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Surface water sources are increasingly subject to proliferation of toxic cyanobacteria. Direct chlorination of source water containing toxic cyanobacterial cells for different treatment purposes might cause cell damage and toxin release. There is limited information available on chlorination of saxitoxins (STXs: saxitoxin, C-toxins, and gonyautoxins) produced by Anabaena circinalis. This work: (1) investigated the impact of chlorination on cell lysis and toxin/odor compound release in natural waters; (2) assessed the rates of chlorination of total STXs, and (3) estimated apparent rate constants for STX oxidation in ultrapure and natural waters. With a chlorine exposure (CT) value of 7.0 mg x min/L all cells lost viability causing toxin release. Cell-membrane damage occurred faster than released STXs oxidation. All saxitoxin and more than 95% of other STX analogues were subsequently oxidized. Kinetic analysis of the oxidation of STX analogues revealed significant differences in the susceptibility to chlorine, saxitoxin being the easiest to oxidize. Also, concentrations of trihalomethanes, haloacetic acids, and N-nitrosodimethylamine as chlorination byproducts were respectively

Various investigations encompassing microbial characterization of external sources of contamination (soil and trenchwater surrounding water mains, flooded air-valve vaults), field pressure monitoring, and hydraulic and transient analyses were conducted in the same distribution system where two epidemiological studies showing an increase in gastrointestinal illness for people drinking tap water were conducted in the 1990's. Interesting results include the detection of microorganisms indicators of fecal contamination in all external sources investigated but at a higher frequency in the water from flooded air-valve vaults, and the recording of 18 negative pressure events in the distribution system during a 17-month monitoring period. Transient analysis of this large and complex distribution system was challenging and highlighted the need to consider field pressure data in the process.

A rapid and reliable method enabling high-throughput sample analysis for quicker data generation, detection, and monitoring of eight selected steroid hormones in water matrixes was developed and validated. Our approach is based on a novel sample introduction method, the laser diode thermal desorption/atmospheric pressure chemical ionization (LDTD/APCI) coupled to tandem mass spectrometry (MS/MS). The optimization of instrumental parameters and a method application are presented. Our method was successfully applied to spiked effluent wastewater in the low-nanogram per liter concentrations with total analysis time reduced to seconds (15 s) using LDTD/APCI-MS/MS compared to minutes with traditional liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS) following solid-phase extraction (SPE). The instrumental detection limits for LDTD/APCI-MS/MS ranged from 5 to 24 microg L(-1) and from 13 to 43 ng L(-1) for the method detection limits. Calibration curves in wastewater matrix showed good linearity (R(2)0.99), and precision (intraday and interday) was below 20%. This work demonstrates that LDTD/APCI-MS/MS could be used for fast and effective quantitative analysis of emerging contaminants in different water matrixes with reduced cost by eliminating the chromatography step used in traditional LC-MS/MS.

Lead samples were collected at the tap from homes with lead service lines (LSLs) in a full-scale utility using both random daytime (RDT) and particulate stimulation sampling (PSS) protocols. Analysis of the results revealed two sources and occurrences of particulate lead. A first source is due to corrosion of lead-bearing elements in the premise plumbing (PP) and occurs mostly at low to moderate concentrations < 3 microg/L, with some sporadic higher concentrations (4-12 microg/L). These spikes were consistently observed and considerably increased using PSS, showing that current sampling protocols may miss a significant portion of particulate lead. The second source results from the adsorption of dissolved lead onto iron deposits in LSL/PP, and is continuously present at low to moderate concentrations. Statistical analyses were validated by physical analyses of: (i) lead scales from LSLs; and (ii) lead particles from tap aerators.

