bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the Adequacy of Selected Micro-Scale Bioassays to Predict the Toxic Potential of Freshwater Sediments through a Tier Process
Authors: Côté Chantale , Blaise Christian , Schroeder Julie , Douville Mélanie , Michaud Jean-René 
Published: March 2019

Abstract
A battery of 20 bioassays was applied to assess test and endpoint performance in detecting the toxic potential of 15 freshwater sediment samples collected in the St. Lawrence River/Great Lakes systems. The bioassays included 18 micro-scale assays performed either on whole sediment, pore water or sediment organic extracts, as well as two standardized whole sediment bioassays undertaken with macroinvertebrates (Chironomus riparius and Hyalella azteca). Physical and chemical parameters of selected sediments were also analyzed to aid in the interpretation of results. Several qualitative and quantitative criteria were established for evaluating the reliability and usefulness of the micro-scale bioassays in predicting sediment toxicity based on a two-tier system. In Tier 1, micro-scale testing results were compared for general concordance with those of the benthic bioassays, benthic community structure index and with sediment contaminant levels. Micro-assays which complied with Tier 1 standards were further evaluated via a Tier 2 process consisting of selected (quantitative and qualitative) scientific and practical criteria. Of the 20 bioassays investigated, the two benthic assays and seven micro-scale assays successfully passed the double-tiered assessment. Micro-scale tests whose results most closely matched those of the benthic tests for appraisal of whole sediment toxicity, sediment contamination level and benthic community structure index included three bacterial assays (ATP assay, a micro-plate adaptation of the Microtox® assay, SOS Chromotest™), one algal assay (algal solid-phase test) and three micro-invertebrate assays (Thamnotoxkit™ F, Daphtoxkit™ F and Hydra assay). Two selected batteries, composed of the seven micro-scale assays and benthic invertebrate bioassays, are proposed for cost-effective appraisal of freshwater sediment toxicity.
An Evaluation of the Use of Soil and Sediment Bioassays in the Assessment of Three Contaminated Sites in Atlantic Canada
Authors: Carter J.A. , Mroz R.E. , Tay K.L. , Doe K.G. 
Published: March 2019

Abstract
Biological tests recommended by Environment Canada (1994) for the assessment of contaminated sites were evaluated at three sites in Atlantic Canada. Soil and sediment samples from contaminated sites in Makinsons, Newfoundland, Weldon, New Brunswick, and Five Island Lake, Nova Scotia, were characterized by chemical analysis and the recommended bioassays. Contaminants in excess of federal and/or provincial guidelines included poly-chlorinated biphenyls (PCBs), total petroleum hydrocarbons (TPH) and heavy metals in Makinsons soil, TPH in Weldon soil, and PCBs and heavy metals in Five Island Lake sediment. Four soil bioassays were conducted: earthworm (Eisenia andrei) survival, lettuce seedling (Lactuca sativa) emergence, algal (Selenastrum capricornutum) population growth inhibition and inhibition of light output in Microtox\xAE (Vibrio fischeri). Sediment bioassessment involved the following tests: midge (Chironomus tentans) growth and survival, amphi-pod (Hyalella azteca) growth and survival, algal population growth inhibition and Microtox. The study demonstrated that the toxicity of samples from contaminated sites may not necessarily be consistent with the results of chemical analyses. However, correlations were identified between soil TPH concentrations and Microtox IC50, and sediment PCB concentrations and algal IC50. Soil bioassay sensitivity was ranked (in order of increasing sensitivity) as earthworm &lt; lettuce = algae &lt; Microtox. Sediment bioassay sensitivity was ranked as Microtox &lt; amphipod &lt; midge &lt; algae. Bioassessment as a supplement to conventional chemical testing at contaminated sites in Canada is recommended.
A Study of ATP and Biodegradation as a Measure of Bacterial Activity in an Anaerobic Fluidized Bed Bioreacto
Authors: Imbeault Nathalie , Paquet Marcel , Côté Raynald 
Published: March 2019

