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The environmental fate of polycyclic aromatic hydrocarbons (PAH) is a significant issue, raising interest in bioremediation. However, the physio-chemical characteristics of PAHs and the physical, chemical, and biological properties of soils can drastically influence in the degradation. Moreover, PAHs are toxic and carcinogenic for humans and their rapid degradation is of great importance. The process of degradation of pollutants can be enhanced by manipulating abiotic factors. The effect of soil pH on degradation of PAHs with a view to manipulating soil pH to enhance the bioremediation of PAH’s was studied. The degradation rate of key model PAHs (Phenanthrene, Anthracene, Fluoranthene, and Pyrene) was monitored in J Arthur Brower’s topsoil modified to a range of pH between pH 4.0 and pH 9.0 at half pH intervals. Photo-catalytic oxidation of PAHs in the presence of a catalyst (TiO2) under UV light at two different wavelengths was studied. The degradation of PAHs during photo-catalytic oxidation was carried out at varying soil pH, whilst the degradation rate of each individual PAH was monitored using HPLC. It was observed that pH 6.5 was most suitable for the photo-degradation of all the PAHs, whilst in general acidic soil had greater photo-degradation rates than alkaline soil pH. Photo-degradation of PAHs at 375 nm exhibited greater degradation rates compared to 254 nm. Phenanthrene at both the wavelengths had greater degradation rate and pyrene has lower degradation rate of the four PAHs. Pure microbial cultures were isolated from road-side soil by shaken enrichment culture and characterized for their ability to grow on PAHs. Bacterial PAH degraders, isolated via enrichment were identified biochemically and by molecular techniques using PCR amplification and sequencing of 16S rDNA. Sequences were analyzed using BLAST (NCBI) and their percentage identity to known bacterial rDNA sequences in the GeneBank database (NCBI) was compared. The 6 bacterial strains were identified as Pseudomonas putida, Achromobacter xylosoxidans, Microbacterium sp., Alpha proteobacterium, Brevundimonas sp., Bradyrhizobium sp. Similarly, fungal PAH degraders were identified microscopically and with molecular techniques using PCR amplification and sequencing of 18S rDNA and identified as Aspergillus niger and Penicillium freii. Biodegradation of four PAHs with two and four aromatic rings were studied in soil with inoculation of the six identified bacteria and two identified fungi over a range of pH. It was observed that pH 7.5 was most suitable for the degradation of all the PAHs maintained in the dark. A degradation of 50% was observed in soil pH 7.5 within first three days which was a seventh of the time taken at pH 5.0 and pH 6.5 (21 days). Greater fungal populations were found at acidic soil pH and alkaline soil pH, in comparison with neutral pH 7.0. Pencillium sp. was found to be more prevalent at acidic pH whilst Aspergillus sp. was found to be more prevalent at pH 7.5-8.0. Bacterial populations were greater at pH 7.5 which was highly correlated with soil ATP levels. It was therefore evident that the greatest rates of degradation were associated with the greatest bacterial population. Soil enzyme activities in general were also greatest at pH 7.5. The converse effect of pH was found with fastest rate of photo-catalytic degradation at the optimal conditions were observed at acidic condition in soil pH 6.5 whilst, the results obtained during biodegradation at the optimal conditions exhibits fastest rate of degradation at alkaline conditions particularly at pH 7.5. Thus, manipulation of soil pH to 7.5 has significant potential to dramatically increase the degradation rate of PAHs.

Detection, identification and separation of polycyclic aromatic compounds in environmental samples are of extreme importance since many of these compounds are well known for their potential carcinogenic and/or mutagenic activities. Selective quenching of molecular fluorescence can be utilized effectively to analyze mixtures containing different polycyclic aromatic hydrocarbons. Molecularly organized assemblies are used widely in detection and separation of these compounds mainly because of less toxicity and enhanced solubilization capabilities associated with these media. Feasibility of using nitromethane and the alkylpyridinium cation as selective fluorescence quenching agents for discriminating between alternant versus nonalternant polycyclic aromatic hydrocarbons (PAHs) is critically examined in several molecularly organized micellar solvent media. Fluorescence quenching is used to probe the structural features in mixed micelles containing the various combinations of anionic, cationic, nonionic and zwitterionic surfactants. Experimental results provide valuable information regarding molecular interactions between the dissimilar surfactants.

