Mercury Removal and Antibacterial Performance of A TiO2–APTES Kaolin Composite
Abdulsalam A.A. Khabdullina S. Sairan Z. Sarbassov Y. Pirman M. Amrasheva D. Kyzas G.Z. Pham T.T. Arkhangelsky E. Poulopoulos S.G.
December 2025Multidisciplinary Digital Publishing Institute (MDPI)
Sustainable Chemistry
2025#6Issue 4
Mercury (Hg2+) contamination in water systems poses a severe environmental and health hazard due to its high toxicity and bioaccumulation potential. In this study, a novel adsorbent was developed by sequentially modifying kaolin via acid–base treatment, titanium dioxide (TiO2) incorporation, and 3-aminopropyltriethoxysilane (APTES) grafting. Batch adsorption experiments revealed that the fully modified kaolin (TiO2-loaded and APTES grafted) exhibited the highest adsorption capacity (25.6 mg/g) compared to the acid–base-treated (5.8 mg/g) and TiO2-loaded (17.7 mg/g) kaolin. Under optimal conditions (75 mg adsorbent dosage; 70 mg/L Hg2+; pH 5), the fully modified kaolin maintained its performance even in the presence of varying ionic strengths, natural organic matter, and competing metal ions. Adsorption kinetics followed a pseudo-second-order model, and the equilibrium data were well fitted by the Langmuir isotherm. Antibacterial activity assay revealed that the TiO2-loaded kaolin effectively inhibited S. aureus (minimum inhibitory concentration = 2.5 mg/mL) and showed moderate activity against E. coli (BL21) (minimum inhibitory concentration = 5 mg/mL). However, antibacterial activity decreased after amine functionalization, indicating a compromise between enhancing adsorption capacity and preserving antibacterial functionality. This study presents a promising cost-efficient approach for the simultaneous removal of Hg2+ ions from water matrices and inhibiting bacterial growth, aligning with SDG 6 (Clean Water and Sanitation).
adsorption , antibacterial activity , APTES-grafting , kaolin , mercury removal , SDG 6 , TiO2-incorporation
Text of the article Перейти на текст статьи
Department of Chemical and Materials Engineering, School of Engineering and Digital Science, Nazarbayev University, Astana, 010000, Kazakhstan
Department of Biology, School of Sciences and Humanities, Nazarbayev University, Astana, 010000, Kazakhstan
Hephaestus Laboratory, School of Chemistry, Faculty of Sciences, Democritus University of Thrace, Kavala, GR-65404, Greece
School of Engineering and Digital Sciences, Nazarbayev University, Astana, 010000, Kazakhstan
Department of Chemical and Materials Engineering
Department of Biology
Hephaestus Laboratory
School of Engineering and Digital Sciences
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026