Performance Evaluation of asymmetric nanofiltration membrane : Effect of dye concentration on dye removal treatment

Abstract

Membranes has been received a great deal of attention as an alternative that can be used for the purification of dye complex wastewater streams. Asymmetric NF membrane meets the necessary standards caused by the capability to retain ions as well as relatively small organic molecules from an aqueous solution. Asymmetric NF membrane was developed to evaluate the efficiency of asymmetric NF membrane for dye removal application. Asymmetric NF membranes were developed by the dry/wet phase inversion method from casting solutions containing 23% Polysulfone (PSf) as polymer and N-methyl-2 pyrrolidone (NMP) as solvent using a semi automated electrically controlled casting machine. Membrane had been fabricated at the three different of shear rate (353.9 s-1, 232.6 s-1 ). Pure water flux was measured before the membranes were characterized in term of salt rejection and theoretical approach. The morphology of the membranes were observed by using Scanning Electron Microscopy (SEM) for identifying of the membrane structure Membrane performance have been measured by employing five aqueous solution of Reactive Black 5 with concentration of 100 mg/I to 500 mg/I. Operating pressure in the range 2 bars to 10 bars were applied. According to the experimental result of pure water flux and applied Steric Hindrance Pore model, the highest shear rate gives the best performance of membrane. In the investigation on effect of dyes concentration, flux was decreased when increasing RBS concentration. Flux decline was happen during the time caused by fouling. RB 5 rejection proportionally increased with the RBS concentration. Donnan effect became a dominant in this separation process. Application of dye removal exceeding 90% of dyes will promise advanced treatment option for pollution control in dye complex wastewater streams.