珠江(广州河段)表层沉积物中重金属的分布特征及相关性研究

随着广州市截污工程的实施,珠江(广州河段)外源污染得到有效控制后,沉积物内源污染将成为影响河流水质的重要因素。在珠江(广州河段)表层沉积物中8种重金属质量分数监测的基础上,对该河段沉积物中重金属的沿程分布特征和横向分布特征进行了全面的分析,并对所测8种重金属之间的相关性进行了研究。结果表明:从沿程分布来看,这8种污染元素的分布特征基本相似,元素的高值区和低值区大致吻合。从横向分布来看,绝大多数污染物在一个断面的最高值和最低值出现的点位基本上是重合的,各种污染物质量分数的最高值绝大部分出现在靠近岸边的点位,并且大部分集中于左岸。而最低值出现在河道中间的比例较高。在所测定的8种元素中,除了Hg和As之外,其它各种元素之间均呈现较明显的正相关关系,特别是Cr和Cd、Cu和Cd、Cr和Cu、Cr和Ni之间的相关性显著。

Distribution characteristics and correlations of heavy metals in the surface sediments in Guangzhou section of the Pearl River

The internal pollution sources are going to be the main factors to influence the water quality of river, with the implementation of interception project, which had effective control of exotic pollution sources of Guangzhou section of the Pearl River. Based on the monitoring results of 8 kinds of heavy metals in the surface sediments, a systematic study has been carried out on the longitudinal and landscape distribution characteristics and the correlations of heavy metals in the surface sediments in Guangzhou section of the Pearl River. The results show that the distribution characteristics of these heavy metals are approximately similar, and the sites with higher and lower content are approximately in accordance, in longitudinal distribution. The sites with the highest and lowest content of most of the heavy metals in a cross section appear approximately at the same location in landscape distribution. Most of the highest content sites appear at the location near bank, especially near the left bank. While most of lowest content sites appear in the middle location of river. There is a significant and positive correlation among heavy metals (except Hg and As), especially between Cr-Cd, Cu-Cd, Cr-Cu and Cr-Ni.