Browsing by Author "Kimura, Susana Y."
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Item Open Access Advanced Oxidation for the Removal of Pharmaceuticals from Municipal Wastewater: Connecting Laboratory to Application Scale(2020-04-27) Hollman, Jordan Daniel; Gopal, Achari; Jackson, Leland J.; Kimura, Susana Y.; Ryan, M. Cathy; Bérubé, Pierre R.The presence of pharmaceuticals in water is an emerging issue in water research, the major source of which is the discharge of treated municipal wastewater. While technologies have been proposed to remove pharmaceuticals from municipal wastewater, a gap between laboratory studies and application scale remains. This thesis connects laboratory investigations and analysis to application scale treatment for the removal of pharmaceuticals from municipal wastewater. Focused on advanced oxidation processes, studies were conducted with controlled laboratory investigations to gain detailed mechanistic understanding to support application scale studies. Venlafaxine was used as a candidate pharmaceutical, with subsequent laboratory studies also investigating carbamazepine, fluoxetine and sulfamethoxazole. Tests were conducted in both pure water and municipal wastewater matrix. Results demonstrated that UV photolysis, UV/H2O2 and ozonation were all effective means of degrading pharmaceuticals in municipal wastewater. UV with peracetic acid was tested and found to provide little advantage over UV/H2O2. Kinetics were assessed and found to follow pseudo first-order degradation in all cases. Total UV fluence was determined to be an effective means of modelling degradation kinetics. Mineralization pathways were found to be congruent with sequential hydroxylation for all compounds investigated at a laboratory scale. Laboratory results informed application scale testing at the Advancing Canadian Wastewater Assets (ACWA) Research Wastewater Treatment Plant. The facility is embedded in a functioning treatment plant and runs as a unit process in an active treatment train, making the results comparable to full implementation. 13 neutral pharmaceuticals were studied, with concentrations in the ng/L-µg/L range. Treatment processes tested at an application scale were UV photolysis, UV/H2O2, ozonation and reverse osmosis. Reverse osmosis showed high removal of 12 of the 13 compounds, though it has the drawback of producing a concentrated waste stream. Ozone was found to be highly effective for degrading most compounds and presents as the most viable process for full implementation. UV photolysis showed modest removal of all compounds. It was noted that laboratory results for UV photolysis were transferable to application scale with total volumetric UV fluence used for comparison. UV/H2O2 showed similar results to UV photolysis at application scale.Item Open Access Bay-region Expanded Perylene Diimides for Green Printed Electronics(2021-01-13) Harris, Dylan Henry; Welch, Gregory C.; Derksen, Darren J.; Ling, Changchun; Kimura, Susana Y.Reported within is the development of a new acid-catalyzed synthesis that provides access to alcohol-processable bay-substituted N-H functionalized PDI derivatives. The results were published in a recent manuscript and have been included in Chapters 1 and 2 of this thesis. Full structural and optoelectronic characterization was performed including optical absorption spectroscopy, cyclic voltammetry (CV), single crystal X-ray diffraction (SC-XRD), H-NMR spectroscopy, C-NMR spectroscopy, MALDI-TOF mass spectrometry, CHN elemental analysis, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Molecular design considerations are presented in the context of density functional theory (DFT) energy level diagrams from collaborators in the Rondeau-Gagné lab at University of Windsor. Organic field effect transistor (OFET) device data was collected via our collaboration with the Lessard lab at University of Ottawa. This thesis strives to highlight multiple ways in which our new synthetic method can be utilized to provide high performing and green solvent processable OFET materials. Successes and failures of the synthesis of new targets are documented and discussed with respect to electronic structure considerations.Item Open Access Biological and Advanced Oxidation Processes for the Treatment of Sulfolane Contaminated Waters(2020-01-07) Khan, Muhammad Faizan; Achari, Gopal; Black, Kerry E.; Kimura, Susana