2009 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.
Filed a patent on a high performance nitrifying sludge for high ammonium concentration and low temperature wastewater treatment. Developed and tested method for long-term preservation of anammox bacteria. Disclosed invention on a method to reduce gaseous ammonia from poultry houses and other rearing facilities and its recovery using gas-permeable membranes. The effectiveness of the green oxidizer (trademark name-TAML) is being tested to destroy estrone in swine lagoon liquid.
The absorption capacity of bio-char (made from animal manure) for removing ammonia and hydrogen sulfide is being assessed for its use in air filtration systems. Completed and published the measurement of greenhouse gas emissions from agricultural sites using open-path optical remote sensing method.
Additional lagoons were sampled for denitrification enzyme activity in the sludge sediment layer as well as within the water column. Additional measurement of greenhouse gasses from riparian buffer contiguous to swine and dairy wastewater spray field showed generally low levels of emission. Analyzed riparian buffer zone microbial community structures using bacterial fingerprinting and 16S rDNA gene sequencing. Utilized Real Time PCR to examine the correlation between microbial denitrification gene densities in riparian buffer soils and anaerobic lagoons with greenhouse gases produced by microbially-mediated pathways. Phosphorus removal via polyaluminum chloride was investigated in swine wastewater treatment wetland as a means for improving long-term phosphorus removal.
Amended bioenergy production scope from biological hydrogen production to include thermochemical conversion and biochar. Determined carbonization kinetics of swine solids. Evaluated the efficiency of a skid-mounted pyrolysis system in producing combustible gases from chicken litter, swine solids, and blended swine solids with rye grass. Gas and solid products were analyzed for calorific values and composition. A new way of analyzing volatile matter and ash from animal manures was developed using a thermogravimetric analyzer. Investigated the bioenergy production potential of Coastal bermuda grass receiving subsurface drip irrigation with advanced-treated swine wastewater.
Abatement of odors from CAFO’s using systems integration: Reductions in malodor were studied in a second-generation Environmentally Superior Technology (EST) wastewater treatment plant over 15 months of operation that included three cycles of pig rearing. The wastewater treatment system consisted of three modules: solids separation, biological nitrogen removal, and phosphorus recovery/wastewater disinfection. While approximately over 90% of the wastewater solids were removed in the first stage of treatment, little reduction in malodorous compounds occurred, indicating that malodors largely remained with the liquid waste stream. The greatest improvements in wastewater quality occurred in the nitrogen treatment module: There was over 90% reduction in malodors as compared to the raw flushed manure. The system consistently achieved high performance standards, even during the first cycle of livestock production when system performance was being optimized. These findings showed that the combination of the processes of solids removal and biological N treatment into a practical treatment system can be very effective in reducing malodors from livestock wastewater.
Use of natural compounds to enhance solids separation of manure: Solid-liquid separation of the raw manure increases the capacity of decision making and opportunities for manure treatment. The separation up-front allows recovery of the organic compounds, which can be used for the manufacture of compost materials and other value-added products or energy production. It also facilitates treatment of the liquid through biological nitrogen removal and phosphorus recovery/disinfection to meet specific environmental standards. It was found that natural occurring flocculants such as chitosan can be as effective as synthetic polymers for the separation of solids and nutrients from concentrated dairy manure effluents. Natural compounds with flocculation capacity may have an important role in waste management in the future because of increased cost of energy and renewed interest on organic farming systems.
New microbial composition for effective low-temperature nitrification: Low nitrification rates during cold weather are often a problem for adoption of biological treatment ammonia in livestock effluents. We discovered a high performance nitrifying sludge (HPNS) with excellent ammonia removal performance during cold weather conditions. The HPNS shows ideal characteristics for application in various bio-treatment fields; it forms large flocs that settle rapidly producing a high-quality effluent. Very-high nitrification rates of 444 mg N/L/day have been confirmed at 5oC and 813mg N/L/day at 10oC. These rates may be the highest reported for nitrification treatment of high-ammonia wastewater at low temperatures. A US Patent Application on this discovery was filed on July 1, 2009 (USPTO 12/495,958). The unique microbial community composition that contained ammonia oxidizers, cold tolerant and floc-forming microorganisms provided a nitrifying sludge capable of high rates of nitrification at cold temperatures much needed for advanced on-farm treatment of liquid livestock manure.
