bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Two Indices of Diatom Inferred pH
Authors: Dickman M. , Hayes P. , Fortescue J. 
Published: March 2019

Abstract
Autecological studies of diatoms as pH indicators have opened the way to estimating a lake's past pH on the basis of its diatom species compos it ion and relative abundance. Estimating the rate of lake acidification from its sediment subfossil diatoms is possible when these subfossils can be identified and accurately enumerated down the length of the lake sediment core. This technique holds considerable promise in assessing the temporal impact of acid precipitation for acid-sensitive lakes.
When diatom inferred pH was regressed against observed pH for 23 lakes located north of Lake Superior a significant (P&lt;0.01) correlation (r=0.71) resulted. Diatom downcore stratigraphy for two of these lakes (lakes Cs & B) indicated that their pH had dropped from 6.3 to 5.3 (Lake Cs) and from 5.6 to 5.3 (Lake B) over the last 20 years. However, when the "B" index was used instead of log alpha, no significant change in downcore diatom inferred pH was apparent for Lake B. We concluded that log alpha was overly sensitive to small changes in the relative abundance of alkaliphilic diatoms. Thus, in lakes where alkaliphilic diatoms are rare, index "B" rather than log alpha should be employed. In lakes of pH 6 or above where the relative abundance of alkaliphilic diatoms is higher (e.g. Cs & Fenton Lakes) index "B" and log alpha provide essentially identical downcore pH profiles.
Distribution of Organochlorine Pesticides and PCBs between Aqueous and Suspended Sediment Phases in the Lower Great Lakes Region
Authors: McCrea Robert C. , Fischer John D. , Kuntz Kenneth W. 
Published: March 2019

Abstract
Suspended sediment and extracts of the aqueous phase were collected in 1981 at eleven locations in the Lower Great Lakes Region and analyzed for 17 organochlorine pesticide residues and PCB's. Mirex, and p,p'-DDE when found were predominantly in the suspended sediment fraction, whereas α-BHC, γ-BHC, dieldrin, endrin, p,p'-TDE and trans-chlordane were most abundant in the aqueous phase. Several pesticide residues, notably cis-chlordane, p,p'-DDT and p,p'-methoxychlor were found to have variable distribution characteristics between the suspended sediment and aqueous phases. The greater proportion of organochlorine pesticides present in Lake Erie and the Niagara River were found in the aqueous phase samples, which contained at least 90% of the total pesticide concentration at 5 of the 6 stations sampled. Virtually all of the organochlorine contaminants present in Lake Ontario were found in the aqueous phase, which contained 100% of the pesticides and 91% of total PCB's. Similar results were obtained for the St Lawrence River.
Use of Laboratory Studies in Assessing the Behaviour of Contaminants in Fish Inhibiting Natural Ecosystems
Authors: Niimi A.J. 
Published: March 2019

Abstract
The behavior of environmental contaminants in fish was examined using information from chemical, toxicological, and physiological laboratory studies, and field residue measurements to establish the relative importance of the bioconcentration and biomagnification pathways, and environmental concentrations on residue accumulation in natural ecosystems. It is suggested that indices such as the bioconcentration factor (BCF) and octanol-water partition coefficient (Kow) can be effectively used to analyze the fate of contaminants in natural ecosystems provided their limitations are recognized. It is proposed that other indices like the bioaccumulation factor (BAF) and biological half-life could also be used for evaluation. A simulation of the contaminant dynamics of a salmonid is presented, and the kinetics are used to illustrate the differences in behavior of the more environmentally relevant organic contaminants present in the Lake Ontario environment.
An Approach to Recognizing Low Level Inorganic Contamination of Groundwaters in Shallow Sedimentary Aquifers
Authors: Howard K.W.F. 
Published: March 2019

