Titre :
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Effect of food:microorganism ratio in activated sludge foam control
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Auteurs :
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H. Chua ;
P. Yu ;
S. Sin ;
K. Tan
|
Type de document :
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article/chapitre/communication
|
Année de publication :
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2000
|
Format :
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p. 1127-1135
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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
;
FOISONNEMENT DES BOUES
;
CONTROLE
;
PREVENTION
;
MOUSSE
|
Résumé :
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Foaming is a common operational problem in activated sludge processes that often adversely affects the quality of the treated effluent. Overgrowth of the filamentous Nocardia spp. in the microbial ecosystem was previously identified as the cause of foaming. In the present study, the specific growth rate of Nocardia amarae was found to be much higher than that of nonfilamentous bacteria under food:microorganism (F:M) ratios lower than 0.5 mg of biological oxygen demand (BOD) (mg of mixed liquor suspended solids [MLSS].d). This indicated that filamentous overgrowth may occur in normal activated sludge processes that are continually operated under the usual F:M range of 0.2-0.6 mg of BOD (mg of MLSS.d). A novel two-component feast-fast operation (FFO) that capitalized on the sensitivity of filamentous bacteria to F:M ratio was designed to prevent and control foaming problems. The F:M ratio in the feasting aeration unit was 0.8 mg of BOD (mg of MLSS.d) whereas that in the fasting aeration unit was 0.2 mg of BOD (mg of MLSS.d).
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Source :
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Applied biochemistry and biotechnology, vol. 84-86
|