Technology to recover phosphorus from solid manure: A process called ‘quick wash’ was developed to recover phosphorus (P) from livestock solid manure. This technology can provide poultry litter management alternatives to reduce the environmental impact of P litter when application onto land is not an option. The quick wash process 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. This technology has the potential of being an important tool for the poultry producer to manage manure and nutrient plans on their farms. It can facilitate P transport in concentrated form from areas where it is in excess for its effective utilization as plant fertilizer. In addition, this technology has the potential of being integrated with bio-energy generation methods such as anaerobic digestion or thermo-chemical conversion that will use the washed litter residue as feedstock.
Removal of phosphorus from livestock effluents: The most common method of disposal of liquid swine manure is land application. Liquid manure generated during swine production is usually stored and treated in anaerobic lagoons with intermittent lagoon effluent disposal through land applications. However, land application of manure effluents promotes phosphorus (P) accumulation in soil and increased potential for P losses through runoff with subsequent water quality deterioration in surface waters. The ARS-patented system developed for removal of P from the liquid manure (US Patent No. 6,893,567 B1) was tested with lagoon liquid collected from ten farms representing typical swine production operations in North Carolina. In this process, lagoon liquid is first treated using biological nitrification, and then P is removed using a lime slurry. In all farms, the new process effectively recovered P as a P-rich material that can be exported from the farm and reused as fertilizer. This technology has the potential to be used to reduce the P content in livestock effluents to levels that would solve problems of excess P accumulation in soil.
Reuse of phosphorus materials recovered from manure: Two new treatment processes have been developed to recover P from manure in concentrated solid form. One of these new treatments recovered P from liquid swine manure while the other new process recovered P from broiler litter. Soil column tests with and without cotton plants showed that the leaching potential of recovered P materials may be lower than more soluble forms of P fertilizers such as triple superphosphate. Both recovered P sources were excellent fertilizer sources. Cotton 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 soil and reducing potential impact on water resources. The results are significant to the fertilizer industry because these materials can be transported off the farm in concentrated form and recycled as plant fertilizer.
In-situ lagoon sludge degradation. Confined swine production generates large volumes of wastewater typically stored and treated in anaerobic lagoon systems. These lagoons may require costly cleanup measures prior to closure. An alternative to lagoon cleanup was investigated by pre-treating the liquid swine manure prior to entering the lagoon by solid-liquid separation only and by the ARS second-generation Environmentally Superior Technology (EST) wastewater treatment that treats liquid manure by biological nitrification/denitrification after solid separation. In a 15-month pilot study, water quality improvements (such as reduction of suspended solids and nitrogen concentrations) with respect to the anaerobic lagoon control were moderate with solid separation only but very significant with the EST wastewater treatment. Consequently, the lagoon reduction of sludge mass was about 34% with solid separation and 50% with the EST treatment when compared to the sludge mass of an anaerobic lagoon control. This finding will help in the development of lower cost lagoon cleanup methods.
Effectiveness of treatment wetland aeration: The effectiveness of introducing diffused aeration in treatment wetlands was evaluated by performing oxygen mass balances in three different treatment wetland systems: marsh-open pond-marsh, marsh-covered pond-marsh, and marsh only. It was rather surprising to find that the diffused aeration in the pond section did not provide any significant oxygen input to the wetland systems. The reason for low diffused aeration efficiency was attributed to the shallow water depth of the pond section with less than 1 m water depth, while municipal aeration basins have water depths typically more than 4 m. Treatment efficiency of marsh only wetland was found to be similar to that of marsh-open pond-marsh or marsh-covered pond-marsh. This result implicates that more costly marsh-pond-marsh wetlands do not necessarily improve livestock wastewater treatment efficiency of marsh only wetland.
