Impact of Media Properties on Biofiltration Efficiency for Reducing Greenhouse Gas Emissions in Livestock Operations
Research Poster Engineering 2025 Graduate ExhibitionPresentation by Johannes Ali
Exhibition Number 138
Abstract
The agricultural sector contributes 18% of global greenhouse gas emissions, with methane and nitrous oxide being the primary culprits, accounting for 98% of these emissions. Enteric fermentation in livestock is the leading source of methane. While methane can be used as an energy source, its low concentrations in livestock facilities make this approach impractical. Instead, biofiltration systems that use microorganisms to metabolize methane into carbon dioxide offer a promising alternative for reducing greenhouse gas emissions. This study focuses on factors affecting the microbial communities responsible for methane oxidation and their role in biofiltration efficiency. Two important factors that influence methane oxidation are moisture content and pH level in the biofilter media. In the initial batch experiments, compost samples at different pH moisture levels were exposed to low concentrations of methane. The gas composition was measured over time and analyzed using logarithmic transformation and linear regression. Non-parametric tests, including the Kruskal-Wallis and post hoc Dunn tests, were used for comparison. Preliminary results suggest that moisture content does not show a linear relationship with methane oxidation rate as excessive moisture may hinder methane breakdown by reducing pore space in the compost, limiting diffusion and the interaction between methane and methane-oxidizing enzymes. Additionally, pH levels diverting from neutral pH decreased methane oxidation and low pH increased nitrous oxide production These findings emphasize the importance of optimizing pH and moisture levels in biofilter media for efficient methane oxidation, improving the overall performance of biofiltration systems for GHG mitigation in agriculture.
Importance
This research is crucial because the agricultural sector is a major source of methane emissions. Finding effective ways to reduce methane emissions from livestock operations is critical for meeting global climate goals. Biofiltration systems are a potential solution by using microorganisms to convert methane into carbon dioxide, which is less harmful to the environment. However, to improve these systems, it is essential to understand the factors that influence the efficiency of methane breakdown, such as moisture content and pH levels in the biofilter material. Studying how these factors affect microbial activity helps identify conditions which maximize methane oxidation in biofilters. This knowledge is key to improving the performance of biofiltration systems and reducing the environmental impact of agriculture.