晋江河口沉积物重金属污染历史与来源

Pollution History and Source Analysis of Heavy Metals in Sediments from Jinjiang River Estuary

为研究沉积物重金属元素的主要来源,分别采用电感耦合等离子体质谱法和冷原子吸收法,测定了晋江河口柱状沉积物中15种重金属元素（Pb、Sr、Cr、Cd、Zn、Cu、Fe、Mn、V、Ni、Co、Cs、Sn、Sb和Hg）的质量分数,结合^210Pb定年技术,运用Pb、Sr同位素示踪技术及多元统计分析方法（聚类分析法）,探讨沉积物中15种重金属元素的垂向分布特征及污染历史.结果表明：1近300a来晋江河口受到不同程度的重金属污染.2柱状沉积物中的Pb主要来自于上游流域的采矿活动（贡献率为47.5%-83.7%）和土壤母质（贡献率为16.3%-52.5%）.3沉积物的^87Sr/^86Sr为0.716 37-0.719 26,高于人为源（≤0.711 72）,说明沉积物中的Sr受人类活动影响较小,主要来源于土壤母质.4聚类分析结果显示,15种重金属元素可分两大类,Ⅰ类为Sr、Hg、Cr、V、Ni和Cs,以自然源为主;Ⅱ类为Pb、Fe、Mn、Zn、Cd、Sb、Sn、Cu和Co,以人为源为主,主要与上游流域的采矿活动有关.

In order to study the main sources of heavy metals in sediments, contents of Pb, Sr, Cr, Cd, Zn, Cu, Fe, Mn, V, Ni, Co, Cs, Sn, Sb and Hg in core sediments collected from Jinjiang River Estuary were determined by inductively coupled plasma-mass spectrometry and cold vapor atomic absorption spectrometry. The vertical distribution characteristics and pollution history of 15 elements in the sediments were discussed based on Pb and Sr isotopic tracing technology and multivariate statistical analysis （ cluster analysis） combined with ^210Pb dating technology. The results showed that Jinjiang River Estuary has been polluted by heavy metals to some extent over the past three centuries. Pb in the core sediments mainly originated from upstream mining activities （ accounting for 47.5% -83.7% ） and the natural soil parent material （accounting for 16.3% -52. 5% ）. Compared with the relatively lower ^87Sr/^86Sr ratios （ ≤0. 711,72） of the anthropogenic sources, ^87Sr/^S6 Sr ratios presented higher values （0. 716,37-0. 719,26） in the core sediments of Jinjiang River Estuary, indicating that Sr in the core sediments mainly came from the natural soil parent material while being less affected by human activities. The results of hierarchical cluster analysis suggested that the above 15 elements could be classified into two groups： Sr, Hg, Cr, V, Ni and Cs were mainly derived from natural sources, while Pb, Fe, Mn, Zn, Cd, Sb, Sn, Cu and Co were mainly originated from anthropogenic sources, and were mainly related to upstream mining activities.