Effects of flow and sediment on the transport and transformation of pollutants in rivers: A review

Flow and sediment are known to be the main carriers of the transport and transformation of pollutants in rivers, and a better understanding of the effect of flow and sediment is therefore of crucial importance for the management of deteriorating water environment. This paper reviews the experimental studies on the effect of flow and sediment on the transport and transformation of pollutants in water, underlying mechanisms, and existing theoretical and mathematical models. In particular, a comparison is made between several models. However, it should be noted that there are some limitations in the experimental methods, the exact mechanism remains controversial, and the theoretical and mathematical models available seem to be not sufficient to characterize the transport-transformation process of pollutants. This underscores the need for further laboratory and field experiments on the interface kinetics of the particles, and theoretical investigation of the transport-transformation process of pollutant in the overlying or underlying water. At last, some directions for further studies are suggested in the study.