Thermodynamic study of lead ion removal by adsorption onto nanographene sheets

Document Type : Research Paper




A batch adsorption study was applied to investigate the adsorption of Pb2+ ions from aqueous solution
by nanographene (nG).The adsorption percentage of Pb2+ions onto nG samples at different initial pH,
contact time (tc), adsorbent dosage (mnG) and temperature (T) were investigated. The results showed
that nG is an excellent adsorbent for Pb2+ions removal from aqueous solutions with an adsorption
percentage of up to 79.8% at initial Pb2+concentration of 20ppm and temperature of 298K.The
experimental data could be well described by the Freundlich and Langmuire isotherm model;
thermodynamic parameters of adsorption process (AG0, AH0, ASo) were also evaluated. The overall
adsorption process was exothermic and spontaneous in nature .The results indicate that Pb2+ions
adsorption onto nG may be chemisorption.