Progress 04/03/10 to 04/02/15

Outputs
Progress Report Objectives (from AD-416): Development and evaluation of manure treatment systems. Specific objectives: (1) Develop treatment technologies and management practices to reduce the concentrations of pharmaceutically active compounds (antibiotics and natural hormones) in manures, litters, and biosolids utilized in agricultural settings; (2) Develop management practices and technologies to minimize greenhouse gas (GHG) emissions from manure and litter storage and from composting operations by manipulating the biological, chemical, and physical processes influencing production and release of ammonia and greenhouse gases during composting; (3) Develop technology and management practices that improve the economics and treatment efficiency of anaerobic digestion of animal manures and other organic feedstocks (e.g. food wastes, crops/residues) for waste treatment and energy production. Approach (from AD-416): Modern livestock production involves the use of large amounts of nutrient inputs as well as antibiotics. Untreated manure is either stored or immediately applied to farmland as a fertilizer. When manure is applied to fields, manure components (nutrients, microorganisms, and remaining antibiotic residues) may reach surface water by volatilization, run-off or leaching. The goal of this research is to improve our basic understanding of two common manure treatment practices (composting and anaerobic digestion) so as to maximize their benefits and minimize their economic and environmental costs. The first objective is to evaluate the efficacy of a series of minimal management options for composting manure and poultry litter on-farm to reduce concentrations of ten widely used pharmaceutically active compounds. Treatments are designed to span a range of practical management options � from the current practice of stockpiling the manure/litter to amending it with straw (to increase aeration) and adding insulating layers of straw. The second objective seeks to reduce the environmental footprint of composting by reducing methane, nitrous oxide, and ammonia emissions during composting. Greenhouse gas and ammonia emissions will be measured using replicate pilot-scale compost piles composed of manure/bedding from the BARC dairy and food/green wastes from local food processors. The first set of treatments will test the timing and frequency of compost mixing and turning. Subsequent experiments will measure and compare gas emissions from replicate piles constructed at initial bulk densities and from piles covered with 7-30 cm layers of finished compost. The third objective involves an evaluation of a relatively low-cost anaerobic digestion system that has significant potential for use on small farms. Six replicate pilot-scale plug-flow digesters, with two operational designs will be studied to provide long-term research on a system that has not been fully explored. Treatment efficiency, capital and operational costs, and gas utilization strategies will be evaluated for each type of system. Costs and benefits of different treatment strategies will be compared to existing manure management practices. The goal of this research is to improve our basic understanding of two common manure treatment practices (composting and anaerobic digestion) so as to maximize their benefits and minimize their economic and environmental costs. All three objectives fall under National Program 214. Under the first objective, we evaluated the efficacy of composting to reduce concentrations of four widely used ionophore feed supplements in dairy manure and poultry litter. Results show that the effectiveness of composting for contaminant reduction is compound and matrix specific. For two of the compounds, composting temperatures were not any more effective than ambient temperature in increasing the rate or extent of contaminant removal. For the other two compounds, composting was an effective treatment, but was likely to be too slow to be useful in practice. Results from this study compliment those from previous studies and allow for practical decisions of whether composting efforts are likely to reduce specific ionophore levels below those in unmanaged manure or poultry stockpiles. Under the second objective, we evaluated the effectiveness of different management practices to reduce greenhouse gas emissions during the composting of dairy manure. Composting is an environmentally friendly technology for treating and recycling a variety of organic wastes. However, gaseous emissions of methane and nitrous oxide are negative consequences of composting because they contribute toward total greenhouse gas (GHG) emissions. Results showed that GHG emissions from piles that were mixed once or twice during a six week trial were about 20% higher than emissions from unmixed piles. Increased GHG emissions were primarily due to increased emissions of carbon dioxide within the first 21 days of composting. Delaying initial mixing of piles from two weeks to five weeks did not reduce total GHG emissions in mixed piles. Although GHG emissions can be reduced by storage of manure in unmixed (static) piles, dairies will have to balance this benefit against the need to mix piles for pathogen and weed seed reduction. Under the third objective, we evaluated a relatively low-cost anaerobic digestion system using unmixed bag digesters that has significant potential for use on small farms. Anaerobic digesters are used on about 300 U.S. dairies for treatment of manure prior to storage and land application. Such digesters reduce emissions of methane (a potent greenhouse gas), reduce manure odors during land application, and provide a means to produce bio-energy and help meet renewable energy targets. However, traditional digesters are too expensive for the vast majority of U.S. farms. Unmixed plug-flow digesters are relatively inexpensive and are commonly used in tropical climates where supplemental heating is not required. Results show that digester performance values were comparable for both types of digesters (traditional vertical tank and unmixed bag digesters). Results also showed that performance of unmixed bag digesters were nearly as good at low temperatures (22 to 28 C) compared to performance at the traditional higher temperature of 35 C. Results from this study are of interest within the dairy and livestock industries as they work to reduce its fossil fuel use and greenhouse gas emissions. Accomplishments 01 Forage radish increases methane production during anaerobic digestion of dairy manure. The economics of dairy manure-based digesters are not always favorable due to the relatively low biogas yield of dairy manure compared to other organic wastes. However, co-digesting dairy manure with other substrates have been shown to increase biogas production up to 5-fold compared to digestion of manure without amendment. As part of a larger effort to evaluate the environmental benefits of the cover crop winter radish, ARS scientists in Beltsville, Maryland, sought to determine optimal mixtures of dairy manure and chopped forage radish for anaerobic digestion. Results showed that methane production increased as the radish content increased. Results also showed that forage radish harvest date did not affect methane production during co- digestion with dairy manure. These results will be useful for those interested in additional benefits of cover crops and dairy farmers interested in increasing methane production in digesters during the winter months when the demand for supplemental heating is the greatest. 02 Evaluation of inexpensive anaerobic digesters for small dairy farms. Anaerobic digesters are used on about 300 U.S. dairies for treatment of manure prior to storage and land application. In a cooperative project between ARS in Beltsville, Maryland, and the University of Maryland, researchers designed and constructed six pilot-scale plug flow digesters, using simple, successful designs used in developing countries modified to function in the temperate climate of the U.S. Results showed that biogas production and solids removal values of the simple unmixed pilot-scale digesters were comparable to values from a traditional farm-scale vertical tank digester. Results from this study are of interest within the dairy and livestock industries as they work to reduce their fossil fuel use and greenhouse gas emissions. 03 Monitoring of endocrine disrupting chemicals in municipal wastewater effluents and Midwestern streams. Municipal wastewater effluents are known contributors of endocrine disrupting chemicals (EDCs) to waterways. From 1999 to 2009 a variety of EDCs were monitored in effluent dominated streams in five Midwestern states ( Indiana, Illinois, Michigan, Minnesota and Ohio). Samples included municipal wastewater effluents, stream samples receiving these effluents, and fish exposed in theses streams. Numerous suspected endocrine disruption causing compounds were detected including the alkyphenolic compounds bisphenol A and triclosan. Analysis of fish tissues and biomarkers indicated widespread occurrence of alkylphenolic compounds and estrogenic chemicals especially in streams that receive wastewater effluents. Establishing benchmark levels and trends for these compounds are important for understanding the scale of their distribution and effect in the environment.

