Oil Sands Extraction Research Articles

A study of sulphur dioxide deposition velocities to snow in northern Canada

In March 1976, a sulphur deposition study was conducted by sampling snow at about 55 sites around an isolated oil sand extraction plant in north-eastern Alberta, Canada. It was concluded from sulphur budget considerations that 0.14% of the sulphur emitted by the source was deposited within a radius of 25km. An SO 2 deposition velocity to snow of 0.25 ± 0.20 cm s −1 was determined by simultaneously measuring sulphur deposition and ambient concentration during a pollution episode. Deposition velocities were also obtained by dividing the measured sulphur deposition rate at each site by the average ground level concentration of sulphur dioxide, computed using the Climatological Dispersion Model A set of 40 log normally distributed deposition velocities resulted with a geometric mean of 0.3–0.4cm s −1 depending on what value of background deposition was chosen. Confidence limits for the geometric mean were 0.2–0.7 cm s −1 (68% confidence) or 0.1–1.3 cm s −1 (95% confidence).

Physical characterization and microbiological settling-rate modification of aqueous suspensions from hot-water-process oil-sands extraction

Sealed samples of specific aqueous hot-water-process-tar-sands-extraction streams and tailings pond sludges have been examined microbiologically and shown to contain compatible micro-organisms. Portions of these have been treated aerobically and anaerobically, with and without added nutrient, to encourage hydrocarbon utilization, and the results compared with experiments conducted with untreated and boiled control samples. While both aerobes and anaerobes appear to be indigenous in the matrices examined, aerobic treatment with nutrient present was found to give optimum solids-settling performance, and anaerobic treatment negligible short-term settling effect, although a slight improvement was noted for longer-term tests.

Toxicity of Oil Sands Plant Wastewaters and Associated Organic Contaminants

Abstract Acute toxicity testing using rainbow trout (Salmo gairdneri Richardson) was conducted on two wastewater streams from an oil sands extraction and upgrading plant. The main effluent stream from the upgrading plant was non-acutely toxic in flow-through bioassay while the construction drainage from the tailings pond dyke was acutely lethal in static bioassay with an extrapolated LC50 of 11% (by volume). With no obvious toxicant present, trace organic analysis was undertaken based on the high indeterminate organic carbon content of the sample. Analysis by GC-MS of the sample was able to identify four compounds: 2, 6-di-tert-butyl-p-cresol, (BHT); di-n-butyl phthalate, (DBP); bis (2-ethylhexyl) adipate, (BEHA); and bis (2-ethylhexyl) phthalate, (BEHP). Toxicity testing of the compounds required the evaluation of various schemes for the preparation of the test mixtures. Direct emulsion of the test compounds in water was ultimately adopted. Ninety-six hour static bioassays with rainbow trout indicated LC50 values of 540 mg/l for BEHP, 3 mg/l for BHT, 1.2 mg/l for DBP, and an approximate range of 54–110 mg/l for BEHA. Loss of emulsified components from the test mixture during the bioassays suggested that calculated LC50 values likely underestimate the actual toxicity of the compounds. The contribution by BEHA and BEHP to the whole effluent toxicity was likely minor while BHT and DBP indicated sufficient acute lethal toxicity to warrant further consideration. The feasibility of trace organic analysis and component toxicity testing as a means for conducting longer term research on oil sands wastewaters was demonstrated.