闽江口表层沉积物重金属分布及其潜在生态风险评价

为加强闽江流域的环境治理以及支撑闽江口重金属污染的管控工作,文章基于闽江口14个采样站位的实测数据,综合运用相关性分析、主成分分析和潜在生态风险指数等方法,系统评价闽江口表层沉积物重金属分布及其潜在生态风险。研究结果表明:闽江口表层沉积物重金属含量差异显著,除个别站位的锌和汞外,其他重金属含量均符合第一类海洋沉积物质量标准;影响铅分布的主要因素是工业排污,影响其他重金属元素分布的主要因素是有机质和沉积环境;闽江口表层沉积物重金属潜在生态风险的低风险程度和中风险程度占比分别为71.43%和28.57%,其中琅岐岛的东部和南部为中风险区,琅岐岛的北部和东北部以及川石水道外侧为低风险区;镉和汞为主要潜在生态风险重金属元素,达到较高风险程度,须加强风险监控。

Distribution and Potential Ecological Risk Evaluation of Heavy Metals in Surface Sediments of Minjiang River Estuary

In order to strengthen the environmental control of Minjiang River Basin and support the management and control of heavy metal pollution in Minjiang Estuary, based on the measured data of 14 sampling stations in Minjiang Estuary, this paper systematically evaluated the distribution of heavy metals and their potential ecological risks in surface sediments of Minjiang Estuary by using the methods of correlation analysis, principal component analysis and potential ecological risk index. The results showed that there were significant differences in the content of heavy metals in the surface sediments of Minjiang Estuary. Except for Zn and Hg at individual stations, the concentrations of other heavy metals were accorded with first class of the national marine sediment quality. The main factor affecting the distribution of lead was industrial sewage, while the main factors affecting the distribution of other heavy metals were organic matter and sedimentary environment. The proportion of low risk and medium risk of potential ecological risk of heavy metals in surface sediments of Minjiang Estuary was 71.43% and 28.57%, respectively. Among them, the east and south of Langqi Island were medium risk areas, and the north and northeast of Langqi Island and the outside of Chuanshi waterway were low risk areas. Cd and Hg were the main heavy metal elements with potential ecological risks, which had reached a high risk level, and risk monitoring work should be strengthened.