In modern separation design, an important part of many phase-equilibrium calculations is the mathematical representation of pure-component and mixture enthalpies. Mixture enthalpy data are important not only for determination of heat loads, but also for the design of distillation units. Further, mixture enthalpy data, when available, are useful for extending vapor-liquid equilibria to higher (or lower) temperatures, through the use of the Gibbs-Helmholtz equation. In this connection excess molar enthalpies for several binary and ternary mixtures involving ethers and hydrocarbons have been measured at the temperature 298.15 K and atmospheric pressure, over the whole mole fraction range. Values of the excess molar enthalpies were measured by means of a modified flow microcalorimeter (LKB 10700-1) and the systems show endothermic behavior. The Redlich-Kister equation has been used to correlate experimental excess molar enthalpy data of binary mixtures. Smooth representations of the excess molar enthalpy values of ternary mixtures are accomplished by means of the Tsao-Smith equation with an added ternary contribution term and are used to construct excess enthalpy contours on Roozeboom diagrams. The values of the standard deviations indicate good agreement between experimental results and those calculated from the smoothing equations. The experimental excess enthalpy data are also correlated and predicted by means of solution theories (Flory theory and Liebermann-Fried model) for binary and ternary mixtures, respectively. These solution theories correlate the binary heats of mixing data with reasonable accuracy. The prediction of ternary excess molar enthalpy by means of the solution theories are also presented on Roozeboom diagrams. The predictions of ternary excess enthalpy data by means of these theories are reasonably reliable.

Aquatic organisms in response to toxic insults from environmental pollutants activate defence systems including the aryl hydrocarbon receptor (AhR) in an attempt to metabolize and excrete these toxicants and their metabolites. These detoxification mechanisms however may come with certain energetic costs. I hypothesize that the activation of the AhR by β-Naphthoflavone (β-NF), a model AhR agonist, results in increased energetic costs requiring metabolic reorganization in rainbow trout hepatocytes. While the results obtained suggest that there are no significant energetic costs of AhR activation, analysis of enzyme activities suggests possible metabolic reorganization. This study also showed significant changes in cellular processes in hepatocytes over the incubation periods which previously were not reported. Furthermore, for the first time in fish hepatocytes, metabolic flux analysis (MFA) was used to examine intra-cellular metabolism, the applicability of which is discussed.

The photo-oxygenation of 2-methylpropane and cyclohexane using visible light in aqueous acidic uranyl ion solutions at ambient temperature and pressure has been undertaken. For 2-methylpropane in the absence of oxygen, the main product (≈90%) is 2-methyl-2-propanol with a quantum yield of 0.021 ± 0.001. In the presence of molecular oxygen, both 2-methyl-2-propanol and 2-propanone (acetone) are found. Based on this, and results of gamma radiolysis of aqueous 2-methylpropane to give 'tert'-butyl radical by electronically excited uranyl ion is proposed. In the absence of oxygen, the quantum yield of 2-methyl-2-propanol shows a sigmoidal dependence on the concentration of perchloric acid. A two-species kinetic model involving an acid-base dissociation of the uranyl ion in the excited state accounts for the observed features. The addition of sodium perchlorate to the 2-methylpropane system has an inhibitory effect on the quantum yield. Excited-state ion pairing between the uranyl ion and perchlorate anion is proposed. Consequently, the two-species acid-base model is expanded upon to yield a three-species acid-base-perchlorate model that seems to account for the results from 0.01-0.4 M perchloric acid concentration. Potassium peroxydisulfate is proven effective to increase the quantum yield of 2-methyl-2-propanol from 0.021 ± 0.001 to greater than unity (1.5 ± 0.1) indicating the existence and importance of thermal chain reactions involving sulfate radical anion. The quantum yield of 2-methyl-2-propanol is found to be dependent on the concentrations of 2-methylpropane, perchloric acid and potassium peroxydisulfate, and inversely dependent on the light intensity. The net consumption of uranyl ion is zero in the presence of potassium peroxydisulfate meaning that the uranyl ion is regenerated, making this a catalytic cycle in terms of uranyl ion. The oxygenation of cyclohexane using photo-excited aqueous uranyl ion gives cyclohexanol and cyclohexanone as the two main isolated products (54%). The overall mechanism is expected to be similar to that for the 2-methylpropane system. Refluxing of this substrate with a reducing agent (CaH2 or LiAlH4) is required prior to photolysis to achieve consistent quantum yields of both products due to thermal autoxidation reactions. The presence of molecular oxygen is found to be important in determining the ratio of alcohol to ketone in the product distribution. Potassium peroxydisulfate significantly enhances the quantum yield of cyclohexanone, leaving the quantum yield of cyclohexanol relatively unchanged (as compared to without added potassium peroxydisulfate), while uranyl ion is not consumed. Possible reactions involving cyclohexyl and cyclohexyl peroxyl radicals are given to account for the experimental results.

