Polycyclic aromatic hydrocarbons (PAHs) are a class of organic molecules suggested to constitute roughly 20% of carbon in the interstellar medium (ISM). These species exist in both neutral and ionic forms and both are potentially involved in processes such as H2 formation. Catalyzing H2 formation necessarily involves the participation of hydrogenated PAHs as reaction intermediates. Employing tandem mass spectrometry and imaging photoelectron photoion coincidence spectroscopy and theory, we have explored the unimolecular reactions of five ionized hydrogenated PAHs that vary in degree and position of hydrogenation: tetralin (1,2,3,4-tetrahydronaphthalene), 9,10-dihydroanthracene (DHA+•), 1,2,3,4-tetra- and 1,2,3,4,9,10-hexa-hydrophenanthrene (THP+• and HHP+•) and 1,2,3,4,5,6,7,8-octahydroanthracene (OHA+•). The major reactions observed were the losses of the hydrocarbons CH3•, C2H4 and C3H5• together with H• atom loss. RRKM modeling of the iPEPICO data suggested that the unimolecular chemistries were based around a two-well potential energy surface in each case. Ionized tetralin can lose all four neutrals via H-shift and ring-opening reactions, or CH3• and C2H4 after interconversion to the 1-methylindane ion, a process similar to that found for ionized 1,2-dihydronaphthalene (isomerizing to form the 1-methylindene ion structure). DHA+• exhibits the same reactions previously observed for 1,2-dihydronaphthalene and 9,10-dihydrophenanthrene, namely competing loss of H• and CH3•. However, the energy required for H•-loss, as predicted by RRKM modeling of the iPEPICO results, was lower than the latter ions, presumably due to an expansion of the electron delocalization across the central ring upon dehydrogenation. OHA+• behaves similarly to ionized tetralin, displaying losses of H•, CH3•, C2H4 and C3H5• in its collision induced dissociation (CID) mass spectra, but under iPEPICO conditions CH3•-loss is not observed. THP+• iii and HHP+• have aspects of both DHA+• and OHA+• chemistries, displaying losses of H•, CH3•, C2H4 and C3H5•. Minimum energies for all observed reaction channels were thus obtained, together with selected mechanisms computationally explored at the B3-LYP/6-31+G(d,p) level of theory. The trend in reactivity in going from tetralin and DHA+• to THP+•, HHP+• and ultimately OHA+• sees decreasing abundance of H• and CH3•-loss and an increasing dominance of the formation of C2H4, C3H5• and higher hydrocarbons with degree of hydrogenation as isomerization to a methyl-substituted ion becomes less significant. As this isomerization decreases in significance, the ions become sources of small hydrocarbon molecules and not hydrogen atoms or molecules.

A creosote treatment facility was active during the 1950’s and 1960’s at a railroad tie yard site. In 1990, creosote contamination was discovered along a creek bank at the site. Phytoremediation was selected as the remedial technology and hybrid poplar trees were planted at the site in 1997. A research project was designed to: 1) characterize the site through collection of soil and ground water samples; 2) assess phytoremediation effects of 3 grasses, clover, fescue and rye, in creosote-contaminated surface soils; 3) perform assessment of the hybrid poplar tree phytoremediation system; 4) develop a hybrid poplar tree evapotranspiration model. This thesis is focused on the first and second items on the research agenda. Soil and ground water samples were collected and analyzed for 6 polycyclic aromatic hydrocarbons (PAHs), acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene and chrysene. Site characterization revealed multiple creosote sources. Areal subsurface bedrock DNAPL distribution, approximately 6500 ft², was much greater than previously reported. Total PAHs (Σ 6 PAHs) in the soil and ground water ranged from below detection limits (BDL) to 8,276 mg/kg and BDL to 1.58 mg/L, respectively. Aqueous phase PAHs should be available for hybrid poplar tree and microbial uptake. Dissolution and diffusion of PAH constituents from the free product phase to the aqueous and soil phases contaminated both matrices. PAH cosolvency effects were also evident. The presence of more soluble PAHs in the aqueous phase enhanced the solubility of two hydrophobic PAHs, chrysene and benzo(b)fluoranthene. Phytoremediation effects of fescue, rye, and clover grasses were assessed in creosote-contaminated surface soils. Over the 9 month period, clover grass growth was very poor. Clover data was not used in comparative analyses. Rye and fescue grasses exhibited acceptable growth. In planted and control (unplanted-amended) plots, acenaphthene, fluorene, phenanthrene, fluoranthene, and pyrene soil concentrations were reduced 72, 50, 73, 55 and 49 percent, respectively. Chrysene reduction was not statistically significant. During the first 4 months of the study, dry site conditions limited grass growth and subsurface biological activity. The site received approximately 16 inches of precipitation during the last 3 months of the study, including multiple, intense precipitation events. The subsurface was saturated for prolonged periods of time and oxygen transfer to indigenous microorganisms was likely limited. The root structures of fescue and rye grasses were neither dense nor complex enough to promote phytoremediation effects. PAH reductions were generally greater for constituents with higher aqueous solubilities. It is thought that PAH losses were primarily due to solubilization and/or microbial uptake. / Master of Science

