Progress 10/01/01 to 09/30/07
Outputs
OUTPUTS: Research continued in characterizing the volume and concentration of flushed dairy manure after mechanical separation and sedimentation, monitoring the biogas production levels and treatment efficiency of the anaerobic digestion process using a fixed-film digester, characterizing the reduction in odor levels, monitoring nutrient transformations, and evaluating pathogen destruction. A prototype fixed-film anaerobic digester has been constructed and operated at the UF-IFAS Dairy Research Unit. A patent based on this digester design was awarded on November 2, 2004 (US Patent No. 6,811,701). Further patent awards include: 1. Fixed-film anaerobic digestion of flushed manure, New Zealand Patent No. 532290, awarded February 8, 2007; 2. Fixed-film anaerobic digestion of flushed manure, Australian Patent No. 2002348041, awarded August 30, 2007. Pending patents include: 1. Fixed-film anaerobic digestion of flushed waste, US Patent Application No. 10/976,079, filed 10/28/04 (accepted 7/12/07); 2. Fixed-film anaerobic digestion of flushed manure, Canadian Patent Application No. 2,464,693, filed 10/23/02; 3. Fixed-film anaerobic digestion of flushed manure, European Patent Application No. 02 784 254.1-2104, filed 10/23/02. Project information was disseminated by conducting field days and on-site tours of the fixed-film anaerobic digester facility at the UF-IFAS Dairy Research Unit, and through presentations and participation at numerous conferences and workshops. Invited speaker at: 2006 Horizons in Livestock Sciences Conference: Research for the Farm of the Future, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Gold Coast, Queensland, Australia, October 9, 2006; Campus and Community Sustainability Conference, University of Florida, Gainesville, Florida, October 25, 2006; Renewable Energy Workshop, Florida Public Service Commission, Tallahassee, Florida, January 19, 2007; 2007 South Central Florida Small Farm and Alternative Enterprise Workshop, Sarasota, Florida, April 26, 2007; Climate Change Conference, Tampa, Florida, May 10, 2007; 2007 Farm to Fuel Summit, Florida Department of Agriculture and Consumer Services, St. Petersburg, Florida, July 19, 2007; Southeast Bioenergy Conference 2007, Tifton, Georgia, August 1, 2007. Invited panelist at: Scientific Advisory Panel Annual Meeting, Dairy Farmers, Inc., Gainesville, Florida, October 26, 2006; U.S. EPA Workshop: Fate and Effects of Hormones in Waste from Concentrated Animal Feeding Operations, Chicago, Illinois, August 20-22, 2007. Information was also made available on the Internet at the following sites: Biogas web-site: http://biogas.ifas.ufl.edu ; Manure Management web-site: http://dairy.ifas.ufl.edu/factsheets/manure.shtml PARTICIPANTS: Dr. A.C. Wilkie served as principal investigator/project director. Partner organizations included the Florida Energy Office and Environmental Defense. Other collaborators included faculty from the departments of Soil and Water Science (W.G. Harris), Animal Sciences (A. de Vries), Dairy Extension (R.G. Giesy), Agricultural and Biological Engineering (R.A. Nordstedt), Microbiology and Cell Science (S.R. Farrah) and from the University of Mauritius (R.D. Sooknah). The project provided education and training opportunites for graduate students (J.A. Davis, A. Malek and J.G. Duncan). The project also provided training opportunities for undergraduate interns as part of a Bioenergy Research Internship program (Y.A. Agboola, G.L. Espinosa, C.L. Levy, S.D. Matthews, L.C. Medina, and P. O'Donoughue). TARGET AUDIENCES: Target audiences include dairy farmers and livestock producers, scientists, agencies, organizations and public citizens involved with waste management, water quality, nutrient management, bioenergy, air quality and greenhouse gas emissions, including: individual farmers; Dairy Farmers, Inc., Maitland, Florida; Sunbelt Milk Producers, Orlando, Florida; National Pork Board, Des Moines, Iowa; Florida Department of Agriculture and Consumer Services; Florida Department of Environmental Protection; Florida Energy Commission; Florida Energy Office; Florida Public Service Commission; AgSTAR Program, U.S. Environmental Protection Agency; Environmental Defense; Natural Resources Conservation Service. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Anaerobic digestion systems provide significant benefits to aid in meeting the increasing environmental regulations and public pressures on dairy farmers regarding manure handling and disposal, while simultaneously providing a source of green energy. However, flushed dairy manure wastewater, defined as the liquid fraction of flushed dairy manure after fibrous solids are removed, is usually too dilute for conventional anaerobic digestion systems. One practical alternative is to apply high-rate anaerobic digestion technology, such as fixed-film digestion, to recover bioenergy and treat the flushed dairy manure wastewater at much shorter residence times (2-4 days) than allowed by conventional technologies. The fixed-film design is suitable for any livestock waste that is subject to dilution with water for transport or processing, such as dairy and swine manure, and can operate at ambient or higher temperatures. The novel fixed-film digester design expands the potential application of anaerobic digestion to dilute livestock waste with significant levels of suspended solids. This holistic manure treatment system not only stabilizes the wastewater but also produces renewable energy (carbon-neutral biogas), controls odors, reduces pathogens, minimizes environmental impact from greenhouse gas emissions, and maximizes fertilizer and water recovery for reuse. The UF-IFAS fixed-film digester serves as a model manure treatment, bioenergy production and odor control system for the dairy industry in Florida and nationwide.
