Characteristics of the concentration and distribution of heavy metals in typical urban discharging pollution river

ICP-MS method was used to analyze the concentration of heavy metals in the North and South discharging pollution river in Tianjin. Concentrations of 13 heavy metals in river water, suspended particulates, sediment, and soil sampled near the riverbank were obtained from lab examination. Results suggest that concentrations of these heavy metals ranged greatly, difference between concentrations in water and suspended particulates even exceed 10 magnitudes. Concentrations of Zn, Cu, Cr, Pb, Ni and Mo account for more than 90% of the overall amount of heavy metals in each compartment. About 24% of total amount of these metals was dissolved in the river water, dominant metals such as Zn, Cu, Cr and Pb are mostly (70%-90%) absorbed on the suspended particulates and tend to deposit to the sediment. Average ratio between concentration of heavy metals in suspended particulates and sediment are 1.3-11.2, the high ratio may be caused by some high values in sample site of 1, 13, 17, 19, 20 and 23 ranged from 10.9 to 55.7, which indicate newly received waste water rich in some heavy metals near these sample sites. The composition of heavy metals and their spacial distribution style in river water, suspended particulates, sediment and soil are all similar, which indicate the possible transfer processes of heavy metals from water to other compartments and through soil runoff to water.