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Effects of sodium hypochlorite exposure mode on PES/PVP ultrafiltration membrane degradation

Effects of sodium hypochlorite exposure mode on PES/PVP ultrafiltration membrane degradation

to the repository administrator: tech-oatao@listes-diff.inp-toulouse.fr This is an author’s version published in: http://oatao.univ-toulouse.fr/20573 To cite this version: Causserand, Christel and Pellegrin, Bastien and Rouch, Jean-Christophe Effects of sodium hypochlorite exposure mode on PES/PVP ultrafiltration membrane

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Permeability and chemical analysis of aromatic polyamide based membranes exposed to sodium hypochlorite

Permeability and chemical analysis of aromatic polyamide based membranes exposed to sodium hypochlorite

In this study, a cross-linked aromatic polyamide based reverse osmosis membrane was exposed to vari- able sodium hypochlorite ageing conditions (free chlorine concentration, solution pH) and the resulting evolutions of membrane surface chemical and structural properties were monitored. Elemental and sur- face chemical analysis performed using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR), showed that chlorine is essentially incorporated on the polyamide layer of a commercially available composite RO membrane, when soaked in chlorine baths, presumably through a two step electrophilic substitution reaction governed by the concentration of hypochlorous acid (HOCl), at pH values above 5. Deconvolution of the FTIR vibrational amide I band experimentally confirmed previ- ous assumptions stated in the literature regarding the weakening of polyamide intermolecular hydrogen bond interactions with the incorporation of chlorine. An increase in the fraction of non associated C O
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ASSESSMENT OF THE ADSORPTION OF AEROMONAS HYDROPHILA ON POLYTHENE IN SODIUM HYPOCHLORITE AND HYDROGEN PEROXIDE TREATED WATER

ASSESSMENT OF THE ADSORPTION OF AEROMONAS HYDROPHILA ON POLYTHENE IN SODIUM HYPOCHLORITE AND HYDROGEN PEROXIDE TREATED WATER

Research in BioSciences, vol. 2, pp. 33–48. - LONTSI DJIMELI C., TAMSA ARFAO A., NOAH EWOTI O.V., NOUGANG M.E., MOUNGANG M.L., BRICHEUX G., NOLA M., SIME-NGANDO T. (2014) Mixture of Sodium Hypochlorite and Hydrogen Peroxide on Adhered Aeromonas hydrophila to Solid Substrate in Water: Impact of Concentration and Assessment of the Synergistic Effect. International Journal of Bacteriology. Volume 2014, Article ID 121367, 13p.

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Adhesion of Candida albicans to polythene in Sodium hypochlorite disinfected aquatic microcosm and potential impact of cell surface properties

Adhesion of Candida albicans to polythene in Sodium hypochlorite disinfected aquatic microcosm and potential impact of cell surface properties

The adhesion of C. albicans cells harvested from different growth stages to polythene in Sodium hypochlorite (NaOCl) treated water, under static and dynamic conditions was carried out. With cells harvested from the lag, exponential, stationary and decline growth phases, the highest abundance of cells adhered was respectively 0.75, 1.18, 0.85 and 0.95 units (Log (CFU/cm²)), when considering the static and dynamic experimental condition. The hydrophobicity values ranged respectively from 17 to 99, 45 to 93, 8 to 93, and from 10 to 83 %. The increase in incubation duration was significantly correlated (P<0.01) to the decrease in the abundance of adhered C. albicans when considering the NaOCl concentrations used. The increase in the NaOCl concentration in water was significantly correlated (P<0.01) to the increase in the abundance C. albicans adhered to polythene when considering the incubation durations. An increase in NaOCl concentration in the water seems significantly correlated with the decrease of the abundance of C. albicans adhered to the substrate (P<0.01) when considering each cell growth phase. Using the H (Kruskal-Wallis) test to compare the registered mean abundances of cells adhered to polythene after living in water treated with various concentrations of NaOCl with respect to the growth phase, a significant difference (P<0.05) was noted with cells coming from the exponential, stationary and decline growth stages. The adhesion of C. albicans to polythene seems to be impacted by various factors with some depending on the cells status.
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Effects of sodium hypochlorite exposure mode on PES/PVP ultrafiltration membrane degradation

