LAUSR

The purpose of this study was to analyze batch and column adsorption kinetics equations of cadmium from aqueous solutions using sugarcane straw nano-structure absorbent. In the batch experiments, adsorption kinetics was investigated. In the column experiments, a fixed-bed column with 84 cm height (27 cm for free board) and 3.4 cm internal diameter was used. Adsorption column performance for 5, 10 and 20 mg/L cadmium ion, for 0.05 L/min continuous flow rate from up to down and 27 cm bed height was used. Experiments were conducted at the pH = 5 and laboratory temperature condition. Second order kinetics model with R2 = 0.974 and RMSE = 0.002 had the highest correlation with laboratory data. The maximum adsorption capacity of second order kinetics model (1.11 mg/g) was exactly equal to maximum actual adsorption capacity. Continuous test results showed that with increasing concentrations of 5 to 20 mg/L cadmium, the maximum adsorption capacity increased from 0.91 to 2.08 mg/g and the adsorption efficiency decreased from 48.8 to 30.32. The model of Thomas and YonNelson with the correlation coefficient up to 0.95 were more consistent with laboratory data of fixed bed columns compared to Bohart-Adams, and Dose Response models.