Kinetic and isotherm parameter determination for the removal of chromium from aqueous solutions by nanoalumina, a nanoadsorbent

Nanoalumina has been employed for the adsorption of chromium from aqueous solutions. The data for best-fit for linear and non-linear forms of kinetic and isotherm models were compared. Non-linear analysis included error analysis using 'Solver add-in' of Microsoft Excel, Origin and MATLAB software's curve fitting tool. MATLAB and Origin curve fitting tool (R2 > 0.96) are better than error analysis method (0.79 < R2 > 0.99) of 'solver add in' for determination of isotherm parameters. Adsorption of chromium on nanoalumina is best explained by Langmuir isotherm model. Linear method is better than non-linear methods to determine the kinetic model. The sum of the square of error among linear and non-linear analysis methods for kinetic models is minimum for linear analysis method (0.008) than all other non-linear analysis methods (0.019-0.478). The adsorption of chromium on nanoalumina is governed by pseudo-second-order kinetics.