A wastewater treatment and reuse system consisting of a tile drainage system, a constructed treatment wetland (CTW), a reservoir, and an irrigation system was established. The system supplied 780 mm of irrigation water for the 1.8 ha of drained land for the 2008 growing season. A hydraulic tracer study conducted in the CTW supported the use of a length to width ratio of 10:1. During 2008, annual nitrate-nitrogen (NO3--N) and Escherichia coli (E. coli) mass reductions were 67.6 and 63.3%, respectively. Elevated E. coli levels were observed in the reservoir during the warm season. Therefore, water may not be safe for irrigating crops consumed raw. The mean first-order areal uptake rate constants generated for NO3--N and E. coli were 8.0 and 6.4 m y-1, respectively, and are recommended for similar CTWs. A wetland area to drainage area ratio of 4.5% is recommended to achieve ? 70 % mass reduction of NO3--N and E. coli

In this thesis, a semi-permeable lining system was proposed to upgrade arctic wastewater stabilization ponds, acting as a biofilter. Although commonplace at lower latitudes, the effects of cold temperatures and short-duration summers on biofilter performance are inadequately studied. The goal of this research was to study the hydraulic and treatment performance of geotextile substrate biofilters under arctic conditions. Filtration experiments were conducted in a laboratory environment. Municipal wastewater was passed through columns containing nonwoven geotextiles over 10 cm of gravel. Three experimental trails were conducted at either 10? or 2?, each lasting 12 weeks. Weekly samples taken before and after filtration were analyzed for various water quality parameters. Hydraulic conductivity was monitored using weekly constant head permeameter tests. Results showed that biomat accumulation is possible on geotextile material over 12 week period. Significant removal of TSS and BOD5 was observed, along with a 1-log reduction in hydraulic conductivity.

Nitrogen compounds, such as aqueous ammonia, are a widespread problem in the wastewater industry as they are toxic to numerous aquatic life, cause eutrophication, and contribute to various environmental concerns. Environment Canada has mandated new wastewater regulations, limiting un-ionized ammonia discharge to 1.25 mg/L, expressed as nitrogen. This study provides insight into methods for removing nitrogen compounds, specifically aqueous ammonia, from wastewater. Two wastewater treatment technologies were compared: Ultra Violet light and an electrochemical process. These treatments were evaluated individually, as well as in combination, to determine potential synergistic effects.

No description available.

The effectiveness of a cheap, low-tech, environmentally and technically favorable treatment of secondary treated municipal wastewater by contaminant removal through a floodplain-soil filter was evaluated using floodplain-simulating field lysimeters, packed with a sandy soil in 2002 and sand in 2003 and 2004. Secondary treated wastewaters from Vaudreuil (2002 and 2003) and Pincourt (2004) Wastewater Treatment Plants were used as influent. This was applied at rates of 0.06, 0.19, and 0.31 m3 m-2 d -1 to vegetated lysimeters, and at a rate of 0.19 m3 m-2 d-1 to bare-soil lysimeters. / Removal of NH4+-N, NO3--N, and COD from the influent was studied in all three years. Irrespective of flow rate or year, the system removed 62~84%, 96~99%, and 6~67% of TKN, NH4+-N, and COD, respectively, from the influent. Under 0.19 m3 m-2 d-1 flow rate, vegetated systems removed slightly more of these constituents from the influent, than did bare-soil lysimeters. Organic degradation mainly occurred in the top 0.1 m soil depth. Degradation of organic and inorganic influent nitrogen increased NO3--N levels in the effluent. Only minimal increases in soil-N levels and N2O emissions occurred with increasing application rates. The nitrogen mass balance accounted for 85∼98% (2003) and 67∼96% (2004) of input nitrogen (through leaching, soil retention, and N2O emissions), the remaining portion being attributable to vegetative effects and volatilization of non-N2O nitrogenous gases. The under established vegetation on the lysimeters reduced nitrogen leaching through soil, being 6% (2003) and 60% (2004) more effective than bare soil. / Effluent water quality improved with decreasing levels of heavy metals. Compared to influent levels, in vegetated lysimeters, under all flow rates, mean effluent As, Cd, Cu, Ni, Pb, and Zn levels had dropped by 58%, 9%, 3%, 37%, 63%, and 52% in 2003, and by 20%, 63%, 5%, 23%, 18%, 57%, and 79% for As, Cd, Cr, Cu, Ni, Pb, and Zn, in 2004. In both years, similar decreases in heavy metal levels occurred in the bare soil lysimeters. Across all flow rates and influent concentrations, soil heavy metal levels increased. In 2004, even low heavy metal content influent further increased (6∼179%) their accumulation in soil. As inputs of heavy metals to the soil increased with the increase in application rates, their associated times to reach maximum permissible limits also decreased. / LEACHN simulation of NO3--N in leachate arising from wastewater application, showed lowered levels with increasing flow rates, due to enhanced denitrification in the resulting anoxic upper soil zones. The simulation under continuous wastewater application at different range of nitrogen concentrations (low, medium, high) showed an increase of NO 3--N levels in the leachate with increasing N-levels. For all flow rates, and under tropical or humid conditions, the effluent NO 3--N levels remained below permissible limits for the low-N content wastewater applications. Intermittent applications, under all wastewater N-contents and flow rates, reduced NO3--N levels in the leachate by 51∼89% compared to continuous wastewater application, and permissible limits were not exceeded. Hence, wastewater with high levels of nitrogenous compounds, as occurs in most developing countries, could be treated by land under an intermittent application pattern, allowing a considerable reduction in nitrate pollution.

