Heavy metals in the surface sediments in Lanzhou Reach of Yellow River, China.

The heavy metal pollution and their fractionations in the surface sediments of Yellow River in Lanzhou Reach was monitored for arsenic (As), lead (Pb), Zinc (Zn), chromium (Cr), copper (Cu) and manganese (Mn) with Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The mean sediment concentrations (in microg/g dry weight) ranged from 13.68-48.11 (As), 26.39-77.66 (Pb), 89.80-201.88 (Zn), 41.49-128.30 (Cr), 29.72-102.22 (Cu), and 773.23-1459.69 (Mn). Spatial distribution showed that each heavy metal concentration remained almost constant in this reach. Correlation coefficients indicated that metals were not strongly associated with sediment sand content or organic carbon content (f(oc)). Labile fractions (exchangeable + carbonate + Fe-Mn oxide) had no significant correlations with sand content or f(oc), either. Results from the present study are useful for understanding heavy metal distributions in a torrential river sediment environment.