bluuebunny/crossref_metadata_2025 huggingface dataset:
Fathead Minnow Lifecycle Tests for Detection of Endocrine-Disrupting Substances in Effluents
Authors: Parrott Joanne L. , Wood Craig S.
Published: May 2018

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

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

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.
A Kinetic Model for Autotrophic Denitrification using Sulphur:Limestone Reactors
Authors: Darbi Ashref , Viraraghavan Thiruvenkatachari
Published: May 2018

The kinetics of autotrophic denitrification of groundwater by Thiobacillus denitrificans in a sulfur:limestone upflow reactor was examined in order to predict effluent concentrations. Experiments were performed using water containing 60 and 90 mg NO3—N/L and sulfur and limestone with average particle size of 3.5 mm. Results clearly showed that nitrate was completely removed from 60 and 90 mg NO3—N/L influent concentrations. The results showed that the autotrophic denitrification rates in sulfur:limestone reactors can be described by half-order kinetics. The half-order reaction rate constants for the entire media were estimated at 1.34 and 1.54 mg1/2/L1/2 h for influent concentrations of 60 and 90 mg NO3—N/L, respectively.
Removal of Arsenic from Groundwater using Crystalline Hydrous Ferric Oxide (CHFO)
Authors: Manna Biswa Ranjan , Dey Soumen , Debnath Sushanta , Ghosh Uday Chand
Published: May 2018

Synthesis of crystalline hydrous ferric oxide (CHFO), a modified iron-based adsorbent, and its arsenic sorption behaviour have been reported. Here, the effects of pH with variation of arsenic concentrations, contact time, pre-drying of CHFO, competition of some other anions and regeneration of arsenicsaturated CHFO are conducted by batch method. The sorption of As(V) is highly dependent on the concentration and pH of the experimental system, while that for As(III) is pH insensitive. As(III) is found to require less contact time to attain equilibrium than that of arsenic(V). Pre-drying of CHFO in the temperature range of 200 to 300°C is found to be effective in removing both As(III) and As(V). Adsorption kinetics follow the first-order Lagergren model. The equilibrium data conform to the Langmuir isotherm. Evaluated Langmuir constants and equilibrium parameter (RL) indicate that CHFO is a better As(III) adsorbent under experimental conditions. Sulphate, phosphate and bicarbonate compete poorly with As(III) sorption. A field test using CHFO-packed fixed-bed column is reported. Effluent water bed volumes of 14,000, 11,000 and 9000 BV (arsenic ≤ 0.01 mg L-1) were obtained in the first, second and third cycle of operation from a groundwater sample (arsenic content: 320.400 μg L-1). Regeneration of the exhausted column was achieved with up to 80 to 85% efficiency using 3 BV of 5 M NaOH solution recycled through the column five times. Arsenic was recovered as As2S3 from the regenerates, to avoid recycling of arsenic into the environment.
Enhanced Prairie Wetland Effects on Surface Water Quality in Crowfoot Creek, Alberta
Authors: Ontkean Gerald R. , Chanasyk David S. , Riemersma Sandi , Bennett D. Rodney , Brunen Jerry M.
Published: May 2018

A three-year study was conducted to examine the effects of a prairie wetland enhanced for waterfowl habitat on surface water quality in the Crowfoot Creek watershed in southern Alberta, Canada. Monitoring was carried out at the Hilton wetland from mid-March to the end of October in 1997 to 1999 at two inflow sites and one outflow site. Data were collected on flow, total phosphorus (TP), total nitrogen (TN), total suspended solids (TSS), and fecal coliform (FC) bacteria. Nutrient concentrations were highest in the spring, and decreased during the remainder of the monitoring period each year. Nutrient concentrations did not change significantly within the wetland due to the form of nutrient, reduced retention times for nutrient uptake, and the addition of nutrients to the water through sediment release and decomposition of organic matter. The wetland acted as both a source and a sink for nutrients, depending on flow volumes. TSS concentrations decreased significantly from inflow to outflow, indicating sedimentation occurred in the wetland. FC bacteria levels were lowest in the spring and increased during the post-spring runoff (PSRO) period. FC bacteria counts decreased significantly within the wetland throughout the entire year. The Hilton wetland was effective in reducing the amounts of TSS and FC bacteria exported from the wetland; however, there was no significant change in nutrient status.
Textile Dye Removal by Membrane Technology and Biological Oxidation
Authors: Gholami Mitra , Nasseri Simmin , Alizadehfard Mohammad-Reza , Mesdaghinia Alireza
Published: May 2018

