Water Quality Research Journal of Canada

WQRJC 2010 45 (1) - Instructions for Authors/Directives aux Auteurs

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WQRJC 2010 45 (1) - Philip H. Jones Award Winners

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WQRJC 2010 45 (1) - GDVFS: A New Toolkit for Analysis and Design of Vegetative Filter Strips Using VFSMOD

The Guelph design tool for vegetative filter strips, GDVFS, is a toolkit for the analysis and design of vegetative filter strips (VFSs). The upland hydrology model UH and the vegetative filter strip model VFSMOD (the two main components of GDVFS) were adopted from an existing interface (VFSMOD-W), and new nutrient and bacteria transport add-ons for UH and VFSMOD were incorporated into GDVFS. Other utilities and tools were also included in GDVFS to provide a capable toolkit for the analysis and design of VFSs. The published evaluation of computational procedures used in GDVFS indicates that these procedures perform very well in the estimation of VFS sediment and phosphorus removal efficiencies. According to these results, comparison of the predicted and observed values for sediment and phosphorus removal efficiencies indicates 10 and 20% error, respectively. This paper provides descriptions on the capabilities and methodology followed in the GDVFS toolkit.

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WQRJC 2010 45 (1) - Frequency Analysis as a Tool for Assessing Adverse Conditions During a Massive Fish Kill in the St. Lawrence River, Canada

During the summer of 2001, the largest fish kill in the recorded history of the St. Lawrence River occurred. More than 25,000 dead carp were recovered. Preliminary analyses suggested hydroclimatic factors may have triggered the fish kill. Long time series of hydroclimatic variables were available upstream and downstream from the study area. In order to investigate if hydroclimatic conditions were extreme during the summer of 2001, frequency analyses were performed on time series of air and water temperature, water level, and solar radiation. During this period, the daily maximum water temperature was abnormally high (return period of 47 years) relative to other years. Air temperature was also high (return period of 22 years) and water level was very low (return period of 67 years). Results showed that hydroclimatic forcings were acting at two different time scales. First, short-term extremes are more likely to have direct impacts on ecosystems, such as lethal stress caused by oxygen depletion in shallow areas. Long-term extremes have indirect effects, which are more difficult to detect, such as immunosuppression. These results reiterate the importance of water temperature in aquatic habitat, particularly in the present context of global warming and climate change.

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WQRJC 2010 45 (1) - Spatial Variability of Reproductive and Size Characteristics of the Northern Mummichog (Fundulus heteroclitus macrolepidotus) Collected Near Municipal Wastewater Discharges

Northern mummichog (Fundulus heteroclitus macrolepidotus) have been widely considered to be suitable for environmental effects monitoring despite concerns of spatial variability observed in energy reserves and reproductive indices. In this study, temporal and spatial variability in gonadosomatic index (GSI), liversomatic index (LSI), and condition factor (K) were examined across two sites in 2006 and 10 sites (four sites exposed to wastewater discharge; six reference sites) in 2007. In 2006 GSI, LSI, and K appeared highly variable and significantly different for both males and females. In 2007, female K and gonad weight were significantly different among all sites. For males, significant differences in K and liver weight were observed among sites. Extensive spatial variation in GSI, LSI, and K observed between reference sites suggests current standardized Canadian Environmental Effects Monitoring (EEM) methods, including effect size and duration of sampling, should not be adopted for use with the northern mummichog F. h. macrolepidotus.

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WQRJC 2010 45 (1) - Chemistry of the Interfaces of an Electric Water Heater: Implications from an Input-Output Analysis

In a case study, this paper responds to increasing public interest in water quality issues by investigating chemical changes as water passes through a domestic water hot water system. Elemental changes were measured by simultaneous analysis of the incoming and outgoing water streams and the deposited sediment from an electric water heater tank. The results may alter some long-held beliefs. The collected and dried sediment from the tank was analyzed for thirty common elements by inductively coupled plasma and atomic absorption techniques. Of the 25 elements found, the dominant seven in order of concentration were magnesium, aluminum, copper, zinc, manganese, iron, and sodium, as well as some surprising traces of other elements. The cold water input and the heated output were also analyzed for thirteen measurable elements. In the heated water output, magnesium had a massive 151% increase in concentration, followed by much more modest increases shown by arsenic, calcium, lead, potassium, silicon, and strontium. None of these mass balance changes compromised the potability of the water. The six elements, aluminum, boron, copper, iron, manganese, and sodium, showed decreases in aqueous concentrations on heating, thereby improving the water quality.

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WQRJC 2010 45 (1) - Research on the Application of Laccase to the Treatment of Oily Wastewater

The feasibility of using laccase to treat oily wastewater was examined. When only laccase was added to the synthetic oily wastewater, the suitable technological conditions were laccase at 3 U/mL, pH at 6.0, a temperature of 30�C, and a reaction time of 6 h for the initial oil concentration of 120 mg/L. Under those conditions, the rate of oil removal was as high as 69%. The effects of Mg²⁺, Mn²⁺, Cu²⁺, and Fe²⁺ ions in wastewater on the rate of oil removal using laccase were investigated. The results showed that Cu²⁺and Fe²⁺ ions obviously inhibited the catalytic performance of laccase under the studied concentration. On the other hand, Mg²⁺ and Mn²⁺ ions only had slight effects on the rate of oil removal for the range of concentrations studied. A 95% oil removal rate could be obtained when actual wastewaters were treated using laccase with the additive chitosan under the suitable technological conditions.

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WQRJC 2010 45 (1) - Contaminant Trends in Suspended Sediments in the Detroit River-Lake St. Clair-St. Clair River Corridor, 2000 to 2004

Suspended sediments from the Detroit River-Lake St. Clair-St. Clair River corridor over the period of 2000 to 2004 were analyzed to examine the spatial distributions of contaminants including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and mercury. Contaminant spatial distributions were similar over the fi ve-year study period, but concentrations varied considerably among sampling locations. Concentrations of PCBs ranged from 22 to 1,200 ng/g (dry weight) in 2004, and from 10 to 2,700 ng/g (dry weight) in 2000; concentrations of PAHs ranged from 640 to 52,000 ng/g (dry weight) in 2004, and from 240 to 82,000 ng/g (dry weight) in 2000; and concentrations of mercury ranged from 0.063 to 0.478 mg/kg (dry weight) in 2004, and from 0.060 to 0.514 mg/kg (dry weight) in 2002. The highest PCB and PAH concentrations were associated with suspended sediments in the lower and middle reaches of the Detroit River in the area of the Trenton Channel, and the outfl ow of the Rouge River. The spatial distributions of mercury were more consistent throughout the entire corridor, indicating the presence of sources in both the lower reaches of the Detroit River and the upper reaches of the St. Clair River. Both the Trenton Channel area of the Detroit River and the upper reaches of the St. Clair River are characterized by heavy historical industrial activity, including steel manufacturing and chlor-alkali production.

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WQRJC 2010 45 (1) - Water Quality Effects from an Aquaculture Operation in a Meromictic Iron Pit Lake in Northwestern Ontario, Canada

In 1989, aquaculture for the production of rainbow trout (Oncorhynchus mykiss) was started in the upper depths of the 180-m deep Caland pit lake formed after the flooding of the former Steeprock Iron Mine. After ten years of operation, water quality was shown to be affected by the fish farm as well as proximal waste and the surficial geology of the area. Meromictic conditions occurred in the pit lake with a dichotomy in water quality versus depth. A cluster of parameters (ammonia, total phosphorus, total Kjeldahl nitrogen, dissolved organic carbon, B, pH, dissolved oxygen) were either in higher concentrations in the mixolimnion or varied little throughout the entire water column, and a second cluster of parameters had higher levels below the chemocline (conductivity, alkalinity, dissolved inorganic carbon, total dissolved solids, nitrate, sulfate, Ca, Mg, hardness, Na, Cl, K, Fe, Mn, Sr, and silicon dioxide). Statistically significant variations in concentrations among many of these chemical parameters were observed between the two years of study, among depths, and among seasons. Nutrient loading from excess fish food and waste increased phosphorus and ammonia levels. The expansion of the fish farm also reduced the levels of dissolved oxygen in the lower depths of the pit lake, thus reducing the volume of usable water for aquaculture purposes. In the early 2000s the fish farm decreased production and those closed in 2006. Later data showed that nitrate and potassium had corresponding decreases in both the monimolimnion and the mixolimnion. Sulfate levels remained elevated.

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WQRJC 2010 45 (1) - Influences of Human Stressors on Fish-Based Metrics for Assessing River Condition in Central Alberta

Economic developments in Alberta have resulted in widespread changes in land use that may deteriorate river conditions for fish. Fish assemblages were characterized with index of biological integrity metrics for the heavily-developed watershed of the Battle River, Alberta. Metric relationships with human stressors were quantified using regression and information theory methods. Although the fauna comprised 14 native species, 50% of the catch was white sucker (Catostomus commersoni Lacepede, 1803). Five statistically unrelated metrics were identified as being responsive to stressors: two trophic guilds, one habitat guild, one reproductive guild, and one measure of community structure. Regression showed that the cumulative effect of human developments, indexed as road density in the basin, was negatively linked to the relative abundance of lithophils and positively linked to the relative abundance of omnivores. Agriculture also threatened the integrity of fish assemblages. Stream sections with higher cattle densities in their basins had fewer lithophils and benthic invertivores; whereas stream sections with higher nutrient concentrations contained fewer species, as well as fewer top carnivores, but more true omnivores. Understanding effects of human footprints that are expanding in western Canada will be critical to the successful management of aquatic resources.

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WQRJC 2010 45 (1) - Caract�risation et traitement physico-chimique des lixiviats de la d�charge publique d'El-Kerma (Alg�rie) par adsorption en discontinu sur de la sciure de bois naturelle et activ�e chimiquement
Characterization and physico-chemical treatment of El-Kerma (Algeria) landfill leachates by batch adsorption on untreated and chemically activated sawdust

La d�charge publique d'El-Kerma d'Oran (Ouest alg�rien) constitue un exemple type de d�t�rioration des ressources naturelles en eau par les d�chets solides. Elle g�n�re des volumes importants de lixiviats � forte charge polluante (CE extr�me de 130 mS/cm et DCO extr�me de 28000 mg d'O₂/L), dont le traitement s'impose. Le traitement physico-chimique des lixiviats de cette d�charge par adsorption en discontinu de la mati�re organique sur de la sciure de bois activ�e � la soude 3 N (SB3), de masse optimale de 0,3 g, � un temps d'�quilibre de 40 min, � pH 11,0 et � une temp�rature de 55�C, a donn� une capacit� maximale d'adsorption de 100 mg/g, selon le mod�le de Langmuir. Cette adsorption est endothermique et s'effectue � une cin�tique rapide et du premier ordre. Les essais de traitement successif des lixiviats bruts effectu�s sur une s�rie de cinq r�acteurs ont permis de r�aliser un taux d'abattement de la mati�re organique de 98 % sur la sciure SB3 et d�s � la sortie du troisi�me r�acteur. Le mat�riau adsorbant utilis� a montr� une efficacit� comparable � celle d'autres mat�riaux largement utilis�s dans l'�puration des effluents.

The uncontrolled landfill of El-Kerma (Western Algeria) constitutes a typical example of deterioration of the natural water resources by solid wastes. It generates large volumes of leachate with a strong polluting load (extreme conductivity of 130 mS/cm, extreme chemical oxygen demand (COD) of 28000 mg O₂/L). Therefore, this leachate should be treated before it is discharged into the environment. The physico-chemical treatment of this landfill leachate by batch adsorption of the organic matter on sawdust activated with a 3 N NaOH solution (SB3) gave a maximum adsorption capacity of 100 mg/g, according to the Langmuir model. This result was obtained for an optimal mass of 0,3 g, with a contact time of 40 min, at pH 11 and a temperature of 55�C. This adsorption is a fast endothermic process, which follows a pseudo first-order kinetic model. Successive treatment tests on untreated leachates have been carried out using a series of five reactors. A 98% abatement rate of the organic matter has been obtained using SB3 sawdust in the outlet of the third reactor. Therefore, the adsorption material used was as effective as other materials widely used in the purification of the effluents.

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WQRJC 2010 45 (1) - Volume 45(1) 2010 Table of Contents with links

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WQRJC 2010 45 (1) - Evaluation of Risk Assessment Tools to Predict Canadian Waterborne Disease Outbreaks

A number of risk assessment tools and guidance documents have been developed by regulatory and nongovernmental bodies to enable risk assessment of drinking water systems. To evaluate the strengths and weaknesses of available risk assessment tools, three of the existing risk assessment tools were applied to waterborne disease outbreaks in North Battleford, Saskatchewan, and Walkerton, Ontario, to determine whether the risk assessment tools would have indicated that the water systems were at risk of failure. Both of these outbreaks are sufficiently well documented to allow testing of the risk assessment tools. Both of the outbreaks occurred partly due to vulnerabilities that prevented the respective water systems from having effective multiple barriers to drinking water contamination. The risk assessment tools generally identified the hazards that resulted in contamination of the source water. However, the different tools had different levels of success in identifying vulnerabilities in the downstream barriers such as treatment processes and water quality monitoring activities. None of the risk assessment tools successfully incorporated the interdependent nature of the multiple barriers of drinking water safety.

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WQRJC 2009 44 (4) - Integrated Land and Water Scenarios of the Raisin River Watershed Using the SWAT Model

This paper investigates the linkage between Canada's National Agri-Environmental Standards Initiative (NAESI) Biodiversity and Water themes by studying how patterns in terrestrial habitat, generated through land cover scenario modelling, influence water quality and quantity in the Raisin River watershed in southeastern Ontario. NAESI developed nonregulatory performance standards that define ideal and achievable levels of environmental quality. The indicators used to investigate the scenario risks included sediment and nutrient concentrations. The SWAT (Soil and Water Assessment Tool)-2005 model was calibrated and validated from 1985 to 2006 for current land cover and five other scenarios: potential natural vegetation (PNV); high biodiversity conservation (HBC); moderate biodiversity conservation; agricultural intensification with limited application of conservation direction; and agricultural intensification with no consideration of conservation direction (ANC). Scenario comparisons are provided for the average annual flow, and concentrations of total suspended sediment (TSS), total nitrogen, and total phosphorus for five watershed locations. The PNV scenario predicted the lowest total flows, and sediment and nutrient concentrations, and the ANC scenario predicted the highest sediment and nutrient concentrations. The SWAT median values for the HBC, "Current," and ANC scenarios at the outlet all exceeded the Ideal Performance Standards, except for the median TSS concentration of the HBC scenario.

