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The ubiquity of pharmaceuticals and personal care products in water systems is well known. With the increasing implementation of water reuse schemes in the US, concern about potential health effects of these compounds in humans has risen. While potential synergistic effects of chronic low doses exposure to a cocktail of these compounds is still being studied, it is prudent to monitor and attenuate these trace organic compounds (TOrCs) from our water sources. This research initially focused on identifying suitable `indicator' TOrCs based on theoretical physico-chemical parameters and actual experimental data. It was concluded that an indicator list will be specific to the goal targeted with dependence on treatment process, occurrence and analytical ease. Quantification of these TOrCs are part per trillion levels in water requires accurate, precise and robust analytical techniques. The next part of this research was spent on developing three different analytical methods with LC-MS/MS for the sensitive detection of TOrCs in several different water matrices including raw sewage and final drinking water. The treatment efficacy of granular activated carbon for attenuation of TOrCs is studied in detail with emphasis on developing correlations between TOrC removal and bulk organic parameters of water like UV absorbance and fluorescence by using rapid small-scale column testing. The results indicate a correlation between removal of TOrCs and bulk organic parameters that is independent of water quality. The effectiveness of commercially available activated carbon based point-of-use (POU) devices for removal of a set of TOrCs from water was evaluated. The data indicated that POUs are a viable option for treatment of TOrCs but specific removal depends on type of device, water quality and amount of water treated. Finally, further research was targeted at identifying transformation products as a result of oxidation of polyfluorinated precursor materials in reclaimed waters. The results illustrated that toxic perfluorocarboxylic acids can be formed on oxidation of fluorotelomer unsaturated carboxylic acids that are known to be present in water.

Wastewater reuse is fast becoming an imperative issue based on the developments in water/wastewater engineering coupled with increasing pressures on water resources. Trace organic compounds (TOrCs) that exist in water/wastewater, are a serious threat once they were released in the environment. During the past decade, there has been much progress toward understanding the occurrence, fate and toxicology of trace organic pollutants that enter the environment in treated wastewater. The objective of the first part of this research was to evaluate the combined effects of sequential anaerobic/aerobic digestion on residual TOrCs, concentrating on chemicals that are responsible for observed estrogenic/androgenic activities in biosolids. Full-scale digestion was simulated using bench-scale bioreactors in which the primary independent variables were retention time, temperature, and oxygen loading during aerobic digestion. Treatment-dependent changes in estrogenic/androgenic activity and concentrations of specific Endocrine disrupting compounds (EDCs) were measured. Results suggest that standard mesophilic anaerobic digestion increases the total estrogenic/androgenic activity of sludge while aerobic digestion was effective in the reduction of estrogenic/androgenic activity as a supplementary treatment stage. The second part of the study was focused on the fate of TOrCs and estrogenic activity in water and sediment of the Santa Cruz River, which is effluent dependent except during infrequent periods of rainfall/runoff in Tucson area. Several sampling campaigns were carried out from 2011 to 2013. Results suggest that some organic TOrCs, including those that contribute to estrogenic activity, were rapidly attenuated with distance and time of travel in the Santa Cruz River. Indirect photolysis of estrogenic compounds through the river might play an important role for the observation of estrogenic activity changes in the SCR. Hydrophobic TOrCs may accumulate in river sediments during dry weather periods. Riverbed sediment quality is periodically improved through storm-related scouring during periods of heavy rainfall and runoff. Wastewater effluent can be applied to the algal biodiesel industry based on regional water stress across the world. In the third part of the research, reclaimed wastewater was explored for this purpose, simultaneously satisfying the needs for water, macronutrients such as nitrogen and phosphorus, and micronutrients necessary for growth of microalgae. At the same time, algal growth in conventionally treated wastewater will improve water quality through the same nutrient removal processes and perhaps by lowering residual levels of trace organics that are an impediment to potable reuse. Results showed that metals levels in most municipal wastewaters are unlikely to disrupt growth, at least by metals tolerant microalgae like Nannochloropsis salina. Cells can grow without inhibition on nutrients from treated municipal wastewater or a centrate stream derived from wastewater treatment. The results also suggest while wastewater provides a suitable nutrient source for algal growth, there is simply not enough municipal wastewater available to support a meaningful biofuels industry without water recycling and nutrient recovery/reuse from spent algae. The last part of the dissertation was the application of water/wastewater treatment techniques, specifically advanced oxidation processes (AOPs) in other industrial sectors. In the integrated circuit production industry, chemical formulations used for megasonic cleaning typically contain hydroxides, peroxides and carbonates, which can affect particle removal efficiency and feature damage. The role of carbonates and ammonia in modulating the oxidation power of megasonic irradiated alkaline solutions through the scavenging of hydroxyl radicals by varying levels of carbonates, bicarbonates, ammonia and solution temperatures on net generation of hydroxyl radicals for applications in semiconductor industry was investigated in this study. The simulation of actual megasonic cleaning process was carried out at acoustic frequency of ~ 1 MHz and different power densities. Carbonate ions were better scavengers of hydroxyl radicals than bicarbonate ions. The effect of bulk solution temperature revealed that the rate of generation of hydroxyl radicals at a power density of 8 W/cm² increased with temperature from 10-30°C, which suggests an increase of transient cavitation with temperature.