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This study investigates the influence of ionic strength on the binding constant (KDOC) between benzo(h)quinoline (BHQ) and LHA by using fluorescence quenching method. Being a basic polycyclic aromatic hydrocarbon, BHQ is the dominated solute as the solution¡¦s pH value is higher than BHQ¡¦s pKb. In contrast, BHQ+ is the major species as the solution¡¦s pH value is lower than BHQ¡¦s pKb. In a salty neutral or basic LHA solution, the cation will bind with the acidic functional groups of LHA, then the conformation of LHA would be coiled up to be small in size. Due to that, leading to the decrease of the corresponding BHQ¡¦s KDOC. Furthermore, the charge density of cation is an important factor in control of the variation of BHQ¡¦s KDOC. The lower charge density of cation is, the less BHQ¡¦s KDOC varied. Besides, SO4 2- may suppress the binding affinity between Na+ and the acidic function groups of LHA, so that lower variation of BHQ¡¦s KDOC was observed than that of Cl- in a Na+ contained LHA solution. In an acidic solution, cation will also bind with the acidic functional groups of LHA, leading to the decrease of the binding sites of BHQ+ on LHA and the corresponding BHQ+¡¦s KDOC. Besides, Mg2+ could provide more binding sites for the acidic functional groups of LHA than Na+, so that the variation of BHQ+¡¦s KDOC with Mg2+ addition is higher than that with Na+ addition.

The objective of this study is to quantify the polycyclic aromatic hydrocarbons (PAHs) of the sediments along the coast of south-western Taiwan and to investigate possible sources. The south-western coastal area is full of heavy industries. There are tens of industrial parks along with export processing zone, steel-making plant, oil refinery, shipbuilding plant, Hsin-ta pelagic fishing port, Hsin-ta thermal power plant and Kaohsiung international port. It is reasonable that the wastewater went into rivers or pipes and eventually enters coast area. Concentrations of total polycyclic aromatic hydrocarbons (PAHs) in the sediments of south-western Taiwan were between 197.3~2498.9 (ng/g ¡Vdw) with the average of 912.0 (ng/g ¡V dw). Among all stations sampled in this study, A3, located at the waterway of Kaohsiung, has the highest value. The wastewater ejected by ships might be the major factor. The second highest value we got is from C2, which located at the area farer from shoreline than A3. Total organic carbon (TOC) versus median particle size has linear relationship, however, total organic carbon (TOC) versus concentrations of polycyclic aromatic hydrocarbons (PAHs) showed no linear relationship. This is probably due to the wide sampling area of this study and sources of polycyclic aromatic hydrocarbons (PAHs) were not the same. Principal component analysis shows three principal components were extracted and up to 78.79% of total variance can be explained. As indicated on rotated loadings, the three major components were characterized by 4-6 rings PAH compounds, 3-4 rings PAH compounds and 2-5 rings PAHs compounds, respectively. Results of Hierachical cluster analysis also show three major groups (Group 1, 2 and 3) can be geographically related. In addition, according to isomer ratios of PAH compounds, pollution sources of each group can be specified. Group 1, stations located northern bound, has mainly pyrogenic pollution sources, while Group2, stations located at central area of this study, has pyrogenic/petrogenic sources. For Group 3, stations located southern bound, was mainly polluted by petroleum. In regards to the sediment quality guidelines, ERL and ERM, there are one third of stations exceed ERL regarding to Acp and Phe, but only station A3 exceeds ERL regarding to F1 and Pyr.

In this study,we used mangrove phytoremediation ecotechniques to treat polycyclic aromtic hydrocarbons (pyrene) contaminated soil. First, we compared the four species of mangroves in Taiwan, Kandelia candel Druce, Rhizophora stylosa Griff, Avicennia marina Vierh and Lumnitzera racemosa Willd, inoculated by endomycorrhizae in no contaminated soils. According to the experimental results, the four species of mangroves could be colonized by Glomus aggregatum and Glomus mosseae. In colonization rate and colonization intensity, Glomus aggregatum were found higher than those of Glomus mosseae. For the degradation efficiencies of pyrene in soils, according to the experimental results, we found that the Lumnitzera racemosa Willd exhibited best growing conditions among the four species. The degradation rates for all tests systems pyrene were measured above 90% . In accordance with passed study, the species of Kandelia candel Druce presented effective efficiencics for pyrene degradation. The speacis of Lumnitzera racemosa Willd and Kandelia candel Druce were planted in the artifical pyrene contaminated soils, which were incubated in a greenhouse , while the control systems without vegetation were used for comparison. After 90 days of incubation, the experimental result showed that the soils planted with Lumnitzera racemosa Willd and Kandelia candel Druce were found able to enhance the microbial and dehydrogenase activities. The addition of Glomus aggregatum could help plants to prevent from the stress of pyrene. The addition of salinity into the siols was a pressure for mangroves so the mangroves, incoculated by endomycorrhizae showed stronger dependence on mycorrhizal fungi than those in the siols of no salinity. In salty siol, mangroves exhibited high effective degradation rates for pyrene. In the siols for the illumination groups, the pyrene degradation rates for all test systems were measured about 85%. The siols for the dark groups showed that the average pyrene degradation rates were about 70%.

