Accurate measurements of the trace nitrogenous atmospheric species amines (NR3) and nitrous acid (HONO) are essential to understanding their chemistry and potential influence on new particle formation and oxidation capacity in the atmospheric boundary-layer, respectively. Ambient Ion Monitor – Ion Chromatography (AIM-IC) methods developed in this work have provided quantitative online observations of atmospheric amines in the gaseous and condensed phases with detection limits of pptv and ng m-3 at hourly time resolution. Size-resolved particle observations demonstrated maximum amine mass loadings in 320 – 560 nm particles, and an increase in importance relative to ammonium for the smallest particles measured (56 – 180 nm). In particular, the size-resolved samples analysed in this work indicate that bulk aerosol measurements may not be appropriate for modelling the atmospheric processes that govern the incorporation of amines and ammonia in to atmospheric particles. Measurements of HONO made during the two intensive field campaigns (NACHTT, CalNex) and a lab study provided a new perspective on the interactions of this trace compound with ground surfaces. Integrated atmospheric column measurements of HONO and NO2 during NACHTT provided clear evidence that the ground surface dominates HONO production and loss at night. Simultaneous measurements of the gas and particle phases made by the AIM-IC system during CalNex demonstrated the potential for reactive uptake of HONO on mineral dust/soil as a nocturnal sink. Similarly, the potential for nitrite salts to react with strong acids, displacing HONO during the day was suggested by this dataset. Lab study results showed that HONO is taken up irreversibly on carbonate salts and real soil extracts. Relative humidity-dependent reactive uptake coefficients were derived. Subsequent release of HONO by displacement reactions with HNO3 and HCl was also confirmed. Together, these field and lab studies have produced a new picture of HONO surface interactions by providing i) a more explicit description of a nocturnal sink of HONO that could act as a surface reservoir and ii) a new mechanism for daytime HONO formation that does not require NO2.

The indoor environment is a potentially dominant source of exposure for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). This thesis describes a study on levels, sources, emissions, and fate of PBDEs and PCBs indoors. PBDEs and PCBs air levels in 20 indoor environments in Toronto were sampled and measured. The geometric means of PBDE (Σ10BDE) and PCB (Σ35PCB) concentrations were 0.072 and 7.2 ng m-3 respectively. Statistical analysis on chemical profiles distinguished the chemical sources in the 20 environments. A multimedia indoor environmental model was applied on two test rooms. Estimated PBDE and PCB emission rates were 5.4-550 ng h-1 and 280-5870 ng h-1 respectively. Particle movement dominates within-room transport processes, and dust removal and air advection are the main chemical loss processes. Temperature, particle concentration and deposition velocity, and air exchange rate are the most influential parameters, which can alter source or sink behaviors of household products for the chemicals.

The indoor environment is a potentially dominant source of exposure for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). This thesis describes a study on levels, sources, emissions, and fate of PBDEs and PCBs indoors. PBDEs and PCBs air levels in 20 indoor environments in Toronto were sampled and measured. The geometric means of PBDE (Σ10BDE) and PCB (Σ35PCB) concentrations were 0.072 and 7.2 ng m-3 respectively. Statistical analysis on chemical profiles distinguished the chemical sources in the 20 environments. A multimedia indoor environmental model was applied on two test rooms. Estimated PBDE and PCB emission rates were 5.4-550 ng h-1 and 280-5870 ng h-1 respectively. Particle movement dominates within-room transport processes, and dust removal and air advection are the main chemical loss processes. Temperature, particle concentration and deposition velocity, and air exchange rate are the most influential parameters, which can alter source or sink behaviors of household products for the chemicals.

Master of Science / Department of Grain Science and Industry / Praveen V. Vadlani / Paper mill sludge is a solid waste generated from the paper-making industry. Cellulose in the sludge can be hydrolyzed into glucose using a cellulase enzyme complex, which can then be fermented to produce value added chemicals, such as lactic acid. The enzyme requirement for hydrolysis of the cellulose in paper sludge was benchmarked against paper pulp. Enzymatic requirements for complete conversion of cellulose in paper pulp was found to be 12 fpu cellulase, supplemented with 5 egu of beta-glucosidase per gram of cellulose. However, beta-glucosidase supplementation had to be increased to 38 egu to obtain a similar level of hydrolysis in the case of paper sludge indicating a decrease in enzyme activity due to sludge components. Response Surface Methodology (RSM) was used to study the lactic acid yield from paper sludge using enzyme dosage and temperature as parameters and operating in simultaneous saccharification and fermentation (SSF) mode. Maximum lactic acid yield of 0.75 g/g glucose was obtained within 36 hours using 10 fpu cellulase supplemented with 32 egu beta-glucosidase at a temperature of 39 degree C. Using the optimization function of the software, the optimal operational conditions for paper sludge hydrolysis were found to be 9 fpu cellulase, 12.5 egu beta-glucosidase at 40 degree C which resulted in a lactic acid yield of 0.58 g /g glucose. Lactic acid producing microbial cultures, Lactobacillus plantarum and Rhizopus oryzae were evaluated for fermentation of the pulp and sludge hydrolyzate at 125-ml shake flask and 2-L fermenter levels. In paper pulp media, the yields obtained by bacterial and fungal fermentations were 0.89 and 0.36 g/g glucose, respectively. In the case of paper sludge, the yield remained same, but inhibition of bacterial growth occurred. This resulted in lower substrate uptake and productivity than those obtained in paper pulp. On the other hand, fungal growth rate was enhanced due to the high solids content of paper sludge. The yield of lactic acid from paper sludge using L. plantarum and R. oryzae was 0.88 and 0.72 g/g glucose, respectively. Microbial cultures native to the sludge were isolated and evaluated for their performance of lactic acid production.

