scholarly journals Quantifying the Effect of COD to TN Ratio, DO Concentration and Temperature on Filamentous Microorganisms’ Population and Trans-Membrane Pressure (TMP) in Membrane Bio-Reactors (MBR)

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1514
Author(s):  
Petros Gkotsis ◽  
Giannis Lemonidis ◽  
Manassis Mitrakas ◽  
Alexandros Pentedimos ◽  
Margaritis Kostoglou ◽  
...  
Keyword(s):  
Data Analysis ◽  
High Temperature ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Soluble Microbial Products ◽  
Mathematical Equation ◽  
Filamentous Microorganisms ◽  
Do Concentration ◽  
Microbial Products

Using moderate populations of filaments in the biomass of Membrane Bio-Reactors (MBRs) is a biological anti-fouling method which has been increasingly applied over the last few years. This study aims to quantify the effect of COD to TN ratio, Dissolved Oxygen (DO) concentration and temperature on filaments’ population and Trans-Membrane Pressure (TMP) in a pilot-scale MBR, with a view to reducing membrane fouling. The novelty of the present work concerns the development of a mathematical equation that correlates fouling rate (dTMP/dt) with the population of filamentous microorganisms, assessed by the Filament Index (FI), and with the concentration of the carbohydrate fraction of Soluble Microbial Products (SMPc). Apart from TMP and SMPc, other fouling-related biomass characteristics, such as sludge filterability and settleability, were also examined. It was shown that at high COD to TN ratio (10:1), low DO concentration in the filaments’ tank (0.5 ± 0.3 mg/L) and high temperature (24–30 °C), a moderate population of filaments is developed (FI = 1–2), which delays the TMP rise. Under these conditions, sludge filterability and settleability were also enhanced. Finally, TMP data analysis showed that the fouling rate is affected by FI and SMPc concentration mainly in the long-term fouling stage and increases exponentially with their increase.

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.

scholarly journals Impact of Chlorinated-Assisted Backwash and Air Backwash on Ultrafiltration Fouling Management for Urban Wastewater Tertiary Treatment

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 733
Author(s):  
Jiaqi Yang ◽  
Mathias Monnot ◽  
Lionel Ercolei ◽  
Philippe Moulin
Keyword(s):  
Physicochemical Properties ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Pilot Scale ◽  
Urban Wastewater ◽  
Cleaning Efficiency ◽  
Filtration Performance ◽  
Potential Damage ◽  
Wastewater Tertiary Treatment

To improve membrane fouling management, the NaClO-assisted backwash has been developed to improve permeability maintenance and reduce the need for intensive chemical cleanings. This study is aimed to focus on the efficiency of NaClO-assisted backwash in real UF pilot scale and with periodic classic backwash (CB) and air backwash (AB). The impacts on hydraulic filtration performance, physicochemical properties of membrane material under different addition frequencies of NaClO, and the performance of chlorinated CB and AB will be discussed. In result, 10 mg Cl2 L−1 NaClO addition in backwash water is confirmed to greatly improve the overall filtration performance and backwash cleaning efficiency. One condition stands out from the other due to better control of irreversible fouling, less NaClO consumption in 10 years prediction, sustainable and adaptable filtration performance, and less potential damage on the physicochemical properties of the membrane. Additionally, it can be inferred from this experiment that frequent contact with NaClO induced some degradation on the PES-made UF membrane surface properties. To retain the best state of UF membrane on anti-fouling and qualified production, the optimized condition with more frequent NaClO contact was not suggested for long-term filtration.

A Short Review of the Effect of Temperature on Soluble Microbial Products in the Membrane Bioreactor Systems

2013 ◽  
Vol 864-867 ◽  
pp. 1482-1485 ◽  
Author(s):  
De Qin Ran ◽  
Lin Guo Lu
Keyword(s):  
Membrane Fouling ◽  
Industrial Wastewater ◽  
Membrane Bioreactor ◽  
Short Review ◽  
Effect Of Temperature ◽  
Soluble Microbial Products ◽  
Future Trends ◽  
The Future ◽  
Microbial Products

The membrane bioreactor (MBR) systems have been actively employed for municipal and industrial wastewater treatments. However, membrane fouling is one of the main obstacles that restrict MBR to wide application while soluble microbial products (SMP) are known as major foulants. The paper reviewed the effect of temperature on SMP in MBR systems. At the end, the future trends in the effect of temperature in the coming years were addressed. It will be conducive to further application of MBR in the future.

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