The objective of this research was to evaluate the effectiveness of two methods for dyestuff removal from a textile waste stream. In the first step, different types of dyes used in textile industries were studied in order to determine the types with highest usage rates. In this regard, basic, reactive, disperse and acidic dyes were selected. In the second step, dye biodegradability was studied through Zahn-Wellens method (ISO-9888 1999). Results showed final chemical oxygen demand (COD) and dye rejection coefficients (R%) of (61%, 57%), (73%, 76%), (25%, 14%), (32%, 8%) for acidic, basic, reactive and disperse dyes, respectively. In the third step, spiral-wound membrane modules nanofilter (NF) with a molecular weight cut off (MWCO) of 300 and 600 dalton (Da) and reverse osmosis (RO) of 50 Da were used. The operating conditions in phase 3 were adjusted as: temperature 30 to 35°C, pressure 4 bar for NF membranes and 7.5 bar for RO, flow rate of 10 L/min, and dye concentration of 0.01%. Results showed that COD and dye rejection coefficients for NF with 300 Da and for acidic, basic, reactive and disperse samples of dyes were (6%, 55%), (44%, 70%), (33%, 36%) and (71%, 93%), respectively. These results for NF with 600 Da were (7%, 54%), (64%, 76%), (33%, 29%), (59%, 92%) and for RO were (95%, 99%), (96%, 98%), (45%, 99.6%). Results clearly showed higher removal efficiency for the membrane treatment than for biodegradability studies.
Adsorption of Cadmium Ions onto the Yellow River Sediment
Authors: Huang Sui Liang
Published: May 2018

Adsorption of cadmium ions onto Yellow River sediment was studied in a batch reactor. Equilibrium adsorption of cadmium ions onto Yellow River sediment can be well described by the Langmuir adsorption isotherm. In view of common experimental conditions in the batch reactor, a set of equations for describing variations of both the dissolved heavy metal pollutant concentration and the particulate heavy metal pollutant concentrations (the adsorption content of heavy metal pollutant on unit weight of sediment) with time was formulated with the use of an adsorptive reaction kinetic equation of heavy metal pollutant, mass balance equation and corresponding initial conditions. Furthermore, formulae for calculating the equilibrium dissolved heavy metal concentration and the equilibrium particulate heavy metal concentration (the equilibrium adsorption content of heavy metal pollutant on unit weight of sediment) in the batch reactor were obtained. These can be used as tools for further study. It was found that the saturation adsorption content, b, constant of adsorption-desorption rate, k, and coefficient of adsorption rate, k1 (and coefficient of desorption rate k2), in the adsorptive reaction kinetic equation of the Langmuir type are independent of the suspended sediment concentration. Adsorption contents of heavy metal pollutants on unit weight of sediment (the suspended particulate heavy metal concentration) decreases with increasing suspended sediment concentration and can be well explained by the law of mass conservation. Adsorption capacity, which is defined as adsorption content of heavy metal pollutant by unit volume of (muddy) water, increases with an increase in either the suspended sediment concentration or initial dissolved heavy metal concentration.
Continuous and Surge Irrigation Effects on Hydraulic Parameters and Water Quality
Authors: Miller Jim J. , Foroud Nader , Lamond Brian J. , Beasley Bruce W. , Handerek Brian P.
Published: May 2018

Limited information exists on comparing the effect of continuous and surge irrigation on hydraulic parameters and water quality under border-strip irrigation in the Canadian Prairies. A site on a clay loam soil in southern Alberta was used to compare these two irrigation methods (three replicates) on plots seeded to barley (Hordeum vulgare) in 1996 and 1997. Irrigation was conducted on border-strip plots in July and August of each year. Irrigation hydraulic parameters, soil water content, chloride and sediment in runoff, chloride in suction lysimeters, soil and shallow groundwater, and the water table level were measured before and after irrigation. Surge irrigation significantly (P ≤ 0.10) reduced the following hydraulic parameters compared to continuous irrigation: irrigation water applied (129–304%), total surface runoff (93–257%), maximum outflow rate (25–146%), advance time to the end of the field (214–273%), total infiltration depth of water (135–390%), and total irrigation time. However, irrigation treatment had no significant effect on surface runoff and infiltration depth of water when expressed as a percentage of the total amount of irrigation water applied. Surge had little or no effect on the concentration, flow-weighted mean concentration (FWMC) and mass loss of chloride and sediment in runoff. The exceptions were in July 1996, where mass loss of chloride was 180% lower under surge; and in August 1997, where the concentration of chloride was 44% lower under surge. Irrigation method had little or no significant effect on the soil water content, concentration of chloride in suction lysimeters and groundwater, the total mass of chloride in the soil profile, and the water table level. However, there was a trend towards lower chloride values under continuous than surge irrigation in the lysimeters and soil, suggesting a potential for greater leaching under the former method. Although surge irrigation had little or no positive effect on water quality compared to continuous irrigation, surge is still the preferred irrigation method because of its many improvements in hydraulic parameters.
Selenium Uptake by a Coal Mine Wetland Sediment
Authors: Baldwin Susan A. , Hodaly Al Henry
Published: May 2018

