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| Registros recuperados: 40 | |
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| Dungan, R.S.; Leytem, A.B.. |
| The generation of airborne microorganisms from concentrated animal-feeding operations (CAFOs) is a concern from a human and animal health perspective. To better understand the airborne microorganisms found in these environments, a number of collection and analytical techniques have been utilized and will be discussed in this review. The most commonly used bioaerosol collection method is the liquid impingement format, which is suitable with a number of culture-based and non-culture molecularbased approaches, such as polymerase chain reaction. However, the vast majority of airborne microorganism studies conducted at CAFOs utilize culture-based analyses. Because of the limitations often associated with culturebased analyses, we focused our... |
| Tipo: Article |
Palavras-chave: Manure; Animal. |
| Ano: 2009 |
URL: http://eprints.nwisrl.ars.usda.gov/1337/1/1314.pdf |
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| Alves, B.S.Q.; Dungan, R.S.; Carnin, R.L.P; Galvez, R.; de Carvalho Pinto, C.R.S.. |
| While most waste molding foundry sands (WFSs) are not hazardous in nature, regulatory agencies are often reluctant to permit their beneficial use in agricultural and geotechnical applications due to concerns over metal leaching. The objective of this study was to quantify total and Toxicity Characteristic Leaching Procedure (TCLP) metals in 16 waste sands from Brazilian ferrous foundries and assess their potential to leach metals to groundwater using a probabilistic model developed by the U.S. EPA. Total and TCLP metal concentrations in the non-hazardous sands fell within ranges as reported in the literature, although some of the leachate concentrations were found to exceed drinking water and groundwater maximum contaminant levels MCLs. Leachate values... |
| Tipo: Article |
Palavras-chave: Foundry sand. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1537/1/1494.pdf |
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| Bougouin, Adeline; Leytem, A.B.; Dijkstra, Jan; Dungan, R.S.; Kebreab, Ermias. |
| Nitrogen (N) excreted in urine by dairy cows can be potentially transformed to ammonia (NH3) and emitted to the atmosphere. Dairy production contributes to NH3 emission, which can create human respiratory problems and odor issues, reduces manure quality, and is an indirect source of nitrous oxide (N2O). The objective of this study was to (i) investigate environmental factors and measurement method that influence NH3 from dairy housing, and (ii) identify key explanatory variables in the prediction of NH3 emissions from dairy barns using a meta-analytical approach. Data from 25 studies were used for the preliminary analysis and data from 10 studies reporting 87 treatment means were used for the meta-analysis. Season, flooring type, manure handling and... |
| Tipo: Article |
Palavras-chave: Air Emissions; Animal Production; Animal health; Manure. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1624/1/1581.pdf |
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| Dungan, R.S.; Klein, Marcus; Leytem, A.B.. |
| Zoonotic pathogens in land-applied dairy wastewaters are a potential health risk. The abundance and occurrence of 10 pathogens and 3 fecal indicators was determined by quantitative real-time PCR (qPCR) in 30 dairy wastewaters from southern Idaho. Samples tested positive for Campylobacter jejuni, stx1- and eaeA-positive Escherichia coli, Listeria monocytogenes, Mycobacterium avium, and Salmonella enterica, with mean recoveries ranging from 1,000 to 10,000 genome copies per mL of wastewater. The most dominant organisms were C. jejuni and M. avium, being detected in up to 21 and 29 of 30 wastewater ponds, respectively. The qPCR detection limits for the putative pathogens in the wastewaters ranged from 16 cells mL for M. avium to 1,689 oocysts mL for... |
| Tipo: Article |
Palavras-chave: Chemistry; Manure. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1473/1/1438.pdf |
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| Dungan, R.S.; Kim, J.; Weon, H.; Leytem, A.B.. |
| The purpose of this research was to characterize the structure and composition of bacterial communities in sandy loam and silty clay soils amended with 30% spent sand from iron, aluminum, and steel foundries. All spent foundry sand (SFS) blends were grown with or without perennial ryegrass and samples were collected at 4 weeks and 6 months. Regions of the 16S rRNA gene were amplified using PCR and subsequently analyzed by DGGE and sequenced for bacterial identification and phylogenetic classification. Cluster analyses of PCR-DGGE banding patterns revealed that SFS blends from week 4 and month 6 produced unique clusters, with most ryegrass treatments clustering away from those without ryegrass. The diversity of the bacterial community revealed that it... |