Y.; Gieg, Lisa Marie; Khan, Faisal MasoodSulfolane contamination has increasingly become a major environmental concern around the world. This research builds on past research on sulfolane degradation using a variety of different advanced treatment technologies. Initially, the performance of an integrated technology combining biological activated sludge with advanced oxidation process (AOP) (UVC/H2O2) in sequence was evaluated in a batch reactor resulting in >81% sulfolane degradation in less than 24 h. Evaluation of the impact of biological process on AOP showed sulfolane concentration beyond 30 mg/L and presence of TSS >44 mg/L can negatively impact the UVC/H2O2 efficiency for sulfolane degradation. The application of UVC/H2O2 after biological treatment was an advantage as UVC/H2O2 could perform dual roles of oxidation and disinfection. As aerobic granulation is perceived to be more advanced than activated sludge process, two approaches of forming sulfolane degrading aerobic granules (SDAG) were investigated. The adaptation of pre-grown granules to sulfolane environment required a longer period to form SDAG compared to coaggregation of pre-grown granules with bacterial culture native to sulfolane contaminated site. Scanning electron microscopic images revealed dominant filamentous bacteria on the surface of granules. The stability and settleability of SDAG were also investigated under different environmental conditions. Subsequently, a novel integration of aerobic granulation with UV/H2O2 process in a continuous flow-through operation sequence showed elimination of more than 99.99% of sulfolane in less than 6.3 h of combined retention time. The degradation kinetics of sulfolane were also evaluated and the flow-through system showed generation and maintenance of a healthy aerobic granular system. Additionally, various key factors were also identified that govern residual H2O2 concentration in UV/H2O2 effluents. Finally, a pilot-scale field investigation was conducted using a pressurized ozone treatment system to degrade sulfolane in contaminated groundwaters. A series of batch and continuous flow systems were studied to determine the degradation kinetics and evaluate augmentation of oxidation process with the addition of secondary chemicals with ozone. Groundwater matrix played a crucial role in the efficacy of ozone treatment and intermittently sparged ozone injection was evaluated as a viable option for ozone field applications. Nevertheless, bromate concentrations higher than drinking water guidelines were detected in treated groundwater after ozone treatment and this will need further research.Item Open Access Emerging disinfection by-product quantification method for wastewater reuse: trace level assessment using tandem mass spectrometry(Royal Society of Chemistry, 2021-01-13) Ortega-Hernandez, Alejandro; Acabaya, Raphael; Verwold, Chad; Montagner, Cassiana Carolina; Kimura, Susana Y.The availability of freshwater sources are declining as the result of increasing populations, economic activities, and climate change. These increasing trends will also drive up the demand for potable water that will require the use of alternative sources including wastewater-impacted and saline waters. Therefore, it is crucial to understand the formation of emerging toxic DBPs from advanced treatment of treated secondary wastewater effluents for potable reuse. In this study, a highly sensitive analytical method was developed to characterize 25 DBPs from 5 chemical classes (haloacetonitriles, halonitromethanes, haloacetaldehydes, haloketones, and iodinated trihalomethanes) in recycled wastewaters using a gas chromatography tandem mass spectrometer (MS/MS). The high sensitivity of MS/MS technology permitted a reduced sample concentration factor (50x) that required only 30 min of extraction time and 10 mL of sample volume. Method detection limits are the lowest reported between 2.0-68.9 ng/L. Matrix effects in secondary wastewater effluents were low (0-30%) compared to ultra pure water. A full-scale facility for wastewater reuse that treated secondary wastewater effluents through microfiltration (UF), followed by ozone (UF/O3) or reverse osmosis (UF/RO) was evaluated. Water samples from each process were chlorinated (HOCl) and chloraminated (NH2Cl) to evaluate DBP precursor removal and DBP formation potential, the first study of its kind. Overall, HOCl formed higher summed