Start-up of two moving bed membrane bioreactors treating saline wastewater contaminated by hydrocarbons

2015 ◽  
Vol 73 (4) ◽  
pp. 716-724 ◽  
Author(s):  
R. Campo ◽  
N. Di Prima ◽  
G. Freni ◽  
M. G. Giustra ◽  
G. Di Bella
Keyword(s):  
Extracellular Polymeric Substances ◽  
Membrane Surface ◽  
Membrane Bioreactors ◽  
Moving Bed ◽  
Biological Removal ◽  
Start Up ◽  
Suspended Biomass ◽  
Polyurethane Sponge ◽  
Microbial Products ◽  
The One

This work aims to assess the acclimation of microorganisms to a gradual increase of salinity and hydrocarbons, during the start-up of two moving bed membrane bioreactors (MB-MBRs) fed with saline oily wastewater. In both systems an ultrafiltration membrane was used and two types of carriers were employed: polyurethane sponge cubes (MB-MBRI) and polyethylene cylindrical carriers (MB-MBRII). A decreasing dilution factor of slops has been adopted in order to allow biomass acclimation. The simultaneous effect of salinity and hydrocarbons played an inhibitory role in biomass growth and this resulted in a decrease of the biological removal efficiencies. A reduction of bound extracellular polymeric substances and a simultaneous release of soluble microbial products (SMPs) were observed, particularly in the MB-MBRII system, probably due to the occurrence of a greater suspended biomass stress as response to the recalcitrance of substrate. On the one hand, a clear attachment of biomass occurred only in MB-MBRI and this affected the fouling deposition on the membrane surface. The processes of detachment and entrapment of biomass, from and into the carriers, significantly influenced the superficial cake deposition and its reversibility. On the other hand, in MB-MBRII, the higher production of SMPs implied a predominance of the pore blocking.

Fouling cake layer in a submerged anaerobic membrane bioreactor treating saline wastewaters: curse or a blessing?

2011 ◽  
Vol 63 (12) ◽  
pp. 2902-2908 ◽  
Author(s):  
I. Vyrides ◽  
D. C. Stuckey
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Large Fraction ◽  
Membrane Bioreactors ◽  
Extracellular Polysaccharides ◽  
Cake Layer ◽  
Anaerobic Membrane Bioreactors ◽  
Suspended Biomass ◽  
Microbial Products

The treatment of inhibitory (saline) wastewaters is known to produce considerable amounts of soluble microbial products (SMPs), and this has been implicated in membrane fouling; the fate of these SMPs was of considerable interest in this work. This study also investigated the contribution of SMPs to membrane fouling of the; (a) cake layer/biofilm layer, (b) the compounds below the biofilm/cake layer and strongly attached to the surface of the membrane, (c) the compounds in the inner pores of the membrane, and (d) the membrane. It was found that the cake/biofilm layer was the main reason for fouling of the membrane. Interestingly, the bacteria attached to the cake/biofilm layer showed higher biodegradation rates compared with the bacteria in suspension. Moreover, the bacteria attached to the cake layer showed higher amounts of attached extracellular polysaccharides (EPS) compared with the bacteria in suspension, possibly due to accumulation of the released EPS from suspended biomass in the cake/biofilm layer. Molecular weight (MW) analysis of the effluent and reactor bulk showed that the cake layer can retain a large fraction of the SMPs in the reactor and prevent them from being released into the effluent. Hence, while cake layers lead to lower fluxes in submerged anaerobic membrane bioreactors (SAMBRs), and hence higher costs, they can improve the quality of the reactor effluent.

scholarly journals Biomass Characteristics and Their Effect on Membrane Bioreactor Fouling

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2867 ◽  
Author(s):  
Petros K. Gkotsis ◽  
Anastasios I. Zouboulis
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Suspended Solids ◽  
Extracellular Polymeric Substances ◽  
Membrane Surface ◽  
Membrane Resistance ◽  
Soluble Microbial Products ◽  
Gelling Properties ◽  
Microbial Products ◽  
Soluble Part

Biomass characteristics are regarded as particularly influential for fouling in Membrane Bio-Reactors (MBRs). They primarily include the Mixed Liquor Suspended Solids (MLSS), the colloids and the Extracellular Polymeric Substances (EPS). Among them, the soluble part of EPS, which is also known as Soluble Microbial Products (SMP), is the most significant foulant, i.e., it is principally responsible for membrane fouling and affects all fundamental fouling indices, such as the Trans-Membrane Pressure (TMP) and the membrane resistance and permeability. Recent research in the field of MBRs, tends to consider the carbohydrate fraction of SMP (SMPc) the most important characteristic for fouling, mainly due to the hydrophilic and gelling properties, which are exhibited by polysaccharides and allow them to be easily attached on the membrane surface. Other wastewater and biomass characteristics, which affect indirectly membrane fouling, include temperature, viscosity, dissolved oxygen (DO), foaming, hydrophobicity and surface charge. The main methods employed for the characterization and assessment of biomass quality, in terms of filterability and fouling potential, can be divided into direct (such as FDT, SFI, TTF100, MFI, DFCM) or indirect (such as CST, TOC, PSA, RH) methods, and they are shortly presented in this review.