Polycyclic aromatic hydrocarbons (PAHs) are in general characterized by high toxicity, persistance, and bio-accumulation in environment. It is important to understand the transport and fate of PAHs in environment. In aquatic environment, PAHs are easily bound with dissolved organic matter (DOM), such as humic substance, and KDOC is usually used in denoting the binding constant. Previously, many investigations focused on the binding of a single PAH to DOM. However, few researches considered the competition effect on the binding of multiple PAHs to DOM. This study therefore explored the competition between the binary PAHs, pyrene and phenanthrene, in binding with humic substances. No significant competition effect in KDOC could be observed between these two compounds with LHA (Leonardite Humic Acid) because of the relatively large variation in KDOC determination. Humic substances from different sources might have different properties. Several characteristic indicators of humic substances were used to interprete the variations of KDOC of pyrene and phenanthrene, such as elemental ratio, total acidity, functional group content, etc. Negative correlations of O/C and phenolic group content to the KDOC of pyrene and phenanthrene were observed (p<0.05). In contrast, positive correlation of aromaticity and £`280 of humic substance to the KDOC of pyrene and phenanthrene were observed (p<0.05). Therefore, the contents of phenolic and aromatic groups of humic substance are essential factors in determining their binding constants with PAHs.

Different sample preparation methodologies were evaluated for the determination of pollutants in different matrices. The methods investigated were chosen on the merits of decreased sample preparation time and low toxic solvent consumption with the aim to provide viable alternatives to more laborious methods, such as, Soxhlet extraction. Techniques were developed to extract and quantify organic pollutants from contaminated soils and water. The results from shake flask extraction of aged phenolic contaminated soils were used in attempt to relate sorption to both the soil, and pollutant properties. This was to help gain an understanding of the transport and fate of phenols in different environmental situations. The partitioning (sorption/desorption) of radiolabelled phenols between aqueous solution and soil was investigated using a modified shake flask technique. This provides additional information which can be related to soil characteristics, hence pertaining to the fate mechanisms involved for phenols in the environment. The results from these investigations suggest that more than one factor contributes to the sorption of phenols in soils.

This thesis is a detailed, multi-waveband study of the inner 14 kpc of the famous spiral galaxy, NCG 891. The primary data have come from the Infrared Space Observatory's Camera. These data are images of the galaxy in 9 different mid-infrared wavebands. We have supported these data with archived data from the Spitzer Infrared Array Camera in 4 similar wavebands. Surface brightness contour maps of the galaxy were created and examined to determine where the mid-infrared emitters are located with respect to the galactic plane. We have determined that the main mid-infrared emission, due to warm dust and PAHs, lies in a thin disk of width 700 - 800 pc, but has faint emission that reaches up to about 2.3 kpc into the halo. The infrared spectral energy distribution (SED) for four environments in NGC 891 were created from the above mentioned wavebands as well as measurements from Spitzer's Multiband Imaging Photometer (3 Far-Infrared wavebands), the Two Micron All Sky Survey J, H, and K near-infrared wavebands, and the Sub-millimeter Common User Bolometer Array 450 and 850 $\mu$m bands. These spectra were fit with a SED model created by Frederic Galliano, and the physical properties of these environments were computed. The maps and SED show that while there is a relatively large amount of dust in NGC 891's halo, there is a depletion of PAHs beyond 2.3 kpc from the mid-plane. This is only the fourth galaxy to date that has PAH emission discovered in the halo, and it is the first in which the SED has been modeled for the halo. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2007-08-15 22:39:02.167

Sediments excavated from dredging operations are known as dredged materials. Beneficial reuse of dredged materials in confined utilization facilities (CUFs) is a new approach that has the potential to productively utilize large quantities of dredged materials. However, several factors can inhibit the use of dredged materials in CUFs. In this study, high levels of salts and polycyclic aromatic hydrocarbons (PAHs) were investigated. In the first part of this study, 176,000 m3 of saline dredged materials was placed into a CUF. In less than 4 years, most of the dredged materials had developed horizonation and converted to Inceptisols. The formation of pedogenic Bg horizons in these soils occurred after a polygonal prism network had developed which partially disintegrated into a blocky structured, oxidized horizon with an abundance of redoximorphic features. During the study period, the soil chemistry of the weathering dredged materials shifted from Na-dominated to Ca and Mg-dominated system, allowing plant invasion. In the second part of the study, a bench-scale greenhouse bioremediation experiment was conducted to test the effectiveness of biosolids, compost, and straw at enhancing PAH degradation. Initial concentrations of PAHs decreased significantly after 150 days using standard methods of extraction. However, at 327 days the concentrations of many PAHs, especially those with higher molecular weights, had rebounded close to initial levels. This indicates that PAH bioremediation studies using organic matter additions and conducted using standard methods of extraction need to be carried out longer periods of time or that extraction methods need to be improved. / Master of Science