This study is conducted at the Trail Road Landfill, located in Nepean, Ontario, Canada. The objective is to investigate the leachate characteristics of changing spatial-temporal patterns in a landfill groundwater environment by comprehensive analyses of annual spatial data. Exploratory statistical data analysis identified the association of B (boron) with K, NH3 and TKN. Raster layers (maps) are created based on the concentrations of required variables in each time interval (year). In this study, it is notable that the raster data layers are used instead of discrete well data. Several change detection methods are applied to determine the spatial and temporal changes of B and its associated variables and to identify the well locations where the changes occurred. These included post-classification visualization, principal component analysis, standard deviation and unsupervised classification (clustering) methods. The suitability of these methods is also discussed. The results determined that during the 1993-95 time period the concentrations of B and its associates was initially increasing, and then decreased substantially. In summary, the study analysed characteristics of pollutants in landfill site groundwater environmental monitoring by using raster data in different change detection methods, and discussed the suitability of the applied methods. The same methodology and analysis techniques can be applied to other variables in similar environmental monitoring studies.

A Neochloris oleoabundans strain screened in our lab was demonstrated to have the ability to accumulate large quantities of triglycerides, the feedstock of biodiesel production, and to remove nitrogen and phosphorus from wastewater efficiently. Box-Behnken experimental design (BBD) and response surface method (RSM) were used to study the effects of a large number of nutrients on cell growth and lipid accumulation. The optimized medium supported a lipid concentration of 641.4 mg/l and a cell density of 2.54 g/l, which were 4.5-fold and 2.2-fold of that obtained with the basic medium, modified Bristol medium (MBM), respectively. The capacity of the strain for phosphorus removal and nitrogen removal was investigated using artificial wastewater and municipal wastewater effluents. It was demonstrated that the strain could achieve near-zero residual phosphate and nitrogen at the end of cultivation when artificial wastewater contained up to 140 mg N-NO 3-/l and 47 mg P-PO43-/l. The rates of the removal of N-NO3- and P-PO4 3-, are 27.5 mg/l·d, and 9.4 mg/l·d, respectively under optimal conditions. It was observed that the nitrogen content of the wastewater effluent was not sufficient and additional nitrogen source (e.g., NaNO 3) of 70 mg/l was required for optimal cell growth, CO2 fixation, and phosphate removal.

The use of co-substrates can significantly enhance biogas production from manure while helping to treat and dispose of high carbon organic wastes from the food processing industry and municipalities. This thesis will focus on the experimental setup and results collected at the University of Guelph -- Campus d'Alfred from a series of Biochemical Methane Potential assays and six 30 L semi-continuous anaerobic digesters operating under mesophilic conditions. The co-substrates investigated during the study include: corn silage, canola meal, whey, glycerine and dissolved air floatation sludge. The use of liquid dairy manure proved to be beneficial for the anaerobic digestion process by supplementing necessary buffering capacity, nitrogen, micro and macro elements for the co-digestion of high carbon organic wastes. Biochemical Methane Potential assays of the co-substrates increased the biogas yield from 5 to 250%. When these co-substrates were elaborated in semi-continuous pilot digesters, volumetric biogas production increased two to three-folds in relation to liquid dairy manure.

Removal of specific contaminants from high ionic strength process residuals, such as concentrate from desalting membranes, may increase the number of alternatives for residual disposal, reuse, and/or resource recovery. In the case of disposal, treatment of these waste streams could expand the number of feasible options while potentially lessening the environmental impacts of the residuals. With regards to increasing utilization of resources, treatment of membrane concentrate prior to the use of crystallization processes such as those used for zero-liquid discharge might increase the overall efficiency of the recovery system as well as improve the quality of the recovered salts by removing seed crystal poisons and potentially toxic constituents. Alternatively, reduction of key constituents to an acceptable level may allow for the treated residuals to be used as irrigation water for salt tolerant plants, saline aquaculture (farming of brine shrimp or other salt water species), or for options not yet identified because of the developing nature of this problem. Finally, treatment of the concentrate may allow for some portion of the residuals stream to be incorporated back into the overall treatment process leading to higher treated water recoveries. This research explored removal of specific pollutants from simulated and real high-pressure membrane concentrates by treatment with ferric chloride or calcium oxide (lime). Ionic strength effects were important in terms of particle aggregation for ferric iron treatments; this phenomenon was reflected in better solid liquid separation at higher ionic strengths (> 0.2 M) than at 0.008 M. Decreasing pH by acid addition to near 6.5 prior to iron treatments generally improved arsenic uptake compared to uptake where pH was not adjusted (pH ∼ 8). Arsenic uptake by solids formed during lime softening increased linearly with increasing lime dose is matrices consisting of calcium only or calcium and magnesium. Based on the results presented in this study, it would seem that precipitation with calcium can be an important mechanism of arsenic removal. Ionic strength effects were not significant during lime softening tests because, unlike the case of in-situ iron precipitation, solids were already present due to the addition of lime as a Ca(OH)2 slurry. Removal of arsenic from full-scale concentrates spiked with arsenic was somewhat similar for lime softening and in-situ iron precipitation. Arsenic was detected by EDX analysis of the solids formed during iron precipitation in the presence of arsenic, however, background noise during analysis of lime softening solids did not allow for arsenic detection. Organic carbon removal from full-scale concentrates was much less than the removals observed for similar doses during treatment of the simulated residuals. Predictions of arsenic removal from the full-scale concentrates (with and without arsenic spike) was relatively good, although more extensive modeling is required and better model parameters should be determined. Based on the economic evaluation of the treatment options for arsenic removal from full-scale residuals, iron coagulation with pH adjustment was cheaper than iron coagulation without pH adjustment option or lime softening for all three full-scale membrane concentrates (with and without arsenic spike).

