Utilization of Chlorella vulgaris to Fixate a High Concentration of Carbon Dioxide in a Compost-based Medium

Abstract

Massive use of fuels by industry increase carbon dioxide (CO2) emissions significantly. Chlorella vulgaris (C. vulgaris) is well known for its ability to fixate CO2 and synthesize it to a lipid. As industry usually emits high concentrations of CO2, it is necessary to investigate the behavior of microalgae in regard to CO2 inflow. We studied cultivation of C. vulgaris in a photobioreactor (volume 18L) in a compost-basedmedium under illumination at 3000 lux for 90 hours. We show that initial cell density 0.137 g·dm-3 is able to fixate CO2 up to 30.31 g·dm-3· day-1 (93.56%) under a CO2 inflow of 23.80 g·hour-1 with biomass productivity 0.44 g·dm-3· day-1 and lipid yield 0.0795 glipid·gcell-1, and it also shows the potential to fixate carbon dioxide 28.43 g·dm-3·day-1 (31.51%) and produce high lipid amounts (0.0739 g·g-1) under a carbon dioxide inflow 48.17 g·hour-1. Cultivation with a higher initial cell density (0.325 g · dm-3) shows better resistance under carbon dioxide inflow 48.17 g·hour-1 with carbon fixation 37.95 g·dm-3·day-1(58%), biomass production 0.82 g·dm-3·day-1, lipid yield 0.0834 g·g-1, and good potential under carbon dioxide inflow 65.96 g·hour-1. This research shows the potential of C. vulgaris in reducing high concentrations of CO2, which is beneficial for biomass and/or lipid production. These are in turn useful for biodiesel and food supplements. Further study is necessary for adapting this potential on a commercial scale.

Keywords

• Carbon dioxide, Chlorella vulgaris, Fixation, Initial cell density