The kinetic approach is suitable for solving complex reactive transport processes in groundwater. If the transport scale is faster than the reaction time scale, the kinetic formulation of reaction modeling can be studied by two different approaches. The time behaviour of the homogenous chemical reaction system can be described either by the deterministic approach or by the stochastic approach. The deterministic approach considers the time evolution as continuous, which is governed by a set of coupled Ordinary Differential Equations (ODEs). The stochastic approach considers the time evolution similar to a random walk process. It is governed by a single differential equation, which is called the master equation. This paper deals with the conventional way of modeling geochemical reaction systems using a deterministic approach with its limitations and the necessity and application of stochastic algorithms (Gillespie’s Algorithms) to PCENAPL dissolution degradation reaction. The simulation of PCENAPL dissolution degradation reaction was done using Gillespie’s Direct Method, a stochastic. The results of concentration profiles of PCENAPL dissolution degradation simulation using ODE and Stochastic Algorithm are compared. From the results obtained, it is concluded that Stochastic Algorithm can be a better approach for reactions occurring simultaneously which involve species of low concentration.
Stochastic algorithm, Dissolution degradation, PCENAPL, Gillespie’s direct method
