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United States Department of Agriculture

Agricultural Research Service

Research Project: BIOLOGICAL TREATMENT OF MANURE TO CAPTURE NUTRIENTS AND TRANSFORM CONTAMINANTS
2008 Annual Report


1a.Objectives (from AD-416)
Develop and evaluate algal systems for the treatment of dairy and swine manure effluents with respect to: a) capturing N and P from raw and anaerobically digested dairy manure effluents; b) utilization of the algal biomass as an organic fertilizer; and c) overall system nutrient uptake efficiency, operational costs, and potential returns of integrated farm-scale systems. Determine levels and biological effects of oxytetracycline and chlorotetracycline in manure from treated animals on biological treatment processes. Determine levels of antibiotic resistant bacteria in treated manures from animals treated with oxytetracycline and chlorotetracycline. Develop technology and management practices that improve anaerobic digestion of dairy and other animal manure by: a) increasing yield of methane gas; b) increasing energy efficiency of the conversion system; and c) reducing cost. Develop technology to increase the efficiency with which the methane is used to economically meet the energy needs of the farm.


1b.Approach (from AD-416)
Laboratory and pilot-scale field studies will be used to evaluate treatment efficiency and cost of microalgal-based treatment technologies at different loading rates of raw and anaerobically digested manure effluents. Dried algal biomass from manure treatment will be tested in growth chamber studies to evaluate the value of the biomass as an organic fertilizer capable of meeting plant nutrient requirements. Laboratory-scale composting, soil incubation, and anaerobic digestion studies will be used to determine the fates of the antibiotics oxytetracycline, chlorotetracycline, and antibiotic-resistant bacteria in manures from therapeutically treated beef calves. Laboratory and pilot-scale field studies will be used to quantitate effects on methane yield of co-digesting dairy manure with agricultural and industrial by-products. Additional studies will focus on use of cold tolerant microbial consortia to improve the rate and yield of methane production during anaerobic digestion of dairy manure at 10-25 C.


3.Progress Report
Work on the use of algal scrubbers to remove nitrogen and phosphorus from dairy manures was phased out. The final tasks included adapting and characterizing a new method for extracting fatty acids from algae. Accelerated solvent extraction (ASE) protocols were optimized for extraction of fatty acids from wastewater grown algae and the extraction efficiencies were characterized. Algal research was replaced by an increased emphasis on composting of poultry litter and evaluation of new uses for manure-based composed. The effectiveness of organic amendments on reducing ammonia volatilization from stored poultry litter was studied. The efficacy of compost socks in capturing motor oil and diesel fuel in contaminated storm water was evaluated.

There is widespread concern for unwanted discharge of pharmaceuticals and hormones to our nation’s water supplies. Commercial animal feeding operations are listed as a major source and there is a need to develop methods to reduce these discharges. To address this need a newly improved technique for oxidizing waste using cheaply obtained ferrate(VI) was tested. Dairy lagoon waste samples are known to contain high levels of hormones excreted by dairy cows as they naturally generate milk for human consumption. Samples of waste dairy lagoon sludge was secured and transported under refrigeration and treated with differing levels of ferrate(VI), ferric chloride (which acts to flocculate the solids), and a control without ferrate. Disappearance of a mix of hormones (estrone, 17beta-estradiol, 17alpha-ethinyl estradiol, estriol, progesterone and testosterone) was followed after these various treatments.

Anaerobic digestion is a biological method used to convert organic wastes into a stable product for land application without adverse environmental effects. The biogas produced can be used as an alternative renewable energy source. Dry anaerobic digestion (> 15% TS: total solid) may have an advantage over wet digestion (<10% TS) because it allows for the use of a smaller volume of reactor and because it reduces wastewater production. In addition, it produces a nutrient-rich effluent that is easier to transport due to decrease water content. Performances of anaerobic digestion of animal manure-switchgrass mixtures were evaluated under dry (15% TS) and thermophilic conditions (55oC).Three different mixtures of animal manure (swine manure, poultry manure, and dairy manure) and switchgrass were digested using batch-operated 1-L reactors. A pilot-scale anaerobic digestion facility has been developed. Replicated experiments can be executed in eight 200-gal tanks. The first studies will be tests of co-digestion of diary manure and food service wastes.

