Titania-Coated Silica Alone and Modified by Sodium Alginate as Sorbents for Heavy Metal Ions

D Kołodyńska; M Gęca; E Skwarek; O Goncharuk

doi:10.1186/s11671-018-2512-7

Titania-Coated Silica Alone and Modified by Sodium Alginate as Sorbents for Heavy Metal Ions

Nanoscale Res Lett. 2018 Apr 12;13(1):96. doi: 10.1186/s11671-018-2512-7.

Authors

D Kołodyńska¹, M Gęca¹, E Skwarek², O Goncharuk³

Affiliations

¹ Department of Inorganic Chemistry, Faculty of Chemistry, Maria Curie Skłodowska University, M. Curie Skłodowska Sq. 2, 20-031, Lublin, Poland.
² Department of Radiochemistry and Colloid Chemistry, Faculty of Chemistry, Maria Curie Skłodowska University, M. Curie Skłodowska Sq. 3, 20-031, Lublin, Poland.
³ Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine, 17 General Naumov Str, Kyiv, 03164, Ukraine. iscgoncharuk@meta.ua.

Abstract

The novel organic-inorganic biohybrid composite adsorbent was synthesized based on nanosized silica-titania modified with alginate within the development of effective adsorbent for heavy metal ions. Effects of metal species Cu(II), Zn(II), Cd(II), and Pb(II); concentrations; pH; temperature; and adsorption onto titania-coated silica (ST20) initial or modified by sodium alginate (ST20-ALG) were studied. The equilibrium and kinetic data of metal ions adsorption were analyzed using Langmuir and Freundlich adsorption models and kinetic models: pseudo first order, pseudo second order, intraparticle kinetic model, and Elovich. The maximum sorption capacities observed were higher for the ST20-ALG composite compared to the initial ST20 oxide for all studied metal ions, namely their values for ST20-ALG were 22.44 mg g^{- 1} for Cu(II) adsorption, 19.95 mg g^{- 1} for Zn(II), 18.85 mg g^{- 1} for Cd(II), and 32.49 mg g^{- 1} for Pb(II). Structure and properties of initial silica-titania ST20 and modified by sodium alginate ST20-ALG adsorbents were analyzed using nitrogen adsorption/desorption isotherms, ATR-FTIR, SEM-EDS, and pHpzc techniques.

Keywords: Adsorption; Heavy metal species; Nanocomposite; Silica; Sodium alginate; Titania.