bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulphur Management Strategies in Anaerobic Treatment of a BCTMP/TMP Effluent
Authors: Stephenson R.J. , Branion R.M.R. , Pinder K.L. 
Published: March 2019

Abstract
Anaerobic treatment of a bleached chemithermomechanlcal/ thermomechanical BCTMP/TMP (2:1 by volume) effluent obtained from Quesnel River Pulp Co. was studied on a laboratory scale at 35°C. The experimental apparatus consisted of upflow anaerobic sludge bed (UASB) acidogenic reactors followed by hybrid upflow anaerobic sludge bed/fixed-film methanogenic reactors.
Under anaerobic conditions, sulphite and sulphate are reduced to sulphide, presenting problems of toxicity, odour, corrosion and reduced methane yields, and treatment efficiencies. The fate of these compounds was examined under various hydraulic retention times and sulphur management strategies, including: (i) pH control; (ii) inhibition of the sulphur reducing bacteria via molybdenum addition; and (iii) stripping hydrogen sulphide dissolved in the reactor liquor by recycling hydrogen sulphide-free off gas.
Controlling the pH of the acidogenic reactor from 5.5 (uncontrolled) to 8.0, in order to shift the formed sulphide species to the less toxic ionic form, appeared to be ineffective in promoting wastewater treatment efficiency. Molybdenum addition to the wastewater, tested at levels from 0.1 to 1.0 mM, was effective at 1.0 mM in retarding sulphide formation. Hydrogen sulphide stripping, using scrubbed and recycled off gas, appeared to be the most effective means of sulphur management for this type of wastewater under these conditions.
Évaluation écotoxicologique de la baie des Anglais à Baie-Comeau (Québec)
Authors: Pellerin-Massicotte Jocelyne , Vincent Bruno , Pelletier Émilien 
Published: March 2019

Résumé
La baie des Anglais à Baie-Comeau (Québec) est un site industriel reconnu comme étant contaminé aux hydrocarbures et aux biphényls polychlorés (BPC). Une expérience de transfert à moyen terme de deux bivalves marins, Mya arenaria et Mytilus edulis L., a été réalisée entre un site de référence en aval de la baie des Anglais (Franquelin) et des sites contaminés près de Baie-Comeau suivant un gradient de contamination déterminé selon des données physico-chimiques antérieures. Les analyses chimiques de contaminants ont montré qu’il n’y a pas eu d’enrichissement en hydrocarbures, au mercure et en BPC pour toute la durée du protocole mais, parmi les sondes bioanalytiques choisies pour évaluer l’état de santé de cet écosystème, celles qui se sont avérées les plus sensibles chez Mya arenaria furent le glycogène et les lipides dans les gonades, et pour les deux bivalves, la fragilité de la membrane lysosomale de la glande digestive qui est un excellent indicateur de stress toxique. Les présents résultats sont compatibles avec un modèle qui consisterait à établir une évaluation ecotoxicologique d’un écosystème que l’on soupçonne perturbé par la pollution par (i) l’analyse de la bioaccumulation des substances toxiques que l’on croit présentes dans l’écosystème (hydrocarbures, BPC et métaux lourds) et (ii) l’évaluation des effets physiologiques et biochimiques des polluants à l’aide de sondes bioanalytiques appropriées.
Potentiel de la spectroscopic par effet mirage au domaine de la pollution de l’eau: effets de polluants sur l’activité photosynthétique
Authors: Charland Marc , Lorrain Lucie , Leblanc Roger M. 
Published: March 2019

Résumé
Suite à l’absorption d’une lumière monochromatique modulée, un échantillon dégage de la chaleur via les processus de désactivation thermique. La spectroscopic photothermique de déflection (par effet mirage) détecte les changements d’indice de réfraction d’un fluide causés par la perte de chaleur de l’échantillon. Cette méthodologie expérimentale permet d’étudier différents niveaux d’organisation de l’appareil photosynthétique. Des spectres d’action ont été obtenus et montrent une bonne résolution. De plus, l’activité de l’échantillon est mesurée via la détermination de l’emmagasinage d’énergie. Il est ainsi possible de suivre l’activité photosynthétique suite à l’addition d’un agent polluant dans le milieu, ce qui confère à la méthode une capacité de déterminer l’effet de cet agent polluant, en plus de son site d’action.
Réponse des cellules du foie de truite arc-en-ciel exposées à des métaux lourds toxiques
Authors: Marion M. , Denizeau F. 
Published: March 2019