Wastewater microbial flocs can protect microorganisms from inactivation by UV light. This effect is detected as tailing at high UV doses in the UV dose response curve. A double-layer structure composed of an inner compact core surrounded by a loose outer layer was proposed by earlier studies to describe UV resistance of microbial flocs. Due to limited oxygen diffusion into the compact cores, the UV inactivation of compact cores and microbial flocs under anaerobic conditions needed to be addressed. The UV disinfection kinetics under anaerobic culturing condition was nearly identical to that of the aerobic study. Moreover, the role of iron concentration on the differences in the UV inactivation kinetics of flocs and cores was assessed. The increase in UV absorbance of floc material due to iron addition could dominate the UV disinfection kinetics of flocs and cores such that they exhibited similar UV disinfection kinetics.

Since humans began to permanently settle locations for extended periods of time there has been the challenge to safely dispose of, or treat human effluent. In specific to the communities of Nunavut and Arctic Canada, the treatment of wastewater has been particularly challenging. The harsh climate, remote nature and socio-economic factors are a few of the aspects which make the treatment of wastewater problematic in Canadian Arctic communities. In the past several decades a number of conventional and alternative wastewater treatment systems (e.g. lagoons and tundra wetlands) have been proposed and implemented in Nunavut and other remote Arctic communities. Knowledge of performance of these systems is limited, as little research has been conducted and regulatory monitoring has been poorly documented or not observed at all. Also, in the past, the rational design process of treatment systems in Arctic communities has not acknowledged cultural and socio-economic aspects, which are important for the long-term management and performance of the treatment facilities in Arctic communities. From 2008 to 2010 I characterized and studied the performance of several tundra wastewater treatment wetlands in the Kivalliq Region of Nunavut, as well as two in the Inuvaliat Region of the Northwest Territories. Performance testing occurred weekly throughout the summer of 2008. Characterization included surveys of plant communities in the tundra wetlands, specifically analyzing the relationship between Carex aquatilis and various nutrient contaminants in wastewater. Through their characterization I was able to provide greater insight into primary treatment zones within the wetland, and identify the main potential mechanisms for the treatment wastewater in the Arctic. I also studied the performance of a horizontal subsurface flow (HSSF) constructed wetland in Baker Lake Nunavut; the first system of its kind in the Canadian Arctic. The weekly performance study showed average weekly percent reduction in all parameters, with small deviations immediately after snow-melt and at the beginning of freeze-up. For the six parameters monitored I observed reductions of 47-94% cBOD5, 57-96% COD, 39-98% TSS, >99% TC, >99% E. coli, 84-99% NH3-Nand 80-99% TP for the six tundra treatment wetlands. Whereas, the wetland characterization study through the use of spatial interpolations on each of the wetlands and their water quality showed that concentrations of the wastewater parameters decreased the most in the first 100m of the wetland in all three treatment wetlands used in this portion of the analysis (Chesterfield Inlet, Paulatuk and Ulukhaktok). Areas of greatest concentration where shown to follow preferential flow paths with concentrations decreasing in a latitudinal and longitudinal direction away from the wastewater source. The Paulatuk and Ulukhaktok treatment wetlands were observed to effectively polish pre-treated wastewater from the facultative lake and engineered lagoon, with removals of key wastewater constituents of cBOD5, TSS and NH3-N to near background concentrations. And despite the absence of pre-treatment in Chesterfield Inlet, the wetland was also observed to effectively treat wastewater to near background concentrations. Further characterization on the composition of the sedge C. aquatilis, showed a high percent cover of the species corresponded with areas of high concentration of NH3-N in the wastewater. A principal components analysis verified the spatial results showing correlation between C. aquatilis cover and NH3-N concentrations. Analysis