Thermodynamic study of lead ion removal by adsorption onto nanographene sheets

Abstract

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