Résumé
Plusieurs métaux toxiques tels le cadmium (Cd), le mercure (Hg) et le cuivre (Cu) possèdent de nombreuses applications domestiques et industrielles. Au Canada, les métaux lourds sont reconnus comme polluants aquatiques majeurs. Notre laboratoire a récemment entrepris l’examen des effets des métaux lourds sur les hépatocytes de truite arc-en-ciel. Vu le manque de connaissances sur les interactions toxiques des métaux chez les organismes aquatiques, une attention particulière est portée à l’étude des mélanges. Les objectifs du présent travail sont (!) de déterminer l’accumulation du Cd, Hg et Cu par les hépatocytes de truite lors d’une exposition à ces métaux, seuls ou combinés, et (ii) de déceler les perturbations métaboliques induites telles que reflétées par l’activité de synthèse protéique des cellules. L’incorporation d’arginine tritiée ([3H]Arg) a été mesurée sur des hépatocytes soumis à des concentrations croissantes de Cd, Hg ou Cu. Dans chaque cas, on a noté une diminution de l’incorporation de 3H dans les protéines cellulaires. Cependant, si on en juge par les niveaux minimums nécessaires pour l’observer, le Cu apparaît comme le métal le moins cytotoxique. Un second groupe d’expériences a cherché à détecter si le Hg ou le Cu pouvaient altérer la réponse toxique causée par le Cd. Une incorporation légèrement plus faible a été observée lorsque le Hg est ajouté au Cd, mais sans que celle-ci soit statistiquement significative. De la même façon avec la paire Cd/Cu, il n’y a pas eu de modulation de la réponse au Cd par l’ajout du Cu. La capture de métaux a été évaluée dans les mêmes conditions que précédemment. L’analyse des métaux montre que les hépatocytes de truite sont capables de capter des quantités significatives des métaux non essentiels Cd et Hg. De plus, aucune compétition réciproque n’est observée pour leur entrée dans les hépatocytes. Enfin, en présence de Cd, la teneur cellulaire en Cu est comparable à celle des témoins. Les modèles cellulaires présentent plusieurs avantages dans le domaine de la toxicologie environnementale dont: la détection du potentiel nocif d’échantillons environnementaux complexes ainsi que l’Investigation du mode d’action des polluants toxiques.
Étude de l’activité photosynthétique à l’aide de la spectroscopic photoacoustique: applications potentielles en écotoxicologie
Authors: Charlebois Denis , Veeranjaneyulu Konka , Leblanc Roger M. 
Published: March 2019

Résumé
La spectroscopic photoacoustique permet la détection de la chaleur émise lors de désactivations thermiques suite à l’absorption, par un échantillon, de la lumière monochromatique modulée. En faisant varier la longueur d’onde du faisceau d’analyse, nous obtenons un spectre comparable à celui obtenu par la spectroscopic d’absorption. La spectroscopic photoacoustique possède l’avantage d’être applicable aux échantillons dont les propriétés optiques ne se prêtent pas aux techniques spectroscopiques conventionnelles, par exemple dans le cas des algues unicellulaires. Cette technique permet, en plus de l’analyse spectrale, la mesure de l’activité photosynthétique d’échantillons sains ou soumis à divers agents environnementaux (polluants, chaleur, …). Des résultats obtenus avec Anacystis nidulans, Phaeodactylum tricornutum et Pisum sativum sont présentés dans le présent travail. Nous croyons que les possibilités de la spectroscopic photoacoustique sont suffisantes pour susciter l’intérêt des chercheurs dans le domaine de la toxicologie et en particulier dans l’évaluation des dangers environnementaux reliés à l’utilisation des substances toxiques.
Endocrine Responses as Indicators of Sublethal Toxic Stress in Fish from Polluted Environments
Authors: Hontela Alice , Rasmussen Joseph B. , Chevalier Gaston 
Published: March 2019