To assess the long-term performance of soil-cement materials used in source-control remediation methods (i.e. cement-based solidification/stabilization), procedures to measure or estimate contaminant migration parameters are essential. Previous research indicates that diffusion may be an important mechanism in contaminant transport through soil-cement materials. However, there is a paucity of information regarding the diffusion of contaminants through these materials. The development of a single-reservoir diffusion apparatus and methodology to assess the effective diffusion coefficient (De) and effective porosity (ne) of dissolved, conservative, inorganic chemicals for saturated, cured, monolithic soil-cement specimens is discussed. This is the only study known to investigate these parameters for these materials. The results of tritiated water diffusion tests on 14 different soil-cement mixtures are presented and the influence of curing time and mixture properties such as water-to-cement ratio, cement content, and grain-size distribution are examined. Results suggest that, to determine reasonable assessments of the longer-term parameters, soil-cement samples should be cured for a minimum of 70 days before commencing diffusion testing. Values of ne (0.21 to 0.41) and De (2.50×10-10 m2/s to 7.0×10-10 m2/s) determined are similar to those previously determined for a number other low-hydraulic conductivity materials (i.e. saturated inactive clays). The water content of the initial mixture is shown to have a substantial effect on the diffusive properties as the results indicate that both the total porosity (n) and the effective porosity, ne, generally increase with increasing initial water content. For the range of soils used in this investigation, grain-size distribution did not have a substantial effect on the values of ne or De determined from diffusion testing. The adaptation of a double-reservoir diffusion testing apparatus and methodology to evaluate the distribution coefficient (Kd) and De of organic contaminants is also presented. This apparatus is used to evaluate Kd and De of benzene, ethylbenzene, naphthalene, and trichloroethylene for three soil-cement mixtures. Values of Kd (0 to 2.5 cm3/g depending on the compound and soil-cement mixture tested) determined from diffusion testing, batch testing, and theoretical estimates from the literature were in general agreement. Values of De for the organic compounds ranged from 1.50×10-10 to 3.0×10-10 m2/s.

The hydrogen absorption behavior of organic-compound clathrate hydrates was investigated using five kinds of organic compounds as well as tetrahydrofuran (THF). These hydrates were pressurized by hydrogen, and Raman analysis, the determination of the amount of hydrogen and calorimetric measurement were carried out. The Raman results show that the samples investigated in this work formed binary clathrate hydrate of hydrogen and each organic compound. The organic-compound clathrate hydrates presented similar performances to that of THF clathrate hydrate regarding hydrogen absorption and heat of dissociation. These results suggested that the organic compounds investigated in this work may become alternatives to THF.

Two different methodologies were used to attempt the synthesis of a novel P‐N ligand, denoted as PACNAC for the similarity to the analogous NACNAC and ACAC ligands. Although the synthesis of PACNAC was not successful, each methodology led to interesting discoveries. First, a number of lithium complexes of ketoimines were isolated and studied by Xray crystallography and NMR spectroscopy revealing some interesting substituent based effects on the structure, solubility and solution state behaviour. The X‐ray data of the two known and two related novel ketoimines were also collected and compared to the lithium complexes. Secondly, the synthesis of novel alkynyl imines along with the new alkynyl diimines by novel synthetic routes and studied by x‐ray crystallography, NMR, electrochemistry, and UV‐Visible spectra. / xvi, 134 leaves : ill. (some col.) ; 29 cm + 1 CD-ROM

