Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, 210096, China.
Environ Sci Pollut Res Int. 2012 Nov;19(9):4042-8. doi: 10.1007/s11356-012-0907-z. Epub 2012 Apr 19.
Heavy metal pollution in road runoff had caused widespread concern since the last century. However, there are little references on metal speciation in multiple environmental media (e.g., rain, road sediments, and road runoff). Our research targeted the investigation of metal speciation in rain, road sediments, and runoff; the analysis of speciation variation and mass balance of metals among rain, road sediments, and runoff; the selection of main factors by principal component analysis (PCA); and the establishment of equation to evaluate the impact of rain and road sediments to metals in road runoff. Sequential extraction procedure contains five steps for the chemical fractionation of metals. Flame atomic absorption spectrometry (Shimadzu, AA-6800) was used to determine metal speciation concentration, as well as the total and dissolved fractions. The dissolved fractions for both Cu and Zn were dominant in rain. The speciation distribution of Zn was different from that of Cu in road sediments, while speciation distribution of Zn is similar to that of Cu in runoff. The bound to carbonates for both Cu and Zn in road sediments were prone to be dissolved by rain. The levels of Cu and Zn in runoff were not obviously influenced by rain, but significantly influenced by road sediments. The masses for both Cu and Zn among rain, road sediments, and road runoff approximately meet the mass balance equation for all rainfall patterns. Five principal factors were selected for metal regression equation based on PCA, including rainfall, average rainfall intensity, antecedent dry periods, total suspended particles, and temperature. The established regression equations could be used to predict the effect of road runoff on receiving environments.
重金属污染在道路径流引起了广泛的关注，自上个世纪以来。然而，很少有参考文献上的金属形态在多种环境介质（如，雨，道路沉积物和径流）。我们的研究针对调查金属形态在雨，道路沉积物和径流;分析形态变化和金属的质量平衡雨，道路沉积物和径流;选择主要因素的主成分分析（PCA）;和建立方程来评估雨和道路沉积物的影响金属在道路径流。顺序提取程序包含五个步骤的金属的化学形态。火焰原子吸收光谱法（岛津，AA-6800）被用来测定金属形态浓度，以及总浓度和溶解浓度。溶解的 Cu 和 Zn 的分数是在雨。锌的形态分布不同于 Cu 的道路沉积物，而 Zn 的形态分布与 Cu 的相似在径流。结合碳酸盐的 Cu 和 Zn 在道路沉积物中容易被雨溶解。 Cu 和 Zn 的水平在径流不受雨的明显影响，但明显受道路沉积物的影响。 Cu 和 Zn 的质量雨，道路沉积物和道路径流大约满足所有降雨模式的质量平衡方程。基于 PCA 选择了五个主要因素的金属回归方程，包括降雨量，平均降雨量强度，前期干燥期，总悬浮颗粒物和温度。建立的回归方程可用于预测道路径流对接收环境的影响。
