No description available.

No description available.

In order to determine the degradation of Naphthenic Acids (NAs) in oil sands process-affected water (OSPW), a series of semi-batch ozonation experiments have been conducted resulting in a maximum reduction of NAs greater than 99%. Compared to the high NAs removal, the reduction of both COD and DOC was much lower under the same conditions. Following ozone treatments of approx. 80 mg/L, the cBOD5 and cBOD5/COD tripled as compared to original OSPW measurements, suggesting ozone-treated OSPW has a higher biodegradability. The ozone treatments also detoxified the OSPW; with an ozone treatment of approx. 100 mg/L, the treated OSPW showed no toxicity using the Mircotox® bioassay. Additionally, the coke-treated OSPW, treated using a coke/water slurry process, was found to be non-toxic with an ozone treatment of approx. 20 mg/L. The results obtained during this study shows the great potential ozonation may offer as a possible water treatment application for oil sands water management. / Environmental Engineering

Due to a policy of no release, oil sands process-affected water (OSPW) produced by the surface-mining oil sands industry in North Eastern Alberta, Canada, is stored on-site in tailings ponds. There is concern regarding the toxic effects of OSPW on aquatic organisms. Knowledge of the chemical composition and toxicity of OSPW is limited. Research is necessary for potential remediation and release of OSPW back into the environment. Due to the large volume and persistency of OSPW, active efforts are necessary for the remediation of OSPW before release and habitat reclamation. Currently, ozonation is considered one possible method for remediation of OSPW by reducing the concentrations of dissolved organic compounds, including naphthenic acids (NAs), which are considered among the primary toxic constituents. However, further work is needed to evaluate the effectiveness of ozonation in reducing the toxicity of OSPW and to ensure that ozonation does not increase the toxicity of OSPW. The overall objective of this work was to determine the toxic effects of OSPW on endocrine disruption and embryo development, using both in vitro and in vivo models, and the effectiveness of ozone treatment for reducing the toxicity of OSPW. In the first study, untreated and ozone-treated OSPW were examined for effects on sex steroid production using the H295R cell line steroidogenesis Assay. The results indicate that exposure to untreated OSPW can significantly decrease synthesis of testosterone (T) and increase synthesis of 17β-estradiol (E2) by 0.55±0.06 and 2.0±0.13-fold, respectively, compared to that of control groups (ρ < 0.05). These effects were due to increased aromatase enzyme activity and decreased E2 metabolism. The results also suggest that ozonation is an effective treatment to reduce concentrations of NAs in OSPW without altering steroidogenesis. In the second study, the T47D-kbluc (estrogen responsive) and MDA-kb2 (androgen responsive) cell assays were used to determine whether OSPW might act as either agonists or antagonists of the estrogen receptor (ER) or androgen receptor (AR), respectively. The estrogenic responses to untreated OSPW were significantly greater by 2.6±0.22-fold compared to control group (ρ < 0.05). Exposure to untreated OSPW produced significant antiandrogenic response in the presence of 0.01, 0.05 and 0.1 nM T by 16±6.5%, 47±7.6% and 75±9.7%, respectively, of that of the corresponding concentrations of T alone (ρ < 0.05). The results suggest that compounds in the dissolved organic fraction of OSPW have estrogenic and anti-androgenic properties, acting as ER agonists and/or AR antagonists. Ozonation of the OSPW partially mitigated the antiandrogenicity but had no effect on the estrogenicity of OSPW. In the third study, the endocrine-disrupting effects of OSPW and ozone-treated OSPW were determined by quantifying relative changes in the abundances of transcripts of genes along the brain-gonad-liver (BGL) axis in male and female fathead minnows (Pimephales promelas). The results indicate that OSPW has endocrine-disrupting effects at all levels of BGL axis and these effects of impaired expression of genes along the BGL axis are sex specific. For example, exposure to OSPW resulted in significantly greater abundances of transcripts of vtg (Vitellogenin), chg-l (Choriogenin L) and chg-h (Choriogenin H minor) by 4.9±1.2, 5.4±1.5 and 3.4±0.78-fold, respectively, compared to those of control groups (ρ < 0.05) in livers from male fathead minnow. However, in livers from female fathead minnows, exposure to OSPW resulted in significantly lesser abundances of transcripts of vtg, chg-l and chg-h by 0.002±0.0011, 0.022±0.007 and 0.036±0.024-fold, respectively, compared to those of control fish (ρ < 0.05). Ozonation of OSPW attenuated the effects on abundances of transcripts of some genes, and the attenuation was more prominent in males than in females. However, impact of ozonation on endocrine-disrupting effects of OSPW was less evident than in the in vitro studies described in Chapter 2 and 3. The results also provide a mechanistic basis for the endocrine-disrupting effects of OSPW from other studies, including impaired reproduction of fathead minnows exposed to OSPW. In the final study the effects of untreated, ozone-treated, and activated charcoal-treated OSPW (OSPW, O3-OSPW, and AC-OSPW) on the survival, growth, and development of embryos of fathead minnows were determined. Compared to the control group, which had an embryo survival rate of 98±2.1%, survival was significantly less when exposed to OSPW (44±7.1%; ρ < 0.05). Eggs exposed to untreated OSPW exhibited a significantly greater rate of premature hatching, and embryos exhibited more frequent spontaneous movements. Incidences of hemorrhage (50±3.4%), pericardial edema (56±7.1%), and malformation of the spine (38±5.4%) were significantly greater in embryos exposed to OSPW compared to control group (ρ < 0.05). Significantly greater concentrations of ROS (1.7±0.11-fold), and greater abundances of transcripts cyp3a, gst, sod, casp9, and apopen (2.4±0.34, 2.2±0.26, 3.1±0.74, 3.3±0.57 and 2.4±0.25-fold, respectively) compared to control groups (ρ < 0.05), indicated that exposure to OSPW caused oxidative stress, which can result in damage to mitochondria and promote activation of caspase enzymes and apoptotic cell death. Removal of dissolved organic constituents in OSPW by ozone treatment, or by activated charcoal, significantly attenuated all of the adverse effects associated with untreated OSPW. The results suggest that the organic fraction of OSPW can negatively impact the development of fathead minnow embryos through oxidative stress and apoptosis, and that ozonation attenuates this developmental toxicity. Overall, the findings from the research described in this thesis provide novel and important insights into the toxicity and mechanisms of the toxicity of OSPW with respect to endocrine disruption and development of embryos of fish. In addition, the research provides compelling evidence that ozonation might be an effective method for accelerating the remediation of OSPW. The results of the research might help regulators develop effective strategies for reclamation, remediation and potential release of OSPW back to the environment.