Publications
- Harris, W.G., Cao, R.X., Nair, V.D., Josan, M.S., Herrera, D.H. and Wilkie, A.C. (2007). Magnesium as inhibitor and enabler of calcium phosphate precipitation. ASA-CSSA-SSSA-CSSS Annual Meetings Abstracts 2007.
- Davis, J., Farrah, S. and Wilkie, A. (2007). Mechanisms of virus adsorption following land application of anaerobically treated flushed dairy manure wastewater. Abstr. 107th Gen. Meet. Am. Soc. Microbiol. 2007. American Society for Microbiology, Washington, DC.
- Giesy, R., de Vries, A., Nordstedt, R., Wilkie, A., Porter, W. and Jackson, J. (2007). Considerations when contemplating an anaerobic digester and electrical generator for your dairy farm. Hoofprints in the Sand 13(2):2-6. June 2007. University of Florida/IFAS Extension Service, Gainesville, Florida.
- Wilkie, A.C. (2007). Biogas and Biofuel Synergies. 2007 Farm to Fuel Summit, Florida Department of Agriculture and Consumer Services, St. Petersburg, Florida, July 19, 2007. http://floridafarmtofuel.com/ppt/2007/Wilkie.ppt
- Wilkie, A.C. (2007). Biogas and Renewable Carbon. Climate Change Conference, Tampa, Florida, May 10, 2007. http://www.ces.fau.edu/ccc/download.phpid=16
- Wilkie, A.C. (2007). Biogas Energy Potential in Florida. Renewable Energy Workshop, Florida Public Service Commission, Tallahassee, Florida, January 19, 2007. http://www.psc.state.fl.us/utilities/electricgas/RenewableEnergy/Wilk ie-UF.ppt
- Wilkie, A.C. (2007). Anaerobic Digestion and Biofuel Synergies. Southeast Bioenergy Conference 2007, Tifton, Georgia, August 1, 2007. http://www.sebioenergy.org/ConferencePDF/Aug1/130-300/B/Ann Wilkie.pdf
- Malek, A. (2007). Enhanced retention of phosphorus applied as flushed dairy manure. Masters thesis, School of Natural Resources and Environment, University of Florida, Gainesville, Florida.
- Giesy, R.G., de Vries, A., Nordstedt, R.A., Wilkie, A.C., Porter, W.A. and Jackson, J.L. (2006). Overcoming obstacles to connecting dairy farm anaerobic digesters and electrical generators to the power grid. UF/IFAS, Gainesville, Florida. 13pp.
- de Vries, A., Giesy, R.G., Wilkie, A.C. and Nordstedt, R.A. (2006). Spreadsheet to calculate the economic feasibility of anaerobic manure digesters on Florida dairy farms. AN176, 2p. Department of Animal Sciences, Florida Cooperative Extension Service, University of Florida/IFAS, Gainesville, Florida. http://edis.ifas.ufl.edu/AN176
- Wilkie, A.C. (2006). Ecological impacts on future farming. In: Handbook and Abstracts, Horizons in Livestock Sciences: Research for the Farm of the Future, Gold Coast International Hotel, Queensland, Australia, October 8-11, 2006, p.12. Commonwealth Scientific and Industrial Research Organisation (CSIRO) Livestock Industries, Queensland, Australia. http://www.livestockhorizons.com/2006%20handbook.pdf
- Sooknah, R.D. and Wilkie, A.C. (2007). Nutrient uptake by floating aquatic macrophytes cultured in anaerobically digested flushed dairy manure wastewater. Ecol. Eng. (submitted).