Abstract
In this study, the formation of the biofilm and the temporal change in the bacterial composition at different whey permeate (wastewater) sugar concentrations were assessed inside a fluidized bed bioreactor. At a sugar concentration of 5 g/L, the efficiency of biodégradation was 10%, while at 20 g/L it was 3%. With time, an increase in the ATP concentration of the bacteria on the coal grains was observed, indicating biofilm formation. To estimate the biodegradation activity in the biofilm, expressed as mass of sugar biodegraded per day and per volume of support, the bacterial ATP was determined by the firefly biolu-minescent enzymatic reaction developed by Karl and Larock (1975). At sugar concentrations of 5 and 20 g/L, the ATP concentrations of the bacteria forming the biofilm were, respectively, 11.6 and 36.0 moles ATP/m3 of support, corresponding, respectively, with lactose rates of 343.7 and 515.5 kg/d m3. There were 13 species of bacteria inventoried in the bioreactor. Pseudomonas maltophilia, P. paucimobilis, P. sp., P. fluorescens, Salmonella sp., Acinetobacter calcoaceti-cus var. lwoffi, Aeromonas hydrophila/caviae, Staphylococcus hominis, S. cohnii, S. aureus, Escherichia coli, Enterobacter faecium, and a filamentous species that could be associated with the genus Methanothrix.
Lessons Learned from the Environmental Management Development in Ukraine Project
Authors: Guilmette Jean-H. 
Published: March 2019

Abstract
The Environmental Management Development in Ukraine project is funded by the Canadian International Development Agency through a contribution agreement signed with the International Development Research Centre. The project began on April 1, 1994, following a prenegotiated detailed project plan established with the full agreement of the Ukrainian Government. A Memorandum of Grant Conditions signed with the Ministry for Environment Protection and Nuclear Safety, set out the management framework for the project. This paper summarizes the final report on activities and lessons learned comprised by the first phase of EMDU1 dubbed EMDU-1 to distinguish it from a new program of activities also involving environmental management development which started on October 1st, 1997.
Effects of Salinity on Physical Characteristics of Activated Sludge Flocs
Authors: Cousin Christopher P. , Ganczarczyk Jerzy J. 
Published: March 2019

Abstract
The effect of increased wastewater salinity on the physical characteristics of activated sludge flocs was studied. Samples of activated sludge were exposed to increments of NaCl and the physical structure of the individual flocs, was then investigated. A time response of the flocs to these changes was also measured. Two separate series of tests were run and for both series, it was determined that as the NaCl concentration increased, the mean floc area, equivalent diameter, perimeter and longest dimension all increased, with the flocs becoming more elongated with decreasing shape factor. The mechanism involved in the increase of the floc sizes is considered to be a combination of electrostatic and hydrophobic interactions. Examination of the size distributions revealed that the data were best fitted by a log normal distribution and that, as the NaCl concentration was increased, the distribution of the characteristic tended to shift towards a higher proportion of larger values, or smaller values for the shape factor results. Both the porosity and boundary fractal dimension were found to provide different values in the two series of tests. The flocs were found to exhibit two distinct Sierpinski fractal dimensions, thus indicating the presence of two pore size populations. The increasing salinity had little effect on the smaller pore size population, but a significant effect on the larger pore size population. The time response test indicated that the flocs achieved the new characteristics in about 15 minutes.
Effect of Filter Media Particle Size Distribution on Filtration Efficiency
Authors: Amini F. , Truong H.V. 
Published: March 2019

Abstract
The results of an experimental study of a sand filter water quality model are presented. The model is built to represent an underground confined water quality sand filter structure. Three types of sands, namely fine, medium and coarse, were used to study the effect of filter media particle size distribution on sediment removal efficiency. The results indicated that the sediment removal efficiency for all sand types decreased with time. The use of medium sand provided the scale model filter with the highest sediment removal efficiency. The finding of this study indicates that the media grain size has a measurable effect on the efficiency of the sand filter water quality structure.
Review of Analytical Methods for the Determination of Nonylphenol and Related Compounds in Environmental Samples
Authors: Lee Hing-Biu 
Published: March 2019

