Simultaneous flocculation and fenton s hydrolysis of nitzschia sp. biomass in aqueous phase for enhanced lipids extraction and biodiesel production

Abstract

In present research the development has been made to obtain Nitzschia sp., based biodiesel in more efficient paradigm through simultaneous flocculation and Fenton s hydrolysis of aqueous biomass, which is a simple, novel and innovative process. Reduced cell destruction, solubilization of neutral lipids, and interference of water molecules with organic solvents all contribute to a poor lipid s extraction yield (less than 50%) when microalgal biomass was in aqueous solution. Therefore, we have adopted Fenton's hydrolysis as a novel technique to extract lipids from Nitzschia sp., biomass i.e., more than 95%, and then trans-esterify them into biodiesel. Consequently, it makes it an innovative and novel process for aqueous phase lipid extraction from Nitzschia sp. biomass. At neutral pH, FeSO4 has shown maximum biomass recovery i.e., 77.86%, at 250 mgL-1 dose, when incubated for 240 minutes. Likewise, FeCl3 was found to be a more efficient flocculant to recover 84% of biomass, when 250 mgL-1 dose was maintained for 120 minutes. Then at optimal conditions of flocculation wet biomass was subjected to Fenton s hydrolysis which resulted in more than 95% of lipids recovery (%wt/wt). Gas chromatography mass spectrometry (GCMS) studies confirmed the production of FAME through transesterification. The samples treated by Fenton's hydrolysis at pH 7, about 26.97% were found to be unsaturated (C14:0, C16:0 and C18:0), 9.33% as monounsaturated (C16:1, C17:1 and C18:1) and 63.7% as polyunsaturated (C16:3, C18:2 and C22:2) fatty acids.