Preparation and characterisation of biosilica from teff (eragrostis tef) straw by thermal method

Abstract

Biosilica was synthesised via thermal method from teff (Eragrostis tef) straw, an African agricultural waste, at three different ashing temperatures. Raw teff, characterised by various method, was subjected to thermal decomposition in static air in an electric muffle furnace at various temperatures for 2 h. X-ray fluorescence (XRF) characterization technique analysis showed thermally treated teff straw ash contains significant amount of biosilica having purity of 85, 91.2 and 91.8% for samples obtained at ashing temperatures of 500 °C, 700 °C, and 900 °C, respectively. Teff straw biosilica samples were also characterised by various sophisticated techniques: FE-SEM/EDX, FTIR), XRD and TEM. Prepared biosilica samples performed well for adsorptive removal of pyridine from aqueous solution. Present experimental results show that teff straw is highly-potent renewable source for biosilica when compared with other materials reported in the literature under similar conditions. © 2017 Elsevier B.V.