bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Quality of Surface Runoff from Grazed Fescue Grassland Watersheds in Alberta
Authors: Mapfumo Emmanuel , Willms Walter D. , Chanasyk David S.
Published: May 2018

A study was conducted at Stavely Research Station, Alberta, to determine the quantity and quality of surface runoff from small grassland watersheds under three grazing intensities, viz. ungrazed, heavy grazing (2.4 animal unit months per hectare, AUM ha-1) and very heavy grazing (4.8 AUM ha-1). The volume of surface runoff varied each year (1998, 1999 and 2000) and also differed across watersheds, with lower runoff in the ungrazed compared with the heavy and very heavy grazed watersheds. Total dissolved solids in surface runoff water ranged between 34 to 360 mg L-1, and that for runoff from the very heavy grazed watershed was greater than that from other watersheds. Electrical conductivity increased with increased grazing intensity on the watershed. In two of three years the very heavy grazed watershed had greater nitrate concentrations than the other two watersheds. In all three years the levels of nitrate were lower than the maximum acceptable level for drinking water (10 mg L-1 as nitrogen). Levels of orthophosphate (PO43-) in surface runoff from all three watersheds and the three years of study were less than 1 mg L-1, and mostly within the range considered typical for rivers and streams. Total carbon (up to 500 mg L-1) was greater than the amounts considered typical for streams and rivers, and most of it was organic carbon. Nuisance organisms such as algae, nematodes, Giardia spp., Cryptosporidium spp. and rotifers were detected in some surface runoff samples. However, no crustaceans were detected. The results of a canonical correlation analysis indicated that the dominant external forcing factors (meteorological and management) in influencing water quality were year of study, water temperature and grazing. Surface runoff discharge did not influence water quality measurements. The dominant water quality parameters were found to be total carbon, organic carbon, total dissolved solids and electrical conductivity. Overall, this study indicated that during the three years, the surface runoff volumes from the watersheds were small and grazing of these watersheds posed little risk of nutrient (e.g., nitrate, ammonia and orthophosphate) contamination of adjacent streams, but organic carbon loading and dissolved solids may be of concern. The presence of parasites was detected in two or less runoff water samples each year, and thus pose little risk of contamination of adjacent streams. However, it may be necessary to monitor parasites especially in areas under cow-calf operations.
Water Table Management as a Natural Bioremediation Technique of Nitrate Pollution
Authors: Elmi Abdirashid A. , Madramootoo Chandra , Egeh Mohamud , Dodds Georges , Hamel Chantal
Published: May 2018

Nitrate-nitrogen (NO3--N) pollution of water resources is a worldwide problem. Field trials were conducted from 1997 to 1998 to investigate the combined impacts of water table management (WTM) and N fertilization rate on soil NO3--N level and concentration of NO3--N in drainage water. Treatments consisted of two water table treatments: free drainage (FD) with open drains at a 1.0-m depth from the soil surface and subirrigation (SI) with a design water table of 0.6 m below the soil surface, and two N fertilizer rates: 200 kg N ha-1 (N200) and 120 kg N ha-1 (N120) in a split-plot design. Subirrigation reduced NO3--N concentration in the soil compared to FD by 37% in the spring of 1997 but not significantly (2%) in 1998; and 45% and 19% in the fall of 1997 and 1998, respectively. Higher rates of fertilization (N200) resulted in greater levels of NO3--N in the soil profile than the N120. Nitrate-N concentrations in drainage water from SI were 74% and 80% lower than those from FD in 1997 and 1998, respectively. Water table management can effectively reduce NO3--N pollution of water.
Improving Filtrate Quality Using Agrobased Materials as Coagulant Aid
Authors: Raghuwanshi Pramod Kumar , Mandloi Monika , Sharma Arvind J. , Malviya Hanumat S. , Chaudhari Sanjeev
Published: May 2018

In the present study, an evaluation of agrobased materials (ABM) as a coagulant aid in conjunction with alum has been conducted to determine their efficacy in water treatment. The agrobased materials evaluated are Surjana seed (Moringa oleifera), Nirmali seed (Strychnos potatorum) and maize (Zeemays). Experiments have been conducted simulating a conventional water treatment train consisting of coagulation-flocculation-settling and granular media filtration. Emphasis has been given to the filtration aspect of the treatment train using synthetic turbid water. The filter performance was defined by water quality and head loss development across the filter bed. When Nirmali seed or maize was used as a coagulant aid, the alum dose required was 25 and 15 mg/L, respectively, and the filtrate turbidity achieved was less than 0.2 NTU, whereas alum alone with a dose of 45 mg/L achieved filtrate turbidity levels higher than 1 NTU. Thus, the use of ABM improved the filtrate quality. Head loss in filter with Surjana seed and Maize as coagulant aids was comparable to that of alum alone, whereas it was higher when Nirmali seed was used as a coagulant aid.
Feldspar for the Treatment of As(III) Contaminated Water
Authors: Singh Dhirendra B. , Tiwary Rajani K. , Tewary Brajendra K.
Published: May 2018