Abstract
Groundwaters from shallow surficial sediments of southern Ontario regularly contain total dissolved solids in excess of the maximum desirable level of 500 mg/L. In such cases a major difficulty lies in determining whether the elevated concentrations reflect contamination of the groundwaters by pollutants or are simply the product of natural rock-water chemical reactions.
A comprehensive hydrochemical study involving major and minor ion analysis of over 260 groundwater samples was carried out in the Duffins Creek - Rouge River drainage basins to the north and east of Metropolitan Toronto. As an aid to interpreting the wealth of data, a specially modified form of trilinear diagram was used to identify uncontaminated waters and determine their degree of chemical variability under naturally evolving conditions. This allowed chemical anomalies to be recognized at concentrations only marginally above background and considerably below present water quality standards. Significantly, most of the anomalies were found to occur either in groundwaters from wells adjacent to major highways, where road de-icing chemicals cause elevated calcium (through ion exchange) and chloride, or in rural areas, where high nitrate concentrations are associated with agricultural practices.
Uptake and Depuration of Two Polycyclic Aromatic Hydrocarbons, Fluorene and Benzo(a)pyrene, in the Mussel Mytilus Edulis and the Diatom Phaeodactylum Tricornuteum
Authors: Majewski H.S. , Scherer E. 
Published: March 2019

Abstract
In laboratory exposures, uptake rates from water for both benzo(a)pyrene and fluorene were 1-2 orders of magnitude higher in missels than in diatoms, while depuration rates were similar. Bioconcentration factors in mussels were 21428 and 394 for benzo(a)pyrene and fluorene, respectively, and 636 and 11 in diatoms. Accumulation of benzo(a)pyrene in mussels through trophic transfer from algae amounted to 1.3% of total residue in molluscs.
Repartition spatiale des contaminants dans les sediments du Lac St-Louis (Fleuve St-Laurent)
Authors: Jarry V. , Ross P. , Champoux L. , Sloterdijk H. , Mudroch A. , Couillard Y. , Lavoie F. 
Published: March 2019

Abstract
Les sédiments de 39 stations du lac St-Louis ont été échantillonnés et analysés pendant l'été 1984 pour la granulométrie, dix éléments majeurs et les contaminants (Ni, Co, Cr, V, Pb, Zn, Hg, As, HCB, pp'-DDE, Aroclor1242™, Aroclorl254™, Aroclorl260™). Dans la plupart des stations les teneurs sont plus élevées que les normes établies par le ministère de l'Environnement de l'Ontario pour le dépôt de déchets de dragage en eau libre. Avec ces données, nous avons réalisé des cartographies du lac, ce qui nous a permis de discerner trois zones où les teneurs en contaminants sont plus élevées : entre la baie de Valois (Dorval) et la Grande Anse (île Perrot), au sud des îles de la Paix (Beauharnois) et au sud de l'île Perrot (Anse au Sable). D'autre part, nous avons calculé des corrélations entre les variables, ce qui nous a permis de constater qu'il existe de fortes corrélations entre les métaux lourds et entre les contaminants organiques entre eux, mais beaucoup moins entre ces deux groupes de contaminants. Finalement, des méthodes statistiques multidimensionnelles ont été utilisées pour regrouper les stations en fonction de leur composition chimique, et cartographier le lac St-Louis. Il en ressort un groupe principal pour les éléments majeurs comprenant les 3 zones de sédimentation. Cependant, ces trois zones semblent avoir des caractéristiques différentes quant à leur composition en contaminants.
Use of Low Pressure Mercury Lamps for the Photodecomposition of Iron Cyanide in Gold Mill Effluents
Authors: Carey J.H. , Zaidi S.A. 
Published: March 2019

Abstract
The use of ultraviolet light (UV) from low pressure mercury lamps for destroying iron cyanide in synthetic and actual gold mill effluents was evaluated in this study.
For the light intensities used in this study, UV irradiation was not able to efficiently destroy cyanide. However, it converted iron cyanide to a weak acid dissociable form which was destroyed by chlorine. Data from several bench-scale tests and one pilot scale test were used to estimate quantum efficiencies (moles iron cyanide destroyed/einstein). These efficiencies ranged from 0.2% to 1%; approximately 30% to 90% lower than those reported in the literature for potassium ferricyanide.
The data collected during the study demonstrated the technical feasibility of using UV in conjunction with chlorination for destroying iron cyanide in gold mill effluents. However, low pressure mercury lamps do not appear to be a practical UV source for this purpose. Irradiation with high intensity lamps may be more practical and is recommended for experimental evaluation.
Natural Removal of Cyanide in Gold Milling Effluents - Evaluation of Removal Kinetics
Authors: Simovic L. , Snodgrass W.J. 
Published: March 2019

