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Several oil sands tailings from Suncor Energy Inc. were analysed with respect to the mobility and solubility of the petroleum hydrocarbon (PHC) contaminants. At sites where oil sands tailings materials have been disposed of and are covered with a growing medium, the PHCs from the tailings may slowly migrate into the reclamation cover, increasing their availability to the plants in the cover system, which could be detrimental to the development and establishment of the plant cover system. This study characterized the PHC content of the tailings and quantified the desorption and diffusion coefficients for F2 and F3 fraction PHCs. All tailings materials collected from Suncor were characterized for initial PHC content. Desorption coefficients were experimentally determined using batch tests for 9 tailings materials (MFT, LG MFT, PT MFT, Tailings Sand, P4 UB Surface, P4 UB Auger, 2:1 CT, 4:1 CT and 6:1 CT). The experimental results from the batch tests were fitted to a Langmuir hyperbolic isotherm model. Diffusion coefficients were determined by fitting the experimental results from a radial diffusion 1-dimensional experiment to a Finite Difference Model. Diffusion coefficients for F2 and F3 Fraction PHCs were developed for 7 tailings materials (MFT, LG MFT, PT MFT, Tailings Sand, 2:1 CT, 4:1 CT and 6:1 CT). The diffusion coefficients (D*) and the Langmuir desorption constants ( and ) developed from these experiments are included in Table A.1. The desorption coefficients resulting from this study are similar to those reported for the desorption of asphaltene, which is one of the components in oil sands tailings. The Langmuir isotherm model was found to be the best fit for the experimental desorption data; the Langmuir isotherm model is commonly used in sorption isotherms of organic chemicals. The results of the radial diffusion experiments agree with diffusion rates found by other researchers in similar porous media. More research may be needed to verify both of these preliminary results for the desorptive and diffusive transport of F2 and F3 PHC fractions in tailings. Tailings composition will continue to change as new technologies for fines settling and bitumen extraction are developed. The diffusion of PHCs from these new materials will need to be examined as it is probable that these changes will affect the transport and mobility of the contaminants.

In order to determine the degradation of Naphthenic Acids (NAs) in oil sands process-affected water (OSPW), a series of semi-batch ozonation experiments have been conducted resulting in a maximum reduction of NAs greater than 99%. Compared to the high NAs removal, the reduction of both COD and DOC was much lower under the same conditions. Following ozone treatments of approx. 80 mg/L, the cBOD5 and cBOD5/COD tripled as compared to original OSPW measurements, suggesting ozone-treated OSPW has a higher biodegradability. The ozone treatments also detoxified the OSPW; with an ozone treatment of approx. 100 mg/L, the treated OSPW showed no toxicity using the Mircotox® bioassay. Additionally, the coke-treated OSPW, treated using a coke/water slurry process, was found to be non-toxic with an ozone treatment of approx. 20 mg/L. The results obtained during this study shows the great potential ozonation may offer as a possible water treatment application for oil sands water management. / Environmental Engineering

[Truncated abstract] As mineral deposits continue to be mined, the non economic gangue materials such as sulphides (e.g. pyrite) that are extracted as part of the ore body or overburden are deposited within the waste rock and/or milled tailings. As a result of natural weathering processes, these reactive materials represent a potential hazard to surrounding environments. A major consequence, resulting from mine-waste impoundments containing sulphidic materials, relates to the offsite movement of low pH leachates containing elevated concentrations of metal ions posing a contamination threat. The processes and mechanisms acting in the formation of acid mine drainage (AMD) are highly variable and, to a high extent, controlled by climatic conditions as the main driver of water flow and wetness of the system which in turn determines the availability of oxygen as well as water for pyrite weathering. In particular, this thesis is based on the hypothesis that in semiarid and arid climates the acid production may be water … The experiments were repeated at different water contents ranging from 0.24 to 0.33 cm3 cm-3. Breakthrough curves (BTC) of Li+, K+, Ca2+, Mg2+, Na+ and pH were measured and described with models of different complexities. This included the use of a simple linear and non-linear isotherms for Li+ alone, a binary Li+ - K+ ion exchange, and a complete multicomponent chemical equilibrium description of ion transport. The latter, by including dissolution of primary minerals which released base cations such as Mg2+, Ca2+ and K+ explained some of the elution patterns of base cations for which the Li+ - K+ exchange was the dominant process. Furthermore, under unsaturated water flow conditions, retardation of Li+ increased with decreasing water content. Thus solute mobility in mafic rock tailings appears to decrease under strongly unsaturated water flow conditions.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1982. / Includes bibliographical references (leaves 159-162).

Thesis (PhD(Geotechnical)(Civil and Biosystems Engineering)) --University of Pretoria, 2007. / Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 62-68). Also available via the Internet.

Thesis (M.Eng.) - Carleton University, 2001. / Includes bibliographical references (p. 156-158). Also available in electronic format on the Internet.

Thesis (M.Eng.)(Geotechnical)--University of Pretoria, 2004. / Includes summary. Includes bibliographical references.

Thesis (M.L.(Prof.))--University of Pretoria, 2004. / Includes summary. Includes bibliographical references.