bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Data Preprocessing and Kernel Selection on Probabilistic Neural Network Modeling of the Acute Toxicity of Chemicals to the Fathead Minnow and Vibrio fischeri Bacteria
Authors: Niculescu Stefan P. , Kaiser Klaus L.E. , Schüürmann Gerritt
Published: March 2019

We investigated the connection between the data preprocessing strategy and kernel choice on the quality of the associated basic probabilistic neural network models for the acute toxicity of various chemicals to the fathead minnow and to Vibrio fischeri bacteria. The models employ exclusively structural parameters and physicochemical properties as inputs. Results show that the Gaussian kernel is preferable over the reciprocal kernel model. Data preprocessing based on the hyperbolic tangent and the sigmoid logistic transforms provides the best results at the level of the cross validation experiment. Improved models based on cross validation partial models and linear corrections were also investigated. The results show that the improved models with data preprocessing based on the hyperbolic tangent and the finite interval transforms are the best with practically identical quality of predictions.
Nonspecific Chlorination of Organics: a Chemistry Unique to Human Industry? (Putting Kraft Mill AOX Emissions into Perspective)
Authors: Archibald Frederick , Valeanu Loredana , Leichtle Gunther , Guilbault Benoit
Published: March 2019

To counter the claim that all biotreated organochlorine (AOX) emissions from modern kraft mills are unnatural and inherently hazardous, it has been argued that over 2400 different AOX compounds are now known to be produced by living organisms. This is an invalid rationale. These 2400 natural compounds are mostly specific halometabolites — each is produced as a large number of identical molecules by a specific enzyme-mediated mechanism. In contrast, in a kraft mill bleachery, heterogeneous wood derivatives are non-specifically chlorinated by hypochlorous acid (HOCl) or hypochlorite ion (OCl-) to produce mixtures containing hundreds of different AOX species. It is therefore much more reasonable to compare mill-derived AOX to other human and natural sources of OCl-/HOCl-generated non-specific AOX.

Chloroperoxidase (CPO)-type enzymes naturally produce HOCl and OCl-from common chloride ions and hydrogen peroxide (H2O2). They have now been demonstrated in bacteria, fungi, algae, lichens, higher plants and animals. We demonstrate that a common fungal CPO can, when applied to soil extracts, lignins, cellulosics, tannins and natural lake water organics, rapidly generate nonspecific AOX.

In agreement with earlier work done in other geographic areas, AOX was found in all of a wide range of samples from the Montreal region, both from urban and relatively remote pristine lakes and woodlands. Much of it is almost certainly produced via nonspecific HOCl/OCl- chlorination.

Finally, we demonstrate that nonspecific AOX is produced by a CPO in mammalian blood as the natural result of the body's immune system fighting infections. Thus, HOCl/OCl- based production of AOX from mixtures of organic molecules is seen to be a common occurrence in nature as well as a product of human technology.
Aluminum Speciation during Drinking Water Treatment
Authors: Srinivasan P.T. , Viraraghavan T. , Kardash B. , Bergman Joe
Published: March 2019

Aluminum is one of the trace inorganic metals present in drinking water. Aluminum present in alum (a widely used coagulant for water treatment) as well as naturally occurring aluminum in raw water is transformed into various forms (speciation) during drinking water treatment. Speciation of aluminum during drinking water treatment is essential to understand the behavior of aluminum and aluminum species removal during water treatment and also to identify the factors influencing residual aluminum in treated waters. In this connection, an aluminum speciation study was conducted at the Buffalo Pound water treatment plant. Aluminum was fractionated into eight different forms (total, soluble + colloidal, soluble, organic, inorganic, particulate, suspended, and colloidal aluminum). Speciation results showed that raw lake water total aluminum concentrations were highly variable, and almost all of the raw water particulate aluminum (predominant species of total aluminum) was present in suspended form. Soluble aluminum levels throughout the plant (raw to treated) were less than 50 µg/L and most of the soluble aluminum was in organic form. The study showed that granular activated carbon was capable of removing soluble aluminum in organic form. Residual aluminum present in treated water consisted of mostly particulate and organic forms of aluminum. Raw water particulate aluminum correlates well (R2 = 0.90) with raw water turbidity, implying that removal of turbidity from raw water will reduce particulate aluminum in treated waters. Similarly the organic fraction of residual aluminum was influenced by the high dissolved organic carbon present in the raw water. As the soluble aluminum concentrations were less than 50 µg/L, the plant would not have any difficulty to meet a guideline value for aluminum in treated waters in the range of 0.1 to 0.2 mg/L as dissolved aluminum.
Factors Affecting Oxygen Transfer in Lab-Scale Activated Sludge Reactors Treating Bleached Kraft Mill Effluent
Authors: Hui K.W. Leo , Duff Sheldon J.B.
Published: March 2019

In aerobic biological wastewater treatment processes, oxygen must be transferred from the gas phase to the liquid phase to support oxidation of dissolved organics and endogenous metabolism by the bacteria. Power required to supply this oxygen in suspended growth systems can represent a significant fraction of the operating costs of such processes. In this study, the interfacial mass transfer coefficient KLa for water was found to be reduced by up to 28% (average 13%) by the addition of antifoaming agent. KLa values were reduced by up to 43% (average 26%) by the dissolved organics in primary treated bleached kraft mill effluent. There was no significant difference between the KLa for water and biologically treated bleached kraft mill effluent.
Volatile Fatty Acids Production by Anaerobic Whey Permeate Biodegradation in a Continuous Bioreactor
Authors: Imbeault Nathalie , Paquet Marcel , Côté Raynald
Published: March 2019

