Studies on Adsorption of Basic Dyes on Activated Carbon Derived from Phragmites australis (Common Reed)

摘要

In this study, the adsorption of two basic dyes, namely, Crystal Violet (CV) and Rhodamine B (RB) from aqueous solution by phragmite australis treated with 40% H3PO4 was investigated. Batch experiments were conducted to study the effect of temperature, contact time, pH and carbon dose. Equilibrium adsorption isotherms and kinetics were investigated. The equilibrium experimental data were analyzed by using the Langmuir, Freundlich, Temkin and Harkin - Jura isotherms. The kinetic data obtained was analyzed using a pseudo - first order, pseudo - second order and intra - particle diffusion equations. Dye adsorption was best described by the Langmuir model and with the pseudo - second order kinetic model. Thermodynamic parameters such as free energy (ΔGo), enthalpy (ΔHo), and entropy changes (ΔSo) were evaluated. The surface morphology of modified phragmite australis was characterized by FT - IR spectroscopy, scanning electron microscope (SEM), surface area and Boehm titrations.