bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrient Removal Technology in North America and the European Union: A Review
Authors: Oleszkiewicz Jan A. , Barnard James L.
Published: May 2018

The European Union (EU) has implemented effluent (emission) standards since 1991, while North America practices a riskbased, imission approach. Progressing eutrophication and large fees for discharged loads push EU countries toward more stringent effluent concentrations, below total nitrogen (TN) levels of 10 mg/L and total phosphorus (TP) levels of 1 mg/L. In North America, the limit of treatment technology (LOT) concept has been defined as the lowest economically achievable effluent quality, which for TN is <1.5 to 3 mg/L and TP is <0.07 mg/L. These limits are becoming targets in fragile ecoregions in North America and drive the technology solutions towards a combination of advanced biological nutrient removal process trains, followed by chemical polishing and solids separation by granular or cloth filters or membranes. In Western Canada one-biomass biological nutrient removal processes are used, such as Westbank or Step-feed, often followed by filtration to achieve low effluent total phosphorus levels. Eastern Canada has a less stringent approach to nitrogen control and practices chemical phosphorus removal. Requirement for total nitrogen removal and rising costs of phosphorus precipitation drive designers towards advanced one-biomass processes and full utilization of carbon (for denitrification and phosphorus removal) available in raw wastewater and primary sludge. New processes are developed to take advantage of carbon available in waste activated sludge or even in the recycled activated sludge. Sludge treatment return streams have high nutrient loads and novel processes are introduced for their treatment, some utilizing generated nitrifier biomass for bio-augmentation of the main stream nitrification process. The impact of sludge processing on the liquid train and vice versa is now fully embedded in the design process.
Relative Performance of Different Shaped Surface Aeration Tanks
Authors: Rao Achanta Ramakrishna , Kumar Bimlesh , Patel Ajey Kumar
Published: May 2018

Surface aeration experiments were conducted in tanks of length to width ratio (L/W) 1.0, 1.5 and 2 as well as circular tanks to study their relative performance on oxygen transfer and energy consumption while re-aerating deoxygenated water. An identical geometric similarity of various linear dimensions of aerators, rotor blades and rotor diameter was maintained for all sizes and shapes of aeration tanks tested. The power consumed per unit volume concept to simulate the oxygen transfer coefficient k was found to be valid for all three shapes of aerators. Simulation equations to predict the oxygen transfer coefficient k for any given dynamic parameter governing the theoretical power per unit volume, X, were developed for rectangular tanks of L/W ratios equal to 1.5 and 2. Results were compared with simulation equations (correlating k and X) for square and circular tanks. A simulation criterion correlating the oxygen transfer coefficient k with actual and effective power consumption per unit volume for three shapes of tanks was developed. Energy consumption per unit volume of water was also analyzed. Examples illustrating the application of results are presented. It has been found that the circular tanks are the most energy efficient, i.e., they produce maximum k for a given effective/actual input energy, followed by square tanks, rectangular tanks of L/W = 1.5 and rectangular tanks of L/W = 2. This suggests that the circular tank performs better as far as power requirements are concerned and hence provide better economy.
Adsorption d'Hg(II) en solution aqueuse par le laitier des hauts fourneaux
Authors: Aziz Abdellah , Iddou Abdelkader , Ouali Mohand Said
Published: May 2018

L'élimination du mercure en solution aqueuse par le laitier des hauts fourneaux a été étudiée en système statique. L'influence de plusieurs paramètres, tels que la concentration initiale, la masse du matériau et sa granulométrie, et le temps de contact, a été mise en évidence. Il a été établi que l'élimination dépend de la concentration initiale du sorbat et de celle du sorbant. Les expériences ont été menées à pH 4 et selon les conditions opératoires, des taux d'élimination de 84 et 54 p. 100 ont été enregistrés pour les granulométries de 250 et 500 µm respectivement pour une masse de 0,5 g de sorbant. L'équilibre sorbant/sorbat a été bien décrit par le modèle cinétique du pseudo-second ordre et par le modèle d'adsorption de Langmuir. La capacité d'adsorption maximale du matériau, selon Langmuir, est de 87,72 µg/g. Selon les résultats obtenus, le laitier des hauts fourneaux peut constituer un support efficace pour l'élimination du mercure des eaux usées industrielles.
Utilisation de dérayures de cuir tanné au chrome pour la décontamination des eaux polluées par les colorants et les huiles
Authors: Gammoun Amal , Tahiri Soufiane , Albizane Abderrahman , Bouhria Mohammed , Azzi Mohammed , de la Guardia Miguel
Published: May 2018

Les dérayures du cuir ont montré une grande capacité d'adsorption des colorants organiques directs. La capacité maximale de rétention est de 333,3 mg/g et de 312,5 mg/g respectivement pour les colorants DR75 et DR80. Un pH acide et une température de l'ordre de 50°C sont favorables à la décoloration. Les essais ont révélé la faisabilité de la décontamination d'un rejet de textile par les dérayures. Le taux d'épuration peut dépasser 90 p.100 dans des conditions précises de pH et de température. Les dérayures brutes et saturées par le colorant DR80 ont montré également une grande capacité d'absorption des huiles (5 à 6,5 g/g). En milieu aqueux, ces déchets fibreux réagissent fortement et instantanément avec les taches d'huile. La capacité des dérayures à éliminer les huiles de l'eau est supérieure à 96 p.100. Un simple écumage permet l'évacuation du polluant absorbé sans attente. Après le traitement, la surface de l'eau devient pratiquement propre.
Assessing Fish Community Structure in Relation to Water Quality in a Small Estuarine Stream Receiving Oil Refinery Effluent
Authors: Vallières Geneviève , Munkittrick Kelly R. , MacLatchy Deborah L.
Published: May 2018

