Abstract: | Cr(VI) adsorption from aqueous solutions on Mg-Al hydrotalcite and Mg-Al hydrotalcite-gibbsite with Al/(Al+Mg) ratios (R) of 0.3 and 0.6 (MgAlHTR = 0.3 and MgAlHTGR = 0.6) was investigated as a function of the pH and chromium concentration. The results showed that the maximum Cr(VI) adsorption by Mg-Al compounds do not depend on the value of R at pH 7. In addition, the chromate equilibrium sorption capacity for MgAlHTGR = 0.6 is at least 4.8 times higher than that for MgAlHTR = 0.3 at pH 5. The Cr(VI) maximum capacities of MgAlHTR = 0.3 and MgAlHTGR = 0.6 at pH 7 were similar, 6.5 and 6.8 mgCr(VI)/g, respectively. |