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Atmospheric Environment (v.66, #)
Development and evaluation of optical fiber NH3 sensors for application in air quality monitoring by Yu Huang; Lucas Wieck; Shiquan Tao (pp. 1-7).
Ammonia is a major air pollutant emitted from agricultural practices. Sources of ammonia include manure from animal feeding operations and fertilizer from cropping systems. Sensor technologies with capability of continuous real time monitoring of ammonia concentration in air are needed to qualify ammonia emissions from agricultural activities and further evaluate human and animal health effects, study ammonia environmental chemistry, and provide baseline data for air quality standard. We have developed fiber optic ammonia sensors using different sensing reagents and different polymers for immobilizing sensing reagents. The reversible fiber optic sensors have detection limits down to low ppbv levels. The response time of these sensors ranges from seconds to tens minutes depending on transducer design. In this paper, we report our results in the development and evaluation of fiber optic sensor technologies for air quality monitoring. The effect of change of temperature, humidity and carbon dioxide concentration on fiber optic ammonia sensors has been investigated. Carbon dioxide in air was found not interfere the fiber optic sensors for monitoring NH3. However, the change of humidity can cause interferences to some fiber optic NH3 sensors depending on the sensor's transducer design. The sensitivity of fiber optic NH3 sensors was found depends on temperature. Methods and techniques for eliminating these interferences have been proposed.► Optical fiber NH3 sensors have been developed. ► The feasibility of using the sensors for air quality monitoring has been investigated. ► The sensors are reversible, can be used for continuous monitoring NH3 in air. ► The sensors are highly sensitive, can detect NH3 in ppbv level. ► Cross responses of the sensors to moisture, CO2 and temperature change have been investigated.
Keywords: Optical fiber chemical sensor; Ammonia sensor; Air quality monitoring; Concentrated animal feeding; Manure; Feedlot
Concentration and particle size distribution of particulate matter inside tunnel-ventilated high-rise layer operation houses by Lingjuan Wang-Li; Zihan Cao; Qianfeng Li; Zifei Liu; David B. Beasley (pp. 8-16).
Particulate matter (PM) is a criteria pollutant emitted from animal feeding operation (AFO) facilities, especially from poultry operation buildings. Fundamental data regarding AFO PM either do not exist, or are not representative of different animal production systems or housing types. This field study investigated particle size distributions (PSDs) and concentrations of total suspended particulate (TSP) in a tunnel ventilated high-rise layer house under different operational conditions. Six low-volume (1m3h−1) TSP samplers were used to collect PM samples on two floors of the high-rise layer houses across four seasons through day/night sampling protocols. The day/night sampling design was to examine animal activity impact. The PM samples were analyzed by a multi-wave length laser diffraction particle size analyzer (LS13 320) for PSDs characterized by mass median diameters (MMDs) and geometric standard deviations (GSDs). It was discovered that the mean TSP concentrations ranged from 1.0±0.5mgm−3 to 5.33±0.36mgm−3 (mean±SD). TSP concentrations in winter were higher than in summer; concentrations on the 2nd floor were higher than that on the 1st floor; concentrations of daytime samples were higher than those of nighttime samples. Animal activity (represented by day/night samples) had the highest impact on TSP concentration as compared to other influential factors (spatial, seasonal, ventilation). No significant seasonal variations of MMD and GSD were observed in most of samples. Majority of day/night MMDs and GSDs demonstrated no significant differences. Thus the impact of animal activity (day vs. night) on MMD and GSD were not significant. Mean MMDs±SDs ranged from 16.81±1.57μm to 20.26±3.53μm, whereas means±SDs of GSDs ranged from 2.38±0.20 to 2.81±0.30. Mean PM2.5 fractions±SDs ranged from 5.03±1.60% to 8.93±0.97%, whereas mean PM10 fractions±SDs ranged from 23.25±5.18% to 38.55±2.96%. Significant seasonal variation in both PM10 and PM2.5 mass fractions were observed.► PM concentration and PSD in an egg production house were measured. ► Significant seasonal & spatial variations in PM concentrations were observed. ► Animal activity had the greatest impact on PM concentration. ► PSDs over different seasons were not significantly different. ► Animal activity impact on PSDs were not significant.
Keywords: Animal feeding operations; Hen layer operation; Particulate matter; TSP; Particle size distribution
Utilizing single particle Raman microscopy as a non-destructive method to identify sources of PM10 from cattle feedlot operations by Qiang Huang; Laura L. McConnell; Edna Razote; Walter F. Schmidt; Bryan T. Vinyard; Alba Torrents; Cathleen J. Hapeman; Ronaldo Maghirang; Steven L. Trabue; John Prueger; Kyoung S. Ro (pp. 17-24).
