The effect of sulfur dioxide on epiphytes was investigated by methods comprising field studies, transplantation and laboratory experiments. In the field studies, an inventory of the epiphytic flora for the region of Wawa, Ontario, was made on the basis of the investigation of 48 sites. A total of 110 epiphytic species (71 lichens, 29 mosses and 10 liverworts) were recorded. The distribution of sulfur dioxide emitted by an iron sintering plant in the area, as well as the pH and sulfate content of surface-water, soil and vegetation, were determined. The fallout pattern of SO2 and the chemical indices (pH & SO4-) of water and soil were correlated with the epiphytic flora of the region. With a rise in the concentration of SO2 in air and of SO4 - in water and soil, a marked reduction in the epiphytes, both as to the number of species and their abundance, was noted. There was also a significant decrease in the sulfur content of the vegetation with an increase in the distance from the center of pollution. According to the pattern of pollution, the investigated region can be delineated into five zones, corresponding with the epiphytic flora. From this survey it has become apparent that there are various degrees of toxiphoby among epiphytes (from highly toxitolerant to highly toxisensitive species), and that there are several species of lichens and mosses, the absence of which can serve as indicators of, SO2-pollution. In the transplant experiments, forty-two circular discs (diam. 4.8 cm), bearing 19 species of mosses and lichens, were cut from the bark of trees growing in unpolluted areas near Ottawa, Ontario. These discs were transplanted onto trees in the region of Sudbury, Ontario, where the atmosphere is heavily polluted by sulfur dioxide. After one year, the majority of the epiphytes growing on these transplanted discs were either dead or seriously damaged, and only a few species such as Bacidia chlorococca and Parmelia sulcata appeared to be toxitolerant. Thalli of Parmelia caperata and P. sulcata, collected from such discs, showed abnormal features on microscopic examination such as: (i) marked reduction in the thickness of the thallus; (ii) formation of a thin layer of a whitish, crystalline, water-insoluble and acetone-soluble substance on the upper surface of the thallus; (iii) plasmolysis, chloroplast damage, and formation of oil-globules in Trebouxia cells, the algal symbiont; and (iv) formation of chlamydospore-like bodies by the fungal symbiont, especially in the lower cortex of the thallus. From these observations it is evident that the epiphytes are affected to various degrees, both externally and internally, by SO2-pollution. In the laboratory experiments, thalli of Xanthoria fallax, X. parietina, Parmelia caperata and Physcia millerana were exposed to 5 ppm sulfur dioxide for 24 hours under various conditions of humidity. Abnormalities such as bleaching of the chlorophyll, permanent plasmolysis, and the formation of sporadic brown spots on the chloroplasts were observed in the algal cells. Sulfurous acid and Mg++ were detected in the extracts of the SO2-exposed thalli. Sulfate concentration increased in thalli exposed to SO2 in increased humidity. The absorption spectrum of chlorophyll extracted from SO2-exposed thalli showed a maximum absorption at 667 mmu characteristic of phaeophytin-a, thus indicating the degradation of chlorophyll-a into phaeophytin-a under the influence of SO2. These observations are of interest with regard to the well known sensitivity of lichens to atmospheric pollution.

Using ion-specific electrode and atomic absorption spectroscopy the heavy metal (HM) binding capacities of four Ottawa area natural water systems supporting algal blooms were examined, and the effects of HM ions and Anabaena 7120 on each other were studied. The HM binding capacities of the natural water systems studied during 1975 were much higher than those reported previously for Ottawa River water. The HM binding capacities of at least two systems had not decreased several months after the blooms disappeared. Ultrafiltration of the water did not decrease the HM binding capacities of the waters indicating that the HM binding substrate had a molecular weight of less than 500. Complete aching of the water samples removed the Hg 2+ binding capacity, indicating that organic carbon compounds formed the predominant HM binding substrate in the four water systems. Concentrations of 10-3M and 10-4M Cu(NO3)2 and Cd(NO3)2 completely inhibited growth of Anabaena 7120 in GO medium. Copper and cadmium concentrations below 10-4M produced an elongated lag phase compared to cultures with no HM ions present in the medium. When 10-5M nitrilotriacetic acid (NTA) was added to the medium with equal concentrations of Cu(NO3)2 or Cd(NO 3)2 the lag phase was further elongated. An elongated lag phase in Anabaena 7120 cultures was produced by 10-5M to 10-7M Pb(NO 3)2. Growth was not inhibited by 10-3, 10-4 or 10-8M Pb(NO3) 2 in GO medium. A heavy white precipitate formed in GO medium containing 10-3M and 10-4M Pb(NO3) 2. Atomic absorption analysis of Anabaena 7120 culture grown in GO medium containing 10-5 Cd(NO3) 2 had the same cadmium concentration associated with the cell fraction after the lag phase as at the beginning. In contrast, copper was almost completely released from the cells at the end of the lag phase.

