bluuebunny/crossref_metadata_2025 huggingface dataset:
Application de la respirométrie pour le suivi de l'activité de la biomasse d'un biofiltre sur lit organique traitant du lisier de porc
Authors: Gilbert Yan , Le Bihan Yann , Buelna Gerardo , Lessard Paul
Published: May 2018

L'opération de systèmes de biofiltration à support organique nécessite le développement de méthodes de suivi simples et rapides La respirométrie de type LSS a donc été adaptée afin d'évaluer l'activité potentielle des organismes hétérotrophes présents dans le biofiltre. Des essais respirométriques ont été réalisés à différentes concentrations de milieu filtrant afin d'adapter la méthode à cette biomasse, fixée sur le support. Des colonnes de biofiltration de laboratoire ont été montées et alimentées à des charges hydrauliques et massiques variables et à des durées de fonctionnement différentes afin d'évaluer l'activité hétérotrophe à divers degrés de colonisation. Même après 60 jours d'opération des biofiltres, pour différentes conditions d'opération, la colonisation du milieu filtrant est toujours en accroissement et le suivi respirométrique reflète une colonisation du milieu filtrant lente dans le temps. L'activité des microorganismes a pu être mise en relation avec la quantité de matière organique cumulée dans le biofiltre. Les relations obtenues démontrent que la charge organique et la charge hydraulique ont une influence importante sur l'activité de la biomasse.
Sorption des ions chromate sur une hydrotalcite de synthèse calcinée
Authors: Bakhti Abdellah , Ouali Mohand SaÏd
Published: May 2018

Nous avons examiné les possibilités de fixation des ions chromate sur une hydrotalcite de synthèse (Mg-Al-CO3) et son produit de calcination à 550ºC. Les différentes analyses physico-chimiques (diffraction des rayons X, analyse thermogravimétrique et composition chimique) ont permis d'une part d'établir la formule chimique du matériau de départ et d'autre part, de mettre en évidence sa propriété de pouvoir se régénérer après calcination ménagée et formation des oxydes mixtes.

La sorption d'ions chromate par le matériau préparé et par son produit de calcination a été étudiée. Nos résultats montrent que la cinétique de sorption est rapide (l'équilibre est atteint au bout de 20 minutes de contact) et que le phénomène dépend du pH. Le traitement, par le matériau calciné, de solutions contenant de 15 à 300 mg/l de Cr(VI) a donné de bons résultats. En effet, la comparaison des capacités de sorption pour les ions Cr(VI) de l'hydrotalcite calcinée avec d'autres phases LDHMg, Al montre bien la supériorité des propriétés sorptives des hydrotalcites calcinées d'où l'utilité de ces matériaux dans le domaine du traitement des eaux usées.
Comportement hydrogéochimique du phosphore dans le réservoir Imfout (Oum Rabiaa, Maroc)
Authors: Taoufik Mohamed , Dafir Jamal Eddine , Kemmou Souad
Published: May 2018

L’étude du phosphore, facteur clef responsable de l'eutrophisation des eaux continentales, a été entreprise au niveau du réservoir Imfout, situé dans la partie aval du bassin Oum Rabiaa, afin de comprendre le fonctionnement hydrogéochimique de cet élément dans ce réservoir. Le régime hydrologique du réservoir, caractérisé par un faible temps de séjour (70 jours en moyenne annuelle) est lié aux apports externes et à la gestion propre du réservoir. Cela contribue à l'homogénéisation de la colonne d'eau qui ne présente aucune stratification thermique ni d'anoxie. Le comportement hydrogéochimique du phosphore dans le réservoir montre que l'influence du réservoir Al Massira situé en amont sur les apports en phosphore semble être partielle. Ce réservoir semble être beaucoup plus contrôlée par : (1) les apports venant du bassin versant local où les flux en phosphore mesurés à l'entrée d'Imfout sont plus importants qu’à la sortie du réservoir Al Massira; (2) la consommation phytoplanctonique de la forme P-PO4 directement assimilable et (3) les échanges au niveau du sédiment, surtout en période estivale. L’étude saisonnière a montré le rôle des différentes fractions du phosphore du sédiment dans le processus d’échange eau – sédiment. La mobilité de ces différentes fractions explique les variations du phosphore sédimentaire. Les résultats témoignent de l'importance de la fraction ferrique dans ces échanges et cette fraction est identifiée comme étant la plus concernée par ces phénomènes.
Preliminary Analysis of Pulp and Paper Environmental Effects Monitoring Data to Assess Possible Relationships between the Sublethal Toxicity of Effluent and Effects on Biota in the Field
Authors: Walker Sherry L. , Lowell Richard B. , Sherry James P.
Published: May 2018

