The extracellular polymeric substances produced by suspended cultures of Escherichia coli, Serratia marcescens, and Brevundimonas diminuta in the presence and absence of bismuth thiols and by activated sludge microorganisms in the presence of glucose were characterized in detail using colorimetric, spectroscopic, and microscopic techniques. 2:1 molar ratio preparations of three lipophilic bismuth thiols BisBAL, BisEDT, and BisPYR) were investigated and BisBAL was found to be most effective for EPS suppression. Extensive homology between EPS samples in the presence and absence of bismuth was observed with proteins, carbohydrates and nucleic acids varying predominantly only in total amounts expressed. Fourier transform infrared spectroscopy FTIR) suggested that a possible mechanism of biofilm disruption by BisBAL is the inhibition of carbohydrate O-acetylation and changes in protein secondary structures. Results suggest that antifouling properties of bismuth thiols originate in their ability to suppress O-acetylation, protein secondary structure formation, and free and bound EPS secretion. Bioflocculation appears to be inhibited through electrostatic repulsions when EPS content was low but was enhanced via polymeric interactions at high EPS concentrations. More specifically, microorganisms appeared to aggregate by producing protein secondary structures including aggregated strands, beta-sheets, alpha- and 3-turn helical structures, O-acetylated carbohydrates, as well as overall C–0,N) and O＝C–OH ＋ O＝C–OR functionalities. Production of reactive oxygen species through photosensitization of polyhydroxylated fullerene fullerol) is shown to enhance viral inactivation rates. The first-order MS2 bacteriophage inactivation rate nearly doubled due to the presence of 102, and increased by 125% due to 102 and superoxide when compared with UV-A illumination alone. When fullerol and NADH were present in solution, dark inactivation of viruses occurred at nearly the same rate as that produced by UV-A illumination without nanoparticles. Mechanisms of loss of virus infectivity were also probed using dsDNA bacteriophages with capsids of different composition T7 and PRD1). The first order inactivation rate of phages in the presence of UV-A illuminated fullerol suspensions varied as MS2 ＞ T7 ＞ PRDI indicating the role of capsid composition in the susceptibility of viruses to singlet oxygen. Damage to T7 and PRD1 capsid proteins was identified using FTIR and sodium dodecyl sulfate-polyacrylamide gel electrophoresis SDS-PAGE). SDS-PAGE analysis revealed the 1O2 induced alterations in capsid proteins such as oxidative cross-linking.

The quest for green chemicals has resulted in an upsurge of research work into porous materials for separation and catalytic purposes of which Metal Organic Framework MOF) belongs. Earlier research work by our group proved that MOF Cu2＋/Fe3＋) could be used successfully to replace nitrobenzene in the oxidation of in-situ hardwood lignin to produce vanillin and syringylaldehyde. Benzenetricarboxylic acid complex of Cu II) and Fe III)； – an MOF, used as an oxidant, was found to convert the phenylpropane C9) units in in-situ poplar lignin to approximately 50% monomers. A comparison of syringyl S) to guaiacyl G) ratios by MOF oxidation to those obtained by nitrobenzene oxidation NBO) were nearly identical for three poplars having S:G ratios in the range of 1.25 – 1.68. When the sample woodmeals were charged with MOF plus oxygen in the presence of 2.0 M NaOH, high yields totaling 40 mole% – 70 mole% of vanillin, vanillic acid, syringylaldehyde and syringic acid were obtained. An investigation into the optimization of oxygen pressure could only narrow the range from a few psig to 60 psig. Total yield in the range of 20 — 26 mole% could be obtained with only 0.6 M NaOH plus Na2CO3. Although not conclusive, there was a substantial amount of data indicating a decrease in catalyst activity with time. Keywords: Metal organic frameworks； Metal oxides； S:G ratio； Hardwoods； Lignin oxidation

