Student: Hannah Molitor, PhD student in Environmental Engineering, University of Iowa
Faculty Advisor: Dr. Jerald Schnoor
Microalgae as Animal Feed to Recover Nutrients and Treat Power Plant Emissions
Conventional agriculture places significant demands on natural resources and is generally inefficient. As organisms with tolerance for varied conditions, microalgae (single-cell photosynthetic microorganisms) are a promising alternative to conventionally grown soy for more rapidly and sustainably produced protein-rich animal feed. Microalgae can use carbon dioxide from combustion emissions and the nutrients from wastewater to produce biomass. However, there are significant barriers to growing nutritious salable microalgae, recovering nutrients from wastewater, and fixing carbon dioxide from power plant emissions in full-scale sustainable operations, which my research seeks to address. Specifically, I use a photobioreactor (vessel to grow microorganisms that use light for energy) to cultivate Scenedesmus obliquus, a nutritious green microalga. My first publication showed that this species can tolerate the high carbon dioxide levels characteristic of power plant or industrial emissions while maintaining favorable protein contents and amino acid profiles. My subsequent publications focused on enhancing microalgal growth rates and harvestability by leveraging the sulfur in combustion emissions, and safely growing microalgae with toxic gases. My current work addresses microalgal growth on wastewaters and energy-efficient harvesting of microalgal biomass from its culture media. Successful scale-up of this research could reduce fertilizer and freshwater resources use, offset wastewater treatment costs, and mitigate greenhouse gas emissions.