Analysis of Fenugreek gum-based microalgae harvesting technology and its mechanism of action

The use of microalgae to produce renewable biomass is a promising approach to addressing environmental and energy challenges, but the high cost of microalgae harvesting limits its industrial application. To explore the efficient and low-cost harvesting of microalgae, a novel method utilizing fenugreek gum for bubble-free harvesting was developed. Single-factor experiments and response surface analysis were used to screen the significant influencing factors. A multi-objective optimization model was established to determine the key factors influencing harvesting efficiency, including pH, sodium cellulose addition, stirring time, stirring speed, flotation material addition, and raw algal volume. This resulted in an optimal harvesting efficiency of 94.026 % and an optimal enrichment ratio of 2.5 %. Based on the life cycle evaluation, it was concluded that the environmental impact of fenugreek gum on climate change was 1.14 kg CO₂ eq, and the production cost was $3.15, which was significantly lower than the traditional harvesting method. Mechanistic Analysis indicates that the adhesion of fenugreek gum to microalgae is achieved through an electrostatic neutralization and adsorption bridging mechanism.