bluuebunny/crossref_metadata_2025 huggingface dataset:
Correction Factor For Anthrone Carbohydrate in Coloured Wastewater Samples
Authors: Leduy A. , Kosaric N. , Zajic J.E.
Published: March 2019

Spectrophotometric determination of total carbohydrate (TCH) in the wastewater samples by anthrone reagent is a simple and rapid method to follow the utilization of substrate, and hence the reduction of BOD5 load during the biological treatment process with chemoheterotrophs. However, for the coloured wastewater samples or treatment plant effluents, a correction factor was found necessary to compensate the colour inferences. Studies were conducted on various waste sulfite liquors (NH3-, Ca-, Mg-, Mixed- and Na-WSL) which provide a wide range of colours from creamy to black. The correction factor was calculated from the deviation of the standard calibration curves of glucose with and without the presence of WSL. These correction factors depended both on the nature and on the amount of WSL present. Within the practical dilution range of various WSL for the determination of TCH (1:1,000 - 4:1,000 v/v), the correction factors varied from 15 to 40%, which is highly significant if the correction was not made. In all WSL samples, the correction factor became more significant at higher concentration of WSL in the solution. Spectrophotometric studies of WSL at various concentrations within the visible range led to the development of the following empirical equation expressing their colour, $$\Lambda = \Lambda _{\rm s}\left( {1 + {[D_{\rm c}/D]}^2} \right)^{{\rm n/2}}$$

where Λ, Λs, Dc, D and n are the maximum transmitted wavelength of WSL solution, the maximum transmitted wavelength of water (solvent), the critical dilution of WSL, the dilution of WSL (reciprocal concentration of colouring materials) and the chromatic index of WSL respectively.
A Mathematical Model of Evaporation and Dissolution From Oil Spills on Ice, Land, Water and Under Ice
Authors: Leinonen P.J. , Mackay D.
Published: March 2019

Mathematical models are presented which quantify the processes of evaporation and dissolution of components of crude oil in three situations: a spill on water, a spill on ice, and a spill under ice cover in which the oil lies between the water and ice phases. Constant spill area is assumed. The evaporation flux is calculated using a mass transfer coefficient based on windspeed and spill dimensions. The dissolution flux can be calculated from two models, a mass transfer coefficient approach and an eddy diffusivity approach involving the integration of a set of partial differential equations in depth and time. The selection of model parameters is discussed. For the three physical situations, using a synthetic crude oil, results are presented giving the relative rates of evaporation and dissolution and the aqueous phase concentration of selected hydrocarbons. The implications of the results for clean-up technology and aquatic toxicity are discussed, particularly with regard to spills under ice.
Non-Point Source Contributions to Water Quality Problems
Authors: McBean E.A. , Gorrie J.E.
Published: March 2019

Non-point source contributions of nitrogen and phosphorus are examined. A useful relation between nitrogen and phosphorus mass flux and instream flow is demonstrated to occur at a number of sampling locations situated on the Saint John River Basin. As well, through a multiple regression study, evidence is presented that argues that the variations in non-point source loadings observed from location to location are explainable in terms of the variations of relatively easily-measured parameters that describe the contributing areas.
Fish Size as a Quantitative Function of Tolerance to Heavy Metals
Authors: Spear P. , Anderson P.D.
Published: March 2019

Variations in tolerance through a size range of test organisms were quantitatively represented by the function. $${\rm R} = {\rm \alpha } + {\rm \beta log C/}{\rm W}^{\rm b} \eqno \lpar1\rpar$$

where R = % quantal response (in probits),

C = concentration of toxicant in the ambient environment,

W = weight of test organism, and,

b = an empirically determined coefficient of weight.

This function expresses the lethal response curves of different sizes of test organisms of three species of fish following exposure to certain discrete heavy metal solutions for 96 hours. A useful derivative of Eq. 1 is, $$\log {\rm M} = {\rm a} + {\rm b log W}$$

where M = LC 50

The application of these weight functions in aquatic bioassay studies is discussed.

The standard bioassay procedure in aquatic toxicology simulates the principle mode of toxicant uptake from the ambient environment by exposing test organisms to aqueous solutions of chemicals for specified periods. The alternative bioassay method involves the administration of toxicants by parenteral (e.g. intraperitoneal , intravenous) or enteral (e.g. oral) routes.

It is accepted procedure in the latter bioassay studies to use a dose proportional to the body weight of the test animal. The assumption for normalizing the dose by the weight of the individual is that the magnitude of response to a given dose will change proportionally with size. For the former type of bioassay, some investigators have concluded that size of the test organism does not influence tolerance parameters (Cairns 1958; Bastos 1954) - Other studies have demonstrated that the magnitude of response varies with size (Weiss and Botts 1957; Mount 1962; Burdick et al. 1955; Skidmore 1967). The problem of size as a modifying factor may be avoided by using test organisms of similar body weight (Doudoroff et al. 1951). For those bioassay studies in which size standardization is either impractical or impossible, a rationale is needed to quantify changes in response attributable to the differences in weight of test organisms.