This paper addresses the production of volatile fatty acids with fermentation of whey permeate under acidogenic conditions. The coal-immobilized biomass of an anaerobic fluidized bed reactor operated with a fairly constant hydraulic residence time of 12 min transformed the substrate (whey permeate i.e., essentially lactose) into a blend of acetic, propionic, butyric and isobutyric acids corresponding to between 2 and 19, 1 and 6, 11 and 30, 0 and 2% of the initial load (carbon basis), respectively. There was a slight decrease in the sugar transformation efficiency (65 to 48%) with the increase of the organic loading rate (OLR) which varied from 586 to 3339 g sugar/Lreactord. At the highest OLR of 3339 g sugar/Lreactor.d, the biomass transformed 19% of the substrate into a blend of acetic, propionic, butyric and isobutyric acids. Residual sugar and bio-gas were 52 and 2%, respectively, of the initial load (carbon basis).

Cet article fait référence L une étude sur la production d’acides gras volatiles par fermentation anaérobie du perméat de lactosérum dans un bioréacteur. La biomasse fixée aux grains de charbon composant le lit fluidisé, opérant avec un temps de rétention hydraulique de 12 minutes, transformait le substrat (perméat i.e., essentiellement lactose) en un mélange d’acide acétique, propionique, n-butyrique et isobutyrique correspondant respectivement L 2 et 19, 1 et 6, 11 et 30, 0 et 2% de la charge initiale (sur la base d’un bilan de carbone). Il a été possible d’observer une légère diminution de l’efficacité de la biodégradation du sucre (65 L 48%) avec une augmentation du taux de charge organique lequel variait de 586 L 3 339 g de sucre/Lréacteurd. L la charge organique la plus forte, soit 3 339 g de sucre/Lréacteur.d, la biomasse transformait le substrat L 19% en un mélange d’acide acétique, propionique, n-butyrique et isobutyrique. La part du sucre résiduel était de 52% et celle du biogaz L 2% (bilan de carbone).
Review of the Aquatic Toxicity, Estrogenic Responses and Bioaccumulation of Alkylphenols and Alkylphenol Polyethoxylates
Authors: Servos Mark R.
Published: March 2019

A review of the available information on the toxicity and bioaccumulation of alkyphenols (AP) and their polyethoxylates (APE) and polyethoxycarboxylates (APEC) was conducted in support of their assessment as Priority Substances under the Canadian Environmental Protection Act. This included an examination of the acute and chronic toxicity of these compounds in a wide variety of aquatic organisms as well as an examination of their potential effects on endocrine function in fish and aquatic invertebrates. Although the data in the literature are scattered among many species, different test methods and chemicals, there is a consistent pattern in the toxicity. Nonylphenol (NP) and octylphenol (OP) are both acutely toxic to fish (17-3000 µg/L), invertebrates (20-3000 µg/L) and algae (27-2500 µg/L). In chronic toxicity tests no observable effect concentrations (NOEC) are as low as 6 mg/L in fish and 3.7 µg/L in invertebrates. There is an increase in the toxicity of both NPEs and OPEs with decreasing EO chain length. NPECs and OPECs are less toxic than corresponding APEs and have acute toxicities similar to APEs with 6-9 EO units. APs and APEs bind to the estrogen receptor resulting in the expression of several responses both in vitro and in vivo, including the induction of vitellogenin. The threshold for vitellogenin induction in fish is 10 µg/L for NP and 3 µg/L for OF. APEs also affect the growth of testes, alter normal steroid metabolism, disrupt smoltificaton and cause intersex (ova-testes) in fish. The available literature suggests that the ability of AP and APEs to bioaccumulate in aquatic biota in the environment is low to moderate, BCFs and BAFs in biota, including algae, plant, invertebrates and fish range from 0.9 to 3400. Although there are relatively few data available for OP or OPEs, their potential to bioaccumulate is expected to be similar to that of corresponding NP and NPEs.
Short Communication: A Note of Caution to Users of ECOSAR
Authors: Kaiser Klaus L.E. , Dearden John C. , Klein Werner , Schultz T. Wayne
Published: March 2019

ECOSAR (1998), a personal computer software program available from the U.S. Environmental Protection Agency (EPA) and affiliated vendors, is used to estimate the toxicity of chemicals to aquatic organisms, particularly fish, daphnid and algae species. It relies on approximately 150 equations, each for a chemical class of substances (Clements et al. 1996), which are linear correlations (SARs) of measured toxicity values of class-representative compounds with their octanol/water partition coefficients, with the latter taken from a database or computed by a companion program.
Pesticides in the Red River and its Tributaries in Southern Manitoba: 1993—95
Authors: Rawn Dorothea F.K. , Halldorson Thor H.J. , Woychuk Robert N. , Muir Derek C.G.
Published: March 2019