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2007). Studying the impact of soluble organics in manure following anaerobic digestion on virus adsorption to sandy soil by fraction analysis. Water Air Soil Pollut. (submitted).
- Wilkie, A.C. (2007). Biomethane from biomass, biowaste and biofuels. In: Bioenergy. J. Wall, C.S. Harwood and A. Demain (eds,), American Society for Microbiology Press, Washington, DC. (In press).
- Harris, W.G., Wilkie, A.C., Cao, X. and Sirengo, R. (2007). Bench-scale recovery of phosphorus from flushed dairy manure wastewater. Bioresour. Technol. (In press).
- Wilkie, A.C. (2007). Eco-Engineering a Sustainable Society. Resource: Engineering & Technology for a Sustainable World 14(6):19-20. August 2007. American Society of Agricultural and Biological Engineers (ASABE), St. Joseph, Michigan.
- Malek, A., Harris, W. and Wilkie, A. (2007). Enhanced retention of phosphorus applied to sandy soils as flushed dairy manure. Abstr. 8th Annual Soil & Water Science Research Forum, p.65. Soil and Water Science Department, University of Florida, Gainesville, Florida.
- Wilkie, A.C. (2006). Manure matters. Impact 22(1):24-25. Fall 2006. University of Florida, Gainesville, Florida. http://impact.ifas.ufl.edu/2006/ImpactVol22No1.pdf
- Wilkie, A.C. (2006). Manure system benefits environment and noses. Explore: Research at the University of Florida 11(2):8-9. Summer 2006. University of Florida, Gainesville, Florida. http://rgp.ufl.edu/publications/explore/v11n2/extract3.html
|
Progress 10/01/05 to 09/30/06
Outputs
Flushed dairy manure wastewater, defined as the liquid fraction of flushed dairy manure after fibrous solids are removed, is usually too dilute for conventional anaerobic digestion systems. One practical alternative is to apply high-rate anaerobic digestion technology, such as fixed-film digestion, to recover bioenergy and treat the flushed dairy manure wastewater at much shorter residence times (2-4 days) than allowed by conventional technologies. The fixed-film design is suitable for any livestock waste that is subject to dilution with water for transport or processing, such as dairy and swine manure, and can operate at ambient or higher temperatures. Research continued in characterizing the volume and concentration of flushed dairy manure after mechanical separation and sedimentation, monitoring the biogas production levels and treatment efficiency of the anaerobic digestion process, characterizing the reduction in odor levels, monitoring nutrient transformations,
and evaluating pathogen destruction.
Impacts
Anaerobic digestion is both a waste treatment technology, which enhances environmental quality, and a sustainable energy-producing technology. In addition to organic matter reduction and waste stabilization, the benefits of the anaerobic digestion process include renewable bioenergy production in the form of biogas as well as environmental benefits in the form of odor control, pathogen reduction, conservation of nutrients, and reduction in greenhouse gas emissions. Anaerobic digestion systems, therefore, provide significant benefits to aid in meeting the increasing environmental regulations and public pressures on dairy farmers regarding manure handling and disposal, while simultaneously providing a source of green energy. This research program was recognized with two awards in 2006: (1) a Sustainable Florida Best Practices Award from the Council for Sustainable Florida, Tallahassee, Florida, for innovative research on livestock waste treatment, odor control, and
bioenergy and biofertilizer production, and (2) a Sustainable Solutions Award from the scientific publishing company Benjamin Cummings, San Francisco, California, that recognizes the efforts of faculty and students towards encouraging sustainable practices on campus and in the community.
Publications
- Harris, W.G., Wilkie, A.C. and Cao, X. (2006). Bench-scale phosphorus recovery from flushed dairy manure wastewater. Bioresour. Technol. (submitted).
- Wilkie, A.C. (2006). The other bioenergy solution: The case for converting organics to biogas. Resource: Engineering & Technology for a Sustainable World 13(8):11-12. American Society of Agricultural and Biological Engineers (ASABE), St. Joseph, Michigan.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2006). Adsorption of viruses to soil: impact of anaerobic treatment. Water Sci. Technol. 54(3):161-167.
- Hanselman, T.A., Graetz, D.A., Wilkie, A.C., Szabo, N.J. and Diaz, C.S. (2006). Determination of steroidal estrogens in flushed dairy manure wastewater by gas chromatography-mass spectrometry. J. Environ. Qual. 35(3):695-700.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2006). Selective growth of Staphylococcus aureus from flushed dairy manure wastewater using acriflavine-supplemented mannitol salt agar. Lett. Appl. Microbiol. 42(6):606-611.