The In Situ Aquifer Test Facility (ISATF) has been established on Suncor Energy Inc’s (Suncor) oil sands mining lease north of Fort McMurray, Alberta to investigate the fate and transport of oil sands process-affected (PA) water in the Wood Creek Sand Channel (WCSC) aquifer. In 2008, the ISATF was used for preliminary injection experiments in which 3,000 and 4,000 L plumes of PA water were created in the WCSC. Following injection, the evolution of the plumes was monitored to determine if naphthenic acids (NAs) naturally attenuated in the WCSC and if trace metals were mobilized from the aquifer solids due to changes in redox conditions. Post-injection monitoring found groundwater velocities through the aquifer were slow (~3-10 cm/day) despite hydraulic conductivities on the order of 10-3 m/s. While microbes in the WCSC were capable of metabolizing acetate under the manganogenic/ferrogenic redox conditions, field evidence suggests naphthenic acids behaved conservatively. Following the injections, there was an apparent enrichment in the dissolved concentrations of iron, manganese, barium, cobalt, strontium and zinc not attributable to elevated levels in the PA injectate. Given the manganogenic/ferrogenic conditions in the aquifer, Mn(II) and Fe(II) were likely released through reductive dissolution of manganese and iron oxide and oxyhydroxide mineral coatings on the aquifer solids. Because naphthenic acids make up the bulk of dissolved organic carbon (DOC) in the injectate and are apparently recalcitrant to oxidation in the WCSC, some question remains as to what functioned as the electron donor in this process.

