Adsorption of Pb(II) and Cu(II) by Alginate-Au-Mica bionanocomposite: Kinetic, isotherm and thermodynamic studies

The present investigation explores with the environmental degradation of Pb(II) and Cu(II) in single and binary system by novel ecofriendly synthesized Alginate-Au nanoparticles-Mica bionanocomposite. The bionanocomposite was characterized by SEM/EDX, TEM, FTIR, XRD and TGA techniques. Adsorption experiments were conducted to investigate the effect of pH, contact time, concentration, temperature on the removal process. The experimental data was best fitted by Freundlich isotherm model for Pb(II) in single and binary system whereas for Cu(II) by Langmuir isotherm model. The kinetic data was found to be best fitted by pseudo second order kinetic model in single and binary system. Adsorption process is endothermic and spontaneous as inferred from thermodynamic studies. The oxalic acid was found to be the best eluent for the desorption of metals. The breakthrough and exhaustive capacities were found to be 300 and 2000 mg g−1 respectively. The nanocomposite can be applied successfully for sequestering heavy metals from industrial wastewaters.