfactants (sodium dodecyl sulfate, dodecyl trimethyl ammonium bromide) were added to the aqueous phase.
• Interfacial phenomena were studied using an optical Schlieren apparatus.
• The role of microbial biomass and polypropylene glycol 2000 was also assessed.

Main Results:

• Sodium dodecyl sulfate and dodecyl trimethyl ammonium bromide significantly increased chloramphenicol mass transfer.
• Interfacial turbulence and rapid surface renewal were identified as the mechanisms for enhanced mass transfer.
• Microbial biomass with sodium dodecyl sulfate showed a moderate increase in mass transfer.
• Dodecyl trimethyl ammonium bromide did not enhance mass transfer, likely due to electrical interactions with biomass.
• Polypropylene glycol 2000 exhibited variable effects on extraction components.

Conclusions:

• Surfactants can be utilized to enhance mass transfer in liquid-liquid extraction systems via interfacial turbulence.
• The presence of biomass and specific surfactant types can modulate these effects.
• Careful consideration of surfactant-biomass and surfactant-antifoaming agent interactions is necessary for process optimization.