This research focused on the effects of un-weathered Macondo crude oil on the growth rates and pigment ratios of phytoplankton isolated from Grand Isle, LA. The experiments involved incubating nutrient-enriched artificial media containing a range of oil concentrations up to 19.2 ppm with small aliquots of coastal water from Grand Isle and measuring the growth rates of the phytoplankton during the subsequent 1014 days and the pigment ratios of the phytoplankton at the end of log-phase growth to determine whether the crude oil affected the growth rate of the phytoplankton and their composition in terms of pigment ratios. Pigment analysis revealed that the cultures consisted almost entirely of diatoms. Results showed that there was a significant effect on diatom growth rates from the concentration of crude oil, the month, and the interaction between oil concentrations and months. In March, April, and May, growth rates at oil concentrations from 0.1 to 0.6 ppm were about 10% higher than controls. At higher oil concentrations there was a negative correlation between oil concentrations and growth rates. The ratio of fucoxanthin to chlorophyll a was positively correlated with oil concentrations in February, March and April, the implication being that the size of the diatom photosynthetic units changed in response to the oil. There was no significant correlation between growth rates and oil concentrations in July and August, nor was there any correlation between pigment ratios and oil concentrations. The July and August phytoplankton grew roughly twice as fast as the March, and April control cultures, although the growth conditions were identical. Analysis with a mathematical model of phytoplankton growth suggested that in the presence of oil, there was a transfer of resources within the March, April, and May phytoplankton, the result being an increase in the size of their photosynthetic units and a decrease in the number of photosynthetic units in response to the presence of oil. The principal antenna pigment was fucoxanthin. The phytoplankton isolated in July and August, in contrast, appeared to be completely unaffected by the presence of oil up to a concentration of 19.2ppm.

The effects of the Deepwater Horizon (DWH) oil spill on the bacterial communities in coastal sediments are relatively known but few studies have been published evaluating the impacts of the spill on oil-degrading bacterial populations in the salt marsh sediments of Barataria Bay, Louisiana. The aims of this study were to determine the effects of the oil spill on the microbial community in Barataria Bay, Louisiana through the determination of predominate species of oil-degrading bacteria in marsh sediments, and to determine how well certain bacterial isolates can degrade crude oil in the region by taking samples from three areas of different oiling categories in April 2012, October 2012 and April 2013, approximately 24, 30, and 36 months after the initial oiling event. Hydrocarbon-degrading bacteria were isolated from the sediment samples using Bushnell Haas (BH) agar enriched with 1% Light Louisiana Sweet (LLS) crude oil. The isolates were subsequently purified on LB agar plates, their genomic DNAs extracted, and 16S rRNA genes amplified by polymerase chain reaction (PCR). The PCR products of 16S rRNA were then sequenced and taxonomically classified based on similarity to known sequences in BLAST database. A total of 460 isolates were obtained, representing 84 species from 45 genera in 6 phyla. Oil degradability of 10 bacterial isolates, designated to Staphylococcus xylosus, Acinetobacter calcoaetious, Pseudomonas stutzeri, Bacillus pumilus, Micrococcus luteus, Rhodococcus equi, Microbacterium esteratomaticum, Vibrio sp., Pseudomonas mendocina, and Agromyces aurantiacus, respectively, was tested in LB broth with 1% LLS crude oil. Their growth and metabolic properties in terms of optical density at 600 nm and pH in culture medium were monitored for 6 days. Among these isolates, Micrococcus luteus, Vibrio sp., Bacillus pumilus, Rhodococcus equi and Microbacterium esteratomaticum appeared to have the greatest ability to degrade LLS crude oil; their growth rates were estimated to be 0.038, 0.037, 0.031, 0.029 and 0.037 per hour, respectively. All isolates showed a decrease in pH in their culture medium during their growth, with M. esteratomaticum having the lowest pH of 5.29 and R. equi having the highest pH of 6.50 at 96 hours of incubation. A decrease in pH in the cultured media is indicative of an accumulation of acid from oxidation reactions carried out by oil-degrading bacteria. The present study provided a comprehensive list of indigenous oil-degrading bacteria in Louisiana marsh sediment, which is critical in developing bioremediation strategies.

