scholarly journals Correction: Membrane fouling characteristics of membrane bioreactors (MBRs) under salinity shock: extracellular polymeric substances (EPSs) and the optimization of operating parameters

2021 ◽  
Author(s):  
Ling Luo ◽  
Hui Zhong ◽  
Ye Yuan ◽  
Wenwang Zhou ◽  
Changming Zhong
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Operating Parameters ◽  
Salinity Shock ◽  
Fouling Characteristics

Correction for ‘Membrane fouling characteristics of membrane bioreactors (MBRs) under salinity shock: extracellular polymeric substances (EPSs) and the optimization of operating parameters’ by Changming Zhong et al., Environ. Sci.: Water Res. Technol., 2021, DOI: .

Membrane fouling characteristics of membrane bioreactor (MBR) under salinity shock：Extracellular Polymeric Substances (EPS) and optimization of operating parameters

2021 ◽  
Author(s):  
Ling Luo ◽  
Hui Zhong ◽  
Ye Yuan ◽  
Wenwang Zhou ◽  
Changming Zhong
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Membrane Bioreactors ◽  
Operating Parameters ◽  
Salinity Shock ◽  
Extracellular Polymer ◽  
Composition Changes ◽  
Fouling Characteristics

This study aims to analyze the composition changes of extracellular polymer (EPS) in membrane bioreactors (MBR) under different salinity shock and their effects on membrane fouling, as well as the...

Correlation between membrane fouling and soluble/colloidal organic substances in membrane bioreactors for municipal wastewater treatment

2005 ◽  
Vol 51 (6-7) ◽  
pp. 1-8 ◽  
Author(s):  
B. Lesjean ◽  
S. Rosenberger ◽  
C. Laabs ◽  
M. Jekel ◽  
R. Gnirss ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Size Exclusion ◽  
Water Phase ◽  
Parallel Operation ◽  
Municipal Wastewater Treatment ◽  
Operational Conditions ◽  
The Difference

Two similar membrane bioreactors of 2 m3 each were operated in parallel over two years under the same operational conditions, fed with the same municipal wastewater. The only process and operational difference between both pilot plants was the position of the denitrification zone (pre-denitrification in pilot 1 and post-denitrification in pilot 2). Despite parallel operation, the two MBRs exhibited different fouling rates and decreases in permeability. These differences could not be accounted for by MLSS concentrations, loading rates, or filtration flux. In a one-year investigation, soluble and colloidal organic material in the activated sludge of both MBR was regularly analysed by spectrophotometric and Size Exclusion Chromatography (SEC) methods. The larger organic molecules present in the sludge water phase (i.e. polysaccharides, proteins and organic colloids) originating from microbial activity (extracellular polymeric substances) were found to impact on the fouling and to explain the difference in membrane performance between the two MBR units. In both pilot plants, a linear relationship could be clearly demonstrated between the fouling rate of the membrane and the concentration of polysaccharides in the sludge water phase during a 5 month operational period at an SRT of 8 days.

Membrane fouling and performance evaluation of conventional membrane bioreactor (MBR), moving biofilm MBR and oxic/anoxic MBR

2014 ◽  
Vol 69 (7) ◽  
pp. 1403-1409 ◽  
Author(s):  
Sher Jamal Khan ◽  
Aman Ahmad ◽  
Muhammad Saqib Nawaz ◽  
Nicholas P. Hankins
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Water Flux ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Membrane Bioreactors ◽  
Nitrogen And Phosphorus ◽  
Biofilm Carrier ◽  
Cake Layer ◽  
And Performance

In this study, three laboratory scale submerged membrane bioreactors (MBRs) comprising a conventional MBR (C-MBR), moving bed MBR (MB-MBR) and anoxic-oxic MBR (A/O-MBR) were continuously operated with synthesized domestic wastewater (chemical oxygen demand, COD = 500 mg/L) for 150 days under similar operational and environmental conditions. Kaldnes® plastic media with 20% dry volume was used as a biofilm carrier in the MB-MBR and A/O-MBR. The treatment performance and fouling propensity of the MBRs were evaluated. The effect of cake layer formation in all three MBRs was almost the same. However, pore blocking caused a major difference in the resultant water flux. The A/O-MBR showed the highest total nitrogen and phosphorus (PO4-P) removal efficiencies of 83.2 and 69.7%, respectively. Due to the high removal of nitrogen, fewer protein contents were found in the soluble and bound extracellular polymeric substances (EPS) of the A/O-MBR. Fouling trends of the MBRs showed 12, 14 and 20 days filtration cycles for C-MBR, MB-MBR and A/O-MBR, respectively. A 25% reduction of the soluble EPS and a 37% reduction of the bound EPS concentrations in A/O-MBR compared with C-MBR was a major contributing factor for fouling retardation and the enhanced filtration capacity of the A/O-MBR.