Impacts
(N/A)

Publications

• Barber, L.B., Loyo-Rosales, J.E., Rice, C., Minarik, T.A., Oskouie, A. 2015. Endocrine disrupting alkylphenolic chemicals and other contaminants in wastewater treatment plant effluents, urban streams and fish in the Great Lakes Region and Upper Mississippi River. Science of the Total Environment. 517:195-206.
• Belle, A., Lansing, S., Mulbry III, W.W., Weil, R. 2015. Anaerobic co- digestion of forage radish and dairy manure in complete mix digesters. Bioresource Technology. 178:230-237.
• Lansing, S., Klavon, K., Mulbry III, W.W., Moss, A. 2015. Design and validation of field-scale anaerobic digesters treating dairy manure for small farms. Transactions of the ASABE. 58(2):1-10.

Progress 10/01/13 to 09/30/14

Outputs
Progress Report Objectives (from AD-416): Development and evaluation of manure treatment systems. Specific objectives: (1) Develop treatment technologies and management practices to reduce the concentrations of pharmaceutically active compounds (antibiotics and natural hormones) in manures, litters, and biosolids utilized in agricultural settings; (2) Develop management practices and technologies to minimize greenhouse gas (GHG) emissions from manure and litter storage and from composting operations by manipulating the biological, chemical, and physical processes influencing production and release of ammonia and greenhouse gases during composting; (3) Develop technology and management practices that improve the economics and treatment efficiency of anaerobic digestion of animal manures and other organic feedstocks (e.g. food wastes, crops/residues) for waste treatment and energy production. Approach (from AD-416): Modern livestock production involves the use of large amounts of nutrient inputs as well as antibiotics. Untreated manure is either stored or immediately applied to farmland as a fertilizer. When manure is applied to fields, manure components (nutrients, microorganisms, and remaining antibiotic residues) may reach surface water by volatilization, run-off or leaching. The goal of this research is to improve our basic understanding of two common manure treatment practices (composting and anaerobic digestion) so as to maximize their benefits and minimize their economic and environmental costs. The first objective is to evaluate the efficacy of a series of minimal management options for composting manure and poultry litter on-farm to reduce concentrations of ten widely used pharmaceutically active compounds. Treatments are designed to span a range of practical management options � from the current practice of stockpiling the manure/litter to amending it with straw (to increase aeration) and adding insulating layers of straw. The second objective seeks to reduce the environmental footprint of composting by reducing methane, nitrous oxide, and ammonia emissions during composting. Greenhouse gas and ammonia emissions will be measured using replicate pilot-scale compost piles composed of manure/bedding from the BARC dairy and food/green wastes from local food processors. The first set of treatments will test the timing and frequency of compost mixing and turning. Subsequent experiments will measure and compare gas emissions from replicate piles constructed at initial bulk densities and from piles covered with 7-30 cm layers of finished compost. The third objective involves an evaluation of a relatively low-cost anaerobic digestion system that has significant potential for use on small farms. Six replicate pilot-scale plug-flow digesters, with two operational designs will be studied to provide long-term research on a system that has not been fully explored. Treatment efficiency, capital and operational costs, and gas utilization strategies will be evaluated for each type of system. Costs and benefits of different treatment strategies will be compared to existing manure management practices. Progress was made on two objectives, both of which fall under National Program 214, and focus on improving our basic understanding of two common manure treatment practices (composting and anaerobic digestion). Under Objective 1, technologies and practices to reduce concentrations of pharmaceutically active compounds in manures, litters, and biosolids, progress in analyzing compost samples for four of the ten pharmaceutically active compounds (PACs) targeted in this project was made. Under Objective 3, a four-month field trial using replicate pilot- scale anaerobic digesters was completed in September 2013 and the initial phase of a temperature optimization study complete in May 2014. Accomplishments 01 Nutrient removal from agricultural drainage water using algal turf scrubbers. One possible approach for removing non-point source nutrients before they reach the Chesapeake Bay is to deploy algal turf scrubbers (ATS) along agricultural drainage canals. In ATS systems, algae grow on dissolved nutrients and are harvested for use as fertilizer or a soil amendment. ARS researchers in Beltsville, MD determined rates of nutrient removal and costs using ATS raceways located on a primary drainage canal on Maryland�s Eastern Shore. Since drainage canals are typically remote from conventional power connections, the ARS researchers also evaluated solar-powered pumping systems for off-grid ATS use. Replicate ATS raceways were operated continuously for five month periods in 2010 and 2011. Results showed that projected nutrient removal costs for a one acre ATS unit are, depending on the source of electricity and capital cost, about $45/lb of nitrogen or more than $250/lb of phosphorus. These nutrient removal costs are more than 10-fold higher than previous estimates because of lower rates of algal growth, lower algal nutrient content, and higher electricity rates compared to those used in previous studies. Algal- based water treatment systems are being evaluated for possible inclusion as a best management practice within the Chesapeake Bay Program Watershed Model. These results are important for this evaluation because they are derived from field-scale experience on agricultural drainage water. 02 The fate and persistence of two commercial bacteriostats in biosolids. Agricultural use of biosolid wastes from sewage treatment plants is prevalent across the U.S. Contamination by their accompanying organic microconstituents can result in releases to the environment and cause possible endocrine disruptive effects on aquatic animals in receiving waters. ARS researchers at Beltsville, MD conducted studies on two popular bacteriostats, triclosan and triclocarban, which involved 1) examining processes leading to their release within the plant, 2) a prototype large scale composting process involving a silage bag system, and 3) fate and persistence after field application over several acres in Virginia. The two bacteriostats served as model compounds. Triclosan was found to degrade in the sewage treatment plant and also disappear in the silage bag at moderate rates and after field spreading. The removal half-life was 104 days. However, triclocarban was much more persistent with an estimated half-life of more than 400 days when field applied in biosolids. Silage bag removal of triclocarban was also minimal. This information is useful to farmers in order to protect streams and waterways adjoining their properties and to policymakers who need better information when offering advice about where and how to use these important soil additives.