Catalysis plays a fundamental role in petroleum refining and basic petrochemical industries creating new routes in the development of industrial processes. Moreover, catalysis has become indispensable to the solution of environmental pollution problems and therefore on public health. World wide concerns for preservation of the environment has motivated the development of ” Green” catalyst based technologies, to achieve a better utilization of petroleum resources and demands for cleaner transportation fuels. These environmental concerns have led to increasingly drastic regulations on sulfur, nitrogen and aromatics content in fuels. Sulfur content in the motor and diesel fuels is continuously reduced by regulations to lower levels. The current specification in Europe and USA calls for maximum sulfur content of 50 ppm in gasoline and diesel by 2005 [1,2], and this level will be reduced to below 10 ppm by 2010 [1]. These facts have created a demand for better and more effective catalysts and catalytic processes to provide cleaner fuels. Transition metal sulfide TMS) catalysts play an important role in the petroleum industry. TMS are unique catalysts for the removal of heteroatoms N, S, O) in the presence of large amounts of hydrogen [3]. Hydrodesulphurization HDS) of petroleum feedstocks are commercially achieved with MoS2 or WS2 supported on alumina and promoted by Co or Ni, [3,4]. Co-promoted catalysts are mainly used for HDS, whereas Ni-promoted catalysts are superior in hydrodenitrogenation HDN) and hydrogenation HYD) reactions [5]. Catalysts currently employed need to be improved to satisfy the imminent restrictions that require the removal of the most refractory species, mainly alkyl-substituted polyaromatic thiophenes. In the current work a new family of unsupported TMS catalysts is presented with volumetric efficiencies significantly greater than current commercial catalysts. The scientific basis behind the activity improvements and the progress toward commercialization is presented.

Cultures of mixed freshwater algae were grown in open batch reactors made up of modified BG-11 media that contained 0, 25, 50 or 100% of the suggested inorganic carbon content (0, 0.5, 0.1 and 0.2 g/L Na2CO3) to assess the subsequent production of the high-value product, sulfoquinovosyl diacylglycerol (SQDG). After 25 days of growth, the reactors were composed of primarily Oscillatoria growth. All four reactors exhibited a trend of increasing biomass and alkalinity with time, and an initial increase then decrease in pH. The total inorganic carbon (TIC) in all reactors exhibited a mirrored, opposite trend as pH, with an initial decrease then increase over time. A positive correlation was found between specific growth rate and amount of initial total inorganic carbon in the reactors. The Monod constants mu max and KS were estimated to be 0.025 hr-1 and 0.00215 mol/L C, respectively. At 95% confidence, the amount of initial TIC significantly affected the total lipid concentration, which increased with time in all reactors, and showed a trend of increasing total lipids with increasing initial TIC. Additionally, the initial TIC did not significantly affect the concentration of SQDG per mL culture or per mg dry biomass, or the percent of SQDG within the total lipids. SQDG content per mg biomass decreased with time for all TIC treatments.

Particle separation technologies have been utilized in many industrial fields, such as pigment and filler production, mineral processing, environmental protection, the food and beverage industry, and the chemical industry, as well as in biomedical application, such as cell biology, molecular genetics, biotechnological production, clinical diagnostics, and therapeutics. A lot of particle separation technologies using various mechanics in terms of the differences in the physical or physico-chemical properties of the particles have been developed. Among these categories, electrical and magnetic separations are of great interest in recent researches. The overall objective of this dissertation is to advance our current knowledge on these two particle separation technologies. Accordingly, it has two major parts: (1) Charge Conditioning for Particle Separation, and (2) Magnetic Filtering for Particle Separation. In the first part, a new DC-corona-based charge conditioner for critical control of electrical charges on particles and a UV aerosol charger for fundamental investigation particle photocharging process were developed. The chargers’ performances including charging efficiencies and charge distributions were evaluated upon different operational conditions such as aerosol flow rates, corona operations, and ion-driving voltages for the charge conditioner, particle material and irradiation intensity for the UV charger. The birth-and-death charging model with the Fuchs limiting sphere theory for calculating the ion-particle combination coefficient was applied to obtain the charging ion concentration inside the charge conditioner. The UV charging model with the photoemission rely on the Fowler- Nordheim law was applied to predict the charging performance of the UV charger. In the second part, a magnetic filter system has been constructed, and its performance has been investigated. To retrieve the magnetic property of characterized particles from the measured penetration data, a numerical model was further developed using the finite element package COMSOL Multiphysics 3.5. The numerical model was first validated by comparing the experimental penetration with the simulation results for the cases of 100, 150, and 250 nm gamma-Fe2O3 particles having the magnetic susceptibility characterized by Vibrating Sample Magnetometer (VSM). The magnetic susceptibilities of other sizes from 100 to 300 nm were then derived from this model according to the measured penetration data. To control or remove the lunar dust through a magnetic approach, eight samples (three JSC-1A series lunar dust simulants, two NU-LHT series lunar dust simulants, and three minerals) in the size range from 150 to 450 nm were characterized. Magnetic susceptibilities were obtained from the difference in particle penetration through magnetic mesh filters with and without an applied external magnetic field.

