Phenol removal from hypersaline wastewaters in a Membrane Biological Reactor (MBR): Operation and microbiological characterisation

摘要

In this study, two Membrane Biological Reactors (MBR) with submerged flat membranes, one at lab-scale conditions and the other at pilot-plant conditions, were operated at environmental temperature to treat an industrial wastewater characterised by low phenol concentrations (8-16mgL~(-1)) and high salinity (～150-160mScm~(-1)). During the operation of both reactors, the phenol loading rate was progressively increased and less than 1mg phenolL-1 was detected even at very low HRTs (0.5-0.7days). Membrane fouling was minimized by the cross flow aeration rate inside the MBRs and by intermittent permeation. Microbial community analysis of both reactors revealed that members of the genera Halomonas and Marinobacter (gammaproteobacteria) were major components. Growth-linked phenol degradation by pure cultures of Marinobacter isolates demonstrated that this bacterium played a major role in the removal of phenol from the bioreactors.