bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards the Development of a Site-Specific Water Quality Objective for Atrazine in the Yamaska River, Quebec, for the Protection of Aquatic Life
Authors: Caux P.-Y. , Kent R.A.
Published: March 2019

The biological effects of xenobiotics in aquatic environments are often a function of the water quality of these systems. The aquatic green alga Selenastrum capricomutum was exposed to 11 concentrations of the herbicide atrazine in the range of 0.8 to 882 μg/L. The incubation media consisted of water collected from the Yamaska River Lac Brome (control) site in the spring and fall. Algae incubated in fall water displayed a significant increase in the intensity of fluorescence as compared to those incubated in spring water. This effect (Kautsky effect) was observed for six intermediate atrazine concentrations which are representative of those found in the field. In situ investigations were also performed on the water quality of four Yamaska River sites to measure both biotic and abiotic (physicochemical) parameters. Of the 35 water quality parameters analyzed, 32 differed significantly spatio-temporally. Of these, only atrazine levels (max. 40 μg/L) exceeded national water quality guidelines for the protection of aquatic life (2 μg/L). Two Yamaska tributaries experienced a reduction in populations of chlorophytic algae immediately following the atrazine application period in early June. These investigations show that herbicide spring “pulse” in river systems may alter the normal succession of phytoplankton communities. Local environmental biotic and abiotic variables likely affect the toxicity of atrazine in the Yamaska River. These results provide the initial basis towards the establishment of a site-specific objective for atrazine in this river basin.
Polychlorinated Biphenyl Congeners and Chlorinated Pesticides in Fish from the Yamaska River Basin, Quebec
Authors: Metcalfe-Smith Janice L. , Maguire R. James , Batchelor Suzanne P.
Published: March 2019

Bottom-feeding fish from the Yamaska River in Quebec and its major tributary, the Noire River (5 female specimens from each site), were analyzed for residues of organochlorine pesticides and PCB congeners in liver, spleen, gonad, kidney, gall bladder, visceral fat and dorsal muscle. Significant quantities of target chemicals were found in the basic extracts as well as the acidic extracts of these fish tissues, suggesting that acidic digestion followed by saponification and extraction with an organic solvent may provide a more complete recovery of organic contaminants residues from biological tissues than conventional techniques. Residues were highest and least variable in fat, therefore this tissue was used to compare patterns of contamination between sites. Fish from the Noire River contained 6X as much ZDDT and 3X as much ZPCBs in their fat than fish from the Yamaska River (2800 versus 440 ng/g and 1700 versus 500 ng/g wet weight, respectively), but no differences between sites were observed for dieldrin, lindane or heptachlor epoxide. Noire River fish exhibited a less degraded pattern of PCB contamination, with proportionately more penta- (15% versus 4%) and less hexa- and heptachlorobiphenyls (70% versus 81%) plus nine more congeners in their fat. They also contained a higher proportion of the toxic congeners (28% versus 17%), had lower lipid contents and were in poorer condition. Thus, further investigation of the sources and effects of persistent organic contaminants in the Noire River basin may be warranted.
Application of Sulfate-Reducing and Sulfide-Oxidizing Bacterial Symbiosis for Wastewater Treatment
Authors: Tare V. , Sabumon P.C.
Published: March 2019

This investigation attempted to advance the state of the art of the process which utilizes the symbiotic relationship between the sulfate-reducing bacteria (SRB) and sulfide oxidizing bacteria (SOB) for degradation of organic matter present in wastewater. Major emphasis has been on the development of the desired microbial system without any external seed and comparative evaluation of the two types of multistage reversing flow bioreactor (MRB) systems. Biological vessels (BVs) in the MRB systems simulate conditions which correspond to configurations described as upflow sludge blanket and stationary fixed film. Two bench-scale models – one designed to achieve self granulation of sludge (SGS), and the second designed to promote growth of SRB/SOB on additional nonreactive surface – were set up and operated over a period of 4 months. Domestic wastewater supplemented with organic matter from sugar cane molasses was used as feed to develop the desired microbial population. Several visual and microscopic observations confirmed the presence of a significant number of SRB and SOB in all the biological vessels. Results indicated that it is possible to develop SGS and a microbial population of SRB and SOB which could attach to the nonreactive surface without any external seeding. Domestic wastewater could serve as a source of these organisms. Immobilized growth conditions and suspended growth conditions in BVs yield similar results in terms of organic matter utilization. The empirical formula for MRB biomass can be expressed as C11O12H36N5S.
Relationship between the Activated Carbon Surface Area and Adsorption Model Coefficients for Removal of Phenol from Water
Authors: Samaras Peter , Diamadopoulos Evan , Sakellaropoulos George P.
Published: March 2019

