Physico-Chemical nanomaterials science

Polyfnctionalized mesoporous silica for the recovery of heavy metals in cation and anion forms from the water solution: comparative and optimization study
Karelina А.A.1, Kobylinska N.G. 2, Dudarko О.A. 3
1 National University of "Kyiv-Mohyla Academy" (NaUKMA), Hryhoriy Skovoroda, 2, Kyiv, 04655 Ukraine
E-mail: karelinanastia1@gmail.com
2 Dumansky Institute of Colloid Chemistry and Water Chemistry of NAS of Ukraine, 42, Vernadsky Blvd, Kyiv, 03680, Ukraine,
3Chuiko Institute of Surface Chemistry of NAS of Ukraine, 17 General Naumov Str., Kyiv, 03164, Ukraine

Chelating and ion-exchange N-functionalized silica as selective adsorbents for removal of heavy metals were synthesized using template method. Fourier transform infrared spectroscopy, N2 adsorption/desorption isotherms and titration analysis conﬁrmed successful functionalisation of the tri-sodium salt of N-(triethoxysilylpropyl)ethylenediaminetriacetic acid (EDTA), primary amine (NH2) and quaternary ammonium salt(QAS) onto the mesoporous silica (SBA-15). The synthesized series of N-functionalized silicas were investigated for removal of Cr(III, VI), Mn(II, VII), Pb(II), Cd(II) and Cu(II) from model water solutions. The removal of metal ions increased with the increase in solution pH and concentration. The adsorption equilibrium data were well ﬁtted to Langmuir isotherm model and maximum monolayer adsorption capacities for cations Pb(II), Cd(II), Cr(III) and Mn(II) were 185.6 mg g-1, 111.2 mg g-1, 57.7 mg g-1 and 49.4 mg g-1, respectively. The chelating interaction was considered as the main adsorption mechanism for metal ions with low oxidation states (Cr(III), Mn(II), Pb(II), Cd(II), and Cu(II)). All these results indicated that the produced N-functionalized silica was promising for applications in environmental and analytical separation ﬁelds.

The authors thank for the financial support of the joint Ukrainian-Indian project "Creation of new organic-inorganic hybrid materials as sorbents for wastewater treatment from heavy metal ions" (2019-2021).