Enhanced olivine dissolution in the presence of marine and freshwater microalgae | Poster Board #529

Enhanced silicate dissolution (ESD) has been recently identified as a potential strategy for the sequestration of CO₂ from the atmosphere by applying crushed minerals to aquatic systems. Few reports have quantitatively examined ESD in the presence of eukaryotic microalgae. In this study, the interaction of olivine with a selection of eukaryotic freshwater and marine microalgal species and their impact on the dissolution of crushed olivine have been examined. Growth and chlorophyll fluorescence measurements demonstrated variable impacts of crushed olivine on cell growth and chlorophyll production for the selected species of microalgae with both slowed and accelerated growth rates observed. Olivine dissolution was evaluated by analyzing the Mg²⁺ content in growth media and microalgal biomass using Inductively Coupled Plasma Optical Emission spectroscopy (ICP-OES) and compared with that of control olivine in the absence of microalgae. During the initial phase of the experiment (0 – 5 days), modest increases in Mg²⁺ released per unit biomass and time were observed for crushed olivine in the presence of several microalgal species relative to the crushed olivine control. The findings of this study are presented to support further evaluation of microalgae as CO₂ sequestration enhancing agents.