There is a strong need for techniques enabling direct assessment of biological activity of biofouling in membrane filtration systems. Here we present a new quantitative and non-destructive method for mapping O 2 dynamics in biofilms during biofouling studies in membrane fouling simulators (MFS). Transparent planar O 2 optodes in combination with a luminescence lifetime imaging system were used to map the two-dimensional distribution of O 2 concentrations and consumption rates inside the MFS. The O 2 distribution was indicative for biofilm development. Biofilm activity was characterized by imaging of O 2 consumption rates, where low and high activity areas could be clearly distinguished. The spatial development of O 2 consumption rates, flow channels and stagnant areas could be determined. This can be used for studies on concentration polarization, i.e. salt accumulation at the membrane surface resulting in increased salt passage and reduced water flux. The new optode-based O 2 imaging technique applied to MFS allows non-destructive and spatially resolved quantitative biological activity measurements (BAM) for on-site biofouling diagnosis and laboratory studies. The following set of complementary tools is now available to study development and control of biofouling in membrane systems: (i) MFS, (ii) sensitive pressure drop measurement, (iii) magnetic resonance imaging, (iv) numerical modelling, and (v) biological activity measurement based on O 2 imaging methodology. © 2011 Elsevier B.V.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was performed by Wetsus, centre of excellence for sustainable water technology, Delft University of Technology and the Marine Biological Laboratory, University of Copenhagen. Wetsus is funded by the Ministry of Economic Affairs. Additional support was due to grants from the Danish Natural Science Research Council (M. S., M. K.). The authors thank the participants of the Wetsus theme 'Biofouling' for the fruitful discussions and their financial support.
ASJC Scopus subject areas
- Filtration and Separation
- Materials Science(all)
- Physical and Theoretical Chemistry