Emissions of particulate matter (PM) from animal feeding operations (AFOs) pose a potential threat to the health of humans and livestock. Current efforts to characterize PM emissions from AFOs generally examine variations in mass concentration and particle size distributions over time and space, but these methods do not provide information on the sources of the PM captured. Raman microscopy was employed as a non-destructive method to quantify the contributions of source materials to PM10 emitted from a large cattle feedlot. Raman spectra from potential source materials (dust from unpaved roads, manure from pen surface, and cattle feed) were compiled to create a spectral library. Multivariate statistical analysis methods were used to identify specific groups composing the source library spectra and to construct a linear discriminant function to identify the source of particles collected on PM10 sample filters. Cross validation of the model resulted in 99.76% correct classification of source spectra in the training group. Source characterization results from samples collected at the cattle feedlot over a two-day period indicate that manure from the cattle pen surface contributed an average of 78% of the total PM10 particles, and dust from unpaved roads accounted for an average of 19% with minor contributions from feed. Results of this work are promising and provide support for further investigation into an innovative method to identify agricultural PM10 sources accurately under different meteorological and management conditions.► Sources of PM10 were examined at a commercial cattle feedlot. ► Raman microscopy was used to analyze potential source materials. ► Developed multivariate statistical model to identify PM10 sources. ► Manure and unpaved roads were two major sources of PM10.
Keywords: Particulate matter; Raman microscopy; Multivariate statistical analysis; Animal feeding operations; PM; 10
Techniques for measuring particle size distribution of particulate matter emitted from animal feeding operations by Lingjuan Wang-Li; Zihan Cao; Michael Buser; Derek Whitelock; Calvin B. Parnell; Yuanhui Zhang (pp. 25-32).
While various techniques for measuring particle size distributions (PSD) of particulate matter (PM) exist, there is no a single agreed upon standard or reference method for PM with different characteristics. This study investigated differences in the PSD measurements by four PSD analyzers: LS13 320 multi-wave length laser diffraction particle size analyzer, LS230 laser diffraction particle size analyzer, LA-300 laser scattering particle size analyzer, and Coulter Counter Multisizer3 (CCM3). Simultaneously collected total suspended particulate (TSP) samples in a commercial egg production house were analyzed by the four analyzers for PSDs. In addition, four types of testing powders (limestone, starch, No.3 micro aluminum, and No.5 micro aluminum) were also analyzed by these four PSD analyzers. The results suggest when comparing measured mass median diameters (MMDs) and geometric standard deviations (GSD) of the PSDs, the laser diffraction method (LS13 320, LS230 and LA-300) provided larger MMDs and broader distributions (GSDs) than the electrical sensing zone method (CCM3) for all samples. When comparing mass fractions of PM10 and PM2.5 between the measured values and the lognormal fitting values derived from the measured MMDs and GSDs, lognormal fitting method produced reasonably accurate PM10 mass fraction estimations (within 5%), but it failed to produce accurate PM2.5 mass fraction estimations. The measured PM2.5 mass fractions significantly differed from the lognormal fitting PM2.5 fractions and the mean differences reached as high as 95%. It is strongly recommended that when reporting a PSD of certain PM samples, in addition to MMD and GSD, the mass fractions of PM10 and PM2.5 should also be reported.► Particle size distributions of PM samples were analyzed by four analyzers. ► Significant differences in PSD measurements were observed. ► Laser diffraction analyzers provided greater and broader PSDs than ESZ analyzer. ► Measured PM2.5 mass fractions differed from the lognormal fitting PM2.5 fractions.
Keywords: Particulate matter; Animal feeding operation; Particle size distribution analyzer; Laser diffraction; Electrical sensing zone; PM; 10; mass fraction; PM; 2.5; mass fraction
Assessment of methods for methyl iodide emission reduction and pest control using a simulation model by Lifang Luo; Daniel J. Ashworth; Jirka Šimunek; Richeng Xuan; Scott R. Yates (pp. 33-40).
The increasing registration of the fumigant methyl iodide within the USA has led to more concerns about its toxicity to workers and bystanders. Emission mitigation strategies are needed to protect the public and environmental health while providing effective pest control. The effectiveness of various methods on emissions reduction and pest control was assessed using a process-based mathematical model in this study. Firstly, comparisons between the simulated and laboratory measured emission fluxes and cumulative emissions were made for methyl iodide (MeI) under four emission reduction treatments: 1) control, 2) using soil with high organic matter content (HOM), 3) being covered by virtually impermeable film (VIF), and 4) irrigating soil surface following fumigation (Irrigation). Then the model was extended to simulate a broader range of emission reduction strategies for MeI, including 5) being covered by high density polyethylene (HDPE), 6) increasing injection depth from 30 cm to 46 cm (Deep), 7) HDPE + Deep, 8) adding a reagent at soil surface (Reagent), 9) Reagent + Irrigation, and 10) Reagent + HDPE. Furthermore, the survivability of three types of soil-borne pests (citrus nematodes [ Tylenchulus semipenetrans], barnyard seeds [ Echinochloa crus-galli], fungi [ Fusarium oxysporum]) was also estimated for each scenario. Overall, the trend of the measured emission fluxes as well as total emission were reasonably reproduced by the model for treatments 1 through 4. Based on the numerical simulation, the ranking of effectiveness in total emission reduction was VIF (82.4%) > Reagent + HDPE (73.2%) > Reagent + Irrigation (43.0%) > Reagent (23.5%) > Deep + HDPE (19.3%) > HOM (17.6%) > Deep (13.0%) > Irrigation (11.9%) > HDPE (5.8%). The order for pest control efficacy suggests, VIF had the highest pest control efficacy, followed by Deep + HDPE, Irrigation, Reagent + Irrigation, HDPE, Deep, Reagent + HDPE, Reagent, and HOM. Therefore, VIF is the optimal method disregarding the cost of the film since it maximizes efficacy while minimizing volatility losses. Otherwise, the integrated methods such as Deep + HDPE and Reagent + Irrigation, are recommended.► The effects of various methods on fumigant emissions and pest control were assessed using a model. ► The models provide reasonably accurate emissions of methyl iodide. ► Being covered by VIF is the best method among nine treatments, followed by integrated methods.
