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.

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.

Effect of low dosages of powdered activated carbon on membrane bioreactor performance

2012 ◽  
Vol 65 (5) ◽  
pp. 954-961 ◽  
Author(s):  
Maxime Remy ◽  
Hardy Temmink ◽  
Wim Rulkens
Keyword(s):  
Activated Carbon ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Membrane Bioreactors ◽  
Powdered Activated Carbon ◽  
Filtration Time ◽  
Sludge Flocs ◽  
Operational Costs ◽  
Long Term Effect

Previous research has demonstrated that powdered activated carbon (PAC), when applied at very low dosages and long SRTs, reduces membrane fouling in membrane bioreactors (MBRs). This effect was related to the formation of stronger sludge flocs, which are less sensitive to shear. In this contribution the long-term effect of PAC addition was studied by running two parallel MBRs on sewage. To one of these, PAC was dosed and a lower fouling tendency of the sludge was verified, with a 70% longer sustainable filtration time. Low PAC dosages showed additional advantages with regard to oxygen transfer and dewaterability, which may provide savings on operational costs.

Application of powdered activated carbon (PAC) for membrane fouling control in a pilot-scale MBR system

2017 ◽  
Vol 75 (10) ◽  
pp. 2350-2357 ◽  
Author(s):  
A. I. Zouboulis ◽  
P. K. Gkotsis ◽  
D. X. Zamboulis ◽  
M. G. Mitrakas
Keyword(s):  
Activated Carbon ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Powdered Activated Carbon ◽  
Short Term ◽  
Batch Mode ◽  
Fouling Control ◽  
Integrated Methodology ◽  
Microbial Products

Membrane fouling is considered to be the most serious drawback in wastewater treatment when using membrane bioreactors (MBRs), leading to membrane permeability decrease and efficiency deterioration. This work aims to develop an integrated methodology for membrane fouling control, using powdered activated carbon (PAC), which will enhance the adsorption of soluble microbial products (SMP) and improve membrane filterability, by altering the mixed liquor's characteristics. Reversible fouling was assessed in terms of sludge filterability measurements, according to the standard time-to-filter (TTF) method, while irreversible fouling was assessed in terms of SMP removal. Results showed that the addition of PAC at the concentration of 3 g/L in the mixed liquor reduced SMP concentration and enhanced substantially the sludge filterability. Furthermore, the TTFPAC/TTFno PAC ratios were lower, than the corresponding SMPPAC./SMPno PAC ratios, indicating that the batch-mode, short-term addition of PAC promotes the reversible, rather than the irreversible fouling mitigation.

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: .

scholarly journals Effect of Powdered Activated Carbon to Reduce Fouling in Membrane Bioreactors: A Sustainable Solution. Case Study

2013 ◽  
Vol 5 (4) ◽  
pp. 1501-1509 ◽  
Author(s):  
Vincenzo Torretta ◽  
Giordano Urbini ◽  
Massimo Raboni ◽  
Sabrina Copelli ◽  
Paolo Viotti ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Membrane Bioreactors ◽  
Powdered Activated Carbon

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.

scholarly journals Powdered Activated Carbon Exacerbates Fouling in MBR Treating Olive Mill Wastewater

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2498 ◽  
Author(s):  
Noya Ran ◽  
Jack Gilron ◽  
Revital Sharon-Gojman ◽  
Moshe Herzberg
Keyword(s):  
Activated Carbon ◽  
Membrane Permeability ◽  
Membrane Fouling ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Powdered Activated Carbon ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Permeate Flux ◽  
Wastewater Treatment Process

Membrane fouling is a major obstacle in membrane bioreactors (MBRs) that treat wastewater. The addition of powdered activated carbon (PAC) is commonly suggested as a way to improve the MBR wastewater treatment process with respect to membrane fouling and effluent quality. Integrating the PAC addition into the MBR may also improve the stability of the acclimated microbial community for biodegrading the recalcitrant organic compounds that can also enhance membrane fouling. In this study, the ability of the MBR-PAC system to decrease membrane fouling was evaluated. Two pilot-scale reactors were operated: one reactor was supplemented with suspended PAC, and one was operated under similar conditions, without PAC. The feed to the reactors comprised domestic and olive oil mill wastewater. Surprisingly, the permeate flux and the membrane permeability decreased faster in the MBR supplemented with PAC compared to the control reactor. Corroborating these MBR fouling results, soluble microbial products (SMPs), originating from the PAC-supplemented reactor, were found to be more adhesive to an ultrafiltration membrane mimetic surface (polyether sulfone) as analyzed in a quartz crystal microbalance with dissipation monitoring (QCM-D). While the PAC had almost no effect on the dissolved organic carbon in the MBR, it altered the molecular weight distribution of the organic molecules in the SMP as observed with gel permeation chromatography: The fractions of 577–789 kDa and the one bigger than 4 × 103 kDa, were elevated and reduced, respectively, by the addition of PAC. A biofilm formation analysis using a confocal laser scanning microscopy showed a higher amount of biofilm on the membrane taken from the PAC reactor, but this membrane showed no traces of PAC particles when analyzed with a scanning electron microscope (SEM). Taken together, altering the composition of the dissolved organic matter in the MBR by PAC addition promoted its adhesion to the membrane, induced biofilm formation, and more prominently, decreased membrane permeability.

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