Pragmatic Approach to the Removal of Cu(II)ions from Aqueous Solution using Silica: A Kinetic, Isothermal and Thermodynamic Study
Kenneth O. Amanze
*
Department of Chemistry, Alvan Ikoku Federal University of Education, Owerri, Nigeria.
Janet O. Amanze
Faculdade de Ciências da Nutrição e Alimentação da Universidade do Porto| FCNAUP. Rua do Campo Alegre, Porto, Portugal.
Glory Okore
Department of Analytical Chemistry, Alvan Ikoku Federal University of Education, Owerri PMB 1033, Imo State, Nigeria.
Lynda C. Ngozi-Olehi
Department of Physical Chemistry, Alvan Ikoku Federal University of Education, Owerri, Nigeria.
Pamela I. Okeke
Department of Physical Chemistry, Alvan Ikoku Federal University of Education, Owerri, Nigeria.
Rosemary I. Uchegbu
Department of Organic Chemistry, Alvan Ikoku Federal University of Education, Owerri PMB 1033, Imo State, Nigeria.
Appolinus I. C. Ehirim
Department of Inorganic Chemistry, Alvan Ikoku Federal University of Education, Owerri, Nigeria.
Gabriel C. Eze
Forensic/Pharmaceutical Chemistry, Western Illinois University, USA.
*Author to whom correspondence should be addressed.
Abstract
The main objective of this study was to investigate the removal of copper(II) ions [Cu (ii)] from aqueous solution by adsorption unto pure silica. The silica was characterized by using Fourier Transform Infra-Red (FT-IR) spectral analysis before and after adsorption of the metal ions. The optimum condition for the adsorption of Cu(II)ions was studied in a batch system by considering the extent of adsorption with respect to pH, contact time, initial copper(II) ion concentration and temperature. Maximum adsorption was recorded at a pH of 7.0 and equilibrium sorption was achieved within 50 minutes of the process. It was observed that the optimum amount of Cu(II)ions absorbed by pure silica was 91.3 mg/g representing 98.86 % at the optimum pH of 7.0. Three kinetic models: Elovich, Pseudo first-order and Pseudo second-order were applied in the analyses. Desorption studies showed that about 24.0 % of the metal ion was desorbed with appropriate eluting agents. The experimental results showed that pure silica is a good adsorbent for the removal of Cu(II)ions from aqueous solutions and may possibly be useful for treating industrial waste waters.
Keywords: Adsorption, Cu(II)ions, kinetic models, desorption, batch system