Characterization of odor released during handling of swine slurry: Part I. Relationship between odorants and perceived odor concentrations

Odor emission from livestock production systems is a major nuisance in many rural areas. This study aimed at determining the major airborne chemical compounds responsible for the unpleasant odor perceived in swine facilities during slurry handling, and at proposing predictive models of odor concentration (OC) based on the concentrations of specific odorants in the air. A multivariate data analysis strategy involving principal components analysis and multiple linear regressions was implemented to analyze the relationships between concentration of 35 gases (measured by GC/MS or gas detection tubes), and the overall OC perceived by sensory analysis. The study compiled data on the concentration of odor and odorants, measured in the headspace of 24 unstored and stored slurry samples collected from three different types of production units on 8 commercial swine farms. Among all the measured constituents, OC was found to have the highest correlation with the sulfur containing compounds (i.e. hydrogen sulfide, dimethylsulfide, dimethyldisulfide, dimethyltrisulfide). The concentration of hydrogen sulfide accounted for 68% of the variation in OC above the stirred slurry samples. The highest concentrations of volatile organic compounds were observed for phenols and indoles, which made a significant contribution to the overall OC when the slurry was fresh. The contribution of ammonia to the OC was only significant in the absence of hydrogen sulfide. The precision of predictive models of OC based on the concentration of specific odorants in the air was satisfactory (R² between 0.66 and 0.89). Hence, this study suggests that monitoring of specific odor compounds released from agitated swine slurry can be used to predict the concentration of odor perceived close to the source (e.g. at storage units), allowing the assessment of odor nuisance potentials.     

Emissions of ammonia, hydrogen sulfide, and odor before, during, and after slurry removal from a deep-pit swine finisher

It is a common practice in the midwestern United States to raise swine in buildings with under-floor slurry storage systems designed to store manure for up to one year. These so-called "deep-pit" systems are a concentrated source for the emissions of ammonia (NH3), hydrogen sulfide (H2S), and odors. As part of a larger six-state research effort (U.S. Department of Agriculture-Initiative for Future Agriculture and Food Systems Project, "Aerial Pollutant Emissions from Confined Animal Buildings"), realtime NH3 and H2S with incremental odor emission data were collected for two annual slurry removal events. For this study, two 1000-head deep-pit swine finishing facilities in central Iowa were monitored with one-year storage of slurry maintained in a 2.4 m-deep concrete pit (or holding tank) below the animal-occupied zone. Results show that the H2S emission, measured during four independent slurry removal events over two years, increased by an average of 61.9 times relative to the before-removal H2S emission levels. This increase persisted during the agitation process of the slurry that on average occurred over an 8-hr time period. At the conclusion of slurry agitation, the H2S emission decreased by an average of 10.4 times the before-removal emission level. NH3 emission during agitation increased by an average of 4.6 times the before-removal emission level and increased by an average of 1.5 times the before-removal emission level after slurry removal was completed. Odor emission increased by a factor of 3.4 times the before-removal odor emission level and decreased after the slurry-removal event by a factor of 5.6 times the before-removal emission level. The results indicate that maintaining an adequate barn ventilation rate regardless of animal comfort demand is essential to keeping gas levels inside the barn below hazardous levels.     

Heavy metals in urban soils of East St. Louis, IL. Part II: Leaching characteristics and modeling

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produced organic and inorganic chemicals, and petroleum refineries. Following a gross assessment of heavy metals in the community soils (see Part I of this two-part series), leaching tests were performed on specific soils to elucidate heavy metal-associated mineral fractions and general leachability. Leaching experiments, including the Toxicity Characteristic Leaching Procedure (TLCP) and column tests, and sequential extractions, illustrated the low leachability of metals in East St. Louis soils. The column leachate results were modeled using a formulation developed for fly ash leaching. The importance of instantaneous dissolution was evident from the model. By incorporating desorption/adsorption terms into the source term, the model was adapted very well to the time-dependent heavy metal leachate concentrations. The results demonstrate the utility of a simple model to describe heavy metal leaching from contaminated soils.     

Development of a livestock odor dispersion model: part II. Evaluation and validation

A livestock odor dispersion model (LODM) was developed to predict odor concentration and odor frequency using routine hourly meteorological data input. The odor concentrations predicted by the LODM were compared with the results obtained from other commercial models (Industrial Source Complex Short-Term model, version 3, CALPUFF) to evaluate its appropriateness. Two sets of field odor plume measurement data were used to validate the model. The model-predicted mean odor concentrations and odor frequencies were compared with those measured. Results show that this model has good performance for predicting odor concentrations and odor frequencies.     