Sediment from a wetland receiving runoff from a coal mine waste dump in the Elk River Valley of southeast British Columbia was assessed for potential selenium uptake. Selenite [SeO32-, Se(IV)] was found to adsorb to the washed sediment at pH 7 to 8, whereas no selenate [SeO42-, Se(VI)] was adsorbed, in the concentration range of 8 to 225 μg L-1 Se as selenite or selenate. Sulfate- and selenate-reducing bacterial activity was detected in the sediment. In the presence of sulfate-reducing bacteria growth medium, Se as selenate was reduced from 619(±53) μg L-1 to 15(±0.7) μg L-1, and in the presence of selenate-reducing bacteria growth medium, Se as selenate was reduced from 364(±66) mg L-1 to 22(±10) mg L-1. Semi-continuous microcosms containing sediment overlaid with selenate (500 μg L-1 Se) and sulfate (0.9 g L-1) containing water were amended with plant debris from the site or nutrients (lactate and fertilizer). Potential selenate reduction rate (0.76 h-1) was highest in the unamended microcosms. Amendment with plant debris from the site had a negative effect on selenate reduction rate in the short term (after one hour) and a positive effect on Se removal in the long term (after one week). This study suggests that wetland sediments at the mine site may be important sinks for Se.
Adsorption-Coagulation for the Decolorisation of Textile Dye Solutions
Authors: Sanghi Rashmi , Bhattacharya Bani
Published: May 2018

Studies were undertaken for the removal of colour from different types of synthetic dye solutions by using powdered activated carbon (PAC) and bentonite clay (BC) as adsorbents. The different types of dyes (direct, mordant and basic) studied were Direct Orange, Eriochrome Black T and Malachite Green. The synthetic dye solutions behaved differently with the two adsorbents. The effect of adsorption by PAC and the further addition of a very small dose of a coagulant polyaluminium chloride (PAlC) on the settling and/or reuse of adsorbents used was studied. PAC and BC, though effective adsorbents, remained suspended in the solution for a long time. PAlC not only enhanced dye removal, but also formed a sludge that settled very quickly and which could also be reused effectively for dye removal.
Récupération du plomb extrait de sol contaminé par adsorption sur des colonnes d'écailles de cacao
Authors: Meunier Nathalie , Haberman Michael , Blais Jean-François , Tyagi ET Rajeshwar Dayal
Published: May 2018

La lixiviation par l'acide chlorhydrique représente une option largement étudiée pour la décontamination des sols pollués par les métaux. Les métaux ainsi solubilisés doivent être éliminés des lixiviats acides générés lors du traitement des sols. La présente étude avait pour objectif d'étudier la performance des écailles de cacao pour la récupération du plomb extrait par lessivage acide de sol contaminé et ce, dans un système d'adsorption en colonnes opéré en phases successives de fixation et d'élution du plomb. Les essais menés avec un ensemble de huit colonnes d'adsorption remplies de 50 g d'écailles de cacao et opérées à différentes charges hydrauliques ont montré qu'un temps de contact minimal de l'ordre de 30 min est nécessaire pour le traitement de 100 mL d'un lixiviat acide (Ci = 36 mg Pb/L et pHi = 2.0) par gramme d'écailles de cacao. Des essais réalisés avec un système de quatre colonnes disposées en série et contenant chacune 80 g d'écailles ont également démontré que le plomb fixé peut être aisément élué par une solution d'acide diluée (HCl 1 N) et que les écailles de cacao peuvent être réutilisées pour plusieurs cycles d'adsorption-élution sans perdre de manière importante leur capacité de fixation du plomb.
Use of QSARs to Promote More Cost-Effective Use of Chemical Monitoring Resources. 2. Screening Chemicals for Hydrolysis Half-Lives, Henry's Law Constants, Ultimate Biodegradation Potential, Modes of Toxic Action and Bioavailability
Authors: Walker John D. , Dimitrova Nadezhda , Dimitrov Sabcho , Mekenyan Ovanes , Plewak Dan
Published: May 2018

To promote more cost-effective use of chemical monitoring resources, quantitative structure activity relationships (QSARs) are proposed as methods to identify chemicals that could be found in, and cause adverse effects to, organisms in water, sediment and soil from the Great Lakes basin. QSARs were used to evaluate the hydrolysis half-lives, Henry's Law constants, ultimate biodegradation potential in water, modes of toxic action and bioavailability of 47 industrial chemicals and pesticides, 20 direct food additives, 13 indirect food additives and 7 pharmaceuticals that were previously predicted to partition to sediment and to have bioconcentration or aquatic toxicity potential or potential to not biodegrade readily in sediment (Walker et al. 2004). Using these QSARs will promote more cost-effective use of chemical monitoring resources by allowing researchers to focus their analytical techniques on measuring chemicals that are not likely to hydrolyze, volatilize or biodegrade rapidly to carbon dioxide, but are likely to have specific modes of toxic action and be bioavailable.
Comparaison de deux méthodes de spéciation du phosphore dans des sédiments de la partie aval du basin Oum Rabiaa (Maroc)
Authors: Taoufik Mohamed , Kemmou Souad , Idrissi Leila Loukili , Dafir Jamal Eddine
Published: May 2018

