bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fractal Analysis of Pore Distributions in Alum Coagulation and Activated Sludge Flocs
Authors: Gorczyca Beata , Ganczarczyk Jerzy 
Published: May 2018

Abstract
The information on floc porosity is essential for estimation of the permeability of the aggregate. The average porosity of alum and activated sludge flocs determined in this study on thin sections of the aggregates was similar, varying in the range from 8 to 9%. Similar porosity of the two different types of aggregates suggested that the permeability of these flocs could also be similar. However, the experimental observations of floc settling rates and floc shape factors did not support this expectation and led to a conclusion that the permeability of an aggregate cannot be estimated based on the average geometric porosity of a floc only. When the size distributions of pores on flocs' sections were analyzed using the concept of fractal geometry, different characteristic values for alum coagulation and activated sludge flocs were found. Larger pore size found in activated sludge flocs allows for more flow through these flocs. Therefore, the size of characteristic pores rather than the average total porosity determines the permeability of an aggregate.
Acid Hydrolysis Lignin as a Sorbent for Naphthalene
Authors: Keane Angela , Ghoshal Subhasis 
Published: May 2018

Abstract
Lignin, a major polymeric constituent of woody plant tissue, is an abundant source of natural organic matter available as a waste product from the pulp and paper and the fuel ethanol industries. In this study, the sorptive capacity of acid hydrolysis lignin for naphthalene, a representative nonpolar hydrophobic organic compound (HOC), was investigated. When powdered lignin is mixed with distilled water, dissolved and/or colloidal organic matter leaches into the aqueous phase imparting a cloudy yellowish colour. A washing and filtering protocol was developed for pretreating the lignin employed in the sorption studies. Results from batch sorption experiments showed that acid hydrolysis lignin has a strong affinity for naphthalene. The Freundlich isotherm coefficients obtained indicate that the sorption isotherm for naphthalene on hydrolysis lignin is nearly linear. A modified Freundlich equation was employed in order to compare sorption data for HOCs on lignin and activated carbon through the use of unit equivalent coefficients. The results presented in this research and in the literature suggest that the two sorbents are comparable in terms of sorption coefficients. It was determined that acid hydrolysis lignin is unsuitable for use in a packed bed since pumping a naphthalene solution through a column packed with lignin caused the wet lignin to become significantly hardened over time, resulting in a large pressure drop across the system.
Occurrence of Butyltin Compounds in Freshwater Mussels (Elliptio complanata) from Contaminated Aquatic Areas in Ontario, Canada
Authors: Yang Fan , Maguire R. James , Chau Yiu K. 
Published: May 2018

Abstract
The antifouling agent tributyltin (TBT) is extremely toxic to some aquatic organisms. The accumulation of butyltin compounds in the tissues of freshwater mussels from contaminated areas in Ontario was studied in the field with caged mussels (Elliptio complanata). Mussels were placed in four sites for 11 months, and one site for 6 months, in locations of previous contamination of water and sediments. Additional cages were exposed for 5 months at two of the sites to study the effect of mussel size on accumulation. The mussels were collected at regular intervals for butyltin analysis. After almost one year of exposure at four locations, the TBT contents in tissue of mussels were 9 to 148 ng as Sn/g (wet weight). The results showed that concentrations of TBT in mussels were related to the mussel size and the concentrations of TBT in contaminated aquatic areas, and that concentrations in mussel tissue increased dramatically over winter. The results of the experiment demonstrated that caged mussels are useful for indicating the presence of TBT in aquatic systems.
Element Concentrations in Groundwater in the Eastern Phosphate Area and Southern Volcanic Area of Syria
Authors: Alhassanieh Oussama , Ghafar Mohamad , Abdul-Hadi Abdul-Rahman 
Published: May 2018