- de Vries, A., Giesy, R.G., Wilkie, A.C. and Nordstedt, R.A. (2006). Spreadsheet to calculate the economic feasibility of anaerobic manure digesters on Florida dairy farms. EDIS publication. Florida Cooperative Extension Service, University of Florida/IFAS, Gainesville, Florida.
- Wilkie, A.C. (2006). Manure matters: UF waste management system produces energy, protects environment and stops annoying odors. Ag Nutrient Management 2(2):26-27.
- Cao, X., Harris, W. and Wilkie, A. (2006). Enhancement of P recovery from flushed dairy wastewater using Mg to prevent Ca carbonate precipitation. Abstr. 7th Annual Soil & Water Science Research Forum, p.50. Soil and Water Science Department, University of Florida, Gainesville, Florida.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2006). Influence of anaerobic treatment on adsorption of viruses to soil. Abstr. 106th Gen. Meet. Am. Soc. Microbiol. 2006. American Society for Microbiology, Washington, DC.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2006). Factors contributing to indicator and pathogenic bacteria reduction during fixed-film anaerobic digestion of flushed dairy manure. In: Fifth Annual Southern BioProducts Conference - Conference Program, April 3-4, 2006, Choctaw, Mississippi, p.37. Mississippi Biomass Council.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2006). The influence of anaerobic digestion on virus retention by soil. Abstr. 2006 Annual Meeting, p.23. Florida Branch, American Society for Microbiology.
- Duncan, J.G. and Wilkie, A.C. (2006). Biogas potential from air potato (Dioscorea bulbifera): evaluation and techniques. Abstr. 8th Annual Environmental Engineering Sciences Poster Symposium. University of Florida, Gainesville, Florida.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2005). Adsorption of viruses to soil: impact of anaerobic treatment. In: Proceedings 13th International Symposium on Health Related Water Microbiology, Swansea, UK, September 5-9, 2005. International Water Association.
- Giesy, R., Wilkie, A.C., de Vries, A. and Nordstedt, R.A. (2005). Economic feasibility of anaerobic digestion to produce electricity on Florida dairy farms. AN159, 8p. Department of Animal Sciences, Florida Cooperative Extension Service, University of Florida/IFAS, Gainesville, Florida. http://edis.ifas.ufl.edu/AN159
|
Progress 10/01/04 to 09/30/05
Outputs
Flushed dairy manure wastewater, defined as the liquid fraction of flushed dairy manure after fibrous solids are removed, is usually too dilute for conventional anaerobic digestion systems. One practical alternative is to apply high-rate anaerobic digestion technology, such as fixed-film digestion, to recover bioenergy and treat the flushed dairy manure wastewater at much shorter residence times (2-4 days) than allowed by conventional technologies. The fixed-film design is suitable for any livestock waste that is subject to dilution with water for transport or processing, such as dairy and swine manure, and can operate at ambient or higher temperatures. Research continued in characterizing the volume and concentration of flushed dairy manure after mechanical separation and sedimentation, monitoring the biogas production levels and treatment efficiency of the anaerobic digestion process, characterizing the reduction in odor levels, monitoring nutrient transformations,
and evaluating pathogen destruction.
Impacts
Anaerobic digestion is both a waste treatment technology, which enhances environmental quality, and a sustainable energy-producing technology. In addition to organic matter reduction and waste stabilization, the benefits of the anaerobic digestion process include renewable bioenergy production in the form of biogas as well as environmental benefits in the form of odor control, pathogen reduction, and reductions in greenhouse gas emissions. Anaerobic digestion systems, therefore, provide significant benefits to aid in meeting the increasing environmental regulations and public pressures on dairy farmers regarding manure handling and disposal, while simultaneously providing a source of green energy.
Publications
- Kennelley, E.D., Mylavarapu, R.S. and Wilkie, A.C. (2004). Initial assessment of a unique soil phosphorus determination method as a tool for field estimation of P-index. ASA-CSSA-SSSA-CSSS Annual Meetings Abstracts 2004.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2005). Adsorption of viruses to soil: impact of anaerobic treatment. Water Sci. Technol. (submitted).
- Hanselman, T.A., Graetz, D.A., Wilkie, A.C., Szabo, N.J. and Diaz, C.S. (2005). Determination of steroidal estrogens in flushed dairy manure wastewater by gas chromatography-mass spectrometry. J. Environ. Qual. (In press).
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2005). Selective growth of Staphylococcus aureus from flushed dairy manure wastewater using acriflavine-supplemented mannitol salt agar. Lett. Appl. Microbiol. (In press).