Impacts
(N/A)

Publications

• Kangas, P., Mulbry III, W.W. 2013. Nutrient removal of agricultural drainage water using algal turf scrubbers and solar power. Bioresource Technology. 152:484-489.
• Lozano, N., Rice, C., Ramirez, M., Torrents, A. 2013. Fate of triclocarban, triclosan and methyltriclosan during wastewater and biosolids treatment processes. Water Research. 47:4519-4527.
• Lozano, N., Andrade, N., Deng, D., Torrents, A., Rice, C., Mcconnell, L.L., Ramirez, M., Millner, P.D. 2014. Fate of microconstituents in biosolids composted in an aerated silage bag. Journal of Environmental Science and Health. 49(A):720-730. DOI:10.1080/10934529.2014.865461.

Progress 10/01/12 to 09/30/13

Outputs
Progress Report Objectives (from AD-416): Development and evaluation of manure treatment systems. Specific objectives: (1) Develop treatment technologies and management practices to reduce the concentrations of pharmaceutically active compounds (antibiotics and natural hormones) in manures, litters, and biosolids utilized in agricultural settings; (2) Develop management practices and technologies to minimize greenhouse gas (GHG) emissions from manure and litter storage and from composting operations by manipulating the biological, chemical, and physical processes influencing production and release of ammonia and greenhouse gases during composting; (3) Develop technology and management practices that improve the economics and treatment efficiency of anaerobic digestion of animal manures and other organic feedstocks (e.g. food wastes, crops/residues) for waste treatment and energy production. Approach (from AD-416): Modern livestock production involves the use of large amounts of nutrient inputs as well as antibiotics. Untreated manure is either stored or immediately applied to farmland as a fertilizer. When manure is applied to fields, manure components (nutrients, microorganisms, and remaining antibiotic residues) may reach surface water by volatilization, run-off or leaching. The goal of this research is to improve our basic understanding of two common manure treatment practices (composting and anaerobic digestion) so as to maximize their benefits and minimize their economic and environmental costs. The first objective is to evaluate the efficacy of a series of minimal management options for composting manure and poultry litter on-farm to reduce concentrations of ten widely used pharmaceutically active compounds. Treatments are designed to span a range of practical management options � from the current practice of stockpiling the manure/litter to amending it with straw (to increase aeration) and adding insulating layers of straw. The second objective seeks to reduce the environmental footprint of composting by reducing methane, nitrous oxide, and ammonia emissions during composting. Greenhouse gas and ammonia emissions will be measured using replicate pilot-scale compost piles composed of manure/bedding from the BARC dairy and food/green wastes from local food processors. The first set of treatments will test the timing and frequency of compost mixing and turning. Subsequent experiments will measure and compare gas emissions from replicate piles constructed at initial bulk densities and from piles covered with 7-30 cm layers of finished compost. The third objective involves an evaluation of a relatively low-cost anaerobic digestion system that has significant potential for use on small farms. Six replicate pilot-scale plug-flow digesters, with two operational designs will be studied to provide long-term research on a system that has not been fully explored. Treatment efficiency, capital and operational costs, and gas utilization strategies will be evaluated for each type of system. Costs and benefits of different treatment strategies will be compared to existing manure management practices. Progress was made on two objectives, both of which fall under National Program 214, and focus on improving our basic understanding of two common manure treatment practices (composting and anaerobic digestion). Under objective 1, technologies and practices to reduce concentrations of pharmaceutically active compounds in manures, litters, and biosolids, we made progress in developing methods for analysis of three of the four pharmaceutically active compounds (PACs) targeted this year in poultry litter and dairy manure. In addition, we completed analyzing composting results for four