Stearoyl-CoA Desaturase-1 (SCD1) is the rate limiting enzyme catalyzing the synthesis of monounsaturated fatty acids. Variation of SCD1 activity and the ratio of saturated to unsaturated fatty acids have been implicated in a variety of diseases including obesity, type II diabetes and cancers. In liver, many factors regulate SCD1 expression including dietary and hormonal factors such as insulin and leptin. We previously showed in hepatic cells that insulin acts through the PI3K and mTOR pathways to upregulate SCD1 expression. In the present study, using HepG2 cells, we characterized the signaling pathway mediating the leptin inhibitory response on SCD1 gene expression. We showed that leptin inhibits SCD1 at the transcriptional level. Inhibition of the ERK1/2 MAPK pathway with the PD98059 reverses the effect of leptin on SCD1 expression. Our data also demonstrated that the effect of leptin is entirely independent of the effect of insulin. Using the pharmaceutical inhibitors Ag490 and SL0101, we showed that the inhibitory effect of leptin is also mediated by the Janus Kinase 2 (Jak2) and p90RSK. EMSA and transfection experiments suggest a key role for the Sp1 transcription factor, which in turn may compete for the binding of other transcription factors such as AP-1, leading to the inhibition of SCD1 transcription. Taken together, our observations showed that, independently of insulin action, leptin exerts an inhibitory effect on SCD1 transcription via a signaling pathway implicating Jak2, ERK1/2, and p90RSK which probably targets the downstream transcription factor Sp1 on the SCD1 promoter.

Negative pressures were measured in a full-scale distribution system following low pressure events at a water treatment plant. Transient analysis was used to model three downsurge events and compare the simulated pressure profiles with field measurement data. The objective of this work is to assess the source of uncertainty and variability associated with the estimation of intrusion volumes calculated by a transient analysis model. This assessment was conducted by comparing actual field pressure measurements and model outputs under various model settings (e.g., cavitation head, wave speed). For the three downsurge events, the modeled pressure profiles matched reasonably well with the measured pressures, as long as the pressures remained positive at a site. When the pressures reached negative values, the amplitude of the modeled pressures was larger than that of the recorded pressures. The difference between measured and modeled pressure is strongly related to a greater energy dissipation in the real distribution system, which is affected by the uncertain presence of air in pipes, the level of network skeletonization, and the allocation of demand. The estimation of intrusion volumes and risk for public health is directly affected by the pressure results obtained using transient analysis. Comparison to field data is therefore important to evaluate the accuracy of such a process.

This study investigates the oxidation of pharmaceuticals, endocrine disrupting compounds and pesticides during ozonation applied in drinking water treatment. In the first step, second-order rate constants for the reactions of selected compounds with molecular ozone (k(O3)) were determined in bench-scale experiments at pH 8.10: caffeine (650+/-22M(-1)s(-1)), progesterone (601+/-9M(-1)s(-1)), medroxyprogesterone (558+/-9M(-1)s(-1)), norethindrone (2215+/-76M(-1)s(-1)) and levonorgestrel (1427+/-62M(-1)s(-1)). Compared to phenolic estrogens (estrone, 17beta-estradiol, estriol and 17alpha-ethinylestradiol), the selected progestogen endocrine disruptors reacted far slower with ozone. In the second part of the study, bench-scale experiments were conducted with surface waters spiked with 16 target compounds to assess their oxidative removal using ozone and determine if bench-scale results would accurately predict full-scale removal data. Overall, the data provided evidence that ozone is effective for removing trace organic contaminants from water with ozone doses typically applied in drinking water treatment. Ozonation removed over 80% of caffeine, pharmaceuticals and endocrine disruptors within the CT value of about 2 mg min L(-1). As expected, pesticides were found to be the most recalcitrant compounds to oxidize. Caffeine can be used as an indicator compound to gauge the efficacy of ozone treatment.

A major strategy to reduce or prevent the formation of undesirable by‐products is to reduce chlorine demand before the application of chlorine. The major objective of this study was to evaluate the performance of different water treatment processes at full scale, specifically the combination of ozonation and biological activated carbon (BAG) filtration, for the removal of chlorine demand over a range of natural organic matrix and water temperature (l°‐23 °C). Both long term and short term chlorine demand were measured using a 2:1/C12:TOC ratio and pH 7,0 phosphate buffer at 20 °C in darkness. Results show that chlorine demand increases over a period of 200 hours and that long term chlorine demand can be modeled using a second order relation. Chlorine demand can be reduced by 55% for short term (4h) and by 61% long term (168h) by coagulation, floculation and sedimentation. The net effect of ozonation is variable depending on the prevalent oxidation conditions and on the organic matrix. In warm tem...