This paper considers the application of a weight factor-tolerance function which quantitatively represents the change in the magnitude of response with increasing size of three species of fish exposed to certain heavy metals. The quantity of the weight function is determined empirically and its value appears unique for species and toxicant. The usefulness of the weight factor in bioassay studies is discussed.
Efficiency of Subsurface Sewage Disposal Systems in Removal of Contaminants From Domestic Sewage
Authors: Brandes M.
Published: March 2019

In order to determine the efficiency of subsurface disposal systems in removal of contaminants, fifteen systems located on three lakes and on the St. Lawrence River in Ontario, were under study for about two years. Tritium (3H) , radioactive phosphorus (32p) and fluorescein were used for tracing the subsurface movement of the septic tank effluent and for determining the time taken by the effluent to reach the receiving waters. It was observed that a considerable part (89 to 98%) of the phosphorus from the effluent was fixed in the soil when the soil contained more than 67% silt and clay. When clayey silt was the filtering medium the concentration of the phosphorus in the ground water dropped to a level of less than 0.2 mg/l (as P) in a distance of 17 meters from the disposal systems. A satisfactory removal of faecal coliform organisms by the same uniform undisturbed clayey silt was also observed. The removal of phosphorus and of faecal coliform organisms by disposal systems built on sandy fill was less efficient. The concentration of nitrates, free ammonia and chlorides in the ground water close to receiving waters was lower than concentrations permissible in public surface water supplies.
Flocculation of Neutralized Mine Drainage With Polymers
Authors: Huck P.M. , Murphy K.L. , LeClair B.P.
Published: March 2019

Metal-bearing wastewaters such as base metal mine drainage are conventionally treated with lime to precipitate the metals as hydroxides. Although the addition of a synthetic polymer has been found to aid clarification in this process, no rational methodology exists for the determination of optimum flocculation conditions.

Using tailored polyacrylamide, the present research examined the effects of polymer properties and mixing conditions on supernatant particulate iron concentrations for synthetic minewaters containing various initial concentrations of that metal. It was found that mixing conditions were more important than polymer properties in producing optimum behaviour. Optimum rapid mix speed appeared to be proportional to minewater strength, while flocculation time varied inversely with strength. The system was sensitive to polymer degree of hydrolysis but not to dosage. At pH 9.5, residual total iron concentrations below 0.2 mg/l were achieved. Mechanistic modeling using the flocculation equation was successful.
Decolourization of Kraft Mill Effluents by Magnesium Coagulation
Authors: Rush R.J. , Oldham W.K. , Stepko W.E.
Published: March 2019

A magnesium-plus-lime coagulation process incorporating magnesium recovery by sludge carbonation, recently developed for water treatment, has been tested for its application to decolonization of kraft mill effluents. Total bleached kraft mill effluent (BKME) after biological treatment and effluent from the first caustic extraction stage of a CEDED bleachery (T-20 effluent) were examined in the laboratory.

Preliminary results of ongoing pilot scale testing of this unique treatment and recovery process on a simulated kraft waste are also presented.

At the bench scale it was shown that a combination of low magnesium and low lime dosages can achieve better decolourization of kraft mill effluents than much greater amounts of lime alone. Colour removals of 90–95% were achieved using either fresh or recycled magnesium.

Results of both laboratory and pilot plant studies showed that greater than 90% magnesium recovery can be attained with proper operation of the sludge carbonator.
Neutralization and Fertilization of Acidified Lakes Near Sudbury, Ontario
Authors: Scheider W. , Dillon P.J.
Published: March 2019

Investigations into the consequences of neutralizing acidic lakes, establishing buffer systems and reducing heavy metal levels by additions of Ca(OH)2 and CaCO3 are described. Two pairs of lakes in the immediate vicinity of Sudbury, Ontario, were chosen for study commencing in June 1973. Prior to treatment, all lakes could be described as soft (hardness 21–47 mg/l as CaCO3), poorly buffered (alkalinity 0.4–2.6 mg/l as CaCO3) with low pH values (4.4–4.5). Sulphate was the dominant ionic constituent in the lakes (26–55 mg/l). Copper and nickel levels were among the highest recorded in the Sudbury region. The low HPC: aciduric ratio (total heterotrophic plate count: acid-tolerant plate count) demonstrates the atypical bacterial composition of the lake waters. The standing stocks of phytoplankton, Zooplankton and zoobenthos were somewhat lower and taxonomic composition abnormal as compared to “typical” oligotrophic lakes on the Canadian Shield as studied in the Experimental Lakes Area of Ontario.

The two downstream lakes were treated in the fall of 1973, one with Ca(OH)2 only; the other with a combination of Ca(OH)2 and CaCO3. The upstream lakes were monitored as controls. Both treated lakes showed an increase in pH to about 7.0 and reductions in total Cu, Ni and Zn levels of 13–83%. The combination treatment proved superior in that a more stable buffer system was established and pH remained near neutrality for the duration of the study.

The rapid pH change (three units in a matter of weeks) caused an initial decline in the standing stock of phytoplankton, Zooplankton and zoobenthos. The bacteria were the first to show a positive response to the altered water chemistry; the HPC: aciduric ratio increasing immediately following treatment. The phytoplanktonic standing stock increased and the taxonomic composition changed the summer following treatment. Numbers of Zooplankton and zoobenthos did not increase the year following treatment, probably because of the relative difficulty in recolonization and their slower reproductive rate.