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WQRJC 2009 44 (4) - The Effects of Final Treated Effluent and In-Mill Waste Streams from a Canadian Thermomechanical Pulp and Paper Mill on Mummichog (Fundulus heteroclitus) Reproduction

The effect on fish reproduction of final treated effluent from a thermomechanical pulp mill in Saint John, New Brunswick, Canada, was studied using mummichog (Fundulus heteroclitus), an endemic fish species of the Atlantic coast of North America. A 1997 artificial stream study at the same mill showed a reduction in gonad sizes in mummichog after a 28-day exposure to 3% final treated effluent. In 2005, we reevaluated final treated effluent, and conducted a toxicity source evaluation to identity waste stream sources within the mill that may cause reproductive effects. Relative to reference, no significant differences in gonad size, plasma levels of gonadal sex steroids, egg production, or stage of egg development were observed in fish exposed to 1, 3, 10, 30, and 100% final treated effluent or in-mill waste streams. Unlike the previous study in 1997, these data indicate a low potential for an effect of final effluent on fish reproduction. Since the 1997 study there were no major process changes that could explain the differences in the results. However, there was high variability in gonad size, egg production, and endocrine endpoints measured in the more recent test, which resulted in low power to detect differences. This has prompted research to refine the current reproductive test by optimizing study design.

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WQRJC 2009 44 (4) - Author Index for Volume 44(2009)

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WQRJC 2009 44 (4) - Key Word Index for Volume 44(2009)

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WQRJC 2009 44 (4) - Referees for Volume 44(2009)

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WQRJC 2009 44 (4) - Multicriteria Review of Nonpoint Source Water Quality Models for Nutrients, Sediments, and Pathogens

There now exists a large number of nonpoint source models that have been developed for watershed management issues. As part of the National Agri-Environmental Standards Initiative (NAESI), it was necessary to evaluate which model or models would be the best choice for examining various best management practices for nutrients, sediments, and pathogens in test watersheds. Environment Canada has committed to the development of environmental performance standards that will guide environmentally sustainable agricultural practices and management. A literature review was carried out and a short list of 13 models was selected that met the basic needs of the project. These models were subsequently evaluated based on a multicriteria analysis that considered 21 model characteristics. A weight and a total score quantify the relative importance of each criterion. The top six models were SWAT (Soil and Water Assessment Tool), AnnAGNPS (Annualized Agricultural Nonpoint Source), BASINS (Better Assessment Science Integrating Point and Nonpoint Sources), GIBSI (Gestion Int�gr�e des Bassins versants � l'aide d'un Syst�me Informatis�), AGNPS (Agricultural Nonpoint Source), and HSPF (Hydrologic Simulation Program - Fortran).

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WQRJC 2009 44 (4) - Application of Clay for Petrochemical Wastewater Pretreatment

Petrochemical industry wastewater is contaminated with nitrogen and phosphorous compounds, mainly ammonium and ammonium nitrogen, and therefore needs treatment before it is released in the watercourse. Usually, petrochemical wastewater treatment is carried out following the ion exchange principle. One of the possibilities of petrochemical wastewater pretreatment is using bentonite clays. Bentonite decreases the concentration of ions in the incoming wastewater and, as a consequence, the ion exchanger placed subsequently works more efficiently. The experiment was carried out with alkali-activated granulated bentonite and acid-activated granulated bentonite. In this work, bentonite particle size, the quantity and the type of bentonite, as well as the time of the contact of bentonite and wastewater were optimized. It was found that the highest percentage of ion removal of 83% for ammonia ions and 71% for phosphate ions was accomplished when the model solution was treated with a mixture of acid- and alkali-activated bentonite for 5 minutes.

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WQRJC 2009 44 (4) - Effects of Two Types of Landfills on River Water Quality and Endocrine Disruptor Concentrations Before and After Rainfall in a Subtropical Climate

One closed uncontrolled landfill, the Neihu garbage dump, and one active controlled landfill, the Sanzhuku sanitary landfill, were selected for investigation of their leachate characteristics and effects on adjacent river water quality before and after rainfall in northern Taiwan. A total of seven samplings were made during February and June 2007, with four samplings done after individual rainfall events on study sites. Water quality of runoff samples collected from the Sanzhuku sanitary landfill showed less pollution than the water quality of leachates collected from the Neihu garbage dump; however, some water quality levels of leachate samples collected from the Neihu garbage dump were relatively high, such as ammonia nitrogen (NH₃-N), orthophosphate (PO₄^3-) and biochemical oxygen demand (BOD₅). At the uncontrolled dump, rainfall lead to dilution effects on river water NH₃-N and PO₄^3- concentrations, but not other water quality parameters. In contrast, the concentrations of bisphenol A (BPA) and nonylphenol were increased in both types of landfills after rainfall in the present study. Dilution effects of rainfall on most water quality parameters and toxicity tests were observed in the Neihu garbage dump leachates after rainfall, but not for the Sanzhuku Landfill runoff. The highest concentration of BPA measured in this study was 25.8 �g�L^-1 in the Sanzhuku sanitary landfill runoff after the heaviest rainfall event, during which 236 mm of rainfall accumulated over four days. The results of this study suggest that both uncontrolled and controlled landfill leachates can be an important potential pollution source of BPA to adjacent water bodies.

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WQRJC 2009 44 (4) - The Use of Carbon and Nitrogen Stable Isotope Analysis to Characterize Food Web Changes in Aquatic Systems for Reclamation of Oil Sands Process-Affected Materials

One strategy for reclamation of oil sands leases in northern Alberta is the construction of lakes and wetlands by capping oil sands process-affected material (OSPM) with water. To assess this approach, experimental sites containing a range of OSPM have been constructed to monitor the evolution of the resulting aquatic habitats. Stable isotopes of carbon and nitrogen were used to assess the effects of OSPM on aquatic food webs. Carbon and nitrogen isotopic signatures of sediment, dissolved inorganic and organic carbon, particulate organic matter, periphyton, plants, plankton, aquatic invertebrates, and fish were used to assess differences related to the naphthenic acid (NA) concentration in OSPM and reference sites. NAs are a principal contaminant of concern in OSPM. Sites were grouped into low (0 to 4 mg/L), medium (4 to 15 mg/L), and high (>15 mg/L) NA concentrations. There were no significant differences in food web area or length among the three NA groupings. In most cases, carbon isotope analyses of samples from low, medium, and high NA concentration sites were not significantly different, suggesting that OSPM is not a significant contributor to food web carbon sources. Significant differences were found in nitrogen isotope signatures between low, medium, and high NA sites. Ammonia from OSPM is suggested as the main contributor to �¹⁵N enrichment.

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WQRJC 2009 44 (4) - Onsite Microbiological Quality Monitoring of Raw Source Water in Cree Community of Mistissini

Access to safe drinking water is a major concern for Canada's First Nations. The main objective of this report was to evaluate the microbiological quality of raw source water used for drinking purposes by the Cree people of Mistissini (Province of Qu�bec, Canada) during summer 2005. Twelve environmental sites and 24 portable water containers used for domestic water collection and storage were sampled and submitted to microbiological determination of total coliforms, Escherichia coli, and Enterococcus sp. using membrane filtration and colourimetric standard methods. The results suggest that the microbiological quality of raw source water sampled from environmental sites is enhanced by storage practices of Mistissini inhabitants as microbial counts have shown a tendency to decrease upon storage and that the targeted fecal indicators (E. coli and enterococci) were quantitatively distributed independently from each other, especially with regards to the type of water source. In conclusion, even if the use of multiple indicators could offer better water quality monitoring, technological constraints limit the use of culture-based methods in such a remote area, underlining the importance of always boiling water from raw water sources before consumption.

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WQRJC 2009 44 (4) - Combined Treatment of Domestic Wastewater using Anaerobic and Solar Photocatalytic Treatment

The present study utilizes anaerobic and solar photocatalytic methods to treat domestic wastewater. For stage I, a granulated hybrid upflow anaerobic sludge blanket reactor (HUASB) with a working volume of 5.9 L was used. It was run in a recirculation mode for 3 days called "one cycle," and 30 cycles were run to find out the stability of the anaerobic treatment. During stage I anaerobic treatment, 90% of the chemical oxygen demand (COD) was removed, and it increased with an increase in digestion period for each cycle. Volatile fatty acids did not cause any operational problems during the stage I anaerobic treatment, being in the range of 280 to 90 mg/L. Stage I treated wastewater was subjected to a stage II solar photocatalytic oxidation method. The optimum pH and catalyst loading for the solar photochemical oxidation were found to be 5 and 200 mg/L, respectively. Stage II, treatment at an optimized condition, removed 66% of organics from the stage I treated wastewater. The combined COD removal due to the combination of these two technologies was found to be 96%.

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WQRJC 2009 44 (4) - Assessment of Northern Mummichog (Fundulus heteroclitus macrolepidotus) as an Estuarine Pollution Monitoring Species

The use of multiple spawning fishes in environmental effects monitoring programs has proven difficult for a number of reasons including the inability to predict reproductive investment and ensure synchronous sampling of reference and impacted populations. The estuarine resident northern mummichog (Fundulus heteroclitus macrolepidotus) has been successfully used as a sentinel for effects of pulp and paper mill effluents in Atlantic Canada and has been proposed for monitoring other anthropogenic impacts. This study investigated the spatial and temporal variability of the somatic parameters used to describe fish performance, specifically measures of energy use and storage, in estuaries located in Prince Edward Island, Canada. Three sites with varying levels of agricultural input were studied. Fish at all sites depleted their energy reserves over winter, as reflected in depressed condition, liver size, and gonad size, but then quickly replenished them in May. These population parameters were highly variable throughout the reproductive season and within an estuary. Spawning was continuous at all sites without indication of lunar or other periodicity. We conclude that repeated sampling is required to assess reproductive output in the northern mummichog and densities of adults and young-of-the-year deserve further investigation as a potentially less logistically demanding indicator of eutrophication.

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WQRJC 2009 44 (3) - A GIS-Based Spatial-Multivariate Statistical Analysis of Water Quality Data in the Porsuk River, Turkey

The study offers a GIS-based multivariate statistical analysis strategy to assess river water quality. Multivariate statistical methods and Geographic Information System (GIS) technology have effectively been used for water quality management. Recognizing the fact that the use of standard statistical methods can be restrictive due to the complexity of water quality datasets, geospatial statistical methods have been recommended for the water quality assessment. The objective of the study was to explore the potential capabilities of GIS-based joint multivariate statistical analysis for water quality assessment of Porsuk River in Turkey. A well-known multivariate statistical technique, principal component analysis (PCA), is incorporated into a geographic database for interpretation of water quality data. To characterize spatial variability of water quality data, spatial PCA was performed on the basis of spatial autocorrelation. Application of the joint spatio-multivariate statistical analysis for interpretation of the water quality database offered a better understanding of the hydrochemistry in the study region.

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WQRJC 2009 44 (3) - Biological Phosphorus Removal and Denitrification of a Fish Farm Effluent in a Sequencing Moving Bed Biofilm Reactor

Removal of phosphate and nitrate from the effluent of a fish farm with a recirculation system was tested in a sequencing moving bed biofilm bioreactor (SMBBR) over a 160-day period. This bioprocess made use of a stock tank (ST) that allowed the same volume of anaerobic water to be reused from one batch to another. Water from the ST contained an excess of a carbon source (acetate), which made it possible to alternate between anaerobic (1.5 h) and aerobic/anoxic (4 h) conditions to achieve enhanced biological phosphorus removal (EBPR). The developed biomass (2,072 mg total solids m^-2�d^-1 and 892 mg total volatile solids m^-2�d^-1 ) removed 7.5 mg of PO₄-P per litre and 8.5 mg of NO₃-N per litre from an influent containing 10 mg of PO₄-P per litre and 21 mg NO₃-N per litre. The dynamic variation of phosphate and chemical oxygen demand (COD) in the influent showed that the biomass was sensitive to the COD_available/P_influent ratio. A ratio of 10 to 15 mg of COD per milligram of P seemed to favour phosphorus accumulating organisms (PAOs). Differences between the nitrate, phosphate, and oxygen reduction kinetics suggested that the denitrification could be attributed to organisms other than PAOs. The SMBBR-ST showed potential for EBPR and for denitrification as well. However, the economic feasibility of implementing such a process in a full-scale operation remains to be demonstrated.

