Microalgae harvesting using colloidal gas aphrons generated from single and mixed surfactants

Area of Science:

• Environmental Science
• Water Treatment Technology
• Microalgae Research

Background:

• Harmful algal blooms (HABs) are a growing threat to ecosystems and human health.
• Microalgae removal is essential for environmental protection and resource recovery.
• Colloidal gas aphrons (CGAs) show potential for contaminant removal in aqueous solutions.

Purpose of the Study:

• To evaluate the efficacy of CGAs in removing various microalgae species.
• To optimize CGA production and microalgae removal using different surfactants and conditions.
• To assess the impact of environmental parameters on microalgae removal efficiency.

Main Methods:

• Preparation of stable CGAs using cationic (HTAB), anionic (SDBS, SDS), and mixed surfactants.
• Investigation of environmental factors (algae concentration, pH, salinity) for Spirulina platensis removal.
• Optimization of operational parameters (surfactant type, flotation time, flowrate, temperature).

Main Results:

• Complete removal of Spirulina platensis, Chlorella vulgaris, and mixed microalgae at pH 5 and 50°C using HTAB-CGAs.
• Achieved approximately 95% removal of Nannochloropsis oculata with mixed surfactant CGAs.
• Demonstrated successful microalgae harvesting using CGAs from both single and mixed surfactants.

Conclusions:

• CGAs are a highly effective technology for harvesting diverse microalgae species.
• Optimized CGA formulations offer efficient solutions for mitigating harmful algal blooms.
• This technology holds significant promise for water purification and resource recovery from microalgae.