DBP levels (0.5-18.5 ug/L) compared to NH2Cl (0.2-8.5 ug/L). HAN was significantly lower in UF/O3/HOCl (59%) and UF/RO/HOCl (99%) compared to UF/HOCl. However, HNM was enhanced after UF/O3/HOCl. In chloraminated samples, UF/O3/NH2Cl produced a higher amount of DBPs compared to UF/NH2Cl including haloacetonitriles, halonitromethanes, haloketones, and iodinated trihalomethanes.Item Open Access Examining the interactions between Pseudomonas aeruginosa and Staphylococcus aureus and their effect on antimicrobial susceptibility(2019-09-11) Monych, Nadia Karen; Turner, Raymond Joseph; Lewis, Ian A.; Lohmeier-Vogel, Elke M.; Kimura, Susana Y.The purpose of this work was to examine the role of biomolecules involved in interspecies interactions changing antimicrobial tolerance, particularly for metals. In this thesis it was determined that compounds from P. aeruginosa were able to alter the tolerance of S. aureus to metal antimicrobials, antiseptics and antibiotics. S. aureus tolerance to Ga(NO3)3, CdSO4 and ZnSO4, the anionic metal(loids) K2TeO3, Na2SeO3 and NaAsO2 as well as tetracycline, nalidixic acid, benzalkonium chloride and hydrogen peroxide were all diminished when exposed to P. aeruginosa spent media. Conversely, P. aeruginosa spent media was able to enhance S. aureus tolerance to NiSO4, CuSO4 and AgNO3. The phenotype was dependent on growing in simulated wound fluid (SWF). When spent media was produced in either LB or a minimal media M9 with casamino acids, no difference in tolerance was provided and instead anti-Staphylococcal compounds were produced. The provided copper and silver tolerance enhancement was found to be multifactorial with both unique and similar contributors for each metal. Copper tolerance is provided by reducing its bioavailability in the media. This is performed by binding to amino acids and dihydroaeruginoate (Dha), an intermediate in the synthesis of the siderophore pyochelin. Changes to the membrane of S. aureus due to inhibition of the agr system by 3-oxo-C12-HSL likely reduces the import of copper and thus its toxicity. Production of outer membrane vesicles (OMVs) induced by the Pseudomonas Quinolone Signal (PQS) contributes to reduced silver toxicity for S. aureus. The compounds contained within OMVs, including PQS, would likely bind silver reducing its bioavailability. Amino acid catabolism of serine and threonine also increases silver tolerance in S. aureus. This likely occurs through reducing the interaction of silver with L-serine dehydratase, a necessary enzyme in conversion of threonine and serine conversion to pyruvate.Item Open Access Formation Potential and Analysis of 32 Regulated and Unregulated Disinfection By-Products: Two New Simplified Methods(Elsevier, 2022-04-23) Murakami, Jillian N.; Zhang, Xu; Ye, Joanne; MacDonald, Amy M.; Pérez Pérez, Jorge; Kinniburgh, David W.; Kimura, Susana Y.Water disinfection is an essential process that provides safe water by inactivating pathogens that cause waterborne diseases. However, disinfectants react with organic matter naturally present in water, leading to the formation of disinfection by-products (DBPs). Multi-analyte methods based on mass spectrometry (MS) are preferred to quantify multiple DBP classes at once however, most require extensive sample pre-treatment and significant resources. In this study, two analytical methods were developed for the quantification of 32 regulated and unregulated DBPs. A purge and trap (P&T) coupled with gas chromatography mass spectrometry (GC-MS) method was optimized that automated sample pre-treatment and analyzed volatile and semi-volatile compounds, including trihalomethanes (THMs), iodinated trihalomethanes (I-THMs), haloacetonitriles (HANs), haloketones (HKTs) and halonitromethanes (HNMs). LOQs were between 0.02-0.4 µg/L for most DBPs except for 8 analytes that were in the low µg/L range. A second method with liquid chromatography (LC) tandem mass spectrometry (MS/MS) was developed for the quantification of 10 haloacetic acids (HAAs) with a simple clean-up and direct injection. The LC-MS/MS direct injection method has the lowest detection limits reported (0.2-0.5 µg/L). Both methods have a simple sample pre-treatment, which make it possible for routine analysis. Hyperchlorination and uniform formation conditions (UFC) formation potential tests with chlorine were evaluated with water samples containing high and low TOC. Hyperchlorination