Environmental Tradeoffs of Alternative Scenarios for Swine Waste Management Technologies: A Life Cycle Perspective

Abstract. Pork is one of the largest and most important agricultural industries in North Carolina and the United States but faces a number of challenges in regards to waste management and environmental impact. In the face of increasingly stringent environmental regulations, decreasing land availability, and higher costs for artificial fertilizer, it is necessary to consider alternative technologies with the potential for improving environmental conditions and creating value added products. The primary purpose of this study was to model and evaluate the environmental tradeoffs between current swine waste management practices in North Carolina and alternative scenarios that include new technologies for waste removal, treatment, and nitrogen recovery. Data was collected from swine finishing farms in southeastern NC, laboratory analyses, and bench scale experiments determine biogas generation from anaerobic digestion and nitrogen recovery from an ammonia air stripping column. Multiple scenarios were created to simulate combinations of alternatives for waste removal, waste treatment, storage, nitrogen recovery, and land application. All scenarios were modeled over a one year time period using a “cradle to gate” approach with 1 kg of raw waste as the functional unit. OpenLCA 1.6 was used for inventory construction and scenario analysis while TRACI 2.0 was used to characterize environmental impacts. Implications of these results for broader environmental assessment are discussed. Funding for this project was provided by a grant from Smithfield Swine Production Group.