Influence of feed conditions on the rejection of salt and dye in aqueous solution by different characteristics of hollow fiber nanofiltration membranes

Abstract

Three different characteristics of self-made hollow fiber nanofiltration (NF) membranes with different structural and electrical properties were evaluated for their suitability for removing salt and colour as a function of feed conditions. Results showed that NF achieved promising dye retention for the reactive dyes used at different concentrations and varied slightly with pH. The retention of salt was found to be dependent on feed properties and membrane electrical properties where higher retentions were achieved under alkaline condition and by using the most negatively charged NF membrane. The enhancement in the membrane negative surface charge resulting from the addition of sulfonated poly (ether ether ketone) (SPEEK) during membrane preparation had also made the NF less fouling-sensitive to dye absorption and improving the economic viability of the treatment process.