formation potential test maximized THMs and HAAs while UFC maximized HANs. Ascorbic acid was found to be an appropriate quencher for both analytical methods. Disinfected drinking water from four water utilities in Alberta, Canada were also evaluated.Item Open Access Haloacetonitrile stability in cell culture media used in in vitro toxicological studies(Elsevier, 2022-12-19) Jayawardana, Thilina K.; Hossain, Md Fahim; Patel, Dhruvin; Kimura, Susana Y.Haloacetonitriles (HANs) are an emerging class of nitrogenous disinfection by-products (DBPs) formed in disinfected drinking water and have been reported to be more cyto- and genotoxic than the regulated DBPs. HANs are also known to hydrolyze under neutral pH and normal room temperature. However, the stability of HANs has not been well characterized in DBP toxicological assessments. Most toxicological assessments expose DBPs up to several days which may result in a mixture of HANs and degradation products that might have underestimated HAN toxicity. In this study, HANs stability was characterized in 1) a buffer solution in sealed vials, 2) cell culture media (CCM) in sealed vials, and 3) CCM in 96 sealed well plates with 5% CO2. Solutions were incubated at 37C for 3 days. MonoHANs were found to be stable in buffer and CCM except when HANs were incubated in CCM in plates where they could possibly be affected by volatilization and photodegradation during sample handling. However, di- and tri- HANs degraded between 70-100% in both buffer solution and CCM. They were also found to be less stable in CCM than in buffer solution possibly from HANs reacting with nucleophiles present in CCM (i.e., amino acids). Identified degradation products include corresponding haloacetamides and haloacetic acids for buffer solutions and only haloacetic acids and an unknown brominated compound for CCM. Results of this study suggests that reported toxicity values might have been underestimated and should consider changing CCM and DBP on a daily basis for a more accurate toxicity measurement.Item Open Access Investigating reactive tropospheric nitrogen oxides by thermal-dissociation cavity ring-down spectroscopy(2021-01-18) Gingerysty, Nicholas John Louis; Osthoff, Hans D.; Gailer, Jürgen G.; Kimura, Susana Y.The nitrogen oxides are important trace constituents of the troposphere that originate mainly from anthropogenic sources. Accurate quantification techniques are needed to characterize their abundance and to assess their impact on air quality. This thesis describes a compact and portable source that delivers nitrous acid (HONO) in high purity (>95%). HONO is produced dynamically by reacting a gas stream containing < 1 part per million (by volume) HCl gas at relative humidity of 30% - 40% with solid sodium nitrite. The production of HONO and absence of impurities such as nitric oxide (NO), nitrogen dioxide (NO2) and nitrosyl chloride (ClNO) were verified by Fourier transform infrared (FTIR) and thermal dissociation cavity ring-down spectroscopy (TD CRDS). The interference from HONO in the measurement of NO2 by photolytic conversion with chemiluminescence detection (P-CL) was investigated in two prototype converters. The first used radiation centred around 395 nm, common in P-CL. The second utilized 415 nm light, where the overlap with the HONO absorption spectrum and expected HONO interference are lower. Mixing ratios of NO2, NOx and HONO entering and exiting the converters were quantified by TD-CRDS. Both converters exhibited high NO2 conversion efficiency (CFNO2 >90%). Plots of CF against flow rate delivered photolysis frequencies of 4.2 s-1 and 2.9 s-1 for NO2 and 0.25 s-1 and 0.10 s-1 for HONO at 395 nm and 415 nm, respectively. The CFHONO was larger than predicted implying that measurements of NO2 by P-CL overestimate NO2 concentrations. Mixing ratios of nitrogen oxides were quantified during the SNOWDOGS campaign in Fort MacKay, AB, in January 2020. The group's TD-CRDS was modified to simultaneously quantify mixing ratios of NO2, HNO3, gas phase NOy, and total NOy (including particulate nitrate). High nitrogen oxide concentrations at night and faster than expected daytime conversion of NO2 to nitric acid (HNO3) and particulate nitrate were observed, indicating that the nitrogen oxides are processed primarily by photochemical reactions in polluted regions at high latitude during winter.Item Open Access Light