Data from the sublethal toxicity testing of effluents may or may not be predictive of field effects. Although qualitative studies have attempted to support a predictive relationship at select sites, few quantitative studies have been undertaken to establish whether general predictive relationships exist for diverse recipient environments. Since Canada's Environmental Effects Monitoring (EEM) Program encompasses a strong field component as well as a suite of sublethal toxicity tests, the Cycle 2 data set of the Pulp and Paper EEM Program presented an opportunity to elucidate whether relationships exist between various sublethal toxicity endpoints used in EEM and field effects that were determined in surveys of benthic invertebrate communities and fish populations. Sublethal toxicity data and key endpoints from the fish (gonad weight, liver weight and condition) and invertebrate surveys (taxon richness and abundance) were quantitatively analyzed using simple bivariate correlation analysis. Our preliminary analysis of the data did not reveal any meaningful general relationships between the field biomonitoring and sublethal toxicity data collected under the Pulp and Paper EEM Program. Although the sublethal toxicity tests are useful to assess changes in effluent quality, their ability to predict the field effects for the key endpoints that are currently measured for fish and benthos in the Pulp and Paper EEM Program remains unsubstantiated.
Investigation of Cause in Pulp and Paper Environmental Effects Monitoring
Authors: Hewitt L. Mark , Dubé Monique G. , Ribey Sandra C. , Culp Joseph M. , Lowell Richard , Hedley Kathleen , Kilgour Bruce , Portt Cameron , Maclatchy Deborah L. , Munkittrick Kelly R.
Published: May 2018

Environmental Effects Monitoring (EEM) Programs in Canada have been developed for the pulp and paper and metal mining industries. The EEM Program conducts cyclical evaluations of receiving environments to determine whether effects exist when facilities comply with existing regulations. Investigation of cause (IOC) is a specific stage in the EEM Program that is used after environmental effects in fish and/or benthos have been detected, confirmed and their extent and magnitude have been documented. This paper presents an overview of the processes associated with this phase of monitoring.

The objective of an IOC is to obtain sufficient information so that the source of the effect can be identified and removed, or its effects reduced to an acceptable level. The initial direction of an IOC is dependent upon the type of response patterns observed for fish and/or benthos during EEM cycles and extent/magnitude studies. The framework presented in this paper is based on an amalgamation of research projects conducted at Canadian pulp mills over the last decade and selected studies are summarized as examples. It also represents an integration of several research philosophies and scientific disciplines. The framework is based on national response patterns from the second cycle of pulp and paper EEM studies. IOCs are directed into either an eutrophication-based investigation or a contaminant-based investigation (including metabolic disruption in fish). The framework is constructed with a progression of investigative levels designed to provide more information on the causative factors. Each of these phases also represents a decision point for stakeholders to determine if sufficient information has been attained about the causal factor(s) and whether the IOC should be concluded. It is expected that the framework will evolve with a growing knowledge base of causal factors, as facilities enter into this phase of the EEM Program.
Site Fidelity of Mummichogs (Fundulus heteroclitus) in an Atlantic Canadian Estuary
Authors: Skinner Marc A. , Courtenay Simon C. , Parker W. Roy , Curry R. Allen
Published: May 2018

The site fidelity of mummichogs (Fundulus heteroclitus) within the upper Miramichi River estuary, New Brunswick, Canada, was investigated to assess the value of using this fish as a sentinel species for monitoring effects of point source anthropogenic effluents such as pulp and paper mill effluent. During the ice-free season (May to November) of 2002, 4123 adult mummichogs (>30 mm TL) were captured, by beach seine and minnow trap, biweekly from four sites within the estuary. Fish were marked intramuscularly using Visible Implant Elastomer (Northwest Marine Technologies, Inc., Shaw Island, Wash., U.S.). Recaptures were made at the marking sites and elsewhere during this period and again during the ice-free season of April to November 2003. A total of 639 (15.5% of those marked) mummichogs were recaptured with 617 (96.6%) found within 200 m of the point of initial release. Twenty-nine of the 617 were recaptured 2 or 3 times at sites of original marking. The remaining 22 recaptured fish moved distances ranging from 600 to 3600 m up- and downstream of initial marking sites. Eighty-two percent of recaptures were made within 12 weeks of the start of marking with the remainder recovered up to 72 weeks later. These findings are consistent with results from studies of mummichog movement in smaller water bodies and other parts of the species' range. With regard to mobility, these results add to the growing body of literature supporting the usefulness of mummichogs as a sentinel species in environmental monitoring programs for point-source impacts in Atlantic Canadian estuaries.
Overview of Methodology and Endpoints in Fathead Minnow Lifecycle Tests Assessing Pulp and Paper Mill Effluents
Authors: Parrott Joanne L.
Published: May 2018

Fathead minnow (Pimephales promelas) lifecycle tests have been used to assess the effects of many North American pulp mill effluents. Fish are exposed under controlled laboratory conditions to final effluent, from the egg stage through hatching, juvenile stage and mature adult stage. Outlined here are methods for the lifecycle test (which takes from 4 to 5 months to complete) with sampling of juvenile fish at 1, 2 and 3 months of age, and sampling of mature adults after breeding. The results of most fathead minnow lifecycle studies have shown that pulp mill effluents cause metabolic and reproductive disruption (enlarged livers, reduced egg production, smaller gonads, decreased sex hormones and reduced secondary sex characteristics). Thus, the fathead minnow lifecycle assay is able to mimic the most commonly observed changes seen in wild fish exposed to pulp mill effluents. Sensitive indicators of reproductive effects in fathead minnows exposed for a lifecycle to pulp mill effluents include secondary sex characteristics, time to first reproduction and number of eggs laid. Egg production is often the most sensitive response to pulp mill effluents. Because of the length and cost of full lifecycle tests, a shortened assay using adult fish was developed as a screen for endocrine-disrupting compounds. This assay, the terminal reproduction test, has been used with success on a few pulp mill effluents. The assay exposes fathead minnow breeding pairs for three weeks to effluent, and compares egg production, sex characteristics and bioindicators of reproductive performance in pre-exposure versus post-exposure fish. For assessment of pulp mill effluents, it appears that the sensitivity of the shortened terminal reproductive fathead minnow assay may be improved by assessing bioindicators of reproductive performance (such as circulating levels of sex hormones, and circulating or hepatic vitellogenin) along with changes in secondary sex characteristics and egg production.
Biological Criteria for Municipal Wastewater Effluent Monitoring Programs
Authors: Kilgour Bruce W. , Munkittrick Kelly R. , Portt Cameron B. , Hedley Kathleen , Culp Joseph , Dixit Sushil , Pastershank Georgine
Published: May 2018