other PACs. Under objective 3, we completed construction of six replicate pilot-scale anaerobic digesters and began field trials in May 2013 using dairy manure from the BARC digester. Accomplishments 01 In the U.S., anaerobic digestion (AD) is an economically viable manure treatment option for large dairies (>500 cows). However, since roughly 90% of U.S. dairies have less than 200 cows, this technology is economically inaccessible to the vast majority of U.S. dairies. As part of a research effort focused on developing designs and strategies to make anaerobic digestion technology available to small farms, ARS and University of Maryland scientists performed an economic assessment of small-scale U.S. digesters using cost data from eight existing 100 to 250-cow dairies and eight theoretical systems. Cash flow analysis results showed that total capital costs, capital costs per cow, and net costs per cow generally decreased with increasing herd size in existing systems. Among existing revenue streams, use of digested solids for bedding generated the highest revenue ($100 per cow per year), followed by biogas use for heating and/or electrical generation ($47 to $72 per cow per year) and CO2 credits ($7 per cow per year). No system had a positive cash flow under the assumed conditions (8% discount rate, 20 year term). However, six of the sixteen systems had positive cash flows when 50% cost sharing was included in the analysis. Our results suggest that, with cost sharing, economically viable AD systems are possible on 250-cow dairies. Additional revenue streams, such as tipping fees for food waste, may reduce the minimum size to 100-cow dairies. These efforts support current efforts within the U.S. dairy industry to increase renewable energy and decrease greenhouse gas emissions on dairy farms. 02 Algal turf scrubbing (ATS) is an engineered wastewater treatment system in which lawn-like, filamentous algae are grown in shallow sloping raceways. Algae grow using the nutrients in the wastewater and are removed from the system by weekly harvesting. Beyond their practical application for wastewater treatment, ATS systems are also useful for answering much more basic questions in biology and ecology. Some species of algae grow very quickly within algal turf scrubbers. However, which species dominate and how fast they grow is partially dependent on the water flow rate through the system. The general goal of this research is to develop automated systems in which a characteristic (such as color, growth rate, or size) of the organisms being grown is used to control the system in which the organisms are grown (for example, by affecting the feeding rate, temperature, or amount of light). The specific objective of these experiments was to evaluate how well algal growth rates could be used to automatically optimize water flow rates in an ATS. Results from computer modeling experiments showed that algal growth rates could be used in concert with a feedback control system to optimize water flow rates. However, in practice, the variability of algal growth rates between weekly harvests frequently confused the feedback control system. Consequently, some experimental trials resulted in optimal flow rates but other trials were not successful. Nonetheless, these results will be useful for scientists trying to develop automated control systems and for companies seeking to grow crops of algae using the least amount of energy.

Impacts
(N/A)

Publications

• Blersch, D., Kangas, P., Mulbry III, W.W. 2013. Autonomous benthic algal cultivator under feedback control of ecosystem metabolism. Environmental Engineering Science. 60:53-60.
• Blersch, D., Kangas, P., Mulbry III, W.W. 2013. Turbulence and nutrient interactions that control benthic algal production in an engineered cultivation raceway. Algal Research. 2:107-112.
• Klavon, K., Lansing, S., Moss, A., Mulbry III, W.W., Felton, G. 2013. Economic analysis of small-scale agricultural digesters in the United States. Biomass and Bioenergy. 54:36-45.
• Mulbry, III, W.W., Reeves, III, J.B., Liu, Y., Zhen, R., Liao, W. 2012. Near- and mid-infrared spectroscopic determination of algal composition. Journal of Applied Phycology. 24:1261-1267.
• Olszewski, J.M., Lozano, N., Haines, C., Rice, C., Ramirez, M., Torrents, A. 2013. The effect of liming on antibacterial and hormone levels in wastewater biosolids. Waste Management and Research. 48:862-870.

