Amino Ethyl-Functionalized SBA-15: A Promising Adsorbent for Anionic and Cationic Dyes Removal

Abstract

<em>Batch Adsorption of Acid Red 37 (AR37) and Basic Orange 2 (BO2) on amino ethyl-functionalized SBA-15 have been studied. SBA-15 was synthesized and functionalized according to the procedure in the literature. Amino ethyl-functionalized SBA-15 showed the BET surface area 520 m²/g and pore diameter 7.02 nm, based on adsorption-desorption of N₂. SEM image shows lengthy fiber-like morphology for the title material. The presence of organic groups in the silica framework was demonstrated by thermogravimetric analysis. The effects of pH, contact time and dye concentration on adsorption were investigated in order to find the optimum adsorption conditions. The results have indicated that modification of adsorbent with a functional group of amino ethyl will remarkably increase the elimination of these two dyes but amino ethyl-functionalized SBA-15 has higher affinity to AR37. The experimental data were analyzed using the Langmuir and Freundlich adsorption models. The data fitted well to the Langmuir model with maximum adsorption capacities 333.3 for Acid Red 37 and 250.0 for Basic Orange 2. Finally, this methodology was applied for the removal of the pollutant dyes from textile wastewater. The results were shown that amino ethyl-functionalized nanoporousSBA-15 acts as an effective sorbent for the removal of both anionic and cationic dyes from aqueous solution.</em>