A study was carried out to develop a kinetic model of the photocatalytic inactivation of Escherichia coli using different TiO2 catalysts. The model developed is based on a reaction scheme that involves effectively coupling mass-transfer fluxes between bacteria and catalyst surface on one hand and bacterial degradation reaction on the other. The photocatalytic results were derived from experiments led in a batch reactor under both dark and Ultra Violet (UV) irradiation conditions. Using a reference catalyst, the robustness of the developed model was tested under solar conditions. The experimental data validated the model as successfully able to reproduce evolutions in the viable bacteria concentration in the range of parameters studied without any further adjustment of the kinetic parameters. The model was used to simulate the bacterial degradation kinetics under different working conditions to describe the partitioning of both bacterial adhesion and photocatalytic reaction in the solution to be treated (c) 2015 American Institute of Chemical Engineers AIChE J, 61: 2532-2542, 2015