Abstract
Development of new methods for detection of sublethal toxic effects of pollutants in aquatic organisms has become a focus of interest in ecotoxicology. The endocrine response to pollutants is an integral part of the homeostatic physiological processes activated in response to environmental stressors including pollutants. Changes in concentrations of hormones, particularly those regulating vital functions such as osmoregulation, energy metabolism, reproduction, or growth, may have potential as early warning indicators of toxic stress in fish. We review the recent literature in fish endocrine toxicology and illustrate the use of hormonal indicators in detection of acid stress in the brook trout. Salvelinus fontinalis, from lakes in the Canadian Shield, and of general toxic stress in the pike, Esox lucius, and the perch, Perca flavescens, from the St. Lawrence River system polluted by a mixture of chemicals.
Phosphorus Removal from Aerated Lagoons Using Alum, Ferric Chloride and Lime
Authors: Narasiah K. Subba , Morasse C. , Lemay J. 
Published: March 2019

Abstract
Laboratory and on-site studies were conducted over a period of 18 months on two wastewater treatment plants. The main objective was the removal of phosphorus. Three coagulants were used: alum, ferric chloride and lime. In the precipitation process, alum was found to react preferentially with polyphosphates, but not with orthophosphates. Seasonal temperature variations in wastewater did not have a detrimental effect on the coagulation and flocculation processes. The molar capacity of alum for precipitating the orthophosphate fraction was greater at the secondary level of treatment than at the primary level. The phosphorus removal efficiency varied between 90 and 95% for all coagulants. For lime, the dosage was relatively high in order to achieve the same degree of dephosphatation, leading to sludge accumulation in the aerated lagoons.
Microbiological Study of the Carboxylation of Phenols by Methanogenic Fermentation: A Summary
Authors: Bisaillon J.-G. , Beaudet R. , Lépine F. , Sylvestre M. 
Published: March 2019

Abstract
An anaerobic consortium was isolated for its ability to degrade phenolic compounds under methanogenic conditions. The addition of proteose peptone to the minimal salt medium was necessary in order to maintain its activity. The consortium was shown to degrade phenol via its carboxylation to benzoate. Potential intermediates of benzoate degradation given as substrates to the consortium suggest that benzoate is transformed to 1-cyclohexene carboxylate and to heptanoate. The carboxylating activity of the consortium is not restricted to phenol but efficiently transforms the ortho but not the meta and para isomers of cresol, fluorophenol and chlorophenol. The carboxylation occurs at the para position relative to the phenolic hydroxyl group. The consortium is composed of seven different morphological forms. Phenol carboxylating microorganisms were evaluated at 1 × l08 − 8 × l09 cells/ml. These microorganisms are probably nonsyntrophic since inhibition of methanogenesis and the presence of hydrogen in the gaseous phase did not prevent the carboxylation of phenol. The carboxylating microorganisms have not yet been isolated but an active consortium containing only five morphological forms has been obtained.
Physical Limnology and Water Quality Modeling of North American Great Lakes
Authors: Murthy C.R. , Schertzer W.M. 
Published: March 2019

Abstract
Physical limnological research relevant to large lake water quality issues conducted in the Laurentian Great Lakes over the last two decades is presented. Particular attention is given to Lake Ontario. Persistent boundary currents are observed near the north and especially the south shore. The coastal boundary layer characteristics are defined as well as coastal upwelling and coastal circulation characteristics, including the occurrence of internal Kelvin wave propagation following major upwelling events. In addition, fundamental turbulent diffusion characteristics, based on large scale experiments and specialized studies, are described.
Physical Limnology and Water Quality Modelling of North American Great Lakes
Authors: Murthy C.R. , Schertzer W.M. 
Published: March 2019

Abstract
Incorporation of physical limnological processes within the water quality/contaminant modelling framework of large lake systems is fundamental for accurate simulation of transport, distribution and pathways of pollutants. Specific examples of water quality/contaminant model applications to the North American Great Lakes are presented with emphasis on models which incorporate physical processes to solve eutrophic and toxic contaminant problems. Examples of circulation and transport model application to lakes and coastal areas as well as thermocline models are briefly described. Water quality models which incorporate such physical limnological processes include eutrophication models, contaminant transport models (river plume, lake and coastal cases). Specific examples are provided primarily from applications in the lower Great Lakes.
Initial Implementation of the Great Lakes Forecasting System: A Real-Time System for Predicting Lake Circulation and Thermal Structure
Authors: Schwab D.J. , Bedford K.W. 
Published: March 2019

