河流重金属污染物迁移转化的数值模拟

在重金属模型研究成果的基础上建立了一维河流重金属迁移转化模型。描述了重金属随水流的迁移过程以及在不同相态之间的转化关系,并运用泥沙工程学原理给出了重金属随泥沙沉降、再悬浮的半经验表达式。结合镉污染事故实测资料,对模型进行了参数率定和验证。计算结果表明,模拟结果较准确,能反映重金属随水流运动和变化的过程。

Numerical Simulation for the Transformation Process of Heavy Metal Contamination Transport in Rivers

Based on the analysis on the existing research fruits results for the heavy metal model,the one-dimensional transformaion model for heavy metal transport in rivers is established.The model describes the transport process of heavy metal along with the stream and the transformation relationship among varied states,and presents the half-experience expression formula for the heavy metal sedimentation and resuspension along with sediment according to the principle of sediment engineering.Combined with the observed data on the cadmium pollution accident in North river in Dec.2005,the parameters of heavy metal model are calibrated and validated.The conclusions are that the simulation effect between calculated value and observed value is good when the concentration value of cadmium in water is comparatively big,and the simulation effect is not ideal when the concentration value of cadmium is comparatively small;when the velocity of flow is less than 0.3 m/s,the sedimentation action of suspended heavy metal in water plays a main role;but When the velocity of flow is greater than 0.3 m/s,the desorption action of deposited heavy metal becomes the primary factor that causes the concentration change of heavy metal.