69 results on '"Michèle Prévost"'
Search Results
2. Locating illicit discharges in storm sewers in urban areas using multi-parameter source tracking: Field validation of a toolbox composite index to prioritize high risk areas
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Martine Lanoue, Mounia Hachad, Michèle Prévost, Richard Villlemur, Sébastien Sauvé, Sung Vo Duy, and Sarah Dorner
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Environmental Engineering ,Sewage ,Outfall ,Stormwater ,Storm ,Wastewater ,Pollution ,Feces ,Water Quality ,Sewerage ,Escherichia coli ,Environmental Chemistry ,Environmental science ,Humans ,Storm drain ,Water quality ,Sanitary sewer ,Water resource management ,Waste Management and Disposal ,Environmental Monitoring - Abstract
In urban areas served by separate sewerage systems, illicit connections to the storm drain system from residences or commercial establishments are frequent whether these misconnections were made accidentally or deliberately. As a result, untreated and contaminated wastewater enters into storm sewers leading to pollution of receiving waters and non-compliance with water quality standards. Typical procedures for detecting illicit connections to the storm sewer system are time consuming and expensive, especially in a highly urbanised area. In this study, we investigated the use of human wastewater micropollutants WWMPs (caffeine, theophylline, and carbamazepine) and advanced DNA molecular markers (human specific Bacteroides HF183 and mitochondrial DNA) as anthropogenic tracers in order to assist identifying potential cross connections. Water samples from storm outfalls and storm sewer pipes in three urban subcatchments were collected in dry weather from 2013 to 2018. All samples contained various concentrations of these markers especially HF183, caffeine and theophylline, suggesting that the storm pipe system studied is widely contaminated by sanitary sewers. None of the traditional indicators or markers tested is sufficient alone to determine the origin of fecal pollution. In a highly urbanised area, the combination of at least three specific human markers was needed in order to locate the residential section with likely misconnections. The human specific Bacteroides HF183, and theophylline appeared to be the most effective markers (along with E. coli) of crossconnections, whereas carbamazepine can provide an indication of contamination through sanitary sewer exfiltration. A composite sewer cross-connection index was developed, and eight misconnected houses were identified and corrected. The index approach enables the reduction of false positives that could lead to expensive interventions to identify cross-connected households. The results show the multiparameter source tracking toolbox as an effective method to identify sewer cross connections for sustainable storm water management.
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- 2021
3. Temporal variability of parasites, bacterial indicators, and wastewater micropollutants in a water resource recovery facility under various weather conditions
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Milad Taghipour, Jane Bonsteel, Samira Tolouei, Sung Vo Duy, Sébastien Sauvé, Sarah Dorner, Laurène Autixier, Michèle Prévost, and Jean-Baptiste Burnet
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Environmental Engineering ,0208 environmental biotechnology ,Cryptosporidium ,Indicator bacteria ,Sewage ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,parasitic diseases ,Escherichia coli ,medicine ,Animals ,Parasites ,Sanitary sewer ,Weather ,Waste Management and Disposal ,Effluent ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Bacteria ,biology ,business.industry ,Ecological Modeling ,Giardia ,Clostridium perfringens ,biology.organism_classification ,Pollution ,020801 environmental engineering ,Environmental chemistry ,Water Resources ,Environmental science ,business - Abstract
Wastewater discharges lead to the deterioration of receiving waters through treated effluents and by-passes, combined and sanitary sewer overflows, and cross-connections to storm sewers. The influence of weather conditions on fecal indicator bacteria, pathogens and wastewater micropollutants on raw and treated sewage concentrations has not been extensively characterized. However, such data are needed to understand the effects of by-pass discharges and incomplete treatment on receiving waters. A water resource recovery facility was monitored for pathogenic parasites (Cryptosporidium oocysts, Giardia cysts), fecal indicator bacteria (Escherichia coli, Clostridium perfringens), and wastewater micropollutants (caffeine, carbamazepine, 2-hydroxycarbamazepine, acesulfame, sucralose, and aspartame) during 6 events under different weather conditions (snowmelt and trace to 32 mm 2-day cumulative precipitation). Greater intra- and inter-event variability was observed for Giardia, E. coli and C. perfringens than for studied WWMPs. Even with the addition of inflow and infiltration, daily variations dominated concentration trends. Thus, afternoon and early evening were identified as critical times with regards to high concentrations and flows for potential by-pass discharges. Peak concentrations of Giardia were observed during the June wet weather event (1010 cysts/L), with the highest flowrates relative to the mean monthly flowrate. Overall, Giardia, E. coli and C. perfringens concentrations were positively correlated with flowrate (R 0.32, p 0.05). In raw sewage samples collected under high precipitation conditions, caffeine, carbamazepine and its metabolite 2-OH-carbamazepine were significantly correlated (p 0.05) with Giardia, E. coli, and C. perfringens demonstrating that they are useful markers for untreated sewage discharges. Data from the study are needed for estimating peak concentrations discharged from wastewater sources in relation to precipitation or snowmelt events.
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- 2019
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4. Occurrence and seasonal distribution of steroid hormones and bisphenol A in surface waters and suspended sediments of Quebec, Canada
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Ken Goeury, Gabriel Munoz, Sung Vo Duy, Michèle Prévost, and Sébastien Sauvé
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Global and Planetary Change ,Environmental Chemistry ,Environmental Science (miscellaneous) - Published
- 2022
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5. Innovative approach and design for environmental protection from arising threats
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Armando Di Nardo, Vasiliki Manakou, Dino Musmarra, Michèle Prévost, Enrico Creaco, Di Nardo, A., Creaco, E., Manakou, V., Musmarra, D., and Prevost, M.
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Conservation of Natural Resources ,Health, Toxicology and Mutagenesis ,MEDLINE ,Environmental Chemistry ,Environmental science ,Ecotoxicology ,General Medicine ,Pollution ,Environmental planning - Published
- 2021
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6. Faucet aerator design influences aerosol size distribution and microbial contamination level
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Eric Déziel, Dominique Charron, Marie-Ève Benoit, Emilie Bédard, Etienne Robert, Michèle Prévost, and Antonella Succar
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Aerosols ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Fouling ,Particle number ,Environmental engineering ,010501 environmental sciences ,01 natural sciences ,Pollution ,Airborne transmission ,6. Clean water ,Aerosol ,Disease Outbreaks ,13. Climate action ,Pseudomonas aeruginosa ,Environmental Chemistry ,Environmental science ,Particle ,Particle size ,Aeration ,Particle Size ,Waste Management and Disposal ,Aerosolization ,0105 earth and related environmental sciences - Abstract
Faucet aerators have been linked to multiple opportunistic pathogen outbreaks in hospital, especially Pseudomonas aeruginosa, their complex structure promoting biofilm development. The importance of bacteria aerosolization by faucet aerators and their incidence on the risk of infection remain to be established. In this study, ten different types of aerators varying in complexity, flow rates and type of flow were evaluated in a controlled experimental setup to determine the production of aerosols and the level of contamination. The aerosol particle number density and size distribution were assessed using a particle spectrometer. The bacterial load was quantified with a 14-stage cascade impactor, where aerosol particles were captured and separated by size, then analysed by culture and flow cytometry. The water was seeded with Pseudomonas fluorescens as a bacterial indicator. Aerosol particle size and mean mass distribution varied depending on the aerator model. Devices without aeration or with laminar flow produced the lowest number and mass of aerosol particles when measured with spectrometry. Models with aeration displayed wide differences in their potential production of aerosol particles. A new aerator with a low flow, no air inlet in its structure, and a spray stream produced 12 to 395 times fewer aerosol particles containing bacteria. However, the impact of low flow on biofilm development and incorporation of pathogens should be further investigated. Repeated use of aerators resulted in fouling which increased the quantity of bacteria released through aerosol particles. An in-depth mechanical cleaning including complete dismantling of the aerator was required to recover initial performances. Aerators should be selected to minimize aerosol production, considering the ease of maintenance and the main water usage at each sink. Low flow aerators produced a lower number of contaminated aerosol particles when new but may be more susceptible to fouling and quickly lose their initial advantage.
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- 2020
7. Limitations of E. coli Monitoring for Confirmation of Contamination in Distribution Systems due to Intrusion under Low Pressure Conditions in the Presence of Disinfectants
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Marie-Claude Besner, Gabrielle Ebacher, Michèle Prévost, and Fatemeh Hatam
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010504 meteorology & atmospheric sciences ,0208 environmental biotechnology ,Geography, Planning and Development ,02 engineering and technology ,Management, Monitoring, Policy and Law ,Contamination ,01 natural sciences ,020801 environmental engineering ,Distribution system ,Intrusion ,Environmental chemistry ,Escherichia coli detection ,Environmental science ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering - Abstract
Low/negative pressure events that increase the risk of contaminant intrusion may take place in distribution systems and may become more common in ageing infrastructure. Guidance on whether ...
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- 2020
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8. Near real-time notification of water quality impairments in recreational freshwaters using rapid online detection of β-D-glucuronidase activity as a surrogate for Escherichia coli monitoring
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Michèle Prévost, Carole Fleury, Jean-Baptiste Burnet, Margot Cazals, Sarah Dorner, Pierre Servais, Rebecca Stott, and François Proulx
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Environmental Engineering ,010504 meteorology & atmospheric sciences ,β d glucuronidase ,Fresh Water ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,Enzymatic assays ,Environnement et pollution ,Feces ,Early-warning systems ,Environmental health ,Water Quality ,medicine ,Escherichia coli ,Environmental Chemistry ,Faecal pollution ,14. Life underwater ,Waste Management and Disposal ,Recreation ,0105 earth and related environmental sciences ,Confusion ,Glucuronidase ,Public health ,Faecal indicator ,Quebec ,Waterborne diseases ,Beach action value ,medicine.disease ,β-D-glucuronidase ,Pollution ,6. Clean water ,3. Good health ,Technologie de l'environnement, contrôle de la pollution ,13. Climate action ,Environmental science ,Traitement des déchets ,Water quality ,medicine.symptom ,Water Microbiology ,Decision making ,Environmental Monitoring ,New Zealand - Abstract
Waterborne disease outbreaks associated with recreational waters continue to be reported around the world despite existing microbiological water quality monitoring frameworks. Most regulations resort to the use of culture-based enumeration of faecal indicator bacteria such as Escherichia coli to protect bathers from gastrointestinal illness risks. However, the long sample-to-result time of standard culture-based assays (minimum 18–24 h) and infrequent regulatory sampling (weekly or less) do not enable detection of episodic water quality impairments and associated public health risks. The objective of this study was to assess the suitability of an autonomous online technology measuring β-D-glucuronidase (GLUC) activity for near real-time monitoring of microbiological water quality in recreational waters and for the resulting beach management decisions. GLUC activity and E. coli concentrations were monitored at three freshwater sites in Quebec, Canada (sites Qc1-3) and one site in New Zealand (site NZ) between 2016 and 2018. We found site-dependent linear relationships between GLUC activity and E. coli concentrations and using confusion matrices, we developed site-specific GLUC activity beach action values (BAVs) matching the regulatory E. coli BAVs. Using the regulatory E. coli BAV as the gold standard, rates of false alarms (unnecessary beach advisories using GLUC activity BAV) and failures to act (failure to trigger advisories using GLUC activity) ranged between 0 and 32% and between 3 and 10%, respectively, which is comparable to the rates reported in other studies using qPCR-defined BAVs. However, a major benefit of the autonomous enzymatic technology is the real-time reporting of threshold exceedances, while temporal trends in GLUC activity can assist in understanding the underlying dynamics of faecal pollution and potential health risks. Our study is the first to describe the applicability of online near real-time monitoring of microbiological water quality as a tool for improved beach management and public health protection., SCOPUS: ar.j, info:eu-repo/semantics/published
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- 2020
9. The Effects of Ferric Sulfate (Fe2(SO4)3) on the Removal of Cyanobacteria and Cyanotoxins: A Mesocosm Experiment
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Michèle Prévost, Hana Trigui, Kim Thien Nguyen Le, Sarah Dorner, Eyerusalem Goitom, and Sébastien Sauvé
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Cyanobacteria ,Health, Toxicology and Mutagenesis ,Toxicology ,medicine.disease_cause ,Ferric Compounds ,cyanobacteria ,cyanobacterial blooms ,Article ,Mesocosm ,chemistry.chemical_compound ,Water column ,cyanotoxins ,medicine ,coagulation ,Sulfate ,Cyanobacteria Toxins ,biology ,Toxin ,microcystins ,water treatment ,biology.organism_classification ,Anti-Bacterial Agents ,Lakes ,chemistry ,Environmental chemistry ,Medicine ,Ferric ,Water treatment ,Cylindrospermopsin ,mesocosms ,ferric sulfate ,medicine.drug - Abstract
Cyanobacterial blooms are a global concern. Chemical coagulants are used in water treatment to remove contaminants from the water column and could potentially be used in lakes and reservoirs. The aims of this study was to: 1) assess the efficiency of ferric sulfate (Fe2(SO4)3) coagulant in removing harmful cyanobacterial cells from lake water with cyanobacterial blooms on a short time scale, 2) determine whether some species of cyanobacteria can be selectively removed, and 3) determine the differential impact of coagulants on intra- and extra-cellular toxins. Our main results are: (i) more than 96% and 51% of total cyanobacterial cells were removed in mesocosms with applied doses of 35 mgFe/L and 20 mgFe/L, respectively. Significant differences in removing total cyanobacterial cells and several dominant cyanobacteria species were observed between the two applied doses, (ii) twelve microcystins, anatotoxin-a (ANA-a), cylindrospermopsin (CYN), anabaenopeptin A (APA) and anabaenopeptin B (APB) were identified. Ferric sulfate effectively removed the total intracellular microcystins (greater than 97% for both applied doses). Significant removal of extracellular toxins was not observed after coagulation with both doses. Indeed, the occasional increase in extracellular toxin concentration may be related to cells lysis during the coagulation process. No significant differential impact of dosages on intra- and extra-cellular toxin removal was observed which could be relevant to source water applications where optimal dosing is difficult to achieve.
