长江中下游河流沉积物和悬浮物中金属元素的形态特征(英文)

采集了长江中下游8个样点沉积物和悬浮物样品(1992年8月)。用连续提取方法提取了金属元素的五种化学形态(可交换态、碳酸盐结合态、铁锰氧化物结合态、有机质-硫化物结合态、残渣态),用ICP-AES分析了所有样品中锂、钠、钾、镁、钙、锶、钛、钒、铬、锰、钴、镍、铝、钇和锆共15种元素的各化学形态的含量,并用聚类分析方法研究了这些元素在形态上的分类特点。结果表明:在沉积物和悬浮物中,碱金属元素(锂、钠和钾)主要以残渣态和可交换态存在;碱土金属元素(镁、钙和锶)各形态含量较为均匀,但钙的碳酸盐态含量很高;锰和钴的铁锰氧化物态含量较高;铁族元素除锰和钴以外(钛、钒、铬、镍)、铝和锆残渣态含量很高、其它形态含量很低。其中,碱金属元素中锂的铁锰氧化物态和有机质-硫化物态占有一定比例;所研究元素中钙的残渣态含量最低。

SPECIATION OF METAL IN SEDIMENTS AND SUSPENDED MATTER IN THE LOWER AND MIDDLE REACHES OF THE CHANGJIANG RIVER

Sediment and suspended matter samples at 8 locations in downstream of the Changjiang River were taken in 1992. Five forms (exchangeable, carbonate, organic, Fe/Mn oxide and residual fractions) of metals were extracted with a sequential procedure. The contents of the five forms for 15 metal elements (Li, Na, K, Mg, Ca, Sr, Ti, V, Cr, Mn, Co, Ni, Al, Y, and Zr) were determined by ICP-AES, and cluster analysis was used for the classification of the elements. Alkaline metals (Li, Na, and K) exist mainly in residual and exchangeable forms. Alkaline-earth metals (Mg, Ca, and Sr) distribute rather evenly among the five forms, but Ca has a very high proportion of carbonate form. Mn and Co have a high proportion of Fe/ Mn oxide-bound form. The iron family (Ti, V, Cr, and Ni, except Mn and Co), Al, and Zr have very high contents of'residual form, and very low contents of the other forms. Furthermore, Li has relatively larger proportions of Fe/Mn oxide and organic forms than Na and K. Among all the elements studied, Ca and Mn have the smallest proportion of residual form.