As part of the long-term strategy for addressing issues related to municipal wastewater effluents (MWWE), Environment Canada is developing environmental quality objectives (EQOs) for the aquatic receiving environment. Recommended biological monitoring components of the aquatic ecosystem include fish communities, benthic macroinvertebrate communities, sentinel fish species and primary producers (macrophytes, attached algae, phytoplankton). A set of criteria was developed for measurable attributes (indicators) of each of those components. Recommended numeric and narrative criteria could be used to determine when MWWE should be managed. Warning-level criteria for indices of benthic community composition are considered effects on indices of composition that deviate from the mean reference response by more than ±2 standard deviations. For sentinel fish population parameters, warning-level effects are considered >25% differences from reference in gonad or liver size, growth, or age, or a >10% change in condition factor. For primary producers, warning-level effects are considered those that coincide with anticipated changes in fish communities based on existing models. Where warning-level criteria are exceeded, it is recommended that monitoring be repeated at two- to three-year intervals. Where continued monitoring demonstrates an increase in the extent or magnitude of effects on indices of benthic community composition, or sentinel fish population parameters, it is recommended that effects be considered unacceptable and that the cause of effects be identified and managed. Losses of non-rare species or shifts in dominance are considered severe fish-community effects that should trigger management (i.e., identification and elimination of causative agents). Domination of the benthic community by one or a few tolerant taxa normally coincides with effects on fish communities, and should also be considered a severe effect that triggers management.
Analyzing the Spatial Distribution of Sediment Contamination in the Lower Great Lakes
Authors: Forsythe K. Wayne , Marvin Chris H.
Published: May 2018

Despite significant reductions in contaminant concentrations over the past 30 years, large areas within Lake Erie and Lake Ontario still exceed Canadian sediment quality guidelines. Hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), lead (Pb) and mercury (Hg) can persist for long periods of time in the environment and cause significant ecosystem damage. Analyses of the spatial distribution of these contaminants were carried out using a GIS-based kriging technique. Initially, statistically valid results were obtained for three of four contaminants in Lake Erie (HCB, Pb, Hg) and two of four (HCB, Hg) in Lake Ontario. Acceptable concentration estimates were subsequently achieved for all contaminants following log-normal transformation kriging analyses. In general, the concentration of contaminants was lower in sediment collected in Lake Erie than in Lake Ontario. In many areas of Lake Erie, the concentrations were under both the probable effect level (PEL) and the threshold effect level (TEL), which relate to the severity of adverse biological effects that may be expected. Greater concentrations of these contaminants were observed in Lake Ontario sediments, which can be partly explained by the bathymetry and current circulation patterns in the lake.
Diatom- and Chironomid-Inferred Eutrophication of Bouchie Lake, British Columbia
Authors: Heinrichs Markus L. , Cumming Brian F. , Laird Kathleen R. , Hart J. Sanford
Published: May 2018

Diatom and chironomid analysis of sediments encompassing the past 400 years from Bouchie Lake, British Columbia, suggests two distinct periods of limnological conditions. Prior to 1950 AD, Fragilaria construens and F. pinnata are the most common diatom species, and Chironomus, Procladius and Tanytarsini dominate the chironomid record. Moderately low nutrient concentrations consistent with oligo-mesotrophic lakes are inferred. From 1950, the diatom assemblage is dominated by Stephanodiscus parvus, a eutrophic indicator, whereas the chironomid communities show a relative increase in littoral taxa coincident with lower head capsule abundance. Higher nutrient levels, specifically total phosphorus, which increased from 8 µg L-1 prior to 1950 to 20 µg L-1 currently, are coincident with midge communities indicative of lower oxygen concentrations. Observed biotic changes and nutrient levels inferred from the sediment core correspond to historical land-use changes.
Removal and Recovery of Cr(VI) from Synthetic and Industrial Wastewater using Bark of Pinus roxburghii as an Adsorbent
Authors: Ahmad Rais , Rao Rifaqat Ali Khan , Masood Mir Mohammad
Published: May 2018

