Optimization of cadmium adsorption on metal organic frameworks MIL-53(Fe) using response surface methodology

Abstract

This research aims to optimize the cadmium adsorption on metal organic frameworks MIL-53(Fe) using response surface methodology. Specifically, the effects of the adsorption parameters, such as contact time, initial cadmium ion concentration and adsorbent dosage were examined. The experimental design and optimization process consisted of a central composite design and a response surface analysis. The adsorption experimental data were analyzed to validate the the quadratic model produced by the response surface methodology. The results indicated that the interaction between contact time and initial cadmium ion concentration affects the cadmium uptake. The maximum cadmium uptake was obtained at the optimum conditions of 85 min contact time, 46 mg adsorbent dosage and 10 mg/L initial concentration of cadmium. A maximum of 74.94% adsorption efficiency was achieved under optimum conditions, with an F-value of 65.37. The model fitting was satisfactory, as the correlation coefficient of experimental (0.9882) and predicted (0.9731) was in good agreement. This study demonstrates the effectiveness of a combined application of central composite design and response surface methodology in evaluating the effects of the factors influencing cadmium adsorption adsorption on MIL-53(Fe).