Harnessing Scenedesmus parvus and Coccomyxa dispar microalgae for lake water remediation and biofuel potential

Abstract

Water pollution is a growing environmental concern that requires effective and sustainable treatment solutions. Microalgae have gained attention for their ability to remediate polluted water while simultaneously producing lipids that can be converted into biofuel. This study investigates the efficacy of Scenedesmus parvus and Coccomyxa dispar in improving raw lake water quality while assessing their potential as biofuel feedstocks through lipid and fatty acids. Both microalgae were cultivated in raw lake water, demonstrating significant pollutant reduction capabilities. Scenedesmus parvus chemical oxygen demand (COD) was reduced from 210 to 79 mg/L, and biochemical oxygen demand (BOD) decreased from 120 to 40 mg/L. Growth analysis revealed that Scenedesmus parvus achieved a higher optical density (OD) of 1 at day 12, indicating a faster proliferation rate compared to Coccomyxa dispar, which reached an OD of 0.4. Lipid extraction using the Soxhlet method identified 70 °C as the optimal temperature for maximum yield, with Scenedesmus parvus producing 24.0 % lipid content and Coccomyxa dispar producing 18 %. Fatty acid composition analysis showed that Scenedesmus parvus contained 40.2 % Palmitic (C16:0) and 22.1 % Oleic (C18:1), whereas Coccomyxa dispar contained 81.2 % Palmitic (C16:0). These findings highlight Scenedesmus parvus as a promising option for both lake water remediation and biodiesel production due to its advantageous fatty acid profile. For biodiesel, which benefits from a balance of saturated and unsaturated fatty acids, Scenedesmus parvus is preferable, while Coccomyxa dispar is better suited for applications requiring high thermal stability and oxidative resistance. These findings highlight the dual benefit of using indigenous microalgae for lakewater remediation and biofuel potential, offering a cost-effective and sustainable approach to water treatment.