Studies on Fouling and its Prevention in MBRs

2010 ◽  
Vol 5 (2) ◽  
Author(s):  
B. Siembida ◽  
P. Cornel ◽  
S. Krause ◽  
B. Zimmermann
Keyword(s):  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
High Flux ◽  
Chemical Cleaning ◽  
Sustainable Operation ◽  
The One ◽  
The Impact ◽  
Very High ◽  
Mechanical Cleaning

Investigations of fouling alleviation and permeability decline in membrane bioreactors (MBR) were carried out at two pilot plants. On the one hand, the minimization of membrane fouling via adding abrasive granulates into activated sludge (submerged operated membrane) was tested. On the other hand, the impact of truly soluble compounds released into the liquid phase of activated sludge on fouling behavior was investigated. The first research into the impact of mechanical cleaning via adding granulates showed the unwanted formation of fouling layers was reduced as a result of abrasion processes. With this method continuous sustainable operation was achieved, without chemical cleaning and, at the same time, reaching very high flux levels up to 40 L/(m2·h) over more than 500 days (>16 months). The investigation of the effect of truly soluble compounds on membrane fouling showed that the permeability decline during 145 days of operation resulted predominantly from wastewater or activated sludge matter larger than 0.04 μm.

Principles of an enhanced MBR-process with mechanical cleaning

2011 ◽  
Vol 64 (10) ◽  
pp. 1951-1958 ◽  
Author(s):  
S. Rosenberger ◽  
F. P. Helmus ◽  
S. Krause ◽  
A. Bareth ◽  
U. Meyer-Blumenroth
Keyword(s):  
Membrane Fouling ◽  
Pilot Plant ◽  
Membrane Bioreactors ◽  
Fluidised Bed ◽  
Chemical Cleaning ◽  
Retention System ◽  
Reactor Geometry ◽  
Membrane Modules ◽  
Physical And Chemical ◽  
Mechanical Cleaning

Up to date, different physical and chemical cleaning protocols are necessary to limit membrane fouling in membrane bioreactors. This paper deals with a mechanical cleaning process, which aims at the avoidance of hypochlorite and other critical chemicals in MBR with submerged flat sheet modules. The process basically consists of the addition of plastic particles into the loop circulation within submerged membrane modules. Investigations of two pilot plants are presented: Pilot plant 1 is equipped with a 10 m2 membrane module and operated with a translucent model suspension; pilot plant 2 is equipped with four 50 m2 membrane modules and operated with pretreated sewage. Results of pilot plant 1 show that the establishment of a fluidised bed with regular particle distribution is possible for a variety of particles. Particles with maximum densities of 1.05 g/cm3 and between 3 and 5 mm diameter form a stable fluidised bed almost regardless of activated sludge concentration, viscosity and reactor geometry. Particles with densities between 1.05 g/cm3 and 1.2 g/cm3 form a stable fluidised bed, if the velocity at the reactor bottom is sufficiently high. Activities within pilot plant 2 focused on plant optimisation and the development of an adequate particle retention system.

scholarly journals Patterned Membrane in an Energy-Efficient Tilted Panel Filtration System for Fouling Control in Activated Sludge Filtration

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 432 ◽  
Author(s):  
Aisyah Osman ◽  
Normi Izati Mat Nawi ◽  
Shafirah Samsuri ◽  
Muhammad Roil Bilad ◽  
Norazanita Shamsuddin ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Aeration Rate ◽  
Membrane Bioreactors ◽  
Widespread Application ◽  
Membrane Area ◽  
Surface Corrugation ◽  
Fouling Control ◽  
The Impact