| Tipo: Article |
Palavras-chave: Soil; Soil quality. |
| Ano: 2009 |
URL: http://eprints.nwisrl.ars.usda.gov/1339/1/1316.pdf |
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| Dungan, R.S.; Bjorneberg, D.L.; Leytem, A.B.. |
| In this study we conducted simulated spray irrigation events of dairy wastewater to assess the impact of pressure and sprinkler type upon post-sprinkler culturable microorganism concentrations. Dairy wastewater was sampled before and after it was pumped through sprinklers typically used on center pivot irrigation systems. Three different sprinklers types were used at three different operating pressures to give a range of water drop sizes. The microorganisms quantified in this study were total coliforms, Escherichia coli, Clostridium perfringens, heterotrophic bacteria, and coliphage. In most cases the pre- and post-sprinkler concentrations were determined to be statistically similar, suggesting that culturable viability was not affected when wastewater... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Manure. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1444/1/1409.pdf |
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| Ippolito, J.A.; Stromberger, M.E.; Lentz, R.D.; Dungan, R.S.. |
| The effects of biochar application to calcareous soils are not well documented. In a laboratory incubation study, a hardwood-based, fast pyrolysis biochar was applied (0, 1, 2, and 10% by weight) to a calcareous soil. Changes in soil chemistry, water content, microbial respiration, and microbial community structure were monitored over a 12-month period. Increasing biochar application rate increased the water holding capacity of the soil-biochar blend, a trait that could be beneficial under water limited situations. Biochar application also caused an increase in plant-available iron and manganese, soil carbon content, soil respiration rates, bacterial populations, and a decrease in soil nitrate-nitrogen concentration. Biochar rates of 2 and 10% altered the... |
| Tipo: Article |
Palavras-chave: Calcareous soil; Nitrogen; Nutrients. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1532/1/1490.pdf |
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| Niu, M; Appuhamy, J.A.D.R.N; Leytem, A.B.; Dungan, R.S.; Kebreab, Ermias. |
| The study aimed to examine, simultaneously, the effects of changing dietary forage and crude protein (CP) contents on methane (CH4) emissions and nitrogen (N) excretion from lactating dairy cows. Twelve post-peak lactating Holstein cows were randomly assigned to 4 treatments from a 2×2 factorial arrangement of two dietary forage levels [37.4% (LF) vs. 53.3% (HF) of DM] and two dietary CP levels [15.2% (LP) vs. 18.5% (HP) of DM] in a 4×4 Latin square design with four 18 d periods. Alfalfa hay was the sole source of dietary forage. Cows were fed and milked twice daily. During the first 14 d, cows were housed in a free-stall barn, where enteric CH4 emissions were measured using the GreenFeed system from d 8 to 14 in each period. Cows were then moved to... |
| Tipo: Article |
Palavras-chave: Air Emissions; Animal Production; Feed preference; Animal. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1618/1/1575.pdf |
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| Dungan, R.S.; Leytem, A.B.. |
| Collection fluids used in liquid-based bioaerosol samplers can influence the viability of microorganisms. In this study we determined the recovery efficiency of vegetative E. coli O157:H7 cells that were spiked into low viscosity evaporating collection fluids during operation of a BioSampler™ for up to 90 min at room temperature. The collection fluids tested were distilled (DI) water, phosphate-buffered saline (PBS) and osmoprotectants consisting of peptone and/or antifoam or betaine at 0.1% (w/w) in DI water. Using DI water, there was a rapid decline in the recovery of culturable E. coli, with only 11, 3, and 0% being recovered after 30, 60, and 90 min, respectively. Recoveries were substantially greater with use of PBS (53, 25, and 16%, respectively) but... |
| Tipo: Article |
Palavras-chave: Air Emissions; Water quality. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1613/1/1570.pdf |
