沥青中多环芳烃荧光特征及其浓度梯度下的响应机制研究

Fluorescence Characteristics of Polycyclic Aromatic Hydrocarbons in Asphalt and Their Fluorescence Changes at Different Concentrations

沥青材料中的多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)是一种严重的环境危害物,是公路工程路域环境污染物的重要来源。针对低环境负荷沥青路面建造对PAHs快速检测分析的需求,以PAHs稠环结构的荧光效应为基础,开展了多来源沥青材料PAHs含量、荧光特征、溶剂环境影响机制以及其荧光强度-浓度相关性研究。研究发现,煤焦油沥青具有典型的聚集诱导荧光猝灭现象,并具有更高的荧光量子效率。以极性、黏度、pH值3组溶剂环境参数为研究对象,探索并建立了沥青材料多环芳烃荧光现象的最佳溶剂环境,即二甲基亚砜、四氢呋喃、去离子水、甘油的体积比为1∶1∶1∶2。在最佳溶剂环境下,3种沥青材料的荧光强度与浓度都展现出了明显的线性关系;而在相同浓度条件下,沥青材料的荧光强度与PAHs含量表现出正相关。研究结果证明了沥青材料荧光强度与PAHs浓度的线性关系,将为沥青材料中PAHs含量检测分析提供理论基础,有效支撑公路工程低环境负荷建造技术的发展。

Polycyclic Aromatic Hydrocarbons(PAHs)in asphalt materials is a type of serious environmental hazard,and the main pollution resource in road engineering.Aiming at the requirement of PAHs rapid detection method in asphalt pavement construction for low environmental hazard,this research concentrated in experiments about PAHs content,fluorescence characteristics,solvent environment impact mechanism and correlation between fluorescence intensity and concentration in different asphalt materials,based on the fluorescence effect of PAHs from condensed ring structure.It is found that coal tar asphalt has a typical aggregation-caused quenching phenomenon and higher fluorescence quantum efficiency.Taking the three solvent environment parameters polarity,viscosity and pH value as the research objects,the optimal solvent environment for the fluorescence phenomenon of PAHs in asphalt materials was explored and established as dimethyl sulfoxide:tetrahydrofuran:deionized water:glycerol=1∶1∶1∶2.Under the optimal solvent environment,fluorescence intensity and concentration of the three asphalt materials all showed obvious linear relationship.Under the same concentration condition,fluorescence intensity of asphalt material showed positive correlation with the PAHs content.This study proves that the asphalt material has the linear relationship between fluorescence intensity and PAHs concentration,which will provide theoretical basis for the detection of PAHs content in asphalt materials,and support the development of low environmental hazard in construction technology for road engineering.