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WQRJC 2009 44 (3) - Chemical Treatment and Enhancement of Bioavailability of Olive Mill Wastewater

In this research, the potential of chemical treatment of olive mill wastewater (OMW) using different compounds such as lime, potassium permanganate, hypochlorite, and Fenton's reagent has been investigated. The capability of these compounds to breakdown the carbonaceous content of OMW was tested at different concentration ratios and contact times using a batch system. Chemical oxygen demand (COD) was used as an indicator for the organic content of the OMW. The results showed that chemical treatment is an effective means of treating highly concentrated wastewater such as OMW. A COD removal of about 90% was obtained at permanganate:COD ratio of 1:25 and contact time of 25 minutes. Using Fenton's reaction, more than 93% COD removal was observed at COD:Fe ratio of 50:1, H2O2:Fe ratio of 10:1, and contact time of 10 minutes. The lowest COD removal was observed using sodium hypochlorite. It was possible to reduce the bioavailability indicator, COD/BOD₅ ratio, by 40 and 50% by treating the OMW with permanganate and Fenton's reagent, respectively. These results along with the short contact time required indicate that chemical treatment is an effective alternative to conventional biological treatment of highly concentrated OMW.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=435

WQRJC 2009 44 (3) - Use of Stable Carbon and Nitrogen Isotopes to Trace Natural and Anthropogenic Inputs into Riverine Systems in the Athabasca Oil Sands Region

Stable isotopes of carbon and nitrogen in fish were examined as a potential tracer of exposure to oil sands constituents in naturally eroded environments and in areas of anthropogenic activity (municipal and industrial effluent discharges; oil sands surface mining) within the Athabasca River drainage basin of northern Alberta, Canada. Longnose sucker (Catostomus catostomus), trout-perch (Percopsis omiscomaycus), and slimy sculpin (Cottus cognatus) showed changes in δ¹³C values with the river gradient. Site-specific differences in the δ¹³C values of fish were more pronounced for the small-bodied fish species in the lower reaches of a tributary (slimy sculpin) and immediately downstream of tributary inputs along the Athabasca River (trout-perch), where potential exposure to the oil sands constituents is elevated. There were also species and site-specific trends for δ¹⁵N values. Site-specific trends attributed to municipal or industrial effluent discharge or tributary inputs may prove to be a useful tool for defining residency on the oil sands deposit. This study has provided baseline data of isotope values for fish species which are currently used (longnose sucker) or may be used in future environmental effects monitoring programs. Defining residency and exposure to the oil sands deposit is critical to establishing exposure-response relationships, particularly since there are new expansions to oil sands mining operations.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=438

WQRJC 2009 44 (3) - Influence of Sediment Grain Size on Elutriate Toxicity of Inorganic Nanomaterials

Knowledge concerning the ecotoxic effects of nanomaterials, chemical structures with novel properties owing to their small sizes (1 to 100 nm), is wanting and deserves to be documented more fully. In this study we conducted testing with the MARA (microbial array for risk assessment) assay-an 11 microbial species 96-well microplate toxicity test measuring growth inhibition-to determine the toxic potential of four metallic nanopowders (MNPs): copper zinc iron oxide, samarium (III) oxide, erbium (III) oxide, and holmium (III) oxide. MTC (microbial toxicity concentration) endpoint values showed a range of toxicity responses generated by individual strains that was MNP-specific. Cluster analysis undertaken with the (n = 11) MTC values of the four MNPs, reflecting a toxic fingerprint proper to each nanochemical, indicated that their modes of action may be different. Experiments were also conducted with an artificial sediment, composed of varying concentrations of silica sand and kaolin (fine particles < 0.004 mm), spiked with each MNP to assess the contribution of fine particles on the resulting elutriate toxicity. The latter was shown to increase as fines contents decreased, except for CuZnFeO where no particular trends were observed. Toxicity testing was then undertaken with each MNP spiked into natural Saint Lawrence River freshwater sediments displaying low, medium, and high fines contents. Once again, analogous results to those obtained with the artificial sediment experiments were observed for MNP elutriate toxicity. Overall, MARA bioassay data indicate that MNP toxicity can be modulated by sediment grain size and that resulting adverse effects on aquatic biota will in part depend on such sediment characteristics.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=431

WQRJC 2009 44 (3) - Perfluorinated Alkyl Acid Concentrations in Canadian Rivers and Creeks

Perfluorinated alkyl acids (PFAs) belong to a family of chemicals that are highly persistent and potentially ecotoxic. They are under scrutiny by government agencies who must determine their risk to humans and the environment. Numerous studies have measured perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in selected areas of the world, but there has been no systematic cross-Canada study of these compounds in surface waters. This report describes the concentrations of PFAs in 38 rivers across Canada (42 to 60�N and 62 to 136�W). Samples were collected upstream and downstream of populated areas. PFOS and PFOA were the predominant PFAs detected. Values of PFOS ranged from <0.020 to 34.6 ng/L and PFOA ranged from 0.044 to 9.9 ng/L. Highest concentrations occurred in areas of high population densities, generally at downstream sites. The shorter chain perfluorocarboxylates (PFCAs) (C₆₉) were present in most samples but the longer chain PFCAs (C₁₀ to C₁₄) were not often detected. Perfluorohexane sulfonate was the next most frequently detected perfluoroalkylsulfonate while perfluoro-1-octanesulfonamide (PFOSA) was detected infrequently.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=437

WQRJC 2009 44 (3) - Performance and Modelling of a Highway Wet Detention Pond Designed for Cold Climate

A wet detention pond in Norway has been monitored for 12 months. The pond receives runoff from a highway with a traffic load of 42,000 average daily traffic. Hydraulic conditions in terms of inflow, outflow, and pond water level were recorded every minute. Water quality was monitored by volume proportional inlet and outlet samples. During most of the year, excellent pollutant removal was achieved; however, during two snowmelt events the pollutant removal was poor or even negative. The two snowmelt events accounted for one third of the annual water load and for a substantial part of the annual pollutant discharge. The performance of the pond was analyzed using a dynamic model and pollutant removal was simulated by first-order kinetics. Good agreement between measurement and simulation could be achieved only when choosing different first-order rate constants for different parts of the year. However, no relation between the rate constants obtained and the time of year could be identified, and neither did the rate constants for different pollutants correlate. The study indicates that even detailed measurements of pollutant input and output allow only average performance to be simulated and are insufficient for simulating event-based variability in pond performance.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=434

WQRJC 2009 44 (3) - Phosphorus Sorption and Sedimentation in a Multipond System within a Headstream Agricultural Watershed

The movement, transformation, and assimilation of phosphorus (P) in a watershed are often related to the physicochemical characteristics of the sediments of the water storage structures in the watershed. Field and laboratory experiments were conducted to study P sorption by pond sediments in a multipond system in a watershed of 6.9 km² in southeastern China. Being scattered in different ambient land uses, and receiving soil particles from various sources, the multipond system provides an excellent research example for P sorption as well as the relationship between pond properties and their location in a watershed. It was found that the pond sediments showed largely variable P sorption capacities in this watershed. The P sorption maximum (S_max) ranged from 390.0 to 729.2 mg/kg, and equilibrium P concentration (EPC₀) ranged from 0.007 to 0.023 mg/L. The mean degree of P saturation (DPS) of the pond sediments was only 9.5%. Due to the large annual delivery of sediments to the ponds by soil erosion, the pond sediments never reached saturation. The location of the ponds could influence the physicochemical properties of sediments and their sorption characteristics. For S_max, the Hill pond value was significantly higher than that for the Village pond. For EPC₀, the result was reverse. The oxalate-extractable Fe (Ox-Fe) and KCl-extractable P (KCl-P) were the key factors that infl uenced P sorption of the pond sediments. Ox-Fe could explain 84% of the variability in S_max and KCl-P could explain 82% of the variability in EPC₀. The acidic and high Fe contents of laterite soil in southeastern China was the most important cause of the high P sorption capacity of the pond sediments.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=433

WQRJC 2009 44 (3) - Experimental Study on the Elimination of Colour and Organic Matter from Wastewater Using an Inexpensive Biomaterial, Chitosan

Chitosan has been investigated as an inexpensive, biologically derived adsorbent and/or primary coagulant for two reactive azo dyes in textile wastewater. At natural pH, complete elimination of colour was achieved from 0.1 g/L aqueous solutions of the textile dyes Procion Orange MX-2R and Procion Red MX-5B with a dose of 6 g of chitosan per litre of dye solution. However, when pH was lowered (to 4.8 and 5.5 respectively), a dose of only 1 g of chitosan per litre was necessary to eliminate colour and drastically reduce TOC (total organic carbon) and chemical oxygen demand for the same concentration of dyes. This allowed about an 80% reduction in sludge volume production. Addition of sodium phosphate dibasic and potassium sulfate improved the dye removal at higher pH. Colour removal decreased significantly with or without added salts as pH was adjusted above 7. Equilibrium adsorption experiments showed that both dye solutions follow the Freundlich isotherm, but not the Langmuir isotherm. Kinetics measurements show a better fi t to the pseudosecond-order Lagergren model than to the first-order Lagergren model. Brunauer-Emmett-Teller, or BET, surface area analysis and scanning electron microscope micrographs were included for better understanding of the nature of the chitosan surface with and without adsorbed dye. Chitosan appears to be a natural, clean and excellent product for the adsorption of Procion Orange MX-2R and Procion Red MX-5B in mildly acidic conditions.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=430

WQRJC 2009 44 (3) - Temperature Impact of the Industrial Cooling Water Discharges in a Long Boat Slip of Hamilton Harbour

The thermal structure of industrial cooling water discharged into a long, narrow and shallow, straight open boat slip (Ottawa Street Slip, [OSS]) was investigated by field measurements during the hottest summer month in 2006. Three-dimensional hydrodynamic and thermal transport models were established and verified with measurements. The main purposes of this study were to understand the mechanism of the thermal structure in the OSS during the hot summer season under the present cooling water discharge conditions, to investigate the influence of harbour water on the thermal structure in the slip, and to establish a means for scientific predictions of the impact of cooling water discharges in a future study. Toward this end, the water temperature at multiple locations along the OSS and meteorological data near the study site were collected during the summer period of 2006. The collected data reveal: (1) during the measured summer period, the water temperature in the slip can be higher than 30�C during a period of high air temperatures; (2) water temperature variations within short periods of 15, 30, 60, and 120 minutes were no more than 4�C during the entire measurement period; (3) water temperature in the slip is controlled by both air and cooling discharge temperatures, and the cooling water temperature�s increase due to industrial cooling processing seems to be relatively independent of the intake water temperature; therefore, the water temperature in the slip varied mainly with the air temperature; (4) since water temperature in the slip seemed to closely follow the intake water temperature, the intake channel may need to be optimized to maximize the possibility of getting the coolest water available from Hamilton Harbour; and (5) the cooler harbour water could not penetrate deeply into the slip. The collected water temperature data were also used for verification of three-dimensional hydrodynamic and transport models. The simulation results showed that the established model could reasonably well reproduce general thermal structures in the entire slip. This achieved the ultimate goal of the study for establishing a model to assess the impacts of further increase of cooling water discharge into the OSS.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=429

WQRJC 2009 44 (2) - Field Evaluation of Long-Term Performance and Use of Biosand Filters in Posoltega, Nicaragua

An evaluation was conducted in 2007 on biosand filters that were installed in Posoltega, Nicaragua in 1999 and 2004.The objectives were to characterize the condition and use of filters eight and three years after installation, determine filter performance of those filters still in use, and identify determinants of successful long-term use and performance. Methods consisted of household identification, user questionnaires, and water quality testing. Of the 234 filters installed, only 24 were found to still be in use. Average log reductions were 1.73 (98%) for total coliforms, 1.36 (96%) for Escherichia Coli, and 0.91 (88%) for turbidity. Statistically significant effects were detected for the magnitude of the contamination of source water, the peak hydraulic loading rate, and the standing depth of water over the filter media. Questionnaire results indicated user training on filter maintenance could improve the peak hydraulic loading rate and hence filter performance. The low rate of sustained use (10%) is an indication of failed implementation, and is attributable to structural failure, particularly cracking of the concrete filters from 2004. Nonetheless, this evaluation demonstrated the biosand filter technology to be robust since those filters still in use were performing as expected three and eight years postimplementation.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=420

WQRJC 2009 44 (2) - Evaluation of Field Testing Techniques Used in a Household Water Treatment Study in Posoltega, Nicaragua

A field evaluation of biosand filters, a method of household water treatment, was conducted in Posoltega, Nicaragua. The evaluation consisted of water quality testing for Escherichia coli and total coliforms using membrane filtration (MF) with m-coliBlue24 growth media, and SolarCult dipslides. For each sample tested, the MF procedure was applied to two volumes differing by an order of magnitude to capture the expected range of microbial contamination. A follow-up laboratory quality assurance/quality control procedure was undertaken to validate the field methods. The average coefficient of variation was 51%, with no statistically significant difference between the field and laboratory data. The MF procedure used with m-coliBlue24 produced useful reproducible results for the microbial concentrations encountered in the field. Dipslide results were found to correlate poorly to the membrane filtration results from the field, and should not be used to test drinking water due to the high limit of detection. They may still be useful for preliminary testing of highly contaminated source water as part of a household water treatment project. Dipslides may also be a useful tool for local health representatives to promote safe water practices within the community since they are simple to use and provide a visual indicator of water quality.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=421

WQRJC 2009 44 (2) - Stream Chloride Monitoring Program of City of Toronto: Implications of Road Salt Application

In cold regions, winter road safety is a major challenge for municipalities and provincial highway transportation agencies. Road salt is widely used to improve winter road conditions, but concerns have been raised about the effects of road salts on the environment. This paper describes a water quality monitoring program designed to measure both background chloride concentrations and the effects of road salt application on stream water quality in four watersheds (Humber River, Don River, Highland Creek, and Morningside tributary of Rouge River) located within the City of Toronto boundary. The effect of road salts on stream water quality was evaluated based on chloride concentration because of its conservative nature. A bilinear correlation was developed to transform measured specific conductance levels in stream water to chloride concentrations. There are no Ontario aquatic fresh water quality guidelines for chloride, but chloride concentrations in almost all the monitored streams in Toronto periodically exceeded chronic and acute chloride threshold levels of the United States Environmental Protection Agency. The City of Toronto has been proactive in its efforts to implement management practices to reduce the impact of road salt application on the environment while maintaining safe driving conditions for its road users. Normalized salt application rates in Toronto have been on a gradual declining trend in the last decade from about 0.08 to 0.07 tonnes of salt applied per centimetre of snowfall per kilometre of lane. With public safety in mind, further reductions in salt application rates are being considered to reduce the adverse environmental effects to acceptable limits.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=427

WQRJC 2009 44 (2) - Environmental Factors Affecting Methoprene Concentrations for West Nile Virus Control in a Storm Sewer System

To address vector-borne West Nile virus in Canada, chemical larvicides (methoprene) are applied to storm sewer system catch basins (CBs) to control mosquitoes. This study assessed the fate and transport of methoprene in such systems over time relative to precipitation. Rainfall and methoprene concentration patterns revealed the effect of dilution, dissolution, and flushing of the larvicide. In the summer and fall of 2003 to 2005, field monitoring studies were conducted in Toronto, Ontario on two CBs, each treated with a control dose of methoprene, supplied in pellet or ingot formulation. Furthermore, in 2005, concentrations at the storm sewer outfall were measured during nine rainfall events. Based on daily monitoring, findings indicate that (1) the methoprene concentration at the CBs fell below the minimum lethal concentration or LC50 one or two weeks after treatment, and remained below LC50 concentrations over 70% of the time; (2) rainfall flushed methoprene from the CBs to the storm sewer outfall at concentrations higher than the levels specified by Ministry of Environment, which may cause ecosystem damage; (3) based on the number of cycles per diem within each CB in each study period, there was no conclusive pattern in the flushing susceptibility of pellets versus ingots; (4) the mean concentration of methoprene increased with reduced CB sump volume; (5) less total precipitation resulted in higher average methoprene concentrations and a higher number of days above the LC50 based on ingot-dosed CBs; (6) counter-intuitive to (4) and (5), larger sump water volumes and greater rainfall resulted in lower mean concentrations and fewer days above the LC50; and (7) a single ingot dosage was comparable in performance to a three pellet dosage.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=422

