Effects of mixed liquor pH on membrane fouling and micro-pollutant removals in membrane bioreactors for municipal landfill leachate treatment

2015 ◽  
Vol 72 (5) ◽  
pp. 770-778 ◽  
Author(s):  
Samunya Sanguanpak ◽  
Chart Chiemchaisri ◽  
Wilai Chiemchaisri ◽  
Kazuo Yamamoto
Keyword(s):  
Landfill Leachate ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Membrane Bioreactors ◽  
Leachate Treatment ◽  
Mixed Liquor ◽  
Municipal Landfill ◽  
Inorganic Substances ◽  
Ph Level ◽  
Ph Variations

This research investigated the membrane fouling and micro-pollutant removals in treatment of municipal landfill leachate at various pH levels (i.e. 5.5, 6.5, 7.5, and 8.5) using membrane bioreactors. The findings revealed that membrane fouling was influenced by the pH level of mixed liquor, with pH 5.5 exhibiting the most severe membrane fouling. At pH 5.5, proteins and carbohydrates were predominant in the membrane foulants, while at pH 8.5 humic-like and inorganic substances constituted the largest proportion of the foulants on the membrane surface. The removal efficiencies of micro-pollutants (bisphenol-A; 2,6-di-tert-butylphenol and 2,6-di-tert-butyl-4-methylbutylphenol) were nevertheless insignificantly influenced by the pH levels of mixed liquor. In addition, the removal rates of the compounds at pH 5.5 were slightly lower vis-à-vis at the higher pH levels. The micro-pollutant retention on the fouled membranes was also significant and highest under the mixed liquor pH of 8.5. Furthermore, the experiments demonstrated that the varying degrees of rejection by the fouled membranes could be attributed to the alteration of foulant characteristics as a result of the pH variations.

Comparison of four types of membrane bioreactor systems in terms of shear stress over the membrane surface using computational fluid dynamics

2013 ◽  
Vol 68 (12) ◽  
pp. 2534-2544 ◽  
Author(s):  
N. Ratkovich ◽  
T. R. Bentzen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Membrane Fouling ◽  
Two Phase Flow ◽  
Membrane Surface ◽  
Cross Flow ◽  
Membrane Bioreactors ◽  
Phase Flow ◽  
Two Phase ◽  
Computational Fluid Dynamics Cfd

Membrane bioreactors (MBRs) have been used successfully in biological wastewater treatment to solve the perennial problem of effective solids–liquid separation. A common problem with MBR systems is clogging of the modules and fouling of the membrane, resulting in frequent cleaning and replacement, which makes the system less appealing for full-scale applications. It has been widely demonstrated that the filtration performances in MBRs can be greatly improved with a two-phase flow (sludge–air) or higher liquid cross-flow velocities. However, the optimization process of these systems is complex and requires knowledge of the membrane fouling, hydrodynamics and biokinetics. Modern tools such as computational fluid dynamics (CFD) can be used to diagnose and understand the two-phase flow in an MBR. Four cases of different MBR configurations are presented in this work, using CFD as a tool to develop and optimize these systems.

Landfill Leachate Treatment by Yeast and Bacteria Based Membrane Bioreactors

2004 ◽  
Vol 39 (9) ◽  
pp. 2391-2404 ◽  
Author(s):  
B. Wichitsathian ◽  
S. Sindhuja ◽  
C. Visvanathan ◽  
K. H. Ahn
Keyword(s):  
Landfill Leachate ◽  
Membrane Bioreactors ◽  
Leachate Treatment

Anodic Oxidation of Effluents from Stages of MBR-UF Municipal Landfill Leachate Treatment Plant

2020 ◽  
Vol 37 (10) ◽  
pp. 702-714
Author(s):  
Zubeda Ukundimana ◽  
Mehmet Kobya ◽  
Philip Isaac Omwene ◽  
Erhan Gengec ◽  
Orhan Taner Can
Keyword(s):  
Anodic Oxidation ◽  
Landfill Leachate ◽  
Treatment Plant ◽  
Leachate Treatment ◽  
Municipal Landfill

scholarly journals Design of a Novel Membrane Draft Tube Jet Loop Reactor (MDJLR) and Treatment of Slaughterhouse Wastewater

