2007 Annual Report
Manure Treatment System Erases Greenhouse Gases: Less greenhouse gas—and more carbon credits per pig—are the latest environment-friendly benefits being credited to an innovative hog waste-management system invented by Agricultural Research Service scientists at Florence, SC. The ARS researchers found that replacing conventional anaerobic lagoon practices with the new aerobic waste management system reduced greenhouse gas emissions by 97 percent. It cut annual emissions from 4,972 tons of carbon dioxide (CO2) equivalents to just 153 tons. This indicates the system may have a role in the fledgling CO2 trading market, which allows farmers to earn money based on how much carbon dioxide and other greenhouse gases they can prevent from entering the atmosphere using alternative technologies. The earned carbon credits can help alleviate installation costs associated with cleaner aerobic systems and facilitate producer adoption of environmentally superior technologies to replace current anaerobic lagoons in the USA. This research contributes to the goals of Problem Area 2, 'Innovative Technology for Collection, Storage, and Treatment' under the Nutrient Management Component of National Program 206.
Wastewater Treatment System with Simultaneous Separation of Phosphorus and Manure Solids: Scientists at ARS Florence invented a new wastewater treatment system and processes for removal of solids, pathogens, nitrogen, and phosphorus from municipal and agricultural wastewater that include the simultaneous separation of solids and phosphorus from wastewater and industrial effluents. A U.S. Patent Application (S.N. 11/820,396) was filed June 19, 2007. The system has been successfully demonstrated full-scale in a swine farm in North Carolina. The combined separation process is more efficient in terms of equipment needs and chemical use. Thus, it reduces installation and operational cost of manure treatment, which will greatly help with adoption of the new treatment technology by swine producers. This research contributes to the goals of Problem Area 2, 'Innovative Technology for Collection, Storage, and Treatment,' under the Nutrient Management Component of National Program 206.
Greenhouse Emissions from Riparian Buffers: Riparian buffers are used throughout the world for the protection of water bodies from nonpoint source pollution, particularly nitrogen. Yet, this water quality protection has the potential of causing air quality degradation from the production of nitrous oxide. We discovered that soil C/N ratios (>25) reduced the potential for nitrous oxide production. We initiated photoacoustic measurements of the actual nitrous oxide emission vs. soil carbon/nitrogen (C/N) ratios to determine if the soil C/N was an easily measured and widely applicable parameter for identification of hot spots of actual nitrous oxide emissions from riparian buffers. Initial results suggest that the actual emissions may be lower than the potential nitrous oxide production. This research contributes to the goals Problem Area 1, 'Understanding the Biological, Chemical, and Physical Mechanisms Affecting Emissions,' and Problem Area 3, 'Control Technologies and Strategies for Emissions,' under the Atmospheric Emissions Component of National Program 206.
Improved Process Model for Ammonia Emission from Treatment Lagoons Under Varying Wind Speeds and Gas Bubbling: Existing mathematical models are severely limited in accuracy for predicting ammonia volatilization from livestock treatment lagoons. We improved process modeling performance by adding two original components:.
Destruction of Hormones Using a Green Oxidant: Hormones in wastewater effluent are an emerging problem for both agriculture and municipalities. We investigated the possibility of destroying these hormones with new green catalyst TAML Activators. TAML is short for iron tetra-amido macrocyclic ligand. The TAML activators were invented by a Carnegie Mellon University scientist. We have evaluated their usefulness under a Materials Transfer Agreement. The research has been conducted collaborative with the ARS in Fargo, North Dakota. The TAML activators were very effective in rapidly destroying all forms of estrogen. There were no deleterious intermediates or byproducts. Initial results suggest the destruction will also be effective in actual wastewater. This research contributes to the goals of Problem Area 4, 'Holistic Treatment Technologies for Nutrients, Pathogens and PACs' under the Pathogens and Pharmaceutically Active Compounds (PACs) Component of National Program 206.
Abatement of Ammonia Emissions from Swine Lagoons Using Solid-Liquid Separation: Substantial abatement of ammonia emissions can be obtained when swine lagoons are retrofitted with a high-rate solid-liquid separation technology. Annual ammonia emissions were reduced in a lagoon with prior solid-liquid separation by 70% with respect to those of the traditional anaerobic lagoon. These results demonstrate that solid-liquid separation technologies can substantially reduce ammonia emissions from swine production operations. This research contributes to the goals of Problem Area 2, 'Innovative Technology for Collection, Storage and Treatment' and Problem Area 3, 'Control Technologies and Strategies for Emissions,' under the Nutrient Management Component and Atmospheric Emissions Component, respectively, of National Program 206.