In an effort to increase biological standing stock, Middle Lake was fertilized with phosphorus 1½ years after neutralization. Numbers of phytoplankton and Zooplankton increased and taxonomic composition shifted.
Potential Effect of Methane Oxidation and Nitrification-Denitrification on the Oxygen Budget of Hamilton Harbour
Authors: Snodgrass W.J.
Published: March 2019

Samples of gas generated by Hamilton Harbour have been collected at a deep water station (20 m) for four months during the summer and early fall of 1975. Methane and nitrogen are the only significant gases collected at the sediments or at the top of the water column. Methane is lost from the rising gas bubble but nitrogen is not lost. Sources of methane and nitrogen gas production are reviewed. Complete oxidation of the methane lost from the gas bubble represents an oxygen sink of 0.3 gm O2/m2/day. Nitrogen production represents an oxygen sink of 0.1 gm O2/m2/day; this assumes that all nitrogen collected is due to nitrification-denitrification of ammonia produced in the sediments. These sinks are respectively estimated to account for 16–32% and 7–14% of the hypolimnetic oxygen demand. These data provide initial order estimates for two components of the hypolimnetic oxygen demand and a partial basis for construction and calibration of an oxygen model for Hamilton Harbour.
Modelling Simulation and Control of an Existing Activated Sludge Wastewater Treatment Process
Authors: Thérien N. , Harrington P.
Published: March 2019

The dynamic response of the activated sludge process in the wastewater treatment plant of the Centre Hospitalier Universitaire de Sherbrooke was analysed with respect to large disturbances in both the flow rate and the quality of wastewater entering the plant.

A mass balance conducted for the organic substrate and biomass entering and leaving the process led to a model consisting of two separate differential equations in terms of BOD and VSS with a two-phase bio-kinetic relationship for the reaction term.

Predictions of the model for BOD and VSS variations in time were compared to experimental observations at the plant. A model using mean daily values for VSS and expressed in terms of BOD for the stream flowing out the clarifier unit in response to flow rate and BOD cyclic fluctuations of the entering wastewater stream to the process was found apt at describing the time at which BOD peaks in the process effluent occurred as well as predicting the magnitude of these peaks.

The dynamic behaviour of the activated sludge process has been simulated for periods of one to several days using this model. Its use in predicting appropriate control action in time in order to improve the treatment efficiency is also indicated.
Contribution a la rationalisation du reseau qualite de l’eau de la Baie James
Authors: Bobée B. , Cluis D. , Tessier A.
Published: March 2019

A water quality sampling programme for James Bay territory established in a previous study has been carried out for the Department of Natural Resources of the Province of Quebec.

The network is composed of 5 base-stations, sampled every fortnight to determine the variability with time of the parameters and 16 satellite-stations, sampled five times yearly with a view to determine the spatial variability.

The data (major ions and certain nutrients) gathered during the 1974–1975 field survey are subjected to an analysis by a multivariate technique (correspondence analysis) in addition to certain classical statistical methods. The latter have shown that the mean values obtained at satellite stations were representative of the annual mean. In addition, the results permit the determination for a given parameter, of the relationship between stations and, for a given station, the relationship between parameters. In both cases, the formulation of predictive equations was attempted.

An overall evaluation of the data by correspondence analysis has permitted: - a more precise definition of the qualitative behaviour of the different sub-basins of the James Bay territory and characterization of their waters;- a proof of the existence of gradual concentration changes in both East-West and North-South directions.

Within the original objectives of the network, the results of the study have led to the following recommendations: - to continue synchronised samplings;- to transform a base station with a low information content into a satellite station;- to create a new base station in the eastern part of the territory.
The Airborne Transmission of Organisms Emitted from Wastewater Treatment Processes
Authors: Crawford G.V. , Jones P.H.
Published: March 2019

Parameters believed to affect the emission and transmission of organisms were studied. The predictive model of Ledbetter and Randall (1965) was found to be more reliable for organism concentrations downwind of a wastewater source than six other models considered. The model predicts total organism, fecal Coliform, total Coliform, fecal streptococci and S. faecal is concen-trations. S. faecal is was selected as the most suitable indicator of the presence of airborne pathogenic organisms emitted from wastewater treatment processes.
The Freshwater Clam (Elliptio Complanata), A Practical Tool for Monitoring Water Quality
Authors: Curry C.A.
Published: March 2019

Freshwater clams (Elliptio complanata) from Balsam Lake were placed in cages in the Humber and Moira Rivers in southern Ontario.

Clams were exposed from 4 to 6 weeks and analyzed for organic trace contaminants (pesticides and PCB's).

Humber River clams accumulated significant levels of PCB's (polychlori-nated biphenyls), EDDT (total l,l,l-trichloro-2,2-bis (p-chlorophenyl) ethane), dieldrin, alpha- and gamma- chlordane after 8 days. Only PCBs and Zddt were accumulated in Moira River clams.

Caged clams proved practical for detecting organic trace contaminants in water after a short exposure period.

