XIONG Yan^1,2, NING Zengping¹, LIU Yizhang¹, ZHAO Yanlong³, WU Shiliang³,LIU Wei³

(1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China;
2. University of Chinese Academy of Sciences, Beijing 100049, China;
3. Water Resources Protection Bureau of Pearl River Water Resources Commission, Guangzhou 510611, China)

Abstract: In order to reveal the distribution characteristics of heavy metals in the Nanpan River Basin (Yunnan section), twenty-five sediment samples were collected. Contents of trace metal in sediments were determined by using inductively coupled plasma mass spectrometry (ICP-MS). Geochemical and statistic methods were applied to analyze the spatial distribution and correlation of heavy metals in sediments of the Nanpan River. Degree of contamination and major pollutant elements in the Nanpan River basin were assessed by using enrichment factor (EF), pollution loading index (PLI) and index of geo-accumulation (Igeo). Results show that the enrichment degree of heavy metal elements in sediments of the Nanpan River are followed the order of Cd>As>Cr>Pb>Sb>Zn>Cu. Cadmium is riched in the whole Nanpan River basin, while the upper river is enriched in Cr and As; the middle reaches are enriched in Pb and Sb; and the lower reaches are enriched in Sb. Lujiang tributary in the middle reaches significantly influences the distribution of elements in sediments of the Nanpan River. Due to nonferrous metal sulfide deposits, mining and smelting factories are located throughout the Nanpan River Basin. Potential sources of heavy metals in sediments of the Nanpan River basin might be the weathering of sulfide and mining/smelting activities. The Nanpan River Basin (Yunnan section) is polluted by heavy metals, and its pollution degree varies from different reaches (middle reaches>upper reaches>lower reaches). Among the major contamination elements in the Nanpan River, Cd and As occupy the first place; Sb and Cr rank the second; while Pb, Zn and Cu take the third place.

Key words: Heavy metal; Sediment; Spatial distribution; Pollution evaluation; The Nanpan River basin

EARTH AND ENVIRONMENT Vol.45, No.2, Tot No.316, 2017, Page 171-178