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The objective of this thesis was to construct general models to predict pollutant fluxes in limnoplankton by incorporating characteristics of the organism and the structures of the chemical. A two-compartmental pharmacokinetic model was used to quantify the pollutant uptake, depuration and intercompartmental exchanges. The model pollutants were phosphorus and 22 organic chemicals. / The rate constants of phosphorus uptake, excretion and intercompartmental changes by algae and cladocerans decreased with cell volume or body size raised to a power close to $-$0.25, except the intercompartmental exchanges for cladocerans which showed more negative slopes. In contrast, uptake, excretion and internal exchange rates per individual increased with cell size or body weight to a power similar to 0.75 with a similar exception for the cladoceran intercompartmental exchanges, which had slopes $<$0.75. / Bioconcentration factors, rate constants and flux rates of uptake and intercompartmental exchange from metabolic pool to structural pool of 22 $ sp{14}$C-labelled organic toxicants by Chlorella pyrenoidosa and Daphnia magna were positively correlated with the octanol/water partition coefficient, molecular weight, parachor, connectivity index, boiling point and melting point, and negatively with aqueous solubility. However, those of elimination and internal transfer from structural pool to metabolic pool showed opposite changes. Comparisons of pharmacokinetic parameters between Daphnia and Chlorella demonstrated that, although all kinetic parameters displayed similar patterns, the relative magnitudes of each corresponding parameters were significantly different between two species.

The genus Helichrysum (Asteraceae) consists of approximately 500 species worldwide, with 245 indigenous to South Africa. As a result of the large number of species, the chemistry and biological activity of several species have not yet been investigated. The aim of this project was to investigate the phytochemistry of three species and propose a synthetic route to one of the antibacterial compounds isolated. An extensive literature review regarding the widespread traditional uses, biological activity and phytochemistry of the South African Helichrysum species is provided. From Helichrysum splendidum, a plant used traditionally to treat rheumatism, two monomeric guaianolides and a dimeric guaianolide, helisplendidilactone, were isolated. The stereochemistry of these known compounds was confirmed and the NMR assignments for certain peaks of helisplendidilactone were corrected. An X-ray structure for helisplendidilactone was obtained for the first time. The phytochemistry of Helichrysum montanum was investigated for the first time and new diastereoisomers of known guaianolides were isolated. The phytochemistry of H. splendidum and H. montanum is remarkably similar and supports their morphological classification in the same taxonomic group. The chloroform:methanol extract of H. montanum yielded a new dimeric guaianolide, 13’-epihelisplendidilactone, which is related to helisplendidilactone, as well as three monomeric guaianolides (of which one is a new diastereomer of a known compound). The extract also yielded spathulenol (a sesquiterpene), umbelliferone (a coumarin) and 4’,5,7-trihydroxy-3,3’,8-trimethoxyflavone (a flavonoid). Thirty-five Helichrysum species were screened for antimicrobial activity against six microorganisms and a preliminary cytotoxic assay, which included the use of “normal” and cancer cell lines, was performed. H. excisum was selected for further study based on the fact that it exhibited promising antimicrobial activity and relative low toxicity. Furthermore, with the exception of the essential oil, the phytochemistry of this species has not been investigated. From the aerial parts of H. excisum, five flavonoids, identified as pinocembrin, gnaphaliin, lepidissipyrone, 5-hydroxy-7,8-dimethoxyflavone and isoscutellarein 7-O-b-glucoside were isolated. Four of these flavonoids have an unsubstituted B-ring, a phenomenon often observed in flavonoids isolated from Helichrysum species. The active antimicrobial component of H. excisum has been identified as lepidissipyrone. Owing to the interesting biological activities reported for phloroglucinol a-pyrones and the synthetic challenges associated with these molecules, lepidissipyrone was selected for a synthetic study. Both the flavanone and pyrone moieties present in lepidissipyrone have been successfully synthesised. A successful strategy towards the CH2 linker between the two units has been illustrated. The strategy could be used to synthesise similar phloroglucinol-derived pyrones. / Thesis (Ph.D.) - University of KwaZulu-Natal, Pietermaritzburg, 2008.