Performance characteristics of surfactant treated commercial polyamide membrane in the nanofiltration of model solution of reactive yellow 160

Top surface modification of commercial PA-NF 150 membrane was carried out by dip-soaking the membrane swatches with predetermined concentration of aqueous solutions of sodium dodecyl sulphonate (SDS), cetyltrimethylammonium bromide (CTAB) and Triton X-100 as anionic, cationic and non-ionic surfactants, respectively. The modified flat sheet membranes were used in the nanofiltration of the Reactive yellow 160 dye waste water in a pilot plant. AFM, FTIR-ATR, and water contact angle measurements were employed to characterize the prepared membranes. Addition of surfactants resulted in membranes with superior dye rejection in comparison to untreated membranes. The percent rejection of dye was in the vicinity of 95% for both CTAB and SDS treated membranes, however the results were different for Triton X-100. CTAB treated PA-NF membrane was observed to have marginally less extent of volumetric flux reduction with time compared to other two surfactant treated membranes. Substantial removal of color was achieved in the nanofiltration experiments with a marked reduction in COD and TDS. The process allowed the production of permeate stream with great reutilization possibilities.