Results reported in this study indicate an apparent correlation
between molecular features and the removal of trace organic
contaminants by a laboratory scale MBR system. The removal
efficiencies of all 14 very hydrophobic trace organic
compounds (Log D at pH 8 > 3.2) selected in this study
consistently showed removal efficiencies in the range
between 85% to removal below the analytical detection limit,
indicating a removal of at least 98%. The occurrence of electron
withdrawing or electron donating functional groups
appears to be another important factor governing their
removal by MBR treatment. All hydrophilic and moderately
hydrophobic (Log D < 3.2) compounds possessing strong
electron withdrawing functional groups consistently showed
removal efficiency of well below 20%. In contrast, high
removal efficiency was observed with most compounds
bearing electron donating functional groups such as hydroxyl
groups and primary amine groups. Nevertheless, further
analysis also revealed several exceptions which remained
unexplainable given the current lack of biochemical data
about these compounds of interest. Based on the reported
data, a qualitative framework for the assessment of trace
organics removal by MBR treatment was presented.