Özkan Demirbaş

The Removal of Victoria Blue from Aqueous Solution by Adsorption on a Low-Cost Material

The use of perlite for the removal of victoria blue from aqueous solution at different concentration, ionic strength, pH and temperature has been investigated. Adsorption process is attained to the equilibrium within 1 h. It is found that the adsorption capacity of perlite samples for the removal of victoria blue increased by increasing pH and temperature, and decreased by expansion and ionic strength. The adsorption isotherms are described by means of the Langmuir and Freundlich isotherms. The adsorption isotherm was measured experimentally at different conditions, and the experimental data were correlated reasonably well by the adsorption isotherm of the Langmuir, and the isotherm parameters (Qm and K) have been calculated for perlite samples as well. It is concluded that victoria blue is physically adsorbed onto the perlite. The removal efficiency (P) and dimensionless seperation factor (R) have shown that perlite can be used for removal of victoria blue from aqueous solutions, but unexpanded perlite is more effective.

Thermodynamics and kinetics of adsorption of a cationic dye onto sepiolite

AbstractThe adsorption kinetics and thermodynamics of Maxilon Red GRL (MR-GRL), a cationic textile dye, onto sepiolite were investigated in aqueous solution in a batch system. The effect of contact time, stirring speed, initial dye concentration, initial solution pH, ionic strength, and temperature was studied. The initial tested concentrations of MR-GRL solution were 1.5 × 10−3, 2.0 × 10−3 and 2.5 × 10−3 mol/L. The effect of pH was analyzed in the pH range from 5 to 10. The effect of ionic strength was investigated at 0.001–0.100 mol/L NaCl salt concentrations. The experiments were carried out at 288, 298, 308, and 318 K set with a thermostat. The all parameters significantly influenced the adsorption rate and capacity. Experimental data were fitted to pseudo-first order, second-order, Elovich equation, mass transfer, and intra-particle diffusion models. The adsorption kinetics data showed that this process can be described by the pseudo-second-order model, from which the rate constant and the adsorption...

Adsorption kinetics of a cationic dye from wastewater

AbstractThe adsorption kinetics and thermodynamics of Maxilon Blue 5G, a cationic textile dye, onto perlite were investigated in aqueous solution in a batch system for determining the effect of contact time, stirring speed, initial dye concentration, initial solution pH, ionic strength and temperature. Experimental data were evaluated according to the pseudo-first, second-order and the Elovich equation, mass transfer and intra-particle diffusion models, and it was found that adsorption kinetics can be described according to the pseudo-second-order model, from which the rate constant and the adsorption capacity were determined. The thermodynamic activation parameters, such as activation energy, enthalpy, entropy and Gibbs free energy, were determined. The obtained results confirmed the applicability of this mineral as an efficient adsorbent for cationic dyes.

Characterization, adsorption, and electrokinetic properties of modified sepiolite

AbstractThe metal ion adsorption and electrokinetic properties of sepiolite modified by 3-(trimetoxysilyl)propyl metaacrylate was studied. The characterization of modified sepiolite was made by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron micrograph (SEM), and differential thermal analysis/thermogravimetry (DTA/TG). The adsorption behavior of Fe(III), Mn(II), Co(II), Zn(II), Cu(II), and Cd(II) metal ions on modified sepiolite from aqueous solutions was investigated as a function of equilibrium pH, temperature, and ionic strength. The adsorption experiments were carried out using a batch method. The initial and final concentrations of heavy metals were determined by means of atomic absorption spectrophotometry. The zeta potential of the modified sepiolite suspensions was measured as a function of metal ion concentration and equilibrium pH using a Zeta Meter 3.0. The results showed that the amount of adsorbed metal ions increased with solution pH, and tha...