Kinetics and thermodynamics of Cd(II) adsorption onto pyrite and synthetic iron sulphide

ERDEM M., Ozverdi A.

Separation and Purification Technology, vol.51, no.3, pp.240-246, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 51 Issue: 3
  • Publication Date: 2006
  • Doi Number: 10.1016/j.seppur.2006.02.004
  • Journal Name: Separation and Purification Technology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.240-246
  • Keywords: cadmium, adsorption, kinetics, isotherms, pyrite, iron sulphide
  • Hacettepe University Affiliated: No


In this paper, the Cd(II) adsorption abilities of pyrite and synthetic iron sulphide (SIS) were studied. Experiments were carried out as a function of pH, Cd(II) concentration, contact time and temperature. Maximum adsorption yields for pyrite and SIS were determined to be 34.2% and 65.8% under the conditions of initial Cd(II) concentration of 100 mg/l, pH 5.4, contact time of 120 min and adsorbent dosage of 20 g/l, respectively. The adsorption data fitted both the Langmuir and Freundlich adsorption models. Adsorption capacities of SIS and pyrite at 25 °C were found to be 3.05 and 2.08 mg Cd(II)/g, respectively. The first-order and pseudo second-order rate expressions were applied to experimental data and it was determined that the adsorption process followed the first-order kinetic model. In addition, activation energy values and some thermodynamic parameters such as ΔG°, ΔH° and ΔS° for the cadmium adsorption processes were calculated from the isotherm and kinetic data. The adsorption of Cd(II) on to SIS and pyrite was found to be endothermic and spontaneous. © 2006 Elsevier B.V. All rights reserved.