Side effects of flux enhancing chemicals in membrane bioreactors (MBRs): study on their biological toxicity and their residual fouling propensity

2008 ◽  
Vol 57 (1) ◽  
pp. 117-123 ◽  
Author(s):  
V. Iversen ◽  
J. Mohaupt ◽  
A. Drews ◽  
M. Kraume ◽  
B. Lesjean
Keyword(s):  
Liquid Phase ◽  
Side Effects ◽  
Oxygen Transfer ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Full Scale ◽  
Soluble Microbial Products ◽  
Biological Toxicity ◽  
Microbial Products ◽  
Colloidal Materials

Soluble and colloidal materials like soluble microbial products (SMP) or extracellular polymeric substances (EPS) are considered to be major foulants in membrane bioreactors (MBRs). Removing these fouling causing substances is thus thought to reduce the fouling of the membrane in general. In addition to traditional strategies for fouling prevention which mostly try to remedy the effects of fouling by air scour, etc., the new and promising method of adding chemicals is being investigated here. Previous tests with 30 different substances have shown that several of these reduce SMP concentration in the supernatant and enhance filtration. Nevertheless, additive dosing might have unknown side effects in filtration systems. Results presented in this study indicate that these additives may themselves cause severe fouling on different membranes if they remain unbound in the liquid phase. Therefore, the thorough control of the dosing rate of these chemicals will be of paramount importance in full scale applications. Biological toxicity of additives was measured in terms of respiration. OUR tests did not show inhibiting effects for most additives. Chitosan even showed an enhanced OUR due to biodegradability. Oxygen transfer could be enhanced for 25% with the addition of a polymer.

Package plant of extended aeration membrane bioreactors: a study on aeration intensity and biofouling control

2005 ◽  
Vol 51 (10) ◽  
pp. 335-342 ◽  
Author(s):  
Z. Ujang ◽  
S.S. Ng ◽  
H. Nagaoka
Keyword(s):  
Membrane Bioreactor ◽  
Membrane Surface ◽  
Membrane Bioreactors ◽  
Detergent Solution ◽  
Nutrients Removal ◽  
Membrane Cleaning ◽  
Detergent Enzyme ◽  
Suspended Biomass ◽  
Biofouling Control ◽  
Set Up

Biofouling control is important for effective process of membrane bioreactor (MBR). In this study, phenomena of biofouling for immersed type extended aeration MBR with two different anti-fouling aeration intensities were studied through a laboratory set up. The objectives of this study were (a) to observe biofouling phenomena of MBR that operates under different anti-fouling bubbling intensity, and simultaneously monitors performance of the MBR in organic carbon and nutrients removal; (b) to compare effectiveness of detergent and detergent-enzyme cleaning solutions in recovering biofouled membranes that operated in the extended aeration MBR. For MBR, which operated under continuous anti-fouling aeration, deposition and accumulation of suspended biomass on membrane surface were prohibited. However, flux loss was inescapable that biofilm layer was the main problem. Membrane cleaning was successfully carried out with detergent-enzyme mixture solutions and its effectiveness was compared with result from cleaning with just detergent solution.

The Effect of Media Fill Ratio on Membrane Fouling in Moving Bed Bioreactors-Membrane Bioreactor

2013 ◽  
Vol 726-731 ◽  
pp. 470-473 ◽  
Author(s):  
Liang Duan ◽  
Yong Hui Song ◽  
Wei Jiang ◽  
Slawomir W. Hermanowicz
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Major Fraction ◽  
Fill Ratio ◽  
Moving Bed ◽  
Large Molecular Weight ◽  
High Fraction ◽  
Microbial Products ◽  
Modified Fouling Index

This research investigated the effect of media fill ratio on membrane fouling in moving bed bioreactors-membrane bioreactor. The results shown the high removal of ammonia and COD, despite the membrane fouling conditions were really different in two bioreactors. The total modified fouling index (MFI) of IFAS 3000 was three times than MFI of IFAS 1500, and the soluble microbial products (SMP) present in the mixed liquor played an important role in the membrane fouling. No more correlation was found between the extracellular polymeric substances (EPS) concentration and fouling, and the average SMP of IFAS 3000 was higher than IFAS 1500. The carbohydrate of SMP occupied high fraction in all reactors. Large molecular weight (MW) components constituted the major fraction of EPS and SMP. The results indicated that higher media fill ratio can decrease membrane fouling effectively.