Abstract
Analytical methods published in the last 20 years for the extraction, chromato-graphic separation, and quantification of alkylphenol ethoxylates (APEO) and related compounds in environmental samples are reviewed. Examples of various isolation and preconcentration techniques for water, effluent, sediment and sludge are presented. This includes procedures from the classical liquid-liquid and Soxhlet extraction to the up-to-date solid phase and supercritical fluid extraction. Chromatographic separation of APEO by normal and reversed phase liquid chromatography (LC) and capillary column gas chromatography (GC) is compared. A variety of quantification methods involving the common LC and GC detectors as well as various mass spectrometric techniques are also discussed.
Review of the Persistence of Nonylphenol and Nonylphenol Ethoxylates in Aquatic Environments
Authors: Maguire R. James 
Published: March 2019

Abstract
Alkylphenol ethoxylates, in particular nonylphenol ethoxylates, are widely used nonionic surfactants that are discharged in high quantities to sewage treatment plants and directly to the environment in areas where there is no sewage or industrial waste treatment. This article reviews the treatability of nonylphenol ethoxylates and nonylphenol in sewage treatment plants and their persistence in aquatic environments. Nonylphenol ethoxylates can be biologically degraded in sewage treatment plants and in natural environments. Some of the degradation products, including nonylphenol, are more persistent than the parent surfactants and they are found in receiving waters of sewage treatment plants. Nonylphenol in particular is found at high concentrations in some sewage sludges that may be spread on agricultural lands. While some sewage treatment plants discharge significant amounts of nonylphenol ethoxylate degradation products in their final effluents and digested sludges compared to what enters the plant, others degrade nonylphenol ethoxylates more or less completely. The differences in treatment efficiency of such compounds and their degradation products among different sewage treatment plants have been attributed to the load of the surfactants in influent streams, plant design and operating conditions, and other factors such as temperature of treatment. The highest nonylphenol ethoxylate elimination rates were achieved in plants characterized by low sludge-loading rates and nitrifying conditions. In natural waters, it appears that parent nonylphenol ethoxylates are not persistent, but some degradation products may have moderate persistence, especially under anaerobic conditions. Recent results from mesocosm experiments indicate moderate persistence of nonylphenol in sediments, with half-lives of 28 to 104 days. Microbial acclimation to the chemicals is an important determinant of persistence vis-à-vis biodegradation. Sunlight photodegradation of such products is also likely important. Further research on the persistence in natural environments of the lower ethoxylate and carboxylate degradation products, as well as nonylphenol, is necessary. Based on the limited data available, nonylphenol and the lower ethoxylates and carboxylates are persistent in groundwater. They are also persistent in landfills under anaerobic conditions, but they do not appear to be persistent in soil under aerobic conditions. Recommendations are made for further research in order to more fully characterize the treatability of nonylphenol ethoxylates and their degradation products in sewage treatment plants and their persistence in the natural environment.
Review of the Environmental Occurrence of Alkylphenols and Alkylphenol Ethoxylates
Authors: Bennie Donald T. 
Published: March 2019

Abstract
Alkylphenol ethoxylates and, in particular, nonylphenol ethoxylates have found many industrial, commercial, institutional and household uses in Canada. These nonionic surfactants are very efficient and cost effective. Their widespread use has led to the detection of the parent surfactants and their degradation products in various environmental matrices. Alkylphenol ethoxylates can be degraded aerobically and anaerobically in natural environments and sewage treatment plants.. The resulting degradation products are more persistent, more toxic, more lipophilic, less water soluble and more estrogenic than their parent compounds. This article reviews the occurrence of nonylphenol polyethoxylates and their degradation products as well as octylphenol poly-ethoxylates and their degradation products. There is limited information available about the concentrations of these substances in their original product formulations. The highest levels of the degradation products, especially nonylphenol, occur in the anaerobically digested sludge of sewage treatment plants. Sludge from these sewage treatment plants may be used as an amendment to agricultural soils. Various sewage treatment plants have wide ranges of discharged effluent concentrations of these compounds — some appear to be very efficient at removing alkylphenolics from their effluent stream. Little information is available about the fate of these substances in their receiving environment, and environmental concentrations and bioaccumulation factors of these contaminants in aquatic biota. More research is required on the uptake, persistence and bioaccumulation of alkylphenolic metabolites in fish, mussels and other aquatic organisms
Sequential Filtration of Surface and Ground Waters from the Rabbit Lake Uranium Mine, Northern Saskatchewan, Canada
Authors: Hollings P. , Hendry M.J. , Kerrich R. 
Published: March 2019

