Improvement in heavy metal removal from aqueous solution using polyetherimide nanofiltration membrane modified by coating approach

considered as a variable (0.5, 1, and 1.5 g/L of guanidine concentration). ATR-FTIR, SEM, AFM, and water contact angle were used to characterize the surface-modified membranes. Also, dry milk powder solution was considered as an organic foulant to assess antifouling features of the fabricated membranes. According to the obtained results, the surface modified membrane with 0.5 g/L of guanidine concentration was the optimal surface-modified membrane with pure water flux (PWF) and flux recovery ratio (FRR) of 11.6 kg/m2.h and 88.8%, respectively. Moreover, the capabilities of the optimal surface-modified membrane and the pristine membrane for rejecting AS5+ and Hg2+ in aqueous solution with concentrations of 20 ppm and 50 mg/L were compared. Based on the obtained results, the optimal surface-modified membrane rejected more than 98.5 % of AS5+ and Hg2+ solutions with 20 and 50 mg/L of metal ion concentrations.