Fresh and Uncalcined Solution Blow Spinning (SBS)-spun PAN and PVDF Nanofiber Membranes for Methylene blue dye Removal in Water

Freshly produced and uncalcined solution blow spun-poly (acrylonitrile) (PAN) and poly (vinylidene fluoride) (PVDF) nanofiber (NF) membranes were utilized as adsorptive membranes for methylene blue (MB) dye in water under batch adsorption. The effects of various initial dye solution concentrations (3-15 mg/L) and contact time (1-10 minutes) versus its adsorption capabilities of the nanofiber membranes were studied. Furthermore, adsorption isotherm that best fit the experimental data was determined. The equilibrium adsorption capacity, qe , for both nanofiber membranes increased with MB concentration of 3 - 7 mg/L but qe considerably decreased when such MB amounts increased to 15 mg/L. The highest qe obtained was 50.78 and 34.97 mg/g for PAN NF and PVDF NF membranes, respectively. Both NF membranes also showed high MB adsorption with increased contact time until equilibrium was reached. PAN demonstrated better adsorption capacity compared to PVDF at all levels of initial dye concentrations studied. Both nanofiber membranes are proposed to conform to the Dubinin-Radushkevich adsorption isotherm model. Using this model, the predicted values for the highest adsorption capacity, qmax, of PAN and PVDF NF membranes are 55.91 mg/g and 44.06 mg/g, respectively.