- Leader, J.W., Reddy, K.R. and Wilkie, A.C. (2005). Optimization of low-cost phosphorus removal from wastewater using co-treatments with constructed wetlands. Water Sci. Technol. 51(9):283-290.
- Wilkie, A.C. (2005). Anaerobic digestion: biology and benefits. In: Dairy Manure Management: Treatment, Handling, and Community Relations. NRAES-176, p.63-72. Natural Resource, Agriculture, and Engineering Service, Cornell University, Ithaca, NY.
- Wilkie, A.C. (2005). Anaerobic digestion of dairy manure: design and process considerations. In: Dairy Manure Management: Treatment, Handling, and Community Relations. NRAES-176, p.301-312. Natural Resource, Agriculture, and Engineering Service, Cornell University, Ithaca, NY.
- Leader, J.W., Reddy, K.R. and Wilkie, A.C. (2005). Performance of Schoenoplectus tabernaemontani (K.C. Gmel.) Palla in experimental co-treatment and constructed wetland mesocosm systems. IWA Specialist Group on Use of Macrophytes in Water Pollution Control Newsletter 29:57-63.
- Hughes, K. and Wilkie, A.C. (Eds.) (2005). Cost-effective and Environmentally Beneficial Dairy Manure Management Practices. 28p. National Dairy Environmental Stewardship Council, Sustainable Conservation, San Francisco, CA.
- Giesy, R., deVries, A., Wilkie, A.C. and Nordstedt, R.A. (2005). Economic feasibility of anaerobic digestion to produce electricity on Florida dairy farms. EDIS publication. University of Florida/IFAS Extension Service.
- Wilkie, A.C. (2005). Anaerobic digestion of dairy manure: design and process considerations. Ag Waste Management 1(2):27-31.
- Wilkie, A.C. (2005). Manure management - sustainable practices. Dairy Update 5(4):2. University of Florida/IFAS Department of Animal Sciences.
- Giesy, R., deVries, A., Nordstedt, R. and Wilkie, A. (2005). Review of the economics of manure systems that generate electricity on dairy farms. Hoofprints in the Sand 11(1):5-6. University of Florida/IFAS Extension Service.
- Wilkie, A.C. (2004). Fixed-film anaerobic digestion of flushed manure. United States Patent No. 6,811,701. U.S. Patent Office, Washington, DC.
- Giesy, R., deVries, A. and Wilkie, A. (2004). Advantages and disadvantages of using manure digesters to generate electricity on Florida dairy farms. Hoofprints in the Sand 10(8):3. University of Florida/IFAS Extension Service.
|
Progress 10/01/03 to 09/30/04
Outputs
Further studies were conducted on the application of fixed-film anaerobic digestion technology for sustainable waste management at dairy farms. The fixed-film anaerobic digester design allows biogas recovery and biological stabilization (permanent odor reduction) of the liquid portion of flushed dairy manure at short hydraulic retention times (3 days), even at ambient temperature conditions. Generally, the fixed-film design is suitable for any livestock waste that is subject to dilution with water for transport or processing, such as dairy and swine manure. Research continued in characterizing the volume and concentration of flushed dairy manure after mechanical separation and sedimentation, monitoring the biogas production levels and treatment efficiency of the anaerobic digestion process, characterizing the reduction in odor levels, monitoring nutrient transformations, and evaluating pathogen destruction. In anaerobic digestion, nutrients such as N and P contained
in the organic compounds are conserved and mineralized to more soluble and biologically available forms. Further processing of the digested effluent is needed, therefore, to reduce the nutrient content. Harnessing solar energy to grow algal biomass or aquatic macrophytes on the digested effluent offers a potential solution to recover nutrients and improve water quality. Studies were conducted to investigate the ability of benthic freshwater algae to recover nutrients from anaerobically digested flushed dairy manure and to evaluate nutrient uptake rates and dry matter/crude protein yields in comparison to a conventional cropping system. Studies were also conducted to evaluate nutrient removal by floating aquatic macrophytes cultured in anaerobically digested flushed dairy manure wastewater.
Impacts
The increase in production and concentration of intensive livestock operations along with increased urbanization of rural regions have resulted in greater awareness and concern for the proper storage, treatment, and utilization of livestock wastes. Anaerobic digestion can offer a beneficial option for livestock waste management. In anaerobic digestion, nutrients are conserved; odors, flies, and pathogens are reduced; and greenhouse gas emissions are eliminated, while a significant amount of energy is recovered in the biogas. The fixed-film anaerobic digester is especially suited to dilute wastewaters, such as flushed dairy manure wastewater, allowing treatment at ambient temperatures and at much shorter residence times (~3 days) compared to conventional technologies. In addition, harnessing solar energy to grow algal biomass or aquatic macrophytes on the digested effluent offers a potential solution to recover nutrients and further improve water quality.
