Membrane filtration has become an interesting common technique for waste-water treatment compared to conventional treatment methods. This is because membrane techniques offer separation that can be achieved at ambient temperature with minimum energy. With this technology, waste water reuse is possible thus curbing the water deficiency that some part of the world is facing today. However, good fouling control is essential for the efficiency of the membrane filtration unit. Hence, a fundamental understanding of fouling is important in improving the performance of the UF membrane. This paper discusses the types of fouling and its mechanisms involved, and examines an existing mathematical model describing the dynamics of fouling. The dominant fouling mechanism was found to be pore blocking and cake formation. With this model, the time-dependent flux and the time required to reach the steady state in a cross-flow filtration can be easily determined. However, the flux in cross-flow filtration at steady state is limited. Such limiting flux is predicted by the models developed based on the theory of concentration polarization. The model are then be simulated under different operating conditions to check for consistencies. Despite that, time scales for pore blocking and cake formation under common operating conditions are also investigated. The local flux in filtration channel, the time to reach steady state and the effect of shear rate on membrane fouling are simulated to illustrate the use of the existing model.