Pesticide concentrations and loadings at three locations along the Red River and on seven of its tributaries in southern Manitoba were determined over a three year period. Samples (18 L) were collected on a biweekly schedule between spring and late autumn in 1994 and 1995 and triweekly throughout the initial year of the study (1993) between June and October. Pesticide recoveries ranged from 14 to 115%, and those with < 80% recovery (bromoxynil, 2,4-D,diclofop, MPCA and triclopyr) were recovery corrected. Maximun concentrations were related to regional use periods, despite greatest runoff occurring during spring melt and early summer rains. Pesticides were not present at elevated levels during this period. The pesticides detected in the highest frequency in the Red River tributaries generally were those used most extensively (e.g., MCPA). MCPA concentaraions for all sites ranged from < 0.01 to990 ng/L. MCPA had the largest loadings of all herbicides in each tributary, although loads were low (9-3100 g) compared to usage. Atrazine and alachlor were frequently detected in the Red River. Atrazine is widely used in the neighbouring U.S. states, and loadings of this chemical in the Red River were similar to loadings of the highly used and less persistant phenoxyacids, although it was used only to a minor extent in Manitoba. Alachor, althiugh not in used in Canada, was present (<0.060-150 ng/L) in the Red River at each sampling site, which reflected U.S. usage of this product. Urban usage of chlorpyrifos, 2,4 D and MCLA contributed to loadings along the Red River. Pesticide concentrations generally were well below Canadian water quality guidelines in the Red River drainage basin; however, chlorpyrifos concentrations occassionally exceeded guideline levels for the production of freshwater aquatic life.
Preferential Leaching in Large Undisturbed Soil Blocks from Conventional Tillage and No-Till Fields in Southern Alberta
Authors: Miller J.J. , Lamond B.J. , Sweetland N.J. , Larney F.J.
Published: March 2019

There is a concern that adoption of conservation tillage practices such as no-till may increase preferential leaching of water and chemicals to the groundwater. Evidence from previous studies of long-term (since 1968) conventional tillage (CT) and no-till (NT) fields in southern Alberta suggests that tillage practice has the potential to influence preferential leaching. However, no studies have been done to test this hypothesis. Our objective was to utilize the two-region (mobile/immobile water) model of solute transport to compare preferential leaching in CT and NT fields of clay loam texture. Four large (46 × 46 × 51 cm) undisturbed blocks of soil were excavated from each tillage field (unreplicated) during the fallow phase of a wheat-fallow rotation. The soil blocks were transported to the laboratory, stored under drying conditions (32 months), and miscible displacement experiments conducted under saturated, steady-state conditions. Because of the long storage period, the focus of our study was on long-term (e.g., structure, earthworm burrows, old root channels) rather than short-term (e.g., tillage of surface soil) tillage effects on preferential leaching. Breakthrough curves (BTCs) for chloride were derived, and the modified convection-dispersion equation fitted to the experimental data using a two-region model (CXTFIT-Version 2.0 ) to allow estimation of the mobile water fraction (B) or extent of preferential leaching. Breakthrough curves for both tillage fields exhibited early initial breakthrough, a rapid rise in tracer concentration, a shift of the BTC peak to the left of one pore volume, and a slow decline (“tailing”) toward zero concentration for the descending limb of the curve. Reasonably good fits were obtained for fitting of the two-region model to the BTCs, as indicated by correlation coefficients ranging from 0.60 to 0.84. Mean values for the mobile water fraction were similar for the CT field (0.78) and NT field (0.80), suggesting no difference in preferential leaching of chloride. We hypothesize that the extent of preferential leaching in earthworm burrows (Aporrectodea caliginosa) in the NT field and leaching in old root channels in the CT field may have been similar. Further research on replicated plots is needed to examine short-term effects of tillage practice (e.g., tillage of surface soil) as well as the individual contribution of earthworm burrows and old root channels, to preferential leaching under CT and NT.
Contamination of Rural Drinking Water Wells by Fecal Origin Bacteria -- Survey Findings
Authors: Conboy M.J. , Goss M.J.
Published: March 2019

In 1997, over 300 rural drinking water wells throughout Southern Ontario and 148 wells in rural Zimbabwe were tested for bacteriological water quality. Total coliform, fecal coliform and fecal streptococci were enumerated in each sample with standard membrane filtration techniques. Clostridium perfringens was monitored by presence or absence. In Ontario, all of the wells were tested in the spring, when the fields were near saturation, and resampled in late summer. Just under 50% of the wells exceeded the Ontario drinking water objectives (DWO) in spring and summer. On both occasions, approximately 20% of the wells tested positive for Clostridium perfringens, which is an indicator for fecal contamination of animal origin. Zimbabwe wells were sampled during the dry season, June 1997. Ninety-five percent of the wells had bacteria in excess of Ontario DWO, and 59% of the wells tested positive for Clostridium perfringens. The wells in Zimbabwe provided a comparison in soil moisture and type, and there were also differences in well construction and management practices. This study shows that a significant percentage of the bacteria of fecal origin found in rural wells originated from animal manure. Some factors affecting well water quality are discussed.
Determination of Heavy Metals in Damascus Drinking Water Using Total Reflection X-Ray Fluorescence
Authors: Bakraji E.H. , Karajo J.
Published: March 2019

