水域底泥中重金属Cd与Pb释放规律的数值模拟

Simulation on release of heavy metals Cd and Pb in sediments

采用实验研究与数值模拟相结合的方法,研究某水域底泥中典型重金属污染物Cd与Pb再释放过程和释放速率。结果表明,底泥中Cd和Pb的释放规律分为快速释放和动态平衡两个阶段,与准二级动力学方程具有较好的匹配度,相关系数R2大于0.99。随着河流流速的加快,底泥中重金属的释放速率增大。分析表明,该区域水质可以在3 h内超过地表水环境质量V类标准。数值模拟结果与实测值之间的相对偏差除一项外均在±10%以内。

The re-release process and the release rate of heavy metals,cadmium and plumbum,which are rich in sediments of a certain water area,were investigated using a combined experimental and numerical method.Results show that the release law of Cd and Pb in sediments is divided into two stages:rapid release and dynamic equilibrium,which is in great agreement with the pseudo second-order kinetic equation with a correlation coefficient R2 above 0.99.As the flow velocity accelerates,the release rate of heavy metals increases.The analysis results indicate that the water quality in the area can exceed the surface water Class V standard less than 3 h,and all but one of the relative deviations between the simulation value and the field survey result are within±10%.