Engineering strategies for enhancing C. vulgaris ESP-31 lipid production using effluents of coke-making wastewater

Microalgae cultivation using wastewater is an approach for simultaneous wastewater treatment and biofuels/chemicals productions. In this study, three microalgae species Chorella vulgaris ESP-31, Chorella sorokiniana CY-1 and Scenedesmus sp. were cultivated using coke-making wastewater generated from a steel-making company. Of these, C.vulgaris ESP-31 had the best tolerance towards wastewater, with maximal biomass concentration of 2.82 g/l and lipid productivity of 32.3 mg/l/d. The highest biomass concentration 3.98 g/l and lipid productivity of 47.1 mg/l/d was obtained in 20% wastewater. Immobilization approach was applied to boost biomass growth and lipid production. Both maximal biomass growth (5.17 g/l) and lipid productivity (68.4 mg/l/d) was significantly enhanced with activated charcoal addition. Semi-batch cultivation resulted in stable biomass production and lipid productivity of 5.18 g/l and 77.3 mg/l/d, respectively. This study has revealed that C. vulgaris ESP-31 is a potential candidate for growth in coke making wastewater and biofuel production.