Efficient dye discoloration of modified Lamiaceae leaves

The powder of Lamiaceae Leaves was modified by Zinc Chloride (ZnCl₂). The Chemical Modified Lamiaceae Leaves Powder (CMLLP) was characterized by BET surface analyzer, FTIR, SEM and Theydan and Ahmed method. It was found that this adsorbent has pH_ZPC of 6.2, surface area of 104.78 m²g⁻¹, pore volume of 0.00464 cc/g and average pore diameter of 2647.813 Å. This sorbent was used as a cheap adsorbent for the extraction of Methylene Blue (MB) from contaminated solutions. The effect of temperature, pH of solution, time of contact and MB primary concentration were also investigated. All of these variables have positive impacts on this adsorption. The data obtained from the isotherm's experiments, were analysed using three models. The obtained results confirmed that model of Langmuir was the most efficient. The capacities of this adsorption were found to be 333.33, 384.62, 434.78 and 476.19 mg g⁻¹ at 25, 35, 45 and 60 °C, correspondingly. Three models of kinetic were applied to determine the constants of this adsorption kinetics. It was observed that the kinetic results follow the 2nd order more than the other two kinetic models. Moreover, thermodynamic constants were determined, which showed that this adsorption is an exothermic and spontaneous process. (paper)