**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** THE GOAL OF THIS SEED PROJECT IS TO STUDY THE CAUSES OF NITROUS OXIDE FORMATION IN BIOFILTERS USED FOR METHANE ABATEMENT OF ENCLOSED LIVESTOCK SYSTEMS. BIOFILTERS ARE A PROMISING SOLUTION FOR MITIGATION OF METHANE EMISSIONS FROM AGRICULTURAL SYSTEMS, BUT THE POTENTIAL GENERATION OF THE POTENT GREENHOUSE GAS NITROUS OXIDE IN THESE BIOFILTERS CAN HINDER THEIR APPLICABILITY. OUR OBJECTIVES ARE TO TEST THE EFFECTS OF (1) THE CONCENTRATION OF AMMONIA IN THE INLET AIR, (2) THE MOISTURE CONTENT, AND (3) THE PACKING MEDIA COMPACTION ON THE BIOFILTER PERFORMANCE AND NITROUS OXIDE FORMATION. OUR CENTRAL HYPOTHESIS IS THAT THESE PROPERTIES HAVE A STRONG INFLUENCE ON THE PRODUCTION OF NITROUS OXIDE IN BIOFILTERS, AND THAT THE UNDERSTANDING OF THESE MECHANISMS CAN HELP US CONTROL THE PRODUCTION OF NITROUS OXIDE IN THE FUTURE. THE RESULTS OF THIS PROJECT WILL ALLOW US TO PROPOSE METHODS TO REGULATE NITROUS OXIDE FORMATION IN METHANE BIOFILTERS AND WILL PROVIDE A STRONG FOUNDATION FOR FUTURE BIOFILTER DESIGNS AND SPECIFICATIONS, WHICH WILL MAKE US COMPETITIVE FOR FUTURE FUNDING TO DEVELOP ECONOMICALLY FEASIBLE METHANE BIOFILTRATION SYSTEMS FOR LIVESTOCK FACILITIES.OUR SYSTEM USES GAS WASTE FROM LIVESTOCK SYSTEMS IN AN ENGINEERED SYSTEM, THE BIOFILTER, THAT COULD BE MADE COMPLETELY FROM BIOBASED MATERIALS AND COMMERCIALIZED IN THE MARKETPLACE. THE MAIN PRODUCT FROM THE BIOFILTERS IS THE METHANE MITIGATION, WHICH IS AN ECOSYSTEM SERVICE WITH AN INCIPIENT, BUT INCREASINGLY RECOGNIZED MARKET. THESE BIOFILTERS WILL CONTRIBUTE TO THE LONG-TERM ECONOMIC AND ENVIRONMENTAL SUSTAINABILITY OF LIVESTOCK PRODUCTION AND PROCESSING SYSTEMS.