A large oil refinery discharges its effluent into Little River, a small estuarine stream entering Saint John Harbour, New Brunswick, Canada. An effects-based approach was used to assess the potential responses of fish and fish habitat to the effluent from the oil refinery. The study included a fish community survey and a water quality survey. Lower abundance, species richness, and biodiversity, as well as increased frequency of empty minnow traps, were found downstream of the effluent discharge. Water quality surveys demonstrated that the receiving environment is subjected to extended periods of low dissolved oxygen levels downstream of the effluent discharge. The anoxic periods correlated with the discharge of ballast water through the waste treatment system.
Road Salt Influence on Pollutant Releases from Melting Urban Snow
Authors: Reinosdotter Karin , Viklander Maria
Published: May 2018

A snow-melting experiment was performed to study the effects of road salt on the melting of urban snow from a snow windrow (pile) along a road in central Luleå, Sweden. Two snow piles were formed in the laboratory, with and without road salt added, and melted under similar conditions. All meltwater was collected and analyzed. The purpose of the experiment was to study the influence of the use of de-icing salt on meltwater quality and the release of pollutants from urban snow. The study indicated that the use of road salt may increase the dissolved metal phase in the urban snow meltwater. Also, the salt seems to have the largest effect at the beginning of the melting period when chloride is leaving the snow pile. Of total chloride, 90% was transported with the first 20% of the meltwater. Concentrations of the particulate-bound metals showed a fairly constant rate of release at the start of melt, but increased rapidly towards the end of the melting period, and this was more pronounced in the case of snow containing high chloride concentrations. Overall, a larger transport of solids was found for the pile with salt due to faster melting. Significantly larger masses of suspended solids and two heavy metals (Cu and Zn) were released with the meltwater from the pile with salt in comparison with the no-salt pile. The rest of the suspended solids and heavy metals stayed in the solid residue remaining at the end of the experiment.
Immunomodulation in Blue Mussels (Mytilus edulis and Mytilus trossulus) Exposed to Municipal Effluent in Eastern Canada
Authors: Coray Camille , St.-Jean Sylvie D. , Bard Shannon Mala
Published: May 2018

The effects on the immune response of the mussels Mytilus edulis and Mytilus trossulus from of life-time exposure to marine pollution found in an industrial shipping port with a military history (Halifax Harbour, Nova Scotia, Canada) were investigated. Parameters measured included phagocytic activity, cellular production of hydrogen peroxide, number of circulating haemocytes, and cellular viability. Mussels sampled within Halifax Harbour had significantly reduced phagocytic activity and significantly reduced production of hydrogen peroxide in comparison with mussels sampled from a reference site outside of Halifax Harbour, indicating that pollution induced immunomodulation. No significant differences were found in number of circulating haemocytes or in cellular viability between mussels sampled within Halifax Harbour and mussels sampled outside Halifax Harbour. Results are discussed in terms of using a multi-assay approach for monitoring environmental pollution.
Evaluation of the Root Zone Water Quality Model (RZWQM) for Southern Ontario: Part I. Sensitivity Analysis, Calibration, and Validation
Authors: Ahmed Imran , Rudra Ramesh , McKague Kevin , Gharabaghi Bahram , Ogilvie John
Published: May 2018

This study focuses on the performance of the Root Zone Water Quality Model (RZWQM) for corn production in southern Ontario. The model was used to simulate the amount of subsurface tile drainage, residual soil nitrate-nitrogen (NO3-N), NO3-N in subsurface drainage water, and crop yield. A precalibration sensitivity analysis of the model was conducted for several key parameters using field data collected at the study site. The RZWQM's hydrology component was most sensitive to the Brooks and Corey fitting parameters and saturated hydraulic conductivity (Ks), while the tile drain flow and the water table depth were sensitive to the Brooks and Corey fitting parameters of bubbling pressure (ψbp) and pore-size-distribution index (λ). The fraction of dead-end pores had relatively little effect on tile drain N loss. The crop yield is most affected by N uptake, age, and evapotranspiration rate. RZWQM simulated evapotranspiration was within the range (568 ± 55 mm) of the observed evapotranspiration. The model simulated corn yield very well (-0.1% difference) at the calibration site; however, it underestimated yield (-14.1%) at the validation site. Overall, the RZWQM simulated tile drain flow, NO3-N loss to tile drainage water, and crop yield with reasonable accuracy, but tended to underestimate the amount of soil NO3-N (mean deviation, -0.971). The inability of the model to handle the spatial and temporal variability of the soil may have affected its prediction accuracy. The model also needs improvement in simulating early spring snowmelt hydrology.
Comparison of Shredded Tire Chips and Tire Crumbs as Packing Media in Trickling Filters
Authors: Mondal Bibek , Warith Mustafa A. , Burns Stephen D.
Published: May 2018