Effects of sodium hypochlorite exposure mode on PES/PVP ultrafiltration membrane degradation

to the repository administrator: tech-oatao@listes-diff.inp-toulouse.fr This is an author’s version published in: http://oatao.univ-toulouse.fr/20573 To cite this version: Causserand, Christel and Pellegrin, Bastien and Rouch, Jean-Christophe Effects of sodium hypochlorite exposure mode on PES/PVP ultrafiltration membrane

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Mixture of Sodium Hypochlorite and Hydrogen Peroxide on Adhered Aeromonas hydrophila to Solid Substrate in Water: Impact of Concentration and Assessment of the Synergistic Effect

Mixture of Sodium Hypochlorite and Hydrogen Peroxide on Adhered Aeromonas hydrophila to Solid Substrate in Water: Impact of Concentration and Assessment of the Synergistic Effect

For each cell growth phase, a significant difference was observed between the mean densities of cells adhered after the action of the different concentrations of the mixture of disinfect[r]

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Multi-scale analysis of hypochlorite induced PES/PVP ultrafiltration membranes degradation

Multi-scale analysis of hypochlorite induced PES/PVP ultrafiltration membranes degradation

PVP Ultrafiltration a b s t r a c t In drinking water production plants, the use of oxidants such as sodium hypochlorite during in-place cleanings may impair the membrane integrity and radically impact the ultrafiltration process efficiency, leading to potential contamination of the permeate water with pathogens. This study investigates the effects of hypochlorite exposure on the properties of a commercially available UF hollow fiber. Mechanical performances and water permeability appeared to be greatly affected by the contact with hypochlorite. Monitoring the molecular changes by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance infrared spectroscopy (ATR-IR), size exclusion chromatography (SEC) and VITA-mode atomic force microscopy (VITA-AFM) revealed high stability of the main polymer constituting the membrane (i.e. polyethersulfone (PES)) and very high reactivity of the additive (i.e. poly(N-vinyl pyrrolidone) (PVP)) towards immersion in aqueous sodium hypochlorite solution with maximal reaction rate for neutral to slightly basic pH. Correlation of those results unexpectedly leads to the conclusion that the overall membrane properties changes are governed by the additive fate.
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Filtration performance and pore size distribution of hypochlorite aged PES/PVP ultrafiltration membranes

Filtration performance and pore size distribution of hypochlorite aged PES/PVP ultrafiltration membranes

The studies concerning the role played by sodium hypochlorite on PES Ultrafiltration membranes [4-13] mainly focus on changes in the macromolecular chemical composition, hydrophilic character, permeability and mechanical properties. However, the impact of NaClO on membrane selectivity by means of tracer’s retention measurements (and selectivity curve determination) has not been thoroughly investigated and understood. The few available publications concerning the effects of the cleaning agent NaClO on retention properties of PES UF membranes [4, 5, 9, 12, 13] only mention the observed retention without taking into account the evolution of permeability, consequently ignoring the impact of concentration polarization and possible fouling on the final retention results. In addition, in most cases, proteins are used as tracers even though they are known to have greater interaction with the membrane material compared to polymeric ones.
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Experimental study of the effects of hypochlorite on polysulfone membrane properties

Experimental study of the effects of hypochlorite on polysulfone membrane properties

Abstract Although chemical solutions are widely employed to clean membranes, they can also be responsible for changes in membrane properties. The two major drawbacks are then either the functional properties of the membrane gradually change, so the production can no longer meet requirements in terms of volume or quality, or the membrane simply breaks up (hollow fibers), and the system has to be shut down during maintenance. The aim of this experimental study was to gain a better understanding of the effect of hypochlorite cleaning solutions in different conditions (various pHs and temperatures) on the changes observed on an ultrafiltration hollow fiber membrane made from polysulfone (PSf) and polyvinylpyrrolidone (PVP). A wide range of methods characterizing the material have been used, from the atomic scale (ESCA) up to the module scale by force measurements on fibers. Exposure to sodium hypochlorite at rather high concentration seems to lead to chain breaking in the PSf molecules (gel permeation chromatography results). The consequences are changes in the membrane texture (scanning electron microscopy images), which are closely related to changes in the mechanical properties of the membrane. Membrane permeability appears to be poorly sensitive to such changes, which can be related to the fact that the permeability relies on the skin properties mainly.
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Études chimique et biologique de l’alginate de sodium oxydé par l’hypochlorite de sodium ou conjugué à la gélatine à travers la réaction de Maillard