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- 2021
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10. The distribution dynamics and desorption behaviour of mobile pharmaceuticals and caffeine to combined sewer sediments
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Sébastien Sauvé, S. Vo Duy, Sarah Dorner, Hans Peter H. Arp, Michèle Prévost, M. Hajj-Mohamad, and H. Darwano
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Geologic Sediments ,Environmental Engineering ,0208 environmental biotechnology ,Stormwater ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,01 natural sciences ,Caffeine ,Desorption ,medicine ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Suspended solids ,Chemistry ,Ecological Modeling ,Sorption ,Pollution ,6. Clean water ,020801 environmental engineering ,Dilution ,Environmental chemistry ,Flushing ,Combined sewer ,medicine.symptom - Abstract
Pharmaceuticals are discharged to the environment from wastewater resource recovery facilities, sewer overflows, and illicit sewer connections. To understand the fate of pharmaceuticals, there is a need to better understand their sorption dynamics to suspended sediments (SS) and settled sediments (StS) in sewer systems. In this study, such sorption dynamics to both SS and StS were assessed using a batch equilibrium method under both static and dynamic conditions. Experiments were performed with natively occurring and artificially modified concentrations of sewer pharmaceuticals (acetaminophen, theophylline, carbamazepine, and a metabolite of carbamazepine) and caffeine. Differences in apparent distribution coefficients, Kd,app, between SS and StS were related to differences in their organic carbon (OC) content, and the practice of artificially modifying the concentration. Kd,app values of modified contaminant concentrations and high OC sediments were substantially higher. Pseudo-second order desorption rates for these mobile compounds were also quantified. Successive flushing events to simulate the addition of stormwater to sewer networks revealed that aqueous concentrations would not necessarily decrease, because the added water will rapidly return to equilibrium concentrations with the sediments. Sorption and desorption kinetics must be considered in addition to dilution, to avoid underestimating the influence of dilution on concentrations of pharmaceuticals discharged to the environment.
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- 2017
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11. Using Advanced Spectroscopy and Organic Matter Characterization to Evaluate the Impact of Oxidation on Cyanobacteria
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Michèle Prévost, Sigrid Peldszus, Caitlin M. Glover, Saber Moradinejad, Benoit Barbeau, Arash Zamyadi, Sarah Dorner, Tahere Zadfathollah Seighalani, and J. Mailly
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Ozone ,oxidation ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,lcsh:Medicine ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,Toxicology ,Cell morphology ,Cyanobacteria ,01 natural sciences ,Article ,chemistry.chemical_compound ,Potassium Permanganate ,Microcystis ,Dissolved organic carbon ,Chlorine ,Organic matter ,Water Pollutants ,Hydrogen peroxide ,intracellular organic matter ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,cell morphology ,Microscopy ,biology ,Spectrum Analysis ,lcsh:R ,enhanced darkfield microscopy/hyperspectral imaging ,Hydrogen Peroxide ,biology.organism_classification ,Flow Cytometry ,Oxidants ,6. Clean water ,Bacterial Load ,020801 environmental engineering ,Potassium permanganate ,Lakes ,chemistry ,13. Climate action ,Environmental chemistry ,Oxidation-Reduction - Abstract
Drinking water treatment plants throughout the world are increasingly facing the presence of toxic cyanobacteria in their source waters. During treatment, the oxidation of cyanobacteria changes cell morphology and can potentially lyse cells, releasing intracellular metabolites. In this study, a combination of techniques was applied to better understand the effect of oxidation with chlorine, ozone, potassium permanganate, and hydrogen peroxide on two cell cultures (Microcystis, Dolichospermum) in Lake Champlain water. The discrepancy observed between flow cytometry cell viability and cell count numbers was more pronounced for hydrogen peroxide and potassium permanganate than ozone and chlorine. Liquid chromatography with organic carbon and nitrogen detection was applied to monitor the changes in dissolved organic matter fractions following oxidation. Increases in the biopolymer fraction after oxidation with chlorine and ozone were attributed to the release of intracellular algal organic matter and/or fragmentation of the cell membrane. A novel technique, Enhanced Darkfield Microscopy with Hyperspectral Imaging, was applied to chlorinated and ozonated samples. Significant changes in the peak maxima and number of peaks were observed for the cell walls post-oxidation, but this effect was muted for the cell-bound material, which remained relatively unaltered.
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- 2019
12. Identification of Factors Affecting Bacterial Abundance and Community Structures in a Full-Scale Chlorinated Drinking Water Distribution System
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Emilie Bédard, Vanessa C. F. Dias, Michèle Prévost, Audrey-Anne Durand, and Philippe Constant
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0301 basic medicine ,lcsh:Hydraulic engineering ,building plumbing ,bacterial community structure ,Geography, Planning and Development ,chlorine residual ,010501 environmental sciences ,Aquatic Science ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,lcsh:Water supply for domestic and industrial purposes ,Tap water ,lcsh:TC1-978 ,Betaproteobacteria ,residence time ,0105 earth and related environmental sciences ,Water Science and Technology ,drinking water distribution system ,lcsh:TD201-500 ,biology ,Planctomycetes ,Community structure ,Alphaproteobacteria ,Bacteroidetes ,high-throughput sequencing ,biology.organism_classification ,6. Clean water ,030104 developmental biology ,Environmental chemistry ,Environmental science ,Water quality ,Proteobacteria - Abstract
Disentangling factors influencing suspended bacterial community structure across distribution system and building plumbing provides insight into microbial control strategies from source to tap. Water quality parameters (residence time, chlorine, and total cells) and bacterial community structure were investigated across a full-scale chlorinated drinking water distribution system. Sampling was conducted in treated water, in different areas of the distribution system and in hospital building plumbing. Bacterial community was evaluated using 16S rRNA gene sequencing. Bacterial community structure clearly differed between treated, distributed, and premise plumbing water samples. While Proteobacteria (60%), Planctomycetes (20%), and Bacteroidetes (10%) were the most abundant phyla in treated water, Proteobacteria largely dominated distribution system sites (98%) and taps (91%). Distributed and tap water differed in their Proteobacteria profile: Alphaproteobacteria was dominant in distributed water (92% vs. 65% in tap waters), whereas Betaproteobacteria was most abundant in tap water (18% vs. 2% in the distribution system). Finally, clustering of bacterial community profiles was largely explained by differences in chlorine residual concentration, total bacterial count, and water residence time. Residual disinfectant and hydraulic residence time were determinant factors of the community structure in main pipes and building plumbing, rather than treated water bacterial communities.
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- 2019
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13. Lead Levels at the Tap and Consumer Exposure from Legacy and Recent Lead Service Line Replacements in Six Utilities
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Jeff Swertfeger, Abby Spielmacher, Laurent Laroche, Graham A. Gagnon, Dan Huggins, Elise Deshommes, Ian Douglas, Benjamin F. Trueman, and Michèle Prévost
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Water pollutants ,Drinking Water ,0208 environmental biotechnology ,Publications ,02 engineering and technology ,General Chemistry ,Environmental exposure ,Environmental Exposure ,010501 environmental sciences ,01 natural sciences ,020801 environmental engineering ,Toxicology ,Lead ,Child, Preschool ,Environmental Chemistry ,Environmental science ,Humans ,Lead (electronics) ,Child ,Service line ,Water Pollutants, Chemical ,0105 earth and related environmental sciences ,Probability - Abstract
Profile, regulatory, and investigative sampling were completed in six utilities to study the impact of partial and full lead service line replacements (LSLRs) on water lead levels (WLLs) and consumer's exposure. As compared to households with no replacement, lead release after partial LSLR (PLSLR) was generally greater in the short term (3-50 days), and comparable or lower in the medium (2 years) and long-term (2 years). This was mainly explained by insufficient time elapsed to stabilize scales after disturbances to the service line. One utility showed sustained lead release over 18 months after PLSLR. Moreover, the reduction in WLLs was small when analyzing results for the same households. As a comparison, full LSLR decreased WLLs drastically and immediately. The occurrence of low (0-5 μg/L) to high (≥50 μg/L) WLLs in the profiles varied between households and reflected the variability of exposure among households in the same system. Using this probability of occurrence, the distribution of WLLs of exposure was estimated for households with or without a PLSLR, and used to model young children blood lead levels (BLLs) for both groups of households. The range of modeled BLLs decreased slightly for households with PLSLR, but still overlapped the range estimated for households with no replacement. This analysis suggests that, in a system, PLSLRs do not reduce young children blood lead levels except in a fraction of households.