WQRJC 2009 44 (2) - Physicochemical Distribution of Metals in the Water Phase of Catch Basin Mixtures

A mixture of sediment and water is formed during the cleansing of catch basins. This paper discusses the concentration levels and distribution of numerous metals and organic carbon (OC) in the water phase of this mixture. The results show that due to the high concentrations of metals in the water phase, the catch basin mixture should be treated before it reaches a recipient. Three sites with different types of area and traffic intensity were sampled. Four fractions were analyzed: unfiltered, dissolved (<0.2 μm), colloidal (0.22 μm to 1 kD [kilodalton]), and truly dissolved (<1 kD). The results of the unfiltered fraction show high concentrations of metals and OC in the catch basin mixture. A comparison of Canadian and Swedish Environmental Protection Agency guidelines and the catch basin mixtures shows that concentrations exceeded the threshold values for As, Cd, Cr, Cu, Ni, Pb, and Zn. Compared with samples from a reference lake in the area, the unfiltered fraction showed high concentrations of all elements. OC seems to have a large impact on the overall speciation of trace metals in the catch basin mixture. To trace the sources of the particulate fraction in the unfiltered samples, Al-normalization was used. Al-normalization indicated that Ca, K, Mg, Na, Mn, Ba, Co, and Cr concentrations could be explained by mineral particles used as traction control. Furthermore, the trace elements As, Cu, Pb, Zn, and Ni were all enriched in the catch basin mixture.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=423

WQRJC 2009 44 (2) - Reduction of Alkali-Labile Phosphates in Mussels Exposed to Primary-Treated Wastewaters Undergoing Ozone and Ultraviolet Disinfection: A Pilot Study

The purpose of this study was to examine the estrogenic potential of a primary municipal effluent, undergoing ozone or ultraviolet disinfection, in Elliptio complanata mussels. Mussels were exposed for seven weeks, using a continuous flowthrough system, to a primary effluent from a major city before and after disinfection. Results showed that the effluents, regardless of the disinfection procedure, readily affected gametogenesis in mussels as determined by gonado-somatic index, and by DNA synthesis as determined by the activity of aspartate transcarbamoylase activity, a rate-limiting enzyme for pyrimidine synthesis. The estrogenic potential of the effluents was observed by the increased levels of alkali-labile phosphate, a generic measure for vitellogenin-like proteins, where the disinfection procedures did not completely remove the estrogenic effects of the primary effluent. Thus, the introduction of an ozone or ultraviolet disinfection step to a primary-treated effluent will likely diminish the estrogenic potential, but not entirely.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=424

WQRJC 2009 44 (2) - Estimation of Biodegradation and Liquid-Solid Partitioning Coefficients for Selected PAHs in Municipal Wastewater Treatment

Batch testing was employed to estimate model parameters that are required for predicting the fate of polynuclear aromatic hydrocarbons (PAHs) in wastewater treatment. Linear partitioning was found to describe the partitioning of PAHs to solids and was best described when the soluble phase of the PAHs was determined by centrifugation alone. The liquid-solid partitioning coefficients obtained for primary and secondary sludges were statistically different, with the latter being higher than the former for most of the PAHs examined in this study. Temperature had a significant impact on the estimated biodegradation rate coefficients (K_b). The biodegradation rate coefficients for anthracene and phenanthrene (three-ring PAHs) were statistically different from benzo(a)anthracene and chrysene (four-ring PAHs). The presence of a nitro-adduct on acenaphthene resulted in a substantial increase in the (K_b) relative to the unsubstituted anthracene and phenanthrene. A sensitivity analysis revealed that the removal of PAHs in a full-scale wastewater treatment plant was most sensitive to the value of the liquid-solid partitioning coefficients. Approximately 60% of the PAHs were removed from the wastewater stream through partitioning to both primary and secondary solids, and subsequent discharge.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=425

WQRJC 2009 44 (2) - Heavy Metals Removal by Hydroxide Precipitation and Coagulation-Flocculation Methods from Aqueous Solutions

The hydroxide precipitation and coagulation-flocculation methods were used to treat wastewater containing lead, zinc, copper, and iron. The concentrations of heavy metals in the synthetic wastewater range from 1 to 14 mg/L for lead, 5 to 90 mg/L for zinc, 3 to 90 mg/L for copper and 5 to 45 mg/L for iron. Individual Zn(II) and Cu(II) with concentrations below 90 mg/L and Fe(III) with concentrations below 45 mg/L were removed up to 99% by the precipitation method in the pH range of 8.7 to 9.6, 8.1 to 11.1, and 6.2 to 7.1, respectively. Though the highest percent removal of Pb(II) by hydroxide precipitation alone was approximately 98%, the final dissolved concentrations did not fulfill the Standard A discharge limit required by the regulations, thus further treatment by the coagulation-flocculation process was performed. Aluminum sulphate (alum), polyaluminum chloride (PACl) and magnesium chloride (MgCl2) have been used as coagulants together with Koaret PA 3230 as coagulant aid to determine the effectiveness of the coagulation method for the removal of individual heavy metals in the wastewater. The effects of parameters such as pH, type, and dosage of coagulant on the percentage of metal removal, and the amount of coagulant aid on the fl ocs settling time were investigated. The jar test showed that up to 99% removal of Pb(II) was attained by the addition of 1,200 mg/L of alum, 150 mg/L of PACl, and 2,000 mg/L of MgCl2 in a pH range of 6.5 to 7.8, 8.1 to 8.9, and 9.7 to 10.9, respectively.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=426

WQRJC 2009 44 (2) - Electrochemical Removal of Copper and Lead from Industrial Wastewater: Mass Transport Enhancement

The effects of ultrasonic frequencies on both the mass transport process and diffusion layer were investigated during electrochemical treatment. The rates of mass transfer at a stainless steel cathode were measured for copper and lead in dilute acidified copper sulphate and lead nitrate solutions at different ultrasonic frequencies. Concentrations in bulk solution were determined by atomic absorption spectrophotometer. By increasing frequencies from 40 to 100 kHz, a high value for the mass transfer coefficient and an effective thinning of the diffusion layer were observed. Higher rates of mass transfer reduced energy consumption. Use of ultrasound with electrochemical processes can provide valuable contributions to remove metallic ions from industrial wastewater without using extra chemicals. The process has efficiently reduced the cost of energy consumption and deposition time.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=419

WQRJC 2009 44 (2) - Electrokinetic Flotation of Process Water from Paint Booths

Electrokinetic flotation (EKF) for separation of paint solids and process water from automotive assembly paint booths was investigated in a series of laboratory-scale batch experiments. The EKF process employs a single electrode-module and a DC (direct current) power supply, but does not use any chemical agents or air supplier. The electrode-module, which consists of parallel electrode plates, was developed and used in the experiments. The influencing parameters of the EKF process for the process water treatment, including the type of paint, initial suspended paint solids (SS) concentration, and applied electric current, were investigated in the experimental program. It was found from this study that the EKF process decreased the SS concentration from 300 to 100 mg/L in 30 minutes at 55 A/m2 in the water-borne paint water, from 150 to 50 mg/L in 5 minutes at 22 A/m2 in the solvent-borne paint water, and from 550 to 100 mg/L in 5 minutes at 44 A/m2 in the mixed paint water, as well as reduced colour and chemical oxygen demand (COD). The study concluded that paint type, initial SS concentration, and electric current are the most important parameters in the EKF process governing the effectiveness of solid/water separation, treatment time, and power consumption. A comparison of SS removal between the chemical coagulation and the EKF treatments showed that SS removal by the EKF process was similar to the chemical treatment. The study concluded that the EKF is an effective technique for solid/water separation in paint booths with simultaneous COD and colour removal.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=428

WQRJC 2009 44 (1) - Overveiw of the Theme Issue: Innovation in Stormwater Management in Canada: The Way Forward

Rapid urban expansion, increased traffic, ageing infrastructure, greater climatic variability, and the need for enhanced sustainability of urban water resources pose significant challenges to conventional stormwater management. Innovative approaches are needed in order to mitigate the risk of flooding, pollution, and aquatic ecosystem degradation, and enhance beneficial uses of urban waters. To examine such approaches, a series of three regional conferences on innovative stormwater management were held in Vancouver, Calgary, and Toronto during 2007 to 2008 under the sponsorship of the Canadian Water Network (CWN) and the Canadian Mortgage and Housing Corporation (CMHC). Authors of selected conference papers providing information on innovative approaches to mitigating the risk of flooding and reducing pollution impacts at the property, neighbourhood, and watershed scales were then invited to submit journal papers, and those accepted in the review process were included in this Special Issue of the Water Quality Research Journal of Canada.

An overview of the selected papers indicates that no single innovative measure is adequate under all circumstances,and a multibarrier approach is deemed to be most effective. Examples of innovations at the property level include harvesting roof runoff and reusing water, managing rainwater by infiltration in swales and into soils in bioretention areas, minimizing impervious surfaces, and using pervious pavement. At the neighbourhood level, runoff impacts are mitigated by designing roads without curbs, gutters, and drain pipes, and diverting runoff into infiltration channels, swales, and wetlands. Creating roads and parking lots with pervious pavement and draining runoff from such surfaces into infiltration basins is also discussed. Among stormwater quality source controls, potential effects of street sweeping on runoff quality enhancement were assessed. New innovations at the watershed scale include: (a) the creation of wide riparian buffer zones that can detain water, remove sediments, and mitigate nutrient export and other pollutant effects, (b) the minimization of channelization of streams and rivers, and (c) the designation of floodwater storage areas. A new water balance model that is linked to a global information system (GIS) and works at all the three scales offers the best option to conceptualize stormwater problems, and their mitigation, in urban watersheds. Finally, the aim of this Special Issue is to promote examples of successful innovative approaches to improving stormwater management in Canadian cities, hoping that other practitioners will build on this experience and bring stormwater management practice to the next higher level.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=407

WQRJC 2009 44 (1) - Evaluation of Mitigation Methods to Manage Contaminant Transfer in Urban Watersheds

Three case studies on trace metal contamination in urban stormwater are presented from the Greater Vancouver area of British Columbia. In the first case study, the spatial and temporal variability in trace metals in sediments were determined in the completely urbanized Brunette watershed. A natural lake in the middle of the watershed acts as a sediment detention system, and an analysis of the sediment core showed the historic accumulation of metal and selective organic contaminants in sediments since the early 1800s. Suspended sediments transported during storm events showed significantly higher concentrations of trace metals than bedload sediments, and the largest proportion of the geochemically active metals was found to be associated with the organic-sulphur-based fraction. Benthic organism survival tests showed mixed results with lower survival and growth in urban sediments than in control sediments from a forested watershed. In the second case study, significant correlations were obtained between percent impervious cover and trace metal concentrations in 28 subwatersheds with various degrees of urbanization. It is shown that imperviousness combined with traffic density can significantly improve the prediction of metal contamination in highly urbanized watersheds. In the third case study five urban stormwater detention systems were examined over one year to determine how effective these systems were in removing metal contamination. The results were highly variable depending on a wide range of physical conditions, land use activities, traffic volume, and detention system designs. The range of total metal detention was between -15 to +72% for copper (Cu), lead (Pb), and zinc (Zn), while iron (Fe) and manganese (Mn) retention was generally poor. Labile Zn was more effectively retained in four of the five ponds, and a significant relationship was found between percent imperviousness, traffic volume, and Zn concentrations in water, sediment, and labile form.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=408

WQRJC 2009 44 (1) - A New Approach in Measuring Rainfall Interception by Urban Trees in Coastal British Columbia

Interception loss plays an important role in controlling the water balance of a watershed, especially where urban development has taken place. The aim of this study was to illustrate the importance of urban trees as a form of 'green infrastructure' where they reduce stormwater runoff and rainwater intensity. In addition, trees cause a delay in precipitation reaching the ground. Interception loss was studied in the North Shore of British Columbia. We applied a unique methodology for measuring throughfall under six different urban trees using a system of long polyvinyl chloride pipes hung beneath the canopy capturing the throughfall and draining it to a rain gauge attached to a data logger. Different tree species (Douglas-fi r [Pseudotsuga menziesii] and western red cedar [Thuja plicata]) in variable landscape sites (streets, parks, and natural forested areas) and elevations were selected to ensure that the system adequately captured the throughfall variability. Interception and throughfall were monitored over a one year cycle for which the results of seven discrete storm events for coniferous trees from the District of North Vancouver during 2007 to 2008 are presented. Cumulative gross precipitation for seven selected events was 377 mm. Average canopy interception during these events for Douglas-fi r and western red cedar were 49.1 and 60.9%, where it corresponded to average net loss of 20.4 and 32.3 mm, respectively. The interception loss varied depending on canopy structure, climatic conditions, and rainfall characteristics.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=414

WQRJC 2009 44 (1) - Treatment Performance of an Extensive Vegetated Roof in Waterloo, Ontario

Vegetated roof technologies are used as treatment measures to mitigate the effects of urban stormwater. A mass balance approach was used to assess the treatment performance of a vegetated roof located on the City Hall in Waterloo, Ontario. The vegetated and control roof sections were instrumented to measure precipitation, storage, and outflow for 18 storm events from June to October, 2006. Concentrations of suspended solids, total phosphorus (TP), and SRP (SRP) in precipitation and roof (vegetated and control) runoff were measured. A total of 155.6 mm of rain fell during the study period. The vegetated roof retained 64.5 mm (43.9%) of the total rainfall while the control roof retained approximately 5.1 mm (4.0%). For individual rain events, the vegetated roof retained an average of 3.5 mm (47.6%), while the control roof retained approximately 0.3 mm (4.7%). Water retention varied with storm size, season, and frequency of storm events. The vegetated roof retained 80.1% of precipitation for storm events <=3.5 mm, and 34.9% for storm events >3.5 mm. TP and SRP concentrations from the vegetated roof were significantly higher than either the precipitation or runoff from the control roof.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=409