Progress 10/01/11 to 09/30/12

Outputs
Progress Report Objectives (from AD-416): Development and evaluation of manure treatment systems. Specific objectives: (1) Develop treatment technologies and management practices to reduce the concentrations of pharmaceutically active compounds (antibiotics and natural hormones) in manures, litters, and biosolids utilized in agricultural settings; (2) Develop management practices and technologies to minimize greenhouse gas (GHG) emissions from manure and litter storage and from composting operations by manipulating the biological, chemical, and physical processes influencing production and release of ammonia and greenhouse gases during composting; (3) Develop technology and management practices that improve the economics and treatment efficiency of anaerobic digestion of animal manures and other organic feedstocks (e.g. food wastes, crops/residues) for waste treatment and energy production. Approach (from AD-416): Modern livestock production involves the use of large amounts of nutrient inputs as well as antibiotics. Untreated manure is either stored or immediately applied to farmland as a fertilizer. When manure is applied to fields, manure components (nutrients, microorganisms, and remaining antibiotic residues) may reach surface water by volatilization, run-off or leaching. The goal of this research is to improve our basic understanding of two common manure treatment practices (composting and anaerobic digestion) so as to maximize their benefits and minimize their economic and environmental costs. The first objective is to evaluate the efficacy of a series of minimal management options for composting manure and poultry litter on-farm to reduce concentrations of ten widely used pharmaceutically active compounds. Treatments are designed to span a range of practical management options � from the current practice of stockpiling the manure/litter to amending it with straw (to increase aeration) and adding insulating layers of straw. The second objective seeks to reduce the environmental footprint of composting by reducing methane, nitrous oxide, and ammonia emissions during composting. Greenhouse gas and ammonia emissions will be measured using replicate pilot-scale compost piles composed of manure/bedding from the BARC dairy and food/green wastes from local food processors. The first set of treatments will test the timing and frequency of compost mixing and turning. Subsequent experiments will measure and compare gas emissions from replicate piles constructed at initial bulk densities and from piles covered with 7-30 cm layers of finished compost. The third objective involves an evaluation of a relatively low-cost anaerobic digestion system that has significant potential for use on small farms. Six replicate pilot-scale plug-flow digesters, with two operational designs will be studied to provide long-term research on a system that has not been fully explored. Treatment efficiency, capital and operational costs, and gas utilization strategies will be evaluated for each type of system. Costs and benefits of different treatment strategies will be compared to existing manure management practices. Progress was made on all three objectives, all of which fall under National Program 214, and focus on improving our basic understanding of two common manure treatment practices (composting and anaerobic digestion) . Under objective 1, technologies and practices to reduce concentrations of pharmaceutically active compounds in manures, litters, and biosolids, we made progress in developing methods for analysis of five of the pharmaceutically active compounds of interest in poultry litter. Under objective 2, practices and technologies to minimize greenhouse gas (GHG) emissions from manure storage and composting operations, we made significant progress in determining the effect of delaying compost mixing on GHG emissions. Under objective 3, we made progress toward completing construction of replicate pilot-scale anaerobic digesters. Construction was delayed by unexpected failure of the digester bag material. More durable digester bags have now been installed. Additional insulation and more efficient heat exchangers are also being installed. Accomplishments 01 Greenhouse gas emissions from dairy manure composting operations. Manur management practices are widely regarded to significantly affect greenhouse gas (GHG) emissions from livestock operations. Unfortunately there is relatively little specific information regarding the effect of different management practices on GHG emissions that is useful to producers. Manure composting is thought to reduce total GHG emissions relative to emissions from untreated manure. The objective of this stud was to characterize emissions from pilot-scale dairy manure compost pile Results from two separate trials showed that total methane emissions decreased significantly as the date of first mixing was delayed. Ultimately, decisions to delay compost turning to reduce GHG emissions will have to be balanced against the schedule required for pathogen reduction.

