Filterability assessment in membrane bioreactors using an in-situ filtration test cell

A new method for the assessment of the filterability in membrane bioreactors was tested for five months in four MBR units in Berlin. The new method BFM (Berlin Filtration Method) for filterability assessment uses a small membrane filtration test cell which can be submerged directly in the biological tanks to determine the filterability of the activated sludge in-situ. The test cell contains an aerated flat-sheet membrane which operates at similar conditions as in the plant. Filterability is expressed in terms of critical flux obtained by performing flux-stepping experiments. The ultimate goal of monitoring the filterability with the device is to detect in real time fouling occurrences due to changes in sludge composition and to adapt accordingly the operating conditions. The usefulness of the device for this purpose was evaluated for five months after monitoring four MBR plants in Berlin with different activated sludge characteristics (MLSS from 5 to 21 g/L, SRT 12–35 d and COD in the supernatant 30–400 mg/L). The first results show a good agreement between the filterability of the sludge with the portable filtration test cell and the filtration performance of the plant. Critical flux values varied between 3 and 30 L/m2 h during the studied period. Useful information concerning the irreversibility of the fouling was provided by looking at the hysteresis curve of the flux-stepping experiments.

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Time-series genome-centric analysis unveils bacterial response to operational disturbance in activated sludge

10.1101/565770 ◽

2019 ◽

Cited By ~ 1

Author(s):

María Victoria Pérez ◽

Leandro D. Guerrero ◽

Esteban Orellana ◽

Eva L. Figuerola ◽

Leonardo Erijman

Keyword(s):

Growth Rate ◽

Time Series ◽

Wastewater Treatment ◽

Activated Sludge ◽

Microbial Communities ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Operating Conditions ◽

The Face

ABSTRACTUnderstanding ecosystem response to disturbances and identifying the most critical traits for the maintenance of ecosystem functioning are important goals for microbial community ecology. In this study, we used 16S rRNA amplicon sequencing and metagenomics to investigate the assembly of bacterial populations in a full-scale municipal activated sludge wastewater treatment plant over a period of three years, including a period of nine month of disturbance, characterized by short-term plant shutdowns. Following the reconstruction of 173 metagenome-assembled genomes, we assessed the functional potential, the number of rRNA gene operons and thein situgrowth rate of microorganisms present throughout the time series. Operational disturbances caused a significant decrease in bacteria with a single copy of the ribosomal RNA (rrn) operon. Despite only moderate differences in resource availability, replication rates were distributed uniformly throughout time, with no differences between disturbed and stable periods. We suggest that the length of the growth lag phase, rather than the growth rate, as the primary driver of selection under disturbed conditions. Thus, the system could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions.IMPORTANCEIn this work we investigated the response of microbial communities to disturbances in a full-scale activated sludge wastewater treatment plant over a time-scale that included periods of stability and disturbance. We performed a genome-wide analysis, which allowed us the direct estimation of specific cellular traits, including the rRNA operon copy number and the in situ growth rate of bacteria. This work builds upon recent efforts to incorporate growth efficiency for the understanding of the physiological and ecological processes shaping microbial communities in nature. We found evidence that would suggest that activated sludge could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions. This paper provides relevant insights into wastewater treatment process, and may also reveal a key role for growth traits in the adaptive response of bacteria to unsteady environmental conditions.

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Evaluating the application of Microbacterium sp. strain BR1 for the removal of sulfamethoxazole in full-scale membrane bioreactors

Water Science & Technology ◽

10.2166/wst.2015.397 ◽

2015 ◽

Vol 72 (10) ◽

pp. 1754-1761 ◽

Cited By ~ 15

Author(s):

A. Fenu ◽

B. M. R. Donckels ◽

T. Beffa ◽

C. Bemfohr ◽

M. Weemaes

Keyword(s):

