title: Fouling of a microfiltration membrane by humic-like substances: a mathematical approach to modelling permeate flux and membrane retention.
abstract: Membrane retention of the humic-like substances present in a soluble microbial products (SMP) suspension was studied by using a dead-end filtration system. The SMP suspension was extracted from the sludge of an enhanced biological phosphorus removal-membrane bioreactor. Our results showed that both adsorption and steric retention of the humic-like substances governed their transport through the membrane during the filtration. The adsorption, which followed pseudo-first order kinetics, did not cause substantial decline of permeate flux. The steric retention, on the other hand, formed a gel layer, which in turn led to a major decrease in the flux. The reduction of permeate flux was well predicted by cake filtration theory. Based on the adsorption and the steric retention, a new model was developed for predicting the overall membrane retention of the humic-like substances. The general trend of the modelled overall retention was in partial agreement with the experimental results.
authors.affiliation: Department of Biotechnology, Chemistry and Bio-science, Aalborg University, Fredriks Bajers Vej 7H, Sohngaardsholmsvej 57, DK-9000 Aalborg East, Denmark E-mail: mlc@bio.aau.dk.
authors.forename: Eskandar
authors.initials: E
authors.lastname: Poorasgari
authors.affiliation: Department of Biotechnology, Chemistry and Bio-science, Aalborg University, Fredriks Bajers Vej 7H, Sohngaardsholmsvej 57, DK-9000 Aalborg East, Denmark E-mail: mlc@bio.aau.dk.
authors.forename: Ali
authors.initials: A
authors.lastname: Farsi
authors.affiliation: Department of Biotechnology, Chemistry and Bio-science, Aalborg University, Fredriks Bajers Vej 7H, Sohngaardsholmsvej 57, DK-9000 Aalborg East, Denmark E-mail: mlc@bio.aau.dk.
authors.forename: Morten Lykkegaard
authors.initials: ML
authors.lastname: Christensen
mesh_terms: D019149:Bioreactors; D005374:Filtration / Q000379:methods*; D006812:Humic Substances / Q000032:analysis*; D008962:Models, Theoretical; D012722:Sewage / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006812:Humic Substances; D012722:Sewage; D014874:Water Pollutants, Chemical