Études chimique et biologique de l’alginate de sodium oxydé par l’hypochlorite de sodium ou conjugué à la gélatine à travers la réaction de Maillard

This work aims to study the chemical modification of sodium alginate by two different ways: Partial oxidation of polysaccharide in the presence of sodium hypochlorite. The latter, is to prepare new alginate / gelatin films by means of Millard reaction. Hydroxylamine and acid-base assay methods were used to quantify the aldehyde and carboxyl groups of oxidized sodium alginate, respectively. Monitoring of the Millard reaction was established by UV-Vis of the intensity of browning, determination of free amino-groups and protein (titration with BCA), calculation the number of moles of ε-amino groups and evaluation the rate of crosslinking are established. The obtained hydrogels were characterized and identified by means of FT-IR, XRD and TGA. The morphology was determined by SEM. All these materials showed an antiradical activity and reducing power. The hemocompatibility test revealed that in vitro compounds are non-hemolytic. Also, these materials indicate an anti-inflammatory activity by inhibition of the denaturation of protein. According to antibacterial test, the hydrogels exhibit an inhibition of the growth of three different bacterial strains (Staphylococus aureus ATCC 25923, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853).
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Modeling of underexpanded reactive CO2-into-sodium jets, in the frame of sodium fast reactors

Modeling of underexpanded reactive CO2-into-sodium jets, in the frame of sodium fast reactors

(SCR) and the reaction products. The exothermic reaction has been proven to occur in the range of temperature between 300 and 700°C. The analysis of reac- tion products showed the presence of the carbon, oxygen and sodium elements, which is consistent with previous literature studies that list CO, Na2CO3 and Na2C2O4 as reaction products [16]. The specific reaction pathways found are different, depending on reactants temperature, as it will be detailed in para- graph 2.2. The present work is aimed at improving the comprehension of the actual interaction mechanism and consequences of a SCR inside a Na-CO2 heat exchanger of a SFR, following the previous results obtained by Gicquel. Considering the operative pressures, a leakage in the CO2-Na heat exchanger would result in a phenomenon analogous to the one already described for the steam generator SWR accidental scenario: an underexpanded reactive CO2- into-liquid-sodium jet. One main difference, from the safety point of view, between the SWR and the SCR, is the proven absence of wastage phenomena in case of SCR [8]. In fact, no corrosive products are created by the SCR. Eoh et al. investigated steam-into-sodium and CO2-into-sodium jet impingement consequences, using an experimental facility allowing to inject highly pressur- ized gas into liquid sodium. Figure 1.7 shows the different consequences of SWR and SCR on a 9Cr-1Mo steel target placed at a distance of 12.0 mm from a 0.3 mm diameter nozzle. Injection pressure was 5.5 MPa for the CO 2 case and 15.0 MPa for the steam case. Liquid sodium initial temperature was 400°C and 450°C. Injection time was 120 seconds for the SCR case and 30 seconds for the SWR case.
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L’oxybate de sodium pour des sédations profondes en fin de vie

L’oxybate de sodium pour des sédations profondes en fin de vie

Les effets indésirables imputables à l’oxybate de sodium étaient principalement mineurs à type de myoclonies pour sept d’entre eux. Ces myoclonies n’ont jamais motivé l’arrêt de la sédation ou l’arrêt de l’oxybate de sodium. Un OAP est survenu chez un seul patient. Le dossier ne précise pas les critères diagnostiques ni sa responsabilité éventuelle dans la survenue du décès mais n’a pas motivé l’arrêt de l’oxybate de sodium. L’OAP peut potentiellement être un effet secondaire de l’oxybate de sodium du fait de la forte teneur en sodium des ampoules. Cependant, bien d’autres facteurs peuvent concourir à la survenue d’un OAP dans ce contexte. La prise en charge de ces effets indésirables a par ailleurs toujours été possible sans la présence d’un réanimateur ou d’un autre spécialiste que les médecins du service de soins palliatifs. Concernant les effets indésirables « généraux » liés à la sédation, on rappelle ici que l’encombrement bronchique retrouvé chez 18 de nos 36 patients est très fréquent (de l’ordre de 50% des patients dans certaines études) lors de la phase agonique et il est difficile de savoir s’il est attribuable à la sédation en général et plus spécifiquement à l’oxybate de sodium ou s’il est le fait de l’évolution naturelle de la maladie du patient (27).
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Étude de l'effet modérateur de sels sur la réaction sodium-eau, pour le "lavage" d'assemblages de combustible irradiés issus de réacteurs à caloporteur sodium