Activated Sludge ◽

Municipal Wastewater ◽

Membrane Bioreactors ◽

Full Scale ◽

Process Conditions ◽

Municipal Wastewater Treatment ◽

Viable Biomass ◽

The One ◽

Micro Organisms

Microbacterium sp. strain BR1 is a bacterial strain that recently received attention for its capability to mineralize sulfamethoxazole (SMX) and other sulfonamides. In this study, the survival of Microbacterium sp. in municipal sludge waters was tested in batch experiments to explore optimal process conditions. Inoculation of Microbacterium sp. was subsequently performed in a pilot membrane bioreactor (MBR) operated in two configurations: treating full-scale MBR permeate (post-treatment) and treating raw municipal wastewater. SMX removal by Microbacterium sp. could not be proved in any of the configurations, except for SMX concentrations far higher than the ones normally found in municipal wastewater. By use of molecular tools (fluorescence in situ hybridization analysis) a low capability to survive in activated sludge systems was assessed. After inoculation, Microbacterium sp. was reduced to a small fraction of the viable biomass. The observed growth rate appeared to be many times lower than the one of typical activated sludge micro-organisms. Possibilities of application in full-scale municipal wastewater treatment are scarce.

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Methods for enumeratingEscherichia coliin subtropical waters

Epidemiology and Infection ◽

10.1017/s0950268800048494 ◽

1991 ◽

Vol 106 (2) ◽

pp. 345-354 ◽

Cited By ~ 2

Author(s):

W. H. S. Cheung ◽

D. K. K. Ha ◽

K. Y. Yeung ◽

R. P. S. Hung

Keyword(s):

Membrane Filtration ◽

Good Alternative ◽

Environmental Waters ◽

Filtration Method ◽

E Coli ◽

Bacterial Indicator ◽

Urease Test ◽

The Uk ◽

Mls Method

SUMMARYThe standard membrane filtration method of the UK has been modified in order to improve its specificity for enumeratingEscherichia coliin the subtropical waters of Hong Kong. This involves incorporating into the membrane lauryl sulphate (mLS) method either anin situurease test (the mLS-UA method), or anin situβ-glucuronidase test (the mLS-GUD method). The false-positive errors of the mLS-UA and mLS-GUD methods are low, ranging from 3–5%. A comparison between the membrane filtration (mLS-UA) method and the multiple tube technique in testingE. coliin subtropical beach-waters has demonstrated that the former can give much more precise counts, and is the method of choice for such a purpose. The mLS-GUD method, for which automated counting ofE. colicolonies is possible, is a good alternative to mLS-UA in routine enumeration of this bacterial indicator in environmental waters.

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A novel In-situ Enzymatic Cleaning Method for Reducing Membrane Fouling in Membrane Bioreactors (MBRs)

Indonesian Journal of Science and Technology ◽

10.17509/ijost.v1i1.2211 ◽

2016 ◽

Vol 1 (1) ◽

pp. 1 ◽

Cited By ~ 3

Author(s):

M. R. Bilad ◽

M. Baten ◽

A. Pollet ◽

C. Courtin ◽

J. Wouters ◽

...

Keyword(s):

Membrane Fouling ◽

High Performance ◽

Membrane Filtration ◽

Membrane Surface ◽

Anion Exchange Chromatography ◽

Magnetic Activity ◽

Exchange Chromatography ◽

Membrane Bioreactors ◽

Cleaning Method

A novel in-situ enzymatic cleaning method was developed for fouling control in membrane bioreactors (MBRs). It is achieved by bringing the required enzymes near the membrane surface by pulling the enzymes to a magnetic membrane (MM) surface by means of magnetic forces, exactly where the cleaning is required. To achieve this, the enzyme was coupled to a magnetic nanoparticle (MNP) and the membrane it self was loaded with MNP. The magnetic activity was turned by means of an external permanent magnet. The effectiveness of concept was tested in a submerged membrane filtration using the model enzyme-substrate of Bacillus subitilis xylanase-arabinoxylan. The MM had almost similar properties compared to the unloaded ones, except for its well distributed MNPs. The enzyme was stable during coupling conditions and the presence of coupling could be detected using a high-performance anion-exchange chromatography (HPAEC) analysis and Fourier transform infrared spectroscopy (FTIR). The system facilitated an in-situ enzymatic cleaning and could be effectively applied for control fouling in membrane bioreactors (MBRs).