The present study investigated the relationship between the activated carbon surface area, as measured by the BET nitrogen adsorption method, and its adsorptive capacity. Aqueous solutions of phenol at pH 7 were used. The activated carbons were produced in the laboratory from raw and demineralized lignite. Adsorption experiments took place under equilibrium or kinetic conditions and the results were simulated by mathematical modelling. Freundlich and Langmuir models were used to describe equilibrium, while the Peel-Benedek non-equilibrium model was applied for the kinetic study. The results showed that for activated carbons produced from different starting materials, the adsorptive capacities could not be solely explained by their BET surface area. While laboratory-made activated carbons with a surface area of 300 m2/g demonstrated similar capacities under equilibrium, their kinetic behaviour was different. Activated carbon produced from raw lignite showed faster kinetics, due to wider porosity, which was facilitated by the mineral matter during activation. These results were in agreement with the mass transfer coefficients in macropores and micropores estimated by the Peel-Benedek model. Comparison of a laboratory-made activated carbon, with a surface area of 500m2/g, with a commercial activated carbon having twice the surface area showed that the maximum adsorptive capacity under equilibrium of the commercial carbon was only 35% higher than that of the lab-made carbon. Yet, the mass transfer coefficients of the commercial carbon were one to two orders of magnitude higher than those of the laboratory-produced carbon. Finally, the use of the qualitative D-R plots has been suggested to elucidate the porous structure of the activated carbons.
Sodium Hypochlorite: its Application and Stability in Bleaching
Authors: Bommaraju Tilak V.
Published: March 2019

One of the end uses of chlorine and sodium hydroxide, both produced by the electrolysis of aqueous sodium chloride, is in the manufacture of sodium hypochlorite, commonly called liquid “bleach.” This article outlines the methods of manufacturing liquid bleach, including the factors involved in the selection of materials of construction for handling chlorine, sodium hydroxide and sodium hypochlorite. Experimental results were presented addressing the stability of sodium hypochlorite as influenced by temperature and pH, and by anionic impurities such as Cl−, ClO3−, CO3− and SO4−, and cationic impurities which include Ca++, Mg++, Cu++, Ni++ and Fe++. Various techniques were also outlined to minimize the formation of chlorates during storage and bleaching and to improve the quality and stability of sodium hypochlorite.
Investigation of Pesticides in Groundwater at Three Irrigated Sites near Outlook, Saskatchewan
Authors: McNaughton D.C. , Crowe A.S.
Published: March 2019

During 1987 and 1988, the pesticides 2,4-D, diclofop-methyl, dicamba, MCPA, triallate and bromoxynil were detected in shallow groundwaters beneath three irrigated research sites in the Outlook Irrigation District of Saskatchewan. All of the pesticide detections were below the limits set by the Canadian Drinking Water Quality Guidelines. Meteorological and hydrogeological conditions are generally not conducive to pesticide leaching to the water table in this region. However, it is suspected that the pesticides applied at the surface were able to migrate to the water table through the numerous vertical fractures that exist in the tills and silts underlying the fields. When combined with irrigation that is applied at these sites, these two factors create a mechanism for the rapid movement of pesticide to a greater depth of leaching than would occur in unfractured soils and with typical precipitation. Further, it is suspected that storage of pesticide in the soil matrix and subsequent desorption during later intense recharge or irrigation events is responsible for observed pesticide detections weeks or months after a pesticide was applied.
Strategy for Phosphorus Control from Estimated Phosphorus Loads and Predicted Total Phosphorus Concentration in Penetang Bay, Georgian Bay, 1973 to 1992
Authors: Sherman R. Keith , Brown Sharon L.
Published: March 2019

Cultural eutrophication has affected Penetang Bay, in southeastern Georgian Bay, since the 1960s. External sources of phosphorus were estimated and open water total phosphorus concentration was predicted in order to establish a rationale for an effective source control strategy for the bay. Seasonal loadings are greatest in the spring due mainly to the watershed sources, with 33-58% of the total annual load entering during the March to May period. Apart from this period, the two sewage plant effluent discharges are the largest sources of phosphorus loading to the bay. On an annual basis, the largest source of phosphorus to the bay is from treated sewage effluent (60%), followed by watershed, shoreline development and urban storm water, respectively. More than 80% of the estimated total annual loads was from sewage effluent, watershed and urban storm sources alone. These sources were estimated annually for the historical period of record (1973-1992). The trophic model predicted the long-term average total phosphorus concentration ([TP]) reasonably well. Predictions of [TP]Bay for individual years were within 1-49% of the measured [TP]Bay. The model predicted [TP]Bay to within 20% of measured values for 14 of the 20 years of record. The model as applied to Penetang Bay is sensitive to changes in sewage plant effluent loading and watershed loading. Model predictions indicate that significant reductions in open water [TP] can be expected following implementation of proposed source control actions. Total loading of phosphorus to the Bay of less than 1,000 kg/year should result in open water [TP]Bay of less than 15 µg/L.
Severn Sound Sediment Chemistry and Bioassessment, 1988–1990
Authors: Krantzberg G. , Sherman R.K.
Published: March 2019

Fine-grained sediment in the embayments of Severn Sound contains metals that exceed the Ontario Ministry of the Environment's lowest effect level, the level at which some disturbance of the sediment dwelling community can be expected. Sediment in Penetang Bay has concentrations of Cr that are above the provincial Severe Effect Level, the level at which a compound is expected to be detrimental to the majority of benthic species. Nevertheless, chronic sediment bioassays resulted in little measurable sublethal toxicity. Based on evidence from weak acid extraction of metals from sediment, the lack of toxicity may be due to the limited bioavailability of metals.

