可变电荷土壤和矿物对Pb^（2＋）和Cu^（2＋）的吸附动力学Ⅵ．搅拌速度和土

Adsorption Kinetics of Pb￣(2h+)and Cu￣(2+) on Variable Charge Soils and Minerals: VI. The Effect of Stirring Speed and Soil/Solution Ratio

利用双离子选择电极法研究了搅拌速度和土／水比对Ｐｂ２＋和Ｃｕ２＋在可变电荷土壤和矿物表面的吸附动力学的影响。结果表明：当搅拌器上所加电压为０—１００Ｖ时，Ｐｂ２＋和Ｃｕ２＋的吸附转化率随电压的增加而增大；当电压＞１００Ｖ后，吸附转化率不再变化。这表明在＜１００Ｖ的低速搅拌下，外扩散是Ｐｂ２＋和Ｃｕ２＋吸附反应的速率控制步骤，而在＞１００Ｖ的高速搅拌下，吸附步骤为速率控制步骤。Ｐｂ２＋和Ｃｕ２＋的吸附量随土／水比的增大而减小。在二级动力学方程中，最大吸附量Ｘｍ随土／水比的增大而减小，动力学常数Ｋ随土／水比的增加而增大。Ｐｂ２＋的Ｘｍ和水／土比（ｍｌ／ｇ）呈极显著正相关。

The effect of stirring speed, which was controlled by applying different potential (volts) to the electromagnetic stirrer,and soil/solution ratio on adsorption kinetics of Pb2+and Cu2+ on variable charge soils and minerals were studied in a vortex batch system with two ion-selective-electrode technique.