Removal of lead(II) ions from aqueous solutions using diatomite nanoparticles

Abstract

In the present study, the performance of diatomite nanoparticles was investigated for the lead(II) ions sorption in a batch mode. The diatomite nanoparticles were characterized using X-ray fluorescence, scanning electron microscopy, dynamic light scattering, and Brunauer–Emmet–Teller analysis. The influence of sorption parameters including pH, contact time, initial concentration, and temperature on the lead ions sorption was evaluated. The maximum adsorption capacity of lead ions onto the diatomite nanoparticles was found to be 103.1 mg g−1 at equilibrium time of 90 min and temperature of 45°C. The kinetic data were analyzed by pseudo-first-order and pseudo-second-order kinetic models. The Freundlich and Langmuir isotherm models were applied to describe the equilibrium data. The kinetic data of lead ions were found to follow the pseudo-first-order kinetic model and the equilibrium data of lead ions sorption were well described by Langmuir isotherm model. Evaluation of thermodynamic parameters indicated that the lead adsorption onto the diatomite nanoparticles was endothermic and spontaneous process. The reusability studies indicated that the lead adsorption capacity did not change remarkably after five sorption–desorption cycles.