Microwave chemistry has expanded over the last two decades due to the enhanced reaction rates achieved for many processes, including organic synthesis, inorganic synthesis and polymerization. Significant time and energy saving can be realized using microwave chemistry, which is important both commercially and for the environment. One of the most exciting and commercially/technologically significant areas where microwave energy has been demonstrated to influence the kinetics and selectivity is in the synthesis of nanoporous materials, such as zeolites. New nanoporous materials can be created, and the times for their syntheses can be significantly reduced, involving using less energy. By reducing the times by up to over an order of magnitude, continuous production would be possible to replace batch synthesis. However, the mechanism and engineering for the enhanced rates of these syntheses are unknown. The results from different laboratories are not consistent, and experimental details are sparse. Therefore, more research is required to unlock the mystery behind this “gee-wiz” chemistry. Furthermore, understanding the fundamental processes leading to rate enhancement by microwaves will also enable the optimization of these microwave heated reactions. In this work, the formation of SAPO-11 (and AlPO-11), silicalite and NaY zeolites under microwave heating was investigated and the influence of various microwave reactor engineering parameters was studied. Microwaves enhanced the SAPO-11 synthesis by two orders of magnitude over the conventional synthesis. Both nucleation and growth steps were enhanced by the presence of microwaves. Fast microwave heating was not solely responsible for this enhancement. This indicates that non-thermal interactions of material with microwaves are present for this synthesis. Many microwave reactor engineering parameters were identified as possibly influencing the microwave synthesis of SAPO-11 (and AlPO-11). These factors are precursor volume, reaction temperature, reactor size, stirring, applicator type and microwave frequency. Among those, the reaction temperature had the greatest influence on this SAPO-11 (and AlPO-11) synthesis. Increasing the reaction temperature decreased the nucleation time and increased the growth rate. The crystallization growth rate in the microwave synthesis showed higher activation energy (1.5 times) compared to the conventional synthesis. However, the pre-exponential factor increased by 8 orders of magnitude in the microwave synthesis. Nucleation rate also showed an increase in the activation energy (3.6 times) and an increase in the pre-exponential factor (10 orders of magnitude) by using microwave heating. This substantial increase in the pre-exponential factor could be the reason behind this microwave synthesis enhancement. High temperature, stirred synthesis, large vessel and using multimode field distribution oven found to be the optimum reaction conditions for microwave synthesis of SAPO-11 (and AlPO-11). Thermal variations within SAPO-11, silicalite and NaY synthesis solutions were measured using a reaction vessel with multiple fiberoptic temperature probes. NaY synthesis solution has the shortest microwave penetration depth among these zeolite synthesis solutions which led to great thermal variations between the region near the wall (high temperature) and the center (low temperature) when placed in a vessel with diameter 20 times larger than its penetration depth. Increasing these thermal variations led to a decrease in the nucleation time and thus enhanced this NaY microwave synthesis. Microwave power delivery mode (pulsed vs. continuous) effect on the synthesis of the three zeolites mentioned above was investigated. Pulsing the microwave power required less average power to maintain the synthesis reaction temperature compared to continuous delivery mode. No effect of using pulsed compared to continuous microwave power delivery was found on the nucleation time and the crystal growth for these zeolite syntheses. However, pulsed microwave power delivery produced smaller particles in the case of SAPO-11. The effect of simultaneous cooling effect on the microwave synthesis of SAPO-11 and silicalite was studied. Increasing the amount of power delivered to the SAPO-11 synthesis while maintaining the reaction temperature fixed using the simultaneous cooling, decreased the nucleation time and increased the growth rate. Smaller particles were formed at high power. Silicalite showed no change in the nucleation time, crystal growth and/or the morphology. This indicates that there is no universal pattern among the microwave synthesis of zeolites. What could be an important factor for one synthesis is not necessarily important for another, and is likely dependant on the dielectric properties and the reaction mechanism. Key words: Zeolite, SAPO-11, silicalite, NaY, microwave synthesis, nucleation, crystal growth, frequency, reactor engineering, overheating, temperature distribution, pulsing power delivery, simultaneous cooling.

