有机磷阻燃剂在成都市大气PM2.5及土壤中的时空分布及来源探析

Caused by the ongoing worldwide concern and restrictions of brominated flame retardants, the production and usage of the alternative--organophosphate esters (OPEs) increased rapidly, hence the concentrations of OPEs in the natural environment rise rapidly in recent years. As a new class of organic pollutants which is not completely secure, OPEs has been highly concerned by the U.S. and European countries, and they pointed out that the city may have become a potentially high risk area of OPEs contamination. Currently Chinese just began this work and the underlying data is minimal. A typical inland citiy- Chengdu was selected as the study area and the monitoring methods of OPEs component would be established. Samples (airborne PM2.5, soil) would be analyzed to obtain basic data of OPEs pollution, and its spatial and temporal distribution character would be discussed. Back trajectories were used to analyze the difference of OPEs bounded to PM2.5 in haze days and non-haze days under different transmission pathways, to explore whether there is significant enrichment effect of OPEs, and to assess the relative importance of local and foreign transmission sources of OPEs. The source apportionment method (molecular markers or ratio method) for OPEs would be explored, combined with principal component analysis, a reasonable source apportionment results would be gotten. This work could provide a scientific basis for urban pollution management, early warning and prevention of newly organic pollution.

随着各国对溴代阻燃剂环境效应的关注及逐步的禁用，有机磷酸酯（OPEs）作为替代产品，近年来的产量和用量均快速提高，其在自然环境中的含量也迅速上升。作为一类并非完全安全的新型有机污染物，OPEs已经受到欧美国家的高度关注，他们指出城市可能已成为一个潜在的OPEs高风险污染区域。目前国内才刚开始此项工作，基础数据甚少。本项目拟选取典型内陆城市—成都市为研究区域，建立典型OPEs组分的监测分析方法，掌握OPEs在成都市大气PM2.5及土壤中的时空分布情况；利用后向轨迹图分析不同气流传输途径时重度灰霾及非灰霾天气下大气PM2.5中OPEs的含量及分布差异，探讨OPEs在灰霾天气是否有明显的富集效应，并评估局地源和外来传输源的相对重要性；探索OPEs的分子标志物或比值法的来源解析方法，结合主成分因子分析法得到合理的源解析结果。该研究结果可为城市环境中新型有机污染的预警及防控提供基础数据和科学依据。

建立了气相色谱-质谱联用仪定量分析大气颗粒物中七种OPEs的实验室分析方法并质控良好,采集了成都市区与郊区各季节大气PM2.5 样品及昼夜样品，分析7种OPEs 的浓度、分布特征、昼夜变化、日变化及空间变化及来源。结果表明，市区采样点大气PM2.5 中Σ7OPEs 平均浓度的季节变化为：夏季(8.84 ng•m-3)>秋季(7.63 ng•m-3)>春季(6.80 ng•m-3)>冬季(4.21 ng•m-3)， 郊区采样点则为冬季(10.33 ng•m-3)>春季(9.17 ng•m-3)>夏季(8.72 ng•m-3)>秋季(8.69 ng•m-3).含量最高的为TBEP，最低的为TDCPP。昼夜变化为白天（Σ7OPEs 质量浓度为8.60ng/m3）小于夜晚（10.88ng/m3）。南北方TBEP 最高，而东西方TnBP 最高。采用后向气流轨迹模型及相关性分析探析PM2.5中OPEs的来源发现外源污染对成都市OPEs 的贡献小，主要与局地源差异有关。. 建立了土壤中OPEs的实验室分析方法并质控，采集了成都市主城区表层土壤，发现∑7OPEs的含量水平在31.6~211 ng•g-1之间，算术平均值为99.9 ng•g-1。所有样品中TBEP均为含量最高的单体，其含量占∑7OPEs总含量的52%~92%。从空间分布来看，成都市西北至东南沿线为OPEs的主要分布带。相关性研究表明，TnBP与TCEP之间有较强的同源性，TBEP、TPhP、TnBP三者之间具有较强的同源性，而TEHP与其他种类OPEs可能不具有同源性。正定矩阵因子分解结果表明，OPEs主要来源有2个，不饱和聚酯树脂产品制造业、建筑物装潢/室内源对成都市土壤中OPEs的贡献率分别为43%和57%。该研究结果可为城市新型有机污染防控提供科学基础。