In the present study, the potential of Pinus roxburghii bark as an adsorbent for the removal of heavy metals such as Cr(VI), Ni(II), Cu(II), Cd(II) and Zn(II) from aqueous solution at ambient temperature was investigated. Adsorption capacity of the material was found to be 4.15, 3.89, 3.81, 3.53 and 3.01 mg g-1 for Cr(VI), Zn(II), Cu(II), Ni(II) and Cd(II), respectively, at an initial metal ion concentration of 50 mg L-1 at pH 6.5. The effect of concentration, contact time, adsorbent dose, solution pH, adsorbent particle size, salinity and hardness on the adsorption of Cr(VI) were studied in detail in batch experiments. The equilibrium contact time for Cr(VI) adsorption was found to be 1 h. Adsorption equilibrium data fit well to the Freundlich isotherm in the concentration range studied. The maximum adsorption (96.2%) was recorded at pH 3 for the initial Cr(VI) concentration of 50 mg L-1. The adsorbed metal ions from industrial wastewater were recovered using 0.1 M HCl solution. The column operation was found to be more effective compared to batch process. The percent recovery of Cr(VI) from industrial wastewater by column operation and batch process was found to be 85.8 and 65%, respectively. The results show that Pinus roxburghii bark can be used as a cost-effective adsorbent for the removal and recovery of Cr(VI) from wastewater.
Transport Modelling of Copper Contamination in Groundwater Caused by a Wood Preservation Plant
Authors: Tombul Mustafa , Koparal Ali Savaş , Öğütveren Ülker Bakır
Published: May 2018

Contaminants can adhere to soil and subsequent rainfall can leach the adhered contaminant into groundwater. Transport models can determine the main features of contaminant and carrier transport in groundwater systems, and therefore determine potential risks for public health and ecosystems.

In this study, the effect of copper contamination caused by a wood preservation plant near Eskişehir, Turkey, on the possible pollution of drinking water supply wells was investigated with two different models. The first model, which deals with the movement of contaminants to groundwater, is a numerical model known as Flonet/Trans (Waterloo Hydrogeologic 1997). It has been used to investigate the change in contaminants from the source with respect to time and distance. The second model, which measures contaminant movement with respect to time and distance through simulations, is an analytical model known as Multi-Flow. It was used for verification of the first model. Both numerical and analytical models have been successfully applied at the work area for investigation of the effects of copper contamination in groundwater. Using the numerical model, the copper concentration in the first observation well was found to be 1.59 mg L-1, and using the analytical model, the copper concentration was found to be 1.35 mg L-1 after 550 days. The measured quantity was 2.11 mg L-1, thus the analytical model is best used for verification of results obtained by simulations of the numerical model.
Characterization of Leachate from a Woodwaste Pile
Authors: Tao Wendong , Hall Ken J. , Masbough Arash , Frankowski Kevin , Duff Sheldon J.B.
Published: May 2018

Leachate was generated when precipitation percolated through a pile of woodwaste, including trimmings, off-specification wood chips, shredded bark and roots, and sawdust from several cedar processing mills. The “young” woodwaste leachate produced in the pile's placement period was amber, acidic (pH 3.4–3.7), nutrient-poor (inorganic nitrogen 1.4–3.2 mg L-1, orthophosphate 3.3–4.3 mg P L-1), of very high oxygen demand (chemical oxygen demand 12,559–14,254 mg L-1, tannin and lignin 3066–5150 mg L-1 as tannic acid, volatile fatty acids 1564–2132 mg L-1), and very toxic to aquatic life (96-h median lethal concentration of 0.74% leachate). The leachate at 1.5 years old in the closure period had lower oxygen demand and higher ammonia, and became less acidic and darker. The leachate had a 5-day biochemical oxygen demand to chemical oxygen demand ratio of 0.33 in the placement period and 0.14 in the late closure period. Volatile fatty acids accounted for 6 to 34% chemical oxygen demand, varying as the pile developed and with woodwaste age. Tannin and lignin accounted for 33 to 45% chemical oxygen demand. More than 98% contaminants were in dissolved form. The monthly variation of leachate quality was likely a result of both temperature and precipitation. pH was significantly correlated to chemical oxygen demand, tannin and lignin, and volatile fatty acids.
Simulation of the Impact of Higher Ammonia Recycle Loads Caused by Upgrading Anaerobic Sludge Digesters
Authors: Kraemer Jeremy T. , Bagley David M.
Published: May 2018

Upgrading conventional single-stage mesophilic anaerobic digestion to an advanced digestion technology can increase sludge stability, reduce pathogen content, increase biogas production, and also increase ammonia concentrations recycled back to the liquid treatment train. Limited information is available to assess whether the higher ammonia recycle loads from an anaerobic sludge digestion upgrade would lead to higher discharge effluent ammonia concentrations. Biowin, a commercially available wastewater treatment plant simulation package, was used to predict the effects of anaerobic digestion upgrades on the liquid train performance, especially effluent ammonia concentrations. A factorial analysis indicated that the influent total Kjeldahl nitrogen (TKN) and influent alkalinity each had a 50-fold larger influence on the effluent NH3 concentration than either the ambient temperature, liquid train SRT or anaerobic digestion efficiency. Dynamic simulations indicated that the diurnal variation in effluent NH3 concentration was 9 times higher than the increase due to higher digester VSR. Higher recycle NH3 loads caused by upgrades to advanced digestion techniques can likely be adequately managed by scheduling dewatering to coincide with periods of low influent TKN load and ensuring sufficient alkalinity for nitrification.
Modelling Human Exposure of Methylmercury from Fish Consumption
Authors: Luk Grace K. , Yeung Wai C. Au
Published: May 2018