Abstract
Research using synthetic solutions was conducted to examine factors influencing the natural removal of cyanides from gold mill lagoons. Factors examined included: pH, temperature, ultraviolet irradiation and degree of aeration. Temperature was the principal factor affecting the rate of cyanide loss from solution. UV irradiation had some effect while the effect of aeration was limited. The dominant mechanism for cyanide removal from solution was volatilization. Cyanide degradation was found to follow a first order reaction with respect to free cyanide and metallo-cyanide complexes of Zn, Ni, Cu and Fe.
Data from each single metallo-cyanide solution were fitted to a mathematical model which considered volatilization of free cyanide, dissociation of the metallo-cyanide species, and one cyanide complex per metal. The best estimates of the rate constants found for the single metallo-cyanide solutions were used to simulate the removal characteristics of cyanide in a synthetic mixed solution of four metals. The coefficient of determination ranged from 0.93 to 0.99 for model predictions fitted to data from single metallo-cyanide solutions. Estimates for volatilization coefficients varied widely with some of the variation resulting from data which did not completely describe the decay process. The simulation of cyanide removal from the synthetic mixed solution suggested the need to recalibrate the model or to examine the formation of more than one metallo-cyanide species.
New Developments in Landfill Leachate Treatment
Authors: Henry J.G. 
Published: March 2019

Abstract
Treatment of Leachate from sanitary landfills has been found to be a much different and more complex problem than the treatment of municipal wastewater. Greater variability in the characteristics and quantities, of the waste, isolation of the landfill site and the need for simple treatment methods are three reasons why leachate treatment needs special consideration. Typical characteristics of this waste are high strength, a low BOD/COD ratio, limited phosphorus and excessive ammonia nitrogen, along with various toxic contaminants.
A number of aerobic and anaerobic methods used to treat leachate are described in this paper and the advantages and shortcomings of each are noted. Supplementary processes including nitrification, nitrogen removal, recirculation and land spraying are also discussed. From experience with these earlier systems it appears that, in the future, more consideration should be given to: equalization of leachate flow, anaerobic rather than aerobic processes, nitrification of the leachate and utilization of landfill gas. Land spraying and recirculation of leachate also warrant wider application.
Leachate Generation and Control at Landfill Disposal Sites
Authors: Pohland Frederick G. , Harper Stephen R. , Chang Ker-Chi , Dertien Joseph T. , Chian Edward S. K. 
Published: March 2019

Abstract
A two-part overview of the state-of-the-art in landfill management is presented with emphasis on the production and characteristics of landfill leachate and gas and methods for control and treatment. The patterns of production of landfill leachate and gas are illustrated with results from a landfill simulation study with and without leachate recycle. Leachate treatment options are summarized and fortified by information derived from selected literature reports.
Leachate Production and Characteristics as a Function of Water Input and Landfill Configuration
Authors: Jasper S.E. , Atwater J.W. , Mavinic D.S. 
Published: March 2019

Abstract
A field sampling programme was carried out at a Vancouver Lower Mainland landfill to study leachate flow and characterization. A water balance and simple hydrogeologic model were developed for the site In order to calculate leachate discharge rates. Details of leachate composition are presented and related to site water input patterns. The interdependance of leachate composition, water input and fill retention time is hypothesized. Implications are presented in terms of site configuration and treatment process design.
Attenuation of Leachate in a Designed, Engineered and Instrumented Unsaturated Zone Beneath a Domestic Waste Landfill
Authors: Robinson Howard D , Lucas John L 
Published: March 2019

Abstract
In recent years the effectiveness and reliability of “dilute and disperse” type landfills has been the subject of much debate. Much research has been reported which supports the view that intergranular unsaturated zones beneath sites can provide a high degree of aquifer protection, although detailed and continuing monitoring of such zones has been extremely rare.
Aspinwall and Company are carrying out a major research project on behalf of the UK Department of the Environment at a landfill site in Southern England, which is operated by ARC South Eastern. The design of this landfill was produced by Aspinwall and Company, and is innovative in that it has incorporated an engineered, semi-permeable, attenuation blanket, using locally-available calcareous sands and silt, emplaced to a minimum height of 6 m above the water table. The site has a licence to deposit up to 1300 tonnes per day of domestic wastes derived from London.
In early 1982 one portion of the quarry floor was selected for a programme of research, and over 100 instruments and sampling devices were installed before waste disposal began. A drilling programme during the summer of 1984 allowed further sampling, and the installation of more instruments within the wastes themselves, now about 2b to 30 m deep.
This paper summarises and describes data obtained over the 3-year monitoring period to early 1985. The performance of the unsaturated zone is assessed, in terms of the attenuation of inorganic ions such as ammonia and chloride, and degradation of organic compounds such as fatty acids, which have occurred as leachate and gases have migrated from the wastes.
RBC Treatment of a Municipal Landfill Leachate: A Pilot Scale Evaluation
Authors: Peddle C. , Atwater J.W. 
Published: March 2019

