南海湖沉积物中Hg的形态分布特征

以包头市南海湖为研究对象，采用连续化学提取法，系统开展了沉积物中Hg的形态分布研究。结果表明，表层沉积物中Hg含量的水平分布总体呈现湖心区低，西南和东北部湖区高的趋势。腐殖酸结合态为表层沉积物中Hg的主导形态，次为交换态和水溶态。表层沉积物中生物有效态Hg的含量甚高，占总汞的76%~94%，对整个生态系统具有潜在危害性。沉积柱芯中总Hg表现为表层富集并随深度增加而降低的变化趋势。B、F站位柱状沉积物中腐殖酸结合态Hg随深度有规律的递减，H站位20 cm以上Hg的主导形态为腐殖酸结合态，残渣态次之；20～30 cm的主导形态则为残渣态及可交换态。

Hg Occurrence and Distribution in Sediments of the Nanhai Lake

The sequential extraction procedure was chosen for the study of speciation of Mercury in sediments of the Nanhai Lake.The fractions of water-soluble and exchangeable Hg are easy to release to the overlying water,and the sum of them account for 30.82 % of the total Hg.Furthermore,there exists positive correlation between these two fractions and the total Hg in overlying water,indicating high potential hazard to the Nanhai Lake.The content of humic acid Hg is the highest both in horizontal and vertical distri...