Total reflection X-ray fluorescence spectrometry and chemical preconcentration have been applied for multi-elemental analysis of Damascus drinking water. Water was taken directly from taps of several city sectors and analyzed for the following trace elements: Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Se and Pb. The detection limits were found to be in the range of 0.1 to 0.4 µg/L. The mean levels of trace elements in the Damascus drinking water were below the World Health Organization drinking water quality guidelines.
Monitoring Agricultural Drainage Ditches and the Receiving Water (Nicomekl River, Surrey, B.C.) for Toxicity to Ceriodaphnia dubia and Probable Cause Due to Organophosphate Contamination
Authors: McLeay M.J. , Hall K.J.
Published: March 2019

The use of organophosphate insecticides on commercial vegetable and blueberry farmlands bordering the Nicomekl River, Surrey, B.C., creates the potential for toxic effects on the biota within the drainage ditches and the river itself. To investigate the frequency and magnitude of the toxicity of drainage ditch water and the river water in the vicinity of ditch discharge points, together with the probable cause, water samples were collected from six drainage ditches, and four river locations, at 3-week intervals between June and November 1997. For each of the water samples collected, chronic (7 ± 1 day) survival and reproduction of the cladoceran test organism Ceriodaphnia dubia were compared to that of Nicomekl River headland waters beyond the influence of commercial growing operations. Portions of samples proving to be lethally toxic to the toxicity-test organism were analyzed for organophosphate insecticides (OPs) and subjected to treatment with piperonyl butoxide to ascertain if OPs were the likely contributing cause of the toxicity.

Throughout the 6-month monitoring period, a total of 50 ditch water samples and 35 Nicomekl river water samples were collected. None of the river water samples tested produced statistically significant mortality. Two (4%) of the ditch water samples were lethally toxic, with 6- and 7-day median lethal concentrations (LC50s) of 39.9 and 36.5%, respectively. Seven (14%) of the ditch water samples and three (9%) of the river water samples inhibited C. dubia reproduction. A biological toxicity identification evaluation using piperonyl butoxide determined that the toxicant(s) in each of the two ditch water samples which proved lethal to C. dubia were likely metabolically active OP insecti-cide(s). Later chemical analyses on stored portions of the samples revealed trace quantities of chlorpyrifos and/or diazinon. These and other non-measured OPs are believed to have been responsible for the observed lethality. The cause of the inhibited reproduction is for the most part unknown. Providing the 1997 growing season is a typical growing season in terms of OP insecticide use and rainfall, the C. dubia toxicity test results suggest that during the growing season the Nicomekl River and its drainage ditches may periodically be contaminated with OP insecticides at concentrations high enough to sublethally or lethally impact sensitive ditch and river invertebrate fish-food organisms.
Interference of Aluminum in Copper Biosorption by an Algal Biosorbent
Authors: Sung Lee Hak , Volesky Bohumil
Published: March 2019

Cu and Al sorption capacities of NaOH-treated Sargassum fluitans biomass were studied using equilibrium methodology. An evaluation of sorption performance and modeling in a two-metal system was carried out using a modified multicomponent Langmuir isotherm. The maximum Cu and Al uptakes calculated from the Langmuir isotherm were 1.54 mmol/g (9.8 weight percent) and 3.75 mmol/g (10.1 weight percent) at pH 4.5, respectively. However, these values were 1.35 mmol/g for Cu and 1.58 mmol/g for Al at pH 3.5. The modified Langmuir model gave the following affinity correlated coefficients: 0.20 for Cu and 6.82 for Al at pH 4.5, and 2.90 for Cu and 3.13 for Al at pH 3.5. The interference of Al in Cu biosorptive uptake was assessed by “cutting” the three-dimensional uptake isotherm surfaces at constant second-metal final concentrations. Equimolar final equilibrium concentrations of Cu and Al of 1 mM at pH 4.5 reduced Cu and Al uptakes by 83.4 and 5.5%, respectively. However, these reductions at pH 3.5 were 53.0 (Cu) and 29.1% (Al).
Extraction and Determination of RDX and HMX in Water
Authors: Vieira Eny M. , Onuska Francis I.
Published: March 2019

The analysis of energetic materials such as RDX and HMX in water at trace levels was accomplished by using micro-extraction by miscible solvents, such as acetonitrile, 2-propanol and acetone, and salting out the organic phase. This paper compares the results obtained with solid-phase extraction (SPE) to those obtained by demixing techniques for spiked Milli-Q water and an unfiltered lake water. A review of the data indicates that demixing with acetonitrile-sodium chloride and 2-propanol ammonium sulfate gives better extraction recoveries than solid-phase extraction. Salting-out extractions are performed in less time and with less solvent than by SPE techniques.
Spatial Characterization of the Occurrence of Road Salts and Their Environmental Concentrations as Chlorides in Canadian Surface Waters and Benthic Sediments
Authors: Mayer T. , Snodgrass W.J. , Morin D.
Published: March 2019

Increased concern over the contamination of surface waters by road salts and their adverse effects on the freshwater organisms led to the inclusion of “road salts” on the second Priority Substances List (PSL2) under the Canadian Environmental Protection Act The list identifies substances that must be assessed on a priority basis to characterize the nature and extent of the risk they pose to the environment or human health. This paper adds to the collection of several reports which constitute “supporting documentation” for the environmental risk assessment of the priority substance “road salts”. It reviews the physical-chemical properties of inorganic salts commonly used for road maintenance and their fate and transport in surface waters and sediments, together with the environmental concentrations of road salt constituents in the context of watershed geology and other environmental factors governing their concentrations. The paper also provides a spatial map of chloride concentrations as a basis for developing an understanding of a spatially based, ecological risk assessment for surface water systems and relates the spatial risk map to observed concentrations of chlorides. The data suggest that the surface waters most sensitive to road salts impacts are small ponds and streams draining large urbanized areas. Environment Canada is presently considering several alternatives for dealing with road salts.
Effects of Irradiation and Freezing on Toxicity of Sewage Sludge Elutriate Samples
Authors: Renoux Agnes Y. , Tyagi Rajeswar D. , Samson Réjean
Published: March 2019

