Zinc adsorption on Na-rectorite and effect of static magnetic field on the adsorption

Rectorite is a kind of rare clay minerals. In this work, the sorption of Zn2+ on Na-rectorite and the effects of static magnetic field on the sorption have been studied. The result from this study indicated that: (1) apparent equilibrium for the sorption of zinc onto Na-rectorite is attained within the first hour; (2) the maximum of the increment of Zn2+ adsorbed by Na-rectorite is obtained between pH 4 and pH 6; (3) magnetic treatment enhances the zeta potential of Na-rectorite dispersions in the absence of Zn2+ and reduces that of the dispersions in the presence of Zn2+; (4) magnetic treatment promotes the sorption of Zn2+ onto Na-rectorite, especially at the low Zn2+ concentration; (5) the effects of static magnetic field decrease the pH of Na-rectorite dispersions whether containing zinc or not. The mechanisms of static magnetic field on the sorption of Zn2+ on Na-rectorite were discussed. (C) 2004 Elsevier B.V. All rights reserved.