bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiostrontium Migration from a 1953-54 Liquid Release to a Sand Aquifer
Authors: Killey R.W.D. , Munch J.H.
Published: March 2019

Aqueous ammonium nitrate solutions containing a variety of fission products were released to an infiltration pit overlying a sand aquifer in the early 1950’s. Almost all of the undecayed 137Cs and 154Eu are still retained within the 5 m thick unsaturated zone beneath the pit. Radiostrontium, however, has moved up to 350 m through the hydrogeologically simple and fast-moving groundwater flow system; the inventory of the aquifer plume’s 90Sr content is in good agreement with the estimated initial release. Data from 6 determinations of plume front position yield a linear increase in distribution ratios for 90Sr at the leading edge, from 0.8 to 4.8 mL·g−1 between 1955 and 1983. Mean Kd’s between 3 and 9 mL·g−1 have been determined from short-term laboratory and field experiments, and the rate of advance of the plume front is expected to reach a steady state within this range. Analyses of 340 contaminated sands and associated pore waters from various locations in the plume provided in situ distribution ratios with a log mean of 12.9 mL·g−1, and with no significant variations between sediments that have been in contact with 90Sr for from 10 to 28 years. Differences between plume front distribution coefficients and the in situ values observed in older portions of the plume are explained primarily by kinetically slow chemisorption onto secondary oxide coatings on the sand surfaces. This reaction apparently has half-reaction times for both sorption and desorption of less than 2 years, and hence can be treated as an equilibrium process in long-term studies. A substantial conflict remaining in the data, however, is the rate of advance of the centre of mass of the plume. Most of the radiostrontium in the aquifer la apparently moving at a much slower rate than the log mean in situ distribution ratio would predict - one explanation for this discrepancy is that 90Sr movement is greatly retarded by volumetrically small sandy silt strata that have much higher sorption capacities than the fine to medium sands that dominate the overall aquifer sampling. A simple, conservative, model that assumes equilibrium sorption of radiostrontium predicts acceptable concentrations of radiostrontium in surface waters at the CRNL property boundary.
Laboratory Simulation of Pentachlorophenol / Phenate Behaviour in an Alluvial Aquifer
Authors: Patterson R.J. , Liebscher H.M.
Published: March 2019

In 1978, about 18,000 litres of a chlorophenol/phenate solution leaked from a sawmill dip tank located approximately 120 metres from the Okanagan River in Penticton, B.C. Results of field studies indicated that the chlorophenol/phenate migrated through a surficial alluvial aquifer toward the river and that the retardation factor for the contaminants was between 1,05 and 1.43. A purge we 11 remedial operation recovered only about 40% of the spilled chlorophenol/phenate. More than five years after the purging operation, low levels of chlorophenol/phenate were still present in the groundwater.

A column test to simulate the subsurface transport and purging behaviour of pentachlorophenol/phenate was conducted in the laboratory under conditions which duplicated, as closely as possible, those in the field. Results, which suggest a retardation factor of about 1.25 and non-equilibrium (i.e. slow) sorption/desorption, can account for the behaviour of the contaminants in the aquifer under natural flow conditions and during purging. The success achieved in the simulation indicates that these types of tests can be applied usefully in the study of contaminant behaviour in the subsurface. In addition, they could play an important role in waste site assessment and remediation programs where purging is an alternative. Data can be obtained at relatively low cost and at an early stage in an investigation, and could be employed to provide a preliminary assessment of the probable efficiency of purging. Moreover, the results could be applied to establish parameters and operating conditions that will improve the effectiveness of costly field tests that must precede the design of an optimal purging system.
Evaluation of Filter Coefficients λ and σ for Iron Removal by Rapid Sand Filtration
Authors: Narasiah K.S. , Dany T.D. Dao
Published: March 2019

Studies wore conducted on a sand bed filter using stock suspension of iron sulfate. By measuring precisely the amount of iron oxide deposited in each layer of sand the coefficients of filter, namely the impediment modulus λ and the specific deposit coefficient σ, are evaluated. Also the phenomenon of “breakthrough” has been explained. From the results obtained it is found that an exponential equation of second degree can adequately describe the process of iron removal by rapid sand filtration.
Relationship Between the Biological Testing of Industrial Effluents and the Quality of Receiving Waters -Some Canadian Case Studies
Authors: Dafoe T. , Carey J.H. , McCrindle S.H. , Wells P.G. , Wilson R.C.H.
Published: March 2019

A summary of selected Canadian experiences in the application of biological tests for controlling and monitoring effluent quality, for setting water quality objectives, and for monitoring receiving waters is presented. ? brief review is made of the approaches for applying biological tests to effluents, to the selection of suitable water quality objectives, and to the conduct of ambient biomonitoring programs. Two case examples from Canada, the Saint John River, New Brunswick, and Canagagigue Creek, Ontario, are evaluated in detail. A number of other Canadian sites where biological tests are being applied are also discussed. The contributions of biological tests on effluents to administrative decisions for pollution control, as well as the limitations of solely using “end of pipe” tests, are emphasized in the paper.
Cell Surface and Aggregation Studies of Microbes from Anaerobic Systems
Authors: Kosaric N. , Mahoney E.M. , Varangu L.K. , Cairns W.L.
Published: March 2019

Studies were performed to evaluate cell surface properties of aggregated microbial granules from anaerobic digestion systems. Cell surface properties (hydrophobicity/hydrophilicity) were obtained by contact angle measurements in an aqueous phase. The cells’ charges were evaluated by measuring zeta potential and settlability was used as a measure of aggregating of cells under various experimental conditions.

