Cellular Automata for Simulation of PCE Degradation in Subsurface Media

Abstract

The contaminant that is being released into the subsurface environment undergoes interactions with water and soil particles. The flow and transport processes in subsurface media are intricately connected at various scales of space, time, transport coefficient sand molecular concentration. The uncertainty existing in the field parameters limits the application of reactive transport models at microscopic level. The difference in scale can be well defined using the intermediate scale called mesoscopicscale, which is between microscopic and macroscopic description Cellular Automata(CA) is a mesoscopic approach to comprehend the emergence of macroscopic phenomena. This is done by modelling the microscopic dynamics through simple rules which as similates all the basic physics and chemistry requirements in terms of conservation laws, symmetry properties, reaction mechanisms etc. CA simulation is free of round-offerrors since it deals with the number of states which are integers and this advantage can be used when non-linear reaction terms are used. This approach captures the inherent microscopic properties by applying macroscopic parameters. In this paper, CA was applied to simulate Perchloroethylene (PCE) degradation in subsurface media and the results were compared with analytical solution. It was observed to have good agreement between model results and analytical results.