Development of a novel Fe@urea nanocomposite for effective harvesting of high lutein-producing microalgae biomass

Abstract

An Innovative microalgae biomass harvesting is addressed through a newly developed Fe@urea nanocomposite (NC) with high lutein and lipid content. The persistent challenge of scaling up microalgae harvesting for large-scale commercial production is undertaken by coating Fe3O4 nanoparticles (NPs) with urea, significantly enhancing biomass harvesting efficiency. This improvement aligns with increased NH2+ groups on the NC's surface, demonstrating superior performance compared to conventional Fe3O4 NPs, especially at pH 4. Characterization using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and zeta potential analysis validate the efficacy of the Fe@urea NC. The elemental composition was analyzed through energy-dispersive X-ray spectroscopy (EDX) to confirm effective urea coating on the NC surface. Remarkably, enhanced Fe@urea-mediated harvesting within one minute is achieved through NH2+-assisted interactions. Optimization experiments varying NC concentrations and culture pH, guided by the Langmuir model, showcase the NC's multifaceted solution, excelling under a magnetic field and also via self-flocculation. Cell viability tests confirm lutein-enriched microalgae cell integrity during harvesting at pH 4, preventing product leaching. This synthesized Fe@urea NC presents an efficient and viable method for microalgae harvesting, holding promising implications for large-scale microalgae biorefinery applications.