Separation and Purification Technology, Vol.177, 142-151, 2017
Adsorption-controlled preparation of anionic imprinted amino-functionalization chitosan for recognizing rhenium(VII)
This study described the synthesis of the Mo(VI)-imprinted ethylenediamine (EDA) grafted chitosan (I-EDA-CS), which is a novel technique in combination with surface imprinting and polymer crosslinking. Results indicated that mass ratio of ammonium molybdate and chitosan as 1 g:25 g-3 g:25 g could be conducive to achieve higher adsorption capacity of Re(VII). The maximum adsorption capacity of Re (VII) was found to be 418.98 mg.g(-1) at 303 K with an initial Re(VII) concentration of 500 mg.L-1, while maximum adsorption of Re(VII) on the non-imprinted absorbent (N-EDA-CS) was just 83.92 mg.g(-1). The maximum selectivity coefficients of the I-EDA-CS for Re(VII)/Cu(II), Re(VII)/Zn(II), Re(VII)/Mn(II), Re(VII)/Fe(II) were 1.29, 1.9, 2.31, 1.81, respectively. It revealed that the Mo(VI)-imprinted adsorbent showed superior selectivity and affinity to Re(VII) in case of the existence of competition ions. The analysis results of FT-IR and XPS confirmed that the high adsorption selectivity of the I-EDA-CS attributed to the chelation and electrostatic attraction between the amine groups and Re(VII) anionic complexes in the "cavities". Imprinted I-EDA-CS was successfully employed for the selective adsorption of Re(VII) from industrial wastewater. (C) 2016 Elsevier B.V. All rights reserved.