Enhanced copper(II) biosorption on SiO2-alginate gel composite: A mechanistic study with surface characterization

Yalcin S., Apak R., Boz İ.

KOREAN JOURNAL OF CHEMICAL ENGINEERING, vol.32, no.10, pp.2116-2123, 2015 (SCI-Expanded, Scopus) identifier identifier

  • Publication Type: Article / Article
  • Volume: 32 Issue: 10
  • Publication Date: 2015
  • Doi Number: 10.1007/s11814-015-0051-9
  • Journal Name: KOREAN JOURNAL OF CHEMICAL ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2116-2123
  • Keywords: Alginate-SiO2 Biocomposite, Cu(II) Adsorption, FTIR-XPS Analyses, Surface Characterization, HEAVY-METAL BIOSORPTION, CALCIUM ALGINATE BEADS, ACTIVATED CARBON, ADSORPTION, BIOMASS, REMOVAL, SILICA, ALGAE, FTIR, XPS
  • Istanbul University-Cerrahpasa Affiliated: No

Abstract

A new SiO2-alginate biocomposite was synthesized with improved mechanical properties, showing chelation capability of divalent metal ions, especially Cu(II), through its carboxylic acid ends. The biocomposite was characterized using scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) techniques. The adsorption of copper(II) onto both H- and Ca-forms of sorbent was investigated as a function of pH and contact time, and adsorption data were modeled with the aid of Langmuir and Freundlich isotherms. The release of Ca(II) ions accompanying copper(II) binding was evaluated by selective surface complexation concept involving ion-exchange. The IR spectra gave detailed information on complexation of carbonyl group with copper ions and on the relative contribution of SiO2 involved in copper uptake. The adsorption edge of copper was within the pH range 4.0-5.5, and the sorbent capacity was determined as 1.85 and 1.10 mmolg(-1) for H- and Ca-forms, respectively.