Deux méthodes de spéciation du phosphore ont été testées sur des sédiments de trois retenues de barrages en série (Imfout, Daourat et Sidi Maâchou) situées dans la partie aval du bassin Oum Rabiaa (Maroc), pour connaître la proportion des fractions mobilisables des sédiments et donc potentiellement assimilables par les algues. Les deux méthodes testées sont celles de Bonzongo et al. (1989) et de Golterman (1996).

La présence de ces trois retenues de barrages en série conditionne la répartition du phosphore des sédiments de ce tronçon en réduisant considérablement les apports phosphorés vers l'aval. Les résultats de la spéciation du phosphore montrent que la variabilité observée entre stations, en termes de valeurs absolues, pour les fractions Fe-P (phosphates liés au fer) et Ca-P (phosphates liés au calcium) est essentiellement le reflet des différentes teneurs en phosphore total (P-total) des sédiments étudiés.

Les deux méthodes testées divergent quant à l'estimation de ces deux fractions. Pour les sédiments étudiés, la quantité de Fe-P extraite avec la méthode de Golterman qui utilise des chélateurs spécifiques est supérieure à celle extraite avec la méthode de Bonzongo et al. (1989) qui utilise NaOH après extraction de la fraction organique à l'H2O2. Pour la fraction Ca-P, les résultats sont un peu plus forts avec la méthode de Bonzongo et al. (1989). Ces différences ont une conséquence importante sur l'estimation des quantités de phosphate mobilisable des sédiments.
A Comparison of Organochlorine Contaminant Levels, on a Lipid Basis, in Sea Lamprey Larvae from Mad River, Lake Huron Basin and Michipicoten River, Lake Superior Basin (1960-1976)
Authors: Renaud Claude B. , Alfonso Noel , Kaiser Klaus L.E. , Comba Michael E.
Published: May 2018

Organochlorine concentrations, on a lipid basis, were determined for formalin-preserved sea lamprey larvae, collected between 1960 and 1976 in the Mad River, Lake Huron basin, and compared with previously published data from Michipicoten River, Lake Superior basin. Although the ages of the lamprey specimens between the two lake basins were different, their lipid content, expressed as a percentage of dry body weight, was comparable. Despite the fact that the samples came from areas separated by about 550 km and with different land use (heavily forested area with mining activities but little agriculture for Lake Superior versus poultry farming, agricultural, urban and military uses for Lake Huron), no statistically significant differences were found for most organochlorine residue concentrations (Σaldrin, ΣCB, Σchlordane, ΣDDT, Σendosulfan and ΣPCB) between the two lake basins. The exception was ΣHCH, which was significantly lower in Lake Huron due to the absence of a high-level period observed in 1970 to 1975 in Lake Superior samples. Additionally, no differences were found between the relative concentrations of the various DDT metabolites between the two basins, but significantly higher relative concentrations of higher chlorinated PCBs (hexa to decachloro congeners) were found in Lake Huron samples. This study demonstrates the usefulness of formalin-preserved museum material to conduct retrospective contaminant analyses. However, given that certain amounts of contaminants were also found in the preservative solution, consideration of these levels is important to properly interpret the results.
A Comparison of Organochlorine Contaminant Levels in the Zebra Mussel, Dreissena polymorpha, versus its Unionid Attachment, Elliptio complanata, in the Rideau River, Ontario
Authors: Renaud Claude B. , Martel André L. , Kaiser Klaus L.E. , Comba Michael E.
Published: May 2018

Organochlorine contaminant levels were compared between the native unionid Elliptio complanata and the exotic zebra mussel, Dreissena polymorpha, at four sites along the Rideau River near Ottawa in 1995. Overall, the two taxa exhibited similar bioaccumulation patterns. PCB congeners, treated individually or as classes, showed strong positive and significant correlations between the two taxa. Additionally, the ratios DDD/ΣDDT, DDE/ΣDDT and DDT/ΣDDT were not significantly different between the two taxa. Mean concentrations of ΣPCB, ΣDDT, and Σchlordane were 65.8, 14.0, 1.2 and 227.9, 10.6, 1.8 ng/g soft tissue dry weight in E. complanata and D. polymorpha, respectively. These three organochlorine groupings accounted for 98.2 and 98.7% of the organochlorine soft tissue dry weight burden in E. complanata and D. polymorpha, respectively. However, while the bioaccumulation patterns were similar in E. complanata and D. polymorpha, the ΣPCB concentration was significantly higher in D. polymorpha. The organochlorine dry weight burden was 2.0 to 5.6 times greater in D. polymorpha compared to that in E. complanata and this was mostly attributable to differences in ΣPCB. This difference may be explained in part by the relative lipid content in D. polymorpha being 1.8 times greater on average than in E. complanata. We conclude that D. polymorpha is a good alternative freshwater biomonitor for E. complanata.
Process Design Parameters for Chinese Municipal Wastewater Treatment Plants
Authors: Palmer Merv , Fritz Jack
Published: May 2018

