The Source, Distribution, and Environmental Effects of Suspended Particulate Matter in the Yangtze River System

Abstract

Suspended particulate matter (SPM) plays a crucial role in biogeochemical cycles in the aquatic environment because of its ubiquitous presence, mobility, and physicochemical properties. This work gathered and summarized the published information about SPM in the Yangtze River system, including source, distribution, and environmental effects. Results indicated that the SPM concentration was high in the flood period and low in the dry period. Compared to midstream and downstream, the SPM concentration was the lowest in the upstream of the Yangtze River system. Furthermore, the level of SPM concentration was influenced by human activities, such as shipping, dredging, construction of water conservancy projects, and industrial/agricultural emissions, as well as natural conditions, such as wind, rainfall, and phytoplankton. Moreover, SPM would impact the element cycle in the water environment, including N, P, heavy metal, and persistent organic pollutants. In addition, SPM adsorbed these elemental ions or particles in water on its surface. Still, this adsorption was usually unstable, and when the properties of SPM itself or external environmental conditions changed, these elements would be released into the surrounding water body. With the flow of SPM in the water, these elements migrated upstream and downstream with the river. Thus, this work reveals the current status of SPM in the Yangtze River system, which provides an essential reference for further research on SPM in the water system.