单组分垃圾厌氧降解初期的产气规律及恶臭特征

研究了垃圾单组分(蛋白类和糖类)厌氧降解初期的产气动态规律和恶臭特征。结果表明,糖类物料厌氧降解的累积产气量大于蛋白类物料,各物料的气体排放动态曲线不同,酪蛋白和淀粉物料呈现Monod型曲线,而纤维素物料呈现2次Monod型曲线;蛋白类物料降解产生的恶臭气体成分更丰富,且动态变化曲线有多种形式:硫化氢、磷化氢和硫8的浓度变化曲线呈单峰型,聚硫醚浓度曲线呈S型,挥发性脂肪酸(VFAs)呈Monod型曲线;臭气强度分析结果表明,蛋白类物料产生的臭气强度高于糖类物料。单组分垃圾产气规律和恶臭特征的研究结果为开发高效恶臭原位控制技术提供了理论基础。     

Role of protein, amino acids, and enzyme activity on odor production from anaerobically digested and dewatered biosolids.

The main objective of this research was to test the hypothesis that bioavailable protein and, more specifically, the sulfur-containing amino acids within the protein, can be degraded by proteolytic enzymes to produce odor-causing compounds--mainly volatile sulfur compounds (VSCs)--during biosolids storage. To achieve these objectives, samples of digester effluent and cake solids were collected at 11 different wastewater treatment plants in North America, and the samples were analyzed for protein and amino acid content and general protein-degrading enzyme activity. At the same time, cake samples were stored using headspace bottles, the concentration of VSCs were measured using gas chromatography, and olfactometry measurements were made by a trained odor panel. The results showed that the bound cake protein content and methionine content was well-correlated with VSC production and the detection threshold measured by the odor panel.     

The Southeastern Aerosol Research and Characterization Study: Part II. Filter-Based Measurements of Fine and Coarse Particulate Matter Mass and Composition

Abstract

The Southeastern Aerosol Research and Characterization Study (SEARCH) was implemented in 1998–1999 to provide data and analyses for the investigation of the sources, chemical speciation, and long-term trends of fine particulate matter (PM_2.5) and coarse particulate matter (PM_10–2.5) in the Southeastern United States. This work is an initial analysis of 5 years (1999–2003) of filter-based PM_2.5 and PM_10–2.5 data from SEARCH. We find that annual PM_2.5 design values were consistently above the National Ambient Air Quality Standards (NAAQS) 15 µg/m³ annual standard only at monitoring sites in the two largest urban areas (Atlanta, GA, and North Birmingham, AL). Other sites in the network had annual design values below the standard, and no site had daily design values above the NAAQS 65 µg/m³ daily standard. Using a particle composition monitor designed specifically for SEARCH, we found that volatilization losses of nitrate, ammonium, and organic carbon must be accounted for to accurately characterize atmospheric particulate matter. In particular, the federal reference method for PM_2.5 underestimates mass by 3–7% as a result of these volatilization losses. Organic matter (OM) and sulfate account for ≥60% of PM_2.5 mass at SEARCH sites, whereas major metal oxides (MMO) and unidentified components (“other”) account for ≥80% of PM_10–2.5 mass. Limited data suggest that much of the unidentified mass in PM_10–2.5 may be OM. For paired comparisons of urban-rural sites, differences in PM_2.5 mass are explained, in large part, by higher OM and black carbon at the urban site. For PM₁₀, higher urban concentrations are explained by higher MMO and “other.” Annual means for PM_2.5 and PM_10–2.5 mass and major components demonstrate substantial declines at all of the SEARCH sites over the 1999–2003 period (10–20% in the case of PM_2.5, dominated by 14–20% declines in sulfate and 11–26% declines in OM, and 14–25% in the case of PM_10–2.5, dominated by 17–30% declines in MMO and 14–31% declines in “ other”). Although declining national emissions of sulfur dioxide and anthropogenic carbon may account for a portion of the observed declines, additional investigation will be necessary to establish a quantitative assessment, especially regarding trends in local and regional emissions, primary carbon emissions, and meteorology.     