Carbonization of swine solids: Biochar or green charcoal made from renewable biomass such as animal manures can provide environmental and economical benefits to livestock farmers. However, there is a lack of knowledge on swine solid carbonization; i.e., the rate of making biochar via pyrolysis reactions. Thermal degradation characteristics and rates were studied using a thermogravimetric analyzer. Kinetic parameters were estimated using three different swine manure solid sources: homogenized flushed manure, dewatered solids, and anaerobic lagoon sludge. These swine solids were thermally degraded in the temperature range of 500–860 K. The lagoon sludge showed the highest onset pyrolysis temperature. The carbonization kinetic parameters such as activation energy provide useful information to develop farm-scale carbonization systems for swine waste treatment.
Bioenergy production potential of Coastal bermudagrass irrigated with advanced-treated swine wastewater: Coastal bermudagrass is commonly used in lagoon spray-fields that receive anaerobic lagoon effluents as part of manure nutrient management plans. Subsurface drip irrigation with advanced-treated swine manure effluent offers a method to irrigate bioenergy crops while meeting both nitrogen and water demands without overloading the crops with nutrients. The effect of subsurface drip irrigation was evaluated with both commercial fertilizer and advanced-treated swine wastewater on the quantity and quality of Coastal bermudagrass bioenergy production. The bermudagrass bioenergy production and combustion characteristics were determined via thermogravimetric analysis (TGA). Relative to commercial nitrogen fertilizer, the least biomass energy density was associated with bermudagrass receiving advanced-treated swine wastewater. The TGA (weight loss) profiles of these two fertilizer treatments were almost identical during combustion. Yet, this bermudagrass exhibited marked increases, between 10 and 28%, in both hay and energy yields per ha. These results demonstrated that a subsurface drip irrigation system for advanced-treated swine effluent application can produce quality hay forage and bioenergy while protecting environmental quality.
A new method for determination of volatile matter and ash in animal manures using thermogravimetric analysis: Animal manure can be used as a feedstock for various thermochemical conversion processes such as pyrolysis and gasification. In order to employ these processes, the manure must be properly characterized for volatile matter and ash contents. Determination of these components for livestock manure is not specifically described in the American Society of Testing and Materials (ASTM) standards. Thermogravimetric analysis (TGA) was used for the rapid assessment of volatile matter and ash content in swine, dairy, rabbit, and poultry manures using coal and coke standards. The TGA analysis results of both volatile matter and ash content in the manures were the same as those values found by non-automated ASTM standards for coal and coke. This new method provides useful information for development of manure thermochemical conversion processes.
Development of a green and profitable manure treatment technology: New and expanding swine production facilities in North Carolina are required to use manure management systems that meet the strictest environmental performance standards in the nation. A second-generation system was developed by ARS-Florence scientists and cooperators that met state environmental standards for manure management. Significant cost reductions were achieved by innovations and on-farm testing; the revamped system was two-thirds less expensive to build and operate than the first-generation system, which was tested in 2003. The new on-farm treatment system used solid-liquid separation and nitrogen and phosphorus removal processes (U.S. Patent Application US 2008/0314837). It removed high levels of several pollutants from manure wastewater, including almost all of the pathogens, odor-causing constituents, and ammonia. Replacing anaerobic-lagoon-based systems with the new technology also reduced greenhouse gas emissions by 97 percent. Animal health and production also benefited. Swine daily weight gain increased, feed conversion improved, animal mortality decreased, and 5.6 percent more hogs were sold per growing cycle. Separated manure solids were converted in a centralized facility into composted materials and used for organic plant fertilizer, soil amendments, and plant growth media. Producers can also profit from the new system by selling greenhouse gas emission reduction credits and water quality credits. This technology was featured in a chapter of “Manufacturing Climate Solutions: Carbon-Reducing Technologies and U.S. Jobs,” published in 2008 by Duke University’s Center on Globalization, Governance & Competitiveness. The new technology could help swine-producing states protect existing jobs and keep the door open for future job expansion.
5.Significant Activities that Support Special Target Populations
Cooperative research with North Carolina A&T State University.
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Szogi, A.A., Vanotti, M.B., Hunt, P.G. 2008. Phosphorus recovery from poultry litter. Transactions of the American Society of Agricultural and Biological Engineers 51(5):1727-1734.