Granular activated carbon (GAC) is used in municipal drinking water treatment plants for the removal of organic compounds (natural and synthetic), taste and odour compounds, as well as for the removal of disinfection by-products (DBPs). Many alternative technologies for GAC regeneration, such as bioregeneration, chemical regeneration, chemical desorption regeneration, and steam regeneration, have been tested in attempts to overcome the shortcomings of thermal regeneration. In this study, the suitability of electrochemical regeneration for municipal drinking water systems was investigated. Three different sample types were obtained; virgin, field spent and field-thermally reactivated GAC. The field spent samples were electrochemically regenerated at 10, 50, 100 and 200mA in a divided cell electrochemical reactor for 5 h. The virgin, the thermal and the electrochemical regenerated samples were analysed for aqueous NOM adsorption, iodine number, surface chemistry, pore size distribution and surface area to evaluate the regeneration efficiency and to characterize the regeneration. The electrochemical reactor was able to regenerate 8--15% of the adsorption capacity of the field spent GAC compared to approximately 100% regeneration efficiency for the thermally regenerated samples. (Abstract shortened by UMI.)

ArcGIS Desktop, one the most well known GIS packages, is designed as a scalable system that can be deployed in every organization, from an individual desktop to a globally distributed network of people. Since ArcGIS is built using Microsoft's component object model (COM) technology, it is customizable and possible to extend using any COM-compliant development language. In the present study, ArcMap v8.2, a component of ArcGIS Desktop, is customized using the built-in Microsoft Visual Basic for applications (VBA) language, to create a user-friendly toolbar, called landfill site selection (LSS) toolbar, specifically designed for preliminary landfill site selection. Such a tailored ArcMap environment will enable engineers with different level of knowledge of GIS, to investigate and compare results of applying different criteria, constraints and scoring schemes on the final suitability map for a landfill site in an area.* (Abstract shortened by UMI.) *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Microsoft Office.

Fractured rock aquifers consist of complex flow systems that impose several constraints on cleanup efforts. Remedial techniques in such aquifers are influenced by diffusion of contaminants into the rock matrix and the subsequent back diffusion into the fracture. In particular, the back diffusion process can release a low concentration of contaminant into the groundwater for an extended period of time alter the main source of contamination is removed from the fracture network. Biofilms have been defined as cells immobilized on a solid surface and embedded in a gel matrix of extra-cellular polymeric substances (EPS) excreted by microorganisms. Biofilms can be stimulated on rock surfaces to act as a barrier in groundwater systems, which influences hydraulic properties of the fractured media as well as the rate of contaminant transport between the rock matrix and the fracture. The main objective of this study was to assess the potential of a biofilm to limit diffusion between the host rock and fracture. The impacts of different types of microorganisms on the diffusion rate were compared, and the performances of the tracers employed in diffusion experiments were evaluated. P. putida, E. coli and an indigenous groundwater population were used to grow biofilm on porous ceramic disks with nominal pore diameter of 6 mum. Disks were installed into stainless steel double-reservoir cells. The source reservoirs were spiked to obtain initial concentrations of 1500 ppm of bromide and 5000 ppb of Lissamine. In total, 17 experiments were conducted to assess the diffusion. Finally, a semi analytical model was used to interpret the geometric factors (tortuosity) of the porous media and the impacts of the biofilm on the effective diffusion coefficient. Results, estimated from bromide and Lissamine concentration profiles, did not suggest a significant impact of biofilm on the diffusion through the ceramic disks. This could be due to heterogeneity of biofilm structures, loose structures of developed biofilms, lack of biofilm penetration into the pores inside the disks as a result of nutrient overloading or biofilm decay/detachment during the test. In addition, Lissamine did not appear to perform as a conservative tracer in some cases where mass balance calculations indicated a loss of dye. It was recommended to characterize the biofilm structure as well as the biofilm impregnated zone, and to adjust the nutrient loading in order to obtain a more packed structure for the biofilm developed by small size bacteria. Recommendations also included a thorough evaluation of Lissamine behaviour as a conservative tracer.