A five stage study was conducted using two trickling filters, one with shredded tire chips (12 to 50 mm) and the other with tire crumbs (1.5 to 6.5 mm) as packing media, and both landfill leachate and synthetically prepared leachate, to evaluate treatment performance. Due to increased surface area and sorption capacity, compared with other materials, a thick layer of biomass developed over the surface of tire chips and crumbs and sloughed off after approximately 21 days. Biochemical oxygen demand, chemical oxygen demand, and ammonia nitrogen removal were in the range of 81 to 96%, 76 to 90%, and 15 to 68%, respectively, under stable conditions. Organic removal and total dissolved solids reduction from the leachate were well correlated, with the exception of when biomass sloughing caused an increase in the organic content. The trickling filter with tire crumb media exhibited a more consistent organic removal throughout the experimental program. Tire chips, being readily available, could be a better alternative to crushed stone or gravel as a packing media in trickling filters. Tire crumbs appeared to be promising for small scale treatment systems.
Bench-Scale Disinfection of Bacteria and Viruses with Pulsed Arc Electrohydraulic Discharge
Authors: Lee Lawrence H. , Arnold Adam J. , Santillan Cutberto A. , Emelko Monica B. , Dickson Sarah E. , Chang Jen-Shih
Published: May 2018

Pulsed arc electrohydraulic discharge (PAED) offers concurrent treatment of chemical and microbial target compounds in water by several mechanisms. Here, Escherichia coli, Bacillus subtilis spore, and MS2 bacteriophage inactivation by PAED were investigated using two bench-scale reactors (0.7 and 3 L). A plasma channel was created between a pair of iron electrodes set 0.5 mm apart in these reactors. Pulsed applied voltage was supplied at approximately 0.3 kJ/pulse (~100 µsec). In the 0.7-L reactor, median E. coli, B. subtilis, and MS2 reductions of 2.4-, 4.6-, and 3.7-log, respectively, were observed after approximately 80 seconds of treatment in water with a conductivity of 14.7 mS; reductions of 2.8-, 4.0-, and 3.7-log, respectively, were observed in treated drinking water filter effluent (conductivity of 610 µS). In the 3-L reactor, at a conductivity of 500 to 600 µS, 1.9- and approximately 0.9-log median reductions of E. coli and B. subtilis were achieved after 500 pulses (~3,300 sec); and, at a conductivity of 4.3 mS, median E. coli reductions of 0.5-log were achieved after 50 pulses (400 sec). Further work is necessary to elucidate the primary mechanism(s) of disinfection acting in the PAED system and how they relate to the reactor design, applied power requirements, and disinfection of specific target microorganisms.
Distinguishing the Hydrochemistry of Two Hydrological Basins in Northern Mexico Using Factor Analysis
Authors: Méndez-Rodriguez Lia C. , Gardner Susan C. , Brito-Castillo Luis , Acosta-Vargas Baudilio , Wurl Jobst , Alvarez-Castañeda Sergio T.
Published: May 2018

Hydrochemical parameters of groundwater from two hydrological basins in northwestern Mexico were measured. In one of them is located the city of Puerto Peñasco, and in the other one is the city of El Rosarito. A factor analysis was used to characterize the main influences that affected the water quality of each region. Based on the results of this method, the aquifer located in Rosarito is mainly affected by seawater intrusion and the presence of high levels of manganese, while the groundwater characteristics at Puerto Peñasco are influenced by reductive conditions, probably caused by bacterial contamination. Although most of the parameters analyzed in this study were within normal ranges for groundwater, knowledge of the factors affecting sources of water can help to develop restoration projects and preventive management practices to prevent an irreversible degradation of groundwater quality.
Water Quality Assessment in the Application of Stormwater Reuse for Irrigating Public Lands
Authors: He Jianxun , Valeo Caterina , Chu Angus , Neumann Norman F.
Published: May 2018

Stormwater reuse for irrigating public lands presents a viable option for reducing potable water demand in urban settings. However, stormwater generally contains high pollutant levels, which may cause adverse effects on public health and the environment. Water quality in a stormwater retention pond in the City of Calgary, Alberta, was examined in order to assess the feasibility of reusing stormwater for irrigation purposes. Field campaigns were conducted in the 2004, 2005, and 2006 irrigation seasons. The water quality data indicated that the pond water quality generally satisfies the requirements for stormwater recycled as irrigation water. Relationships between stormwater quality and climatological variables were investigated using correlation and regression analysis. Their correlations suggest that intermittent rain events contribute to elevated microbial levels and total suspended solids (TSS). Other climatological variables—air temperature, cloud cover, wind speed, and relative humidity—are also correlated with certain water quality parameters including fecal coliform (FC), TSS, nutrients, and conductivity. Formulated regression equations demonstrate good predictions of observed FC and TSS using climatological variables. Results showing stormwater quality as a function of climatological variables imply that climate change might have potential influence on stormwater quality.
Factors Influencing Formation of Trihalomethanes in Drinking Water: Results from Multivariate Statistical Investigation of the Ontario Drinking Water Surveillance Program Database
Authors: Chowdhury Shakhawat , Champagne Pascale , McLellan P. James
Published: May 2018

