Zeng Wei-Te, Yang Yong-Peng, Zhang Dong-Qiang, Liu Bing, Zhang Hang-Fei, Wu Duo-Yu, Wang Xiao-Lin
Hainan Marine Geological Survey, Haikou 570206, China.
College of Marine Geosciences, Ocean University of China, Qingdao 266100, China.
Huan Jing Ke Xue. 2018 Mar 8;39(3):1085-1094. doi: 10.13227/j.hjkx.201705159.
The distribution characteristics of the content of As, Cr, Cu, Hg, Pb, Zn, and Cd were researched based on the geochemical analysis of 159 surface sediment samples in Haikou Bay, Puqian Bay, Dongzhai Harbor, and Mulan Bay Mathematical statistics methods were used to interpret the sources of heavy metals, and the main controlling factors for heavy metal distribution were confirmed, having been analyzed qualitatively and semi-quantitatively. The results showed that the average contents of As, Cd, Cr, Cu, Hg, Pb, and Zn were 8.40, 0.06, 32.50, 8.32, 0.02, 18.77, and 35.87 μg·g, respectively. High contents of Cr, Cu, Hg, Pb, and Zn are mainly distributed in estuaries and harbors. The content of As increased gradually from south to north in the research area, while Cd gathered mainly in Haikou Bay. The source of Cu, Zn, Hg, Pb, Cr, and Cd in sediment was terrestrial input, which was controlled by anthropogenic pollution and migration of weathered products from mother rock. The source of As could be overseas material input. The grain size of sediment was the main factor controlling the contents of Cu, Zn, Hg, Pb, and Cr, and it was found that sediments with a finer grain size have more heavy metals adsorbed. The high As content was controlled mainly by the natural geological background factor, while the content of Cd reflected the difference in regional pollution caused by differing development in cities. Three surface sediment samples were evaluated as class Ⅱ of the National Marine Sediment Standard due to the content of As, while six surface sediment samples were evaluated as class Ⅱ due to the content of Cr, of which the pollution degree was moderate. The concentrations of Cd, Cu, Hg, Pb, and Zn in all of the 159 sediment samples fall in the Ⅰ class, of which the pollution degree is low. The degree of pollution for seven heavy metals were arranged in the following order:As > Cr > Pb > Zn > Cu > Cd > Hg. The potential ecological risk assessment results indicated that all heavy metals in surface sediment caused low levels of pollution generally, and that each heavy metal element was at a low ecological risk level. The order for the ecological risk of the seven heavy metals was:As > Hg > Cd > Pb > Cu > Cr > Zn; therefore, As was the main ecological risk factor. In general, the potential ecological risk for heavy metals was low, which illustrated that the marine environment in the study area was excellent.
基于对海口湾、铺前湾、东寨港和木兰湾159个表层沉积物样品的地球化学分析，研究了砷、铬、铜、汞、铅、锌和镉含量的分布特征。运用数理统计方法解释重金属的来源，并通过定性和半定量分析确定了重金属分布的主要控制因素。结果表明，砷、镉、铬、铜、汞、铅和锌的平均含量分别为8.40、0.06、32.50、8.32、0.02、18.77和35.87μg·g。铬、铜、汞、铅和锌的高含量主要分布在河口和港口。研究区域内砷含量自南向北逐渐增加，而镉主要聚集在海口湾。沉积物中铜、锌、汞、铅、铬和镉的来源为陆源输入，受人为污染和母岩风化产物迁移的控制。砷的来源可能是海外物质输入。沉积物粒度是控制铜、锌、汞、铅和铬含量的主要因素，发现粒度较细的沉积物吸附的重金属更多。高砷含量主要受自然地质背景因素控制，而镉含量反映了城市发展差异导致的区域污染差异。3个表层沉积物样品因砷含量被评为国家海洋沉积物标准Ⅱ类，6个表层沉积物样品因铬含量被评为Ⅱ类，污染程度为中等。159个沉积物样品中镉、铜、汞、铅和锌的浓度均属于Ⅰ类，污染程度较低。7种重金属的污染程度排序为：砷＞铬＞铅＞锌＞铜＞镉＞汞。潜在生态风险评估结果表明，表层沉积物中的所有重金属总体上造成的污染程度较低，各重金属元素的生态风险水平较低。7种重金属的生态风险排序为：砷＞汞＞镉＞铅＞铜＞铬＞锌；因此，砷是主要的生态风险因素。总体而言，重金属的潜在生态风险较低，说明研究区域的海洋环境优良。
