Color removal and COD reduction of biologically treated textile effluent through submerged filtration using hollow fiber nanofiltration membrane

► Submerged NF could remove color and COD from biologically treated textile effluent. ► The submerged NF membrane retained the electrolytes to a very small extent. ► Steady flux of 5.15 l/m2 h could be obtained at TMP of 0.8 bar and VCF of 4.0. ► Color removal rate of 99.3% and COD reduction rate of 91.5% could be obtained. ► Submerged NF membrane module possessed high water cleaning efficiency.