The potential for metals to enter the food web was suggested by metal bioaccumulation observed for test species. Chromium and Ni concentrations in mayflies were significantly correlated with total Cr and Ni in sediment, and Zn and Cu tissue concentrations were not correlated with total metals in sediment. In general, the bioaccumulation of Cd, Cr, Cu, Ni and Pb by test species was more strongly correlated with extractable metals and with metals in the <63 µm size fraction than with total metals in bulk sediment, demonstrating that the total sediment pool of metals was not biologically available.

Remedial actions for sediment in Severn Sound should focus on source control and natural sediment recovery, given the lack of sublethal chronic toxicity. Confirmation that active sources are not present and an ability to predict the natural recovery period for marginally contaminated regions would assist in fully restoring the sound.
Theoretical Study on Two-Stage Anaerobic-Aerobic Biological Treatment of a CTMP Effluent
Authors: Liu H.W. , Lo S.N. , Lavallée H.C.
Published: March 2019

Basic equations based upon the Monod kinetic model are presented for a two-stage, sequential anaerobic-aerobic treatment system. The effects of operating conditions, such as hydraulic retention time, mean cell age, concentration of microorganisms and initial substrate concentration, on the behaviour of the two-stage system for the treatment of a CTMP effluent were studied theoretically. This was done in terms of removal of BOD5 and RFA, and sensitivity to changes in operating conditions. The study revealed that unstable operation of the anaerobic process could be due to the treatment being carried out in a time range in which the operation was very sensitive to the variation in either hydraulic retention time or mean cell age.
Theoretical Study on Two-Stage Anaerobic-Aerobic Biological Treatment of a CTMP Effluent: Part 2: Optimization of Treatment System
Authors: Liu H.W. , Lo S.N. , Lavallée H.C.
Published: March 2019

A general method based upon the Monod kinetic model for optimizing the two-stage sequential anaerobic-aerobic treatment system was established. Using this method, the total treatment time required for a fixed overall treatment efficiency for a CTMP effluent was minimized with respect to the substrate removal in the anaerobic stage, and the corresponding optimal reactor volume ratio between the two stages was determined. The effects of the principal operating conditions (concentration of microorganisms and initial substrate concentration) on the minimum total treatment time and the optimal reactor volume ratio required for the two-stage treatment of the CTMP effluent were demonstrated. Procedures in consideration of both BOD5 and RFA removals for optimizing the two-stage treatment of the CTMP effluent are presented.
Major and Trace Element Content of Shallow Groundwater Associated with Dryland Saline Soils in Southern Alberta
Authors: Miller J.J. , Read B.J. , Wentz D.J. , Heaney D.J.
Published: March 2019

A survey of shallow groundwaters associated with 72 dryland saline sites in southern Alberta was conducted from 1990 to 1992 to determine the major and trace element concentrations in relation to the Canadian drinking and livestock water quality guidelines. The recommended limits for drinking water were exceeded at more than half the sites for total dissolved solids (100%), SO4-S (90%), Se (86%) and Mn (74%), at less than half the sites for As (48%), Fe (40%), Cd (39%), Pb (26%), Cl (22%), NO3-N (11%), B (1%) and Zn (1%), and at none of the sites for Cu. The recommended limits for livestock water were exceeded at more than half the sites for Se (86%), SO4-S (83%) and total dissolved solids (76%), at less than half the sites for As (43% when added and 2% when not added to feed), Pb (24%), Cd (18%), NO3-N (1%) and B (1%), and at none of the sites for Ca, Co, Cu, Mo and Zn. Topographic position, sampling year and cropping practice upslope and in the saline area had a significant (P<0.05) effect on the concentrations of certain elements. We recommend that shallow groundwater near saline areas be tested before it is consumed by humans or livestock.
Valorisation des eaux de drainage minier acide pour la déphosphatation des eaux usées municipales
Authors: Bouchard C. , Sérodes J.-B. , Gélinas P.
Published: March 2019

Les résultats d’une étude expérimentale de valorisation directe d’une eau de drainage minier acide comme agent de déphosphatation d’une eau usée municipale sont présentés dans cet article. Il ressort qu’une concentration égale à deux fois et demi la dose stoechiométrique en eau de drainage minier acide serait requise pour la déphosphatation d’une eau usée municipale partiellement traitée ce qui représente une dose légèrement supérieure à la dose requise en alun. Les concentrations en métaux lourds des eaux déphosphatées ainsi que celles des boues sont, dans la majeure partie des cas, en deça des normes et recommandations en vigueur ce qui indique, a priori, la faisabilité de cette valorisation. L’étude montre que le pH de l’effluent municipal ne serait pas significativement affecté par ce type de déphosphatation. Le développement d’un procédé de concentration de ce type d’effluent minier constitue la prochaine étape dans ce projet de valorisation.
Potential Contribution of Nutrients and Polycyclic Aromatic Hydrocarbons from the Creeks of Cootes Paradise Marsh
Authors: Chow-Fraser Patricia , Crosbie Barb , Bryant Douglas , McCarry Brian
Published: March 2019

