This study develops a new numerical model adopting a generic relation between the nonaqueous phase liquid (NAPL) mass and aqueous-phase NAPL concentration to simulate the relationship between NAPL contaminant mass discharge and contaminant mass reduction in the source zone, which plays a critical role to assist with site management decisions on contaminated zone remediation. The model can accommodate any contaminant mass and concentration relations and applicable to the situations when groundwater flowrate in the NAPL source zone varies in any form temporally. Therefore, the combined effects of mass–concentration relation and groundwater flowrate variations can be examined. It is hypothesized that the NAPL mass–concentration relations reflect the spatial variability of porous media in the subsurface. The developed model is compared with results from field monitoring sites and found to exhibit high flexibility and capability in capturing the observed complex NAPL source zone dynamics. Using six contaminant mass and concentration functions of varying shapes, we show that contaminant mass and concentration relation has pronounced effects on contaminant mass discharge dynamics in addition to the groundwater flowrate temporal variations. In general, the coupled mass–concentration relation and groundwater flowrate variations demonstrate stronger capability in capturing the NAPL source zone dynamics under a wide range of field porous medium conditions reported in the literature than the models that only consider groundwater flux variations. In particular, the concave mass–concentration models can be used in less heterogeneous porous media, while the convex mass–concentration models are more appropriate in more heterogeneous site conditions.

这项研究建立了一个新的数值模型，该模型采用了非水相液体（NAPL）质量与水相NAPL浓度之间的一般关系来模拟NAPL污染物质量排放与源区污染物质量减少之间的关系，这对协助有关污染区修复的现场管理决策。该模型可以适应任何污染物的质量和浓度关系，并适用于NAPL源区中地下水流量随时间以任何形式变化的情况。因此，可以检查质量浓度关系和地下水流量变化的综合影响。假设NAPL的质量浓度关系反映了地下多孔介质的空间变异性。将开发的模型与现场监测站点的结果进行比较，发现该模型在捕获观察到的复杂NAPL源区动力学方面表现出很高的灵活性和能力。使用六个形状变化的污染物质量和浓度函数，我们表明，污染物质量和浓度关系除了地下水流量的时间变化外，还对污染物质量排放动力学产生显着影响。通常，与只考虑地下水通量变化的模型相比，耦合的质量浓度关系和地下水流量变化表明，在文献中报道的广泛的现场多孔介质条件下，捕获NAPL源区动力学的能力更强。特别是，凹面质量浓度模型可用于异质性较差的多孔介质中，