The operating characteristics of thirteen municipal wastewater treatment plants (WWTPs) with design capacities between 50,000 and 300,000 m3/d (mean 75,000 m3/d) were studied. The treatment processes used by these plants included one biofilter (BIO); two A/O (activated sludge anaerobic and aerobic processes in sequence); four A2/O (modified A/O with anaerobic, annoxic (denitrification) and aerobic cells in sequence); three oxidation ditches (OXD); two A/B (absorption-bio-oxidation two-stage [anaerobic cell followed by aerobic cell]); and one sequencing batch reactor (SBR). The study objective was to determine whether the WWTPs were operating at design conditions, and if not, to try to identify the causes of under-performance. All the WWTPs produced a treated effluent quality which was in compliance with a few exceptions. Nine WWTPs were operating with a mean of 62% of the design hydraulic flows. Thirteen WWTPs were operating at a mean of 56% of the design five-day biochemical oxygen demand (BOD) and at 84% of the design total suspended solids (TSS) loadings. Three WWTPs received high-strength wastewater (WW) (BOD >400 mg/L), four normal-strength WW (BOD = 150 to 260 mg/L) and five received weak-strength WW (BOD <150 mg/L). WW strength appeared to be a local characteristic. The mean capital treatment plant costs for one cubic metre of WW per day was 232 USD (104 to 444 USD); consequently, between 80 and 100 MUSD capital investment in WWTPs is unused.
Development of Predictive Models for the Formation of Trihalomethanes and Haloacetic Acids during Chlorination of Bromide-Rich Water
Authors: Lekkas Themistokles D. , Nikolaou Anastasia D.
Published: May 2018

The formation of disinfection by-products (DBPs) during chlorination of drinking water is an issue which has drawn significant scientific attention over the last few years, due to the adverse effects of these compounds on human health. The complicated mechanisms of the formation of DBPs are still under investigation, and modelling attempts are being made. One of the major factors affecting the yields of DBPs is the concentration of bromide ion. In bromide-rich waters, the brominated species—bromoform, dibromoacetic acid—which are considered more toxic than their chlorinated analogues, may be the major species formed and therefore the consumption of these waters may be more harmful to human health than the consumption of water containing chlorinated species (chloroform, dichloroacetic acid). During this study, the effect of bromide ion on DBP formation was investigated by bench-scale chlorination experiments and statistically evaluated for individual species of DBPs. The importance of interactions between pairs of chlorination factors, pH, bromide concentration, chlorine dose and time for DBP formation was highlighted by statistical analysis results. Moreover, multiple regression models were developed for the concentrations of total trihalomethanes and total haloacetic acids, the two major DBP groups formed. The models developed provide satisfactory estimations of, but also indicate different formation mechanisms for, these two groups of DBPs.
Evaluation of Activated and Non-Activated Tar Sands for the Removal of Phenol and Cadmium from Aqueous Solutions
Authors: Zeatoun Lua'y , Younis Noor , Rafati Rana
Published: May 2018

Locally available tar sands were used for the removal of phenol and cadmium ions from their aqueous solutions. Batch sorption experiments showed that tar sands did not remove phenol from aqueous solutions, but they were effective in cadmium adsorption. Cadmium uptake was found to increase with an increase in initial concentration of the metal ions, temperature, pH and sorbent amount. On the other hand, the presence of ions such as sodium, Na+, suppressed the uptake of cadmium ions. Physical activation of the tar sands influenced the adsorption process negatively. The sorption process was relatively fast and the equilibrium isotherm data were well represented by the Langmuir model.
Adsorption of As(III) from Aqueous Solution onto Iron Oxide Impregnated Activated Alumina
Authors: Kuriakose Shugi , Singh Tony Sarvinder , Pant Kamal K.
Published: May 2018

