Impacts of hydrophilic colanic acid on bacterial attachment to microfiltration membranes and subsequent membrane biofouling

WATER RESEARCH

卷:76

Article

Yoshida, Keitaro¹  Tashiro, Yosuke^1,2  May, Thithiwat¹  Okabe, Satoshi¹ 

[1] Hokkaido Univ, Fac Engn, Div Environm Engn, Kita Ku, Sapporo, Hokkaido 0608628, Japan

[2] Shizuoka Univ, Grad Sch Engn, Dept Appl Chem & Biochem Engn, Naka Ku, Hamamatsu, Shizuoka 4328561, Japan

关键词: Membrane fouling;    Bacterial attachment;    Colanic acid;    Extracellular polymeric substances (EPS);   

DOI  :  10.1016/j.watres.2015.02.045

来源: Elsevier

【 摘 要 】

In order to examine the interactions between physicochemical properties of specific extracellular polymeric substances (BPS) and membrane biofouling, we investigated the impacts of hydrophilic colanic acid, as a model extracellular polysaccharide component, on initial bacterial attachment to different microfiltration (MF) membranes and membrane biofouling by using Escherichia coli strains producing different amounts of colanic acid. In a newly designed microtiter plate assay, the bacterial attachment by an E. coli strain RcsF, which produces massive amounts of colanic acid, decreased only to a hydrophobic membrane because the colanic acid made cell surfaces more hydrophilic, resulting in low cell attachment to hydrophobic membranes. The bench-scale cross-flow filtration tests followed by filtration resistance measurement revealed that RcsF(+) caused severe irreversible membrane fouling (i.e., pore-clogging), whereas less extracellular polysaccharide-producing strains caused moderate but reversible fouling to all membranes used in this study. Further cross-flow filtration tests indicated that colanic acid liberated in the bulk phase could rapidly penetrate pre-accumulated biomass layers (i.e., biofilms) and then directly clogged membrane pores. These results indicate that colanic acid, a hydrophilic extracellular polysaccharide, and possible polysaccharides with similar characteristics with colanic acid are considered as a major cause of severe irreversible membrane fouling (i.e., pore-clogging) regardless of biofilm formation (dynamic membrane). (C) 2015 Elsevier Ltd. All rights reserved.

【 授权许可】

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