Measured physical/chemical properties of chemicals can be impacted by varying environmental conditions, subsequently influencing chemical environmental fate and exposure. For example, salinity has been reported to influence the water solubility of organic chemicals entering marine ecosystems. However, there is limited data available on salinity impacts on chemical sorption as well as bioavailability and exposure estimates used in the chemicals regulatory assessment. The salinity impact were demonstrated on the estimates of environmental fate of model compounds with different polarities including pesticides, and polycyclic aromatic sulfur heterocycles (PASHs). The n-octanol/water partition coefficient (KOW) was measured in both distilled-deionized water as well as artificial seawater (3.2%). A linear correlation curve estimated salinity may increase the log KOW value 2.6% per one log unit increase in distilled water (R2 = 0.968). The water solubility, bioconcentration factor, organic carbon soil/sediment sorption coefficient, and acute toxicity in fish were estimated for chemicals using the measured log KOW values by EPI SuiteTM. The water solubility of pesticides was measured in both distilled-deionized water as well as artificial seawater (3.2%). Salinity appears to generally decrease the water solubility and increase partitioning potential. Environmental fate estimates indicate elevated chemical sorption to sediment, bioavailability, and toxicity in artificial seawater suggesting that salinity should be accounted when conducting exposure estimates for marine organisms. In addition, the relative impact of volatilization and hydroxyl radical degradation on estimates of PASH overall dissipation after entry into aquatic ecosystems as a function of depth (0.1, 1 and 2 m) were investigated using the EPA Exposure Analysis Modeling System (EXAMS). The hydroxyl radical rate constant (K.OH) and Henrys law constant (H) of PASHs were determined in distilled water. Simulated dissipation of PASHs using EXAMS suggest that volatilization is a dominant fate pathway for the higher molecular weight and less polar C2-DBT and C4-DBT at all depths and DBT and C1-DBT at 0.1 m. However, model scenarios suggest hydroxyl radical degradation may significantly contribute to the degradation of more polar DBT and C1-DBT at 1 m and 2 m depths.

In-Situ Chemical Oxidation (ISCO) injections were performed at Petro Stopping Centers # 10 (Petro) in December 2013 and June 2015. The methodology was direct injection of a heavy oxidizer, RegenOx®, followed by a time-release oxygen compound, ORC Advanced®, into a plume of gasoline sitting on top of the water in the aquifer in hope that this remediate the aquifer. Both chemicals are registered trademarks of the Regenesis® Company. The levels of contaminates have dropped considerably. However, Petro has not achieved closure criteria according to RECAP standards. The site is classified as a GW-1B, subject to the most stringent of remediation standards, due to its ability to be used as a drinking water source. The analytical results show undulating contaminate levels, dropping to below detectable levels then resurging to levels above acceptable RECAP standards. Levels show steady decline in all the monitoring wells including downgradient monitoring wells. The undulating phenomenon can be explained by desorption of COCs, incidental spilling of gasoline, or the clays affinity for organics. Further investigation into the clay will provide a better idea of which hypothesis is closer to the truth. During a sampling event, 3/19/15, levels were below detectable concentrations in all samples. Lab error offers a possible explanation for this event, the site still has contamination on it, if that sampling event produced clean samples is highly suspect. The injections were successful at bringing gasoline contaminate concentrations down directly after an injection period. The method is effective and easy to apply. The resurgence of contaminates at this site is up for discussion and further study but, the method of remediation used at Petro is an effective tool in remediating a gasoline contaminated aquifer. Suggestions for improving the effectiveness of this method with the use of other injection materials in conjunction with the chemicals used in this project are mentioned in the discussion and conclusion sections of this thesis. Data referenced in this thesis is publicly available at the Louisiana Department of Environmental Quality document search website EDMS under the Agency Interest(AI) number 5962.