Publications
- Wilkie, A.C., Smith, P.H. and Bordeaux, F.M. (2004). An economical bioreactor for evaluating biogas potential of particulate biomass. Bioresour. Technol. 92(1):103-109.
- Sooknah, R.D. and Wilkie, A.C. (2004). Nutrient removal by floating aquatic macrophytes cultured in anaerobically digested flushed dairy manure wastewater. Ecol. Eng. 22(1):27-42.
- Hanselman, T.A., Graetz, D.A. and Wilkie, A.C. (2004). Comparison of three enzyme immunoassays for measuring 17β-estradiol in flushed dairy manure wastewater. J. Environ. Qual. 33(5):1919-1923.
- Hanselman, T.A., Graetz, D.A. and Wilkie, A.C. (2004). Immunoassay quantification of steroidal estrogen hormones in manure, soil, and water. In: Program and Abstracts, Sustainable Land Application Conference, January 4-8, 2004, Lake Buena Vista, Florida, p.100. Soil and Water Science Department, University of Florida/IFAS, Gainesville, Florida.
- Hanselman, T.A., Graetz, D.A. and Wilkie, A.C. (2003). Limitations of immunoassay for the quantification of 17beta-estradiol in dairy manure. ASA-CSSA-SSSA Annual Meetings Abstracts 2003.
- Wilkie, A.C. (2003). Anaerobic digestion of flushed dairy manure. The Progressive Dairyman 17(11):12-13,16-17.
- Leader, J.W., Reddy, K.R. and Wilkie, A.C. (2004). Optimization of low-cost phosphorus removal from wastewater using co-treatments with constructed wetlands. In: 9th International Conference on Wetland Systems for Water Pollution Control, vol. 2. Avignon (France), September 26-30, p.683-691. International Water Association.
- Westhead, E., Pizarro, C., Mulbry, W. and Wilkie, A.C. (2004). Recycling of manure nutrients: treatment of anaerobically digested dairy manure with freshwater algae. In: Anaerobic Digestion 2004--Anaerobic Bioconversion for Sustainability, Proceedings of the 10th World Congress, vol. 3, 1785. International Water Association.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2004). Bacterial indicator decimation in flushed dairy manure wastewater by ambient temperature fixed-film anaerobic digestion. In: Anaerobic Digestion 2004--Anaerobic Bioconversion for Sustainability, Proceedings of the 10th World Congress, vol. 3, 1734-1736. International Water Association.
- Sooknah, R.D. and Wilkie, A.C. (2004). Evaluating floating aquatic macrophytes in improving the water quality of anaerobically digested flushed dairy manure wastewater. In: Anaerobic Digestion 2004--Anaerobic Bioconversion for Sustainability, Proceedings of the 10th World Congress, vol. 4, 2170-2173. International Water Association.
- Wilkie, A.C. (2004). Biogas and Anaerobic Digestion: Fundamentals and Applications. Global Climate Energy Program (GCEP), Biomass Energy Workshop, Stanford University, California, April 27, 2004. http://gcep.stanford.edu/news_event_04_26_04_biomas.html
- Wilkie, A.C. (2004). Fixed-film Digesters. AgSTAR Program Conference on Anaerobic Digestion of Animal Wastes, St. Louis, Missouri, March 24-25, 2004. http://www.epa.gov/agstar/conference04.html
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2004). Enhanced selectivity of mannitol salt agar for Staphylococcus aureus using acriflavine for examining flushed dairy manure wastewater. Abstr. 104th Gen. Meet. Am. Soc. Microbiol. 2004, Q-104. American Society for Microbiology, Washington, DC.
