THERMODYNAMICS AND ADSORPTION STUDIES OF DYE (RHODAMINE-B) ONTO NATURAL DIATOMITE


Koyuncu M., Kul A. R.

PHYSICOCHEMICAL PROBLEMS OF MINERAL PROCESSING, vol.50, no.2, pp.631-643, 2014 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 50 Issue: 2
  • Publication Date: 2014
  • Doi Number: 10.5277/ppmp140217
  • Journal Name: PHYSICOCHEMICAL PROBLEMS OF MINERAL PROCESSING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.631-643
  • Keywords: diatomite, rhodamine B, adsorption, thermodynamics, Langmuir isotherm, Freundlich isotherm, AQUEOUS-SOLUTION, CALCINED DIATOMITE, METHYLENE-BLUE, WASTE-WATER, REMOVAL, EQUILIBRIUM, SORPTION, GREEN
  • Van Yüzüncü Yıl University Affiliated: Yes

Abstract

Thermodynamics and adsorption studies were conducted with a dye of rhodamine-B on natural diatomite. Adsorption of the dye was investigated with an initial dye concentration at pH 8 +/- 0.2, 303, 313 and 323 K. The adsorption experiments were carried out isothermally at three different temperatures. The Langmuir and Freundlich isotherm models were used to describe the equilibrium data and the results were discussed in details. The kinetic data agreed with the pseudo-first order model with rate constants (k(2)) in the range of 3.05-1.59.10(-1) g/mg min. The thermodynamic parameters such as standard free energy, entropy change and enthalpy were calculated for natural diatomite. These values showed that adsorption of rhodamine-B on natural diatomite was a spontaneous and endothermic process.