Removal of lead(II), copper(II), cobalt(II) and nickel(II) ions from aqueous solutions using carbon gels

Abstract

The carbon gel and carbon gel doped with 0.5, 1 and 2 wt% of graphite intercalation compound were used for the removal of heavy metals from aqueous solutions. These materials were prepared by a sol-gel process that involves a polycondensation of resorcinol and formaldehyde. Nitrogen adsorption, scanning electron microscopy, energy dispersive spectroscopy and fourier transform infrared spectroscopy were used for a morpho-structural adsorbent investigation. In the present paper, Cu, Co, Pb and Ni ions adsorption experiments were carried out in batch conditions under magnetic stirring. The effect of some parameters such as contact time, metal ions' concentration and pH were examined. Adsorption data on all sorbents, followed both the Frendlich and Langmuir models. The data better fitted the Langmuir isotherm than the Frendlich one. The highest degree of removal was achieved for Pb ions at the initial concentration of 10 mg/l and for 2 g/l adsorbent dose. Adsorption results expressed as adsorption capacities showed that carbon gel doped with 2 wt% of graphite intercalation compound is the best adsorbent.