Advances in analytical chemistry have resulted in a growing body of literature showing measurable concentrations of pharmaceuticals in both drinking and wastewater. Removal of such chemicals is typically inefficient and often poorly characterized. To characterize one such method of removal (micellar enhanced ultrafiltration, (MEUF)), interactions of a cetyl trimethylammonium bromide (CTABr) surfactant and sulfonamide antibiotics were examined by NMR and semi-equilibrium dialysis (SED). The locus and orientation of binding in a micelle was established for seven sulfonamides by 1H NMR, and it was found that hydrophilic sulfonamides showed weak coordination with the micelle, whereas hydrophobic sulfonamides penetrated into the micellar interior with coordination of the SO2NH group to the charged surface layer. Binding constants were determined by 1H NMR and showed apparent order of magnitude differences between nuclei. Several compounds were unable to be characterized in this manner due to low change in chemical shift with addition of CTABr. SED was performed as an alternative method to determine binding constants. Values determined in this manner were higher than those determined by 1H NMR. Binding constants were converted into changes in Gibbs free energy and used to evaluate and, where necessary, modify the orientation and locus proposed by 1H NMR. Attempts are made to correlate binding constants with octanol-water partition coefficients to determine if a free energy relationship can be derived. Characterization of these systems may allow for a predictive methodology to determine the MEUF removal efficiencies of new sulfonamide and surfactant combinations. It is also hoped that this work may be generalized to predict MEUF efficiency for a wide range of contaminants that might be found in wastewater. / Thesis (Master, Chemistry) -- Queen's University, 2011-01-31 09:46:28.248

Thesis (MEngSc)(Civil Eng) --University of Melbourne, Dept. of Civil and Environmental Engineering, 2009. / Typescript. Includes bibliographical references.

Calcium carbonate minerals (CaCO3) are important for our understanding of past marine conditions as well as tools for constructing paleoclimate. However, very little experimental work has been done to determine the influence of oxygen depletion on the geochemistry of CaCO3. To determine how oxygen depletion affects elemental incorporation and partitioning, aragonite was grown inorganically in artificial seawater at pressures of 1 atm and 5 bars (0.1%CH4-N2 mixture). Solution of Na2CO3 was used to induce aragonite precipitation. N2 was bubbled through solution in order to minimize oxygen content and iron powder was used to trap remaining O2. Experimental products (aragonite and fluid) were analyzed with ICP-MS, and isotope ratio mass spectrometer. Results suggest that Eh affects incorporation of Mn, S, Cu, and V into aragonite. No methane oxidation was observed.

The focus of this study was the development of an improved correlation that more accurately quantifies the relationships between optimum salinity, optimum solubilization ratios, chemical formulation variables such as surfactant and co-solvent structures, and the EACN. Entrained in this study are improved correlations for co-solvent partition coefficients and correlations for the optimum salinity and solubilization ratio with EACN. Several trends in the oil-water partition coefficient were observed with the alcohol type (IBA and phenol), the number of ethylene oxide groups in the co-solvent, the EACN of the oil, temperature, and salinity. New EACN measurements were made using optimized formulations containing various combinations of primary surfactants, co-surfactants, co-solvents and alkali. The new EACN measurements ranged from 11.3 to 21.1. These new data significantly expand the total number of reliable EACN values available to understand and correlate chemical EOR formulation results. An improved correlation that more accurately quantifies the relationship between surfactant structure, co-solvents, oil, temperature, and optimum salinity was developed using a new and much larger high quality formulation dataset now available from studies done in recent years in the Center for Petroleum and Geosystems Engineering at the University of Texas at Austin. The correlation is useful for understanding the now very large number of microemulsion phase behavior experiments as well as the uncertainties associated with these data, and for suggesting new chemical structures to develop and test. / text