Flocculation tests have shown to be a good indicator of aggregation ability between cells. Aggregation can be modulated by changing those environmental and engineering parameters which can be measured by contact angle and zeta potential.
Organochlorine Residues in Brook Trout and Yellow Perch From New Brunswick and Nova Scotia (Canada) Lakes
Authors: Peterson R. , Ray S.
Published: March 2019

Brook trout and yellow perch collected while surveying New Brunswick and Nova Scotia headwater lakes were analyzed for DDT metabolites, chlordane, hexacyclohexane isomers, hexachlorobenzene, toxaphene and PCB’s. Concentrations of DDT metabolites were much higher from fish taken from lakes in north-central N.B. (200-700 ng/g wet wt) than from fish taken elsewhere (<10 ng/g). Seventy to 90% of the DDT metabolites was DDE. Chlordane (3-13 ng/g) was analyzed in seven trout, six of them from central N.B. areas with intensive agriculture. Isomers of hexachlorocyclohexane were in highest concentration from north-central N.B. (10-20 ng/g), eastern N.S. (5-15 ng/g) and southern N.B. (5-20 ng/g). In most cases, alpha-hexachlorocyclohexane (lindane) was the isomer in highest concentration. Concentrations of hexachlorobenzene in fish tissues was highly variable with no obvious geographic bias. PCB’s were detected in very few fish, and no toxaphene was detected.
Lake Superior Atmospheric Wet Deposition 1980-1983
Authors: Chan C. H. , Perkins L. H.
Published: March 2019

Wet deposition estimates were computed from monthly wet precipitation samples collected in the Lake Superior Basin. Sulphate and nitrogen loadings from wet precipitation corresponded to 142 and 40 thousand tonnes per year. On a percentage basis, wet deposition of sulphate and nitrogen accounted for 21% and 54%, respectively, of the total load. Atmospheric sources for other major ions ranged from 1 to 10%. Atmospheric deposition at the eastern end of Lake Superior was higher than the western end of the Basin. The relative accuracy of these estimates were examined in relation to the changes in lake chemistry in Lake Superior from 1973 to 1983.
La toxicité léthale aiguë des effluents industriels au Québec vis-à-vis de la truite arc-en-ciel
Authors: Biaise C. , Costan G.
Published: March 2019

De 1975 à 1984, plus de 300 échantillons d’effluents industriels provenant de 160 sites industriels de la province de Québec ont été bioanalysés afin d’évaluer leur toxicité létale aiguë envers la truite arc-en-ciel. Six secteurs industriels étaient représentés par ces prélèvements: Pâtes et Papiers (PP) , Minier (M), Chimique (C), Alimentaire (A), Raffineries (R), Textiles (T). Diverses façons d’analyser les données ont permis de dégager d’intéressantes informations liées à leurs toxicités respectives. Tout d’abord, le groupe PP, A et T est apparu globalement plus toxique que le groupe C, M et R. De plus, quatre secteurs ont démontré une ressemblance marquée au niveau de leur expression toxique (i.e. CL50-96 h), soit le secteur PP avec le secteur A et le secteur M avec le secteur R. Par ailleurs, l’étude des données de TL50 a indiqué que de 6 S 20% de ceux-ci (selon le secteur) sont atteints au delà de 24 h d’exposition. Ce constat plaide en faveur de la réalisation de CL50 de 96 h afin de ne pas sous-estimer les effets toxiques. D’autre part, des CL50 aussi basses que 1 v/v % (nos données) et 0,1 v/v % (données rapportées ailleurs) ont été obtenues pour des effluents finaux rejetés dans le milieu aquatique. Enfin, une analyse plus poussée de 23 effluents finaux du secteur PP n’ayant subi aucun traitement a permis de relier leur toxicité à certains paramètres physico-chimiques (sulfures, Mn, DCO, solides totaux, phénols) analysés en support aux bioanalyses.
Deemulsification of Water-in-Oil Emulsion with Sludges
Authors: Kosaric N. , Duvnjak Z.
Published: March 2019

Aerobic sludge from a municipal activated sludge treatment plant, sludge from a conventional municipal anaerobic digester, aerobic sludge from an activated sludge process of a petroleum refinery, and granular sludge from an upflow sludge blanket reactor (USBR) were tested in the deemulsification of a water-in-oil emulsion. All sludges except the last one, showed a good deemulsification capability and could he used for a partial deemulsification of such emulsions. The rate and degree of the deemulsifications increased with an increase in sludge concentrations. The deemulsifications were faster at 85°C and required smaller amounts of sludge than in the case of the deemulsifications at room temperature.

An extended stirring (up to a certain limit) in the course of the dispersion of sludge emulsion helped the deemulsification. Too vigorous agitation had an adverse effect.