The Southeastern Aerosol Research and Characterization Study: Part II. Filter-based measurements of fine and coarse particulate matter mass and composition

The Southeastern Aerosol Research and Characterization Study (SEARCH) was implemented in 1998-1999 to provide data and analyses for the investigation of the sources, chemical speciation, and long-term trends of fine particulate matter (PM2.5) and coarse particulate matter (PM10-2.5) in the Southeastern United States. This work is an initial analysis of 5 years (1999-2003) of filter-based PM2.5 and PM10-2.5 data from SEARCH. We find that annual PM2.5 design values were consistently above the National Ambient Air Quality Standards (NAAQS) 15 microg/m3 annual standard only at monitoring sites in the two largest urban areas (Atlanta, GA, and North Birmingham, AL). Other sites in the network had annual design values below the standard, and no site had daily design values above the NAAQS 65 microg/m3 daily standard. Using a particle composition monitor designed specifically for SEARCH, we found that volatilization losses of nitrate, ammonium, and organic carbon must be accounted for to accurately characterize atmospheric particulate matter. In particular, the federal reference method for PM2.5 underestimates mass by 3-7% as a result of these volatilization losses. Organic matter (OM) and sulfate account for approximately 60% of PM2.5 mass at SEARCH sites, whereas major metal oxides (MMO) and unidentified components ("other") account for > or = 80% of PM10-2.5 mass. Limited data suggest that much of the unidentified mass in PM10-2.5 may be OM. For paired comparisons of urban-rural sites, differences in PM2.5 mass are explained, in large part, by higher OM and black carbon at the urban site. For PM10, higher urban concentrations are explained by higher MMO and "other." Annual means for PM2.5 and PM10-2.5 mass and major components demonstrate substantial declines at all of the SEARCH sites over the 1999-2003 period (10-20% in the case of PM2.5, dominated by 14-20% declines in sulfate and 11-26% declines in OM, and 14-25% in the case of PM10-2.5, dominated by 17-30% declines in MMO and 14-31% declines in "other"). Although declining national emissions of sulfur dioxide and anthropogenic carbon may account for a portion of the observed declines, additional investigation will be necessary to establish a quantitative assessment, especially regarding trends in local and regional emissions, primary carbon emissions, and meteorology.     

Comparison of modified montmorillonite adsorbents. Part II: The effects of the type of raw clays and modification conditions on the adsorption performance

This paper builds on the preceding researches to study the effects of the type of clays (montmorillonites K10, KSF) and modifying conditions on the structure and adsorption behavior of resulting clay adsorbents. The raw clays were modified by polymeric Al/Fe species, hexadecyl-trimethylammonium (HDTMA) surfactant and a complex of polymeric Al/Fe-HDTMA. X-ray diffraction spectra was applied to analyze the structure of the raw and modified clays. After modification, the basal spacing of the clays varied, depending on the types of raw clay and modification conditions. Copper and phenol were selected as adsorbates for evaluating the adsorption performance of various clays, which was affected significantly by the types of raw clay and modification conditions. In general the inorganic contaminant (e.g., Cu) tend to be adsorbed by the polymeric Al/Fe modified clay and the organic impurities (e.g., phenol) will be preferably captured by the surfactant modified clay; both due to the specific surface properties resulting from introducing the modifiers. The complex modified clays possessed the ability of adsorbing both inorganic and organic contaminants. In addition, the d 0 0 1 spacing of modified KSF was greater than that of K10; the adsorption performance with modified KSF was thus greater than that with the modified K10. Finally, the ratio of modifiers to the clay (metal:surfactant:clay) has been observed to affect the adsorption performance; the optimal conditions have been defined.     

Continuous four-dimensional source attribution for the Berlin area during two days in July 1994. Part II: Sensitivity studies

The multiple nested three-dimensional (3D) mesoscale Eulerian grid point model MM5 is directly coupled with a Lagrangian particle trajectory model in order to perform a four-dimensional source attribution for the area of Berlin based on the horizontal distribution of the import probability density (IPD). The technical aspects are already demonstrated in the companion paper A (Part I) including the illustration of the meteorological situation at the two consecutive days of investigation and a primarily 3D source attribution. We conducted further sensitivity studies concerning the effect of vertical mixing, the static stability of the particles/emissions and the regarded time scale on the IPD distribution which is extended to four dimensions. The main results are:

• •Heterogeneity and temporal variability of the wind field enhance the contributions of nearby sources (emissions) to the total import of the receptor in contrast to stationary wind fields which increase the scope of the IPD distribution in the upstream direction.
• •Regions of static stability, for example morning hour inversion layers, enhance the contribution of far distance sources with longer import times.
• •The import velocities increase, as far as long distance source-receptor transitions are concerned, because they are mostly realised via higher transport paths.
• •The third (vertical) dimension is not negligible for the task of a complete source attribution, as a considerable amount of elevated emissions, preferably out of 300±100 m elevation, reaches the receptor box which is only 50 m in depth. Hence, downward mixing of elevated and far distance sources is an important process and driven by the diurnal course of turbulence and low level jets within the PBL
• •On the short time scale (few days), the source attribution is not independent from the regarded time scale (simulation time) due to the neglecting of older emissions released before the beginning of the simulation.

