No description available.

Human society has influenced the environment for at least the last 15000 years but, since the Industrial Revolution, the resultant environmental impacts have been widely used in many studies for reconstructing this impact over medium timescales (tens to hundreds of years). Few long-term studies of hydrological change exist and sediments are useful as surrogates for direct monitoring since they are sensitive to change within the catchment. This study uses the properties of urban lake sediments in order to reconstruct environment pollution history. The two principal objectives of this study were the reconstruction of historical atmospheric, point source and diffuse heavy metal pollution in an urban environment and the evaluation of the lake-sediment record as a source of proxy hydrological data over the last 100-150 years. A paired lake-catchment study was undertaken by comparing the records contained in a closed and an open lake. The closed lake (Swanswell Pool) is situated in the centre of the city of Coventry where the main source of pollution is atmospheric. This site provides a contrast to an open basin (Wyken Pool) with a multi-source catchment in addition to atmospheric influx. Trends in urban lake sediment cores indicate increasing heavy metal concentrations upcore, with cultural enrichment factors for individual heavy metals of between 55.4 and 2.6. Storage of heavy metals in the catchment of the closed basin were significant, although it was found that up to 85% of the Zn and 90% of the Pb were actually stored in the lake sediments. Catchment sources contributed up to 5 times more than the atmosphere in the Wyken Slough catchment. Heavy metals budgets were calculated, and these showed that loadings of metals have increased by up to 7.5 times between 1850 and the present day. Sequential digestion of the lake sediments at both sites showed that the important fractions containing heavy metals were Fe and Mn oxides and organic matter. The heavy metals associated with these fractions could be remobilised with changing environmental conditions, but an analysis of contemporary water quality indicated that, at present, suitable Eh and pH conditions for remobilisation did not occur. It was concluded that these urban lakes do preserve the heavy metals record and can provide surrogate data on medium-term environmental change. However, the complex mixture of materials associated with urban sedimentation resulted in a lack of correlation between heavy metals and mineral magnetic properties in either lake, and in the catchment of Wyken Slough. Hence mineral magnetic properties of sediments in urban catchments do not appear to be a suitable surrogate for heavy metals analysis. Urban lakes appear to provide a much-neglected opportunity for palaeolimnological reconstruction over a period when little directly monitored data exists.

Master of Science / Investigations of fluvial and estuarine sediments have indicated stormwater is an important source of heavy metals to Port Jackson estuary and high concentrations of these sedimentary contaminants are a threat to the healthy functioning of the estuarine ecosystem. Stormwater remediation devices have been installed in stormwater channels entering the estuary, however these devices are mainly for removing gross pollutants and are ineffective in removing heavy metals from stormwater. A thorough characterisation of heavy metal inputs and behaviour has been undertaken by sampling, analysing and modelling heavy metals in stormwater entering Port Jackson estuary to provide a rigorous data base for future remediation efforts. A conceptual model of transport and fate of heavy metals in stormwater entering Port Jackson estuary has also been developed to identify heavy metals, subcatchments and flow regimes requiring remediation, and to assist in designing remediation devices for optimum removal of heavy metals from stormwater. Modelling of stormwater using the Model for Urban Stormwater Improvement Conceptualisation (MUSIC) indicated that the average annual discharge of stormwater from the Port Jackson catchment was 215,307 ML. Average annual loadings of arsenic, cadmium, chromium, copper, nickel, lead and zinc in stormwater discharging to Port Jackson estuary were 0.8, 0.5, 1.7, 3.2, 1.1, 3.6 and 17.7 tonnes per year, although comparison to other studies in the catchment suggests these values may be underestimations of actual loadings by 1.3 to 10 times. The proportion of heavy metals discharged under low-flow conditions (<5mm of rainfall in 24 hours), medium-flow conditions (between 5 and 50mm in 24 hours), and high-flow conditions (>50 mm of rainfall in 24 hours) was 6.5%, 62.5% and 31%, respectively. The conceptual model indicates stormwater loadings of copper, lead and zinc pose a risk to the health of riverine and estuarine ecosystems in the catchment and these metals should be targeted for remediation. Stormwater channels which should be prioritised for remediation include the channels entering southern embayments west of Darling Harbour; Duck, Parramatta and Lane Cove Rivers; and the channels and rivers entering Neutral, Long and Sugarloaf Bays. Stormwater loadings of lead are predominantly associated with suspended particulates, whereas loadings of copper and zinc are equally partitioned between dissolved and particulate phases. Stormwater remediation strategies should target both dissolved and particulate phases to ensure effective removal of copper, lead and zinc. Research suggests heavy metals in stormwater discharged to the estuary under high-flow conditions are rapidly exported seaward and bypass the estuary. Preliminary research also suggests that under medium-flow conditions, particulate heavy metals bypass the embayments of Port Jackson and are deposited in the main channel. Once deposited in the main channel, particulate heavy metals are likely to be remobilised and removed from the estuary through multiple phases of resuspension. Although further research is required in this area, this preliminary research suggests remediation should target low-flow conditions. The findings of the current research could be used to identify appropriate remediation strategies for dissolved and particulate phase heavy metals in stormwater discharging to Port Jackson estuary. However, in designing stormwater remediation devices, consideration should also be given to the range of contaminants that may be present in stormwater entering Port Jackson estuary (including suspended solids, nutrients, pesticides and organics).

Thesis (MAppSc) -- Auckland University of Technology, 2004. / Also held in print (104 leaves, ill., 30 cm.) in Wellesley Theses Collection. (T 639.41 PER)

Thesis (M.App.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 218-225). Also available in electronic format on the Internet.

Thesis (M.S.) in Biochemistry--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 49-57).

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--Michigan State University. Dept. of Chemistry, 2008. / Title from PDF t.p. (viewed Aug. 14, 2009). Includes bibliographical references (p. 149-151). Also issued in print.