Contamination of soil with Polycyclic Aromatic Hydrocarbons (PAHs) is a serious environmental issue because some PAHs are toxic, carcinogenic and mutagenic. Bioremediation is a promising option to completely remove PAHs from the environment or convert them to less harmful compounds. One of the main challenges in bioremediation of PAHs in a conventional roller bioreactor is the limitation on mass transfer due to the strong hydrophobicity and low water solubility of these compounds. To address this challenge, a novel bead mill bioreactor (BMB) was developed by Riess et al. (2005) which demonstrated a significant improvement in the rates of mass transfer and biodegradation of PAHs. <p> In this study, to further improve mass transfer rates, baffles have been installed in both the conventional and bead mill bioreactors. Mass transfer rates of 1000 mg L-1 suspended naphthalene, 2-methylnaphthalene and 1,5-dimethylnaphthalene, three model compounds of PAHs, have been investigated in four bioreactors: conventional (control), baffled, BMB and baffled bead mill bioreactors. The baffled bioreactor provided mass transfer coefficients (KLa) that were up to 7 times higher than those of the control bioreactor. <p> Bioremediation of suspended naphthalene or 2-methylnaphthalene as a single substrate and their mixtures was studied using the bacterium <i>Pseudomonas putida </i>ATCC 17484. Both baffled and bead mill bioreactors provided maximum bioremediation rates that were 2 times higher than the control bioreactor. The maximum bioremediation rates of 2-methylnaphthalene were further increased in the presence of naphthalene by a factor of 1.5 to 2 compared to the single substrate. <p> Another rate-limiting step for bioremediation of PAH-contaminated soil is the strong sorption between the contaminant and soil. To find out the effect of sorption on the bioavailability of naphthalene, the appropriate sorption isotherms for three types of soils (sand, silt and clay) have been determined. It was observed that the sorption capacity of soils for naphthalene was proportional to the organic carbon content of the soils. The mass transfer of soil-bound naphthalene from the artificially prepared contaminated soils with short contamination history to the aqueous phase was studied in both the control and bead mill bioreactors. It was observed that the mass transfer was unexpectedly fast due to the increased interfacial surface area of naphthalene particles and the weak sorption between naphthalene and soils. It was concluded that artificially, naphthalene contaminated soils would likely not be any more difficult to bioremediate than pure naphthalene particles.

