新乡市机动车排放对道路灰尘中重金属与多环芳烃污染的影响

以新乡市主要道路的地表灰尘为样本,采用电感耦合等离子体质谱仪和气相色谱质谱联用仪分别测定所含5种重金属(Cd、Pb、Cr、Cu和Zn)和15种多环芳烃(polycyclic aromatic hydrocarbons,PAHs)的含量,并探究了机动车排放对其污染特征的影响.结果显示,重金属和PAHs的含量范围分别为2. 58～1 560 mg·kg~(-1)和ND～1. 30 mg·kg~(-1),其含量总体上随灰尘粒径减小而增高.组成上,重金属以Zn为主,PAHs主要以高环为优势组分.空间分布上,重金属和PAHs含量存在差异:人民路、小店工业园区和水泥厂附近道路灰尘中的重金属总含量最高,而PAHs含量的高值出现在人民路、高速上口和107国道的灰尘中.Pearson相关分析表明,5种重金属与15种PAHs间基本不存在正相关关系.通过聚类分析和因子分析发现,新乡市道路灰尘中的重金属基本不受机动车排放影响,而PAHs受机动车排放影响较大.

Effects of Vehicle Emissions on Heavy Metals and Polycyclic Aromatic Hydrocarbons Pollution in Road Dust in Xinxiang

In this study, samples were taken of the surface dust of main roads in Xinxiang City, and the concentrations of five heavy metals (Cd, Pb, Cr, Cu and Zn) and fifteen polycyclic aromatic hydrocarbons (PAHs) were determined by inductively coupled plasma mass spectrometry (ICP-MS) and gas chromatography-mass spectrometry (GC-MS), respectively. Meanwhile, the effects of vehicle emissions on the pollution characteristics were investigated. The results showed that the concentrations of heavy metals and PAHs ranged from 2.58 to 1560 mg·kg^-1 and ND to 1.30 mg·kg^-1, respectively. Overall, the concentrations of heavy metals and PAHs increased with a decrease in dust particle size. In terms of composition, the heavy metals were dominated by Zn while the high-molecular-weight PAHs were mainly homologous. In spatial distribution, the concentrations of heavy metals and PAHs were different. The total concentrations of heavy metals in road dust near Renmin Road, Xiaodian Industrial Park, and Cement Plant were the highest, while the high concentrations of PAHs appeared in the dust of Renmin Road, Upper Expressway, and 107 National Highway. Pearson correlation analysis showed that there was no positive correlation between the five heavy metals and fifteen PAHs. Then cluster analysis and factor analysis indicated that the PAHs were greatly affected by vehicle emissions, while the heavy metals were basically unaffected.