The deemulsification effect of sludge became less visible with an increase in the dilution of emulsion which caused an increase in its spontaneous deemulsification.
A Comparison of Anaerobic Reactors Operating With and Without the Addition of Sulfates
Authors: Hilton Barry L. , Oleszkiewicz Jan A.
Published: March 2019

Three pairs of anaerobic upflow sludge bed reactors were compared. Each pair received the same amount of whey and waste sulfite liquor. Sulfate loaded gas-stripped reactor R4 performed as well as its methanogenic (no addition of sulfates) counterpart R6. The performance of unstripped sulfate-loaded reactors R1 and R3 was comparable to the gas-stripped R2 and R4 only when reactor loads were below 3 kg COD/m3·d and 0.5 kg S/m3·d. At higher loads the performance deteriorated significantly. Syntrophic generation of methane and sulfides was found to be the prerequisite to attaining high removals of COD.
Removal of Organic Carbon and Chlorine from a Kraft Mill Wastewater by Pretreatment with Catalyzed Ozone and Powdered Activated Carbon
Authors: Sierka R. A. , Bryant C. W.
Published: March 2019

Effluents from the chlorine pulp-bleaching process have been shown to contain miscellaneous organic-Cl compounds including chloro-phenols , -catecols, -resin acids, and simple haloforms such as chloroform. Less defined materials such as chlorolignins with apparent molecular weights ranging from 500 to over 30,000 have also been found in these effluents. The total quantity of organically bound chlorine has been estimated to be 5 kilograms per tonne of pulp, or 250,000 tonnes per year worldwide (Kringstad and Lindstrom, 1984).

Recent work in Sweden (Sjostrom et al., 1985 and 1982) and Norway of the total organic halide (TOX) parameter in characterizing chlorination by-products found in pulp and paper wastewater. A comparison of TOX data with data defining concentrations of specific organo-Cl compounds revealed that a very large fraction of the TOX pool has yet to be identified.

Many pulp and paper mills in the United States and Scandinavia employ aerated lagoons for the removal of biochemical oxygen demand, suspended solids, and nitrogenous compounds.
Benzene and Toluene Levels in the Upper St. Clair River
Authors: Comba Michael E. , Kaiser Klaus L.E.
Published: March 2019

Analyses of St. Clair River bottom water samples along 20 transects, each comprising three stations at 10 m, 25 m, and 100 m offshore, show inputs of benzene and toluene in the nearshore zone along the highly industrialized area below Sarnia, Ontario. Minimum loadings of 18 kg·day−1 benzene and 15 kg·day−1 toluene are calculated from the observed concentrations. In addition, a number of other volatile hydrocarbons were present in most samples and were tentatively identified as five to six carbon atom containing branched alkanes.
Use of Peat in Septic Tank Effluent Treatment - Column Studies
Authors: Rana Shahid , Viraraghavan T.
Published: March 2019

Studies were undertaken to examine the performance of peat filters under dynamic operating conditions. Five laboratory columns were used to determine the treatment capacity of peat at varying hydraulic and organic loadings.

The columns with 200, 250, 300, 350 and 500 mm of peat compacted to a density of 100 kg/m3 were studied treating septic tank effluent. All the columns were dosed at uniform rates of 64 mm/d, 89 mm/d, 115 mm/d and 140 mm/d of septic tank effluent for periods of 14, 16, 10 and 4 weeks respectively. Results of column studies showed SS removal of 85-99%, BOD, COD removals in the 40 to 80% range, TKN removal of 0 to 90% and phosphorus removal of 0 to 25%. In general, excellent ( > 95%) fecal coliform reduction was obtained.
Impacts on River Discharge of Changes in Glacierized Components of Mountain Basins
Authors: Johnson Peter G. , David Claude
Published: March 2019

A reliable and predictable water supply is essential to any development in mountainous regions. Large glacierized components of basins can produce surplus or deficit conditions as climate changes from season to season and as the ice extent fluctuates through time. Shorter time frame glaciological changes can produce stream diversion, catastrophic floods or very Irregular flow regimes. The major impact on water quality is the high level of and variations in sediment load concentrations which occur with the regime fluctuations. Sediment concentration regimes occur both in phase and out of phase with flow regimes.
Etude préliminaire de la qualité des eaux de surface de 15 cours d’eau majeurs du Nouveau-Québec
Authors: Langlois C.
Published: March 2019

Dans le cadre de l’entente Canada-Québec sur la surveillance continue de la qualité de l’eau, la Direction des eaux intérieures et des terres (région du Québec) a entrepris en 1983 un programme de surveillance dans des cours d’eau se déversant dans les baies d’Hudson et d’Ungava. Les principaux objectifs de ce programme sont l’acquisition de données de base, l’évaluation de l’état actuel de l’environnement aquatique et la détection de tendances temporelles à long terme. Toutes les stations sont situées sur des cours d’eau jaugés et l’échantillonnage se fait généralement trois fois par année. Les échantillons d’eau sont analysés pour les tests physiques, les ions majeurs, les éléments nutritifs, les métaux, les biphényles polychlorés (BPC) et les pesticides organochlorés (OC). Les résultats obtenus tendent à démontrer que le transport à longue distance des polluants toxiques constitue la principale menace à moyen terme pour la qualité du milieu aquatique au Nouveau-Québec.
The Impact of Effluents from a Uranium Mine and Mill Complex in Northern Saskatchewan on Contaminant Concentrations in Receiving Waters and Sediments
Authors: Hynes Thomas P. , Schmidt Randy M. , Meadley Tim , Thompson Neill A.
Published: March 2019

Data are provided on the release of 5 radionuclides, 17 metals and 7 major ions from a uranium mining operation in northern Saskatchewan. The downstream concentration of these contaminants is documented, and the point of “no discernible impact” is determined. Sediments in a downstream lake are monitored for uranium and molybdenum, and the post-release fate of these metals is discussed.
Determination of Hydrocarbon Uptake and Effects on Mackenzie River Fishes Using Bile Analysis
Authors: Morgan J.D. , Vigers G.A. , Nix P.G. , Park J.M.
Published: March 2019

