Abstract
Adsorption properties of waste brick dust (WBD) were studied by the removing of Pb(II) and Cs(I) from an aqueous system. For adsorption experiments, 0.1 M and 0.5 M aqueous solutions of Cs(+) and Pb(2+) and two WBD (Libochovice-LB, and Tyn nad Vltavou-TN) in the fraction below 125 µm were used. The structural and surface properties of WBD were characterized by X-ray diffraction (XRD) in combination with solid-state nuclear magnetic resonance (NMR), supplemented by scanning electron microscopy (SEM), specific surface area (S(BET)), total pore volume and zero point of charge (pH(ZPC)). LB was a more amorphous material showing a better adsorption condition than that of TN. The adsorption process indicated better results for Pb(2+), due to the inner-sphere surface complexation in all Pb(2+) systems, supported by the formation of insoluble Pb(OH)(2) precipitation on the sorbent surface. A weak adsorption of Cs(+) on WBD corresponded to the non-Langmuir adsorption run followed by the outer-sphere surface complexation. The leachability of Pb(2+) from saturated WBDs varied from 0.001% to 0.3%, while in the case of Cs(+), 4% to 12% of the initial amount was leached. Both LB and TN met the standards for Pb(II) adsorption, yet completely failed for any Cs(I) removal from water systems.