The research described in the thesis details the investigation of build-up and wash-off process kinetics of Polycyclic Aromatic Hydrocarbons (PAHs) and heavy metals in urban areas. It also discusses the design and development of a rainfall simulator as an important research tool to ensure homogeneity and reduce the large number of variables that are usually inherent to urban water quality research. The rainfall simulator was used to collect runoff samples from three study areas, each with different land uses. The study areas consisted of sites with typical residential, industrial and commercial characteristics in the region. Build-up and wash-off samples were collected at each of the three sites. The collected samples were analysed for a number of chemical and physico-chemical parameters. In addition to this, eight heavy metal elements and 16 priority listed PAHs were analysed in five different particle size fractions of the build-up and wash-off samples. The data generated from the testing of the samples were evaluated using multivariate analysis, which reduced the complexity involved in determining the relative importance of a single parameter in urban water quality. Consequently, variables and processes influencing loadings and concentrations of PAHs and heavy metals in urban stormwater runoff from paved surfaces at any given time were identified and quantified using Principal Component Analysis (PCA). Furthermore, the process kinetics found were validated using a multivariate modelling approach and Partial Least Square (PLS) regression, which confirmed the transferability of chemical processes in urban water quality. Fine particles were dominant in both the build-up and wash-off samples from the three sites. This was mirrored in the heavy metal and PAH concentrations at the three sites, which were significantly higher in particles between 0.45-75μm than in any other fraction. Thus, the larger surface area and electrostatic charge of fine particles were favourable in sorbing PAHs and heavy metals. However, factors such as soil composition, total organic carbon (TOC), the presence of Fe and Mn-oxides and pH of the stormwater were all found to be important in partitioning of the metals and PAHs into different fractions. Additionally, PAHs were consistently found in concentrations above their aqueous solubility, which was attributed to colloidal organic particles being able to increase the dissolved fraction of PAHs. Hence, chemical and physico-chemical parameters played a significant role in the distribution of PAHs and heavy metals in urban stormwater. More importantly, the research showed the wide range of factors that distribute metals and PAHs in an urban environment. Furthermore, it indicated the need for monitoring these parameters in urban areas to ensure that urban stormwater management measures are effective in improving water quality. The build-up and wash-off process kinetics identified using PCA at the respective land uses were predicted using PLS and it was found that the transferability of the governing processes were high even though the PAHs and metal concentrations and loads were highly influenced by the source strength at each site. The increased transferability of fundamental concepts in urban water quality could have significant implications in urban stormwater management. This is primarily attributed to common urban water quality mitigation strategies relying on studies based on physical concepts and processes derived from water quantity studies, which are difficult to transfer between catchments. Hence, a more holistic approach incorporating chemical processes compared to the current piecemeal solutions could significantly improve the protection of key environmental values in a region. Furthermore, urban water quantity mitigation measures are generally designed to reduce the impacts of high-flow events. This research suggests that fairly frequent occurring rainfall events, such as 1-year design rainfall events, could carry significant heavy metal and PAH concentrations in both particulate and dissolved fractions. Hence, structural measures, designed to decrease quantity and quality impact on receiving waters during 10 or 20-year Average Recurrence Interval (ARI) events could be inefficient in removing the majority of PAHs and heavy metals being washed off during more frequent events. The understanding of physical and chemical processes in urban stormwater management could potentially lead to significant improvements in pollutant removal techniques which in turn could lead to significant socio-economic advantages. This project can serve as a baseline study for urban water quality investigations in terms of adopting new methodology and data analysis.

The release of toxic metal species is of concern due to their detrimental effects on the environment and human health. Industrial effluents are a major source of mobilised metal species. Suitable technologies are needed to sequester toxic metal species at the point of source. Biosorption, which is based on the passive adsorption of contaminants onto biological materials, promises to offer an effective alternative or complementary step to existing treatment methods. However, to date there has been no widespread commercialisation of the technique. This is partly due to an insufficient understanding of the complex underlying mechanisms which makes it difficult to select suitable biomass for specific remediation problems and to predict process performance. This study characterised two gram-positive, thermophilic bacteria, Anoxybacillus flavithermus (BF) and Geobacillus stearothermophilus (BS), harvested at two different growth times, with regard to their acid-base and Cd�⁺ adsorption behaviour. The aim was to investigate the metal cation adsorption properties of thermophilic bacteria which has not been studied previously, and to gain a better understanding of the interactions responsible for bacterial metal cation adsorption. Experimental techniques employed in this study included microscopy to establish cell and cell wall morphology, batch acid-base and Cd�⁺ adsorption experiments to quantify proton active surface functional groups and Cd�⁺ adsorption, electrophoretic mobility measurements to assess the overall surface charge of the bacteria and in situ attenuated total reflection infrared (ATR-IR) spectroscopy to reveal the chemical identities of functional groups. Chemical equilibrium models based on batch acid-base titration and electrophoretic mobility data were developed to quantitatively describe proton active surface functional groups. These groups can also interact with metal cations. It was found that growth time was an important factor in all experiments with the differences between growth times often being more pronounced than the differences between the two bacterial strains. Microscopy revealed a gram-positive cell wall structure with different widths and staining behaviour for exponential phase cells of BF and BS. Stationary / death phase cells showed disintegrating cell walls. Acid-base titrations indicated that all cells possessed buffering capacity over the whole investigated pH range (pH 2 - 10). From electrophoretic mobility measurements, isoelectric points of ~ 3.2 for BF and < 1.8 and ~ 4.2 for exponential and stationary / death phase cells of BS respectively were estimated. Chemical equilibrium models including a Donnan electrostatic model were derived which described both the batch acid-base titration data and the electrophoretic mobility data reasonably well, although a comparison with IR data suggested room for further improvement. In situ ATR-IR spectroscopy of hydrated bacterial cells at various pH values revealed amide and carboxyl groups and a contribution from phosphate / polysaccharide moieties. Group specific interactions with Cd�⁺ were not detected, however, a partially reversible absorbance increase of all peaks suggested conformational changes in the presence of Cd�⁺. BF and BS adsorbed ~ 70 [mu]mol Cd�⁺ (g dry bacterial)⁻� at pH 5 in 0.01 M NaNO₃. Release of major cations occurred concomitantly with Cd�⁺ adsorption. The buffering and Cd�⁺-binding capacities of BF and BS were found to be comparable to those of mesophilic bacteria and ion exchange was identified as an important adsorption mechanism.

Bibliography: leaves 153-156. / ix, 156 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis describes the experiments conducted to determine the mechanisms that cause the decline in shoot Zn concentration and the responses of the wheat plant to Zn deficiency and chlorosulfuron stress. Root tip extension is used as a measure of wheat root growth during exposure to the sulfonylurea herbicide chlorsulfuron. Wheat plants differing in Zn efficiency are grown in HEDTA chelate-buffered nutrient solution in controlled conditions. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

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Bibliography: leaves 153-156. / ix, 156 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis describes the experiments conducted to determine the mechanisms that cause the decline in shoot Zn concentration and the responses of the wheat plant to Zn deficiency and chlorosulfuron stress. Root tip extension is used as a measure of wheat root growth during exposure to the sulfonylurea herbicide chlorsulfuron. Wheat plants differing in Zn efficiency are grown in HEDTA chelate-buffered nutrient solution in controlled conditions. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

Diss. (sammanfattning) Stockholm : Tekn. högsk. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Univ., 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Thesis (Ph. D) -- University of Western Sydney, Nepean, 1999. / A thesis presented for the degree of Doctor of Philosophy, Centre for Electrochemical Research and Analytical Technology, University of Western Sydney, Nepean. Includes bibliographical references.