bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of Taste and Odour Compounds by Conventional Granular Activated Carbon Filtration
Authors: Ridal Jeff , Brownlee Brian , McKenna Gerry , Levac Norman 
Published: May 2018

Abstract
In recent years, musty-earthy tastes in drinking water have become a seasonal problem (September to November) for communities that draw their water from the upper St. Lawrence River. The source of the problem is attributed to the presence of geosmin and 2-methylisoborneol (MIB) at concentrations ranging from 5 to 60 ng/L. In 1997 and 1998, the Cornwall Water Purification Plant added granular activated carbon (GAC) to conventional gravity filters to control taste and odour compounds. We report on a study to test the efficiency of these conventional GAC-capped filters to reduce geosmin and MIB concentrations in finished water as a function of filter age, initial chlorine residual and contact time. GAC–capped filters removed on average 60% of the MIB and 80% of the geosmin from the source water after 2 and 12 months of filter operation. However, testing after 24 months operation showed reduced efficiency. Amounts removed ranged between 13 and 20% (15% average) for MIB and 50 to 57% (54% average) for geosmin in these filters. Testing also suggested that filter efficiency was greater with longer contact times and with higher chlorine residuals (in the range 0.1 to 0.6 mg free Cl2/L). In addition to carbon age, chlorine residual and contact time, flow channelization and slow release of the taste and odour compound load (particularly MIB) from the GAC bed may affect apparent filter efficiency.
Evaluation of Particle Removal at Water Treatment Plants in Nova Scotia
Authors: Eisnor John D. , O'Leary Kevin C. , Gagnon Graham A. 
Published: May 2018

Abstract
The physical removal of colloidal particles, microorganisms and other particulate material is an important objective for drinking water utilities. Because of the low concentration of suspended material in drinking water, turbidity has traditionally been the main water quality parameter for assessing particle removal in water treatment. However, particle counting is becoming increasingly popular for process optimization in conventional plants and for monitoring membrane integrity in new microfiltration and/or ultrafiltration plants. The research describes a survey of particle removal at four water treatment plants in Nova Scotia. Turbidity and particle counts were analyzed in both raw and filtered water. The treatment processes of the four plants was compared using particle count data. The results indicate that particle counters are able to detect decreases in filter performance earlier than turbidimeters.
An Overview of Substances Present in Canadian Aquatic Environments Associated with Endocrine Disruption
Authors: Hewitt Mark , Servos Mark 
Published: May 2018

Abstract
Numerous environmental contaminants have been associated with the ability to affect the endocrine status of animals and with the potential to elicit effects on individuals or populations in Canadian aquatic environments. Potential endocrine disrupting substances (EDS) consist of almost every class of environmental contaminants reported to date, including industrial chemicals, historical and current use pesticides, metals, and different classes of natural products. It has been difficult to establish cause-and-effect relationships with potential EDS for several reasons: i) the diversity of ways that chemicals can influence endocrine systems challenges efforts to characterize chemicals that can cause endocrine responses, ii) many responses in aquatic biota have been associated with complex mixtures where the causative agents remain unidentified, and iii) most literature information deals with mammalian studies using pure compounds so there is considerable uncertainty regarding extrapolation to aquatic species and efficacy of environmental concentrations. An overview of the literature on EDS, specific to exposure within Canadian aquatic environments, is presented to emphasize the diversity and complexity of chemicals capable of altering endocrine function.
Sediment Management: Ecological and Ecotoxicological Effects Must Direct Actions
Authors: Krantzberg Gail , Zarull Michael A. , Hartig John H. 
Published: May 2018

Abstract
The need for guidance on the bioassessment and management of contaminated sediment has been articulated by Remedial Action Plan practitioners, the International Joint Commission, scientists, and managers in many jurisdictions. Encouragingly, a convergence of opinion, on what constitutes a comprehensive sediment assessment, is beginning. However, there continues to be a need for methods to interpret and integrate multiple pieces of information on sediment chemistry, biological information from field monitoring and laboratory sediment bioassessment in an ecologically meaningful way. This paper recommends an approach to comprehensive sediment bioassessment that is driven by the need to rehabilitate “beneficial uses” as described in the Great Lakes Water Quality Agreement. The paper also highlights advances in data interpretation that are facilitating he development of sediment management strategies.
Approche géomatique pour simuler l'érosion hydrique et le transport des sédiments à l'échelle des petits bassins versants
Authors: Duchemin Marc , Lachance Marius , Morin Guy , Lagacé Robert 
Published: May 2018