Étude de l'effet modérateur de sels sur la réaction sodium-eau, pour le "lavage" d'assemblages de combustible irradiés issus de réacteurs à caloporteur sodium

53 Le sodium est un matériau qui réagit avec le di oxygène de l’atmosphère. Même à température ambiante, il se recouvre rapidement d’un film passif d’oxyde de sodium. Pour ces raisons, on cherche à protéger le sodium de l’humidité de l’atmosphère qui est aussi un facteur de modification de l’état de surface du sodium. Le sodium est donc conservé en boîte à gants inertée (gaz inerte : argon) pour le conserver le plus propre possible. Le dispositif d’introduction du sodium est conçu de façon à ce que l’échantillon de sodium puisse être acheminé depuis la boîte à gants jusqu’au dispositif sans être en contact avec l’atmosphère. Ce système est représenté en Figure 16. Un creuset métallique fermé par une vanne étanche manuelle V6 est introduit en boîte à gants, vanne V6 ouverte, via un sas. L’intérieur du creuset est inerté via la procédure d’inertage du sas. La vanne étant alors ouverte, l’échantillon de sodium est introduit. Après fermeture de la vanne V6, le creuset est sorti et acheminé jusqu’au dispositif sur lequel il est fixé via un joint de type métal-métal. L’électrovanne V7 solidaire du dispositif, est ouverte pour permettre l’inertage du dispositif jusqu’à la vanne V6. Elle est ensuite fermée et V6 est ouverte manuellement.
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One-Step Synthesis of Sodium Trimetaphosphate (Na3P3O9) from Sodium Chloride and Orthophosphoric Acid

One-Step Synthesis of Sodium Trimetaphosphate (Na3P3O9) from Sodium Chloride and Orthophosphoric Acid

(5) Kutun, S.; Akseli, A. New elution agent, sodium trimetaphos- phate, for the separation and determination of rare earths by anion- exchange chromatography. J. Chromatogr., A 1999, 847, 261. (6) Li, B. Z.; Wang, L. J.; Li, D.; Chiu, Y. L.; Zhang., Z. J.; Shi, J.; Chen., X. D.; Mao, Z. H. Physical properties and loading capacity of starch-based microparticles crosslinked with trisodium trimetaphos- phate. J. Food Eng. 2009, 92, 255.

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Influence de la microstructure de la thorine yttriée sur sa tenue au sodium, en vue de réaliser des sondes à oxygène dans les réacteurs au sodium de IVème Génération.

Influence de la microstructure de la thorine yttriée sur sa tenue au sodium, en vue de réaliser des sondes à oxygène dans les réacteurs au sodium de IVème Génération.

27 D’ici à 2030, la demande énergétique aura vraisemblablement doublé sous l’effet conjugué de l’augmentation progressive de la population mondiale et de la croissance économique des pays émergents. Afin d’y répondre tout en tenant compte de l’épuisement à moyen ou long terme des ressources, il devient donc indispensable de disposer de sources d’énergie compétitives [1]. Créé en 2000, le Forum International Génération IV, regroupant à ce jour 14 pays membres, est ainsi le cadre d’une coopération internationale en matière de Recherche et Développement pour le nucléaire du futur. Différents objectifs ont été instaurés comme une sûreté renforcée, des réacteurs durables et économes en uranium, l’amélioration de la résistance à la prolifération nucléaire (en brûlant les stocks de plutonium), ainsi que la réduction à long terme de la radiotoxicité des déchets de haute activité et de longue période… Dans ce but, six concepts de réacteurs ont été retenus. Pour certains concepts, il s’agit de réacteurs à neutrons rapides (RNR) associés à différents caloporteurs (gaz, sodium, plomb), ainsi que de réacteurs à eau supercritique (RESC), gaz à très haute température (RTHT) et à sels fondus (RSF) [2].
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Sodium Dihydrogen Phosphate Starting From Sodium Chloride and Orthophosphoric Acid Via Cation Resin Exchange

Sodium Dihydrogen Phosphate Starting From Sodium Chloride and Orthophosphoric Acid Via Cation Resin Exchange

acidifying the quantity of resin present in the column. Then, the column was rinsed with 50 mL of water following the regeneration. For all the steps 1 to 3, the total quantity of liquid phase from the outlet of the reactor (including rinsing water) was recovered. ICP-AES and ion chromatography were carried out for determining the content of sodium, chloride, and phosphate. This allowed calculating the mass balance of each component.

