Studies of CO2 Sequestration by Anabaena Viriabilis in Stirred Tank batch type Photobioreactor

Abstract

Global warming is posing serious threat to our environment. Malignant manifestations of this phenomenon are weather extremities, rise in sea levels, annihilation of species, glaciers‘ retreat, and similar other calamities. Increasing amount of carbon dioxide (CO2) gas is mainly responsible for global warming. Although chemical methods are currently being employed, but rays of hope lies with biological methods only to curb increasing CO2 concentration. Currently large scale use of biological method is still subject to research. However with improving photobioreactor design and identification of promising strains (of microalgae and cyanobacteria) has strengthen the confidence of researchers. Microalgae and cyanobacteria are most suitable candidates to serve the cause as they are able to capture solar energy and CO2 with an efficiency of 5-10 times greater than that of higher plants. This technique can help mitigate global warming and produce a large number of value-added products like pigments, carotenoids, proteins, carbohydrates, lipids, biodiesel etc. This dissertation describes the effectiveness of Anabaena viriabilis, used in a photobioreactor at different CO2 concentration i.e. 0.04%, 5%, 7.5%, 10%, 12.5%, and 15%, in BG (-N) 11 media with 10% (of total media volume) inoculum. CHNS analysis has shown that with increasing CO2 concentration the composition of cyanobacteria in regard with carbon varies. At 10% CO2 concentration all the kinetic parameters as well as total CO2 fixed and fixation rate were found maximum. The pH and CO2 concentration for this culture were also optimized.