Removal of crystal violet from aquatic environment by surfactant-modified dolomite

Abstract

This paper presents the adsorption of crystal violet (CV+) from aqueous solution on surfactant-modified dolomite. Liquid phase batch operations were carried out to observe the effect of various experimental parameters such as initial dye concentration, adsorbent dosage, pH and NaCl concentration. The optimum conditions for these parameters were calculated by Taguchi method. Equilibrium isotherm data were analyzed according to Langmuir, Freundlich and Temkin equations. The experimental data fitted well to Freundlich adsorption model. The maximum adsorption capacities by Langmuir analysis were determined to be 49.261mg/g at 22℃ that indicates suitable performance by of this adsorbent. The pPseudo-first-order and, pseudo-second-order kinetics and the intraparticle diffusion models were also evaluated for the adsorption of CV+ onto surfactant-modified dolomite. The positive value of free energy change confirmed the nature of physisorption of dye onto adsorbent.