Appendices data can be found at: A: http://dx.doi.org/10.15142/T35P49 B: http://dx.doi.org/10.15142/T3201B C: http://dx.doi.org/10.15142/T3X59V D: http://dx.doi.org/10.15142/T3SG6K F: http://dx.doi.org/10.15142/T3NP4N

Le Bassin d’Arcachon est une lagune très riche écologiquement et suscite un attrait touristique et ostréicole important. Cette pression anthropique a soulevé ces dernières années des questions sociétales quant à sa qualité environnementale. Ainsi, ancrés dans des projets soutenus par les acteurs locaux (Région Aquitaine, Syndicat Intercommunal du Bassin d’Arcachon, Conseil général de la Gironde), ces travaux de thèse ont permis de dresser un bilan de la qualité de ce système et de ses bassins versants relativement à l’introduction des hydrocarbures aromatiques polycycliques (substances prioritaires selon la directive cadre sur l’eau, UE, 2000). Ces polluants organiques sont présents dans les différents compartiments environnementaux suivis (sédiments, colonne d’eau) de la lagune, en concentrations élevées pour quelques sites et pouvant induire des effets toxiques chez le biota aquatique. Ils sont généralement présents dans les eaux et sédiments des tributaires à un niveau bruit de fond, mais des concentrations importantes ont été observées pour un ruisseau, ainsi que lors d’un évènement de tempête. Ils sont principalement issus des processus de combustion incomplète de matières organiques (gaz d’échappement, chauffage, feux de forêt) ; des apports terrigènes et diagénétiques de pérylène ont également pu être mis en évidence. Les transferts des HAP vers le biota benthique (huître), et leur bioaccumulation sont effectifs malgré des capacités de dépuration importante relativement à d’autres classes de composés organiques hydrophobes. Comme alerté par le réseau national d’observation coordonné par IFREMER, les teneurs dans les organismes augmentent depuis une dizaine d’année, et s’approchent aujourd’hui de la valeur guide AFSSA pour la consommation humaine. Outre l’aspect de qualité environnementale, ces résultats peuvent apporter des informations quant aux problématiques nationales actuelles de surveillance chimique des productions conchylicoles (DGAL, 2008 ; AFSSA, 2008). / Abstract

Thesis (MTech (Environmental Management))--Cape Peninsula University of Technology, 2015. / This study was conducted to investigate the occurrence of PAH degrading microorganisms in two river systems in the Western Cape, South Africa, and their ability to degrade two PAH compounds (acenaphthene and fluorene). A total of 19 bacterial isolates were obtained from the Diep- and Plankenburg Rivers. These microorganisms were first identified phenotypically on various selective and general media (such as nutrient agar, Eosine Methylene Blue and Mannitol Salts Agar), followed by staining and biochemical testing, followed by molecular identification using 16S rRNA and PCR. The isolates were then tested for acenaphthene and fluorene degradation first at flask scale and then in a Stirred Tank Bioreactor at varying temperatures (25ºC, 30ºC, 35ºC, 37ºC, 38ºC, 40ºC and 45ºC). All experiments were run without the addition of supplements, bulking agents, biosurfactants or any other form of biostimulants. Four of the 19 isolated microorganisms were identified as acenaphthene and fluorene degrading isolates. Three of the four microorganisms identified as PAH degrading isolates were Gram negative isolates. Results showed that Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila efficiently degraded fluorene (99.90%, 97.90%, 98.40% and 