The presence of trihalomethanes (THMs) in drinking water is an important issue in the context of their potential health effects. Numerous studies have developed models in the past three decades relating THMs concentrations to different factors (e.g., dissolved organic carbon [DOC], chlorine dose, pH, etc.). Previous studies characterized the importance of specific factors through controlled studies using synthetic water or source waters from a small number of water treatment plants. Few studies have reported looking for factors related to THMs formation system-wide across many different water supply systems, and in environments where many factors vary simultaneously. This study presents the results of a multivariate statistical analysis for 162 water supply systems in Ontario, Canada for 2000 to 2004. Principal component analysis (PCA) was applied to determine important factors and possible clusters of variation. PCA identified DOC, chlorine dose, pH, temperature, and reaction time as significant factors for THMs formation. Separate clusters were observed for DOC-colour; chlorine dose-total/free residual chlorine; and hardness-alkalinity. Each cluster indicated factors varying together and representing significant variation. Temperature and pH were found significant and uncorrelated throughout the analysis. The multivariate analysis is the first phase of a continuing investigation into THMs formation with the ultimate goal of developing a predictive model, which can be used to perform human health risk-cost balance studies for drinking water quality management.
The Effect of Short-Term Dissolved Oxygen Transients on Activated Sludge
Authors: Zhang Yi , Allen D. Grant
Published: May 2018

The effect of short-term dissolved oxygen (DO) disturbances on municipal activated sludge was studied, in a batch system, with respect to changes in supernatant turbidity, suspended solid (SS) concentrations, proteins, polysaccharides, and cations in the extracellular polymeric substances (EPS). Results showed that turbidity increased by 20 times when the DO concentration decreased below 0.5 mg/L, and supernatant SS concentrations increased by 1 to 2 times with DO reduction, implying the presence of more unsettled particles in the supernatant. Concomitantly, soluble proteins increased from less than 1 mg/L to up to 30 mg/L, and bound proteins decreased by more than 15% under DO limitation. Further enzymatic tests confirmed that, compared with polysaccharides, proteins were more involved in preventing sludge deflocculation. The DO stress also caused significant changes in the bulk concentrations of K+ and Ca2+; K+ increased by 40% and Ca2+ decreased by 30%. When the DO concentration was restored after 6 hours, reversible changes were observed in supernatant turbidity and SS, and concentrations of EPS proteins and cations, indicating a possible physiological response of microorganisms to a short-term low DO disturbance.
Étude comparative de deux floculants pour le traitement physicochimique d'une eau usée municipale : chitosane et polymère de synthèse
Authors: Babineau Daniel , Chartray Dominique , Leduc Roland
Published: May 2018

Le traitement des eaux usées municipales par voie physico-chimique requiert généralement l'utilisation d'un coagulant à base de sels métalliques et d'un floculant (ou aide-coagulant) synthétique. L'application du concept de développement durable dans le traitement des eaux privilégie une approche utilisant des produits renouvelables tels les biopolymères naturels. Des essais avec du chitosane (biopolymère naturel) comme floculant ont été effectués à l'échelle du laboratoire (jar test) et à l'échelle réelle (station municipale de type physico-chimique) afin de mieux comprendre les particularités liées à l'utilisation de ce produit naturel lors du traitement des eaux. Les essais à l'échelle réelle réalisés dans deux filières parallèles de traitement ont comparé l'utilisation de la combinaison alun et polymère de synthèse anionique (AL/PS) à la combinaison alun et chitosane (AL/CH). Des abattements de la DCO de 87 %, des MES de 95 % et de 93 % pour le Ptot ont été observés avec la combinaison AL/CH. Ces résultats d'abattement de la DCO et des MES sont semblables à ceux obtenus dans la filière de traitement AL/PS. Certains essais indiquent un dosage de coagulant (alun) inférieur de 24,8 % avec la combinaison AL/CH. L'abattement du Ptot est constamment plus élevé avec la combinaison AL/PS en raison du dosage plus élevé de coagulant.
Identification of Sphingomonads on the Basis of Polymerase Chain Reaction Amplified 16S rRNA Gene
Authors: Tokajian Sima , Farah Maya , Hashwa Fuad
Published: May 2018

Sphingomonas is a genus that is basically of environmental origin but can also be associated with health hazards, especially in the hospital environment where there is a great need to properly monitor water sources. The abundance and frequent isolation of derivatives of yellow pigmented colonies from drinking water samples in Lebanon—where an intermittent mode of supply is employed, and which induces frequent biofilm sloughing—necessitated the establishment of a rapid and feasible assay to screen specifically for sphingomonads. In this study, 50 isolates recovered from drinking water with yellow- to orange-pigmented colonies were used to establish a polymerase chain reaction-based (PCR-based) screening assay. The use of sphingomonad specific modified primers gave one common band with a size of 320 bp in all resumptive and sequence confirmed sphingomonads. However, no amplification was observed with Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Applying the PCR-based assay described in this paper increased both the efficiency and the reliability of screening for sphingomonads in water samples, thereby minimizing related risk factors.
Distribution of 14C-labelled Atrazine, Methoxychlor, Glyphosate, and Bisphenol-A in Goldfish Studied by Whole-Body Autoradiography (WBARG)
Authors: Rouleau Claude , Kohli Jagmohan
Published: May 2018