Abstract
The concentration of the elements K, Ca, Mg, Na, Sr, Al, As, Ba, Br, Ce, Cr, Fe, Nb, Rb, Se, Sm, V, Zn, Co, Cs, U, Sb, Sc, Th, Eu and Hf in groundwater samples from the eastern phosphate and the southern volcanic area of Syria were investigated using INAA (instrumental neutron activation analysis) and γ-spectroscopy. The concentrations of first and second group elements are higher in the phosphate area than in the volcanic area. The concentrations of Fe, Co, Cr, Sc, Eu and Sm are high in some samples from the southern volcanic area. This can be explained by the occurrence of these elements in surrounding rocks and the solubility of their compounds. The results are compared with drinking water limits from different countries.
Thallium Contamination of Water in Canada
Authors: Cheam Ven 
Published: May 2018

Abstract
Thallium is highly toxic but has been an obscure element compared to its three popular neighbours, lead, mercury and cadmium. It is partly due to the scarcity of its analytical data, caused by its high analytical detection limit relative to the other three elements and by its generally low level in the environment. We have developed a highly sensitive instrument, a Laser-Excited Atomic Fluorescence Spectrometer, to study thallium contamination in some important Canadian ecosystems from the Arctic (containing very low thallium concentration) to coal-related industries across Canada and even to the study of thallium toxicity in an invertebrate, Hyalella azteca. Overall, our data indicate that the coal power plants and mines contain higher thallium concentrations than the other ecosystems studied, and the eastern region has the highest Tl concentrations compared to other regions. The range of thallium concentration in ng/L for the Arctic snow and ice was between not detected and 8.4, for the Great Lakes waters 0.9 to 48, for pore waters 0.1 to 213, for western coal power plants and mines 0.1 to 1326, for central coal power plants 1.2 to 175, for eastern coal power plants and mines 0.2 to 23605, and for miscellaneous sites across Canada not detected to 4390 ng/L. Some of these high concentrations and those high ones reported in industrial wastewaters exceeded the chronic toxicity endpoints for Hyalella azteca mortality, growth and reproduction, thus can cause serious distress to the environment. All data were integrated into a map of thallium distribution, the first one in Canada. Natural background level of thallium for the Arctic was estimated to be 0.02 to 0.03 pg/g.
Sublethal Toxicity Findings by the Pulp and Paper Industry for Cycles 1 and 2 of the Environmental Effects Monitoring Program
Authors: Scroggins Richard P. , Miller Jennifer A. , Borgmann Anne I. , Sprague John B. 
Published: May 2018

Abstract
Sublethal toxicity tests successfully measured the improved quality of pulp mill effluents from the first cycle of environmental effects monitoring (1992–1996) to the second cycle (1997–2000). Test endpoints showed notable shifts to higher concentrations (less toxic). During the second cycle of monitoring, significantly more tests showed no effect in full-strength effluent. Five case studies were considered as part of this exercise. Most of the improvement came with installation of secondary treatment. Twelve Ontario mills with secondary treatment showed reduced toxicity, compared to results with primary treatment. All 29 sets of sublethal data showed higher IC25s during the second cycle, and 23 of these differences were statistically significant. Any other changes between the two cycles of study caused only marginal overall improvement in toxicity, judging by 12 freshwater mills in British Columbia which had secondary treatment during both cycles. Sublethal tests successfully predicted the zone of potential effect in receiving water, agreeing with effects observed in biological surveys. Overlapping zones from multiple discharges could also be demonstrated. In a situation near Niagara Falls, sublethal tests estimated the proportions of toxic loading that four mills contributed to one water body. The prediction was realistic; the actual toxicity found for a mixed effluent was 57% of that predicted from separate toxicities. The conservative prediction agrees with the usual less-than-additive sublethal action of combined toxicants.
Development of a Monitoring Design for Examining Effects in Wild Fish Associated with Discharges from Metal Mines
Authors: Ribey Sandra C. , Munkittrick Kelly R. , McMaster Mark E. , Courtenay Simon , Langlois Claude , Munger Steve , Rosaasen Arden , Whitley Gerry 
Published: May 2018