Abstract
L'existence de problèmes d'érosion hydrique à différents endroits d'un bassin versant se manifeste souvent par la présence d'une quantité excessive de sédiments en suspension dans les cours d'eau. L'évaluation indirecte de l'érosion par la mesure des sédiments en suspension transportés à l'exutoire des bassins versants permet ainsi d'avoir une bonne idée de l'impact environnemental des activités agricoles. Il s'avère toutefois essentiel, dans une perspective de gestion de la qualité de l'eau à l'échelle d'un bassin versant, de pouvoir estimer l'érosion hydrique et le transport des sédiments en suspension afin d'identifier les zones problématiques. Cette estimation implique la manipulation d'une somme considérable d'informations pour décrire l'environnement du bassin versant et l'emploi de modèles mathématiques complexes pour simuler les processus hydrologiques et sédimentologiques en jeu. Le recours aux modèles informatiques d'érosion hydrique et aux systèmes d'information géographique (SIG) est alors de mise. Cet article présente le développement et l'application d'une approche géomatique de simulation qui implique l'utilisation conjointe du modèle hydrologique CEQUEAU, du modèle d'érosion MODÉROSS et du système d'information géographique IDRISI. Plus précisément, cet article présente de quelle façon le progiciel CEQÉROSS a été utilisé pour prédire le comportement hydrosédimentologique d'un petit bassin versant agricole du Québec. Les charges sédimentaires totales simulées à l'exutoire du bassin versant de Lennoxville s'élevaient à 27,5 tonnes et 54,1 tonnes pour les années hydrologiques 1991–1992 et 1992–1993 respectivement. Ces valeurs se comparent avantageusement aux charges sédimentaires totales de 30,3 tonnes et 51,3 tonnes observées durant ces mêmes périodes. Les résultats obtenus montrent également que la nature épisodique du transport des sédiments en suspension à l'exutoire du bassin versant de Lennoxville pendant la période 1991–1993 a été bien reproduite par CEQÉROSS. L'approche géomatique proposée est suffisamment conviviale et fiable pour s'inscrire à l'intérieur d'un ensemble d'outils de gestion agroenvironnementale.
Kinetics and Activation Parameters for the Alkaline Aqueous Rearrangement of Trichorfon [O,O-Dimethyl-(2,2,2-Trichloro-1-Hydroxyethyl) Phosphonate] to Dichlorvos [O,O-Dimethyl-O-(2,2-Dichloroethenyl)Phosphate]
Authors: Dust Julian M. , Warren Christopher S. 
Published: May 2018

Abstract
The kinetics of the alkaline rearrangement of O,O-dimethyl-(2,2,2-trichloro-1- hydroxyethyl)phosphonate, (trichlorfon, 1), the active insecticidal component in such formulations as Dylox, was followed at 25±0.5°C by high pressure liquid chromatography (UV-vis detector, 210 nm). The rearrangement product, O,Odimethyl- O-(2,2-dichloroethenyl)phosphate (dichlorovos, 2), which is a more potent biocide than trichlorfon, undergoes further reaction, and the kinetics, consequently, cannot be treated by a standard pseudo-first-order plot. A two-point van't Hoff (initial rates) method was used to obtain pseudo-first-order rate constants (kѱ) at 25, 35 and 45°C: 2.6 × 10-6, 7.4 × 10-6 and 2.5 × 10-5 s-1, respectively. Arrhenius treatment of this data gave an activation energy (Ea) of 88 kJ·mol-1 with a pre-exponential factor (A) of 5.5 × 109 s-1. Kinetic trials at pH 8.0 using phosphate and tris buffer systems show no buffer catalysis in this reaction and indicate that the rearrangement is subject to specific base catalysis. Estimates are reported for pseudo-first-order half-lives for trichlorfon at pH 8.0 for environmental conditions in aqueous systems in the Corner Brook region of western Newfoundland, part of the site of a recent trichlorfon aerial spray program.
Prévision de l'adsorption de molécules organiques en solution aqueuse en fonctions de quelques caractéristiques physico-chimiques de charbons actifs
Authors: Baudu Michel , Guibaud Gilles , Raveau David , Lafrance Pierre 
Published: May 2018