The advantages of using clams over fish and water samples for bio-monitoring are discussed as well as the practical considerations to further enhance the usefulness of this organism.
Field Evidence of Denitrification in Shallow Groundwater Flow Systems
Authors: Gillham R.W. , Cherry J.A.
Published: March 2019

A detailed hydrogeological study in a small agricultural watershed near Lake Erie in southwestern Ontario has provided evidence that denitrification is widespread in shallow groundwater in this area. In the groundwater zone of the unconfined sandy aquifer that underlies the study area, NO3- concentrations within two metres of the water table are commonly between 5 and 50 mg/1 (expressed as N). At greater depth, however, NO3- concentrations are generally less than 0.02 mg/1. The aquifer varies in thickness from 3 to 10 m. The transition zone between the high nitrate zone and the low nitrate zone is very thin. In the high nitrate zone, dissolved oxygen occurs at concentrations above 2 mg/1 , methane is absent, and Eh values obtained by the platinum electrode method are greater than 300 mV. In the low nitrate zone, dissolved oxygen occurs at levels less than 2 mg/1, methane is present, and Eh values are generally between 50 and 200 mV. The hydrogeologic conditions are such that it is very improbable that these trends are due to different groundwater sources. The data support the hypothesis that denitrification is the cause of the lack of NO3- in the deeper part of the aquifer. Nitrate and dissolved oxygen data from shallow groundwater zones in four other agricultural watersheds in southwestern Ontario support this conclusion.
Simulation of Advanced Wastewater Treatment Systems
Authors: Lam P.T. , Farquhar G.J. , McBean Edward A.
Published: March 2019

Simulation models for advanced wastewater treatment system component processes were identified or developed as necessary. They were used to simulate the performance of existing systems including lime treatment, ammonia stripping, recarbonation, filtration and carbon adsorption. Comparisons between predicted and measured effluent properties were reasonable. The component models were combined into an integrated model and used to simulate the operation of the Santee Project advanced wastewater treatment system. Simulations were again reasonable. It was concluded that the combined model could be used to provide realistic estimates of system efficiency response to variations in input parameters.
Identification of Groundwater Discharge Zones in a Reach of Hillman Creek in Southern Ontario
Authors: Lee David Robert , Hynes H.B.N.
Published: March 2019

Several new techniques were used to identify zones of groundwater and contaminant inflow to the headwaters area of a small stream draining an agricultural watershed in southwestern Ontario. Along a 3 km length of stream, seepage meters were used to measure and collect seepage flux and mini-piezometers were used to measure piezometric head relative to the stream and to collect pore water 0.6 m below the streambed.

Measurement of seepage flux at 43 locations along a 3 km segment of Hillman Creek showed that most of the study section was a groundwater discharge zone. Spatial differences in seepage flux ranged from less than 0.001 to nearly 9 cm m s 1. During the growing season there was a marked diurnal change in seepage rate at several locations and this was also reflected by a corresponding change in stream discharge.

Paired samples, one from a piezometer 0.6 m below streambed and one from the adjacent seepage meter, were significantly correlated (P < 0.01) with respect to specific conductance, chloride and inorganic carbon concentration. This suggested that in many instances site-specific estimates of chemical inputs from groundwater to surface water can be estimated quickly without the necessity of allowing natural groundwater flow to flush out the water initially trapped within the seepage container. Seepage meters can be used to measure seepage flux and the small piezometers can be used to obtain samples. The concentrations of non-conservative solutes (organic carbon, nitrate + nitrite nitrogen, and phospate) in seepage meter samples were not significantly correlated with the concentrations in corresponding mini-piezometer samples.
Improving the Performance of the Activated Sludge Process: A Time Controlled Flow Equalisation Basin
Authors: Thérien N. , Marcos B. , Muratet G.
Published: March 2019

The performance of a time controlled flow equalisation basin in minimizing the mean daily concentration of organic substrate flowing out the clarifier unit has been investigated. This was done considering fluctuations in both the flowrate and organic content of the entering raw water stream to an activated sludge process.

A differential model apt at describing the dynamic behaviour of the activated sludge process of an existing wastewater treatment plant for periods of one to several days has been used. The control strategy, consisting in finding how much wastewater to pump in time from the basin to the aeration unit has been designed using iteration in control vector space with a second order minimization algorithm based on the concept of dynamic programming.

Situations for which this procedure would lead to an optimal control policy are discussed and an actual case of this occuring is shown for the data gathered at the plant.

The results obtained are also compared to more conservative and known control policies for the operation of an equalisation basin.
Process Development for the Removal of Radium-226 from Uranium Mining and Milling Effluents
Authors: Huck P.M. , Wilkinson P. , Averill D.W.
Published: March 2019

This study examined physica]-chemica1 processes for the removal of 226Ra from uranium mining and milting effluents. Following batch optimization experiments, a bench scale continuous-flow process consisting of precipitation, coagulation, flocculation and sedimentation was designed and tested. The continuous-flow process produced an effluent containing total 226Ra activity levels below 10 pCi/L, thus meeting the study objective, although a relatively low clarifier overflow rate was used. The filterable radium results from continuous-flow operation confirmed the predictions made from batch kinetic data, but the filterable radium objective of 3 pCi/L was not met. The study indicated that a mechanically-based system might be feasible for the removal of radium from uranium mining and milling effluents. The bench scale data were used to design a continuous-flow pilot scale process for demonstration of the treatment technology developed.
Nappes d'huile: prediction de leurs deplacements comme agent efficace d'un plan de mesure d'urgence
Authors: Coupal B. , de Broissia M.
Published: March 2019

