Adsorption Kinetics and Equilibria of Basic Dyes onto Zeolite in Single and Binary Component Systems


Hisarli G., Tezcan C., Atun G.

CHEMICAL ENGINEERING COMMUNICATIONS, cilt.199, ss.1412-1436, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 199 Konu: 11
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1080/00986445.2012.668590
  • Dergi Adı: CHEMICAL ENGINEERING COMMUNICATIONS
  • Sayfa Sayıları: ss.1412-1436

Özet

Adsorptive removal of Basic Blue 3 (BB 3) and Basic Red 18 (BR 18) by a clinoptilolite-type natural zeolite from their single-component solutions has been studied in the temperature range of 298-328 K. Experimental equilibrium results are well described by the Freundlich and the Langmuir isotherm models. The model parameters obtained for single-solute systems at 298K have been used for the prediction of adsorption isotherms in binary dye solutions using multicomponent isotherm models. Competitive adsorption results between BB 3 and BR 18 in binary solutions satisfactorily fit the extended Freundlich, extended Langmuir, and modified Langmuir models. A site distribution function that gives information about affinity of adsorption sites for competing species in binary systems has been mathematically calculated using the Freundlich parameters. Time-dependent results for single and binary dye solutions have been analyzed according to a pseudo-second-order kinetic model based on chemisorption and a McKay model assuming two resistance diffusion processes, respectively. The diffuse reflectance FT-IR spectra indicate that the dyes are adsorbed via electrostatic interactions in external rings of clinoptilolite by replacing the zeolitic water in a single system, and they diffuse through the liquid associated with zeolitic water in TO4 tetrahedra (T: Al, Si) in a mixed solution.