Ceramic membranes are commonly used for asymmetric structures with a porous base and an active membrane layer. The macroporous base provides mechanical stability, while the active layer serves as a separator for microfiltration, ultrafiltration and nanofiltration (10 µm to 1 CD). Inorganic ceramic membranes are used for cross-flow filtration (tangential flow filtration). The turbid liquid passes through the inorganic membrane layer into the middle of the channel at high speed. Under the action of transmembrane pressure (TMP), the pure liquid with the micromolecule passes vertically through the membrane layer until penetration, while the solid and large molecule is rejected into the retentate. In this way, the nutrient liquid is purified, concentrated and cleaned.
Inorganic ceramic membranes have an asymmetrical structure consisting of three layers: a filtration membrane layer, a middle layer and a support layer. The pressure loss of such an asymmetrical structure is small, which means that the ceramic membrane has a better recovery of daily operation.