Quantifying filamentous microorganisms in activated sludge before, during, and after an incident of foaming by oligonucleotide probe hybridizations and antibody staining

Oerther, Daniel B.; Reyes, Francis L. de los; Reyes, Mariela; Raskin, Lutgarde

doi:10.1016/s0043-1354(01)00057-4

Cited by 52 publications

(42 citation statements)

References 25 publications

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“…For each site tested, foam potential increased with TSS ( Figure 4). The relationship in each case was found to be nonlinear, confirming similar observations [51]. For routine plant monitoring this test should be performed at the operational MLSS.…”

Section: Influence Of Mlss Concentrationsupporting

confidence: 83%

“…Despite the range of methods which have already been used to evaluate foaming characteristics, to date there is no standard method for assessing the foam potential or stability of activated sludge [2] ( Table 1). Due to its simplicity and ease of operation, the Alka-Seltzer test remains the most popular method for both researchers and operators [40,[49][50][51][52]. Some significant relationships have been identified using this test.…”

Section: Assessing Severity Of Activated Sludge Foaming and Use Of Fomentioning

confidence: 99%

“…Some significant relationships have been identified using this test. For example, seasonal foaming events were directly linked with increased values of measured foam potential [51], and using this method a threshold level of foam potential that was necessary to start foaming was proposed [40]. Unlike many of the tests detailed in Table 1, the Alka-Seltzer test is widely employed by plant operators.…”

Section: Assessing Severity Of Activated Sludge Foaming and Use Of Fomentioning

confidence: 99%

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Evaluating the Measurement of Activated Sludge Foam Potential

Fryer

O’Flaherty

Gray

2011

Water

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Abstract:The most widely used technique for assessing the propensity of activated sludge to suffer from biological foaming is to measure foam potential. This involves measuring the amount of foam produced from sludge under conditions of controlled aeration. Two approaches have been adopted: (1) Air is passed through specially designed columns from fine porous diffusers at a fixed rate to form uniform sized bubbles or (2) employing Alka-Seltzer ™ tablets which effervesce when added to the sludge. Both tests generate foam formation which can then be quantified. Foam assessment in activated sludge is reviewed. A sintered disc aeration column was compared with the Alka-Seltzer ™ test method and both methods examined under a range of different environmental conditions. Foam potential measured by the sintered disc method displayed better repeatability compared to the Alka-Seltzer test. The use of a wire cage placed over the tablets greatly improved the precision of the Alka-Seltzer test. A positive linear correlation was also found between foam potential and temperature (4-20 °C). Sludge solids concentration was also shown to influence foaming potential making comparisons between reactors problematic. Recommendations on how to improve the repeatability of foam potential measurements are given.

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Section: Influence Of Mlss Concentrationsupporting

confidence: 83%

Section: Assessing Severity Of Activated Sludge Foaming and Use Of Fomentioning

confidence: 99%

Section: Assessing Severity Of Activated Sludge Foaming and Use Of Fomentioning

confidence: 99%

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Evaluating the Measurement of Activated Sludge Foam Potential

Fryer

O’Flaherty

Gray

2011

Water

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“…Yet, under those conditions a reliable identification of M. parvicella is possible. Low rDNA levels, because of low metabolic activity of bacteria, and a possible incomplete permeability of the cell wall for the probe can result in poor quantification of M. parvicella by in situ hybridization (Bradford et al, 1998;Oerther et al, 2001). A more exact quantification using quantitative PCR or qPCR (often referred to as real-time PCR) using the SYBR chemistry has recently been published (Kaetzke et al, 2005).…”

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

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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.

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“…Such foaming is primarily generated by highly hydrophobic cells and metabolites of foam-causing microorganisms, such as Nocadia, Microthix parvicella [5,6] and Gordonia spp. [7]. Many studies have been conducted to evaluate the conditions that lead to the proliferation of filamentous microorganisms in activated sludge in an attempt to define strategies to control foaming.…”

Section: Introductionmentioning

confidence: 99%

Foaming control by automatic carbon source adjustment using an ORP profile in sequencing batch reactors for enhanced nitrogen removal in swine wastewater treatment

Chen

Kim

Yang

et al. 2009

Bioprocess Biosyst Eng

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Incomplete denitrification and ammonia accumulation were found to cause proliferation of filamentous microorganisms in sequencing batch reactors (SBRs) for swine wastewater treatment. Foaming was observed in response to the accumulation of 115.2 and 12.2 mg/L of nitrate and ammonia, respectively. The mixed liquor suspended solids (MLSS) level in SBRs was decreased to 2,000 mg/L and the suspended solids in the effluent reached 200 mg/L when foaming appeared. However, the use of swine waste as an external carbon source for enhanced biological nitrogen removal was found to effectively control the foaming caused by filamentous microorganisms. Therefore, an optimum strategy for the addition of swine waste was designed using integrated real-time control to provide pulse input control of slurry based on the ''nitrate knee'' in the oxidation-reduction potential profile. In this case, the MLSS concentration was maintained at an average value of approximately 7,550 mg/L, while the SS in the effluent was less than 30 mg/L.

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Quantifying filamentous microorganisms in activated sludge before, during, and after an incident of foaming by oligonucleotide probe hybridizations and antibody staining

Cited by 52 publications

References 25 publications

Evaluating the Measurement of Activated Sludge Foam Potential

Evaluating the Measurement of Activated Sludge Foam Potential

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

Foaming control by automatic carbon source adjustment using an ORP profile in sequencing batch reactors for enhanced nitrogen removal in swine wastewater treatment

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