Surfactant selection for a liquid foam-bed photobioreactor.

Area of Science:

• Biotechnology
• Chemical Engineering
• Algal Biotechnology

Background:

• Microalgae cultivation is crucial for sustainable production.
• Liquid foam-bed photobioreactors offer innovative potential for microalgae production.
• Selecting appropriate foam stabilizing agents (surfactants) is critical for efficient reactor operation.

Purpose of the Study:

• To identify optimal surfactants for liquid foam-bed photobioreactors.
• To evaluate surfactants based on foaming properties, biodegradability, microalgae transport, and toxicity.
• To compare nonionic, cationic, and anionic surfactants with Chlorella and Scenedesmus microalgae.

Main Methods:

• Screening of ten surfactants based on four key criteria.
• Assessing foaming properties: foam stability, liquid holdup, and bubble size.
• Evaluating biodegradability, microalgae concentration in foam, and toxicity at specific concentrations.

Main Results:

• Poloxameric surfactants (Pluronic F68, P84) showed acceptable foaming properties.
• Natural surfactants (BSA, Saponin) and Tween 20 were rapidly biodegradable.
• Cationic surfactant CTAB uniquely increased microalgae concentration in foam; Pluronics were non-toxic at high concentrations.

Conclusions:

• Pluronics (F68 and P84) are the most suitable surfactants for liquid foam-bed photobioreactors.
• Pluronic F68 demonstrated slightly superior performance and is recommended for practical application.
• This research provides valuable insights for optimizing microalgae cultivation technologies.