PFOS在针铁矿表面化学吸附及微观过程机理研究

The distribution, adsorption and desorption of perfluorooctane sulfonate (PFOS) on natural minerals is an important factor which influence its environmental behavior such as concentration, migration, transformation, bioavailability, toxicity in environment. The key step to understand this factor is to clear the microscopic structure and morphology of PFOS on complex micro-surfaces. The study of microscopic structure has been always the reseach forefront and difficulty of environmental science internationally. It is widely believed that PFOS adsorbed on mineral as outer-sphere complexes by electrostatic and hydrophobic interactions. However, we assume that a sulfonic acid group and ferrite hydroxyl can react each other and form inner-sphere complexes, basing on the principle of hard-soft-acid-base (HSAB). To confirm this hypothesis, synchrotron radiation and other spectroscopic techniques (XANES, EXAFS, ATR-FTIR, Raman, XPS, XRF, etc.) are employed, combining with quantum chemical calculations as well as aquatic chemistry experiment and one-dimensional column experiments, to investigate the microscopic adsorption structure and morphology of PFOS on goethite, and to explore the essential effect of interfacial microstructure on macro environmental behavior. This study will rich the adsorption mechanisms of PFCs on interfacial mineral surfaces, make sense on further understanding their environmental behavior, and provide a theoretical basis for the effective prevention and control of PFCs pollution.

全氟辛烷磺酸（PFOS）在环境天然矿物上的分配和吸附解吸是影响其在环境中的浓度、迁移、转化、生物可利用性、毒性等环境行为的重要因素。而PFOS在环境微界面上的微观结构与形态研究是深入理解PFOS在矿物上吸附行为的关键步骤，也是国际上环境科学研究前沿和难点。人们普遍认为PFOS在天然矿物上的吸附是通过静电力和疏水作用的外层吸附。但是基于软硬酸碱理论，磺酸基团与铁氧羟基能够发生化学反应。为了验证这一假设，项目拟选取针铁矿作为吸附界面，采用同步辐射等微观谱学技术方法（XANES，EXAFS，ATR-FTIR，Raman，XPS，XRF等），结合量子化学理论计算，以及宏观水化学与一维柱实验，明确PFOS界面分子微观吸附结构与形态，研究和探索微观机理对宏观环境行为的本质影响。研究结果将丰富PFCs的矿物界面吸附机理，对深入理解PFCs的环境行为有重要意义，为有效防治与控制PFCs污染提供理论依据。