scholarly journals Biofouling Formation and Bacterial Community Structure in Hybrid Moving Bed Biofilm Reactor-Membrane Bioreactors: Influence of Salinity Concentration

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1133 ◽  
Author(s):  
Alejandro Rodriguez-Sanchez ◽  
Juan Leyva-Diaz ◽  
Barbara Muñoz-Palazon ◽  
Maria Rivadeneyra ◽  
Miguel Hurtado-Martinez ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Electric Conductivity ◽  
Bacterial Community Structure ◽  
Membrane Surface ◽  
Membrane Bioreactors ◽  
Biofilm Reactor ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Α Diversity

Two pilot-scale hybrid moving bed biofilm reactor-membrane bioreactors were operated in parallel for the treatment of salinity-amended urban wastewater under 6 hours of hydraulic retention time and 2500 mg L−1 total solids concentration. Two salinity conditions were tested: the constant salinity of 6.5 mS cm−1 electric conductivity (3.6 g L−1 NaCl) and the tidal-like variable salinity with maximum 6.5 mS cm−1 electric conductivity. An investigation was developed on the biofouling produced on the ultrafiltration membrane surface evaluating its bacterial community structure and its potential function in the fouling processes. The results showed that biofouling was clearly affected by salinity scenarios in terms of α-diversity and β-diversity and bacterial community structure, which confirms lower bacterial diversity under variable salinity conditions with Rhodanobacter and Dyella as dominant phylotypes. Microorganisms identified as bio-mineral formers belonged to genera Bacillus, Citrobacter, and Brevibacterium. These findings will be of help for the prevention and control of biofouling in saline wastewater treatment systems.

Influences of electroosmosis and electrophoresis on permeate flux and membrane fouling in submerged membrane bioreactors (SMBRs)

2016 ◽  
Vol 74 (3) ◽  
pp. 766-776 ◽  
Author(s):  
Secil Bayar ◽  
Ahmet Karagunduz ◽  
Bulent Keskinler
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Membrane Bioreactors ◽  
Polymeric Membrane ◽  
Soluble Microbial Products ◽  
Permeate Flux ◽  
Electrical Field ◽  
Cake Layer ◽  
Significant Process ◽  
Microbial Products

The objective of this study was to investigate the influences of electroosmosis (EO) and electrophoresis (EP) on the permeate flux in submerged membrane bioreactors. When a polymeric membrane is placed in between an anode and a cathode, both EO and EP occur simultaneously, causing enhancement in flux. Results showed that after 150 min of filtration, the permeate fluxes were 60, 115, 175 and 260 L/m2/h at 0, 30, 40 and 50 V, respectively. It was shown that the EO was linearly changing with increasing voltage, reaching up to 54 L/m2/h at 50 V. EP was found to be a significant process in removing soluble microbial products from the membrane surface, resulting in an increase in permeate flux as the filtration progressed. About 20-fold of smaller protein and carbohydrate concentrations were found in the cake layer when the electrical field (EF) was applied. However, the EF application promoted pore fouling, because of the calcium and magnesium scaling.

Characterisation of biofilm constituents and their effect on membrane filterability in MBRs

2008 ◽  
Vol 58 (10) ◽  
pp. 1933-1939 ◽  
Author(s):  
T. C. A. Ng ◽  
H. Y. Ng
Keyword(s):  
Structural Characteristic ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Significant Fraction ◽  
Bulk Solution ◽  
Soluble Microbial Products ◽  
Microbial Products ◽  
Solution Changes

Fouling is still one of the main issues in the operation of membrane bioreactors (MBRs). While most attention has been paid to extracellular polymeric substances (EPS) and soluble microbial products (SMP) in the bulk solution, changes in membrane filterability may be more adequately described by the structural characteristic of the fouling layer or biofilm. This study shows that membrane filterability and the rise in TMP is associated to the changes in the biofiom structure, and polysaccharides may be the most significant fraction that affects fouling.

Modeling of the attached and suspended biomass fractions in a moving bed biofilm reactor

Chemosphere ◽  
2021 ◽  
Vol 275 ◽  
pp. 129937
Author(s):  
Alessandro di Biase ◽  
Maciej S. Kowalski ◽  
Tanner R. Devlin ◽  
Jan A. Oleszkiewicz
Keyword(s):  
Biofilm Reactor ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Suspended Biomass
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