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- 2018
14. Adsorption characteristics of multiple microcystins and cylindrospermopsin on sediment: Implications for toxin monitoring and drinking water treatment
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Sébastien Sauvé, Michèle Prévost, Ehsan Maghsoudi, Sarah Dorner, and Sung Vo Duy
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Cyanobacteria ,Geologic Sediments ,Langmuir ,Microcystins ,Bacterial Toxins ,0207 environmental engineering ,02 engineering and technology ,Microcystin ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Water Purification ,chemistry.chemical_compound ,Alkaloids ,Adsorption ,Desorption ,Freundlich equation ,Uracil ,020701 environmental engineering ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Chromatography ,Cyanobacteria Toxins ,biology ,Drinking Water ,biology.organism_classification ,6. Clean water ,Lakes ,chemistry ,13. Climate action ,Environmental chemistry ,Marine Toxins ,Water treatment ,Cylindrospermopsin ,Water Pollutants, Chemical - Abstract
Adsorption of mixtures of cyanotoxins onto sediment as a dominant mechanism in the elimination of cyanotoxins from the aqueous phase has not been extensively investigated. The aim of this study was to investigate adsorption and desorption behavior of six microcystins including microcystin (MC)-LR, RR, YR, LY, LW and LF and cylindrospermopsin (CYN) on natural sediment. Freundlich and Langmuir isotherms could be fitted for MC-LR, RR, YR and CYN. Sorption kinetics showed immediate rapid adsorption for all cyanotoxins: CYN, MCLW and MCLF were adsorbed 72.6%, 56.7% and 55.3% respectively within 2 h. Results of desorption experiments demonstrated that less than 9% of cyanotoxins desorbed from sediment within 96 h. Adsorption of cyanotoxins onto three fractionated sediments particles, clay-silt (
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- 2015
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15. Seasonal variations of steroid hormones released by wastewater treatment plants to river water and sediments: Distribution between particulate and dissolved phases
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Hadis Yarahmadi, Sung Vo Duy, Mounia Hachad, Sarah Dorner, Sébastien Sauvé, and Michèle Prévost
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Geologic Sediments ,Environmental Engineering ,0211 other engineering and technologies ,Sewage ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Waste Disposal, Fluid ,Rivers ,Environmental Chemistry ,Humans ,Gonadal Steroid Hormones ,Waste Management and Disposal ,Effluent ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,Suspended solids ,business.industry ,Drinking Water ,Quebec ,Particulates ,Pollution ,6. Clean water ,Waste treatment ,Wastewater ,13. Climate action ,Environmental chemistry ,Environmental science ,Sewage treatment ,Water treatment ,Steroids ,Seasons ,business ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Extensive environmental monitoring was conducted in an urban river impacted by multiple combined sewer overflows (CSOs) and wastewater treatment plant (WWTP) discharge points. Temporal and spatial distributions of dissolved and particulate steroids (progesterone (Prog), testosterone (Testo), medroxyprogesterone (MDRXY-Prog), levonorgestrel (Levo), norethindrone (Nore), estrone (E1), estradiol (E2), estriol (E3), and 17α-ethinylestradiol (EE2)) were investigated in sewage, WWTP effluents, receiving river water and sediments, and in drinking water plant (DWP) intakes. Steroids were detected in both dissolved and particulate phases with mean concentrations from 21ngL-1 to 389ngL-1 in raw sewage and from 10ngL-1 to 296ngL-1 in treated wastewater. The particle-associated steroids represented 0-82% of their total concentration as some steroids like E1 and E3 were detected only in the dissolved phase while MDRXY-Prog (81%), Nore (71%), and EE2 (>75%) were primarily detected in the particulate phase. Particle-associated steroids were detected in spring samples from river water with mean concentrations ranging from 5.4ngL-1 to 35.7ngL-1 compare to 3ngL-1 to 6.8ngL-1 in summer samples. Levels of particle-associated Testo, Nore, E2 and Levo in DWP intakes (406.2-13,149.1ngg-1) were similar to those found in raw sewage (336.6-7628.8ngg-1), indicating their persistence in the suspended phase from discharge points. Total steroids measured in sediments were in the range of 7-1213ngg-1, 5-25ngg-1, and 22-226ngg-1 in autumn, spring, and summer, respectively. Our findings confirm the presence and seasonal variation of a mixture of particle-associated steroids in drinking water sources. The presence of high concentrations of a mixture of particle-associated steroids in DWP intakes highlight the need for highly effective particle-removal processes to eliminate these recalcitrant compounds during drinking water production. Finally, the detected concentrations raise concerns about their potential environmental effects.
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- 2017
16. Cyanotoxin degradation activity and mlr gene expression profiles of a Sphingopyxis sp. isolated from Lake Champlain, Canada
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Ehsan Maghsoudi, Nathalie Fortin, Charles W. Greer, Sébastien Sauvé, Antoine Pagé, Sarah Dorner, Christine Maynard, Sung Vo Duy, and Michèle Prévost
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0301 basic medicine ,Microcystins ,Microcystin ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,Microbiology ,03 medical and health sciences ,Bacterial Proteins ,Gene expression ,Gene cluster ,Environmental Chemistry ,Gene ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,biology ,Public Health, Environmental and Occupational Health ,Quebec ,General Medicine ,Gene Expression Regulation, Bacterial ,Ribosomal RNA ,Cyanotoxin ,Hydrogen-Ion Concentration ,16S ribosomal RNA ,biology.organism_classification ,Sphingopyxis ,Sphingomonadaceae ,Lakes ,030104 developmental biology ,Biodegradation, Environmental ,chemistry ,Transcriptome ,Water Pollutants, Chemical - Abstract
A bacterium capable of degrading five microcystin (MC) variants, microcystin-LR, YR, LY, LW and LF at an initial total concentration of 50 μg l−1 in less than 16 hours was isolated from Missisquoi Bay, in the south of Quebec, Canada. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Sphingopyxis sp., designated strain MB-E. It was shown that microcystin biodegradation activity was reduced at acidic and basic pH values. Even though no biodegradation occurred at pH values of 5.05 and 10.23, strain MB-E was able to degrade MCLR and MCYR at pH 9.12 and all five MCs variants tested at pH 6.1. Genomic sequencing revealed that strain MB-E contained the microcystin degrading gene cluster, including the mlrA, mlrB, mlrC and mlrD genes, and transcriptomic analysis demonstrated that all of these genes were induced during the degradation of MCLR alone or in the mixture of all five MCs. This novel transcriptomic analysis showed that the expression of the mlr gene cluster was similar for MCLR alone, or the mixture of MCs, and appeared to be related to the total concentration of substrate. The results suggested that the bacterium used the same pathway for the degradation of all MC variants.
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- 2017
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17. Short- and Long-Term Lead Release after Partial Lead Service Line Replacements in a Metropolitan Water Distribution System
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Shokoufeh Nour, Elise Deshommes, Dominique Deveau, Michèle Prévost, and Laurent Laroche
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0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Distribution system ,Time frame ,Animal science ,Water Supply ,Environmental Chemistry ,Risk communication ,Lead (electronics) ,0105 earth and related environmental sciences ,Waste management ,Water pollutants ,Drinking Water ,Water ,General Chemistry ,Particulates ,020801 environmental engineering ,Term (time) ,Lead Poisoning ,Lead ,Environmental science ,Sanitary Engineering ,Service line ,Water Pollutants, Chemical - Abstract
Thirty-three households were monitored in a full-scale water distribution system, to investigate the impact of recent (2 yr) or old partial lead service line replacements (PLSLRs). Total and particulate lead concentrations were measured using repeat sampling over a period of 1-20 months. Point-of-entry filters were installed to capture sporadic release of particulate lead from the lead service lines (LSLs). Mean concentrations increased immediately after PLSLRs and erratic particulate lead spikes were observed over the 18 month post-PLSLR monitoring period. The mass of lead released during this time frame indicates the occurrence of galvanic corrosion and scale destabilization. System-wide, lead concentrations were however lower in households with PLSLRs as compared to those with no replacement, especially for old PLSLRs. Nonetheless, 61% of PLSLR samples still exceeded 10 μg/L, reflecting the importance of implementing full LSL replacement and efficient risk communication. Acute concentrations measured immediately after PLSLRs demonstrate the need for appropriate flushing procedures to prevent lead poisoning.
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- 2017
18. Evaluating rain gardens as a method to reduce the impact of sewer overflows in sources of drinking water
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Samuel Bolduc, Alain Mailhot, Martine Galarneau, Michèle Prévost, Sarah Dorner, Laurène Autixier, and Anne-Sophie Madoux-Humery
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Hydrology ,Conservation of Natural Resources ,geography ,Environmental Engineering ,geography.geographical_feature_category ,Climate Change ,Drinking Water ,Rain ,Stormwater ,Drainage basin ,Gardening ,Wastewater ,Pollution ,Rain garden ,Environmental Chemistry ,Environmental science ,Combined sewer ,Precipitation ,Source water protection ,Surface runoff ,Waste Management and Disposal ,Environmental Monitoring - Abstract
The implications of climate change and changing precipitation patterns need to be investigated to evaluate mitigation measures for source water protection. Potential solutions need first to be evaluated under present climate conditions to determine their utility as climate change adaptation strategies. An urban drainage network receiving both stormwater and wastewater was studied to evaluate potential solutions to reduce the impact of combined sewer overflows (CSOs) in a drinking water source. A detailed hydraulic model was applied to the drainage basin to model the implementation of best management practices at a drainage basin scale. The model was calibrated and validated with field data of CSO flows for seven events from a survey conducted in 2009 and 2010. Rain gardens were evaluated for their reduction of volumes of water entering the drainage network and of CSOs. Scenarios with different levels of implementation were considered and evaluated. Of the total impervious area within the basin directly connected to the sewer system, a maximum of 21% could be alternately directed towards rain gardens. The runoff reductions for the entire catchment ranged from 12.7% to 19.4% depending on the event considered. The maximum discharged volume reduction ranged from 13% to 62% and the maximum peak flow rate reduction ranged from 7% to 56%. Of concern is that in-sewer sediment resuspension is an important process to consider with regard to the efficacy of best management practices aimed at reducing extreme loads and concentrations. Rain gardens were less effective for large events, which are of greater importance for drinking water sources. These practices could increase peak instantaneous loads as a result of greater in-sewer resuspension during large events. Multiple interventions would be required to achieve the objectives of reducing the number, total volumes and peak contaminant loads of overflows upstream of drinking water intakes.
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- 2014
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19. Wastewater micropollutants as tracers of sewage contamination: analysis of combined sewer overflow and stream sediments
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Sarah Dorner, H. Darwano, M. Hajj-Mohamad, Khadija Aboulfadl, H. Guérineau, Anne-Sophie Madoux-Humery, Sébastien Sauvé, and Michèle Prévost
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Geologic Sediments ,Chromatography ,Sewage ,Chemistry ,business.industry ,Extraction (chemistry) ,Public Health, Environmental and Occupational Health ,Sediment ,General Medicine ,Wastewater ,Management, Monitoring, Policy and Law ,Contamination ,Dilution ,Fecal coliform ,Limit of Detection ,Environmental chemistry ,Environmental Chemistry ,Combined sewer ,business ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
A sensitive method was developed to measure the sediment concentration of 10 wastewater micropollutants selected as potential sanitary tracers of sewage contamination and include: nonsteroidal anti-inflammatory drugs (acetaminophen - ACE and diclofenac - DIC), an anti-epileptic drug (carbamazepine - CBZ), a β-blocker (atenolol - ATL), a stimulant (caffeine - CAF), a bronchodilator (theophylline - THEO), steroid hormones (progesterone - PRO and medroxyprogesterone - MedP), an artificial sweetener (aspartame - APM) and personal care products (N,N-diethyl-3-methylbenzamide - DEET). Natural sediments (combined sewer overflow and stream sediments) were extracted by ultrasonic-assisted extraction followed by solid-phase extraction. Analyses were performed using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) using atmospheric pressure chemical ionisation in positive mode (APCI+) with a total analysis time of 4.5 min. Method detection limits were in the range of 0.01 to 15 ng g(-1) dry weight (dw) for the compounds of interest, with recoveries ranging from 75% to 156%. Matrix effects were observed for some compounds, never exceeding |±18%|. All results displayed a good degree of reproducibility and repeatability, with relative standard deviations (RSD) of less than 23% for all compounds. The method was applied to an investigation of stream and combined sewer overflow sediment samples that differed in organic carbon contents and particle size distributions. Acetaminophen, caffeine and theophylline (as confounded with paraxanthine) were ubiquitously detected at 0.13-22 ng g(-1) dw in stream bed sediment samples and 98-427 ng g(-1) dw in combined sewer overflow sediment samples. Atenolol (80.5 ng g(-1) dw) and carbamazepine (54 ng g(-1) dw) were quantified only in combined sewer overflow sediment samples. The highest concentrations were recorded for DEET (14 ng g(-1) dw) and progesterone (11.5 ng g(-1) dw) in stream bed and combined sewer overflow sediment samples, respectively. The ratio of concentration to its limit of detection (C : LOD) in sediments for a subset of compounds were compared to their C : LOD in water. In waters with a large capacity for dilution relative to fecal sources, the C : LOD ranges in sediments were greater than in water. Thus monitoring programs for fecal source tracking using wastewater micropollutants should consider sediment sampling, particularly for waters with highly diluted sources of fecal contamination.
