Commitment for a Cleaner India: Utilization of CO₂ and Sewage Wastewater by Green Algae Scenedesmus sp. Under Laboratory Conditions

Carbon dioxide (CO₂) emission is globally increasing every year accelerating the issue of climate change. Conversion of CO₂ into biomass by photosynthesis helps to overcome the challenges of global warming while producing fuel, feed, and value-added products. Green microalgae Scenedesmus sp. was studied for the biomass generation potential utilizing CO₂ without adding any other carbon (C) source. Optical density (OD), cell count, elemental C, and total organic carbon (TOC) were determined for the produced biomass. The results demonstrated that the OD and TOC increased from 0.4 to 2.6 and from 51 to 380 ppm, respectively. The elemental C was found to be 47% of the produced biomass. It was also of interest to determine the possibility of using sewage wastewater for growing Scenedesmus sp. without additional nutrient. The growth of Scenedesmus sp. was evaluated in BBM media and in sewage wastewater. The results indicate that the OD of Scenedesmus cultures was similar in control and primary sewage wastewater. TOC of the pellet in primary wastewater was around 91% of the culture grown in control. This study confirmed that Scenedesmus sp. can effectively utilize atmospheric CO₂ and can grow in sewage wastewater as well.