These efforts support NP 206 Nutrient Management Problem Area 2. Innovative Technology for Collection, Storage, and Treatment; Byproducts Problem Area 3. Byproduct Utilization Technologies; Byproducts Problem Area 4. Energy from Byproducts and Pathogens; and Pathogens Problem Area 4. Holistic Treatment Technologies for Nutrients, Pathogens and PACs.


4.Accomplishments
1. Reducing Pharmaceutically Active Compounds in Manure. Dairy lagoon waste samples are known to contain high levels of hormones excreted by dairy cows as they naturally generate milk for human consumption. Samples of waste dairy lagoon sludge was secured and transported under refrigeration and treated with differing levels of ferrate(VI), ferric chloride (which acts to flocculate the solids), and a control without ferrate. Disappearance of a mix of hormones (estrone, 17beta-estradiol, 17alpha-ethinyl estradiol, estriol, progesterone and testosterone) was followed after these various treatments. In those samples receiving the highest ferrate(VI) treatment greater than 50% of a typical background level of 17beta estradiol (approximately 0.02 mg/L) was destroyed; therefore, treatment of dairy lagoon wastes with ferrate(VI) may be an environmentally sound approach to reduce estrogenic compounds. NP 206 Pathogens Problem Area 4. Holistic Treatment Technologies for Nutrients, Pathogens and PACs. Traditional and alternative livestock manure, runoff, wastewater control, and treatment systems are primarily designed for the control of nutrients. However, other fecal-derived contaminants such as pathogens, hormones, and PACs also can be present in these waste streams. The fate of these manure-borne contaminants in treatment systems is largely unknown. Gaining knowledge of the fate of pathogens and PACs during collection, storage and treatment will lead to the development of management practices that optimize manure-borne contaminant control.

2. Beneficial uses for manure byproducts. Determined efficacy of compost socks in capturing motor oil and diesel fuel in contaminated storm water. Results from laboratory-scale experiments showed that synthetic fabric socks filled with mature compost were effective in capturing >95% of motor oil and diesel fuel in contaminated storm water. Byproducts Problem Area 3. Byproduct Utilization Technologies. Agricultural, municipal, and industrial processes result in a wide array of byproducts. Many of these byproducts, if properly processed and used, may have specific benefits to water quality, soil quality, plant health, plant productivity, and to reduce undesirable air emissions. In order to achieve these benefits, the byproducts need to be utilized in an environmentally sound manner that reduces the cost of disposal or converts them into marketable assets. Although the agricultural potential of a number of byproducts has already been assessed, there are many materials and applications for which little scientific information exists or potential benefits have yet to be identified.

3. Adapted and characterized new method for extracting fatty acids from algae. Accelerated solvent extraction (ASE) is an automated extraction method that uses high temperature and pressure conditions to improve extraction efficiency. ASE protocols were optimized for extraction of fatty acids from wastewater grown algae and the extraction efficiencies were characterized. This work demonstrates the usefulness of the ASE technique in characterizing new materials for their potential use as biodiesel feedstocks. NP 206 Byproducts Problem Area 4. Energy from Byproducts and Pathogens. New technologies are needed or need to be optimized to convert abundant, renewable agricultural residues and byproducts into energy. Manure, crop residues, food processing wastes, and other agricultural byproducts have the potential to be converted to various forms of energy if cost-effective conversion strategies can be developed. Potential conversion technologies include anaerobic digestion to produce methane, gasification, direct burning, and fermentation to fuel alcohol. The production of the liquid fuel ethanol is particularly attractive as it can be transported offsite for sale and use. Many agricultural byproducts have carbohydrate contents that make them promising sources of fermentable sugars for ethanol fermentation. However, in most cases, serious technical constraints to their exploitation exist and specific conversion strategies need to be developed for individual feedstocks.


5.Significant Activities that Support Special Target Populations
None.


6.Technology Transfer

Number of New CRADAS1

Review Publications
Koyuncu, I., Arikan, O.A., Wiesner, M.R., Rice, C. 2008. Removal of Hormones and Antibiotics by Nanofiltration Membranes. Journal Membrane Science. 309:94-101.

Arikan, O., Rice, C., Codling, E.E. 2008. Occurrence of Antibiotics and Hormones in a Major Agricultural Watershed. International Conference on Diffuse Pollution. 226:121-131.

Last Modified: 11/23/2014
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