莱州湾表层沉积物重金属分布特征及生态环境评价

基于莱州湾154个表层沉积物地球化学分析数据,结合相关地质资料,分析莱州湾表层沉积物重金属的分布规律及其来源,采用尼梅罗综合指数法进行评价。结果表明,Cu、Pb、Zn、Cr、As、Hg、Cd等7种元素平均含量分别为21.9610-6、21.9910-6、60.4110-6、60.0010-6、12.6410-6、0.05110-6、0.1210-6;空间分布特征整体表现为重金属高值区在莱州湾的西部海域,来自莱州湾西部的陆源性输入和湾内潮流运动规律是造成这种分布趋势的影响因素;Cu、Pb、Zn主要来源于岩石的自然风化和侵蚀过程,Cr、Cd既有自然源的贡献,也受到人为活动的影响,而As、Hg主要受人为活动影响;小清河入海口附近海域、老黄河入海口附近海域和黄河入海口附近海域污染指数最高,莱州湾东南海域污染指数最低,呈西高东低的趋势。

Distribution patterns and ecological assessment on heavy metals in the surface sediments of Laizhou Bay

This paper, based on the 154 of geochemical data of surface sediments and other geological data, deals with the distribution pattern of heavy metals in the Laizhou Bay, and uses the Nemerow comprehensive index method to evaluate the economical of the region. The results show that, in the surface sediments of the study area, the average contents of Cu, Pb, Zn, Cr, As, Hg, Cd are 21.9610-6, 21.9910-6, 60.4110-6, 60.0010-6, 12.6410-6, 0.05110-6, 0.1210-6 respectively. The content is relatively higher in the west part of the study area for most heavy metals, which is obviously caused by the land source input form the west and movement rule of tidal current. The Cu, Pb, Zn are mainly derived from the natural weathering and erosion processes of rocks. The Cr, Cd are influenced by both the natural and the anthropogenic sources. The As, Hg are derived chiefly from the anthropogenic sources. The pollution index present the highest value in the waters near the Xiaoqing River estuary, the old Huanghe River subaqueous delta and the Yellow River Estuary. On the Contrary, the pollution index is the lowest in the southeast region of Laizhou Bay. The Nemerow comprehensive index of heavy metal decreases from west to east.