The objective of this research was to predict the persistence of potential future contaminants in indirect potable reuse systems. In order to accurately estimate the fates of future contaminants in indirect potable reuse systems, results describing persistence from EPI Suite were modified to include sorption and oxidation. The target future contaminants studied were the approximately 2000 pharmaceuticals currently undergoing testing by United States Food and Drug Administration (US FDA). Specific organic substances such as analgesics, antibiotics, and pesticides were used to verify the predicted half-lives by comparing with reported values in the literature. During sub-surface transport, an important component of indirect potable reuse systems, the effects of sorption and oxidation are important mechanisms. These mechanisms are not considered by the quantitative structure activity relationship (QSAR) model predictions for half-lives from EPI Suite. Modifying the predictions from EPI Suite to include the effects of sorption and oxidation greatly improved the accuracy of predictions in the sub-surface environment. During validation, the error was reduced by over 50% when the predictions were modified to include sorption and oxidation. Molecular weight (MW) is an important criteria for estimating the persistence of chemicals in the sub-surface environment. EPI Suite predicts that high MW compounds are persistent since the QSAR model assumes steric hindrances will prevent transformations. Therefore, results from EPI Suite can be very misleading for high MW compounds. Persistence was affected by the total number of halogen atoms in chemicals more than the sum of N-heterocyclic aromatics in chemicals. Most contaminants (over 90%) were non-persistent in the sub-surface environment suggesting that the target future drugs do not pose a significant risk to potable reuse systems. Another important finding is that the percentage of compounds produced from the biotechnology industry is increasing rapidly and should dominate the future production of pharmaceuticals. In turn, pharmaceuticals should become less persistent in the future. An evaluation of indirect potable reuse systems that use reverse osmosis (RO) for potential rejection of the target contaminants was performed by statistical analysis. Most target compounds (over 95%) can be removed by RO based on size rejection and other removal mechanisms.

It is estimated that wind induced soil transports more than 500 x 106 metric tons of fugitive dust annually. Soil erosion has negative effects on human health, the productivity of farms, and the quality of surface waters. A variety of different polymer stabilizers are available on the market for fugitive dust control. Most of these polymer stabilizers are expensive synthetic polymer products. Their adverse effects and expense usually limits their use. Biopolymers provide a potential alternative to synthetic polymers. They can provide dust abatement by encapsulating soil particles and creating a binding network throughout the treated area. This research into the effectiveness of biopolymers for fugitive dust control involved three phases. Phase I included proof of concept tests. Phase II included carrying out the tests in a wind tunnel. Phase III consisted of conducting the experiments in the field. Proof of concept tests showed that biopolymers have the potential to reduce soil erosion and fugitive dust transport. Wind tunnel tests on two candidate biopolymers, xanthan and chitosan, showed that there is a proportional relationship between biopolymer application rates and threshold wind velocities. The wind tunnel tests also showed that xanthan gum is more successful in the field than chitosan. The field tests showed that xanthan gum was effective at controlling soil erosion. However, the chitosan field data was inconsistent with the xanthan data and field data on bare soil.

Palladium based catalysts are attractive for methane combustion at low temperature. However, at temperatures below 450&deg；C, their tendency to deactivate hinders their usefulness. An examination of the mechanism for combustion of methane over palladium based catalysts revealed insight into the cause for catalytic deactivation. The reaction mechanism was studied using a continuous flow of CH 4 plus 16O2 or 18O2 over various combinations of isotopically labelled PdO/metal oxide catalysts. Our experimental results are consistent with a PdO/Pd redox combustion mechanism. However, the oxide supports are shown to provide oxygen to the catalytic combustion products. PdO/Pd serves as a porthole for gas phase oxygen to dissociate, migrate to the oxide support, and exchange with oxygen from the oxide support. The migration and exchange process allows oxygen that was originally bonded to the support to participate in the catalytic combustion reaction. The rate of oxygen exchange is temperature and support dependent. Catalytic deactivation in the temperature regime below 450&deg；C has been attributed to a hydroxyl or water inhibition effect. We investigated this effect to better understand the mechanism for catalytic deactivation. Comparative in-situ FTIR transmission spectroscopy experiments revealed that water or hydroxyl accumulation occurs on the oxide supports during catalytic methane combustion and deactivation. The water/hydroxyl accumulation on the support is slow to desorb. In light of our finding that oxygen from the support is utilized in the methane combustion process, we propose that hydroxyl/water accumulation on the support impedes the catalytic combustion reaction by hindering oxygen mobility on the oxide support. We support this hypothesis by demonstrating that the presence of water on the catalyst inhibits oxygen exchange with the oxide support.