Nonpersistent contaminants represent thousands of chemicals used as pesticides, pharmaceuticals, personal care products, additives, etc. Because of this diversity, the assessment of the environmental risks they may pose for the environment represents a formidable task. Identification of target organs is key information needed to orient further research on newlyinvestigated organic xenobiotics. We used whole-body autoradiography to visualize the distribution of 14C-labelled atrazine, methoxychlor, glyphosate, and bisphenol-A in goldfish (Carassius auratus) and identify target organs. Fish were exposed for 2 days (glyphosate and bisphenol-A) and 7 days (atrazine and methoxychlor) to the radiolabelled compounds at a concentration of 15 nM. They were then frozen, embedded in carboxymethylcellulose gel, 20-μm-thick cryosections were collected, freeze-dried, and exposed to phosphor screens to visualize the tissue distribution of radioactivity. Goldfish did not accumulate glyphosate. The three other compounds were accumulated, mostly in the gall bladder. Nevertheless, unforeseen accumulation sites were observed; atrazine accumulated in the uveal tract of the eye, high levels of radioactivity were found in the cerebrospinal fluid of goldfish exposed to methoxychlor, and an important accumulation of bisphenol-A was seen in urine, oral mucosa, esophagus, and intestinal lumen. The potential toxicological consequences of the accumulation of these chemicals at very specific locations within the fish body are discussed and further research suggested.
Exposure to Model-Scale Sewage Treatment Plant Effluent Affects Circulating Sex Steroids in Rainbow Trout
Authors: Parrott Joanne L. , McMaster Mark E. , Verma Subhash , Trowbridge David
Published: May 2018

Reproductive steroids were assessed in immature rainbow trout (Oncorhynchus mykiss) after 21-day exposures to 10% primary or 100% secondary-treated model-scale sewage treatment plant (STP) effluent. Plasma testosterone was elevated over 4-fold in rainbow trout exposed to 10% primary model STP effluent and 100% secondary model STP effluent, and 1.7-fold and 2.5-fold in trout exposed in the following years, 2 and 3, respectively. Exposure to the positive control compound, 17β-estradiol (100 ng/L), raised plasma estradiol concentrations of exposed trout, but had few effects on plasma testosterone concentrations. There was no induction of ethoxyresorufin-O-deethylase (EROD) activity by any treatment, but liver-somatic indices were elevated in year-1 fish exposed to 10% primary or 100% secondary-treated model STP effluent. The results show that exposure to this model STP effluent can increase circulating testosterone concentrations. The rainbow trout 21-day test proved to be a simple bioassay that holds promise for onsite assessments of effluents.
Innovation in Stormwater Management in Canada: The Way Forward
Authors: Marsalek Jiri , Schreier Hans
Published: May 2018

Rapid urban expansion, increased traffic, ageing infrastructure, greater climatic variability, and the need for enhanced sustainability of urban water resources pose significant challenges to conventional stormwater management. Innovative approaches are needed in order to mitigate the risk of flooding, pollution, and aquatic ecosystem degradation, and enhance beneficial uses of urban waters. To examine such approaches, a series of three regional conferences on innovative stormwater management were held in Vancouver, Calgary, and Toronto during 2007 to 2008 under the sponsorship of the Canadian Water Network (CWN) and the Canadian Mortgage and Housing Corporation (CMHC). Authors of selected conference papers providing information on innovative approaches to mitigating the risk of flooding and reducing pollution impacts at the property, neighbourhood, and watershed scales were then invited to submit journal papers, and those accepted in the review process were included in this Special Issue of the Water Quality Research Journal of Canada.

An overview of the selected papers indicates that no single innovative measure is adequate under all circumstances,and a multibarrier approach is deemed to be most effective. Examples of innovations at the property level include harvesting roof runoff and reusing water, managing rainwater by infiltration in swales and into soils in bioretention areas, minimizing impervious surfaces, and using pervious pavement. At the neighbourhood level, runoff impacts are mitigated by designing roads without curbs, gutters, and drain pipes, and diverting runoff into infiltration channels, swales, and wetlands. Creating roads and parking lots with pervious pavement and draining runoff from such surfaces into infiltration basins is also discussed. Among stormwater quality source controls, potential effects of street sweeping on runoff quality enhancement were assessed. New innovations at the watershed scale include: (a) the creation of wide riparian buffer zones that can detain water, remove sediments, and mitigate nutrient export and other pollutant effects, (b) the minimization of channelization of streams and rivers, and (c) the designation of floodwater storage areas. A new water balance model that is linked to a global information system (GIS) and works at all the three scales offers the best option to conceptualize stormwater problems, and their mitigation, in urban watersheds. Finally, the aim of this Special Issue is to promote examples of successful innovative approaches to improving stormwater management in Canadian cities, hoping that other practitioners will build on this experience and bring stormwater management practice to the next higher level.
Treatment Performance of an Extensive Vegetated Roof in Waterloo, Ontario
Authors: Vander Linden Kyle , Stone Micheal
Published: May 2018

Vegetated roof technologies are used as treatment measures to mitigate the effects of urban stormwater. A mass balance approach was used to assess the treatment performance of a vegetated roof located on the City Hall in Waterloo, Ontario. The vegetated and control roof sections were instrumented to measure precipitation, storage, and outflow for 18 storm events from June to October, 2006. Concentrations of suspended solids, total phosphorus (TP), and SRP (SRP) in precipitation and roof (vegetated and control) runoff were measured. A total of 155.6 mm of rain fell during the study period. The vegetated roof retained 64.5 mm (43.9%) of the total rainfall while the control roof retained approximately 5.1 mm (4.0%). For individual rain events, the vegetated roof retained an average of 3.5 mm (47.6%), while the control roof retained approximately 0.3 mm (4.7%). Water retention varied with storm size, season, and frequency of storm events. The vegetated roof retained 80.1% of precipitation for storm events ≤3.5 mm, and 34.9% for storm events >3.5 mm. TP and SRP concentrations from the vegetated roof were significantly higher than either the precipitation or runoff from the control roof.
Evaluation of Green Roofs for Runoff Retention, Runoff Quality, and Leachability
Authors: Van Seters Tim , Rocha Lisa , Smith Derek , MacMillan Glenn
Published: May 2018