Urban arterial corridors are landscapes that give rise to short and long-term exposures to transportation-related pollution. With high traffic volumes, congestion, and a wide mix of road users and land uses at the road edge, urban arterial environments are important targets for improved exposure assessment to traffic-related pollution. Applying transportation management strategies to reduce emissions along arterial corridors could be enhanced if the ability to quantify and evaluate such actions was improved. However, arterial roadsides are under-sampled in terms of air pollution measurements in the United States and using observational data to assess such effects has many challenges such as lack of control sites for comparisons and temporal autocorrelation. The availability of traffic-related data is also typically limited in air monitoring and health studies. The work presented here uses unique long-term roadside air quality monitoring collected at the intersection of an urban arterial in Portland, OR to characterize the roadside atmospheric environment. This air quality dataset is then integrated with traffic-related data to assess various methods for improving exposure assessment and the roadside environment. Roadside nitric oxide (NO), nitrogen dioxide (NO2), and particle number concentration (PNC) measurements all demonstrated a relationship with local traffic volumes. Seasonal and diurnal characterizations show that roadside PM2.5 (mass) measurements do not have a relationship with local traffic volumes, providing evidence that PM2.5 mass is more tied to regional sources and meteorological conditions. The relationship of roadside NO and NO2 with traffic volumes was assessed over short and long-term aggregations to assess the reliability of a commonly employed method of using traffic volumes as a proxy for traffic-related exposure. This method was shown to be insufficient for shorter-time scales. Comparisons with annual aggregations validate the use of traffic volumes to estimate annual exposure concentrations, demonstrating this method can capture chronic but not acute exposure. As epidemiology and exposure assessment aims to target health impacts and pollutant levels encountered by pedestrians, cyclists, and those waiting for transit, these results show when traffic volumes alone can be a reliable proxy for exposure and when this approach is not warranted. Next, it is demonstrated that a change in traffic flow and change in emissions can be measured through roadside pollutant concentrations suggesting roadside pollution can be affected by traffic signal timing. The effect of a reduced maximum traffic signal cycle length on measurements of degree of saturation (DS), NO, and NO2 were evaluated for the peak traffic periods in two case studies at the study intersection. In order to reduce bias from covariates and assess the effect due to the change in cycle length only, a matched sampling method based on propensity scores was used to compare treatment periods (reduced cycle length) with control periods (no change in cycle length). Significant increases in DS values of 2-8% were found along with significant increases of 5-8ppb NO and 4-5ppb NO2 across three peak periods in both case studies. Without matched sampling to address the challenges of observational data, the small DS and NOx changes for the study intersection would have been masked and matched sampling is shown to be a helpful tool for future urban air quality empirical investigations. Dispersion modeling evaluations showed the California Line Source Dispersion Model with Queuing and Hotspot Calculations (CAL3QHCR), an approved regulatory model to assess the impacts of transportation projects on PM2.5, performed both poor and well when predictions were compared with PM2.5 observations depending on season. Varying levels of detail in emissions, traffic signal, and traffic volume data for model inputs, assessed using three model scenarios, did not affect model performance for the study intersection. Model performance is heavily dependent on background concentrations and meteorology. It was also demonstrated that CAL3QHC can be used in combination with roadside PNC measurements to back calculate PNC emission factors for a mixed fleet and major arterial roadway in the U.S. The integration of roadside air quality and traffic-related data made it possible to perform unique empirical evaluations of exposure assessment methods and dispersion modeling methods for roadside environments. This data integration was used for the assessment of the relationship between roadside pollutants and a change in a traffic signal setting, a commonly employed method for transportation management and emissions mitigation, but rarely evaluated outside of simulation and emissions modeling. Results and methods derived from this work are being used to implement a second roadside air quality station, to design a city-wide integrated network of air quality, meteorological, and traffic data including additional spatially resolved measurements with feedback loops for improved data quality and data usefulness. Results and methods are also being used to design future evaluations of transportation projects such as freight priority signaling, improved transit signal priority, and to understand the air quality impacts of changes in fleet composition such as an increase in electric vehicles.