WQRJC 2009 44 (1) - Evaluation of Green Roofs for Runoff Retention, Runoff Quality, and Leachability

This three-year study evaluates the quantity and quality of runoff from an extensive green roof on a multistory building in Toronto. Laboratory physical, chemical, and leachate analyses of eleven commercially available green roof growing media were also undertaken to help identify the potential influence that the growing media may have on runoff chemistry. Continuous precipitation and runoff data collected over 18 months outside of the winter period indicated that the green roof discharged 63% less runoff than a neighbouring conventional modified bitumen roof. Runoff volumes from the green roof averaged 42% less than the conventional roof in April and November, and between 70 and 93% less during the summer months. Water samples were collected from both roofs during 21 rain events in 2003 and 2004 and analyzed for general chemistry (e.g., pH, total suspended solids), metals, nutrients, bacteria (n = 16), and polycyclic aromatic hydrocarbons (n = 18). Loads of most chemical variables in green roof runoff were lower than from the conventional roof. Exceptions included constituents such as calcium, magnesium, and total phosphorus, which were either naturally present in the media or were added to promote plant growth. Total phosphorus concentrations in green roof runoff were significantly higher than the conventional roof (alpha = 0.001), and regularly exceeded the Ontario receiving water objective (0.03 mg/L). Phosphorus concentrations fell significantly after the first year of monitoring (alpha = 0.001), suggesting that the nutrient is being leached from the media. Chemical analyses of green roof growing media showed that levels of most constituents were similar to or lower than typical background concentrations for agricultural soils in Ontario. However, leachate concentrations from several media exceeded receiving water standards for phosphorus, aluminum, copper, iron, and vanadium. This study highlights the importance of engineering green roof media to minimize leaching of nutrients and other contaminants while maintaining their ability to support plant growth.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=412

WQRJC 2009 44 (1) - Street Sweeping as a Method of Source Control for Urban Stormwater Pollution

The effectiveness of street sweeping as a source control measure for stormwater pollution was tested at a site in Toronto, using three types of sweepers employed by the City. A paired-plot experimental design was employed along an arterial road with a traffi c volume of 26,000 vehicles/day. Typically, after several days of dry weather, one roadway plot was swept by the available sweeper (treated) and the following plot was left unswept (control). After sweeping, sediment on the roadway was sampled on both plots; wet samples were collected by washing off one half of each plot, and dry samples were collected by vacuum cleaning the remaining halves of both plots. Differences between swept and unswept plots were assessed by comparing: (a) conventional sediment quality parameters, total residue mass, and particle sizes for dry sediment samples, and (b) toxicity, conventional water quality parameters, and particle sizes in wet samples. Results were highly variable and contained large uncertainties. The greatest environmental benefits of sweeping were the reduction of the total mass of sediment on road surfaces and a reduction in some dissolved metals in the runoff (e.g., Cr and Zn).

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=410

WQRJC 2009 44 (1) - Characteristics of Sediment Removal in Two Types of Permeable Pavement

This study investigates the processes and characteristics of solids removal in two types of permeable pavement: UNI Eco-Stone and porous asphalt. The mechanisms and processes behind solids removal within permeable pavement structures was studied for these two types of permeable pavements using both field installations and laboratory experiments. Results from the study showed that both pavement types are capable of excellent total suspended solids removal, in the range of 90 to 96% removal of solids from influent. Particle size distribution analysis of accumulated sediment within the pavement structure and in the influent and effluent showed that the particles in the effluent of the pavements are substantially finer than that in the influent. Laboratory results involving no crust formation indicated that, although solids removal occurs throughout the entire structure, the "sieving action" occurs primarily at the geotextile interface.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=413

WQRJC 2009 44 (1) - Effectiveness of Compost Biofilters in Removal of Sediments from Construction Site Runoff

The effectiveness of compost biofilters in removal of suspended sediments from stormwater runoff was evaluated. Field experiments were conducted in the summer of 2006 at the Guelph Turf Grass Institute, University of Guelph, to verify the sediment removal efficiency of the compost biofilter from synthetic stormwater runoff. The average sediment removal efficiency of 8-inch (20-cm) compost biofilters (socks) for 5, 10, and 15 rolls were 34, 48, and 60%, respectively. The average sediment removal efficiency for 18-inch (45-cm) socks for 5, 10, and 15 rolls were 69, 84, and 95%, respectively. The decrease in sediment removal efficiency of the biofilter over time was significant. The average sediment removal efficiency of 5 rolls of the 18-inch (45-cm) sock started to decrease gradually from 70 to 62, 58, 56, and 54% after 1, 5, 10, 15, and 20 consecutive runs. Sediment removal efficiency of the biofilter for sediment particles in the size range of clay was found to be 30%, while for coarser particles such as fine silt and coarse silt was 50 and 80% removal efficiencies, respectively.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=411

WQRJC 2009 44 (1) - Sediment Assessment of Stormwater Retention Ponds within the Urban Environment of Calgary, Canada

The treatment of urban stormwater by retention ponds is known to be effective for water quality improvement as well as storm flow management and, in the past two decades, has become widely implemented. However, limited research has been conducted on the quality of sediment deposited in ponds. Therefore this study focuses on contaminant concentrations within the sediment from stormwater ponds built in Calgary, Canada. Electrical conductivity and the sodium adsorption ratio consistently exceeded the Canadian Council of Ministers of the Environment (CCME) agricultural soil quality guidelines, indicating a city-wide salt contamination issue. F3 hydrocarbon fractions, cadmium, chromium, copper, lead, selenium, and zinc were also identified as parameters of concern. In particular, the 61 Avenue SE duck pond displayed the greatest diversity and severity of contaminants due to the industrial catchment area. Removal and disposal options were limited due to the characteristics of the sediment. The examination of the solids content illustrated that all retention ponds will require the sediment to be dewatered prior to disposal. Disposal options were subsequently restricted to landfill disposal due to salt, metal, and/or hydrocarbon parameters exceeding CCME soil guidelines. One exception was the Deerfoot Trail and Highway 22X pond which could be directly disposed of in areas designated as commercial and industrial land use.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=417

WQRJC 2009 44 (1) - Developing Capacity for Large-Scale Rainwater Harvesting in Canada

Rainwater harvesting (RWH) is the ancient practice of capturing rainwater from impervious surfaces and storing it for future use. Harvesting roof runoff for domestic purposes has historically been prevalent in rural areas of Canada and the practice is currently experiencing revived interest and uptake in the urban environment. When implemented on a wide scale, RWH can contribute to both stormwater abatement and water conservation, serving to relieve pressure on existing infrastructure and potentially delay the need for infrastructure expansion. While such benefits are known, there remain several barriers that impede widespread implementation. These include cost, liability concerns, and a lack of clear policy for RWH. This paper outlines the benefits of RWH and describes findings of recent research that has attempted to develop some of the technical, administrative, and market capacity needed to overcome these barriers, focussing on water quality, design practices, economic analysis, and policy development.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=418

WQRJC 2009 44 (1) - Culex Mosquitoes, West Nile Virus, and the Application of Innovative Management in the Design and Management of Stormwater Retention Ponds in Canada

Stormwater best management practices have helped to address environmental concerns regarding peak water flows and accumulation of sediment and contamination by pollutants, but often overlook potential public health repercussions such as creating habitat for virus-carrying mosquitoes. Retention ponds frequently hold standing water for more than two weeks during the mosquito breeding season, creating development habitat for the aquatic stages of West Nile virus vectors. To avoid this problem, knowledge of vector ecology should be incorporated in the design of best management practices and integrated stormwater management plans. An integrated approach that incorporates hydrological management of water depth, flow, and surface agitation combined with manipulation of native biota and habitats based on the unique ecology and behaviour of the vector species can deter egg-laying mosquitoes by mimicking natural processes. Such an approach could help prevent disease transmission and alleviate the need for widespread application of pesticides.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=415

WQRJC 2008 43 (4) - Concentrations of Endotoxins in Waters Around the Island of Montreal, and Treatment Options

Endotoxins are a component of most Gram negative bacteria, and some cyanobacteria. They may be toxic to humans when inhaled or injected, but the effects are unclear when they are ingested. In fact, low concentrations may protect children against certain allergies. Data for endotoxins in Quebec waters are unavailable, hence this study mapped levels in the waters around Montreal, using two commercial test methods. The recently developed factor C method had a greater linear range and was more convenient to use than the widely used Limulus amebocyte lysate (LAL) method. Although the methods gave endotoxin values of the same order, a consistent relationship between the two could not be established. Endotoxin concentrations in the untreated waters varied from 32 to 1,188 EU/mL, comparable in the literature from pristine waters to wastewaters. Values were generally lower in the summer. Filtration is known to be partially effective at removing endotoxins, but the effects of disinfection are not well established. Accordingly, chlorination, ozonation, and ultraviolet light were tested for the destruction of endotoxins in water, at doses found during drinking water disinfection. While chlorine and ultraviolet light had minimal effects on endotoxin levels, ozone could achieve up to 60% reductions at Ct values (concentration x contact time) as low as 2.5 mg•min/L.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=403

WQRJC 2008 43 (4) - Identification of Sphingomonads on the Basis of Polymerase Chain Reaction Amplified 16S rRNA Gene

Sphingomonas is a genus that is basically of environmental origin but can also be associated with health hazards, especially in the hospital environment where there is a great need to properly monitor water sources. The abundance and frequent isolation of derivatives of yellow pigmented colonies from drinking water samples in Lebanon-where an intermittent mode of supply is employed, and which induces frequent biofilm sloughing-necessitated the establishment of a rapid and feasible assay to screen specifi cally for sphingomonads. In this study, 50 isolates recovered from drinking water with yellow- to orange-pigmented colonies were used to establish a polymerase chain reaction-based (PCR-based) screening assay. The use of sphingomonad specific modified primers gave one common band with a size of 320 bp in all resumptive and sequence confirmed sphingomonads. However, no amplification was observed with Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Applying the PCR-based assay described in this paper increased both the efficiency and the reliability of screening for sphingomonads in water samples, thereby minimizing related risk factors.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=399

WQRJC 2008 43 (4) - Swimming in Sewage: Indicators of Faecal Waste on Fish in the Saint John Harbour, New Brunswick

Despite increased recognition of the risks to the health of humans and the environment, untreated municipal wastewaters are still discharged into waterways worldwide. One of the primary concerns related to its discharge into surface waters is the risk to human health through the transmission of pathogens associated with faecal matter. Saint John, New Brunswick, is one of the few Canadian cities that still releases untreated sewage into its urban waterways and harbour. Water faecal coliform levels, an indicator of faecal waste and associated pathogens, are well above recreational guidelines in some of these areas. Although it is not encouraged by the municipality, recreational fishing occurs in these areas and this raises concerns regarding the potential for disease transmission during the handling of these fish. To investigate the potential for fish to be a vehicle of pathogen transmission to humans, the skin of wild fishes (smelt, Osmerus mordax, and mummichog, Fundulus heteroclitus) and caged mummichog was sampled for faecal coliforms from several sites in Saint John between August and November of 2005. Water faecal coliform levels at sites used for caging studies and wild fish collections, and the duration of caging were compared with the number of faecal coliforms on the surface of the fish. Skin samples from the two fish species collected from the wild indicated elevated levels of fecal coliforms in some locations. Both wild and caged fish showed that the amount of faecal coliform on fish skin is influenced by the water faecal coliform levels.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=401

WQRJC 2008 43 (4) - Distribution of ¹⁴C-labelled Atrazine, Methoxychlor, Glyphosate, and Bisphenol-A in Goldfish Studied by Whole-Body Autoradiography (WBARG)

Nonpersistent contaminants represent thousands of chemicals used as pesticides, pharmaceuticals, personal care products, additives, etc. Because of this diversity, the assessment of the environmental risks they may pose for the environment represents a formidable task. Identification of target organs is key information needed to orient further research on newlyinvestigated organic xenobiotics. We used whole-body autoradiography to visualize the distribution of ¹⁴C-labelled atrazine, methoxychlor, glyphosate, and bisphenol-A in goldfish (Carassius auratus) and identify target organs. Fish were exposed for 2 days (glyphosate and bisphenol-A) and 7 days (atrazine and methoxychlor) to the radiolabelled compounds at a concentration of 15 nM. They were then frozen, embedded in carboxymethylcellulose gel, 20-μm-thick cryosections were collected, freeze-dried, and exposed to phosphor screens to visualize the tissue distribution of radioactivity. Goldfish did not accumulate glyphosate. The three other compounds were accumulated, mostly in the gall bladder. Nevertheless, unforeseen accumulation sites were observed; atrazine accumulated in the uveal tract of the eye, high levels of radioactivity were found in the cerebrospinal fluid of goldfish exposed to methoxychlor, and an important accumulation of bisphenol-A was seen in urine, oral mucosa, esophagus, and intestinal lumen. The potential toxicological consequences of the accumulation of these chemicals at very specific locations within the fish body are discussed and further research suggested.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=404

WQRJC 2008 43 (4) - Influence of Polymer Selection on Nutrient Phase Separation for Waste Activated Sludge Thickening at Bench Scale

The use of polymers to condition waste activated sludge prior to thickening is a common practice at domestic wastewater treatment plants. In this study, the performance of various commercially available granular polymers was observed. Thickening by gravity belt thickener was simulated at the bench scale, and the thickened sludge and filtrate produced were examined. Laboratory analysis was used to determine the differences in nutrient chemical concentration in the thickened solids and filtrate produced by different polymers. By examining the content of nutrient chemicals such as total Kjeldahl nitrogen (TKN), ammonia nitrogen, and total phosphorous, this research showed that polymer choice could affect the chemical composition of thickened sludge and filtrate with respect to nutrients. Results showed that the total phosphorous and TKN concentrations in the thickened sludge and filtrate were affected by polymer selection, which suggested that the chemical loading on the plant due to filtrate recycle, and the nutrient content of thickened sludge delivered to the digester are affected by polymer choice. Polymer optimization studies that examine nutrient properties of filtrate and thickened sludge beyond the basic total suspended solids analysis may be advantageous to minimize recycling of these compounds into the filtrate phase.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=405