The Microtox® assay (Vibrio fischeri) was used to determine if the handling of environmental or industrial samples affects their toxicity. Irradiation and 3-month freezing of sewage sludge elutriates decreased the toxicity of these samples as measured using the Microtox® test. The effect of storage at -20°C was also confirmed with the lettuce Lactuca sativa root elongation assay. Statistical independence (P >0.05) between each handling and previous sludge treatment was observed, however, which indicated the possibility of comparing toxicity data obtained from different samples handled consistently.
Structure and Porosity of Alum Coagulation Flocs
Authors: Gorczyca B. , Ganczarczyk J.
Published: March 2019

It is generally assumed that flocs grow according to the following model: primary particles form compact flocculi which assemble themselves into microflocs. Microflocs bind together to form floc aggregates. The main difference between flocculi, microflocs and floc aggregates is their structure. Porosity can be used to indicate differences in this structure. The objective of this study was to establish whether alum flocs disperse into floc components that represent different structures, as indicated by different porosities. Alum coagulation floes were broken up with increasing amounts of mixing energy. The size and porosity of the studied particles were determined on microtome sections of the resin-stabilized samples. The results, as expected, indicated that the size and porosity of alum flocs decreased with the increase of applied mixed energy. Fractal analysis of pores revealed that alum floes contained at least three distinctive populations of pores: small, medium and large. The three pore populations indicate three levels of aggregation, i.e., flocculi, microflocs and floe aggregates. The results of this study confirm the previous theoretical and experimental investigations that argued for the multilevel floc structure.
Development of a Protocol for Sampling Faecal Coliform Bacteria Originating from Manure in the Vadose Zone
Authors: Unc Adrian , Goss Michael J.
Published: March 2019

Contamination of water resources with components of manure is a significant concern in Ontario. One aspect is the potential for bacterial transport through the vadose zone to groundwater following field application of manure. One obstacle to characterizing the movement of faecal bacteria in the vadose zone is the sampling of soil solution for bacteria. Porous-cup suction samplers are commonly used in estimating solute transport through this zone. However, there is little information on the calibration of such samplers for estimating numbers of bacteria in soil solution. This paper reports an attempt to make such a calibration. Tests were carried out under laboratory conditions which simulated the sampling of soil solution under field situation. As the suction applied was less than the air entry value for the ceramic porous cups used, the saturation status of the medium surrounding the cups was only important in terms of the number of colonies-forming units collected and not whether they were detected. The results indicated that although there were limitations in the use of the porous-cup suction samplers for bacterial sampling because of filtration effects, such samplers could be used for field collection of faecal bacteria from soil solution in situations with contrasting initial boundary conditions.
Performance of UASB Reactors at 6 to 32°C in Municipal Wastewater Treatment
Authors: Singh Kripa Shankar , Viraraghavan T.
Published: March 2019

The feasibility of using a high-rate upflow anaerobic sludge blanket (UASB) system for the treatment of low-strength municipal wastewater at 6 to 32°C was investigated for temperate climate applications. UASB reactors could be started up successfully in about 60 days at 20°C. Under stable conditions, the removal of COD, BOD and SS ranged from 38 to 90%, 47 to 91% and 50 to 92%, respectively, for a temperature range of 6 to 32°C. Sulfate reduction ranged from 10 to 90%, showing a decreasing trend with a decrease in temperature at each HRT. The average biogas production and methane content ranged from 167 to 199 mL CH4/g-CODremoved and 65 to 86%, respectively. The recovery of methane in the gas phase was very low compared with soluble COD removals, especially during operation at lower temperatures (6 to 15°C). Digital image analysis and scanning electron microscopy results indicated the aggregation of biomass in the form of flocs and small granules. The mean size of aggregated sludge particles increased from 0.2 to 3.0 mm, with a sludge volume index of 18 ± 2 mL/g during the operation.
Pollution métallique et organique des eaux et des sédiments d’un cours d’eau marocain par les rejets liquides urbains
Authors: Khamar Mohamed , Bouya Driss , Ronneau Claude
Published: March 2019