     

Flotation of metal-loaded clay anion exchangers. Part II: the case of arsenates

Hydrotalcite-like materials, or otherwise termed layered double hydroxides, are clays with an ability to remove anions. As they usually are in powder form, these sorbents often present appreciable problems in the solid/liquid separation process following the sorption stage. Sorptive flotation of metal-loaded particles was investigated in this paper, as an alternative two-stage process. In the sorption process, satisfactory removals of arsenic(V) were obtained onto synthetic hydrotalcite particles from water. The effect of some parameters, like the solution ionic strength, concentrations, temperature, etc. was examined. During the second stage of the process, hydrotalcite fine particles were removed from the liquid phase by dispersed-air flotation; various surfactants were tested in relation to the ionic strength of the solution. The combined process of sorptive flotation provides promising results for arsenic removal.     

Mercury sources and physicochemical characteristics in ice,snow, and meltwater of the Laohugou Glacier Basin,China

Environmental Science and Pollution Research - In this work, samples of surface snow, surface ice, snow pit and meltwater from the Laohugou Glacier No. 12 on the northern edge of Tibetan Plateau...     

Effect of composting on characterization and leaching of copper, manganese, and zinc from swine manure.

This research was conducted to study the influence of composting on the concentrations, water solubility, and phase association of Cu, Mn, and Zn from swine (Sus domesticus) feces. Composting of separated swine manure was performed in two piles for 122 days. The metal concentrations increased rapidly during the first 49 days and leveled off thereafter. All metal concentrations increased approximately 2.7-fold in the final compost due to decomposition of organic matter. A sequential extraction protocol was used to evaluate the humification process and partition metals into water-soluble, exchangeable, organically complexed, organically bound, solid particulate, and residual fractions. Temporal changes in the water-soluble fractions of Cu, Mn, and Zn were reflected by water-soluble organic C concentrations, which rapidly increased to a maximum at Day 18 and declined thereafter. An increase in the humic acid/fulvic acid ratio in Na4P2O7 or NaOH extracts at various stages of composting represented the humification process. During composting, the major portions of Cu, Mn, and Zn were in the organically-bound, solid particulate, and organically complexed fractions, respectively. Metal distributions in different chemical fractions were generally independent of composting age and, thus, independent of respective total metal concentrations in the composts.     

Heavy Metals in Urban Soils of East St. Louis,IL Part II: Leaching Characteristics and Modeling

ABSTRACT

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produced organic and inorganic chemicals, and petroleum refineries. Following a gross assessment of heavy metals in the community soils (see Part I of this two-part series), leaching tests were performed on specific soils to elucidate heavy metal-associated mineral fractions and general leachability. Leaching experiments, including the Toxicity Characteristic Leaching Procedure (TLCP) and column tests, and sequential extractions, illustrated the low leachability of metals in East St. Louis soils. The column leachate results were modeled using a formulation developed for fly ash leaching. The importance of instantaneous dissolution was evident from the model. By incorporating desorption/adsorption terms into the source term, the model was adapted very well to the time-dependent heavy metal leachate concentrations. The results demonstrate the utility of a simple model to describe heavy metal leaching from contaminated soils.     

Fate and transport of monoterpenes through soils. Part II: calculation of the effect of soil temperature, water saturation and organic carbon content

This theoretical study was performed to investigate the influence of soil temperature, soil water content and soil organic carbon fraction on the mobility of monoterpenes (C10HnOn') applied as pesticides to a top soil layer. This mobility was expressed as the amount volatilized and leached from the contaminated soil layer after a certain amount of time. For this, (slightly modified) published analytical solutions to a one dimensional, homogeneous medium, diffusion/advection/biodegradation mass balance equation were used. The required input-parameters were determined in a preceding study. Because the monoterpenes studied differ widely in the values for their physico-chemical properties, the relative importance of the various determinants also differed widely. Increasing soil water saturation reduced monoterpene vaporization and leaching losses although a modest increase was usually observed at high soil water contents. Organic matter served as the major retention domain, reducing volatilization and leaching losses. Increasing temperature resulted in higher volatilization and leaching losses. Monoterpene mobility was influenced by vertical water flow. Volatilization losses could be reduced by adding a clean soil layer on top of the contaminated soil. Detailed insight into the specific behaviour of different monoterpenes was obtained by discussing intermediate calculation results; the transport retardation factors and effective soil diffusion coefficients. One insight was that the air-water interface compartment is probably not an important partitioning domain for monoterpenes in most circumstances. The results further indicated that biodegradation is an important process for monoterpenes in soil.     

