水生态学杂志2022，Vol.43Issue(1)：16-23,8.DOI:10.15928/j.1674-3075.202109150324
三峡库区及上游表层沉积物重金属形态特征及其生态风险
Fraction Characteristics and Ecological Risk of Heavy Metals in Surface Sediments of Three Gorges Reservoir and the Upper Reaches
摘要
Abstract
The characteristics and potential ecological risk of heavy metals in surface sediments from the Three Gorges Reservoir area and the upper reaches were studied, aiming to provide basic data for the prevention and control of heavy metal pollution in the reservoir area. In November 2020, 21 sediment samples were collected from the Hejiang and Jiangjin sections in the upper reaches, Banan and Changshou sections in the Three Gorges Reservoir area. The total concentrations and fractions of Cu, Pb, Cr, Cd, As and Hg were analyzed by using continuous extraction method. Results show that the average concentration of heavy metals in sediments were in the order of Cr>Pb>Cu>As>Cd>Hg, and the levels of Cu, Pb and Cd were higher than the background values of the Yangtze River basin. Heavy metals presented obvious spatial distribution differences, and were higher in Changshou section compared with other sections. The fraction of each form varied significantly among the heavy metals. The proportion of Fe-Mn oxide fraction of Pb was as high as 34.99%-43.17%. Cd had the highest percentage of the exchangeable fraction, accounting for 17.41%, 16.65%, 20.56% and 18.88% in the sediments of Hejiang, Jiangjin, Banan and Changshou sections, respectively. The residual fractions of As, Hg, Cu and Cr were relatively high and the residual fraction percentages of Hg and Cr exceeded 80% and 88%, respectively. Ecological risk assessment results show that the pollution load index (PLI) and the potential ecological risk index (RI) values were 0.90-1.61 and 112.49-245.03, respectively, and the index value in the Changshou and Banan sections was higher. The comprehensive evaluation show that the heavy metal pollution was serious in the sediment of Changshou and Banan sections in the Three Gorges Reservoir area and at a moderate pollution level. Cd and Pb were the primary heavy metal pollutants, and Cd was more bioavailable and posed larger potential ecological risk.关键词
重金属/形态/生态风险/表层沉积物/三峡水库Key words
heavy metal/ fraction/ ecological risk/ surface sediment/ Three Gorges Reservoir分类
资源环境引用本文复制引用
董纯,杨志,朱其广,唐会元,李嗣新,陈小娟..三峡库区及上游表层沉积物重金属形态特征及其生态风险[J].水生态学杂志,2022,43(1):16-23,8.基金项目
国家自然科学基金(51779158). （51779158）
