The effect of hydrocarbon on a pilot plant membrane bioreactor system

The paper reports the main results from an experimental gathering campaign carried out on a bench scale plant for the evaluation of hydrocarbon effect on the system performance. In particular, a membrane bioreactor (MBR) under submerged configuration was analysed. The MBR plant was fed with synthetic wastewater containing hydrocarbons. Organic carbon, hydrocarbons and ammonium removal, kinetic constants, extracellular polymeric substances (EPSs) production and membranes fouling rates have been assessed. The observed results highlighted good system performance in terms of both COD removal and nitrification, thus showing a sort of biomass adaptation to hydrocarbon. Such a result has been also confirmed by the biomass respirometric tests. Moreover, membrane fouling analysis showed an increase of the total resistance in the last period of the experiments. Such a result was most likely due to the hydrocarbon which caused an irreversible fouling due to oil deposition onto the membrane surface.