Cultivation of Spirulina platensis using NPK-10:26:26 complex fertilizer and simulated flue gas in sintered disk chromatographic glass bubble column

Abstract

A cost effective fertilizer based optimum culture medium was formulated for the mass production of Spirulina platensis using NPK-10:26:26 complex fertilizer in air agitated sintered disk chromatographic glass bubble column and the growth results were compared with the standard Zarrouk’s culture medium. The optimum loadings of NPK-fertilizer and sodium bicarbonate was found to be 0.76 and 10.0gL−1 respectively and corresponding maximum dry biomass concentration with 1.82gL−1 was obtained at the tenth day of biomass growth. Optimally formulated fertilizer medium was then used for the cultivation of Spirulina using simulated flue gas which was similar to diesel generator exhaust. Flue gas was fed to the bubble column reactor in a semi-batch fashion and Spirulina cultivation was carried out using NPK-fertilizer culture medium involving sodium hydroxide. Biomass productivity and CO2 fixation rate was enhanced with the increased loading of sodium hydroxide in the culture medium. Maximum biomass concentration with 1.85gL−1 was obtained at the sixth day of biomass growth when average CO2 solubility was maintained at 4.84gL−1. Finally, flue gas assisted biomass growth using optimum NPK-10:26:26 complex fertilizer medium was compared with standard Zarrouk’s culture medium using sintered disk chromatographic gas bubble column reactor and improved growth results (∼4.0%) with enhanced lipid accumulation (∼5.0%) were obtained using NPK-10:26:26 fertilizer medium as compared to the Zarrouk’s culture medium. An almost 50.0% cost saving was achieved due to the use of low cost NPK-10:26:26 complex fertilizer as a nutrient for Spirulina growth in comparison to standard Zarrouk’s culture medium.