This project proposes a new urban aquifer strategy that utilizes stormwater to create a cascading plaza and an improved 'great street' in Washington DC. A system of urban aquifers is developed beneath the surface of the street, perched atop the compacted, impermeable soils below. This set of aquifers prevents stormwater from entering the existing combined sewer and allows trees to draw water from this new groundwater source and develop expansive root systems. On the surface, stormwater flows through interconnected planters where it irrigates and is filtered by vegetation before infiltrating to recharge the aquifer. At Cascade Plaza, sloping topography intersects the aquifer, and the new groundwater seeps out of the plaza steps, turning them into a miniature cascade, by gravity and water pressure alone. It collects in a web of runnels, pools at the lowest point, and overflows in high water, mysteriously disappearing below ground again to fill an underground reservoir. In this unique ecological system, water flows both above and below ground to mitigate excess stormwater and make the street and plaza more beautiful. / Master of Landscape Architecture / This project proposes a new urban aquifer strategy that utilizes stormwater to create a cascading plaza and an improved ‘great street’ in Washington DC. A system of urban aquifers is developed beneath the surface of the street, perched atop the compacted, impermeable soils below. This set of aquifers prevents stormwater from entering the existing combined sewer and allows trees to draw water from this new groundwater source and develop expansive root systems. On the surface, stormwater flows through interconnected planters where it irrigates and is filtered by vegetation before infiltrating to recharge the aquifer. At Cascade Plaza, sloping topography intersects the aquifer, and the new groundwater seeps out of the plaza steps, turning them into a miniature cascade, by gravity and water pressure alone. It collects in a web of runnels, pools at the lowest point, and overflows in high water, mysteriously disappearing below ground again to fill an underground reservoir. In this unique ecological system, water flows both above and below ground to mitigate excess stormwater and make the street and plaza more beautiful.

Biofiltration is one of many ecosystem services provided by mussels. Besides filtering and clearing waters from miscellaneous harmful particles and debris, mussels also have the ability to lower the turbidity of the water. How the presence of mussels affect macrophyte growth is however a less researched area of science. In this study I try to assess if the presence of Unio tumidus have an effect on the growth of Eleocharis acicularis. I used mesocosms containing individuals from both species and through continuous measurements of water chemistry as well as the measuring the difference in plant biomass between the start of the experiment and the harvest at the end of the experiment. The only significant effect observed was on conductivity which increased by 82% in aquaria with mussels as opposed to only 74% in those without. Interestingly there was no increase in the mean biomass of the plants, instead there was a decrease in mean plant biomass over time. / Biofiltration är en av många ekosystemtjänster som musslor tillhandahåller. Förutom att rena stora mängder vatten från diverse skadliga ämnen så sänker även musslors biofiltration turbiditeten i vattnet. Hur musslornas närvaro påverkar makrofyter är dock ett mindre utforskat område. I den här studien undersöker jag huruvida närvsaro av Unio tumidus påverkar tillväxt hos Eleocharis acicularis. Jag använde mesocosmer innehållande individer av båda arter och genomförde kontinuerliga mätningar av vattenkemin samt mätte förändringar i biomassan hos växterna. Musslorna hade inte en signifikant effekt på vare sig pH, turbiditet, nivåer av chlorophyll-a eller biomassa hos växterna. Den enda variabeln som musslorna visade sig ha en signifikant effekt på var konduktiviteten, som ökade signifikant med 82% i akvarierna med musslor kontra en ökning på endast 74% i akvarierna utan musslor. Intressant nog så minskade växterna i biomassa över tid.

