Titre :
|
Scum in activated sludge plants : Impact of non-filamentous and filamentous bacteria
|
Auteurs :
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H. Lemmer ;
G. Lind ;
E. Muller ;
AL Et
|
Type de document :
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article/chapitre/communication
|
Année de publication :
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2000
|
Format :
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p. 34-40
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Langues:
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= Anglais
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Catégories :
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TRAITEMENT DE L'EAU RESIDUAIRE
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Mots-clés:
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BOUES ACTIVEES
;
BACTERIE FILAMENTEUSE
;
MOUSSE
;
DETERGENT AGENT DE SURFACE
|
Résumé :
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Excessive scum production is a widespread phenomenon in present activated sludge wastewater treatment. The question how foaming is initiated and stabilized is still unanswered. Hydrophobic wastewater ingredients and surface active material such as synthetic surfactants are discussed among others as major causative agents for scum production. Focusing on biological impacts non-filamentous bacteria isolated from scum turned out to contribute to flotation by both cell surface hydrophobicity and emulsification activity, depending on the prevailing substrate and milieu conditions. The biological characterization of scum based on microscopic sludge investigation of conspicuous microorganisms resulted in a significant shift of filamentous and non-filamentous organism populations with Gram-positive bacteria prevailing in present nutrient removal plants as compared to the situation ten years ago. Their hydrophobic cell surface is supposed to support adherence and stabilization of interfaces and thus promote sludge flotation.
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Source :
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Acta hydrochimica et hydrobiologica, vol.28, n°1
|