This paper addresses the treatment of arsenic(III) contaminated water by adsorption technique using an unconventional adsorbent, feldspar. The removal of As(III) is dependent on contact time, concentration, pH and temperature of the solution, particle size of the feldspar and the agitation rate of the system. The maximum adsorption, i.e., 90.19%, was achieved after 100 min at the arsenic concentration 13.35 µmol L-1, with 40 g L-1 of feldspar of particle size ≈200 µm at pH 6.5, temperature 20 ± 0.5 °C and agitation rate 125 rpm. The pH of the system has played a key role in the uptake, and pH 6.5 has been determined as optimum. The process of uptake is exothermic and follows the first-order adsorption rate expression. The applicability of the Langmuir isotherm was tested for the As(III)-feldspar system at optimum conditions. The diffusion coefficients as well as thermodynamic parameters have been determined to explain the results. A model has been developed to predict the uptake capacity of the adsorbent under certain given conditions.
Spatial and Temporal Distribution of Fecal Indicator Bacteria within the Oldman River Basin of Southern Alberta, Canada
Authors: Hyland Romney , Byrne James , Selinger Brent , Graham Thomas , Thomas James , Townshend Ivan , Gannon Victor
Published: May 2018

Fecal coliform (FC) and Escherichia coli (EC) concentrations in the Oldman River and its tributaries, and in irrigation canals in southern Alberta, Canada, were monitored during 1998, 1999 and 2000. High FC and EC counts were found in drainages from agricultural lands in all years and in the Oldman River downstream of the City of Lethbridge wastewater treatment plant (WTP) during 1998. A significant decrease in the FC and EC concentrations downstream from the Lethbridge WTP was observed in 1999, after an upgrade to the WTP, which included a UV disinfection system. Spikes in FC and EC concentrations were observed in surface waters following heavy rainfall events. It is possible that a decrease in precipitation was responsible for decreases in the FC and EC concentrations observed in the Oldman River over the three years of the study. The increase in FC and EC counts in the tributaries and irrigation canals during this same period presumably reflects greater waste inputs from agricultural lands.
A Conceptual Model for Cryptosporidium Transport in Watersheds
Authors: Park Chan Hee , Huck Peter M.
Published: May 2018

This paper describes a conceptual model to estimate Cryptosporidium parvum oocyst transport from source to water treatment plant intake. The intent of the model is ultimately to be able to predict oocyst concentrations at an intake to an order-of-magnitude level. The transport and fate mechanisms included are: oocyst detachment from waste or soil, generation of runoff, overland transport, reservoir and in-stream transport, and oocyst die-off. The model is formulated in finite difference form, and deals with both non-point sources from manure-applied areas, and point sources from wastewater treatment plants. An important contribution of this work is the recognition that the settling rates of free and floc- or particle-associated oocysts can be considerably different. This has important implications for their transport.

A finite difference scheme was developed for five sections of a hypothetical watershed: a point source, a lake or reservoir (which can be modelled as either a continuous stirred tank reactor or an ideal rectangular setting tank), the section of stream channel from the outlet of the lake or reservoir to the confluence with another stream, a tributary with a non-point source, and the stream section from the confluence to a water treatment plant intake. The stream confluence is handled with a simple mass and flow balance. It would be very expensive to collect the necessary data to test the model. Because an appropriate data set was not available, the model was tested by means of a sensitivity analysis for the hypothetical watershed, using reasonable parameter settings for the base case.

The major contribution of the model is in defining the mechanisms involved in oocyst transport within a watershed. It gives important insights into the significance of various factors, provides a basis for data collection, and identifies areas where experimental investigations are required to avoid the need for simplifying assumptions. At its current state of development, the model cannot be used to provide quantitative predictions, but defines a base from which further detailed modelling can be developed to aid in decisionmaking for pathogen control. Using the framework that this model provides, contributions from other sources of Cryptosporidium oocysts such as domestic animals and combined sewage overflows could also be modelled.
Actinomycetes in the Elbow River Basin, Alberta, Canada
Authors: Zaitlin Beryl , Watson Susan B. , Dixon Jamieson , Steel Deborah
Published: May 2018

Actinomycetes can produce significant amounts of the earthy-muddy odour compounds geosmin and 2-methylisoborneol (MIB). These filamentous bacteria are found in both terrestrial and aquatic environments, and are particularly abundant in soil. They can enter freshwater systems via terrestrial runoff and subsequently cause taste and odour outbreaks in drinking water. Since it is well known that actinomycete growth and odour production is modified strongly by environmental factors such as moisture and nutrient levels, we hypothesized that watershed and stream characteristics should influence the potential odour impact of soil runoff on surface water. In this study, 1) the relationship between actinomycete abundance and characteristics such as stream discharge, turbidity and Escherichia coli levels was investigated, and 2) actinomycetes from contrasting terrestrial sources were examined for differences in their geosmin and MIB production. Actinomycetes and stream characteristics were sampled from the Elbow River, an important drinking water source for the City of Calgary (Alberta, Canada), and three tributary streams. Actinomycetes from forested regions and agricultural land were tested for taste and odour compound production. Actinomycete levels in streams were found to correlate closely with E. coli levels and to a lesser extent with turbidity, suggesting that actinomycetes are particularly abundant in runoff from terrestrial sources with fecal contamination. Most of the 18 actinomycete isolates tested were able to produce geosmin and/or MIB regardless of their terrestrial sources, suggesting that taste and odour outbreaks due to actinomycetes may be more influenced by differences in abundance than differences in source.
New Microcystin Concerns in the Lower Great Lakes
Authors: Murphy Tom , Irvine Kim , Guo Jay , Davies John , Murkin Henry , Charlton Murray , Watson Susan
Published: May 2018