The optimal parameters affecting the adsorption of arsenic ions As(III) on iron oxide impregnated activated alumina (IOIAA) were determined by conducting batch and column experiments. The adsorption of As(III) was strongly dependent on pH, temperature and initial adsorbate concentration. The adsorption process satisfied the Langmuir and Freundlich isotherms. Equilibrium studies were conducted to obtain the thermodynamic parameters and data showed the endothermic nature of adsorption. Kinetics studies showed that a pseudo first-order rate equation successfully described the adsorption process. Equilibrium was attained within 10 h and the time taken to attain equilibrium was independent of initial arsenite concentration. Column studies showed that adsorption was strongly dependent on empty bed contact time. Column design parameters such as the time taken for the establishment of primary adsorption zone, fractional capacity, length of primary adsorption zone and the percentage saturation at breakpoint were calculated to be in the range of 18.3 to 70.4 h, 0.39 to 0.63, 3.0 to 3.85 cm and 69.6 to 81.5%, respectively. The observations mentioned above provide a direct relationship between the length of the adsorption zone (δ) and percent saturation at break point.
Arsenic Adsorption from Aqueous Solutions on an Fe(III)-Si Binary Oxide Adsorbent
Authors: Zeng Le
Published: May 2018

This study investigated arsenate and arsenite adsorption on an iron(III) oxide/silica adsorbent that had a Fe/Si molar ratio of 3. Batch experiments were conducted with regard to adsorption kinetics, isotherms, pH effects and interference of phosphate and sulfate on arsenic adsorption. The adsorption of arsenite was faster than that of arsenate. The adsorption kinetics could be well described by the power function equation for both arsenate and arsenite. The arsenate and arsenite adsorption isotherm data were satisfactorily fitted by the Redlich-Peterson, Freundlich-Langmuir and Langmuir models. The equilibrium adsorption capacity for As(III) was larger than that for As(V). This capacity for both As(III) and As(V) increased with temperature, from 11.3 to 14.9 (mg As/g) for As(V) and from 21.1 to 21.5 (mg As/g) for As(III) when the temperature was increased from 20 to 35°C. The arsenate adsorption was significantly reduced at pH above 7.5, while the arsenite adsorption was almost independent of pH in the range of 3 to 9. The calculated thermodynamic parameters including ΔG°, ΔH° and ΔS° reflected the spontaneous nature of As(V) and As(III) adsorption on this binary oxide adsorbent. The opposite values of ΔH° indicated that the adsorption of As(V) was exothermic, whereas that of As(III) was endothermic. It was found that the interference of phosphate at pH 7.4 was more significant for arsenate adsorption than for arsenite adsorption. In contrast, sulfate had insignificant interference on arsenic adsorption at the tested sulfate concentration up to 460 mg/L and pH 7.4.
Modification and Application of the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) for the Communication of Drinking Water Quality Data in Newfoundland and Labrador
Authors: Khan Amir Ali , Paterson Renée , Khan Haseen
Published: May 2018

In Newfoundland and Labrador (NL), drinking water quality monitoring is conducted by the provincial government on all public water supply systems and results are communicated to communities on a quarterly basis. This paper describes the application of the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) as a communications tool for reporting the drinking water quality results. The CCME WQI simplifies the communication of results while integrating local expert opinion, without challenging the integrity of the data. The NL Department of Environment and Conservation successfully tested the use of the CCME WQI on selected drinking water quality data sets, and developed a phased approach for its implementation as a practical means of presenting available physical, chemical, organic and microbiological results to communities. The CCME WQI index categorization schema was modified by adding a new ranking category to incorporate local expert opinion. This paper describes the development of the phased approach for calculating water quality indices, the testing methodology used, the rationale for modifying the existing CCME WQI index categorization schema, and the implementation of an automated CCME WQI calculator in the provincial drinking water quality database. The paper also discusses the challenges encountered in using the CCME WQI especially with respect to incorporation of contaminants, microbiological and trihalomethanes data. The benefits and downfalls of this application are also discussed.
Impacts of Substituting Aluminum-Based Coagulants in Drinking Water Treatment
Authors: Niquette Patrick , Monette Frédéric , Azzouz Abdelkrim , Hausler Robert
Published: May 2018

Aluminum-based coagulants in drinking water treatment are widely used across Canada. According to the literature, the presence of aluminum in drinking water poses possible risks to humans. Preliminary studies investigating the use of alternative coagulating agents such as iron-based coagulants, lanthanide salts and organic coagulants have already revealed that their implementation is possible, but require further studies concerning their technical, economical, social and environmental impacts. The identified alternative coagulants need on-site studies, operator formation and/or further research and development for their industrial utilization and the production of safe drinking water.
Evolution of Ontario's Stormwater Management Planning and Design Guidance
Authors: Bradford Andrea , Gharabaghi Bahram
Published: May 2018

