Removal of Heavy Metal Ions from Aqueous Pb-EDTA and Cu-EDTA Solutions Using Nanosized ZnO Powders by Solution-Combustion Method
ZnO nanopowder was prepared by a novel “solution-combustion method (SCM)” and it was used as a semiconductor photocatalyst to evaluate its photoreduction properties. Aqueous Pb-EDTA and Cu-EDTA solutions of heavy metal ions (Pb and Cu) were used for the photocatalysis reaction under UV illumination. The result was then compared with other semiconductor photocatalyst powder such as TiO2 powder (P25; Degussa) and TiO2 powder prepared by homogeneous precipitation process at low temperature (HPPLT). In the removal of Pb++ ions, the ZnO nanopowder showed 2.6 fold higher removal rate than P25 TiO2 powder and 1.8 fold higher than HPPLT TiO2. Also the ZnO nanopowder showed the highest removal rate of the Cu++ ions from the solution among the different photocatalyst powders compared. The superior photoreduction ability of the ZnO nanopowder appears to be due to its excellent UV absorption characteristics. This was confirmed by the photoluminescence (PL) measurement.
T. Ohji, T. Sekino and K. Niihara
J. H. Lee et al., "Removal of Heavy Metal Ions from Aqueous Pb-EDTA and Cu-EDTA Solutions Using Nanosized ZnO Powders by Solution-Combustion Method", Key Engineering Materials, Vols. 317-318, pp. 837-840, 2006