A ground-water prototype detection system was developed to measure in situ electrical conductivity (EC) of ground water. The system, termed “permanent conductivity points” (PCP), consisted of a number of conductivity cells individually comprised of two-array electrodes attached to a rigid pipe. This system was a “long” conductivity meter permanently installed into the aquifer. It was developed to detect and delineate deicing materials deposited into the ground water of an unconfined sandy roadside aquifer. Measurements from the PCPs provided maximum EC values, which provided a measure of the plume contaminant strength. An extensive site characterization was performed using standard characterizing tools to provide soil, ground water, and the soil/ground-water matrix properties. This information was used to describe the research aquifer, to provide in sight for PCP installation, and to corroborate the PCP measurements. The calibration of the PCPs was performed in the laboratory under carefully controlled conditions providing a reliable calibration factor. Numerous in situ EC measurements were compared to the PCP measurements. The most appropriate comparison was the low-flow ground-water sampling ports (WSP) that were placed directly adjacent to the conductivity cells. Numerous profiles, cross sections, and temporal plots from PCP EC measurements were presented to better describe the delineation of the deicing material in the underlying roadside aquifer. The PCPs were monitored between 1 June 1998 and 19 December 2000 during the research project, encompassing two road-salting seasons. The PCPs proved to be useful in detecting the presence of deicing materials. The maximum contaminant plume EC PCP readings were just over 7500 μS/cm and the ambient were around 70 μS/cm. PCPs were also beneficial in delineating the shape and extent of the contaminant plume. The maximum measured width of the contaminant plume was 60 m and the maximum measured thickness was 10 to 12 m using PCP data. A potential cost savings using PCP technology for long-term ground-water monitoring is possible for geoenvironmental engineering consulting firms when the installation cost, material cost, and personnel sampling-time needed with standard ground-water monitoring wells is considered. The PCP is a low-cost technology that is beneficial for long-term ground-water quality monitoring.

The primary goal of this research was to improve understanding of the fouling of low pressure hollow fiber membranes used in drinking water treatment. The major difference of this study compared to other reported studies was the use of a hollow fiber membrane module at operating conditions mimicking those of full-scale practice. Two poly(vinylidene-fluoroethylene) based hollow fiber membranes (A and B) were tested. Different types of fouling indices (total, hydraulic irreversible, chemical irreversible) developed based on a resistance in series model were used to assess membrane performance. Data from bench-scale and full-scale plants were compared to validate the use of fouling indices. The impact of dissolved organic nitrogen (DON) on membrane fouling was demonstrated with model waters containing humic substances and several model organic nitrogen compounds. Three different natural water sources normalized to the same organic content were tested. Fouling indices determined from the resistance in series model approach were more applicable for natural waters than for model waters. Fouling was proportional to throughput for both raw and pretreated water and at different flux rates. Pretreatment (coagulation) reduced hydraulic irreversible fouling. Most fouling was reversed by hydraulic and chemical cleaning. Specific flux and fouling indices of the bench-scale system were higher than those of the full-scale system but the fouling index ratios were comparable suggesting a similar fouling nature. A minimum of a few days of testing is recommended for longer-term membrane performance assessment. The impact of high DON concentration on membrane fouling was insignificant. Membrane fouling was dependant on foulant properties other than, or in addition to, molecular size and the DON/DOC ratio. With three different natural water sources normalized to a similar organic content, membrane fouling was specific to membrane type and water source. High initial total and hydraulic irreversible fouling rates did not lead to high chemical irreversible fouling rates. It is not possible to generalize the impact of different water sources on membrane fouling. Membrane surface anlyses showed that hydraulically irreversible organic foulants were detected as mostly hydrocarbons/polysaccharides, humic substances and peptide/protein. Humic substances and peptide/protein were found to be organic foulants regardless of their molecular weight and origin. Chemical cleaning with chlorine solution was effective in removing all inorganic foulants and most organic foulants.

