Mercury adsorption from fuel ethanol onto phosphonated silica gel prepared by heterogenous method

Ethanol is one of the most important renewable biofuels contributing to the reduction of negative environmental impacts generated by the worldwide utilization of fossil fuels, and the presence of metal ions in fuel ethanol has significant effect on the performance and the quality of fuel. In the present work, silica gel functionalized by poly(triethylenetetraminomethylenephosphonic acid) SG-Cl-T-P was successfully developed by heterogenous synthesis method, and the adsorption capacity of Hg(II) from fuel ethanol via SG-Cl-T-P was examined. The adsorption isotherms were fitted by the Langmuir model, the Freundlich model and the Dubinin-Radushkevich (D-R) model. Furthermore, the adsorption study was analyzed kinetically. The thermodynamic parameters, including the Gibbs free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were calculated, they were −3.24 kJ mol−1 (35 °C) , 29.25 kJ mol−1, and 106.20 J K−1 mol−1, respectively.