A simple on-line method was developed for the analysis of pharmaceuticals, pesticides and some metabolites in drinking, surface and wastewater samples. The technique is based on the use of on-line solid-phase extraction combined with liquid chromatography electrospray tandem mass spectrometry with positive electrospray ionization (LC-ESI(PI)-MS/MS). The injection of only 1 mL of filtered water sample is used with a total analysis time of 20 min, including the period required to flush the SPE cartridge with organic solvent and reconditioning the LC column. Method detection limits were in the range of 2 to 24 ng L(-1) for the compounds of interest, with recoveries from 87 to 110% in surface as well as wastewater samples. Matrix effects were observed for some compounds without exceeding more than 25%. All results displayed a good degree of reproducibility, with relative standard deviations (RSD) of less than 12% for all compounds. Moreover, at least 200 samples were analyzed without altering the performance of the pre-concentration column. This method was preferred over traditional off-line procedures because it minimizes tedious sample preparation, increases productivity and sample throughput. The analysis of various water and wastewater samples showed that caffeine, carbamazepine and atrazine could be detected in all the samples analysed and the selected compounds are always present in at least one of the sample types.

Relatively limited information is available regarding the impacts of temperature on the adsorption kinetics and equilibrium capacities of granular ferric hydroxide (GFH) for arsenic (V) and arsenic (III) in an aqueous solution. In general, very little information is available on the kinetics and thermodynamic aspects of adsorption of arsenic compounds onto other iron oxide-based adsorbents as well. In order to gain an understanding of the adsorption process kinetics, a detailed study was conducted in a controlled batch system. The effects of temperature and pH on the adsorption rates of arsenic (V) and arsenic (III) were investigated. Reaction rate constants were calculated at pH levels of 6.5 and 7.5. Rate data are best described by a pseudo first-order kinetic model at each temperature and pH condition studied. At lower pH values, arsenic (V) exhibits greater removal rates than arsenic (III). An increase in temperature increases the overall adsorption reaction rate constant values for both arsenic (V) and arsenic (III). An examination of thermodynamic parameters shows that the adsorption of arsenic (V) as well as arsenic (III) by GFH is an endothermic process and is spontaneous at the specific temperatures investigated.

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 excellent performance for the direct analysis of water and wastewater with respect to calibration curve linearity, analytic specificity, sensitivity, and carryover, as well as overall method accuracy and precision. With a runtime of 15 min, a minimum of 200 samples were analyzed using a single online solid-phase extraction (SPE) column without noticeable differences in system performance. Because of the ruggedness and simplicity of this system, generic methods can be easily developed and applied for the high-throughput analysis of a wide variety of compounds without the need to resort to laborious offline SPE sample preparation.

Biofilms were grown in annular reactors supplied with drinking water enriched with 235 µg 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 (α), beta (β), and gamma (γ) subclasses of Proteobacteria, respectively. The stability of biofilm composition was checked after the onset of colonization between T = 42 days and T = 113 days. From 56.0% to 75.9% of the cells detected through total direct counts with DAPI (4'-6-diamidino-2-phenylindole) were also detected with the EUB338 probe, which targets the 16S rRNA of most bacteria. Among these cells, 16.9%–24.7% were targeted with the BET42a probe, 1.8%–18.3% with the ALF1b probe, and

The impact of disinfection efficacy in natural waters was evaluated by performing disinfection assays using four untreated surface waters of various qualities and ultra-pure buffered waters as a baseline condition for comparison. Bacillus subtilis spores were spiked in these waters and disinfection assays were conducted at 22 °C using either free chlorine or chlorine dioxide. Assays using indigenous aerobic spores were also completed. The inactivation kinetics in natural and ultra-pure buffered waters were not statistically different (at p = 0.05 ) while using free chlorine, as long as disinfectant decay was taken into account. Filtering natural waters through a 0.45 μm did not improve the sporicidal efficacy of chlorine. For three out of the four waters tested, the efficacy of chlorine dioxide was greater in natural waters compared to that observed in ultra-pure buffered waters. Such results are consistent with previous observations using ultra-pure waters supplemented with NOM-extract from the Suwannee River. Similar to free chlorine results, the impact of filtration (0.45 μm) on the efficacy of chlorine dioxide was not statistically significant.