Abstract
La production d'eau potable nécessite parfois une filtration sur charbon actif en vue d'éliminer des micropolluants organiques. Afin de développer un modèle prévisionnel de la durée de vie de ces filtres, il est nécessaire de bien connaître les caractéristiques des charbons influençant l'adsorption. Des caractéristiques de la structure physique (porosité et surface) et chimiques (fonction de surface), le potentiel zêta et les constantes thermodynamiques de neuf charbons actifs ont été déterminées et des essais de corrélation ont indiqué une certaine ligne de conduite pour l'utilisation de charbons de différentes origines. Des cinétiques et des isothermes d'adsorption de l'atrazine et du phénol ont été réalisées, ceci afin de mieux comprendre l'influence de la structure et des caractéristiques physico-chimiques des charbons sur les mécanismes d'adsorption. L'étude a mis en évidence les points suivants : (i) le nombre de sites primaires polaires d'adsorption augmente lorsque le nombre de fonctions acides augmente et lorsque le nombre de fonctions basiques diminue ; (ii) la capacité maximale d'eau adsorbée augmente avec la surface spécifique et diminue avec le nombre de fonctions acides du charbon ; (iii) l'adsorption de l'atrazine (molécule peu polaire) est en partie contrôlée par des paramètres physiques comme la surface spécifique ; (iv) les groupements polaires facilitent l'adsorption du phénol (molécule très polaire), et : (v) les valeurs du potentiel zêta sont difficiles à interpréter : la présence de groupements fonctionnels non déterminés pourrait intervenir sur les mécanismes d'adsorption.
Application of Faecal Sterol Ratios in Sediments and Effluents as Source Tracers
Authors: Marvin Chris , Coakley John , Mayer Tatiana , Brown Mitra , Thiessen Lina 
Published: May 2018

Abstract
An analytical method to determine faecal sterols was developed and applied to the analysis of samples including pig manure, sewage treatment plant sludge and combined sewer overflow effluent. Compounds including coprostanol (5β-cholestan-3β-ol), epicoprostanol (5β-cholestan-3α-ol), cholesterol (cholestan-5-en-3β-ol) and dihydrocholesterol (cholestanol, 5α-cholestan-3β-ol) were quantified in these source samples and their relative ratios calculated to investigate their potential application as source tracers. A mean coprostanol:epicoprostanol ratio of 7.6 ± 1.17 was calculated for pig manure samples from three Ontario livestock operations. This ratio was much lower (approximately 1.8) for sewage treatment plant sludge while the ratio for a combined sewer overflow effluent was very high (approximately 70). This approach, with the addition of physical measurements (e.g., current velocities) and meteorological data, may assist in determination of the influence of shore-based activities, including sewage treatment and livestock operations, on aquatic systems.
Heavy Metal Removal by the Waste Biomass of Penicillium chrysogenum
Authors: Skowroński Tadeusz , Pirszel Jacek , Skowrońska Barbara Pawlik 
Published: May 2018

Abstract
Metal sorption capacity of the granulated biosorbent derived from the waste biomass of Penicillium chrysogenum was examined. The potential metal sorption abilities of the biosorbent were estimated as the cation-exchange capacity, using a potentiometric titration. The total binding capacity, calculated for the pH range 3 to 8 was about 511 µeq/g dry weight. The granular biosorbent was capable of Cd, Zn, Cu and Pb binding. The kinetics of the heavy metal sorption were typical of the microbial dead biomass; metals were bound in the first few minutes. Sorption was a saturable process and the maximum sorption capacity, calculated from the Langmuir equation for the particular heavy metals was: 96 mg Pb; 21.5 mg Cd; 13 mg Zn and 11.7 mg Cu (per g dry weight). Optimum pH values for Cd, Zn and Cu sorption were about 7, while for Pb about 6. Heavy metal removal from different solutions was examined using the biosorption columns packed with P. chrysogenum, which efficiently removed Cd from 1 mM Cd solution, or Cd and Zn from the industrial wastewater. The studied biosorbent was capable of accumulating Cd and Zn even at the high Ca concentration.
Impact of Bleached Kraft Pulp Mill Effluent on the Nearshore Benthic Community of Jackfish Bay, Lake Superior
Authors: Sibley Paul K. , Dixon D. George , Barton David R. 
Published: May 2018

