Adsorption of p-Nitrophenol and Pb (II) ions onto untreated biosorbent prepared from Geranium Plant Waste: Single component adsorption, thermodynamic and kinetic study

The capability of untreated biosorbent derived from Geranium Plant Waste (GPW-U)for the adsorption of p-nitrophenol and Lead (II) ions from aqueous solutions was examined. The influence of various experimental parameters, including pH, biosorbent dosage, contact duration,initial concentration and temperature, was analyzed using a batch method. The experimentalisotherm data were evaluated through the Langmuir and Freundlich adsorption isotherms. The adsorption mechanism was investigated utilizing both the first-pseudo and second-pseudo-order models. Adsorption isotherms at varying temperatures were analyzed to determine thermodynamic parameters such as free energy change, enthalpy change, and entropy change. Thermodynamic studies indicate the feasibility and spontaneity of the adsorption process, as well as its exothermic or endothermic characteristics. The surface area of the biosorbent was calculated using the BET method. Characterization of the biosorbent was performed using XRD,FTIR and FESEM-EDS techniques. This study achieves the adsorption of 86% for P-NP and83% for Pb (II) ions.