Analysis of bile for polynuclear aromatic hydrocarbon metabolites in resident freshwater fishes and experimentally exposed fish in the Mackenzie River indicated that bile analysis provided a more sensitive biochemical indicator of hydrocarbon contamination than analysis of water, sediments or suspended sediments. This paper reports the first estimates of hydrocarbon bioaccumulation in bile from controlled in situ exposures of fish to hydrocarbons, as well as preliminary evidence of effects on fish livers.
Northern Water Quality Monitoring Workshop Observations, Conclusions, Recommendations
Authors: Kwiatkowski R.E. , Olding B. , Vaughan H. , Whitfield P.
Published: March 2019

Development continues to occur in the North. With development, there is the potential for ecological damage. This is particularly true in the North, with its harsh environment coupled with its fragile ecosystems. One of these systems, the aguatic ecosystem, is the focal point of this special issue of the Water Pollution Research Journal of Canada. The ten preceedinq papers were presented at the Northern Water Quality Monitoring Workshop, held in Yellowknife, May 4-7, 1987. The Workshop was organized into three basic stages. Day 1 was devoted to invited presentations from data users while days 2 to 4 were devoted to scientific presentations on: General Monitoring, Mining and Hydrocarbons. The scientific presentations were followed by Workgroup Sessions and a Plenary session daily. This paper attempts to highlight the various views and opinions, often without creditation, from the verbatim transcripts of the invited presentations (day 1), Workgroup Sessions and Plenary Sessions (days 2-4) found in Inland Waters/Land Directorate, Technical Workshop Series No. 7, Northern Water Quality Monitoring, 1988.
Bioconcentration of Chlorophenols by Juvenile Chinook Salmon (Oncorhynchus tshawytscha) Overwintering in the Upper Fraser River: Field and Laboratory Tests
Authors: Rogers I. H. , Servizi J. A. , Levings C. D.
Published: March 2019

Juvenile chinook salmon were sampled from August 1986 to March 1987 at stations near Prince George and Quesnel, influenced by sewage and pulp mill discharges. Maximum densities of 0.2 fish·mࢤ2 were recorded. Salmon were collected at reference sites in November 1986 and at Agassiz in April 1987.

Fingerling chinook were exposed at 0.7°C to a commercial wood preservative containing 2,3,4,6 - tetrachlorophenol (TeCP) and pentachlorophenol (PCP) in the laboratory to simulate winter conditions in the upper Fraser River. Fish exposed for 62 days to 2 ug·Lࢤ1 contained a mean of 224 ng·gࢤ1 TeCP and 431 ng·gࢤ1 PCP.

Chlorophenol uptake in feral fish was low. However, 3,4,5-trichloro-guaiacol levels to 304 ng·gࢤ1 and tetrachloroguaiacol values to 136 ng·gࢤ1 were measured in March. Fish from Agassiz, 518 km downstream of Quesnel, also contained these two substances. Thus chinook salmon can bioconcentrate persistent chlorophenols and chloroguaiacols directly from cold water (< 1°C). The biological consequences are uncertain.
Modelling Stormwater Related Chlorophenol Releases to the Fraser River Using the Motz-Benedict (Moben) Model
Authors: Krahn Peter K. , Shrimpton Julie A.
Published: March 2019

Stormwater runoff from surface treated lumber storage areas on the lower Fraser River was estimated to range from 489,092 m3/yr to 775,794 m3/yr. The loading of total Chlorophenols was estimated to range from 226 kg/yr to 916 kg/yr. The fate of chlorophenol contaminated stormwater released from treated lumber storage yards to the Fraser River is predicted by application of the Motz-Benedict (MOBEN) Model for effluent discharge to a river. The simulation predicted that a plume at 100 ug/L total Chlorophenols could extend up to 12 metres from shore and 60 metres downstream of discharge.
Modelling the Transport and Pathways of Tetrachlorophenol in the Fraser River
Authors: Lam D.C.L. , McCrimmon R.C. , Carey J.H. , Murthy C.R.
Published: March 2019

A mathematical model was developed to simulate the advection, sorption, photolysis and sedimentation of 2,3,4,6-tetrachlorophenol (TeCP) in the Fraser River Estuary. By adjusting the loading estimates, the computed concentration could be brought to within a mean relative error of about 10 to 21% when compared to the observed data measured at three stationary sites during two study periods. For high flows, as in the study period in June, the transport was dominantly in the downstream direction. For low flows, as in the study period in November, both downstream and upstream transports were possible depending on the tidal flows. Because of the relatively low adsorption capacity, most of the TeCP existed in the dissolved phase. Analyses show that, in order of decreasing sensitivity, loading, flow, sorption, photolysis and settling could affect the simulated results. The use of nonstationary data was recommended to improve the temporal and spatial coverage in the water quality monitoring programme.
Water Exchange Between Lake Ontario and Hamilton Harbour: Water Quality Implications
Authors: Barica J. , Charlton M.N. , Poulton D.J. , Kohli R.
Published: March 2019