Abstract
We assessed the impact of bleached kraft pulp mill effluent on benthic invertebrate community structure in the shallow (1 m) nearshore waters of Jackfish Bay, Lake Superior. Duplicate benthic samples were collected from 0.5 m2 quadrats at twenty-three stations along two shorelines of Jackfish Bay up to 1800 m from the point of effluent discharge, and from a reference station located within the Jackfish Bay study area. Detrended correspondence analysis (DCA) revealed a gradient of stations on both shorelines which was strongly correlated with distance from effluent outfall and hence exposure to the effluent plume. Within this gradient were two distinct clusters of stations. The first cluster contained all but one station on both shores &lt;300 m from the outfall; these stations receive constant exposure to the effluent and were dominated (&gt;90%) by tubificids (Limnodrilus hoffmeisteri, Tubifex tubifex, T. ignotus and Spirosperma ferox) and the naidid Chaetogaster diaphanus. The second cluster contained all stations on both shores &gt;300 m from the outfall; community structure at these stations was generally comparable to that at the reference site and was characterized by several species of Chironomidae, C. diaphanus and Nais barbata, and low numbers of several insect taxa. The results of this study show that benthic community structure in nearshore environments can be significantly impacted by pulp mill effluent and should be considered in monitoring assessments. At Jackfish Bay, such impacts appear to be restricted primarily to within the first 500 m of effluent discharge.
Natural and Constructed Wetlands in Canada: An Overview
Authors: Kennedy Gavin , Mayer Tatiana 
Published: May 2018

Abstract
A review of freshwater wetland research in Canada was conducted to highlight the importance of these ecosystems and to identify wetland research needs. Both natural and constructed wetland systems are discussed. Natural wetlands are an important part of the Canadian landscape. They provide the habitat for a broad variety of flora and fauna and contribute significantly to the Canadian economy. It is estimated that the total value derived from consumptive and non-consumptive activities exceeds $10 billion annually. The past decades have witnessed the continued loss and degradation of wetlands in Canada. In spite of recent protection, Canadian wetlands remain threatened by anthropogenic activities. This review shows that more research on fate and transport of pollutants from urban and agricultural sources in wetland systems is needed to better protect the health and to assure the sustainability of wetlands in Canada. Furthermore, improved knowledge of hydrology and hydrogeochemistry of wetlands will assure more effective management of these ecosystems. Lastly, better understanding of the effect of climate change on wetlands will result in better protection of these important ecosystems.
Constructed wetlands are man-made wetlands used to treat non-point source pollution. The wetland treatment technology capitalizes on the intrinsic water quality amelioration function of wetlands and is emerging as a cost-effective, environmentally friendly method of treating a variety of wastewaters. The use of wetland technology in Canada is, however, less common than in the U.S.A. A number of research needs has to be addressed before the wetland treatment technology can gain widespread acceptance in Canada. This includes research pertaining to cold weather performance, including more monitoring, research on design adaptation and investigation of the effects of constructed wetlands on wildlife.
Wastewater Sludge as a New Medium for Rhizobial Growth
Authors: Rebah Faouzi Ben , Tyagi Rajeshwar D. , Prévost Danielle , Surampalli Rao Y. 
Published: May 2018

