Title of article :
Potential of mechanical cleaning of membranes from a membrane bioreactor
Author/Authors :
Paula van den Brink، نويسنده , , Frank Vergeldt، نويسنده , , Henk Van As، نويسنده , , Arie Zwijnenburg، نويسنده , , Hardy Temmink، نويسنده , , Mark C.M. van Loosdrecht، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2013
Abstract :
Several membrane fouling mechanisms have been identified in membrane bioreactors. While cake layers can be removed by physical cleaning, irreversible fouling such as a gel layer is difficult to remove by physical cleaning during filtration. Harsh mechanical cleaning was applied in this study to evaluate how much fouling could be maximally removed and distribution of remaining fouling was investigated. The fouling resistance of several membranes operated at different relatively low fluxes was followed during long term continuous flux operation. Remaining fouling was observed with scanning electron microscopy (SEM) and magnetic resonance imaging (MRI). Dead-end filtration tests with mechanically cleaned membranes showed a decreased permeability. To determine whether bacteria were present in the remaining fouling, oxygen consumption was quantified. Even after harsh mechanical cleaning, membrane samples showed considerable oxygen consumption. SEM did not show fouling inside the membrane. Of several membranes operated for at least 1 year, the permeate side was covered with bacteria and extracellular polymeric substances (EPS). These results show that fouling cannot be removed completely by harsh mechanical cleaning and that both feed and permeate side of the membrane contains biofouling. This fouling on the permeate side should not be neglected when designing membrane cleaning.
Keywords :
Biofilm , Remaining fouling , MRI measurements , Permeate side , Membrane bioreactors
Journal title :
Journal of Membrane Science
Journal title :
Journal of Membrane Science