Molecular Simulation of Atrazine Adhesion and Diffusion in a Saturated Sand Model

Abstract

This paper presents an extensive study about atrazine behavior in saturated sands by the aid of molecular simulation techniques. Systems have been described in a simplified way to predict adhesion and diffusion phenomena, and to give useful insights at the atomistic level. Diffusion coefficients, binding energies, and concentration profiles have been determined as a function of interlayer distances and atrazine concentration. Combined Monte Carlo, Molecular Mechanics, and Molecular Dynamics techniques have been used. In silico results have been compared with available experimental data for validation, and with similar in silico experiments, finding a good agreement. Results confirm a moderate atrazine adhesion onto silica framework and a more favorable tendency to bind with water. Atrazine diffusion has been found to be influenced by concentration and interlayer distance. Encouraging results show how these techniques can be generalized and made applicable for soil contamination modelling at the atomistic level in a more extensive way.

Keywords:

• diffusion
• molecular modelling
• pesticide
• sand contamination