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United States Department of Agriculture

Agricultural Research Service

2008 Annual Report

1a.Objectives (from AD-416)
Develop and evaluate environmentally superior technologies to prevent off-farm release of nutrients and to reduce pathogens, odors, and ammonia emissions. Develop information and technologies to enhance or retrofit existing manure treatment systems to help producers meet environmental criteria (nutrients, emissions, and pathogens). Improve and refine constructed natural treatment technologies to effectively manage nutrients including reducing emissions of ammonia and nitrous oxide. Develop and evaluate new and improved technologies that concentrate/sequester nutrients from manures or create value added products including conversion of livestock waste to energy. Evaluate swine wastewater treatment systems that can be used to reduce emissions, manage nutrients, and control pathogens on small farms. Develop cooperative activities as needed to conduct the research.

1b.Approach (from AD-416)
This research will take a synergistic approach towards developing more effective animal waste treatment practices and holistic systems to solve these problems. Four complementary approaches will be pursued. First, environmentally superior technologies and combination of technologies will be developed and evaluated to prevent off-farm release of nutrients and to reduce pathogens, odors, and ammonia emissions. These technologies include improved solid-liquid separation, phosphorus extraction, enhanced biological nitrogen treatment, anaerobic ammonia oxidation, litter wash, material science and green oxidant application development, and their integration into systems of treatment technologies. Second, investigations will be conducted to further our limited knowledge on biology of anaerobic lagoons and develop technologies that can be used to retrofit existing manure treatment systems. To accomplish this, we will use state-of-the-art tools such as non-invasive estimation of oxygen absorption, enzyme activities, emission quantification with open-path laser ammonia detector, and we will develop an improved bio-filtration method to clean barn air. Third, research will be conducted to enhance constructed natural treatment technologies such as constructed wetlands, floating wetlands and riparian zones to more effectively manage nutrients using passive systems. Fourth, we will develop guidelines, protocols and standards for the beneficial use of manure by-products. These include improved methods to recycle and recover nutrients from anaerobic lagoon sludge and to produce hydrogen from livestock manure. Results from this project will advance the state of science for more effective animal waste treatment and implementation of environmentally-safe alternatives to traditional land application. Systems of treatment technologies that capture nutrients, reduce emissions, and kill pathogens need to be developed and evaluated. Small farms will require systems that meet environmental regulations and have a reasonable initial cost.

3.Progress Report
National Program (NP) 206 Manure and Byproduct Utilization; Nutrients Component, Focus Area 2: Demonstrated in a swine farm at full scale a more economical second generation Agricultural Research Service patented wastewater treatment system, costs were reduced fourfold; Tested on-farm rotary-press for dewatering swine manure and completed bench testing of natural flocculant; Performed liquid-solid separation experiments of dairy manure using polymer to determine dosage requirements; Filed a patent on method to extract phosphorus from solid manure (poultry and swine); Found nitrifying community that can oxidize ammonia at very low temperatures (5 degrees Celsius); Developed a new method to generate nitrite with potential use in anammox; Tested a high performance anammox pilot reactor that removed >1.5 kg nitrogen per cubic meters per day; and Enzyme-linked immunosorbent assay is being used to measure the effectiveness of the green oxidizer (trademark name–TAML) activators for destruction of estrone in swine lagoon effluent. NP 206; Atmospheric Emissions Component, Focus Area 2: Evaluated the effectiveness of the polyvinyl alcohol-coated activated carbon as a biofilter medium in removing ammonia and hydrogen sulfide from livestock air; Greenhouse gases were measured from a bench-scale biofiltration system effluent; Optical remote sensing system was evaluated for its accuracy in measuring ammonia emissions from distributed sources; The optical remote sensing system was used to measure ammonia emission from a swine farm; Flux chambers with a photoacoustic gas analyzer were used to measure ammonia and greenhouse gas emissions from treatment lagoons; Denitrification enzyme activities from lagoons were low and inconsistent with high levels of denitrification. NP 206; Holistic Treatment Technologies for Nutrients, Pathogens, Pharmaceutically Active Compounds, and Hormones Component, Focus Area 3: Mixed chamber microcosms were used to measure nitrous oxide emission in riparian buffers; the greatest emissions were associated with the addition of nitrate; Marsh-pond-marsh wetlands and continuous wetlands have proven good for the removal of estrogen as well as nitrogen; they were retrofitted to inject polyaluminum chloride into the inflow swine wastewater to improve phosphorus removal. NP 206; Byproduct Utilization Technologies, Focus Area 4: Experiments for in-situ sludge degradation were completed; Published experimental results of phosphorus (P) immobilization by amending soils with water treatment residual; Completed soil fertility tests and data analysis of soils amended with phosphorus materials recovered from poultry litter; Amended bioenergy production scope from biological hydrogen production to include anaerobic digestion, thermochemical conversion and biochar; Completed combustion and energy content analyses of bermudagrass irrigated with swine wastewater; Bench and micro-scale pyrolysis experiments using various manures and blending feedstocks were initiated to generate ‘green coal’; and Began thermal analysis of the combustion characteristics of ‘green coal.’

