Microalgae: potential agents for CO2 mitigation and bioremediation of wastewaters

Abstract Microalgae have the potential to clean up a polluted environment, owing to their CO2 fixation and organic reduction capabilities. It is estimated that about 1.83 kg of CO2 gets converted to 1 kg of dry algal biomass under ideal conditions. Thus, microalgae provide an effective solution for carbon capture in a sustainable manner. Carbon capture and storage using microalgae is considered a promising alternative to many existing CO2 abatement strategies mainly due to its advantage of generating carbon credits. Photoautotrophic microalgal species can used to fix CO2 present in flue gases generated at power plants or other emission sources. The key challenge to the generation of algal biomass on a large scale includes requirement of huge volumes of water. Use of wastewater streams can reduce the need for freshwater substantially, sometimes even by over 90%. The organic matter as well as the inorganic salts available in the effluents act as nutritive substrate for microalgal growth. Due to this nutrient removal efficiency, microalgae provide an additional advantage of wastewater remediation. Presently, the importance of microalgae based simultaneous air and wastewater treatment technology is increasing due to its economic and eco-friendly nature.