Solvent extraction techniques of lipid from algal species in wastewater treatment station

Abstract

Biodiesel production process relies on various key steps one of which is the lipid extraction from microalgae cells using economic techniques. In this study, Algal community structure and physicochemical parameters of the wastewater treatment plant (Beni-Suef, Egypt), are determined from March 2016 to February 2017. In this study, we focused on the lipid extracted from wild mixed culture of Chlorella sp. which is the dominant from December 2016 to February 2017. Lipid content and fatty acid profiling of Chlorella sp. are investigated using three different methods (1) conventional extraction (CE), (2) ultrasonic assisted extraction (UAE) and (3) microwave assisted solvothermalextraction (MASE). MASE showed the highest lipid yield of 37.9±0.13%. SEM micrographs showed that MASE had the most distributive effect for algae cells compared to UAE and CE. Six different solvents are tested for MASE technique namely hexane: isopropanol (3:2), hexane: ethanol (1:1), chloroform: methanol (1:1), diethyl ether, ethanol and methanol. A strong linear relation between the direct electric constant and yield percent is obtained with methanol showing the highest yield. The GC-analysis of extracted lipids shows that methanol resulted in the highest percentage of palmitic acid (45.5%). The chemical composition of extracted lipids shows promise towards further conversion to biodiesel.