Impacts
(N/A)

Publications

• Varel, V.H., Wells, J., Shelver, W.L., Rice, C., Armstrong, D.L., Parker, D.B. 2012. Effect of anaerobic digestion temperature on odour, coliforms and chlortetracycline in swine manure or monensin in cattle manure. Journal of Applied Microbiology. 112:705-715.
• Lozano, N., Rice, C., Pagano, J., Zintek, L., Barber, L., Murphy, E.W., Nettesheim, T., Minarik, T., Schoenfuss, H. 2012. Tissue concentrations of organic contaminants in fish and their biological effects in a wastewater- dominated urban stream. Science of the Total Environment. 420:191-201.
• Lozano, N., Rice, C., Ramirez, M., Torrents, A. 2012. Fate of triclosan and methyltriclosan in soil from biosolids application. Environmental Pollution. 160:103-108.
• Chen, R., Yuea, Z., Deitza, L., Liu, Y., Mulbry III, W.W., Liao, W. 2012. Use of an algal hydrolysate to improve enzymatic hydrolysis of anaerobically digested fiber. Bioresource Technology. 108:149-154.
• Mulbry III, W.W., Reeves III, J.B., Millner, P.D. 2012. Use of Mid- and Near-Infrared Spectroscopy to Track Degradation of Polyactide Eating Utensils and Containers During Composting. Internet Journal of Vibrational Spectroscopy. 109:93-97.