The movement of oil slicks on open waters has been predicted, using both deterministic and stochastic methods. The first method, named slick rose, consists in locating an area specifying the position of the slick during the first hours after the spill. The second method combines a deterministic approach for the simulation of current parameters to a stochastic method simulating the wind parameters. A Markov chain of the first order followed by a Monte Carlo approach enables the simulation of both phenomena. The third method presented in this paper describes a mass balance on the spilt oil, solved by the method of finite elements. The three methods are complementary to each other and constitute an important point for a contingency plan.
Mixing Design for Air Agitated Rectangular Tanks
Authors: Akhtar W. , Mathur G.P. , Dickey D.S.
Published: March 2019

Design equations have been developed to estimate liquid velocities and mixing times in air agitated tanks. Determination of the gas rate necessary for adequate agitation in a given geometry is possible with this information. Air agitation offers benefits of increased dissolved oxygen and cost effective mixing for some waste water treatment applications.

Empirical expressions for surface and bottom velocities, as a function of gas flow rate and tank geometry have been developed from laboratory measurements. Since neither statistical nor dimensional analysis of the laboratory results could prove conclusively the correct form of the velocity correlations, the different correlation forms were used to verify large scale velocity measurements. Only one of the three trial correlations correctly predicted large scale velocities. The importance of these velocity correlations is evident from experience with mechanical agitator design, which shows that liquid velocity is the appropriate design criterion for most similar applications.

Mixing times were measured experimentally in the laboratory and studied with a mathematical model. The model was an unsteady state mass balance containing convective flow terms with turbulent dispersion super-imposed on the flow. The velocities for the convective flow terms were calculated from the empirical velocity correlations. Estimates of the turbulent dispersion coefficients were investigated experimentally.

Because multiple velocity correlations and a computer model for mixing time are difficult to use when performing design calculations, empirical correlations for bulk velocity and mixing time were derived. Combined with a relationship for power input, the design correlations provide information necessary to determine operating conditions in large scale, air agitated tanks. The effects of tank geometry on air agitated design have been explored within a range of typical construction dimensions. Thus, the principal elements of a complete design approach to air agitated rectangular tanks are presented.
Development and Application of a Water Quality Model for Use in an Environmental Assessment
Authors: Halbert B.E. , Ibbotson B.G. , Scharer J.M.
Published: March 2019

A model was developed for application in an environmental assessment study to allow predictions to be made of future water quality trends with respect to alternative proposals for expanding uranium mining activities in Elliot Lake, Ontario. Four water quality parameters were determined to be of particular importance in the assessment and were the subject of detailed investigations. Results of the model simulations formed the basis for assessing alternative development strategies and identifying those strategies which were most compatible with protection of the environment.
Accumulation du mercure chez certaines especes de poissons du Lac Saint-Louis en aval de Beauharnois
Authors: Gamache P. , Valiquette Y. , Chodorowski A. , Pichet P.
Published: March 2019

Les teneurs en mercure de jeunes perchaudes (Perca flavescens) et de jeunes crapets-soleil (Lepomis gibbosus) capturés au lac Saint-Louis indiquent une variabilité élevée entre les individus. Le niveau d'accumulation du mercure varie selon les stations et les deux espèces étudiées et n'est pas directement relié au niveau de mercure dans les sédiments. Les niveaux moyens observés sont inférieurs à ceux déjà publiés pour des individus plus âgés de la même région, indiquant une accumulation avec l'âge. La teneur en mercure du cerveau chez le crapet de roche (Ambloplites rupestris) et le crapet-soleil varie avec la teneur moyenne dans le poisson.
Some Hydrodynamic Characteristics of Three-Phased Fluidized Beds
Authors: Hermanowicz S.W. , Ganczarczyk J.J.
Published: March 2019

Hydrodynamic behaviour of three-phase (gas-liquid-solids) fluidized bed was examined. Values of liquid dispersion coefficient and gas-to-liquid mass transfer coefficient were estimated. Both coefficients were independent of the liquid flow rate but highly dependent on gas flow rate. Dimensionless relationships were developed for both coefficients and the gas flow number. Gas transfer (aeration) efficiency was limited by the coalescence of gas bubbles. Gas slugging in the bed was observed and conditions of slug formation were investigated. Porosity of the bed higher than a certain critical value is required to prevent slugging in beds of small diameter.
The Influence of Benthic Biota on Copper Speciation and Distribution in Freshwater-Sediment Systems
Authors: Krantzberg G. , Stokes P.M.
Published: March 2019

An investigation was made of the effects exerted by benthic macroinvertebrate communities on copper speciation in sediments from a lake which is becoming acidified. In laboratory microcosms, benthic macroinvertebrate communities stimulated the flux of copper from sediment to water. The presence of the macro-benthos resulted in a redistribution of physico-chemical copper species within the sediment with a transfer from more strongly complexed forms (HC1 extractable) to adsorbed and cation exchangeable forms (MgCl2 extractable). The role of bio-turbation in copper transformations is discussed.
Effect of Spent Sulfite Liquor on Growth and Ethanol Fermentation Efficiency of Saccharomyces Ellipsoideus
Authors: Kosaric N. , Ho K.K. , Duvnjak Z.
Published: March 2019

The objective of this study was to evaluate the extent of inhibition of yeast growth and alcohol biosynthesis when spent sulfite liquor (SSL) was incorporated into growth media.

