Journals Proceedings

Abstract

Bulk (silica gel) and nanometer silica, and their corresponding modified particles with a Schiff base binding moiety were prepared and their applications as adsorbents for Cu, Pb, Cd, Co, Ni and Zn ions were investigated. The Schiff base ionphore anchored on the silica particles was 3-methoxy salicylaldimine propyl triethoxy silane. The effect of parameters influencing the efficiencies of the studied adsorbents such as aqueous phase pH, shaking time, amount of sorbent, temperature and initial concentration of the investigated metal ions were assessed and discussed. It is shown that the modification affects significantly the adsorptive characteristics of the sorbent. The modified adsorbent shows to be selective adsorbent towards copper and lead ions. Comparison of the modified bulk silica gel and the corresponding nanoparticles reveals that, the later does not show a significant enhancement for uptaking the studied metal ions with respect to former. The advantage of applying the modified nanoparticles was that the more rapid kinetics with respect to the bulk modified sorbents. For the modified bulk and nanoparticles the graphical correlation of various adsorption isotherm models like, Langmuir, Freundlich and Tempkin have been carried out. The adsorption of these metal ions has been found endothermic. The kinetic studies suggest the process following pseudo second order kinetics