The In Situ Aquifer Test Facility (ISATF) has been established on Suncor Energy Inc’s (Suncor) oil sands mining lease north of Fort McMurray, Alberta to investigate the fate and transport of oil sands process-affected (PA) water in the Wood Creek Sand Channel (WCSC) aquifer. In 2008, the ISATF was used for preliminary injection experiments in which 3,000 and 4,000 L plumes of PA water were created in the WCSC. Following injection, the evolution of the plumes was monitored to determine if naphthenic acids (NAs) naturally attenuated in the WCSC and if trace metals were mobilized from the aquifer solids due to changes in redox conditions. Post-injection monitoring found groundwater velocities through the aquifer were slow (~3-10 cm/day) despite hydraulic conductivities on the order of 10-3 m/s. While microbes in the WCSC were capable of metabolizing acetate under the manganogenic/ferrogenic redox conditions, field evidence suggests naphthenic acids behaved conservatively. Following the injections, there was an apparent enrichment in the dissolved concentrations of iron, manganese, barium, cobalt, strontium and zinc not attributable to elevated levels in the PA injectate. Given the manganogenic/ferrogenic conditions in the aquifer, Mn(II) and Fe(II) were likely released through reductive dissolution of manganese and iron oxide and oxyhydroxide mineral coatings on the aquifer solids. Because naphthenic acids make up the bulk of dissolved organic carbon (DOC) in the injectate and are apparently recalcitrant to oxidation in the WCSC, some question remains as to what functioned as the electron donor in this process.

As part of their reclamation plan, oil sands operators propose to transfer the mature fine tailings, which are a by-product of the oil sands extraction process, to open-pits and cap them with either a layer of surface water or oil sands process-affected waters (OSPW). These oil sands pit lakes are expected to develop habitats with productive capabilities comparable to natural lakes in the region. The studies presented in this thesis evaluate the potential impact of OSPW and its associated constituents [i.e. acid-extractable organics (e.g. naphthenic acids; NAs) and salts] on the reproductive physiology of adult fathead minnow (Pimephales promelas). Through 14-21 day fathead minnow reproduction assays it was demonstrated that aged OSPW can impair spawning, lower plasma sex steroid concentrations, and reduce male secondary sexual characteristics. The acid-extractable organics in OSPW were demonstrated to have an adverse effect on fathead minnow reproductive physiology. Other studies showed that the high salinity which characterizes OSPW also influences toxicity. When fathead minnows were exposed to the OSPW extract and 700 mg/l of NaHCO3, the NaHCO3 reduced the inhibitory effects of the extract on the numbers of reproductive tubercles and plasma testosterone levels by reducing the uptake of NAE to the fish. Embyro and larval bioassays also revealed that NaHCO3 reduces the acute toxic effects of the OSPW extract. An assessment of a wild population of fathead minnows inhabiting an OSPW pond determined that there were differences in the condition factor (CF), gonadosomatic indices (GSIs), liver somatic indices (LSIs), male secondary sexual characteristics, and 11-ketotestosterone concentrations in the fathead minnows from the OSPW pond relative to fish collected at reference sites. The opercula of fathead minnows from the OSPW pond also differed from those of reference fish and an examination of the gills revealed that were a number of proliferative and degenerative alterations relative to reference fish. Collectively, these studies demonstrate that aged OSPW has the potential to negatively affect the reproductive physiology of fathead minnows and suggest that aquatic habitats with high NAs concentrations (>10 mg/l) will have adverse effects on fish. / Canadian Natural Resources Ltd., Canadian Water Network, Canadian Oil Sands Network for Research and Development (CONRAD), Imperial Oil Ltd., NSERC, Shell Canada Energy, Suncor Energy Inc., Syncrude Canada Ltd., and Total E&P Canada

No description available.

