Nanofiltration (NF) and reverse osmosis (RO) and are membrane-based separation processes which can be used for treatment of industrial effluents and wastewater recycling. In the present study, performance of functionalized nanofiltration (FNF-400) and thin film composite (TFC) polyamide RO membranes has been investigated for the treatment of industrial effluent consisting of 5710 ppm total dissolved solids (TDS), 4050 ppm chemical oxygen demand (COD) and 8.4 ppm biochemical oxygen demand (BOD). Effect of various parameters such as applied pressure and feed composition on parameters such as permeate conductivity and flux, TDS rejection, turbidity removal besides COD and BOD reduction was evaluated. At a constant feed pressure of 21 bar, higher average flux of 36.95 L/m(2) h was observed in case of NF when compared to 18.77 L/m(2) h for RO. The % rejections of TDS, turbidity and COD were observed to be 85%, 97.8% and 73.33% for NF and 95%, 100% and 86.66%, respectively for RO systems. A statistical mechanical model was developed for commercial NF and RO systems. The economic estimation of commercial NFIRO systems was carried out which reveals that NF process is more economical due to lower operating pressures and consequently lesser energy consumption. (C) 2013 Elsevier B.V. All rights reserved.