During the summer of 1994, we compared the physical and nutrient characteristics of the three main tributaries of Cootes Paradise: Spencer, Chedoke and Borer’s creeks. On all sampling occasions, concentrations of CHL α and nutrients were always lowest in Borer’s Creek and highest in Chedoke Creek. There were generally 10-fold higher CHL α concentrations and 2 to 10 times higher levels of nitrogen and phosphorus in Chedoke Creek compared with Spencer Creek. Despite this, the light environment did not differ significantly between Spencer and Chedoke creeks because the low algal biomass in Spencer Creek was balanced by a relatively high loading of inorganic sediments from the watershed. Laboratory experiments indicated that sediments from Chedoke Creek released up to 10 µg/g of soluble phosphorus per gram (dry weight) of sediment, compared with only 2 µg/g from Spencer Creek. By contrast, sediment samples from Spencer Creek contained levels of polycyclic aromatic hydrocarbon that were as high as or higher than those from Chedoke Creek, and much higher than those found in Borer’s Creek. The distribution of normalized PAH concentrations suggests a common source of PAHs in all three tributaries, most likely automobile exhaust, since there were high concentrations of fluoranthene and pyrene, both of which are derivatives of engine combustion.
Zonation of Contaminated Bottom Sediments in Hamilton Harbour as Defined by Statistical Classification Techniques
Authors: Poulton Donald J. , Morris William A. , Coakley John P.
Published: March 2019

Hamilton Harbour, a 2,150-ha embayment at the western end of Lake Ontario, is the receiving water for a number of industrial and municipal effluents. Their accumulation over the past decades has resulted in a seriously degraded aquatic environment that is now being subjected to remedial actions. Chemical determinations of total and weak acid-extractable metals were carried out on 40 sediment samples from the harbour. These data were subjected to two multivariate statistical techniques to assess their ability to discriminate samples that could be associated with common sources or transport processes. The techniques used were ratio matching followed by cluster analysis and principal component analysis. The cluster analysis technique resolved six groups related to contaminant sources, sandy, relatively clean nearshore areas and a large contaminated central area. The principal components technique supported this by showing factors related to the large central area as a result of sediment focusing, plus a factor related to contaminant source input and one related to input of silt-sized particles rich in Ca and Sr. Two “outlier” samples were noted, one related to a heavily contaminated area near the steel industries and one consisting of virtually pure sand at the northeastern corner of the harbour.
Chemical Equilibrium Data Bases and Tools for Calculating Zinc Sulfide Geochemistry in Freshwater Sediments and its Toxicity
Authors: McMahon J.A. , Snodgrass W.J.
Published: March 2019

This paper evaluates chemical modelling tools, thermodynamic equilibrium data, and field data appropriate for estimating the concentration of zinc and other relevant metals in freshwater sediments. To identify the expected primary zinc species, a literature search was completed which summarized the available knowledge. Within the available literature, the largest variability was found in the metal sulfide system. A critical review of the data, together with application of a consistent procedure for incorporating primary sulfide constants in a thermodynamic data base, was used to reduce the variation in the reported values for the solubility and complexation constants. The primary soluble forms of zinc, iron and lead for two field sites impacted by zinc discharges (Hamilton Harbour impacted by steel mill and treated urban wastewater discharges and a base metal mine impacted site) were ZnOHHS0, Fe2+ and Pb(HS)3, respectively. Implications of this work for the evaluation of aquatic toxicity in aquatic sediments are also presented. The chemical equilibrium model used in this study—solid phase speciation measurements—and a sediment phase mass balance model can form the basis for determining the toxicity status of a system due to zinc contamination.
Burlington Bay, Lake Ontario: Its Paleolimnology Based on Fossil Ostracodes
Authors: Delorme L. Denis
Published: March 2019

The history of Burlington Bay for the last 8,400 years has recorded two significant changes in its environment. The first occurred about 2,540 years ago, resulting from a change in mean annual temperature. This, in turn, changed the chemistry of the bay water. The second change occurred about 125 years ago (ca. 1865 A.D.). This time, it was the impact of agricultural practices and industrialization. Agricultural practices caused the lake to become eutrophic. This rapidly (within 40 years) changed the bottom water oxygen conditions to anaerobic. Industrialization had an impact on the fauna and the flora. Some fauna became locally extinct while some phytoplankton became deformed.
Risk Assessment of Copper-Contaminated Sediments in the Tsolum River Near Courtenay, British Columbia
Authors: Deniseger John , Kwong Y.T. John
Published: March 2019

Acidic drainage originating from an abandoned copper mine on Mt. Washington has given rise to elevated dissolved copper concentrations that may threaten aquatic life throughout most of the Tsolum River watershed on central Vancouver Island. Only sediments in the upper portion of the watershed near the mine site, however, have tested acutely toxic to the amphipod Hyalella azteca. Despite evidence of mechanical transport of copper up to 18 km down-stream from the mine site, the sediment-bound copper in the lower watershed appear to be highly stable such that the copper-rich sediments are unlikely to become a secondary source of dissolved copper. In addition to copper attenuation through dilution, extensive wetland areas in the lower watershed contribute significant amounts of dissolved organic carbon that form stable complexes with copper and ameliorate the toxic effects of dissolved copper. These observations imply that successful reclamation at the mine site is probably sufficient to assure acceptable water quality farther downstream.
Minimizing Combined Sewer Overflows in Real-Time Control Applications
Authors: Pleau Martin , Methot François , Lebrun Andrée Moïra , Colas Hubert
Published: March 2019

