Spatial distribution characteristics and ecological risks of vanadium in sediments from Jianhu Lake, Northwest Yunnan Province, China

The inductively coupled plasma-optical emission spectrometer (ICP-OES) was used to determine the concentrations of vanadium in surface and columnar sediments from Jianhu Lake. The modified BCR sequential extraction method was used to extract the different fractions of vanadium, and then the characteristics of spatial distribution and ecological risks of vanadium were assessed, the effects of sediment particle size on the concentrations of vanadium and its fractions were also studied. The results showed that the sediment particles in surface and columnar sediments in Jianhu Lake were mainly composed of silt and fine sand, and the concentrations of vanadium in fine particles were higher. The concentration of vanadium in surface sediments from Jianhu Lake was (117.82±63.31)mg/kg, and its horizontal distribution varied substantially. The concentrations of vanadium in exchangeable, reducible, oxidizable, and residual fraction were (8.91±8.91), (18.36±10.53), (7.67±7.67), (80.22±58.71) mg/kg, respectively. This indicated that vanadium mainly presented in the form of residual fraction. Furthermore, the clay and silt in sediments had a great influence on the reducible and residual fractions of vanadium. The vertical distribution of vanadium also varied greatly, and the concentration of vanadium in bottom sediments was higher than that in surface layer. In addition, the concentrations of vanadium were affected by clay and silt in some areas of Jianhu Lake. The degree of vanadium pollution was mild in sediments from Jianhu Lake, and the potential ecological risks of vanadium were low in most areas. The contamination levels and the potential ecological risks of vanadium in the bottom sediments were higher than those in surface layer. © 2019, Editorial Board of China Environmental Science. All right reserved.