Carbon dioxide assisted Spirulina platensis cultivation using NPK-10:26:26 complex fertilizer in sintered disk chromatographic glass bubble column

• Spirulina platensis cultivation using NPK-10:26:26 complex fertilizer and CO2.
• Spirulina growth using sintered disk chromatographic glass bubble column.
• Biological conversion of 100% CO2.
• Bubble size distribution and mass transfer effects.
• Estimation of chlorophyll, protein and lipid in Spirulina biomass.

A cost effective fertilizer based optimum culture medium was formulated for the cultivation of Spirulina platensis using NPK-10:26:26 complex fertilizer in CO2-agitated sintered disk chromatographic glass (SDCG) bubble column and the growth results were compared with the standard Zarrouk's culture medium. To formulate optimum culture medium, biomass growth was carried out under varying NPK-10:26:26 complex fertilizer and sodium bicarbonate using air-agitated SDCG-bubble column. Optimally formulated fertilizer medium was then used to cultivate biomass using CO2–air mixture which was fed to the column in a semi-batch fashion. To maintain desired alkalinity in the NPK fertilizer culture medium, S. platensis was cultivated using sodium hydroxide (NaOH). Effect of CO2 and NaOH loading on biomass growth was also studied and 100% CO2 with 8.4 g l−1 NaOH yields maximum biomass concentration with 1.83 g l−1 at the fourth day (96 h), whereas 20% and 50% CO2 loading with 8.4 g l−1 NaOH yields maximum biomass concentration of 1.82 g l−1 and 1.80 g l−1 at fifth day (120 h) and sixth day (144 h) respectively. An enhancement of biomass growth rate, CO2 fixation rate, and protein–lipid accumulation in biomass was also taken place using CO2-assisted biomass growth in SDCG-bubble column as compared to air-agitated bubble column using NPK fertilizer and sodium bicarbonate.