WQRJC 2008 43 (4) - Exposure to Model-Scale Sewage Treatment Plant Effluent Affects Circulating Sex Steroids in Rainbow Trout

Reproductive steroids were assessed in immature rainbow trout (Oncorhynchus mykiss) after 21-day exposures to 10% primary or 100% secondary-treated model-scale sewage treatment plant (STP) effluent. Plasma testosterone was elevated over 4-fold in rainbow trout exposed to 10% primary model STP effluent and 100% secondary model STP effluent, and 1.7-fold and 2.5-fold in trout exposed in the following years, 2 and 3, respectively. Exposure to the positive control compound, 17Β-estradiol (100 ng/L), raised plasma estradiol concentrations of exposed trout, but had few effects on plasma testosterone concentrations. There was no induction of ethoxyresorufi n-O-deethylase (EROD) activity by any treatment, but liver-somatic indices were elevated in year-1 fish exposed to 10% primary or 100% secondary-treated model STP effluent. The results show that exposure to this model STP effluent can increase circulating testosterone concentrations. The rainbow trout 21-day test proved to be a simple bioassay that holds promise for onsite assessments of effluents.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=406

WQRJC 2008 43 (4) - Relative Body Size Influences Breeding Propensity in Fathead Minnows: Implications for Ecotoxicology Testing Procedure

Numerous factors affect the ability or choice of fishes to breed. For example, studies demonstrate that the appropriate amount of light, temperature, and food must be present before many species will breed. For some species, we are also aware of social factors that affect breeding, such as the size or colour of one's potential mates. Although studies on mate choice (i.e., choice of one potential mate over another) and factors affecting breeding are extensive, there remain significant gaps in our knowledge with regard to scientifically important species. For instance, the fathead minnow (Pimephales promelas), used by numerous researchers as a test subject in reproductive toxicology and behavioural ecology, has well established physical parameters known to facilitate breeding. Conversely, there is very little data describing social factors which may influence breeding. The purpose of the current study was to examine some of the factors affecting mate choice in the fathead minnow. Results indicate a consistent relationship between male and female size length and mass), which can be used to predict the probability of a couple's breeding potential. Specifically, we found that female minnows prefer larger males. In successful pairs there was a greater difference in size between the male and female as compared with unsuccessful pairs. The findings of this study could substantially improve methods for reproductive studies in laboratories or artificial streams by decreasing both the number of pairs tested against baseline performance criteria and the time needed to establish actively breeding individuals. This will decrease the cost and increase the efficiency of future studies, as well as add ecologically interesting knowledge to the literature regarding a scientifically important, ubiquitous, and representative North American fish species.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=400

WQRJC 2008 43 (4) - Filtration du bleu de m�thyl�ne, du chrome hexavalent et de l'acide �thyl�ne diamine t�trac�tique sur une membrane c�ramique d'ultrafiltration � base de ZnAl₂O₄-TiO₂
Filtration of Methylene Blue, Hexavalent Chromium, and Ethylenediaminetetracetic Acid through an Ultra-Filtration Ceramic ZnAl₂O₄-TiO₂-based Membrane

Dans ce travail, nous avons �tudi� la r�tention du bleu de m�thyl�ne (BM), du chrome hexavalent Cr(VI) et de l'acide �thyl�ne diamine t�trac�tique (EDTA) par une membrane ZnAl₂O₄-TiO₂. Les r�sultats obtenus ont montr� que cette membrane pr�sente une charge r�siduelle qui d�pend fortement du pH. L'effet de la pression et de la concentration sur le taux de rejet des esp�ces filtr�es est �tudi�. La r�tention des esp�ces ioniques est due � un m�canisme fond� sur les interactions �lectrostatiques entre les charges port�es par la membrane et les ions. Le taux de rejet du BM diminue avec l'augmentation du pH, une situation qui provoque une diminution progressive de la charge positive de la membrane. Dans le cas du Cr(VI) et de l'EDTA, un pH alcalin est favorable pour une bonne r�tention car la charge membranaire devient moins positive, le chrome est sous forme de CrO₄^2- et l'EDTA appara�t sous ses formes les plus anioniques. L'effet de la pression sur le taux de rejet des solut�s a montr� que la contribution convective domine aux fortes pressions et conduit � des r�tentions maximales du fait que le flux convectif du solvant J_v augmente et vient diluer le perm�at.

In this work, the retention of methylene blue (MB), hexavalent chromium Cr(VI) and ethylenediaminetetracetic acid (EDTA)by a membrane ZnAl₂O₄-TiO₂ was studied. The results obtained show that this membrane carries a residual charge which depends strongly on the pH. The effect of pressure and concentration on the retention rate of filtered species was investigated. The retention of the ionic species is due to a mechanism based on the electrostatic interactions between the membrane charge and the ions. The retention rate of MB decreases with the increase of pH because the resulting alkanisation causes a progressive decrease of the positive charge of the membrane. In the case of Cr(VI) and EDTA, an alkaline pH is favourable for a good retention because the membrane charge becomes less positive, chromium is in the form of CrO₄^2- and the EDTA appears in its most anionic forms. The effect of pressure on the solute retention rates shows that the contribution due to convection predominates at high pressures and favours maximum retention as the convective flux of the solvent J_v increases and causes a dilution of the permeate.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=402

WQRJC 2008 43 (2/3) - An Assessment of Environmental Changes in Three Lakes from King's County (Nova Scotia, Canada) Using Diatom-Based Paleolimnological Techniques

Paleolimnological approaches using sedimentary diatom assemblages were used to assess water quality changes over the last approximately 200 years in three lakes from King's County, Nova Scotia. In particular, the role of recent shoreline development in accelerating eutrophication in these systems was assessed. Sediment cores collected from each lake were analyzed for their diatom assemblages at approximately 5-year intervals, as determined by ²¹⁰Pb dating. Analyses showed that each system has changed, but tracked different ecosystem changes. Tupper and George lakes recorded shifts, which are likely primarily related to climatic warming, with diatom assemblages changing from a preindustrial dominance by Aulacoseira spp. to present-day dominance by Cyclotella stelligera. In addition to the recent climatic-related changes, further diatom changes in the Tupper Lake core between approximately 1820 and 1970 were coincident with watershed disturbances (farming, forestry, and construction of hydroelectric power infrastructure). Black River Lake has recorded an increase in diatom-inferred total phosphorus since about 1950, likely due to impoundment of the Black River system for hydroelectric generation and subsequent changes in land runoff. Before-and-after (i.e., top-bottom) sediment analyses of six other lakes from King's County provided further evidence that the region is being influenced by climatic change (decreases in Aulacoseira spp., increases in planktonic diatom taxa), as well as showing other environmental stressors (e.g., acidification). However, we recorded no marked increase in diatom-inferred nutrient levels coincident with shoreline cottage development in any of the nine study lakes. Paleolimnological studies such as these allow lake managers to place the current limnological conditions into a long-term context, and thereby provide important background data for effective lake management.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=398

WQRJC 2008 43 (2/3) - Spatial Distribution and Characterization of Contaminated Soils in Riverbanks of Saint-Fran�ois and Massawippi Rivers (Southern Qu�bec)

Soils contaminated with hydrocarbons (C₁₀ to C₅₀) and other contaminants were recently discovered in the banks of the Saint-Fran�ois and Massawippi Rivers, which are between the municipalities of Eustis and Drummondville (southern Qu�bec). It is probable that this contamination originated from accidental or illegal discharges at the site of the old Eustis mine located near the Massawippi River. The contaminated layers sometimes extend more than one metre in the banks. Unlike water quality monitoring, which resulted in numerous government reports, no studies have been done on the contamination of Saint-Fran�ois and Massawippi riverbanks or river bed sediments, even though these rivers pass through former industrial and mining areas. This study provides an evaluation of the spatial distribution of the contamination along the riverbank and characterizes the contaminated soils in order to evaluate the concentration levels of hydrocarbons and other pollutants (e.g., heavy metals). The results obtained show that the banks of the Windsor area are more contaminated by hydrocarbons (C₁₀ to C₅₀) than the other sites. The other pollutants (heavy metals, PCBs polychlorinated biphenyl], and PAHs [polycyclic aromatic hydrocarbons]) indicated low levels of contamination, except for some metals (Cu and Zn). The Minist�re du D�veloppement Durable, de l'Environnement et des Parcs uses three generic criteria or levels (A, B, and C) to determine the degree of soil contamination. The levels B and C indicate the presence of contaminants in soil, and these levels have certain usage constraints.

Des sols contamin�s aux hydrocarbures (C₁₀-C₅₀) et d'autres contaminants ont �t� d�couverts r�cemment dans les berges des rivi�res Saint-Fran�ois et Massawippi, entre les municipalit�s de Eustis et Drummondville (sud du Qu�bec). Il est probable que cette contamination provienne d'un d�versement accidentel ou ill�gal dont la source serait l'ancienne mine de Eustis situ�e au abord de la rivi�re Massawippi. La couche contamin�e se retrouve parfois � plus d'un m�tre de profondeur des berges. Malgr� qu'il existe de nombreux rapports gouvernementaux sur la qualit� de l'eau de ce bassin, aucune �tude sur la contamination des berges et des s�diments du lit n'a �t� r�alis�e le long des rivi�res Saint-Fran�ois et Massawippi, m�me si ces rivi�res circulent � travers d'anciennes zones industrielles et mini�res. Cette �tudie vise � �valuer la distribution spatiale de la contamination le long des berges et dresse une caract�risation du type et du niveau de concentration des hydrocarbures et autres contaminants (ex. m�taux lourds). Les r�sultats obtenus indiquent que certaines berges sont davantage contamin�es par des hydrocarbures (C₁₀-C₅₀), en particulier dans le secteur de Windsor. Les autres polluants (m�taux lourds, BPC et HAP) indiques des faibles niveaux de contamination � l'exception de certains m�taux (Cu et Zn). Pour les sites plus pollu�s, ils sont inclus dans les crit�re B et C qui pr�sente certaines contraintes d'utilisation du sol en tenant compte des normes du Minist�re du D�veloppement durable, de l'Environnement et des Parcs.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=397

WQRJC 2008 43 (2/3) - Distinguishing the Hydrochemistry of Two Hydrological Basins in Northern Mexico Using Factor Analysis

Hydrochemical parameters of groundwater from two hydrological basins in northwestern Mexico were measured. In one of them is located the city of Puerto Pe�asco, and in the other one is the city of El Rosarito. A factor analysis was used to characterize the main influences that affected the water quality of each region. Based on the results of this method, the aquifer located in Rosarito is mainly affected by seawater intrusion and the presence of high levels of manganese, while the groundwater characteristics at Puerto Pe�asco are influenced by reductive conditions, probably caused by bacterial contamination. Although most of the parameters analyzed in this study were within normal ranges for groundwater, knowledge of the factors affecting sources of water can help to develop restoration projects and preventive management practices to prevent an irreversible degradation of groundwater quality.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=382

WQRJC 2008 43 (2/3) - Potato Land Use and Nitrate Runoff Characteristics of Two Subcatchments of the Wilmot River Watershed, Prince Edward Island (PEI), Canada

Two subcatchments in the upper reaches of an arable watershed in central Prince Edward Island (PEI), farmed mostly to potatoes (in rotation), were monitored year-round for nitrate runoff. Land management inventories were done every fall and spring and assessed against nitrate runoff through regression analysis for the period 1991 to 2004. Nitrate concentration (averaging approximately 7 mg�L^-1 over 14 years) in the outfl ow varied considerably yearly (standard deviation: 2.76) and monthly (standard deviation: 3.43), and exceeded quality guidelines (of 13 mg�L^-1) for aquatic life in freshwaters at about a 6% frequency, averaging a nitrate-dollar loss of $1.70 per hectare per year.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=393

WQRJC 2008 43 (2/3) - Influence of Livestock Manure Type on Transport of Escherichia coli in Surface Runoff

Since livestock manure type may influence transport of Escherichia coli (E. coli) in runoff, the choice of which type of livestock manure to apply to cropland may be a potential beneficial management practice (BMP) to reduce and manage E. coli in runoff. Four common manure types (beef, dairy, chicken, hog) were applied to a clay loam soil in small runoff boxes, and a rainfall simulator was used to generate artificial runoff. Runoff samples were collected at three successive time intervals (0 to 5, 5 to 15, 15 to 30 min) and analyzed for flow-weighted mean concentrations (FWMC) of E. coli as well as mass loss of E. coli expressed as a percentage of total E. coli applied. Manure treatment had a significant (p �� 0.10) influence on FWMC of E. coli in runoff. The FWMC of E. coli in runoff for the dairy (33.3 CFU per 100 mL) treatment was similar to the control (3.2 CFU per 100 mL), but E. coli concentrations for the beef (955 CFU per 100 mL), chicken (1,134 CFU per 100 mL), and hog (368 CFU per 100 mL) treatments were all significantly greater than the control. The FWMC values were not significantly different among the four manured treatments except for dairy versus chicken manure, where values were significantly lower for dairy manure. Concentrations of E. coli were less than the guideline for recreation waters (< 200 CFU per 100 mL) for the control and dairy treatment, but exceeded this guideline for beef, chicken, and hog manures, suggesting that dairy manure may be better than the other three manures for protecting surface water bodies for recreational use. Our study suggests that manure type may be a possible BMP to manage and control FWMC of E. coli in surface waters.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=386

WQRJC 2008 43 (2/3) - Transport of Lithium Tracer and E. coli in Agricultural Wastewater Treatment Wetlands

