Modification de la matière organique lors des traitements conventionnels de potabilisation

Lefebvre, E.; Croué, Jean-Philippe

doi:10.7202/705233ar

Cited by 6 publications

(3 citation statements)

References 9 publications

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“…This enabled the coagulant to target other organic compounds that would normally be less well removed, a phenomena seen before in IEX treated water prior to coagulation (Metcalfe et al, 2015). These results align with that seen previously, where some researchers have seen improved removal of HPO (Sharp et al, 2006a;Matailanen et al, 2010), while others have seen no significant change in the removal of organic fractions of different hydrophobicity (Lefebvre and Croue, 1995).…”

Section: The Removal Of Fractions Of Differing Hydrophobicitysupporting

confidence: 86%

The combined influence of hydrophobicity, charge and molecular weight on natural organic matter removal by ion exchange and coagulation

et al. 2020

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Three different source waters were investigated using virgin and pre-used anion exchange resins, coagulation, and ion exchange combined with coagulation (IEX&Coagulation). The hydrophobicity, size distribution and charge of natural organic matter (NOM) were used to evaluate its removal. Dissolved organic carbon (DOC) removal by pre-used IEX resin was 67-79%. A consistent ratio of different hydrophobicity fractions was found in the removed DOC, while the proportion and quantity of the molecular weight fraction around 1 kDa was important in understanding the treatability of water. For pre-used resin, organic compounds were hypothesised to be restricted to easily accessible exchange sites. Comparatively, virgin resin achieved higher DOC removals (86-89%) as resin fouling was absent. Charge density and the proportion of the hydrophobic fraction were found to be important indicators for the specific disinfection byproduct formation potential (DBP-FP). Treatment of raw water with pre-used resin decreased the specific DBP-FP by between 2-43%, while the use of virgin resin resulted in a reduction of between 31-63%. The highest water quality was achieved when the combination of IEX and coagulation was used, reducing DOC and the specific DBP-FP well below that seen for either process alone.

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Section: The Removal Of Fractions Of Differing Hydrophobicitysupporting

confidence: 86%

The combined influence of hydrophobicity, charge and molecular weight on natural organic matter removal by ion exchange and coagulation

et al. 2020

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“…The much more favorable effect of the AOM-O 3 is in agreement with the action of ozone, which renders organic matter more biodegradable by breaking chemical bonds, aromatic cycles, etc. (10,11,21,28,30,35). It is indeed highly probable that the compounds released by Chlorella algae are high-molecular-weight biopolymers (polysaccharides such as cellulose, pectin, etc.)…”

Section: Discussionmentioning

confidence: 99%

Escherichia coli Behavior in the Presence of Organic Matter Released by Algae Exposed to Water Treatment Chemicals

