Suncor south tailings pond research program : geotechnical investigations

This study investigated the geochemical impact of seepage from an oil sands tailings impoundment on sediments and groundwater resources at Suncor Energy's south tailings pond. The study examined the potential for attenuation of inorganic contaminants and trace metal releases. Binding capacity was investigated in relation to seepage interactions with native sediments. Cations displaced through interactions with ingressing process water were characterized. The study hypothesized that ion sorption affinity was governed by ion charge; size; properties of the solid exchanger; the quantity and ratios of the various solutes; and the total solution concentration. Batch sorption studies were conducted to investigate the effects of adsorptive and ion exchange reactions on the mitigation and mobilization of major cations and trace metals. Models were designed to simulated the capture system behaviour of most major cations. The study demonstrated that the sodium (Na) will replace calcium (Ca) and magnesium (Mg) and precipitate out as CO3 salts. It was concluded that the ion exchange theory offers a suitable explanation of Ca and Mg system behaviour. tabs., figs.