The preferential flow of water and solutes through soils is considered as one of the major processes, which carry the risk of polluting the most precious groundwater resources. Due to the high economic and social costs involved in mitigating the adverse effects on human health, there is a great concern about preventing groundwater pollution. Therefore, it is important to develop methods of increasing the accuracy in measuring and modelling preferential flow, which requires a thorough understanding of the factors affecting preferential flow and the extent of their contribution. This study investigates the effect of conventionally tilled CT) and not-tilled NT) soil management practices in the field and heterogeneities introduced by soil tongues formed at inter-soil horizon boundaries in the laboratory and a computer model on preferential flow. Soil water content sensors were installed in each CT and NT plot across crop-rows under corn and soybean cultivation and data were analyzed over two temporal scales. The analysis of water content data obtained in eight columns down to a depth of 40 cm indicated that more short term event based) preferential flow pore-scale) occurs in NT plot compared to CT plot. The consistent patterns of mean relative difference MRD) of water content over the consecutive non-growing seasons regardless of the crop grown during the growing season suggest that there could be long term preferential flow . pathways Darcian scale) in both NT and CT plots. The laboratory experiments were carried out using a physical model containing two artificial soil tongues constructed at the boundary of a layered soil profile. The lower layer consisted of coarse sand and the upper tonguing layer was constructed using fine sand. Results showed that water and solute are transported faster through the fine sand tongues compared to the inter-tongue zones of coarse sand. These results were accurately simulated by VS2DTI software package. Further simulations using VS2DTI revealed that the level of transport through soil tongues depends on the number of soil tongues, their spacing and distribution. Furthermore, it was determined that the shape of the soil tongue, its length, and width influence the rate of preferential flow and the volume of soil profile containing solutes.

Pharmaceuticals and personal care PPCPs) and endocrine disrupting compounds EDCs) are microcontaminants that are widely distributed in the aquatic environment and have been found in both untreated and treated drinking water. In this study, transformation rates for 15 model PPCPs and EDCs were monitored in deionized water DIW), dechlorinated tap water PTW) from Peterborough, Ontario Le. high DOM, hard water), and water from Plastic Lake PLW) in Haliburton County, Ontario Le. low DOM, soft water) under treatment with low-pressure and medium-pressure mercury arc lamps. In some treatments, waters were amended with 4 mg/L H2O2 and/or 15 mg/L NO3 -. Spectrophotometric titrations were performed to determine micropolluant pKas. Time-based photochemical rate constants, molar absorption coefficients, and quantum yields mol/einstein) were determined for irradiations at 253.7 nm in DIW at pH 7.2 for sulphamethoxazole, sulphachloropyridazine, nonylphenol, acetaminophen, and triclosan. The rate constants for loss under direct photolysis with a LP lamp at sub mug/L concentrations were 3.9 ＋/- 0.7) x 10-4 s-1 for triclosan, 3.8 ＋/- 0.4) x 10-4 s-1 for sulphamethoxazole, 7.0 ＋/- 2.4) x 10-5 s-1 for nonylphenol, 5.3 ＋/- 1.1) x 10-5 s-1 for sulphachloropyridazine, and 2.4 ＋/- 1.2) x 10-5 s-1 for acetaminophen. Second-order OH&middot； radical rate constants determined using a competition kinetics method with para-chlorobenzoic acid only varied by a factor of two, from 5.2 ＋/-0.4 x 109 M-1 s-1 for caffeine to 10.8 ＋/- 0.9 x 109 M-1 s-1 for estrone, which are close to diffusion rates. Without addition of NO3- or H2O2, transformation rates were generally higher in DIW than in PTW. Addition of NO3- increased the rates of transformation for 12 compounds in the three test waters, while rates for bisphenol A, atenolol, and ibuprofen were not influenced. Addition of H2O2 increased removals of all compounds in both DIW and PLW. With the exception of 4-nonylphenol, all compounds showed lower transformation rates in the presence of both added NO3- and H2O2 than with only the larger contributor of the two, indicating that the presence of N03- can compete for reaction with H2O2 and the presence of H2O2 can compete for reactions with N03-. Treatment with UV alone allows for maximum 15 % transformation of microcontaminants at the fluences normally used for disinfection of drinking water. However, the UV/H2O2 treatment method is effective for the removal of microcontaminants from water. Keywords: UV and UV/H2O2, drinking water treatment, quantum yield, pKa determinations, &middot；OH radical rate constants, pharmaceuticals and personal care products, Endocrine-disrupting compounds, low-pressure and medium-pressure Hg lamps.