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 viable count [DVC]) for the direct enumeration, at the single-cell level, of highly diluted viable cells of members of the family Enterobacteriaceae in freshwater and drinking water after membrane filtration. The approach (DVC-FISH) uses a new direct detection device, the laser scanning cytometer (Scan RDI). Combining the DVC-FISH method on a membrane with Scan RDI detection makes it possible to detect as few as one targeted cell in approximately 10 8 nontargeted cells spread over the membrane. The ability of this new approach to detect and enumerate VBNC enterobacterial cells in freshwater and drinking water distribution systems was investigated and is discussed.

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 temperature are frequent in the spring and fall. Ammonia removals were monitored and the fixed nitrifying biomass was measured using a method of potential nitrifying activity. The impact of temperature was evaluated on two different filter media: an opened superstructure wood-based activated carbon and a closed superstructure activated carbon-based on bituminous coal. The study was conducted at two levels: pilot scale (first-stage filters) and full-scale (second-stage filters) and the results indicate a strong temperature impact on nitrification activity. Ammonia removal capacities ranged from 40 to 90% in pilot filters, at temperatures above 10 degrees C, while more than 90% ammonia was removed in the full-scale filters for the same temperature range. At moderate temperatures (4-10 degrees C), the first stage pilot filters removed 10-40% of incoming ammonia for both media (opened and closed superstructure). In the full-scale filters, a difference between the two media in nitrification performances was observed at moderate temperatures: the ammonia removal rate in the opened superstructure support (more than 90%) was higher than in the closed superstructure support (45%). At low temperatures (below 4 degrees C) both media performed poorly. Ammonia removal capacities were below 30% in both pilot- and full-scale filters.

As water quality variations in distribution systems may be influenced by a variety of factors (treatment breakthrough, intrusion, microbial regrowth), it is often quite difficult to identify the sources of water quality problems. In order to facilitate such a task, a study has been undertaken in which an integrated data management approach has been proposed. The central element of this approach is an interactive database analyser that is used for database requests and data visualization. Each water quality problem (positive coliform sample, consumer complaint...) may be investigated by looking at the related events that occurred in a specific spatial and temporal frame. Results of the request are directly displayed on a GIS interface for visualization.

Background This study investigated the oxidation of selected progestagenic steroid hormones by potassium permanganate at pH 6.0 and 8.0 in ultrapure water and wastewater effluents, using bench-scale assays. Second order rate constants for the reaction of potassium permanganate with progestagens (levonorgestrel, medroxyprogesterone, norethindrone and progesterone) was determined as a function of pH, presence of natural organic matter and temperature. This work also illustrates the advantages of using a novel analytical method, the laser diode thermal desorption (LDTD-APCI) interface coupled to tandem mass spectrometry apparatus, allowing for the quick determination of oxidation rate constants and increasing sample throughput. Results The second-order rate constants for progestagens with permanganate determined in bench-scale experiments ranged from 23 to 368 M-1 sec-1 in both wastewater and ultrapure waters with pH values of 6.0 and 8.0. Two pairs of progestagens exhibited similar reaction rate constants, i.e. progesterone and medroxyprogesterone (23 to 80 M-1 sec-1 in ultrapure water and 26 to 149 M-1 sec-1 in wastewaters, at pH 6.0 and 8.0) and levonorgestrel and norethindrone (179 to 224 M-1 sec-1 in ultrapure water and 180 to 368 M-1 sec-1 in wastewaters, at pH 6.0 and 8.0). The presence of dissolved natural organic matter and the pH conditions improved the oxidation rate constants for progestagens with potassium permanganate only at alkaline pH. Reaction rates measured in Milli-Q water could therefore be used to provide conservative estimates for the oxidation rates of the four selected progestagens in wastewaters when exposed to potassium permanganate. The progestagen removal efficiencies was lower for progesterone and medroxyprogesterone (48 to 87 %) than for levonorgestrel and norethindrone (78 to 97%) in Milli-Q and wastewaters at pH 6.0-8.2 using potassium permanganate dosages of 1 to 5 mg L-1 after contact times of 10 to 60 min. Conclusion This work presents the first results on the permanganate-promoted oxidation of progestagens, as a function of pH, temperature as well as NOM. Progestagen concentrations used to determine rate constants were analyzed using an ultrafast laser diode thermal desorption interface coupled to tandem mass spectrometry for the analysis of water sample for progestagens.

