Using a mathematical model that includes the influence of bottom sediments, we conducted a comprehensive study of the migration of benzene as a result of its continuous release into a mountain river. Our migration model consists of two equations that accurately describe the movement of pollutants within the river system, considering crucial factors such as flow velocity, diffusion, sorption, and desorption by river sediments. Through meticulous laboratory experiments, we have successfully determined the distribution parameters that govern the behavior of benzene within the water-sediment system. Leveraging advanced computer modeling techniques, we have generated intricate spatiotemporal profiles illustrating benzene concentrations in both water and sediments. Furthermore, we have identified consistent patterns in the fluctuations of benzene concentrations that exhibit strong correlation with the specific composition of river sediments. Importantly, these foundational relationships can be extrapolated to diverse river systems and various categories of pollutants.