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| Lou, Lifang; Ashworth, Daniel; Dungan, R.S.; Xuan, Richeng; Yates, S.R.. |
| For fumigants, information on transport and fate, as well as pest control, is needed to develop management practices with the fewest human and environmental health risks while offering sufficient pest control efficacy. For this purpose, a 2-D soil chamber (60 cm wide, 60 cm long, and 6 cm thick) with a surface-mounted flux chamber was designed to determine volatilization, spatial and temporal distribution of soil gas-phase concentration, degradation and organism survivability after methyl iodide (MeI) fumigation. Three types of pests (barnyardgrass seed [Echinochloa crus-galli], citrus nematode [Tylenchulus semipenetrans], and fungi [Fusarium oxysporum]) were used to give a broad spectrum of pest control information. After MeI fumigation at a rate of 56.43... |
| Tipo: Article |
Palavras-chave: Soil. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1395/1/1369.pdf |
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| Miguel, Roberto E.; Ippolito, J.A.; Leytem, A.B.; Porta A, Atilio; Noriega, Roxana B. Banda; Dungan, R.S.. |
| Waste molding and core sands from the foundry industry have been successfully used around the world as byproducts in geotechnical and agricultural applications. Although waste foundry sands (WFSs) are generally not considered hazardous in nature, relevant data are not available in Argentina. This study aimed to quantify metals in waste molding and core sands from foundries using a variety of metal-binder combinations. Metal concentrations in WFSs were compared to those in virgin silica sands (VSSs), surface soil and soil guidance levels according to hazardous waste law 24.051 from the Argentinean Secretariat of Environment and Sustainable Development. A total analysis for Ag, Al, Ba, Be, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Te, Tl, V, and Zn... |
| Tipo: Article |
Palavras-chave: Foundry sand. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1462/1/1427.pdf |
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| Dungan, R.S.; Leytem, A.B.. |
| Purple sulfur bacteria (PSB) in livestock wastewaters use reduced sulfur compounds and simple volatile organics as growth factors. As a result, the presence of PSB in manure storage ponds or lagoons is often associated with reduced odors. In this study, our objectives were to use molecular- and culture-based techniques to evaluate the occurrence of PSB in eight dairy wastewater ponds and identify physiochemical properties that might cause blooms to occur. Community DNA was extracted from composited wastewater samples, then the PufM gene and a conservative sequence for Chromatiaceae were amplified. Analysis of the 16S rRNA genes from denaturing gradient gel electrophoresis (DGGE) bands indicated that all of the dairy wastewater ponds contained sequences... |
| Tipo: Article |
Palavras-chave: Air Emissions. |
| Ano: 2015 |
URL: http://eprints.nwisrl.ars.usda.gov/1604/1/1562.pdf |
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| Leytem, A.B.; Dungan, R.S.; Bjorneberg, D.L.; Koehn, A.C.. |
| Concentrated dairy operations emit trace gases such as ammonia (NH3), methane (CH4), and nitrous oxide (N2O) to the atmosphere. The implementation of air quality regulations in livestock-producing states increases the need for accurate on-farm determination of emission rates. The objective of this study was to determine the emission rates of NH3, CH4, and N2O from the open-freestall and wastewater pond source areas on a commercial dairy located in southern Idaho. Gas concentrations and wind statistics were measured each month and used with an inverse dispersion model to calculate emission rates. Average emissions per cow per day from the open-freestall source area were 0.10 kg NH3 and 0.47 kg CH4. Average emissions from the wastewater ponds (g m-2 d-1)... |
| Tipo: Article |
Palavras-chave: Air Emissions; Animal Production; Manure Management. |
| Ano: 2013 |
URL: http://eprints.nwisrl.ars.usda.gov/1501/1/1464.pdf |
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| Leytem, A.B.; Dungan, R.S.. |
| livestock operations can potentially affect air quality at local, regional, and even global scales. These pollutants, many of which are generated through various anthropogenic activities, are being increasingly scrutinized by regulatory authorities. Regulation of emissions from livestock production systems will ultimately increase on farm costs, which will then be passed onto consumers. Therefore, it is essential that scientifically based emission factors are developed for on-farm emissions of air quality constituents to improve inventories and assign appropriate reduction targets. To generate a larger database of on-farm emissions, the USDA–ARS created the workgroup Livestock GRACEnet (Greenhouse gas Reduction through Agricultural Carbon Enhancement... |
