Membrane fouling in a membrane bioreactor: A novel method for membrane surface morphology construction and its application in interaction energy assessment

The fouling mechanism of the anion exchange membrane (AEM) induced by natural organic matter (NOM) in the absence and presence of calcium ions was systematically investigated via the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) approach. Sodium alginate (SA), humic acid (HA), and bovine serum albumin (BSA) were utilized as model NOM fractions. The results indicated that the presence of calcium ions tremendously aggravated the NOM fouling on the anion exchange membrane because of Ca-NOM complex formation. Furthermore, analysis of the interaction energy between the membrane surface and foulants via xDLVO revealed that short-range acid–base (AB) interaction energy played a significant role in the compositions of interaction energy during the electrodialysis (ED) process. The influence of NOM fractions in the presence of calcium ions on membrane fouling followed the order: SA > BSA > HA. This study demonstrated that the interaction energy was a dominating indicator for evaluating the tendency of anion exchange membranes fouling by natural organic matter.

Download Full-text

Exerting ultrasound to control the membrane fouling in filtration of anaerobic activated sludge—mechanism and membrane damage

Water Science & Technology ◽

10.2166/wst.2008.120 ◽

2008 ◽

Vol 57 (5) ◽

pp. 773-779 ◽

Cited By ~ 24

Author(s):

Xianghua Wen ◽

Pengzhe Sui ◽

Xia Huang

Keyword(s):

Activated Sludge ◽

Hydroxyl Radicals ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Chemical Interaction ◽

Membrane Surface ◽

Membrane Damage ◽

Operational Conditions ◽

Fouling Control ◽

Cake Layer

In this study, ultrasound was applied to control membrane fouling development online in an anaerobic membrane bioreactor (AMBR). Experimental results showed that membrane fouling could be controlled effectively by ultrasound although membrane damage may occur under some operational conditions. Based upon the observation on the damaged membrane surface via SEM, two mechanisms causing membrane damage by exerting ultrasound are inferred as micro particle collide on the membrane surface and chemical interaction between membrane materials and hydroxyl radicals produced by acoustic cavitations. Not only membrane damage but also membrane fouling control and membrane fouling cleaning were resulted from these mechanisms. Properly selecting ultrasonic intensity and working time, and keeping a certain thickness of cake layer on membrane surface could be effective ways to protect membrane against damage.

Download Full-text

Influences of fractal dimension of membrane surface on interfacial interactions related to membrane fouling in a membrane bioreactor

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2017.03.107 ◽

2017 ◽

Vol 500 ◽

pp. 79-87 ◽

Cited By ~ 14

Author(s):

Xiang Cai ◽

Lining Yang ◽

Zhiwei Wang ◽

Meijia Zhang ◽

Liguo Shen ◽

...

Keyword(s):

Fractal Dimension ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Membrane Surface ◽

Interfacial Interactions

Download Full-text

Biomass Characteristics and Their Effect on Membrane Bioreactor Fouling

Molecules ◽

10.3390/molecules24162867 ◽

2019 ◽

Vol 24 (16) ◽

pp. 2867 ◽

Cited By ~ 5

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.

Download Full-text

Influence of Membrane Structure and Chemical Characteristics on Separation and Fouling of Nanofiltration Membranes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.864-867.394 ◽

2013 ◽

Vol 864-867 ◽

pp. 394-398

Author(s):

Li Qing Zhang ◽

Gang Zhang

Keyword(s):

Surface Morphology ◽

Membrane Fouling ◽

Membrane Structure ◽

Membrane Surface ◽

Chemical Characteristics ◽

Surface Chemical ◽

Nanofiltration Membranes ◽

Factors Affecting ◽

Comprehensive Literature Review ◽

Physical Chemical

Nanofiltration membranes act an important role in the advanced water treatment as well as waste water reclamation and other industrial separations. Therefore, an understanding of the factors affecting NF separation and membrane fouling in high-pressure membrane systems is needed. Recent studies have shown that membrane surface morphology and structure as well as surface chemical characteristics influence permeability, rejection, and fouling behavior of nanofiltration (NF) membranes. A comprehensive literature review is reported, targeting the physical-chemical characteristics of NF membrane affecting separation and fouling, including pore size, porosity, surface morphology (measured as roughness), surface charge, and hydrophobicity/ hydrophilicity.

Download Full-text

A real trial of a long-term non-fouling membrane bioreactor for saline sewage treatment

Water Science & Technology ◽

10.2166/wst.2011.409 ◽

2011 ◽

Vol 63 (7) ◽

pp. 1519-1523 ◽

Cited By ~ 1

Author(s):

Peng Bai ◽

Jin Wang ◽

Guang-Hao Chen

Keyword(s):

Membrane Fouling ◽

Membrane Bioreactor ◽

Membrane Surface ◽

Pilot Trial ◽

Sewage Treatment ◽

Power Source ◽

Permeate Flux ◽

Mixing Condition ◽

Water Ratio

This paper reports on a pilot trial of a novel MBR developed with coarse-pore membrane module by the authors. The plant was operated for 370 days with up to 7 m3/d raw saline sewage after 3-mm screening. The plant performed successfully without membrane fouling for 270 days except an accidental power source failure for 30 h, during which membrane was fouled under no aeration and mixing condition. EPS increases in both the reactor and the bio-cake on the membrane surface explained this fouling. The average TSS, COD and TKN removal efficiency were 92, 90, and 93%, respectively, under a high effective permeate flux of 4.8 m/d and a low air-to-water ratio of 15.

Download Full-text