A method for treating a body of a polluted porous medium, includes the steps of: preparing a reactive solution containing nanoparticles; injecting the reactive solution into the body of the polluted porous medium so as to decompose pollutants in the polluted porous medium by reacting the nanoparticles with the pollutants; and applying an electric field to the body of the polluted porous medium so as to enhance transporting effect of the nanoparticles in the body of the polluted porous medium.