Yang, X. and Wang, Z.-L., 2017. Distribution of dissolved, suspended, and sedimentary heavy metals along a salinized river continuum.

Attention has been increasingly focused on the geochemical behavior of heavy metals in high-salinity estuaries, but how the salinity gradient affects the behavior of heavy metals in low-salinity rivers is not clear. In this paper, the distribution of Cr, Cu, Co, and Ni were assessed according to the proportions in three phases (dissolved, suspended particle, and surface sediment) along the Jiyunhe River in northern China. Dissolved heavy metals had a significantly positive correlation with salinity (p < 0.01), increasing along a salinity gradient from upstream to the river mouth. Suspended particulate materials were mainly derived from particles like clay rather than algae. With salinity greater than 2‰, suspended heavy metals were released into the water, bringing about an increase in dissolved heavy metal content. High deviations of Cr from conservative mixing behavior occurred downstream of an urban area. In the low-salinity area, heavy metals were mainly released from particles and increased along a salinized and degraded river continuum. The distribution coefficient implied that under a salinity effect, Cr and Cu exhibited higher ecological risk and mobility, whereas Co and Ni seemed to be more conservative in the sediment of the Jiyunhe River.