Abstract
As part of the amended Metal Mining Liquid Effluent Regulations under the Fisheries Act, mines will be required to develop and conduct Environmental Effects Monitoring (EEM). EEM will be done to evaluate the effects of mine effluent on fish, fish habitat, and fish usability. Mines will be required to determine if there are changes in fish populations and/or in the usability of fish due to mine effluent. The EEM program has been designed with a tiered monitoring approach, with the first phase determining if an effect is present. Subsequent phases of EEM will focus on continued monitoring and determining the magnitude, geographic extent, and cause of effects (if any). Fish collected from the area exposed to mine effluent will be compared to fish from a reference area in order to determine if there is an effect, if the effect is mine related and the cause of the effect within the effluent. The fish population survey will examine the growth, reproduction, condition, and survival of one or more resident sentinel fish species. Fish usability will be determined based on the appearance of fish, their use, and the contaminant levels in fish tissue. It is recognized that some mines may not be able to implement a fish monitoring program as outlined, so it has been recommended that alternative methods, such as a caged bivalves or on-site bioassays, may also be used. Frequency of monitoring will be dependent on the previous results of the fish and benthic invertebrate monitoring phases.
L'enlèvement biologique du phosphore dans les technologies à biofilm : une synthèse de la problématique
Authors: Zelovic Tanja Baljic , Leduc Roland 
Published: May 2018

Abstract
Cet article synthétise l'état actuel des connaissances sur l'application de la technologie du biofilm pour l'enlèvement biologique du phosphore (EBP). Il présente d'abord les principaux mécanismes de l'EBP, ensuite les caractéristiques du procédé à biofilm, et poursuit avec celles qui sont favorables pour la réalisation de la biodéphosphatation. Les différentes configurations du processus de biodéphosphatation par biofilm étudiées à ce jour sont présentées, ainsi qu'une révision des facteurs particuliers qui influencent l'EBP dans un biofilm. Une attention particulière est apportée aux processus opérant en continu.
Analysis of Surface Water Quality in Tehran
Authors: Asadollah-Fardi Golamreza 
Published: May 2018

Abstract
Box-Jenkins and exponential smoothing time series analysis of the monthly water quality in surface water in Tehran was conducted as a case study. Various univariate models were developed for each determinand. Most of the models were seasonal, indicating that the water quality determinands vary throughout the year. The models follow the same pattern of variations present in the data. This study shows the credibility of the models, therefore the models may be used for future design purposes.
Optimizing the Management of Soil Erosion
Authors: Nikkami Davood , Elektorowicz Maria , Mehuys Guy R. 
Published: May 2018

Abstract
To reduce the environmental and economical impact of soil erosion resulting from improper management of land-use activities, a study was initiated by the Iranian Ministry of Construction on Syahrood, one of the sub-basins of the Damavand watershed in Iran. Land-use optimization is one of the appropriate strategies for soil conservation. It can empower the decision maker or watershed manager to choose from different land-use scenarios to reach the best decision with the different combinations of variables.
The output results of the sediment yield model, including the integration of the Modified Universal Soil Loss Equation (MUSLE) with Spatial Analysis System-Geographic Information System (SPANS-GIS), along with the net income of each land use were used as input in the land-use optimization model for minimizing the sediment yield and maximizing farm production of each land use. The multi-objective linear programming simplex method of Steuer (1995) was used to solve the problem. The optimization process allocated dryland farming areas to rangelands if no changes were made to the current supporting practice system. The expected annual sediment yield from the entire sub-basin was reduced by 2420 tonnes/year (or by 5%) and the annual net farm income was increased by 3.99 billion Iranian Rial/year (or by 134%).
Concentrations of Some Lipophilic Chemicals in Fresh Water May Be Underestimated by Conventional Dichloromethane Extraction
Authors: Maguire R. James , Comba Michael E. , Cannon Christina M. 
Published: May 2018