The thermodynamic history of the Earth is preserved in the trace element record created through igneous processes. The ability to interpret that record depends on the accuracy and precision of numerical models that connect igneous processes with their geochemical consequences. This project answers three major questions concerning the relationship between trace element partitioning and the processes that influence it. One: using a common igneous mineral, clinopyroxene, as a base, how complete is the dataset on which our understanding of this relationship relies? Two: what are the dangers involved with basing models on experiments that contain higher than natural concentrations of trace elements? Three: how accurate and precise is the current numerical model that describes this relationship, and can it be improved? This project determined that the data contain gaps at high pressures and temperatures, are limited for felsic rock compositions, and are lacking for hydrous conditions. A set of experiments conducted on plagioclase feldspar crystallization from a base MORB composition containing various levels of dopants at below wt% levels reveals the presence of non-Henry's Law partitioning behavior through the disruption of the phase equilibria of the system. Lastly, the current clinopyroxene/melt rare earth element partitioning model (Wood and Blundy, 2003) is shown to reasonably, though less than ideally, describe the relationship between igneous processes and their trace-element partitioning results using the thermodynamics of the system. The accuracy was improved through adding a regression, which is based on the major element concentrations of the clinopyroxene and melt to the original numerical expressions. / Graduation date: 2012

The Henry's law constant is important in the gas-liquid mass transfer process. This study investigates the apparent dimensionless Henry's law constant, also known as the gas-liquid partition coefficient (K'H), of both hydrophilic (methanol, isopropanol and acetone) and hydrophobic (toluene and p-xylene) organic compounds. The K'H in deionized (DI) water, wastewater with a maximum total dissolved organic carbon (DOC) content of 700 mg/L, and DI water mixed with a maximum activated sludge suspended solid (SS) concentration of 40,000 mg/L, are measured by the single equilibrium technique (SET) at 288 K, 293 K, 298 K and 303 K. Experimental results indicate that the K'H of the three tested volatile organic compounds (VOCs) varies according to three situations. First, the K'H of the hydrophilic compounds in mixed liquor with the maximum suspended solid concentration is higher than that in DI water. The maximum rates of increase of K'H from KH in the SS range between 288 K and 303 K are 27.2% for methanol, 23.5% for isopropanol and 16.1% for acetone. Second, the K'H values for toluene and p-xylene are lower than those in DI water. Between 288 K and 303 K, the maximum reduce rate of K'H from KH in the SS range are 87.3% for toluene and 93.0% for p-xylene. Third, the K'H values of all of the test compounds in the wastewater are lower than those in DI water. The maximum rates of decrease of K'H from KH in the DOC concentration range between 288 K and 303 K are 1.2% for methanol, 1.1% for isopropanol, 1.7% for acetone, 14.3% for toluene and 20.1% for p-xylene. A model is presented to related K'H to wastewater DOC and concentration of SS in the activated sludge, using an organic carbon-water partition coefficient (KOC) and activated sludge-water partition coefficient (KSS) as model parameters. The model is verified, and model parameters for test compounds are estimated. Temperature variations of K'H can be regressed using van't Hoff's equation. The gas-water phase change enthalpy £GH'gw rises approximately linearly with increasing SS for hydrophobic toluene and p-xylene. K'H variation can be controlled by SS concentration and temperature in activated sludge system. The temperature effect of KOC and KSS are also observed. KOC and KSS decrease with as the temperature rises from 288 K to 303 K. The VOCs phase change enthalpy and entropy can be calculated using thermodynamic analysis. The partition of VOCs into the organic carbon phase releases energy, and thus prefers low temperatures. Lower temperatures and higher SS concentrations lead to lower K'H for hydrophobic VOCs, while higher SS concentrations result in higher K'H for hydrophilic VOCs. Organic-rich wastewater or low-biomass mixed liquor can successfully remove hydrophilic VOCs from contaminated air streams by bioscrubber. However, bioreactors scrubbed with high biomass-containing mixed liquor perform better than regular activated sludge concentration in removing hydrophobic VOCs. The experimental results thus support the design and operation of bioscrubber and suspended operable bioreactors.