- Kennelley, E.D., Wilkie, A.C. and Mylavarapu, R. (2004). Soil phosphorus determination in the field: A quick and easy new method. In: Program and Abstracts, Sustainable Land Application Conference, January 4-8, 2004, Lake Buena Vista, Florida, p.106. Soil and Water Science Department, University of Florida/IFAS, Gainesville, Florida.
|
Progress 10/01/02 to 10/01/03
Outputs
Since many dairies are heavily reliant on hydraulic flushing for manure management, large volumes of wastewater are generated. These dilute wastewaters represent a significant bioenergy resource if processed by anaerobic digestion. Flushed dairy manure wastewater - defined as the liquid fraction of flushed dairy manure after particulate solids are removed - is usually too dilute for conventional anaerobic digestion systems. One practical alternative is to apply high-rate anaerobic digestion technology, such as fixed-film digestion, to recover energy and treat the flushed dairy manure wastewater at much shorter residence times (less than three days) than allowed by conventional technologies. The fixed-film anaerobic digester design allows biogas recovery and biological stabilization (permanent odor reduction) of the liquid portion of flushed dairy manure even at ambient temperature conditions. Generally, the fixed-film design is suitable for any livestock waste that is
subject to dilution with water for transport or processing, such as dairy and swine manure. The bioenergy potential of the feedstock is an important parameter in sizing a fixed-film digester and calculating cost-benefit ratios. Chemical oxygen demand (COD) reduction is linked to methane production - for every kilogram of COD converted, 0.35 m3 of CH4 is produced, which is equivalent to 12,000 BTU. For a given dairy farm, the COD concentration of the separated flushed dairy manure is a function of site-specific factors such as the number of cows and the flushwater volume contributing to the waste stream. Therefore, it is important to characterize the wastewater and compile baseline data with regard to number of animals, degree of confinement and type of bedding, feed ration/dry matter intake, volume of flushwater usage, extent of solids separation, and other relevant parameters, in order to design an appropriate fixed-film anaerobic digester for a given farm situation. Research
continues in characterizing the volume and concentration of flushed dairy manure after mechanical separation and sedimentation, monitoring the biogas production levels and treatment efficiency of the anaerobic digestion process, characterizing the reduction in odor levels, monitoring nutrient transformations, and evaluating pathogen destruction and hormone degradation.
Impacts
The increase in production and concentration of intensive livestock operations along with increased urbanization of rural regions have resulted in greater awareness and concern for the proper storage, treatment, and utilization of livestock wastes. Anaerobic digestion can offer a beneficial option for livestock waste management. In anaerobic digestion, nutrients are conserved; odors, flies, and pathogens are reduced; and greenhouse gas emissions are eliminated, while a significant amount of energy is recovered in the biogas.
Publications
- Wilkie, A.C. (2003). Anaerobic digestion of flushed dairy manure. In: Proceedings - Anaerobic Digester Technology Applications in Animal Agriculture - A National Summit, p.350-354. Water Environment Federation, Alexandria, Virginia, 2003.
- Wilkie, A.C. (2003). Fixed-film digesters: a case study. AgSTAR Digest, Winter 2003:10-11. EPA-430-F-02-028.
- Kebede-Westhead, E., Pizarro, C., Mulbry, W.W. and Wilkie, A.C. (2003). Production and nutrient removal by periphyton grown under different loading rates of anaerobically digested flushed dairy manure. J. Phycol. 39(6):1275-1282.
- Davis, J.A., Wilkie, A.C. and Farrah, S.R. (2003). The use of anaerobic digestion to control bacterial indicators and mastitic pathogens in flushed dairy manure. Abstr. 103rd Gen. Meet. Am. Soc. Microbiol. 2003, Q-255, p.560. American Society for Microbiology, Washington, DC.
- Mulbry, W., Kebede-Westhead, E., Pizarro, C.X. and Wilkie, A.C. (2002). Growth of benthic algae on dairy manure. ASA/CSSA/SSSA Annual Meetings, November 10-14, Indianapolis, Indiana. CR Rom publication.
- Hanselman, T.A., Graetz, D.A. and Wilkie, A.C. (2003). Fate of poultry manure estrogens in soils: A review. Soil Crop Sci. Soc. Fla. Proc. 62:8-12.
- Hanselman, T.A., Graetz, D.A. and Wilkie, A.C. (2003). Manure-borne estrogens as potential environmental contaminants: A review. Environonmental. Sci. Technol. 37(24):5471-5478.
