The performance of a membrane bioreactor (MBR) system and the extension and mechanisms thatlead to the formation of the fouling may differ in relation to the start-up. As a consequence, theMBR start-up may constitute a crucial point that drastically influence the MBR performance in itslifespan. Indeed, the start-up influences the mechanisms of membrane fouling whose effects, in thecase of irreversible cake deposition, can be modified only by a chemical membrane washing. Inorder to gain insights about the effect of the start-up on a MBR system, a MBR pilot plant wasbuild-up and a mathematical model developed. The MBR system was constituted by a hollow fibremembrane module installed in submerged configuration in a pilot aerobic reactor. Particularly, twodifferent start-up procedures have been considered: inocolum of biomass and no inoculum ofbiomass. The whole experimental campaign was divided in two periods, lasting 65 days each:during the first period, the pilot plant was started-up without inoculum of activated sludge and nosludge withdrawal was performed; on the contrary during the second period, the MBR pilot plantwas started-up with sludge inoculum and the sludge concentration was kept constant. Amathematical model was applied to the two periods in order to integrate the insights coming theexperimental analysis about the advantages/disadvantages of carrying out a MBR start-up with orwithout inoculum. The model takes into account both biological and physical phenomena thatjointly play important rules in the assessment of MBR system performance. The evolution offouling and TMP in both periods were analyzed. Both experimental and model resultsdemonstrated that the best choice in terms of start-up of MBR systems comes from a compromisebetween minimization of the fouling issues and, on the other hand, high system performance.
|Numero di pagine||10|
|Stato di pubblicazione||Published - 2010|