“…Previous studies have demonstrated the potential of primary and secondary sludge from municipal wastewater treatment plants as biodiesel feedstock. For instance, Dufreche et al (2007), Mondala et al (2009), Revellame et al (2010 and Olkiewicz et al (2015) reported that the biodiesel generated from wastewater treatment plants sludge mainly contains methyl esters of palmatic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). This biodiesel composition is similar to that of some vegetable oil biodiesel such as olive, corn and rapeseed (Ramos et al, 2009), which had the better properties because of the greater monounsaturated content.…”