Adsorption study of heavy metal ions from aqueous solution by nanoparticle of wild herbs

Wild herbs (Equisetum, EH and Teucrium, TH) were used as environment friendly adsorbents in the present study. This study focuses on the investigation of the adsorption ability of Co, Cd and Li from aqueous solution. The adsorption of heavy metals onto EH and TH was dependent on particle size, dose, solution pH, contact time, and temperature. Kinetic data were tested using pseudo-first-order and pseudo-second-order kinetic models. The best fit was obtained with the pseudo-second-order kinetic model. Langmuir and Freundlich models have been applied to calculate adsorption data and the thermodynamic parameters; entropy, ΔS°, enthalpy, ΔH°, and the Gibbs free energy, ΔG°; were determined. The results suggests that the adsorption of heavy metals by the wild herbs are endothermic and a spontaneous process. Thus, it was concluded that EH and TH are promising adsorbents for the adsorption of heavy metals from aqueous solutions.