Pollution Characteristics and Ecological Risk Assessment of Vanadium in Sediments of the Three Gorges Reservoir (Chongqing-Yichang Section)

Abstract

In order to investigate the pollution characteristics of vanadium in sediments of the Three Gorges Reservoir (TGR), 67 sediment samples were collected from the section between Chongqing to Yichang in TGR. The concentration and chemical speciation of vanadium were measured and the spatial distribution of vanadium was discussed. Current pollution level of vanadium in TGR sediments was assessed by index of geoaccumulation and Häkanson ecological risk index. The results showed that:1the range of vanadium concentrations in TGR was 89.4-175.2 mg·kg-1 and the average concentration was 123.7 mg·kg-1, which was slightly higher than the background value in sediments of Yangtze River. 2the spatial distribution of vanadium in TGR sediments showed that vanadium concentrations in the mainstream of TGR were higher than those in tributaries and the vanadium contents in the sediments in downstream were higher than those in upstream in term of the mainstream of TGR. 3highest vanadium concentration was found in the sediment in a developed county, indicating that this high level of vanadium concentration was attributed to anthropogenic input. 4chemical forms of vanadium in sediments were mainly in residual state (80%-89%, mass fraction), which had a significant positive correlation with total concentrations in sediments. 5vanadium contamination degree and potential environmental risk in TGR sediments were weak.