bluuebunny/crossref_metadata_2025 huggingface dataset:
Contamination métallique de Mytilus galloprovincialis et des sédiments au niveau de l'estuaire de Bouregreg (Maroc)
Authors: Tahiri Latifa , Bennasser Laila , Idrissi Larbi , Fekhaoui Mohammed , Abidi Abdallah El , Mouradi Aziza
Published: May 2018

Le présent travail consiste à évaluer le degré de contamination de lestuaire de Bouregreg (Maroc) à travers le suivi spatio-temporel des teneurs de certains éléments métalliques (Cd, Cr, Cu, Fe, Pb et Zn) au niveau des sédiments et chez la moule Mytilus galloprovincialis. L'écosystème est soumis à de nombreux rejets complexes d'origine diverse. Une situation qui se complique davantage au niveau de l'estuaire par le jeu des marées rendant difficile l'évacuation aisée de la charge polluante résultant de l'activité anthropique.

Les résultats obtenus font état d'une contamination métallique généralisée le long de l'estuaire, importante pendant l'été au niveau des sédiments et pendant lhiver chez la moule. Le degré de contamination le plus élevé correspond au plomb avec des taux quatre fois supérieurs aux normes de la CEE. La consommation de la moule provenant de l'estuaire de Bouregreg reste redoutable et dangereuse quant aux risques toxicologiques que peut induire sa contamination.
Use of Activated Oil Shale for the Removal of 2,4-Dichlorophenol from Aqueous Solutions
Authors: Al-Asheh Sameer , Banat Fawzi , Masad Asmahan
Published: May 2018

Sorption of the phenolic compound 2,4-dichlorophenol (2,4-DCP) by pyrolyzed and different forms of treated residue of Jordanian oil shale was examined. Pyrolyzed oil shale was prepared using a fluidized bed reactor at 520ºC in the presence of nitrogen. Physical activation was carried out by treating the resultant pyrolyzed oil shale with CO2 at 830ºC, while chemical activation of oil shale was carried out using KOH and ZnCl2 as impregnating agents. Uptake of 2,4-DCP onto the different types of sorbents increased in the order ZnCl2-OS > Pyr-OS > CO2-OS, with minimal uptake when KOH-OS was used. The process was found to be exothermic in nature. An increase in the initial pH of the solution negatively influenced the sorption of 2,4-DCP. The isotherm experimental data fitted reasonably to the Langmuir, Freundlich and Redlich-Paterson models. According to kinetics studies, the rate of 2,4-DCP sorption onto ZnCl2-OS was faster than that by Pyr-OS. Three kinetics models, namely the Morris-Weber model, Lagergren model, and pseudo-second-order model (PSOM), were applied to represent the experimental results for both pyrolyzed and ZnCl2-oil shale sorbents.
Three Decades of Swedish Experience Demonstrates the Need for Integrated Long-Term Monitoring of Fish in Marine Coastal Areas
Authors: Sandström Olof , Larsson Åke , Andersson Jan , Appelberg Magnus , Bignert Anders , Ek Helene , Förlin Lars , Olsson Mats
Published: May 2018

The first attempts to monitor coastal fish in Sweden were made in the 1960s and 1970s. Ecological, physiological, biochemical and environmental chemistry data were collected in separate projects. When the National Marine Monitoring Programme was revised in 1992, a new strategy was introduced for assessments of long-term trends in coastal fish communities. Annual integrated monitoring of contaminants, biomarkers and population and community indicators of ecosystem health was started in selected areas using common sentinel species. Data from one monitoring area at the coast of the Baltic proper are analyzed in this paper. The results have shown a shift in fish community structure indicating changes in ecosystem productivity. Trends have been detected in growth rate (positive) and relative gonad size (negative) in perch (Perca fluviatilis), suggesting a metabolic disturbance according to the predictive response model developed for interpretations. One factor which may have contributed to the reduced GSI was a decrease in mean age of sampled fish during the period of study. Chemical exposure was indicated by a 3-fold increase of EROD activity during the monitored 15-year period. However, concentrations of most measured contaminants in perch have decreased during the same period. The experience of the integrated approach has shown that a tentative analysis of cause and environmental significance could be made, improving the assessment, but there still remain unsolved questions to be answered in follow-up studies. The analysis has also shown the importance of long-term monitoring at several levels of biological organization to distinguish between natural variation and low-level effects on ecosystems.
Snowmelt and Growing Season Phosphorus Flux in an Agricultural Watershed in South-Central Alberta, Canada
Authors: Ontkean Gerald R. , Chanasyk David S. , Bennett D. Rodney
Published: May 2018

A three-year study was conducted to examine the spatial and temporal variability of phosphorus concentrations and mass loads within four sub-basins in the Crowfoot Creek watershed in southern Alberta, Canada. Monitoring was carried out at the inflows and outflows of the four sub-basins from mid-March until the end of October in 1997 to 1999. Data were collected on flow, total phosphorus (TP) and total dissolved phosphorus (TDP). The TP and TDP concentrations increased and were greatest during spring snowmelt and rainfall runoff events. Median TP concentrations varied from 0.022 to 1.141 mg L-1 and median TDP concentrations varied from 0.005 to 1.031 mg L-1. Within the sub-basins, phosphorus concentrations generally increased between inflow and outflows. The presence of grassland and well-developed crop cover adjacent to the watercourses generally resulted in a greater proportion of TDP in runoff. The proportion of TP as TDP varied from 31 to 97% and appeared to be affected by the timing of the storm and antecedent moisture conditions of the soil. The proportion of phosphorus exported during events made up from 1 to 83% of the total phosphorus load during the post-spring runoff period. Phosphorus concentrations exceeded Alberta surface water quality guidelines most of the time; however, the addition of irrigation return flow water generally improved water quality in Crowfoot Creek.
Application of CCME Procedures for Deriving Site-Specific Water Quality Guidelines for the CCME Water Quality Index
Authors: Khan Amir Ali , Tobin Annette , Paterson Renée , Khan Haseen , Warren Richard
Published: May 2018