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- 2014
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20. Assessing microbial risk through event-based pathogen loading and hydrodynamic modelling
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Ray Dewey, Thomas A. Edge, Michèle Prévost, Samira Tolouei, Milad Taghipour, William J. Snodgrass, Sarah Dorner, and Robert C. Andrews
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Environmental Engineering ,Wet weather ,010504 meteorology & atmospheric sciences ,Event based ,Cryptosporidium ,Context (language use) ,010501 environmental sciences ,Risk Assessment ,01 natural sciences ,Feces ,Rivers ,Microbial risk ,Escherichia coli ,Environmental Chemistry ,Source water protection ,Weather ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Ontario ,Hydrology ,Sewage ,biology ,Drinking Water ,Giardia ,Water Pollution ,biology.organism_classification ,Pollution ,6. Clean water ,Fecal coliform ,Lakes ,13. Climate action ,Hydrodynamics ,Water Resources ,Environmental science ,Water Microbiology ,Environmental Monitoring - Abstract
The aim of this study was to assess the variability of microbial risk associated with drinking water under various contaminant loading conditions in a drinking water source. For this purpose, a probabilistic-deterministic approach was applied to estimate the loadings of Cryptosporidium, Giardia, and Escherichia coli (E. coli) from fecal contamination sources during both dry and wet weather conditions. The relative importance of loads originating from various fecal contamination sources was also determined by a probabilistic approach. This study demonstrates that water resource recovery facilities were the dominant source of Giardia, yet rivers were more important with regards to Cryptosporidium. Estimated loadings were used as input to a three-dimensional hydrodynamic model of Lake Ontario; the fate and transport of microbial organisms were simulated at the influent of a drinking water intake. Discharge-based hydrodynamic modelling results were compared to observed concentrations. Simulated probability distributions of concentrations at the intake were used as an input to a quantitative microbial risk assessment (QMRA) model such that the variability of microbial risk in the context of drinking water could be examined. Depending on wind and currents, higher levels of fecal contamination reached the intake during wet weather loading scenarios. Probability distribution functions of Cryptosporidium, Giardia and E. coli concentrations at the intake were significantly higher during wet weather conditions when compared to dry conditions (p 0.05). For all contaminants studied, the QMRA model showed a higher risk during wet weather (over 1 order of magnitude) compared to dry weather conditions. When considering sewage by-pass scenarios, risks remained below 2.7 × 10
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- 2019
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21. Effect of temperature on oxidation kinetics of testosterone and progestogens by ozone
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Benoit Barbeau, Hadis Yarahmadi, Sung Vo Duy, Michèle Prévost, Arash Zamyadi, and Sébastien Sauvé
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Ozone ,Process Chemistry and Technology ,medicine.medical_treatment ,Medroxyprogesterone ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Steroid ,chemistry.chemical_compound ,Reaction rate constant ,020401 chemical engineering ,Wastewater ,chemistry ,Environmental chemistry ,Ultrapure water ,medicine ,Levonorgestrel ,0204 chemical engineering ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Biotechnology ,Hormone ,medicine.drug - Abstract
Increasing presence of endocrine disrupting compounds (EDCs) in water sources and their adverse health effects on aquatic life are major concerns for water utilities and authorities worldwide. The oxidation kinetics for degradation of ozone resistant steroid hormones were investigated to quantify their removal in natural water under varying water temperatures and pH. Studying effect of temperature on oxidation of these compounds is one of the novel aspects of this research. The fate of four progestogens (progesterone, medroxyprogesetrone, levonorgestrel, and norethindrone) and, for the first time, of the androgenic steroid testosterone, in the presence of ozone was measured at bench scale in ultrapure water, natural surface water and wastewater. The estimated second order constant rate for testosterone of 590±0.13 M−1s−1 was comparable to our estimates and previous reports for similar structure progesterone (444-601 M−1s−1) and medroxyprogesterone (532±0.04 M−1s−1) and significantly lower than for levonorgestrel (2233 M−1s−1) and norethindrone (2292 M−1s−1). For all compounds the second-order rate constants increased from 3 folds for norethindrone to 5.5 folds for progesterone with temperatures ranging from 5 to 35 °C. The required activation energy was estimated for the five selected steroids and ranged from 30 Kj mol−1 (norethindrone) to 39 Kj mol−1 (progesterone). The removal rates of the selected compounds were predicted in natural water and wastewater. Finally, we showed that ozonation using typical disinfection dosages (CtO3= 2 mg min L−1) were capable of removing 77% (progesterone) to 99% (levonorgestrel) at 21 °C and even less (47% medroxyprogesterone to 96% norethindrone) at 5 °C of the selected compounds.
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- 2019
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22. Oxidation of Microcystis aeruginosa and Anabaena flos-aquae by ozone: Impacts on cell integrity and chlorination by-product formation
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Michèle Prévost, Lucila Adriani Coral, Fátima de Jesus Bassetti, Benoit Barbeau, Arash Zamyadi, and Flávio Rubens Lapolli
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Microcystis ,Environmental Engineering ,Ozone ,Lysis ,Haloacetic acids ,Halogenation ,chemistry.chemical_compound ,medicine ,Dolichospermum flos-aquae ,Microcystis aeruginosa ,Viability assay ,Waste Management and Disposal ,Cell damage ,Water Science and Technology ,Civil and Structural Engineering ,biology ,Anabaena ,Chemistry ,Ecological Modeling ,biology.organism_classification ,medicine.disease ,Pollution ,Carbon ,Disinfection ,Kinetics ,Environmental chemistry ,Oxidation-Reduction ,Trihalomethanes ,medicine.drug - Abstract
Pre-ozonation of cyanobacterial (CB) cells in raw water and inter-ozonation of settled water can cause CB cell damage. However, there is limited information about the level of lysis or changes in cell properties after ozonation, release of intracellular compounds and their contribution to the formation of disinfection by-products (DBPs). This study aims to: (1) assess the extent of the pre-ozonation effects on CB cell properties; (2) determine the CT (ozone concentration × detention time) values required for complete loss of cell viability; and (3) study the DBPs formation associated with the pre-ozonation of cyanobacterial cells in laboratorial suspensions. To these ends, both Microcystis aeruginosa and Anabaena flos-aquae suspensions were prepared at concentrations of 250,000 cells mL(-1) and 1,500,000 cells mL(-1) and were subjected to ozone dosages of 0.5, 2.0 and 4.0 mg L(-1) at pH 6 and pH 8. A quick and complete loss of viability was achieved for both CB species after exposure (CT) to ozone of
- Published
- 2013
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23. Species-dependence of cyanobacteria removal efficiency by different drinking water treatment processes
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Michèle Prévost, Sébastien Sauvé, Arash Zamyadi, Christian Bastien, Sarah Dorner, Donald Ellis, and Anouka Bolduc
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Environmental Engineering ,Microcystins ,Bacterial Toxins ,0207 environmental engineering ,Portable water purification ,02 engineering and technology ,010501 environmental sciences ,Biology ,Cyanobacteria ,Aphanizomenon ,Waste Disposal, Fluid ,01 natural sciences ,Water Purification ,Species Specificity ,Microcystis ,Raw water ,020701 environmental engineering ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Anabaena ,Drinking Water ,Ecological Modeling ,Quebec ,Environmental engineering ,Eutrophication ,Cyanotoxin ,biology.organism_classification ,Pollution ,6. Clean water ,Environmental chemistry ,Water treatment ,Filtration ,Environmental Monitoring ,Waste disposal - Abstract
Accumulation and breakthrough of several potentially toxic cyanobacterial species within drinking water treatment plants (DWTP) have been reported recently. The objectives of this project were to test the efficiency of different treatment barriers in cyanobacterial removal. Upon observation of cyanobacterial blooms, intensive sampling was conducted inside a full scale DWTP at raw water, clarification, filtration and oxidation processes. Samples were taken for microscopic speciation/enumeration and microcystins analysis. Total cyanobacteria cell numbers exceeded World Health Organisation and local alert levels in raw water (6,90,000 cells/mL). Extensive accumulation of cyanobacteria species in sludge beds and filters, and interruption of treatment were observed. Aphanizomenon cells were poorly coagulated and they were not trapped efficiently in the sludge. It was also demonstrated that Aphanizomenon cells passed through and were not retained over the filter. However, Microcystis, Anabaena, and Pseudanabaena cells were adequately removed by clarification and filtration processes. The breakthrough of non toxic cyanobacterial cells into DWTPs could also result in severe treatment disruption leading to plant shutdown. Application of intervention threshold values restricted to raw water does not take into consideration the major long term accumulation of potentially toxic cells in the sludge and the risk of toxins release. Thus, a sampling regime inside the plant adapted to cyanobacterial occurrence and intensity is recommended.
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- 2013
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24. The impact of drinking water, indoor dust and paint on blood lead levels of children aged 1–5 years in Montréal (Québec, Canada)
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Patrick Levallois, Julie St-Laurent, Denis Gauvin, Marilène Courteau, Michèle Prévost, Céline Campagna, France Lemieux, Shokoufeh Nour, Monique D'Amour, and Pat E Rasmussen
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Male ,Percentile ,Epidemiology ,blood lead levels ,Air pollution ,Toxicology ,medicine.disease_cause ,Lead poisoning ,children ,Tap water ,Environmental health ,medicine ,Humans ,Lead (electronics) ,business.industry ,Drinking Water ,Quebec ,Public Health, Environmental and Occupational Health ,Infant ,Dust ,Environmental Exposure ,Environmental exposure ,Odds ratio ,medicine.disease ,Pollution ,Confidence interval ,Logistic Models ,paint ,Lead ,Air Pollution, Indoor ,Child, Preschool ,Environmental chemistry ,Original Article ,Female ,business - Abstract
Lead is neurotoxic at very low dose and there is a need to better characterize the impact of domestic sources of lead on the biological exposure of young children. A cross-sectional survey evaluated the contribution of drinking water, house dust and paint to blood lead levels (BLLs) of young children living in old boroughs of Montréal (Canada). Three hundred and six children aged 1 to 5 years and currently drinking tap water participated in the study. For each participant, residential lead was measured in kitchen tap water, floor dust, windowsill dust and house paint and a venous blood sample was analyzed. Multivariate logistic regression was used to evaluate the association between elevated BLL in the children (≥ 75th percentile) and indoor lead contamination by means of odds ratios (OR) using 95% confidence intervals (CI). There was an association between BLL ≥75th percentile (1.78 μg/dL) and water lead when the mean water concentration was >3.3 μg/L: adjusted OR=4.7 (95% CI: 2.1–10.2). Windowsill dust loading >14.1 μg/ft2 was also associated with BLL ≥1.78 μg/dL: adjusted OR=3.2 (95% CI: 1.3–7.8). Despite relatively low BLLs, tap water and house dust lead contribute to an increase of BLLs in exposed young children.
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- 2013
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25. Fecal contamination of storm sewers: Evaluating wastewater micropollutants, human-specific Bacteroides 16S rRNA, and mitochondrial DNA genetic markers as alternative indicators of sewer cross connections
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Mounia Hachad, Marc-André Blais, M. Hajj-Mohamad, Richard Villemur, Guy Deschamps, Sarah Dorner, Sébastien Sauvé, Michèle Prévost, École Polytechnique de Montréal (EPM), Réseau de Suivi du Milieu Aquatique [Montreal], Université Laval [Québec] (ULaval), Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), This work was funded by NSERC, the Canadian Research Chair on Source Water Protection, the NSERC Industrial Chair on Drinking Water, and the Canada Foundation for Innovation., and The authors gratefully acknowledge technical staff of Polytechnique de Montreal, the City of Montréal, INRS Institut Armand Frappier and the Chemistry Department of Université de Montréal for providing scientific support and technical assistance during the project.