Emitting Diode Based Photocatalytic Treatment of Sulfolane Contaminated Water using Nanomaterials(2020-05-14) Dharwadkar, Sripriya; Achari, Gopal; Kimura, Susana Y.; Black, Kerry E.Sulfolane is a highly water soluble and stable compound that is used in many industries due to its excellent performance as an industrial solvent. Elevated levels of sulfolane have been detected in groundwater in Alberta due to accidental release from gas treatment plants. Stringent environmental regulatory requirements regarding sulfolane have generated a need for effective water treatment technologies for removal of sulfolane. This research investigates a photocatalytic water treatment system aimed at removing sulfolane from groundwater. In particular, degradation of sulfolane using a photoreactor fitted with light emitting diodes (LEDs) was studied. The performances of commercial TiO2 powder (P25) and reduced graphene oxide TiO2 composite (RGO-TiO2) were compared. The impact of matrix effects and type of irradiation were investigated for photocatalytic degradation of sulfolane. In addition, a reusability test was conducted for the photocatalyst to examine the degradation of sulfolane in consecutive cycles with new batches of sulfolane contaminated water. The results demonstrated that the combination of UVA-LED and P25 yields better performance than UVA-LED and RGO-TiO2 for the degradation of sulfolane. UVA-LEDs displayed more efficient use of photon energy when compared with the mercury lamps. A significant decrease in sulfolane degradation was observed in the presence of anions and co-contaminants. LED based TiO2 photocatalysis was effective in degrading sulfolane even after three photocatalytic cycles. Oxidants and nanomaterials were used to improve TiO2 based photocatalytic degradation of sulfolane. Hydrogen peroxide (H2O2), sodium persulfate (PS) and ozone (O3) were the oxidants studied and carbon nanotubes (CNT) and nanosized zero valent iron (nZVI) were used as the nanomaterials. The impact of these oxidants and nanomaterials at various dosages were evaluated in both Milli-Q water and groundwater. The results indicate that with a suitable dose of oxidants or nanomaterials, photocatalytic degradation of sulfolane in Milli-Q water can be enhanced. The addition of ozone contributed to a significant increase in sulfolane degradation rate in Milli-Q water. The experiments conducted in groundwater showed that oxidants (H2O2, PS and O3) increased the degradation of sulfolane while the nanomaterials (CNT and nZVI) impeded sulfolane degradation in groundwater.Item Open Access New Iodine-based Electrochemical Advanced Oxidation System for Water Disinfection: Are Disinfection By-products a Concern?(Elsevier; IWA Publishing, 2021-06-23) Verwold, Chad; Ortega-Hernandez, Alejandro; Murakami, Jillian; Patterson-Fortin, Laura; Boutros, Jenny; Smith, Richard; Kimura, Susana Y.A novel electrochemical Advanced Oxidation System (AOS) has been recently developed for water disinfection where iodide is used to generate active iodine species in-situ. However, the presence of iodide during water disinfection can lead to the formation of iodinated disinfection byproducts (I-DBPs), which have been shown to be more cyto- and genotoxic than their chlorinated and brominated analogs. In this study, the formation of DBPs was assessed in ultrapure water, river water and secondary wastewater effluents treated by the AOS. A comprehensive total organic halogen and target DBP analysis was used that included 25 unregulated DBPs, and the total organic halogen (TOX) quantified as total organic chlorine (TOCl), total organic bromine (TOBr), and total organic iodine (TOI). Ultrapure water disinfection only quantified iodoform (TIM) at a maximum concentration of 0.90 ± 0.05 µg/L. River water results show that TOI increase from 1.3 ± 0.3 µg/L before disinfection (t=0) to a maximum of 3.5 ±1.1 µg/L. TIM and bromodiiodomethane (BDIM) were the only targeted iodo-trihalomethanes (I-THMs) that were quantified with a maximum total I-THM concentration of 0.44 µg/L. Secondary wastewater effluent disinfection results show that TOI increased from 1.8 ± 0.3 µg/L (t=0) to a maximum concentration of 35.3 ± 0.3 µg/L. Iodide and iodate were the main iodinated species exiting the AOS system with a iodine recovery of 94-101%. The results from this study show that the AOS formed low levels of iodinated DBPs in treated water