This three-year study evaluates the quantity and quality of runoff from an extensive green roof on a multistory building in Toronto. Laboratory physical, chemical, and leachate analyses of eleven commercially available green roof growing media were also undertaken to help identify the potential influence that the growing media may have on runoff chemistry. Continuous precipitation and runoff data collected over 18 months outside of the winter period indicated that the green roof discharged 63% less runoff than a neighbouring conventional modified bitumen roof. Runoff volumes from the green roof averaged 42% less than the conventional roof in April and November, and between 70 and 93% less during the summer months. Water samples were collected from both roofs during 21 rain events in 2003 and 2004 and analyzed for general chemistry (e.g., pH, total suspended solids), metals, nutrients, bacteria (n = 16), and polycyclic aromatic hydrocarbons (n = 18). Loads of most chemical variables in green roof runoff were lower than from the conventional roof. Exceptions included constituents such as calcium, magnesium, and total phosphorus, which were either naturally present in the media or were added to promote plant growth. Total phosphorus concentrations in green roof runoff were significantly higher than the conventional roof (α = 0.001), and regularly exceeded the Ontario receiving water objective (0.03 mg/L). Phosphorus concentrations fell significantly after the first year of monitoring (α = 0.001), suggesting that the nutrient is being leached from the media. Chemical analyses of green roof growing media showed that levels of most constituents were similar to or lower than typical background concentrations for agricultural soils in Ontario. However, leachate concentrations from several media exceeded receiving water standards for phosphorus, aluminum, copper, iron, and vanadium. This study highlights the importance of engineering green roof media to minimize leaching of nutrients and other contaminants while maintaining their ability to support plant growth.
Developing Capacity for Large-Scale Rainwater Harvesting in Canada
Authors: Farahbakhsh Khosrow , Despins Christopher , Leidl Chantelle
Published: May 2018

Rainwater harvesting (RWH) is the ancient practice of capturing rainwater from impervious surfaces and storing it for future use. Harvesting roof runoff for domestic purposes has historically been prevalent in rural areas of Canada and the practice is currently experiencing revived interest and uptake in the urban environment. When implemented on a wide scale, RWH can contribute to both stormwater abatement and water conservation, serving to relieve pressure on existing infrastructure and potentially delay the need for infrastructure expansion. While such benefits are known, there remain several barriers that impede widespread implementation. These include cost, liability concerns, and a lack of clear policy for RWH. This paper outlines the benefits of RWH and describes findings of recent research that has attempted to develop some of the technical, administrative, and market capacity needed to overcome these barriers, focussing on water quality, design practices, economic analysis, and policy development.
Environmental Factors Affecting Methoprene Concentrations for West Nile Virus Control in a Storm Sewer System
Authors: Li James Y. , Lo Ching , Luciani Peter D. , Des Lauriers Angelune , Sze Kevin , Shao Jiang , Komer Wayne , Wilkinson Ken , Truen David , Anderton Rod
Published: May 2018

To address vector-borne West Nile virus in Canada, chemical larvicides (methoprene) are applied to storm sewer system catch basins (CBs) to control mosquitoes. This study assessed the fate and transport of methoprene in such systems over time relative to precipitation. Rainfall and methoprene concentration patterns revealed the effect of dilution, dissolution, and flushing of the larvicide. In the summer and fall of 2003 to 2005, field monitoring studies were conducted in Toronto, Ontario on two CBs, each treated with a control dose of methoprene, supplied in pellet or ingot formulation. Furthermore, in 2005, concentrations at the storm sewer outfall were measured during nine rainfall events. Based on daily monitoring, findings indicate that (1) the methoprene concentration at the CBs fell below the minimum lethal concentration or LC50 one or two weeks after treatment, and remained below LC50 concentrations over 70% of the time; (2) rainfall flushed methoprene from the CBs to the storm sewer outfall at concentrations higher than the levels specified by Ministry of Environment, which may cause ecosystem damage; (3) based on the number of cycles per diem within each CB in each study period, there was no conclusive pattern in the flushing susceptibility of pellets versus ingots; (4) the mean concentration of methoprene increased with reduced CB sump volume; (5) less total precipitation resulted in higher average methoprene concentrations and a higher number of days above the LC50 based on ingot-dosed CBs; (6) counter-intuitive to (4) and (5), larger sump water volumes and greater rainfall resulted in lower mean concentrations and fewer days above the LC50; and (7) a single ingot dosage was comparable in performance to a three pellet dosage.
Physicochemical Distribution of Metals in the Water Phase of Catch Basin Mixtures
Authors: Karlsson Kristin , Westerstrand Magnus , Viklander Maria , Ingri Johan
Published: May 2018