L’oued Sebou, l’une des ressources en eau les plus importantes du Maroc, reçoit quotidiennement un important volume d’eaux usées de la ville de Fès. La présente étude analyse l’impact de ces rejets sur la qualité de ce système aquatique. Les métaux lourds et éléments toxiques (Cr, Zn, Fe, Co, As, Ba, Sr, Ag, Hg, Sb et Rb) ont été déterminés, par activation neutronique, dans l’effluent urbain et dans les eaux et les sédiments du cours en amont et en aval de sa confluence avec les rejets. Les résultats ont montré qu’il y a une forte contamination du cours d’eau par ces métaux et que les facteurs de contamination les plus élevés ont été observés pour Cr et Zn, alors que Hg, Ag et As ne se retrouvent que dans les stations avales. De plus, dans les stations avales il y a une forte augmentation de la charge organique (DCO, DBO, matières organique volatiles), de la salinité et de la teneur en ammonium, en orthophosphates, en sulfate, en sodium et en calcium, et une chute drastique de la teneur en oxygène dissous. Outre la dégradation de la qualité des eaux, on a relevé une chute importante de l’indice biotique qui passe de 8 en amont à 2 en aval. Du fait du régime hydrologique du cours d’eau et des conditions climatiques de la région, les métaux lourds accumulés dans les sédiments peuvent être remobilisés et constituent un risque d’une contamination à grande échelle.
Effect of Additives on Biological Treatment of Landfill Leachate
Authors: Pouliot Julie-Marie , Yanful Ernest K. , Bassi Amarjeet S.
Published: March 2019

Aerobic batch bioreactors were used in this research to study the effects of different additives on the biological treatment of landfill leachate. Those additives were phosphoric acid, powdered activated carbon, polyethylenimine and BOD Balance™. Both synthetic and natural landfill leachates were investigated. The natural leachate was collected at a landfill site near London, Ontario. It was observed that the addition of phosphoric acid increased the COD utilization rate as well as decreased the effluent COD. The other additives did not affect the effluent COD but were found to have a small influence on the COD utilization rates, especially PEI and BOD Balance. A maximum average COD utilization rate of 90 mg L-1 h-1 was obtained with the following combination of additives: phosphoric acid and BOD Balance at 5 mg L-1.
The Urban Drainage Program of Canada’s Great Lakes 2000 Cleanup Fund
Authors: Kok Sandra , Shaw J. , Seto P. , Weatherbe D.
Published: March 2019

Since 1990, Canada’s Great Lakes 2000 Cleanup Fund, which is administered by Environment Canada, has been supporting the development and implementation of cleanup technologies to control municipal pollution sources, to clean up contaminated sediments, and to rehabilitate fish and wildlife habitats. These efforts are focused on Canada’s 16 Great Lakes Areas of Concern (AOCs) identified by the International Joint Commission for priority cleanup action and restoration of beneficial uses. Remedial Action Plans (RAPs) developed by federal/provincial teams and the public provide the strategy for restoring the beneficial uses of the AOCs.

Impairments in beneficial uses in the AOCs have been, in part, caused by discharges from combined sewer overflows (CSOs), Stormwater and sewage treatment plants (STPs). To assist municipalities in addressing the problems posed by urban drainage (CSOs and Stormwater), the Cleanup Fund’s Urban Drainage Program has been supporting the development and demonstration of innovative, cost-effective technologies and approaches. These projects include high-rate treatment of CSOs, real-time control of CSOs, performance assessment of Stormwater treatment technologies, pollution prevention and control plans, and development of Stormwater management planning tools for urban areas. These projects are carried out in collaboration with the Ontario Ministry of the Environment, municipalities, professional groups, universities and conservation authorities and other Environment Canada’s facilities (National Water Research Institute and Wastewater Technology Centre).

The Urban Drainage Program has been instrumental in advancing the state of the art in CSO and Stormwater management in Ontario. Projects supported under the program have quantified pollutant loadings from municipal wastewater sources in several Ontario Areas of Concern, provided hard data on the performance of best management practices for Stormwater treatment, identified and evaluated new cost-effective technologies for CSO reduction and Stormwater treatment, and developed strategies and decision-making tools for Stormwater management

The work done through the Urban Drainage Program is making it possible for Great Lakes communities to achieve important environmental objectives at significantly lower cost As a result, the communities should be able to achieve many of these objectives much earlier than they would have if their choices had been limited to more conventional and capital-intensive solutions. Although the program has focused on the needs of Areas of Concern in the Great Lakes basin, the lessons learned there can easily be applied to communities in other parts of the country and around the world.
Using Benthic Assessment Techniques To Determine Combined Sewer Overflow and Stormwater Impacts in the Aquatic Ecosystem
Authors: Rochfort Q. , Grapentine L. , Marsalek J. , Brownlee B. , Reynoldson T. , Thompson S. , Milani D. , Logan C.
Published: March 2019

Urban wet-weather sources of pollution such as Stormwater and combined sewer overflows (CSOs) can contribute significantly to the contamination of receiving waters, particularly in sediment depositional areas near outfalls. Analyses of sediment chemistry alone are not sufficient to fully assess the effects of these discharges. Toxicity testing and evaluations of benthic invertebrate communities, in conjunction with chemical analyses, provide a more complete characterization. This study assessed relationships among three separate aspects of the benthic environment:sediment chemistry (metals, PAHs and nutrients) and particle size, sediment toxicity (ten endpoints with four benthic taxa), and benthic invertebrate community structure. In this initial survey, ten sites in five different study areas, representing a range of receiving water environments exposed to Stormwater and CSO discharges, were sampled in October 1998. Results of analyses indicated that while contaminant (metals and PAHs) concentrations were relatively high in sediments, biological effects were not evident Toxicity of sediments was low and altered benthic communities were not detected. Neither toxicity endpoints nor benthic community descriptors were related to sediment contaminant levels. To improve the power of these assessments, future investigations of Stormwater and CSO discharge impacts should use “upstream/downstream” sampling designs and study sites with minimal variability of habitat conditions.
Algal Communities as a Biological Indicator of Stormwater Management Pond Performance and Function
Authors: Olding Daniel D.
Published: March 2019