Water samples were collected in the summer of 2001 for microcystin analysis, nutrients and algal enumeration from Hamilton Harbour (Lake Ontario), Wendt Beach (Lake Erie) and Presque Isle (Lake Erie). Microcystin concentrations varied largely and were present at acute toxicity levels only in some wind-concentrated scums of blue-green algae (>90% Microcystis, primarily M. botrys, M. viridis and some M. wesenbergii) in Hamilton Harbour. In Hamilton Harbour, microcystin-RR was the main microcystin with microcystin-YR and -LR also present. The two samples of August 17 and September 7, taken during the peak of the cyanobacterial bloom, contained 60 and 400 μg/L, respectively. A few dying birds were seen in the Hamilton scums. The concentrations of microcystins at the Lake Erie sites were less than 1 μg/L, yet dead birds were common. The major limitation with this approach is that current analysis (ELISA and HPLC) methods are unable to measure covalently bound microcystins, the form that is assimilated into the food chain.
Innovative Biological Treatment Processes for Wastewater in Canada
Authors: Mulligan Catherine N. , Gibbs Bernard F.
Published: May 2018

Biological treatment of wastewater has been employed successfully for many types of industries. Aerobic processes have been used extensively. Production of large amounts of sludge is the main problem and methods such as biofilters and membrane bioreactors are being developed to combat this phenomenon. Anaerobic waste treatment has undergone significant developments and is now reliable with low retention times. The UASB, the original high rate anaerobic reactor, is now becoming less popular than the EGSB reactor. New developments such as the Annamox process are highly promising for nitrogen removal. For metal removal, processes such as biosorption and biosurfactants combined with ultrafiltration membranes are under development. Biosurfactants have also shown promise as dispersing agents for oil spills. If space is available, wetlands can be used to reduce biological oxygen demand (BOD), total suspended solids (TSS), nutrients and heavy metals. These innovative processes are described in this paper in terms of applications, the stage of development, and future research needs particular to Canada.
Physiological and Biochemical Responses of Ontario Slimy Sculpin (Cottus cognatus) to Sediment from the Athabasca Oil Sands Area
Authors: Tetreault Gerald R. , McMaster Mark E. , Dixon D. George , Parrott Joanne L.
Published: May 2018

This study was conducted to evaluate whether a laboratory exposure of reference fish to oil sands sediment could produce biochemical responses (increases in 7-ethoxyresorufin-O-deethylase [EROD] activity and decreases in vitro steroid production capacity) similar to fish caught in the Athabasca Oil Sands area. Sediment samples from the Steepbank River, Alberta, were collected outside of the oil sands area at a reference site (S-Ref), within the oil sands areas where oil sand compounds leach naturally into the surface water (S-Nat), and within the natural-leach deposit areas, but also adjacent to anthropogenic mining activity (S-Dev). In the laboratory, an Ontario reference population of slimy sculpin (Cottus cognatus) were exposed to sediment concentrations of 10 or 20 g/L, for 4 and 8 d. A period of 4 d was sufficient to induce EROD activity in this species by these sediments. The EROD activity measured in exposed fish was comparable to that measured in fish native to the oil sands area. This study was not capable of predicting a reduced ability of gonadal tissue of exposed fish to produce steroid hormones in vitro, as was demonstrated in the wild fish assessment of 1999 and 2000. The short-term laboratory bioassay exposing slimy sculpin to sediment from the Athabasca Oil Sands area was not a suitable surrogate for field studies, however it could be an important tool in identifying MFO-inducing compounds in Athabasca Oil Sands sediment using a Toxicity Identification Evaluation (TIE).
Adsorption of Cadmium from Aqueous Solutions by Edible Mushrooms (Agaricus bisporus and Lentinus edodes)
Authors: Mathialagan Thyagarajan , Viraraghavan Thiruvenkatachari , Cullimore Denis Roy
Published: May 2018

Fungal organisms can remove heavy metals from aqueous solutions. Macro fungi such as Agaricus bisporus and Lentinus edodes (shiitake), commonly called mushrooms, are edible and are grown commercially. Laboratory batch studies were conducted at room temperature (21 ± 1°C) to determine the potential of these fungal biomasses for adsorption of cadmium from aqueous solutions containing 1 mg/L cadmium. Results from batch studies showed that biomasses prepared from A. bisporus and L. edodes had good potential for removing cadmium from aqueous solutions. The maximum adsorption capacity of A. bisporus and L. edodes for uptake of cadmium from aqueous solutions was 2.08 and 0.716 mg/g, respectively. The equilibrium time for adsorption was found to be 6 and 1 h for A. bisporus and L. edodes, respectively. 68% cadmium removal was achieved with A. bisporus and 45% with L. edodes. The optimum initial pH was found to be 6.0 and 5.0 for A. bisporus and L. edodes, respectively. Isotherm studies suggested that cadmium adsorption by both the mushrooms followed the Freundlich isotherm. Desorption of cadmium from mushrooms by dilute HCl was minimal (19%), but rapid.
Improvement of Anaerobic Sludge Digestion by Disintegration of Activated Sludge using Vacuum Process
Authors: Abbassi Bassim E.
Published: May 2018

