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No description available.

No description available.

An investigation of heavy metal concentrations in sediments from Coxs River catchment, a tributary of the Hawkesbury-Nepean River system, has been undertaken. A number of digestion methods were assessed for the determination of Pb, Cu, Cd, Zn, Ni, Mn, Fe, Co and Cr in reference materials by flame AAS. The method that produced the best recovery is reverse aqua regia, HNO3-HC1 with ultrasonification followed by heating on a hotplate. Based on analysis of sediments from 133 sites, background concentrations were established. Elevated heavy metal concentrations were recorded in some samples. The three most polluted areas were investigated for heavy metal associations and distributions. Metal bioavailability was assessed from sediment samples by using selective extraction techniques. The association of heavy metals with different solid phases was assessed by a sequential extraction technique involving a series of extraction reagents. Pd, Cu, Fe and Cr were mainly associated with Fe/Mn oxides and organic matter plus sulphide phases. While Cd, Zn, Ni and Co which behave similarly were extracted from each step, the largest percentages of these metals were found in Fe/Mn oxides and organic matter phases. Mn was different to other metals, in that it predominantly associated with the ion exchangeable form. / Master of Science (Hons)

The aim of this project was to identify a suitable solution to the problem of landfill leachate at the North Katoomba landfill site. Options were affected by a range of constraints including economics, location and the intrusion of ground water into the landfill. The initial goal was to contain and treat the leachate on site, with the eventual target to discharge into the nearest receiving waters. A constructed wetland option was devised and researched, involving identification of the major pollutants contained within the leachate, developing a concept design and estimating the likely removal efficiencies expected. Investigations identified the primary pollution parameters as microbial and nutrients. Metals were found to be low in concentration although the wetland has the capacity to deal with these pollutants should they become part of the pollution plume. A bench scale constructed wetland system was developed to give an indication of the removal efficiencies. The results suggest that a constructed wetland system would be appropriate for treating landfill leachate at the North Katoomba site. It is recommended that a constructed wetland be established in the field to determine the long term treatment prospects and the potential management problems in a practical application. / Master of Science (Hons)

This study addresses the central problem of how the behaviour of individuals may be co-ordinated to manage collective natural resources, and in particular, to what degree this can be achieved through voluntary, community based means under a free market policy regime. This question was explored by researching how local groups known as Landcare, or Care groups, are managing waterways in Waikato, New Zealand, and specifically by examining their effectiveness in controlling non-point source contaminants to water originating from agricultural land.An action research approach was used to investigate research questions regarding what motivates actors to support activity to enhance water quality, the effectiveness of such activity in addressing non-point source discharges to water, and the equity issues which are associated with environmental management through Landcare. This study suggests that neo-liberal philosophies of governance, while favouring voluntary resource management, disregard the conditions which, in practice, underpin effective and equitable examples of this type of activity. A call is therefore made for a more active role for government, in directly supporting local action, in compensating for the impacts of free-market policies on natural resource use, and in facilitating the representation of the diversity of views in environmental management. Action research, participatory planning, and other learning based and communicative processes could be usefully employed to guide and inform such interventions / Doctor of Philosophy (PhD)

Graduation date: 2002

Previous studies have shown that rainbow trout exposed to dieldrin via diet for 9 to 12 weeks increased biliary excretion of a subsequent dose of [¹⁴C]dieldrin by 500%. This was not explained by induction of the cytochrome P-450 (CYP) system involved in oxidative metabolism of these compounds. We hypothesized that epoxide hydrolase activity increased in dieldrin fed-fish. Epoxide hydrolase is an enzyme that catalyzes the hydrolysis of epoxide compounds to their corresponding diols. For instance, dieldrin is metabolized to 6,7 trans-aldrindihydrodiol. This study investigated the activity of epoxide hydrolase in microsomes and cytosol of rainbow trout fed a diet that contained 0 or 15 ppm dieldrin. Fish were fed control or dieldrin diet (0.324 ug/g body weight/day) for 3, 6, or 9 weeks. There was a small increase in mortality and decrease in body weight among dieldrin-fed fish after 9 weeks. After week 9, dieldrin-fed fish were fed a control diet for an additional 3 weeks because of these signs of toxicity. At week 12, the difference of body weight between control and treated was not significant. Microsomal and cytosolic epoxide hydrolase activities were measured with a radiometric assay which determined differential partitioning of the parent compound (epoxide) in dodecane and the metabolite (diol) in the aqueous phase. Assays were run at optimal pH and temperature using [³H]trans-stilbene oxide (pH 7) as substrate for cytosol and [³H]cis-stilbene oxide (pH 8) as substrate for microsomes. In order to prevent competition for reaction with stilbene oxide, depletion of glutathione was efficiently achieved by dialysis at 4°C for 2 hours at room temperature in buffer [pH 7.5, potassium phosphate 10 mM, KCL 0.15 M, EDTA 1 mM, BHT 0.1 mM, 0.1 mM PMSF]. Protein quantification was determined by using BCA assay and concentrations were always between 5 and 25 ug/ml in the final assay volume. Epoxide hydrolase activities were not significantly different in cytosol or microsomes from control and dieldrin-fed fish. Dieldrin residues in liver were analyzed by gas chromatography with electron capture detection (GC/ECD). The concentration in the liver increased with time of exposure and declined markedly in fish fed dieldrin for 9 weeks and then fed control diet. No dieldrin was detected in livers from control fish. / Graduation date: 2003

Selected physicochemical properties of Little Lick Creek, in Hartford City, Indiana, were determined in the fall of 1969. Subsurface samples from five stations, two upstream and two downstream from a discharge point: at the. Minnesota Mining and Manufacturing Companywere analyzed. A complex effluent containing a dye entered the creek from the paper plant. Dissolved oxygen and biochemical oxygen demand determinations of the water downstream from the discharge displayed changes in water quality of the creek. The water temperature rose significantly after the discharge water entered the creek. A cell count study of the Cyanophyta of the creek was also determined.Little Lick Creek was considered polluted below the paper products plant discharge based on the observed changes in the water tested. Cyanophyta populations were apparently reduced by the effluent.Ball State UniversityMuncie, IN 47306

The outfalls of the eight tributaries entering Grand Lake-St. Marys were monitored during the eleven month period from August, 1972 through June, 1973. Both biological and physical parameters were measured at all sites.The biological parameters that were measured included; fecal coliforms, fecal streptococci, Salmonella spp., Shigella spp., Proteus spp., seudomonas,aeruginosa and Staphylococcus aureus. The physical parameters were; pH, turbidity, water temperature, dissolved oxygen and local rainfall.All eight outfalls were shown to exceed the limits recommended by the U.S. Public Health Service for fecal coliform counts. The ratio of fecal coliforms to fecal streptococci suggested that the pollution came from both human and animal wastes that were carried into the lake in stormwater runoff. The low fecal counts obtained away from the tributaries, in the center of the lake, indicated that the lake was able to recover from the pollution entering at the outfalls. Primary contact recreation in the vicinity of the tributary outfalls is not recommended but the remainder of the lake presents no apparent health hazard.Ball State UniversityMuncie, IN 47306