Reduction of toxic metals in aquatic systems using mineral adsorbents. Reduction of aqueous lead usingzinc oxide-kaolinite and zinc oxide-montmorillonite composites

      Аннотация: The presence of ZnO coating significantly enhanced the adsorption of Pb2+ ions by kaolinite. This paper investigated synthesis, characterization of ZnO-kaolinite composite and its application in Pb2+ ions removal. Synthesis involved trimetric process and characterization involved the use of standard laboratory procedures. Lead adsorption on ZnO-kaolinite composite was investigated in batch experimental condition at ambient temperature. Reaction mechanism indicated less than one proton coefficient. The mass transfer rates were higher than values for the bare kaolinite. In addition, the intraparticle diffusion contained intercept c equals 592.31, ? 0. This was higher than the value for the uncoated kaolinite. Effect of Pb2+ initial concentration, the concentration of particle and ageing, exhibited differences in magnitude and in other situations, different characteristics when compared with bare kaolinite. Reactions based on Pb2+ initial concentration indicated that the active and reactive sites of the ZnO-kaolinite composite gradually became saturated as the concentration was increased. Reactions based on solid concentration -Cp, demonstrated a complex change in adsorption.

Ключевые слова: Coating, concentration, adsorption