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Time Series Genome-Centric Analysis Unveils Bacterial Response to Operational Disturbance in Activated Sludge

mSystems ◽

10.1128/msystems.00169-19 ◽

2019 ◽

Vol 4 (4) ◽

Cited By ~ 4

Author(s):

María Victoria Pérez ◽

Leandro D. Guerrero ◽

Esteban Orellana ◽

Eva L. Figuerola ◽

Leonardo Erijman

Keyword(s):

Growth Rate ◽

Time Series ◽

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Full Scale ◽

Operating Conditions ◽

Lag Phase

ABSTRACT Understanding ecosystem response to disturbances and identifying the most critical traits for the maintenance of ecosystem functioning are important goals for microbial community ecology. In this study, we used 16S rRNA amplicon sequencing and metagenomics to investigate the assembly of bacterial populations in a full-scale municipal activated sludge wastewater treatment plant over a period of 3 years, including a 9-month period of disturbance characterized by short-term plant shutdowns. Following the reconstruction of 173 metagenome-assembled genomes, we assessed the functional potential, the number of rRNA gene operons, and the in situ growth rate of microorganisms present throughout the time series. Operational disturbances caused a significant decrease in bacteria with a single copy of the rRNA (rrn) operon. Despite moderate differences in resource availability, replication rates were distributed uniformly throughout time, with no differences between disturbed and stable periods. We suggest that the length of the growth lag phase, rather than the growth rate, is the primary driver of selection under disturbed conditions. Thus, the system could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions. IMPORTANCE Disturbance is a key determinant of community assembly and dynamics in natural and engineered ecosystems. Microbiome response to disturbance is thought to be influenced by bacterial growth traits and life history strategies. In this time series observational study, the response to disturbance of microbial communities in a full-scale activated sludge wastewater treatment plant was assessed by computing specific cellular traits of genomes retrieved from metagenomes. It was found that the genomes observed in disturbed periods have more copies of the rRNA operon than genomes observed in stable periods, whereas the in situ mean relative growth rates of bacteria present during stable and disturbed periods were indistinguishable. From these intriguing observations, we infer that the length of the lag phase might be a growth trait that affects the microbial response to disturbance. Further exploration of this hypothesis could contribute to better understanding of the adaptive response of microbiomes to unsteady environmental conditions.

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Comparison of linear alkylbenzene sulfonates removal in conventional activated sludge systems and membrane bioreactors

Water Science & Technology ◽

10.2166/wst.2004.0331 ◽

2004 ◽

Vol 50 (5) ◽

pp. 219-225 ◽

Cited By ~ 15

Author(s):

H. De Wever ◽

S. Van Roy ◽

C. Dotremont ◽

J. Müller ◽

T. Knepper

Keyword(s):

Activated Sludge ◽

Membrane Bioreactors ◽

Operating Conditions ◽

Biological Degradation ◽

Linear Alkylbenzene ◽

Conventional Activated Sludge ◽

Operational Variables ◽

Linear Alkylbenzene Sulfonates ◽

Model Components ◽

Activated Sludge Systems

The potential of a membrane bioreactor (MBR) and a conventional activated sludge (CAS) system to remove polar micropollutants was evaluated using linear alkylbenzene sulfonates (LAS) as model components. Removal efficiencies over 97% were achieved in both reactor systems. The appearance of biological breakdown metabolites and the respirometric response of the sludges to LAS addition indicated that LAS removal was due to biodegradation, rather than sorption phenomena. The effect of operational variables, such as hydraulic retention time, LAS composition and hydrophobicity of the membrane used in the MBR, was negligible in the range tested. A stepwise increase in LAS influent concentration resulted in higher residual effluent concentrations but did not change the procentual removal efficiency. Because an increase in LAS and SPC effluent concentration occurred to a larger extent in the CAS than in the MBR under similar operating conditions, MBRs may turn out to be be more robust with respect to biological degradation of micropollutants than CAS.

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