Date of Graduation


Document Type


Degree Name

Master of Science in Biological Engineering (MS)

Degree Level



Food Science


Yi Liang

Committee Member

Thomas A. Costello

Second Committee Member

Susan E. Watkins


Applied sciences, Health and environmental sciences, Ammonia, Biofilter, Broiler, Heat production, Nitrous oxide, Windrow


Ammonia emission from animal feeding operations (AFOs) has negative effects on environment and animals' health. Thus measuring and mitigating ammonia emission from AFOs is important for environmental protection. In chapter I, different ammonia measurements were discussed and a mitigation technology- biofilter was represented.

In-house windrowing of built-up litter has been used by broiler producers to reduce pathogen loads and rejuvenate litter for the next flock. When litter is piled up for an extended period during downtime, heat generated by the litter pile can become a substantial heat source due to the metabolism of microorganisms. In chapter II, heat production rates of windrowed and non-windrowed litter were calculated. Windrow trials were conducted for five consecutive flocks as litter accumulated from fresh beddings over a year period. Temperatures and relative humidity of the ambient and air inside the commercial houses were continuously recorded with portable loggers during downtime, as well as temperatures of windrowed and un-windowed litter. The specific heat productions were between 0.50 and 1.54 W/kg litter (wet basis) for windrowed litter and 0.63 to 0.89 W/kg litter (wet basis) for non-windrowed litter except for the summer trial. Specific heat production from Non-windrow, Windrow_1 and Windrow_2 are not significantly different (p=0.868).

Biofilter is a technique using biomass to capture and biologically degrade process pollutants. In chapter III, relationships between ammonia removal efficiency (RE) and residence time (RT), ammonia removal and nitrous oxide production, nitrogen transformation, and carbon dynamics were investigated. A laboratory scale biofilter was built and set inside a chicken house. Ammonia, nitrous oxide concentrations from both inlet and outlets were measured. Samples were taken and total nitrogen (N), total carbon (C), ammonium-N, nitrate-N, and nitrite-N were analyzed. Ammonia RE was a linear function (p