Abstract
This work explores the feasibility of natural fibers derived from Ficus carica plant as an alternative precursor for the preparation of activated carbon via microwave assisted H3PO4 activation. The properties of activated carbon were investigated by scanning electron microscope (SEM) and Fourier transform spectroscopy (FTIR). The operational parameters, chemical impregnation ratio, microwave power and irradiation time on the carbon yield and adsorption capability were investigated. Adsorption performance of Cu(II) and Ni(II) onto activated carbon was investigated as a function of pH, contact time, initial metal ion concentration and temperature. The adsorption capacity of Cu(II) and Ni(II) onto the adsorbent was found to be 23.08 and 18.78mg/g, respectively. Adsorption of metal ions followed second order kinetics with best fit for Fraundlich adsorption isotherm. The values of thermodynamic parameters such as enthalpy change (ΔH°), entropy change (ΔS°) and free energy change (ΔG°) were evaluated for the adsorption of both the metal ions. Adsorption of metal ions onto activated carbon was spontaneous and endothermic in nature. The results suggested that activated carbon developed from natural fibers successfully improved the metal ions adsorption capacity. On the basis of our findings, the adsorbent could be used as a detoxifying agent for better management of industrial effluents.