Pesticides are used globally and are often found within bodies of water. The EPA investigates the potential environmental impact through computer modeling in order to help mitigate some of the regulatory burden of pesticide fate investigation. Currently when pesticides enter a water body, the Exposure Analysis Modeling System (EXAMS) estimates partitioning depth as 5 cm and assumes equal distribution. This assumption was tested with a wide variety of pesticides with varying Koc ranges and water solubilities. Savillex 150 ml Teflon tubes were filled with wetland and ricefield sediments with fresh and seawater as the aqueous phase. The seven pesticides tested included, quinclorac, bentazon, 2,4-D, atrazine, dicloran, flutolanil, and trifluralin had reported Koc ranges as low as 20 and as high as 15800. Pesticides were sprayed onto the top layer of water and allowed to partition over 24 hours. Once suspended, 0.5 cm segments were sonicated and analyzed by Agilent 1260 Infinity High Performance Liquid Chromatography. Normalized applied mass percentages were calculated by comparison to pesticide standards that ran simultaneously with all samples. The majority of pesticides were found in the overlying water layer and within the first 0.5 cm of sediment. Salinity of the aqueous phase was shown to increase pesticide sediment concentration, but did not increase partitioning depth.

Ambient sulfate aerosols are composed of sulfuric acid, ammonium sulfate, or other sulfate salt mixtures, and the term "total sulfate" includes these substances of diverse chemical and physical properties. Measurements of total sulfate are often made, but without measurements of the associated cations they are inadequate to assess the contribution of aerosols to acid rain, damage to surfaces, heterogeneous oxidation of SO(,2), and human health effects. In this study the chemical properties of sulfate aerosols were investigated in the northeastern U.S. by measurements of acidity, ionic composition, and particle morphology over a range of conditions. / Aerosols were collected from an aircraft during three field programs: spring and fall 1979 and summer 1980. Strong and weak aerosol acidity was determined by extraction of filters and Gran titrations, and for 30 samples the weak acidity comprised x (+OR-) s = 26 (+OR-) 12% of the total acidity. The strong acid and ammonium concentrations were found to balance the sulfate with the ratio of equivalents ({H('+)} + {NH(,4)('+)})/{SO(,4)('=)} = 1.03 (+OR-) 0.14 for 36 samples. The strong acidity averaged 25 (+OR-) 18% of the total sulfate. A phase diagram was used to show that the aerosols were often liquid at ambient humidity, and for 24 liquid samples the calculated pH was 0.11 (+OR-) 0.59. / Inspecting particles by electron microscopy showed that under most conditions accumulation mode aerosols collected in the boundary layer were composed of sulfate particles which were internally mixed, indicating that individual particle composition could be inferred from bulk measurements. Evidence for oxidation of SO(,2) to H(,2)SO(,4) in cloud droplets was obtained in samples collected near clouds, representing a potentially major pathway for SO(,2) oxidation in the lower troposphere. / Elemental size distributions determined by cascade impactors and x-ray analysis showed distinct seasonal differences. While sulfate concentrations averaged 16.7 (+OR-) 9.9 (mu)g/m('3) in summer and 6.68 (+OR-) 3.27 in fall, chlorine concentrations were much higher in fall suggesting loss of HCl from the more acidic summertime aerosols. The sulfur size distributions showed that summer particles contained twice the mass per particle as those during fall, indicating a possible enhancement of sulfate in aerosol droplets by a liquid-phase SO(,2) oxidation mechanism. / Source: Dissertation Abstracts International, Volume: 43-01, Section: B, page: 0081. / Thesis (Ph.D.)--The Florida State University, 1982.

