Investigation of Membrane Processes in Blood Purification

Hemodialysis (blood purification in patients that suffers irreversible kidney failure) is one of the most important applications of membrane processes in which membrane module is usually in the form of hollow fiber. Blood and dialysate flow countercurrently in inner and outer of the fibers, respectively. Membranes ideally show suitable sieving coefficient that adjusts with the normal kidney action, high blood compatibility, high chemical and thermal resistance (for reuse). To approach high blood purification flux, membranes with hydrophobic polymer supports, having high chemical and thermal resistance, and hydrophilic additives should be used. In hemodialysis, cellulose acetate membranes have advantages such as good biocompatibility and relatively low cost, however, they behave low chemical and thermal resistance. Hemodialysis membranes are generally prepared via phase inversion. Chemical species can be bonded on the surface of membranes to increase their blood compatibility. The main objective of this article is to study the history of hemodialyzers and their optimal performance. Also various membranes, modules and blood purification equipments are investigated.