Sustainable Biodiesel Production from Wastewater-Cultivated Microalgae

<p dir="ltr">This thesis explores the use of nutrient-rich agro-industrial wastewaters, specifically egg-washing and aquaculture effluents for cultivating the microalgae <i>Chlorella vulgaris</i> and <i>Nannochloropsis</i> to enable sustainable biodiesel production and biological carbon capture. Six pretreatment methods (UV-C, moist heat, microwave, electrocoagulation, sonication, and thermal treatment) were applied to improve lipid extraction, followed by solvent-based recovery using methanol, chloroform, acetone, and hexane. Among all methods, electrocoagulation yielded the highest lipid content in <i>C. vulgaris</i> (37.5%) and improved FAME profiles, with elevated levels of methyl palmitate (C16:0) and methyl oleate (C18:1). GC–MS analysis confirmed that wastewater-grown biomass, especially from egg-washing effluent, supported higher lipid yields and biodiesel quality. This work demonstrates a cost-effective, environmentally friendly strategy that couples wastewater treatment with microalgae-based biofuel production, contributing to circular bioeconomy and climate mitigation efforts.</p>