An investigation into phytoplankton and periphyton algal communities of two recently constructed Stormwater management ponds suggests that Stormwater impacts on biological communities are reduced during passage through the ponds, providing a degree of protection for biological communities in their receiving waters. In both ponds, disturbance effects from the incoming Stormwater on algal community richness and evenness appear to be greatest in the sediment forebay and are reduced in the main pond. However, the nature of the disturbance in the two systems can be seen to be fundamentally different from a biological perspective, with Rouge Pond functioning primarily to reduce toxins harmful to algal communities (e.g., heavy metals), and Harding Pond acting to reduce nutrients. The taxonomic composition of the two sites provides an indication of the quality of the incoming Stormwater. Rouge Pond, which contains many marine and brackish water species, receives Stormwater runoff from a major highway, while Harding Pond, containing more nutrient rich species, receives Stormwater primarily from residential properties. Despite the nutrient-rich conditions present in both ponds, nuisance blue-green algae (cyanobacte-ria) are conspicuously absent, and the ponds appear to have little potential for developing harmful algal blooms. The lack of blue-green algae can be linked to the hydraulic functioning of the ponds, suggesting that Stormwater facilities may be engineered to inhibit undesirable algal communities.
Winter Flow Dynamics of an On-Stream Stormwater Management Pond
Authors: Marsalek P.M. , Watt W.E. , Marsalek J. , Anderson B.C.
Published: March 2019

The winter operation of an on-stream Stormwater management pond, located in Kingston, Ontario, Canada, was studied with respect to ice cover formation and breakup, density stratification, velocity field under the ice cover, and the risk of sediment washout The pond freezes over in late November, with the ice thickness reaching up to 0.5 m. During the first half of the winter period, the ice thickness was well described by Stefan’s formula with empirical coefficients appropriate for shallow water bodies. The pond was chemically stratified, with total dissolved solids concentrations up to 1200 mg L-1 observed close to the bottom. The meromictic stability of this stratification was calculated as 882 g . cm.cm-2. Measurements of the velocity field under the ice cover indicated a flow pattern comprising a fast flow region, a small dead zone and a large recirculation zone to the north and south of the fast flow trajectory, respectively. Such a pattern agreed well with that simulated by a CFD model (PHOENICS_). During a snowmelt event, the near-bottom velocities reached up to 0.05 m . S-1, but were not sufficient to scour the bottom sediment.
Estimating the Relative Leaching Potential of Herbicides in Alberta Soils
Authors: Hill B.D. , Miller J.J. , Harker K.N. , Byers S.D. , Inaba D.J. , Zhang C.
Published: March 2019

Our objective was to use a simple screening model to predict the relative leaching of herbicides in Alberta soils to allow producers the option of choosing herbicides with lower leaching potential. Physical properties for each herbicide were obtained from the literature and the Laskowski model was used to calculate the leaching potential (LP) of the herbicides. Relative LP rankings (LPR) were then created by ranking herbicide LP values on a 1 to 9 scale (1 = no leaching; 9 = high leaching). The leaching rates of nine herbicides (2,4-D, dicamba, MCPA, diclofop, quinclorac, bromoxynil, fenoxaprop, triallate and trifluralin) were then determined on soils from the five major soil zones of Alberta (Brown, Dark Brown, Grey, Dark Grey and Black) using small packed soil columns. Eluate fractions were analyzed using a MSD-GC method. Although there were differences related to soil organic matter content, the relative rates of leaching among the nine herbicides were generally quite consistent. Dicamba, 2,4-D, MCPA and quinclorac leached most readily, followed by bromoxynil, and then diclofop, fenoxaprop and triallate, and finally trifluralin, which did not leach. These soil column results and previous field results validated the LPR for most of the nine herbicides. The LPR did appear to underestimate the leaching of MCPA, bromoxynil and quinclorac. LPR values (1 to 9 scale) are a convenient way to convey herbicide leaching information to producers and could easily be included in herbicide guides along with certain provisos.
Emergências na sociedade contemporânea
Authors: Daré Paula Serafim , Vallada Candido Pinto
Published: March 2019

O que não se tornou emergência, no sentido de prontidão para a ação, no mundo da internet? Nele, o ritmo dos acontecimentos se assemelha ao de um filme em alta velocidade. A sensação que temos é a de que se não lermos hoje, não visualizarmos ou respondermos algo prontamente, já estaremos desatualizados ou desconectados. A velocidade da internet muitas vezes não é a nossa, mas se impõe sem piedade. As transformações tecnológicas aparecem na sociedade como facilidades, encurtamento de tempo e distâncias, acesso às informações e ao conhecimento, mas vêm acompanhadas do temor de não darmos conta do volume do que se deve saber, fazer, produzir ou consumir.
Introduction
Authors: Paradis Patricia , Fehr Colton
Published: March 2019

Patricia Paradis is Executive Director of the Centre for Constitutional Studies and Editor of the Constitutional Forum. Colton Fehr holds an LLM from the University of Toronto and is a PhD Candidate in the Faculty of Law, University of Alberta. He was Assistant Editor on this issue of the Constitutional Forum.
The Original Living Tree
Authors: Honickman Asher
Published: March 2019