Abstract
The Great Lakes Forecasting System is a real-time coastal prediction system for forecasting, on a daily basis, the physical state of each of the Great Lakes for the next two days. Forecast variables include the surface water level fluctuation, horizontal and vertical structure of temperature and currents, and turbulence. The system uses meteorological observations, satellite data, and forecasts from numerical weather prediction models as input. Lake circulation and thermal structure are calculated using a three-dimensional hydrodynamic prediction model. Output from the model is used to provide information on the current state of the lake and to predict changes for the next two days. This information is used by scientists, government agencies, commercial operations, and the public for enhancement of commercial and recreational activity, resource management, and hazard avoidance.
This paper describes system design, data acquisition and analysis procedures, the hydrodynamic model, and sample model output. The initial implementation of the system provides daily nowcasts of system variables for one lake, Lake Erie. Requirements for implementing actual lake forecasts are discussed.
Mixed Layer Models and Their Application to Water Quality Problems
Authors: McCormick M.J. 
Published: March 2019

Abstract
Four one-dimensional models which have been used to characterize surface mixed layer (ML) processes and the thermal structure are described. Although most any model can be calibrated to mimic surface water temperatures, it does not imply that the corresponding mixing processes are well described. Eddy diffusion or "K" models can exhibit this problem. If a ML model is to be useful for water quality applications, then it must be able to resolve storm events and, therefore, be able to simulate the ML depth, h, and its time rate of change, dh/dt. A general water quality model is derived from mass conservation principles to demonstrate how ML models can be used in a physically meaningful way to address water quality issues.
Transfer Function Model for Current to Wind
Authors: Virta J. , Elo A.-R. 
Published: March 2019

Abstract
In some cases it may be useful to study the dependence of physical variables, like the current velocity or the depth of an isotherm in a lake, on the wind velocity from experimental data. In this study a transfer function model is applied to the current velocity vector for three separate cases. The first case concerns the hypolimnetic current in a sound between two basins (surface areas of 26.4 km2 and 52.1 km2) of a large lake in the temperature-stratified situation. In the second case, time series analysis is applied to the oscillatory currents in the hypolimnion of a stratified lake (surface area of 13.6 km2), and the third case concerns near surface currents in a homogeneous lake (surface area of 154 km2). The results of the transfer function may be used for computation of steady-state current due to long periods of constant wind, and also for comparison of measured and computed oscillatory characteristics of current velocity. The results from each of the computations were rather promising.
Operational Model and its Validation with Drift Tests in Water Areas Around the Baltic Sea
Authors: Koponen J. , Virtanen M. , Vepsä H. , Alasaarela E. 
Published: March 2019

Abstract
Three-dimensional (3-D) mathematical models of water currents, transport, mixing, reaction kinetic, and interactions with bottom and air have been used in Finland regularly since 1982 and applied to about 40 cases in large lakes, inland seas and their coastal waters. In each case, model validity has been carefully tested with available flow velocity measurements, tracer studies and water quality observations.
For operational use, i.e., for spill combatting and sea rescue, the models need fast response, proven validity and illustrative visualization. In 1987-90, validated models were implemented for operational use at five sea areas along the Finnish coast. Further validation was obtained in model applications from nine documented or arranged cases and from seven emergency situations. Sensitivity tests supplement short-term validation. In the Bothnian Sea, it was nescessary to start the calculation of water currents three days prior to the start of the experiment to reduce initial inaccuracies and to make the coastal transport estimates meaningful.
Fractal Dimensions and Shape Factors of Digested Sludge Particle Aggregates
Authors: Námer Juraj , Ganczarczyk Jerzy J. 
Published: March 2019

Abstract
In a previous paper, digested sludge particle aggregates were examined by an image analysis system and by a free-settling multi-exposure photographic method. Based on microscopic observations, it was found that these aggregates exhibited the characteristics of statistically self-similar fractals. The experimentally determined terminal settling velocities and 2-D settling shape factors, which described the irregularity of aggregates during the settling operation, were utilized in this work to estimate the parameters of a settling equation in which the fractal geometry of aggregates was incorporated. Based on these equations, the 2-D and 3-D size-density fractal dimension of digested sludge particles were determined.
Partitioning of Heavy Metals in Some Quebec Municipal Sludges
Authors: Ravishankar B.R. , Auclair J.-C. , Tyagi R.D. 
Published: March 2019

