Lenhard R J, Rayner J L, Davis G B
CSIRO Land and Water, Private Bag No. 5, Wembley, WA 6913, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Australia.
CSIRO Land and Water, Private Bag No. 5, Wembley, WA 6913, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Australia.
J Contam Hydrol. 2017 Oct;205:1-11. doi: 10.1016/j.jconhyd.2017.06.002. Epub 2017 Jun 9.
A model is presented to account for elevation-dependent residual and entrapped LNAPL above and below, respectively, the water-saturated zone when predicting subsurface LNAPL specific volume (fluid volume per unit area) and transmissivity from current and historic fluid levels in wells. Physically-based free, residual, and entrapped LNAPL saturation distributions and LNAPL relative permeabilities are integrated over a vertical slice of the subsurface to yield the LNAPL specific volumes and transmissivity. The model accounts for effects of fluctuating water tables. Hypothetical predictions are given for different porous media (loamy sand and clay loam), fluid levels in wells, and historic water-table fluctuations. It is shown the elevation range from the LNAPL-water interface in a well to the upper elevation where the free LNAPL saturation approaches zero is the same for a given LNAPL thickness in a well regardless of porous media type. Further, the LNAPL transmissivity is largely dependent on current fluid levels in wells and not historic levels. Results from the model can aid developing successful LNAPL remediation strategies and improving the design and operation of remedial activities. Results of the model also can aid in accessing the LNAPL recovery technology endpoint, based on the predicted transmissivity.
本文提出了一个模型，用于在根据井中当前和历史流体水位预测地下轻质非水相液体（LNAPL）比容（单位面积的流体体积）和 transmissivity 时，分别解释水饱和带上方和下方与高程相关的残余和截留 LNAPL。基于物理的自由、残余和截留 LNAPL 饱和度分布以及 LNAPL 相对渗透率在地下垂直切片上进行积分，以得出 LNAPL 比容和 transmissivity。该模型考虑了地下水位波动的影响。给出了针对不同多孔介质（壤质砂土和粘壤土）、井中流体水位以及历史地下水位波动的假设预测。结果表明，对于井中给定的 LNAPL 厚度，无论多孔介质类型如何，从井中 LNAPL - 水界面到自由 LNAPL 饱和度接近零的较高高程的高程范围是相同的。此外，LNAPL transmissivity 在很大程度上取决于井中当前的流体水位，而不是历史水位。该模型的结果有助于制定成功的 LNAPL 修复策略，并改进修复活动的设计和操作。基于预测的 transmissivity，该模型的结果还可以帮助评估 LNAPL 回收技术的终点。