Keywords: Methyl iodide; Emission; Modeling; Pest control; PesticideAbbreviations; MeI; methyl iodide; VIF; virtually impermeable film; HDPE; high density polyethylene film; LDPE; low density polyethylene; MeBr; methyl bromide; CT; concentration-time index; 1,3-D; 1,3-dichloropropene; CP; chloropicrin; for fumigation treatment: HOM; using soil with high organic matter content; VIF; being covered by virtually impermeable film; Irrigation; irrigating soil surface following fumigation; HDPE; being covered by high density polyethylene; Deep; increasing injection depth from 30 cm to 46 cm; Reagent; adding a reagent at soil surface
Effects of soil moisture on the diurnal pattern of pesticide emission: Numerical simulation and sensitivity analysis by Rivka Reichman; Scott R. Yates; Todd H. Skaggs; Dennis E. Rolston (pp. 41-51).
Accurate prediction of pesticide volatilization is important for the protection of human and environmental health. Due to the complexity of the volatilization process, sophisticated predictive models are needed, especially for dry soil conditions. A mathematical model was developed to allow simulation of the diurnal variation of pesticide volatilization as affected by soil-water content, the air–solid interface partition coefficient, soil-water retention function and soil surface resistance processes. The model formulation considered two possible water retention functions and two soil surface resistance functions. To test the model, simulations were performed for ten successive days of drying under typical semi-arid summer conditions following application of the pesticide diazinon to either a loam or sand soil. Results showed that the temporal variation and magnitude of diazinon emission were strongly affected by the air–solid interface partition coefficient, soil-water content and the surface resistance function. The model was capable of simulating complex diurnal patterns in the peak emission rates which are caused by changes in soil water content and air–solid partitioning. The water retention function formulation had only a minor effect on the simulated water content and volatilization rates, whereas the soil surface resistance function significantly influenced the volatilization rate. Neither the water retention function nor the soil surface resistance formulation had a significant effect on the simulated soil temperature.► A framework is provided to understand temporal patterns in the volatilization rate. ► The effect of soil moisture and evaporation on the daily peak flux is elucidated. ► The model predicts different patterns for daytime or nighttime peak flux rates. ► The temporal pattern in the daily flux rate is correctly described with the model.
Keywords: Non-isothermal volatilization model; Water retention models; Soil surface resistance models; Soil temperature modeling; Pesticide vapor adsorption; Diazinon
Effects of soil moisture on the diurnal pattern of pesticide emission: Comparison of simulations with field measurements by Rivka Reichman; Scott R. Yates; Todd H. Skaggs; Dennis E. Rolston (pp. 52-62).
Pesticide volatilization from agricultural soils is one of the main pathways in which pesticides are dispersed in the environment and affects ecosystems including human welfare. Thus, it is necessary to have accurate knowledge of the various physical and chemical mechanisms that affect volatilization rates from field soils. A verification of the influence of soil moisture modeling on the simulated volatilization rate, soil temperature and soil-water content is presented. Model simulations are compared with data collected in a field study that measured the effect of soil moisture on diazinon volatilization. These data included diurnal changes in volatilization rate, soil-water content, and soil temperature measured at two depths. The simulations were performed using a comprehensive non-isothermal model, two water retention functions, and two soil surface resistance functions, resulting in four tested models. Results show that the degree of similarity between volatilization curves simulated using the four models depended on the initial water content. Under fairly wet conditions, the simulated curves mainly differ in the magnitude of their deviation from the measured values. However, under intermediate and low moisture conditions, the simulated curves also differed in their pattern (shape). The model prediction accuracy depended on soil moisture. Under normal practices, where initial soil moisture is about field capacity or higher, a combination of Brooks and Corey water retention and the van de Grind and Owe soil surface resistance functions led to the most accurate predictions. However, under extremely dry conditions, when soil-water content in the top 1 cm is below the volumetric threshold value, the use of a full-range water retention function increased prediction accuracy. The different models did not affect the soil temperature predictions, and had a minor effect on the predicted soil-water content of Yolo silty clay soil.► We investigate soil moisture effects on diazinon volatilization from soil. ► Volatilization is simulated with a comprehensive non-isothermal model. ► Simulated volatilization rates are compared with measured values. ► Soil-water content strongly affects the magnitude and timing of volatilization.► Soil-water content impacts volatilization because of its effect on vapor sorption.
Keywords: Model validation; Volatilization rates; Diazinon; Soil moisture effect
The role of carbon dioxide in emission of ammonia from manure by Sasha D. Hafner; Felipe Montes; C. Alan Rotz (pp. 63-71).