The increasing concern over potential health effects of pharmaceutically active compounds (PhACs) and endocrine disrupting compounds (EDCs) in drinking water has led to an increase in assessment of drinking water treatment plant efficiencies at removing these emerging micropollutants. For the most part, tight commercial membrane processes such as nanofiltration (NF) and reverse osmosis (RO) successfully eliminate PhACs and EDCs, however these are costly processes and infrequently implemented in North American treatment facilities. The more frequently used microfiltration (MF) and loose ultrafiltration (UF) membranes are ineffective in the removal of these compounds. This thesis focuses on developing tight charged ultrafiltration (UF) membranes which could effectively remove PhACs and EDCs from drinking water without compromising flux and cost. The approach centers on developing the membrane surface charge by incorporating charged surface modifying macromolecules (CSMMs) as additives. Four CSMMs (MDI-PPG-HBS, MDI-PEG200-HBS, MDI-PEG400-HBS, MDI-DEG-NDS) were evaluated at three different casting conditions for poly(ether sulfone) (PES) based membranes. The modified membranes were compared to controls (without CSMMs) and one commercial membrane (NF270, Dow/Filmtec). Membrane properties including flux, molecular weight cut off, surface porosity, charge and hydrophilicity were evaluated and compared to the removal of four representative PhACs and EDCs (sulfamethazine, carbamazepine, bisphenol A and ibuprofen) at the mg/L-level. The experimental membranes only achieved a temporary partial removal of the PhACs and EDC tested, thus further development is required. Given the temporary target compound removal and the large membrane pores, size exclusion and charge repulsion are not the dominant removal mechanism. From the removal pattern, and the fact that removal increased with increasing solute hydrophobicity, it is assumed that initial removal is caused by adsorption to the membrane. The membranes developed were tight by conventional ultrafiltration standards but did not achieve the performance desired. In general, it was found that the CSMM-modified membranes did not significantly outperform the control membranes. CSMM-modified membranes tested generally produced less hydrophilic membranes with increasing pre-gelation time or PES concentration, in comparison to the control membranes. Pre-gelation time (i.e., three minutes versus no pre-gelation time) increases membrane porosity, and therefore flux is increased, without compromising removal. Increased PES concentration (i.e., 20% PES in comparison to 18% PES) yields more distinct effects from the different CSMMs. From these results, the most promising casting condition appears to be 20% PES and the CSMMs achieving the best removal are MDI-PEG 400-HBS and MDI-PPG-HBS. As increased surface porosity was achieved, continuing this line of research by optimizing membrane preparation conditions to decrease the pore size may produce the desired characteristics. It is recommended that further tests be performed at increased PES concentrations and with pre-gelation time to achieve better results.

Equilibrium adsorption properties are studied on zeolites for the application of upgrading biogas from landfills. Pure adsorption isotherms of carbon dioxide (CO2) and methane (CH4) measured with a constant volume apparatus. The Henry's Law constant and the heat of adsorption for NaLSX is also determined. The adiabatic working capacity and selectivity of four adsorbents is compared. NaLSX showed the highest capacity for CO2 at elevated temperatures. The binary equilibrium of CO2/CH4 on NaLSX is measured in a modified gas chromatograph at total mixture pressures of 1 and 3.3 atmospheres. The adsorbed phase is dominated by CO2 with a selectivity of 20 to 100 for the separation of CO2 and CH4. The increase in total pressure resulted in an increase in adsorbent capacity and a decrease in selectivity. Finally, an economic analysis relates landfill size to PSA operational costs and returns.

