The influence of sludge properties in SMEBR and conventional MBR pilot systems on membrane fouling was investigated. Generated data were analyzed using statistical analysis Pearson's product momentum correlation coefficient (r(p)). Analysis showed that TMP had strong direct (r(p) = 0.9182) and inverse (r(p) = -0.9205) correlations to mean particle size diameter in MBR and SMEBR, respectively. TMP in SMEBR had a strong direct correlation to the sludge mixed liquor suspended solids concentration (MLSS) (r(p) = 0.7757) while a weak direct correlation (r(p) = 0.1940) was observed in MBR. SMEBR showed a moderate inverse correlation (r(p) = -0.6118) between TMP and soluble carbohydrates (EPSc) and a very weak direct correlation (r(p) = 0.3448) to soluble proteins (EPSp). Conversely, EPSp in MBR had more significant impact (r(p) = 0.4856) on membrane fouling than EPSc (r(p) = 0.3051). The results provide insight into optimization of operational conditions in SMEBR system to overcome membrane fouling. (C) 2012 Elsevier Ltd. All rights reserved.