1. Development of technology to recover phosphorus from solid manure: Phosphorus (P) extraction from solid manure is an attractive approach when P land application is not an option. A process called ‘quick wash’ was developed to recover phosphorus from livestock solid manure. It is comprised of a rapid reaction to extract the manure-bound phosphorus that subsequently is quickly concentrated and recovered preventing unnecessary carbon and nitrogen oxidation. Results from laboratory and field prototype system studies indicate that up to 80% of phosphorus can be selectively removed and recovered from poultry litter. This technology has the potential of being an important tool for the poultry producer to manage manure and nutrient plans on their farms by recycling phosphorus back to crops. This technology gives an opportunity to recycle phosphorus from areas where it is in excess to areas with relatively low soil phosphorus. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Emissions; Problem Area 2: Emission Factors from Livestock Facilities.

2. Replacement of swine waste lagoons with second generation environmentally superior technology: To be permitted, new swine waste management systems in North Carolina need to meet the strict performance standards of an environmentally superior technology (EST). These technologies must be able to substantially remove nutrients, heavy metals, emissions of ammonia, odors, and pathogens. Scientists at Agricultural Research Service designed and demonstrated a second generation treatment system for swine waste that can achieve the high treatment performance standards of an EST, yet it is four times more economical than the first generation system. The system combines solid-liquid separation, biological ammonia treatment, and phosphorus removal and produces a deodorized and disinfected liquid effluent. The second generation system was installed full-scale in a 5,150-head finishing swine operation and demonstrated under steady-state conditions during three pig production cycles. Ammonia concentration in air of the barns was significantly reduced, and animal health and productivity were enhanced. These findings showed that two or more simple processes can be combined into a practical system to achieve the new EST performance standards and that these cleaner technologies can have significantly positive impacts on the environment and the livestock industry. Consequently, in July 2007 the State of North Carolina enacted Senate Bill 1465 that made permanent the environmental performance standards of an EST as a requirement for either the construction of new swine farms or expansion of existing swine farms in North Carolina. It also established a Lagoon Conversion Program that provides financial incentives to assist producers in the conversion of anaerobic swine lagoons to EST. This research contributes to National Program 206: Manure and Byproduct Utilization; Component: Emissions; Problem Area 2: Emission Factors from Livestock Facilities.

3. Reduction of malodors from swine production operations using second generation treatment technologies: An alternative treatment system was evaluated for odor control. The system included solid separation and nutrient removal processes. The evaluation included the analysis of six selected odor compounds that are known contributors to malodor in the liquid. Results showed that the concentrations of malodorous compounds were reduced by almost 99%. The majority of this odor reduction occurred during the biological N treatment step. Agricultural Research Service scientists made two important advances with odor research:.
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.

6.Technology Transfer

Number of Web Sites Managed1
Number of Non-Peer Reviewed Presentations and Proceedings13
Number of Newspaper Articles and Other Presentations for Non-Science Audiences1
Number of Other Technology Transfer3

Review Publications
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.

Last Modified: 3/2/2015
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