When considering pathways of contaminants to pristine areas, the focus has been largely on atmospheric and oceanic transfer. In this study, sediment cores were used to study a far less investigated but very effective pathway of persistent organic pollutants (POPs) to pristine ecosystems: the biotransport by migrating sockeye salmon (Oncorhynchus nerka). To quantify the importance of salmon as a biotransporter of contaminants, surface sediments of lakes in Alaska and British Columbia spanning a wide gradient of salmon returns (0--40,000 salmon per km2) were analyzed. Regressions of contaminant concentrations in the surface sediments with the number of returning salmon revealed a very strong, positive relationship. Especially for the lakes that received high numbers of spawners, sockeye salmon were found to be a more important source of PCBs (Polychorinated biphenyls) than the atmosphere. Furthermore, the quality of the relationship of PCB concentration with sockeye salmon spawners was found to be best for PCB congeners that are most abundant in sockeye salmon muscle tissue. Down-core profiles were analyzed to examine if the relationship between contaminant concentrations and sockeye salmon numbers can also be found historically within a lake. To investigate this question, contaminant concentrations in the 210Pb dated sediments were compared to historical sockeye salmon counts provided by authorities in Alaska and British Columbia. The results indicate that although it is possible to find the relationship between sockeye salmon spawners and contaminant concentration in down-core profiles, it is influenced by numerous factors. Such factors can arise from contaminant patterns that result from sources other than salmon, or simply very low sedimentation rates, which lead to very low resolutions in the down-core profiles.

Mercury (Hg) is a contaminant of global concern due to its toxicity to humans and other organisms. Methylmercury (MeHg) is the most hazardous form of mercury commonly found in the environment, as it bioaccumulates in aquatic food webs. Its production has been linked with microbial sulfate reduction in soils and sediments. Mine tailings cover vast land areas and release acidity and toxic metals, including Hg, to the environment. Sulfate-reducing bacteria (SRB) are active in mine tailings, indicating the potential for MeHg formation. This study investigated MeHg levels in mine tailings and the chemical and microbiological factors that might lead to significant MeHg contamination. Acidic base-metal tailings from northern Ontario were examined because they host active SRB but Hg and MeHg concentrations were unknown. Gold mine tailings from Nova Scotia were studied because Hg amalgamation was used there around 1860-1940, leaving Hg-rich tailings of unknown MeHg content and microbiology. MeHg accumulated in organic material in both environments. Acidic tailings contained negligible levels of MeHg, except for the Kidd Metsite tailings, which featured ≤ 12 nmol kg-1 MeHg in bulk tailings and 88 pM MeHg in porewaters, corresponding to a zone of sulfate reduction in the surficial layer (pH 3.7). Gold mine tailings featured a wide range of both HgT (0.2 - 53.5 mumol kg-1) and MeHg (< detection limit - 56.4 nmol kg-1). HgT levels decreased with distance from the stamp mills where ore was pulverized and treated with Hg. MeHg was influenced by multiple factors including HgT concentration, hydrological conditions, redox conditions, and demethylation. Seasonal fluctuations in MeHg were observed in one bog-type gold tailings dump. Analysis of DNA from MeHg-contaminated tailings and cultures detected Gram-positive (Firmicutes) and -negative (Deltaproteobacteria ) SRB in both types of tailings. A Deltaproteobacteria related sequence from the Kidd Metsite was unrelated to cultured lineages but 98-99% related to sequences detected in acid mine drainage elsewhere. This organism may be an important contributor to MeHg levels in acidic situations. DNA from gold tailings and cultures revealed a highly biodiverse bacterial community that included at least five Deltaproteobacteria spp. and sequences related to Hg-resistant genera.

One critical source, which adds to the anthropogenic methane (CH 4) emissions, is solid waste disposal. The biogas generated from biodegradation of solid waste in landfills, known as landfill gas (LFG), consists of CH 4, carbon dioxide (CO2), plus trace amounts of non-methane organic compounds (NMOCs). Most of the existing landfills around the world do not have LFG collection setups, and the emissions are just released into the atmosphere. Oxidation of CH4 and NMOCs by methanotrophic bacteria within the landfill cover (LFC) provides a sink for these harmful fugitive emissions. The scope of this research was to carry out a comprehensive study on the biological oxidation of CH4 and NMOCs in the LFC, under diverse operating conditions. To achieve this goal, various parameters affecting the oxidation process, including cover medium, temperature, saturation limit and nutrients addition, were studied. Statistical analysis and modeling were carried out to estimate the interactions between several parameters under investigation, and to draw conclusions about the combined effects of these parameters on the LFC system. The effects of NMOCs on CH4 oxidation capacity of the LFC were examined in batch scale and continuous flow column experiments. Additionally, the co-metabolic abilities of methanotrophs were explored and the biological bio-degradation rates on NMOCs were estimated under different temperature and moisture content levels. Artificial neural networks (ANN) modeling technique was used to describe the complex input/output relationships and to simulate the CH4 oxidation rates in the presence of NMOCs under diverse conditions that are representative of LFC system.