Au Canada, en 2006, plus de 27 millions de tonnes de déchets solides non-dangereux (DS) ont dû être éliminées. Au Québec, la principale méthode utilisée pour ce faire est l'enfouissement. Par exemple, en 2000, plus de 75% des 7 millions de tonnes de DS étant éliminées l'ont été par enfouissement. Cette méthode a pour inconvénient majeur la génération de lixiviat résultant de la percolation des eaux de précipitations au travers des masses de déchets. Ce lixiviat est généralement capté et doit être traité avant d'être rejeté vers un milieu récepteur. Les systèmes de traitement présentement utilisés peuvent s'avérer coûteux en plus de devoir être opérés par du personnel spécialisé. De plus, avec l'arrivée en 2009 au Québec d'une nouvelle réglementation sur les lieux d'enfouissement de DS, plusieurs de ces systèmes risquent de ne plus répondre aux normes quant aux concentrations en polluants dans les eaux traitées, particulièrement en ce qui a trait au zinc et à l'azote ammoniacal. Dans cette optique, des essais ont été effectués au Centre de recherche industrielle du Québec (CRIQ), en collaboration avec l'Université Laval, afin d'évaluer la performance de la biofiltration sur support organique pour le traitement du lixiviat de lieux d'enfouissement de DS. Deux biofiltres ayant chacun un diamètre de 200 mm et une hauteur de garnissage de 1500 mm ont été alimentés avec un lixiviat prélevé sur un site d'enfouissement existant. Un suivi bimensuel des paramètres normes par le règlement sur l'enfouissement et l'incinération des matières résiduelles (REIMR) a été effectué sur le lixiviat en entrée et en sortie de ces biofiltres, et ce pour une période d'opération de plus de 300 jours. D'autre part, cinq colonnes ayant chacune un diamètre de 76 mm et une hauteur de garnissage de 300 mm ont été construites et différents médias ont été mis à l'essai pour évaluer leur capacité à capter les métaux résiduels à la sortie d'un des biofiltres. Les résultats obtenus laissent entrevoir que la technologie de biofiltration sur support organique combinée à une couche de média spécifique pour le captage des métaux permet de traiter le lixiviat d'un lieu d'enfouissement de DS de manière à ce que leur rejets respectent l'ensemble des normes stipulées par le REIMR.

Au Biodôme de Montréal, la culture d'algues marines pourrait contribuer à l'amélioration de l'habitat aquatique et permettre à l'institution de combler ses exigences en termes de qualité de l'eau. En effet, les macroalgues peuvent diminuer les concentrations en nitrates et en phosphates générés par la décomposition des déchets métaboliques des animaux captifs puisqu'elles absorbent ses nutriments pour combler leurs besoins de croissance. L'objectif de ce projet est de contribuer au développement d'un biofiltre macroalgal adapté aux conditions d'opération de l'écosystème marin du Biodôme de Montréal. Les performances de bioremédiation de deux espèces d'algues marines indigènes, Palmaria palmata et Ulva lactuca, ont été évaluées sous des conditions expérimentales similaires à celles des bassins d'exposition, soit deux températures (5 et 10°C) et trois concentrations élevées en nitrate et phosphate (2 856:194 vs. 3 570:242 vs. 4 284:291 µM NO₃-:PO₄³⁻). Après six jours de culture, nos résultats démontrent 1) que les différentes concentrations en nutriments et la température n'influencent pas significativement la vitesse d'absorption des nutriments chez les deux espèces; 2) que la croissance de P. palmata n'est pas influencée par les traitements et 3) qu'U. lactuca démontre une croissance maximale à 10°C et à concentration intermédiaire. Le niveau élevé de saturation tissulaire en N, en lien avec les conditions environnementales nutritives du milieu de culture, limiterait l'absorption des nutriments et la croissance des macroalgues. Entre les deux espèces, U. lactuca semble une meilleure candidate que P. palmata dans nos conditions expérimentales, car elle démontre une vitesse d'absorption des nitrates trois fois supérieure (1,76 ± 0,59 vs. 0,65 ± 0,15 mg N MS⁻¹ d⁻¹), une vitesse d'absorption des phosphates deux fois supérieure (0,32 ± 0,21 vs. 0,14 ± 0,11 mg P DW⁻¹ d⁻¹) et un taux de croissance trois fois supérieur à P. palmata (2,12 ± 0,89 vs. 0,64 ± 0,18 % MF d⁻¹). Pour poursuivre le développement d'un biofiltre macroalgal efficace, l'accès à la lumière, le contrôle du pH et la disponibilité en microéléments devraient être optimisés

