Removal of lead(II) from aqueous solution by adsorption on carbon aerogel using a response surface methodological approach

Recently a new form of activated carbon has appeared: carbon aerogel (CA). Its use for the adsorptive removal of inorganic compounds (and especially metal ions) has not been studied. The purpose of this study is to investigate the adsorption of Pb(II) on carbon aerogel from aqueous solution. Batch mode experiments were carried out to assess the adsorption equilibrium and kinetic behavior of Pb(II) in aqueous solution. This allowed for the computation of the kinetic parameters and maximum metal ion adsorption capacities. The influence of three parameters, adsorbent concentration (0.02-0.1 g), pH (2-7), and temperature (20-70 degrees C), on the percentage removal of Pb(II) was also examined, using a response surface methodological approach. Box-Behnken design was used for designing the experiments as well as for full response surface estimation. It was shown that a second-order polynomial regression model could properly evaluate the experimental data. This was evidenced by the high R-2 value of 0.9655. The optimum conditions for maximum removal were found to be as follows: adsorbent concentration (0.1 g), pH range (4-7), and temperature (70 degrees C).