A membrane bioreactor enhances the overall biological performance of a conventional activated sludge system for wastewater treatment by producing high-quality effluent suitable for reuse. However, membrane fouling hinders the widespread application of membrane bioreactors by reducing the hydraulic performance, shortening membrane lifespan, and increasing the operational costs for membrane fouling management. This study assesses the combined effect of membrane surface corrugation and a tilted panel in enhancing the impact of air bubbling for membrane fouling control in activated sludge filtration, applicable for membrane bioreactors. The filterability performance of such a system was further tested under variable parameters: Filtration cycle, aeration rate, and intermittent aeration. Results show that a combination of surface corrugation and panel tilting enhances the impact of aeration and leads to 87% permeance increment. The results of the parametric study shows that the highest permeance was achieved under short filtration–relaxation cycle of 5 min, high aeration rate of 1.5 L/min, and short switching period of 2.5 min, to yield the permeances of 465 ± 18, 447 ± 2, and 369 ± 9 L/(m2h bar), respectively. The high permeances lead to higher operational flux that helps to lower the membrane area as well as energy consumption. Initial estimation of the fully aerated system yields the energy input of 0.152 kWh/m3, much lower than data from the full-scale references of <0.4 kWh/m3. Further energy savings and a lower system footprint can still be achieved by applying the two-sided panel with a switching system, which will be addressed in the future.

scholarly journals Long-Term Investigation into the Membrane Fouling Behavior in Anaerobic Membrane Bioreactors for Municipal Wastewater Treatment Operated at Two Different Temperatures

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 231
Author(s):  
Yi Ding ◽  
Zhansheng Guo ◽  
Zhenlin Liang ◽  
Xuguang Hou ◽  
Zhipeng Li ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Municipal Wastewater Treatment ◽  
Sludge Flocs ◽  
Microbial Product ◽  
Anaerobic Membrane Bioreactors ◽  
Sludge Particle

In this study, the characteristics of activated sludge flocs were investigated and their effects on the evolution of membrane fouling were considered in the anaerobic membrane bioreactors (AnMBR), which were operated at 25 and 35 °C for municipal wastewater treatment. It was found that the membrane fouling rate of the AnMBR at 25 °C was more severe than that at 35 °C. The membrane fouling trends were not consistent with the change in the concentration of soluble microbial product (SMP). The larger amount of SMP in the AnMBR at 35 °C did not induce more severe membrane fouling than that in the AnMBR at 25 °C. However, the polysaccharide and protein concentration of extracellular polymeric substance (EPS) was higher in the AnMBR at 25 °C in comparison with that in the AnMBR at 35 °C, and the protein/polysaccharide ratio of the EPS in the AnMBR at 25 °C was higher in contrast to that in the AnMBR at 35 °C. Meanwhile, the fouling tendencies measured for the AnMBRs could be related to the characteristics of loosely bound EPS and tightly bound EPS. The analysis of the activated sludge flocs characteristics indicated that a smaller sludge particle size and more fine flocs were observed at the AnMBR with 25 °C. Therefore, the membrane fouling potential in the AnMBR could be explained by the characteristics of activated sludge flocs.

Identification of activated sludge properties affecting membrane fouling in submerged membrane bioreactors

2006 ◽  
Vol 51 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Fangang Meng ◽  
Hanmin Zhang ◽  
Fenglin Yang ◽  
Shoutong Zhang ◽  
Yansong Li ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Sludge Properties

Membrane bioreactors for wastewater treatment: A review of mechanical cleaning by scouring agents to control membrane fouling

2017 ◽  
Vol 307 ◽  
pp. 897-913 ◽  
Author(s):  
Muhammad Aslam ◽  
Amine Charfi ◽  
Geoffroy Lesage ◽  
Marc Heran ◽  
Jeonghwan Kim
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Mechanical Cleaning

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

2015 ◽  
Vol 72 (10) ◽  
pp. 1754-1761 ◽  
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.

scholarly journals The impact of anionic polyacrylamide (APAM) on ultrafiltration efficiency in flocculation-ultrafiltration process