Since its development in 2001, the Canadian Council of Ministers of the Environment (CCME) Water Quality Index (WQI) has established itself as a valuable tool for communicating ambient water quality data. Due to the high natural background levels of particular parameters in water bodies throughout the country it is often necessary to use Site-Specific Water Quality Guidelines (SS-WQGs) as opposed to generic national Water Quality Guidelines (WQGs) or provincial Water Quality Objectives (WQOs) in the CCME WQI model to obtain truly representative rankings. SS-WQGs have only been developed for a limited number of ambient water quality sites and this has been a major hurdle to the widespread use and acceptance of the CCME WQI. This paper presents the adaptation and implementation of an existing CCME-approved SS-WQGs derivation method called the background concentration (BC) procedure into a Site-Specific Water Quality Index (SS-WQI) calculator and tool. It discusses the application of the SS-WQI calculator to compute water quality indices for five pristine ambient water quality sites in Newfoundland and Labrador. The effects of using five different BC-based SS-WQGs (mean; median; mean ± one standard deviation; mean ± two standard deviations; 90th and 10th percentile) are examined. The paper also discusses the challenges and benefits of using this methodology and provides recommendations for further testing.
Characterization of Particles in Fresh and Primary-Treated Log Sort Yard Runoff
Authors: Doig Peter , van Poppelen Paul , Baldwin Susan A.
Published: May 2018

Runoff from three southwest British Columbia (B.C.), Canada (Sunshine Coast), log sort yards was characterized to determine the colloidal and particulate fraction structures and the distribution of organic and metal constituents. Runoff from these sites, resulting from rainfall and on-site sprinkling, contains suspended and colloidal particles that are largely organic. At one log sort yard, the runoff receives primary treatment in a lagoon, whereas at the other sites, at the time of the study, runoff was directly discharged into the aquatic environment. The fresh runoff contained a high strength of organic compounds as determined by chemical oxygen demand (COD) analyses, which ranged from 346 to 3690 mg L-1. For a rainfall-generated runoff sample, particulates (particles greater than 1–2 µm) contributed up to 52% of the total COD and colloids (particles between 20 nm and 1–2 µm) 39%. Following primary treatment in the lagoon, organic compounds present were mostly colloidal. In both samples (fresh and primary-treated) zinc and aluminum concentrations exceeded the B.C. Approved Water Quality Guidelines. Primary treatment experiments revealed that 27 to 54% of the COD could be removed by settling, depending on the initial concentration. An additional 33% of COD was removed, probably due to biological degradation during the settling time. Chemical oxygen demands of the final treated effluents remained relatively high (378–533 mg L-1) showing that not all the suspended material could be removed through settling and biodegradation and that other treatments are required.
Kinetics and Mass Transfer Studies on the Adsorption of Arsenic onto Activated Alumina and Iron Oxide Impregnated Activated Alumina
Authors: Singh Tony Sarvinder , Pant Kamal K.
Published: May 2018

The present investigation deals with the uptake of As(III) and As(V) ions from aqueous solution by activated alumina and a new laboratory-prepared sorbent—iron oxide impregnated activated alumina. Iron oxide impregnation onto activated alumina significantly increased the percent arsenic removal and adsorption capacity for As(III) and As(V) ions. The maximum As(III) and As(V) removals were 96.8% and 98.4%, respectively, by iron oxide impregnated activated alumina (IOIAA). Maximum As(III) and As(V) removal of 94.2% and 96.1% was observed over activated alumina. Kinetic studies were performed at different initial sorbate concentrations to determine the mechanism of mass transfer of sorbate onto this sorbent. The maximum removal of As(III) and As(V) by activated alumina and iron oxide impregnated alumina takes place within 6 h and attains equilibrium within 12 h. First-order Lagergren kinetics explained the adsorption of arsenic over activated alumina whereas a pseudo-second order rate equation explained the behaviour of As(III) adsorption over iron oxide impregnated activated alumina. Diffusional effects in solid pellets were also investigated to understand the mechanism of adsorption. These results indicate that the mechanism of arsenic adsorption is complex on both sorbents as both pore diffusion and surface diffusion contribute to the arsenic removal. During the initial period, surface diffusion was predominant but as the adsorption progresses, pore diffusion dominated the rate of adsorption.
Iron-Coated Sponge as Effective Media to Remove Arsenic from Drinking Water
Authors: Nguyen Tien Vinh , Vigneswaran Saravanamuthu , Ngo Huu Hao , Pokhrel Damodar , Viraraghavan Thiruvenkatachari
Published: May 2018

