S Ranjbari - Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran,
S.A Hosseini - Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran,
E Bet-Moushoul - Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran,
K Farhadi - Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran,

Polyethersulfone (PES)-based mixed matrix membranes (MMMs) with the incorporation of inorganic fillers were prepared using phase inversion method, and resulting PES/leonardite nanostructures were characterized by SEM, AFM, and contact angle measurements. Three different amounts of leonardite nanoparticles were introduced into the casting solutions to obtain the optimum value. It was found that the hydrophilicity of the obtained MMMs was remarkably improved by modification with leonardite nanostructures. Besides, the permeate flux and the anti-fouling properties of all prepared membranes were also studied. The scanning electron microscopy (SEM) images displayed a finger-like and porous structure for all modified membranes. The pure water flux enhanced from 25.3 g/m2 h (the unmodified membrane) to 62.65 g/m2 h (the modified membrane including 0.01 wt.% of leonardite nanoparticles). The membrane antifouling properties were examined by using the egg albumin solution as the model system. The %FFR of the prepared membranes increased from 66.6% for unmodified membrane to 92.3 at highest additive loading, while increasing the leonardite amount from 0.00 to 0.01wt.% led to a decrease of Rir from 33.3% to 7.69%, respectively. The membrane with 0.005 wt% of leonardite nanoparticles exhibited high efficiency and stability in fluoride removal up to 97%.

Polyethersulfone, Leonardite nanoparticles, Fluoride, Membrane technology, Waste water treatment