Improving anaerobic digester performance through microaeration

PI: Neslihan Akdeniz


Akdeniz is an assistant professor and extension specialist in the Department of Biological Systems Engineering at UW–Madison. Her research interests include livestock and poultry environments, manure management and nutrient utilization, and diseased animal tissue containment strategies.

Graduate student (pictured above): Ellie Froelich received her bachelor’s degree in biological systems engineering from the UW–Madison. As an undergraduate she gained a breadth of experience in sanitation procedures, assessing water quality, and extracting DNA, RNA, and NA as well as preforming PCR tests. Froelich is currently pursuing a master’s degree in biological systems engineering.

Anaerobic digestion is the process of microbial decomposition of organic substances, including dairy manure, in the absence of oxygen. Anaerobic digestion is an effective tool but is too costly for many farms largely due to the ongoing high maintenance costs driven by corrosion from reduced sulfur contamination of the gas. Due to its toxicity and adverse effects to equipment, it is critical to remove hydrogen sulfide from biogas. One low-cost method to remove hydrogen sulfide from biogas is to create a microaerobic environment in the anaerobic digestion reactor. This process allows sulfur oxidizing bacteria, already present in the digester, to oxidize the hydrogen sulfide effectively using it as an energy source. This project aims to create steady state AD systems with a variety of microaerobic conditions that facilitate biological sulfur oxidation. The outcomes of this study aim to increase understanding of the fundamentals of this process and gain knowledge related to optimizing these systems.

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