Biodiesel properties of Neochloris oleoabundans grown in sludge waste

Within the bioremediation framework, this study was aimed at finding out the optimal amount of sludge waste consumption and microalgal growth conditions of Neochloris oleoabundans in order to reach a significant fat production and chemical transformation of microalgal lipids into biodiesel. The effects of the lipid extraction methods – using ionic liquids and chloroform – on the total amount of fat, the individual fatty acid concentrations, and the biodiesel properties were assessed and compared to the EN 14214 and ASTM D6751−02 biodiesel standards. The microalgae strains grown in the optimized sludge waste medium with a dilution of 0.65 g/L wet sludge, and extracted by ionic liquid:chloroform mixed solvent, resulted being the most significant strains to obtain the highest quality of biodiesel with a density of 0.887 g cm−3, kinematic viscosity of 4.7 mm2 s−1, higher heating value of 40.21 MJ kg−1, iodine value of 107.3 g I2 100 g−1 fat, and cetane number of 50. •Sludge waste feedstock was optimized for N. oleoabundans growth.•N. oleoabundans grown in sludge feedstock is suitable for biodiesel production.•Biodiesel properties complied with EN 14214 and ASTM D6751−02 biodiesel standards.