Fabrication of carboxylic functionalized superparamagnetic mesoporous silica microspheres and their application for removal basic dye pollutants from water

Superparamagnetic mesoporous silica microspheres embedded with a silica-coated superparamagnetic iron oxide nanoparticles core and mesoporous silica shell have been prepared using stearyltrimethyl ammonium bromide (STAB) as surfactant template. The superparamagnetic mesoporous silica microspheres then were modified with anhydride functionalized silane to graft carboxylic groups and developed for removing basic dye pollutants, e.g., Methylene Blue (MB) and Acridine Orange (AO) from wastewaters. The results show that the as-prepared adsorbent exhibits high adsorption capacity, extremely rapid adsorption rate and separation convenience for basic dye pollutants removal. Furthermore, the as-prepared adsorbent can be regenerated by simple washing with acid solution to recover both the adsorbents and the adsorbed dyes. The regenerated adsorbent can be reused for dye removal and the adsorption efficiency is still above 88% even after use for seven times. So it can be used as an economic recyclable tool for dyes pollutants removal from wastewater. (c) 2010 Elsevier Inc. All rights reserved.