Abstract
This study evaluated the on-site treatment of a weak municipal landfill leachate with a Rotating Biological Contactor (RBC) at pilot scale (0.9 m dia.). The leachate generally had COD and NH3-N values of less than 1000 mg/L and 50 mg/L respectively. A high treatment efficiency for both carbon removal and nitrification was achieved despite variable and intermittent loading conditions. The effluent filtrable BOD5 was generally less than 10 mg/L and the effluent NH3-N concentration was usually less than 1.0 mg/L. This effluent quality was achieved at mass loading levels comparable to those for sewage treatment (10.0 kg BOD5/ 1000 m2 · d for carbon removal and 0.7 kg TKN/1000 m2·d). An aside to this study showed that trace organics, some of which are on the EPA priority pollutant list, were present in this leachate and were effectively removed by the RBC.
The Control of Iron Bacterial Plugging of a Well by Tyndallization Using Hot Water Recycling
Authors: Cullimore D. R. , Mansuy N. 
Published: March 2019

Abstract
A small diameter water well drilled in 1977 in the Town of Bulyea, Saskatchewan generated such a rapid plugging (biofouling) that by 1979 the flow rate was reduced by 59%. Heavy growths of non-specific iron bacteria were found in the water and biofouling projected to be the principal cause of the flow loss. Tyndallization (repeated pasteurizations) treatment was applied using a hot water recycling system installed above the well head. Using a displacement passive gravity direct injection of hot water at 82°C from a water heater into the well, a sequential elevation of water column temperatures occurred until bio-film dispersion occurred (pasteurization) at 45°C+. A recovery to original flow specifications was repeatedly obtained at time intervals ranging from 6 to 403 days. Between treatments, a recurrence of biofouling was noted with flow reductions of 0.06 – 0.07 1/min/day frequently being noted. The rate of plugging appeared to be affected by the previous sequence of pasteurization treatments. Tyndallization was found to satisfactorily control iron bacterial biofouling and maintain flow rates.
Effects of Bleached Kraft Mill Effluent on Freshwater Fish: A Canadian Perspective
Authors: Kovacs T. 
Published: March 2019

Abstract
The published information on sublethal effects of untreated and biologically-treated bleached kraft mill effluents (BKME) on freshwater fish has been critically reviewed from a Canadian perspective. Despite the vast data base, a clear assessment of BKME effects to fish was difficult. Based on the available information to date, BKME discharges do not seem to cause serious sublethal toxic effects on fish at concentrations expected to be found in Canada's receiving freshwaters. Only the tainting of fish flesh (a non-toxic effect) has been identified to be a possible consequence of BKME discharges at certain dilution levels. In order to properly assess the effect of BKME, future studies should be aimed at identifying possible problems relating to fish tainting compounds, fish reproduction, early development and habitat alteration (e.g. colour, nutrients).
Application of Image Analysis System for Study of Activated Sludge Flocs
Authors: Li Da-hong , Ganczarczyk J. J. 
Published: March 2019

Abstract
The computerized image analysis system has been successfully used for determination and statistical processing of the following geometric characteristics of activated sludge flocs: longest dimension, breadth, equivalent diameter, cross-sectional area, perimeter, elongation, and circularity. These parameters could be effectively and precisely determined by the system applied. In addition, the studied method, as compared to direct microscope observation and photography floc-sizing methods, was found to be more accurate, less time-consuming, and less dependent on the investigators.
Organics Removal by Anaerobic-Aerobic Treatment of Potato-Processing Wastewater at Different Temperatures
Authors: Lin K.C. 
Published: March 2019