Mercury and its compounds are widely distributed in the environment and the principal cause of methylmercury accumulation in humans is fish consumption. The rate of methylmercury accumulation depends on many factors including the amount, size, type and frequency of fish consumed, as well as contamination levels in the aquatic habitat. The ability to predict accurately human exposure to methylmercury through fish consumption is essential to the setting of public consumption guidelines. This paper describes the development of an innovative method of estimating human exposure to methylmercury through sport fish consumption by mathematical modelling. Through a judicious combination of fish methylmercury bioaccumulation models and survey information on human fish-eating habits, the model allows for a scientifically based estimation of the average daily exposure to methylmercury from fish consumption. It provides a practical tool to estimate the methylmercury uptake from a fish diet as governed by the diet frequency, fish species and fish size. The efficacy of the model is demonstrated by application to six common Lake Ontario fish species. Results showed that the human methylmercury exposure from fish consumption is a serious issue, as demonstrated by the exceedance of the tolerable daily intake levels in many instances. It was also found that the level of human methylmercury uptake depends heavily on the species of fish consumed; among the six species studied, walleye carries the highest risk, followed by yellow perch, while rainbow trout seems to be the safest with the lowest bioaccumulation levels.
Organic Contaminants in Canadian Municipal Sewage Sludge. Part II. Persistent Chlorinated Compounds and Polycyclic Aromatic Hydrocarbons
Authors: Kohli Jagmohan , Lee Hing-Biu , Peart Thomas E.
Published: May 2018

Thirty-five sewage sludge samples collected across Canada were analyzed for 18 polycyclic aromatic hydrocarbons (PAHs), 17 congeners of polychlorinated biphenyls (PCBs) and seven selected chlorinated compounds. Samples were prepared by accelerated solvent extraction and standard column cleanup procedures using silica gel and Florisil. Gas chromatography with electron-capture detection was used for the determination of PCBs. Gas chromatography/mass spectrometry with electron-impact ionization and methane negative ion chemical ionization were used for the detection of PAHs and the chlorinated compounds, respectively. PAHs were detected in nearly all samples, with a total concentration ranging from 0.14 to 209 µg/g (median 3.65 µg/g) on a dry weight basis. Phenanthrene, fluoranthene and pyrene were present at the highest concentrations, with medians ranging from 0.56 to 0.58 µg/g. PCBs were also found in all samples, with a total PCB concentration ranging from 31 to 323 ng/g. The most abundant PCBs (congeners 52, 101 and 110) had median concentrations of 12 ng/g or above. While pentachlorobenzene and hexachlorobenzene were observed in all sludge, at low ng/g levels, no other less chlorinated benzenes have been detected in the same samples. Octachlorostyrene was only found in the Ontario samples, with concentrations ranging from 0.3 to 11.5 ng/g (median 0.9 ng/g). For the chlorinated insecticides, only p,p'-DDE, α- and γ-chlordane were found on a more regular basis, with median concentrations of 12.0, 0.4 and 0.8 ng/g, respectively. These results suggest that the above toxic chemicals are occurring in Canadian sewage samples and are persistent enough to survive the existing sewage treatment processes.
Dissolved Phosphorus Losses in Tile Drainage under Subirrigation
Authors: Stämpfli Nicolas , Madramootoo Chandra A.
Published: May 2018

Recent studies have shown subirrigation (SI) to be effective in reducing nitrate losses from agricultural tile drainage systems. A field study was conducted from 2001 to 2002 in southwestern Québec to evaluate the effect of SI on total dissolved phosphorus (TDP) losses in tile drainage. In an agricultural field with drains installed at a 1-m depth, a SI system with a design water table depth (WTD) of 0.6 m below the soil surface was compared with conventional free drainage (FD). Subirrigation increased drainage outflow volumes in the autumn, when drains were opened and water table control was interrupted for the winter in the SI plots. Outflows were otherwise similar for both treatments. Throughout the study, the TDP concentrations in tile drainage were significantly higher with SI than with FD for seven out of 17 of the sampling dates for which data could be analyzed statistically, and they were never found to be lower for plots under SI than for plots under FD. Of the seven dates for which the increase was significant, six fell in the period during which water table control was not implemented (27 September 2001 to 24 June 2002). Hence, it appears that SI tended to increase TDP concentrations compared with FD, and that it also had a residual effect between growing seasons. Almost one-third of all samples from the plots under SI exceeded Québec's surface water quality standard (0.03 mg TDP L-1), whereas concentrations in plots under FD were all below the standard. Possible causes of the increase in TDP concentrations in tile drainage with SI are high TDP concentrations found in the well water used for SI and a higher P solubility caused by the shallow water table.
Investigation of Titania Addition into Tar Sands for Removal of Phenol from Aqueous Solutions
Authors: Zeatoun Lua'y , Al-Sharif Munjed , Al-Bsoul Abeer
Published: May 2018

Tar sands were found to remove significant amounts of phenol from aqueous solution in the presence of titania; about 70% at an initial concentration of 10 ppm. Batch sorption experiments showed that phenol uptake was increased with either an increase in initial phenol concentration, percentage of titania in the sorbent or pre-activation temperature. On the other hand, the presence of soft ions such as sodium, Na+, or potassium, K+, or the increase of solution temperature suppressed the uptake of phenol. Physical pre-activation of the tar sands influenced the adsorption process positively. The sorption process appears to be exothermic and relatively fast; the equilibrium isotherm data were well represented by either Langmuir or Freundlich models.
Assessing the Chemical Sensitivity of Freshwater Fish Commonly Used in Toxicological Studies
Authors: Teather Kevin , Parrott Joanne
Published: May 2018

