Role of transparent exopolymeric particles in membrane fouling: Chlorella vulgaris broth filtration

Recent reports show strong evidence for the involvement of transparent exopolymer particles (TEPs), mainly produced by microalgae in natural environments, in membrane fouling in a wide range of membrane filtration processes. The objective of this study is to fundamentally investigate the direct role of TEPs on membrane fouling by using different Chlorella vulgaris broth solutions and different fractions of such broth (the soluble and bound fractions, the cells separated from these fractions and the cells with their bound sugars, separated from the soluble fraction) as filtration feed. The relation between the feed properties and their filterability over three membranes was determined. Scanning electron microscopy and light microscopy showed that the foulant types differed for each broth fraction and confirmed the role of TEPs in the fouling of microfiltration membranes. In addition, this study contributes to the role of TEPs in the filtration of microalgae cultivated for commercial reasons. (C) 2012 Elsevier Ltd. All rights reserved.