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Genetic Markers ,Veterinary medicine ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Indicator bacteria ,Sewage ,010501 environmental sciences ,Biology ,Wastewater ,medicine.disease_cause ,01 natural sciences ,Feces ,Theophylline ,Caffeine ,medicine ,Escherichia coli ,Environmental Chemistry ,Sanitary sewer ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Acetaminophen ,[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,business.industry ,Quebec ,biology.organism_classification ,Pollution ,6. Clean water ,Bacteroidales ,3. Good health ,Fecal coliform ,Carbamazepine ,business ,Water Microbiology ,Source tracking ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
International audience; A set of fecal indicator bacteria and alternative markers were tested for their use to identify priority sectors of two urban watersheds in the Greater Montreal region with unintended household sewage connections to storm drainage systems. Analyses were performed for thermotolerant (fecal) coliforms (FC), Escherichia coli, human-specific Bacteroidales (HF183) and mitochondrial DNA (Hmt) markers, carbamazepine (CBZ), caffeine (CAF), theophylline (THEO) and acetaminophen (ACE). A high incidence of human fecal contamination was observed, illustrating the need for a method to appropriately prioritize sectors for the rehabilitation of sewer cross-connections. Concentrations of alternative markers were not significantly different between the residential and industrial/commercial/institutional (ICI) sectors. However, median E. coli concentrations were higher in the residential as compared to ICI sectors (p 0.61, p 0.59, p
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- 2016
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26. Breakthrough of cyanobacteria in bank filtration
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Marie-Laure de Boutray, Benoit Barbeau, Pirooz Pazouki, Sarah Dorner, Michèle Prévost, Arash Zamyadi, and Natasha McQuaid
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Cyanobacteria ,Environmental Engineering ,Microcystins ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,law.invention ,Source water ,law ,Botany ,Phycocyanin ,Phytoplankton ,Waste Management and Disposal ,Filtration ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,biology ,Ecological Modeling ,biology.organism_classification ,Pollution ,020801 environmental engineering ,Lake water ,Travel time ,Lakes ,Environmental chemistry ,Seasons ,Bloom - Abstract
The removal of cyanobacteria cells in well water following bank filtration was investigated from a source water consisting of two artificial lakes (A and B). Phycocyanin probes used to monitor cyanobacteria in the source and in filtered well water showed an increase of fluorescence values demonstrating a progressive seasonal growth of cyanobacteria in the source water that were correlated with cyanobacterial biovolumes from taxonomic counts (r = 0.59, p
- Published
- 2016
27. Impact of water treatment on the contribution of faucets to dissolved and particulate lead release at the tap
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Elise Deshommes, Shokoufeh Nour, Michèle Prévost, Clément Cartier, and Benoit Richer
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Environmental Engineering ,Colony Count, Microbial ,Chloride ,Mass Spectrometry ,Statistics, Nonparametric ,Phosphates ,Water Purification ,chemistry.chemical_compound ,Tap water ,medicine ,Sulfate ,Waste Management and Disposal ,Water Science and Technology ,Civil and Structural Engineering ,Chemistry ,Drinking Water ,Ecological Modeling ,Metallurgy ,Quebec ,Particulates ,Pollution ,Corrosion ,Galvanic corrosion ,Zinc ,Lead ,Prisons ,Environmental chemistry ,Regression Analysis ,Water treatment ,Sanitary Engineering ,Leaching (metallurgy) ,Water quality ,Water Pollutants, Chemical ,Environmental Monitoring ,medicine.drug - Abstract
A field study was performed in a building complex to investigate the extent and sources of lead (Pb) release in tap water and brass material was found to be the main contributor in the very first draw (250 mL). Based on these results, a pilot installation was built to study Pb leaching from old and new faucets in the presence and absence of a connection to Cu piping. Four water quality conditions were tested: i) no treatment; ii) addition of 0.8 mg P/L of orthophosphate; iii) pH adjustment to 8.4; and iv) adjustment to a higher chloride to sulfate mass ratio (CSMR; ratio from 0.3 to 2.9). Pb concentrations in samples taken from the faucets without treatment ranged from 1 to 52 μg/L, with a mean of 11 μg/L. The addition of orthophosphate @ 0.8 mg P/L (OrthoP) was the most effective treatment for all types of faucets tested. On average, OrthoP reduced mean Pb leaching by 41%, and was especially effective for new double faucets (70%). In the presence of orthophosphates, the relative proportion of particulate Pb (Pbpart) (>0.45 μm) increased from 31% to 54%. However, OrthoP was not efficient to reduce Zn release. The higher CSMR condition was associated with greater dezincification of yellow brass but not of red brass. Corrosion control treatment influenced Pb concentration equilibrium, directly impacting maximal exposure. Significantly higher Pb release (3 fold) was observed for 1 of the 8 faucets connected to Cu exposed to high CSMR water, suggesting the presence of galvanic corrosion.
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- 2012
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28. Pb Particles from Tap Water: Bioaccessibility and Contribution to Child Exposure
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Elise Deshommes and Michèle Prévost
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In vitro test ,Chemistry ,Drinking Water ,Metallurgy ,Biological Availability ,Infant ,Environmental Exposure ,General Chemistry ,Particulates ,Particle type ,Lead ,Tap water ,Environmental chemistry ,Soil water ,Humans ,Environmental Chemistry ,Computer Simulation ,Particulate Matter ,Sanitary Engineering ,Particle Size ,Aeration ,Leaching (agriculture) ,Child ,Laboratories - Abstract
High particulate lead (Pb) levels can be measured in tap water, but the hazard linked to particulate Pb ingestion is unknown. An in vitro test was developed to determine the bioaccessibility of Pb particles from tap water, based on the Relative Bioaccessibility Leaching Procedure validated for soils, and applied to lab-generated particles and field particles collected behind the aerator tap. Field particles were found in 43% of the 342 taps investigated equipped with an aerator, and contained significant amounts of Pb (0.003-71%, median 4.7%). The bioaccessibility of lab-generated particles ranged from 2 to 96% depending on the particle type (Pb(II)BrassPb(IV)solder), while that of field particles was distributed between 1.5 and 100% (median 41%). The hazard of particulate Pb ingestion depends on the amount and concentration ingested, and the bioaccessibility of the particulate Pb forms involved. Using the Integrated Exposure Uptake Biokinetic model, the impact of particulate Pb on the exposure of children aged 0.5-7 for the distribution system studied was the most significant when considering a fraction of the exposure from large buildings.
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- 2012
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29. Toxic cyanobacterial breakthrough and accumulation in a drinking water plant: A monitoring and treatment challenge
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Arash Zamyadi, Sébastien Sauvé, Yan Fan, Sarah Dorner, Michèle Prévost, Sherri L. MacLeod, and Natasha McQuaid
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Cyanobacteria ,Powdered activated carbon treatment ,Environmental Engineering ,Halogenation ,Microcystins ,Portable water purification ,Water Purification ,Water Supply ,polycyclic compounds ,Raw water ,Water pollution ,Waste Management and Disposal ,Water Science and Technology ,Civil and Structural Engineering ,biology ,Chemistry ,Ecological Modeling ,Water Pollution ,Eutrophication ,Cyanotoxin ,biology.organism_classification ,Pollution ,Equipment Failure Analysis ,Charcoal ,Environmental chemistry ,Water treatment ,Water Microbiology ,Oxidation-Reduction ,Filtration - Abstract
The detection of cyanobacteria and their associated toxins has intensified in recent years in both drinking water sources and the raw water of drinking water treatment plants (DWTPs). The objectives of this study were to: 1) estimate the breakthrough and accumulation of toxic cyanobacteria in water, scums and sludge inside a DWTP, and 2) to determine whether chlorination can be an efficient barrier to the prevention of cyanotoxin breakthrough in drinking water. In a full scale DWTP, the fate of cyanobacteria and their associated toxins was studied after the addition of coagulant and powdered activated carbon, post clarification, within the clarifier sludge bed, after filtration and final chlorination. Elevated cyanobacterial cell numbers (4.7 × 10(6)cells/mL) and total microcystins concentrations (up to 10 mg/L) accumulated in the clarifiers of the treatment plant. Breakthrough of cells and toxins in filtered water was observed. Also, a total microcystins concentration of 2.47 μg/L was measured in chlorinated drinking water. Cyanobacterial cells and toxins from environmental bloom samples were more resistant to chlorination than results obtained using laboratory cultured cells and dissolved standard toxins.
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- 2012
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30. Use of in vivophycocyanin fluorescence to monitor potential microcystin-producing cyanobacterial biovolume in a drinkingwater source
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Arash Zamyadi, David F. Bird, Michèle Prévost, Sarah Dorner, and Natasha McQuaid
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Cyanobacteria ,Canada ,Microcystis ,Chlorophyceae ,Fresh Water ,Microcystin ,Management, Monitoring, Policy and Law ,Sensitivity and Specificity ,Fluorescence ,Water Supply ,Phytoplankton ,Phycocyanin ,Botany ,Biomass ,chemistry.chemical_classification ,biology ,fungi ,Public Health, Environmental and Occupational Health ,General Medicine ,Contamination ,biology.organism_classification ,Spectrometry, Fluorescence ,chemistry ,Environmental chemistry ,Water treatment ,Seasons - Abstract
The source water of a drinking water treatment plant prone to blooms, dominated by potential microcystin-producing cyanobacteria, was monitored for two seasons in 2007-2008. In the 2008 season, the median value for potential microcystin-producing cyanobacterial biovolume was 87% of the total phytoplankton biovolume in the untreated water of the plant. Depth profiles taken above the plant's intake identified three sampling days at high risk for the contamination of the plant's raw water with potentially toxic cyanobacteria. Chlorophyceae and Bacillariophyceae caused false positive values to be generated by the phycocyanin probe when cyanobacteria represented a small fraction of the total phytoplanktonic biovolume present. However, there was little interference with the phycocyanin probe readings by other algal species when potential microcystin-producing cyanobacteria dominated the phytoplankton of the plant's untreated water. A two-tiered method for source water monitoring, using in vivo phycocyanin fluorescence, is proposed based on (1) a significant relationship between in vivo phycocyanin fluorescence and cyanobacterial biovolume and (2) the calculated maximum potential microcystin concentration produced by dominant Microcystis sp. biovolume. This method monitors locally-generated threshold values for cyanobacterial biovolume and microcystin concentrations using in vivo phycocyanin fluorescence.
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- 2011
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31. Seasonal variations in the occurrence and fate of basic and neutral pharmaceuticals in a Swedish river–lake system
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Leif Kronberg, Gesa A. Weyhenmeyer, Atlasi Daneshvar, Michèle Prévost, and Jesper Svanfelt
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Chlorophyll a ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,Adrenergic beta-Antagonists ,Fresh Water ,Water Purification ,chemistry.chemical_compound ,Rivers ,Environmental monitoring ,medicine ,Environmental Chemistry ,Effluent ,Chromatography, High Pressure Liquid ,Sweden ,Hydrology ,Ecology ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Hydrogen-Ion Concentration ,Seasonality ,medicine.disease ,Pollution ,chemistry ,Wastewater ,Chlorophyll ,Environmental science ,Anticonvulsants ,Water treatment ,Seasons ,Surface water ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
The seasonal variations in the occurrence of carbamazepine, atenolol, metoprolol, sotalol, and acebutolol were studied at seven sites along River Fyris from December 2007 to December 2008. Samples were collected from the effluent of a waste water treatment plant (WWTP), at one upstream site, and five downstream sites of the WWTP. During one occasion in May 2008, water samples were collected at different locations and depths in the recipient lake. All analytes except of acebutolol were present in both the river and the lake at quantifiable amounts at all sampling occasions. Carbamazepine was found in similar concentrations (about 90 ng L(-1)) at all sampling sites and all studied depths (0.5-40 m) in the lake, indicating high environmental persistence of this compound. A clear seasonal pattern was observed for the natural attenuation of the beta-blockers in the river, with the highest attenuation occurring in summer and the lowest in winter. The loss of beta-blockers on a distance of 1320 m reached up to 75% during summer time but was insignificant during winter. The seasonal variations in the loss followed the seasonal variations in water temperature and chlorophyll a mass flow suggesting that biotransformation and adsorption are the main processes responsible for the loss of the studied pharmaceuticals in River Fyris downstream the WWTP.
