Filamentous organisms observed in activated sludge

Eikelboom, Dick H.

doi:10.1016/0043-1354(75)90182-7

Cited by 349 publications

(221 citation statements)

References 30 publications

Supporting

Mentioning

207

Contrasting

Unclassified

Order By: Relevance

“…Les organismes filamenteux recensés dans sept stations où l'on traite les effluents d'usines de pâtes et papiers sont : type 0092, Nocardia sp., type 1701, H. hydrossis (STROM et JENKINS, 1984). (EIKELBOOM, 1975 ;PIPES, 1978).…”

Section: Fiche 28 : Organismes Filamenteuxunclassified

Approche pour l'identification des causes de la mauvaise décantation des solides biologiques

Blanchard¹,

Desjardins²,

Brière³

et al. 2005

rseau

View full text Add to dashboard Cite

Les procédés d'épuration biologique à culture libre (boues activées) comprennent habituellement un décanteur qui permet de concentrer les solides biologiques en vue de leur recirculation en tête du réacteur biologique. Lorsque ce décanteur fonctionne mal on observe une perte de solides biologiques (SB), ce qui se traduit par une augmentation de la concentration des matières en suspension (MES) dans l'effluent du décanteur secondaire et par une baisse des performances du procédé d'épuration. Lorsque la concentration de MES dans l'effluent du décanteur secondaire est trop élevée on mesure l'indice de volume des boues (IVB). Un IVB faible indique que les solides biologiques ont de bonnes caractéristiques de décantation de sorte que la cause de la mauvaise efficacité du décanteur est d'ordre physique et peut être identifiée facilement. Lorsque l'IVB est élevé, la mauvaise décantation est alors causée par un désordre de l'écosystème qui se traduit le plus souvent par une croissance excessive d'organismes filamenteux. Les causes et les solutions d'un tel problème sont alors difficiles à identifier. Pour ce travail, les auteurs ont réalisé une importante revue bibliographique dont les résultats sont présentés sous la forme d'un cheminement critique (fig. 1). Dans cette figure, les cases numérotées de 1 à 48 sont liées par des énoncés logiques. Ainsi, en répondant à des questions simples, il est possible de cheminer dans la figure 1 et d'identifier les causes les plus probables du déséquilibre microbiologique ainsi que les solutions qui ont déjà été apportées avec succès. De plus les auteurs ont associé à chaque case une fiche technique (portant le même numéro que la case) sur laquelle sont présentées des explications et la liste des références consultées.Activated sludge is a microbiological aerated sewage treatment process which includes a secondary clarifier to separate the treated effluent from the biological solids. Part of the concentrated solids is recirculated to maintain an adequate concentration of mixed liquor suspended solids (MLSS) In the aerated basin. When the secondary clarifier malfunctions, some biological solids are lost to the effluent : the process efficiency drops and the concentration of suspended solids (SS) increases. When the SS in the effluent is too high the sludge volume index (SVI) must be measured. A low SVI means that the biological solids have good sedimentation characteristics : the problem is thon physical in nature and is easily identified. When the SVI is high, the problem is due to a disturbance of the microbiological ecosystem, which is at the origin of excessive filamentous organism growth. The origins and solutions of such a problem are much harder to find. To this end the authors proceeded with an important review of the literature, the results of which are summarized through a critical path, in figure 1. Files from 1 to 48 are linked by logical statements in such a way that by answering simple questions, one can proceed through the files and identify the must probable cause of t...

show abstract

Section: Fiche 28 : Organismes Filamenteuxunclassified

Approche pour l'identification des causes de la mauvaise décantation des solides biologiques

Blanchard¹,

Desjardins²,

Brière³

et al. 2005

rseau

View full text Add to dashboard Cite

show abstract

“…More than 30 different filament morphotypes have been described in activated sludge systems treating primarily municipal wastewater (Eikelboom, 1975(Eikelboom, , 2000 and many more are encountered in industrial treatment plant communities (Eikelboom, 2006;Eikelboom and Geurkink, 2002). Several global surveys have shown that Candidatus Microthrix parvicella (hereinafter referred to as M. parvicella) is most frequently responsible for the problems of solid-liquid separation in bulking and foaming (Jenkins et al, 2004;Martins et al, 2004;Wanner, 1994).…”

Section: Introductionmentioning

confidence: 99%

“…Some isolates have been cultured (Blackall et al, 1995(Blackall et al, , 1996Eikelboom, 1975;Rossetti et al, 1997;Seviour et al, 1994;Slijkhuis, 1983aSlijkhuis, , 1983bTandoi et al, 1998;Van Veen, 1973) and only a few of them are maintained in pure culture (Blackall et al, 1995;Rossetti et al, 1997;Seviour et al, 1994). Its slow growth rate and difficulty in storing isolates and in generating phenotypic information have hindered attempts to elucidate the reasons for the proliferation of M. parvicella in WWTPs.…”