Abstract
A re-analysis of water samples collected to determine the occurrence of lipophilic organochlorine chemicals, total polychlorinated biphenyls (PCBs) and polynuclear aromatic hydrocarbons (PAHs) in six tributaries to Lake Ontario in 1997 to 1998 has shown relatively high concentrations of some of those chemicals in extracts of chromic acid-digested water after the water had been extracted at neutral pH. For organochlorine chemicals and PCBs the effect was dramatic—for some tributaries the sums of concentrations of the chemicals in the acidic extracts over all sampling dates were larger than the sums of concentrations of the chemicals in the (neutral) water plus suspended solids fraction that had been determined previously. In addition, some chemicals were found in the acidic extracts that were not found in the prior extracts of (neutral) water plus suspended solids. Although some individual PAHs were found at relatively high concentrations in the acidic extracts compared to extracts of (neutral) water plus suspended solids, in general the phenomenon was not significant for total PAHs. The implication of our finding is that conventional dichloromethane extraction of neutral (filtered) water and the suspended solids phases can significantly underestimate the concentrations of some lipophilic chemicals such as chlorinated hydrocarbons and PCBs in fresh water, leading to an underestimation of their loadings to aquatic ecosystems. However, it should be noted that the biological availability of chemicals that are only extractable after rigorous extraction of the water may be doubtful.
The Effect of Nozzle Type on Air Entrainment by Plunging Water Jets
Authors: Bagatur Tamer , Baylar Ahmet , Sekerdag Nusret 
Published: May 2018

Abstract
In this study, for the plunging water jet aeration system using various inclined nozzle types, bubble penetration depth, air entrainment rate, water jet expansion, effect of water jet circumference at impact point, oxygen transfer coefficient and oxygen transfer efficiency which changed depending on the water jet velocity, were researched in an air-water system. Numerous studies were conducted with circular nozzles. The present study describes new experiments performed with different nozzle types. Three types of nozzles were examined, i.e., those with circular, ellipse and rectangle duct with rounded ends. Experimental results showed that water jets produced with ellipse and rectangle duct with rounded ends nozzles have very different flow characteristics, entrainment patterns on free water jet surface, and submerged water jet region within the receiving tank. Higher air entrainment rate and oxygen transfer efficiency was observed in the rectangle duct with rounded ends nozzle due to water jet expansion. Bubble penetration depth, however, is lower for the rectangle duct with rounded ends nozzle than for the other nozzles. The ellipse nozzle provided the highest bubble penetration depth. These results showed that it is appropriate to use ellipse nozzle in aeration of deep pool and rectangle duct with rounded ends nozzle in the applications where high bubble concentration is desirable.
Estimation of Bench-Scale Chlorine Decay in Drinking Water Using nth-Order Kinetic and Back Propagation Neural Network Models
Authors: Rodriguez Manuel J. , Milot Julie , Sérodes Jean-Baptiste , Pacaud Adèle 
Published: May 2018

Abstract
This paper presents the development of two models for simulating residual chlorine decay in raw and treated waters collected from six different utilities of the Quebec City area. The data for modelling was generated by means of several bench-scale chlorination assays undertaken with chlorine doses that varied according to the content of natural organic matter in the water. The first model is a classical kinetic model in which chlorine decay is represented by a first or a second order function, according to the contact time of chlorine. A decay coefficient is estimated based on water quality and operational parameters, using linear regression. The second is a non-linear back propagation neural network model in which all the parameters responsible for chlorine decay are processed within a single model. The performances of both models were evaluated and compared using the database for model development and an independent database for validation. Both models demonstrated acceptable abilities for simulating residual chlorine decay. However, the back propagation neural network model gave significantly better results for conditions involving high chlorine dosage, high organic matter content and long reaction times during chlorination experiments. In the other cases, the performance of the kinetic model was slightly superior. Back propagation neural networks are also advantageous because they do not require assumptions about model order or the estimation of a chlorine decay coefficient. Also included in the paper is a discussion of possible strategies for use in future research work in order to generalize the results obtained.
Fathead Minnow Lifecycle Tests for Detection of Endocrine-Disrupting Substances in Effluents
Authors: Parrott Joanne L. , Wood Craig S. 
Published: May 2018