Hamilton Harbour is an enclosed body of water situated at the western end of Lake Ontario and containing about 2.8 x 108 m3 of water, polluted by municipal and industrial effluents. It is connected to Lake Ontario by a ship canal, which facilitates a substantial exchange of water between the two water bodies. Exchange of harbour and lake water through the canal reduces the theoretical hydraulic residence time of the harbour and contributes to improvement of the harbour water quality through dilution and oxygenation. Without it, the Hamilton Harbour water quality situation would be more critical. The beneficial effect of dilution by Lake Ontario far exceeds contamination of western Lake Ontario by Hamilton Harbour water.
Satellite Observations of Sediment Transport Patterns in the Lac Saint-Pierre Region of the St. Lawrence River
Authors: Bruton J.E. , Jerome J.H. , Bukata R.P.
Published: March 2019

Satellite data from Landsats 4 and 5 were utilized to delineate the seasonal variations of sediment transport zones in the Lac Saint-Pierre region of the St. Lawrence River corridor. A seasonally cyclic succession of patterns displaying persistent, mutually independent, and extensive (in both space and time) turbidity zones was clearly in evidence. Visible and thermal data in both imagery and digital formats were used to show the close relationships existing among the distinct zonal synoptic patterns, the bathymetry of lake and river, and the near surface aquatic temperatures.
Sorption of the Pesticide Aldicarb by Soil: Its Mobility Through a Saturated Medium in the Presence of Dissolved Organic Matter
Authors: Lafrance P. , Ait-ssi L. , Banton O. , Campbell P.G.C. , Villeneuve J.P.
Published: March 2019

Adsorption characteristics of the radiolabeled pesticide aldicarb (2-methyl-2-(methyl-14C-thio)-propionaldehyde-O-methycarbamoyO-oxime) on loamy sand and its mobility through a water-saturated soil column were studied. This study emphasizes the effect of soil organic carbon content and of dissolved humic materials on the sorption characteristics of aldicarb. Dissolved humic substances at 25 mg/L present a very small binding affinity for aldicarb (“association constant” ≈ 20 [nmol/g carbon]/[nmol/g water]) and do not significantly affect the sorption rate for this pesticide. Freundlich isotherms were determined for aldicarb sorption on the original soil (% o.c. = 2.2) and on soil samples treated to reduce the initial soil organic carbon content (% o.c. = 0.8). If linear isotherms are assumed, the adsorption coefficient KD is nearly three-fold higher for the original soil than for the treated soil samples. The ratios of the KD values obtained for adsorption in the presence and in the absence of dissolved humic substances (25 mg/L) were 1.3 and 1.4, respectively, for the original and for the treated soil samples: this indicates that humic substances could modify only slightly aldicarb transport in soil. Effluent concentration profiles for the movement of the radiolabeled pesticide through a 30-cm long saturated soil column indicate a retardation factor R = 1.4. This R value is related to hydrolysis product of aldicarb, since no detectable parent compound was found in the column effluent. Results showed 45% loss of the initial radioactivity applied on the soil column: this could be attributed to irreversible adsorption and to biodegradation of the pesticide compounds.
Review of Field Applications of the Microtox Test in Great Lakes and St. Lawrence River Waters
Authors: Kaiser Klaus L.E. , Lum Ken R. , Palabrica Virginia S.
Published: March 2019

The Microtox™ toxicity test, a bioassay employing the luminescent marine bacterium Photobacterium phosphoreum as the test organism, has previously been used in field and laboratory research for the assessment of water contamination in the Detroit River and in Lake St. Clair. The test results indicated locations and zones of impaired water quality and were found to be useful in connection with other studies of the same areas.

This review presents new Microtox toxicity data on the St. Lawrence River and discusses the results in conjunction with other biological, chemical and physical data collected at the same time. It assesses the advantages and limitations of this bioassay for exploratory work on water contamination in the Great Lakes and in other aquatic organisms.
Determination of Biomass in Activated Sludge Containing Large Quantities of Carbonaceous Solid Carriers
Authors: Senthilnathan PR. , Ganczarczyk J. J.
Published: March 2019

The exact estimation of biomass in the presence of carbonaceous carriers is an unresolved problem. Inaccuracy arises from the use of mixed liquor volatile suspended solids (MLVSS) determination as the measure of biomass, due to the volatilization properties of some carrier particles at 550°C. Problems are also associated with the differential ignition technique and nitric acid digestion technique, which are used instead of the MLVSS determination. Therefore, a method of calculating the biomass content by the determination of nitrogen in the mixed liquor suspended solids is proposed. In this paper, the proposed method is compared with the differential ignition technique. The Nitric acid digestion technique was not used in this study due to the explosive nature of one of the carbonaceous carriers when digested with nitric acid. It was found that calculation based on the nitrogen analysis gave a more reliable estimate of biomass in systems containing carbonaceous particles than the differential ignition technique.
Impaired Swimming Performance of Acid-exposed Arctic Charr, Salvelinus Alpinus L.
Authors: Hunter L.A. , Scherer E.
Published: March 2019

Arctic charr (Salvelinus alpinus L.) were exposed to five levels of acidity between pH 6 and pH 3.8. Swimming performance as determined by critical swimming speeds was 67.5 cm · sࢤ1 or 4.4 body lengths per second for untreated fish (pH 7.8). Performance declined sharply below pH 4.5; at pH 3.8 it was reduced by 35% after 7 days of exposure. Tailbeat frequencies and ventilation rates showed no dose-response effects. At swimming speeds between 20 and 50 cm · sࢤ1, ventilation rates at all levels of acidity were higher than at the control level.
A Microtox Test Survey of Lake St. Clair Water
Authors: Kaiser Klaus L.E. , Ribo Juan M. , Kwasniewska Kazimiera
Published: March 2019

