Fuzzy logic models for time-variant specific fluxes during crossflow microfiltration of several feed suspensions under a wide range of hydrodynamic parameters were derived and validated. The coefficient of efficiency values, which quantifies the degree of agreement between experimental observations and numerically calculated values were found greater than 0 96 for all cases. An important contribution of this research is that it is demonstrated that a single robust fuzzy model can quantitatively capture cumulative effects of a range of particle sizes on membrane fouling Hence, empirical models incorporating fuzzy logical operators appear to encompass overall effects of non-linear colloidal transport and deposition mechanisms as well as changes in cake morphology and resistance with hydrodynamics better than mathematically complicated mechanistic models This also suggests the use of fuzzy logic algorithms in programmable control systems for improved on-site operation of membrane-based liquid-solid separation employed in municipalities and industries. (C) 2009 Elsevier B.V. All rights reserved.