bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbial Responses to Trace Elements and Nutrients in the St. Lawrence River
Authors: Rao S.S. , Mudroch A. 
Published: March 2019

Abstract
Over 100 surface sediment samples from Lac St. Louis (St. Lawrence River) were examined for various microbial physiological types and densities. These organisms were correlated to the concent rat ions of trace elements (Ni, Co, Cr, V, Cu, Pb, Zn, As, Fe, Mn and Ti) and nutrients (P and organic matter). Results indicated a relationship between bacterial densities and trace element concentrations. Data also suggested there was an apparent indication of bacterial inhibit ion due to toxic substances in the lake sediment. Generally, high and low bacterial density zones existed in the sediment with low bacterial density zones being associated with high concentrations of trace elements. Because of the relationships and the distribution of trace elements and organic matter, the lake bottom exhibited a heterogeneous nature. The availability of trace elements in the surface sediments was assessed by determination of chemical species of the trace elements in solutions obtained by elutriation of the sediment with distilled water. Data and methodology are presented.
Water Research to 2020: Issues and Opportunities
Authors: Ongley Edwin D. 
Published: March 2019

Abstract
Important water issues having environmental, social and economic consequences for the Canadian public will require federal leadership. Knowledge gaps often inhibit effective policy advice to various levels of government. Many emerging water issues are manifestations of larger global phenomena, such as climate change.
Public policy concerns will likely require research into such topics as long-range hydrological forecasting, drought forecasting and the use of non-standard proxy data to extend hydrological records, and incorporation of hydrological information into econometric modelling. Toxic chemicals management will require more focussed research on pathways, fate and effects of contarinants within land-water systems, including important developments in ecotoxicology and knowledge of effects of chronic exposure of humans to toxins. Long-range planning in the north requires improvements in knowledge of arctic hydrology, aquatic ecology and toxic input. Climate change may place greater stress on groundwater resources. Knowledge of persistence and fate of toxins in groundwater is poor. It is not yet known whether toxic rain is a national concern.
Large savings can be made in the pollution Control industry by operations research. Research into pollution control technologies has major economic implications for the Canadian environmental industry. Socio-economic research is needed into legal and social implications of alternative environmental ethics, of various forms of demand management, of risk assessment, and of means for dealing with uncertainty in public policy development. The interrelationship of research and water management, and of the nature of university involvement in the national effort must be reassessed. Greater focus of effort around issues of national concern will be necessary.
Sediment Microbial Activity in Acidic and Non-Acidic Lakes
Authors: Burnison B. K. , Rao S. S. , Jurkovic A. A. , Nuttley D. J. 
Published: March 2019

Abstract
The sediments from an acidic lake, a slightly acidic lake and a non-acidic lake were studied to determine the effect of lake acidification on organic biodegradation rates and bacterial numbers. Organic biodegradation was determined by mano-metric respirometry and mineralization of 14C-labeled compounds. All measurements were normalized to the same temperature (20°C). The oxygen consumption rate and bacterial numbers (based on spread plate counts) were greater in the non-acidic lake sediment throughout the study period. The oxygen consumption rates in the other lake sediments were 18-20 times lower and the bacterial numbers were 15 times lower than the non-acidic lake. In contrast, the results from experiment s using 14C-labeled glucose and glutamic acid often showed that the acidic sediments had twice the heterotrophic potential of the non-acidic sediments. 14C-labeled compounds should be used cautiously when measuring the acidification effects on organic matter decomposition.
Organic and Inorganic Contaminants in the St. Lawrence River: Some Preliminary Results on Their Distribution
Authors: Lum Ken R. , Kaiser Klaus L.E. 
Published: March 2019