Ammonia emission from manure is a significant loss of fixed N from agricultural systems and contributes to air pollution and ecosystem degradation. Despite the development of numerous mathematical models for predicting ammonia emission, the interactions between CO2 emission, manure pH, and ammonia emission are not completely understood. Others have recognized that CO2 emission from manure can increase the surface pH, and so increase the rate of NH3 emission, but this interaction has not been completely described or quantified. In this work, we present a model of simultaneous NH3 and CO2 emission that includes equilibrium acid/base reactions, kinetically-limited CO2 hydration/dehydration reactions, and diffusive transport. Our model accurately predicted the increase in NH3 emission from simple solutions due to CO2 emission, while an equilibrium-only model did not. Model predictions showed that when NH3 and CO2 emission occur simultaneously, CO2 emission generally increases NH3 emission rate by causing an elevation in surface pH. For thin stagnant layers, this response occurs under a wide range of conditions, although the magnitude of the effect is dependent on manure composition, temperature, surface mass transfer coefficient, and other parameters. Kinetically-limited CO2 hydration/dehydration reactions moderate this interaction, so equilibrium-based models tend to over-predict NH3 emission in the absence of significant carbonic anhydrase activity. Predicted emission from deep, mixed manure showed less dependence on CO2 emission, although higher rates of CO2 hydration/dehydration increase this effect. Interactions between CO2 and NH3 emission influence the effect of model parameters on NH3 emission and result in some unexpected responses. Future work should clarify the processes controlling CO2 speciation and transport in manure, including CO2 minerals, bubble transport, and CO2 hydration/dehydration rates. Our model can inform the development of simpler models for estimating NH3 emission, and the design of experiments aimed at quantifying processes that influence NH3 emission from manure. The effects of CO2 on NH3 emission deserve more attention, and both experimental and modeling approaches are needed to understand the interactions that control NH3 emission.► We developed a chemical/physical model of ammonia emission from manure. ► Carbon dioxide emission influences ammonia emission by elevating pH. ► Carbon dioxide emission affects the response of ammonia emission to model parameters. ► Slow hydration/dehydration reactions moderate the effect of carbon dioxide emission.
Keywords: Ammonia emission; Carbon dioxide emission; Manure; Chemical speciation; Mass transfer; Model
Standardization of flux chamber and wind tunnel flux measurements for quantifying volatile organic compound and ammonia emissions from area sources at animal feeding operations by David Parker; Jay Ham; Bryan Woodbury; Lingshuang Cai; Mindy Spiehs; Marty Rhoades; Steve Trabue; Ken Casey; Rick Todd; Andy Cole (pp. 72-83).
A variety of portable wind tunnels and flux chambers have been used to measure fluxes of volatile organic compounds (VOC) and ammonia (NH3) at animal feeding operations (AFO). However, there has been little regard to the extreme variation and potential inaccuracies caused by air velocity or sweep air flow rates that are either too low or too high to simulate field conditions. There is a need for correction factors to standardize flux chamber and wind tunnel measurements. In this manuscript, we present results of water evaporative flux and VOC flux measurements with the EPA flux chamber and a small wind tunnel. In the EPA flux chamber, water evaporative flux was positively correlated with sweep air flow rate (SAFR) between 1 and 20 L min−1 ( r2 = 0.981–0.999) and negatively correlated with sweep air relative humidity between 0 and 80% ( r2 = 0.982–0.992). Emissions of gas-film controlled compounds like NH3 and VOC at AFOs were positively correlated with evaporation rates between 0.6 and 2.8 mm d−1. We demonstrate a simple methodology for standardizing and comparing different chamber types by measuring water evaporation within the chamber using a gravimetric mass balance approach under controlled laboratory conditions. A water evaporative flux ratio correction factor (EFRCF) was used to improve the accuracy of field-measured VOC and NH3 chamber flux measurements. In a field study, both the EPA flux chamber (SAFR = 5 L min−1) and small wind tunnel (SAFR = 1 L min−1) underestimated the true field emissions of VOC, with EFRCFs of 2.42 and 3.84, respectively. EFRCFs are recommended for all but the driest of soil and manure conditions.► We compare flux measurements with portable flux chambers and wind tunnels. ► We examine the effect of sweep air flow rate, relative humidity, and source size on flux magnitude. ► Flux of odorous compounds at animal feeding operations were linearly correlated with evaporative flux. ► A method for standardizing and comparing different chamber types was developed using evaporative flux as a surrogate. ► The use of evaporative flux ratio correction factors will greatly improve the accuracy of flux measurement from area sources.
Keywords: Emission rate; Flux; Area source; Feedlot; Lagoon; Flux chamber; Wind tunnel; Ammonia; VOC
Empirical model of odor emission from deep-pit swine finishing barns to derive a standardized odor emission factor by Günther Schauberger; Teng-Teeh Lim; Ji-Qin Ni; Dwaine S. Bundy; Barry L. Haymore; Claude A. Diehl; Ravi K. Duggirala; Albert J. Heber (pp. 84-90).
