Abstract:Effects of modification time, sulfuric acid concentration, and L/S on adsorption behavior of Cd6+ in wastewater with montmorillonite were investigated by orthogonal experiments applying sulfuric acid as surface modifier agents. The results indicate that modified montmorillonite has good adsorption performance by enlargement interlayer spacing of modified montmorillonite, high adsorption activity and purity. Cd6+ removal rate is 77.99%, which is 24.26 percent point higher than that of original sample, under the modification conditions including modification time of 180 min, sulfuric acid concentration of 2 mol/L, and L/S=4/1. Cd6+ removal rate by modified montmorillonite is 87.95%, which is 34.22 percent point higher than the original sample, under the modification conditions including adsorption time of 120 min, L/S=25/1, pH value of 5, and initial concentration of Cr6+ of 10 mg/L. Adsorption of modified montmorillonite on Cd6+ is of multi-layer and reversible, which meets Freundlich Isotherm Model (R2=0.999 19).