The thesis mainly focused on the implementation of advanced oxidation processes for the elimination of three non-steroidal anti-inflammatory drugs-ketoprofen, naproxen and piroxicam in waters. The three compounds are among the most used medicines, whose presence in waters poses a potential ecotoxicological risk. Due to the low pharmaceuticals removal efficiency of traditional wastwater treatement plants, worldwide concerns and calls are raised for efficient and eco-friendly technologies. Advanced oxidation processes, such as ozonation-biofiltration, electro-Fenton and anodic oxidation processes, which attracted a growing interest over the last two decades, could achieve almost complete destruction of the pollutants studied. Firstly, removal of selected pharmaceuticals from tap water was investigated by electrochemical advanced oxidation processes "electro-Fenton" and "anodic oxidation" with Pt or boron-doped diamond anode and carbon felt cathode at lab-scale. Removal rates and minieralization current efficencies under different operatioanl conditions were analysed. Meanwhile, intermediates produced during the mineralization were also identified, which helps to propose plausible oxidation pathway of each compound in presence of *OH. Finally, the evolution of the global toxicity of treated solutions was monitored using Microtox method, based on the fluorescence inhibition of Vibrio fischeri bacteria. In the second part, the three nonsteroidal anti-inflammatory molecules added in organics-free or surface water were treated under varying ozone treatment regimes with the quite well established technology ozone/biofiltration. A bench-scale biological film was employed to determine the biodegradability of chemical intermediates formed in ozonized surface water. Identification of intermediates formed during the processes and bacterial toxicity monitoring were conducted to assess the pharmaceuticals degradation pathway and potential biological effects, respectively

Biological filtration (Biofiltration) processes have been used first in Europe and then in North America for decades, however currently there is not a good overall parameter to guide biofiltration design and operation except adopting parameters from traditional particle- removal filtration process. On the basis of the biofilm model developed by Rittmann and McCarty (1980a) and the pseudo-analytical solution for the model, Zhang and Huck (1996a) obtained an analytical solution for PF (plug flow) reactors (which can be used for biofilters approximately) after demonstrating that axial dispersion could be reasonably ignored and developed a new parameter, X*, which incorporates considerations of physical contact time, filter media particle size, kinetics, etc. A small-scale application on peers’ engineering/research data by Huck (1999) demonstrated it was a better indicator than other parameters for biofiltration performance. By collecting, screening and investigating literature on AOC, BDOC and odorous compounds removal by biofiltration process, this thesis applied the X* concept to the collected investigations to assess process performances among different target parameters, different filters and different investigations. To the author’s knowledge, this is the first such attempted comprehensive comparison of literature studies, interpreted in terms of a common parameter (X*). The wide ranges of particle sizes, EBCTs, temperatures and high diversity of pre-treatment and operation conditions for the collected cases were considered to be able to well represent biofiltration practices for studied removal targets. No significant relationship between EBCTs and removal percentages were found, indicating that EBCT alone is not able to guide biofiltration design and operation. Based on kinetics parameter comparison, BDOC removal-X* relationship was established. A new parameter, θα, was developed in this thesis to refer to estimated X* values only considering EBCT and particle size. θα parameter values were estimated by comparison of ratios of θα products ((θα)’) based on the properly chosen calculation bases. Distribution of the θα values for temperature-favored (i.e. temperature ≥15°C) AOC and BDOC removal biofiltration processes matched the established removal-X* relationship reasonably. Given the exploratory nature of this research and the complexity of attempting quantitations, fits were assessed based on visual comparison. With the assistance of supporting information and by adopting available temperature activity coefficients, temperature-adjustment coefficients for θα values were determined for the different temperature ranges. Temperature-adjusted AOC and BDOC removal-θα relationships were developed and temperature-adjusted θα parameter values for AOC and BDOC removal were also estimated. Comparisons were conducted, showing fair matches based on visual examinations, for most of the temperature ranges. No relationships were found between ozone dosages and AOC/BDOC removal percentages and the statistical analysis indicated there was significant difference of removal efficiencies between ozonated and non-ozonated influents for biofilters, suggesting ozonation may not only increase the amount of BOM for following biofilter and increase the biodegradability of bulk water; it may also increase the biodegradability of AOC and BDOC themselves. It may not be realistic to obtain the estimated θα values for MIB and geosmin removal by biofiltration. However, plotting θα product vs. removal percentage for the collected MIB and geosmin removal cases shows more positive co-relationships than EBCT-removal percentage relationships visually. A utilization factor η was proposed to guide biofilter design and operation and to assess “over-design” and “under-operated”. Biofilter over-design or under-operated is common for the collected cases. In general, examining X* (or θα, a parameter incorporating the physical components of X*) provided useful information in terms of evaluation and prediction of biodegradable organic compounds removal by biofiltration, which confirms that X* is a better parameter for biofiltration design and operation than other parameters, such as EBCT.