Elements Influencing Cost Allocation in the Pinal Creek Aquifer,Arizona, USA. Part II: Geochemical Controls on Groundwater Quality Recovery

This is the second article in a three-part series (all published in this volume) describing the framework used to quantitatively allocate mass loading of metals to the Pinal Creek alluvial aquifer among multiple sources. This contribution describes the formation of, and zonations within, the 20 km plume, which consists of a Peripheral Margin (pH > 5.5), the Intermediate Zone (pH 4.2–5.5), and an Acidic Core (pH < 4.2), where metal-bearing iron oxyhydroxides and acid-bearing minerals (jarosite, Al[OH]SO₄, and FeSO₄ cements) have precipitated. While source remediation has improved groundwater quality, temporal reductions in solute concentrations at downgradient wells exhibit asymptotic behavior due to ongoing dissolution of acid-bearing precipitates, demonstrating that the total mass of metals released to the system over the last 75 years will dictate the ultimate remedial duration and cost. Column experiments, geochemical modeling, and analysis of empirical data indicate a minimum range of remedial time frames from about 20 years in the Peripheral Margin to more than 140 years in the Acidic Core. This analysis comprises a hitherto neglected element of cost allocation by causatively linking historical releases to the current and future environmental degradation that will incur response costs.     

Biosolids-amended soils: Part I. Effect of biosolids application on soil quality and ecotoxicity.

Investigations of potential risk from biosolids generally indicate that land application does not threaten human or ecosystem health, but questions continue to arise concerning the environmental effects of this practice. This research project was initiated to evaluate ecotoxicity resulting from the amendment of soils with biosolids from municipal wastewater treatment plants. Toxicity was evaluated using standard tests, including earthworm mortality, growth, and reproduction; seedling germination and root elongation; microbial respiration; and nematode mortality and reproduction. Nineteen municipal wastewater treatment plants were identified to participate in an initial screening of toxicity, and five were chosen for a more detailed evaluation. In addition, two soils with historically high applications of high-metal biosolids were evaluated. Contaminants examined were zinc, copper, nickel, chromium, arsenic, cadmium, lead, and coplanar polychlorinated biphenyls (PCBs). Single applications had no effect on soil metal concentrations. Coplanar PCBs were not detectable in any of the soils or biosolids. All target organisms were sensitive to reference toxicants. Limited toxicity was observed in a small number of the amended soils, but no patterns emerged. Approximately one-half of the negative effects of biosolids on bioindicators could be attributed to routine properties, such as slight depression of pH and/or elevated salinity. None of the accumulated metal concentrations were excessive, and most would not be considered elevated. These observations suggest that current regulations for application of biosolids to soils are providing adequate ecosystem protection.     

Monitoring personal,indoor, and outdoor exposures to metals in airborne particulate matter: Risk of contamination during sampling,handling and analysis

Rigorous sampling and quality assurance protocols are required for the reliable measurement of personal, indoor and outdoor exposures to metals in fine particulate matter (PM_2.5). Testing of five co-located replicate air samplers assisted in identifying and quantifying sources of contamination of filters in the laboratory and in the field. A field pilot study was conducted in Windsor, Ont., Canada to ascertain the actual range of metal content that may be obtained on filter samples using low-flow (4 L min⁻¹) 24-h monitoring of personal, indoor and outdoor air. Laboratory filter blanks and NIST certified reference materials were used to assess contamination, instrument performance, accuracy and precision of the metals determination. The results show that there is a high risk of introducing metal contamination during all stages of sampling, handling and analysis, and that sources and magnitude of contamination vary widely from element to element. Due to the very small particle masses collected on low-flow 24-h filter samples (median 0.107 mg for a sample volume of approximately 6 m³) the contribution of metals from contamination commonly exceeds the content of the airborne particles being sampled. Thus, the use of field blanks to ascertain the magnitude and variability of contamination is critical to determine whether or not a given element should be reported. The results of this study were incorporated into standard operating procedures for a large multiyear personal, indoor and outdoor air monitoring campaign in Windsor.