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Made available in DSpace on 2018-08-01T21:58:47Z (GMT). No. of bitstreams: 1 tese_10597_Dissertação Tamires FINAL 08042017.pdf: 3045708 bytes, checksum: 346790de110160baf3a5382b4013c028 (MD5) Previous issue date: 2017-02-20 / O petróleo ainda continua sendo a maior fonte de energia não renovável do planeta. No seu estado bruto tem pouca utilidade. No entanto, seus derivados apresentam alto valor econômico. Nas etapas de processamento primário do petróleo alguns compostos de ocorrência natural são indesejáveis, como os ácidos naftênicos, resinas, asfaltenos, compostos sulfurados e metálicos. O poder corrosivo dos ácidos naftênicos preocupa as indústrias petrolíferas devido ao prejuízo causado nas tubulações e refinarias. Estudos recentes indicam que uma parcela desses ácidos quando submetidos a elevadas temperaturas (>280°C) pode sofrer reações de descarboxilação e degradação térmica, originando dióxido de carbono (CO2) e ácidos de cadeias menores como produtos de degradação. Os ácidos de cadeias menores juntamente com os ácidos naftênicos que se mantiveram preservados são corrosivos e o CO2 ao entrar em contato com água forma o ácido carbônico (H2CO3), podendo contribuir nas taxas de corrosão nos equipamentos do refino. Assim, o presente trabalho consistiu no desenvolvimento de uma metodologia para quantificação online do CO2 liberado no processo de destilação de petróleo. A metodologia desenvolvida foi baseada na técnica de microcromatografia gasosa. Os dados quantitativos de concentração de CO2 gerados pela microcromatografia foram relacionados com os valores de temperaturas de destilação, obtendo-se assim uma variação na concentração de CO2 de acordo com a temperatura de destilação do óleo. Com os resultados obtidos observou-se que para todos os petróleos destilados houve uma tendência na formação do gás CO2 partir de temperaturas superiores a 200°C. Na tentativa de elucidar a possível origem deste gás, supôs um mecanismo de descarboxilação para tais ácidos

The overall objective of these experiments was to augment our understanding of how naphthenic acids stimulate metabolism and growth of bean plants. Three separate studies were carried out with bush bean plants (Phaseolus vulgaris L. cultivar Top Crop) to determine: 1) the effect of potassium naphthenates (KNap) on the uptake, distribution, and incorporation of phosphorus-32, 2) the metabolism of the individual naphthenic acid, potassium cyclohexanecarboxylate (KCHC), in leaves and roots, and 3) the effect of KNap and KCHC on the uptake and metabolism of glucose by excised root tips. 1) Fourteen-day-old plants growing in a phosphate-free (-P) or a complete (+P) nutrient solution were sprayed to drip with a 0.5% solution of KNap. Twenty-four hours after spraying, the roots of both control and treated plants were exposed for 2 hours to a nutrient solution containing ³²P. Following the exposure to ³²P, the plants were returned to their original nutrient solutions. Control and treated plants were withdrawn 4, 8, 12, and 24 hours after exposure to ³²P, and were separated into leaf blades, stems, and roots. Acid soluble, acid insoluble, and total ³²P activity, or total phosphorus were determined at each sampling time. KNap treatment increased by 7 to 9% the intake of ³²P by plants grown in the -P or +P nutrient solution. The increases, however, lacked statistical significance at the 0.05 level. The rate at which ³²P was translocated out of the roots of plants grown in the -P nutrient only was increased significantly by treatment, in spite of the fact that at the 24 hour sampling time 84% of the total ³²P label remained in root tissues. At the same sampling time 32% of the total ³²P label was found in the roots of plants grown in the +P nutrient. While KNap treatment significantly increased ³²P activity in stems of -P grown plants over the sampling period, activity in stems of control and treated plants grown in the +P nutrient was similar. Naphthenate treatment increased the rate of incorporation of ³²P into both the acid soluble (sugar phosphates, nucleotides, phospholipids) and acid insoluble (nucleic acids, phosphoproteins) fractions of leaves of plants grown in the +P nutrient solution. Acid soluble ³²P activity declined in all root tissues over the sampling period as acid soluble ³²P-containing compounds, primarily orthophosphate, were translocated acropetally. The percentage acid insoluble ³²P activity in the roots of KNap-treated plants was significantly greater than that found in the roots of control plants at the 24 hour sampling time. Naphthenate treatment did not affect the amount of total P (³¹P + ³²P) in the two P fractions of the three plant organs. The augmented incorporation of ³²P into the acid soluble and acid insoluble fractions is further evidence of the KNap-stimulated P metabolism reported by other workers. 