Surface water samples of 67 stations throughout Lake St. Clair and parts of the St. Clair River delta were tested for acute toxicity to Photobacterium phosphoreum with the Microtox™ test. The results indicate the existence of zones of low toxicity in most of the northern, western and southern nearshore areas (up to approximately 5 km from shore) of the lake, and generally absence of toxicity in the central offshore part and the eastern nearshore area of the lake and in the river.
A Method of Metal Removal
Authors: Kuyucak Nural , Volesky Bohumil
Published: March 2019

Selected non-living, inactivated materials of biological origin, such as algae, fungi, bacteria and their products, have been screened for their metal uptake capacity from solutions. Each biomass type exhibited different performance for metal species tested. The biosorbent performance also varied broadly with pH of the solution used.

The biomass of a green alga Halimeda opuntia and a brown alga Sargassum natans have been identified for their extreme potential to concentrate chromium and gold, respectively. The optimum pH was 4-6 for chromium uptake and below 3 for gold uptake. A brown marine alga Ascophyllum nodosum sequestered cobalt well at pH 4.5 outperforming activated carbon and ion exchange resins. The optimum pH for silver uptake by biomass of a red alga Chondris crispus and for arsenic uptake by yeast Saccharomyces cerevisiae covered a broad range of pH 2-6 and pH 4-9, respectively. A red marine alga Palmaria palmata was the most functional biomass in sequestering platinum at pH below 3.

The biosorptive uptake of chromium and gold was rather specific. It was not affected by the presence of other cations such as Cu2+, UO22+, Ca2+, Ni2+ or anions such as CO32−. Kinetics of the metal uptake, except for gold, was generally very rapid.

Sequestered metals could be eluted from the biomass and the biosorbent material can subsequently be reused many times over. The work demonstrates existing potential of a new group of biosorbent materials of microbial origin which can be effectively applied in a novel process of metal recovery from dilute solutions. The process of biosorption has a commercial potential as documented by several new enterprises currently aggressively entering the field.
Alternative Approaches to the Monitoring of Toxic Organic Compounds in Surface Waters
Authors: Vaughan Hague H. , Zakrevsky Jean-Guy
Published: March 2019

The effectiveness of present approaches to the monitoring of toxic organic chemicals in surface waters is questioned on the basis of cost and limited analytical or interpretive capabilities. Cursory examination of routinely generated chromatograms shows that a significant number of compounds exist in the environment about which little or nothing is presently known because of an increasingly rooted acceptance of “list” or “target” approaches to environmental chemistry. A redirection towards broad spectrum approaches is advocated. Such approaches would further allow for the simplication of information generation by concentrating analytical and interpretive efforts on those chromatographic peaks which directly reflect the ‘treatment’ or ‘difference’ established through the sampling scheme (e.g., upstream vs downstream, before treatment vs after, inflow vs outflow, toxic vs non-toxic, one season vs another, epilimnion vs hypolimnion, etc.). Upon consideration of existing technology, a plan of action is presented.
Designing Site-Specific Water Quality Objectives and Monitoring
Authors: Valiela D. , Whitfield P. H.
Published: March 2019

The development of site-specific water quality guidelines and objectives requires considering seasonal variability, biologically critical periods, interactions with other variables, and effects of cumulative exposure and lags in functional responses. Designing an effective and efficient monitoring program to determine compliance with site-specific objectives involves allocating the sampling effort according to these factors. We outline a hierarchical approach to determining this allocation process.
Identification of Surface Water Acidification Sources in Nova Scotia
Authors: Howell Geoff , Gélinas Ron , Slaats Jan
Published: March 2019

A microcomputer-based geographic information system (GIS) was used to integrate and analyse water quality and population density data in an attempt to distinguish between local and transboundary acidification sources in Nova Scotia. Using water colour as an indicator of organic acidity and population density as an indicator of local mineral acid sources, a potential local acidification source map was derived. This map indicated that 23% of the 332 lakes considered had a high potential for local source acidification while the other 77% had high LRTAP potential. An acidification response map using the ratio of total alkalinity to excess calcium and magnesium as an indicator of the theoretical loss of pre-acidification alkalinity was then combined with the potential local acidification source map. The resulting source/response map indicated that 46% of the sites have experienced significant LRTAP acidification while a further 20% have been acidified by local/natural sources. The remaining 34% of the sites have exhibited limited acidification response indicating that they are situated in areas of low terrain sensitivity.
Contamination Hazard from Waste Disposal Sites near Receding Great Lakes Shorelines
Authors: Coakley J.P.
Published: March 2019

Of the approximately 4000 waste disposal sites in Ontario, more than 230 are located within 5 km of the shoreline of the lower Great Lakes. Sixty sites are within 1 km of the shore. Unlike the more resistant bedrock shores of the Upper Great Lakes, the shoreline between Midland (Georgian Bay) and Kingston (Lake Ontario) is composed primarily of unlithified glacial deposits, and thus is prone to significant erosion. This report presents an examination of the potential for contamination of nearshore lake waters either directly through shoreline recession at the waste site, or indirectly through the transport to the lake of leachates from the nearby sites via groundwater discharges. Recession-related hazards were identified at three sites (two on Lake Ontario and one on Lake Erie). Groundwater contamination hazards were harder to identify due to insufficient subsurface and hydrogeological information. However, 31 sites, less than 0.2 km from the shore, were identified as potentially hazardous; 19 of these were located in the northern Lake Ontario shore zone.
Fate of selected volatile organic substances in aqueous environment
Authors: Chodola Glen R. , Biswas Nihar , Bewtra Jatinder K. , St. Pierre Carl C. , Zytner Richard G.
Published: March 2019