A mixture of sediment and water is formed during the cleansing of catch basins. This paper discusses the concentration levels and distribution of numerous metals and organic carbon (OC) in the water phase of this mixture. The results show that due to the high concentrations of metals in the water phase, the catch basin mixture should be treated before it reaches a recipient. Three sites with different types of area and traffic intensity were sampled. Four fractions were analyzed: unfiltered, dissolved (<0.2 µm), colloidal (0.22 µm to 1 kD [kilodalton]), and truly dissolved (<1 kD). The results of the unfiltered fraction show high concentrations of metals and OC in the catch basin mixture. A comparison of Canadian and Swedish Environmental Protection Agency guidelines and the catch basin mixtures shows that concentrations exceeded the threshold values for As, Cd, Cr, Cu, Ni, Pb, and Zn. Compared with samples from a reference lake in the area, the unfiltered fraction showed high concentrations of all elements. OC seems to have a large impact on the overall speciation of trace metals in the catch basin mixture. To trace the sources of the particulate fraction in the unfiltered samples, Al-normalization was used. Al-normalization indicated that Ca, K, Mg, Na, Mn, Ba, Co, and Cr concentrations could be explained by mineral particles used as traction control. Furthermore, the trace elements As, Cu, Pb, Zn, and Ni were all enriched in the catch basin mixture.
Estimation of Biodegradation and Liquid-Solid Partitioning Coefficients for Selected PAHs in Municipal Wastewater Treatment
Authors: Parker Wayne J. , Monteith Hugh D. , Pileggi Vince
Published: May 2018

Batch testing was employed to estimate model parameters that are required for predicting the fate of polynuclear aromatic hydrocarbons (PAHs) in wastewater treatment. Linear partitioning was found to describe the partitioning of PAHs to solids and was best described when the soluble phase of the PAHs was determined by centrifugation alone. The liquid-solid partitioning coefficients obtained for primary and secondary sludges were statistically different, with the latter being higher than the former for most of the PAHs examined in this study. Temperature had a significant impact on the estimated biodegradation rate coefficients (Kb). The biodegradation rate coefficients for anthracene and phenanthrene (three-ring PAHs) were statistically different from benzo(a)anthracene and chrysene (four-ring PAHs). The presence of a nitro-adduct on acenaphthene resulted in a substantial increase in the Kb relative to the unsubstituted anthracene and phenanthrene. A sensitivity analysis revealed that the removal of PAHs in a full-scale wastewater treatment plant was most sensitive to the value of the liquid-solid partitioning coefficients. Approximately 60% of the PAHs were removed from the wastewater stream through partitioning to both primary and secondary solids, and subsequent discharge.
Use of Stable Carbon and Nitrogen Isotopes to Trace Natural and Anthropogenic Inputs into Riverine Systems in the Athabasca Oil Sands Region
Authors: Farwell Andrea J. , Parrott Joanne L. , Sherry Jim P. , Tetreault Gerald R. , Van Meer Terry , Dixon D. George
Published: May 2018

Stable isotopes of carbon and nitrogen in fish were examined as a potential tracer of exposure to oil sands constituents in naturally eroded environments and in areas of anthropogenic activity (municipal and industrial effluent discharges; oil sands surface mining) within the Athabasca River drainage basin of northern Alberta, Canada. Longnose sucker (Catostomus catostomus), trout-perch (Percopsis omiscomaycus), and slimy sculpin (Cottus cognatus) showed changes in δ13C values with the river gradient. Site-specific differences in the δ13C values of fish were more pronounced for the small-bodied fish species in the lower reaches of a tributary (slimy sculpin) and immediately downstream of tributary inputs along the Athabasca River (trout-perch), where potential exposure to the oil sands constituents is elevated. There were also species and site-specific trends for δ15N values. Site-specific trends attributed to municipal or industrial effluent discharge or tributary inputs may prove to be a useful tool for defining residency on the oil sands deposit. This study has provided baseline data of isotope values for fish species which are currently used (longnose sucker) or may be used in future environmental effects monitoring programs. Defining residency and exposure to the oil sands deposit is critical to establishing exposure-response relationships, particularly since there are new expansions to oil sands mining operations.
Biological Phosphorus Removal and Denitrification of a Fish Farm Effluent in a Sequencing Moving Bed Biofilm Reactor
Authors: Restrepo Juan D. , Labelle Marc-André , Parent Serge , Villemur Richard , Juteau Pierre , Comeau Yves
Published: May 2018

Removal of phosphate and nitrate from the effluent of a fish farm with a recirculation system was tested in a sequencing moving bed biofilm bioreactor (SMBBR) over a 160-day period. This bioprocess made use of a stock tank (ST) that allowed the same volume of anaerobic water to be reused from one batch to another. Water from the ST contained an excess of a carbon source (acetate), which made it possible to alternate between anaerobic (1.5 h) and aerobic/anoxic (4 h) conditions to achieve enhanced biological phosphorus removal (EBPR). The developed biomass (2,072 mg total solids m-2 d-1 and 892 mg total volatile solids m-2 d-1 ) removed 7.5 mg of PO4-P per litre and 8.5 mg of NO3-N per litre from an influent containing 10 mg of PO4-P per litre and 21 mg NO3-N per litre. The dynamic variation of phosphate and chemical oxygen demand (COD) in the influent showed that the biomass was sensitive to the CODavailable/Pinfluent ratio. A ratio of 10 to 15 mg of COD per milligram of P seemed to favour phosphorus accumulating organisms (PAOs). Differences between the nitrate, phosphate, and oxygen reduction kinetics suggested that the denitrification could be attributed to organisms other than PAOs. The SMBBR-ST showed potential for EBPR and for denitrification as well. However, the economic feasibility of implementing such a process in a full-scale operation remains to be demonstrated.
Onsite Microbiological Quality Monitoring of Raw Source Water in Cree Community of Mistissini
Authors: Bernier Jean-Luc T. , Maheux Andrée F. , Boissinot Maurice , Picard François J. , Bissonnette Luc , Martin Daniel , Dewailly Éric , Bergeron Michel G.
Published: May 2018

