Trace metal speciation in the Pieman River catchment, western Tasmania

The Pieman River catchment has seen continuous mining of economic deposits of gold, silver, lead, copper, zinc and tin since the 1870’s. Tributaries of this river which receive mining effluent, either directly or from acid mine drainage (AMID), have total metal concentrations considerably above background levels and are of regulatory concern. The lower Pieman River is however classified as a State Reserve in which recreational fishing and tourism are the major activities. It is therefore important that water entering the lower Pieman River from upstream hydroelectric impoundments is of high quality. Metals in natural waters exist in a variety of dissolved, colloidal and particulate forms. The bioavailability and hence toxicity of heavy metal pollutants is very dependant on their physico form. Knowledge of the speciation of a metal in natural aquatic environments is therefore necessary for understanding its geochemical behaviour and biological availability. Complexation of metal ions by natural ligands in aquatic systems is believed to play a significant role in controlling their chemical speciation. This study has investigated temporal and spatial variation in complexation of metal ions in the Pieman River. The influence of pH, temperature, organic matter, salinity, ionic strength and time has been investigated in a series of field studies and in laboratory-based experiments which simulated natural and anthropogenic disturbances. Labile metals were measured using two techniques in various freshwater and estuarine environments. Diffusive gradients in thin-films (DGT) allowed in situ measurement of solution speciation whilst differential pulse anodic stripping voltammetry (DPASV) was used to measure labile metal species in water samples collected from the catchment. Organic complexation was found to be a significant regulating mechanism for copper speciation and the copper-binding ligand concentration usually exceeded the total copper concentration in the river water. Complexation was highly dependent on pH and at the river-seawater interface was also regulated by salinity, probably as a result of competitive complexation by major ions in seawater (eg. Ca 2+ ions). Zinc complexation was also evident, however total zinc concentrations in the water column often far exceeded the potential binding capacity of available ligands. In addition to organic complexation, Zn speciation may also be associated with adsorption by flocculated or resuspended colloidal Mn and/or Fe oxyhydroxides. Metal ion complexation and hence speciation was found to be highly variable within the Pieman River catchment. This presents major difficulties for environmental managers, as it is therefore not possible to make catchment-wide assumptions about the bioavailability of these metals. These results emphasise the importance of site-specific sampling protocols and speciation testing, ideally incorporating continuous, in situ monitoring.

Exploring the dynamics of accountability relationships : a grounded theory approach

Examines accountability relationships within the organisational context of a local council. Results indicate that accountability is an intensely personal, complex, and context-bound phenomenon. A framework of accountability is suggested, linking the context and characteristics of accountability relationships with particular cognitive and emotive accountability outcomes.

Recovery of estuaries following disturbance by pollutants

The recovery of a heavily polluted estuary was assessed by comparing the structure of its intertidal community with six other estuaries. Results indicated that some recovery had occurred, however improvements in the study methodology were required to further clarify the ecological status of the creek.

The combined effect of light intensity and temperature on the chlorophyll and carotenoid pigments of phytoplankton

Chlorophyll a and other photosynthetic pigments are used as indicators of phytoplankton biomass, composition and physiological state. Extraction and HPLC procedures were developed to analyse for chlorophyll and carotenoid pigments. The effect of the environment on pigment production must be quantified before the pigments can be used to accurately estimate biomass or quantitatively describe phytoplankton composition.

Scalpel slaves or cyborgs? : cosmetic surgery and embodied identity

This thesis explores individuals' experiences of cosmetic surgery in Melbourne. The research conducted with recipients of cosmetic surgery is a complex and ambiguous practice simultaneously encompassing pain and pleasure, agency and constraint, empowerment and conformity. By providing a more nuanced representation of people's experiences of such surgery, the thesis envisions a subjectivity that may better account for individuals' active and lived relationship to their bodies.

Lay meanings and practices of medicinal use in a multicultural context : a qualitative study among Anglo-Celtic and Russian Australians in Melbourne

Describes medicinal use among Anglo-Celtic and Russian Australians. Cultural constructions of medicines are embedded in health beliefs; shaped by experiences with health care within socio-economic and political contexts. Cultural practices of medicinal use are best understood in the context of lay models of rationality and recognition of the conflict existing between the lay and expert models.

Degradation of VOCs using non-film titania in a hybrid process

This study reports the preparation and characterization of titanium dioxide (TiO2)-based non-film catalysts, reactor design and their utilization in a hybrid dynamic degradation of acetone and toluene. The behaviours of deactivation and regeneration of catalysts are explored as well. The regression equations of conversion rate in differing operating modes are concluded.

The effect of increased water prices on construction

The research aimed to investigate the effect an increase in water prices would have on construction. It was found that while there is a considerable amount of water embodied in construction the actual effect of a water tax on construction would be minimal unless implemented at the highest rate.

Influence of land cover on water resources

The influence of land cover on water quality and quantity was examined using a multidisciplinary approach that integrated land use maps, historical databases, and statistical modelling. Systematic changes in the Glenelg Hopkins landscape were identified, in addition to a relationship between greater proportions of vegetation and better water quality.

Measuring dairy farm performance

To fully consider production impacts, this thesis adopts a systems perspective and uses a biophysical model, DairyMod, to measure the interactions between system components and gauge the environmental impact of dairy farming arising from nitrogen use. Performance from the perspective of both the individual farmer and society is examined.