Arsenic (As) contamination in drinking water is a serious problem in a number of countries in the world, especially in small communities and developing countries. Arsenic is related to many health diseases. Several technologies such as coagulation, adsorption, ion exchange and membrane processes, etc., are used in removing arsenic from water. In this study, a new material, namely iron-coated sponge (IOCSp), was developed and used to remove As, and it was found that IOCSp has a high capacity for removing both As(V) and As(III). Each gram of IOCSp adsorbed about 160 µg of As upon a 9-h contact of IOCSp with As solution. A dynamic filter column conducted showed that even a small quantity of IOCSp (8 g) could reduce As from 156 µg/L to a concentration of less than 50 µg/L while treating 75 L of groundwater contaminated with arsenic. Both the filtration rate and the size of the sponge had an effect on effluent quality, and the amount of water treated to the acceptable quality.
Arsenic Adsorptive Media Technology Selection Strategies
Authors: Westerhoff Paul , De Haan Michelle , Martindale Alan , Badruzzaman Mohammad
Published: May 2018

More stringent arsenic regulations are requiring water utilities of all sizes to install treatment systems on wells which historically only had chlorination. A case study is presented for evaluating arsenic adsorption media at a well site in Mesa, Arizona, but the approach and methodological conclusions are transferable to any arsenic treatment system. The goal of this project is to develop a comprehensive, cost-effective and rapid approach for selecting arsenic adsorptive media. Batch laboratory tests, labscale continuous flow column tests and pilot-scale tests were conducted to evaluate removal efficiency, robustness, operational benefits and cost effectiveness of eight different commercially available adsorbents. Batch tests conducted at multiple pH levels provided limited benefit when compared against continuous flow rapid small-scale column tests (RSSCTs) to evaluate arsenic removal capability by different media. Breakthrough curves of arsenic, vanadium, silica and other trace metals corresponded well between lab-scale RSSCT and field-based pilot scale, suggesting that RSSCTs offer a timesaving approach for adsorptive media selection. Leaching tests on spent media verified that media could be safely disposed and high-resolution microscopic analysis indicated that calcium and silica accumulate on media surfaces and affect the longevity of arsenic removal systems.
An AlgaSORB Column for the Quantitative Sorption of Arsenic(III) from Water Samples
Authors: Prasad Bhim Bali , Banerjee Souri , Lakshmi Dhana
Published: May 2018

This study examines a new Scytonema-based biosorbent (AlgaSORB-scy) using column chromatography for the biosorption of total inorganic arsenic [As(III) and As(V)] from aquatic samples. The AlgaSORB-scy was prepared by immobilizing a cyanobacterial biofilm (Scytonema-dimethyl-formamide slurry) over a polymer-modified silica gel and then characterized for stability and sorption/elution conditions under dynamic equilibrations followed by differential pulse polarographic detection. The sorbent exhibited a 100% affinity for As(III) in a multi-elemental solution [in the absence of As(V)] at pH 6.9 and a flow rate of 1 mL min-1 giving rise to a preconcentration factor as high as 44-fold. The interference caused by As(V) in the sorption of As(III) on AlgaSORB-scy necessitated the pre-reduction of As(V) into As(III) by sodium sulfite. The biosorbent was found to be suitable for total arsenic enrichment in the form of As(III) species and demonstrated a better endurance with a recyclability of up to 59 cycles of sorption-elution. The polymeric spacer between the cyanobacterial biofilm and the silica gel enabled the biofilm monolayer to be held firmly onto a solid support and be accessible for quantitative arsenic uptake without encountering any problems of interfacial overlapping, re-adsorption, or matrix effects in the drinking water supplied.
Development of a Fluorescent Multiwell Assay for Evaluating the Capacity of the Ciliated Protozoan Tetrahymena for Bacterivory in Water Samples
Authors: Power Mary E. , Sotornik Dana , Pinheiro Marcel D.O. , Dayeh Vivian R. , Butler Barbara J. , Slawson Robin , Lee Lucy E.J. , Lynn Denis H. , Bols Niels C.
Published: May 2018

Bacterivory by ciliates in various water ecosystems, both natural and artificial, plays a significant role on the microbial population composition and consequently affects water quality. A convenient, rapid and inexpensive methodology to evaluate the capacity of the ciliate protozoan Tetrahymena thermophila for bacterivory was developed utilizing fluorescent protein expressing bacteria (FPEB) in a microtitre plate fluorimeter. Bacterivory was correlated with a loss in fluorescence measured in the fluorimeter and confirmed by fluorescence microscopy showing that the FPEB were engulfed during the assay and subsequently lost their fluorescence, whereas Cytochalasin B, a known inhibitor of phagocytosis, prevented a decrease in relative fluorescence units (RFUs). The ciliate bacterivory (CB) assay has a great dynamic range allowing the assay to be performed with a variety of predator:prey concentrations. A model toxicant, CuCl2, known to have a toxicological impact on protozoa and often present in different types of wastewater, resulted in measurable decreases in bacterivory. As well, starvation of Tetrahymena for 24 h resulted in reduced bacterivory. In the future, the CB assay could be developed for water monitoring purposes to rapidly assess water samples for the capacity to support bacterivory as an indicator of ecosystem health.
Comparison of Toxicity and Bioaccumulation of Tributyltin in Hyalella azteca and Five Other Freshwater Invertebrates
Authors: Bartlett Adrienne J. , Borgmann Uwe , Dixon D. George , Batchelor Suzanne P. , Maguire R. James
Published: May 2018

