Removal of Organic and Inorganic Contaminants from Oil Sands Tailings using Carbon Based Adsorbents and Native Sediment

Abstract

The extraction and refinement of oil sands bitumen produces substantial quantities of liquid tailings and solid coke. Tailings contain metals and naphthenic acids, which require remediation before mine closure. Adsorption is a potential remediation technique which may reuse stockpiled petroleum coke. This thesis investigates the adsorption of contaminants on sediment, petroleum coke and biochar. The determination of naphthenic acid concentration using ESI-FTICR-MS was also explored. Results suggest limited adsorption of naphthenic acids on sediment occurred, while petroleum coke and biochar removed elevated concentrations of naphthenic acids and metals. Pretreating petroleum coke by acid washing increased its ability to adsorb contaminants by removing surface bound impurities. Electrospray ionization was a strong semi-qualitative tool for naphthenic acid measurement, but deviated significantly from other methods for quantitative measurement. In summary, the adsorption of oil sands contaminants is feasible using carbonaceous adsorbents. Metal release was limited when pretreated petroleum coke and biochar was used.