The effects of water acidification on the composition of the adenine nucleotide pool and locomotor behavior of the estuarine teleost Fundulus grandis were investigated. Fish exposed for up to 96 hours to reduced pH exhibited highly significant declines in ATP concentration, total adenylate concentration, and adenylate energy charge, i.e., / (ATP) + 1/2(ADP)(' ) / (AMP) + (ADP) + (ATP)(, ) / in brain, liver, and gill tissues. Muscle energy charge and ATP also decreased concurrent with increased ADP concentration, and particularly AMP concentration. Therefore, the total adenylate concentration was only slightly reduced. Exposure to pH 4.0 and 5.0 media produced the greatest declines in these parameters. Less pronounced declines were observed in fish exposed to pH 6.5 water. The greatest changes occurred within the first 24 to 48 hours of acidification but statistical analysis indicated that the hydrogen ion concentration was more important in altering adenylate metabolism than the length of exposure. / Low pH water induced changes in the daily locomotor activity pattern of F. grandis, particularly at pH 5.0 and 4.0. Box-Jenkins time series analysis was applied to the behavioral bioassay, permitting quantitative assessment of activity rhythm changes resulting from exposure to acidity. Activity data were obtained using an infrared photoelectric detection system. Results of time series model identification and estimation programs indicated a progressive decline in the daily rhythmicity of locomotor activity as the degree of acidification increased. Fish generally displayed hyperactive responses to low pH water with increased activity during the normally inactive diurnal periods. Under these conditions, extensive mucification, altered body coloration, difficulties in orientation and buoyancy control, and a cessation of feeding also occurred. The results of these studies suggest that environmental pH levels below 6.5 may critically impair energy metabolism and behavioral functions of fishes. / Source: Dissertation Abstracts International, Volume: 41-03, Section: B, page: 0874. / Thesis (Ph.D.)--The Florida State University, 1980.

The estuarine benthic and fouling communities form essential elements in the trophodynamics of detrital and benthic ecosystems, the mediation of mineral recycling, and initial colonization of submerged surfaces. Changes in the structure of these vital communities have traditionally proved labo / Source: Dissertation Abstracts International, Volume: 41-11, Section: B, page: 4053. / Thesis (Ph.D.)--The Florida State University, 1980.

An explosively deepening storm or 'bomb' (hereafter quotes omitted) is defined by Sanders and Gyakum (1980) as an extratropical cyclone whose central mean sea-level pressure falls at least 1 mb per hour for 24 hours. The composites constructed from the daily global analyses generated and archived at the European Center for Medium Range Weather Forecasts (ECMWF) accurately describe the three-dimensional kinematic and thermodynamic structure of bombs over the entire depth of the troposphere. Furthermore, a regional $-\overline{\omega\sp\prime\alpha\sp\prime}$ covariance is used for describing the intensity of baroclinic instability and hence cyclogenesis. / Numerical experimentation of explosive east coast cyclogenesis is performed using the Florida State University Global Spectral Model (FSUGSM). The three cases examined here are the Presidents' Day storm of 18-19 February 1979 and the North Atlantic and Pacific bombs of 18-20 January 1979 which formed off the east coasts of the United States and Japan respectively. The use of a global model provides a framework for studying the phenomena on the 3-5 day time scale and for examining the sensitivity of the forecasts to data analysis in regions several thousand km upstream of the storm domain. A technique is developed to uniquely partition and quantify the role of the dynamical and physical processes in the explosive cyclogenetic process. Additionally, the complete model-generated four-dimensional data sets are used to compute residual-free Eulerian vorticity budgets. / The results of this work reveal that explosive cyclogenesis is a baroclinic phenomena in which the rapid intensification in the presence of pronounced middle and upper tropospheric forcing is enhanced by a highly destabilized lower troposphere that is strongly heated and moistened by upward (positive) oceanic sensible and latent heat fluxes. The focus of the ongoing research is shifting away from the problem of actually predicting explosive cyclogenesis toward improving the skill of bomb forecasts and simultaneously extending the range of predictability of such events. / Source: Dissertation Abstracts International, Volume: 49-10, Section: B, page: 4209. / Major Professor: T. N. Krishnamurti. / Thesis (Ph.D.)--The Florida State University, 1988.