Livestock production accounts for a third of total U.S. anthropogenic methane (CH4) emissions. Mitigating these greenhouse gas (GHG) emissions is central to efforts aimed at curbing near-term climate change, but low-cost, practical technologies are needed to reduce fugitive CH4 from farms. Biofilters have mitigation potential, but current designs for odor are limited in their ability to capture CH4. Fungi have been shown to improve capture of hard-to-target gases in other biofilter applications and were investigated here for their ability to capture CH4. Using a lab-scale biofilter, several fungal species were shown to improve CH4 capture compared to a bacterial system and sterile control. A subsequent experiment with Pleurotus ostreatus found capture to increase with increasing levels of fungal biomass. Using a chromatographic isotherm, the ability of fungal materials to sorb CH4 was confirmed, and again greater sorption of CH4 was possible when fungal biomass was increased. These results demonstrate the ability of fungi to capture CH4 and warrant their investigation as a way to improve the CH4 mitigation capacity of livestock emission biofilters.
Bibliographical noteFunding Information:
The authors graciously thank Dr. Raymond Hozalski (University of Minnesota) for his feedback on isotherm experimental design and Dr. Justin Kaffenberger (University of Minnesota) for his analytical support. Funding for this project was provided by the USDA National Institute of Food and Agriculture (USDA/2012-69002-19880) and the USDA-NIFA Mcintire Stennis Project (No. MIN-12-074) at the University of Minnesota.
- Chromatographic isotherm
- Pleurotus ostreatus
- Wood chips