Decolorization of the aqueous Safranin O dye solution using Thuja orientalis as biosorbent

Abstract EN

The object of this study was to evaluate the efficiency of safranin O (SFO), dye removal with application of Thuja orientalis as a low-cost biosorbent.

The biosorption equilibrium level was determined as a function of pH, adsorbent dose, contact time and temperature.

Surface area and pore size distribution were measured for the adsorbent.

Thuja has a good removal effeciency for SFO dye.

The adsorption kinetics data were best fit for the pseudo-second order kinetic (the regression coefficient = 0.999).

The experimental equilibrium adsorption data are tested for the Langmuir, freundlich, Temkin and Dubinin-Radushkevich isotherm modles.

From the values of the regression coefficient the results indicate the following order to fit the isotherm Freundlich > Temkin > Dubinin-Radushkevich > Langmuir.

A chemical adsorption process was indicated by the value of the mean free energy of adsorption obtained from the Dubinin-Radushkevich isotherm.

Standard free energy of adsorption (ΔG°) and the change in the standard enthalpy (ΔH°) and the standard entropy (ΔS°) were calculated to predict the nature of adsorption.