高密度电阻率法监测纳米胶体 在多孔介质中运移的实验

利用高密度电阻率法监测纳米胶体在饱和多孔介质中的运移过程。对纳米胶体和保守性示踪剂在末端 的电导率穿透曲线进行了比较。结果表明,纳米胶体与保守性示踪剂在多孔介质中的运移过程非常相似,均可 用一维对流弥散方程进行拟合。通过对不同截面、不同电极间距、竖直方向的电阻穿透曲线的比较,说明利用 高密度电阻率仪监测纳米胶体在多孔介质中的运移是可行的。无论是传统示踪剂还是纳米胶体,在同一截面上 不同电极间距几个测点的穿透曲线非常相似,沿着水流向前推进的溶液锋面到达同一电极截面的时间非常接 近,说明多孔介质是非常均质的。同时高密度电阻率法可以动态反映砂柱中纳米胶体运移的时空变化特征。

Experiment of Monitoring Transport Nano-scale Colloids in Porous Media Using High-Density Electrical Resistivity Method

Based on column experiments in laboratory, the transport properties of nano-scale colloids in sand por- ous media are monitored by a high-density electrical resistivity prospecting system. The electrical conductivity breakthrough curves of colloids and tracers at the end of the column are compared. The result indicates that the transport of nano-scale colloids in porous media is similar to the conservative tracers, and both can be fitted by the one dimensional convection dispersion equation. Comparision of the breakthrough curves of measured points at different electrode sections, different electrode intervals at the same section and the vertical direction demon- strates that electrical resistivity method can be used to monitor the colloid transport in the porous medium. Break- through curves of different electrode intervals at the same electrode sections are simimlar, and the time of the so- lution fronts which arrives at the same eletrode section for different measured points is close, and it demonstrates that the porous media it is highly homogeneous. Meanwhile, high-density electrical resistivity method can dynam- ically reflect the characteristics of the transport of nano-scale colloids in the sand column.