Abstract
Preparation and characterisation of chemically modified, improved biosorbent, xanthated Lagenaria vulgaris shell (xLVB), and its application for Cu(II) ions removal from aqueous solutions, were investigated in the present study. The chemically modified material was characterised by using FTIR, SEM and EDX analysis. Equilibrium isotherms and kinetics were obtained and the effect of various parameters including contact time, initial pH, biosorbent dosage, particle size, temperature, initial Cu(II) concentration was studied under batch conditions. xLVB was applied to test the sorption of Cu(II) ions in batch column system with recirculation of aqueous phase. The experimental data were best fitted by using pseudo-second order kinetics and the Langmuir isotherm model; equilibrium within less than 40 min and sorption capacity of 25.2 mg g(-1) for Cu(II) ions, at 20 degrees C were achieved. With increasing temperature from 10 to 40 degrees C the free energy change was negative, suggesting that the biosorption was exothermic and spontaneous.