Although many commercial chemicals can dissociate, the study of the biological and environmental fate of ionogenic organic chemicals (IOCs) is still in its infancy. Uptake of the veterinary drug diclofenac in vultures and cattle was successfully simulated with a newly developed physiologically-based pharmacokinetic model for IOCs, lending credence to diclofenac’s proposed role in South Asian vulture population declines. Proteins and phospholipids rather than total lipids control the tissue distribution of diclofenac. A method was developed to simultaneously extract neutral and acidic pesticides and benzotriazoles from water samples with recoveries ranging 70-100%. This method was applied to samples from a laboratory calibration experiment of the Polar Organic Chemical Integrative Sampler. The sampler had higher uptake for neutral and acidic pesticides when filled with triphasic sorbent admixture and OASIS MAS sorbent, respectively. While either sorbent can also be applied for methylated benzotriazoles, neither is capable of quantitatively sampling all three compound groups.

Master of Science / Department of Biological and Agricultural Engineering / Kyle Douglas-Mankin / Opportunities for alternative biofuel feedstocks are widespread for a number of reasons: increased environmental and economic concerns over corn production and processing, limitations in the use of corn-based ethanol to 57 billion L (15 billion gal) by the Energy Independence and Security Act (US Congress, 2007), and target requirements of 136 billion L (36 billion gal) of renewable fuel production by 2022. The objective of this study was to select the most promising among currently available crop models that have the potential to model sweet sorghum biomass production in the central US, specifically Kansas, Oklahoma, and Texas, and to develop and test sweet sorghum crop parameters for this model. Five crop models were selected (CropSyst, CERE-Sorghum, APSIM, ALMANAC, and SORKAM), and the models were compared based on ease of use, model support, and availability of inputs and outputs from sweet sorghum biomass data and literature. After reviewing the five models, ALMANAC was selected as the best suited for the development and testing of sweet sorghum crop parameters. The results of the model comparison show that more data are needed about sweet sorghum physiological development stages and specific growth/development factors before the other models reviewed in this study can be readily used for sweet sorghum crop modeling. This study used a unique method to calibrate the sweet sorghum crop parameter development site. Ten years of crop performance data (Corn and Grain Sorghum) for Kansas Counties (Riley and Ellis) were used to select an optimum soil water (SW) estimation method (Saxton and Rawls, Ritchie et al., and a method that added 0.01 m m [superscript]-1 to the minimum SW value given in the SSURGO soil database) and evapotranspiration (ET) method (Penman-Montieth, Priestley-Taylor, and Hargraeves and Samani) combination for use in the sweet sorghum parameter development. ALMANAC general parameters for corn and grain sorghum were used for the calibration/selection of the SW/ET combination. Variations in the harvest indexes were used to simulate variations in geo-climate region grain yield. A step through comparison method was utilized to select the appropriate SW/ET combination. Once the SW/ET combination was selected the combination was used to develop the sweet sorghum crop parameters. Two main conclusions can be drawn from the sweet sorghum crop parameter development study. First, the combination of Saxton and Rawls (2006) and Priestley-Taylor (1972) (SR-PT) methods has the potential for wide applicability in the US Central Plains for simulating grain yields using ALMANAC. Secondly, from the development of the sweet sorghum crop model parameters, ALMANAC modeled biomass yields with reasonable accuracy; differences from observed biomass values ranged from 0.89 to 1.76 Mg ha [superscript]-1 (2.8 to 9.8%) in Kansas (Riley County), Oklahoma (Texas County), and Texas (Hale County). Future research for sweet sorghum physiology, Radiation Use Efficiency/Vapor Pressure Deficit relationships, and weather data integration would be useful in improving sweet sorghum biomass modeling.