The amount of excess sludge production from wastewater treatment plants is continuously increasing. Therefore, minimization of excess sludge is becoming increasingly important. The aim of bacterial cell disintegration is the release of the cell contents as an aqueous extract. This accelerates the cell hydrolysis that is usually considered to be the rate-limiting step in the sludge stabilization. Vacuum disintegration can activate the biological hydrolysis process and therefore, significantly increase the stabilization rate of the secondary sludge. It has been shown that when subjecting the sludge to 30 min of vacuuming, the COD concentration in the supernatant increased from 120 mg/L to more than 300 mg/L. Sodium dodecyl sulfate surfactant and lime have been used in different concentrations to enhance the hydrolysis process. The results show an additional increase in the supernatant COD concentration. For disintegrated excess sludge, an improved and accelerated anaerobic digestion is detected. The digestion process is characterized by higher degradation with increased disintegration.
An Investigation of Effect of Stepped Chutes with End Sill on Aeration Performance
Authors: Emiroglu M. Emin , Baylar Ahmet
Published: May 2018

Dissolved oxygen is essential to healthy streams and lakes. The dissolved oxygen level is an indication of how polluted the water is and how well the water can support aquatic plant and animal life. A higher dissolved oxygen level indicates better water quality. There is a significant oxygen transfer associated with most hydraulic structures because the air entrained into the flow is split into small bubbles, which greatly increases the surface area for transfer. Stepped chutes are a particular instance of this, and the aeration efficiency of such structures has not been studied in the laboratory and field. In this paper, the aeration performance of the stepped chutes with and without end sill was investigated in a large laboratory stepped chute. An empirical correlation predicting the oxygen transfer efficiency was developed for stepped chutes. The results indicated that l/h and s/h had a significant effect on the aeration efficiency of stepped chutes.
Occurrence of Polycyclic and Nitro Musk Compounds in Canadian Sludge and Wastewater Samples
Authors: Lee Hing-Biu , Peart Thomas E. , Sarafin Kurtis
Published: May 2018

Fragrances such as synthetic musk compounds are commonly used as additives in a wide range of consumer and personal-care products. At the end of their life cycle, most of these compounds will end up in municipal sewage systems. In this work, we report the occurrence of selected polycyclic and nitro musk compounds in sewage sludge, influent, effluent, as well as some industrial wastewater samples collected in Canada. A newly developed supercritical carbon dioxide extraction technique was used for the extraction of residual musk fragrances in the sludge. Final analysis was performed by gas chromatography/ mass spectrometry (GC/MS) using electron-impact and methane negative ion chemical ionization techniques. The results indicated that Galaxolide® (HHCB), Tonalide® (AHTN), musk xylene (MX), and musk ketone (MK) were the most common musk compounds in the Canadian environment, as they were found in every sample in this study. In the same sludge sample, levels of HHCB and AHTN (ranging from 1.3 to 26.7 μg/g) were often found to be about 1000 times higher than those of MX and MK (ranging from 1.4 to 422 ng/g). Similarly, in the sewage influent and effluent collected in Ontario, the levels of HHCB and AHTN (ranging from 159 to 2411 ng/L) were much higher than those of MX and MK (ranging from 1 to 84 ng/L). The levels of musk compounds varied widely in industrial wastewaters. In one sample collected from a detergent manufacturer, the levels of HHCB, AHTN, MX, and MK were found to be 54,200, 13,300, 5480, and 2.2 ng/L, respectively. It was also noted that the levels of MX and MK observed in the samples collected from the commercial laundries in Toronto were significantly higher than those found in domestic sewage.
Efficiency of Packed Cage RBC System for Treatment of Wastewater Containing Surfactants
Authors: Sirianuntapiboon Suntud , Srikattanaprom Panthong
Published: May 2018

The chemical oxygen demand (COD) and five-day biological oxygen demand (BOD5) removal efficiencies of a packed cage rotating biological contactor (RBC) system under a hydraulic retention time (HRT) of 16 h declined from 93.90% to 78.58% and 78.61% and 96.27% to 84.83% and 87.93%, respectively, with an increase of sodium dodecyl sulphate (SDS) and triton X-100 loading from 0.00 to 1.25 mg/m2·d. Reactor no. 1 of the system changed to anaerobic when the system was operated under an HRT of 8 h with surfactant loading of up to 2.55 mg/m2·d. However, reactor no. 2 of the system was aerobic and the dissolved oxygen was higher than 3.00 mg/L. The study showed that this type of packed cage RBC system could be applied for treating the cosmetic industry wastewater with surfactant loading of up to 2.55 mg/m2·d under an HRT of 8 h.
Role of Nozzles with Air Holes in Air Entrainment by a Water Jet
Authors: Emiroglu M. Emin , Baylar Ahmet
Published: May 2018

When a water jet impinges a pool of water at rest, air bubbles may be entrained and carried a distance below the pool's surface. This process is called plunging water jet entrainment and aeration. This paper describes an experimental study of the air entrainment rate of circular nozzles with and without air holes, and in particular, the effect of varying numbers and positions of air holes and distance between the location of the air holes and nozzle exit. A negative pressure occurred due to the air holes on the circular nozzles. This phenomenon affected air entrainment. The differences in air entrainment rate were related to changes in the jet shape. It was demonstrated that the air entrainment rates of the circular nozzles with air holes were significantly higher than those of circular nozzles without air holes.
A Review of Water Reuse and Recycling, with Reference to Canadian Practice and Potential: 2. Applications
Authors: Exall Kirsten
Published: May 2018

