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The reclamation of mature fine tailings (MFT) is a critical challenge for the oil sands industry in western Canada, and a nonradioactive, automated, and inexpensive method to monitor the MFT solidification is needed. The objective of this paper is to evaluate the feasibility of a dual-probe heat pulse (DPHP) method to measure MFT solid percentage. Dual-probe heat pulse measurements were performed on three MFT samples, each at various solid percentages. A linear relationship (y = 0.9495x + 0.0558) was established between the DPHP-measured solid percentage (y) and that of oven-dry method (x). Six additional MFT samples were collected and measured to validate the DPHP method. The specific heats of the six MFT solids were measured independently using a modulated differential scanning calorimetry method, and the sensitivity of DPHP-measured MFT solid percentage to the specific heat of MFT solids was evaluated. The result shows that the DPHP method can be used to accurately measure MFT solid percentages, and the accuracy can be further improved if the specific heat of the MFT solids is measured independently. [ABSTRACT FROM AUTHOR]

Saturated hydraulic conductivity (Ks) is an important soil hydraulic property that affects water flow and the transport of dissolved solutes. Obtaining sufficient and reliable Ks data for large-scale process modeling is always a challenge due to the extremely high spatial variability. The objectives of this study were (i) to determine if a monofractal or multifractal approach is needed to describe the variability in Ks and its soil surrogates, and (ii) to identify which soil property best reflects the spatial distribution of Ks across a wider range of scales. Saturated hydraulic conductivity and soil physical property data were collected from a 384-m transect, located at Smeaton, 5K, Canada. Observation scale variability and relationships were examined using statistical and geostatistical methods. Statistical scale-invariance was evaluated through the Hurst scaling parameter (H). Multiple scale variability and relationships were studied using multifractal and joint multifractal techniques. Results indicate that for all the studied vari- ables 0.80 < H < 0.90, suggesting a certain degree of statistical scale-invariance and long-range dependency. At the observation scale, the variability in Ks was significantly related to sand (SA) and silt (SI) distribution (R = 0.40 for SA and -0.39 for SI, P < 0.01; n = 128), whereas, across a wider range of scales, the variability in Ks was related only to clay (CL) and organic C (OC). The result indicates scale dependent relationships between Ks and soil physical properties, which implies that the success of predictive models such as pedotransfer functions (PTFs) and Ks aggregation techniques depends largely on the correspondence between observation and implementation scales. [ABSTRACT FROM AUTHOR]