Bouteleux

Saby²,

Tozza

et al. 2005

Appl Environ Microbiol

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When exposed to oxidation, algae release dissolved organic matter with significant carbohydrate (52%) and biodegradable (55 to 74%) fractions. This study examined whether algal organic matter (AOM) added in drinking water can compromise water biological stability by supporting bacterial survival. Escherichia coli (1.3 ؋ 10 5 cells ml ؊1 ) was inoculated in sterile dechlorinated tap water supplemented with various qualities of organic substrate, such as the organic matter coming from chlorinated algae, ozonated algae, and acetate (model molecule) to add 0.2 ؎ 0.1 mg of biodegradable dissolved organic carbon (BDOC) liter ؊1 . Despite equivalent levels of BDOC, E. coli behavior depended on the source of the added organic matter. The addition of AOM from chlorinated algae led to an E. coli growth equivalent to that in nonsupplemented tap water; the addition of AOM from ozonated algae allowed a 4-to 12-fold increase in E. coli proliferation compared to nonsupplemented tap water. Under our experimental conditions, 0.1 mg of algal BDOC was sufficient to support E. coli growth, whereas the 0.7 mg of BDOC liter ؊1 initially present in drinking water and an additional 0.2 mg of BDOC acetate liter ؊1 were not sufficient. Better maintenance of E. coli cultivability was also observed when AOM was added; cultivability was even increased after addition of AOM from ozonated algae. AOM, likely to be present in treatment plants during algal blooms, and thus potentially in the treated water may compromise water biological stability.In spite of the disinfection processes, bacterial proliferation can be observed in drinking water distribution network systems (20,26,37,42) proving that certain bacterial populations are able to adapt, transiently or permanently, to the oligotrophic conditions of distribution networks (16,17). This phenomenon has been described for fecal indicators such as coliform bacteria, particularly Escherichia coli (16), and poses the problem of compliance with water quality health regulations.Although multiple factors certainly affect microbial growth phenomena, organic matter in treated waters, mainly the biodegradable fraction, has a determining effect since it provides a carbon and energy source essential to the growth of heterotrophic bacteria, including coliforms (16,19,25,38,39,42). Atypical events (algal bloom, swelling, rainfall, etc.) capable of modifying the quality of the organic matter in raw and treated waters have been suggested to be a catalyst for coliform growth (3, 18, 23). Lake et al. (15) showed that there is a strong link between the end of the algal bloom and the presence of coliforms in the distribution system, leading to a situation incompatible with health standards. Algal products in the treated water were suspected of providing a good nutritional source for bacterial regrowth in the distribution system. In addition to the natural capacity of algae to secrete organic compounds, massive contamination at the inlet of a treatment plant using preoxidation can lead to algal cell lysis and re...

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“…(LEFEBVRE et CROUE, 1995). La présence de phénols dans l'environnement provient des eaux résiduaires et des flux d'air rejetés lors de la production, de la transformation ou de l'utilisation du phénol.…”

Section: Introductionunclassified

Coagulation-floculation au sulfate d’aluminium de composés organiques phénoliques et effet de sels de calcium et de magnésium

Hecini

Achour

2014

rseau

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L’objectif de la présente étude est d’observer l’efficacité de la coagulation-floculation par le sulfate d’aluminium sur l’élimination des composés organiques à fonctions phénoliques (phénol et pyrogallol). L’intérêt s’est porté plus particulièrement sur l’incidence de sels minéraux constitutifs de la dureté « calcium et magnésium » et souvent présents dans la matrice minérale des eaux algériennes. Des essais de Jar-Test ont été réalisés sur les deux composés phénoliques dissous dans l’eau distillée seule, puis enrichie en sels minéraux. Ces essais ont été réalisés sur des solutions synthétiques d’eau distillée enrichies par les ions de calcium et de magnésium introduits sous différentes formes (CaCl2•2H2O; CaSO4•2H2O; CaCO3; MgCl2•6H2O; MgSO4•7H2O) et, enfin, avec les eaux souterraines de la région. Différents paramètres réactionnels ont été variés (ex. : l’effet du pH et l’influence de la teneur en sels) et cette approche a permis une meilleure compréhension des mécanismes d’interactions composés phénoliques / sels calciques et magnésiens. Les résultats obtenus indiquent que l’efficacité du procédé dépend du nombre et de la position des groupements phénoliques sur les molécules. Les principaux mécanismes seraient soit une adsorption physique, soit un échange de ligand ou une complexation à la surface des flocs d’hydroxydes d’aluminium. L’ajout de sels minéraux semble améliorer les rendements d’élimination de composés phénoliques testés et avoir un effet sur la gamme optimale de pH de coagulation. Une application de ce procédé à des eaux minéralisées (eaux de forage) de la région de Biskra, située au sud-est de l’Algérie, a abouti à une amélioration des rendements comparés à ceux dans de l'eau distillée.

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Modification de la matière organique lors des traitements conventionnels de potabilisation

Cited by 6 publications

References 9 publications

The combined influence of hydrophobicity, charge and molecular weight on natural organic matter removal by ion exchange and coagulation

The combined influence of hydrophobicity, charge and molecular weight on natural organic matter removal by ion exchange and coagulation

Escherichia coli Behavior in the Presence of Organic Matter Released by Algae Exposed to Water Treatment Chemicals

Coagulation-floculation au sulfate d’aluminium de composés organiques phénoliques et effet de sels de calcium et de magnésium

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