sources that are comparable to the levels found in disinfected drinking water and wastewater.Item Open Access Novel Analytical Method for Trace Level Quantification of Disinfection By-Products in Recycled Wastewaters(2020-12-08) Ortega, Alejandro Rene; Kimura, Susana Y.; Thurbide, Kevin B.; Achari, Gopal; van Humbeck, Jeffrey F.The work of this thesis quantifies and characterizes unregulated priority disinfection by-products (DBPs) in a full-scale potable wastewater reuse treatment plant. DBPs are small organic molecules formed from the reaction between natural organic matter (NOM) and disinfectants. Unregulated DBPs display genotoxic, cytotoxic and potentially carcinogenic properties to humans. Wastewater reuse is an area of growing interest as freshwater sources are being depleted due to increasing human population and climate change. Secondary effluent treated with microfiltration (UF), ozone, and reverse osmosis waters were disinfected to observe the change in DBP composition throughout various stages of the treatment train process. First, a novel multiple reaction monitoring (MRM) method was developed on a gas chromatography – triple quadrupole mass spectrometer (GC-MS/MS) that quantifies 25 DBPs formed from chlorinated and chloraminated wastewater effluents. The order of optimization of each DBP class involved the determination of chemical transitions, collision energies, dwell times, time segments and determination of method detection limits. The optimization of these parameters led to a highly sensitive quantification method for the DBPs found in this method. Method detection limits ranged from 2.0 - 68.9 ng/L. Next, a liquid – liquid extraction (LLE) method for sample analysis was modified to account for the large increase in sensitivity that comes with a triple quadrupole. MS/MS instruments are highly advantageous because of the selection of specific chemical transitions for quantification. This specificity results in precise quantification due to the large signal to noise ratio of each chemical fragment at trace levels. The LLE method was reduced 10 fold in terms of time, reagents, and sample volume compared to published methods. The last part of this work looked at the DBP composition of each water matrix across three seasons of the year. Specifically, waters were sampled in fall, winter, and summer to observe how the change in precursors affected DBP formation.Item Open Access Reactions involving fracturing chemical additives with implication in delayed H2S production(2019-09-06) Marrugo Hernandez, Juan Javier; Marriott, Robert A.; Birss, Viola I.; Roesler, Roland; Kimura, Susana Y.; Plata, Desirée L.Shale gas is fast becoming the primary source of liquefied natural gas, a must needed fuel in a society trying to lower carbon emissions. When producing shale reservoirs, hydraulic fracturing in combination with horizontal drilling are the chosen technologies to extract hydrocarbons economically and efficiently. An issue faced during production from hot shale gas reservoirs (T > 100 °C) is the presence of hydrogen sulfide (H2S) and organo-sulfur compounds (CxHy-SH) in the production fluids. These sulfur species can have a significant economic impact on the overall production as the gas now has to be treated to remove the unwanted components. In this work, the decomposition of selected chemical additives contained within fracturing fluids are investigated as an alternative explanation to the H2S formation in hot shale sweet gas reservoirs. Initially, high-pressure and high-temperature decomposition/hydrolysis of sulfur-containing biocides and corrosion inhibitors were studied, and the mechanisms of H2S generation were proposed. Although the results were definitive, sulfur-containing additives are not always applied. Therefore, in researching a more universal explanation of non-biogenic souring, an undeniable fact came to light: the water used in hydraulic fracturing is not degassed, thus it is saturated with oxygen at field conditions. As such, the oxygen present in the fluid can react with native H2S to generate elemental sulfur. Under downhole conditions elemental sulfur can react with hydrocarbons regenerating H2S. For this reason and to further prove this hypothesis, the kinetics and equilibrium products of sulfur-methanol reaction in aqueous conditions was studied under various downhole conditions e.g. temperature, pressure, pH and salinity.