Common water reuse applications include agricultural and landscape irrigation with treated municipal wastewater, industrial recirculation of process waters, rainwater collection, and groundwater recharge for non-potable and indirect potable reuse. As compared to other countries worldwide, water reuse is currently practised infrequently in Canada, with the focus of most of the water reuse effort within Canada on agricultural irrigation applications. Landscape irrigation and other non-potable urban uses are practised to some extent, but provide an opportunity for expanded application of reclaimed water. Similarly, while water recycling is practised to various degrees within specific industrial sectors, further industrial water reuse and recycling affords an opportunity to conserve large volumes of water. The Canada Mortgage and Housing Corporation (CMHC) has supported a great deal of research into treatment and reuse of domestic greywater for non-potable uses within individual buildings, as well as some work on rainwater collection and use. Groundwater recharge and potable reuse are practised to some extent in extremely dry regions of the world, but public health concerns with respect to emerging trace contaminants may limit the spread of these reuse applications. The main issues associated with each of the above applications are reviewed, and the state of Canadian water reuse and recycling is described.
Determination of 3,3'-Dichlorobenzidine in Industrial Wastewaters
Authors: Lee Hing-Biu , Peart Thomas E. , Terry Ken , Maguire James
Published: May 2018

A solid-phase extraction, chemical derivatization, and gas chromatography/mass spectrometry (GC/MS) method has been developed for the determination of trace 3,3'-dichlorobenzidine (DCB) in industrial wastewater samples. Instead of an octadecylsilane (ODS) cartridge, a Porapak RDX cartridge was used since the latter could be optimized for the extraction of DCB. After the pre-concentration, interfering coextractives in the sample were selectively removed from the cartridge by elution with a 1:1 mixture of acetonitrile and water. DCB was then eluted with acetonitrile and derivatized with pentafluoropropionic acid anhydride. The product was subsequently analyzed by GC/MS in either the electron impact or negative ion chemical ionization mode. Recoveries of DCB and the surrogate, DCB-d6, were better than 90% at spiking levels of 10, 1, and 0.1 µg/L. Based on a concentration factor of 100, the detection limits for DCB in wastewater samples were determined to be 0.1 µg/L by electron impact GC/MS detection, and 0.01 µg/L by negative ion chemical ionization GC/MS detection, respectively. This method has been successfully applied to wastewater samples collected in the Toronto area.
Aquifer Geometry and Hydrochemical Framework of the Shallow Alluvial Aquifers in the Western Part of the Yamuna River Basin, India
Authors: Zaheeruddin  , Khurshid Shadab
Published: May 2018

The Yamuna basin constitutes a part of the Ganga plain which is one of the most densely populated regions and one of the largest groundwater repositories on the earth. Agricultural activities, population growth, rapid industrialization, and unplanned urbanization in the plain have resulted in various geo-environmental hazards, in particular, deterioration of groundwater quality. This studies the aquifer geometry and geochemical evaluation of groundwater in terms of its suitability for domestic and agricultural uses. Groundwater in the basin occurs in Quaternary alluvium and fractures in highly consolidated Alwar quartzites. Hydrogeological cross sections revealed a two- to three-tier aquifer system down to 100 m below ground level. The aquifer sequence comprises of clay, silt, different grades of sand and gravel in varying proportions. Climatic conditions, weathering and anthropogenic activities control the groundwater chemistry in the basin. The pH and electrical conductivity (EC) of the groundwater is variable (pH = 5.5–8.8; EC = 500–6700 µS/cm). At most places, the groundwater is alkaline, hard, and saline. In general, the groundwater has a composition expressed in equivalent units of Na+>Ca2+>K+>Mg2+ for cations and Cl->SO42->HCO3->CO32- for anions. The majority of the samples analyzed are classified as Na-Cl water which imparts residual sodium carbonate (RSC) hazards in irrigation use. The next dominant water types are Ca-Mg-Cl and Ca-Mg-HCO3-. Groundwater with a higher proportion of NO3-, Na+, F-, and K+ at a few sites represents the influence of anthropogenic sources on groundwater composition. An excess of alkali metals (Na+ + K+) over Cl- reflects input from the weathering of sodium- and potassium-rich minerals. The high %Na, EC and sodium adsorption ratio (SAR) values at a few sites restrict its suitability for irrigation.
Interaction of Ozone with Formic Acid: A System which Supresses the Scavenging Effect of HCO3-/CO32-
Authors: Yapsaklı Kozet , Can Zehra S.
Published: May 2018