Ontario's Stormwater Management, Planning and Design Manual released in March 2003 integrates some of the advancements made in stormwater management since the 1994 version of the Manual was published. Perhaps the most significant update is the recognition of in-stream erosion control and water balance objectives in addition to flood and water quality objectives for stormwater management. Specific design criteria which would allow these objectives to be achieved are not set out, but procedures that can assist in the development of criteria based on local watershed and receiving water conditions are described. While refinements will undoubtedly be needed, approaches to designing end-of-pipe facilities to prevent undesirable geomorphic changes are included. Approaches to protect groundwater and baseflow characteristics are also included although guidance on addressing potential trade-offs between groundwater quantity and quality is an additional challenge for the future. Little design guidance is available in Ontario on techniques to mitigate impacts on wetlands, however, developments from other jurisdictions may be transferable. The 2003 Manual promotes an integrated, treatment train approach to stormwater management that emphasizes prevention first, followed by lot-level and conveyance controls and finally, endof- pipe controls. Some information on better site design techniques is incorporated but in comparison to other jurisdictions, less emphasis has been placed on low-impact development strategies. Ontario's approach to design for water quality (suspended solids) control has evolved little. To complement the prevention and treatment train philosophy, the removal efficiency approach to sizing end-of-pipe facilities needs to be used in conjunction with effluent criteria and/or minimum requirements for source protection. Significant advancements in stormwater modelling over the last decade are not well reflected in the Manual; the limited discussion of modelling focusses on an event-based approach. Whether event or continuous modelling is utilized, Ontario practitioners will need guidance on adapting input data to account for the anticipated effects of climate change. Development of sound guidance on monitoring increasingly complex, multi-objective stormwater management systems and the ecosystems they are designed to protect will be critical to ensure that the knowledge gained from performance evaluations may continue to be utilized to refine the design and management of stormwater systems.
A Water Elutriation Apparatus for Measuring Settling Velocity Distribution of Suspended Solids in Combined Sewer Overflows
Authors: Krishnappan Bommanna G. , Marsalek Jiri , Exall Kirsten , Stephens Robert P. , Rochfort Quintin , Seto Peter
Published: May 2018

An elutriation apparatus has been proposed for determining the settling velocity distributions of suspended solids in combined sewer overflows (CSOs). The apparatus consisted of a series of interconnected cylindrical settling chambers, through which the sample was drawn using a peristaltic pump attached to the outlet of the last settling chamber. Since the diameters of the cylinders were progressively increasing, sediment with different settling velocities settled in different cylinders. By measuring the amount of sediment in each cylinder, the settling velocity distribution was deduced. The apparatus was tested using samples from a CSO outfall in Hamilton, Ontario, Canada. The test results showed that the apparatus performed well for determining settling characteristics of suspended solids and chemical distribution in different settling fractions. The effectiveness of polymer addition to enhance flocculation and settling of CSOs was also tested in this apparatus. The elutriation apparatus proposed here offers several advantages over the traditional methods (i.e., settling columns) of measurements of settling velocity distributions. The main advantage is its ability to measure the distributions under dynamic conditions, i.e., in the presence of flow. Consequently, the elutriation apparatus reproduces flow conditions in actual settling tanks better than conventional settling columns.
Numerical Modelling of Enhancing Suspended Solids Removal in a CSO Facility
Authors: He Cheng , Marsalek Jiri , Rochfort Quintin
Published: May 2018

One of the most common methods of combined sewer overflow (CSO) treatment is by conventional settling, the efficiency of which depends on the properties of solid particles and the characteristics of the flow transporting these solids. Since the geometry and hydraulics of CSO facilities are often very complex, traditional design methods based on many simplifying assumptions may not predict well the actual operational performance. Therefore, there is a growing need for new tools assisting engineers in design or operation of CSO storage and treatment facilities. In a study of such a CSO facility, a commercial computational fluid dynamics (CFD) model (FLUENT) was used to investigate flow and sediment behaviour, and to explore the ways of optimizing the overall facility performance by adding flow conditioning baffles to improve particle settling. A two-stage approach was adopted; flow patterns were simulated first by means of a volume of fluid (VOF) model and subsequently formed a basis for simulating particle transport by the discrete phase (DP) model. The simulation results for water surface, flow fields in different structure configurations, and particle capture rates in three parallel CSO storage/treatment tanks are presented for various flow conditions.
Practical Perspective on Real-Time Control
Authors: Colas Hubert , Pleau Martin , Lamarre Jean , Pelletier Geneviève , Lavallée Pierre
Published: May 2018

Environmental regulation is evolving and will require billions of dollars in investments to improve the operation of wastewater systems and to control the wet-weather pollution. The optimization of existing facilities before building new ones has been emphasized as a preferred strategy and, consequently, municipalities are learning that they can avoid costly and unnecessary capital improvement projects. Real-time control is a technology that serves to optimize the operation of wastewater systems. However, it is still not widely used, although it is gaining acceptance in the municipal engineering community. More and more municipalities are evaluating the potential of real-time control for their systems. Nevertheless, there are relatively few examples of actual real-time control applications or publications on this topic. Many issues still need to be addressed, ranging from the evaluation of real-time control to its implementation. Some of the criteria that favour the implementation of real-time control systems are presented, including safety, reliability, adaptability and flexibility, and such a presentation is complemented by case studies of operational real-time control systems illustrating these characteristics.
An Effects-Based Assessment of Slimy Sculpin (Cottus cognatus) Populations in Agricultural Regions of Northwestern New Brunswick
Authors: Gray Michelle A. , Munkittrick Kelly R.
Published: May 2018

