سیدعبداللطیف هاشمی فرد

Due to the broad application of membrane technology in the various industries, improving the structure and properties of the membrane is always one of the interesting fields for many researchers. Several methods have been proposed to improve the structure and properties of the membrane that one of the simplest and effective means of them is addition of the additives intpo dope solution.This study focuses on the effect of three normal alkanes as additive on the structure and performance parameters of ultrafiltration (UF) flat sheet polyethersulfone (PES) membranes. Asymmetric PES membrane was fabricated by phase inversion method and N-hexane, N-decane and Tetradecane were used as additive and water as the coagulation bath. The effects of different concentration of these additives on the solution parameters were investigated by ternary phase diagram and viscosity measurement. Also the membranes structure were estimated by the various tests and the performance of membranes studied by oily wastewater treatment finally. Since these additive are immiscible in the caugalation bath so the behaviour of them during phase inversion is similar to PES behaviour and exit from the system by addition the non-solvent. Results showed that addition of these additives increase the overall and surface porosity of membranes and exit of additives as a nono droplets is the major reasons of changes. Finally it can be concluded that by controlling the concentration of these additives can be control the structure and performance of membranes in order to application different industries.