Using information from published studies, the relative sensitivity of various freshwater fish to a range of chemicals was examined. Specifically, the objectives were to: (1) determine which species are used most often in toxicity tests, (2) assess the relative sensitivity of these species to various chemicals, and (3) determine whether the two most commonly tested species exhibit differences in their relative sensitivity to different classes of chemicals. Fathead minnows, rainbow trout and bluegill sunfish were the three most commonly used species in 96-h LC50 tests. Of the nine species examined, coho salmon and rainbow trout were the most sensitive species to 190 chemicals, while goldfish and carp were the least sensitive. Fathead minnows and rainbow trout were not equally sensitive to 13 different classes of chemicals; for example, while trout were significantly more sensitive to metals, fathead minnows were more sensitive to hydrocarbons. Such comparisons are expected to be useful for predicting the relative responses of different species to previously untested chemicals in such groups, and in gaining insight into physiological modes of action.
Preservation and Field Speciation of Inorganic Arsenic Species in Groundwater
Authors: Samanta Gautam , Clifford Dennis A.
Published: May 2018

This research describes the development of a dual preservation- and field-speciation technique for As(III) and As(V) speciation of a sample preserved with ethylenediaminetetraacetic acid (EDTA) and acetic acid (HAc). The new method was compared with existing preservation- and field-speciation methods and was shown to be accurate and precise in spite of possible interference from ferrous iron in the sample. The new preservation-speciation method was further evaluated on 55 drinking water wells (18 samples in triplicate) in Minnesota, North Dakota and California with the result that As(III) measured by field-speciation agreed with subsequent (within 1–3 d) laboratory speciation on the preserved sample with a slope of 0.98 and a correlation coefficient of r2 = 0.999. Preserved samples stored in the dark at room temperature (22–24°C) could maintain their species distribution for 30 to 85 d.
Removal of Arsenate from Aqueous Solution Using Nanoscale Iron Particles
Authors: Yuan Ching , Lien Hsing-Lung
Published: May 2018

Removal of As(V) using nanoscale iron particles was examined in batch reactors. Nanoscale iron particles, utilizing zerovalent iron with a diameter less than 100 nm as reactive materials, have been demonstrated to effectively remediate a wide variety of common environmental contaminants. In this study, characterization of nanoscale iron particles and their corrosion products was conducted using SEM-EDX, XRD, BET surface area analyzer and Laser Zee Meter. SEM-EDX results indicated adsorption of arsenic onto the iron surface, and XRD analysis found the formation of iron corrosion products including lepidocrocite, magnetite and/or maghemite at a reaction period of 7 d. Measurements of zeta potential revealed that the nanoscale iron particles have a zero point of charge at pH 4.4. Increasing adsorption amounts of arsenic with decreasing pH can therefore be attributed to the positive surface charge of the particles at lower pH. The maximum adsorption capacity of nanoscale iron particles determined by the Langmuir equation was about 38.2 mg/g. Normalization of the adsorption capacity to specific surface areas provides insight into the importance of iron types and the contact time of reactions in influencing arsenic uptake.
Million Dollar Arsenic Removal Plants in West Bengal, India: Useful or Not?
Authors: Hossain M. Amir , Mukharjee Amitava , Sengupta Mrinal Kumar , Ahamed Sad , Das Bhaskar , Nayak Bishwajit , Pal Arup , Rahman Mohammad Mahmudur , Chakraborti Dipankar
Published: May 2018

The effectiveness of arsenic removal plants (ARPs) to provide safe water was evaluated based on a study of 577 ARPs out of 1900 installed in 5 arsenic-affected districts of West Bengal, India. Out of 577, 145 (25.1%) were found in defunct condition. Both raw and filtered water from 305 ARPs were analyzed for total arsenic concentration. Forty-eight ARPs were installed despite raw water arsenic concentrations below the Indian standard (50 µg/L) and in 22 cases even below the WHO guideline value (10 µg/L). Among the 264 ARPs having raw water arsenic above 50 µg/L, 140 (53.1%) and 73 (27.7%) failed to remove arsenic below the WHO guideline value and Indian standard, respectively. The highest arsenic concentration in treated water was 705 µg/L. Analysis of 217 treated water samples for iron showed that 175 (80.6%) failed to remove iron below 300 µg/L. The treated water became coloured on standing 6 to 8 h, for 191 (44.2%) ARPs and 25 (5.8%) produced bad-odoured water. Overall, the study showed that 475 (82.3%) of the ARPs were not useful. The reasons for ineffectiveness and poor performance of these ARPs include improper maintenance, sand gushing problems, a lack of user-friendliness and absence of community participation. A comparative study of ARPs in two different blocks (Domkol in Murshidabad district and Swarupnagar in North 24 Parganas) showed that 39 (80%) and 38 (95%) ARPs, respectively, were not useful. Further study in Gram Panchayet Kolsur, Deganga block, North 24 Parganas, showed that 14 (87.5%) ARPs were not useful. Proper watershed management with active participation from the villagers is urgently required for successful mitigation.
Comparaison entre débits réservés écologiques et débits lâchés en aval des barrages au Québec : Influence du mode de gestion des barrages, de la taille des bassins versants et de la saison
Authors: Lajoie Francis , Assani Ali A. , Matteau Martin , Mesfioui Mhamed , Roy André G.
Published: May 2018