An essential element of the reclamation strategy proposed by the oil sands mining industry in northern Alberta, Canada, includes the creation of wetlands for the bioremediation of mining waste materials. The mining process used to extract oil from these deposits results in the production of large volumes of process-affected water (OSPW) and sediments (OSPS), which must be incorporated into wetlands as a component of the reclaimed landscapes. Wood frogs (<i>Rana sylvatica</i>) are an abundant native species that might be expected to inhabit these reclaimed wetlands. The objective of this study was to determine potential detrimental effects of OSPW and OSPS on the growth and development of wood frogs. Several morphological (weight, length, condition factor) and biochemical (whole body tadpole thyroid hormone and triglyceride concentrations and metamorph hepatic glycogen concentration) endpoints were assessed in conjunction with hatchability and survivability of wood frog eggs and tadpoles exposed to process-affected materials (OSPM) under field and laboratory conditions.<p> As part of this study, assay techniques were optimized to enable simultaneous measurement of whole body 3,5,3-triiodothyronine (T3), thyroxine (T4) and triglyceride (TG) concentrations in wood frog tadpoles. These assays were used to monitor changes in T3, T4 and TG in wood frog tadpoles during development from hatching to metamorphosis (Gosner stages 19-46), to establish baseline levels for subsequent application of the assays to evaluate contaminant effects. The results indicated peak T3 and T4 concentrations occurred during metamorphic climax (Gosner stages 40-46) and prometamorphosis (Gosner stages 31-40), respectively. Maximal TG concentrations were also observed during prometamorphosis. These assays were further employed to assess body condition and development in wood frogs during a field study in 2005, and the following laboratory studies in 2006 and 2007.<p> In summer 2005, 29 reclaimed and five unimpacted wetlands were monitored for use by native amphibians, and tadpoles and newly-metamorphosed wood frogs were collected from a subset of sites as a preliminary assessment of contaminant effects. Endpoints such as metamorph hepatic glycogen and whole body tadpole T3, T4 and triglyceride concentrations were compared among six impacted and three reference wetlands. The surveys indicated 60% of OSPW-impacted wetlands were used by breeding adult amphibians, while wood frog tadpoles and newly-metamorphosed frogs were observed in 37 and 30% of OSPW wetlands, respectively. In general, lower whole body tadpole T3 and triglyceride concentrations were observed in wood frogs from wetlands containing OSPM. In contrast, hepatic glycogen concentrations in newly-metamorphosed frogs and whole body tadpole T4 and T3/T4 concentrations were comparable among the reference and impacted wetlands. In addition, the differences observed in total body weight and length of tadpoles and newly-metamorphosed wood frogs among OSPM and reference sites were likely due to minor differences in developmental stages of the animals collected from the various wetlands, rather than any contaminant effect.<p> In 2006 and 2007, wood frog eggs and tadpoles were exposed to several sources of OSPW and OSPS collected from reclaimed Suncor and Syncrude wetlands under controlled laboratory conditions. Hatchability was reduced in eggs exposed to water from only one of the OSPW sites, compared with the other process-affected ponds and the control water (P<0.05). In contrast, survivability of tadpoles was significantly reduced (P<0.05) in all the impacted sites in both years, with nearly all OSPW sites having <10% survival. The exposure study evaluated the toxicity of five types of OSPS. Results indicated no impact of OSPS exposure on survivability of tadpoles, but showed reduced whole body weight (in three OSPS treatments), length (in two OSPS treatments) and body condition (in one OSPS) of tadpoles exposed to process-affected substrates tested (P<0.05). Whole body T3 and T4 concentrations in tadpoles from OSPS treatments were not different from the control treatment, but tadpole TG concentration was reduced in groups exposed to two impacted substrates (P<0.05). Water quality measurements, including determination of dissolved metals were conducted in an initial attempt to relate any potential toxic effect on wood frog growth and development to specific contaminants.<p> Results of the laboratory studies strongly suggest that exposure to OSPW and OSPS may adversely affect wood frog growth and survival. However, these findings were not entirely consistent with field observations and results of concurrent mesocosm studies. Further research is therefore needed to fully evaluate the suitability of reclaimed oil sands wetlands to support indigenous amphibian population. Future work should focus on the cumulative effects of water and substrates, as well as the effect of OSPM ageing on acute and chronic toxicity.

