Teramoto Elias Hideo, Chang Hung Kiang
Laboratório de Estudos de Bacias, Centro de Estudos Ambientais, UNESP - Universidade Estadual Paulista, Av. 24A, 1515, Rio Claro, Sao Paulo, Brazil.
Departamento de Geologia Aplicada, Centro de Estudos Ambientais, UNESP - Universidade Estadual Paulista, Av. 24A, 1515, Rio Claro, Sao Paulo, Brazil.
J Contam Hydrol. 2017 Mar;198:37-47. doi: 10.1016/j.jconhyd.2017.01.002. Epub 2017 Jan 18.
Mass transfer of light non-aqueous phase liquids (LNAPLs) trapped in porous media is a complex phenomenon. Water table fluctuations have been identified as responsible for generating significant variations in the concentration of dissolved hydrocarbons. Based on field evidence, this work presents a conceptual model and a numerical solution for mass transfer from entrapped LNAPL to groundwater controlled by both LNAPL saturation and seasonal water table fluctuations within the LNAPL smear zone. The numerical approach is capable of reproducing aqueous BTEX concentration trends under three different scenarios - water table fluctuating within smear zone, above the smear zone and partially within smear zone, resulting in in-phase, out-of-phase and alternating in-phase and out-of-phase BTEX concentration trend with respect to water table oscillation, respectively. The results demonstrate the model's applicability under observed field conditions and its ability to predict source zone depletion.
被困在多孔介质中的轻质非水相液体（LNAPL）的传质是一个复杂的现象。地下水位波动被认为是导致溶解烃浓度产生显著变化的原因。基于现场证据，这项工作提出了一个概念模型和一个数值解，用于描述被困的LNAPL向地下水的传质过程，该过程受LNAPL饱和度和LNAPL涂抹带内季节性地下水位波动的控制。该数值方法能够再现三种不同情况下的水中BTEX浓度趋势——地下水位在涂抹带内波动、在涂抹带上方波动以及部分在涂抹带内波动，分别导致相对于地下水位振荡的同相、异相以及同相和异相交替的BTEX浓度趋势。结果证明了该模型在观测到的现场条件下的适用性及其预测源区枯竭的能力。