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- 2010
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32. Oxidation kinetics of cyclophosphamide and methotrexate by ozone in drinking water
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Romain Broséus, Araceli Garcia-Ac, Benoit Barbeau, Simon Vincent, Michèle Prévost, and Sébastien Sauvé
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Antimetabolites, Antineoplastic ,Spectrometry, Mass, Electrospray Ionization ,Environmental Engineering ,Ozone ,Health, Toxicology and Mutagenesis ,Radical ,Portable water purification ,Water Purification ,chemistry.chemical_compound ,Reaction rate constant ,Water Supply ,Environmental Chemistry ,Solid phase extraction ,Cyclophosphamide ,Chromatography, High Pressure Liquid ,Aqueous solution ,Chemistry ,Solid Phase Extraction ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Hydrogen-Ion Concentration ,Pollution ,Kinetics ,Methotrexate ,Environmental chemistry ,Ultrapure water ,Water treatment ,Oxidation-Reduction ,Water Pollutants, Chemical ,Nuclear chemistry - Abstract
This study investigates the aqueous degradation by ozone of two target cytostatic drugs, cyclophosphamide and methotrexate. A column switching technique for on-line solid phase extraction (SPE) coupled to electro-spray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used for the simultaneous detection of the trace contaminants. The second-order kinetic rate constants for the reaction of cyclophosphamide with molecular ozone and hydroxyl radicals were determined in bench-scale experiments at pH 8.10. The molecular ozone oxidation kinetics was studied in buffered ultrapure water and compared to the oxidation kinetics in natural water from a municipal drinking water treatment plant in the province of Quebec (Canada). For cyclophosphamide, the degradation rate constant with molecular ozone in ultrapure water was low (k(O3)=3.3+/-0.2M(-1)s(-1)) and the extent of oxidation was linearly correlated to the ozone exposure. The impact of water quality matrix on oxidation efficacy was not significant during direct ozone reaction (k(O3) =2.9+/-0.3M(-1)s(-1)). The rate constant with hydroxyl radicals was higher at 2.0 x 10(9) M(-1)s(-1). Methotrexate reacted quickly with molecular ozone at dosages typically applied in drinking water treatment (k(O3)>3.6 x 10(3)M(-1)s(-1)). Overall, the results confirmed that organic compounds reactivity with ozone was dependent of their chemical structure. Ozone was very effective against methotrexate but high oxidant concentration x contact time (CT) values were required to completely remove cyclophosphamide from drinking water. Further studies should be conducted in order to identify the ozonation by-products and explore the impact of ozone on their degradation and toxicity.
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- 2010
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33. Pressure Monitoring and Characterization of External Sources of Contamination at the Site of the Payment Drinking Water Epidemiological Studies
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Jean Lavoie, George D. Di Giovanni, Romain Broséus, Pierre Payment, M. C. Besner, Michèle Prévost, NSERC Industrial Chair on Drinking Water, Department of Civil, Geological and Mining Engineering, École Polytechnique de Montréal (EPM), Service de l'Environnement, City of Laval [Québec, Canada], Texas AgriLife Research Center at El Paso, Texas A&M University System, Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), and This research was supported by the Canadian Water Network, a center of excellence program funded by the Government of Canada
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Canada ,[SDV.BIO]Life Sciences [q-bio]/Biotechnology ,Gastrointestinal Diseases ,Population ,0207 environmental engineering ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,River water ,Feces ,Tap water ,Water Supply ,MESH: Canada ,Pressure ,Environmental Chemistry ,[INFO.INFO-BT]Computer Science [cs]/Biotechnology ,MESH: Water Supply ,020701 environmental engineering ,Water pollution ,education ,MESH: Gastrointestinal Diseases ,0105 earth and related environmental sciences ,education.field_of_study ,Bacteria ,Environmental engineering ,MESH: Feces ,General Chemistry ,Contamination ,6. Clean water ,MESH: Water Microbiology ,Fecal coliform ,MESH: Bacteria ,Wastewater ,Environmental science ,Water quality ,Water Microbiology ,MESH: Pressure - Abstract
International audience; The 1990s epidemiological studies by Payment and colleagues suggested that an increase in gastrointestinal illnesses observed in the population consuming tap water from a system meeting all water quality regulations might be associated with distribution system deficiencies. In the current study, the vulnerability of this distribution system to microbial intrusion was assessed by characterizing potential sources of contamination near pipelines and monitoring the frequency and magnitude of negative pressures. Bacterial indicators of fecal contamination were recovered more frequently in the water from flooded air-valve vaults than in the soil or water from pipe trenches. The level of fecal contamination in these various sources was more similar to levels from river water rather than wastewater. Because of its configuration, this distribution system is vulnerable to negative pressures when pressure values out of the treatment plant reach or drop below 172 kPa (25 psi), which occurred nine times during a monitoring period of 17 months. The results from this investigation suggest that this distribution system is vulnerable to contamination by intrusion. Comparison of the frequency of occurrence of negative pressure events and repair rates with data from other distribution systems suggests that the system studied by Payment and colleagues is not atypical.
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- 2009
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34. Vulnerability of Quebec drinking-water treatment plants to cyanotoxins in a climate change context
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Arash Zamyadi, Michèle Prévost, Pierre Chevalier, Annie Carrière, and Benoit Barbeau
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Microbiology (medical) ,Powdered activated carbon treatment ,Microcystins ,Climate Change ,Disinfectant ,Bacterial Toxins ,Context (language use) ,Water industry ,Cyanobacteria ,Risk Assessment ,Algal bloom ,Water Purification ,Toxicology ,Risk Factors ,Water Supply ,Water pollution ,Waste Management and Disposal ,Water Science and Technology ,Cyanobacteria Toxins ,business.industry ,Quebec ,Public Health, Environmental and Occupational Health ,Infectious Diseases ,Environmental chemistry ,Environmental science ,Marine Toxins ,Water treatment ,Public Health ,Water quality ,business - Abstract
Cyanobacteria are a growing concern in the province of Quebec due to recent highly publicised bloom episodes. The health risk associated with the consumption of drinking water coming from contaminated sources was unknown. A study was undertaken to evaluate treatment plants' capacity to treat cyanotoxins below the maximum recommended concentrations of 1.5 μg/L microcystin-LR (MC-LR) and the provisional concentration of 3.7 μg/L anatoxin-a, respectively. The results showed that close to 80% of the water treatment plants are presently able to treat the maximum historical concentration measured in Quebec (5.35 μg/L MC-LR equ.). An increase, due to climate change or other factors, would not represent a serious threat because chlorine, the most popular disinfectant, is effective in treating MC-LR under standard disinfection conditions. The highest concentration of anatoxin-a (2.3 μg/L) measured in natural water thus far in source water is below the current guideline for treated waters. However, higher concentrations of anatoxin-a would represent a significant challenge for the water industry as chlorine is not an efficient treatment option. The use of ozone, potassium permanganate or powder activated carbon would have to be considered.
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- 2009
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35. Evaluating aerobic endospores as indicators of intrusion in distribution systems
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Jean Lavoie, Benoit Barbeau, Clément Cartier, Michèle Prévost, Raymond Desjardins, and Marie-Claude Besner
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Distribution system ,Intrusion ,Environmental chemistry ,Water contamination ,Environmental engineering ,Environmental science ,General Chemistry ,Endospore ,Water Science and Technology - Published
- 2009
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36. On-line solid-phase extraction coupled to liquid chromatography tandem mass spectrometry for the analysis of cyanotoxins in algal blooms
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Sébastien Sauvé, Michèle Prévost, Audrey Roy-Lachapelle, Sung Vo Duy, and Paul B. Fayad
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Microcystins ,Harmful Algal Bloom ,Bacterial Toxins ,Microcystin ,Toxicology ,Mass spectrometry ,Cyanobacteria ,Algal bloom ,chemistry.chemical_compound ,Alkaloids ,Liquid chromatography–mass spectrometry ,Tandem Mass Spectrometry ,Solid phase extraction ,Uracil ,chemistry.chemical_classification ,Detection limit ,Chromatography ,Cyanobacteria Toxins ,Chemistry ,Solid Phase Extraction ,6. Clean water ,Environmental chemistry ,Marine Toxins ,Cylindrospermopsin ,Marine toxin ,Chromatography, Liquid ,Environmental Monitoring ,Tropanes - Abstract
An analytical method based on on-line SPE-LC-HESI-MS/MS has been developed for the detection and quantification of eight selected cyanotoxins in algal bloom waters that include mycrocystins, anatoxin-a and cylindrospermopsin. The injection volume was 2 mL according to the expected concentration of cyanotoxins in matrix. The method provides an analysis time of 7 min per sample, acceptable recovery values (91-101%), good precision (RSD < 13%) and method limits of detection at the sub-microgram per liter levels (0.01-0.02 μg L(-1)). A detailed discussion on optimization parameters that have an impact on the overall performance of the method are presented. In particular, method optimization permitted the chromatographic separation of anatoxin-a and phenylalanine, an isobaric interference with a similar chromatographic characteristics. All optimization and validation experiments for the on-line SPE method and chromatographic separation were performed in environmentally relevant algal bloom water matrices. The applicability of the method was tested on several algal bloom water samples from monitored lakes across the province of Quebec (Quebec, Canada) known to produce cyanotoxins. All of the targeted cyanotoxins were detected with the exception of cylindrospermopsin. In addition, it was found that total microcystin concentrations in several surface water samples exceeded the proposed guidelines established by the province of Quebec in Canada of 1.5 μg L(-1) as well as the World Health Organization of 1 μg L(-1) for both free and cell-bound microcystin-LR equivalent.
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- 2015
37. Biodegradation of multiple microcystins and cylindrospermopsin in clarifier sludge and a drinking water source: effects of particulate attached bacteria and phycocyanin
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Ehsan Maghsoudi, Nathalie Fortin, Sung Vo Duy, Michèle Prévost, Charles W. Greer, Sébastien Sauvé, Sarah Dorner, and Paul B. Fayad
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microcystin ,Microcystins ,Health, Toxicology and Mutagenesis ,Bacterial Toxins ,Fresh Water ,Microcystin ,Cyanobacteria ,biodegradation ,Clarifier ,Water Purification ,Microbiology ,clarifier sludge ,chemistry.chemical_compound ,Alkaloids ,Phycocyanin ,cylindrospermopsin ,Biomass ,Uracil ,Water pollution ,chemistry.chemical_classification ,Cyanobacteria Toxins ,Sewage ,Drinking Water ,Public Health, Environmental and Occupational Health ,Flocculation ,General Medicine ,Biodegradation ,Pollution ,phycocyanin ,Lakes ,Biodegradation, Environmental ,chemistry ,Environmental chemistry ,sludge management ,Water treatment ,Cylindrospermopsin ,Water quality ,Half-Life - Abstract
The effects of particulate attached bacteria (PAB) and phycocyanin on the simultaneous biodegradation of a mixture of microcystin-LR, YR, LY, LW, LF and cylindrospermopsin (CYN) was assessed in clarifier sludge of a drinking water treatment plant (DWTP) and in a drinking water source. The biomass from lake water and clarifier sludge was able to degrade all microcystins (MCs) at initial concentrations of 10μgL-1 with pseudo-first order reaction half-lives ranging from 2.3 to 8.8 days. CYN was degraded only in the sludge with a biodegradation rate of 1.0×10-1d-1 and a half-life of 6.0 days. This is the first study reporting multiple MCs and CYN biodegradation in the coagulation-flocculation sludge of a DWTP. The removal of PAB from the lake water and the sludge prolonged the lag time substantially, such that no biodegradation of MCLY, LW and LF was observed within 24 days. Biodegradation rates were shown to increase in the presence of C-phycocyanin as a supplementary carbon source for indigenous bacteria, a cyanobacterial product that accompanies cyanotoxins during cyanobacteria blooms. MCs in mixtures degraded more slowly (or not at all) than if they were degraded individually, an important outcome as MCs in the environment are often present in mixtures. The results from this study showed that the majority of the bacterial biomass responsible for the biodegradation of cyanotoxins is associated with particles or biological flocs and there is a potential for extreme accumulation of cyanotoxins within the DWTP during a transient bloom. © 2015 Elsevier Inc.