| Tipo: Article |
Palavras-chave: Air Emissions; Application guidelines; Chemistry. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1542/1/1499.pdf |
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| King, B.A.; Dungan, R.S.; Bjorneberg, D.L.. |
| Wind drift and evaporation losses (WDELs) are an often discussed topic in regards to center pivot sprinkler irrigation efficiency. Opinions on the magnitude of WDELs vary widely, in part due to the wide variation in WDEL values published in the literature. The magnitude of WDELs reported in the literature range from 2 to 45%. The common technique employed to measure WDEL is to use catch cans and compare the measured volume of catch with the volume of water applied based on sprinkler nozzle size, operating pressure and spacing with the difference being WDEL. The inaccuracies of catch cans resulting from wind effects on catch efficiency and evaporation of water from the catch can prior to measurement have led to the wide range in WDEL reported in the... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Center pivot. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1470/1/1435.pdf |
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| Franklin, A.M.; Aga, D.S.; Cytryn, Eddie; Durso, L.M.; Mclain, J.E.; Pruden, Amy; Roberts, M.C.; Rothrock, Jr, M.J.; Snow, D.D.; Watson, J.E.; Dungan, R.S.. |
| The presence of antibiotic drug residues, antibiotic resistant bacteria, and antibiotic resistance genes in agroecosystems has become a significant area of research in recent years, and is a growing public health concern. While antibiotics are utilized for human medicine and agricultural practices, the majority of antibiotic use occurs in food animals where these drugs have historically been used for growth promotion, in addition to prevention and treatment of disease. The widespread use of antibiotics combined with the application of human and animal wastes to agricultural fields introduces antibiotic-related contamination into the environment. While overt toxicity in organisms directly exposed to antibiotic in agroecosystems is generally not an issue due... |
| Tipo: Article |
Palavras-chave: Air Emissions; Animal; Runoff; Manure. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1614/1/1571.pdf |
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| Miguel, Roberto E.; Dungan, R.S.; Reeves III, J.B.. |
| Foundries around the world discard millions of tonnes of molding and core sand each year even though they can be beneficially used in manufactured soils and geotechnical applications. Despite their usefulness as an aggregate replacement, some environmental authorities are concerned over potential negative impacts associated with residual organic binders in waste foundry sands (WFSs). In this study, chemically bound molding and core sands were obtained from aluminum, bronze and iron foundries that used alkyd urethane, phenolic urethane, Novolac, and natural organic binders. The aim was to use mid-infrared (MIR) spectrometry to assess changes within the molding and core sands during the casting process, with a specific focus on proximity to the casting... |
| Tipo: Article |
Palavras-chave: Foundry sand. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1536/1/1493.pdf |
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| Dungan, R.S.. |
| Airborne microorganisms and microbial byproducts from intensive livestock and manure management systems are a potential health risk to workers and individuals in nearby communities. This report presents information on zoonotic pathogens in animal wastes and the generation, fate, and transport of bioaerosols associated with animal feeding operations and land applied manures. Though many bioaerosol studies have been conducted at animal production facilities, few have investigated the transport of bioaerosols during the land application of animal manures. As communities in rural areas converge with land application sites, concerns over bioaerosol exposure will certainly increase. While most studies at animal operations and wastewater spray irrigation sites... |
| Tipo: Article |
Palavras-chave: Manure Management; Manure. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1405/1/1375.pdf |
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| Registros recuperados: 40 | |
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