Malgré la présence de nombreux barrages au Québec, il n'existe encore aucune étude pour vérifier si les normes de débits réservés écologiques élaborées par Belzile et al. (1997) et adoptées par le ministère de l'Environnement du Québec (FAPAQ 1999) sont respectées en aval de ces barrages. Cette étude avait pour but de vérifier le respect de ces normes en rapport avec les régimes hydrologiques (modes de gestion) de barrages, la taille des bassins versants et la saison, trois facteurs qui influencent significativement l'ampleur des modifications hydrologiques induites par les barrages au Québec. Il ressort de cette étude que les débits réservés écologiques ne sont pas respectés en aval des barrages. La fréquence de ce non-respect (fréquence au nondépassement des débits réservés) ainsi que l'écart entre les débits réservés et les débits lâchés en aval des barrages dépendent de ces trois facteurs. En ce qui concerne le régime hydrologique, l'écart entre les débits réservés et les débits lâchés en aval des barrages est plus élevé en régime d'inversion (barrages associés aux réservoirs) qu'en régime du type naturel (barrages associés surtout aux centrales hydroélectriques). Quant à la taille des bassins versants, la fréquence et l'écart diminuent avec la taille des bassins versants. Cette influence de la taille des bassins versants est plus marquée sur l'écart entre les débits que sur la fréquence au non-dépassement des débits réservés. Enfin, la fréquence au non-dépassement des débits réservés est plus élevée au printemps qu'en hiver dans les deux régimes hydrologiques. La différence entre les deux saisons est surtout marquée en régime d'inversion. En revanche, l'écart entre les débits réservés et les débits lâchés en aval des barrages n'est pas influencé par la saison.
Selecting a Pesticide Fate Model at the Watershed Scale Using a Multi-criteria Analysis
Authors: Quilbé Renaud , Rousseau Alain N. , Lafrance Pierre , Leclerc Jacinthe , Amrani Mohamed
Published: May 2018

Numerous models have been developed over the last decades to simulate the fate of pesticides at the watershed scale. Based on a literature review, we inventoried thirty-six models categorized as management, research, screening or multimedia models, each of them having specific strengths and weaknesses. Given this large number of models, it may be difficult for potential users (stakeholders or scientists) to find the most suited one with respect to their needs. To help in this process, this paper proposes a pragmatic approach based on a multi-criteria analysis. Selection criteria are defined following the user's needs and classified in five classes: modelling characteristics, output variables, model applicability, possibilities to simulate best management practices (BMPs) and ease of use. The relative importance of each criterion is quantified by a weight and the total score of a model is calculated by adding the resulting weights of satisfied criteria. This selection framework is illustrated with a case study that consists in selecting a model to develop water quality standards at the watershed scale with respect to the implementation of BMPs. This resulted in the selection of three models: BASINS, SWAT and GIBSI.
Post-Treatment of Anaerobic Bioreactor Effluent Using Jet Loop Reactor (JLR)
Authors: Tai Choo S. , Singh Kripa S. , Grant Shannon R.
Published: May 2018

A novel post-treatment system, jet loop reactor (JLR), was proposed for anaerobic bioreactor effluent polishing purposes. The performance of the JLR, with respect to residual organics, total Kjeldahl nitrogen (TKN) and ammonia-nitrogen removal at different hydraulic retention times (HRTs), was the main focus of this study. The JLR, on average, was capable of removing approximately 99% of ammonia-nitrogen and 95% of TKN at HRTs of 8 and 5 h, respectively. The integrated system had an average removal of more than 85% of total BOD and COD and more than 95% of filtered BOD and COD. However, the JLR did not have a consistent performance due to dynamic MLSS concentration (and SRT). Overall the results indicate that the JLR can be considered as a feasible alternative for post-treatment of anaerobic bioreactor effluent.
Relationship between Habitat Quality and Occurrence of the Threatened Black Redhorse (Moxostoma duquesnei) in Lake Erie Tributaries
Authors: Reid Scott M.
Published: May 2018

Recovery planning for the nationally threatened black redhorse (Moxostoma duquesnei) is limited by a lack of knowledge regarding species ecology, population size and factors that affect distribution and abundance. Generalized additive models (GAM) were used to evaluate the influence of habitat quality on the distribution of the black redhorse in the Grand River (Ontario) and 11 western Lake Erie tributaries (Ohio). Black redhorse were captured at 26% of Grand River sites and 6% of western Lake Erie tributary sites. In western Lake Erie tributaries, black redhorse were more likely to be found at sites of intermediate upstream drainage area (a surrogate for watercourse size) and less likely to be found at sites with poor substrate, pool, cover and channel conditions. In the Grand River, occurrence was negatively associated with higher gradients and small and large upstream drainage areas. Habitat quality was found to be associated with the distribution of golden redhorse (M. erythrurum) but not the other two co-occurring redhorse species. Site occupancy was negatively associated with poor substrate and pool conditions. Results from this study indicate that, in areas of black redhorse occurrence, river reaches with clean, coarse bed material, well-developed riffles and pools, and stable channels require specific protection. Repatriation efforts in formerly occupied watercourses will likely require restoration of the condition of these habitats.
Chloride as an Indicator of Non-point Source Contaminant Migration in a Shallow Alluvial Aquifer
Authors: Manwell Bryer R. , Ryan M. Cathryn
Published: May 2018

