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United States Department of Agriculture

Agricultural Research Service


Location: Coastal Plain Soil, Water and Plant Conservation Research

2010 Annual Report

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

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

3.Progress Report
Filed an invention patent on a novel bacterial strain of Anammox bacteria Brocadia caroliniensis that oxidizes ammonia and releases di-nitrogen; the bacteria was deposited in Agricultural Research Culture Collections (Peoria, Illinois). Filed an invention patent on a method to reduce gaseous ammonia from poultry houses and other rearing facilities and its recovery using gas-permeable membranes. Conducted experiments of immobilization of Anammox bacteria in polymer pellets, which were used for treatment of livestock wastewater. Conducted experiments of stable partial nitrification of swine wastewater using High Performance Nitrifying Sludge. The evaluation of gas permeable membrane technology was made for removing ammonia from liquid manure.

Collected additional data on the absorption capacity of biochar (made from animal manure) for removing ammonia and hydrogen sulfide.

Published a journal paper on denitrification activity in swine wastewater lagoons; collected and analyzed denitrification and nitrous oxide emission data from additional control riparian buffers. Analyzed data and reported the improvement in phosphorus removal via addition of polyaluminum chloride in swine wastewater treatment wetland.

Developed and tested process control schemes for production of a consistent biochar product; analyzed energy, composition and thermal degradation characteristics of high and low temperature biochars (350°C and 700°C) from dairy, swine, turkey, poultry, and feedlot manures. Assessed the adsorption capacity of manure based-biochars for aqueous copper, zinc, and cadmium. Completed evaluation of a skid-mounted commercial batch pyrolysis system to produce energy and biochar from blended animal manures.

1. Invented and Developed a Second-Generation Treatment System for Management of Livestock Manure: ARS Scientists at Florence, South Carolina, and business cooperators have developed a streamlined second-generation swine manure management process that delivers healthier pigs, healthier profits, and a healthier environment. A U.S. Patent 7,674,379 was issued in 2010. The system used solid-liquid separation and nitrogen and phosphorus removal processes that replaced traditional anaerobic lagoons with a system that produces a clean, deodorized, and disinfected effluent. It was certified by the State of North Carolina as an Environmentally Superior Technology (EST) due to its efficacy in reducing problems of ammonia emissions, excess nitrogen and phosphorus, pathogens, odors, and heavy metals. North Carolina and USDA NRCS’s Environmental Quality Incentives Program started a statewide Lagoon Conversion Program (LCP) that provides financial support to livestock farmers installing an EST for manure management. The revamped system met EST standards at one-third the cost of the previous version. The new system also cut emissions of methane and nitrous oxide—powerful greenhouse gases—by 97 percent. Animal health and production also benefited: Swine daily weight gain increased, feed conversion improved, and animal mortality decreased. Using the second-generation system instead of the lagoon system, the farmer sold 61,400 pounds more hogs –a 5.8% increase- per growing cycle. This technology was featured as an example of five carbon-reducing technologies that can quickly create green jobs in America in the report “Manufacturing Climate Solutions: Carbon-Reducing Technologies and U.S. Jobs,” that was presented at the first Middle Class Task Force meeting organized by the White House. The new technology is being commercialized by Terra Blue Inc., of Clinton, N.C. The scientists received the 2010 Federal Laboratory Consortium (FLC) for Excellence in Technology Transfer.

2. Technology to recover phosphorus from solid manure: A process called ‘quick wash’ was developed to recover phosphorus (P) from livestock solid manure to reduce the environmental impact of P litter. This technology provides an alternative to poultry litter management when application onto land is not an option in areas such as Georgia, North Carolina, and Chesapeake Bay. The quick wash technology is comprised of a process to form a concentrated phosphorus solid material, and a washed poultry litter residue containing low phosphorus and most of the original organic carbon and nitrogen. This technology will help the poultry producer to better 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. Renewable Organics LLC applied for exclusive licensing of ARS patent rights.

3. Discovery of a novel anaerobic ammonia oxidation (anammox) bacteria species in swine effluent: Scientists at ARS Florence discovered and isolated a new anammox bacteria from manure effluents. The anammox process offers a low-cost alternative for removal of ammonia from wastewater because it requires half the aeration. The new anammox bacterial species (Brocadia caroliniensis, NRRL International Budapest Deposit B 50286) thrives in high ammonia environments. The bacteria is capable of reactivation after freeze drying (lyophilization), which helps with commercialization. A provisional US Patent Application was filed on February 18, 2010 (USPTO No. 61/298,952). Average ammonia removal rates obtained with this new anammox bacterium were higher than 1.7 kg of nitrogen per cubic meter per day. Development of manure treatment systems based on newly discovered anammox isolated from manure will increase the treatment efficiency and reduce overall treatment cost of manure and industrial effluents with high ammonia concentration.

4. Removal and recovery of ammonia gas from animal production systems: Volatilization of ammonia inside poultry housing often results in an excessive accumulation of ammonia in the air, which can negatively affect the health of both workers and birds. A new technology is being developed that has the potential to reduce ventilation and energy needs to lower ammonia in the air in poultry barns and composting systems. A provisional US Patent Application was filed on March 17, 2010 (USPTO No. 61/314,683). Results are cleaner air inside the barns with benefits to animal health and reduced environmental emissions, and the recovered ammonia can be re-used as concentrated plant fertilizer. The technology also has applications for reducing ammonia from composting systems.