Most drugs undergo passive transport during absorption and distribution in the body. It is desirable to predict passive permeation of future drug candidates in order to increase the productivity of the drug discovery process. Unlike drug-receptor interactions, there is no receptor map for passive permeability because the process of transport across the lipid bilayer involves multiple mechanisms. This work intends to increase the understanding of permeation of drug-like molecules through lipid bilayers. Drug molecules in solution typically form various species due to ionization, complexation, etc. Therefore, species specific properties must be obtained to bridge the experiment and simulations. Due to the volume contrast between intra- and extravesicular compartments of liposomes, minor perturbations in ionic and binding equilibria become significant contributors to transport rates. Using tyramine as a model amine, quantitative numerical models were developed to determine intrinsic permeability coefficients. The microscopic ionization and binding constants needed for this were independently measured. The partition coefficient in 1,9-decadiene was measured for a series of compounds as a quantitative surrogate for the partitioning into the hydrocarbon region of the bilayer. These studies uncovered an apparent long-range interaction between the two polar substituents that caused deviations in the microscopic pKa values and partition coefficient of tyramine from the expected values. Additionally the partition coefficients in the preferred binding region of the bilayer were also measured by equilibrium uptake into liposomes. All-atom molecular dynamics simulations of lipid bilayers containing tyramine, 4- ethylphenol, or phenylethylamine provided free energies of transfer of these solutes from water to various locations on the transport path. The experimentally measured partition coefficients were consistent with the free energy profiles in showing the barrier in the hydrocarbon region and preferred binding region near the interface. The substituent contributions to these free energies were also quantitatively consistent between the experiments and simulations. Specific interactions between solutes and the bilayer suggest that amphiphiles are likely to show preferred binding in the head group region and that the most of hydrogen bonds involving solutes located inside the bilayer are with water molecules. Solute re-orientation inside the bilayer lowers the partitioning barrier by allowing favorable interactions.

A new approach for predicting octanol-water partition coefficients (Log P) of linear perfluorinated compounds, making use of the limited experimental data available, previous observations and the consistent similarities observed between the experimental and calculated (with electronic structure methods and using EPI suite) slopes of the linear plots of Log P values with the number of carbon atoms (N = 2 to 11) is described here. Eight families of linear organic compounds were investigated: carboxylic acids, perfluorinated carboxylic acids, sulfonic acids and perfluorinated sulfonic acids, together with their corresponding conjugate bases. To the best of our knowledge, this work reports the first application of density functional theory methods to the calculation of Log P values of perfluorinated compounds. A second part of the thesis, describes the study of the thermodynamic stability of the PFOA family of 39 structural isomers with the M06-2X, LC-ωPBE, B97D and B3LYP functionals and with the PM6 method. The PM6 results closely resemble the M06-2X results for neutral PFOAs, but greatly disagree regarding anions. The four functionals applied behave similarly from a qualitative point of view, but quantitatively speaking, the LC-ωPBE and B97D results are between the M06-2X and B3LYP stability results. M06-2X ranks highly substituted isomers as more stable than did B3LYP, and ranks less-branched isomers quite low in relative stability compared to B3LYP. Various similarities with a former PFOSs study applying the M06-2X and B3LYP functionals have been identified. The degree of branching within structural isomers cannot always be precisely determined, and is not the only aspect that determines thermodynamic stability; the pattern of substitution seems to also play a significant role. / Graduate