Phytoremediation systems for petroleum hydrocarbons rely on a synergistic relationship between plants and their root-associated microbial communities. Plants exude organic compounds through their roots, which increase the density, diversity and activity of plant-associated microorganisms, which in turn degrade hydrocarbons. Understanding the mechanisms driving this relationship poses one of the more intriguing challenges in phytoremediation research. This study was designed to address that challenge. Plant-microbe interactions in a weathered-hydrocarbon contaminated soil were examined under controlled growth chamber, and field conditions. In both environments single-species grass treatments initially facilitated greater total petroleum hydrocarbon (TPH) degradation than <i> Medicago sativa </i> (alfalfa), mixed species, or control treatments. In growth chamber studies increased degradation was linked to increased aliphatic-hydrocarbon degrader populations within the rhizosphere. Under field conditions, specific recruitment of endophytic aliphatic-hydrocarbon degraders in response to high TPH levels may have facilitated increased degradation by the grass <i> Elymus angustus</i>(Altai wild rye, AWR). AWR stably maintained these communities during times of local drought, enabling them to act as subsequent source populations for rhizosphere communities. The broad phylogenetic diversity of AWR endophytes, compared to the <i> Pseudomonas</i>-dominated communities of other plants, contributed to the observed stability. The relative composition of exudates released by plants also impacted both degradation activity and potential. Alfalfa released higher concentrations of malonate, which hindered degradation by decreasing metabolic activity and concomitantly inhibiting catabolic plasmid transfer. In contrast, AWR exudates contained high levels of succinate, which was linked to increased catabolic gene expression and plasmid transfer. A reciprocal relationship between exudation patterns and endophytic community structure likely exists, and both parameters have a specific influence on rhizosphere degradation capacity. In this study, grasses were more successful in maintaining the specific balance of all parameters required for the transfer, preservation, and stimulation of hydrocarbon catabolic competency.

<p>Polycyclic aromatic hydrocarbons (PAHs) are important contaminants that are found in increasing amounts in aquatic ecosystems. One of the sites that that is contaminated by extremely high levels of PAHs is the Atlantic Wood Industries Superfund Site on the Elizabeth River, VA. The Atlantic killifish (<italic>Fundulus heteroclitus</italic>) from this site exhibit increased levels of antioxidants, increased sensitivity to hypoxia, and increased expression of enzymes involved in glycolytic metabolism, suggesting that exposure to PAHs in the environment may induce changes in mitochondrial function and energy metabolism. Normal mitochondrial activity is crucial to an organism's survival. Therefore, gaining a better understanding of how mitochondria are affected by environmental contaminants such as PAHs is a pressing research objective. As a first step in understanding changes in cellular bioenergetics of aquatic organisms in response to PAHs, this research focused on the effect of benzo[a]pyrene (BaP), a representative PAH, on mitochondria the killifish model and on comparison of the mitochondria of the PAH-adapted killifish from the Elizabeth River Superfund Site to reference site fish. In order to assess the extent of mitochondrial DNA damage in the killifish, a PCR-based assay (LA-QPCR) for nuclear and mitochondrial DNA (nDNA, mtDNA) damage was adapted to this model and validated in with UV exposure and BaP exposure studies, as well as with <italic>ex situ</italic> study examining DNA damage in killifish inhabiting the Elizabeth River Superfund site. With the newly adapted LA-QPCR, mtDNA and nDNA damage in the killifish from the Elizabeth River Superfund site and from a reference site (King's Creek, VA) that were treated with BaP were examined. Similar increases in mitochondrial and nuclear DNA damage were observed in King's Creek fish treated with BaP. Killifish from the Elizabeth River showed high levels of basal nDNA and mtDNA damage compared to fish from the reference site, but the level of damage induced due to BaP treatment was much lower in Elizabeth River killifish. Laboratory-reared offspring from both populations showed increased BaP-induced damage in mtDNA, relative to nDNA. Similar to the adult experiment, the Elizabeth River larvae had higher levels of basal DNA damage than those from the reference site, but were less impacted by BaP exposure. Results suggest that BaP exposure can have important energetic consequences and that multi-generational exposure in the wild may lead to adaptation that dampens DNA damage arising from BaP exposure. Since the toxic effects of many PAHs are the result of bioactivation by cytochrome P4501A (CYP1A), the existence of enzymes that can potentially metabolize PAHs in mitochondria was verified. Using Western blot, protein similar in size to microsomal CYP1A was identified with monoclonal antibody against scup CYP1A in the mitochondrial fraction from adult male killifish livers. The size of the protein in the mitochondria was the similar to that of microsomal CYP1A. Fish dosed with BaP had increased EROD activity in the liver mitochondrial fraction compared to controls. In killifish larvae dosed with BaP and benzo[k]fluoranthene (BkF), CYP1A protein levels as well as enzyme activity were elevated. However, fish from the Elizabeth River Superfund site showed recalcitrant mitochondrial CYP1A protein levels and enzyme activity in a similar manner to microsomal CYP1A. Finally, the hypothesis that energy metabolism of BaP-treated fish may be different from the control group and that killifish from the Elizabeth River Superfund site may also have altered energy metabolism compared to reference site fish was tested. Respiration of killifish embryos treated with BaP from both populations was measured. Compared to the King's Creek control fish, all other treatment groups showed decrease in oxygen consumption, indicating lower respiration rate. However, when activities of key enzymes involved in glycolysis (PK) and anaerobic metabolism (LDH) in adult killifish liver and muscle were measured, no differences in the enzyme activities were observed in BaP-treated group compared to the control group. Moreover, metabolomic analysis on BaP treated King's Creek and Elizabeth River killifish showed no difference in the profile in all four treatment groups. The findings in this thesis contribute to the understanding of how BaP, a common environmental pollutant in the aquatic ecosystem, targets the mitochondria in fish model. Nevertheless, deeper examination of how BaP may impact mitochondrial function in killifish and potentially influence adaptation of killifish at a highly contaminated site is necessary. Further studies will elucidate whether such impacts can potentially affect the energy budget and organism level fitness in populations in the wild.</p> / Dissertation

