Amino-modified hollow alumina spheres: effective adsorbent for Cd 2+ , Pb 2+ , As(V), and diclofenac removal

• Published in: Environmental science and pollution research international 2021-01
• Main Authors: Nikolić, Vesna, Tomić, Nataša, Bugarčić, Mladen, Sokić, Miroslav, Marinković, Aleksandar, Veličković, Zlate, Kamberović, Željko
• Format: Article
• Language: English
• ISSN: 1614-7499
• DOI: 10.1007/s11356-020-12157-1

A simple sol-gel method and external gelatinization method of hollow alumina spheres synthesis were developed in this study. The spheres were modified with polyethyleneimine (PEI) producing PEI-Al O via (3-glycidyloxypropyl)trimethoxy-silane, GLYMO, linker. Characterization results, obtained using XRD and SEM microscopy revealed spherical geometry with a hollow core of PEI-Al O adsorbent. Introduction of a large number of the amino group, 6.9 mmol g , contributes to achieving high adsorption capacities, q , of 95.6, 124.9, 61.3, and 125.9 mg g for Cd , Pb , As(V), and DCF, respectively, which is obtained by using the Langmuir model. Thermodynamic studies indicated feasible adsorption and higher spontaneity with temperature increase. The kinetic study conveniently modeled using pseudo-second-order (PSO) and Weber-Morris kinetic model, as well as single resistance mass transfer model, indicated a change of the contribution of diffusional processes during adsorption with a dominance of intra-particle diffusion. The fixed-bed column adsorption data, fitted using Bohart-Adams, Clark, Yoon-Nelson, and Thomas models, showed lower capacity in comparison to batch study, and thus clear potential applicability of PEI-Al O was deduced even at a high loading of feed water.