Evaluation of alternative sludge settleability indices

Lee, Sang-Eun; Koopman, Ben; Bode, H.; Jenkins, David

doi:10.1016/0043-1354(83)90273-7

Cited by 52 publications

(22 citation statements)

References 2 publications

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“…In their study, the critical value forecasting filamentous bulking was found to be 10 3 cm/ mg. Similar results were also reported by Lee et al, 67 who investigated the relationship between filament levels and several quantitative indexes of sludge settleability for the purpose of the routine application of the filament content tests to the activated sludge process. These indexes included diluted SVI, SVI at SS concentrations of 1.5, 2.5, and 3.5 g/€, and stirred SVI at 2.5 g/t SS.…”

Section: Crc Critical Reviews In Environmental Controlsupporting

confidence: 82%

Physical Characteristics of Activated Sludge Flocs

Ganczarczyk

Jenkins

1986

Critical Reviews in Environmental Control

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Section: Crc Critical Reviews In Environmental Controlsupporting

confidence: 82%

Physical Characteristics of Activated Sludge Flocs

Ganczarczyk

Jenkins

1986

Critical Reviews in Environmental Control

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“…An SVI of less than 60 mL g À1 is normally indicative of a readily settleable sludge [31]. It was, therefore, surprising to find that the effluent suspended solids from this reactor was, on average, over 150 mg L À1 .…”

Section: Discussionmentioning

confidence: 98%

“…[30]. With a SVI of less than 100 mL g À1 being considered desirable [31], Fig. 8 shows that this aspect of sludge quality of both the systems was good.…”

Section: Settleabilitymentioning

confidence: 93%

Development and examination of a granular nitrogen-fixing wastewater treatment system

Pratt

Tan

Gapes

et al. 2007

Process Biochemistry

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“…Néanmoins l'indice de volume de la boue ou IVB, c'est-à-dire le volume occupé par un gramme de boue après un certain temps de décantation (en général 30 minutes) est le paramètre encore le plus fréquemment employé aujourd'hui pour caractériser la capacité de compaction naturelle d'une boue. La fiabilité de ce paramètre semble maintenant acceptée {LEE et al, 1983 ;DAIGGER et ROPER, 1985) après avoir été contestée pendant un certain temps (DICK et VESILIND, 1969 ;WPCF, 1977) ; sa détermination, simple, est inclue aux procédures habituelles de gestion des unités de traitement {WPCF, 1977). On peut aussi déterminer 1'IVB en fonction du temps pour produire une courbe de décantation qui indique la vitesse de décantation de la boue ainsi que son volume final.…”

Section: -1 Paramètres éTudiésunclassified

Effets de paramètres d'opération sur la décantation de boues biologiques d'une unité de traitement d'eaux usées de raffinerie

Arcand¹,

Paris²,

Rouleau³

et al. 2005

rseau

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La qualité de l'effluent des systèmes de biotraitement par boues activées est souvent limitée par la performance de l'unité de décantation. Cette étude analyse les causes possibles des difficultés d'opération rencontrées dans la décantation des boues évacuées aux décanteurs secondaires d'une raffinerie de pétrole. Les objectifs visent à déterminer et à quantifier l'effet des paramètres d'opération qui affectent le fonctionnement du décanteur, en les reliant si possible à son mauvais fonctionnement, à évaluer de l'ajout d'alun et à proposer des méthodes correctives pour améliorer l'efficacité de décantation.L'étude montre que :- l'efficacité des décanteurs sera améliorée si le niveau d'oxygène dissous et la concentration en matières totales en suspension (MTS) dans le bassin d'aération sont respectivement maintenus entre 0,9 à 1,3 ppm et 4 300 à 4 800 mg/L;- le pH de la liqueur mixte ne semble pas influencer la décantabitité;- l'addition d'alun doit être évitée ou maintenue inférieure à 50 mg/L;- l'agitation et les vitesses linéaires élevées dans les conduites d'alimentation des décanteurs doivent être évitées.The wastewater treatment systems built in the seventies for treating the effluents from oil refineries often fail to comply with new environmental standards. The present study focuses mainly on the problem of sludge settling in the clarifiers. The purpose of this work was to determine the effect of various parameters on the settling characteristics of the activated sludge, to evaluate the rote of alun as a flocculating agent and to characterize the operation of the clarifiers primarily as it relates to the settling problem. The influence of the quantity of the alun added and of the stirring speed on the settling characteristics of the sludge were determined in jar tests. The effects, on the performance of the clarifiers, of the level of dissolved oxygen in the bioreactor, of the pH and of the concentration in total suspended solids (TSS) maintained in the mixed liquor, were also investigated.The studies on the sludge settleability led to the following conclusions :- the concentration in dissolved oxygen and the concentration in TSS in the aeration tank are two parameters which have a critical effect on the effluent quality. The optimal operating intervals for these parameters are from 0.9 to 1.3 ppm for dissolved oxygen and from 4 300 to 4 800 mg/L for the TSS;- the pH of the mixed liquor is not a main factor and does not seem to have any effect on the sludge settleability;- the addition of alum in excess of 50 mg/L has an adverse effect on the sludge settling characteristics. Addition of alum below this level, however, improves the clarity of the residual liquor. Nevertheless, the addition of this flocculating agent is not recommended;- the high flowrates and violent mixing in the piping system used to feed the mixed liquor from the aeration tank to the clarifiers adversely affects the solid-liquid separation in the clarifiers.By simply stopping the addition of the flocculating agent, maintaining the dissol...

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Evaluation of alternative sludge settleability indices

Cited by 52 publications

References 2 publications

Physical Characteristics of Activated Sludge Flocs

Physical Characteristics of Activated Sludge Flocs

Development and examination of a granular nitrogen-fixing wastewater treatment system

Effets de paramètres d'opération sur la décantation de boues biologiques d'une unité de traitement d'eaux usées de raffinerie

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