Variation of Membrane Fouling Characteristics at Salinity Wastewater in an Intermittently Aerated Membrane Bioreactor

2015 ◽  
Vol 1092-1093 ◽  
pp. 1029-1032
Author(s):  
Kang Xie ◽  
Jing Song ◽  
Si Qing Xia ◽  
Li Ping Qiu ◽  
Jia Bin Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
High Salinity ◽  
Average Molecular Weight ◽  
Zeta Potentials ◽  
Microbial Products ◽  
Salinity Wastewater ◽  
Fouling Characteristics

In this study, the variation of Zeta potentials and distribution of molecular weight in Extracellular Polymeric Substances (EPS) and soluble microbial products (SMP) were investigated. It is indicated that the salinity is effect on Zeta potentials significantly. When the salinity increased from 0 g/L to 35 g/L, the Zeta potentials decreased gradually. The average molecular weight is mainly over 30 KDa in EPS and SMP at 0 g/L salinity, and is mainly below 10 KDa at 10 g/L and 35 g/L salinity. This result is evident that the variation of molecular weight is contributed to high salinity.

scholarly journals The Effect of Salinity on Membrane Fouling Characteristics in an Intermittently Aerated Membrane Bioreactor

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Kang Xie ◽  
Siqing Xia ◽  
Jing Song ◽  
Jixiang Li ◽  
Liping Qiu ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Ammonia Nitrogen ◽  
Saline Wastewater ◽  
Sludge Characteristics ◽  
Filtration Resistance ◽  
Microbial Products ◽  
Fouling Characteristics

The effect of salinity on the membrane fouling characteristics was investigated in the intermittently aerated membrane bioreactor (IAMBR). Five different salinity loadings were set from 0 to 35 g·L−1(referring to NaCl), respectively. The removal of total organic carbon (TOC) and ammonia-nitrogen (NH4+-N) was gradually decreased with increasing salinity. The variation of membrane filtration resistance, particle size distribution (PSD), extracellular polymeric substances (EPS), soluble microbial products (SMP), and relative hydrophobicity (RH) analysis revealed that salinity has a significant effect on sludge characteristics in IAMBR. The results also indicated that the membrane fouling is often caused by the integration of sludge characteristics in saline wastewater.

Improving the performance of membrane bioreactors by powdered activated carbon dosing with cost considerations

2010 ◽  
Vol 62 (1) ◽  
pp. 172-179 ◽  
Author(s):  
W. Yang ◽  
M. Paetkau ◽  
N. Cicek
Keyword(s):  
Activated Carbon ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Operating Cost ◽  
Membrane Bioreactors ◽  
Powdered Activated Carbon ◽  
Membrane Cleaning ◽  
17Β Estradiol ◽  
Overall Performance ◽  
The Cost

Effects of powdered activated carbon (PAC) dosing on the overall performance of membrane bioreactors (MBR) were investigated in two bench-scale submerged MBRs. Positive impacts of PAC dosing on membrane fouling and the removal of 17β-estradiol (E2) and 17α-ethyinylestradiol (EE2) were demonstrated over a six-month stable operational period. PAC dosing in the MBR increased the removal rates of E2 and EE2 by 3.4% and 15.8%, respectively. The average soluble extracellular polymeric substances (EPS) and colloidal total organic carbon (TOC) concentrations in the PAC-MBR sludge was 60.1% and 61.8% lower than the control MBR sludge, respectively. Lower soluble EPS and colloidal TOC concentrations in the PAC-MBR sludge resulted in a slower rate of trans-membrane pressure (TMP) increase during MBRs operation, which could prolong the lifespan of membranes. Cost assessment showed that PAC dosing could reduce the operating cost for membrane cleaning and/or membrane replacement by about 25%. The operating cost for PAC dosing could be offset by the benefit from its reducing the cost for membrane maintenance.