This study evaluates the suitability of using Hyalella azteca as a predictor of the risk that tributyltin (TBT) poses to freshwater invertebrates by comparing the toxicity and bioaccumulation of TBT in H. azteca to five species: Hexagenia limbata, Physella gyrina, Tubifex tubifex, Chironomus riparius and Daphnia magna. Young from each species were added to aquaria containing sediment spiked with TBT concentrations of 0,28.6, 258 and 1900 ng Sn/g dry weight. Chironomus riparius data could not be quantified reliably due to poor control survival. Bioaccumulation of TBT in the five remaining species was similar at sediment concentrations of 258 ng Sn/g, and the bioaccumulation relationships of P. gyrina and H. azteca were virtually identical. No toxicity was evident in any test species at body concentrations of 1100 to 1800 ng Sn/g. Body concentrations of 4000 to 6000 ng Sn/g were associated with significant (p < 0.05) mortality in H. limbata, P. gyrina, T. tubifex and D. magna, but not in H. azteca. However, bioaccumulation of TBT in H. azteca was comparable and can be used in predicting the effects of environmental TBT concentrations on these four species of freshwater invertebrates.
A Microwave-assisted Extraction Method for the Determination of Synthetic Musks in Sewage Sludge
Authors: Svoboda M. Lewina , Yang Jian-Jun , Falletta Patricia , Lee Hing-Biu
Published: May 2018

An efficient microwave-assisted extraction (MAE) procedure has been optimized for the determination of polycyclic and nitro musks in sewage sludge. A centrifuged sludge cake sample (from 1 to 2.5 g ), mixed with 10 g of anhydrous sodium sulfate in a Teflon cell, was extracted with 30 mL of a 1:1 (v/v) mixture of acetone and hexane for 35 min, including a 15-min ramp with a 20-min hold at a controlled temperature of 110°C. After 30 min of cooling, the extract was evaporated and cleaned up on a silica gel column. A concentrated sample extract was then analyzed by gas chromatography/mass spectrometry (GC/MS) in the electron impact mode for the polycyclic musks and in negative ion chemical ionization mode for the nitro musks. This new method has been validated by comparing it to an established accelerated solvent extraction (ASE) method, with method detection limits ranging from 27 to 41 ng/g for the polycyclic musks, and approximately 4 ng/g for the nitro musks. Recoveries of most compounds in spiked samples ranged from 80 to 105%, although the MAE method produced lower recoveries for the nitro musks than the ASE method in archived sludge samples. The results generated by this MAE method were consistent with those prepared by previously reported techniques such as supercritical fluid extraction.
Pilot Treatment of OCC-based Paper Mill Wastewater Using Pulsed Electrocoagulation
Authors: Perng Yuan-Shing , Wang Eugene I-Chen , Yu Shih-Tsung , Chang An-Yi , Shih Chi-Yuan
Published: May 2018

There is an increasing trend towards the closure of white water recirculation loops in papermaking, often leading to need for system modification. A pilot-scale study was conducted using pulsed electrocoagulation technology to treat the wastewater of an old corrugated containerboard (OCC)-based paper mill, to evaluate its treatment performance. The operating variables were: a current density of 0 to 240 A/m2, a hydraulic retention time of 8 to 16 min and a coagulant (anionic polyacrylamide) dosage of 0 to 30 mg/L. The water quality indicators investigated were electrical conductivity, suspended solids (SS) and chemical oxygen demand (COD). The results obtained during the pilot-scale studies were favourable. Under the operating conditions without coagulant addition, the highest removals for conductivity, SS and COD were 47.7%, 99.3% and 75%, respectively. The use of coagulant remarkably enhanced the removal of both conductivity and COD. Using a coagulant dosage of 30 mg/L, the highest removal rates achieved for the three water quality indicators were 54.5%, 99.6% and 92.7%, respectively. These water quality levels are adequate to allow for the reuse of at least a part of the treated wastewater as makeup process water in papermaking.
A Shortened Adult Fathead Minnow Reproduction Test Developed for Investigation of Cause and Investigation of Solution Work Involving Pulp and Paper Mill Effluents
Authors: Kovacs Tibor , Martel Pierre , Ricci Maria
Published: May 2018

The regulatory Environmental Effects Monitoring (EEM) program in Canada has found that pulp and paper mill effluents reduce the gonad size of wild fish. In such cases, there is a need for Investigation of Cause (IOC) and Investigation of Solution (IOS) studies to find the cause(s) for these responses as well as cost-effective mitigation strategies. IOC and IOS work requires the availability of practical (in terms of time and effluent volume needs) and biologically meaningful tests for assessing fish reproduction in the laboratory. One available fish reproduction test uses adult fathead minnow (Pimephales promelas) and involves a two- to three-week pre-exposure period and a three-week exposure to a test substance. Work was undertaken to determine if both the pre-exposure and effluent-exposure phases could be reduced, leading to a shorter test with a lower effluent volume requirement. For this purpose, effluent samples were taken from two thermomechanical (newsprint) pulp mills and used in tests with ≤7 days of pre-exposure and 5 to 6 days of effluent exposure. Egg production was monitored in each test, and in tests with effluents from one mill, other endpoints - such as gonad somatic indices and whole-body sex steroid levels, as well as vitellogenin activity in males - were measured. The shortened fish reproduction test in this study provided results similar to tests of longer duration, specifically in terms of egg production, and was able to distinguish between pulp and paper mill effluents of different potencies. The test was also found to be directly applicable for toxicity identification evaluation work as it was clearly able to distinguish between the solids and soluble fractions of a biotreated newsprint mill effluent. As such, the test is a promising tool for EEM-related IOC and IOS work.
Optimization of Acetylcholinesterase and Metabolic Enzyme Activity in Multiple Fish Species
Authors: Georgiades Eugene T. , Holdway Douglas A.
Published: May 2018