Formic acid, mainly found in its ionized form at pH values greater than 3.75, is among the major by-products of drinking water ozonation. This study focusses on ozone decomposition reactions when formate ion is present. A mechanistic model was developed for ozone decomposition in the presence of formate ion and alkalinity. n-chlorobutane (BuCl) was used as a hydroxyl radical probe. The proposed mechanism is a combination of all the reactions provided in the literature for ozone decomposition, ozone-formate ion interactions, and formate ion and certain inorganic radical interactions in aqueous solutions. The validity of the proposed mechanism was tested by comparing the experimental data collected at different initial ozone and formate ion concentrations, pH and alkalinity to the model predictions. The model was capable of predicting the ozone decomposition and BuCl oxidation data extremely well when 1.53 M-1s-1 (knew) was used as the reaction rate constant for the reaction between ozone and formate ion, as opposed to the value provided in the literature (100 M-1s-1). Furthermore, according to the proposed model formate ion suppresses the scavenging effect of HCO3- and CO32- ions because the reaction of formate ion with CO3*- radical regenerates the OH* radical that is scavenged by the HCO3- and CO32- ions. This was tested by observing ozone decomposition at different levels of alkalinity in the presence of formate ion. The experimental data did not present any significant effect of alkalinity on the decomposition rate. In addition, the model provided highly reliable predictions of the experimental data collected in the presence of alkalinity when knew was used.
Changes in Immunological Parameters and Disease Resistance in Juvenile Coho Salmon (Oncorhynchus kisutch) in Response to Dehydroabietic Acid Exposure under Varying Thermal Conditions
Authors: Tierney Keith B. , Stockner Eric , Kennedy Christopher J.
Published: May 2018

This study explored the effects of a sublethal 96-h dehydroabietic acid (DHAA) exposure on aspects of the immune system of juvenile coho salmon under varying temperature conditions. Coho were exposed to DHAA concentrations below the determined LC50 value of 0.94 mg/L (95% confidence limits of 0.81 to 1.24 mg/L) for 96 h at either their acclimation temperature (8 or 18°C), or during an acute warm-shock (8 to 18°C) or cold-shock (18 to 8°C). Acclimation temperature alone significantly affected hematocrit (Hct), neutrophil respiratory burst activity (RBA) and leucocyte proportions. With temperature-shock, leucocrit (Lct), RBA and leucocyte proportions were altered. All parameters were affected by DHAA exposure, but not always in a dose-dependent manner. Across groups, DHAA caused Hct, lysozyme, thrombocyte, neutrophil and monocyte proportions to increase, and Lct, RBA and lymphocyte proportions to decrease. DHAA-temperature interactions resulted in the exacerbation of DHAA-induced effects. Exposure temperature had the most significant effect on the susceptibility of coho to Aeromonas salmonicida; fish were more susceptible at cold temperatures and when subjected to a temperature-shock compared to their respective controls. DHAA exposure modulated the response of temperature-shocked fish to this pathogen.
Cadmium Biosorption by S. fluitans: Treatment, Resilience and Uptake Relative to Other Sargassum spp. and Brown Algae
Authors: Davis Thomas A. , Ali Fadi El Cheikh , Giannitti Elisa , Volesky Bohumil , Mucci Alfonso
Published: May 2018

Species of the brown algae Sargassum have been targeted for use in the implementation of strategies to remediate toxic heavy metal contamination in effluents and drinking waters. This work focusses on some of the intrinsic physico-chemical properties of the algal material and aspects of the sorption mechanism, in particular: their maximal metal uptake, the influence of particle size and their resilience to leaching during equilibrium batch experiments. In addition to S. fluitans, the database on cadmium uptake capacities by Sargassum is extended to include S. thunbergii and S. oligocystum, and these are compared to those of two common brown algae. Results of our experiments demonstrate that cadmium sorption is independent of the range of particle sizes investigated (<2 and 3–6 mm), thereby indicating that sorption is not a function of the specific surface area of the biomass exposed to the solution. Dissolved organic carbon (DOC) analyses reveal that leaching to the cadmium solutions during the metal sorption reaction is independent of the biomass preparations used to obtain the two size fractions but decreases with increasing final cadmium concentration.
Determination of System Losses of Geosmin and MIB in Bench-Scale Filtration Apparatus
Authors: Elhadi Sarah L.N. , Huck Peter M. , Slawson Robin M.
Published: May 2018

Geosmin and 2-methylisoborneol (MIB) are two of the causative compounds responsible for the earthy/musty odour problem in drinking water. They are a major concern for the water treatment industry because they are difficult to remove by conventional water treatment practices and are fairly resistant to chemical oxidation. Various studies have been conducted at both bench and full scale to examine the removal of these compounds by adsorption and/or biological filtration. Lack of study at realistic odour compound concentrations and disregard for losses of these compounds by other means (i.e., volatilization or adsorption) represent some of the limitations of such studies. The bench-scale investigation reported herein focussed on system design and minimization of system losses. The results indicated that the preferred system design included the use of Teflon feed bottles, Teflon tubing, and a glass filter column in which the influent feed line descended close to the media surface. Such a design minimized system losses of both geosmin and MIB to 42 and 30%, respectively, based on target influent concentrations of 200 ng/L.
Effect of Aeration on Fresh and Aged Municipal Solid Waste in a Simulated Landfill Bioreactor
Authors: Warith Mostafa A. , Takata Graham J.
Published: May 2018

Municipal solid waste (MSW) is slow to stabilize under conventional anaerobic landfill conditions, demanding long-term monitoring and pollution control. Provision of aerobic conditions offers several advantages including accelerated leachate stabilization, increased landfill airspace recovery and a reduction in greenhouse gas emissions.