Effects of powdered activated carbon dosing on sludge characteristics and estrogen removal in membrane bioreactors

2010 ◽  
Vol 61 (9) ◽  
pp. 2193-2198 ◽  
Author(s):  
W. Yang ◽  
M. Paetkau ◽  
N. Cicek
Keyword(s):  
Activated Carbon ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Powdered Activated Carbon ◽  
Soluble Carbohydrates ◽  
Experimental Conditions ◽  
Sludge Characteristics ◽  
17Β Estradiol ◽  
The Mean

Sludge characteristics associated with filterability as well as the removal of a natural estrogen 17β-estradiol (E2) and a synthetic estrogen 17α-ethyinylestradiol (EE2) were investigated in submerged membrane bioreactors (MBR) with and without the addition of powdered activated carbon (PAC) under the same experimental conditions. Positive impacts of PAC dosing on membrane fouling and the removal of E2 and EE2 were demonstrated over a six months stable operational period. Experimental results showed that PAC dosing resulted in lower concentrations of soluble extracellular polymeric substances (EPS) and colloidal total organic carbon (TOC) in the PAC-MBR sludge. The average soluble EPS and colloidal TOC concentrations in the PAC-MBR sludge was 60.1% and 61.8% lower than the control MBR sludge, respectively. Regardless of PAC dosing, concentrations of colloidal TOC were strongly related to concentrations of soluble EPS and soluble carbohydrates in the sludge. In addition, the mean flocs size of the sludge with PAC dosing was shifted from 49.4 μm to 60.3 μm. PAC dosing in the MBR increased the removal rates of E2 and EE2 by 3.4% and 15.8%, respectively.

Physico-chemical characterisation versus in situ micro-structural characterisation of membrane fouling in membrane bioreactors

2011 ◽  
Vol 63 (8) ◽  
pp. 1781-1787 ◽  
Author(s):  
T. C. A Ng ◽  
H. Y. Ng
Keyword(s):  
Membrane Fouling ◽  
Laser Scanning ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Critical Flux ◽  
Membrane Materials ◽  
Physico Chemical

Fouling characteristics of aerobic submerged membrane bioreactors were analysed under two different membrane materials. Polyethersulfone (PES) membranes were found to foul faster at sub-critical flux than polyolefin (PO) membranes. Physico-chemical characterisation, by means of comparison of extracellular polymeric substances (EPS) and soluble microbial products (SMP) concentrations, as well as the mixed liquor suspended solids (MLSS) concentration were unable to explain the differences in membrane fouling of the contrasting membrane materials. The use of confocal laser scanning microscopy (CLSM) to image organic foulants directly on the membrane surface, coupled with image analyses showed that membrane fouling mechanism shifted from a biofilm initiated process on PO membranes to a bio-organic dominated process on PES membranes under sub-critical flux conditions. These results show that physico-chemical characterisation of an MBR process may not effectively distinguish the effectiveness of different membrane materials, so long as operating conditions are identical, and that characterisation of foulants on the membrane surfaces was necessary to elucidate the differences in membrane fouling.

Real-time monitoring of membrane bioreactors with 2D-fluorescence data and statistically based models

2011 ◽  
Vol 63 (7) ◽  
pp. 1381-1388 ◽  
Author(s):  
C. F. Galinha ◽  
G. Carvalho ◽  
C. A. M. Portugal ◽  
G. Guglielmi ◽  
R. Oliveira ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Fluorescence Spectroscopy ◽  
Real Time ◽  
Membrane Fouling ◽  
Oxygen Demand ◽  
Principal Component ◽  
Time Frame ◽  
Membrane Bioreactors ◽  
Operating Parameters ◽  
Latent Structures

The application of membrane bioreactors (MBR) for wastewater treatment is growing worldwide due to their compactness and high effluent quality. However, membrane fouling, mostly associated to biological products, can reduce MBR performance. Therefore, it is important to monitor MBRs as close to real-time as possible to accelerate control actions for maximal biological and membrane performance. 2D-fluorescence spectroscopy is a promising on-line tool to simultaneously monitor wastewater treatment efficiency and the formation of potential biological fouling agents. In this study, 2D-fluorescence data obtained from the wastewater and the permeate of a MBR was successfully modelled using projection to latent structures (PLS) to monitor variations in the influent and effluent total chemical oxygen demand (COD). Analysis of the results also indicated that humic acids and proteins highly contributed to the measured COD in both streams. Nevertheless, this approach was not valid for other performance parameters of the MBR system (such as influent and effluent ammonia and phosphorus), which is usually characterised through a high number of analytical and operating parameters. Principal component analysis (PCA) was thus used to find possible correlations between these parameters, in an attempt to reduce the analytical effort required for full MBR characterisation and to reduce the time frame necessary to obtain monitoring results. The 3 first principal components, capturing 57% of the variance, indicated and confirmed expected relationships between the assessed parameters. However, this approach alone could not provide robust enough correlations to enable the elimination of parameters for process description (PCA loadings ≤ 0.5). Nevertheless, it is possible that the information captured by 2D-fluorescence spectroscopy could replace some of the analytical and operating parameters, since this technique was able to successfully describe influent and effluent total COD. It is thus proposed that combined modelling of 2D-fluorescence data and selected performance/operating parameters should be further explored for efficient MBR monitoring aiming at rapid process control.

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