An approach to design and operate real-time control system for combined sewer overflows is proposed. The methodology is based on nonlinear programming with the peculiarity that all the constraints are linear. The problem definition guarantees a non-null optimization space while preserving the physical and dynamical constraints of the state variables. The nonlinear cost function allows standard control objectives to be met and simulation of the behavior associated with storage facilities and actuators. The linear flow dynamic constraints are defined to simulate flow attenuation as well as to reject unknown disturbances.
Fluorides in Wastewater Discharges: Toxic Challenges to the St. Lawrence River Biological Community
Authors: Wallis Peggy , Gehr Ronald , Anderson Perry
Published: March 2019

This literature review examines the risk to fluvial organisms of fluoride released to the St. Lawrence River by the Montréal Urban Community waste-water treatment plant. The following key points are presented regarding the behaviour of fluoride in aquatic systems: fluoride is not removed by primary sewage treatment methods; fluoride from the treatment plant is rapidly diluted to background levels; aquatic plants do not accumulate significant levels of fluoride; fluoride is generally sequestered in the shell/exoskeleton/skeleton and skin of animals and released via the urinary system; fluoride ion is not very toxic in aquatic systems; there is rarely a large difference between acute and chronic (or lethal and sublethal) threshold levels of fluoride in aquatic systems; the most sensitive aquatic organisms are trout and fingernail clams; finally, the only significant evidence of synergistic action is with aluminium. It is concluded that fluoridation of the city of Montréal’s drinking water would not pose any significant additional risk to the biological community in the receiving waters of the St. Lawrence River.
Extending Retention Times in a Stormwater Pond with Retrofitted Baffles
Authors: MATTHEWS R.R. , Watt W.E. , Marsalek J. , Anderson B.C. , Crowder A.A.
Published: March 2019

Dye-tracing experiments performed in a stormwater pond in Kingston Township, Ontario revealed low average retention times, mainly due to the small size of the pond. However, simulations of the pond flow regime using a numerical model indicated irregular circulation patterns, resulting in short-circuiting and dead zones in the pond. Installation of baffles as a retrofitting measure increased the length-to-width ratio of the flow path in the pond from 1.5:1 to 4.5:1 and corrected the observed flow regime problems. Results of dye-tracing studies performed after the retrofit demonstrated an increase in retention times with a reduction in the speed and volume of short-circuiting flow, and a decrease in wind generated flow patterns due to the installation of the baffles. In addition, an increase in the hydraulic efficiency of the pond (defined as the ratio of measured to volumetric retention times) from 0.65 to 0.86 has been observed. An increase in pollutant removal through sedimentation processes has been inferred from a comparison of retention time distributions measured before and after baffle installation.
Modelling, Design and Optimization of a Combined Sewer Overflow Treatment System
Authors: Gall B. , Averill D. , Weatherbe D.
Published: March 2019

A process modelling and simulation program is being developed as part of a pilot-scale study of satellite treatment options for the control of combined sewer overflows (CSOs). The initial objectives are (1) the development of mathematical models for satellite wastewater treatment processes; (2) the implementation of these models in a computer simulator; and 3) the application of these models to provide a preliminary design of a full-scale CSO treatment facility that will satisfy the local regulatory agency. Results to date show that the models and simulation algorithms constitute a useful planning level tool for investigating CSO control options. The results also indicate the direction of further model development work.
Real-Time Control of Combined Sewer Overflows in Hamilton-Wentworth Region
Authors: Stirrup M. , Vitasovic Z. , Strand E.
Published: March 2019

The Regional Municipality of Hamilton-Wentworth operates and maintains a large combined sewer system in the Great Lakes basin. During dry weather and small storm events, two large interceptor sewers convey all sanitary and storm flows to the Woodward Avenue wastewater treatment plant. Larger rainfall events, specifically high intensity summer thunderstorms, generate flows which exceed the design capacity of the sanitary interceptors and result in combined sewer overflows to Hamilton Harbour and Cootes Paradise, which ultimately discharge to Lake Ontario. The Region is implementing a comprehensive program for reducing the pollution caused by these overflows. This program includes the construction of several off-line detention storage facilities and the implementation of a real-time control system for combined sewer overflow reduction. Real-time control will enable maximum utilization of the storage available within the combined sewer network and help reduce the frequency and volume of combined sewer overflows. New hydrologic and hydraulic simulation models have been specially developed for this project to help identify, test and implement optimal real-time control strategies. This paper discusses some of the more important aspects related to the design and implementation of the Region’s real-time control system, and focuses mainly on the development of these hydrologic and hydraulic simulation models.
Systemic Barriers to the Restoration of Aquatic Ecosystems
Authors: Ellsworth J.
Published: March 2019

An ecosystem perspective is interdisciplinary and holistic, recognizing the interconnections among ecosystem components. The ecosystem approach incorporates social, economic and environmental elements into its definition (Environment Canada 1995). In instances where ecosystem initiatives fail to generate the body of public and political support necessary to address complex issues, barriers can often be found in the ecosystem initiatives themselves. Systemic barriers to the restoration of aquatic ecosystems are generated by the reluctance of some initiatives to go beyond pure sciences and an inability to integrate social, economic and environmental interests. It is common practice to allow the issues at hand to define the scale of an ecosystem initiative. Experience has shown that the issues at hand can also define the appropriate level of engagement. This paper explores Level 3: Community-Based Ecosystem Initiatives and the qualities that enable Level 3 initiatives to avoid and overcome systemic barriers to the restoration of aquatic ecosystems.
The Sewage Issue in Hamilton Harbour: Implications of Population Growth for the Remedial Action Plan
Authors: Charlton Murray N.
Published: March 2019

