2008 Annual Report
1)measurement of a suite of odor compounds in water provides quantitative and accurate assessment of odor reduction by treatment technologies; and.
2)multi-stage treatment systems incorporating biological nitrogen removal can greatly reduce malodorous compounds in liquid swine manure. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Emissions; Problem Area 2: Emission Factors from Livestock Facilities 4. Identification of emerging biological and thermochemical conversion technologies: Analysis and assessment: The use of biological and thermochemical conversion (TCC) technologies in livestock waste-to-bioenergy treatments can provide livestock operators with multiple value-added, renewable energy products. These products can meet heating and power needs or serve as transportation fuels. The primary objective of this work is to assess both established and emerging energy conversion opportunities that can transform the treatment of livestock waste from a liability to a profit center. Based on theoretical considerations and limited experimental data, an evaluation into the direct TCC processing of raw wet wastes such as swine manure determined that catalytic hydrothermal processing could produce more energy than could be produced from either combusting brown coal or anaerobic digestion. This work is the first step for presenting information to livestock operators regarding the various scenarios for integrating current manure management processes with TCC technologies. Successful implementation of TCC technologies as a waste treatment option would not only reduce associated disposal costs, but it would also produce both energy and relatively clean water. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Byproducts; Problem Area 4: Energy from Byproducts. 5. Nitrification treatment adapted to high-ammonia and low-temperatures: Adaptation of nitrification to high nitrogen load and cold weather are important considerations for stabilized performance of biological processes applied to continuous animal production systems. High ammonia-tolerant bacteria were isolated from manure sludges and used to treat concentrated animal wastewater; they enabled fast ammonia removal using aeration treatment without the problem of ammonia volatilization loss. Nitrification activity was not severely affected by low water temperatures (3-5 degrees Celsius). This indicated excellent acclimation to winter conditions. The nitrification culture was used to seed a full-scale plant for swine wastewater; the biological process removed >95% of the ammonia from wastewater containing 1000-2000 parts per million ammonia. Thus, the technology is well suited for nitrification of high-ammonia livestock wastewater under cold weather conditions. The concept of using specialized bacteria cultures for high strength animal wastewaters and cold temperatures is an important finding that provides more economical animal wastewater treatment. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Emissions; Problem Area 2: Emission Factors from Livestock Facilities 6. Molecular biological characterization of microorganisms adapted to high ammonia and low temperature environments: A microbial activated sludge community isolated by Agricultural Research Service scientists, adapted to high nitrogen load and cold weather, and capable of high rates of nitrification, has been characterized for both bench-scale and full-scale systems. This community has shown higher performance levels at cold temperatures (3 to 5 degrees Celsius) than other previously identified microbial communities under similar conditions. Molecular techniques were applied to this community to determine if this performance was due to novel microorganisms or a consortium of microorganisms that have been previously characterized. Over 150 molecular isolates were examined, using a 16S rDNA library and DNA sequencing, and characterized into 18 bacterial phylotypes. While these phylotypes correspond to previously characterized microorganisms, their interactions as part of the same community have not been previously reported. It is these community interactions of this microbial population that serve as the basis for the enhanced wastewater treatment capabilities under cold weather and high ammonia levels. This finding will help in the development of even more economical animal wastewater treatment systems. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Emissions; Problem Area 2: Emission Factors from Livestock Facilities. 7. Capture, concentration and reuse of phosphorus materials from manure: Two new treatment processes have been developed to recover phosphorus (P) from manure in concentrated solid form. One of these new treatments recovered P from liquid pig manure while the other new process extracted and recovered P from poultry litter. Soil fertility tests using ryegrass showed that both recovered P sources were an excellent slow release phosphorus fertilizer. Ryegrass dry matter yields obtained using recovered P were similar to commercial triple superphosphate. The recovery of P from both liquid pig manure and poultry litter is useful for solving distribution problems of excess manure P in soils, and it allows significant amounts of this nutrient to be recycled. The results are of significance for the fertilizer industry and farmers because the recovered P can be transported off the farm in concentrated form and recycled as plant fertilizer. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Byproducts; Problem Area 1: Phytoavailability and Bioavailability of Nutrients, Trace Elements and Xenobiotics in Byproducts Considered for Beneficial Use. 8. Riparian buffers are used extensively to protect water bodies from nitrogen pollution: There is relatively little information on the impact of riparian buffers on production of nitrous oxide. This research assessed nitrous oxide production in riparian buffers of the southeastern Coastal Plain from three different aspects. The first assessment was via denitrification enzyme activity (DEA) measured by the acetylene inhibition method. Using this technique, the soil carbon/nitrogen ratios >25 soil were found to be a controlling factor in nitrous oxide production. The second assessment was via soil microbial composition. Molecular techniques were used to compare the composition of bacterial communities in four riparian buffers with different DEA values. The clone libraries of 16S rDNA genes were constructed, and phylogenetic analyses were performed. A total of 350 clones from four sites, ranging from low to high DEA levels, were analyzed. The predominant bacterial divisions present in all four 16s rDNA libraries belonged to the alpha, beta, and gamma subdivisions of the phylum Proteobacteria. The phylum Acidobacteria was also well represented amongst all four sites. The third assessment directly assessed nitrous oxide emission using a static chamber technique with a photoacoustic multi-gas analyzer. Nitrous oxide emissions were assessed in the context of soil characteristics along with emissions of ammonia, carbon dioxide, and methane. Nitrous oxide emissions were only significant when the soil was spiked with nitrate. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Nutrient Management; Problem Area 3: Management Tools for Indexing and Evaluating Nutrient Fate and Transport. 9. Bioenergy production potential from Coastal bermudagrass receiving advanced-treated swine wastewater: Coastal bermudagrass has routinely been incorporated as part of a manure management plan that receives the nutrients and water in the liquid fraction of swine lagoons through irrigation. Subsurface drip irrigation (SDI) with treated swine manure effluent provides a means to irrigate future bioenergy crops without excessively overloading the crops with nutrients. Agricultural Research Service scientists examined the effect of subsurface drip irrigation with both commercial fertilizer and advanced-treated swine wastewater to meet nitrogen and water demands on both the quantity and quality of bermudagrass bioenergy production. Relative to commercial nitrogen fertilizer, the least biomass energy density was associated with bermudagrass receiving treated swine wastewater. Yet, this bermudagrass exhibited marked increases, between 10 and 28%, in both hay and energy yields per ha. The decrease in energy density of wastewater irrigated grass could be attributed to increased concentrations of potassium, calcium, and sodium. After thermal conversion, these compounds are known to remain in the ash portion thereby decreasing the energy density. Nonetheless, the loss of energy density using treated effluent via SDI may be offset by the positive influence of these three elements for their catalytic properties in downstream thermal conversion processes such as promoting a lesser char yield and greater combustible gas formation. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Byproducts; Problem Area 4: Energy from Byproducts. 10. Enhance removal of ammonia and odor from the air of animal houses: Reducing ammonia emission from livestock facilities is an important issue for many communities and livestock producers. Additionally, ammonia and hydrogen sulfide may adversely affect the health of animals and humans. Agricultural Research Service (ARS) scientists evaluated the effectiveness of a specially designed synthetic biofilter medium, activated carbon particles coated with polyvinyl alcohol gel (PVA), for removing ammonia and hydrogen sulfide from livestock facilities. The PVA biofilters required significantly lower energy to push the air through the biofilter than widely used compost biofilters. Even though ARS scientists also discovered that the PVA biofilters produced small quantities of a greenhouse gas nitrous oxide, the biofilters removed most of ammonia (80%) and hydrogen sulfide (97%). This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Nutrient Management; Problem Area 3: Management Tools for Indexing and Evaluating Nutrient Fate and Transport. 11. Applications of water treatment residuals can significantly reduce soil phosphorus (P) concentrations: Annually, the USA produces millions of tons of agricultural, industrial, and municipal byproducts that are viewed as waste material. Many of these byproducts have physical and chemical properties that make them potentially useful as soil amendments to correct soil nutrient imbalances. Water treatment residuals (WTRs) are a byproduct produced during the drinking water purification process. It was shown that WTRs mixed into soils with high P concentrations can significantly sequester and convert soluble P into insoluble P form, thus lowering the potential for off-site movement of this nutrient. Prior to these studies, little information was available on the potential benefit of application of WTRs to land. These results have provided state regulators and water work managers with critical information to plan and make decisions regarding WTRs use as a soil amendment. This project helps solve problems of National Program 206: Manure and Byproduct Utilization; Component: Byproducts; Problem Area 3: Byproduct Utilization Technologies.
5.Significant Activities that Support Special Target Populations
Cooperative research with North Carolina A&T State University.
Ro, K.S., Cantrell, K.B., Elliott, D., Hunt, P.G. 2007. Catalytic wet gasification of municipal and animal wastes. Industrial and Engineering Chemistry Research. 46:8839-8845.
Cantrell, K.B., Ro, K.S., Mahajan, D., Anjom, M., Hunt, P.G. 2007. Role of thermochemical conversion in livestock waste-to-energy treatments: Obstacles and opportunities. Industrial and Engineering Chemistry Research 46(26):8918-8927.
Hunt, P.G., Matheny, T.A., Ro, K.S. 2007. Nitrous oxide accumulation in soils from riparian buffers of a Coastal Plain watershed - Carbon/nitrogen ratio control. Journal of Environmental Quality. 36(5):1368-1376.
Novak, J.M., Szogi, A.A., Watts, D.W., Busscher, W.J. 2007. Water treatment residuals amended soils release Mn, Na, S and C. Soil Science. 172(12):992-1000.
Ro, K.S., Hunt, P.G., Poach, M.E. 2007. Wind-driven surficial oxygen transfer. Critical Reviews in Environmental Science and Technology. 37:539-563.
Cantrell, K.B., Ducey, T.F., Ro, K.S., Hunt, P.G. 2008. Livestock waste-to-bioenergy generation opportunities. Bioresource Technology. 99:7941-7953.
Cantrell, K.B., Chastain, J.P., Moore, K.P. 2008. Geotextile filtration performance for lagoon sludges and liquid animal manures dewatering. Transactions of the ASABE 51(3):1067-1076.
Garcia, M.C., Vanotti, M.B., Szogi, A.A. 2008. Simultaneous separation of phosphorus sludge and manure solids with polymers. Transactions of the ASABE 50(6):2205-2215. Ro, K.S., Szogi, A.A., Vanotti, M.B., Stone, K.C. 2008. Process model for ammonia volatilization from anaerobic swine lagoons incorporating varying wind speeds and gas bubbling. Transactions of the ASABE 51(1):259-270.
Szogi, A.A., Vanotti, M.B. 2007. Abatement of ammonia emissions from swine lagoons using polymer enhanced solid-liquid separation. Applied Engineering in Agriculture 23(6):837-845.
Vanotti, M.B., Szogi, A.A., Vives, C.A. 2008. Greenhouse gas emission reduction and environmental quality improvement from implementation of aerobic waste treatment systems in swine farms. Journal of Waste Management. 28:759-766.