Important Driving Forces in Various Membrane ProcessesMain Driving ForcePressure gradientConcentration gradientGradient in electrical potentialTemperature gradientTypical Transmembrane Pressures and Recoveries for Pressure Driven Membrane ProcessSystem RecoveryFrom fluid mechanics, we know that the relationship between the height of a column of waterand the pressure at its base is P. Therefore, theheights of columns of water that would have the specified pressures are MF membranes are porous, with characteristic pore diameters on the order of 0.01–2 mm. These membranes are capable of removing particles and some colloidal matter from the feed, but virtually no solutes