Bacteria Propel Gains in Ammonia Removal: Using an innovative bacterial process, ARS scientists are paving the way for new, cost-efficient and large-scale methods of removing ammonia from livestock wastewater. In tests with anammox -- a technology that uses rare anaerobic bacteria to convert nitrite and ammonium to harmless dinitrogen gas -- the scientists have scored noteworthy results. They are the first researchers to isolate from animal wastewater the planctomycetes bacteria used in the anammox process. They have also highlighted anammox's commercial potential by removing nitrogen from wastewater at rates higher than those achieved with conventional methods and lower cost. This finding can be of significant importance to farming systems because excess ammonia in modern, industrial-type livestock production is a global problem, and the use of conventional biological nitrogen removal methods is usually hindered by operational cost, which can be lowered four-fold with the anammox process. This research contributes to the goals of Problem Area 2, 'Innovative Technology for Collection, Storage, and Treatment,' under the Nutrient Management Component of National Program 206.
Denitrification Enzyme Activity in Swine Lagoons: Establishing the mechanisms of nitrogen cycling in livestock wastewater lagoons is important both to understanding current practices and to advancing treatment technology. Recent publications of high levels of di-nitrogen emissions and high levels of potential surficial oxygen transfer indicated that large amounts of nitrogen may be removed via denitrification in anaerobic lagoons. If this denitrification is occurring via classical denitrification, the denitrification enzyme levels should be correspondingly high. We measured denitrification enzyme activity (DEA) in eight lagoons with varying loads of swine wastewater. A university research lagoon had moderately high levels of DEA. However, the commercial lagoons had surprisingly low DEA. These results suggest that di-nitrogen may be produced at different levels and by different mechanisms in different lagoons. This research contributes to the goals of Problem Area 1, 'Understanding the Biological, Chemical, and Physical Mechanisms Affecting Emissions,' and Problem Area 2, 'Innovative Technology for Collection, Storage, and Treatment,' under the Atmospheric Emissions Component and Nutrient Management Component, respectively, of National Program 206.
Wet Gasification of Animal and Municipal Wastes for Energy Generation and Waste Treatment: We investigated the applicability of the new wet gasification technology to treat and harness energy from animal and municipal wastes. Based on theoretical considerations and limited experiments with dairy manure wet gasification, we project that wet wastes such as swine manure and sewage sludge could be fed directly into a wet-gasifier. They would produce more energy than combusting the same amount of brown coal. The costs of a conceptual first generation wet gasification manure management system for a model swine farm were significantly higher than that of traditional anaerobic lagoon systems. However, there are many significant environmental advantages of the wet gasification:.
Recovery and Reuse of Phosphorus Materials: Recycling and reuse of phosphorus (P) is becoming important for both the fertilizer industry and farmers because world phosphorus reserves are limited. Phosphorus materials were recovered from the full-scale wastewater treatment plant using the NC approved Environmentally Superior Technology (EST). Leaching soil column studies with and without cotton plants showed that P availability was similar when soil was fertilized with commercial triple superphosphate (TSP), broiler litter, or recovered P material. Movement of soil P below the depth where fertilizer materials were placed (15-cm depth) occurred only for soil columns with TSP treatment. Results suggest the recovered P from swine wastewater can be useful as a readily available P fertilizer for cotton but less prone to leaching than commercial TSP. This research contributes to the goals of Problem Area 3, 'Byproduct Utilization Technologies,' under the Byproducts Component of National Program 206.
Research continues on two Specific Cooperative Agreements with North Carolina A&T State University. Additionally, several students interacted with customers/stakeholders at an ARS Customer Workshop held in Florence, South Carolina.
Ro, K.S., Hunt, P.G. 2006. A new unified equation for wind-driven surficial oxygen transfer into stationary water bodies. Transactions of the American Society of Agricultural and Biological Engineers. 49(5):1615-1622.
Loughrin, J.H., Szogi, A.A., Vanotti, M.B. 2006. Reduction of malodorous compounds from liquid swine manure by a multi-staged treatment system. Applied Engineering in Agriculture. 22(6):867-873
Ro, K.S., Hunt, P.G. 2007. Characteristic wind speed distributions and reliability of the logarithmic wind profile. Journal of Environmental Engineering. 133(3):313-318.
Ro, K.S., Hunt, P.G., Poach, M.E. 2006. Wind-driven surficial oxygen transfer and dinitrogen gas emission from treatment lagoons. Journal of Environmental Science and Health. 41:1627-1638.
Poach, M.E., Hunt, P.G., Reddy, G.B., Stone, K.C., Johnson, M.H., Grubbs, A. 2007. Effect of intermittent drainage on swine wastewater treatment by marsh-pond-marsh constructed wetlands. Ecological Engineering 30:43-50.
Shappell, N.W., Billey, L.O., Forbes, D., Poach, M.E., Matheny, T.A., Reddy, G.B., Hunt, P.G. 2007. Estrogenic activity and steroid hormones in swine wastewater processed through a lagoon constructed-wetland system.. Environmental Science and Technology 41(2):444-450.
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.