An examination of acetylcholinesterase (AChE), citrate synthase (CS) and lactate dehydrogenase (LDH) activities in the brains of a range of fish species, occupying different trophic levels, is useful to investigate the full extent of the effects of sublethal or pulse exposures to pesticides. This investigation explores the optimization of microplate procedures for AChE, CS and LDH measurements in the brain tissue of species commonly used in laboratory investigations and those common to Canadian watersheds. A microplate assay was optimized for the measurement of AChE in the brain homogenates of seven fish species. The critical aspects of this assay requiring optimization were pH, substrate concentration and tissue dilution. Incubation with specific cholinesterase inhibitors indicated that enzymatic activity in the brain homogenates of each species was attributed to AChE only. Microplate assays were also optimized for the measurement of the metabolic enzymes, CS and LDH, in the brain homogenates of six fish species. For these assays, low interspecies variability was exhibited between optimized factors including pH, substrate, chromogen and cofactor concentrations. For each assay optimized, enzyme activities in the brain homogenates were stable for 2 to 3 hours post-thaw. Results from the present study will aid future ecotoxicological investigations of the potential impacts of AChE inhibition on neuronal glucose metabolism.
Persistence of Tributyltin-Induced Imposex in Dogwhelks (Nucella lapillus) and Intersex in Periwinkles (Littorina littorea) in Atlantic Canada
Authors: Coray Camille , Bard Shannon M.
Published: May 2018

Imposex in gastropods such as dogwhelks (Nucella lapillus) is a sexual abnormality that can cause sterility through the superimposition onto females of male sexual characteristics such as a penis homologue and/or vas deferens. Intersex similarly affects periwinkles (Littorina littorea) and is characterized by a phenotypic disturbance of sex determination between gonad and genital tract. A major culprit in causing imposex and intersex in aquatic gastropods is tributyltin (TBT), which is primarily used as a biocidal compound in antifouling paints, but is also present in sewage and wastewater due to industrial use. Since 1989, TBT has been banned in Canada for use on boats under 25 m in length, and in 2003, the ban was extended to include vessels of any length. However, observations of persistent imposex and intersex in marine snails from Halifax Harbour, Nova Scotia, Canada, suggest that current TBT controls are ineffective to eliminate this environmental problem in active ports. Dogwhelk imposex incidence ranged from 19% at the mouth of Halifax harbour to 100% midharbour, while no dogwhelks were found at the harbour head. Dogwhelks from uncontaminated reference sites outside the harbour yielded no cases of imposex. Imposex frequency and Relative Penis Size Index decreased at some of the sites between 1995 and 2006, but imposex frequency increased from 65 to 100% near a container pier, suggesting that TBT from antifouling paint on large (>25 m) vessels like container ships may still be a strong environmental concern in Halifax Harbour. Periwinkles can tolerate higher TBT exposure and can be found where dogwhelks have been extirpated because of TBT contamination. Intersex incidence ranged from 0% outside the harbour to 100% at the head of the harbour at sites where no dogwhelks were found. Intersex indices corresponded with imposex indices where dogwhelks were found, and were relatively high (>2.0) where dogwhelks were absent. Intersex rates and severity remained constant between 1996 and 2006. These data suggest that TBT-induced imposex may be at least partially responsible for the absence of dogwhelks in certain areas of Halifax Harbour. We also examined the impact of the loss of whelks, important predators for dominant mussels, on intertidal community structure and function. Due to the persistence of TBT in sediments and input of TBT into aquatic environments from sources other than vessel antifouling systems, current TBT controls may be of limited effectiveness in minimizing endocrine disruption and population decline in susceptible marine gastropods.
The Presence of Selected Pharmaceuticals and the Antimicrobial Triclosan in Drinking Water in Ontario, Canada
Authors: Servos Mark R. , Smith Martha , McInnis Rodney , Burnison B. Kent , Lee Bill-H. , Seto Peter , Backus Sean
Published: May 2018

The presence of pharmaceuticals and personal care products in the environment is a rapidly emerging international issue. A variety of drugs have been found in sewage effluents and surface waters in Europe, the United States, and Canada. This study examines the presence of selected pharmaceuticals (8 acidic drugs) and the antimicrobial substance, triclosan, in raw water and finished water of drinking water plants across southern Ontario. Twenty drinking water treatment plants that represented a variety of water sources and treatment process parameters were sampled. None of the raw or finished water samples taken from wells showed detectable levels of any of the acidic drugs or triclosan. River water samples downstream of sewage effluent outfalls showed the highest levels of contamination of the source water. Levels of naproxen and ibuprofen were elevated to levels as high as 176 and 150 ng/L, respectively, in raw water entering the treatment plants from a river source. Low levels of gemfibrozil (19.2 ng/L), diclofenac (15 ng/L), indomethacin (6 ng/L), and the antimicrobial triclosan (34 ng/L) could be also detected in raw water from river sources. Raw water taken from large lakes also had very low but detectable levels of several acidic drugs, suggesting that these chemicals are widespread in the environment. Although treatment systems are not designed to remove these specific types of substances, most of the acidic drugs were not detectable in finished waters. Naproxen and triclosan were detectable in finished water but were significantly reduced in concentration relative to the raw water. The concentration of ibuprofen was detectable in the finished water of almost all treatment plants that used surface water as a source. This work demonstrates the potential of Ontario source waters, particularly river water sources, to contain trace levels of selected pharmaceuticals and personal care products. There is a need to complete a more comprehensive assessment of these compounds in source waters and of the factors influencing their treatment and removal from finished drinking water.
An Evaluation of Rapid Bioassessment Protocols for Stream Benthic Invertebrates in Southern Ontario, Canada
Authors: Borisko Jeff P. , Kilgour Bruce W. , Stanfield Les W. , Jones F. Chris
Published: May 2018

