Important Driving Forces in Various Membrane ProcessesMain Driving ForcePressure gradientConcentration gradientGradient in electrical potentialTemperature gradientTypical Transmembrane Pressures and Recoveries for Pressure Driven Membrane ProcessSystem RecoveryMolecularMacromolecularMicroparticleMacroparticleSizes of materials of interestMembrane processesConventional processes