文摘
In this present study, an inorganic-biopolymer composite based on chitosan-zirconium(IV) was prepared and investigated as a biosorbent for the removal of vanadium(V) ions from aqueous solution. The resulting composite before and after adsorbed V(V) were characterized by using FT-IR, XRD, SEM and EDS, respectively. Various relevant parameters affecting the adsorption capacity such as pH, initial concentration, contact time, temperature and co-existing ions were evaluated. The results demonstrated that the optimum pH was found to be 4.0 and the equilibrium was achieved after 4 h for V(V) adsorption. The Langmuir isotherm model could be well described the adsorption of V(V), with the maximum adsorption capacity of 208 mg g鈭? at 30 掳C. The kinetics data were well fitted to pseudo-second-order equation, indicating that chemical sorption as the rate-limiting step of adsorption mechanism. The calculated thermodynamic parameters such as 螖G掳, 螖H掳 and 螖S掳 indicated that the adsorption process was feasible, spontaneous and endothermic in nature. Moreover, co-existing ions including nitrate, chloride and sulfate had a certain effect on the uptake of V(V). The V(V) loaded chitosan-zirconium(IV) composite could be regenerated by 0.01 mol L鈭? sodium hydroxide, with efficiency greater than 95%.