Odor emission from swine housing is influenced by the herd characteristics and building environment. The following three specific factors were identified as inputs to a swine house odor emission model: indoor temperature, barn ventilation rate, and pig activity. Model input parameters were determined based on tests of four, identical, 1000-head, mechanically-ventilated swine finishing houses. Each building had two sidewall curtains, a curtain on the west end wall, five exhaust fans on the east end wall, four pit ventilation fans, and long-term manure storage beneath a fully slatted floor. Odor concentrations of 112 odor samples were determined using dynamic forced-choice olfactometry with four to six trained panelists. The emission model showed that the standard live mass specific odor emission factor was 48 OU s−1 per 500 kg live mass or animal unit (AU), and it corresponded to an indoor temperature of T0 = 20 °C, a ventilation rate of V0 = 200 m3 h−1 (55.6 × 10−3 m3 s−1) per pig (maximum capacity for summer time), and the daily mean animal activity. The rate of odor emission from a swine finishing house can be calculated based on these parameters coupled with the number of animals, the mean live mass, and the standard live mass specific odor emission factor. Using this process-based odor emission model, the odor emission estimation and therefore the input for odor dispersion models can be improved to obtain more reliable estimates of separation distance for siting future pig farms.Display Omitted► Odor emission of livestock buildings can be a major source for nuisance. ► Odor emission rate is necessary for modeling setback distances. ► Odor release is mainly modified by indoor temperature, ventilation rate and animal activity. ► A odor emission model was derived for swine finishing barns.
Keywords: Odor emission rate; Model; Indoor temperature; Ventilation rate; Airflow rate; Livestock; Odor; Fattening pig
Odorous VOC emission following land application of swine manure slurry by David B. Parker; John Gilley; Bryan Woodbury; Ki-Hyun Kim; Geordie Galvin; Shannon L. Bartelt-Hunt; Xu Li; Daniel D. Snow (pp. 91-100).
Swine manure is often applied to crop land as a fertilizer source. Odor emissions from land-applied swine manure may pose a nuisance to downwind populations if manure is not applied with sufficient forethought. A research project was conducted to assess the time decay of odorous volatile organic compound (VOC) emissions following land application of swine manure. Three land application methods were compared: surface application, incorporation 24 h after surface application, and injection. Emission rates were measured in field plots using a small wind tunnel and sorbent tubes. VOCs including eight volatile fatty acids, five aromatics, and two sulfur-containing compounds were quantified by gas chromatography-mass spectrometry. In most cases, a first order exponential decay model adequately described the flux versus time relationship for the 24 h period following land application, but the model sometimes overestimated flux in the 6–24 h range. The same model but with the time term squared adequately predicted flux over the entire 24 h period. Three compounds (4-methylphenol, skatole, and 4-ethylphenol) accounted for 93 percent of the summed odor activity value. First order decay constants ( k) for these three compounds ranged from 0.157 to 0.996 h−1. When compared to surface application, injection of swine manure resulted in 80–95 percent lower flux for the most odorous aromatic compounds. These results show that VOC flux decreases rapidly following land application of swine manure, declining below levels of detection and near background levels after 4 to 8 h.► We measured VOC emission rates following land application of swine manure. ► An exponential decay model with time squared term accurately fit to the data. ► Three chemical compounds accounted for 93 percent of the odor activity value. ► Emission rates declined rapidly, returning to background levels in 6–8 h. ► Injection of swine manure decreased VOC emissions by 80–95 percent.
Keywords: Odor; Swine; Manure; Volatile organic compound; Air quality
Measuring gas emissions from animal waste lagoons with an inverse-dispersion technique by Kyoung S. Ro; Melvin H. Johnson; Kenneth C. Stone; Patrick G. Hunt; Thomas Flesch; Richard W. Todd (pp. 101-106).
Measuring gas emissions from treatment lagoons and storage ponds poses challenging conditions for existing micrometeorological techniques. This is due to non-ideal wind conditions, such as those induced by trees and crops surrounding the lagoons, and lagoons with dimensions too small to establish equilibrated microclimate conditions within the water boundary. This study evaluated the accuracy of an emerging backward Lagrangian stochastic (bLS) inverse-dispersion technique to measure lagoon emissions. It used a fabricated floating emission source with known emission rates from an irrigation pond that resembled typical treatment lagoon environments. The measured parameters were wind statistics and downwind path-integrated concentrations. Anemometers were located on the upwind, downwind, or side berm parallel to wind. Additionally, the berm surface was deliberately roughened during the summer by placing pine straw bales along the berms to simulate vegetation growth. Regardless of the surface roughness, when the surrounding vegetation (i.e. corn field) was short during spring and fall, using an anemometer located on the upwind berm produced the most accurate results (0.93±0.19). However, during the summer, the adjacent corn crop grew more than 2 m high. Consequently, the anemometer had to be moved to the side berm. This resulted in a decrease in accuracy to 0.81±0.18. Yet, even with less than idealized conditions, the bLS inverse-dispersion technique still produced reasonably accurate emission rates. This demonstrated the robustness of this easy-to-use bLS inverse-dispersion technique for complex agricultural emission measurements.► We evaluated the accuracy of the bLS technique for measuring gas emissions from a lagoon. ► The bLS technique accurately measured gas emissions from the lagoon. ► The anemometer located on the upwind berm produced the most accurate results. ► Alternative data filtering criteria were suggested.