Agricultural waste must be managed effectively to protect surface and groundwater resources, as well as human health. Constructed wetlands can provide a low-cost environmentally acceptable method for the treatment of agricultural wastewater. An ionic tracer (Lithium chloride [LiCl]) and a biotracer (a naladixic acid-resistant strain of Escherichia coli) were injected into six pilot-scale constructed wetlands treating dairy wastewater: three surface-flow (SF) wetlands and three subsurfaceflow (SSF) wetlands. Each wetland was 3.9-m long and 1.7-m wide. Residence time distribution functions were calculated for each wetland to investigate the hydraulic behaviour of each system during winter and summer conditions. During the summer study, the mean residence times for SF wetlands 2, 4, and 6 were 12, 16, and 14 days, respectively, while the mean residence time for SSF wetlands 1, 3, and 5 were 23, 18, and 22 days, respectively. The longitudinal dispersion coefficients were in the order of 10-6 m²�s-1 for each wetland during the summer and winter. The mean residence time for SF wetlands 2, 4, and 6 during the winter study were 8, 10, and 10 days, respectively, while the mean residence time for SSF wetlands 1, 3, and 5 were 8, 9, and 10 days, respectively. E. coli effluent peaks often occurred prior to Li peaks, suggesting that bacteria may be motile within the wetland environment. This study suggests that dispersion is an important mass transport process in both SF and SSF wetlands. Long-term operation of SF and SSF treatment wetlands may cause reduced retention times and treatment efficiency due to organic matter accumulation and channelling. Cold winter temperatures may also increase the survival of bacteria within treatment wetland systems, decreasing the wetland's ability to reduce bacteria concentrations during the winter months.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=396

WQRJC 2008 43 (2/3) - Water Quality Assessment in the Application of Stormwater Reuse for Irrigating Public Lands

Stormwater reuse for irrigating public lands presents a viable option for reducing potable water demand in urban settings. However, stormwater generally contains high pollutant levels, which may cause adverse effects on public health and the environment. Water quality in a stormwater retention pond in the City of Calgary, Alberta, was examined in order to assess the feasibility of reusing stormwater for irrigation purposes. Field campaigns were conducted in the 2004, 2005, and 2006 irrigation seasons. The water quality data indicated that the pond water quality generally satisfies the requirements for stormwater recycled as irrigation water. Relationships between stormwater quality and climatological variables were investigated using correlation and regression analysis. Their correlations suggest that intermittent rain events contribute to elevated microbial levels and total suspended solids (TSS). Other climatological variables-air temperature, cloud cover, wind speed, and relative humidity-are also correlated with certain water quality parameters including fecal coliform (FC), TSS, nutrients, and conductivity. Formulated regression equations demonstrate good predictions of observed FC and TSS using climatological variables. Results showing stormwater quality as a function of climatological variables imply that climate change might have potential influence on stormwater quality.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=390

WQRJC 2008 43 (2/3) - The Benefits of Biotreatment for Reducing the Effects of Pulp and Paper Mill Effluents on Fish Reproduction in Laboratory Tests

Pulp and paper mill effluents have been reported to cause changes in reproductive indicators of fish in laboratory and field studies. These changes include reduced egg production and gonad size, and altered hormone levels and expression of secondary sex characteristics. We examined the performance of biotreatment plants for their potential in abating effects of pulp and paper mill effl uents on fish reproduction under laboratory conditions. A bleached kraft mill effluent (BKME) treated in an aerated lagoon and a thermomechanical pulp mill effluent (TMPE) treated by aerobic sludge in a sequential batch reactor were selected for study. Mature fathead minnows (Pimephales promelas) were exposed to effluents before and after biotreatment under continuous renewal conditions for 21 days. Egg production was monitored daily, while morphometric parameters (length, weight, gonad size), secondary sexual characteristics, and steroid hormone and vitellogenin levels were measured at the end of the effluent exposure. The effluent from both mills before biotreatment impaired the reproductive capacity of minnows (egg production) at concentrations of 10 and 20% vol/vol, but not at 2% vol/vol. Exposure to biotreated effluents from both mills at concentrations of 2, 10, 20, and 40% vol/vol caused no significant differences in overall reproductive capacity of minnows as compared with controls. These results indicate that biotreatment can significantly improve the quality of a BKME and an effluent from a TMP mill with respect to the reproductive capacity of fish as determined in laboratory tests.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=387

WQRJC 2008 43 (2/3) - Quantification of Plant Sterols in Pulp and Paper Mill Effluents

Pulp and paper mill effluents (PPMEs) may contain high levels of otherwise naturally occurring organic pollutants such as plant sterols, which are suspected endocrine disrupting chemicals. Exposure to such chemicals may cause various physiological and morphological abnormalities that have been reported in the fish and other aquatic life inhabiting PPME receiving waters. Plant sterols, or phytosterols, form a constituent of wood extractives that may be released into the effluents during the pulping and paper making processes. Isolation and analysis of sterols from the complex mixture of PPMEs is challenging and standard analytical protocols do not exist. The need for having a reliable method for analyzing a particular environmental contaminant such as plant sterols cannot be overemphasized. In the present study a technique was modified for reliable analysis of PPME sterols. The technique involves liquid-liquid extractions using methyl-t-butyl ether and trimethyl-silylation derivatizations of the extracted sterols. Identification and quantification of the PPME sterols were accomplished by gas chromatography and mass spectrometry. Analytical problems were resolved by conducting multiple extractions, drying the sterol extracts, and redissolving and silylating the extracts at an increased derivatization temperature of 70 �C. This shortened the suggested incubation period from 12 to 4 h. The modified technique offered improved method sensitivity and reproducibility, and successfully quantified campesterol, �-sitosterol, �-sitostanol, stigmasterol, stigmastanol, cholesterol, and ergosterol in PPMEs. Primary and secondary treated PPMEs analyses suggested 800 � 190 �g/L total sterols in primary effluents, and 211 � 90 �g/L in biologically treated final effluents. �-Sitosterol, �-sitostanol, and campesterol alone accounted for about 80% of the total sterols. A general comparison of the sterols in primary and secondary effluents suggested about 73% removal across the secondary treatment systems sampled.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=392

WQRJC 2008 43 (2/3) - Application of SCR Technology for Degradation of Reactive Yellow Dye in Aqueous Solution

The effect of sonochemical reactors (SCR) technology upon the degradation of reactive yellow dye has been studied and reported here. Sonochemical reactors (ultrasound irradiation) produce strong cavitation in aqueous solution causing shock wave and reactive free radicals by the violent collapse of the cavitation bubble. These effects should contribute to destruction as well as the decomposition of dyes. This research investigated the efficacy of sonochemical reactors for decolourizing reactive yellow dyes in aqueous solution. In this research, the influence of concentration, frequency, treatment time, and reactor power on the dye decomposition were investigated. The results obtained from the study carried out have shown that SCR can be used effectively for degradation of reactive yellow dyes. The results suggested sonochemical reactors provided maximum destruction, and 120 min treatment time at 130 kHz and 500 W were the most effective for the maximum degradation of reactive yellow dye.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=384

WQRJC 2008 43 (2/3) - Factors Influencing Formation of Trihalomethanes in Drinking Water: Results from Multivariate Statistical Investigation of the Ontario Drinking Water Surveillance Program Database

The presence of trihalomethanes (THMs) in drinking water is an important issue in the context of their potential health effects. Numerous studies have developed models in the past three decades relating THMs concentrations to different factors (e.g., dissolved organic carbon [DOC], chlorine dose, pH, etc.). Previous studies characterized the importance of specific factors through controlled studies using synthetic water or source waters from a small number of water treatment plants. Few studies have reported looking for factors related to THMs formation system-wide across many different water supply systems, and in environments where many factors vary simultaneously. This study presents the results of a multivariate statistical analysis for 162 water supply systems in Ontario, Canada for 2000 to 2004. Principal component analysis (PCA) was applied to determine important factors and possible clusters of variation. PCA identified DOC, chlorine dose, pH, temperature, and reaction time as significant factors for THMs formation. Separate clusters were observed for DOC-colour; chlorine dose-total/free residual chlorine; and hardness-alkalinity. Each cluster indicated factors varying together and representing significant variation. Temperature and pH were found significant and uncorrelated throughout the analysis. The multivariate analysis is the first phase of a continuing investigation into THMs formation with the ultimate goal of developing a predictive model, which can be used to perform human health risk-cost balance studies for drinking water quality management.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=389

WQRJC 2008 43 (2/3) - The Effect of Short-Term Dissolved Oxygen Transients on Activated Sludge

The effect of short-term dissolved oxygen (DO) disturbances on municipal activated sludge was studied, in a batch system, with respect to changes in supernatant turbidity, suspended solid (SS) concentrations, proteins, polysaccharides, and cations in the extracellular polymeric substances (EPS). Results showed that turbidity increased by 20 times when the DO concentration decreased below 0.5 mg/L, and supernatant SS concentrations increased by 1 to 2 times with DO reduction, implying the presence of more unsettled particles in the supernatant. Concomitantly, soluble proteins increased from less than 1 mg/L to up to 30 mg/L, and bound proteins decreased by more than 15% under DO limitation. Further enzymatic tests confirmed that, compared with polysaccharides, proteins were more involved in preventing sludge deflocculation. The DO stress also caused significant changes in the bulk concentrations of K⁺ and Ca²⁺; K⁺ increased by 40% and Ca²⁺ decreased by 30%. When the DO concentration was restored after 6 hours, reversible changes were observed in supernatant turbidity and SS, and concentrations of EPS proteins and cations, indicating a possible physiological response of microorganisms to a short-term low DO disturbance.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=383

WQRJC 2008 43 (2/3) - Study on the Performance of an Anoxic Biotrickling Filter for the Removal of Hydrogen Sulphide from Biogas

The paper presents aspects related to the performance of an anoxic biotrickling filter designed for hydrogen sulphide (H₂S) removal from biogas. In this process, nitrate was supplied through a nutrient solution as an electron acceptor for anoxic growth of H₂S-oxydizing microorganisms. The biotrickling filter's packing media consisted of a layer of plastic fibres over volcanic rocks in a ratio 0.78:1 by volume. The total volume of packing media was 0.014 m³. Several H₂S loading rates (IL) were tested under continuous dynamic conditions, ranging between 20 and 550 g of H₂S feed/(m³bed�day). Maximum process performance (>95%) was observed for IL ranging up to approximately 300 g of H₂S feed/(m³bed�day). The degradation of hydrogen sulphide occurred with the formation of both sulphate and elemental sulphur, their formation ratio being dependent on H₂S loading rate. Elemental sulphur was found to be the dominant degradation product, particularly at IL > 96.18 g of H₂S feed/(m³bed�day). The use of two biotrickling filters in series was also tested, and a significant improvement in process performance was observed. This technology allows simple operation with low maintenance and has the potential for sulphur recovery.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=385

WQRJC 2008 43 (2/3) - �tude comparative de deux floculants pour le traitement physicochimique d'une eau us�e municipale : chitosane et polym�re de synth�se
Comparative Study of Two Flocculants in the Physical-Chemical Treatment of Municipal Wastewater: Chitosan and a Synthetic Polymer

Le traitement des eaux us�es municipales par voie physico-chimique requiert g�n�ralement l'utilisation d'un coagulant � base de sels m�talliques et d'un floculant (ou aide-coagulant) synth�tique. L'application du concept de d�veloppement durable dans le traitement des eaux privil�gie une approche utilisant des produits renouvelables tels les biopolym�res naturels. Des essais avec du chitosane (biopolym�re naturel) comme floculant ont �t� effectu�s � l'�chelle du laboratoire (jar test) et � l'�chelle r�elle (station municipale de type physico-chimique) afin de mieux comprendre les particularit�s li�es � l'utilisation de ce produit naturel lors du traitement des eaux. Les essais � l'�chelle r�elle r�alis�s dans deux fili�res parall�les de traitement ont compar� l'utilisation de la combinaison alun et polym�re de synth�se anionique (AL/PS) � la combinaison alun et chitosane (AL/CH). Des abattements de la DCO de 87 %, des MES de 95 % et de 93 % pour le P_tot ont �t� observ�s avec la combinaison AL/CH. Ces r�sultats d'abattement de la DCO et des MES sont semblables � ceux obtenus dans la fili�re de traitement AL/PS. Certains essais indiquent un dosage de coagulant (alun) inf�rieur de 24,8 % avec la combinaison AL/CH. L'abattement du P_tot est constamment plus �lev� avec la combinaison AL/PS en raison du dosage plus �lev� de coagulant.

The treatment of municipal wastewaters by physical-chemical methods normally requires the use of a metallic salt coagulant and a synthetic coagulant aid. Integrating the sustainable development concept in the treatment of waters favours the use of renewable resources such as natural biopolymers. In order to better understand the peculiarities of using a product of natural origin in municipal wastewater treatment, laboratory testing (jar tests) was achieved with chitosan as a coagulant aid, as well as full-scale testing in a medium size physical-chemical wastewater treatment plant. The full-scale test was performed in two parallel, identical systems treating the same wastewater under the same conditions. The one using a combination of alum with a synthetic polymer (AL/SP) was compared with the other which used alum and chitosan (AL/CH). Removals for COD, SS, and total phosphorus reached 87%, 95% and 93%, respectively, for the AL/CH combination. These results are similar to those obtained for COD and SS with the AL/SP combination. Some results show a coagulant dosage (alum) up to 24.8% lower with chitosan as the usual coagulant aid. For total phosphorus, however, the results show that removals were higher with the AL/SP combination because of a higher coagulant dosage.

