applicability of tempkin equilibrium and elovich kinetics for chemisorption of brown he-2g on calendula officinalis

Calendula officinalis is a low-cost material used as adsorbent for the removal of textile dye, brown he-2g. the effect of ph, concentration of dyes, adsorbent dose and contact time were obtained by batch adsorption technique. the results were analyzed by adsorption isotherm models (freundlich, langmuir, redlich-peterson and tempkin). the results were in good agreement with langmuir model and the redlich-peterson isotherm models. the langmuir monolayer adsorption quantity was found to be, 76.56 mg g-1 brown he-2g. pseudo-first-order, pseudo-second-order, intraparticle diffusion and tempkin kinetic models were used to fit the experimental data, it was well fitted into pseudo second order kinetics. ft-ir and sem analysis have effectively supported the adsorption of brown he2g on the adsorbent.