2) KCHC-7-¹⁴C administered to leaf disks in the light or to roots of intact seedlings in the dark was rapidly converted to a mixture of two conjugated metabolites: the glucose ester and the aspartic acid amide. The root-feeding experiment indicated that following their synthesis in root tissues both conjugates were translocated acropetally. The results of amino acid analyses of the acid hydrolysates of several unidentified metabolites strongly suggest that KCHC-7-¹⁴C was also conjugated with a low molecular weight polypeptide. 3) Three sets of root tips cut from 7-day-old seedlings were incubated in a medium containing ¹⁴C glucose for 3 hours. Two of the three sets were pretreated in a solution of KCHC or KNap for 6 hours. Each naphthenate treatment significantly increased ¹⁴C activity in the ethanol-soluble (amino acids, glucose, etc.), ethanol-insoluble (polysaccharides, protein, etc.), and respired CO₂ fractions. The individual naphthenic acid, KCHC, had the greater effect on the uptake and metabolism of labelled glucose. Results also indicated that not only were the uptake of glucose and CO₂ production increased significantly by each treatment, but also amino acids containing the glucose carbon passed more quickly through soluble amino acid pools in root tissues, and were more rapidly fixed into protein. In light of the finding that naphthenate conjugates and not the free acid were detected in the tissue, it may be that the conjugates were associated in a causal way with the stimulated uptake and metabolism of labelled glucose. / Science, Faculty of / Botany, Department of / Graduate

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<p>In general, the research focuses on sequestration of naphthenic acids (NAs) from simulated oil sands process water (OSPW) conditions using engineered copolymers known as &beta;-cyclodextrin-based polyurethanes. The thesis research is divided into two main parts; <i>i)</i> synthesis and characterization of &beta;-cyclodextrin-based polyurethanes, and <i>ii)</i> sorption studies of the copolymer materials with NAs from aqueous solutions.</p> <o>In the first part, &beta;-cyclodextrin (&beta;-CD) was crosslinked with five types of linker molecules, respectively, under various synthetic conditions. The various diisocyanates investigated as linkers include the following: 1,6-hexamethylene diisocyanate (HDI), 4,4'-dicyclohexylmethane diisocyanate (CDI), 4,4'-diphenylmethane diisocyanate (MDI), 1,4-phenylene diisocyanate (PDI) and 1,5-naphthalene diisocyanate (NDI). The polyurethanes (PUs) were systematically designed at different mole ratios of monomers by maintaining &beta;-CD and varying the relative mole ratio of diisocyanate monomer from unity to greater values. Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFTS), solid state ¹³C CP-MAS NMR, solution state ¹H/¹³C NMR spectroscopy, thermogravimetric analysis (TGA), elemental analysis (CHN), nitrogen porosimetry, and a dye-based (p-nitrophenol; PNP, and phenolphthalein; phth) sorption method were used to characterize the copolymer materials. In general, the &beta;-CD PUs were insoluble in water except for &beta;-CD crosslinked with HDI at the 1:1 mole ratio which was moderately water soluble. All techniques show complementary results about the structural and compositional characterization, particularly for the estimation of the ratios between the co-monomers. The optimal preparation of copolymer materials for sorption-based applications occurs for &beta;-CD/linker monomer mole ratios from 1:1 to 1:3. There is a maximum limit of the crosslinking density which is ~ 1:7 (&beta;-CD:linker) according to the steric effects of the substituents in the annular region of &beta;-CD. Also, the copolymers were generally found to be mesoporous with relatively low surface area (BET; ~10¹ m²/g) and they appear to exhibit swelling in aqueous solution due to hydration as observed from the estimation of the dye-based surface areas using PNP. The surface accessibilities of the &beta;-CD inclusion sites ranged between 1-100%, as evidenced by the decolourization of phenolphthalein (phth) due to the formation of 1:1 &beta;-CD/phth inclusion complexes.