Sequestration of nickel from aqueous solution onto activated carbon prepared from Parthenium hysterophorus L.

In the present study, nickel removal efficiency of sulphuric acid-treated Parthenium carbon (SWC) from simulated wastewater has been investigated. Batch mode adsorption experiments have been conducted by varying pH, nickel concentration, adsorbent dose and contact time. Ni(II) removal was pH-dependent and found to be maximum at pH 5.0. The maximum removal of Ni(H) was achieved within 4 h after the start of every experiment. The equilibrium adsorption data were fitted to Freundlich and Langmuir adsorption isotherm models to evaluate the model parameters. Both models represented the experimental data satisfactorily. The monolayer adsorption capacities of SWC as obtained from Langmuir isotherm was found to be 17.24 mg/g. The Lagergren first-order model was less applicable than pseudo-second-order reaction model. The adsorbent was also characterized including infrared spectroscopy and scanning electron microscopy. The FT-IR study indicated the presence of O-H, C-H, C = O and C-O groups in the adsorbent. (C) 2008 Elsevier B.V. All rights reserved.