Recently in Atlantic Canada, there has been increased concern associated with potato farming due to an increase in the frequency and magnitude of fish kills downstream of agricultural cultivation activities following major storm events. Over a period of three years (1999–2001), we monitored the population structure and physiological performance of slimy sculpin (Cottus cognatus) within the Little River, located in an intensive potato cultivation region of northwestern New Brunswick. The slimy sculpin, a small-bodied benthic fish, was considered suitable for monitoring due to its natural abundance throughout the system, limited mobility, lack of commercial fishing pressures, and easily measured life history characteristics. Rather than focus on particular agricultural stressors, an effects-based assessment of the fish in the system was conducted to determine whether there were observable and persistent responses of sculpin in the agricultural region. We found that the local population structure at agricultural sites consisted of fewer young-of-the-year sculpin in 2 of 3 fall collections. In comparison with forested reaches, adult sculpin were larger but with smaller gonads, and females had smaller livers, gonads, and fewer and smaller eggs. These biological responses were reduced in the fall of the third year following drier conditions than the previous two years. The effects-based approach successfully demonstrated biological impacts on sculpin both temporally and spatially and therefore the species' potential for studying non-point source impacts in environmental monitoring.
Extending Uncertainty Analysis of a Hydrodynamic-Water Quality Modelling System using High Level Architecture (HLA)
Authors: Lindenschmidt Karl-Erich , Rauberg Jan , Hesser Fred B.
Published: May 2018

This paper illustrates the coupling of water quality model components in High Level Architecture (HLA), a computer architecture for constructing distributed simulations. HLA facilitates interoperability among different simulations and simulation types and promotes reuse of simulation software modules. It was originally developed for military applications but the platform is finding increasing applicability for civilian purposes. The models from the Water Quality Analysis Simulation Program (WASP5) were implemented in HLA to extend its Monte Carlo uncertainty analysis capabilities. The models include DYNHYD (hydrodynamics), EUTRO (phytoplankton and nutrient dynamics) and TOXI (sediment and micropollutant transport). The uncertainty analysis investigated the impact of errors in the hydrodynamic parameters (weir discharge and roughness coefficients) and boundary conditions (upstream and tributary discharge) on the uncertainty in the water quality output variables. It was found that the contribution of the hydrodynamic parameter error to the water quality output uncertainty is comparable to that obtained from the error in the water quality parameters. The error in the boundary condition input data is also an important contributor to model uncertainty.
Pilot-Scale Performance of Iron and Arsenic Removal from Contaminated Groundwater
Authors: Manna Biswaranjan , Ghosh Uday Chand
Published: May 2018

Pilot-scale performance in reducing excess iron and arsenic from contaminated groundwater has been systematically reported. Here, a double column unit, the first packed with β-MnO2 and the second with crystalline FeOOH (goethite variety), with filters attached to the outlet of hand-pump tube-wells has been used in the field. Results showed that the filters generate 10,000 to 15,000 BV and 19,000 to 35,000 BV water with iron ≤ 0.3 mg/L and arsenic ≤10 µg/L from groundwater having influent iron and arsenic levels of 3.75 to 7.25 mg/L and 70 to 220 µg/L, respectively. The downflow rate of effluent water was 237.6 to 305.5 L/m2-min. The performance results were achieved with a single charging of the iron and arsenic removal media. Toxicity characteristic leaching procedure (TCLP) tests of the waste (arsenic content: 2.4 g/kg) showed that it is not hazardous to the environment and does not pose any risk to users. Cost evaluation showed $US0.50 to 0.70 per 1000 gallons of treated water and, hence, the technology is cost-effective for countries such as India and Bangladesh.
Comparative Evaluation of Natural Polyelectrolytes Psyllium and Chitosan as Coagulant Aids for Decolourization of Dye Solutions
Authors: Sanghi Rashmi , Bhattacharya Bani
Published: May 2018

The aqueous solutions of three different highly coloured anionic dyes (reactive, acidic and direct dyes), commonly used in the dyeing process, were studied for decolourization by coagulation. For optimum results the variables studied with polyaluminium chloride (PAC) were pH, dosage and temperature. Coagulation efficiencies of natural polyelectrolytes such as psyllium and chitosan alone or as coagulant aids in conjunction with PAC were studied and compared. In conjunction with a minimal dose of PAC, chitosan and psyllium were found to be very effective for the decolourization of acidic and direct dyes. Reactive dyes with anthraquinone chromophore were the most difficult to decolourize.