1a. Objectives (from AD-416)
1. Develop improved treatment technologies to better manage manure from swine, poultry and dairy operations to reduce releases to the environment of odors, pathogens, ammonia, and greenhouse gases as well as to maximize nutrient recovery. 2. Develop renewable energy via thermochemical technologies and practices for improved conversion of manure into heat, power, biofuels, and biochars. 3. Develop guidelines to minimize nitrous oxide emissions from poultry and swine manure-impacted riparian buffers and treatment wetlands. 4. Develop beneficial uses of manure treatment technology byproducts.
1b. Approach (from AD-416)
This research will take a synergistic approach towards developing innovative and effective animal manure treatment practices and holistic systems. This research will pursue four complementary bioresource management approaches. First, improved treatment technologies to better manage manure from swine, poultry, and dairy operations will be developed to reduce releases into the environment of odors, pathogens, ammonia, and greenhouse gases as well as to maximize nutrient recovery. These technologies include improved solid liquid separation, enhanced biological nitrogen treatment by anaerobic ammonia oxidation, recovery of ammonia from manure using gas permeable membranes, recovery of phosphorus from solid manure, wastewater treatment using constructed wetlands, in-house composting of poultry litter, and their integration into systems of treatment technologies. Second, investigations will be conducted to develop thermochemical technologies and practices for improved conversion of manure into heat, power, biofuels, and biochars. Manure based feedstocks for thermochemical conversion will be evaluated. Improved methods to condition manures for biochar and combustible gas production using pyrolysis will be determined. An efficient carbonization process for production of manure biochars with specific composition and properties for beneficial use will be developed. Third, research will be conducted to develop guidelines to more effectively manage and minimize nitrous oxide emissions from poultry and swine manure impacted riparian buffer zones and treatment wetlands. Fourth, we will develop beneficial uses for manure byproducts. These include the use of manure biochars as adsorbants for gaseous and aqueous contaminants, as soil amendments to improve physical and chemical properties, and as fertilizer source for crop production. Results from this project will advance the state of the science for more effective animal waste treatment and implementation of environmentally safe alternatives to traditional land application.
3. Progress Report
Filed a patent application (U.S. Patent Application 61314683, 3/15/2011) on a system and method for passive capture of gaseous ammonia in enclosures such as poultry barns. The invention includes the passage of gaseous ammonia through microporous gas-permeable membranes and its capture in a circulating acidic solution with simultaneous production of a concentrated non-volatile ammonium salt. The final products are cleaner air inside the barns with benefit for animal health and reduced environmental emissions, and concentrated liquid nitrogen that can be re-used in agriculture. Conducted experiments for phosphorus recovery from swine manure solids using the ‘quick wash’ technology developed by ARS Florence, South Carolina, scientists. Conducted a study on the temporal effects of microbial populations in an aerobic swine wastewater treatment system. Samples taken over a thirteen month period from each point in the wastewater treatment system were used to collect microbial community DNA. The DNA results revealed levels of organisms specific to the biological processes of nitritation (oxidation of ammonia to nitrite) and nitratation (oxidation of nitrite to nitrate). Conducted study on riparian buffer soils from selected sites in the Mid-Atlantic and southeastern Coastal Plain areas to evaluate microbial communities responsible for biological nitrogen transformations (nitrification-denitrification). Microbial DNA was extracted from soil samples and assayed to determine the abundance of genes involved in soil nitrification and denitrification cycles. ARS scientists at New Orleans, Louisiana, and Florence, South Carolina, conducted collaborative investigations to determine the effectiveness of manure biochars as binders of heavy metals in soils. High temperature biochars made from feedlot manure, turkey, and poultry litter exhibited the greatest heavy metal soil retention. These results suggest their utilization for sequestering heavy metal, thereby reducing contaminant movement in soils and improve water quality. Greenhouse experiments were conducted to test plant response to biochar fertilized soils. A trial was completed using high and low biochars made from five manures (dairy, swine, poultry, beef, and turkey) that were added as phosphorus sources to pots planted to ryegrass.
1. Biochars made from manures and crop residues improve soil carbon sequestration, water storage, fertility, and remove harmful chemicals. Investigators at the ARS Florence location produced biochars, a charcoal-like product, during carbonization of manure and plant waste materials using both thermal and hydrothermal processing. Both of these processes were optimized to produce biochars with diverse chemical and physical properties. Laboratory research showed that biochars made from nut shells were effective at increasing soil carbon sequestration while biochar made from grasses increased soil water storage. Manure biochars contained plentiful plant nutrients such as nitrogen, phosphorus, and potassium, but were blended with other plant-based biochars to produce a more nutrient balanced fertilizer-like product. Location scientists also discovered that hydrochar, the biochar made from hydrothermally processing poultry litter, can be used as an environmental adsorbent for effectively removing harmful chemicals such as endocrine disrupting chemicals and estrogens. Production of these biochars and their blends leads to an alternative use of agricultural byproducts that can increase soil carbon sequestration and water storage, provide essential plant nutrients and reduce levels of contaminants in soils.
2. Systems and methods for reducing ammonia emissions from liquid effluents and for recovering ammonia. ARS researchers at Florence, South Carolina, invented (U.S. Patent Application Serial No. 13/164,363 – Filed June 20, 2011) a new system and methods for the removal, recovery and use of ammonia from ammonia containing liquid effluents such as animal and municipal wastewater. The invention allows for both the passage of ammonia through microporous hydrophobic gas-permeable membranes and its capture in a circulated stripping solution with concomitant production of a concentrated non-volatile ammonium salt. The potential benefits are reduced ammonia emissions from liquid manure, cleaner air inside the barns with benefits to animal health, and recovery of ammonia as a concentrated liquid nitrogen reusable as a plant fertilizer.
3. Novel anammox bacteria for wastewater treatment. Investigators at ARS Florence, South Carolina, discovered a novel anammox bacteria having Accession Deposit Number NRRL B-50286, and the characteristics of oxidizing ammonia and releasing di-nitrogen under anaerobic conditions. The novel bacterial strain Candidatus Brocadia caroliniensis of this invention (U.S. Patent Application Serial No. 13/013,874 – Filed January 26, 2011) may be used for the treatment of wastewater having undesirable levels of ammonia, including agricultural, industrial, or municipal wastewaters. Compared to conventional biological nitrogen removal methods, this anammox microbial method reduces 60% of the energy for aeration and does not require external carbon addition. In addition, by-products do not include greenhouse gases (methane and nitrous oxide). This leads to a significant decrease in operational costs and provides environmental credit benefit for the users of this new technology.
4. State-of-the-art control system ensures biochar reproducibility. Engineers at ARS-Florence designed and tested a novel control system for consistent batch production of biochar, a charcoal-like byproduct of carbonization of manure and plant waste materials. This automated control scheme precisely tuned the production process to a desired temperature. Using the highly accurate controls, swine-based biochars produced in both high and low temperature regimes were rich in stable carbon structures with predictable, repeatable design characteristics.
Cao, X., Ro, K.S., Chappell, M., Li, Y., Mao, J. 2011. Chemical structures of swine-manure chars produced under different carbonization conditions investigated by advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Energy and Fuels. 25:388-397.