オゾン酸化・析出反応によって生成した二酸化マンガンによる希薄溶液からのカドミウムイオンの除去

概要

論文の詳細を見る
Removal of cadmium and zinc ions from diluted solutions of their sulfate solutions with manganese dioxide, produced by ozone oxidation-precipitation reaction (OMD) under different conditions, has been investigated paying particular attention to correlation between the ion-uptake and the water content of OMD. Uptake of Cd2+ which is demonstrated to be an ion exchange reaction increases with an increase in the water content of OMD. The adsorbed water, which is liberated at lower temperature up to 200 °C, as well as the structural water of MnO2 takes part in the ion exchange reaction. One of the most outstanding features of OMD over both electrolytic MnO2 and chemically precipitated one is that OMD has a higher water content and shows fairly stronger ion exchanger nature than the other types of MnO2. For removal of Cd2+ with a reduced amount of Cd-contaminated MnO 2 residues, a two-stage treatment is considered to be effective. The first stage is addition of OMD in a small excess with respect to Cd2+ to uptake this ion at high efficiency and the second stage is addition of a small amount of OMD to make a high OMD / Cd2+ mole ratio to capture the remaining Cd2+ down to an adequately low concentration. Zinc ion was observed to be removed from its dilute solution by OMD addition in a similar manner to cadmium ion.
社団法人資源・素材学会の論文
2000-12-25