Eco-friendly microalgae harvesting using lipid-cored particles with a comparative life-cycle assessment

Area of Science:

• Biotechnology
• Environmental Science
• Chemical Engineering

Background:

• Microalgae harvesting faces challenges in efficiency, cost, and environmental impact.
• Traditional methods often involve energy-intensive processes and chemical inputs.
• Developing sustainable and cost-effective harvesting solutions is crucial for microalgae applications.

Purpose of the Study:

• To develop and evaluate lipid-cored particles (LCPs) for efficient microalgae harvesting.
• To optimize LCPs using chitosan (CS) modification for enhanced performance.
• To assess the environmental impact and mechanisms of LCP-based microalgae harvesting.

Main Methods:

• Lipid-cored particles (LCPs) were synthesized and modified with Cetyltrimethylammonium bromide (CTAB) and chitosan (CS).
• Harvesting efficiency was tested using Chlorella vulgaris.
• Mechanisms were investigated using zeta potential, microscopy, fractal dimension analysis, and Excitation-emission matrices (EEM).
• Life cycle assessment (LCA) was performed to evaluate environmental impacts.

Main Results:

• Chitosan-modified LCPs (CS-LCPs) achieved a maximum harvesting efficiency of 97.14%.
• Microscopic and EEM analyses confirmed CS-LCPs embedding within microalgal flocs and bridging networks.
• Life cycle assessment indicated that LCPs have the lowest global warming potential (GWP) among tested methods.
• CS-LCPs demonstrated a viable, low-carbon, and cost-effective harvesting alternative.

Conclusions:

• Lipid-cored particles, particularly CS-LCPs, represent a highly efficient method for microalgae harvesting.
• This approach offers significant advantages in terms of cost-effectiveness and reduced environmental footprint.
• LCPs provide a promising sustainable solution for industrial microalgae cultivation and processing.