The Gaoping (GP) river which has the largest drainage basin and is the second longest river in Taiwan. Highly erodible sedimentary and metamorphic rocks in the drainage basin, coupled with a steep landscape, humid climate, frequent typhoons and earthquakes, provide favorable conditions for bedrock weathering and soil erosion in the GP drainage basin. Its exceptionally high sediment yield and tidal-dominated dispersal system presents a unique case for comparative study. In this study, we collected sediment and soil samples not only from estuary region but also traced up to upper stream areas of the GP drainage. We analyze the content of n-alkanes in the sediments and soils of GP river-sea system, and utilize compositional patterns to discuss the sources and process of transmission of terrigenous organic matter of GP river-sea system. Analyzed results show that the average carbon chain distribution shows same pattern for rocks, riverine and seafloor sediments but is different with soil samples. Hierarchical cluster analysis helps us to distinguish differently compositional patterns of n-alkanes. And the riverine, seafloor and rock samples have high similarity, except for soils. The spatial distribution of the carbon preference index (CPI) and temporal distribution of CPI in cores, show that values are all close to ~1, but not for soils (>2). This result indicates that for the past 150 years, lower CPI values not merely from petroleum pollutions, but also due to thermal mature terrestrial organic matter eroded from bedrock caused by tectonic and climatic events, such as typhoons and earthquakes.