2017 ◽  
Vol 75 (8) ◽  
pp. 1982-1989 ◽  
Author(s):  
Ruijun Zhang ◽  
Shengnan Yuan ◽  
Wenxin Shi ◽  
Cong Ma ◽  
Zhiqiang Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Aluminium Chloride ◽  
Optimal Dosage ◽  
Cleaning Efficiency ◽  
Chemical Cleaning ◽  
Membrane Cleaning ◽  
Effluent Quality ◽  
Adsorption Sites ◽  
The Impact ◽  
Anionic Polyacrylamide

With the purpose of improving the ultrafiltration (UF) efficiency, anionic polyacrylamide (APAM) has been used as a coagulant aid in the flocculation-UF process. In this study, the impact of APAM on UF efficiency has been investigated with regard to membrane fouling, membrane cleaning and effluent quality. The results indicated that the optimal dosage of APAM had positive impacts on membrane fouling control, membrane cleaning and effluent quality. According to the flux decline curve, scanning electron microscopy and contact angle characterization, the optimal dosage of APAM was determined to be 0.1 mg/L coupled with 2 mg/L (as Al3+) poly-aluminium chloride. Under this optimal condition, membrane fouling can be mitigated because of the formation of a porous and hydrophilic fouling layer. APAM in the fouling layer can improve the chemical cleaning efficiency of 0.5% NaOH due to the disintegration of the fouling layer when APAM is dissolved under strong alkaline conditions. Furthermore, with the addition of APAM in the flocculation-UF process, more active adsorption sites can be formed in the flocs as well as the membrane fouling layer, thus more antipyrine molecules in the raw water can be adsorbed and removed in the flocculation-UF process.

A cost optimization study of flux and fouling rate for UF in the water industry

2008 ◽  
Vol 8 (1) ◽  
pp. 113-120 ◽  
Author(s):  
G. K. Pearce
Keyword(s):  
Membrane Fouling ◽  
Cost Optimization ◽  
Plant Size ◽  
Operating Pressure ◽  
High Flux ◽  
Chemical Cleaning ◽  
Critical Flux ◽  
Membrane Area ◽  
Optimization Study ◽  
The Relationship

Designing a commercial UF/MF system is an exercise in compromise. Selecting a high flux reduces capex by minimizing the membrane area required, but increases operating costs due to the increased chemical cleaning frequency, higher waste disposal volumes, and higher operating pressure. Most commercial systems are designed to run at fluxes significantly above the critical flux, so a degree of fouling and a reliance on chemical cleaning is inherent to the design. This paper examines the relationship between flux and membrane fouling rate through a review of experimental field data. The analysis shows that fouling rate increases exponentially with flux, with a function dependent upon the characteristics of the feed. The paper then presents the results of a cost optimization study in which Total Water Cost (TWC) is evaluated as a function of feed source and plant size for different CIP cleaning frequencies. The minimum TWC occurs in all cases for CIP frequencies of between 1/week and 1/month. Smaller plants with low fouling feeds have an optimum near 1 CIP/week using a relatively high flux design. In contrast, feeds with higher fouling propensity, and medium or large plant sizes have a TWC optimum close to 1 CIP/month, and should use a lower design flux. It is suggested that the flux corresponding to the TWC optimum should be designated the sustainable flux.

scholarly journals Effects of a low-strength magnetic field on the characteristics of activated sludge for membrane fouling mitigation

RSC Advances ◽  
2019 ◽  
Vol 9 (16) ◽  
pp. 9180-9186 ◽  
Author(s):  
Ren Zhijun ◽  
Wang Pengfei ◽  
Tian Jiayu ◽  
Zhang Zhiliu
Keyword(s):  
Magnetic Field ◽  
Microbial Community ◽  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Sludge Characteristics ◽  
Fouling Mitigation ◽  
Low Strength

This study aims to investigate the performance of a low-strength magnetic field in membrane bioreactors (MBRs) for membrane fouling mitigation and its effects on sludge characteristics and microbial community.

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