</p> <p>In the second part, the inclusion of NAs and its surrogates with three well known types of cyclodextrin (&alpha;-, &beta;-, and &gamma;-CD) was confirmed using negative ion mode electrospray ionization (ESI). The CDs were found to form well-defined 1:1 inclusion complexes. The binding constant (K2) of NAs and its surrogates inclusion with &beta;-CD was determined indirectly using the spectral displacement technique and were found to be 10³-10⁴ M^-1 (surrogates) and ~ 10⁴ M^-1 (NAs), respectively. Furthermore, the binding constants were found to increase with an increase of the lipophilic surface area (LSA) of the surrogates. The sorption results of NAs with three different types of &beta;-CD materials (i.e. &beta;-CD PU, &beta;-CD crosslinked with epichlorohydrin (EP) and a silica-based mesoporous material containing &beta;-CD), showed &beta;-CD PU had a greater affinity. The sorption capacity (~ 0 - 75.5 mg NAs/g copolymer) and binding affinity (~10³ - 10⁴ M^-1) of &beta;-CD PUs varied due to the nature of linker monomer and the mole ratio of the co-monomers. Aromatic-based copolymers showed high sorption binding affinity while aliphatic-based copolymers showed a relatively high sorption capacity at the co-monomer ratio. Finally, Syncrude-Derived NAs showed fluorescent characteristics which contradict the classic definition of NAs. Further studies using UV-Vis and fluorescence emission spectroscopy showed potential development of an analytical method that can be used to quantify NAs in OSPW for <i>in-situ</i> field applications.

The adsorption characteristics of an oil sands tailings water (OSTW) mixture of naphthenic acids were determined using a batch partitioning method for two soils from the Alberta oil sands region. The soils were mineral peat mixtures produced during salvage operations, with Soil 1 having a higher organic carbon fraction (foc) than Soil 2. Naphthenic acids are a significant toxic byproduct of bitumen extraction, and are acutely toxic to aquatic organisms. The sorption of naphthenic acids as affected by a high ionic strength solution was examined using a synthetic groundwater (SGW) mixture.<p>The adsorption isotherms were found to be linear in all cases. All tests were conducted at 4oC, and at a pH of 8.0 ± 0.4, reflective of the conditions in a tailings settling facility near Fort McMurray, AB. The adsorption characteristics of the naphthenic acids in the SGW solution were compared to that of the mixture in Milli-Q water for the two soils. In the presence of SGW, the adsorption coefficient (Kd) for the mixture of naphthenic acids on Soil 1 was an order of magnitude higher than that observed with the same soil and the Milli-Q water mixture, increasing from 1.9 ± 0.2 mL/g to 17.8 ± 1.5 mL/g. The adsorption coefficient for the mixture of naphthenic acids on Soil 2 was also observably higher in the SGW mixture, increasing from 1.3 ± 0.15 mL/g to 3.7 ± 0.2 mL/g. In order to determine whether preferential sorption is exhibited by a particular species within the mixture, the relative fractional abundance of the individual naphthenic acids was plotted as a 3-dimensional histogram for carbon numbers 5 to 37. It was found that for all Z families (where Z is a measure of the number of carbon ring structures), naphthenic acids within the middle range of carbon numbers showed preferential sorption. A two sample t-test confirmed that the naphthenic acids in the carbon number groupings 15 to 24 and 25 to 37 sorbed significantly in the SGW mixture when compared to those in the carbon number grouping of 5 to 14. It was concluded that select constituents of oil sands naphthenic acids mixtures sorb strongly to soil under conditions of elevated salinity and therefore adsorption could be an important attenuating mechanism in groundwater transport. Furthermore, preferential sorption of the individual naphthenic acids is important with respect to toxicity since lower molecular weight naphthenic acids are believed to have a more pronounced toxic effect. Overall, the measured adsorption coefficients indicate that there can be significant sorption of OSTW derived naphthenic acids to soils.

