Physicochemical properties of suspended sediment in typical waters of the mid-lower Yangtze River Basin

The physicochemical properties of suspended sediment show regional differences. Based on scanning electron microscopy-energy dispersive X-ray spectrometry, we qualified the grain size, roundness, roughness and chemical composition of suspended sediment of four typical waters of the mid-lower Yangtze River Basin. The following results were observed: The grain size and roundness of suspended sediment in Yangtze Estuary were the largest, at 7.45 μm and 1.344, respectively. Grain-size and roundness significantly varied between research points. Water velocity had a positive effect on grain size and roundness. The concentration of suspended solids had a positive effect on roughness. Taking Zn as an example, the results of a comparison of coupled functions with the measured values (average R2 = 0.8) indicates that the roundness, roughness and Al content of particles obviously affected the heavy metal adsorption. This study not only explores the environmental effect of the physicochemical of suspended sediment but also provides comprehensive data for the numerical simulation of suspended sediment dynamics.