Progress 10/01/10 to 09/30/11

Outputs
Progress Report Objectives (from AD-416) Development and evaluation of manure treatment systems. Specific objectives: (1) Develop treatment technologies and management practices to reduce the concentrations of pharmaceutically active compounds (antibiotics and natural hormones) in manures, litters, and biosolids utilized in agricultural settings; (2) Develop management practices and technologies to minimize greenhouse gas (GHG) emissions from manure and litter storage and from composting operations by manipulating the biological, chemical, and physical processes influencing production and release of ammonia and greenhouse gases during composting; (3) Develop technology and management practices that improve the economics and treatment efficiency of anaerobic digestion of animal manures and other organic feedstocks (e.g. food wastes, crops/residues) for waste treatment and energy production. Approach (from AD-416) Modern livestock production involves the use of large amounts of nutrient inputs as well as antibiotics. Untreated manure is either stored or immediately applied to farmland as a fertilizer. When manure is applied to fields, manure components (nutrients, microorganisms, and remaining antibiotic residues) may reach surface water by volatilization, run-off or leaching. The goal of this research is to improve our basic understanding of two common manure treatment practices (composting and anaerobic digestion) so as to maximize their benefits and minimize their economic and environmental costs. The first objective is to evaluate the efficacy of a series of minimal management options for composting manure and poultry litter on-farm to reduce concentrations of ten widely used pharmaceutically active compounds. Treatments are designed to span a range of practical management options � from the current practice of stockpiling the manure/litter to amending it with straw (to increase aeration) and adding insulating layers of straw. The second objective seeks to reduce the environmental footprint of composting by reducing methane, nitrous oxide, and ammonia emissions during composting. Greenhouse gas and ammonia emissions will be measured using replicate pilot-scale compost piles composed of manure/bedding from the BARC dairy and food/green wastes from local food processors. The first set of treatments will test the timing and frequency of compost mixing and turning. Subsequent experiments will measure and compare gas emissions from replicate piles constructed at initial bulk densities and from piles covered with 7-30 cm layers of finished compost. The third objective involves an evaluation of a relatively low-cost anaerobic digestion system that has significant potential for use on small farms. Six replicate pilot-scale plug-flow digesters, with two operational designs will be studied to provide long-term research on a system that has not been fully explored. Treatment efficiency, capital and operational costs, and gas utilization strategies will be evaluated for each type of system. Costs and benefits of different treatment strategies will be compared to existing manure management practices. Although composting is an effective practice for stabilizing manure nutrients prior to land application, emissions of ammonia, methane, and nitrous oxide during composting are negative environmental consequences of this process. There is a need to determine the emissions of these gases during typical farm-scale composting operations and to test the effectiveness of different management measures to reduce emissions. Pilot-scale dairy manure composting studies were completed during the year using a photoacoustic gas analyzer for measuring ammonia, methane, carbon dioxide and nitrous oxide emissions. There is a global need to reduce dependency on fossil energy and to make use of sustainable energy feedstocks. Current anaerobic digestion technology in the U.S. is focused on large-scale dairy farms (greater than 500 cows). However, the vast majority of dairies (in the U.S. and elsewhere) have less than 200 cows. There is an urgent need to develop and support inexpensive anaerobic digestion systems for these small farms. One approach to increase biogas production at small dairies is to develop low cost digester systems. Nine pilot-scale low-cost digesters are under construction at the BARC dairy. Use of these digesters in concert with conventional digesters will allow direct comparison of biogas production under different loading rates and operating conditions. Accomplishments 01 Greenhouse gas emissions from dairy manure composting operations. Manur management practices are widely regarded to significantly affect greenhouse gas (GHG) emissions