Formation and ripening of alginate-like exopolymer gel layers during and after membrane filtration

The properties of biofilm EPS are determined by the multiple interactions between its constituents and surrounding environment. Because high complexity EPS, constituents' characterisation is still far from thorough, identification these cannot be done yet. Therefore, we use gels bacterial alginate-like exopolysaccharides (ALEs) as a model component for in this work. These have been examined their cohesive function CaCl2 KCl concentration. Hereto, ALE gel layers were formed on membranes dead-end filtration solutions. Accumulation cations Ca2+ K+ could well predicted Donnan equilibrium based fixed negative charges ALE. This suggests that there no specific binding to time scale experiments, ions can distribute freely over solution. concentration was estimated around 1 mmol/g VSS (volatile suspended solids, organic mass) equilibrium. Moreover, an accumulation H+ predicted. Gels with more supernatant compact bore higher osmotic pressure than those less CaCl2, revealing role network crosslinking. It hypothesised mechanism later transitions into rearrangement molecules, which eventually leads fibrous structure large voids.