also showed strong positive relationship between sites closer to the source of wastewater and C. aquatilis. No correlation was found between the other parameters analyzed and C. aquatilis. The first year of study of the HSSF constructed wetland showed promising mean removals in cBOD5, COD, TSS, E. coli, Total Coliforms, and TP throughout the summer of 2009; removals of 25%, 31%, 52%, 99.3%, 99.3%, and 5% were observed respectively. However, the second year of study in 2010 the system did not perform as expected, and concentrations of effluent actually increased. I concluded that a high organic loading during the first year of study saturated the system with organics. Finally, a review of planning process and regulatory measures for wastewater in Arctic communities and the impending municipal wastewater standards effluent resulted in the following recommendations; i) wastewater effluent standards should reflect the diverse arctic climate, and socio-economic environment of the northern communities, ii) effluent standards should be region or even community specific in the Arctic, and iii) for planning and management of wastewater incorporation of Inuit understanding of planning and consultation needs to be incorporated in the future. This research has several major implications for wastewater treatment and planning for Nunavut and other Arctic Regions. The performance and characterization of tundra treatment wetlands fills significant gaps in our understanding of their performance and potential mechanisms of treatment, and treatment period in the Kivalliq Region. Although the HSSF constructed wetland failed, further research into engineered/augmented treatment wetlands should be considered as they provide low-cost low maintenance solutions for remote communities. Finally, the data collected in this study will provide significant insight into the development of new municipal wastewater effluent standards for northern communities, which will be reflected in the Fisheries Act.

No description available.

No description available.

Azolla filiculoides has been evaluated for the adsorption of trace toxic metals from aqueous solution. The adsorption performance of the material was compared with commercial resins and fitted using the Langmuir and Freundlich models. The Freundlich model described the adsorption of copper and cadmium. Whilst the Langmuir isotherm had the better fit of the mercury data. The assumptions of the Freundlich model include multi-layer adsorption and different functional group binding. Conversely the Langmuir model suggests mono-layer adsorption and can infer single group reactivity. The pH effect on the uptake of the metals was investigated and an increase in removal was observed at higher pH with all the metals studied. The material has been thoroughly characterised using physical methods, such as, scanning electron microscopy X-ray photoelectron spectroscopy and electrophoretic mobility measurements. This enabled conclusions to be made regarding the surface functionality of the solid. Chemical characterisation included direct titrations, revealing a gradual dissociation of acidic groups as the pH increased within the experimental range. Kjeldahl nitrogen and amino acid analysis of several biological materials that have been used in metal sorption experiments showed A. filiculoides as having a large proportion of these cell constituents. The kinetics of metal ion uptake by the biosorbent was investigated and compared with commercially available resins. The kinetics are slower than conventional ion exchange resins and carbon adsorbents but entirely adequate for utilisation in a column process. The mechanism hypothesized for metal ion removal by the biosorbent is primarily attributed to ionogenic groups exchanging ions for copper and cadmium removal. Mercury on the other hand is said to be predominantly involved in a reduction-precipitation reaction on the surface of the adsorbent. Regeneration was successfully accomplished for copper and cadmium after minicolumn trials, with greater than 95 % elution of the metals using 0.1M HCI. The mini column trials showed a sharp breakthrough for these metals singularly and a dynamic equilibrium was observed during multi-metal processing. Mercury removal was much slower and more difficult with the same eluant, achieving a maximum of 50% removal. A method for a semi-continuous biosorbent process has been evaluated and proven to be successful in processing metal laden solution.