Removal of Fe(II) from aqueous solution using pomegranate peel carbon: equilibrium and kinetic studies

Pomegranate peel carbon was tested for its ability to adsorb iron(II) ions from solutions withalterations in the parameters such as pH, contact time, sorbent weight, metal concentration, and temperature. Results: The adsorption process was analyzed on the basis of pseudo-first-order, pseudo-second-order kinetic models and also by Freundlich and Langmuir isotherm models. The maximum adsorption capacity for pomegranate peel activated carbon as calculated by Langmuir model was found to be 18.52 mg g^−1 at pH 6.0 and 1 g L^−1 of biosorbent concentration at 29°C. Conclusions: The ability of new sorbent is compared with other biomass waste materials. Thermodynamic parameters such as the changes of free energy, enthalpy, and entropy were also evaluated. The results indicated that the sorption of iron(II) ions onto the pomegranate peel carbon was an exothermic process that could be well fitted with the Langmuir adsorption model and pseudo-first-order kinetic model.