Laboratory studies were conducted to evaluate the influence of several processes on the behaviour and fate of synthetic volatile organic chemicals in an aqueous environment. Five organic priority pollutants, benzene, methylene chloride, tetrachloroethylene, toluene and trichloroethylene, were investigated to determine their susceptibility to the transformation processes of direct photolysis and hydrolysis under various pH, temperatures and concentrations. In addition, benzene, methylene chloride, tetrachloroethylene, toluene and trichloroethylene were examined for volatilization from the water surface as well as mass flux by diffusion into water.

The experimental findings for direct photolysis indicated that the susceptibility was negligible for all the selected organic compounds. However, methylene chloride, tetrachloroethylene and trichloroethylene were found to be susceptible to hydrolysis when the aquatic environment is basic and has an elevated temperature. Benzene, methylene chloride, tetrachloroethylene, toluene and trichloroethylene exhibited relatively rapid rates of volatilization and these rates were significantly influenced by the area to volume ratio. The overall Liquid film coefficients at the water-air interface for benzene, methylene chloride, tetrachloroethylene, toluene and trichloroethylene were observed to be 0.21, 0.69, 0.64 and 0.07 m/d, respectively, under the specified conditions.

The mass flux experiments indicated that, under quiescent conditions, the mass transfer occurring at the water-chemical interfaces of submerged pools of tetrachloroethylene and methylene chloride was low, thus providing an opportunity for clean up. Benzene and toluene floated to the surface and rapidly volatilized into the atmosphere. Mathematical equations have been developed to predict mass flux of such substances under given conditions.
Evaluation de la vulnérabilité des eaux souterraines à la contamination par les pesticides. Une Application du Logiciel VULPEST dans la Région de Portneuf (Québec, Canada)
Authors: Banton O. , Lafrance P. , Villeneuve J. -P.
Published: March 2019

Dans les zones d’activités agricoles du Canada, on observe l’apparition de plus en plus fréquente de cas de contamination d’eau de puits municipaux ou privés par des pesticides. L’étude présentée dans cet article constitue une application d’une méthode d’évaluation probabiliste de la vulnérabilité des eaux souterraines réalisée au moyen de la modélisation stochastique. Le logiciel VULPEST, qui est destiné à l’évaluation prédictive de la vulnérabilité, est basé sur la simulation du transport du pesticide dans la zone non-saturée du sol. Il a été appliqué sur un site agricole du Québec présentant une contamination des eaux souterraines par le pesticide aldicarbe avec des concentrations pouvant atteindre 30 µg/L. Pour cette étude, des prélèvements de sol ont été effectués sur neuf stations réparties sur un maillage de 80 m x 80 m, afin de déterminer les caractéristiques des distributions statistiques des principaux paramètres physiques. L’application du logiciel VULPEST sur le site de Ste-Catherine, comté de Portneuf, a montré la vulnérabilité de ce site au pesticide concerné. Les résultats, qui ont été comparés aux mesures de concentration réelles, ont montré la qualité des prévisions qui auraient pûe réalisées grâce au logiciel, avant même l’application du pesticide.
Indirect Supercritical Fluid Extraction of Organics from Water Matrix Samples
Authors: Pawliszyn Janusz B. , Alexandrou Nick
Published: March 2019

Inexpensive and easy to automate instrumentation and procedures for rapid isolation of environmental pollutants from water matrix is described. In this method the organic contaminants are first adsorbed onto the solid sorbent. After the removal of moisture from the extraction vessel the supercritical fluid extraction of sorbent follows. Then the analyte is transferred directly onto the front of the gas chromatographic capillary column with the help of a piece of small I.D. fused silica capillary. The whole isolation process is controlled by a single ten-port valve. Performance of this technique is evaluated using water spiked with a mixture of polychlorinated benzenes. Full recoveries of analytes are obtained by this simple method. The total time of extraction was about 1 hour per sample. The application of this approach to the analysis of aqueous suspensions is discussed.
Isotopic and Diatom Evidence of Bacterial Sulphate Reduction in Sediments
Authors: Rao S. S. , Dickman M. D. , Thode H. G.
Published: March 2019

Sulphur contents and sulphur isotope ratios (δ34 So/00 values) in deep sediments (10–12 cms; circa 50–100 years before the present) and surface sediments (0–2 cm; circa 0–10 years before the present) from eight lakes located north of Lake Superior, Canada indicated that surface sediments had a significantly higher sulphur content (largely organic sulphur) per gram dry weight and a lower sulphur isotope ratio than the deeper layers.

The increased sulphur content and decreased sulphur isotope ratios (δ34 S0/00 values) in the surficial sediments were much greater for the lakes near and downwind from the Wawa sintering plant than for more remote lakes reflecting the impact of the sintering plant emissions on the lake environment.

A significant relationship was observed between the sulphate reducing bacterial populations and the magnitude of the isotope shift in the study lakes. It was evident from the data that the greater the abundance of sulphate reducers the greater was the surface sediment sulphate content and the degree of isotope fractionation in the anaerobic and organic rich sediments. The surface sediments of the eight study lakes revealed isotopic evidence of bacterial sulphate reduction. The deeper sediments, however, did not reveal such a condition due to the absence of sulphate reducers.