Abstract
The objective of this study was to demonstrate that municipal and industrial wastewater sludges could be used as a sole raw material to sustain growth of rhizobia. Growth of two different groups of rhizobium (fast growing: Sinorhizobium meliloti, Rhizobium leguminosarum bv viciae; and slow growing: Bradyrhizobium japonicum and Bradyrhizobium elkanii) was tested on primary, secondary and mixed sludges obtained from different wastewater treatment plants. The results obtained in Erlenmeyer flasks indicated that slow- and fast-growing rhizobia grew well in sludge. Generally, the number of cells of rhizobia exceeds 1 × 109 cfu/mL in 72 h. The composition of sludges varies with the sludge type and origin. The sludge composition affected the generation time, cell yield and nodulation index. Higher solids concentration tended to give higher generation time. The high sludge metals concentration did not affect the growth kinetics of rhizobia. However, primary sludge could inhibit cell growth. Acid, alkaline and oxidative pre-treatments increased the primary sludge biodegradability and consequently the cell count of S. meliloti. Pre-treatment of pulp and paper sludge with NaOH enhanced the bacterial cell concentration to a maximum 1 × 1010 cfu/mL. Sludge pre-treatment decreased the generation time and reduced the process time.
Flow Rates Through Alum Coagulation and Activated Sludge Flocs
Authors: Gorczyca Beata , Ganczarczyk Jerzy 
Published: May 2018

Abstract
The liquid velocity inside alum and activated sludge flocs was calculated using the size, settling velocity and permeability of activated sludge flocs. The permeability of activated sludge flocs has been determined experimentally. The permeability of alum coagulation flocs was assumed to be half of the permeability of activated sludge flocs based on the size of the pores in these flocs. The average flow velocity inside an activated sludge floc was calculated to be 1575 µm/s, which is in the range of the flow experimentally measured inside biofilms at a distance of about 100 µm from the substratum by Beer et al. (1995). The flow inside an alum coagulation floc was calculated to be 318 µm/s. The flow velocity inside the same flocs estimated with Davies permeability model were 0.7 µm/s for activated sludge flocs and 20 µm/s for alum coagulation flocs. Therefore, the flow velocities estimated on the basis of experimentally determined permeability were much higher than the velocities calculated with Davies permeability model.
Davies permeability model assumes homogeneous distribution of porosity inside an aggregate. Direct observations made during the analysis of floc sections have proven this assumption to be wrong. Flocs have fractal structure and the models predicting their permeability should be based on this feature. Flow rates through alum and activated sludge flocs predicted on the basis of the fractal model of a floc compared well with experimental results.
A Comparison of Methods for Normalizing Residues of Organic Contaminants in Zebra Mussels (Dreissena polymorpha), with Implications for Biomonitoring Programs
Authors: Metcalfe-Smith Janice L. , Comba Michael E. , Kaiser Klaus L.E. , Solla Shane R. De 
Published: May 2018

Abstract
There has been little consistency to date in the method used to express concentrations of organic contaminants in zebra mussels collected from the Great Lakes. Concentrations have been reported on a wet whole (with shells), dry whole, wet soft tissue, dry soft tissue, and lipid weight basis. This study examined residues of organic contaminants in samples of zebra mussels collected from 24 sites in the lower Great Lakes and St. Lawrence River, to determine if the way in which the residues were normalized could affect the precision of estimated concentrations or the spatial trends observed. Variation in the moisture content of soft tissues was minimal, so normalizing to wet or dry soft tissue weight would yield consistent results. Moisture content of whole mussels was more variable, and relative proportions of soft tissues and shell vary with size, season and location—potentially confounding spatial trends. Lipid content also varies greatly among locations, seasons and years, and lipid-normalized residues were much more variable than residues normalized to whole or soft tissue weight. Furthermore, site-to-site trends based on lipid-normalized data did not always agree with those based on other components of the organism, and thus should not be interpreted in isolation.
Modelling Air-Water Exchange Process of Pentachlorophenol in the Aquatic Environment
Authors: Chi Jie , Huang Guo-Lan 
Published: May 2018

Abstract
To study the effects of the surface microlayer (SM) on the air-water exchange process of pentachlorophenol (PCP), simulated experiments were carried out in a microcosm containing air, water and sediment. A four-compartment (i.e., air, SM, water and sediment) fugacity model was successfully applied to the simulated experiments in the microcosm. Data obtained from the four-compartment model calculation yielded a more satisfactory fit with experimental results than the use of a model that does not address the effects of the SM compartment. Results of model calculation show that 97.8% of PCP is distributed to the water phase in the aquatic environment, and 82.2% PCP is removed by the advective outflow and biodegradation in the water phase. The results obtained demonstrate that the higher photodegradation rate of PCP in the SM reduces the concentration of PCP in the air phase.