In this study, we sampled stream benthos using rapid bioassessment methods (i.e., D-nets, coarse taxonomy) from sites in and around Toronto, Ontario that represented a range of stream characteristics (e.g., drainage areas). The protocols were developed by or adapted from: (1) Toronto and Region Conservation Authority, (2) Ontario Ministry of Natural Resources, (3) Ontario Benthos Biomonitoring Network/Ministry of the Environment, and (4) Canadian Aquatic Biomonitoring Network/Environment Canada. Summary indices (Hilsenhoff's modified Biotic Index [HBI]; percent of fauna as Ephemeroptera, Plecoptera, and Trichoptera [% EPT]; number of taxa [S]; and Shannon's Diversity Index [H']) calculated from the resulting data were used to evaluate differences between protocols in a series of analyses including analysis of variance and variance components analysis. The study found that sampling method was an unimportant source of variation in summary index values relative to other factors such as the stream or year sampled. The largest percent variance amongst stream or year factors (main and interactions) was at least three times greater than the corresponding method related percent variances. The results of this study suggest that these four bioassessment methods are interchangeable within the context of large geographic scales or for the detection of major impacts. In cases where impacts to the benthic community are subtle, protocols should include one or more of discrete habitat sampling, replication, and lower taxonomic resolution. The data and findings here may help agencies integrate different sampling protocols into their biomonitoring and assessment programs.
Evaluation of the Root Zone Water Quality Model (RZWQM) for Southern Ontario: Part II. Simulating Long-Term Effects of Nitrogen Management Practices on Crop Yield and Subsurface Drainage Water Quality
Authors: Ahmed Imran , Rudra Ramesh , McKague Kevin , Gharabaghi Bahram , Ogilvie John
Published: May 2018

Loss of nitrogen from the agricultural production system is of concern in Ontario. The challenge for researchers and farmers is to fulfill crop water requirements while limiting chemical movement with surface and subsurface runoff. The main objective of this study was to evaluate the long-term effects of current N management practices for corn production for two different soil types using the Root Zone Water Quality Model (RZWQM) for southern Ontario conditions. The model simulated the amount of subsurface tile drainage, residual soil nitrate-nitrogen (NO3-N), NO3-N in subsurface drainage water, and crop yield. The validated RZWQM for silt loam and sandy loam soils showed that the relative long-term effectiveness of the most economic rate of nitrogen (MERN) for corn production fluctuates significantly from year-to-year in response to weather patterns. In addition, soil type had a small but significant effect on the MERN. Side-dress application of N on sandy loam resulted in significant reduction in corn yield and NO3-N loss to shallow groundwater. Also, crop rotation from corn-soybean to corn-soybean-soybean resulted in a greater reduction of NO3-N loads in the tile outflow on silt loam soil than on sandy loam soil. Overall, the RZWQM simulated tile drain flow, NO3-N loss, and crop yield with reasonable accuracy. However, more field work is needed to assist with identifying suitable values for a number of coefficients used in the RZWQM's nutrient component for Ontario conditions.
Environmental and Economic Evaluation of Cow-Calf Wintering Site Runoff Control as a Beneficial Management Practice to Improve Surface Water Quality
Authors: Wuite James J. , Chanasyk David S. , Akbar Muhammad A.
Published: May 2018

A runoff diversion-collection system was evaluated as a beneficial management practice (BMP) for minimizing the impact of wintering site runoff on the water quality of an adjacent reach in the headwaters sub-basin of the Haynes Creek Watershed in central Alberta. Significant (α = 0.05) post-BMP mean annual load reductions of 13, 47, and 17% for dissolved, particulate, and total phosphorus, respectively, were realized. Mean annual loads of nitrate nitrogen and total Kjeldahl nitrogen were also reduced by 83 and 22%, respectively. The sum of total loads of Kjeldahl nitrogen and nitrate-plus-nitrite nitrogen, a surrogate measure of total nitrogen, also showed a reduction of 29%. However, mean annual load of total residue increased by 15%. Despite significance at the wintering site, these water quality changes were not statistically detected at the outlet of the subbasin. In spite of the measureable improvement in downstream water quality, adoption of the studied BMP represented a net economic cost to the producer under the current management conditions at the site. Furthermore, there appeared a need for concurrent implementation of BMPs in the headwaters sub-basin to be able to register any detectable changes in water quality at its outlet.
Trophic Status Evaluation for 154 Lakes in Quebec, Canada: Monitoring and Recommendations
Authors: Cloutier Rosa Galvez , Sanchez Michelle
Published: May 2018

Based on chlorophyll a, total phosphorus, transparency (Secchi disk), and total nitrogen, 154 lakes located in southern regions of the Quebec province were classified according to their trophic status. Various classification methods were presented and discussed. The evaluation of existing relationships among quality parameters were established, and suggestions for priority actions and restoration initiatives were given. The ‘Reseau de surveillance de lacs’ of the Ministère de développement durable, environnement et parcs is considered as a very successful program that should be increasingly supported by the government. The program meets sustainable development principles in watershed management. The results showed that although the majority of lakes surveyed were within optimal conditions (oligotrophic status), 22 lakes required closer surveillance and more effective nutrient control measures.
Modelling Nitrification of a Lagoon Effluent in Moving-Bed Biofilm Reactors
Authors: Houweling Dwight , Monette Frédéric , Millette Louise , Comeau Yves
Published: May 2018

