Thesis Archive
Carbon Dioxide Utilization and Biomass Productivity of Spirulina Platensis in Bicarbonate-Based Integrated Carbon Capture and Algae Production System
Batac, Christelle Paula C.
Gathercole, Nadeine S.
Maravilla, Ana Katrina F.
Abstract:
Carbon capture sequestration (CCS) is an emerging study that effectively reduces carbon dioxide emissions through capture and storage. However, due to the increase in cost of carbon capture, transportation, and storage, further modifications were done on the method in order to lessen the expenses for carbon capture. One method is through the use of microalgae under Bicarbonate-based Integrated Carbon Capture and Algae Production System (BICCAPS) which simultaneously lessens carbon dioxide emissions and converts this to biomass as an alternative source of energy. In this study, culture conditions for Spirulina Platensis were manipulated, namely culture media and bicarbonate loading, in order to achieve ideal biomass productivity and carbon dioxide utilization. S. Platensis was cultivated in open system conditions under three culture media, namely modified Zarrouk’s, NPK-based media, and NPK-based media with A5 solution, which produced biomass productivities of 11.19, 11.00, and 22.08 mg L-1 day-1, respectively. The system was allowed to grow in each media for 31 days which resulted to evident stationary phases in the three systems. These systems were then utilized for further cultivation under carbon capture method. In BICCAPS, 0.1M bicarbonate salts were used as carbon sources, namely NaHCO3, KHCO3, and an equimolar mixture of NaHCO3-KHCO3, for S. Platensis under the three culture media specified. Analysis for biomass productivities, maximum specific growth rate, and inorganic carbon conversion were obtained in order to identify the efficiency of the bicarbonate salts to the growth of the microalgae. Under BICCAPS, results show that the control systems of each medium yielded the highest biomass productivities with values of 10.42, 10.51, and 10.81 mg L-1 day-1; however, these systems also produced the lowest inorganic carbon conversion, generating values of 0.292, 0.250, and 0.220 mM day-1. Excluding the control systems, it was observed that equimolar mixture of NaHCO3-KHCO3 in Zarrouk’s medium was the most suitable system to be used for S. Platensis, garnering a maximum biomass productivity of 7.37 mg L-1 day-1, maximum specific growth rate of 0.0703 day-1 and inorganic carbon conversion of 4.192 mM day-1.
Adviser:
Beltran, Arnel B.