Poorasgari Eskandar, Farsi Ali, Christensen Morten Lykkegaard
Department of Biotechnology, Chemistry and Bio-science, Aalborg University, Fredriks Bajers Vej 7H, Sohngaardsholmsvej 57, DK-9000 Aalborg East, Denmark E-mail:
Water Sci Technol. 2016;73(12):3033-40. doi: 10.2166/wst.2016.176.
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.