The liquor was pretreated by boiling, steam stripping or aeration in order to eliminate the factors causing growth inhibition. While these treatments did reduce the growth inhibiting effects of SSL, complete elimination of inhibition was not possible.
Adsorption of Trihalomethanes in Pilot Scale GAC Columns
Authors: Forsyth D.E. , Gammie L. , Bing-Song Xu , Huck P.M.
Published: March 2019

A four month pilot scale study was undertaken at the Buffalo Pound Water Treatment Plant near Regina, Saskatchewan to examine the removal of trihalomethanes and other organic substances from finished drinking water using three commercial granular activated carbons. Complete trihalomethane removals were achieved initially but percentage removals declined to low levels near the end of the study. THM removal occurred almost entirely in the top part of the columns. As the study progressed, levels reported at intermediate sampling ports were lower than those in the effluents. In addition, the lower portions of the column were unable to remove THM's once removals began to decline in the upper portions, suggesting premature exhaustion of the lower column segments. The results suggest that for carbon types and raw water conditions similar to those of this study, activated carbon contactors for trihalomethane removal should consist of shallow beds.
The Calibration and Evaluation of Dissolved Oxygen Sensors in an Activated Sludge Plant
Authors: Speirs G. , Chapman D. , Luxon E. , Matthews J.
Published: March 2019

The performance of three types of dissolved oxygen (DO) sensors was evaluated in a pilot scale activated sludge plant. As the instruments were interfaced to a minicomputer, a curve fitting technique was developed to compensate for instrument non-linearity. Weighted regression was performed to update initial calibrations.

Fouling due to the microbial growth on the surface of the probe was the principal cause of decline in sensor performance with time. The rate of fouling depended on the type of sensor used, the mode of operation, the frequency of maintenance and the velocity of fluid past the probe. A number of alternatives were evaluated for reducing or compensating for the effects of fouling and other causes of inaccuracy.

To determine the suitability of sensors for tracking DO concentration during non-steady state tests for determining overall mass transfer coefficients (KLa), the probes were subjected to repeated step changes in DO concentration. First-order time constants (τ) for the sensors were estimated based on the results of each step.
Treatment of Landfill Leachate by an Anaerobic Filter Part 2: Pilot Studies
Authors: Henry J.G. , Prasad D. , Scarcello J. , Hilgerdenaar M.
Published: March 2019

A 4-month study of pilot-scale anaerobic filters was conducted on the treatment of leachate generated from the Beare Road Landfill site in Metropolitan Toronto. The study examined filter performance in both upflow and downflow modes of operation using two types of support media, via plastic biorings and granite stones. No significant difference in removal efficiences, quantity of gas produced and its methane content, was found between upflow and downflow anaerobic filters nor between the plastic biorings and the granite stone media. An efficiency of 66-72% COD removal was achieved at a hydraulic detention time as low as 12 hours. The total gas production ranged between 400-500 L/kg COD destroyed. Methane content in the gas remained between 80-84%.
Extended Solids Residence Time Decreases Biosludge Disposal Volumes from an Oil Refinery Activated Sludge Plant
Authors: Gurak R.S. , McKillican W.B. , Uppal A.
Published: March 2019

At Imperial Oil, the activated sludge process (ASP) is used to treat oily process water streams. Recent pilot studies at Imperial Oil Research demonstrated that extended solids residence time (SRT) in activated sludge processes is achievable by controlling the biosludge waste rate from the aeration basin. This method was successfully commercialized at Imperial's Sarnia Refinery. Results to date show that the extended SRT operation has led to a reduction in biosludge disposal volumes and has eliminated one half of the digestion requirements. Overall, the effluent quality has been improved. The effluent contaminant levels continue to be lower than both the Federal and Provincial discharge guidelines for Refinery process waste waters.
Acute Toxicity of Cadmium, Copper, Mercury and Zinc to Chydorus Sphaericus (Cladocera) from Three Quebec Lakes
Authors: Lalande Marc , Pinel-Alloul B.
Published: March 2019

Most experiments on the effects of pollutants on zooplankton have been done with laboratory-cultured Daphnia species, but relatively few have been based on the naturally-occuring crustaceans. This study deals with cultures of Chydorus sphaericus, a cladoceran from three Quebec lakes (one polluted lake and two nonpolluted lakes), in a comparative toxicity test involving four heavy metals. Experiments were performed according to a static toxicity protocol, using at least five concentrations per test, five replicates per concentration, ten organisms per replicate and 200 ml volumes of metal solutions. The 48-hr EC50 of each individual metal and of the combination of metals were determined for each culture and for different size classes. The overall toxicity trend is : mixture > Hg >> Cu ≥ Cd > Zn. Juveniles appeared to be more sensitive than adults to heavy metals, but the observed differences were not statistically significant. Contrary to expectation, cultures from nonpolluted lakes showed higher EC50 mean values than the strain originating from a polluted lake.
Aluminum Speciation and Movement in Three Small Watersheds in the Southern Laurentians
Authors: Hendershot V. H. , Lalande H. , Dufresne A.
Published: March 2019