Air injection was applied over 130 days to bench-scale bioreactors containing fresh and aged MSW representative of newly constructed and pre-existing landfill conditions. In the fresh MSW simulation bioreactors, aeration reduced the average time to stabilization of leachate pH by 46 days, TSS by 42 days, TDS by 84 days, BOD5 by 46 days and COD by 32 days. In addition, final leachate concentrations were consistently lower in aerated test cells. There was no indication of a gradual decrease in the concentration of ammonia, and it is likely this high ammonia concentration would continue to be problematic in bioreactor landfill applications.

This study focussed only on biodegradability of organics in the solid waste. The concentrations of the nonreactive or conservative substances such as chloride and/or heavy metals remain in the bioreactor landfills due to the continuous recirculation of leachate.

The results of this study demonstrate the potential for air injection to accelerate stabilization of municipal solid waste, with greatest influence on fresh waste with a high biodegradable organic fraction.
Simulation of Oxygen Transfer Rates in Circular Aeration Tanks
Authors: Rao Achanta Ramakrishna , Laxmi B.V. Bharathi , Narasiah K. Subba
Published: May 2018

Experiments were conducted to study the performance of circular and square tank surface aerators on the oxygen transfer coefficient and to a limited extent on power requirements. All the tanks are geometrically similar except for their shapes. They consist of a rotor of diameter, D, fixed with six flat blades rotating with a speed, N, in pure waters of viscosity, υ, at room temperature. A simulation equation to predict the oxygen transfer coefficient, k = KLa20(υ/g2)1/3 for any given dynamic parameter governing the theoretical power per unit volume, X = N3D2/(g4/3υ1/3) was developed for circular tank aerators. The data on square tank aerators support another such simulation equation developed earlier for square tanks. A comparison of results, while re-aerating the same volume of water in both the shapes of tanks, leads to the interesting conclusion that for a given rotor speed the oxygen transfer rate is substantially more in square tanks than in circular tanks; whereas for a given effective input power to the rotor the oxygen transfer rate is more in circular tanks than in square tanks. This suggests that square tanks are preferred to circular tanks to raise the oxygen concentrations at a faster rate, whereas the circular tanks are advantageous as far as power requirements are concerned.
Radiation-Induced Degradation and the Effect of Scavengers on Benzene, Monochlorobenzene and 1,2-Dichlorobenzene in Aqueous Solutions
Authors: Takriti Salaheddin
Published: May 2018

The degradation of benzene, monochlorobenzene and 1,2-dichlorobenzene in aqueous solution by gamma irradiation was investigated. The effect of the irradiated solution composition was studied. The results showed that benzene is more resistant to destruction than chlorinated benzenes. The presence of oxidizing and reducing reactive species and the rapid reaction rates with halogenated benzenes increased the degradation rate of the pollutants. Dechlorination of CB and 1,2-DCB was observed. High performance liquid chromatography (HPLC) and spectroscopy (UV-Vis) were used to monitor changes in the radiation solutions. The final aqueous irradiation products were shown to be a complex mixture of by-products. The addition of scavengers such as methanol and ethanol required larger doses to decompose the pollutants when compared to those solutions with no additives.
Wet-Weather Flow Management in the Great Lakes Areas of Concern
Authors: Kok Sandra
Published: May 2018

Under the Government of Canada's Great Lakes Program, the Great Lakes Sustainability Fund and its predecessor programs (the Great Lakes Cleanup Fund and the Great Lakes 2000 Cleanup Fund) were established to implement cleanup actions and strategies that would contribute to the restoration of beneficial uses in environmentally degraded areas (known as Areas of Concern) in the Great Lakes basin. The Great Lakes Sustainability Fund is administered by Environment Canada on behalf of eight Government of Canada departments. Contributing to impaired beneficial uses are municipal wastewaters generated from the urban centres in the Great Lakes Areas of Concern. These municipal wastewaters include treated sewage and wetweather discharges of combined sewer overflows and stormwater runoff. This paper provides an overview of the Municipal Wastewater Program of the federal government's Great Lakes Sustainability Fund and highlights the progress made to date under the program towards wet-weather flow management and the Program's role in developing and demonstrating sustainable approaches and technologies in the Great Lakes Areas of Concern.
The Role of Water Balance Modelling in the Transition to Low Impact Development
Authors: Graham Patrick , Maclean Laura , Medina Dan , Patwardhan Avinash , Vasarhelyi Gabor
Published: May 2018

Low impact development (LID) is increasingly being viewed by local governments and developers alike as a viable approach to stormwater management that can effectively protect aquatic habitat and water quality. LID relies on distributed runoff management measures that seek to control stormwater volume at the source by reducing imperviousness and retaining, infiltrating and reusing rainwater at the development site.

