Impact of flow regime on pressure drop increase and biomass accumulation and morphology in membrane systems

WATER RESEARCH

卷:44

Article

Vrouwenvelder, J. S.^1,2  Buiter, J.³  Riviere, M.⁴  van der Meer, W. G. J.^5,6  van Loosdrecht, M. C. M.²  Kruithof, J. C.¹ 

[1] Wetsus, Ctr Excellence Sustainable Water Technol, NL-8900 CC Leeuwarden, Netherlands

[2] Delft Univ Technol, Dept Biotechnol, NL-2628 BC Delft, Netherlands

[3] Univ Duisburg Essen, D-47057 Duisburg, Germany

[4] Ecole Natl Super Chim, F-35708 Rennes 7, France

[5] Univ Twente, NL-7500 AE Enschede, Netherlands

[6] Vitens, NL-8200 BB Lelystad, Netherlands

关键词: Flow regime;    Shear force;    Linear flow velocity;    Biofilm streamers;    Two phase bubble flow;    Feed spacer channel pressure drop;    Biomass cohesion strength;    Flush;    Biofouling;    Nanofiltration;    Reverse osmosis;    Drinking water;   

DOI  :  10.1016/j.watres.2009.09.054

来源: Elsevier

【 摘 要 】

Biomass accumulation and pressure drop development have been studied in membrane fouling simulators at different flow regimes. At linear flow velocities as applied in practice in spiral wound nanofiltration (NF) and reverse osmosis (RO) membranes, voluminous and filamentous biofilm structures developed in the feed spacer channel, causing a significant increase in feed channel pressure drop. Elevated shear by both single phase flow (water) and two phase flow (water with air sparging: bubble flow) caused biofilm filaments and a pressure drop increase. The amount of accumulated biomass was independent of the applied shear, depending on the substrate loading rate (product of substrate concentration and linear flow velocity) only. The biofilm streamers oscillated in the passing water. Bubble flow resulted in a more compact and less filamentous biofilm structure than single phase flow, causing a much lower pressure drop increase. The biofilm grown under low shear conditions was more easy to remove during water flushing compared to a biofilm grown under high shear. To control biofouling, biofilm structure may be adjusted using biofilm morphology engineering combined with biomass removal from membrane elements by periodic reverse flushing using modified feed spacers. Potential long and short term consequences of flow regimes on biofilm development are discussed. Flow regimes manipulate biofilm morphology affecting membrane performance, enabling new approaches to control biofouling. (c) 2009 Elsevier Ltd. All rights reserved.

【 授权许可】

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