A pilot study was performed at the Sainte-Julie wastewater treatment plant to evaluate the potential of using the Moving-Bed biofilm reactor (MBBR) process for removing BOD5 (5-day biochemical oxygen demand) and ammonia nitrogen in a two-stage process at the exit of the first lagoon. Nitrification was observed in the first reactor at rates similar to those reported in the literature for a similar biomass carrier when bulk liquid dissolved oxygen (DO) concentrations were 6 g of O2 per m3. Nitrification rates were significantly reduced when DO was reduced to 3 g of O2 per m3. DO concentrations were maintained at 6 g of O2 per m3 in the second reactor, and nitrification rates comparable to those reported in the literature were observed for a temperature range of 3 to 16°C. An empirical DO-limited model was validated for the first reactor while in the second reactor nitrification was found to be either DO limited or total-ammonia-nitrogen limited, depending on nitrification rates in the upstream reactor. The DO-limited model predicts that the MBBR process is more sensitive to organic load than it is to temperature. A commercially available numerical model was calibrated to the results of the pilot study. Model results indicate that detachment and attachment rates play an important role in determining nitrification rates in the biofilm. Similar nitrification rates in an MBBR system installed upstream and downstream from an aerated lagoon in winter conditions were predicted using the empirical DO-limited model.
Air-Water Oxygen Transfer with Multiple Plunging Jets
Authors: Deswal Surinder , Verma Dharam Veer Singh
Published: May 2018

Despite numerous works reporting on oxygen transfer by plunging jets, few studies have been carried out on multiple plunging jets. In this paper, the volumetric oxygen-transfer coefficient and oxygen-transfer efficiency of multiple plunging jets in a pool of water for different configurations in terms of varying numbers of jets and jet diameters were studied experimentally. This research suggests that the volumetric oxygen-transfer coefficient and oxygen-transfer efficiency of the multiple plunging jets for air/water systems were significantly higher than those of a single plunging jet for same flow area and other similar conditions. A relationship between the volumetric oxygen-transfer coefficient and jet parameters is also proposed. The suggested relationship predicted the volumetric oxygen-transfer coefficient for single and multiple plunging jet(s) within a scatter of ±15%.
Modeling and Assessment of the Produced Water Discharges from Offshore Petroleum Platforms
Authors: Chen Zhi , Zhao Lin , Lee Kenneth , Hannath Charles
Published: May 2018

There has been a growing interest in assessing the risks to the marine environment from produced water discharges. This study describes the development of a numerical approach, POM-RW, based on an integration of the Princeton Ocean Model (POM) and a Random Walk (RW) simulation of pollutant transport. Specifically, the POM is employed to simulate local ocean currents. It provides three-dimensional hydrodynamic input to a Random Walk model focused on the dispersion of toxic components within the produced water stream on a regional spatial scale. Model development and field validation of the predicted current field and pollutant concentrations were conducted in conjunction with a water quality and ecological monitoring program for an offshore facility located on the Grand Banks of Canada. Results indicate that the POM-RW approach is useful to address environmental risks associated with the produced water discharges.
Disinfection By-Products (DBPs) in Drinking Water from Eight Systems Using Chlorine Dioxide
Authors: Rodriguez Rocio Aranda , Koudjonou Boniface , Jay Brian , LeBel Guy L. , Benoit Frank M.
Published: May 2018

A study was initiated to determine the presence of organic disinfection by-products (DBPs) in drinking water treated with chlorine dioxide (ClO2). One potential advantage for the use of ClO2 as a disinfectant is the reduced formation of organic DBPs. Generally, water treated with ClO2 produces chlorite and chlorate ions, but there is limited information regarding the presence of halogenated organic DBPs. Eight systems that use chlorine dioxide as part of the water disinfection process were investigated. All systems in this study applied chlorine as a primary or secondary disinfectant in addition to ClO2. To evaluate seasonal and spatial variations, water samples were collected during cold water (February to March 2003) and warm water (July to August 2003) months at five sites for each system: raw water (R, before treatment), treated water (T, after treatment but before distribution), and three points along the same distribution line (D1, D2, D3). Sampling and analysis were conducted according to established protocols. A suite of 27 organic DBPs including haloacetic acids (HAA), trihalomethanes (THM), haloacetonitriles (HAN), haloketones, haloacetaldehydes (HA), chloropicrin, and cyanogen chloride were examined. In addition, the concentration of oxyhalides (chlorite and chlorate ions) and auxiliary parameters were also determined.

