改性蒙脱石对废水中Cr^(6+)的吸附性能研究

Adsorption Characteristics of Modified Montmorillonite on Cr^(6+) in Wastewater

以蒙脱石为原料、硫酸为改性剂,采用正交试验研究了改性时间、硫酸浓度和固液比对蒙脱石吸附废水中Cr^(6+)吸附效果的影响。研究表明,改性后的蒙脱石层间距增大,吸附活性增强,纯度提高,具有较好的吸附性能。在改性时间180min、硫酸浓度2mol/L、固液比1∶4时,蒙脱石对Cr^(6+)的去除率达到77.99%,较原样提高24.26个百分点。当吸附时间120min、固液比1∶25、pH=5、Cr^(6+)初始浓度10mg/L时,改性蒙脱石对Cr^(6+)的去除率为87.95%,较原样提高了34.22个百分点。改性蒙脱石对Cr^(6+)的吸附更符合Freundlich等温吸附方程式,拟合系数为0.999 19,吸附方式更符合多分子层吸附,是可逆吸附。

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 of2 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).