<p>In general, the research focuses on sequestration of naphthenic acids (NAs) from simulated oil sands process water (OSPW) conditions using engineered copolymers known as &beta;-cyclodextrin-based polyurethanes. The thesis research is divided into two main parts; <i>i)</i> synthesis and characterization of &beta;-cyclodextrin-based polyurethanes, and <i>ii)</i> sorption studies of the copolymer materials with NAs from aqueous solutions.</p> <o>In the first part, &beta;-cyclodextrin (&beta;-CD) was crosslinked with five types of linker molecules, respectively, under various synthetic conditions. The various diisocyanates investigated as linkers include the following: 1,6-hexamethylene diisocyanate (HDI), 4,4'-dicyclohexylmethane diisocyanate (CDI), 4,4'-diphenylmethane diisocyanate (MDI), 1,4-phenylene diisocyanate (PDI) and 1,5-naphthalene diisocyanate (NDI). The polyurethanes (PUs) were systematically designed at different mole ratios of monomers by maintaining &beta;-CD and varying the relative mole ratio of diisocyanate monomer from unity to greater values. Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFTS), solid state ¹³C CP-MAS NMR, solution state ¹H/¹³C NMR spectroscopy, thermogravimetric analysis (TGA), elemental analysis (CHN), nitrogen porosimetry, and a dye-based (p-nitrophenol; PNP, and phenolphthalein; phth) sorption method were used to characterize the copolymer materials. In general, the &beta;-CD PUs were insoluble in water except for &beta;-CD crosslinked with HDI at the 1:1 mole ratio which was moderately water soluble. All techniques show complementary results about the structural and compositional characterization, particularly for the estimation of the ratios between the co-monomers. The optimal preparation of copolymer materials for sorption-based applications occurs for &beta;-CD/linker monomer mole ratios from 1:1 to 1:3. There is a maximum limit of the crosslinking density which is ~ 1:7 (&beta;-CD:linker) according to the steric effects of the substituents in the annular region of &beta;-CD. Also, the copolymers were generally found to be mesoporous with relatively low surface area (BET; ~10¹ m²/g) and they appear to exhibit swelling in aqueous solution due to hydration as observed from the estimation of the dye-based surface areas using PNP. The surface accessibilities of the &beta;-CD inclusion sites ranged between 1-100%, as evidenced by the decolourization of phenolphthalein (phth) due to the formation of 1:1 &beta;-CD/phth inclusion complexes.</p> <p>In the second part, the inclusion of NAs and its surrogates with three well known types of cyclodextrin (&alpha;-, &beta;-, and &gamma;-CD) was confirmed using negative ion mode electrospray ionization (ESI). The CDs were found to form well-defined 1:1 inclusion complexes. The binding constant (K2) of NAs and its surrogates inclusion with &beta;-CD was determined indirectly using the spectral displacement technique and were found to be 10³-10⁴ M^-1 (surrogates) and ~ 10⁴ M^-1 (NAs), respectively. Furthermore, the binding constants were found to increase with an increase of the lipophilic surface area (LSA) of the surrogates. The sorption results of NAs with three different types of &beta;-CD materials (i.e. &beta;-CD PU, &beta;-CD crosslinked with epichlorohydrin (EP) and a silica-based mesoporous material containing &beta;-CD), showed &beta;-CD PU had a greater affinity. The sorption capacity (~ 0 - 75.5 mg NAs/g copolymer) and binding affinity (~10³ - 10⁴ M^-1) of &beta;-CD PUs varied due to the nature of linker monomer and the mole ratio of the co-monomers. Aromatic-based copolymers showed high sorption binding affinity while aliphatic-based copolymers showed a relatively high sorption capacity at the co-monomer ratio. Finally, Syncrude-Derived NAs showed fluorescent characteristics which contradict the classic definition of NAs. Further studies using UV-Vis and fluorescence emission spectroscopy showed potential development of an analytical method that can be used to quantify NAs in OSPW for <i>in-situ</i> field applications.