Section: Introductionmentioning

confidence: 99%

Development and evaluation of a TaqMan duplex real-time PCR quantification method for reliable enumeration of Candidatus Microthrix

Vanysacker

Denis

Roels

et al. 2014

Journal of Microbiological Methods

View full text Add to dashboard Cite

Candidatus Microtrhix parvicella is one of the most common filamentous bacteria reported to be involved in bulking and foaming problems in activated sludge plants worldwide. In order to detect and quantify both M. parvicella and Microthrix calida by quantitative PCR (qPCR), primers targeting 16S rDNA genes were designed. The qPCR reaction was optimized by using the TaqMan technology and an internal positive control was included to ensure the absence of PCR inhibitors. A total of 29 samples originating from different wastewater treatment plants were analyzed and the results were compared by using conventional microscopy, fluorescent in situ hybridization and an existing SYBR Green-based assay. Our assay showed a 100% specificity for both M. parvicella and M. calida, a sensitivity of 2.93 × 10 9 to 29 copy numbers/reaction, an amplification efficiency of 93% and no PCR inhibition. By performing a spiking experiment including different Microthrix concentrations, recovery rates ranging from 65 to 98% were obtained. A positive correlation with the SYBR Green assay (R 2 = 0.85) was found and most of the samples were in accordance with the microscopical observation. In comparison with SYBR Green assay, the probe-based TaqMan assay had a much lower detection limit. Compared with microscopy, some samples had a lower or higher enumeration when using qPCR. In conclusion, a qPCR method is forwarded here that could be useful as an early warning tool for fast and reliable detection of Microthrix in for instance sludge bulking events.

show abstract

“…The filamentous bacteria in wastewater treatment plants (WWTPs) have attracted considerable attention because of their role in the operational problems of bulking and foaming (Eikelboom, 1975;Nielsen et al, 2009). These organisms are thought to have an important role in the formation of flocs with good settling properties by providing the structural matrix around which floc material aggregates.…”

Section: Introductionmentioning

confidence: 99%

“…These filamentous bacteria were originally separated on the basis of few morphological characters and staining reactions, leading to the recognition of several morphotypes (Eikelboom, 1975;Jenkins et al, 2004). This scheme is still widely used by the industry, but many of these bacteria have now been properly identified phylogenetically, following their isolation into axenic cultures or by fluorescence in situ hybridization (FISH) (see Nielsen et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Genomic and in situ investigations of the novel uncultured Chloroflexi associated with 0092 morphotype filamentous bulking in activated sludge

et al. 2016

View full text Add to dashboard Cite

Overgrowth of filamentous bacteria in activated sludge wastewater treatment plants (WWTPs) leads to impaired sludge settleability, a condition known as bulking, which is a common operational problem worldwide. Filaments with the Eikelboom 0092 morphotype are commonly associated with such bulking episodes. Members of the uncultured B45 phylotype, which is embraced within the phylum Chloroflexi, were recently shown to exhibit this morphology. Although these organisms are among the most abundant populations recorded in activated sludge processes, nothing is known about their metabolic characteristics. In this study, a genome sequence, representing the B45 phylotype, was retrieved from a metagenome generated from an activated sludge WWTP. The genome consisted of two chromosomes and one plasmid, which were 4.0, 1.0 and 0.04 Mbps in size, respectively. A metabolic model was constructed for this organism, based on annotation of its genome, showing its ability to generate energy by respiration, utilizing oxygen, nitrite or nitrous oxide as electron acceptors, or by fermentation of sugars. The ability of B45 members to ferment sugars under anaerobic conditions was validated in situ with microautoradiography-fluorescence in situ hybridization. The provisional name of 'Candidatus Promineofilum breve' is proposed for this species. This study represents the first detailed information on an uncultured genus of filamentous organisms from activated sludge.

show abstract

Filamentous organisms observed in activated sludge

Cited by 349 publications

References 30 publications

Approche pour l'identification des causes de la mauvaise décantation des solides biologiques

Approche pour l'identification des causes de la mauvaise décantation des solides biologiques

Development and evaluation of a TaqMan duplex real-time PCR quantification method for reliable enumeration of Candidatus Microthrix

Genomic and in situ investigations of the novel uncultured Chloroflexi associated with 0092 morphotype filamentous bulking in activated sludge

Contact Info

Product

Resources

About