Abstract
Volatile hydrocarbons (VHC’s) have been measured at many locations in the St. Lawrence River, Several concentrations of VHC’s were higher than those measured at other polluted Great Lakes sites, e.g. the St. Clair River. Tributaries to the St. Lawrence River were found to be significant sources of VHC’s.
Cadmium in the St. Lawrence River is mostly found in dissolved (bioavailable) forms as compared to the Mississippi River where dissolved cadmium accounts for about 10% of the total cadmium. The major sources of cadmium appear to be in the Montreal area.
Although the analytical results show local impairment in water quality, intensive sampling is required to pinpoint sources and/or quantify loadings, However, none of the VHC or cadmium concentrations exceed water quality guidelines or objectives. In fact there are no guidelines for most VHC’s. Nevertheless, the concentrations of VHC’s and cadmium found should have no toxic effect on aquatic organisms.
The results of this study indicate that there are major sources of VHC’s and cadmium in Quebec. For example, inputs on the southwestern portion of Lac St.Louis may be a major source of perchloroethylene, and effluents in the vicinity of the Montreal STP may be a major source of cadmium. U.S. tributaries, e.g. the Grassy River, may also be a significant source of VHC’s.
A Review of Remedial Measures for Groundwater Pollution in Canada
Authors: Schmidt J.W. 
Published: March 2019

Abstract
An overview of groundwater contamination and remedial measures undertaken in Canada is presented. Information drawn from a consultant’s report to Environment Canada has been briefly summarized. It is noteworthy that at the majority of the 173 sites identified, substantive remedial actions have been undertaken. In addition, two case histories where remedial actions are currently underway are highlighted.
Screening / Indicator Parameters for Organic Contaminants in Groundwater
Authors: Feenstra Stan 
Published: March 2019

Abstract
Parameters such as total organic carbon (TOC), chemical oxygen demand (COD), oil and grease, total kjeldahl nitrogen (TKN), Microtox Toxicity, total phenolics, total organic halogen (TOX), total aromatic hydrocarbons (TAH), total chromatographable organics (TCO) and total volatile organics (TVO) have been used as screening/indicator parameters for the monitoring of organic contaminants in groundwater. The suitability of these various parameters will depend on the selectivity of the analysis method to the organic contaminants of interest, the detection limit of the method relative to the concentrations of interest, the background concentrations of the screening/indicator parameters in the groundwater and any analytical interferences. There are no screening/indicator parameters currently available which are suitable for all situations in which toxic organic contaminants are of concern at sub-milligram per litre concentrations. Suitable screening/indicator parameters must be selected on a case-by-case basis depending on the organic contaminants of interest, the concentrations at which they are a concern, and the presence of any interferences. However, in general, because the organic contaminants which are most frequently of concern in groundwater are chlorinated compounds, total organic halogen (TOX) will likely be the most commonly applicable screening/indicator parameter.
Surface Area and Radionuclide Sorption in Contaminated Aquifers
Authors: Inch K.J. , Killey R.W.D. 
Published: March 2019

Abstract
Strong linear correlations between 90Sr and 60Co sorption and BET surface area have been found in samples of sands from three contaminated aquifers. The sands have a granitic mineralogy, and the sequence for both surface area and radionuclide retention is vermiculite &gt;&gt; sericite &gt; amphibole &gt; muscovite = biotite &gt; feldspar &gt; quartz. Where aqueous geochemistry of the aquifer is relatively constant, a strong linear correlation between whole-sediment surface area and in situ radionuclide distribution coefficients was found. Distribution coefficients cannot be reliably predicted from surface area measurements if substantial differences in major ion chemistry are known or suspected at the various soil sampling localities. From the results presented here, we conclude that surface coatings (predominantly iron oxyhydroxides) provide most of the surface area and sorption capacity. Particle mineralogy has a major influence on the development of coatings, but plays a minor role in the direct sorption of contaminants.
Migration and Fate of Aldicarb in the Sandstone Aquifer of Prince Edward Island
Authors: Priddle M.W. , Jackson R.E. , Novakowski K.S. , Denhoed S. , Graham B.W. , Patterson R.J. , Chaput D. , Jardine D. 
Published: March 2019