Leaking of petroleum products from storage tanks is a commonly found cause of soil contamination. Among those petroleum products, diesel-oil contaminated soils are more difficult to treat compared to gasoline (a more volatile petroleum product). With the growing interest in environmental remediation, various approaches have been proposed for treating petroleum-hydrocarbon (PH) contaminated sites. Given that it is often not possible to remove the released oil or remediate the site completely within a short period of time, using the in situ remedial technology, soil excavation followed by more cost-effective technology should be applied to accelerate the efficiency of site cleanup. In the first-part of this study, laboratory degradation experiments were conducted to determine the optimal operational conditions to effectively and economically bioremediate diesel-fuel contaminated soils. In the second part of this study, a combined full-scale landfarming and biopile system was operated to cleanup diesel fuel-contaminated soils. In the laboratory study, except of frequent soil tilling for air replacement, different additives were added in the laboratory bioreactors to enhance the total petroleum hydrocarbon (TPH) removal efficiency. The additives included nutrients, TPH-degrading bacteria, activated sludge, fern chips, and kitchen waste composts. PH-degrading bacteria were isolated from PH-contaminated soils and activated sludge was collected from a wastewater treatment plant containing PH in the influent. PH-degrading bacteria and sludge were added to increase the microbial population and diversity. Fern chips and kitchen waste composts were added to increase the soil permeability. Results indicate that the bioreactor with kitchen waste compost addition had the highest TPH removal rate. The observed TPH-removal ratios for the compost, activated sludge, PH-degrading bacteria, fern chips, nutrients, TPH-degrading bacteria addition, and control (with HgCl2 addition) groups were 80.5%, 78.6%, 77.4%, 75.1%, 73.3%, 66.1%, and 1.6% respectively. In the field study, activated sludge was selected as the additive from the engineering point of view. With the addition of activated sludge, an increase of 20% was observed for TPH removal ratio. Results from the denaturing gradient gel electrophoresis (DGGE) tests show that the detected PH-degrading bacteria in the activated sludge included the following: Pseudomonas sp., Pseudoxanthomonas sp., Rhodocyclaceae bacterium, Variovorax sp., Acidovorax sp., Leptothrix sp., Alcaligenaceae bacterium, and Burkholderia sp. Some of these bacteria became dominant species in the field after a long-term operation, which was beneficial to the soil bioremediation. Results indicate that the in situ bioremediation has the potential to be developed into an environmentally and economically acceptable remediation technology.

Caspian region&#039 / s hydrocarbon deposits constitute one of the significant reserves in the world. This has caused a competition among state and non-state actors in exploiting these resources since 19th century. After the Soviet demise, the newly independent states embraced the economic gains made possible with the existence of these reserves. However oil production may have negative implications on environment, ecological balance and biodiversity if carried out in an uncontrolled manner. This study aims to identify these negative impacts and measures taken to control this process. Measures taken on national, regional and international levels are analyzed to find out the extent of their effectiveness in protecting the environment during oil operations. National legal frameworks of each littoral state, impacts of civil society organizations, regional and international legal frameworks and efforts of international organizations are evaluated. Since most of these improvements are relatively new with no viable outcome at hand, the process rather than the results is focused on. The application of time, holism and action-orientation parameters to these improvements to find out the environmental effectiveness of each shows that there is a preliminary burgeoning awareness in matters of environmental protection yielding to more effective efforts than before. Yet the economic gains remain too significant a temptation for the states in the region to be sacrificed. In the cases where measures taken to protect the environment undermine these economic gains, environmental effectiveness is forsaken.

Hydrocarbon (HC) microseepages can be indicator of possible reservoirs. For that reason, mapping the microseepages has potential to be used in petroleum exploration. This study presents a methodology for mapping HC microseepages and related clay mineral alteration in Gemrik Anticline, Adiyaman. For this purpose samples were collected from the potential seepage zones and tested by geochemical analysis. All samples were found to contain some HC. Then, an ASTER image of the region was obtained and a band combination was generated to map this particular region. To map related clay mineral alteration, firstly reflectance spectra of samples were measured using field spectrometer. Secondly, spectrally-known samples were analyzed in USGS Library to determine the reflectance spectra of the constitutional clay minerals in the samples. Lastly, the reflectance characteristics of selected end v members were represented as ASTER band combinations based on their spectral absorption characteristics and literature information. Crosta Technique was used to determine required principal components to map HC microseepage and related clay mineral alteration. Then, this methodology is applied to the whole ASTER image. Ground truth study showed that more than 65% of the revisited anomalies show similar prospects to that of the referenced anticline regardless of their geochemical content. In order to certify the ASTER band combination for mapping HC microseepages, anomalous and non-anomalous pixels were selected from the resultant HC map and given as training data samples to AdaBoost loop which is an image processing algorithm. It has been found that ASTER band combination offered for mapping HC microseepages is similar to that of AdaBoost Algorithm output.