河流底泥重金属污染与释放特征研究

摘要

The existing forms of heavy metals in sediments were analyzed by BCR3 sequential extraction procedures. The results illustrate that the average values of Cu and Pb were 2. 45 and 1. 91 times than background value respectively ,and the mobility of heavy metals follow the order:Pb> Cu> Cr. The release characteristics and factors affecting the releasing of heavy metals were studied. Experimental results of heavy metals releasing indicate that the releasing of Cu was best fitting to the second-order equation ,and Pb and Cr was much better to fit with parabolic diffusion equation and Elovich equation. The quantity of releasing heavy metals closely related to pH ,salinity ,temperature and mud ratio.%采用BCR3态连续提取法对底泥中重金属的含量及形态特征进行分析。结果表明，底泥中Cu ， Pb的平均值分别超过背景值的2．45，1．91倍，重金属迁移性的大小为Pb＞Cu＞Cr。研究了底泥中重金属释放特征及影响因素，实验结果表明，Cu的脱附符合二级反应动力学方程拟合，Pb ，Cr的脱附符合抛物线扩散方程和Elovich方程；pH、盐度、温度、泥水比等因素影响重金属的释放量。