|
Progress 10/01/01 to 10/01/02
Outputs
Anaerobic treatment can reduce the odor potential and pathogen levels in flushed dairy manure wastewater (FDMW) while conserving plant-available nutrients and producing energy. However, a major impediment to implementing high-rate anaerobic digestion technology, such as fixed-film digestion, to treat FDMW is the general lack of data characterizing the wastewater. An analysis was conducted, therefore, of the characteristics of FDMW after primary treatment. For a milking herd average of 359 cows and a wastewater production of 502 000 L/d, the FDMW exhibited average TS, VS, and COD-T levels of 3580, 2210, and 3530 mg/L, respectively. Analyses of FDMW parameters and manure excretion estimates indicated that 53.3% of the TS, 39.6% of the VS, and 57.6% of the COD-T remained in the FDMW after screening and sedimentation. The separation of fibrous solids increased the COD to VS ratio of the FDMW. Average wastewater temperature (estimated from soil temperature data) was found
to significantly affect both the separation of wastewater TS, VS, and COD-T and the partitioning of wastewater parameters between the particulate and soluble phases. Higher average FDMW temperatures tended to increase levels of parameters in the FDMW by reducing separator and sedimentation removal efficiencies. The ratio of soluble COD (COD-S) to dissolved VS (DVS) increased with increasing temperature, while the ratio of particulate COD (COD-P) to volatile suspended solids (VSS) decreased, indicating that significant levels of biological activity occurred in the sedimentation basin at higher temperatures. The VS measurement does not accurately measure the methane potential of components in FDMW compared to COD measurements. In spite of the fact that over 60% of the VS is removed by screening and sedimentation, more than half of the methane potential remains in the FDMW since the solids that are removed are relatively non-degradable fibers and do not contribute to methane production.
Model equations were developed to predict COD-T levels in FDMW as a function of fresh flushwater usage and cow numbers for similar dairy operations, providing an important design parameter for implementation of fixed-film anaerobic digestion systems. In anaerobic digestion, nutrients such as N and P contained in the organic compounds are conserved and mineralized to more soluble and biologically available forms. Further processing of the digested effluent is needed, therefore, to reduce the nutrient content. Harnessing solar energy to grow algal biomass on the digested effluent offers a potential solution to recover nutrients and improve water quality. Studies were conducted to investigate the ability of benthic freshwater algae to recover nutrients from anaerobically digested flushed dairy manure and to evaluate nutrient uptake rates and dry matter/crude protein yields in comparison to a conventional cropping system. Combining conventional cropping systems with an algal treatment
system could facilitate more efficient crop production and farm nutrient management, allowing dairy operations to be environmentally sustainable on fewer acres.
Impacts
Anaerobic digestion under controlled conditions, as in a fixed-film reactor, has many practical advantages for animal feeding operations. This holistic manure treatment system not only stabilizes the wastewater, but also produces energy, controls odors, reduces pathogens, minimizes environmental impact from waste emissions, and maximizes fertilizer and water recovery for reuse. The fixed-film anaerobic digester is especially suited to dilute wastewaters, such as flushed dairy manure wastewater, allowing treatment at ambient temperatures and at much shorter residence times (less than three days) compared to conventional technologies. In addition, harnessing solar energy to grow algal biomass on the digested effluent offers a potential solution to recover nutrients and further improve water quality.
Publications
- Wilkie, A.C. and Mulbry, W.W. (2002). Recovery of dairy manure nutrients by benthic freshwater algae. Bioresour. Technol. 84(1), 81-91.
- Wilkie, A.C. (2002). Reducing dairy manure odor and producing energy. In: Renewable Energy from Organics Recycling, p.58-60. The JG Press, Inc., Emmaus, Pennsylvania.
- Davis, J., Wilkie, A.C. and Farrah, S.R. (2002). Fate of bacterial indicators and pathogens in anaerobically digested dairy wastewater. Abstr. 2002 Annual Meeting, No. 8, p.18. Southeastern Branch, American Society for Microbiology.
- Davis, J.A., Farrah, S.R. and Wilkie, A.C. (2002). Bacterial indicator and pathogen reduction in anaerobically treated flushed dairy manure. Abstr. 2002 Annual Meeting, p.6. Florida Branch, American Society for Microbiology.
- Animal waste management: technology for odor control, energy production and nutrient recovery. Myakka 2(2):3. Summer 2002. Soil and Water Science Department, University of Florida, Gainesville.
- Ukrainian farmers seek waste treatment technology. International Focus 13(4), 2002. http://international.ifas.ufl.edu/focusweb/focusaug02007.htm UF/IFAS Office of International Programs.
- Florida researcher works to reduce manure odor while producing energy. Wisconsin State Farmer May 3, 2002, p.7C.
- Digester gobbles up odors. AgWeb News January 17, 2002. http://www.agweb.com/news_show_news_article.asp?articleID=83281&newsc at=GN
- Dairy Today: Digester gobbles up odors. AgWeb News January 5, 2002. http://www.agweb.com/news_show_news_article.asp?articleID=82850&newsc at=GN
- Digester gobbles up odors. Dairy Today 18(1):17-18. January, 2002.
|
|