Abstract
Potato-processing wastewater was treated in a lab-scale UASBR-UAF-EAAS system between 1O–25°C. The overall COD and BOD removals were 98–99%; SS and VSS removals averaged 99%. Over 94% of the above were removed in the anaerobic stage. The first unit (UASBR) was much more sensitive to temperature change than the subsequent units in series. Solids settling in the EAAS clarifier was better at 10°C than at 25°C. Sludge removal from the UASBR was required when sludge height exceeded 70% of the volume. No filter clogging was observed in this study. Within 10–25cC, the lower the temperature, the lesser was the amount of biogas produced by the anaerobic units, but the higher the methane content in the biogas.
Benthic Communities in Five Major Rivers of the Hudson Bay Lowland, Canada
Authors: Campbell D. , Kwiatkowski R. , McCrea R.C. 
Published: March 2019

Abstract
A total of one hundred and twenty six species of macroinvertebrates were collected from five major Ontario rivers (Moose, Albany, Attawapiskat, Winisk and Severn) of the Hudson Bay Lowland. Benthic communities in all rivers were dominated primarily by chironomids and oligochaetes except in the East channel of the Moose River where gastropods were also a common taxon. Diversity, as measured by both species richness and the Shannon-Weiner index, was not significantly different in each river. Species distribution was related to substrate composition, river velocity and depth at each station. Community similarity analysis showed that rivers geographically closest together, sharing common flow directions and similar drainage basins resembled each other most in terms of benthic communities. The exception to this was the East channel of the Moose River which showed little resemblance to the other Lowland rivers studies. This was attributed to the highly channelized nature of the Moose River and the origin of the East channel itself which is fed by waters draining the Clay Belt, a unique subprovince of the Canadian shield.
Volatile Halocarbon Contaminant Survey of the St. Clair River
Authors: Kaiser Klaus L.E. , Comba Michael E. 
Published: March 2019

Abstract
Analysis of over 30 volatile halocarbon contaminants in St. Clair River bottom water samples at 20 transects, each covering the three stations at 10 m, 25 m, and 100 m offshore shows considerable inputs of perchloroethylene and carbon tetrachloride in the nearshore zone along the highly industrialized area below Sarnia, Ontario. Minimum loadings of 32 kg.day−1 perchloroethylene and of 22 kg.day−1 carbon tetrachloride are calculated from the observed concentrations. In addition, smaller loadings of 1,1,1-trichloroethane, chloroform, and a variety of other volatile compounds, some of which have yet to be identified, are indicated.
Chlorinated Organics in Nearshore Waters and Tributaries of the St. Clair River
Authors: Oliver Barry G. , Kaiser Klaus L.E. 
Published: March 2019

Abstract
The concent rat ions of hexachloroethane (HCE), hexachlorobutadiene (HCBD), pentachlorobenzene (QCB), hexachlorobenzene (HCB) and octachlorostyrene (OCS) in large volume water samples show that the major sources of these chemicals to the St. Clair River are Dow Chemical Company effluents and, to a lesser degree, Sarnia’s Township ditch which drains one of Dow’s waste disposal sites. Tributaries entering the river on both sides of the Canada/United States border contain measurable concentrations of these chemicals indicating low level contamination throughout the area. The degree of water/suspended sediment partitioning of the chemicals (Kp) was studied. Kp values for the individual chemicals changed in a manner consistent with changes in their physical-chemical properties.
Chlorinated Contaminants in St. Clair River Sediments
Authors: Oliver Barry G. , Pugsley Chris W. 
Published: March 2019

Abstract
The concentrations of many chlorinated organics including chlorobenzenes, hexachloroethane, hexachlorobutadiene, octachlorostyrene, carbon tetrachloride, and perchloroethylene have been measured in an extensive number of bot torn sediment samples from the St. Clair River. The sediment data pinpointed major sources of contamination in the Sarnia industrial area and demonstrated widespread downstream contamination to Lake St. Clair.
Chlorinated Organic Contaminants on suspended Sediments in Lake St. Clair
Authors: Charlton Murray N. , Oliver Barry G. 
Published: March 2019

Abstract
Sediment traps were used to study the presence and fate of chlorinated organics on suspended material in Lake St. Clair. The bulk of the material caught by the traps was resuspended bottom sediment. The highest concentrations of organics were usually found in the center of the lake while the lowest concentrations were found in the southeast area near the Thames River outlet. Organic contaminants were distributed throughout the lake on suspended material. Some results suggest that lateral mixing of contaminants in the St. Clair River results in transboundary pollution. Evidence of sporadic loadings of PCB was found. Inter-contaminant ratios were fairly consistent throughout the St. Clair-Detroit system indicating eventual transport of industrial contaminants from the St. Clair River to Lake Erie.