黄河内蒙古段沉积物中汞含量及形态研究

摘要

Concentration and species distribution of mercury in the Yellow River sediment cores in Inner Mongolia reach was researched. Mercury in sediments was divided into five fractions such as soluble and exchangeable,bound to carbonates and Fe-Mn oxides,bound to humus,bound to dissoluble organic matter and in sulfide phase and residual and extracted by advanced Tessier sequential extraction procedure. Mercury concentra-tions were determined by hydride generation atomic fluorescence spectrophotometers. The results show that the total mercury concentration is 12. 1-47. 1μg·kg-1 ,averagely 21. 4μg·kg-1 . Overall,mercury concentration in the left bank was higher than that of in the right bank and it increases firstly and then decreases along the river. Mercury in the sediment was mainly bound to humus and secondly residual. Mercury bound to humus is significantly decreased with depth and the others are increased with the depth.%为探明黄河内蒙古段水体沉积物中的汞含量及其形态分布特征，以黄河内蒙古段干流水体柱状沉积物为研究对象，采用改进的Tessier形态逐级提取法，分级提取水溶及可交换态、碳酸盐及铁锰氧化物结合态、腐殖质结合态、难溶有机质结合态及硫化物态和残渣态5种形态汞，用氢化物发生－原子荧光分光光度法测定汞含量，结果表明：黄河内蒙古段柱状沉积物中汞含量为12．1～47．1μg／kg，平均为21．4μg／kg；从整体上看，左岸沉积物中汞含量高于右岸，从上游至下游，汞含量呈先上升后下降趋势；沉积物中汞以腐殖质结合态为主，残渣态次之；腐殖质结合态汞含量随深度增加呈明显下降趋势，其他形态汞含量随深度增加呈上升趋势。