Much work remains to be done in the implementation and restoration of the beneficial-use phase of the Great Lakes Remedial Action Plans. As plans were being made to reduce nutrient loads at many Areas of Concern, other plans to accommodate population growth were occurring. Population growth has the potential to slow or reverse progress in eutrophication control. A recent proposal to expand one of the local sewage plants without enhancing the treatment level caused a review of Remedial Action Plan goals and water quality responses in Hamilton Harbour. Data on Hamilton Harbour show that phosphorus in the water responds well to load reductions. Moreover, the response of water quality indicators, chlorophyll and Secchi transparency is consistent with expectations of the Organization for Economic Cooperation and Development worldwide relationships. Thus, there is little doubt that proposed expansion of the sewage treatment plant would harm the harbour or that the Remedial Action Plan goals can be achieved by nutrient load reductions. A new proposal to discharge the treated sewage into Lake Ontario instead of the harbour is discussed.
Sediment Resuspension and Dissolved Oxygen Levels Associated with Ship Traffic: Implications for Habitat Remediation
Authors: Irvine K.N. , Droppo I.G. , Murphy T.P. , Lawson A.
Published: March 2019

Many of the Great Lakes Areas of Concern include harbours and navigable channels that experience disturbance of bed sediment due to the passage of large ships. Sediment resuspension due to ship passage may impact efforts to restore habitat and remediate contaminated bed sediment through in situ treatment. To examine the impacts of ship passage, water column profiles of temperature, pH, turbidity and dissolved oxygen, as well as suspended sediment samples, were taken at varying distances behind ships entering an industrial slip area of the Hamilton Harbour Area of Concern during the summer of 1995. Weekly water column profiles and suspended sediment samples also were collected at three sites in the slip area and a harbour control site to characterize ambient water quality. Ship passage significantly increased turbidity above ambient levels due to sediment resuspension, although the increase was less in the deeper areas of the slip. Levels of turbidity and suspended sediment concentration associated with ship passage exceeded that recommended for a moderate level of fish habitat protection. In association with the increased turbidity, levels of dissolved oxygen declined and often were less than 5 and 6.5 mg L-1, the Canadian Water Quality Guideline for later life stage warm and cold water fisheries, respectively. Based on the sample data and in situ flume experiments, the estimated depth of bed erosion due to a ship passage ranged from 1 to 8 mm. The impacts of sediment disturbance due to a ship passage should be considered when selecting and designing appropriate sites and technologies for remediation.
Hydrogeochemistry of Toxic Elements in Urbanized Geotechnical Systems
Authors: Volkov S.N.
Published: March 2019

In urbanized geotechnical systems (UGSs), the majority of problems related to the ecological hydrochemistry of Cd, Pb, Ni and other heavy metals are the result of emergent characteristics of a system as a whole as opposed to individual pollution sources. In petrochemical UGSs, pollution of the environment from compounds containing methylating or alkylating agents results in an increase in the mobility of Cd, Pb, Ni, Cr and As. This process is controlled by environmental and microclimatic factors rather than by pollution sources. Under conditions of predominant dust and element effects, geo-chemically paradoxical associations of Cd with Ni, Mn and Cr can be formed in the main life support media in mining and metallurgical UGSs. Uncontrolled processes of hydrochemical interactions take place in complex multifunctional UGSs, leading to a change in speciation of heavy metals, particularly cadmium. This report is part of a 5-year study of the geotechnical systems in the Urals.
Manganese Greensand for Removal of Arsenic in Drinking Water
Authors: Subramanian K.S. , Viraraghavan T. , Phommavong T. , Tanjore S.
Published: March 2019

The present study was initiated to identify treatment techniques suitable for the removal of As from small community groundwater supplies below the current interim maximum acceptable (IMAC) concentration of 25 µg/L prescribed in the Guidelines for Canadian Drinking Water Quality. The effectiveness of manganese greensand filtration (MGSF), including the effect of Fe(II) in the influent, was studied in batch (intermittent) and column (continuous) modes. Batch studies based on the Freundlich adsorption isotherm model showed that the percent removal efficiency of arsenic by MGSF to the IMAC value was 60 for 24-h equilibration. Column studies gave an overall percent removal efficiency of 41. However, in the presence of Fe(II), especially at an Fe/As concentration ratio of 20, manganese greensand gave an overall efficiency of 83% and a throughput volume of 1,440 L. Results showed that at a Fe/As ratio of at least 20 and in the presence of Fe(II), manganese greensand is capable of removing As to below the IMAC value, under continuous mode of operation and when the influent As concentration is <200 µg/L.
Created and Restored Marshes in the Lower Fraser River, British Columbia: Summary of their Functioning as Fish Habitat
Authors: Levings CD. , Nishimura D.J.H.
Published: March 2019