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- 2015
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38. The impact of natural organic matter on free chlorine and chlorine dioxide disinfection efficacy
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Mélanie Rivard, Benoit Barbeau, and Michèle Prévost
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chemistry.chemical_classification ,Chlorine dioxide ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,Radical ,chemistry.chemical_element ,Natural organic matter ,Spore ,chemistry.chemical_compound ,chemistry ,Environmental chemistry ,Chlorine ,Organic matter ,Water treatment ,Water Science and Technology - Abstract
The objective of this study was to assess the effect of natural organic matter (NOM) on disinfection efficacy using two types of disinfectants: Cl2 and ClO2. Bacillus subtilis spores were used as a surrogate for monitoring disinfection efficacy. The effect of natural organic matter was tested using two series of experimental assays. Initially, assays were conducted in ultra-pure buffered waters supplemented with various NOM extracts. Second, confirmation assays were performed on three surface waters. In both natural and synthetic waters, the presence of NOM improved disinfection efficacy where chlorine dioxide was used. This phenomenon was significant, as Ct values required for 2 log inactivation of B. subtilis spores were reduced by a factor of 2.3 to 7.1 depending on the NOM source and concentration. However, such a phenomenon was not observed while disinfecting with free chlorine. It is proposed that (i) free radicals are generated following the reaction of chlorine dioxide and NOM and (ii) those radicals can enhance chlorine dioxide disinfection efficacy.
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- 2006
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39. Examination of discrete and counfounding effects of water quality parameters during the inactivation of MS2 phages and Bacillus subtilis spores with chlorine dioxide
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Benoit Barbeau, Debra Huffman, Chandra Mysore, Raymond Desjardins, Bernard Clément, and Michèle Prévost
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Environmental Engineering ,polycyclic compounds ,Environmental Chemistry ,General Environmental Science - Abstract
The role of water quality (pH, temperature, turbidity, and natural organic matter (NOM)) on the efficacy of chlorine dioxide to inactivate Bacillus subtilis spores and MS2 phages was investigated in synthetic waters. Modelling the curves describing tailing inactivation with a parallel Chick-Watson model proved to be a valid approach. The formation of aggregates was exacerbated when using chlorine dioxide as opposed to free chlorine. The origin of these aggregates lies in the interactions of chlorine dioxide with the water matrix and the microorganisms. Higher temperature and higher turbidity were dominant factors in predicting spores tailing, while decreasing the pH from 8.5 to 6.5 was responsible for increasing the fraction of MS2 aggregates from 0.06% to 9.0% (138-fold). The resistance of aggregates were, on average, 18–21 times higher than for single organisms. The addition of dissolved organic carbon significantly (p < 0.01) improved inactivation with chlorine dioxide. Turbidity (5 NTU) did not significantly hinder MS2 inactivation, but it increased the concentration–time (Ct) 1-log of B. subtilis spores from 386 to 600 mg·min·L–1. Key words: drinking water, disinfection, spores, MS2 coliphages, chlorine dioxide, water quality, turbidity, natural organic matter.
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- 2005
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40. Examination of discrete and counfounding effects of water quality parameters during the inactivation of MS2 phages and Bacillus subtilis pores with free chlorine
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Chandra Mysore, Michèle Prévost, Debra Huffman, Benoit Barbeau, and Raymond Desjardins
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Environmental Engineering ,biology ,Hypochlorous acid ,Chemistry ,Hypochlorite ,chemistry.chemical_element ,Bacillus subtilis ,biology.organism_classification ,Spore ,Microbiology ,chemistry.chemical_compound ,Environmental chemistry ,Dissolved organic carbon ,Chlorine ,Environmental Chemistry ,Water quality ,Turbidity ,General Environmental Science - Abstract
The role of water quality (pH, temperature, turbidity, and natural organic matter (NOM)) on the efficacy of chlorine to inactivate Bacillus subtilis spores and MS2 phages was investigated in synthetic waters. A half-factorial statistical experimental design was employed to reduce the number of assays. Temperature and pH were found to be by far the most important variables in explaining chlorine efficacy, that is 78% of the variability in the experimental domain studied (pH, 6.58.5; temperature, 722 °C; dissolved organic carbon (DOC), 05 mg/L, 05 nephelometric turbidity units (NTUs)). The interaction between pH and temperature was also significant, being the third most important factor, explaining 11% of the variability. For both MS2 phages and B. subtilis spores, hypochlorous acid efficacy was less sensitive than hypochlorite ions to a modification of water temperature. Such effect is not taken into account in the current United States Environmental Protection Agency (USEPA) concentrationtime (Ct) tables. Once the consumption of disinfectant by natural organic matter (NOM) was taken into account, the presence of NOM had either no impact on MS2 phage inactivation or significantly improved B. subtilis spore inactivation. The role of inorganic turbidity was either not statistically significant or negligible. Little or no protection was therefore provided by kaolin particles, up to a concentration of 5 mg/L ([Formula: see text]5 NTU).Key words: drinking water, disinfection, spores, MS2 coliphages, chlorine, water quality, turbidity, natural organic matter.
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- 2004
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41. Comparing Static Mixer Performances at Pilot and Full Scale for Ozonation,Inactivation ofBacillus subtilis, and Bromate Formation in Water Treatment
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Paula Agutter, Richard Lake, Chandra Mysore, Jérôme Leparc, and Michèle Prévost
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Environmental Engineering ,Ozone ,biology ,Full scale ,Environmental engineering ,Bacillus subtilis ,Static mixer ,Bromate ,Pulp and paper industry ,biology.organism_classification ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Environmental Chemistry ,Water treatment ,Dissolution ,Contactor - Abstract
The potential benefits of using a static mixer for ozone dissolution was evaluated through comprehensive pilot- and full-scale studies under a variety of operating conditions and source waters. The static mixer pilot unit was operated side-by-side to a full-scale plant which also employed static mixers for ozonation. Based on the results obtained from this pilot study (and at other sites), it appears that an optimal ozone dose (≤0.5mgO3/mgC) applied through a static mixer dissolution system integrated with a well-designed downstream contactor can result in enhanced microbial inactivation while keeping bromate formation below 10μg/L.
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- 2004
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42. Evaluation of the impact of design and operation parameters on direct filtration
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Maurice Tchio, Alain Gadbois, Raymond Desjardins, Boniface Koudjonou, and Michèle Prévost
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Flocculation ,Environmental Engineering ,Anthracite ,Mineralogy ,Pulp and paper industry ,Soil gradation ,law.invention ,Hydraulic head ,Pilot plant ,law ,Environmental Chemistry ,Environmental science ,Turbidity ,Raw water ,Filtration ,General Environmental Science - Abstract
This paper discusses the impacts of common design and operation parameters on direct filtration (DF) performance. These tests were carried out in a 45-m3/d pilot plant. The raw waters used were obtained by spiking a natural water with a kaolin suspension. The DF treatment comprises coagulation, flocculation, and filtration on a sand or anthracite bed. Seven parameters were studied over a wide range of design and operation conditions: effective size of the media (ES) 0.4 or 2.0 mm, depth of media (HMED) 50 or 300 cm, water head (WH) 50 or 300 cm, filtration rate (FR) 5 or 30 m/h, uniformity coefficient (UC) 1.3 or 1.5, raw water turbidity (TURB_RW) 1 or 5 nephelometric turbidity units (NTU), type of filtering media (MEDIA) sand or anthracite. The analysis of filter performance was based on the quantity and quality of filtered water produced and the cost of the filtration plant relative to each configuration. The results show that four of the parameters studied (ES, HMED, FR, and WH) have the most significant impacts on the filter performance and govern more than 77% of the performance criteria examined. This study also showed that the use of high-rate filtration increases the net productivity of the filters. However, to comply with filtered water quality requirements, the other three parameters should be set to appropriate values, since interactions among all four parameters are very high. The global cost analysis showed that a well designed and properly operated high-rate filtration process is more cost-effective than low-rate filtration. Key words: direct filtration, high-rate filters, cost analysis, statistical experimental design, Pareto chart.
- Published
- 2003
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43. A bench-scale evaluation of different treatment options to produce bio-stable drinking water
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Michèle Prévost, Patrick Laurent, Benoit Barbeau, and Pierre Servais
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Environmental Engineering ,Waste management ,Bench scale ,Environmental Chemistry ,Environmental science ,Treatment options ,Water quality ,General Environmental Science - Abstract
Owing to increasingly stringent water quality regulations and concerns about emerging pathogens, many drinking water utilities are having to modify their treatment lines. Bench-scale evaluation can be a useful means for carrying out a preliminary assessment of treatment modifications under consideration. An example of such an evaluation, performed as an initial screening of treatment options for a big North American utility, is presented here. Four sampling campaigns aimed at investigating at a bench-scale the impact of different treatments (coagulation-flocculation-settling, moderate ozonation, and filtration; high dosage ozonation; chlorination followed by dechlorination) on water quality were performed in this study. Testing involved measurement of water quality parameters (turbidity, dissolved organic carbon, ultraviolet absorbance, specific ultraviolet absorbance) with special attention paid to parameters driving regrowth potential (biodegradable dissolved organic carbon (BDOC) and bacterial abundances). Main results show that ozonation always increases BDOC levels. "Full treatment" (coagulation-flocculation-settling, moderate ozonation, filtration) would not change the regrowth potential of the raw water drastically. A high dosage ozonation ("high O3" scenario) could result in a substantial seasonal increase in BDOC concentrations. It would be logical to follow up this conclusion with a consideration of whether or not the higher bacterial regrowth that would take place in the distribution system, and due to these increases in BDOC concentration, could be controlled by maintaining oxidant residuals during distribution. Key words: drinking water, bench-scale, biological stability, water treatment, biodegradable dissolved organic carbon.
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- 2003
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44. Impacts of global change on the concentrations and dilution of combined sewer overflows in a drinking water source
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Robert Leconte, Isabelle Jalliffier-Verne, Uriel Huaringa-Alvarez, Pierre Servais, Sarah Dorner, Michèle Prévost, Martine Galarneau, and Anne-Sophie Madoux-Humery
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Hydrology ,Pollution ,Environmental Engineering ,media_common.quotation_subject ,Climate Change ,Drinking Water ,Outfall ,Climate change ,Waste Disposal, Fluid ,Spatio-Temporal Analysis ,Water Supply ,Snowmelt ,Environmental Chemistry ,Environmental science ,Water treatment ,Combined sewer ,Water quality ,Source water protection ,Waste Management and Disposal ,Water Pollutants, Chemical ,media_common ,Environmental Monitoring - Abstract
This study presents an analysis of climate change impacts on a large river located in Quebec (Canada) used as a drinking water source. Combined sewer overflow (CSO) effluents are the primary source of fecal contamination of the river. An analysis of river flowrates was conducted using historical data and predicted flows from a future climate scenario. A spatio-temporal analysis of water quality trends with regard to fecal contamination was performed and the effects of changing flowrates on the dilution of fecal contaminants were analyzed. Along the river, there was a significant spatial trend for increasing fecal pollution downstream of CSO outfalls. Escherichia coli concentrations (upper 95th percentile) increased linearly from 2002 to 2012 at one drinking water treatment plant intake. Two critical periods in the current climate were identified for the drinking water intakes considering both potential contaminant loads and flowrates: local spring snowmelt that precedes river peak flow and extra-tropical storm events that occur during low flows. Regionally, climate change is expected to increase the intensity of the impacts of hydrological conditions on water quality in the studied basin. Based on climate projections, it is expected that spring snowmelt will occur earlier and extreme spring flowrates will increase and low flows will generally decrease. High and low flows are major factors related to the potential degradation of water quality of the river. However, the observed degradation of water quality over the past 10 years suggests that urban development and population growth may have played a greater role than climate. However, climate change impacts will likely be observed over a longer period. Source water protection plans should consider climate change impacts on the dilution of contaminants in addition to local land uses changes in order to maintain or improve water quality.
