Removal of Cu²⁺ from aqueous solution by Chitosan/Rectorite nanocomposite microspheres

Abstract

The novel chitosan/rectorite nanocomposite microspheres were prepared by controlling mass ratios of chitosan and rectorite at 6:1. The microspheres were characterized by Fourier transform infrared spectrophotometer, X-ray diffraction, and scanning electron microscope. The interlayer distance of rectorite was enlarged from 2.53 to 3.01 nm. Adsorption of Cu²⁺ from aqueous solution onto chitosan/rectorite nanocomposite microspheres was studied. The results showed that the Cu²⁺ adsorption process is dependent on pH, contract time, initial CR concentration, and temperature. The maximal Cu²⁺ uptake was 190.2 mg g⁻¹ in the test. The adsorption kinetics, isotherms, and thermodynamics were also studied. The maximum sorption capacities calculated from the pseudo-second-order rate equation and Langmuir isotherm were 209.5 and 201.6 mg g⁻¹, respectively, which were close to the experimental values. Adsorption thermodynamics study indicated the spontaneous nature and endothermic of the adsorption process.

Keywords:

• Chitosan
• Rectorite
• Microspheres
• Adsorption
• Cu²⁺

Acknowledgement

Contract grant sponsor: National Natural Science Foundational of China (50904047); Wuhan Science and Technology Bureau (201271031420); Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University (HBRCEBL2011-2012002).