A study of three forested watersheds in southern Quebec shows that stream water chemistry, in particular the concentration of reactive Al, is dependent on the flowpath of water, Analyses of soil solutions and stream waters are used to identify the source of water under different streamflow conditions. During periods of baseflow the water flows through deep soil horizons, or bedrock, and very low concentrations of reactive Al are measured in the streams. During stormflow, generated by heavy rainfall, the pH decreases and the amount of soluble Al increases, Although very high levels of total reactive Al were measured (a maximum of 635 µg/L), the amount of uncomplexed, monomeric Al remained low; in only one of the basins did the concentration exceed the 200 µg/L level where Al toxicity to fish becomes a severe problem.
The Fate of 3-Trifluoromethyl-4-Nitrophenol (TFM) in Quiescent Waters and Its Impact on Benthos
Authors: Scott Brian F. , Carey John H. , Nagy Elmer , Dermott Ronald
Published: March 2019

The lampricide, 3-trifluoromethyl-4-nitrophenol (TFM), was added to three lined, sedimented ponds to determine the fate of this chemical and its effect on the benthos of quiescent waters. Two ponds were treated with the commercial formulation and the third was treated with purified TFM. Water column, sediment and benthos samples were taken regularly but not necessarily simultaneously. The initial distribution of TFM in the water column was monitored as was the rate of disappearance of TFM which was calculated to be 0.068 day-1.

Appreciable concentrations of TFM were found in the sediment over the two weeks following treatment, with only trace concentrations detected 117 days after treatment. No known decomposition products of TFM were detected in the water or sediment samples. Only the oligochaete and mollusc populations decreased after treatment, but they had returned to levels in the control pond within a year after addition of the chemical.
Identification of Taste and Odour Compounds from Western Lake Ontario
Authors: Brownlee B.G. , Painter D.S. , Boone R.J.
Published: March 2019

During August, 1983 geosmin was identified in a municipal water supply drawn from western Lake Ontario. The geosmin concentrations were 0.01-0.07 μg L-1, within the range for threshold odour concentration of 0.01-0.2 μg L-1. 2-Methylisoborneol was not detected. The odour 'event' coincided with a dieoff of Cladophora in the lake, but we were not able to establish a direct link between the dieoff and geosmin production. Decomposing Cladophora in shoreline areas produced a strong odour in the air. 3-Methylindole, elemental sulfur, dimethyl tetrasulfide, and dimethyl pentasulfide were tentatively identified in water samples collected from these areas, but geosmin and 2-methylisoborneol were not detected.
Chemical Speciation of Long-Lived Radionuclides in a Shallow Ground Water Flow System
Authors: Champ D.R. , Young J.L. , Robertson D.E. , Abel K.H.
Published: March 2019

The chemical speciation, ionic plus particulate forms, of long-lived isotopes of Pu, Am, Cm, Cs, Sr, Ni, I, and Tc was determined in four contaminant plumes at the Chalk River Nuclear Laboratories. Comparative data were also determined for shorter-lived isotopes of Ce, Eu, Fe, Co, Ru, Zr and Sb. Anionic species were the predominant solution species, and hence the mobile form, for many of the elements. Complexation by organic ligands, both natural and synthetic, was postulated to be important in mobilizing Co, Ce, Cs, Eu, Sb, Zr, Fe, Ni, I, Pu and possibly Am. Thermodynamically-predicted aqueous speciation was consistent with our data for only four elements; Ru, Sr, I and Tc. The chemical speciation of Am was found to be particularly anomalous in the study sites. On the basis of our data we conclude that the predictions of Kd-based models for radionuclide mobility must be carefully evaluated with respect to the adequacy of the speciation assumptions of the Kd approach.
Uranium Tailings Acidification and Subsurface Contaminant Migration in a Sand Aquifer
Authors: Dubrovsky N.M. , Morin K.A. , Cherry J.A. , Smyth D.J.A.
Published: March 2019

Investigations of the geochemistry of inactive pyritic uranium tailings in the Elliot Lake Mining district of Ontario have focused on the Nordic tailings management area, where two impoundments are located in natural bedrock basins. The tailings are 8-12 m thick and overlie a localized deposit of glaciofluvial sands. Analyses of the solid, liquid, and gas phases in the vadose zone of the tailings show that gas-phase oxygen levels drop rapidly within 0.7 to 1.5 m of the surface, indicating rapid oxygen consumption during pyrite oxidation. Oxidation during the past 15 to 20 years has caused a marked depletion of near-surface pyrite.

The oxidation of pyrite in the vadose zone imparts to infiltrating precipitation high concentrations of Fe, SO42-, various heavy metals, and a pH generally between 1.5 and 4. The acidic infiltration moves downward at a rate of 0.2 to 2.0 m/yr, displacing high-pH groundwater that originated as process water discharged from the mill. It now occupies the entire tailings thickness over a small area of the tailings.

