Effect of regeneration conditions on the cyclic performance of amine-modified SBA-15 for removal of copper from aqueous solutions: Composite surface design methodology Original Research Article

The effect of regeneration conditions (solution type, concentration, volume, and temperature) on propylamine-functionalized mesoporous silica was investigated after three adsorption–desorption cycles, under different batchwise regeneration conditions. Three criteria were used to determine the effect of regeneration conditions, namely: adsorption capacity, structural stability and amine loading and accessibility. Using a composite surface design methodology, the effect of these regeneration conditions on the performance of the adsorbent was investigated. It was found that all the studied parameters have a statistically significant influence on the working adsorption capacity with the order: concentration > solution type > temperature > solution volume. With respect to structural properties and amine content, none of the factors was found to be significant. Regeneration using EDTA was found to be more efficient than acid treatment.