梁子湖近代沉积物重金属含量研究初探

Research on Heavy Metal Content of Recent-year Sediments in Liangzi Lake

通过对湖北省梁子湖高分辨率沉积物中重金属元素的研究 ,得到了梁子湖区近代环境污染的波动记录。对所测数据进行因子分析和聚类分析 ,得到影响沉积物中重金属含量和组成的物质来源 ,其中 Cd、Ni、Fe主要反映了流域侵蚀作用控制的重金属分布 ;Zn、Pb、Mn、Co、Cu主要反映了人为污染 (尤其是大气干湿沉降 )对重金属含量变化规律的影响。据分析结果推测 ,深 35～ 4 0 cm处元素含量高峰值对应于 19世纪末近代工业兴起 ,环境变化所致 ;2 0 cm处高峰值对应于上世纪中叶以武汉钢铁公司为代表的现代工业污染留下的物质记录 ;10 cm至表层金属含量逐渐增加 ,为改革开放以来城市和城镇工业的发展导致的大气污染物中重金属含量的急剧升高 ,该结果说明利用梁子湖区高分辨率金属沉积记录研究人类活动重大环境污染事件对环境的影响是切实可行的。

With the development of modern industry since 1880s, human activities have had a great impact on environment. As a record of the impact which human activities have imposed environment, lake sediments have the advantages of keeping abundant information, higher time resolution and extensive geographic coverage in comparison with other natural sediment records. By the testing of the heavy metals in high resolution sediment of Liangzi Lake, the authors of the paper obtained the undulation records of the recent contamination. Factor analysis and cluster analysis were used to analyse the data, indicating the contribution of Cd, Ni, Fe was mainly reflections of catchments erosion; the contribution of Zn, Pb, Mn, Co , Cu was caused by the human activities, especially the air pollution. It was shown that the beginning stage of modern industry in late 1880s had influence on high numerical values of 35～40cm, industry contamination of middle part of last century on high numerical values of 20cm and industrial atmospherical pollutant since the reformation and opening to the outside world on high numerical values of 10cm to the surface. The results were anastomosed with the records of historical literatures. Environment quality was assessed to be lightly contaminative with the method of contaminate exponent.