An essential element of the reclamation strategy proposed by the oil sands mining industry in northern Alberta, Canada, includes the creation of wetlands for the bioremediation of mining waste materials. The mining process used to extract oil from these deposits results in the production of large volumes of process-affected water (OSPW) and sediments (OSPS), which must be incorporated into wetlands as a component of the reclaimed landscapes. Wood frogs (<i>Rana sylvatica</i>) are an abundant native species that might be expected to inhabit these reclaimed wetlands. The objective of this study was to determine potential detrimental effects of OSPW and OSPS on the growth and development of wood frogs. Several morphological (weight, length, condition factor) and biochemical (whole body tadpole thyroid hormone and triglyceride concentrations and metamorph hepatic glycogen concentration) endpoints were assessed in conjunction with hatchability and survivability of wood frog eggs and tadpoles exposed to process-affected materials (OSPM) under field and laboratory conditions.<p> As part of this study, assay techniques were optimized to enable simultaneous measurement of whole body 3,5,3-triiodothyronine (T3), thyroxine (T4) and triglyceride (TG) concentrations in wood frog tadpoles. These assays were used to monitor changes in T3, T4 and TG in wood frog tadpoles during development from hatching to metamorphosis (Gosner stages 19-46), to establish baseline levels for subsequent application of the assays to evaluate contaminant effects. The results indicated peak T3 and T4 concentrations occurred during metamorphic climax (Gosner stages 40-46) and prometamorphosis (Gosner stages 31-40), respectively. Maximal TG concentrations were also observed during prometamorphosis. These assays were further employed to assess body condition and development in wood frogs during a field study in 2005, and the following laboratory studies in 2006 and 2007.<p> In summer 2005, 29 reclaimed and five unimpacted wetlands were monitored for use by native amphibians, and tadpoles and newly-metamorphosed wood frogs were collected from a subset of sites as a preliminary assessment of contaminant effects. Endpoints such as metamorph hepatic glycogen and whole body tadpole T3, T4 and triglyceride concentrations were compared among six impacted and three reference wetlands. The surveys indicated 60% of OSPW-impacted wetlands were used by breeding adult amphibians, while wood frog tadpoles and newly-metamorphosed frogs were observed in 37 and 30% of OSPW wetlands, respectively. In general, lower whole body tadpole T3 and triglyceride concentrations were observed in wood frogs from wetlands containing OSPM. In contrast, hepatic glycogen concentrations in newly-metamorphosed frogs and whole body tadpole T4 and T3/T4 concentrations were comparable among the reference and impacted wetlands. In addition, the differences observed in total body weight and length of tadpoles and newly-metamorphosed wood frogs among OSPM and reference sites were likely due to minor differences in developmental stages of the animals collected from the various wetlands, rather than any contaminant effect.<p> In 2006 and 2007, wood frog eggs and tadpoles were exposed to several sources of OSPW and OSPS collected from reclaimed Suncor and Syncrude wetlands under controlled laboratory conditions. Hatchability was reduced in eggs exposed to water from only one of the OSPW sites, compared with the other process-affected ponds and the control water (P<0.05). In contrast, survivability of tadpoles was significantly reduced (P<0.05) in all the impacted sites in both years, with nearly all OSPW sites having <10% survival. The exposure study evaluated the toxicity of five types of OSPS. Results indicated no impact of OSPS exposure on survivability of tadpoles, but showed reduced whole body weight (in three OSPS treatments), length (in two OSPS treatments) and body condition (in one OSPS) of tadpoles exposed to process-affected substrates tested (P<0.05). Whole body T3 and T4 concentrations in tadpoles from OSPS treatments were not different from the control treatment, but tadpole TG concentration was reduced in groups exposed to two impacted substrates (P<0.05). Water quality measurements, including determination of dissolved metals were conducted in an initial attempt to relate any potential toxic effect on wood frog growth and development to specific contaminants.<p> Results of the laboratory studies strongly suggest that exposure to OSPW and OSPS may adversely affect wood frog growth and survival. However, these findings were not entirely consistent with field observations and results of concurrent mesocosm studies. Further research is therefore needed to fully evaluate the suitability of reclaimed oil sands wetlands to support indigenous amphibian population. Future work should focus on the cumulative effects of water and substrates, as well as the effect of OSPM ageing on acute and chronic toxicity.