Keywords: Treatment lagoon emission; Backward Lagrangian stochastic; Inverse-dispersion technique; Optimal anemometer location; Accuracy; Wind interference
Mass transfer coefficients of ammonia for liquid dairy manure by Venkata K. Vaddella; Pius M. Ndegwa; Jeffrey L. Ullman; Anping Jiang (pp. 107-113).
Available data indicate that 75–80% of total nitrogen entering a dairy operation is lost as ammonia (NH3) via manure storage systems such as anaerobic lagoons. Direct measurement of NH3 emissions from manure holding systems can be complicated and expensive; however, process-based emission models can provide a cost-effective alternative for estimating NH3 emissions. The overall NH3 mass transfer coefficient ( KOL) is an important component of any NH3 emission process-based model. Models relying purely on theoretically-derived mass transfer coefficients have not adequately predicted NH3 emissions from livestock manure, and these values are lacking in general for liquid dairy manure handling systems. To provide critically needed KOL data for dairy facilities, this study directly measured NH3 loss from dilute dairy manure slurries placed in a laboratory convective emission chamber to determine realistic NH3 KOL values under conditions typically experienced in the Pacific Northwest. The KOL values increased as liquid temperature and air velocity increased and decreased as air temperature and total solids content increased, exhibiting an overall range of 1.41 × 10−6–3.73 × 10−6 m s−1. These values were then used to develop a non-linear empirical model of KOL for dilute dairy manure slurries ( R2 = 0.83). The KOL exhibited sensitivity to the four model parameters considered in descending order: liquid manure temperature, ambient air temperature, wind or air velocity, and total solids concentration. The suite of KOL values applicable to liquid dairy manure and the establishment of an empirical model that yields accurate KOL estimates under a range of conditions for use in process-based models provide valuable tools for predicting NH3 emissions from dairy operations.► The mass transfer coefficient ( KOL) of ammonia (NH3) increased with liquid temperature ( TL) and air velocity ( Vair). ► The KOL decreased with increases in air temperature ( Tair) and total solids (TS) concentration. ► The KOL sensitivity to key factors, in descending order, was: TL, Tair, Vair, and TS concentration.
Keywords: Ammonia emissions; Overall mass transfer coefficient (; K; OL; ); Process-based models; Convective emission chamber; Dairy manure
Seasonal variation of methane flux from coastal saline rice field with the application of different organic manures by A. Datta; Jagadeesh B. Yeluripati; D.R. Nayak; K.R. Mahata; S.C. Santra; T.K. Adhya (pp. 114-122).
A field experiment was conducted in an irrigated saline rice field of Gadakujang (a fishing hamlet of coastal Odisha, India, ravaged by the super cyclone of 1999 and cyclone BOB02 of 2006), to study the effects of locally available organic and fresh green manure amendment to the saline soil on methane (CH4) emission during wet and dry seasons using the conventional closed chamber flux measurement method. In a first report of this kind, CH4 emission vis-à-vis yield improvement of rice with different locally available organic manure application from coastal saline rice field soil of Odisha, is reported. The study confirms that CH4 flux from the saline soil planted to rice is significantly lower than that of irrigated inland non-saline rice field during both wet and dry seasons. Cumulative seasonal CH4 flux from different treatments of the coastal saline rice field ranged between 119.51 and 263.60 kg ha−1 during the wet season and 15.35–100.88 kg ha−1 during the dry season. Lower CH4 emission during the dry season may be attributed to the increased soil salinity (EC1:2) that went up from 0.76 dS m−1 during the wet season to 3.96 dS m−1 during the dry season. Annual CH4 emission per Mg grain yield was significantly low from plots treated with locally available green manure Morning glory ( Ipomoea lacunosa) (17.27) with significantly high rice grain yield. Study indicates that Morning glory may be used as a potential green manure to increase grain yield and reduced CH4 emission from the coastal saline rice ecosystems of the tropics.► Coastal rice field which is occasionally submerged with saline sea water. ► Organic/green manure application for more than five years. ► Seasonal (dry and wet) variation of methane emission from different treatments. ► Study of yield attributes with methane emission. ► Comparison of methane emission from coastal saline and inland non-saline rice field.
Keywords: Coastal rice paddy; Fresh green manure; Farmyard manure; Methane flux
Effect of inorganic fertilizers (N, P, K) on methane emission from tropical rice field of India by A. Datta; S.C. Santra; T.K. Adhya (pp. 123-130).
In the tropical experimental rice field of Central Rice Research Institute, Odisha, India, an experiment was conducted during the dry season (January–April) and wet season (July–November) of rice cultivation to study the effect of nitrogen (N), phosphorus (P) and potassium (K) fertilizer application on grain yield and methane (CH4) emission. The experiment was carried out with five treatments (No fertilizer (control), N-fertilizer, P-fertilizer, K-fertilizer and N + P + K fertilizer) with three replicates of each under a completely randomized block design. Significantly higher CH4 emission was recorded from all plots during wet season. Among fertilizer applied plots, significantly higher CH4 emission was recorded from N-fertilizer applied plots (dry season: 80.27 kg ha−1; wet season: 451.27 kg ha−1), while significantly lower CH4 emission was recorded from N + P + K applied plots (dry season: 34.60 kg ha−1; wet season: 233.66 kg ha−1). Low cumulative CH4 emission to grain yield ratio was recorded from N + P + K applied plots during both seasons (83.57 kg Mg−1 grain yield during dry season and 77.14 kg Mg−1 grain yield during wet season). CH4 emission from different treatment was positively correlated with microbial biomass carbon ( r = 0.516), readily mineralizable carbon ( r = 0.621) and sugar ( r = 0.340) content of the soil. Negative CH4 emission was recorded during the fallow period which may be attributed to higher methanotrophic bacterial population. Study suggests that the effects of P and K-fertilizer on CH4 emission from rice field along with the CH4 emission during the fallow period need to be considered to reduce the uncertainty in upscaling process.► Study of methane emission from Aeric Endoaquept. ► Significant reduction of methane emission with P and K-fertilizers. ► Low methane emission from N + P + K applied plots.
