Phaeodactylum tricornutum derived biosilica purification for energy applications

The use of biosilica, obtained from living diatoms, for energy applications has recently shown a great promise, mainly due to the high production cost of such materials to the use of non-environmentally friendly processes. This study aims to analyze the frustule composition of Phaeodactylum tricornutum dried biomass particularly concerning the silicon percentage. To remove the organic and inorganic impurities, frustules were purified by acid cleaning, with different results dependent on the conditions applied. SEM/EDS analysis was used to observe frustules morphology and obtain the Si concentration. The treatment, consisting of HCl cleaning followed by baking process, revealed to damage the frustule structure, while the Si content reached 41.01 ± 8.80 wt% (dry weight). The selection of the most adequate method depends on the final use of the frustules and their applications.