Szogi, A.A., Vanotti, M.B. 2009. Removal of phosphorus from livestock effluents. Journal of Environmental Quality 38:576-586.
Ducey, T.F., Jackson, L., Orvis, J., Dyer, D.W. 2009. Transcript analysis of nrrF, a Fur repressed sRNA of Neisseria gonorrhoeae. Microbial Pathogenesis 46:166-170.
Garcia, M.C., Szogi, A.A., Vanotti, M.B., Chastain, J.P., Millner, P.D. 2009. Enhanced solid-liquid separation of dairy manure with natural flocculants. Bioresource Technology 100:5417-5423.
Cantrell, K.B., Stone, K.C., Hunt, P.G., Ro, K.S., Vanotti, M.B., Burns, J.C. 2009. Bioenergy from Coastal bermudagrass receiving subsurface drip irrigation with advance-treated swine wastewater. Bioresource Technology 100:3285-3292.
Szogi, A.A., Vanotti, M.B. 2009. Prospects for phosphorus recovery from poultry litter. Bioresource Technology 100:5461-5465.
Vanotti, M.B., Szogi, A.A., Millner, P.D., Loughrin, J.H. 2009. Developmement of second-generation Environmentally Superior Technology for treatment of swine manure in the USA. Bioresource Technology 100:5406-5416.
Ro, K.S., Cantrell, K.B., Hunt, P.G., Ducey, T.F., Vanotti, M.B., Szogi, A.A. 2009. Thermochemical conversion of livestock wastes: Carbonization of swine solids. Bioresource Technology 100:5466-5471.
Vanotti, M.B., Szogi, A.A. 2008. Water quality improvements of wastewater from confined animal feeding operations after advanced treatment. Journal of Environmental Quality 37(5):S86-S96.
Ward, T.J., Ducey, T.F., Usgaard, T.R., Dunn, K.A., Bielawski, J.P. 2008. Multilocus Genotyping Assays for SNP-based Subtyping of Listeria monocytogenes. Applied and Environmental Microbiology. 74(24):7629-7642.
Loughrin, J.H., Vanotti, M.B., Szogi, A.A., Lovanh, N.C. 2009. Evaluation of second-generation multistage wastewater treatment system for the removal of malodorous compounds from liquid swine waste. Journal of Environmental Quality. 38:1739-1748.
Vanotti, M.B., Szogi, A.A. 2009. Technology for recovery of phosphorus from animal wastewater through calcium phosphate precipitation. In: Ashley, K., Mavinic, D. and Koch, F. (editors). Nutrient Recovery from Wastewater Streams. London, United Kingdom:IWA Publishing. p. 459-468.
Shappell, N.W., Vrabel, M.A., Madsen, P.J., Harrington, G.E., Billey, L.O., Hakk, H., Larsen, G.L., Beach, E.S., Horwitz, C.P., Ro, K.S., Hunt, P.G., Collins, T.J. 2008. Destruction of estrogens using Fe-TAML/peroxide catalysis. Environmental Science and Technology 42:1296-1300.
Cantrell, K.B., Walker, T.H. 2009. Influence of temperature on growth and peak oil biosynthesis in a carbon-limited medium by Pythium irregulare'. Journal of the American Oil Chemists' Society. 86(8):791-797.
Ro, K.S., Johnson, M.H., Varma, R.M., Hashmonay, R.A., Hunt, P.G. 2009. Measurement of greenhouse gas emissions from agricultural sites using open-path optical remote sensing method. Journal of Environmental Science and Health Part A 44(10):1011-1018.
Ro, K.S., Mcconnell, L.L., Johnson, M.H., Hunt, P.G., Parker, D. 2008. Livestock air treatment using PVA-coated powdered activated carbon biofilter. Applied Engineering in Agriculture. 24(6):791-798.
Vanotti, M.B., Szogi, A.A., Bernal, M.P., Martinez, J. 2009. Livestock waste treatment systems of the future: A challenge to environmental quality, food safety, and sustainability. OECD Workshop. Bioresource Technology 100:5371-5373.