Keywords: Fertilizer management; Rice field; Methane emission; Seasonal variation
Endosulfan in the atmosphere of South Florida: Transport to Everglades and Biscayne National Parks by Cathleen J. Hapeman; Laura L. McConnell; Thomas L. Potter; Jennifer Harman-Fetcho; Walter F. Schmidt; Clifford P. Rice; Bruce A. Schaffer; Richard Curry (pp. 131-140).
Nutrient inputs from urban encroachment and agricultural activities have been implicated in contributing to the environmental health decline and loss of organism diversity of South Florida ecosystems. Intensive agricultural pesticide use may also challenge these ecosystems. One possible mechanism is pesticide release to the atmosphere after application. The process is enhanced in this region due to the calcareous soils, frequent rainfall, and high humidity and temperatures. This study examined the atmospheric fate of the widely-used insecticide endosulfan. Air samples were collected over a five-year period (2001–2006) at a site within the agricultural community of Homestead, Florida and at sites located in nearby Biscayne and Everglades National Parks (NPs). Mean gas phase air concentrations of α-endosulfan were 17 ± 19 ng m−3 at Homestead, 2.3 ± 3.6 ng m−3 at Everglades NP, and 0.52 ± 0.69 ng m−3 at Biscayne NP. Endosulfan emissions from agricultural areas around Homestead appeared to influence air concentration observations at the NP sites. During an intensive sampling campaign, the highest total endosulfan concentrations at the NP sites were observed on days when air parcels were predicted to move from Homestead towards the sampling locations. The α-endosulfan fraction (α/(α + β)) was used to examine the contribution of pesticide drift versus volatilization to the overall residue level. The formulated product has an α fraction of approximately 0.7, whereas volatilization is predicted to have an α fraction of ≥0.9. The median α- fraction observed during periods of high agricultural activity at Homestead and Everglades NP was 0.84 and 0.88, respectively, and during periods of low agricultural activity the median at Homestead was 0.86, indicating contributions from drift. The median α fraction at Everglades NP was 1.0 during periods of low agricultural activity, while Biscayne NP was 1.0 year round indicating air concentrations are primarily influenced by regional volatilization.Display Omitted► Endosulfan measured in air at agricultural site and 2 national parks in South Florida. ► Highest values at National Parks observed when air parcels moved from ag site. ► α-endosulfan fraction [α/(α + β)] used to examine endosulfan sources to the air. ► Drift and volatilization/isomerization were major sources at ag and Everglades sites. ► Volatilization/isomerization was the primary emission source to Biscayne site.
Keywords: Endosulfan; Florida; Everglades; Biscayne Bay; Air quality; Volatilization; Isomerization; Drift
Presence of carbaryl in the smoke of treated lodgepole and ponderosa pine bark by Chris J. Peterson; Sheryl L. Costello (pp. 141-144).
Lodgepole and ponderosa pine trees were treated with a 2% carbaryl solution at recreational areas near Fort Collins, CO, in June 2010 as a prophylactic bole spray against the mountain pine beetle. Bark samples from treated and untreated trees were collected one day following application and at 4-month intervals for one year. The residual amount of carbaryl was determined, and bark samples were burned to examine the smoke for the active ingredient. Smoke recovered from spiked bark samples showed a very high correlation between the treated rate and the concentration recovered from the smoke. Residual carbaryl on the bark was relatively stable throughout the study and carbaryl was detected in the smoke throughout the duration of the test.► We measure residual carbaryl on field treated pine bark and in wood smoke. ► Carbaryl levels remain steady or decline slightly in one year. ► Carbaryl is detected in the smoke of burned treated bark.
Keywords: Mountain pine beetle; Dendroctonus; Longevity; Smoke
Presence of organophosphorus pesticide oxygen analogs in air samples by Jenna L. Armstrong; Richard A. Fenske; Michael G. Yost; Kit Galvin; Maria Tchong-French; Jianbo Yu (pp. 145-150).
A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (<30 ng m−3) typical of ambient or residential levels. Overall, the 2008 study data had significantly greater oxon than expected by artificial transformation, but the exact amount of environmental oxon in air remains difficult to quantify with the current sampling method. Failure to conduct laboratory analysis for chlorpyrifos-oxon may result in underestimation of total pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity equivalent factor approach should be used to determine potential health risks from exposures.► Chlorpyrifos-oxon is formed during air sampling with matrices containing XAD-2. ► Chemical analysis without measurement of oxon underestimates air concentrations. ► Comparisons of lab and field data suggest that oxon is present in community air. ► Accounting for chemical mixtures of parent OPs and oxons in air is important. ► Small amounts of oxon in air have a large effect on human health risk estimates.