The rate of lake acidification as inferred from the downcore diatom inferred pH profile for each of the study lakes was not significantly correlated with the amount of sulphur in the lake sediments, nor was it correlated with the density of sulphate reducing bacteria or shifts in the sulphur isotope ratios (δ34S).
Use of a Chi-Squared Procedure for Comparison of Complex Gas Chromatograms
Authors: Rodger C. E. , Huck P. M. , Daignault S. A. , Williams D. T.
Published: March 2019

This paper describes the use of a statistical technique involving the chi-squared test to assist in the interpretation of broad spectrum gas chromatographic data.

The GC data were collected during the operation of a pilot plant which examined in parallel four alternative drinking water disinfectants – chloramines, chlorine, chlorine dioxide and ozone. Treatment process samples were obtained by passing water through XAD-2 resin which was then extracted and the extracts concentrated and used for GC analysis and mutagenicity testing. The pilot plant treated three seasonally distinct types of water-winter, spring thaw and spring-summer.

A large number of XAD-2 adsorbable and gas chromatographable organic compounds were present in the raw water, producing chromatograms having a large number of peaks. Oxidant addition resulted in some change in the chromatograms, but the basic fingerprint remained largely unaltered. The chi-squared technique was used to make semi-quantitative comparisons of the chromatograms over time and among the four oxidants. Chromatograms showing abnormal peak counts often corresponded to mutagenic or toxic events.
Lake Renewal Rate and Water Quality Implications
Authors: Kudelska Danuta M.
Published: March 2019

Water exchange in lakes reflects on their trophic status and has implications on water quality. However, in contrary to common belief, beneficial effects of dilution or ‘flushing’, due to high hydraulic load, should not be expected in the case of polluted tributaries. Research conducted in Poland on several hundred lakes indicated, that 80% of lakes with intensive water renewal rates, (200%/y to 21400%/y) were characterized with bad water quality. Those lakes with low, (30% or less) water renewal rate per annum mostly had good or even very good water quality. Inferior water quality of lakes having low water renewal rate was usually associated with the presence of point sources of pollution. Contribution from the tributary sources would improve the lake water quality only if reduction of the loadings to the rivers is achieved through watershed pollution control.
Reductive Dehalogenation of Environmental Contaminants: A Critical Review
Authors: Baxter R. M.
Published: March 2019

It is generally recognized that reductive processes are more important than oxidative ones in transforming, degrading and mineralizing many environmental contaminants. One process of particular importance is reductive dehalogenation, i.e., the replacement of a halogen atom (most commonly a chlorine atom) by a hydrogen atom.

A number of different mechanisms are involved in these reactions. Photochemical reactions probably play a role in some instances. Aliphatic compounds such as chloroethanes, partly aliphatic compounds such as DDT, and alicyclic compounds such as hexachlorocyclohexane are readily dechlorinated in the laboratory by reaction with reduced iron porphyrins such as hematin. Many of these are also dechlorinated by cultures of certain microorganisms, probably by the same mechanism. Such compounds, with a few exceptions, have been found to undergo reductive dechlorination in the environment.

Aromatic compounds such as halobenzenes, halophenols and halobenzoic acids appear not to react with reduced iron porphyrins. Some of these however undergo reductive dechlorination both in the environment and in the laboratory. The reaction is generally associated with methanogenic bacteria. There is evidence for the existence of a number of different dechlorinating enzymes specific for different isomers.

Recently it has been found that many components of polychlorinated biphenyls (PCBs), long considered to be virtually totally resistant to environmental degradation, may be reductively dechlorinated both in the laboratory and in nature. These findings suggest that many environmental contaminants may prove to be less persistent than was previously feared.
Developments in Legislation Related to Treatment of Petroleum Refinery Effluents: A Canadian Overview
Authors: Putnam David L.
Published: March 2019

Public concern over toxic contaminants in drinking water and the environment in general has put increasing pressure on governments to develop and enforce stringent environmental regulations. An overview of developments in Canadian federal and provincial legislation related to the regulation of petroleum refinery effluent quality is provided. Current knowledge of Canadian petroleum refinery effluent quality and level of treatment is summarized.
Current Practice for Treatment of Petroleum Refinery Wastewater and Toxics Removal
Authors: Dold P.L.
Published: March 2019

Current practice and experience in the treatment of petroleum refinery wastewater is reviewed briefly, with emphasis on the fate of toxic contaminants. The sources and composition of the wastewater are described in terms of the parameters adopted for evaluating the performance of individual treatment units. The parameters include oil and grease content and sulphide concentration for evaluating the primary treatment units: sour water stripping, API separation and dissolved air flotation (DAF). COD, BOD, suspended solids and “listed” trace contaminant concentrations are considered in the description of biological activated sludge secondary treatment. Current treatment technology achieves a significant reduction in toxic contaminants and other pollutants generated in the petroleum refining process, with the principle reduction occurring in the activated sludge system. The removal mechanisms considered in activated sludge are biological degradation, nitrification, stripping of VOC’s, biosorption, bioaccumulation of heavy metals and heavy metal precipitation. A number of potential problems associated with activated sludge treatment are identified; amongst others, high effluent COD’s, presence of toxic contaminants (at low concentrations) in the treated effluent, inhibition, poor sludge settleability, and waste sludge disposal.