Physicochemical gradients, diffusive flux, and sediment oxygen demand within oil sands tailings materials from Alberta, Canada

Biogeochemical Characterization of Metal Behavior from Novel Mussel Shell Bioreactor Sludge Residues

“…Although no increase in H 2 S was observed in the water cap of these experiments, it suggests that the observed decrease of measurable sulfide flux may in part be due to secondary processes (e.g., sulfide precipitation or a decrease in sulfur reducing bacteria). This result is similar to those found in Reid et al [21] and was suggested to be related to the formation of sulfides causing an increase in porosity. Sulfides, such as FeS 2 have a defined crystalline cubic structure.…”

“…A 2 × 2 experimental design (with replicates) allowed two environmental conditions (anoxic and oxic) to be tested, and determined the microbial impact (biotic vs. abiotic) on the sludge. This study design has been used in numerous past studies to address environmental impacts of various materials [20][21][22]. The four experimental conditions discussed in this study are biotic anoxic, abiotic anoxic, biotic oxic, and abiotic oxic.…”

“…HS − , O 2 , and redox microelectrode sensors (Unisense Science, Denmark) were used to measure vertical gradients approximately 1 cm above and 1 cm below the sediment water interface, a method developed by Revsbech, (1989) [23] but more explicitly following methods by Reid et al (2016) [20]. The sensor measurements were taken near the center of the mesocosm, and before each sediment sampling period, so the profiles would be undisturbed.…”