One of the main arguments in Canada in favour of the “living tree” doctrine is that it has deep roots in our constitutional tradition. As the Supreme Court of Canada said in Reference Re Same-Sex Marriage, the living tree is “one of the most fundamental principles of Canadian constitutional interpretation.” The argument goes something like this: beginning with the famous “Persons case” of 1929 (Edwards v. Canada(Attorney General)), the Judicial Committee of the Privy Council recognized the Constitution to be a living tree, capable of evolving to meet new social and economic realities, and this method of constitutional interpretation has remained fundamental to Canada’s constitutional order ever since.
FOOD–DRUG INTERACTION AND THEIR CLINICAL IMPLICATIONS: SELECTED INVESTIGATIONS
Authors: ELGADIR M. ABD
Published: March 2019

Food-drug interactions occur as a result of pharmacokinetic or pharmacodynamics mechanisms. Pharmacokinetic mechanisms include what the body does to a drug while Pharmacodynamics mechanisms involve what drugs do to the body. Many types of food have been shown to influence metabolism and the absorption of drugs. Large numbers of drugs are produced and introduced yearly. The interaction between Food and drug may cause negative effects in the nutritional status of the patient as well as safety and efficacy of drug therapy. Due to the possibility of unexpected or poor outcomes, generally, food-drug interactions, in this case, should be avoided. As the good clinical practice, drugs taken by mouth must be absorbed either through the lining of the stomach or the small intestine. Reduction in the absorbance of a drug might be influenced by the presence of food in the digestive tract. The avoidance of such interactions could be possible if the drug is taken 1 hour before or 2 h after eating the food. The effects of several types of food such as milk or milk products, grapefruit and grapefruit juice, bananas, oranges, legumes, fermented meats and pickled fish and some nutrient elements such as calcium, potassium, magnesium, iron, zinc, and vitamin K are highlighted in this paper including their clinical implications.
CASE STUDY ON BETA BLOCKERS INDUCED PSORIASIS
Authors: RAJAN ASHA K. , S. VEDHA PAL JEYAMANI , U. KAVIYA , S. INDUMATHI , R. DIVYA
Published: March 2019

Drug-induced Psoriasis is one among the common etiological factors of Psoriasis reported worldwide. Familiar drugs known to cause psoriasiform eruptions include Anti-malarials, Beta blockers, NSAIDs, Lithium. etc. Certain antihypertensives like ACE inhibitors, diuretics are also documented to have caused psoriatic episodes.

A 57 y old South-Indian male patient with a history of Hypertension, Diabetes Mellitus, Atrial Fibrillation for 4 y; was on antihypertensive therapy for Hypertension and Atrial Fibrillation with proponolol for past 2 y and metoprolol initially. He was presented to the hospital two weeks after switching on to Metoprolol therapy for chief complaints of erythematous scaly lesions especially over both the extremities and paronydrial appearance of nails. Initially, he was on Propranolol therapy which was then shifted to Metoprolol due to an appearance of oral lesions in the mouth. Metoprolol was now discontinued and switched on to Atenolol. After 1-2 w of therapy with Atenolol, the lesions were found to disappear and no recurrence of psoriatic conditions were found.

Proper reviewing of medical history for any allergic reactions and the optimization of drug therapy through Therapeutic Drug Monitoring could be initiated by Clinical Pharmacist in order to avoid such drug-induced flares.
ANALYSIS OF FATTY ACIDS FROM OIL OF GREEN TEA (CAMELLIA SINENSIS L) BY GAS CHROMATOGRAPHY COUPLED WITH FLAME IONIZATION DETECTOR AND ITS ANTICANCER AND ANTIBACTERIAL ACTIVITY IN VITRO
Authors: Das Koushik , Mandal Meghamala , Nandi Dilip Kumar , Das Balaram , J Sreenivas R
Published: March 2019

Objective: Tea is a widely consumed beverage worldwide. The effect of green tea is mainly due to its high polyphenols-(-) epigallocatechin-3-gallate (EGCG) content in the culture of cancer cell and bacterial cells. The present work was carried out to investigate the efficacy of green tea oil (GTO) against cancer cells and bacterial cells.
Methods: In this study green tea oil was prepared from green tea for different experiment and determination of fatty acids profile from green tea oil. In the present study, peripheral blood lymphocyte (PBL) was chosen as human peripheral blood lymphocytes and blood cancer MCF-7 cells were chosen as human cancer cells. To fulfill our aims and also to evaluate the activity of this phytomedicine against normal lymphocytes and cancer cells the cell samples were divided into 26 experimental groups in the following ways. Each Petri dish contains 2 X 105 cells.
Results: GTO shows a potent anticancer agent but nontoxic to normal cells. The GTO decreases the reduced glutathione (GSH) level and increase the oxidized glutathione (GSSG) level significantly (P<0.05) in MCF-7 cells. But in lymphocytes the GSH level and GSSG level were almost the same with the control group but doxorubicin (DOX) significantly decreased the GSH and increase the GSSG level. Green tea oil treatment causes generation of reactive oxygen species (ROS) in MCF-7 cells revealed by DCFH2DA staining. Agar diffusion test shows the GTO is effective against multi-drug resistant bacteria.
Conclusion: This phytomedicine has a potent anticancer activity without damaging the normal lymphocytes. So, this drug can be used for further treatment of anticancer and antibacterial.