Abstract
The persistence of aldicarb in groundwater of the fractured, sandstone aquifer of Prince Edward Island, Canada is assessed. Two potato fields were instrumented with nests of piezometers which were used in the hydraulic and chemical testing of the sandstone aquifer. Groundwaters were sampled and analysed for pH, EH, dissolved oxygen and ammonia, major ions and the toxic aldicarb species - aldicarb, aldicarb sulfoxide and aldicarb sulfone. Aldicarb persistence appears related to (1) its application at time of planting when soil water temperatures are low (&lt;10°C) and (2) the inhibiting pH effect that the oxidation of ammonia-based fertilizers has on aldicarb degradation. It is recommended that aldicarb (i.e. Temik) be applied at the time of plant emergence rather than seeding, and only where the depth to the water table is 5 metres or more.
Chlorophenols and Chlorinated Hydrocarbons in Starry Flounder (Platichthys stellatus) and Contaminants in Estuarine Sediments near a Large Municipal Outfall
Authors: Rogers Ian H. , Hall Kenneth J. 
Published: March 2019

Abstract
Starry flounders, collected near a large municipal sewage outfall in the Fraser River Estuary, between March 1984 and April 1985, were quantified for chlorophenols, DDTs, and PCBs. Sediments from the polluted zone were analyzed for EPA Priority Pollutants and herbicides. Muscle tissue contained maximum chlorophenol levels about one half the Canadian limit and one tenth the limit for PCBs in edible fish tissue. Contaminants in matched tissue samples from the polluted zone and an adjacent control area showed statistically significant higher levels of all target compounds in muscle tissue from the outfall area except for DDD which was greater in the control. Bone and liver tissue were rich in PCBs and DDTs. The sediments contained phthalate esters, PCBs, PAHs and phenol. However the levels of pesticides, chlorophenols and herbicides were close to or below the detection limits. The sediment data were compared with values from nine other sites in the estuary.
Automatic Control of Supplemental Chemical Addition for Primary Treatment Enhancement
Authors: Forgie D.J.L. , Kerc P.T. 
Published: March 2019

Abstract
Chemical coagulation can be used to improve the efficiency of a primary wastewater treatment plant. Using statistical and fuzzy mathematical techniques, models of this process were developed from data gathered at a plant which was using liquid alum and a polymeric coagulant aid to reduce its primary effluent strength. Mathematical simulation of on-line process control using these models and fixed and variable chemical feed rate regimes were conducted using “typical day” influent strength and flow rate data. The results of these simulations show that on-line process control with a variable feed regime adjusted on the basis of current and projected conditions would generally provide a more effective use of chemicals than a fixed feed rate regime. Only at higher target efficiencies did the fixed feed rate regime approach the effectiveness of the variable fixed rate regime.
Concentration of Tributyltin in the Surface Microlayer of Natural Waters
Authors: Maguire R. James , Tkacz Richard J. 
Published: March 2019

Abstract
High concentrations of the very toxic antifouling agent tributyltin have been found in 24 surface microlayer samples in a survey of 74 locations in Ontario, Quebec, and New York State. In 6 of these 24 locations the concentration of tributyltin in the surface microlayer exceeded the 24-hr LC-50 value for adult rainbow trout. The most heavily contaminated area was the mouth of the Moira River at Belleville, Ontario, where the concentration of tributyltin in the surface microlayer was 42 times the 24-hr LC-50 value for trout. The concentration of tributyltin in the surface microlayer was occasionally so much greater than that in subsurface water that the microlayer contained a significant amount of tributyltin relative to that in the whole depth of the subsurface water. Similar findings were observed for the less toxic degradation products of tributyltin - dibutyltin, monobutyltin and inorganic tin.
Impact of Acid Drainage Pollution from Mineralized Slate at Halifax Airport
Authors: Lund Ole Peter , Vaughan James G. , Thirumurthi Dhandapani 
Published: March 2019