Membranes ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 155
Author(s):  
Burhanettin Farizoğlu ◽  
Süleyman Uzuner
Keyword(s):  
Membrane Fouling ◽  
High Efficiency ◽  
Draft Tube ◽  
Membrane Surface ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Membrane Module ◽  
Circulation Rate ◽  
Slaughterhouse Wastewater ◽  
Loop Reactor

The most important obstacle to the widespread use of membrane bioreactors (MBRs) is membrane fouling. In this study, a high-efficiency compact MBR was developed. Therefore, the draft tube of the jet loop reactor (JLB) was planned for use as a membrane module. The high-velocity jet streams, which are present according to the nature of the JLBs, provide high crossflow (cut-off force) on the membrane surface. Thus, the produced membrane module is operated in submerged membrane mode. This enhanced JLB modification is named the membrane draft tube jet loop reactor (MDJLR). This new system has a KLa value of 139 h−1 (at E/V of 2.24 kW m−3). In the next stage, treatment of slaughterhouse wastewater with the MDJLR was carried out. Under the 5.5 kg COD m−3 d−1 loading rate, efficiencies over 97% were achieved. The system operated continuously for 50 days without membrane backwashing or cleaning. During this period, fluxes of 3 L m−2·h−1 were approximately obtained at operating conditions of 850 mg L−1 MLSS (mixed liquor suspended solids) concentration, 1 bar suction pressure (∆P), and 3000 L h−1 circulation rate. This developed MDJLR will make jet loop membrane bioreactors (JLMBRs) and MBRs more compact and improve their performance.

Membrane fouling caused by sub-micron particles in a mixed liquor suspension of an MBR

2013 ◽  
Vol 67 (11) ◽  
pp. 2602-2607 ◽  
Author(s):  
K. Kimura ◽  
R. Ogyu ◽  
T. Miyoshi ◽  
T. Naruse ◽  
T. Tsuyuhara ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Size Fraction ◽  
Fourier Transform Infrared ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Ftir Analysis ◽  
Mixed Liquor ◽  
Pore Plugging

Membrane fouling needs to be mitigated for widespread use of membrane bioreactors (MBRs). It has been pointed out that particles with small sizes found in supernatants (sub-micron particles) of mixed liquor suspensions of MBRs are important in the evolution of membrane fouling of this technology. However, information on characteristics of sub-micron particles in MBRs is still insufficient. In this study, a pilot-scale MBR treating municipal wastewater was used to investigate and characterize sub-micron particles in an MBR and to identify the size fraction(s) responsible for irreversible fouling in an MBR. It was clearly shown that characteristics of sub-micron particles in the MBR varied considerably depending on their sizes. Results of Fourier transform infrared (FTIR) analysis and monosaccharide analysis suggested that irreversible fouling in this study was mainly caused by the specific size fraction of 0.1–0.45 μm, which was close to the size of micropores of the membrane used. Pore plugging might explain this to some extent.

Simulation of membrane fouling considering mixed liquor viscosity and variation of shear stress on membrane surface

2011 ◽  
Vol 63 (2) ◽  
pp. 270-275 ◽  
Author(s):  
Hlwan Moe Zaw ◽  
Tari Li ◽  
H. Nagaoka
Keyword(s):  
Shear Stress ◽  
Standard Deviation ◽  
Membrane Fouling ◽  
Shear Force ◽  
Extracellular Polymeric Substances ◽  
Membrane Surface ◽  
Force Sensor ◽  
Bulk Liquid ◽  
Mixed Liquor ◽  
Flat Sheet

Simulation of membrane fouling in MBR was conducted considering accumulation, detachment and consolidation of extracellular polymeric substances accumulated on membrane surface. The fluctuation of shear stress working on membrane surface and the influence of the viscosity of mixed liquor were considered for the evaluation of shear stress. A flat-sheet-type membrane module was used and the change of trans-membrane pressure was measured in a laboratory-scale MBR reactor. Shear stress working on membrane surface caused by aeration was measured by a shear force sensor changing viscosity of bulk liquid. Effective shear stress on membrane surface was defined in the model as the sum of time-averaged shear stress and three times of standard deviation. The increase in the trans-membrane pressure was accurately simulated by the developed model suggesting validity of the developed fouling model and the idea of the effective shear stress on membrane surface.

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