Abstract
Major, trace and rare earth element analyses were conducted on water samples from four sites at the Cameco Rabbit Lake uranium mine in northern Saskatchewan, Canada. Samples were collected from the mill discharge, raise water, the tailings and an adjacent well. Water samples were sequentially filtered through 3.0-µm, 0.45-µm, 0.2-µm, 0.1-µm and 0.02-µm Millipore filters. Trace element and metal abundances were higher in unfiltered samples directly related to the tailings management facility (TMF) than the adjacent ground-water sample. The majority of the metals, including As and Ni, were trapped on the 3.0-µm filter, with the remainder of the metals in all four samples either in solution or transported by extremely small colloidal material (&lt;0.02 µm). Filtration through a 3-µm filter resulted in a substantial decrease in the absolute abundances of the REE in the samples directly associated with the TMF; however further filtration through progressively finer filters did not result in detectable variations in REE abundances. In the TMF-related samples removal of suspended sediment by the 3-µm filter resulted in changes in the REE patterns which were not observed in subsequent filtrations. The well sample did not display major variations in REE abundances with filtration, reflecting the lower colloidal load in that sample. Consequently, filtration through 3.0-µm or 0.45-µm filters will remove the majority of colloidal material at the Rabbit Lake uranium mine.
Modélisation hydro-bio-chimique du bassin versant de la rivière Saint-Charles
Authors: Vescovi Luc , Rousseau Alain N. , Mailhot Alain , Villeneuve Jean-Pierre 
Published: March 2019

Abstract
Cet article présente la démarche de modélisation hydrologique qui a été réalisée à l’aide des données existantes sur le bassin versant de la rivière Saint-Charles. Les débits sur le bassin sont obtenus à l’aide du modèle CEQUEAU. Les débits obtenus par CEQUEAU sont utilisés par la suite lors de la modélisation bio-chimique, qui est le sujet d’un second article. Cette étude est réalisée dans l’optique de voir dans quelle mesure une telle approche de modélisation est facile d’utilisation pour le gestionnaire de la ressource eau. Les résultats de simulations de CEQUEAU sont bons pour la partie rurale du bassin. À cause du manque de données disponibles sur les bassins des principaux tributaires, en particulier celui de la rivière Lorette, les résultats y sont moins bons. Pour la partie urbanisée du bassin les différences entre les débits observés et les débits simulés sont imputables au manque de données observées, à une forte influence anthropique sur la gestion de l’eau et vraisemblablement à une trop grande simplification mathématique des processus hydrologiques en milieu urbain.
Evaluation of Polyalkastyrene Absorbent Beads for the Remediation of PCE in Groundwater
Authors: Venhuis M. , Lesage S. , Millar K.R. , Crowe A.S. 
Published: March 2019

Abstract
Passive groundwater remediation technologies are increasingly considered because they require very little long-term maintenance and are thus more cost effective than active systems such as pump-and-treat, which require the continuous upkeep of a groundwater pumping system and of an above-ground water treatment plant. Barriers are being installed in the ground to either prevent the flow of contaminated water from one property to another, or to remove the contaminants from the water as it passes through a porous reactive barrier. Absorbents which irreversibly incorporate spilled solvents into their structure have been developed to clean surface spills. This project was aimed at evaluating the performance of the absorbents with dissolved organic contaminants. It was found that while they did sorb aqueous phase compounds, it was through adsorption, not absorption and that it was therefore reversible. As adsorbents, the polymers marketed as Imbiber Beads® and Expandabeads® were not as effective as activated carbon.
Fly Ash for Colour Removal from Synthetic Dye Solutions
Authors: Viraraghavan T. , Ramakrishna K.R. 
Published: March 2019