Abstract
In January 1982, 224,000 m3 of excavated slate at the Halifax International Airport was placed at a disposal site situated in the watershed of the Salmon River. When acid drainage from the site was identified in June 1982, lime addition and settling (ponds) were initiated as treatment. Acid drainage continued into the watershed, contributing 250,000 kg of acidity (CaC03) annually.
An environmental impact study was conducted to determine the effects of this loading on the Salmon River aquatic system. The study concluded that there was significant loading of acidity and heavy metals. The lowering of pH from 4.6-5.2 to 3.8-4.6, combined with aluminum concentrations of 0.3-0.5 mg/l, had adverse physiological effects on fish in two lakes.
Priority Site Selection for Degraded Areas in the Aquatic Environment
Authors: Dutka B.J. , Jones K. , Xu H. , Kwan K.K. , McInnis R. 
Published: March 2019

Abstract
The suitability of a variety of biochemical, microbiological and bioassay tests to become part of a battery of test procedures to identify degraded or degrading sediments and waterbodies are evaluated in this report. Data were obtained from 40 river (Detroit and Niagara) and inshore Lake Erie sampling sites. These data indicate that the top six areas of highest concern were: (1) mouth of the Rouge R., (2) mouth of Little R., (3) mouth of Two Mile Creek at Tonawanda, N.Y., (4) offshore Port Burwell, (5) mouth of Turkey Creek, and (6) Detroit R. offshore of the Grosse Ile WTP
An Investigation of the Distribution of Trihalomethanes Within GAC Contactors
Authors: Andrews R.C. , Huck P.M. , Gammie L. 
Published: March 2019

Abstract
This study examined the loading distribution of trihalomethanes and total organic carbon within pilot scale granular activated carbon (GAC) contactors receiving finished drinking water and operating in the downflow mode. Three carbons originating from different sources were used for this comparison. Observed column loadings were compared to isotherms. As well, loadings were evaluated as a function of carbon particle size.
Significantly higher loadings of trihalomethanes were found in the upper 10 cm (7%) of the GAC beds. Enhanced adsorption in this region was correlated with finer size carbon particles. Isotherms successfully predicted full bed depth trihalomethane loadings for two of the carbons but underestimated loadings in the top 10 cm. A replacement of the top 30 cm of the carbon in one of the beds resulted in a noticeable capacity increase for trihalomethanes.
Treatment of Domestic Strength Wastewater with Anaerobic Hybrid Reactors
Authors: Droste R.L. , Guiot S.R. , Gorur S.S. , Kennedy K.J. 
Published: March 2019

Abstract
Anaerobic treatment of dilute synthetic wastewater (300-1,000 mg chemical oxygen demand/L using laboratory upflow sludge blanket filter reactors with and without effluent recycle is described. Treatment of dilute synthetic wastewater at hydraulic retention times less than 1 and 2 h in reactors without and with recycle, respectively, resulted in biomass washout as the solids retention time decreased to less than 12 d. Reseeding would be required to operate at these critical hydraulic retention times for extended periods. Treatment of dilute synthetic wastewater at hydraulic retention times between 3-12 h resulted in soluble COD removal efficiencies between 84-95% treating 300 mg COD/L. At a 3 h hydraulic retention time, solids retention time of 80 d and stable reactor biomass concentrations of 25 g volatile suspended solids/L were maintained.
Improving Aquatic Environmental Impact Assessment in Canada – A Northern Case Study
Authors: Duncan William F. A. , Neil Elizabeth M. 
Published: March 2019

Abstract
This paper presents and applies a conceptual framework which addresses the causal relationships linking contaminant doses with responses in aquatic environments. The paper is focused on metal contaminants and reviews a northern case study in which the framework was applied. The approach emphasizes the environmental factors regulating the potential effects of contaminants and stresses the importance of understanding the physical environmental processes in monitoring design and the selection of linkages between the contaminant dose and the valued ecosystem components.
Treatment of and Gold Recovery from Effluent at Giant Yellowknife Mines Limited
Authors: Halverson G.B. , Raponi T.R. 
Published: March 2019