Non-point source (NPS) contamination in the context of surface and ground water interaction was investigated in the Elbow River, Alberta, Canada. Groundwater flow direction, water table elevation, baseflow recession, chloride, nitrate and microbiological measurements were made to determine the interaction of several small tributaries and a small hamlet with Elbow River-associated groundwater. Groundwater flow in the alluvial aquifer adjacent to the Elbow River is predominantly subparallel to the river, but can vary seasonally by as much as 30°. Bedrock constricts the alluvial aquifer downgradient of the tributaries and the hamlet, causing groundwater to emerge into the Elbow River at this point. Chloride mass flux estimates suggest that septic effluent from the hamlet enters the groundwater immediately downgradient of the hamlet and discharges to the river from 5 to 12 km downgradient. A tributary creek which joins the Elbow River just above the bedrock constriction also contributes significant chloride to the river, and had significantly higher bacterial loads than the Elbow River, suggesting that land uses on this creek are also a significant source of contamination. Geologic sources, cattle grazing on the alluvial aquifer, road salting, golf course fertilizer use and wildlife are also potential contaminant sources.
Performance of Laboratory-Scale Wetlands Planted with Tropical Ornamental Plants to Treat Domestic Wastewater
Authors: Zurita Florentina , de Anda Jose , Belmont Marco A.
Published: May 2018

This work proposes an innovative wastewater treatment system that consists of a constructed subsurface flow wetland planted with ornamental flowers of high market value. In addition to the benefit of the water treatment, this cash crop provides a profitable business by producing commercial flowers that can meet all biological and safety requirements in order to be commercialized. This characteristic of the treatment system makes it very valuable for application in developing countries. Five different species of ornamental plants were studied from September 2004 to January 2005. Several water quality parameters were evaluated at the inlet and outlet of a laboratory-scale system. COD was reduced by more than 75% in all cases; BOD and nitrogen were removed by more than 70%, except in one cell; phosphorus was reduced by more than 66% and the dissolved oxygen increased from 0.175 to 5.8 mg L-1. Total and fecal coliforms were removed in the wetland by more than 99.3%. According to these results, it is feasible to couple ornamental flower production with wastewater treatment. A pilot-scale study is recommended in order to validate the preliminary results under more realistic conditions.
Impact des rejets industriels sur l'environnement : cas de l'accumulation du chrome dans les différents compartiments aquatiques le long du littoral Casablanca – Mohammadia
Authors: Bouthir Fatima Zohra , Souabi Salah , Chafik Abdelghani , Benbrahim Samir , Sifeddine Mustapha
Published: May 2018

En absence de normes de rejet, les rejets industriels au Maroc sont rejetés dans le milieu naturel, en particulier marin, sans aucun traitement préalable. Aussi, l'objectif du présent travail est d'étudier l'impact des rejets industriels riches en chrome au niveau des différents compartiments aquatiques (mollusques, poissons, algues et sédiments) le long de huit stations de prélèvements sur le littoral entre Casablanca et Mohammadia, durant une période de cinq années (été 1998 – printemps 2002); en plus, cette étude vise à évaluer l'espèce la plus bioindicatrice de pollution par le Cr. Les teneurs en Cr les plus élevées accumulées par les moules ont été détectées le long de l'Oued El Malleh (S2) et au niveau du site S6 de Oukacha (respectivement 18,7 et 14,4 mg/kg poids sec), soient deux secteurs recevant la majorité des eaux usées des unités industrielles de Mohammadia et de Ain Sebâa. Ces résultats sont cohérents avec les fortes concentrations en Cr (300 mg/ kg poids sec) détectées dans les sédiments prélevés aux stations S2 et S6. Ce dernier site a montré également des teneurs assez élevées de l'ordre de 9,70 et 25,90 mg/ kg poids sec respectivement pour l'Ulva lactuca et la Corallina officinalis. Les résultats d'accumulation du Cr chez deux espèces de poissons, le mulet Mugil cephalus et le sar Diplodus sargus, ont montré des teneurs plus élevées chez le mulet que chez le sar. L'étude comparative des concentrations en Cr entre les différents compartiments biologiques étudiés montre que la moule M. galloprovincialis est un excellent bioindicateur de pollution par le Cr, révélant des concentrations plus élevés que les autres espèces d'algues et de poissons.
Biomass Acclimatization to Sequentially Varying Substrates in an Upflow Anaerobic Sludge Blanket (UASB) Bioreactor
Authors: Tan Yee Ying Jennifer , Hashim Mohd. Ali , Ramachandran K.B.
Published: May 2018

In this study, an upflow anaerobic sludge blanket (UASB) bioreactor was sequentially subjected to high-strength synthetic, low-strength synthetic and domestic wastewaters. From COD removal data, supported by volumetric loading rate, hydraulic retention time, pH and qualitative biogas production data, it was observed that the biomass in the bioreactor took about twice the time required to acclimatize to a change in substrate characteristics or composition compared to a much more drastic quantitative change, i.e., more than 95% difference, in substrate concentration. As the initial experiment coincided with the bioreactor start-up, it could also be concluded that the feeding regime did not shorten the overall start-up time of a UASB bioreactor meant to treat domestic wastewater, but its eventual success was probably more assured.