Abstract
Fly ash was investigated for its ability to adsorb dyes from aqueous solutions. Batch pH, kinetic and isotherm studies were performed on a laboratory scale with synthetic dye solutions made up of four different commercial grade dyes. Fly ash samples with differing compositions and particle sizes were employed to understand the effect of fly ash composition and particle size on their dye removal capacity. The first-order rate equation by Lagergren was tested on the kinetic data, and isotherm data was analyzed for possible agreement with the Langmuir and Freundlich adsorption isotherm equations. The removal capacity of fly ash for the different dyes was compared with that of granular activated carbon under identical conditions. Results showed that fly ash exhibited reasonably good dye removals for Basic Blue 9, Acid Blue 29 and Acid Red 91, while the removals by fly ash exceeded that of granular activated carbon for Disperse Red 1. Lime content in fly ash seemed to influence dye adsorption to a significant degree — better adsorption was observed at lower particle sizes because of the increased external surface area available for adsorption. Acid Blue 29 adsorption by fly ash provided the best fit for the Lagergren first-order plot. Because high pH and heavy metals (leached from fly ash) in the treated wastewater may exceed the limits set in municipal sewer-use bylaws, engineering and economic feasibility assessment should include these aspects when considering fly ash for colour removal.
Effects of Dilution and Fungal Pretreatment on Anaerobic Biodegradability of Oxygen Delignification Process Spent Liquor
Authors: Yerushalmi Laleh , Hodgson Jonathan , Jasim Khalid S. , Guiot Serge R. 
Published: March 2019

Abstract
The effects of several pretreatment techniques, including dilution, fungal pretreatment and addition of hydrogen peroxide on the enhancement of anaerobic biodegradability of spent liquor (SL) of the oxygen delignification process of recycled fibers, were evaluated. A 14% COD removal efficiency and a 37% acidification were obtained by the untreated effluent, indicating its low degree of biodegradability. After pretreatment, the efficiency of COD removal and the overall yield of methane production were increased by 24% to 246% and by 26% to 396%, respectively, compared to the untreated liquor. The acidification of spent liquor also increased to more than 70% following the pretreatment. Kinetics analysis of methane production and COD removal implied the production of inhibitory metabolites during the anaerobic biodegradation. The optimal dilution factor for the spent liquor sample under study, to reduce toxi-city while maximizing the specific rates of COD removal and methane production, was predicted to be less than five times.
The Presence of Coliform Bacteria in Canadian Pulp and Paper Mill Water Systems — a Cause for Concern?
Authors: Archibald Frederick 
Published: March 2019

Abstract
A question raised again and again over many decades by pulp and paper mill personnel and local authorities in many countries is, "Does the finding of large numbers of coliform enteric bacteria in the mill water or biotreatment system indicate a real health hazard for the mill workers or the downstream public?" Some of the difficulties in answering this question arise from the widespread misunderstanding of what coliform indicator (enumeration) tests can tell us. Increasing scientific understanding over the last 30 years has greatly altered the coliform indicator tests, the types of bacteria enumerated, and our ability to distinguish harmless from pathogenic (disease-producing) bacteria. This brief review discusses our current understanding of where and when it is appropriate to use coliform indicator assays and the meaning of the results.
Aquatic Toxicity and Environmental Impact of Leachate Discharges from a Municipal Landfill
Authors: Rutherford L.A. , Matthews S.L. , Doe K.G. , Julien G.R.J. 
Published: March 2019

Abstract
The final leachate from a municipal landfill, using a wetland tertiary treatment system, and water in the receiving environment were chemically characterized and evaluated for acute and sublethal aquatic toxicity. In addition, the effects of leachate discharges on the benthic macroinvertebrate community were determined. Samples were not acutely toxic to rainbow trout (Oncorhynchus mykiss), Daphnia magna and Vibrio fischeri. There was no detrimental effect on the survival and reproduction of Ceriodaphnia dubia, although a slight effect on reproduction was detected in river water at the control station (700 m upstream). Moderate toxicity to Selenastrum capricornutum was detected at the control and at station #2 (40 m from the outfall). Ames tests revealed no mutagenic or cyto-toxic effects in the final leachate or in river water downstream. Benthic macroinvertebrate sampling revealed that the leachate discharge had a localized impact on community structure near the outfall, but by 50 m downstream, the conditions were approaching those upstream of the discharge point.