Abstract
The milling of refractory gold ore at Giant Yellowknife Mines Limited results in several effluent waste streams which are combined and sent to a tailings pond. Prior to being released to the environment, tailings effluent is treated to make the solution environmentally acceptable. This involves removing contaminants such as cyanide, arsenic and heavy metals. Initial investigations into various treatment processes to remove cyanide and arsenic showed that alkaline chlorination and iron salt precipitation were the best available technologies. In 1976 Giant Yellowknife Mines and Environment Canada entered into a DPAT (Development of Pollution Abatement Technology) program to investigate various treatment processes for the removal of cyanide and arsenic including those stated. In August 1981, the Effluent Treatment Plant became operational employing an “alkaline chlorination-arsenic precipitation-flocculation process. This paper describes the development of the effluent treatment process, process chemistry, plant facilities, plant practice and reviews the Effluent Treatment Plant performance over its six seasons of operation to date.
Subsequent analysis of the discharge from the Effluent Treatment Plant in 1982 showed that recoverable quantities of gold were being discharged to the environment through the final decant. Laboratory testwork showed that these gold values could be effectively recovered on activated carbon by passing the decant solution through a bed of activated carbon. A description of the various carbon column configurations used as well as operational and cost analyses for each are included.
The Influence of Surface Coal Mining on Potential Salmonid Spawning Habitat in the Fording River, British Columbia
Authors: MacDonald D.D. , McDonald L.E. 
Published: March 2019

Abstract
A total of six sites, with similar physical and hydraulic characteristics, located upstream and downstream of the Fording Coal Ltd. mining operation were selected to assess the Influence of mining activities on the quality of stream-bed substrates. The particle size distributions of gravel-bed materials in the Fording River were described using substrate statistics commonly found in the literature. Statistically significant differences (p &lt; 0.001) between upstream (control) and downstream sites were detected in the percentage of sediments smaller than 2.00 mm and 6.35 mm. The differences between upstream and downstream sites were also statistically significant (p &lt; 0.005) for the variables geometric mean particle diameter and Fredle Index. Differences between areas were evident for both sampling periods (September 1985 and April 1986). The biological significance of these differences in stream-bed composition was examined using empirically derived egg to fry survival models for salmonids currently available in the literature. The preliminary results of this study suggest that activities associated with coal mining can increase the content of fine sediment in stream-bed substrates, and thereby compromise the production of salmonids when stream reaches downstream of the development are used as spawning habitats.
Hydrocarbons and Complaints About Fish Quality in the Mackenzie River, Northwest Territories, Canada
Authors: Lockhart W.L , Metner D.A. , Murray D.A.J. , Muir D.C.G. 
Published: March 2019

Abstract
The Mackenzie River in northwestern Canada is the largest North American source of freshwater to the Arctic Ocean There are continuous discharges of petroleum into the river from an oil field at Norman Wells both from refinery and natural seepage sources. Recently oil production was expanded using several artificial islands constructed in the river Coincident with the expansion native DENE fishermen in downstream communities complained that the quality of fish deteriorated. Specifically, the liver of burbot (Lota lota) was reported to have become small and dark in colour, and our investigation of that complaint is the subject of this report. Examination of the burbot revealed that the liver condition was associated with a low content of fat The question posed was whether this quality problem could be related to petroleum inputs from Norman Wells. Residue analyses of the fish showed low, but consistent, contamination with low-boiling aromatic hydrocarbons, with fish taken in winter more highly contaminated than fish taken in summer. The low levels in summer fish were found in fish from many freshwater locations with no obvious connection to a petroleum source This may reflect a broad atmospheric dispersal of these materials. Burbot from the lower Mackenzie River did not have elevated liver mixed-function oxidase enzyme activities relative to a reference population from Lake Winnipeg Experimental treatments with oil induced these enzyme activities, and so fish seem unlikely to have been affected by the enzyme inducing components of petroleum. Experimental starvation of burbot in the laboratory resulted in a loss of liver fats and in development of apparently the same liver condition The condition of the fish seems more likely to be of natural origin through factors related to nutrition or parasitism, although pollution cannot be ruled out definitively. Unexpectedly high concentrations of toxaphene (up to 5000 ng/g wet weight) and other organochlorines were found in burbot livers