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 from the E. coli specific β-glucuronidase gene (uidA), the primary pair producing a 486-bp fragment that was used as template for the nested primer pair delineating a 186-bp fragment. This protocol can detect 1–10 bacterial cells/50 mL water sample within 6–8 h, in contrast to traditional culturing or Southern hybridization methods which require 2–3 days for results.Key words: nested PCR, sensitive, detection, potable water.

Monitoring and analysis of trace contaminants such as pharmaceuticals and pesticides require the preservation of the samples before they can be quantified using the appropriate analytical methods. Our objective is to determine the sample shelf life to insure proper quantification of ultratrace contaminants. To this end, we tested the stability of a variety of pharmaceutical products including caffeine, natural steroids, and selected pesticides under refrigerated storage conditions. The analysis was performed using multi-residue methods using an on-line solid-phase extraction combined with liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) in the selected reaction monitoring mode. After 21 days of storage, no significant difference in the recoveries was observed compared to day 0 for pharmaceutical products, while for pesticides, significant losses occurred for DIA and simazine after 10 days (14% and 17% reduction respectively) and a statistically significant decrease in the recovery was noted for cyanazine (78% disappearance). However, the estrogen and progestogen steroids were unstable during storage. The disappearance rates obtained after 21 days of storage vary from 63 to 72% for the feminizing hormones. Overall, pharmaceuticals and pesticides seem to be stable for refrigerated storage for up to about 10 days (except cyanazine) and steroidal hormones can be quite sensitive to degradation and should not be stored for more than a few days.

