Amine-grafted alumino-siloxane hybrid porous granular media: A potential sol–gel sorbent for treating hazardous Cr(VI) in aqueous environment

Amine grafted alumino-siloxane hybrid was processed first via sol–gel assisted in situ coagulation and poly-condensation reaction. Spherical granular media was then fabricated through nanocasting followed by self assembly techniques. Two kinds of hybrid granular sorbents namely aminated boehmite (A-HB) and boehmite/silica (A-HBS) were prepared and characterized for the chemical, structural and surface properties using FTIR, BET-surface area, SEM, and Zeta potential measurements. Cr(VI) adsorption efficiency of the resulted mesoporous sol gel hybrid sorbents was systematically carried out at varying pH, dosage, concentration, temperature and ionic strength. From the experimental data, the adsorption kinetics and isotherms were studied and verified with standard models such as Lagergren pseudo-first-order and pseudo-second-order kinetic models and Langmuir, Freundlich, Sips, Redlich–Peterson and Toth isotherm models. The adsorption efficiency of the hybrids was also compared with the already reported conventional sorbents from the literature.

Amine grafted alumino-siloxane beads were processed via sol–gel assisted in situ coagulation and poly-condensation reaction. Spherical granular media was then fabricated through nanocasting followed by self assembly techniques. These mesoporous, high surface area hybrids were found to be very effective for decontaminating Cr(VI) from the aqueous environment.Figure optionsDownload as PowerPoint slideHighlights
► Mesoporous alumino-siloxane hybrid beads were synthesized via sol gel method.
► These granular media were effective to remove Cr(VI) from wastewater.
► Kinetics, isotherm models and thermodynamic parameters were investigated.
► Kinetic data were well described by the pseudo-second-order model.
► The adsorption isotherms match well with sips isotherm model.