This study aims at the enhancement in nanofiltration process of aqueous solutions of inorganic salts and provides reference values for industrial application.Gas-sparged nanofiltration experiments with aqueous solution of MgSO4 were performed using a DK2540F element spiral nanofilitration membrane module.The permeate flux and the enhancement from gas sparging were measured in the following operation ranges:temperature 28-36℃

feed concentration 20-50 g·L-1

transmembrane pressure 0.4-0.7 MPa

air/liquid ratio 1.0-3.5

and air velocity 1.0-3.5 m·s-1.The effects of different conditions on the permeate flux

rejection and increment rate of permeate flux of nanofiltration membrane were investigated.The experimental results show that gas sparging can significantly increase the permeate flux and rejection of MgSO4 aqueous solution

appropriate temperature is between 30℃ and 40℃ and feed concentration

transmembrane pressure

and air/liquid have profound effects on the permeate flux and rejection rate of MgSO4 aqueous solution

and the flux enhancement is more significant at higher feed concentration

lower transmembrane pressure

and higher air/liquid.