Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/29/2005
Publication Date: 7/9/2007
Citation: Vanotti, M.B., Szogi, A.A., Hunt, P.G., Millner, P.D., Humenik, F.J. 2007. Development of environmentally superior treatment system to replace anaerobic swine lagoons in the usa. Bioresource Technology 98:3184-3194.
Interpretive Summary: A new method invented by Agricultural Research Service (ARS) scientists and collaborators for treating swine-production wastewater may benefit swine producers and the environment alike. The treatment system performs three critical processes in animal-waste management: It separates solids and liquids from swine wastewater while recovering organic matter; it removes ammonia from wastewater using adapted nitrifying; and it transforms phosphorus removed from wastewater into a solid, marketable fertilizer, while converting leftover effluent into a sanitized liquid used to clean swine houses and for crop irrigation. A full-scale version of the system was installed on a 4,400-head swine-finishing facility in North Carolina and evaluated during one year. Its construction and demonstration was part of an agreement between Smithfield Foods, Premium Standard Farms, and the North Carolina Attorney General's office to use environmentally superior technology to replace current waste lagoons. The researchers tested the system’s ability to eliminate animal-waste discharge--along with related release of ammonia, odor, and pathogens--to surface and ground waters. They also evaluated its ability to stem soil and groundwater contamination by nutrients and heavy metals. The system removed more than 97 percent of total suspended solids from wastewater during the tests. It stripped the water of 95 percent of total phosphorus, 99 percent of its ammonia, 98 percent of its copper, 99 percent of its zinc, more than 99 percent of its biochemical oxygen demand, and more than 97 percent of its odor-causing components. The reduction in fecal microorganisms achieved in this system resulted in disinfected effluent. It was verified--at full-scale--that the system is technically and operationally feasible. These findings overall showed that cleaner alternative technologies can have significant positive impacts on the environment and the livestock industry.
Technical Abstract: A full-scale treatment system for treatment of swine manure was developed to eliminate discharge to surface and ground waters and contamination of soil and groundwater by nutrients and heavy metals, along with related release of ammonia, odor, and pathogens. The system greatly increased the efficiency of liquid-solid separation by polymer injection to increase solids flocculation. Nitrogen management to reduce ammonia emissions was accomplished by passing the liquid through a module where bacteria transformed ammonia into harmless nitrogen gas. Subsequent alkaline treatment of the wastewater in a phosphorus module precipitated phosphorus and killed pathogens. Treated wastewater was recycled to clean swine houses and for crop irrigation. The system was tested during one year in a 4,400-head finishing farm as part of the Agreement between swine producers Smithfield Foods, Premium Standard Farms, and Frontline Farmers, and the Attorney General of North Carolina to replace current waste treatment anaerobic lagoons with environmentally superior technology. The on-farm system removed 97.6% of the suspended solids, 99.7% of BOD, 98.5% of TKN, 98.7% of ammonia, 95% of total P, 98.7% of copper and 99.0% of zinc. It also removed 97.9% of odor compounds in the liquid and reduced pathogen indicators to non-detectable levels. Based on performance obtained, it was determined that the treatment system met the Agreement’s technical performance standards that define an environmentally superior technology. These findings overall showed that cleaner alternative technologies are technically and operationally feasible and that they can have significant positive impacts on the environment and the livestock industry.