While several studies have linked network and in-fracture scale properties to conservative transport behavior in subsurface fractured media, studies on reactive transport cases remain relatively underdeveloped. In this study, we explore the behavior of an irreversible kinetic reaction during the interaction of two solute plumes, one consisting of species A and the other species B. When the plumes converge, these species react kinetically to form a new species C via \(A+B\xrightarrow {k} C\). This reactive system is studied using a three-dimensional discrete fracture network (DFN) model coupled with reactive Lagrangian particle tracking. We find that the interplay of network topology and chemical properties of the reactive solutes controls reactive transport processes. The network topology drives species A and B together, and the chemical properties dictate whether and how quickly a reaction occurs. Results demonstrate that reactions are most likely to occur in high-velocity fractures that make up the network backbone. The interplay between species’ chemical properties and transport is characterized by a non-dimensional Damköhler (Da) number. We show that the spatial distribution of reactions is sensitive to Da, which subsequently influences late-time tailing behavior in outlet breakthrough time distributions. The results of this study provide initial insights into how an irreversible reaction occurs during transport in a fracture network, using a methodology that can be applied to study reactive transport in a wide range of fractured media environments and contexts.

尽管有几项研究将网络和裂缝尺度性质与地下裂缝性介质中的保守输运行为联系起来，但有关反应性输运案例的研究仍相对欠发达。在这项研究中，我们探索了两个溶质羽流相互作用期间不可逆动力学反应的行为，其中一个由物种A组成，另一个物种B组成。当羽流收敛时，这些物种通过\（A + B \ xrightarrow {k} C \）在动力学上反应形成新物种C。使用三维离散断裂网络（DFN）模型与反应性拉格朗日粒子跟踪相结合，对该反应堆系统进行​​了研究。我们发现网络拓扑结构和反应性溶质的化学性质之间的相互作用控制了反应性传输过程。网络拓扑将物种A和B共同驱动，化学性质决定了反应是否发生以及反应发生的速度。结果表明，反应最有可能发生在构成网络主干的高速裂缝中。物种的化学性质与运输之间的相互作用以无量纲的达姆勒（Da）数为特征。我们表明反应的空间分布对Da敏感，随后会影响出口突破时间分布中的后期拖尾行为。这项研究的结果提供了一种初步的见解，可以使用一种可用于研究在各种裂缝性介质环境和环境中进行反应性运输的方法，来初步了解裂缝网络在运输过程中如何发生不可逆反应。