Keywords: Air monitoring; Exposure; Organophosphorus pesticides; Oxon; Toxicity equivalent concentration; XAD resin
Assessing atmospheric nitrogen deposition to natural and semi-natural ecosystems – Experience from Danish studies using the DAMOS by Ole Hertel; Camilla Geels; Lise Marie Frohn; Thomas Ellermann; Carsten Ambelas Skjøth; Per Løfstrøm; Jesper H. Christensen; Helle Vibeke Andersen; Robert George Peel (pp. 151-160).
Local agricultural emissions contribute significantly to the atmospheric reactive nitrogen loads of Danish terrestrial ecosystems. In the vicinity of the sources this may be up to 6–8kgNha−1yr−1 depending on location and ecosystem type. This contribution arises from dry deposition of gas phase ammonia derived from local livestock production. Long-range transport, however, often constitutes the largest contribution to the overall atmospheric terrestrial reactive nitrogen loadings in Denmark. This is often in the range 10–15kgNha−1yr−1 and consists mainly of aerosol phase nitrate and ammonium (reaction products of nitrogen oxides and ammonia), but also dry deposition of other reactive nitrogen compounds (mainly nitrogen oxides in the form of gas phase nitric acid and nitrogen dioxide). In Denmark’s environmental management of the sensitive terrestrial ecosystems modelling tools are required that account for both the local and the long-range transported contributions. This motivated development of the Danish Ammonia MOdelling System (DAMOS) that has been successfully applied to the assessment of atmospheric nitrogen loadings to sensitive Danish ecosystems. We present here three different examples of such assessments. Our results show that ecosystems located in Western Denmark (Case 1) receive the highest loads of atmospheric nitrogen depositions which generally exceed the critical load. This part of the country has the highest livestock density. In the Eastern part of the country, the atmospheric loadings are often below or close to the lower end of the interval for critical load values. These lower loads in Eastern Denmark (Case 2) are due to lower density of agricultural activities, as well as, lower precipitation rates, which leads to less wet deposition of reactive nitrogen. In general there is a gradient in atmospheric deposition over the country, with the highest depositions in the South-Western part of Denmark (Case 3) due to long-range transport contributions from North-Western Europe, but also due to local ammonia deposition associated with the high local emission from the high density livestock farming in this area.► Many DK ecosystems receive atmospheric nitrogen loadings exceeding critical loads. ► Local agriculture may contribute to dep. to ecosystems of up to 6–8kgNha−1yr−1. ► Many ecosystems have largest contribution from LRT; often 10–15kgNha−1yr−1. ► Clear gradient over DK with highest loads in South-West & lowest in North-East. ► Assessing deposition to ecosystems most include both local scale & LRT models.
Keywords: Nitrogen deposition; Atmospheric ammonia; Environmental assessment; Critical loads; DAMOS
Biosphere-atmosphere exchange of volatile organic compounds over C4 biofuel crops by Martin Graus; Allyson S.D. Eller; Ray Fall; Bin Yuan; Yaling Qian; Philip Westra; Joost de Gouw; Carsten Warneke (pp. 161-168).
Significant amounts of ethanol are produced from biofuel crops such as corn and, in the future, likely switchgrass. The atmospheric effects of growing these plant species on a large scale are investigated here by measuring the plant-atmosphere exchange of volatile organic compounds (VOCs). Field grown corn and switchgrass emit VOCs at flux rates of 4.4 nmolC m−2 s−1 (10−9 mol carbon per square meter leaf area per second) and 2.4 nmolC m−2 s−1, respectively. Methanol contributes ∼60% to the molar flux but small emissions of carbonyls, aromatic compounds and terpenoids are relatively more important for potential air quality impacts. Switchgrass can act as a sink for carbonyls and aromatic compounds with compensation points of a few hundred pptv. In switchgrass moderate drought stress may induce enhanced emissions of monoterpenes, carbonyls and aromatics. Per liter of fuel ethanol produced, the estimated VOC emissions associated with the biomass growth of corn (7.8 g l−1) or switchgrass (6.2 g l−1) are in the same range as the VOC emissions from the use of one liter gasoline in vehicle engines. VOC emissions from the growing of biofuel crops can therefore be a significant contributor to the VOC emissions in the life cycle of biofuels. The VOC emissions from corn and switchgrass are small compared to those of tree species suggested as biofuel crops. Due to their reactivity with respect to OH the emissions from corn and switchgrass are not likely to have a significant impact on regional ozone formation.► Growing biofuel feedstock emits several grams of BVOC per liter fuel produced. ► Cars emit similar amounts of VOC per liter gas consumed, but with different impact. ► VOCs emissions from corn and switchgrass are small compared to woody feedstock. ► Switchgrass acts as a sink for carbonyls and aromatics at a few hundred pptv. ► VOCs from switchgrass or corn unlikely contribute significantly to ozone formation.
Keywords: Biofuel crops; Volatile organic compounds (VOC); Biogenic VOC emissions; VOC sink; Biofuel life cycle; Proton transfer-reaction mass spectrometry (PTR-MS)