99.50%) and acenaphthene (98.60%, 95.70%, 90.20% and 99.90%) at 37ºC, 37ºC, 30ºC and 35ºC, respectively. The degradation of fluorene was found to be more efficient and rapid compared to that of acenaphthene and degradation at Stirred Tank Bioreactor scale was more efficient for all treatments. Throughout the biodegradation experiments, there was an exponential increase in microbial plate counts ranging from 5 x 104 to 9 x 108 CFU/ml. The increase in plate count was observed to correlate with the efficient degradation temperature profiles and percentages. The PAH degrading microorganisms isolated during this study significantly reduced the concentrations of acenaphthene and fluorene and can be used on a larger, commercial scale to bioremediate PAH contaminated river systems. Other factors that influence the optimal expression of biodegradative potential of microorganisms other than temperature and substrate (nutrient) availability, such as pH, moisture and salinity will be investigated in future studies, as well as the factors contributing to the higher fluorene degradation compared to acenaphthene. Furthermore, the structure and toxicity of the by-products and intermediates produced during microbial metabolism of acenaphthene and fluorene should be investigated in further studies.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg 2014 / Polycyclic Aromatic Hydrocarbons (PAHs) are environmental contaminants which are formed during combustion of organic material such as coal, petroleum compounds and meat. Other sources of PAHs include automobile exhaust, coal tar and crude oil. Natural sources of PAHs include volcanoes, forest fires. Some PAHs are known to be carcinogenic and toxic. They are available to aquatic organisms such as fishes through contaminated sediments and other marine organisms. Due to their toxicity, it is essential to study and monitor PAHs in the environment. In this study, the quechers extraction method was developed and optimised for the extraction of 5 PAHs (Naphthalene, acenaphthene, phenanthrene, fluoranthene, and pyrene). The optimised parameters were the extraction speed, extraction time, volume of solvent, type of solvent, the mass of salt (MgSO4), the mass of fish used for extraction, mass of sorbent (PSA) and the type of sorbent used. After optimisation, the optimised QuEChERS extraction method was then compared to the Soxhlet extraction method. Firstly by spiking with different concentration and comparing the recoveries. Recoveries obtained where similar, this shows that the QuEChERS method is efficient for extraction of PAHs. The optimised QuEChERS extraction method and Soxhlet extraction were applied for analysis of PAHs in real fish samples. Fish samples were obtained from two dams, Jericho dam in Mpumalanga and Hartbeespoort dam in Gauteng. The result obtained for both extraction method were compared. The concentration of PAHs obtained for both methods were similar. Naphthalene was not detected in Hartbeespoort dam. The concentration of PAHs in Hartbeespoort and Jericho dam using QuEChERS extraction method range from 0.8 μg/kg to 739 μg/kg and 0.8 μg/kg to 7.4 μg/kg respectively. Acenaphthene and phenanathrene were not detected in all fish sample from Jericho dam, while pyrene was not detected in some of the fish samples from Jericho dam. Application of Soxhlet extraction to real sample gave concentration ranging from 1.9 μg/kg to 908 μg/kg for Hartbeespoort dam and 1.2 μg/kg to 18.7 μg/kg for Jericho dam. High concentration of PAHs was obtained from Hartbeespoort dam.

