TY - JOUR
T1 - Nanofiltration and reverse osmosis surface topographical heterogeneities
T2 - Do they matter for initial bacterial adhesion?
AU - Allen, Ashley
AU - Semião, Andrea J.C.
AU - Habimana, Olivier
AU - Heffernan, Rory
AU - Safari, Ashkan
AU - Casey, Eoin
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/7/5
Y1 - 2015/7/5
N2 - The role of the physicochemical and surface properties of NF/RO membranes influencing bacterial adhesion has been widely studied. However, there exists a poor understanding of the potential role membrane topographical heterogeneities can have on bacterial adhesion. Heterogeneities on material surfaces have been shown to influence bacterial adhesion and biofilm development. The purpose of this study was therefore to investigate whether the presence of membrane topographical heterogeneities had a significant role during bacterial adhesion as this could significantly impact on how biofouling develops on membranes during NF/RO operation. An extensive study was devised in which surface topographical heterogeneities from two commercial membranes, NF270 and BW30, were assessed for their role in the adhesion of two model organisms of different geometrical shapes, Pseudomonas fluorescens and Staphylococcus epidermidis. The influence of cross-flow velocity and permeate flux was also tested, as well as the angle to which bacteria adhered was compared to the flow direction. Bacterial adhesion onto the membranes and in their surface topographical heterogeneities was assessed using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), fluorescence microscopy and image analysis. Results showed that up to 30% of total adhered cells were found in membrane defect areas when defect areas only covered up to 13% of the membrane surface area. This suggests that topographical heterogeneities may play a significant role in establishing environmental niches during the early stages of biofilm development. Furthermore, no noticeable difference between the angle of cell attachment in defect areas compared to the rest of the membrane surface was found.
AB - The role of the physicochemical and surface properties of NF/RO membranes influencing bacterial adhesion has been widely studied. However, there exists a poor understanding of the potential role membrane topographical heterogeneities can have on bacterial adhesion. Heterogeneities on material surfaces have been shown to influence bacterial adhesion and biofilm development. The purpose of this study was therefore to investigate whether the presence of membrane topographical heterogeneities had a significant role during bacterial adhesion as this could significantly impact on how biofouling develops on membranes during NF/RO operation. An extensive study was devised in which surface topographical heterogeneities from two commercial membranes, NF270 and BW30, were assessed for their role in the adhesion of two model organisms of different geometrical shapes, Pseudomonas fluorescens and Staphylococcus epidermidis. The influence of cross-flow velocity and permeate flux was also tested, as well as the angle to which bacteria adhered was compared to the flow direction. Bacterial adhesion onto the membranes and in their surface topographical heterogeneities was assessed using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), fluorescence microscopy and image analysis. Results showed that up to 30% of total adhered cells were found in membrane defect areas when defect areas only covered up to 13% of the membrane surface area. This suggests that topographical heterogeneities may play a significant role in establishing environmental niches during the early stages of biofilm development. Furthermore, no noticeable difference between the angle of cell attachment in defect areas compared to the rest of the membrane surface was found.
KW - AFM
KW - Biofouling
KW - Nanofiltration
KW - Reverse osmosis
KW - Topography
UR - http://www.scopus.com/inward/record.url?scp=84926175219&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2015.03.029
DO - 10.1016/j.memsci.2015.03.029
M3 - 文章
AN - SCOPUS:84926175219
SN - 0376-7388
VL - 486
SP - 10
EP - 20
JO - Journal of Membrane Science
JF - Journal of Membrane Science
ER -