Abstract
The process efficiency of metal bioleaching from sewage sludges depends upon various physicochemical characteristics of sludges and the forms in which metals are present in these sludge solids. The aim of this research work was to evaluate the metal speciation in some Quebec sludges with the help of a sequential extraction procedure, in order to better predict the bioleaching process. The distribution of Al, Cu, Fe, Mn and Zn in exchangeable, sorbed, organically bound, carbonate, and residual forms were compared among both undigested and digested sludges. Metal redistribution after aerobic sludge stabilization was also studied.
Results indicate that the organic and residual fractions were the principal metal binding phases. Copper was present mostly in the residual fraction while the other metals were mostly organically bound. Statistical tests showed that metal speciation varied significantly from one sludge to another. In terms of metal distribution pattern observed, these sludges could not be regrouped according to the sludge type, their total solids concentration or their total metal concentration. However, the variation in metal distribution among Quebec sludges was similar to the variation range found in the U.K. and U.S. sludges. The metals showed a tendency to redistribute and move towards the organic fraction in stabilized sludges. In conclusion, the present study shows that sewage sludges of different origins do not have similar metal distribution and hence, the speciation of metals must be considered for each sludge on an individual basis in order to predict their fate during the bioleaching process.
Heavy Metal Content of the Keban Lead Plant Slag and Movement of Metals in Soil of the Surrounding Region
Authors: Rüstem Gül 
Published: March 2019

Abstract
The heavy metal content of the Keban lead plant (KLP) slag, its variation with time under rain and snow, the capacity of the Keban region soil to remove heavy metal ions, and the distribution of these metals in soil were investigated. For this purpose, the dilute acetic acid extraction test of the U.S. Environmental Protection Agency was applied to the slag samples and amounts of heavy metals extracted with hot (80°C) 4 M HNO3 from soil samples at different depths were determined. The concentrations of heavy metal ions in the soil varied with depth, and the heavy metal content of the slag changed with time, showing effects of rain and melt water from snow. From the observed relationships, which take into account the heavy metal content of the slag and the capacity of the soil to remove metal ions leached from the slag, it was concluded that KLP slag from different sites can be applied to land.
Environmental Effects of Aluminum Used in Water Treatment Plants of Rio de Janeiro State, Brazil
Authors: Azcue Jose M. , Malam Olaf , Pfeiffer Wolfgang G. 
Published: March 2019

Abstract
The effect of the extended use of alum on the concentration of aluminum in water treatment was investigated. Water from the Paraiba do Sul-Guandu River (PSR-GR) system, collected after conventional treatment, was analyzed from the six water treatment plants (WTPs). One of the WTPs, the Guandu WTP, supplies water to the city of Rio de Janeiro (11 million inhabitants) with a flow of 40 m3/s. The concentrations of aluminum found were near and sometimes over the values recommended by the World Health Organization (200 µg/L), with an average concentration of 306 µg/L, reaching seasonally maximum values of 877 µg/L at the WTP and 2,100 µg/L in household taps. The discharge of alum sludge back to the river system is the predominant pathway in the aluminum cycling in the study area, followed by sedimentation and enhanced availability to the biota.
Environmental Chemical Behaviour of Metal Contaminants in Aquatic Environments in China
Authors: Liu J.Y. , Lin Y.H. , Mao M.Z. 
Published: March 2019

Abstract
The chemical species of metal contaminants and their transformation in aquatic systems are largely dependent on environmental conditions. This paper reports on some work on metal contamination in a number of rivers in China. Speciation by sequential extraction and some physicochemical processes involving the transformation and transport of metals in the aquatic systems are also reported.
Sunlight Photocatalytic Degradation of o-Chloroaniline
Authors: Daoxin You , Yongsheng Chen , Shugui Dai 
Published: March 2019

Abstract
o-chloroaniline (o-CA) is a priority organic pollutant that exists widely in industrial pesticide wastewater. Recent reviews on the wastewater treatment methods for the pesticide industry indicate that the treatment methods utilized do not always lead to complete degradation of o-CA. The photocatalytic degradation behaviour of o-CA has been studied in the presence of a catalyst. The effects of the kind of catalyst, pH of the solution and the influence of dissolved oxygen have been examined. After treatment, the organic pesticide wastewater with chloroanilines was non-toxic, and chloroanilines were almost completely degraded after a certain period of irradiation (photodegradation up to 98%, COD removal up to 62.6%.) Experiments on photocatalytic degradation of o-CA with sunlight showed a promising route for pesticide wastewater treatment.