Early conventional stormwater management practices tended to focus on stormwater quantity and controlling a few extreme rainfall events, whereas the more frequent storms, which represent the majority of total runoff volume, carry most of the pollutants, and control the geomorphology of streams, were addressed in stormwater quality design practiced during the last decade. These frequent events are most effectively managed with a volume control approach, often described as stormwater source control or Low impact development (LID). Such an approach is described in this paper, demonstrating how water balance modelling can be an effective tool for evaluating and supporting implementation of LID options such as bioretention, pervious paving, numerous types of infiltration systems, rainwater reuse and green roofs. It also discusses recently developed water balance modelling software, including an Internet-based planning tool and a design optimization tool.
Accumulation of Trace Metals in Freshwater Invertebrates in Stormwater Management Facilities
Authors: Anderson Bruce C. , Bell Tracy , Hodson Peter , Marsalek Jiri , Watt W. Edgar
Published: May 2018

Availability and uptake of metals in the accumulated sediments in stormwater treatment facilities was assessed by the metal accumulation patterns observed in freshwater mussels, as the first step in an Environmental Risk Assessment (ERA). Freshwater mussels, Elliptio complanata, were caged in various locations in several stormwater treatment facilities and control sites in southeastern Ontario. Mussels were sampled at 2, 5.5, 8, 11 and 14 weeks, and Ni, Cr, Cu, Cd and Pb concentrations in soft tissues were determined by ICP-MS. Selection of these metals was based on previous studies which had identified them in substantial quantities in stormwater pond sediments. A significant decrease in Ni concentrations and an increase in Pb concentrations relative to background levels were observed. Concentrations of Cu, Cd and Cr were generally not significantly different from background.

Total metal concentrations in sediments were also determined, and compared with the observed mussel metal concentrations. No correlations were observed between total metals in sediment and the accumulated burden in the mussels. The results suggest that Pb is a possible concern in these stormwater facilities due to its availability. Ni, Cr and Cd did not appear to be in bioavailable forms and Cu had limited availability. The study was complementary to other work examining trace metals in stormwater management facilities, and provides further useful information about the habitat quality of these facilities, and the ecotoxicological risks that might be posed to resident species.
Feasibility of Stormwater Treatment by Conventional and Lamellar Settling With and Without Polymeric Flocculant Addition
Authors: Wood Jim , Dhanvantari Samir , Yang Mingdi , Rochfort Quintin , Chessie Patrick , Marsalek Jiri , Kok Sandra , Seto Peter
Published: May 2018

Stormwater treatment by lamellar and conventional clarification, with and without flocculant addition, was investigated in Toronto, Ontario, using a pilot-scale rectangular clarifier vessel with removable lamellar plates. During the 2001 to 2003 field seasons, 76 stormwater runoff events were characterized with respect to flow and quality, and further investigated for stormwater treatment. Most stormwater constituent concentrations at this site exceeded those for the U.S. NURP median urban site. A cationic polymeric flocculant dosed at 4 mg/L, with lamellar clarification, provided the best results with a total suspended solids (TSS) removal of 83% at total vessel surface loads up to 36 m/h. The clarification processes produced a concentrated sludge, which was strongly polluted by heavy metals and would require special disposal procedures.
Receiving Water Response to a Master Plan for Wet Weather Flow Management Developed for the City of Toronto
Authors: D'Andrea Michael , Snodgrass William J. , Chessie Patrick D.
Published: May 2018

The City of Toronto has development a Wet Weather Flow Management Master Plan incorporating a new philosophy in wet weather flow management where rainwater is recognized as a resource. Wet weather flows are to be managed on a watershed basis, and a hierarchical approach to wet weather flow management is to be used, starting with at source, followed by conveyance and finally end-of-pipe control measures. The study area extended across the City of Toronto, encompassing six major watersheds and the waterfront. The Plan development followed the planning principles of Ontario's Environmental Assessment Act and incorporated broad public and agency consultation. A series of 13 objectives was identified and grouped into four major categories: water quality, water quantity, natural areas and wildlife, and sewer system. An innovative approach was used which integrated hydrologic, hydraulic and water quality predictions from land-based, watershed and lake models, respectively, to assess the effectiveness of various strategies.

The receiving water response indicated that source controls and conveyance controls were insufficient to achieve the receiving water objectives of the Plan. This was only possible through the implementation of a comprehensive set of measures consisting of: source controls, conveyance controls, end-of-pipe controls, basement flooding protection works, stream restoration works, shoreline management, enhanced municipal operations and an enhanced public education and community outreach program. Overall benefits expected through the Plan include: swimmable waterfront beaches, control of combined sewer overflows in compliance with legislative requirements, basement flooding protection, protection of the City's infrastructure from stream erosion, restoration of degraded local streams and aquatic habitat and the reduction of algal growth along the waterfront, and improved stream water quality in area watercourses. The cost of the Plan over the 25 years is estimated to be $1.047 billion with an additional $233 million in operational and maintenance costs.
UV Spectrophotometry as a Non-parametric Measurement of Water and Wastewater Quality Variability
Authors: Thomas Olivier , Baurès Estelle , Pouet Marie-Florence
Published: May 2018

The composition of water and wastewater, varying temporally and spatially, depends on factors such as environmental context, types of pollution sources, weather conditions leading to dilution or solids transportation, length of sewer network, etc. Because quantitative parameters are often not adapted for the characterization of wastewater quality variability, a non-parametric measurement is proposed, based on comparison of the UV absorption spectra of samples. The presence of isosbestic points, occurring in the set of spectra either directly or indirectly after normalization, allows quantification of the variability of a given water or effluent. A normalization step is used when dilution exists in the case of a mixture of water types (discharge or rain). Several examples show how to calculate the variability or to estimate the dilution factor from UV spectra data, even without results of physicochemical parameters.