5. Evaluation of denitrification enzyme activity in anaerobic lagoons: The cycling of nitrogen in swine wastewater treatment lagoons involves the conversion of ammonia to nitrate -- nitrification and the conversion of nitrite to nitrous oxide or di-nitrogen gas – denitrification. This cycling was assessed by measuring the abundances of four major enzymes of the nitrification and denitrification process. Their abundances were measured via molecular techniques using common primers in the wastewater of eight commercial swine anaerobic lagoons. The abundance of the four enzymes ranged from 0.04 to 5.29% of the total lagoon bacterial enzymes. Thus, there was clearly no indication of very high levels of nitrification and denitrification as measured by the relative abundances of these nitrification and denitrification enzymes. Yet, the abundances are equal to those reported for some treatment systems used to biologically treat and remove ammonia from industrial, municipal, and agricultural waste. Thus, these findings do not provide clear evidence for or against high levels of nitrogen removal from these lagoons via nitrification and denitrification. Instead, they along with other published research suggest that lagoons are complex in their cycling of nitrogen.

6. In-situ Lagoon Cleanup. 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. In practice, liquid and sludge need to be removed by pumping, usually at great expense of energy, and land applied at agronomic rates on adjacent fields without damage to ground or surface water. Alternative lagoon cleanup methods were investigated in a pilot lagoon study by pre-treating the liquid swine manure prior to entering the lagoon. The study consisted of comparing side by side the effect of solid-liquid separated effluent and the ARS second-generation Environmentally Superior Technology (EST) wastewater treatment (solid-liquid separation followed by biological N treatment) on water quality improvement and sludge mass reduction. As a control, an anaerobic lagoon regularly loaded with raw manure was included in the study. Lagoon liquid was monitored for water quality improvements on a monthly basis. After 15 months, water quality improvements with respect to the anaerobic lagoon control (such as reduction of suspended solids, chemical oxygen demand, and N concentration) were moderate with separated liquid but highly significant with the biological N pre-treatment. Anaerobic sludge mass reduction with respect to the control was significant for both pre-treatments; sludge mass reduction was 34% with separated liquid alone and 45% with biological N pre-treatment. This finding will help in the development of lower cost lagoon cleanup methods.

7. Manure treatment using a skid-mounted batch pyrolysis system. A skid-mounted commercial pyrolysis system was evaluated to produce energy from animal manures. The skid-mounted reactor system heated the manures to 620°C without presence of oxygen. The tests included chicken litter, swine solids, and swine solids blended with rye grass as feedstocks. The gases produced from the pyrolysis system had heating values lower than that of natural gas. These gases can be fed into an electrical generation system for on-farm production of electrical power. About 43 to 49% of the original mass of the manures were converted to biochar (i.e., charcoal). The heating values of the biochar made from swine solids and the mixture were similar to coals; the heating value of chicken litter biochar was slightly below that of coal due to high level of ash. The manure biochars contained high levels of phosphorous and potassium, which could be used as a low-grade fertilizer.

8. Production of biochar from poultry manure: Because of high fossil fuel costs and limited disposal options, utilization of poultry litter as an energy source and suitability of the biochar byproduct as a soil fertilizer/amendment was determined through pyrolysis reactions and laboratory studies. Energy content measurements revealed that poultry litter did contain a heating value as high as 60% of coal’s higher heating value. Biochar produced from poultry litter had a phosphorus content from 2 to and 4% suggesting its use as a soil fertilizer.

9. Carbonization of swine solids: High temperature pyrolysis of swine manure and blends generates energy co-products similar to low grade coals and natural gas. Commercial testing of high temperature pyrolysis of swine manure and a blend of swine manure and ryegrass generated a solid char product with an energy equivalent to that of coals and a combustible gas with an energy density slightly less than that for natural gas (methane).

Review Publications
Ro, K.S., Hunt, P.G., Johnson, M.H., Matheny, T.A., Forbes, D., Reddy, G.B. 2010. Oxygen transfer in marsh-pond-marsh constructed wetlands treating swine wastewater. Journal of Environmental Science and Health Part A. 45:377-382.

Szogi, A.A., Bauer, P.J., Vanotti, M.B. 2010. Fertilizer effectiveness of phosphorus recovered from broiler litter. Agronomy Journal. 102(2):723-727.

Cantrell, K.B., Hunt, P.G., Ro, K.S., Stone, K.C., Vanotti, M.B., Burns, J.C. 2010. Thermogravimetric characterization of irrigated bermudagrass as a combustion feedstock. Transactions of the American Society of Agricultural and Biological Engineers. 53(2):413-420.

Cantrell, K.B., Martin, J.H., Ro, K.S. 2010. Application of thermogravimetric analysis for the proximate analysis of livestock wastes. Journal of American Society for Testing and Materials International. 7(3):Paper ID JAI102583 (available online at

Ducey, T.F., Vanotti, M.B., Shriner, A.D., Szogi, A.A., Ellison, A.Q. 2010. Characterization of a microbial community capable of nitrification at cold temperature. Bioresource Technology. 101:491-500.

Hunt, P.G., Stone, K.C., Matheny, T.A., Poach, M.E., Vanotti, M.B., Ducey, T.F. 2009. Denitrification of nitrified and non-nitrified swine lagoon wastewater in the suspended sludge layer of treatment wetlands. Ecological Engineering. 35(10):1514-1522.

Jackson, L.A., Ducey, T.F., Zaitshik, J.B., Orvis, J., Dyer, D.W. 2010. Transcriptional and functional analysis of the Neisseria gonorrhoeae fur regulon. Journal of Bacteriology. 192(1):77-85.

Forbes, D.A., Reddy, G.B., Hunt, P.G., Poach, M.E., Ro, K.S., Cyrus, J.S. 2010. Comparison of aerated marsh-pond-marsh and continuous marsh constructed wetlands for treating swine wastewater. Journal of Environmental Science and Health. 45(7):803-809.

Last Modified: 4/20/2014
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