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- 2014
45. Fate of toxic cyanobacterial genera from natural bloom events during ozonation
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Flávio Rubens Lapolli, Sarah Dorner, Arash Zamyadi, Michèle Prévost, Lucila Adriani Coral, and Benoit Barbeau
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Cyanobacteria ,Environmental Engineering ,Haloacetic acids ,Aphanizomenon ,Water Purification ,Ozone ,Microcystis ,medicine ,Organic matter ,Waste Management and Disposal ,Water Science and Technology ,Civil and Structural Engineering ,chemistry.chemical_classification ,biology ,Anabaena ,Ecological Modeling ,Quebec ,Disinfection by-product ,Cyanotoxin ,biology.organism_classification ,Pollution ,6. Clean water ,Disinfection ,Lakes ,chemistry ,Environmental chemistry ,medicine.drug - Abstract
Intense accumulation of toxic cyanobacteria cells inside plants, unsuccessful removal of cells and consequent breakthrough of cells and toxins into treated water have been increasingly documented. Removal or destabilisation of cells in the pre-treatment stage using pre-ozonation could be an efficient practice as ozonation has been proven to be effective for the removal of cells and toxins. However, several unknowns including the ozone demand, the potential release of cell-bound toxins and organic matter and their impact on treatment train needs to be addressed. The general objective of this work was to study the impact of direct ozonation on different potentially toxic cyanobacteria genera from natural blooms. Water samples from five cyanobacterial bloom events in Lake Champlain (Canada) were ozonated using 2-5 mg/L O3 for a contact time of maximum 10 min. Cyanobacterial taxonomic enumeration, cyanotoxins, organic matter and post-chlorination disinfection by-product formation potential analyses were conducted on all samples. Anabaena, Aphanizomenon, Microcystis and Pseudanabaena were detected in bloom water samples. Total cell numbers varied between 197,000 and 1,282,000 cells/mL prior to ozonation. Direct ozonation lysed (reduction in total cell numbers) 41%-80% of cells and reduced released toxins to below detection limits. Microcystis was the genus the least affected by ozonation. However, DOC releases of 0.6-3.5 mg/L were observed leading to maximum 86.92 μg/L and 61.56 μg/L additional total THMs (four trihalomethanes) and HAA6 (six haloacetic acids) formation, respectively. The results of this study demonstrate that vigilant application of pre-ozonation under certain treatment conditions would help to avoid extreme toxic cells accumulation within water treatment plants.
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- 2014
46. Changes in Escherichia coli to Cryptosporidium ratios for various fecal pollution sources and drinking water intakes
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Benoit Barbeau, Sarah Dorner, George D. Di Giovanni, Pierre Servais, Isabelle Papineau, Michèle Prévost, Pierre Payment, Cindy Lalancette, Institut Armand Frappier (INRS-IAF), Réseau International des Instituts Pasteur (RIIP)-Institut National de la Recherche Scientifique [Québec] (INRS), Polytechnique Montréal, Département des Génies Civil, Géologique et des Mines, École Polytechnique de Montréal (EPM), Ecologie des Systèmes Aquatiques, Université libre de Bruxelles (ULB), School of Public Health, Center for Infectious Diseases, The University of Texas Health Science Center at Houston (UTHealth), and This study was supported by the NSERC Industrial Chair onDrinking Water at the Polytechnique Montre´ al, which isjointly funded by the City of Montreal, John-Meunier/VeoliaWater, the City of Laval, and the Natural Sciences and EngineeringResearch Council of Canada
- Subjects
Pollution ,Veterinary medicine ,Environmental Engineering ,media_common.quotation_subject ,[SDV]Life Sciences [q-bio] ,0207 environmental engineering ,Indicator bacteria ,Sewage ,Cryptosporidium ,02 engineering and technology ,Fecal pollution ,010501 environmental sciences ,01 natural sciences ,Water Purification ,Feces ,parasitic diseases ,Escherichia coli ,Drinking water ,Fecal indicators ,020701 environmental engineering ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,media_common ,[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,biology ,business.industry ,Ecological Modeling ,Source water ,biology.organism_classification ,[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology ,6. Clean water ,Fecal coliform ,Wastewater ,13. Climate action ,Environmental chemistry ,Environmental science ,Water treatment ,business ,Surface water - Abstract
International audience; Assessing the presence of human pathogenic Cryptosporidium oocysts in surface water remains a significant water treatment and public health challenge. Most drinking water suppliers rely on fecal indicators, such as the well-established Escherichia coli (E. coli), to avoid costly Cryptosporidium assays. However, the use of E. coli has significant limitations in predicting the concentration, the removal and the transport of Cryptosporidium. This study presents a meta-analysis of E. coli to Cryptosporidium concentration paired ratios to compare their complex relationships in eight municipal wastewater sources, five agricultural fecal pollution sources and at 13 drinking water intakes (DWI) to a risk threshold based on US Environmental Protection Agency (USEPA) regulations. Ratios lower than the USEPA risk threshold suggested higher concentrations of oocysts in relation to E. coli concentrations, revealing an underestimed risk for Cryptosporidium based on E. coli measurements. In raw sewage (RS), high ratios proved E. coli (or fecal coliforms) concentrations were a conservative indicator of Cryptosporidium concentrations, which was also typically true for secondary treated wastewater (TWW). Removals of fecal indicator bacteria (FIB) and parasites were quantified in WWTPs and their differences are put forward as a plausible explanation of the sporadic ratio shift. Ratios measured from agricultural runoff surface water were typically lower than the USEPA risk threshold and within the range of risk misinterpretation. Indeed, heavy precipitation events in the agricultural watershed led to high oocyst concentrations but not to E. coli or enterococci concentrations. More importantly, ratios established in variously impacted DWI from 13 Canadian drinking water plants were found to be related to dominant fecal pollution sources, namely municipal sewage. In most cases, when DWIs were mainly influenced by municipal sewage, E. coli or fecal coliforms concentrations agreed with Cryptosporidium concentrations as estimated by the meta-analysis, but when DWIs were influenced by agricultural runoff or wildlife, there was a poor relationship. Average recovery values were available for 6 out of 22 Cryptosporidium concentration data sets and concomitant analysis demonstrated no changes in trends, with and without correction. Nevertheless, recovery assays performed along with every oocyst count would have enhanced the precision of this work. Based on our findings, the use of annual averages of E. coli concentrations as a surrogate for Cryptosporidium concentrations can result in an inaccurate estimate of the Cryptosporidium risk for agriculture impacted drinking water intakes or for intakes with more distant wastewater sources. Studies of upstream fecal pollution sources are recommended for drinking water suppliers to improve their interpretation of source water quality data.
- Published
- 2014
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47. Application of in vivo measurements for the management of cyanobacteria breakthrough into drinking water treatment plants
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Michèle Prévost, Donald Ellis, Arash Zamyadi, Mouhamed Ndong, Christian Bastien, Anouka Bolduc, and Sarah Dorner
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Cyanobacteria ,Drinking Water ,Public Health, Environmental and Occupational Health ,Portable water purification ,General Medicine ,Management, Monitoring, Policy and Law ,Biology ,biology.organism_classification ,Clarifier ,Water Purification ,In vivo ,Environmental chemistry ,Environmental monitoring ,Phycocyanin ,Environmental Chemistry ,Water treatment ,Raw water ,Water Microbiology ,Environmental Monitoring - Abstract
The increasing presence of potentially toxic cyanobacterial blooms in drinking water sources and within drinking water treatment plants (DWTPs) has been reported worldwide. The objectives of this study are to validate the application of in vivo probes for the detection and management of cyanobacteria breakthrough inside DWTPs, and to verify the possibility of treatment adjustment based on intensive real-time monitoring. In vivo phycocyanin YSI probes were used to monitor the fate of cyanobacteria in raw water, clarified water, filtered water, and chlorinated water in a full scale DWTP. Simultaneous samples were also taken for microscopic enumeration. The in vivo probe was successfully used to detect the incoming densities of high cyanobacterial cell number into the clarification process and their breakthrough into the filtered water. In vivo probes were used to trace the increase in floating cells over the clarifier, a robust sign of malfunction of the coagulation–sedimentation process. Pre-emptive treatment adjustments, based on in vivo probe monitoring, resulted in successful removal of cyanobacterial cells. The field results on validation of the probes with cyanobacterial bloom samples showed that the probe responses are highly linear and can be used to trigger alerts to take action.
- Published
- 2014
48. Changes in chlorine and DOX Concentrations in Distribution Systems
- Author
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Michèle Prévost, Pierre Lafrance, Raymond Desjardins, and Hélène Baribeau
- Subjects
Detection limit ,education ,0207 environmental engineering ,chemistry.chemical_element ,Biomass ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,01 natural sciences ,6. Clean water ,Corrosion ,Distribution system ,chemistry ,Environmental chemistry ,Halogen ,polycyclic compounds ,Warm water ,Chlorine ,Water quality ,020701 environmental engineering ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
The fate of disinfectants and disinfection by-products (DBPs) has been studied in laboratories under a variety of controlled, constant conditions, but limited information is available about their fate in full-scale distribution systems. A study of the City of Laval (Quebec) distribution system examined changes in the concentrations of chlorine and dissolved organic halogens (DOX) as the water flows through the distribution system. Water was collected in small- and large-diameter pipes with respect to the residence time (RT) of each sampling point. Free and total chlorine concentrations decreased with increasing RT in the distribution system. The influence of pipes on chlorine decay was particularly important in warm water; at similar RTs, chlorine concentrations were lowest in the small-diameter pipes, greater in the main pipes, and greatest in the batch incubations. The presence of corrosion by-products in pipes appeared to be the major factor influencing chlorine decay in the distribution system. DOX concentrations generally increased with increasing RT in the presence of free chlorine and decreased when free chlorine concentrations were below the method detection limit. Results pointto significant pipe influence on DOX concentrations. DOX decay seemed to be attributable to the chemical instability of some DBPs and the presence of microbial biomass.
- Published
- 2001
- Full Text
- View/download PDF
49. Suspended particles in the drinking water of two distribution systems
- Author
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Vincent Gauthier, Jean Claude Block, Michèle Prévost, Robert Millette, and Benoit Barbeau
- Subjects
Hydrology ,chemistry.chemical_classification ,Suspended solids ,Range (particle radiation) ,Laminar flow ,Fraction (chemistry) ,Particulates ,chemistry ,Environmental chemistry ,Environmental science ,Organic matter ,Water quality ,Raw water ,Water Science and Technology - Abstract
The concentrations of suspended particles were measured in the drinking water of two distribution systems, and the nature of these particles documented. The concentrations of particulate matter were invariably found to be small (maximum 350 μg/L). They are globally in the very low range in comparison with dissolved matter concentrations, which are measured in several hundreds of mg/L. Except during special water quality events, such as turnover of the raw water resource, results show that organic matter represents the most important fraction of suspended solids (from 40 to 76%) in treated and distributed water. Examination of the nature of the particles made it possible to develop several hypotheses about the type of particles penetrating Montreal's distribution system during the turnover period (algae skeleton, clays). These particles were found to have been transported throughout the distribution systems quite easily, and this could result in the accumulation of deposits if their surface charge were ever even slightly destabilised, or if the particles were to penetrate the laminar flow areas that are fairly typical of remote locations in distribution systems.
- Published
- 2001
- Full Text
- View/download PDF
50. The Use of Jar-Filtration Tests to Compare Performances of Coagulants in Direct Filtration
- Author
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Michèle Prévost, Raymond Desjardins, and Souleymane Ndiongue
- Subjects
inorganic chemicals ,Aluminium chloride ,Alum ,Environmental engineering ,chemistry.chemical_element ,General Medicine ,Aluminium sulfate ,Pulp and paper industry ,complex mixtures ,Chloride ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Aluminium ,medicine ,Environmental Chemistry ,Water treatment ,Turbidity ,Waste Management and Disposal ,Filtration ,Water Science and Technology ,medicine.drug - Abstract
Modified jar tests were performed in order to compare performances of coagulants treating, by direct filtration, raw water having a low turbidity and dissolved organic carbon. The object of this direct filtration is to produce water with a turbidity equal to or less than 0.10 NTU. The tests comprise a coagulation step with a laboratory flocculator, followed by a filtration step on a granular medium. Two poly aluminium silicate sulphates (PASS 100 and PASS 55), poly aluminium chloride (PACl), aluminium sulphate (alum), Ferriclear (prehydrolized ferric sulphate) and ferric chloride were studied. It was observed that all these coagulants are capable of lowering the turbidity of filtered water to 0.10 NTU or even less. Among the aluminium-based coagulants, PACl seems to be the most effective; while for iron-based coagulants, ferric chloride performs best. Although the doses are higher, alum offers a commercial advantage over the other aluminium-based coagulants because it costs less. When the turbidity object...
- Published
- 2000
- Full Text
- View/download PDF
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