Chlorite was found in treated (T) and distributed (Dx) waters. The chlorite ion levels decreased along the distribution system (T > D1 > D2 > D3). At T sites, the levels ranged from 10 to 870 µg/L (winter), and from 300 to 1,600 µg/L (summer). Chlorite was not found in treated or distributed water in the one system that used ozone. Chlorate ion levels ranged from 20 to 310 µg/L (winter), and 80 to 318 µg/L (summer). Chlorate levels remained relatively constant throughout the distribution system. THM and eight HAA (HAA8) accounted for approximately 85% of the total DBPs (wt/wt) analyzed, followed by total HA (up to 7%) and HAN (3%). THM in distributed water were found at concentrations between 1.8 and 30.6 µg/L (winter), and 3.3 and 93.6 µg/L (summer). For HAA8, the levels ranged from 13 to 52 µg/L (winter), and 16 to 111 µg/L (summer). Chloral hydrate ranged from 0.2 to 5.2 µg/L (winter), and 0.4 to 12.2 µg/L (summer). The temporal and spatial variations observed in previous studies were confirmed in the current study as well.
Impact of Particulate Matter on Distribution System Disinfection Efficacy
Authors: Wojcicka Linda , Baxter Carole , Hofmann Ron
Published: May 2018

Microorganisms have been shown to survive drinking water disinfection and remain viable in disinfected waters despite the presence of disinfectant residuals. This may be partially attributed to protection by particulate matter. The aim of this study was to determine the effects of the presence of particulate matter on disinfection kinetics. Sphingomonas paucimobilis ATCC 10829 and Helicobacter pylori ATCC 43504 were used in inactivation experiments in the presence and absence of soil, corrosion, and wastewater particles. The results showed that the presence of such particles tended to inhibit chlorine and monochloramine inactivation, although the magnitude of the impact under the conditions tested was small (e.g., 1-log reduction in inactivation for several minutes of contact time in the presence of less than 1 mg/L of disinfectant).
Potato Land Use and Nitrate Runoff Characteristics of Two Subcatchments of the Wilmot River Watershed, Prince Edward Island (PEI), Canada
Authors: Edwards Linnell , Burney Jack R. , Brimacombe Michael , MacRae Allan H.
Published: May 2018

Two subcatchments in the upper reaches of an arable watershed in central Prince Edward Island (PEI), farmed mostly to potatoes (in rotation), were monitored year-round for nitrate runoff. Land management inventories were done every fall and spring and assessed against nitrate runoff through regression analysis for the period 1991 to 2004. Nitrate concentration (averaging approximately 7 mg L-1 over 14 years) in the outflow varied considerably yearly (standard deviation: 2.76) and monthly (standard deviation: 3.43), and exceeded quality guidelines (of 13 mg L-1) for aquatic life in freshwaters at about a 6% frequency, averaging a nitrate-dollar loss of $1.70 per hectare per year.
Quantification of Plant Sterols in Pulp and Paper Mill Effluents
Authors: Mahmood-Khan Zahid , Hall Eric R.
Published: May 2018

Pulp and paper mill effluents (PPMEs) may contain high levels of otherwise naturally occurring organic pollutants such as plant sterols, which are suspected endocrine disrupting chemicals. Exposure to such chemicals may cause various physiological and morphological abnormalities that have been reported in the fish and other aquatic life inhabiting PPME receiving waters. Plant sterols, or phytosterols, form a constituent of wood extractives that may be released into the effluents during the pulping and paper making processes. Isolation and analysis of sterols from the complex mixture of PPMEs is challenging and standard analytical protocols do not exist. The need for having a reliable method for analyzing a particular environmental contaminant such as plant sterols cannot be overemphasized. In the present study a technique was modified for reliable analysis of PPME sterols. The technique involves liquid-liquid extractions using methyl-t-butyl ether and trimethyl-silylation derivatizations of the extracted sterols. Identification and quantification of the PPME sterols were accomplished by gas chromatography and mass spectrometry. Analytical problems were resolved by conducting multiple extractions, drying the sterol extracts, and redissolving and silylating the extracts at an increased derivatization temperature of 70°C. This shortened the suggested incubation period from 12 to 4 h. The modified technique offered improved method sensitivity and reproducibility, and successfully quantified campesterol, β-sitosterol, β-sitostanol, stigmasterol, stigmastanol, cholesterol, and ergosterol in PPMEs. Primary and secondary treated PPMEs analyses suggested 800 ± 190 µg/L total sterols in primary effluents, and 211 ± 90 µg/L in biologically treated final effluents. β-Sitosterol, β-sitostanol, and campesterol alone accounted for about 80% of the total sterols. A general comparison of the sterols in primary and secondary effluents suggested about 73% removal across the secondary treatment systems sampled.
Study on the Performance of an Anoxic Biotrickling Filter for the Removal of Hydrogen Sulphide from Biogas
Authors: Soreanu Gabriela , Falletta Patricia , Béland Michel , Edmonson Kara , Seto Peter
Published: May 2018

The paper presents aspects related to the performance of an anoxic biotrickling filter designed for hydrogen sulphide (H2S) removal from biogas. In this process, nitrate was supplied through a nutrient solution as an electron acceptor for anoxic growth of H2S-oxydizing microorganisms. The biotrickling filter's packing media consisted of a layer of plastic fibres over volcanic rocks in a ratio 0.78:1 by volume. The total volume of packing media was 0.014 m3. Several H2S loading rates (IL) were tested under continuous dynamic conditions, ranging between 20 and 550 g of H2S feed/(m3bed·day). Maximum process performance (>95%) was observed for IL ranging up to approximately 300 g of H2S feed/(m3bed·day). The degradation of hydrogen sulphide occurred with the formation of both sulphate and elemental sulphur, their formation ratio being dependent on H2S loading rate. Elemental sulphur was found to be the dominant degradation product, particularly at IL > 96.18 g of H2S feed/(m3bed·day). The use of two biotrickling filters in series was also tested, and a significant improvement in process performance was observed. This technology allows simple operation with low maintenance and has the potential for sulphur recovery.