Adsorption behavior of indium(III) on modified solvent impregnated resins (MSIRs) containing sec-octylphenoxy acetic acid

A modified solvent impregnated resin (MSIR) was prepared by impregnation of sec-octylphenoxy acetic acid (CA-12) on styrene–divinylbenzene copolymer support (HZ818) after nitration of the benzene rings present in its structure. The MSIRs were characterized by thermogravimetric and Fourier Transform infrared spectroscopy (FTIR) analysis. The adsorption behavior of indium(III) on MSIRs was examined by batch and column method in hydrochloric acid medium. It was shown that optimal pH for indium(III) adsorption was 3.0. The adsorption isotherms were found to follow Langmuir model at different temperatures, and the maximum adsorption capacity enhanced with increasing temperature. The value of enthalpy change was positive, indicating that the adsorption of indium(III) with MSIRs is endothermic. Kinetic data indicated that the adsorption of indium(III) was in a good agreement with the pseudo second-order rate equation. The MSIRs sustained adsorptivity well after three recycles comparing with the SIRs.