| Summary: | Carbon nanofibers (CNFs) were synthesized by using a safe and less hazardous method, compared to using floating catalysts in chemical vapor deposition (CVD) process. This process used C2H2 as carbon source and oil palm kernel shell-based powdered activated carbon (PAC) as cheap solid substrate. Use of nickel (Ni2+) impregnated PAC as fixed substrate for the synthesis of CNF is one of the novelties of the research work accomplished by the authors. The PAC CNFs porous nanocomposite product was used for the sorption of lead ions (Pb2+) from synthetic aqueous solution. Kinetics of Pb2+ adsorption and isotherms were investigated by varying initial concentration of lead and contact time. PAC CNFs were found to remove Pb2+ better at acidic pH of about 5.5. Langmuir and Freundlich isotherms were applied to the sorption equilibrium data to find the best fitted model. Langmuir isotherm model with R-2 = 0.965 fitted the adsorption data better than the Freundlich isotherm. The kinetic processes of Pb2+ adsorption on CNFs were investigated by applying different kinetic models, namely zero-order, pseudo-first-order and pseudo-second-order. The pseudo-second-order rate equation exhibited the best results with R-2 = 0.999, q(e) = 74.79 (mg/g) and K-2 = 0.029 (min " g/mg). The novel nanocomposite product seemed to have the potential to remove Pb2+ ions from aqueous solution.
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