Investigations of PAH-Mineral Surface Interactions Using Luminescence and NMR Spectroscopies

摘要CTS-9630577多环芳烃是世界上分布最广泛的环境污染物之一。了解多环芳烃在水环境中的吸附过程非常重要，因为吸附反应会极大地影响它们的流动性、化学反应性、生物利用度和毒性，以及我们修复多环芳烃污染场地的能力。拟议的项目是一项多学科的努力，将使用荧光和核磁共振(核磁共振)光谱仪在分子水平上探测多环芳烃-矿物表面吸附反应。对吸附的多环芳烃荧光强度、精细结构、各向异性和激基/激基络合物形成的稳态和时间分辨测量，以及核磁共振旋转展宽，将提供多环芳烃分子与矿物表面之间相互作用的强度和接近距离的信息。其具体目标是：(1)开发荧光和核磁共振技术来研究水环境体系特有的各种多环芳烃-无机表面反应，(2)比较和对比从各种有机溶剂和不同粘度的水溶液的简单模型体系中获得的两种类型的光谱信息，(3)监测不同矿物的吸附多环芳烃光谱性质，(4)监测不同溶液化学条件下吸附的多环芳烃的光谱性质，并监测不同表面负载的吸附多环芳烃光谱性质。拟议研究项目的结果将加强对低碳环境中多环芳烃的去向和迁移进行建模的努力。研究结果还将有助于设计多相光解体系来降解多环芳烃。除了解决多环芳烃-矿物表面相互作用的基本问题外，该项目还将推动新的荧光和核磁共振技术的发展。

ABSTRACT CTS-9630577 Polycyclic aromatic hydrocarbons (PAHs) are some of the most widespread of environmental pollutants. Understanding PAH sorption processes in aqueous environmental is important because sorption reactions can greatly affect their mobility, chemical reactivity, bioavailability and toxicity, as well as our ability to remediate PAH-contaminated sites. The proposed project is a multidisciplinary effort that will use fluorescence and Nuclear Magnetic Resonance (NMR) spectroscopies to probe PAH-mineral surface sorption reactions at a molecular level. Steady-state and time-resolved measurements of adsorbed PAH fluorescence intensity, fine structure, anisotropy and excimer/exciplex formation in addition to NMR rotational line-broadening will provide information on the strength of interaction and distances of approach between PAH molecules and mineral surfaces. The specific objectives are to: (1) develop fluorescence and NMR techniques for studying the various PAH-inorganic surface reaction particular to aqueous environmental systems, (2) compare and contrast the information obtained from the two types of spectroscopy for simple model systems of various organic solvents and aqueous solutions of varying viscosity, (3) monitor adsorbed PAH spectroscopic PAH spectroscopic properties for different minerals, (4) monitor the spectroscopic properties of adsorbed PAHs with varying solution chemistry conditions, and monitor adsorbed PAH spectroscopic properties for different surface loadings. Results from the proposed research project will enhance efforts to model the fate and transport of PAH in low carbon environments. The results will also help the design of heterogeneous photolytic systems for the destruction of PAHs. In addition to addressing the fundamental questions of PAH-mineral surface interactions, this project will also motivate for the development of new fluorescence and NMR techniques.