📄 Abstract
Antibiotic residues in aquatic environments contribute to antimicrobial-resistance risks and require effective removal technologies. In this study, an aminosilane-modified iron oxide–silica composite (FNS) was synthesized and evaluated for ampicillin (AMP) removal from aqueous solution. The iron-oxide component was prepared by alkaline precipitation of Fe(III), while amine-functionalized silica was obtained by a sol–gel route using tetraethyl orthosilicate (TEOS) and (3-aminopropyl)trimethoxysilane (APTMS). The two components were combined at iron oxide:NH₂/SiO₂ mass ratios from 1:1 to 1:7. The 1:3 composite exhibited the highest AMP removal, approximately 82% under the investigated conditions, although BET surface area continued to increase at larger silica fractions. AMP removal was strongly pH-dependent, with the best performance at pH 4, and the removal profile approached a plateau after about 120 min. The pH response, together with the point of zero charge (pHₚzc ≈ 3.46), supports a mechanism governed by the combined effects of surface charge, AMP speciation, hydrogen bonding, and specific interactions between AMP functional groups and silanol, amine, and oxide surface sites. These results show that the adsorption performance of FNS is controlled by a balance between accessible surface area and interfacial chemistry rather than by BET area alone.
🏷️ Keywords
📚 How to Cite:
Thi Hau NGUYEN, Anh Kim NGUYEN , SYNTHESIS OF AN AMINOSILANE-MODIFIED IRON OXIDE–SILICA COMPOSITE FOR AMPICILLIN REMOVAL FROM AQUEOUS SOLUTION , Volume 12 , Issue 10, October 2026, EPRA International Journal of Multidisciplinary Research (IJMR) , Pages: 263 - 269 , DOI: https://doi.org/10.36713/epra31824