Organizational theory can assist in better understanding how changes made in clinical practice can be sustained in healthcare organizations. Organizational learning and knowledge transfer theories were used to develop and test a theoretical model, “Sustaining in Memory” (SIM) model, to explore how organizations disperse or distribute newly transferred knowledge in knowledge reservoirs situated in the organization. Three hypotheses were generated from the theoretical model and tested with data from a cross sectional postal survey of 148 patient/resident care units in one large Canadian province where a CPG on prevention of falls was widely disseminated. Findings confirmed that fall prevention practice knowledge was transferred and embedded in all six knowledge reservoirs; however, there were three specific knowledge reservoirs that were found to be significant predictors of perceived CPG adherence (activities consistent with the CPG recommendations). These were staff, policy and role expectation knowledge reservoirs. There was variation in the adherence to the eight CPG recommendations with greater adherence to recommendations that were mandatory. Additionally, findings showed that the relationship between staff knowledge reservoir and CPG adherence was the only relationship moderated by the practices that helped to prevent/address knowledge loss through various activities designed for reviewing and updating practice knowledge. Interestingly, although CPG adherence was reported significantly greater in LTC resident care units, its association with patient outcomes was much weaker than in hospital patient care units. Hospital units had significantly greater correlation between perceived CPG adherence and all four of the falls prevention outcomes reported by study participants. Lastly, quality management culture as managed by senior leaders in the organization was also found to be a significant predicator of adherence to the CPG. The research study validated key assumptions made in the theoretical model while helping to clarify the distinct influence of different knowledge reservoirs. The SIM model provided an alternate perspective within which to study knowledge transfer and sustainability of clinical practices and has potential to apply to other change initiatives. This study answered the call for greater theoretically driven studies of CPG implementation as well as attention on the organizational influences of CPG implementation and sustainability.

The preservative concentration difference in treated wood was investigated to understand the component distribution; a study of different chemical extractions of treated wood waste was carried out and certain reagents were realized to be feasible to the preservative component removal. During fixation, the preservative components redistributed between earlywood and latewood and concentration gradients at depths also developed. Different solvent extractions of CCA treated wood were tested and ion exchange, chelation and metal dissolving were all mechanisms for component extraction. The transition of Cr(III) to Cr(VI) by oxidizing reagents (NaClO and H2O2) can make possible the direct reuse of extracted chemicals as a preservative. Different reaction factors in the oxidant extractions were compared and higher pHs significantly improved the oxidizing capability of the reagents and CCA component removal. Fresh and aged CCA treated wood generally responsed similarly to the oxidant extractions. However, arsenic in aged wood was more difficult to be removed by NaClO, while, H2O2 was more efficient to extract CCA components from aged wood than fresh wood. Monoethanolamine (Mea) efficiently extracted copper (above 90%) from ACQ treated wood and the formation of stable neutral Cu(Mea)2 in sufficient Mea solution is the main mechanism for Mea extraction. Little wood structure degradation occurred during the process. Mea (10%~15%) extraction was fast and the effect of temperature was insignificant. Cu diffusion in the longitudinal direction was the most significant compared to other wood directions. To further promote Mea extraction, repeated extraction (batch-based and column-based) was performed and proved to be more efficient, feasible and economical than one-time extraction. Column-based continuous Mea extraction showed both high Cu removal (up to 99%) and Cu accumulation in the extract. After the preservative treated wood waste is decontaminated significantly, the extract solution can be reused by directly mixing with the preservative treating solution, which is the most straightforward procedure for the recycling of chemicals removed from the preservative treated wood.

Mercury is an environmental contaminant of global concern. The distribution of mercury in freshwater systems is poorly characterized in Mexico, despite widespread contamination from industrial and urban effluents. The land use, geology, and hydrology of the Lake Zapotlán basin, Mexico are conducive to the delivery of elevated mercury in water to the lake due to untreated wastewater discharge, deforestation, and local volcanic history. To assess a mercury exposure risk to fish consumers, the concentrations of total Hg (THg) in water inputs, surface waters, sediments, and the commercial catch of tilapia and carp were investigated. Results indicate that despite high particle-bound inputs of THg to the lake in runoff and wastewater, THg in sediments and surface waters were low. Dense Typha latifolia dominated wetlands are believed to retain THg inflow from water inputs. Concentrations of THg in tilapia and carp were low, suggesting low mercury bioavailability in this system.

The popularity of Farmers’ markets is on the rise; in Canada there are 425 farmers’ markets, with over 130 in Ontario alone (Feagan, Morris, & Krug, 2004). Farmers’ markets provide high quality, local produce and are often considered an environmentally sustainable food practice (Taxel, 2003; King 2008). United States studies have scrutinized farmers’ markets as exclusionary white spaces that are not equitably accessible, but similar Canadian studies are rare. A case study at the Wychwood Artscape Barns, located in an economically and culturally diverse neighbourhood, in Toronto Ontario has been conducted. Demographics surveys of patrons were compared with existing demographic data; interviews were conducted to discover who shops at the market and for what reasons; results were analyzed using whiteness theory. Results were consistent with U.S. studies – Wychwood Farmers’ Market patrons were white, high income,individuals with university educations; these individuals shop at the market disproportionally to the demographic data.