At one location a well-defined plume of high-Fe2+ tailings-derived groundwater has developed in the sand aquifer adjacent to the tailings. The plume consists of three zones: an inner core characterized by Fe > 5000 mg/L, pH < 4.8, and elevated concentrations of several heavy metals and radionuclides; an outer zone with Fe < 2500 mg/L, pH > 5.5, and relatively low concentrations of heavy metals and radionuclides; and a transition zone separating the two. Although the average linear groundwater velocity is about 440 m/yr near the dam, reactions such as mineral dissolution, precipitation and coprecipitation retard the migration of the front of the inner core, producing an observed frontal migration rate of approximately 1 m/yr.

Groundwater from the outer zone of the plume flows laterally towards a small stream, where a portion of it is now discharging into the stream bed. The discharge results in the precipitation of amorphous ferric hydroxide on the stream bed. Most of the H+ produced by Fe precipitation is buffered, and only a moderate decrease in stream pH is observed. Inner zone conditions will not reach the stream unless input of low-pH groundwater from the tailings continues for several hundred years.

Although the rate of pyrite oxidation in the Nordic Main tailings has been decreasing, there is sufficient pyrite in the tailings to generate high-Fe groundwater for several decades or more. Calculated groundwater migration rates indicate that in the next few decades acidic, low-pH groundwater will occupy the entire tailings thickness over most of the tailings area, causing an increase in the total flux of contaminated groundwater into the underlying aquifer. The outer zone of the plume has already arrived at a small stream, and acidification of the surface waters may increase if the Fe concentration in the groundwater seepage increases.
The Impact of Mining and Smelting on Trace Metal Distribution in Lake Sediments Around Rouyn-Noranda, Quebec
Authors: Arafat Nabil M.
Published: March 2019

Metal leachate from sediment cores obtained from seven lakes around Noranda Copper smelter in Quebec exhibited maximum levels of 7297 μg/g, 14469 μg/g and 246750 μg/g of Cu, Zn and Fe respectively in lakes near the emissions source, and lower levels in lakes away from the smelter. The sediment enrichment factor (SEF) among these lakes varied with respect to distance from the smelter. Lakes within 10 km from the smelter had an (SEF) of 166, 118 and 130 for Cu, Zn and Pb respectively; lakes at 25 km or more had SEF's ranging from 1 to 5.5, with the exception being lake Duparquet, where Mo value of 25 was obtained. These enrichment factors are among the highest recorded in the world.
Seasonal Variations of 2,4-D in Buckhorn Lake
Authors: Nagy E. , Painter D.S.
Published: March 2019

A five month survey of 2,4-D in Buckhorn Lake water and sediment, combined with streamflow data, produced estimates of the chemical in the lake. The peak concentrations in the water alone were significantly higher than the documented uses would permit. Two distinct concentration peaks were shown by the chemical: one during the June milfoil control season, and one in late August, indicating a release of 2,4-D from the collapsed and decaying milfoil beds. The observed rates of disappearance of the chemical agreed with reported values, showing a limited persistence in the lake. The presence of 2,4-D in the spring sediments was attributed to land runoff.
Toxicity of Para-Chloro Substituted Benzene Derivatives in the Microtox™ Test
Authors: Kaiser Klaus L.E. , Ribo Juan M. , Zaruk Brian M.
Published: March 2019

This paper gives the results of part of a systematic investigation into contaminant toxicity to Photobacterium phosphoreum in the Microtox™ test. Reported are the toxicity values for 39 para-chloro substituted benzene derivatives of the general formula l-Cl-C6h4-4-X=CH2CH(NH2)COOH, F, SO2NH2, OCH2COOH, CH2COOH, CONHNH2, NHCOCH3, CONH2, CH=CHCOOH, SeOOH, CH2NH2, CH2CH2NH2, NO2, H, CF3, CHO, CH2OH, OH, CH3, CCl3, COCH3, COOH, NH2, SO2C6H5, Cl, CH2COCH3, COCl, CN, OCH3, NCO, NHCH3, I, COC6H5, CH2Cl, SH, CH2SH, NCS, CH2CN and SO2C6H4Cl. Except for the last compound, whose solubility is below the required concentration, the toxicities increase in the presented order with a total range of more than three orders of magnitude.

The data are discussed in terms of quantitative structure-toxicity correlations with compound-specific structural parameters. In combination with a previously developed submodel on chlorinated benzenes, phenols, nitrobenzenes and anilines, the observed relationships allow the prediction of the toxicity of some 780 possible chloro derivatives of the general formula C6H5-nClnX, where n=<5 and X is a functional group as listed above.
Non-Intrusive Estimation of Active Volume in Anaerobic Reactors
Authors: Hall Eric R.
Published: March 2019

A stimulus-response and flow modelling technique was developed for the examination of internal mixing patterns in high rate anaerobic reactors. This method allowed the effects of biomass accumulation to be monitored in a non-intrusive manner which avoided interruption of the reactor operation. The analysis was applied to three pilot scale systems which utilized different reactor designs for anaerobic wastewater treatment.

The results of multiple tracer studies demonstrated that high rate anaerobic processes most closely resemble well mixed reactors. However, significant deviations from ideal behaviour were noted. A flow model incorporating bypass and dead volume was found to adequately describe the measured tracer results. Estimates of reactor actively mixed working volumes obtained by the modelling approach were highly correlated to void volumes measured by an intrusive technique. The stimulus-response methodology is suitable for routine application in full scale facilities where an assessment of biomass accumulation effects is required.