Abstract
The goal of this study was to assess the responses of fathead minnows (FHM) exposed to known endocrine-disrupting substances (EDS) in our labs. As well, we wanted to examine the applicability and sensitivity of the full lifecycle FHM test for use on-site, exposing fish to a complex environmentally relevant Canadian effluent. Fathead minnows exposed from the egg stage to ethinylestradiol (EE2, 0-32 ng/L) or methyltestosterone (MT, 0-3200 ng/L) had decreased growth (length, weight) at high concentrations. Development of secondary sex characteristics was a sensitive indicator of exposure to androgen and estrogen. Fish exposed to MT showed premature male sex characteristics such as nuptial tubercles by 30 days post-hatch (dph). These changes were more dramatic in older fish (at 60 and 90 dph), which showed premature male sex characteristics at very low MT concentrations (100 ng/L). Fish exposed to 3.2 ng/L EE2 had premature development of ovipositors at 60 dph. As well, exposure to very high MT concentrations (1000 and 3200 ng/L) caused development of ovipositors after 60 days (but not at 20 and 30 dph), presumably due to aromatization of MT to methylestradiol (as suggested by other researchers). The fathead minnow lifecycle assay, tested with a known estrogen and androgen, proved to be useful for detection of EDS-related changes caused by a real-life effluent mixture. Lifecycle exposures of fathead minnow eggs to bleached sulphite mill effluent (BSME) showed changes in secondary sex characteristics and growth. In contrast to EE2 and MT, fish exposed to BSME had increased growth. Changes in secondary sex characteristics of fish were seen in both male and female minnows exposed to BSME, but there was an overall shift towards increasing numbers of female fish (based on external sex). The full lifecycle assay provides a definitive test for reproductive/EDS effects, and it appears that some of the most sensitive endpoints we studied were the premature development of secondary sex characteristics.
Portrait of Drinking Water Quality in Small Quebec Municipal Utilities
Authors: Coulibaly Housseini D. , Rodriguez Manuel J. 
Published: May 2018

Abstract
This study of small Quebec municipal drinking water utilities (i.e., those serving 10,000 or fewer people) focuses on a portrait of microbiological water quality (based on total and fecal coliform data) and distribution system management strategies. It also addresses relationships between some important water quality and operational parameters and management strategies, as well as total or fecal coliform occurrences. Along with descriptive analyses, statistical means tests (Student t-tests) were performed to identify significant differences between utilities with high coliform occurrence and utilities with low coliform occurrence according to chlorine dose, distribution system flushings, pipe age, main breakage, and some environmental factors. Even though many interesting trends have been noted, only a few resulted in statistically significant differences. For surface water utilities using chlorination alone, the mean difference of annual system flushings proved statistically significant. In addition, some agricultural land-use indicators within the municipal territory appeared significantly correlated with coliform occurrences.
Characterization of Particles in Slow Sand Filtration at North Caribou Water Treatment Plant
Authors: Gorczyca Beata , London David 
Published: May 2018

Abstract
Microscopic analysis of particles in water can indicate the size of filter media required, and can be used to monitor filter performance. This study investigated a malfunctioning slow sand filter in a water treatment facility on a First Nations community in Northern Ontario. There has been a boil-water advisory in the community due to high turbidity in the drinking water since the plant was put into operation. Also, the slow sand filters in the plant clog frequently resulting in outflow volumes significantly below the plant design capacity.
On-line particle counts and microscopic analysis of water were conducted in the plant at various points before and after the slow sand filters. Microscopic analysis of the slow sand filter effluent showed that the high water turbidity was due to an increased concentration of particles smaller than 2 µm in size. This observation could not have been made with the particle counter data alone, as it is not capable of measuring particles of that size. Visual inspection of microscopic images of these small particles indicated that they were being washed out from the filter media, and did not originate from the raw water.
Significant numbers of large filter-clogging diatoms (up to 50 µm in size) were identified under the microscope; yet, the particle counter did not report particles larger than 15 µm in raw water supply. Turbidimeters and particle counters were found to be unable to identify these diatoms, due to the transparent nature of the cell walls of these microorganisms. It is likely that most of these diatoms originated from sediment accumulated in the raw water intake pipe.