Biological filtration (Biofiltration) processes have been used first in Europe and then in North America for decades, however currently there is not a good overall parameter to guide biofiltration design and operation except adopting parameters from traditional particle- removal filtration process. On the basis of the biofilm model developed by Rittmann and McCarty (1980a) and the pseudo-analytical solution for the model, Zhang and Huck (1996a) obtained an analytical solution for PF (plug flow) reactors (which can be used for biofilters approximately) after demonstrating that axial dispersion could be reasonably ignored and developed a new parameter, X*, which incorporates considerations of physical contact time, filter media particle size, kinetics, etc. A small-scale application on peers’ engineering/research data by Huck (1999) demonstrated it was a better indicator than other parameters for biofiltration performance. By collecting, screening and investigating literature on AOC, BDOC and odorous compounds removal by biofiltration process, this thesis applied the X* concept to the collected investigations to assess process performances among different target parameters, different filters and different investigations. To the author’s knowledge, this is the first such attempted comprehensive comparison of literature studies, interpreted in terms of a common parameter (X*). The wide ranges of particle sizes, EBCTs, temperatures and high diversity of pre-treatment and operation conditions for the collected cases were considered to be able to well represent biofiltration practices for studied removal targets. No significant relationship between EBCTs and removal percentages were found, indicating that EBCT alone is not able to guide biofiltration design and operation. Based on kinetics parameter comparison, BDOC removal-X* relationship was established. A new parameter, θα, was developed in this thesis to refer to estimated X* values only considering EBCT and particle size. θα parameter values were estimated by comparison of ratios of θα products ((θα)’) based on the properly chosen calculation bases. Distribution of the θα values for temperature-favored (i.e. temperature ≥15°C) AOC and BDOC removal biofiltration processes matched the established removal-X* relationship reasonably. Given the exploratory nature of this research and the complexity of attempting quantitations, fits were assessed based on visual comparison. With the assistance of supporting information and by adopting available temperature activity coefficients, temperature-adjustment coefficients for θα values were determined for the different temperature ranges. Temperature-adjusted AOC and BDOC removal-θα relationships were developed and temperature-adjusted θα parameter values for AOC and BDOC removal were also estimated. Comparisons were conducted, showing fair matches based on visual examinations, for most of the temperature ranges. No relationships were found between ozone dosages and AOC/BDOC removal percentages and the statistical analysis indicated there was significant difference of removal efficiencies between ozonated and non-ozonated influents for biofilters, suggesting ozonation may not only increase the amount of BOM for following biofilter and increase the biodegradability of bulk water; it may also increase the biodegradability of AOC and BDOC themselves. It may not be realistic to obtain the estimated θα values for MIB and geosmin removal by biofiltration. However, plotting θα product vs. removal percentage for the collected MIB and geosmin removal cases shows more positive co-relationships than EBCT-removal percentage relationships visually. A utilization factor η was proposed to guide biofilter design and operation and to assess “over-design” and “under-operated”. Biofilter over-design or under-operated is common for the collected cases. In general, examining X* (or θα, a parameter incorporating the physical components of X*) provided useful information in terms of evaluation and prediction of biodegradable organic compounds removal by biofiltration, which confirms that X* is a better parameter for biofiltration design and operation than other parameters, such as EBCT.

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