Increasing attention has been given to the role of colloids in accelerating contaminant transport as evidence of significant subsurface transport of contaminants continues to be presented. Colloid migration models typically include the processes of advection, dispersion, deposition and release. Present models are limited in their ability to predict the transport and fate of colloids due to limited understanding of the interaction between these processes. The objective of this research is to gain a better understanding of the physical/chemical factors which affect the transport of colloidal particles. Laboratory-scale experiments were conducted in two phases to examine the effects of different chemical and physical factors on colloid transport. In the first phase, pulses of 1.09 and 0.28 $\mu$m fluorescent particles were injected into sand-packed columns under constant chemical conditions, and the response monitored over time. The second phase consisted of making a step change in solution chemistry (reduction in ionic strength or increase in pH) or flowrate to the system and monitoring the fluorescence response over time. The relative impact of various processes including advection, deposition/release, retardation and hydrodynamic chromatography on colloidal transport was evaluated using experimental results. Various mathematical models were evaluated for their effectiveness in describing the observed colloid migration. Results of finite pulse experiments conducted under constant chemical conditions confirm that solution chemistry is a key factor affecting particle deposition and release. Deposition results show evidence of the effects of hydrodynamic chromatography and retardation. As expected, deposition increases with increasing ionic strength. Perturbations in solution chemistry caused the subsequent release of particles. However, the amount released was only a fraction of the total deposit. The release process warrants further research.

During the 1950's, 60's and 70's, a great number of military and civilian airfields dumped thousands of gallons of fuel, waste oils and solvents into the subsurface environment as part of routine fire training activities. These areas now pose a threat to humans and wildlife. This research investigates bioventing and biosparging as remedial alternatives at Plattsburgh Air Force Base (PAFB) where soils are heavily contaminated with JP-4 and solvents. To begin the investigation, site geology and contaminant constituents were thoroughly characterized. Installation and sampling of soil gas monitoring points confirmed the presence of hydrocarbon and TCE vapors in the vadose zone as well as a gradient of decreasing oxygen and increasing carbon dioxide from the ground surface to the water table indicative of aerobic hydrocarbon degradation. New models were developed and used to determine soil gas constituent mass fluxes during ambient and bioventing/biosparging conditions. Mass fluxes of hydrocarbons, TCE, oxygen and carbon dioxide were calculated during ambient conditions based on the soil gas profiles. Combining this information with contaminant characterization and extent yielded an estimated cleanup time of approximately 150 years. After the initial characterization, the bioventing system, operating above the water table, was activated followed by sampling and analysis of O2, CO2, TCE, and HCs. Following 6 months of operation, compound mass fluxes under the pilot scale bioventing system indicated an increase in the hydrocarbon degradation rate by a factor of 4 for an estimated cleanup time of 37 years. After ending the bioventing phase, the biosparging system, injecting air below the water table, was subsequently activated and the same soil gas constituents measured over a period of 4 months. Compound mass flux results indicated a hydrocarbon degradation rate increase over ambient conditions by a factor of 2 (75 years). A new, near surface soil gas measurement tool was developed allowing sample collection in shallow (1m) soils with high resolution (2cm). Based on the pilot scale bioventing and biosparging results, either one or a combination of both of these remedial alternatives would accelerate the cleanup process at PAFB for a reasonable cost.

An investigation of manganese release from manganese oxide coated filter media, observed in a water treatment plant (WTP), was performed. The study involved collection of the ground water (GW) and the full scale green sand (GS) filter media, 16S rRNA gene sequencing of the extracted DNA from freshly sampled GW and GS, laboratory column experiments with the collected GS and GW followed by 16S rRNA gene sequencing of the DNA from GS used in the laboratory column experiments. In 16S rRNA gene sequencing of the DNA collected from the GW and GS, Geobacteraceae, Burkholderia ferrariae, Galionella feruginea, Ochrobactrum, Mesorhizobium, Pseudomonas and Methylobacrum were found as the most dominant species. Among the sequenced microorganisms, ∼20% for the GW and ∼45% for the GS microorganisms were manganese reducers. In laboratory column experiments, a significant level of manganese release was observed from the column with adequate carbon source and non-autoclaved media. The manganese release continued as long as the carbon source was available and no chlorine was added. 16S rRNA gene sequencing results, performed with the DNA from GS before and after the application pre-filter chlorine, showed a significant decrease in the manganese reducers (40% as compared to 97% for the sodium acetate fed non chlorinated situation). The molecular analysis results are in excellent agreement with the laboratory column experiment observation and strongly suggest that the manganese release can occur in GW treatment plants due to the activity of manganese reducing microorganisms; a high level of solution phase free chlorine can limit the release. Possibe manganese-NOM interaction/complexation in raw, filter influent and filter effluent water samples collected from several WTPs was investigated via the high performance size exclusion chromatography (HPSEC) method with continuous UV detection coupled with an inductively coupled plasma mass spectrometer (ICP-MS). The HPSEC-UV254-ICPMS results showed two major UV 254 peaks and one manganese peak at different HPSEC elution times suggesting no significant NOM-manganese complexation. In laboratory column experiments with full scale filter media, some NOM adsorption was observed for media grains having a larger aluminum to manganese coating ratio, however no correlation could be demonstrated regarding how different molecular size fraction of NOM may impact manganese removal by the oxide coated media.