Estudos de coeficiente de partição mostram que o valor de Kp do metal pode variar ordens de grandeza conforme as características físico-químicas do solo. Portanto, o Kp é um parâmetro sensível no modelo de avaliação de risco à saúde humana, e normalmente é um valor nominal adotado por agências ambientais que pode não representar adequadamente o solo em estudo e implicar erros no cálculo do risco. Este trabalho tem como objetivos: avaliar a contaminação do solo adjacente à usina termoelétrica de Figueira por metais tóxicos; determinar o Kp dos metais As, Cd, Co, Cr, Cu, Mo, Ni, Pb e Zn no solo pela razão entre a concentração do metal obtida por digestão com HNO3 concentrado e a concentração do metal obtida por extração com EDTA 0,05 mol L-1 (KpEDTA) ou Ca(NO3)2 0,1 mol L-1 (KpCa(NO3)2); e avaliar a influência do uso dos diferentes valores de Kp no modelo de avaliação de risco à saúde humana C-Soil no cálculo do risco. As principais conclusões foram: os metais contaminantes do solo de Figueira foram As, Cd, Mo, Pb e Zn, e o As foi o elemento mais crítico; tanto o valor de KpCa(NO3)2 quanto o de KpEDTA poderiam ser utilizados no cálculo do risco à saúde humana, no caso de Figueira, exceto para o Pb, mas o KpEDTA seria mais recomendado, por apresentar valores com menor dispersão; os valores nominais de KpCSoil dos metais poderiam ser utilizados para o cálculo de risco à saúde humana no caso de Figueira, ou seja, não teria necessidade de se determinar valores de Kp locais (KpEDTA e KpCa(NO3)2), exceto para o Pb. / Studies of partition coefficient show that Kp values of metals can vary orders of magnitude according to the soil physical-chemistry characteristics. Therefore, the Kp is a sensible parameter in human health risk assessment model. In general, a default value is adopted by environmental agencies and often it is not represent suitably the soil studied and can cause errors in the risk calculation. The objectives of this work are: evaluate the heavy metals soil contamination around the Figueira coal-fired power plant; determine the metal Kp of As, Cd, Co, Cr, Cu, Mo, Ni, Pb and Zn in soil by the ratio between the metal concentration obtained by concentrate HNO3 digestion and the metal concentration obtained by extraction with EDTA 0,05 mol L-1 (KpEDTA) or Ca(NO3)2 0,1 mol L-1 (KpCa(NO3)2); and evaluate the influence of the application of different Kp values in human health risk assessment C-Soil model in risk calculation. The main conclusions of the present study were: As, Cd, Mo, Pb e Zn were the Figueira soil metal contaminants, being As the pollunt of major human health concern; either KpCa(NO3)2 or KpEDTA values could be used for human health risk calculation, in Figueira case, except for Pb, and the KpEDTA values were preferably recommended due to the less dispersion of their values; the KpCSoil metals default values could be applied for the human health risk calculation in Figueira case, in other words, it would not have necessity to determine Kp values of region (KpEDTA and KpCa(NO3)2), except to Pb.

Water, suspended particle and sediment samples from Kao-ping estuary were collected and measured for concentrations of polycyclic aromatic hydrocarbons (PAHs) during March 2004 and April 2005. In addition, sediments from neighboring coastal area were also analyzed to estimate distribution, transportation and possible sources of PAHs. Total PAH concentrations varied from 33.0 to 910 ng/g dry weight (dw) in coastal sediments, and diagnostic ratios reflect a mixed sources of petrogenic and pyrolytic inputs. Due to the contribution of Kao-ping River, spatial distribution of PAH concentrations at coastal sediments near river mouth varied dramatically. Results of hierachical cluster analysis showed that PAH concentration distribution was influenced by Kao-ping canyon, and biogenic source might be the major PAH source for offshore sediments. Total PAH concentrations in river sediment varied from 63.0 to 720 ng/g dw. Higher concentration was measured between the Water Main pipe and Shuang-yuan Bridge, and possible sources were from both petrogenic and pyrolytic sources. Sediment of Dung-gang harbour had highest concentration, 28,000ng/g dw, in this study, which was contributed from petrogenic sources due to its intensive boating activities. Except fluorene and phenanthrene in harbour sediments, individual PAH concentrations of other sediments are lower or near the Effect Range Low value, concentrations might lead to possible adverse effects upon organism. Total PAH concentrations varied from 5.0 to 82.0 ng/L in suspended particulate phase and from 5.5ng/L to 46.0ng/L in dissolved phase, respectively. Most of high molecular weight PAH concentrations (>5-ring PAHs) in dissolved phase were below method detection limits. The partition coefficients¡]Koc¡^values of PAHs were 1 to 2 orders higher than predicted values. It might be attributed to soot particles which have extremely high sorption capacities. Correlation coefficients between total PAH concentrations in sediments versus total organic carbon¡]TOC¡^ and fine particle content¡]<63£gm%¡^were significant ¡]R=0.575, 0.800, 0.851 and 0.657, P<0.01¡^. In addition, PAHs in suspended particulate phase and dissolved phase were also significantly correlated to particulate organic carbon¡]POC¡^ and dissolved organic carbon¡]DOC¡^, respectively. The distribution of calculated PAH concentrations from organic carbon was higher in surface water than bottom water. Unlike salinity, there was no decreasing or increasing trend of these concentrations among river samples. It is possible that contamination was not come from upstream, but from estuary area where plume was lifted and diffused upstream by neat seawater. The flux in Wan-da Bridge was higher than downstream estuary area that might be due to PAH concentrations reduction by sedimentation or degradation.