Dans la présente étude, nous montrons l'évolution de l'eau dans un réseau de distribution. Ce réseau a été construit dans les années 70 à l'aide de conduites d'acier ou de fonte ductile munies d'un revêtement intérieur de ciment. Il est alimenté par des eaux de très bonne qualité qui circulent d'abord dans une suite de conduites maîtresses (de 2 700 mm à 900 mm) jusqu'à un secteur de petites conduites maillées (200 et 300 mm). Des échantillons d'eau ont été prélevés à 14 reprises durant une année, le long de la conduite maîtresse (le temps de séjour y varie de 0 h à 13,6 h) et dans le secteur de petites conduites (de 13,6 h à 18,4 h). Nous avons mesuré la température, le pH, plusieurs sous-produits de désinfection dont les trihalométhanes et les aldéhydes, le carbone organique total et biodégradable ainsi que les concentrations de bactéries hétérotrophes aérobies et anaérobies facultatives (BHA) et les comptes directs totaux mesurés en épifluorescence. Le réseau a très peu d'effet sur l'évolution des sous-produits de désinfection. En effet, les résultats obtenus à partir des échantillons témoins (eaux traitées conservées dans un flacon propre à la même température que dans le réseau) sont semblables à ceux obtenus à partir des eaux prélevées dans le réseau de distribution.Les concentrations de bactéries ainsi que les concentrations de CODB sont assez stables dans le réseau. Il est intéressant de noter qu'il y a de 0,2 à 0,45 mg/l de CODB, ce qui est supérieur à la concentration minimale de 0,15 mg/l requise pour la croissance des bactéries. Par contre, le chlore résiduel libre est toujours supérieur à 0,20 mg/l. Une seule exception, le 11 juillet 1994, dans le secteur de petites conduites, le chlore résiduel a baissé jusqu'à 0,16 mg/l. Durant cette journée, nous avons observé une légère augmentation des comptes directs totaux mesurés en épifluorescence., Studies were performed to follow the changes in water quality along a distribution system. The distribution system under study is divided into two parts: main pipes starting from the plant (from 2 700 mm to 900 mm diameter) feeding a small pipes sector (200 mm and 300 mm diameter). Residence times range from 0 to 13.6 hours in main pipes and from 13.6 h to 18.4 h in small pipes. All pipes are made of steel or ductile iron and their interior is lined with concrete; there is therefore little corrosion. Since the raw water is of such high quality, the treatment plant is very simple: a direct filtration on sand followed by ozonation and chlorine disinfection. Samples were taken on 14 occasions, during a full year period, in the distribution system and in the treatment plant after chlorination. These last samples were incubated in clean flasks at the network temperature. Measurements of temperature, pH, disinfection by-products (trihalomethanes, aldehydes, haloacetonitriles, haloacetones and chloropicrine), total organic carbon (TOC), biodegradable dissolved organic carbon (BDOC) and number of bacteria (heterotrophic plate count and total direct count by epifluorescence) were completed.The distribution network seems to have very little effect on chlorine demand and disinfection by-products. Results from water incubated in flasks are similar to those from distribution network. After more than 18 hours contact time, the chlorine residual is still higher than 0.2 mg/l in most of the samples taken in the distribution network and in the flask. It should be noted that the initial chlorine concentrations range from 0.65 mg/l (cold water) to 1.00 mg/l (warm water). Chlorine demand and trihalomethane (THM) curves are typical, a rapid increase with time followed by a relatively stable level. THM concentrations in the distribution network are low: a typical value of 14 µg/l after 13.6 hours contact time is detected. The maximum concentration of 43 µg/l of total THM was measured in a dead end. In this latter sample, 42 % of the THM was present as bromodichloromethane and 39 % as chloroform. Other by-products such as haloacetonitrile, haloacetone and chloropicrine were always detected in very small concentrations.Aldehyde concentrations in treated water were low, between 21 and 42 µg/l. These concentrations were stable throughout the distribution system. Fixed and free biomass seems to have very little effect on these biodegradable compounds. These results were confirmed by BDOC results. BDOC in treated water ranges from 0.2 to 0.45 mg/l and remains stable in the distribution system. These low BDOC concentrations and the chlorine residual of approximately 0.2 mg/l seem to be sufficient to prevent regrowth in the distribution system. Total direct counts by epifluorescence showed almost no increase of bacterial density except for the July 11th sample. This is the only day where the free chlorine residual dropped below 0.2 mg/l, with values of free chlorine residual dropping as low as 0.16 mg/l.

Catalogue de l'exposition "La Maison Mame, deux siècles d'édition à Tours", Château de Tours, Tours, 18 mars-30 avril 2011; National audience; A l'occasion du bicentenaire de la naissance d'Alfred Mame, ce livre propose de retracer l'histoire de cette grande maison d'édition installée à Tours dès le début du XIXe siècle. La dynastie des Mame sera en effet à la tête de cet empire de l'édition pendant presque deux siècles. Les imprimeurs Mame ont tenu un rôle de pionnier dans l'industrialisation de l'édition française, non seulement par l'ampleur et la modernité de l'imprimerie qu'ils dirigent, mais aussi par l'intuition qu'ils développent, très tôt, de la manière dont un éditeur moderne doit structurer son catalogue pour conquérir un marché de grande envergure. Cette maison règne aussi sur toute la chaîne du livre regroupée dans l'usine de Tours : de la papeterie à proximité de Tours, en passant par les auteurs dits maison, jusqu'à la fabrication et la diffusion du livre.