The adsorption characteristics of an oil sands tailings water (OSTW) mixture of naphthenic acids were determined using a batch partitioning method for two soils from the Alberta oil sands region. The soils were mineral peat mixtures produced during salvage operations, with Soil 1 having a higher organic carbon fraction (foc) than Soil 2. Naphthenic acids are a significant toxic byproduct of bitumen extraction, and are acutely toxic to aquatic organisms. The sorption of naphthenic acids as affected by a high ionic strength solution was examined using a synthetic groundwater (SGW) mixture.<p>The adsorption isotherms were found to be linear in all cases. All tests were conducted at 4oC, and at a pH of 8.0 ± 0.4, reflective of the conditions in a tailings settling facility near Fort McMurray, AB. The adsorption characteristics of the naphthenic acids in the SGW solution were compared to that of the mixture in Milli-Q water for the two soils. In the presence of SGW, the adsorption coefficient (Kd) for the mixture of naphthenic acids on Soil 1 was an order of magnitude higher than that observed with the same soil and the Milli-Q water mixture, increasing from 1.9 ± 0.2 mL/g to 17.8 ± 1.5 mL/g. The adsorption coefficient for the mixture of naphthenic acids on Soil 2 was also observably higher in the SGW mixture, increasing from 1.3 ± 0.15 mL/g to 3.7 ± 0.2 mL/g. In order to determine whether preferential sorption is exhibited by a particular species within the mixture, the relative fractional abundance of the individual naphthenic acids was plotted as a 3-dimensional histogram for carbon numbers 5 to 37. It was found that for all Z families (where Z is a measure of the number of carbon ring structures), naphthenic acids within the middle range of carbon numbers showed preferential sorption. A two sample t-test confirmed that the naphthenic acids in the carbon number groupings 15 to 24 and 25 to 37 sorbed significantly in the SGW mixture when compared to those in the carbon number grouping of 5 to 14. It was concluded that select constituents of oil sands naphthenic acids mixtures sorb strongly to soil under conditions of elevated salinity and therefore adsorption could be an important attenuating mechanism in groundwater transport. Furthermore, preferential sorption of the individual naphthenic acids is important with respect to toxicity since lower molecular weight naphthenic acids are believed to have a more pronounced toxic effect. Overall, the measured adsorption coefficients indicate that there can be significant sorption of OSTW derived naphthenic acids to soils.

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Oil sands companies produce substantial quantities of tailings known to contain high concentrations of dissolved organic by-products. The use of petroleum coke was proposed as a potential adsorbent for organic contaminant removal from tailings pond water. Physical activation was used to create a greater surface area and porosity within the delayed and fluid coke. Increased temperature (900oC), steam rate (0.5 mL/min), and activated time (6 h) led to high iodine numbers of 670 and 620 mg/g for activated delayed and fluid cokes, respectively. For both best activated cokes, the micropore to mesopore ratio was approximately 50:50. When 5 g/L of activated delayed and fluid cokes were added to the tailings water, 91% of the dissolved organic carbon and 92% of the naphthenic acids were removed. Such analyses indicate that an oil sands waste by-product can be used to treat tailings pond water to remove toxic and corrosive organic contaminants. / Geoenvironmental Engineering