Master of Science in Biological and Agricultural Engineering (MSBAE)
Biological and Agricultural Engineering
Over application of phosphorus and the loss of ammonia-nitrogen to runoff and volatilization have resulted in the buildup of phosphorus in agricultural top soils around the world, and especially in the United States. Over the past few decades, raising livestock has trended towards the development of the Confined Animal Feeding Operations (CAFO’s) which produce large volumes of wastes that need to be treated before being land applied. Nutrient treatment systems have typically focused on one nutrient singularly: either nitrogen or phosphorus. In order to develop a total nutrient system a phosphorus and nitrogen system had to be developed and evaluated before combining them to represent a complete system. A pilot phosphorus treatment system consisting of hydrated lime precipitation treatment was evaluated on both an alligator ranch and a dairy parlor research station. An 88% reduction of total phosphorus in the alligator raising pen wastewater was achieved and a 99% reduction of total phosphorus was achieved in the dairy parlor wastewater. The system added $0.00197/gal-year when treating the alligator wastewater and added $0.00033 /gal-year when treating the dairy parlor wastewater. A pilot nitrogen treatment system consisting of a nitrification reactor utilizing rice hulls as the bacterial growth media was developed at the lab scale before eventually being implemented in a field scale nutrient treatment system. The lab scale results showed 50% ammonia oxidation occurring at 30-hrs, 48-hrs, and 48-hrs after commencement of the three experiments. They were encouraging enough to continue on to total nutrient treatment system development. A total nutrient treatment system was designed to both remove phosphorus and to keep usable nitrogen in the wastewater. A 99% reduction in total phosphorus was achieved in a matter of hours and 50% oxidation of the total ammonia was achieved in 5-days and 4-days of treatment in each field-trial. The total treatment system had the potential to save $2,500 annually in nitrogen kept in solution and not lost to volatilization and added $1.78 /cow-year in phosphorus recovery through the hydrated lime treatment.
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Davis, Troy Francis, "Development of a total nutrient treatment system for alligator and dairy parlor wastewater using hydrated lime and organic bacterial growth media" (2011). LSU Master's Theses. 2516.
Sheffield, Ronald E.