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WQRJC 2008 43 (2/3) - Evaluation of Plantain Peelings Ash Extract as Coagulant Aid in the Coagulation of Colloidal Particles in Low pH Aqua System

The use of plantain peelings ash extract (PPAE) as a coagulant aid in a low pH water was evaluated in the present studies. Plantain peelings were collected, washed, dried, and ashed in a furnace. The ash was extracted using deionized water, and the chemical composition was examined using an atomic absorption spectrophotometer. Synthetic turbid water of varying turbidities (50, 100, 300 NTU) and varying pHs (2, 3, 4) were prepared by clay dispersion in deionized water. The optimum alum dosages for the coagulation of colloidal particles in different turbid waters of varying pHs were determined by method of continuous variation using the jar test procedure. The residual turbidities of the treated waters were determined, and the alum doses that gave the minimum residual turbidities were taken as the optimum dosage for the removal of colloidal particles. The use of PPAE as a coagulant aid with alum showed an improvement in the value of residual turbidities of the treated waters. Results obtained from the different studies showed that treated waters of lower residual turbidities were obtained from synthetic waters of higher initial turbidities and pHs. The pH of the treated water decreased with an increase in alum dosage, whereas an increase in the pH value was observed with the addition of PPAE as a coagulant aid. High correlation coefficient values (r²) were obtained when the changes in pH (i.e., ΔpH = pH_f -pH_i) of the treated waters were correlated with alum and PPAE additions, and mathematical relationships were derived from the linear graph. Studies on the effect of flocculation time on residual turbidity showed that an optimum flocculation time of 30 minutes was attained, when alum was used alone, before redistribution and redispersion of the flocs was noticed. This phenomenon did not occur when PPAE was used as a coagulant aid.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=391

WQRJC 2008 43 (2/3) - Optimization of Solids Separation in Dissolved Air Flotation

Sizes of flocs were analyzed to identify characteristics of the particle size distribution optimal for separation by dissolved air flotation (DAF). Optical microscopes and two particle counters were used for floc sizing. A Brightwell Technologies particle counter was found to provide floc size measurements in agreement with improved microscopic methods. The particle counter provided distribution of flocs with sizes down to 1 micron (�m). This allowed for inclusion of flocs with size ranging from 5 to 1 �m, which were excluded from the analyses in the earlier study. Four alum dosages were applied: 15, 25, 40, and 60 mg/L. The turbidity and colour of the DAF effluent at alum dosages of 25, 40, and 60 mg/L were very similar. However, the analysis of the flocs in the treated effluent revealed that, at the alum dose of 60 mg/L, particle removal was the best. Therefore, this dosage was selected as optimal for the solid/liquid separation process. The average size of coagulation flocs at 60 mg/L was approximately 30 �m, and was equal to the estimated size of air bubbles produced by the saturator. Therefore, this study confirms the finding of the earlier work claiming that the optimum DAF performance is attained when the mean floc size and the bubble size are equal. Similar size of floc and bubble indicates that flocs act predominantly as nuclei for bubble formation. This finding contributes to the knowledge of mechanisms of floc air bubble attachment in DAF.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=388

WQRJC 2008 43 (1) - Inactivation of the Bacteriophage MS2 by the Ciliated Protozoan, Tetrahymena thermophila

Because the range of biological mechanisms responsible for the inactivation of viruses in man-made and natural water systems is poorly understood, the involvement of the free-living ciliated protozoan, Tetrahymena thermophila, in viral inactivation was investigated. The ciliate was found to remove the bacteriophage MS2 when the phage and ciliate were co-incubated in a simple salt solution. MS2 was enumerated as plaque forming units (pfus). MS2 removal was achieved only by living and not formalin-fixed ciliates, and was blocked by treatments that impaired the formation of food vacuoles. These treatments were cytochalasin B and low temperature. When fl uorescently labelled with SYBR gold prior to co-incubation, MS2 were seen inside Tetrahymena within vesicles that had the shape and size of food vacuoles. The number of pfus associated with Tetrahymena was low. This suggests that the engulfment of the phage into food vacuoles led to the inactivation of MS2, which is frequently used as a surrogate for poliovirus in environmental microbiology. In the future, a broader understanding of the capacity of ciliates to inactivate viruses could lead to methods for improving water quality through the manipulation of ciliate populations and activities.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=378

WQRJC 2008 43 (1) - Impact of Particulate Matter on Distribution System Disinfection Efficacy

Microorganisms have been shown to survive drinking water disinfection and remain viable in disinfected waters despite the presence of disinfectant residuals. This may be partially attributed to protection by particulate matter. The aim of this study was to determine the effects of the presence of particulate matter on disinfection kinetics. Sphingomonas paucimobilis ATCC 10829 and Helicobacter pylori ATCC 43504 were used in inactivation experiments in the presence and absence of soil, corrosion, and wastewater particles. The results showed that the presence of such particles tended to inhibit chlorine and monochloramine inactivation, although the magnitude of the impact under the conditions tested was small (e.g., 1-log reduction in inactivation for several minutes of contact time in the presence of less than 1 mg/L of disinfectant).

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=376

WQRJC 2008 43 (1) - Bench-Scale Evaluation of Sonication as a Pretreatment Process for Ultraviolet Disinfection of Wastewater

It is generally known that sonication improves ultraviolet (UV) disinfection kinetics of municipal effluents by breaking large suspended particles. However, the feasibility of sonication as a pretreatment technology largely depends on wastewater quality and discharge requirements. The purpose of this study was to investigate the potential benefits of ultrasound for improving the UV disinfectability of various effluent types, including primary, activated sludge, and trickling filter effluents. It was found that the tailing level of the dose-response curve at high UV doses (>40 mJ/cm²) decreased with the increased sonication time. The reduction in the tailing level had a strong correlation with the decrease in the number concentration of large particles (>60 μm) such that 1 log reduction in the number concentration of large particles resulted in 1.4, 1.1, and 1.7 log reductions in the tailing level for primary, activated sludge, and trickling filter effluents, respectively. However, the improvement in the UV disinfectability due to sonication was partly offset by the reduction in the UV transmittance of the effluent.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=372

WQRJC 2008 43 (1) - A Literature Review of Ultrasound Technology and Its Application in Wastewater Disinfection

In recent years, there has been an increase in the application of ultraviolet (UV) light as an alternative to chemical disinfection technologies. However, in the case of poor quality effl uents, the practical limit of UV disinfection of wastewater is dictated by disinfection-resistant, particle-associated bacteria. Although these particles may be removed by fi ltration, an alternative method to reduce the impact of suspended particles on disinfection effi ciency is to decrease particle size using ultrasound technology. Mechanical forces exerted on particles due to the collapse of cavitation bubbles created by sonication break suspended particles into small fragments. In this paper, a critical review of ultrasound application for wastewater treatment is presented with emphasis on disinfection. Much of the work in this area remains at the laboratory scale. As a result, there is a need for fundamental information regarding the effect of sonication on the kinetics of disinfection and interaction of ultrasound with suspended particles. Such information is necessary for process engineering, design, and scale-up of ultrasound systems.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=375

WQRJC 2008 43 (1) - Editorial

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WQRJC 2008 43 (1) - Effect of Suspended Particles on Disinfection of a Physicochemical Municipal Wastewater with Peracetic Acid

The aim of this study was to elucidate the role of total suspended solids (TSS, which are claimed to be responsible for protecting embedded microorganisms) during disinfection of wastewater with peracetic acid (PAA). In particular, the focus was on a physicochemical effluent, having been treated with ferric chloride for TSS and phosphorus removal. Batch disinfection tests with various PAA dosages and contact times were carried out on the effluent from Montreal's wastewater treatment plant which uses only chemical precipitation and primary sedimentation. In addition to these samples, disinfection of "medium" and "highly" filtered effluents, obtained by sequential fi ltration through 120- and 10-&um;m nominal pore size membrane laboratory filters, was investigated. Modified second-order and Selleck model kinetics were used with moderate success to describe disinfectant consumption and microbial inactivation rates, respectively. This study showed that the overall amount of protection afforded by TSS to the microbial indicator considered (i.e., fecal coliforms in this case) was approximately 1.9 logs. TSS size was a key variable in this protection; approximately 1.3 logs and an additional 0.6 logs was the protection afforded by TSS greater than 120 μm, and between 10 μm and 120 μm, respectively. Fecal coliform inactivation of 3.8 to 7.3 logs after 40 minutes contact time could be achieved with a PAA dosage of 2 or 8 mg/L, respectively, in a highly filtered effluent.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=373

WQRJC 2008 43 (1) - Bench-Scale Disinfection of Bacteria and Viruses with Pulsed Arc Electrohydraulic Discharge

Pulsed arc electrohydraulic discharge (PAED) offers concurrent treatment of chemical and microbial target compounds in water by several mechanisms. Here, Escherichia coli, Bacillus subtilis spore, and MS2 bacteriophage inactivation by PAED were investigated using two bench-scale reactors (0.7 and 3 L). A plasma channel was created between a pair of iron electrodes set 0.5 mm apart in these reactors. Pulsed applied voltage was supplied at approximately 0.3 kJ/pulse (~100 �sec). In the 0.7-L reactor, median E. coli, B. subtilis, and MS2 reductions of 2.4-, 4.6-, and 3.7-log, respectively, were observed after approximately 80 seconds of treatment in water with a conductivity of 14.7 mS; reductions of 2.8-, 4.0-, and 3.7-log, respectively, were observed in treated drinking water filter effluent (conductivity of 610 �S). In the 3-L reactor, at a conductivity of 500 to 600 �S, 1.9- and approximately 0.9-log median reductions of E. coli and B. subtilis were achieved after 500 pulses (~3,300 sec); and, at a conductivity of 4.3 mS, median E. coli reductions of 0.5-log were achieved after 50 pulses (400 sec). Further work is necessary to elucidate the primary mechanism(s) of disinfection acting in the PAED system and how they relate to the reactor design, applied power requirements, and disinfection of specific target microorganisms.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=379

WQRJC 2008 43 (1) - Synergistic Benefi ts Between Ultraviolt Light and Chlorine-Based Disinfectants for the Inactivation of Escherichia coli

Ultraviolet light is increasing in popularity as a primary disinfectant in drinking water treatment because of its effectiveness against chlorine-resistant pathogens and lack of disinfection by-product (DBP) formation. Previous bench-scale studies have shown that there are possibly synergistic benefits in reducing heterotrophic bacteria when ultraviolet (UV) light is coupled with chlorine (Cl₂) or monochloramine (NH₂Cl). Additional experiments have demonstrated that synergy exists between various disinfectants in controlling numerous bacteria, viruses, and protozoan. Few studies, to date, have specifi cally investigated synergy with UV in combination with chlorine-based drinking water disinfectants including chlorine dioxide (ClO₂), Cl₂, and NH₂Cl. This preliminary study looked at the effectiveness of seven disinfection strategies (UV, Cl₂, ClO₂, NH₂Cl, UV/Cl₂, UV/ClO₂, and UV/NH₂Cl) against Escherichia coli in a single-species system at various combinations of disinfectant dose and contact time. Spiked solutions containing E. coli were treated by UV alone, chemical disinfectant alone, or UV coupled with chemical disinfectant. It was found that the combined disinfection strategies achieved the highest removal. Data were additionally analyzed for synergistic benefits, and each combination had a positive result. Results suggest that drinking water utilities may see enhanced removal of bacteria and potentially other pathogens due to synergistic benefits when UV was used in combination with any chlorine-based disinfectant. However, more data are required to conclusively determine synergistic relationship(s) between UV light and chlorine-based disinfectants.

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=377

WQRJC 2008 43 (1) - Disinfection By-Products (DBPs) in Drinking Water from Eight Systems Using Chlorine Dioxide

A study was initiated to determine the presence of organic disinfection by-products (DBPs) in drinking water treated with chlorine dioxide (ClO₂). One potential advantage for the use of ClO₂ as a disinfectant is the reduced formation of organic DBPs. Generally, water treated with ClO₂ produces chlorite and chlorate ions, but there is limited information regarding the presence of halogenated organic DBPs. Eight systems that use chlorine dioxide as part of the water disinfection process were investigated. All systems in this study applied chlorine as a primary or secondary disinfectant in addition to ClO₂. To evaluate seasonal and spatial variations, water samples were collected during cold water (February to March 2003) and warm water (July to August 2003) months at five sites for each system: raw water (R, before treatment), treated water (T, after treatment but before distribution), and three points along the same distribution line (D1, D2, D3). Sampling and analysis were conducted according to established protocols. A suite of 27 organic DBPs including haloacetic acids (HAA), trihalomethanes (THM), haloacetonitriles (HAN), haloketones, haloacetaldehydes (HA), chloropicrin, and cyanogen chloride were examined. In addition, the concentration of oxyhalides (chlorite and chlorate ions) and auxiliary parameters were also determined.
Chlorite was found in treated (T) and distributed (Dx) waters. The chlorite ion levels decreased along the distribution system (T > D1 > D2 > D3). At T sites, the levels ranged from 10 to 870 �g/L (winter), and from 300 to 1,600 �g/L (summer). Chlorite was not found in treated or distributed water in the one system that used ozone. Chlorate ion levels ranged from 20 to 310 �g/L (winter), and 80 to 318 �g/L (summer). Chlorate levels remained relatively constant throughout the distribution system. THM and eight HAA (HAA8) accounted for approximately 85% of the total DBPs (wt/wt) analyzed, followed by total HA (up to 7%) and HAN (3%). THM in distributed water were found at concentrations between 1.8 and 30.6 �g/L (winter), and 3.3 and 93.6 �g/L (summer). For HAA8, the levels ranged from 13 to 52 �g/L (winter), and 16 to 111 �g/L (summer). Chloral hydrate ranged from 0.2 to 5.2 �g/L (winter), and 0.4 to 12.2 �g/L (summer). The temporal and spatial variations observed in previous studies were confirmed in the current study as well.

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WQRJC 2008 43 (1) - Selecting Water Disinfection Processes using Fuzzy Synthetic Evaluation Technique

Drinking water treatment strategies generally involve treatment processes such as screening, coagulation/fl occulation, sedimentation, and fi ltration/adsorption followed by disinfection. Disinfection approaches include chlorine/chlorine (chloramine), granular activated carbon with post chlorine (chloramine), ozone/chlorine (chloramine), chlorine dioxide/ chlorine (chloramine), chloramine/chloramine, and ultraviolet radiation/chlorine (chloramine). However, comparative evaluation of these disinfection methodologies and their application to a particular source of water is rare. In this study, a framework for multicriteria decision making has been developed. Human health risk, cost, technical feasibility, and disinfection performance have been incorporated as the criteria for evaluation of the disinfection approach. A fuzzy synthetic evaluation technique has been incorporated where fuzzy triangular membership functions were developed to capture the uncertainties of the basic attributes. This paper compares three disinfection approaches: chlorination, granular activated carbon with post chlorination, and chloramination through a multistage hierarchy risk management model in which the analytical hierarchy process has been used to determine the relative importance of various attributes at different hierarchy levels. The evaluation process was found to be sensitive to the assignment of relative importance of the attributes. Chlorination was evaluated as the best disinfection approach in most of the cases.

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WQRJC 2008 43 (1) - Instructions for Authors/Directives aux auteurs

For more information visit: http://www.cawq.ca/cgi-bin/journal/abstract.cgi?language=english&pk_article=381