Ecological comparisons of transplanted, natural (reference) and disrupted (unvegetated) marsh sites on the Fraser River estuary, British Columbia, were conducted between 1991 and 1994. The study examined vegetative biomass and cover, invertebrate abundance, fish abundance, fish residency, fish food, and submergence time for the three habitats. Standing crop biomass at three transplant sites was within the range of values for reference sites, but was much lower at an unstable site where sediment slumping had occurred. The percent cover of Lyngbyei's sedge (Carex lyngbyei) in eight transplant sites was 0.05) was observed among marsh sites when chum salmon (Oncorhynchus keta) and chinook salmon (O. tschawytscha) fry abundance were compared. However, chinook and sockeye smolt catches were significantly different (p>0.05) was observed among marsh sites when chum salmon (Oncorhynchus keta) and chinook salmon (O. tschawytscha) fry abundance were compared. However, chinook and sockeye smolt catches were significantly different (p<0.05) among marsh sites and were usually higher at disrupted sites. In nine sites in the North Arm and Deas Slough area chum fry residency was examined. At one transplant site (DEI) marked chum fry were caught up to 48 h after release. No fry were caught 1 h after release at a transplant site (Dll) and a disrupted site (DE4). At the remaining sites, fry were caught up to 1 and 3 h after release. At all sites, over 80% of the total number of food organisms examined in chum fry stomachs were harpacticoid copepods. Mean submergence time for reference marshes ranged from 33.2 to 50.7%, but for transplanted sites the value ranged from 26.4 to 60.1%. Our study shows that numerous factors need to be examined in determining if restored marshes will function as natural habitats. The development of a standardized set of reference criteria would assist in evaluating whether or not transplanted marshes are functioning as designed.
Uptake and Bioconcentration of 2,2′,4,4′,5,5′-Hexachlorobiphenyl by Lotic Periphyton
Authors: Sallenave R.M. , Day K.E.
Published: March 2019

Laboratory experiments were conducted to examine the uptake and bioconcentration of 2,2′,4,4′,5,5′-hexachlorobiphenyl (HCBP), a model hydrophobic organic compound, in lotic periphyton. The instantaneous rate of uptake and bioconcentration factor (BCF) were determined by following the time course of uptake of 14C-HCBP in periphytic communities established on glass slides. The rate of accumulation was highest in the first 3 hours, and steady state was reached within 8 days. The bioconcentration factor on a dry weight basis (BCFd) averaged 21,000. The results of a depuration experiment indicated that HCBP desorbed from periphyton, but at a much slower rate than its adsorption. The results support the hypothesis that the mechanism of uptake of HCBP in periphyton is a rapid surface sorption followed by a much slower transfer into lipids, and that sorption is largely dependent on the surface area available. The results of this study suggest that lotic periphyton provide a large surface area for adsorption and uptake of persistent hydrophobic compounds such as HCBP and, depending on the extent of grazing pressure, could greatly influence the fate and transport of these compounds in lotic systems.
CTMP Wastewater Treatment Using a Rotating Biological Contactor
Authors: Mathys R.G. , Branion R.M.R. , LO K.V. , Anderson K.B. , Leyen P. , Louie D.
Published: March 2019

Studies on the treatment of CTMP mill wastewater were done using a laboratory-scale rotating biological contactor (RBC). Analysis of the wastewater is given. The effects of organic loading rates in the range 0.007 to 0.033 kg BOD m-2 day1 (0.012 to 0.055 kg COD m-2 day-1) and temperature (20 and 31°C) on the percent removal of BOD and COD are presented. Average BOD (COD) removals ranged from 70% (46%) at 20°C to 86% (72%) at 31°C. The acetic acid content of the wastewater was almost completely biologically oxidized in the RBC and very little acetic acid volatilization was observed. Sulfite and sulfide compounds tended to be oxidized to sulfate compounds during the RBC treatment. Over the range of dissolved oxygen (DO) concentrations (0.3 to 2.0 mg/L) measured in the RBC trough, DO appeared to have no effect on BOD removal, even though some of these DO levels were very low. The discs carried wet microbial biofilms of the order of 0.5 kg m-2. Biomass sloughed off the discs at a rate that was approximately 0.04 kg m-2 day-1.
The Effect of Ambient Concentrations of Chlorate on Survival of Freshwater Aquatic Invertebrates
Authors: Dosdall L.M. , Goodwin L.R. , Casey R.J. , Noton L.
Published: March 2019

Chlorate (ClO3-) is present in some pulp and paper mill wastewater as a byproduct of the use of chlorine dioxide in the bleaching processes. Chlorate is harmful to some species of algae and consequently research was undertaken to determine its impact on survival of freshwater aquatic invertebrates. Five species representing four orders of Insecta (Plecoptera: Isoperla transmarina (Newman); Ephemeroptera: Baetis tricaudatus Dodds and Tricorythodes minutus Traver; Hemiptera: Dasycorixa hybrida (Hungerford); and Coleoptera: Haliplus sp.) were exposed to 5.0, 50.0 and 100.0 mg L-1 chlorate for 10 days. The plecopteran Isoperla longiseta Banks was exposed to 0.5, 5.0 and 50.0 mg L-1 chlorate for 10 days. Survival of specimens exposed to chlorate did not differ significantly from that of the controls. The LC50 for Daphnia magna Straus, determined using the 48 h acute lethality test, was estimated at 3,162 mg L-1. Chlorate levels from a bleached kraft pulp mill in northwestern Alberta that employs 100% chlorine dioxide substitution in its bleaching process ranged from nondetectable. (<0.002 mg L-1) to approximately 75 mg L-1 in effluent at the point of entry to the river system. At 25 and 127 km downstream from the mill, highest levels of chlorate in water samples were 3.25 and 1.00 mg L-1, respectively. Comparisons of laboratory results with field measurements suggest that chlorate discharges from this pulp mill would have no adverse effect on the survival of the aquatic insect species evaluated here.
Occurrence of Alkylphenoxyacetic Acids in Canadian Sewage Treatment Plant Effluents
Authors: Lee Hing-Biu , Weng Jianhua , Peart Thomas E. , Maguire R. James
Published: March 2019

