珠江口海域表层沉积物中重金属分布特征及其污染评估

Distribution Characteristics of Heavy Metals in Surface Sediments of the Pearl River Estuary and Contamination Assessment

本文对取自珠江口海域的55个表层沉积物进行了重金属元素的测试与分析,结果表明:各重金属含量由北向南整体呈减小的变化趋势,锌(Zn)含量最高(135.61μg/g),其次为铬(Cr)(75.05μg/g)、铜(Cu)(43.23μg/g)、铅(Pb)(42.67μg/g)、砷(As)(22.01μg/g)、镉(Cd)(0.52μg/g),汞(Hg)含量最低(0.18μg/g)。结合总有机碳数据,利用线性拟合分析发现其和重金属含量间有显著正相关,表明沉积物中总有机碳含量对重金属的分布有一定的影响作用,重金属元素彼此间显著的正相关表明其来源和迁移途径具有一定的相似性。基于海洋沉积物质量标准和地质累计指数法,本文计算出研究区沉积物中重金属元素Cr、Zn、Hg、Cu、As和Cd含量符合海洋沉积物质量第二类标准,Pb含量符合海洋沉积物质量第一类标准,各重金属元素基本处于无污染至中度污染状态,表明研究区表层沉积物中重金属元素的污染水平较低。本文探讨了珠江口海域表层沉积物中重金属元素的含量及分布特征,并评价了其污染程度,丰富了珠江口海域有关重金属污染的研究。

55 surface sediments taken from the Pearl River Estuary were tested and analyzed for heavy metal elements in this paper,and the results showed that the contents of each heavy metal showed an overall decreasing trend from north to south,with the highest Zn 135.61滋g/g was the highest,followed by Cr 75.05滋g/g,Cu 43.23滋g/g,Pb 42.67滋g/g,As 22.01滋g/g,Cd 0.52滋g/g,and Hg 0.18滋g/g were the lowest.Combined with the total organic carbon data,linear fitting analysis revealed a significant positive correlation between TOC and heavy metal content,indicating that the TOC content in sediments has a certain effect on the distribution of heavy metals,and the significant positive correlation between heavy metal elements indicates that their sources and migration pathways are somewhat similar.Based on the marine sediment quality standard and the geologic cumulative index method,the paper calculated that the content of heavy metal elements Cr,Zn,Hg,Cu,As and Cd in the sediments in the study area meets the second category standard specified in the marine sediment quality,and the content of Pb meets the first category standard of the marine sediment quality,and the heavy metal elements are basically in the state of non-pollution to medium-pollution,which indicates that the contamination level of the heavy metal elements in the surface sediments in the study area is low.The paper discussed the content and distribution characteristics of heavy metal elements in surface sediments in the Pearl River Estuary,and evaluated the degree of contamination,which enriches the research on heavy metal contamination in the Pearl River Estuary.