Orientador: Altair Benedito Moreira / Banca: Eduardo Alves de Almeida / Banca: Ronaldo José Torres / Resumo: Hidrocarbonetos Policíclicos Aromáticos (HPA) fazem parte de uma classe de compostos denominados Substâncias Tóxicas Persistentes, tendo como principais características elevada toxicidade e persistência no ambiente, sendo as fontes petrogênicas, pirogênicos e biogênicas as que mais contribuem para o aporte destes compostos. A Bacia Hidrográfica do Turvo/Grande (BHTG) é caracterizada por pequenos parques industriais e intensa atividade agrícola com destaque a cana-de-açúcar, que vem acompanhada por processos de queimadas. Neste contexto, este trabalho teve como principal objetivo utilizar a determinação de 1-hidróxipireno em bílis de peixes como biomarcador de exposição para HPA e também determinar o histórico destes em sedimentos de rios da BHTG. As coletas de amostras de peixe (160 amostras) e sedimento (superficial e profundidade) nos rios Preto (CAPRP), Turvo (PORTUR e RTURG) e Grande (RGRANDE) foram feitas em dois períodos distintos: fevereiro e julho de 2010. A determinação do 1-hidroxipireno nas amostras de bílis de peixes foi realizada de acordo com o método proposto por Ariase et alii (1993). Os HPA dos sedimentos foram extraídos de acordo com o método 3540C (EPA) e a quantificação foi realizada empregando Cromatografia Líquida de Alta Eficiência com detector de Fluorescência (HPLC-DF). As concentrações do 1-hidróxipireno no ponto RTURG da coleta de fevereiro de 2010 variaram na faixa de 210 a 1025 µg L-1, com valor médio de 780 ± 281 µg L-1. Para as amostras de peixes coletadas em julho de 2010 no ponto CAPRP, os valores estiveram na faixa de 397 - 6463 µg L-1, com valor médio de 1300 ± 1130 µg L-1. Para os pontos PORTUR e RTURG, os valores médios de concentração de 1-hidróxipireno na bílis dos peixes foram... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Polycyclic Aromatic Hydrocarbons (PAHs) constitute a class of compounds denominated as Persistent Toxic Substances, having as main characteristics high toxicity and persistence in the environment, being that the sources petrogenic, pyrogenic and biogenic contribute most to the intake of these compounds. Turvo/Grande watershed (BHTG) is characterized by a small industrial facilities and intensive agriculture especially sugarcane activity, which is accompanied by the burning process. In this context, this work aimed to use the determination of 1-hydroxypyrene in fish bile as a biomarker of exposure to PAHs and also determine the history of these in the sediments from BHTG rivers. The sampling of fish (160 samples) and sediment (surface and deep) in the Preto (CAPRP), Turvo (PORTUR e RTURG) e Grande (RGRANDE) rivers, were made in two distinct periods: February and July of 2010. The determination of 1-hydroxypyrene in fish bile samples was performed according to the method proposed by Ariase et alii (1993). PAHs were extracted of the sediments according to the method 3540C (EPA) and the quantification was performed using high performance liquid chromatography with fluorescence detector (HPLC-FD). Concentrations of 1-hydroxypyrene is fish bile samples collected in RTURG (February 2010) ranged from 210 to 1025 µg L-1, the average values 780 ± 281 µg L-1. For fish samples collected in CAPRP in July 2010 , values ranged 397-6463 µg L-1, with an average of 1300 ± 1130 µg L-1. For PORTUR and RTURG, the mean concentration of 1-hydroxypyrene in fish bile were 1643 ± 744 µg L-1 and 588 ± 183 µ g L-1, respectively. PAHs concentration along the sediment profile showed similar behavior. In general, for all PAHs there was a trend of reduction with increasing depth in sediment cores. The total concentration... (Complete abstract click eletronic access below) / Mestre

Thesis advisor: Lawrence T. Scott / Thesis advisor: James P. Morken / Expeditious establishment of molecular complexity in a stereoselective manner is a prominent goal in organic synthesis. In this regard, multicomponent coupling reactions have received substantial attention due to their ability to access complex molecules from simple starting materials in a single step. Chapter 1 is a comprehensive review on catalytic bismetallative multicomponent reactions. The scope of this process in terms of both bismetallic reagents and the pi components are broad enough to be generally applied to more elaborate synthetic sequences. Particularly, contemporary applications of the bismetallative multicomponent coupling reactions, in which high enantio- and/or diastereoselectivities are displayed, have enabled the