What exactly do we mean by ultrafiltration and for which processes can it be used? Ultrafiltration is a process in which a pressure-driven process using a specific size membrane is used to separate macromolecular weights from a solution, thereby allowing the transfer of the low molecular weight (permeate). Ultrafiltration is exclusively defined by the pore size range (0.1 – 0.001 microns) (Dhawan). Ultrafiltration is used in a wide range of applications, such as food and beverage, chemical, pharmaceutical, medical, drinking water, wastewater, etc. This research review will focus on the industrial applications and transportation processes that make ultrafiltration unique, as well as the industry standard for separation. The rapid development of ultrafiltration for industrial processes is possible thanks to the advent of high-flux anisotropic membranes, capable of distinguishing molecular sizes from 10 A to 10 µ (Porter, 1972). The high molecular weight solute that passes through the membrane, but does not pass through it, is released as a retentate (concentrate). The solution that passes through the membrane is called permeate, as shown in Figure 1. This figure shows the basic structure of a hollow membrane where the feed of the material you want to separate enters, and where the permeate (ultrafiltrate) and the retentate. exits. In different industrial processes, one may wish to retain the permeate, the retentate or a combination of the two. Mass balance, momentum balance and flux Figure 1: Flow and flow in a hollow fiber for ultrafiltration (Yeh, 2009) Let's take a closer look at what ultrafiltration drives from a mathematical point of view. In Figure 1, the feed solution is controlled by volumetric flow rate (qi/Ni), pressure (∆Pi) and concentration (Ci). This power solution produces a mass balance which results in the flux (J) relative to the fibers (dz): (Yeh, 2009) The momentum balance must also be taken into account: (Yeh, 2009) It can be assumed that the volumetric flow rate will be reduced in the same way as the Hagen–Poiseuille equation, due to the laminar flow in the tube in the experiment Yeh, H. in 2009, it takes into account the convection as well as the balance of mass and momentum: (Yeh, 2009) Equation 3 assumes that the volumetric flow rate is relatively large compared to that of the permeation flow rate. This mainly occurs in an exponential pattern along the membrane tube. This model simply states that when working with a pressure-driven ultrafiltration process, as pressure increases, a ceiling (limiting) flow will occur regardless of the increase in pressure. We know that the relationship between membrane pressure (∆ρ) and permeate flux leads us to the following conclusion (Yeah, 2009).