Alkylphenoxyacetic acids such as 4-tert-octylphenoxyacetic acid (OP1EC) and nonylphenoxyacetic acid (NF1EC) are metabolites of non-ionic surfactants derived from the ethoxylation of 4-tert-octylphenol (OP) and nonylphenol (NP). Although the occurrence of OP1EC and NP1EC was suspected in many Canadian sewage treatment plant effluents due to the extensive use of the alkylphenol ethoxylate surfactants and their degradation under sewage treatment conditions, the acids have never been reported due to the lack of authentic standards. In this work, OP1EC and NP1EC were synthesized by the condensation of OP and NP, respectively, with chloroacetic acid in the presence of a base. With these standards, the occurrence of OP1EC and NP1EC in Canadian sewage treatment plant effluents was confirmed for the first time. The level of OP1EC ranged from 0.18 to 1.2 μg/L and from 0.45 to 6.8 μg/L, in the primary and final effluents, respectively. In contrast, the level of NP1EC in the same sample was much higher and it ranged from 2.4 to 17.7 μg/L in the primary effluents and from 3.2 to 703 μg/L in the final effluents.
Groundwater Contamination by Chlorinated Hydrocarbon Impurities Present in Soil Fumigant Formulations
Authors: Zebarth B.J. , Szeto S.Y. , Hii B. , Liebscher H. , Grove G.
Published: March 2019

Groundwater contamination of the Abbotsford aquifer by 1,2-dichloropropane (1,2-DCP) was reported previously. The purpose of the present study is to quantify groundwater contamination by other chlorinated hydrocarbon compounds which are present in fumigant formulations containing 1,2-DCP. Widespread contamination of 1,2,2-trichloropropane (1,2,2-TCP) was measured consistent with a non-point source. 1,2,2-TCP concentration generally decreased with depth suggesting a surface source. Localized contamination by 1,2,3-trichloro-propane, 2,3-dichloropropene and 1,3-dichloropropane was detected. Detection of these compounds was associated with higher concentrations of 1,2-DCP suggesting contamination by these compounds may have been from the same fumigant sources. The lack of a decrease in the concentration of most of these compounds over time suggests that the measured contamination will persist for some time. The results highlight the potential for persistent trace impurities in chlorinated fumigant formulations to contaminate groundwater in vulnerable aquifers.
Toxicity of Tributyltin to Four Species of Freshwater Benthic Invertebrates Using Spiked Sediment Bioassays
Authors: Day Kristin E. , Maguire R. James , Milani Danielle , Batchelor Suzanne P.
Published: March 2019

The toxicity of tributyltin (TBT) in sediment in fresh water was determined using spiked sediment bioassays for four benthic invertebrates, (the oligochaete worm Tubifex tubifex, the chironomid Chironomus riparius, the amphipod Hyalella azteca, and the mayfly Hexagenia). Although there was some degradation of spiked TBT into dibutyltin (DBT) and monobutyltin (MBT) in the sediment-water mixtures during the equilibration phase before toxicity testing, the contribution of these degradation products to the observed toxicity was assumed to be minimal based on evidence that TBT is up to orders of magnitude more toxic to many aquatic organisms than its degradation products. The results of this work indicated that Hexagenia was the most sensitive benthic organism to TBT of the four organisms tested (by factors up to about 7), with an IC50 (growth) value for TBT of 0.6 µg Sn/g dry weight. This value is about six times greater than mean concentrations of TBT observed in sediment in fresh water in surveys conducted across Canada before and after the regulation of antifouling uses of TBT in 1989. However, maximum TBT concentrations in sediment before and after regulation exceeded the IC50 (growth) value for Hexagenia, and were close to the lower limits of toxicity ranges for H. azteca and T. tubifex (cocoons/adult and young/adult). Consequently, at the time of surveys before and after the TBT regulation there was potential for adverse effects of TBT in some sediments to some freshwater benthic species.
Review of Biodegradability Tests for the Purpose of Developing Regulations
Authors: Kaiser Klaus L.E.
Published: March 2019

The goal of this review is to propose acceptable testing method(s) for the measurement of the biodegradability of a chemical under both waste treatment and typical environmental conditions, particularly those relevant to Canada. A mul-titier biodegradability test system is recommended for the protection of the environment and human health. The tiers are comprised of International Organisation for Standardisation (ISO) standard tests for rapid biodegradability (headspace carbon dioxide evolution test, ISO #9439), for inherent biodegradability (activated sludge simulation test, ISO #11733) under oxidative conditions, and for biodegradability under anaerobic conditions (ultimate anaerobic biodegradability test, ISO #11734).