study of this area to make a significant step forward. Chapter 2 presents nickel-catalyzed coupling reactions of aldehyde, diene, and a diboron reagent in the presence of a trialkyl phosphine ligand. Compared to borylation reactions with one pi-component, these borylative multicomponent reactions (involving two pi components) lead to formation of a new C-C bond between the pi components as well as generation of highly functionalized, stereodefined products. Chapter 3 describes a remarkable turnover in regioselectivity of the borylative multicomponent coupling when PCy3 is replaced with P(SiMe3)3. In particular, the products from the reactions with P(SiMe3)3 feature three contiguous stereocenters and an alpha-chiral allylboronate. The effect of P(SiMe3)3 ligand on the product selectivity is intriguing. According to the experimental and computational results, it has an ability to act as an electron acceptor, which will facilitate reductive elimination from the intermediate nickel complex during the course of the reaction. In Chapter 4, we show that borylative ketone-diene coupling reactions can be accomplished in high yields and with excellent levels of diastereocontrol. This reaction occurs in a predictable fashion, yet with regioselection that is distinct from related aldehyde-diene coupling reactions. The reaction products from these coupling processes, which possess tertiary alcohol functionality and an allylic alcohol moiety, are particularly well suited for the preparation of polyketide natural products. Chapter 5 presents investigations on bowl-shaped geodesic polyarenes, which are the missing links between the "classic" planar polycyclic aromatic hydrocarbons (PAHs) and the spheroidal fullerenes. The present study has shown that open geodesic polyarenes can feature chemistry inherent to both classes of aromatics. The curved pi system induces unequal environments on the two faces of circumtrindene, significant strain energy to the molecule, and non-identical bond lengths. Along with the electronic effects, the stereoelectronic effect enabled the site-selective functionalization with fullerene-type chemistry. On the other hand, the edge carbons, which are not present in fullerenes, still possess reactivity of common planar PAHs. Chapter 6 describes the intermolecular oxidative cyclotrimerization reactions of alkenes and aromatic compounds with DDQ and trifluoromethanesulfonic acid. The Scholl-type oxidation reactions involving alkenes have never been demonstrated. Moreover, the DDQ/acid system has never been used for the intermolecular oxidative cyclization reactions. This convenient non-metallic reagent system (DDQ/TfOH) is advantageous over the metal-based Scholl-type oxidants because it eliminates the possibility of halogenation of aromatic compounds and the reduced oxidant can be reoxidized. In Chapter 7, the regioselective formation of cyclic trimers from substituted benzenes and heteroaromatic compounds is demonstrated. This DDQ/TfOH method provides a simple and convenient synthetic route toward star-shaped oligomers containing triphenylene or isotruxene cores. Furthermore, the experimental outcome suggests that this oxidative process proceeds by an electron transfer mechanism. This is the first experimental evidence for mechanistic details on the Scholl-type oxidation. / Thesis (PhD) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Poon, Ching Ho. / "October 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 95-102). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.3 / TABLE OF CONTENTS --- p.4 / ABSTRACT --- p.6 / 摘要 --- p.8 / ABBREVIATIONS --- p.10 / LIST OF FIGURES --- p.11 / Chapter CHAPTER 1 --- GENERAL INTRODUCTION --- p.14 / Chapter CHAPTER 2 --- MATERIALS AND METHODS --- p.26 / Chemicals and materials --- p.26 / Mammalian cell culture --- p.27 / Reporter gene assay --- p.28 / Semi-quantitative real-time PCR --- p.30 / RNA degradation assay --- p.31 / Western Blotting --- p.32 / Electrophoretic mobility shift assay (EMSA) --- p.34 / EROD assay in intact cells --- p.35 / Statistical Analysis --- p.35 / Chapter CHAPTER 3 --- Two citrus bioflavonoids suppress DMBA-induced CYP1 gene expression and activity via antagonizing AhR transactivation activity --- p.36 / Chapter CHAPTER 4 --- Modulation of AhR-mediated CYP1 enzymes transcription by licorice flavonoids isoliquiritigenin --- p.60 / Chapter CHAPTER 5 --- Protein kinase signaling pathways are not involved in the modulation of AhR transactivation activity by flavonoids --- p.81 / Chapter CHAPTER 6 --- SUMMARY --- p.94 / BIBLIOGRAPHY --- p.97