Novel biopolymer templated hierarchical silicalite-1 as an adsorbent for the removal of rhodamine B

The synthesis of a novel type of hierarchical silicalite-1, using tetrapropylammonium hydroxide (TPAOH) and sodium alginate as microporous and mesoporous templates respectively, has been done for its utilization in dye removal from aqueous streams. The adsorption studies indicate that the hierarchical silicalite-1 exhibits improved adsorption performance than the conventional silicalite-1 for Rh B removal; attributed to the freshly generated mesopores in addition to the intrinsic micropores in them. This observation has been complemented by the results from nitrogen adsorption (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) examinations. The effect of experimental conditions such as initial dye concentration, contact time and adsorbent amount on the dye removal process has also been studied. The adsorption and kinetic studies reveal that the rhodamine B adsorption on hierarchical silicalite-1 follows Freundlich isotherm and pseudo-second-order kinetic models. (C) 2018 Elsevier B.V. All rights reserved.