Access to safe drinking water is a major concern for Canada's First Nations. The main objective of this report was to evaluate the microbiological quality of raw source water used for drinking purposes by the Cree people of Mistissini (Province of Québec, Canada) during summer 2005. Twelve environmental sites and 24 portable water containers used for domestic water collection and storage were sampled and submitted to microbiological determination of total coliforms, Escherichia coli, and Enterococcus sp. using membrane filtration and colourimetric standard methods. The results suggest that the microbiological quality of raw source water sampled from environmental sites is enhanced by storage practices of Mistissini inhabitants as microbial counts have shown a tendency to decrease upon storage and that the targeted fecal indicators (E. coli and enterococci) were quantitatively distributed independently from each other, especially with regards to the type of water source. In conclusion, even if the use of multiple indicators could offer better water quality monitoring, technological constraints limit the use of culture-based methods in such a remote area, underlining the importance of always boiling water from raw water sources before consumption.
Multicriteria Review of Nonpoint Source Water Quality Models for Nutrients, Sediments, and Pathogens
Authors: Booty William , Benoy Glenn
Published: May 2018

There now exists a large number of nonpoint source models that have been developed for watershed management issues. As part of the National Agri-Environmental Standards Initiative (NAESI), it was necessary to evaluate which model or models would be the best choice for examining various best management practices for nutrients, sediments, and pathogens in test watersheds. Environment Canada has committed to the development of environmental performance standards that will guide environmentally sustainable agricultural practices and management. A literature review was carried out and a short list of 13 models was selected that met the basic needs of the project. These models were subsequently evaluated based on a multicriteria analysis that considered 21 model characteristics. A weight and a total score quantify the relative importance of each criterion. The top six models were SWAT (Soil and Water Assessment Tool), AnnAGNPS (Annualized Agricultural Nonpoint Source), BASINS (Better Assessment Science Integrating Point and Nonpoint Sources), GIBSI (Gestion Intégrée des Bassins versants á l'aide d'un Systéme Informatisé), AGNPS (Agricultural Nonpoint Source), and HSPF (Hydrologic Simulation Program - Fortran).
Integrated Land and Water Scenarios of the Raisin River Watershed Using the SWAT Model
Authors: Wong Isaac W. , Booty William G. , Benoy Glenn , Nielsen Cathy , Fong Phil , McCrimmon R.Craig
Published: May 2018

This paper investigates the linkage between Canada's National Agri-Environmental Standards Initiative (NAESI) Biodiversity and Water themes by studying how patterns in terrestrial habitat, generated through land cover scenario modelling, influence water quality and quantity in the Raisin River watershed in southeastern Ontario. NAESI developed nonregulatory performance standards that define ideal and achievable levels of environmental quality. The indicators used to investigate the scenario risks included sediment and nutrient concentrations. The SWAT (Soil and Water Assessment Tool)-2005 model was calibrated and validated from 1985 to 2006 for current land cover and five other scenarios: potential natural vegetation (PNV); high biodiversity conservation (HBC); moderate biodiversity conservation; agricultural intensification with limited application of conservation direction; and agricultural intensification with no consideration of conservation direction (ANC). Scenario comparisons are provided for the average annual flow, and concentrations of total suspended sediment (TSS), total nitrogen, and total phosphorus for five watershed locations. The PNV scenario predicted the lowest total flows, and sediment and nutrient concentrations, and the ANC scenario predicted the highest sediment and nutrient concentrations. The SWAT median values for the HBC, "Current," and ANC scenarios at the outlet all exceeded the Ideal Performance Standards, except for the median TSS concentration of the HBC scenario.
Evaluation of Risk Assessment Tools to Predict Canadian Waterborne Disease Outbreaks
Authors: Summerscales Ian Michael , McBean Edward A.
Published: May 2018

A number of risk assessment tools and guidance documents have been developed by regulatory and nongovernmental bodies to enable risk assessment of drinking water systems. To evaluate the strengths and weaknesses of available risk assessment tools, three of the existing risk assessment tools were applied to waterborne disease outbreaks in North Battleford, Saskatchewan, and Walkerton, Ontario, to determine whether the risk assessment tools would have indicated that the water systems were at risk of failure. Both of these outbreaks are sufficiently well documented to allow testing of the risk assessment tools. Both of the outbreaks occurred partly due to vulnerabilities that prevented the respective water systems from having effective multiple barriers to drinking water contamination. The risk assessment tools generally identified the hazards that resulted in contamination of the source water. However, the different tools had different levels of success in identifying vulnerabilities in the downstream barriers such as treatment processes and water quality monitoring activities. None of the risk assessment tools successfully incorporated the interdependent nature of the multiple barriers of drinking water safety.