Threshold concentration of easily assimilable organic in feedwater for biofouling of spiral-wound membranes
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Microbiologische waterkwaliteit
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“One of the major impediments in the application of spiral-wound membranes in water treatment or desalination is clogging of the feed channel by biofouling which is induced by nutrients in the feedwater. Organic carbon is, under most conditions, limiting the microbial growth. The objective of this study is to assess the relationship between the concentration of an easily assimilable organic compound such as acetate in the feedwater and the pressure drop increase in the feed channel. For this purpose the membrane fouling simulator (MFS) was used as a model for the feed channel of a spiral-wound membrane. This MFS unit was supplied with drinking water enriched with acetate at concentrations ranging from 1 to 1000 μg C·L−1. The pressure drop (PD) in the feed channel increased at all tested concentrations but not with the blank. The PD increase could be described by a first order process based on theoretical considerations concerning biofilm formation rate and porosity decline. The relationship between the first order fouling rate constant Rf and the acetate concentration is described with a saturation function corresponding with the growth kinetics of bacteria. Under the applied conditions the maximum Rf (0.555 d−1) was reached at 25 μg acetate-C·L−1 and the half saturation constant kf was estimated at 15 μg acetate-C·L−1. This value is higher than ks values for suspended bacteria grown on acetate, which is attributed to substrate limited growth conditions in the biofilm. The threshold concentration for biofouling of the feed channel is about 1 μg acetate-C·L−1.”
(Citaat: Hijnen, W.A.M., Biraud, D., Cornelissen, E.R., Kooij, D. van der – Threshold concentration of easily assimilable organic in feedwater for biofouling of spiral-wound membranes – Environmental Science & Technnology 43(2009)13, p.4890-4895 DOI: 10.1021/es900037x)
Erratum: Hijnen, W.A.M., Biraud, D., Cornelissen, E.R., Kooij, D. van der – Threshold concentration of easily assimilable organic in feedwater for biofouling of spiral-wound membranes – Environmental Science & Technnology 45(2011)4, p.1744-1745 DOI: 10.1021/es104170p) http://pubs.acs.org/doi/abs/10.1021/es104170p