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RHEOLOGICAL PROPERTIES OF SODIUM ALGINATE SOLUTIONS

RHEOLOGICAL PROPERTIES OF SODIUM ALGINATE SOLUTIONS

ionic strength has not yet been established. These results agree with results of Ramón et al (2010). 31 Sodium alginate, like basically all the monovalent salts of alginate, is highly soluble in water owing to the favorable entropic contribution from the free countreions. This consideration leads immediately to identification of the presence of high amount of supporting salt as a limiting condition for the solubilization of the polyanion. In fact, the addition of 1:1 salts will progressively disfavor the solubility of the alginate chain, leading eventually to phase separation. The salting-out effect can be efficiently used for the fractionation of alginates. In addition, concentration of supporting salt even lower that 0.1M slows down the kinetics of dissolution of alginate particles and
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KV4.3 Expression Modulates NaV1.5 Sodium Current

KV4.3 Expression Modulates NaV1.5 Sodium Current

K V 4.3 via β1 to form a macromolecular complex. In neurons, both sodium and potassium channels mainly localize at the axon initial segment (AIS), a subcellular region involved in AP genesis. Ion channel recruitment to the AIS is highly dependent on the cytoskeleton and associated proteins which densely populate this region ( Brachet et al., 2010; Leterrier et al., 2011; Vacher et al., 2011 ). A comparable structure is observed at the intercalated discs in adult cardiomyocytes, a subcellular region also characterized by a high density of sodium channels ( Agullo- Pascual et al., 2014; Marsman et al., 2014; El Refaey et al., 2017 ). Our findings, together with existing knowledge, may suggest a potential subcellular co-localization of K V 4.3 and Na V 1.5 in
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Evaluation of the Physical Stability of Zinc Oxide Suspensions Containing Sodium Poly-(acrylate) and Sodium Dodecylsulfate

Evaluation of the Physical Stability of Zinc Oxide Suspensions Containing Sodium Poly-(acrylate) and Sodium Dodecylsulfate

Polymers and surfactants are used together in several applications. As a result, interactions between polymers and charged surfactants in aqueous solutions have attracted increasing attention because of their complex behaviors and potential applications in rheological control, detergency, and pharmaceutical formulations. [15] Yet, there are very few investigations on the interactions between carboxylates, such as poly-(acrylic) acid (PAA), and anionic surfactants, such as sodium dodecylsulfate (SDS). Using fluorescence, conductivity and viscosity measurements, Binana-Limbele and Zana [16] and Iliopoulos et al. [17] concluded that there was no direct interaction between SDS and NaPAA. How- ever, obviously, as a sodium salt, the latter decreases the critical micelle concentration (CMC) of SDS through electrostatic effects. On the other hand, Maltesh and Somasundaran [18] reported that, in an earlier study, Eliassaf had observed that, at low values of pH, the reduced viscosity of PAA increased as SDS concentration was increased. Through a fluorescence spectroscopic investi- gation, Maltesh and Somasundaran [18] found that these interactions depended significantly on PAA concentration and pH (ionization degree of PAA). Wang and Tam [19] also reported evidence of interaction between SDS and PAA for a neutralization degree of PAA lower than 0.2. Hydrocarbon chains of SDS cooperatively bind to apolar segments of PAA through hydrophobic interaction.
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Electron photoemission from sodium and carbon clusters

Electron photoemission from sodium and carbon clusters

From the theoretical perspective, the description of quantum many-body sys- tems has experienced major changes, too. Starting with phenomenological shell models like the Clemenger-Nilsson model [20] for simple metal clusters, static many-body [21] and time-dependent perturbative approaches [22], full time-de- pendent many-body calculations [23, 24] determining the dynamical response of clusters are commonly performed today. This was, of course, made possible only by the enormous evolution of computing facilities in the past decades. A theoreti- cal tool of choice is the time-dependent density-functional theory (TDDFT). The method derived in 1964 by Hohenberg and Kohn [25], is nowadays widely used to describe the electronic structure and dynamics in atoms, molecules, clusters and bulk material. This thesis deals with the calculation of PES and PAD from sodium and carbon clusters using TDDFT. It is outlined as follows:
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