Removal of copper ions from water using epichlorohydrin cross-linked beta-cyclodextrin polymer: characterization, isotherms and kinetics.

Beta-cyclodextrin (beta-CD) cross-linked with epichlorohydrin to form water insoluble beta-cyclodextrin polymer (beta-CDP) has been shown to be an effective sorbent for sorption of organic particles, but the sorption of copper (Cu2+) in aqueous solutions by beta-CDP has not been conducted. The objective of this study was to explore the sorption mechanism of beta-CDP for copper. The effects of different experimental conditions such as pH, ionic strength, contact time, and temperature were inspected using a batch method. In addition, binding scheme was estimated by using Fourier transform infrared (FTIR) spectroscopy, Xray photoelectron spectroscopy (XPS), a scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET) analysis. The adsorption of Cu2+ was observed to be higher at pH 6.0. The kinetic study revealed that the adsorption is fitted well by the pseudo-second-order kinetic model. The maximum binding of Cu2+ was estimated to be 111.11 mg/g through the Langmuir isotherm model--much higher than the existing sorption technologies. Hence, the adsorption-desorption trends of epichlorohydrin cross-linked with beta-CD, along with its good recyclability, establish an alternative, effective, and novel remediation technology for the removal of Cu2+ from aqueous solutions.