مشخصات پژوهش

Abstract The pollution of natural waters with aromatic amines is of serious environmental concern. The aim of this work was to enhance the ability of chitosan for selective and effective removal of aromatic amines from natural waters. The chitosan was modified with the inclusion of nano-Al2O3 and then the impregnation with Cu2þ solution. The study on the chemical structure of the modified adsorbent by Fourier transform infrared spectroscopy showed the formation of a complex between amine groups of the chitosan and Cu(II) on the adsorbent surface. It was found that the modified adsorbent, Cu–chitosan/nano-Al2O3, has more porous surface morphology and so more specific surface area available for adsorption. The adsorption properties of the modified adsorbent toward aniline and dimethyl aniline as typical aromatic amines were investigated using kinetics and isotherm studies at room temperature. The adsorption equilibrium data were fitted well by the Freundlich isotherm model. The kinetic data exhibited a non-linear fit to pseudo-second-order model for both aniline and dimethyl aniline. The adsorption capacity of Cu–chitosan/nano-Al2O3 was much higher than that of neat chitosan and chitosan/nano-Al2O3. The adsorbent had high selectivity for adsorption of aniline and dimethyl aniline in the presence of chloride, nitrate, sulfate, phosphate, and carbonate as natural waters common anions. The modified adsorbent exhibited good regeneration ability. The results showed that the introduced adsorbent can be employed as an effective chitosan-based adsorbent for selective removal of aromatic amines from natural waters.