| Popis: |
Algal biofuel is a promising green energy for the future, but harvesting algae remains a major challenge. To overcome this obstacle, magnetic separation using magnetic nanoparticles is proposed as a simple, highly efficient yet cost-effective method to collect microalgae. Magnetite (Fe3O4) nanoparticles are the typical materials of choice, but their performance varies depending on the pH of the water, furthermore, they can be toxic to algal cells. Hence, a more stable and non-toxic alternative replacement for Fe3O4 is needed. In this work, we explore the use of biocompatible manganese-containing magnetic ferrite nanoparticles (NPs) to harvest Chlorella sorokiniana and Scenedesmus obliquus microalgae. Using this novel NP, we achieved a harvesting efficiency of roughly 90% for Chlorella sorokiniana and 80% for Scenedesmus obliquus up to three cycles consistently throughout a wide pH range of 2–12. This was due to the high stability and reversible attachment of the NPs to the algal cells. Surface analysis of the NPs-Algae by Fourier transformed infrared (FTIR), the microbial adhesion to hydrocarbons (MATH), zeta potential, and the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory indicated acid-base interactions and hydrophobicity effects are the driven forces for NPs-algae interaction instead of simple electrostatic attraction. Overall, our study provided a more efficient magnetic harvesting approach for algae and a more in-depth understanding of the separation mechanisms to improve and advance the algae biofuel industry. |
