Michèle Prévost

Learn More
A rapid epifluorescence staining method using the LIVE/DEAD Bacterial Viability Kit (BacLight) was applied to estimate both viable and total counts of bacteria in drinking water. BacLight is composed of two nucleic acid-binding stains: SYTO 9 and propidium iodide. SYTO 9 penetrates all bacterial membranes and stains the cells green, while propidium iodide(More)
The impact of temperature on nitrification in biological granular activated carbon (GAC) filters was evaluated in order to improve the understanding of the nitrification process in drinking water treatment. The study was conducted in a northern climate where very cold water temperatures (below 2 degrees C) prevail for extended periods and rapid shifts of(More)
A rapid and sensitive method for the detection of low levels of bacteria in potable water was developed. The fecal indicator bacterium Escherichia coli was used as the test organism in a filtration concentration - nested polymerase chain reaction (PCR) protocol, combined with ethidium bromide visualization of PCR products. Two sets of primers were designed(More)
Biofilms were grown in annular reactors supplied with drinking water enriched with 235 microg C/L. Changes in the biofilms with ageing, disinfection, and phosphate treatment were monitored using fluorescence in situ hybridization. EUB338, BET42a, GAM42a, and ALF1b probes were used to target most bacteria and the alpha (alpha), beta (beta), and gamma (gamma)(More)
A pilot experiment examined lead leaching from four representative configurations of service lines including: (1) 100% lead (Pb), (2) 100% copper (Cu), (3) 50% Pb upstream of 50% Cu, and (4) 50% Pb-downstream of 50% Cu using a range of flow rates. The cumulative mass of lead release indicated that a typical partial replacement configuration (50% lead(More)
Direct chlorination of toxic cyanobacteria cells can occur at various stages of treatment. The objectives of this work are to determine and model the extent of Microcystis aeruginosa cells lysis, toxins and organic compounds release and oxidation, and quantify the subsequent disinfection by-products formation. Chlorine exposure (CT) values of 296 and 100 mg(More)
Water quality assessment involves the specific, sensitive, and rapid detection of bacterial indicators and pathogens in water samples, including viable but nonculturable (VBNC) cells. This work evaluates the specificity and sensitivity of a new method which combines a fluorescent in situ hybridization (FISH) approach with a physiological assay (direct(More)
Toxic cyanobacteria threaten the water quality of drinking water sources across the globe. Two such water bodies in Canada (a reservoir on the Yamaska River and a bay of Lake Champlain in Québec) were monitored using a YSI 6600 V2-4 (YSI, Yellow Springs, Ohio, USA) submersible multi-probe measuring in vivo phycocyanin (PC) and chlorophyll-a (Chl-a)(More)
This paper describes a fully automated online method for solid-phase extraction coupled with liquid chromatography and tandem mass spectrometry using atmospheric pressure ionization (LC-LC-APPI-MS/MS) to simultaneously detect selected dissolved natural and synthetic hormones at concentrations as low as 5 ng/L from aqueous matrices. The method shows(More)
Dwellings with/without a lead service line [LSL] were sampled for lead in tap water in Montreal, during different seasons. Short-term simulations using these results and the batchrun mode of the Integrated Exposure Uptake Biokinetic (IEUBK) model showed that children's exposure to lead at the tap in the presence of an LSL varies seasonally, and according to(More)