from livestock operations. Unfortunately there is relatively little specific information regarding the effect of different management practices on GHG emissions that is useful to producers. Manure composting is thought to reduce total GHG emissions relative to emissions from untreated manure. The objective of this stud was to characterize emissions from pilot-scale dairy manure compost pile Results from unmixed flat-top or conically shaped piles suggest that pi shape does not significantly influence GHG emissions. However, preliminary results suggest that pile composition may have a large effec on overall emissions. In the BARC dairy in Beltsville, Maryland, solids are screened out of the scraped manure slurry prior to anaerobic digesti of the manure liquids. The screened solids are composted along with manure and bedding from other parts of the dairy. Our preliminary resul showed that emissions of methane (an undesirable greenhouse gas) increas with increasing amounts of dairy solids in the compost piles. Although screened dairy solids are typically present as a minor component in compost piles, additional studies are needed to determine the effect (if any) of low levels of screened dairy solids on methane emissions. 02 Over four billion pounds of chicken feather waste is generated by the U. poultry industry each year. Although feathers are typically disposed of in landfills, a new use for feather fiber is as a component of biopolyme The primary advantage of feather-based biopolymers is that they reduce the use of petroleum-based feedstocks. However, an added benefit of som biopolymers is that they degrade relatively quickly under composting conditions. Since the fate of feather-based biopolymers during composti has not been studied previously, the aim of this study was to characteri the biodegradability of two biopolymers containing different amounts of poultry feather fiber. Our results showed that feather fiber was not degraded in either biopolymer after composting feather-fiber biopolymer fragments under standard conditions (60 days at 135 F). Raw feather fib (primarily composed of the protein keratin) is itself quite resistant to microbial breakdown. However, results from other studies have shown tha raw feather fiber can be degraded using special keratinase-producing fun and bacteria. Additional studies are needed to see whether these organisms can speed the degradation of feather-fiber bioplastics. 03 Although algal cultivation and algae-based wastewater treatment systems have been in use for decades, there is renewed interest in such systems because of the potential use of the algal byproduct as a fertilizer or biofuel feedstock. Given the possible use of algal systems for treating varied sources of agricultural wastewater, robust and inexpensive method of analysis for algal components are needed. At the present time, most algal samples are analyzed by conventional wet chemical methods, such as the Kjeldahl procedure for total nitrogen and phosphorus or by combustio techniques for total carbon or nitrogen. These procedures, while accura can be time consuming and expensive, and they generate chemical wastes. Infrared reflectance spectroscopy is an alternative method of analysis f determining the composition of a wide variety of materials ranging from forages and grains, food products, manure, and soil. Infrared spectroscopy can accurately and rapidly determine sample composition, while greatly reducing the waste associated with conventional analysis systems. The objective of this study was to investigate the feasibility of using near-infrared reflectance spectroscopy (NIRS) and mid-infrared reflectance spectroscopy (MIRS) to determine the composition of algal samples. Results showed that that both NIRS and MIRS can accurately determine ash and total nitrogen concentrations, but not phosphorus, sug lipid, or fatty acid concentrations in algal samples. Given these results, it may be possible to adapt and develop inexpensive infrared- based analyzers for determining ash and nitrogen concentrations in algal samples.

Impacts
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Publications

• Ahn, H., Smith, M.C., Schmidt, W.F., Huda, M.S., Reeves III, J.B., Mulbry III, W.W. 2011. Biodegradability of injection molded bioplastics containing polylactic acid and poultry feather fiber. Bioresource Technology. 102:4930-4933.
• Ahn, H., Mulbry III, W.W., White, J.W., Ingram, S.K. 2010. Pile mixing increases greenhouse gas emissions during composting of dairy manure. Bioresource Technology. 102:2904-2909.
• Adey, W., Kangas, P., Mulbry Iii, W.W. 2011. Algal turf scrubbing: cleaning surface waters with solar energy while producing a biofuel. Bioscience. 61:434-441.