Dr. Izuru Sennaha
Associate Professor, Energy and Environment Engineering Course, University of the Ryukyus, Japan.

Speech title: Development of Macro algae Cultivation as Marin Biomass Resources Using Carbon Dioxide dissolved in seawater and Surrounding Flow

Abstract: In our laboratory, we are conducting research on cultivation method of marine algae from the engineering view, utilizing the findings that have been engaged in research on heat and mass transfer in the Faculty of Engineering. Currently, we are conducting research on the following two themes. First, to cultivate algae using seawater in which carbon dioxide is dissolved. Second, about influence of flow field around the algae. The flow field plays an important role when algae absorb CO₂ and nutrients necessary for growth from seawater. In this study, we investigated the effects of the macro algae cultivation using carbon dioxide dissolved seawater and surrounding flow on the growth of the promising Gracilaria tikvahiae as a biomass resource. According to the results of the recent study, the highest growth of G. tikvahiae was obtained with high concentration carbon dioxide (1%), which was 28 times the normal condition. As a result, the current velocity of seawater is playing an important role in the exchange of the materials surrounding seaweed. The study confirmed that growth of Gracilaria tikvahiae is promoted by an appropriate flow rate and that as high the current velocity will be as more inhibition growth can be. From these viewpoints, this study introduce some experiment results on the growth of algae and the influence of the flow related to mass transfer including CO₂.