Changes of membrane performance in the Removal Tetracycline Process by Nanofiltration and Reverse Osmosis

Abstract:

Based on the methods of dynamic and static, a study was made of the characteristics of removing tetracycline (TC) from drinking water by aromatic polyamide nanofiltration (NF) membrane & Reverse osmosis(RO) membrane was studied. The results showed that TCs removal by NF and RO accompanied the process of adsorption, and adsorption capacities of tetracycline by NF and RO was up to 35% and 40%, respectively. The adsorption capacity of TCs was proportional to its initial concentration，but there was no significant correlation between the equilibrium adsorption rate and its initial concentration. It elaborated the characteristic of static adsorption of TCs on the membrane surfaces fitted with Freundlich adsorption isotherms model. Besides, the significance of the adsorption of TCs by NF and RO membranes confirmed by the infrared spectrogram and scanning electron micrograph. Being kinds of adsorption sites on membrane surface for adsorbing TC simultaneously, adsorption contained membrane pore adsorption, which could lead to irreversible membrane fouling.