Hooman JanfeshanAraghi - P.H.D Candidate, Faculty of Environment and Energy, Islamic Azad University (Science and Research Branch),
Sina Ettehadi - Construction Engineering and Management, Department of Civil and Environmental Engineering, Amirkabir University of Technology (Polytechnic of Tehran), Tehran (IRAN
Majid Abbaspour - Professor of Faculty of Environment and Energy, Islamic Azad University (Science and Research Branch), Tehran,Iran
Amirhossein Javid - Associate Professor of Faculty of Environment and Energy, Islamic Azad University (Science and Research Branch)

In the present study is attempted to solve the diffusion equation in 1D and 2D environments using smoothed particle hydrodynamic (SPH) technique . For assuring of the accuracy and veracity of the modeling results, the modeling output results are compared with the analytical solution to determine the accuracy of SPH method. The maximum difference between numerical simulation and analytical solution was less than 0.1%, respectively in 1D and 2D environments. Also pollution concentration are reported in specific point of environment. The results of the simulations showed that SPH method is able to model and predict the diffusion of pollutant in large-scale environments. Due to the Lagrangian and mesh-free particle method, this model can be used to determine the duration of pollution reaches in a specific place of the environment and the variation of pollutant concentration changes in this place.

Diffusion equation; mesh-free particle method; Smooth Particle Hydrodynamic method;Lagrangian method